JP7686550B2 - Drive unit - Google Patents

Description

The present invention relates to a drive device for a vehicle for transmitting the driving force of a drive source.

In recent years, a wide variety of drive devices that transmit the driving force of electric motors have been developed for vehicles such as automobiles. Patent Document 1 describes a drive device that uses a parallel two-shaft mechanism and is used in hybrid vehicles that can run on an engine and an electric motor. Patent Document 2 describes a drive device that includes a mechanism for reducing the driving force of the engine or motor.

JP 2007-296869 A JP 2019-1206 A

There are concerns that such drive devices for vehicles that include electric motors as a drive source will require more space and will be heavier as the performance of the vehicles and electric motors improves and the control, including the transmission, becomes more complex.

The present invention was made in consideration of these circumstances, and aims to provide a vehicle drive unit for transmitting driving force from a drive source that can suppress an increase in installation space and achieve weight reduction.

In order to solve the above problems, the driving device of the present invention comprises:
An input shaft on the drive source side;
an output shaft that transmits the driving force of the driving source to a driving wheel side;
a transmission mechanism that transmits the driving force from the input shaft to the output shaft,
The speed change mechanism includes:
a first transmission mechanism that reduces the rotation speed of the input shaft and transmits the reduced rotation speed to the output shaft;
a second transmission mechanism capable of transmitting rotation of the input shaft to the output shaft at a speed faster than that of the first transmission mechanism,
the first transmission mechanism includes a two-way clutch capable of selectively transmitting, to the output shaft, rotation of the input shaft in a direction in which the vehicle moves forward and rotation of the vehicle moves backward;
the second speed change mechanism includes a clutch mechanism capable of transmitting the rotation of the input shaft in the forward direction to the output shaft by frictional engagement;
The input shaft and the output shaft are arranged in parallel,
the first transmission mechanism includes a first gear provided on the input shaft and rotating integrally with the input shaft, and a second gear provided on the output shaft and meshing with the first gear,
the two-way clutch is provided between the second gear and the output shaft,
the second transmission mechanism includes a third gear that is provided on the input shaft and rotates integrally with the input shaft and has a larger diameter than the first gear, and a fourth gear that is provided on the output shaft and meshes with the third gear and has a smaller diameter than the second gear,
the clutch mechanism is provided between the fourth gear and the output shaft,
A plurality of teeth are formed at predetermined intervals in the circumferential direction on the outer periphery of the output shaft,
The two-way clutch is
the second gear includes an outer ring that rotates integrally with the second gear, a first claw member that is held on the outer ring so as to be pivotable in the radial direction and that, when it pivots radially inward to mesh with the toothed portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves backward, a first elastic member that urges the first claw member in the meshing direction with the toothed portion, a second claw member that is held on the outer ring so as to be pivotable in the radial direction and that, when it pivots radially inward to mesh with the toothed portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves forward, and a second elastic member that urges the second claw member in the meshing direction with the toothed portion ,
The elastic force of the second elastic member is set to be smaller than the elastic force of the first elastic member,
When a centrifugal force exceeding a predetermined magnitude acts on the first and second claw members due to rotation of the outer ring, the second elastic member is compressed by the second claw member until the second claw member is disengaged from the tooth portion, and the first elastic member is not compressed by the first claw member and maintains engagement with the tooth portion .
The drive device of the present invention further comprises:
An input shaft on the drive source side;
an output shaft that transmits the driving force of the driving source to a driving wheel side;
a transmission mechanism that transmits the driving force from the input shaft to the output shaft,
The speed change mechanism includes:
a first transmission mechanism that reduces the rotation speed of the input shaft and transmits the reduced rotation speed to the output shaft;
a second transmission mechanism capable of transmitting rotation of the input shaft to the output shaft at a speed faster than that of the first transmission mechanism,
the first transmission mechanism includes a two-way clutch capable of selectively transmitting, to the output shaft, rotation of the input shaft in a direction in which the vehicle moves forward and rotation of the vehicle moves backward;
the second speed change mechanism includes a clutch mechanism capable of transmitting the rotation of the input shaft in the forward direction to the output shaft by frictional engagement;
The input shaft and the output shaft are arranged in parallel,
the first transmission mechanism includes a first gear provided on the input shaft and rotating integrally with the input shaft, and a second gear provided on the output shaft and meshing with the first gear,
the two-way clutch is provided between the second gear and the output shaft,
the second transmission mechanism includes a third gear that is provided on the output shaft and rotates integrally with the output shaft and has a smaller diameter than the second gear, and a fourth gear that is provided on the input shaft and meshes with the third gear and has a larger diameter than the first gear,
the clutch mechanism is provided between the fourth gear and the input shaft,
A plurality of teeth are formed at predetermined intervals in the circumferential direction on the outer periphery of the output shaft,
The two-way clutch is
the second gear includes an outer ring that rotates integrally with the second gear, a first claw member that is held on the outer ring so as to be pivotable in the radial direction and that, when it pivots radially inward to mesh with the toothed portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves backward, a first elastic member that urges the first claw member in the meshing direction with the toothed portion, a second claw member that is held on the outer ring so as to be pivotable in the radial direction and that, when it pivots radially inward to mesh with the toothed portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves forward, and a second elastic member that urges the second claw member in the meshing direction with the toothed portion ,
The elastic force of the second elastic member is set to be smaller than the elastic force of the first elastic member,
When a centrifugal force exceeding a predetermined magnitude acts on the first and second claw members due to rotation of the outer ring, the second elastic member is compressed by the second claw member until the second claw member is disengaged from the tooth portion, and the first elastic member is not compressed by the first claw member and maintains engagement with the tooth portion .
The drive device of the present invention further comprises:
An input shaft on the drive source side;
an output shaft that transmits the driving force of the driving source to a driving wheel side;
a transmission mechanism that transmits the driving force from the input shaft to the output shaft,
The speed change mechanism includes:
a first transmission mechanism that reduces the rotation speed of the input shaft and transmits the reduced rotation speed to the output shaft;
a second transmission mechanism capable of transmitting rotation of the input shaft to the output shaft at a speed faster than that of the first transmission mechanism,
the first transmission mechanism includes a two-way clutch capable of selectively transmitting, to the output shaft, rotation of the input shaft in a direction in which the vehicle moves forward and rotation of the vehicle moves backward;
the second speed change mechanism includes a clutch mechanism capable of transmitting the rotation of the input shaft in the forward direction to the output shaft by frictional engagement;
The input shaft and the output shaft are arranged on the same axis,
the first transmission mechanism includes a planetary gear mechanism including a sun gear, a plurality of planetary gears meshing with the sun gear, a planetary carrier supporting the plurality of planetary gears so as to be rotatable about their axes, and a ring gear meshing with the plurality of planetary gears;
The output shaft is connected to the planetary carrier,
the two-way clutch is provided between the input shaft and the planetary gear mechanism,
The clutch mechanism is provided between the input shaft and the planetary carrier,
The input shaft constitutes an inner ring of the two-way clutch,
A plurality of teeth are formed at predetermined intervals in the circumferential direction on an outer periphery of the input shaft,
The sun gear constitutes an outer ring of the two-way clutch,
The two-way clutch is characterized in that it has a first pawl member that is held on the outer wheel so as to be able to swing radially, and that, when it swings radially inward to engage with the tooth portion, locks the relative rotation of the output shaft relative to the outer wheel in the direction in which the vehicle moves forward, and a second pawl member that is held on the outer wheel so as to be able to swing radially, and that, when it swings radially inward to engage with the tooth portion, locks the relative rotation of the output shaft relative to the outer wheel in the direction in which the vehicle moves backward.
The drive device of the present invention further comprises:
An input shaft on the drive source side;
an output shaft that transmits the driving force of the driving source to a driving wheel side;
a transmission mechanism that transmits the driving force from the input shaft to the output shaft,
The speed change mechanism includes:
a first transmission mechanism that reduces the rotation speed of the input shaft and transmits the reduced rotation speed to the output shaft;
a second transmission mechanism capable of transmitting rotation of the input shaft to the output shaft at a speed faster than that of the first transmission mechanism,
the first transmission mechanism includes a two-way clutch capable of selectively transmitting, to the output shaft, rotation of the input shaft in a direction in which the vehicle moves forward and rotation of the vehicle moves backward;
the second speed change mechanism includes a clutch mechanism capable of transmitting the rotation of the input shaft in the forward direction to the output shaft by frictional engagement;
The input shaft and the output shaft are arranged on the same axis,
the first transmission mechanism includes a planetary gear mechanism including a sun gear, a plurality of planetary gears meshing with the sun gear, a planetary carrier supporting the plurality of planetary gears so as to be rotatable about their axes, and a ring gear meshing with the plurality of planetary gears;
The output shaft is connected to the planetary carrier,
the two-way clutch is provided between the input shaft and the planetary gear mechanism,
The clutch mechanism is provided between the input shaft and the planetary carrier,
The input shaft is formed in a cylindrical shape and constitutes an outer ring of the two-way clutch,
the ring gear constitutes an inner ring of the two-way clutch,
A plurality of teeth are formed at predetermined intervals in the circumferential direction on an outer periphery of the ring gear,
The two-way clutch includes a first pawl member that is held by the outer ring so as to be able to swing in the radial direction, and that, when it swings radially inward to mesh with the tooth portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves backward; a first elastic member that urges the first pawl member in the meshing direction with the tooth portion; a second pawl member that is held by the outer ring so as to be able to swing in the radial direction, and that, when it swings radially inward to mesh with the tooth portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves forward; and a second elastic member that urges the second pawl member in the meshing direction with the tooth portion .
The elastic force of the second elastic member is set to be smaller than the elastic force of the first elastic member,
When a centrifugal force exceeding a predetermined magnitude acts on the first and second claw members due to rotation of the outer ring, the second elastic member is compressed by the second claw member until the second claw member is disengaged from the tooth portion, and the first elastic member is not compressed by the first claw member and maintains engagement with the tooth portion .

The present invention provides a vehicle drive unit for transmitting driving force from a drive source, which can reduce the amount of space required for installation and achieve weight reduction.

FIG. 1 is a skeleton diagram showing the configuration of a drive device according to a first example of the first embodiment. FIG. 2 is a partial cross-sectional view taken along the axial direction of a main part of the drive device. FIG. 3 is an enlarged cross-sectional view showing a main portion of the two-way clutch, as viewed from one axial side. Figure 4 is a cross-sectional view of a main portion of a two-way clutch, showing the state as viewed from one axial side, where Figure 4(a) shows a state in which both the first and second pawl members are engaged with the tooth portions, Figure 4(b) shows a state in which the first pawl member is engaged with the tooth portions and the second pawl member is not engaged with the tooth portions, and Figure 4(c) shows a state in which neither the first or second pawl member is engaged with the tooth portions. FIG. 5 is a skeleton diagram showing the configuration of a drive device according to a second example of the first embodiment. FIG. 6 is a skeleton diagram showing the configuration of a drive device according to a first example of the second embodiment. FIG. 7 is an enlarged cross-sectional view showing a main portion of a two-way clutch and a planetary gear mechanism of a drive device according to a first example of the second embodiment, as viewed from one axial side. FIG. 8 is a skeleton diagram showing the configuration of a drive device according to a second example of the second embodiment. FIG. 9 is an enlarged cross-sectional view showing a main portion of a two-way clutch and a planetary gear mechanism of a drive device according to a second example of the second embodiment, as viewed from one axial side.

Hereinafter, a driving device according to each embodiment of the present invention will be described with reference to the drawings.
The drive device according to each embodiment of the present invention is used in a vehicle that uses an electric motor as a drive source, and is of a type in which the driving force of the electric motor is transmitted to an output shaft as low-speed rotation or high-speed rotation via a two-speed transmission.

First, the directions related to the drive device according to each embodiment are defined. In each embodiment, the axial direction refers to the axial direction of the input shaft connected to the drive shaft of the electric motor and the output shaft to which the driving force of the electric motor is output, and the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction of the input shaft and the output shaft. In addition, with regard to the axial direction, in Figs. 1, 2, 5, 6, and 8, the left side of the paper is one axial side, and the right side of the paper is the other axial side. With regard to the circumferential direction, in Figs. 3, 4, 7, and 9, the direction rotating clockwise toward the paper is one circumferential direction, and the direction rotating counterclockwise toward the paper is the other circumferential direction.

A drive device according to a first example of a first embodiment of the present invention will now be described with reference to the drawings.
FIG. 1 is a skeleton diagram showing the configuration of a drive device 1 according to a first example of the first embodiment.
FIG. 2 is a partial cross-sectional view of a main part of the drive device 1 taken along the axial direction.
FIG. 3 is a cross-sectional view showing a main portion of the two-way clutch 8, as viewed from one axial side.

As shown in FIG. 1, the drive unit 1 according to this embodiment has an input shaft 4 connected to the drive shaft of the electric motor 2, and an output shaft 6 arranged parallel to the input shaft 4. The driving force of the electric motor 2 is transmitted from the input shaft 4 to the output shaft 6 via a two-way clutch 8 or a friction engagement device 12, which will be described later.

In this embodiment, the input shaft 4 and the output shaft 6 are each formed in a cylindrical shape. A first connecting gear 14 for transmitting the driving force of the electric motor 2 to the output shaft 6 at a low rotation speed, and a second connecting gear 16 for transmitting the driving force from the electric motor 2 to the output shaft 6 at a high rotation speed are provided coaxially with the input shaft 4. The first connecting gear 14 and the second connecting gear 16 are provided side by side in the axial direction in this order from one axial side to the other axial side. The second connecting gear 16 has a larger diameter than the first connecting gear 14. The first connecting gear 14 and the second connecting gear 16 are provided on the input shaft 4 so as not to rotate relative to the input shaft 4.

A two-way clutch 8 and a friction engagement device 12 are provided coaxially with the output shaft 6. The two-way clutch 8 and the friction engagement device 12 are provided in the axial direction in this order from one axial side to the other axial side. The two-way clutch 8 is connected to the first connecting gear 14 of the input shaft 4, and the friction engagement device 12 is connected to the second connecting gear 16 of the input shaft 4. The first connecting gear 14 and the two-way clutch 8 constitute a low-speed shift mechanism 17, and the second connecting gear 16 and the friction engagement device 12 constitute a high-speed shift mechanism 18. The low-speed shift mechanism 17 and the high-speed shift mechanism 18 constitute a two-speed shift mechanism. The drive unit 1 transmits the driving force of the electric motor 2 to the output shaft 6 via the low-speed shift mechanism 17 when the speed of the vehicle (not shown) is in the low-speed range, and transmits it to the output shaft 6 via the high-speed shift mechanism 18 when the speed of the vehicle is in the high-speed range. The driving force of the electric motor 2 transmitted to the output shaft 6 is transmitted to a differential gear mechanism 23, which is the drive mechanism for the drive wheels 22, via an output gear 20 fixed to the output shaft 6.

As shown in Figures 2 and 3, the two-way clutch 8 has an annular outer ring 24 and a torque transmission mechanism that enables torque transmission from the outer ring 24 to the inner ring. In this embodiment, the inner ring of the two-way clutch 8 is the output shaft 6. In detail, an enlarged diameter portion 6a formed on a portion of the output shaft 6 that faces the inner peripheral surface of the outer ring 24 in the radial direction is configured to engage with the torque transmission mechanism of the two-way clutch 8. The torque transmission mechanism in this embodiment is a ratchet mechanism, and includes a plurality of first claw members 26 and a plurality of second claw members 28 that are provided at predetermined intervals around the inner peripheral portion of the outer ring 24 (see Figures 3 and 4). Note that Figure 3 shows one first claw member 26 and one second claw member 28 that is adjacent to the first claw member 26 in the circumferential direction.

A plurality of teeth 30 are formed at equal intervals around the entire circumference of the outer periphery of the enlarged diameter portion 6a of the output shaft 6. The teeth 30 protrude radially outward and extend in the axial direction. The teeth 30 form ratchet teeth with which the first pawl member 26 and the second pawl member 28 mesh. Specifically, one circumferential side of the teeth 30 forms a first meshing portion 30a that meshes with the first pawl member 26, and the other circumferential side of the teeth 30 forms a second meshing portion 30b that meshes with the second pawl member 28.

An annular low-speed gear 32 is arranged on the outer periphery of the outer ring 24. The low-speed gear 32 has a cylindrical portion 34 and an inward flange portion 36 formed on the other axial side of the cylindrical portion 34. The low-speed gear 32 is fitted to the output shaft 6 via a rolling bearing 38 fitted to the inner periphery of the inward flange portion 36 so as to be rotatable relative to the output shaft 6. The outer ring 24 of the two-way clutch 8 is fitted to the inner periphery of the cylindrical portion 34 of the low-speed gear 32. In other words, the low-speed gear 32 and the outer ring 24 of the two-way clutch 8 rotate together. A gear 32a is formed on the outer periphery of the cylindrical portion 34 of the low-speed gear 32, and the gear 32a is always engaged with the first connecting gear 14 of the input shaft 4. Therefore, the outer ring 24 of the two-way clutch 8 and the first connecting gear 14 are always connected via the low-speed gear 32, and the input shaft 4 and the outer ring 24 of the two-way clutch 8 rotate in opposite directions.

The first claw member 26 is held in a recess 42 provided on the inner periphery of the outer ring 24. The recess 42 is a recess that opens inward on the inner periphery of the outer ring 24. The first claw member 26 has a predetermined circumferential length and is composed of a central portion 44 having a partially cylindrical outer periphery, a protruding portion 46 protruding from the central portion 44 to one circumferential side, and a claw portion 48 protruding from the central portion 44 to the other circumferential side. The central portion 44 of the first claw member 26 is held rotatably in the recess 42. That is, the first claw member 26 is held in the recess 42 so that the claw portion 48 can swing radially around the central portion 44. The first claw member 26 has a rotation center in the central portion 44, but a center of gravity in the claw portion 48. The claw portion 48 of the first claw member 26 is biased radially inward by a spring 50 that may be a coil or other type.

When the claw portion 48 of the first claw member 26 swings radially inward, the claw portion 48 engages with the first meshing portion 30a of the tooth portion 30 of the expanded diameter portion 6a of the output shaft 6, and the first claw member 26 thereby engages with the tooth portion 30. By engaging with the tooth portion 30, the first claw member 26 locks the clockwise rotation of the output shaft 6 relative to the outer ring 24, i.e., in one circumferential direction. On the other hand, when the output shaft 6 rotates counterclockwise relative to the outer ring 24, i.e., in the other circumferential direction, the first claw member 26 does not engage with the tooth portion 30, and allows the output shaft 6 to rotate.

The second claw member 28, like the first claw member 26, is held in a clearance portion 52 provided on the inner circumference of the outer ring 24, and is composed of a central portion 54, a protruding portion 56, and a claw portion 58. The claw portion 58 is biased radially inward by a spring 60, but the circumferential direction is opposite to that of the first claw member 26. As a result, the second claw member 28 is in a meshed state with the tooth portion 30 by the claw portion 58 meshing with the second meshing portion 30b of the tooth portion 30 of the enlarged diameter portion 6a of the output shaft 6, and in contrast to the first claw member 26, it locks the counterclockwise relative rotation of the output shaft 6 with respect to the outer ring 24, while allowing the output shaft 6 to rotate clockwise relative to the outer ring 24.

In this way, the ratchet mechanism is composed of the first claw member 26 and the second claw member 28 held on the inner periphery of the outer ring 24, the springs 50, 60, and the multiple teeth 30 formed on the enlarged diameter portion 6a of the output shaft 6.

In this embodiment, the two-way clutch 8 has an elastic force of the spring 50 biasing the first claw member 26 and an elastic force of the spring 60 biasing the second claw member 28 that are different in magnitude. Specifically, the elastic force of the spring 60 biasing the second claw member 28 is set to be smaller than the elastic force of the spring 50 biasing the first claw member 26. The elastic force of the spring 60 biasing the second claw member 28 is set to a magnitude that compresses it by a predetermined amount when a predetermined force is applied, as described below.

As described below, when the driving force of the electric motor 2 is transmitted to the outer ring 24 of the two-way clutch 8 and the outer ring 24 starts to rotate, the centrifugal force caused by the rotation of the outer ring 24 acts on the first claw member 26 and the second claw member 28. When the centrifugal force acts, the first claw member 26 and the second claw member 28 try to swing in a direction in which the claw members 48, 58 move radially outward around the central portions 44, 54, respectively, because the centers of gravity of the first claw member 26 and the second claw member 28 are at the claw portions 48, 58, respectively. Then, the springs 50, 60 that bias the first claw member 26 and the second claw member 28 are pressed radially outward, i.e., in a compressing direction, by the claw portions 48, 58, respectively. When the rotation of the outer ring 24 becomes faster and the centrifugal force acting thereon becomes larger, the spring 60 that biases the second claw member 28 is compressed by the claw portion 58. When the rotation speed of the outer ring 24 becomes faster than a predetermined rotation speed and the centrifugal force acting on the second claw member 28 becomes greater than a predetermined magnitude F1, the spring 60 is greatly compressed by the claw portion 58, and the entire claw portion 58 is positioned radially outward from the tooth portion 30. In this state, the second claw member 28 and the tooth portion 30 are in a non-meshing state. The predetermined rotation speed of the outer ring 24 at which a centrifugal force of the predetermined magnitude F1 is generated is R1. The spring 50 biasing the first claw member 26 does not compress significantly even when a centrifugal force of the predetermined magnitude F1 acts on the first claw member 26, and has an elastic force that maintains the meshing with the tooth portion 30.

The elastic force of the springs 50 and 60, the centrifugal force of the predetermined magnitude F1 at which the spring 60 is greatly compressed, and the predetermined rotational speed R1 of the outer ring 24 when the centrifugal force of the predetermined magnitude F1 is generated are appropriately designed taking into account the magnitude of the torque to be transmitted, the vehicle speed, etc.

Next, the configuration of the friction engagement device 12 will be described.
As shown in FIG. 2 , the friction engagement device 12 of this embodiment is a wet clutch 3 .

The wet clutch 3 has a cylindrical clutch case 7. The clutch case 7 is arranged coaxially with the output shaft 6. An inward flange 9 is provided at one axial end of the clutch case 7, and a cylindrical member 68 is fitted into a hole 10 at the center of the inward flange 9. In detail, the clutch case 7 is fitted into the other axial end of the outer circumferential surface of the cylindrical member 68. The cylindrical member 68 is fitted into the output shaft 6 via a rolling bearing 70 so as to be rotatable relative to the output shaft 6. Therefore, the clutch case 7 is fitted into the output shaft 6 so as to be rotatable relative to the output shaft 6 via the cylindrical member 68 and the rolling bearing 70.

As shown in FIG. 2, a plurality of annular clutch plates 13 are fitted to the inner periphery of the clutch case 7 so as to be movable in the axial direction but unable to rotate relative to the clutch case 7. A plurality of annular clutch discs 15 are also arranged on the inner periphery of the clutch case 7. The plurality of annular clutch discs 15 are fitted to the outer periphery of a cylindrical clutch hub 62 arranged concentrically with the clutch case 7 so as to be movable in the axial direction but unable to rotate relative to the clutch hub 62. The clutch hub 62 is fixed to the output shaft 6 and rotates integrally with the output shaft 6. The plurality of clutch plates 13 and the plurality of clutch discs 15 are arranged alternately in the axial direction.

At the other axial end of the inner periphery of the clutch case 7, there is provided an end plate 19 for holding the clutch plate 13 and clutch disc 15 in a fixed state at the other axial end, and a retaining ring 21 for holding the end plate 19 inside the clutch case 7. The clutch plate 13 and clutch disc 15 are pressed axially by a piston 66 driven axially by a piston drive mechanism 64 arranged adjacent to the drive unit 1, and frictionally engage with each other. This causes the wet clutch unit 3 to be in an engaged state. When the wet clutch unit 3 is in an engaged state, torque is transmitted from the clutch case 7 to the output shaft 6 via the clutch hub 62. Note that the piston drive mechanism 64 is not directly related to the present invention, so a detailed description will be omitted.

A gear 83 is formed on one axial side of the outer peripheral surface of the cylindrical member 68. An annular high-speed gear 72 is arranged on the outer peripheral side of the gear 83 of the cylindrical member 68. The high-speed gear 72 has a smaller diameter than the low-speed gear 32 of the low-speed transmission mechanism 17, and is fitted to the output shaft 6 so as to be rotatable relative to the output shaft 6 via a rolling bearing 74 fitted to one axial side of the inner peripheral portion. The gear portion 83 of the cylindrical member 68 is integrally fitted to the high-speed gear 72 on the other axial side of the inner peripheral portion of the high-speed gear 72. As a result, the high-speed gear 72 and the clutch case 7 rotate together. A gear 72a is formed on the outer peripheral portion of the high-speed gear 72, and the gear 72a is always engaged with the second connecting gear 16 of the input shaft 4. Therefore, the clutch case 7 and the second connecting gear 16 are always connected via the high-speed gear 72, and the input shaft 4 and the clutch case 7 rotate in opposite directions.

Next, the operation of the drive unit 1 according to this embodiment will be described. The following description of the operation is an example in which the drive unit 1 is mounted on a vehicle (not shown). The following description of the operation will be given with one axial side defined as the front in Figs. 1 and 2, and the drive unit 1 viewed from the front.
Figures 4 are cross-sectional views of the two-way clutch 8, showing the state as viewed from one axial side, with Figure 4(a) showing the state in which both the first pawl member 26 and the second pawl member 28 are engaged with the tooth portion 30, Figure 4(b) showing the state in which the first pawl member 26 is engaged with the tooth portion 30 and the second pawl member 28 is not engaged with the tooth portion 30, and Figure 4(c) showing the state in which neither the first pawl member 26 nor the second pawl member 28 is engaged with the tooth portion 30.

When a vehicle (not shown) starts moving forward from a stopped state, the input shaft 4 connected to the electric motor 2 rotates in one circumferential direction. The rotation of the input shaft 4 is transmitted as low-speed rotation to the outer ring 24 of the two-way clutch 8 via the first connecting gear 14 and the low-speed gear 32, and the outer ring 24 of the two-way clutch 8 rotates in the other circumferential direction.

At this time, the multiple clutch plates 13 and multiple clutch disks 15 of the wet clutch 3 of the friction engagement device 12 are in a disengaged state. In other words, the wet clutch 3 is controlled to be in a disengaged state. In this state, the rotation of the input shaft 4 in one circumferential direction is transmitted to the clutch case 7 via the second connecting gear 16 and the high-speed gear 72, and the clutch case 7 rotates in the other circumferential direction, but torque is not transmitted to the output shaft 6 via the clutch hub 62. Note that at this time, the clutch case 7 is rotating in the other circumferential direction at a higher speed than the output shaft 6.

When the vehicle is stopped, the outer ring 24 of the two-way clutch 8 does not rotate, so no centrifugal force acts on the second claw member 28. Also, the rotational speed of the outer ring 24 when a low-speed rotation is input from the input shaft 4 is slower than the above-mentioned predetermined rotational speed R1. In other words, the predetermined rotational speed R1 of the outer ring 24 is set to be faster than the rotational speed of the outer ring 24 when a low-speed rotation is input. Therefore, the magnitude of the centrifugal force acting on the second claw member 28 due to the rotation of the outer ring 24 when a low-speed rotation is input is smaller than the above-mentioned predetermined magnitude F1. For this reason, the spring 60 that biases the second claw member 28 is not compressed, and the first claw member 26 and the second claw member 28 are both engaged with the tooth portion 30 as shown in FIG. 4(a). Therefore, when the outer ring 24 rotates in the other circumferential direction in FIG. 4(a), the first claw member 26 meshes with the teeth 30 of the enlarged diameter portion 6a of the output shaft 6, causing the output shaft 6 to rotate together with the outer ring 24 in the other circumferential direction, and the driving force from the electric motor 2 is transmitted to the output shaft 6. At this time, the rotation speed of the input shaft 4 is reduced and transmitted to the output shaft 6. The driving force from the electric motor 2 transmitted to the output shaft 6 is transmitted to the differential gear mechanism 23, which is the drive mechanism for the drive wheels 22, via the output gear 20 (see FIG. 2) fitted to the output shaft 6.

In this way, when the vehicle starts or runs at low speeds, the driving force from the electric motor 2 is transmitted from the input shaft 4 to the output shaft 6 via the low-speed transmission mechanism 17, i.e., the two-way clutch 8.

Next, the operation of the drive unit 1 when the transmission of the drive unit 1 is shifted from the low speed change mechanism portion 17 to the high speed change mechanism portion 18 will be described.
When the vehicle starts moving and accelerates, the transmission of the drive unit 1 changes gear from the low speed change mechanism portion 17 to the high speed change mechanism portion 18 .
When the vehicle accelerates, the rotation speed of the input shaft 4 connected to the electric motor 2 increases, and the rotation speed of the outer ring 24 of the two-way clutch 8 increases. Accordingly, the centrifugal force acting on the second claw member 28 increases. When the rotation speed of the outer ring 24 exceeds a predetermined rotation speed R1 and the magnitude of the centrifugal force acting on the second claw member 28 exceeds a predetermined magnitude F1, the spring 60 biasing the second claw member 28 is greatly compressed by the claw portion 58, and the entire claw portion 58 is positioned radially outward from the tooth portion 30. In this state, as shown in FIG. 4B, the two-way clutch 8 maintains a state in which the first claw member 26 is engaged with the tooth portion 30, but the second claw member 28 is not engaged with the tooth portion 30.

In this state, the wet clutch 3 is controlled to switch from a non-engaged state to an engaged state. Specifically, the piston 66 is driven by the piston drive mechanism 64, and the multiple clutch plates 13 and multiple clutch disks 15 of the wet clutch 3 are pressed in the axial direction and frictionally engaged with each other. This causes the wet clutch 3 to be in an engaged state. As described above, at the time of low rotation input, i.e., when the wet clutch 3 is in an unengaged state, the clutch case 7 rotates in the other circumferential direction at a higher speed than the output shaft 6. When the wet clutch 3 is in an engaged state in this state, the clutch case 7, the clutch hub 62, and the output shaft 6 rotate together in the other circumferential direction, and the high-speed rotation is transmitted from the clutch case 7 to the output shaft 6 via the clutch hub 62. That is, the driving force of the electric motor 2 is transmitted to the output shaft 6 as a high-speed rotation. At this time, the rotation of the input shaft 4 is not decelerated, but is transmitted to the output shaft 6 at a constant speed or at an increased speed. Alternatively, when the rotation of the input shaft 4 is decelerated and transmitted to the output shaft 6, the rate of deceleration is smaller than when it is transmitted via the low-speed gear 32.

When the driving force of the electric motor 2 is transmitted to the output shaft 6 as high-speed rotation, the rotation speed of the output shaft 6 in the other circumferential direction increases. When the rotation speed of the output shaft 6 increases, the rotation speed of the output shaft 6 becomes faster than the rotation speed of the outer ring 24 of the two-way clutch 8, which rotates integrally with the low-speed gear 32. That is, in FIG. 4(b), the output shaft 6 rotates relative to the outer ring 24 of the two-way clutch 8 in the other circumferential direction. Then, the first claw member 26 is pushed radially outward by the tooth portion 30 against the biasing force of the spring 50, and is in a non-engagement state with the tooth portion 30, allowing the output shaft 6 to rotate in the other circumferential direction. Therefore, as shown in FIG. 4(c), both the first claw member 26 and the second claw member 28 of the two-way clutch 8 are in a non-engagement state with the tooth portion 30, and the driving force is not transmitted from the outer ring 24 to the output shaft 6. That is, the driving force from the electric motor 2 is transmitted from the input shaft 4 to the output shaft 6 via the high-speed transmission mechanism 18, i.e., the friction engagement device 12.

During high-speed driving after shifting from the low-speed transmission mechanism 17 to the high-speed transmission mechanism 18, the two-way clutch 8, which is always connected to the low-speed gear 32, is in an idling state, and no torque is transmitted to the output shaft 6 via the two-way clutch 8.

Next, the operation of the drive unit 1 when the vehicle moves backward will be described.
When the vehicle moves backward, the input shaft 4 connected to the electric motor 2 rotates in the other circumferential direction. When the vehicle moves backward, the wet clutch 3 of the friction engagement device 12 is controlled to a disengaged state, and the rotation of the input shaft 4 is transmitted as a low-speed rotation to the two-way clutch 8 via the first connecting gear 14 and the low-speed gear 32, and is transmitted to the output shaft 6 via the two-way clutch 8. At this time, as shown in FIG. 4(a), the first claw member 26 and the second claw member 28 of the two-way clutch 8 are both engaged with the teeth 30. Therefore, when the outer ring 24 of the two-way clutch 8 rotates in one circumferential direction in FIG. 4(a), the output shaft 6 rotates in one circumferential direction together with the outer ring 24 due to the engagement between the second claw member 28 and the teeth 30 of the enlarged diameter portion 6a of the output shaft 6. When the vehicle moves backward, the driving force from the electric motor 2 is transmitted to the output shaft 6 in this manner.

In this way, the drive unit 1 of this embodiment can simplify the structure, prevent an increase in installation space, and reduce weight.

Next, a drive device 11 according to a second example of the first embodiment will be described.
In the description of the second embodiment, the same components as those in the first embodiment will be designated by the same reference numerals as in the first embodiment with reference to FIGS. 1 to 4, and detailed description of these components will be omitted.

FIG. 5 is a skeleton diagram showing the configuration of a drive device 11 according to a second example of the first embodiment.
Similar to the first embodiment described above, the drive device 11 of this embodiment has an input shaft 4 connected to the drive shaft of the electric motor 2, and an output shaft 6 arranged parallel to the input shaft 4. The driving force of the electric motor 2 is transmitted from the input shaft 4 to the output shaft 6 via a two-way clutch 8 or a friction engagement device 12. The drive device 11 of this embodiment differs from the first embodiment in that the friction engagement device 12 is provided on the input shaft 4, and a second connecting gear 16 is provided on the output shaft. The other configurations are similar to those of the first embodiment.

As shown in FIG. 5, a friction engagement device 12 for transmitting the driving force from the electric motor 2 to the output shaft 6 at high speed and a first connecting gear 14 for transmitting the driving force from the electric motor 2 to the output shaft 6 at low speed are provided coaxially with the input shaft 4. The friction engagement device 12 and the first connecting gear 14 are provided side by side in the axial direction in this order from one axial side to the other axial side. The first connecting gear 14 is provided on the input shaft 4 so as not to rotate relative to the input shaft 4.

The friction engagement device 12 is a wet clutch 3 of the same configuration as in the first embodiment (see FIG. 2). The wet clutch 3 has a clutch hub 62 fixed to the input shaft 4 and rotating integrally therewith, and a clutch case 7 fitted to the input shaft 4 so as to be rotatable relative to the input shaft 4. As in the first embodiment, a clutch plate 13 and a clutch disc 15 are provided inside the clutch case 7. A high-speed gear 72 is connected to the clutch case 7. The high-speed gear 72 has a larger diameter than the first connecting gear 14. The clutch case 7 and the high-speed gear 72 rotate integrally.

A second connecting gear 16 and a two-way clutch 8 are provided coaxially on the output shaft 6. The second connecting gear 16 and the two-way clutch 8 are arranged in the axial direction from one axial side to the other axial side in this order.

The two-way clutch 8 has the same configuration as in the first embodiment (see Figures 2 and 3). That is, the two-way clutch 8 has an annular outer ring 24 and a ratchet mechanism that is a torque transmission mechanism, and the output shaft 6 constitutes the inner ring of the two-way clutch 8. As in the first embodiment, an annular low-speed gear 32 is arranged on the outer periphery of the outer ring 24, and the outer ring 24 and the low-speed gear 32 rotate together. The low-speed gear 32 is always engaged with the first connecting gear 14 of the input shaft 4. Therefore, the outer ring 24 and the first connecting gear 14 of the two-way clutch 8 are always connected via the low-speed gear 32, and the input shaft 4 and the outer ring 24 of the two-way clutch 8 rotate in opposite directions. The first connecting gear 14 and the two-way clutch 8 constitute the low-speed transmission mechanism 17.

The second connecting gear 16 has a smaller diameter than the low-speed gear 32 of the low-speed transmission mechanism 17, and is provided on the output shaft 6 so as not to rotate relative to the output shaft 6. The second connecting gear 16 is always meshed with the high-speed gear 72 of the friction engagement device 12. Therefore, the clutch case 7 of the friction engagement device 12 and the second connecting gear 16 are always connected via the high-speed gear 72, and the input shaft 4 and the clutch case 7 rotate in opposite directions. The second connecting gear 16 and the friction engagement device 12 constitute the high-speed transmission mechanism 18. The low-speed transmission mechanism 17 and the high-speed transmission mechanism 18 constitute a two-speed transmission.

The driving force of the electric motor 2 transmitted from the input shaft 4 via the transmission to the output shaft 6 is transmitted to the differential gear mechanism 23, which is the drive mechanism for the drive wheels 22, via the output gear 20 fixed to the output shaft 6, as in the first embodiment.

Next, the operation of the drive unit 11 according to this embodiment will be described. The following explanation of the operation will be given with one axial side as the front in FIG. 5, and the drive unit 11 viewed from the front.

When a vehicle (not shown) starts moving forward from a stopped state, the input shaft 4 connected to the electric motor 2 rotates in one circumferential direction. The rotation of the input shaft 4 is transmitted as low-speed rotation to the outer ring 24 of the two-way clutch 8 via the first connecting gear 14 and the low-speed gear 32, and the outer ring 24 of the two-way clutch 8 rotates in the other circumferential direction.

At this time, the multiple clutch plates 13 and multiple clutch disks 15 (see FIG. 2) of the wet clutch 3 of the friction engagement device 12 are in a disengaged state. In other words, the wet clutch 3 is controlled to be in a disengaged state. In this state, rotation in one circumferential direction of the input shaft 4 is not transmitted from the clutch hub 62, which rotates integrally with the input shaft 4, to the clutch case 7.

As described in the first embodiment, when the vehicle is stopped, the outer ring 24 of the two-way clutch 8 does not rotate, so no centrifugal force acts on the second claw member 28. In addition, the rotational speed of the outer ring 24 when a low-speed rotation is input from the input shaft 4 is slower than the predetermined rotational speed R1, and the magnitude of the centrifugal force acting on the second claw member 28 is smaller than the predetermined magnitude F1. For this reason, the spring 60 that biases the second claw member 28 is not compressed, and both the first claw member 26 and the second claw member 28 are engaged with the tooth portion 30 (see FIG. 4(a)). Therefore, in this embodiment, as in the first embodiment, when the outer ring 24 rotates in the other circumferential direction in FIG. 4(a), the output shaft 6 rotates in the other circumferential direction together with the outer ring 24 due to the engagement between the first claw member 26 and the tooth portion 30 of the output shaft 6, and the driving force from the electric motor 2 is transmitted to the output shaft 6. At this time, the rotational speed of the input shaft 4 is reduced and transmitted to the output shaft 6. The driving force from the electric motor 2 transmitted to the output shaft 6 is transmitted to a differential gear mechanism 23, which is the drive mechanism for the drive wheels 22, via an output gear 20 (see FIG. 2) fitted to the output shaft 6.

In this state, the second connecting gear 16 rotates in the other circumferential direction together with the output shaft 6. The rotation of the second connecting gear 16 is transmitted to the clutch case 7 via the high-speed gear 72, and the clutch case 7 rotates in one circumferential direction, but since the wet clutch 3 is controlled to be in a non-engaged state, the clutch case 7 is in an idling state relative to the input shaft 4 and the clutch hub 62. At this time, the clutch case 7 rotates in one circumferential direction at a slower speed than the input shaft 4.

In this way, when the vehicle starts or runs at low speeds, the driving force from the electric motor 2 is transmitted from the input shaft 4 to the output shaft 6 via the low-speed transmission mechanism 17, i.e., the two-way clutch 8.

Next, the operation of the drive unit 1 when the transmission of the drive unit 11 is shifted from the low speed change mechanism portion 17 to the high speed change mechanism portion 18 will be described.
When the vehicle accelerates after starting, the transmission of the drive unit 11 shifts from the low speed change mechanism portion 17 to the high speed change mechanism portion 18 .
When the vehicle accelerates, the rotational speed of the outer wheel 24 exceeds a predetermined rotational speed R1, and the magnitude of the centrifugal force acting on the second pawl member 28 exceeds a predetermined magnitude F1, the spring 60 biasing the second pawl member 28 is greatly compressed by the pawl portion 58, and the pawl portion 58 as a whole is positioned radially outward from the tooth portion 30. In this state, as shown in Figure 4(b), in the two-way clutch 8, the first pawl member 26 maintains a state of meshing with the tooth portion 30, but the second pawl member 28 is not meshed with the tooth portion 30.

In this state, the wet clutch 3 is controlled to switch from a non-engaged state to an engaged state, as in the first embodiment. Specifically, the piston 66 is driven by the piston drive mechanism 64, and the wet clutch 3 is engaged. As described above, when a low rotation input is applied, i.e., when the wet clutch 3 is in a non-engaged state, the clutch case 7 rotates in one circumferential direction at a slower speed than the input shaft 4. When the wet clutch 3 is engaged in this state, the input shaft 4, the clutch hub 62, and the clutch case 7 rotate together in one circumferential direction, and high-speed rotation is transmitted from the clutch case 7 to the output shaft 6 via the high-speed gear 72 and the second connecting gear 16. In other words, the driving force of the electric motor 2 is transmitted to the output shaft 6 as high-speed rotation.

When the driving force of the electric motor 2 is transmitted to the output shaft 6 as high-speed rotation, the rotation speed of the output shaft 6 in the other circumferential direction increases. When the rotation speed of the output shaft 6 increases, the rotation speed of the output shaft 6 becomes faster than the rotation speed of the outer ring 24 of the two-way clutch 8, which rotates integrally with the low-speed gear 32. That is, in FIG. 4(b), the output shaft 6 rotates relative to the outer ring 24 of the two-way clutch 8 in the other circumferential direction. Then, the first claw member 26 is pushed radially outward by the tooth portion 30 against the biasing force of the spring 50, and is in a non-engagement state with the tooth portion 30, allowing the output shaft 6 to rotate in the other circumferential direction. Therefore, as shown in FIG. 4(c), both the first claw member 26 and the second claw member 28 of the two-way clutch 8 are in a non-engagement state with the tooth portion 30, and the driving force is not transmitted from the outer ring 24 to the output shaft 6. That is, the driving force from the electric motor 2 is transmitted from the input shaft 4 to the output shaft 6 via the high-speed transmission mechanism 18, i.e., the friction engagement device 12.

During high-speed driving after shifting from the low-speed transmission mechanism 17 to the high-speed transmission mechanism 18, the two-way clutch 8, which is always connected to the low-speed gear 32, is in an idling state, and no torque is transmitted to the output shaft 6 via the two-way clutch 8.

Next, the operation of the drive unit 1 when the vehicle moves backward will be described.
When the vehicle moves backward, the input shaft 4 connected to the electric motor 2 rotates in the other circumferential direction. When the vehicle moves backward, the wet clutch 3 of the friction engagement device 12 is controlled to a disengaged state, and the rotation of the input shaft 4 is transmitted as a low-speed rotation to the two-way clutch 8 via the first connecting gear 14 and the low-speed gear 32, and is transmitted to the output shaft 6 via the two-way clutch 8. At this time, as shown in FIG. 4(a), the first claw member 26 and the second claw member 28 of the two-way clutch 8 are both engaged with the teeth 30. Therefore, when the outer ring 24 of the two-way clutch 8 rotates in one circumferential direction in FIG. 4(a), the output shaft 6 rotates in one circumferential direction together with the outer ring 24 due to the engagement between the second claw member 28 and the teeth 30 of the enlarged diameter portion 6a of the output shaft 6. When the vehicle moves backward, the driving force from the electric motor 2 is transmitted to the output shaft 6 in this manner.

In this way, with the drive device 11 of this embodiment, as with the first embodiment, the structure can be simplified, the increase in installation space can be suppressed, and weight can be reduced.

Next, a drive mechanism according to a second embodiment of the present invention will be described.
The drive device according to the second embodiment of the present invention is different from the first embodiment in that an input shaft to which a driving force from an electric motor is input and an output shaft to which the driving force is output to a drive unit are arranged on the same axis. Note that, in the description of each example of the second embodiment, the same reference numerals are used for configurations similar to those of the first embodiment by referring to Figures 1 to 5, and detailed description of these configurations is omitted.

First, a driving device 101 according to a first example of the second embodiment will be described.
FIG. 6 is a skeleton diagram showing the configuration of a driving device 101 according to a first example of the second embodiment.
FIG. 7 is an enlarged cross-sectional view showing the main parts of the two-way clutch 108 and the planetary gear mechanism 127 of the drive device 101 according to this embodiment, as viewed from one axial side.
6, a drive device 101 according to this embodiment has an input shaft 104 connected to the drive shaft of the electric motor 2, and an output shaft 106 arranged coaxially with the input shaft 104. The driving force of the electric motor 2 is transmitted from the input shaft 104 to the output shaft 106 via a speed change device. The speed change device includes a two-way clutch 108, a planetary gear mechanism 127, and a friction engagement device 12.

In this embodiment, the input shaft 104 is formed in a cylindrical shape. A two-way clutch 108 and a friction engagement device 12 are provided coaxially with the input shaft 104 on the outer periphery of the input shaft 104. The two-way clutch 108 and the friction engagement device 12 are provided side by side in the axial direction from one axial side to the other axial side in this order.

In this embodiment, the input shaft 104 constitutes the inner ring of the two-way clutch 108. Specifically, the portion 104a of the input shaft 104 constitutes the inner ring of the two-way clutch 108. As shown in FIG. 7, a plurality of teeth 30 are formed in the circumferential direction on the outer periphery of the portion 104a of the input shaft 104. The configuration of the teeth 30 is the same as in the first embodiment. The outer ring 124 of the two-way clutch 108 is provided with a plurality of first claw members 26 and a plurality of second claw members 28, each of which has the same configuration as in the first embodiment. A gear 125 is formed in the circumferential direction on the outer periphery of the outer ring 124.

The drive device 101 of this embodiment is equipped with a planetary gear mechanism 127 in which the outer ring 124 of the two-way clutch 108 serves as a sun gear. The planetary gear mechanism 127 is equipped with a sun gear, which is the outer ring 124 of the two-way clutch 108, a plurality of planetary gears 129 that mesh with the sun gear, a planetary carrier 131 that supports each of the plurality of planetary gears 129 so that they can rotate on their own axes, and a ring gear 133 that meshes with the plurality of planetary gears 129. The ring gear 133 is fixed to, for example, a transmission case 135 so as not to rotate.

The two-way clutch 108 transmits the driving force of the electric motor 2 from the input shaft 104 to the planetary carrier 131 via the planetary gear 129 by meshing the first claw member 26 or the second claw member 28 with the teeth portion 30 of the input shaft 104. The planetary carrier 131 is connected to the output shaft 106.

The friction engagement device 12 is a wet clutch 3 having a configuration similar to that of the first embodiment, in which the clutch hub 62 is fixed to the input shaft 104, and the clutch case 7 is connected to the planetary carrier 131 of the planetary gear mechanism 127. The wet clutch 3 is switched between an engaged state and an unengaged state by a piston drive mechanism 64 (see FIG. 2) similar to that of the first embodiment. In the engaged state, the wet clutch 3 integrally connects the input shaft 104 and the planetary carrier 131.

The driving force of the electric motor 2 transmitted from the input shaft 104 to the output shaft 106 via the transmission is transmitted to the differential gear mechanism 23, which is the drive mechanism for the drive wheels 22, in the same manner as in the first embodiment.

Next, the operation of the drive device 101 according to this embodiment will be described. The following explanation of the operation will be given with one axial side as the front in FIG. 6, and the drive device 101 viewed from the front.

When a vehicle (not shown) starts moving forward from a stopped state, the input shaft 104 connected to the electric motor 2, i.e., the inner ring of the two-way clutch 108, rotates in one circumferential direction in FIG. 7. At this time, the wet clutch 3 is controlled to be in an idling state, i.e., in a non-engaged state. Also, in the two-way clutch 108, as in the first embodiment, when the rotational speed of the outer ring 124 is slower than a predetermined rotational speed R1 and the magnitude of the centrifugal force acting on the second claw member 28 is smaller than a predetermined magnitude F1, i.e., when the vehicle is stopped or the vehicle speed is in the low speed range, both the first claw member 26 and the second claw member 28 are engaged with the teeth 30 of the input shaft 104. Therefore, in FIG. 7, when the input shaft 104, i.e., the inner ring of the two-way clutch 108, rotates in one circumferential direction, the two-way clutch 108 transmits the torque of the electric motor 2 from the inner ring, which is the input shaft 104, to the outer ring 124, which is the sun gear of the planetary gear mechanism 127, by meshing the first pawl member 26 with the tooth portion 30, and the outer ring 124 rotates in one circumferential direction.

When the outer ring 124 of the two-way clutch 108 rotates in one circumferential direction, the rotation of the outer ring 124 is transmitted to the planetary carrier 131 via the multiple planetary gears 129, and the planetary carrier 131 rotates in one circumferential direction. At this time, the rotation of the outer ring 124 is decelerated and transmitted to the planetary carrier 131. In this way, the torque of the electric motor 2 is transmitted from the planetary carrier 131 to the output shaft 106 as a low-speed rotation, and the output shaft 106 rotates in one circumferential direction. The driving force from the electric motor 2 transmitted to the output shaft 106 is transmitted to the differential gear 23, which is the drive mechanism of the drive wheels 22, via the output gear 120 engaged with the output shaft 106.

In this way, when the vehicle starts moving or travels at low speeds, the driving force from the electric motor 2 is transmitted from the input shaft 104 to the output shaft 106 via the two-way clutch 108 and the planetary gear mechanism 127. In other words, the two-way clutch 108 and the planetary gear mechanism 127 constitute the low-speed transmission mechanism 117.

Next, the operation of the driving device 101 when the transmission of the driving device 101 changes speed from a low speed state to a high speed state will be described.
When the vehicle accelerates, the rotational speed of the sun gear of the planetary gear mechanism 127, i.e., the outer ring 124 of the two-way clutch 108, exceeds a predetermined rotational speed R1, and the magnitude of the centrifugal force acting on the second pawl member 28 exceeds a predetermined magnitude F1, the spring 60 biasing the second pawl member 28 is greatly compressed by the pawl portion 58, and the entire pawl portion 58 is positioned radially outward from the tooth portion 30. In this state, in the two-way clutch 108, the first pawl member 26 maintains a state of meshing with the tooth portion 30, but the second pawl member 28 is not meshed with the tooth portion 30.

In this state, the wet clutch 3 is controlled to switch from a non-engaged state to an engaged state. Specifically, the piston 66 (see FIG. 2) is driven by the piston drive mechanism 64, and the wet clutch 3 is engaged. When the wet clutch 3 is engaged, the input shaft 104 and the planetary carrier 131 rotate together in one circumferential direction, and high-speed rotation is transmitted from the clutch hub 62 to the planetary carrier 131 via the clutch case 7. At this time, the rotation of the input shaft 104 is not decelerated, but is transmitted to the planetary carrier 131 at a constant speed. In this way, the driving force of the electric motor 2 is transmitted to the output shaft 104 as high-speed rotation. In other words, the wet clutch 3 constitutes the high-speed transmission mechanism 118.

During high-speed travel after shifting from a low-speed state to a high-speed state, the input shaft 104 and the planetary carrier 131 rotate at the same speed in one circumferential direction. At this time, the outer ring 124 of the sun gear, i.e., the two-way clutch 108, rotates in one circumferential direction at a faster speed than the planetary carrier 131 due to the input of rotation from the planetary carrier 131 via the planetary gear 129. That is, the outer ring 124 rotates in one circumferential direction at a faster speed than the input shaft 104. Then, the first claw member 26 has the claw portion 48 pushed radially outward by the tooth portion 30 against the biasing force of the spring 50, and is in a non-meshing state with the tooth portion 30, allowing the outer ring 124 to rotate relative to the input shaft 104 in one circumferential direction. That is, no driving force is transmitted from the input shaft 104 to the outer ring 124 via the two-way clutch 108.

When the vehicle moves backward, the input shaft 104 connected to the electric motor 2, i.e., the inner ring of the two-way clutch 108, rotates in the other circumferential direction in FIG. 7. At this time, the wet clutch 3 is controlled to be in an idling state, i.e., in a non-engaged state. In addition, the first claw member 26 and the second claw member 28 of the two-way clutch 108 are both engaged with the teeth 30 of the input shaft 104. Therefore, when the input shaft 104, i.e., the inner ring of the two-way clutch 108 rotates in the other circumferential direction in FIG. 7, the two-way clutch 108 transmits the torque of the electric motor 2 from the input shaft 104, which is the inner ring, to the outer ring 124, which is the sun gear of the planetary gear mechanism 127, by the engagement of the second claw member 28 with the teeth 30, and the outer ring 124 rotates in the other circumferential direction. When the outer ring 124 of the two-way clutch 108 rotates in the other circumferential direction, the rotation of the outer ring 124 is transmitted to the planetary carrier 131 via multiple planetary gears 129, the planetary carrier 131 rotates in the other circumferential direction, and the output shaft 106 rotates in the other circumferential direction. When the vehicle moves backwards, the driving force from the electric motor 2 is transmitted to the output shaft 106 in this manner.

Next, a driving device 201 according to a second example of the second embodiment will be described.
FIG. 8 is a skeleton diagram showing the configuration of a driving device 201 according to a second example of the second embodiment.
FIG. 9 is an enlarged cross-sectional view showing a main portion of the two-way clutch and planetary gear mechanism 227 of the drive device 201 according to this embodiment, as viewed from one axial side.
As shown in Fig. 8, a drive device 201 according to this embodiment, like the first embodiment, has an input shaft 204 connected to the drive shaft of the electric motor 2, and an output shaft 206 arranged coaxially with the input shaft 204. The driving force of the electric motor 2 is transmitted from the input shaft 204 to the output shaft 206 via a speed change device. The speed change device includes a two-way clutch 208, a planetary gear mechanism 227, and a friction engagement device 12.

In this embodiment, the input shaft 204 is formed in a cylindrical shape. A two-way clutch 208 and a friction engagement device 12 are provided coaxially with the input shaft 204 on the inner periphery of the input shaft 204. The two-way clutch 208 and the friction engagement device 12 are provided side by side in the axial direction from one axial side to the other axial side in this order.

In this embodiment, the input shaft 204 constitutes the outer ring of the two-way clutch 208. As shown in FIG. 9, the inner periphery of the input shaft 204 is provided with a plurality of first claw members 26 and second claw members 28, each having the same configuration as in the first embodiment. A plurality of teeth 30 are formed around the circumferential direction on the outer periphery of the inner ring 237 of the two-way clutch 208. The configuration of the teeth 30 is the same as in the first embodiment. A gear 239 is formed around the circumferential direction on the inner periphery of the inner ring 237 of the two-way clutch 208.

The drive unit 201 of this embodiment includes a planetary gear mechanism 227 in which the inner ring 237 of the two-way clutch 208 serves as a ring gear. The planetary gear mechanism 227 includes a ring gear that is the inner ring 237 of the two-way clutch 208, a plurality of planetary gears 229 that mesh with the ring gear, a planetary carrier 231 that supports each of the plurality of planetary gears 229 so that they can rotate on their own axes, and a sun gear 241 that meshes with the plurality of planetary gears 229. The sun gear 241 is fixed to the transmission case 135, for example, so as not to rotate.

The two-way clutch 208 transmits the driving force of the electric motor 2 from the input shaft 204, which is the outer ring, to the planetary carrier 231 via the planetary gear 229 by meshing the first claw member 26 or the second claw member 28 with the teeth 30 of the inner ring 237. The planetary carrier 231 is connected to the output shaft 206.

The friction engagement device 12 is a wet clutch 3 having a configuration similar to that of the first embodiment, with the clutch case 7 connected to the input shaft 204 and the clutch hub 62 connected to the planetary carrier 231 of the planetary gear mechanism 227. The wet clutch 3 is switched between an engaged state and an unengaged state by a piston drive mechanism 64 (see FIG. 2) similar to that of the first embodiment. In the engaged state, the wet clutch 3 integrally connects the input shaft 204 and the planetary carrier 231.

The driving force of the electric motor 2 transmitted from the input shaft 204 to the output shaft 206 via the transmission is transmitted to the differential gear mechanism 23, which is the drive mechanism for the drive wheels 22, in the same manner as in the first embodiment.

Next, the operation of the drive device 201 according to this embodiment will be described. The following explanation of the operation will be given with one axial side as the front in FIG. 8, and the drive device 201 viewed from the front.

When a vehicle (not shown) starts moving forward from a stopped state, the input shaft 204 connected to the electric motor 2, i.e., the outer ring of the two-way clutch 208, rotates in the other circumferential direction in FIG. 9. At this time, the wet clutch 3 is controlled to be in an idling state, i.e., in a non-engaged state. Also, in the two-way clutch 208, as in the first embodiment, when the rotational speed of the outer ring is slower than a predetermined rotational speed R1 and the magnitude of the centrifugal force acting on the second claw member 28 is smaller than a predetermined magnitude F1, i.e., when the vehicle is stopped or the vehicle speed is in the low speed range, the first claw member 26 and the second claw member 28 are both engaged with the teeth 30 of the inner ring 237. Therefore, in FIG. 9, when the input shaft 204, i.e., the outer ring of the two-way clutch 208, rotates in the other circumferential direction, the two-way clutch 208 transmits the torque of the electric motor 2 from the outer ring, which is the input shaft 204, to the inner ring 237, which is the ring gear of the planetary gear mechanism 227, by meshing between the first pawl member 26 and the tooth portion 30, and the inner ring 237 rotates in the other circumferential direction.

When the inner wheel 237 of the two-way clutch 208 rotates in the other circumferential direction, the rotation of the inner wheel 237 is transmitted to the planetary carrier 231 via the multiple planetary gears 229, and the planetary carrier 231 rotates in the other circumferential direction. At this time, the rotation of the inner wheel 237 is decelerated and transmitted to the planetary carrier 231. In this way, the torque of the electric motor 2 is transmitted from the planetary carrier 231 to the output shaft 206 as a low-speed rotation, and the output shaft 206 rotates in the other circumferential direction. The driving force from the electric motor 2 transmitted to the output shaft 206 is transmitted to the differential gear 23, which is the drive mechanism of the drive wheels 22, via the output gear 220 engaged with the output shaft 206.

In this way, when the vehicle starts moving or travels at low speeds, the driving force from the electric motor 2 is transmitted from the input shaft 204 to the output shaft 206 via the two-way clutch 208 and the planetary gear mechanism 227. In other words, the two-way clutch 208 and the planetary gear mechanism 227 constitute the low-speed transmission mechanism 217.

Next, the operation of the drive device 201 when the transmission of the drive device 201 changes speed from a low speed state to a high speed state will be described.
When the vehicle accelerates, the rotational speed of the input shaft 204, i.e., the outer ring of the two-way clutch 208, exceeds a predetermined rotational speed R1, and the magnitude of the centrifugal force acting on the second pawl member 28 exceeds a predetermined magnitude F1, the spring 60 biasing the second pawl member 28 is greatly compressed by the pawl portion 58, and the entire pawl portion 58 is positioned radially outward from the tooth portion 30. In this state, in the two-way clutch 208, the first pawl member 26 maintains a state of meshing with the tooth portion 30, but the second pawl member 28 is not meshed with the tooth portion 30.

In this state, the wet clutch 3 is controlled to switch from a non-engaged state to an engaged state. Specifically, the piston 66 (see FIG. 2) is driven by the piston drive mechanism 64, and the wet clutch 3 is engaged. When the wet clutch 3 is engaged, the input shaft 204, i.e., the outer ring of the two-way clutch 208 and the planetary carrier 231 rotate together in the other circumferential direction, and high-speed rotation is transmitted from the clutch case 7 to the planetary carrier 231 via the clutch hub 62. At this time, the rotation of the input shaft 204 is not decelerated, but is transmitted to the planetary carrier 231 at a constant speed. In this way, the driving force of the electric motor 2 is transmitted to the output shaft 206 as high-speed rotation. In other words, the wet clutch 3 constitutes the high-speed transmission mechanism 218.

During high-speed running after shifting from a low-speed state to a high-speed state, the input shaft 204, i.e., the outer ring of the two-way clutch 208 and the planetary carrier 231 rotate at the same speed in the other circumferential direction. At this time, the ring gear, i.e., the inner ring 237 of the two-way clutch, rotates in the other circumferential direction at a speed faster than the planetary carrier 231 due to the input of rotation from the planetary carrier 231 via the planetary gear 229. In other words, the inner ring 237 rotates in the other circumferential direction at a speed faster than the input shaft 204. Then, the first claw member 26 has the claw portion 48 pushed radially outward by the tooth portion 30 against the biasing force of the spring 50, and is in a non-meshing state with the tooth portion 30, allowing the inner ring 237 to rotate relative to the input shaft 204 in the other circumferential direction. In other words, no driving force is transmitted from the input shaft 204 to the inner ring 237 via the two-way clutch 208.

When the vehicle moves backward, the input shaft 204 connected to the electric motor 2, i.e., the outer ring of the two-way clutch 208, rotates in one circumferential direction in FIG. 9. At this time, the wet clutch 3 is controlled to be in an idling state, i.e., in a non-engaged state. In addition, the first claw member 26 and the second claw member 28 of the two-way clutch 208 are both engaged with the teeth 30 of the inner ring 237. Therefore, when the input shaft 204, i.e., the outer ring of the two-way clutch 208 rotates in one circumferential direction in FIG. 9, the two-way clutch 208 transmits the torque of the electric motor 2 from the input shaft 204, which is the outer ring, to the inner ring 237, which is the ring gear of the planetary gear mechanism 227, by the engagement of the second claw member 28 with the teeth 30, and the inner ring 237 rotates in one circumferential direction. When the inner wheel 237 of the two-way clutch 208 rotates in one circumferential direction, the rotation of the inner wheel 237 is transmitted to the planetary carrier 231 via the multiple planetary gears 229, the planetary carrier 231 rotates in one circumferential direction, and the output shaft 206 rotates in one circumferential direction. When the vehicle moves backwards, the driving force from the electric motor 2 is transmitted to the output shaft 6 in this manner.

In this way, according to the drive devices 101 and 201 of each example of the second embodiment, as in the first embodiment, the structure can be simplified, the increase in installation space can be suppressed, and weight can be reduced.

Although each embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiments and can be modified as appropriate. For example, the present invention can also be applied to a vehicle that uses an engine as a drive source.

Reference Signs List 1, 11, 101, 201 Drive device 2 Electric motor 3 Wet clutch 4, 104, 204 Input shaft 6, 106, 206 Output shaft 7 Clutch case 8, 108, 208 Two-way clutch 12 Friction engagement device 14 First connecting gear 16 Second connecting gear 17, 117, 217 Low-speed change mechanism 18, 118, 218 High-speed change mechanism 24, 124, 224 Outer ring 26 First claw member 28 Second claw member 30 Tooth portion 62 Clutch hub 127, 227 Planetary gear mechanism 129, 229 Planetary gear 131, 231 Planetary carrier 133 Ring gear 237 Inner ring 241 Sun gear

Claims (6)

An input shaft on the drive source side;
an output shaft that transmits the driving force of the driving source to a driving wheel side;
a transmission mechanism that transmits the driving force from the input shaft to the output shaft,
The speed change mechanism includes:
a first transmission mechanism that reduces the rotation speed of the input shaft and transmits the reduced rotation speed to the output shaft;
a second transmission mechanism capable of transmitting rotation of the input shaft to the output shaft at a speed faster than that of the first transmission mechanism,
the first transmission mechanism includes a two-way clutch capable of selectively transmitting, to the output shaft, rotation of the input shaft in a direction in which the vehicle moves forward and rotation of the vehicle moves backward;
the second speed change mechanism includes a clutch mechanism capable of transmitting the rotation of the input shaft in the forward direction to the output shaft by frictional engagement;
The input shaft and the output shaft are arranged in parallel,
the first transmission mechanism includes a first gear provided on the input shaft and rotating integrally with the input shaft, and a second gear provided on the output shaft and meshing with the first gear,
the two-way clutch is provided between the second gear and the output shaft,
the second transmission mechanism includes a third gear that is provided on the input shaft and rotates integrally with the input shaft and has a larger diameter than the first gear, and a fourth gear that is provided on the output shaft and meshes with the third gear and has a smaller diameter than the second gear,
the clutch mechanism is provided between the fourth gear and the output shaft,
A plurality of teeth are formed at predetermined intervals in the circumferential direction on the outer periphery of the output shaft,
The two-way clutch is
the second gear includes an outer ring that rotates integrally with the second gear, a first claw member that is held on the outer ring so as to be pivotable in the radial direction and that, when it pivots radially inward to mesh with the toothed portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves backward, a first elastic member that urges the first claw member in the meshing direction with the toothed portion, a second claw member that is held on the outer ring so as to be pivotable in the radial direction and that, when it pivots radially inward to mesh with the toothed portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves forward, and a second elastic member that urges the second claw member in the meshing direction with the toothed portion ,
The elastic force of the second elastic member is set to be smaller than the elastic force of the first elastic member,
A drive device characterized in that when a centrifugal force exceeding a predetermined magnitude acts on the first pawl member and the second pawl member due to rotation of the outer ring, the second elastic member is compressed by the second pawl member until the second pawl member is disengaged from the tooth portion, and the first elastic member is not compressed by the first pawl member and maintains engagement with the tooth portion . An input shaft on the drive source side;
an output shaft that transmits the driving force of the driving source to a driving wheel side;
a transmission mechanism that transmits the driving force from the input shaft to the output shaft,
The speed change mechanism includes:
a first transmission mechanism that reduces the rotation speed of the input shaft and transmits the reduced rotation speed to the output shaft;
a second transmission mechanism capable of transmitting rotation of the input shaft to the output shaft at a speed faster than that of the first transmission mechanism,
the first transmission mechanism includes a two-way clutch capable of selectively transmitting, to the output shaft, rotation of the input shaft in a direction in which the vehicle moves forward and rotation of the vehicle moves backward;
the second speed change mechanism includes a clutch mechanism capable of transmitting the rotation of the input shaft in the forward direction to the output shaft by frictional engagement;
The input shaft and the output shaft are arranged in parallel,
the first transmission mechanism includes a first gear provided on the input shaft and rotating integrally with the input shaft, and a second gear provided on the output shaft and meshing with the first gear,
the two-way clutch is provided between the second gear and the output shaft,
the second transmission mechanism includes a third gear that is provided on the output shaft and rotates integrally with the output shaft and has a smaller diameter than the second gear, and a fourth gear that is provided on the input shaft and meshes with the third gear and has a larger diameter than the first gear,
the clutch mechanism is provided between the fourth gear and the input shaft,
A plurality of teeth are formed at predetermined intervals in the circumferential direction on the outer periphery of the output shaft,
The two-way clutch is
the second gear includes an outer ring that rotates integrally with the second gear, a first claw member that is held on the outer ring so as to be pivotable in the radial direction and that, when it pivots radially inward to mesh with the toothed portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves backward, a first elastic member that urges the first claw member in the meshing direction with the toothed portion, a second claw member that is held on the outer ring so as to be pivotable in the radial direction and that, when it pivots radially inward to mesh with the toothed portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves forward, and a second elastic member that urges the second claw member in the meshing direction with the toothed portion ,
The elastic force of the second elastic member is set to be smaller than the elastic force of the first elastic member,
A drive device characterized in that when a centrifugal force exceeding a predetermined magnitude acts on the first pawl member and the second pawl member due to rotation of the outer ring, the second elastic member is compressed by the second pawl member until the second pawl member is disengaged from the tooth portion, and the first elastic member is not compressed by the first pawl member and maintains engagement with the tooth portion . An input shaft on the drive source side;
an output shaft that transmits the driving force of the driving source to a driving wheel side;
a transmission mechanism that transmits the driving force from the input shaft to the output shaft,
The speed change mechanism includes:
a first transmission mechanism that reduces the rotation speed of the input shaft and transmits the reduced rotation speed to the output shaft;
a second transmission mechanism capable of transmitting rotation of the input shaft to the output shaft at a speed faster than that of the first transmission mechanism,
the first transmission mechanism includes a two-way clutch capable of selectively transmitting, to the output shaft, rotation of the input shaft in a direction in which the vehicle moves forward and rotation of the vehicle moves backward;
the second speed change mechanism includes a clutch mechanism capable of transmitting the rotation of the input shaft in the forward direction to the output shaft by frictional engagement;
The input shaft and the output shaft are arranged on the same axis,
the first transmission mechanism includes a planetary gear mechanism including a sun gear, a plurality of planetary gears meshing with the sun gear, a planetary carrier supporting the plurality of planetary gears so as to be rotatable about their axes, and a ring gear meshing with the plurality of planetary gears;
The output shaft is connected to the planetary carrier,
the two-way clutch is provided between the input shaft and the planetary gear mechanism,
The clutch mechanism is provided between the input shaft and the planetary carrier,
The input shaft constitutes an inner ring of the two-way clutch,
A plurality of teeth are formed at predetermined intervals in the circumferential direction on an outer periphery of the input shaft,
The sun gear constitutes an outer ring of the two-way clutch,
the two-way clutch has a first pawl member that is held on the outer wheel so as to be able to swing radially, and that, when it swings radially inward to mesh with the tooth portion, locks the relative rotation of the output shaft with respect to the outer wheel in the direction in which the vehicle moves forward, and a second pawl member that is held on the outer wheel so as to be able to swing radially, and that, when it swings radially inward to mesh with the tooth portion, locks the relative rotation of the output shaft with respect to the outer wheel in the direction in which the vehicle moves backward, An input shaft on the drive source side;
an output shaft that transmits the driving force of the driving source to a driving wheel side;
a transmission mechanism that transmits the driving force from the input shaft to the output shaft,
The speed change mechanism includes:
a first transmission mechanism that reduces the rotation speed of the input shaft and transmits the reduced rotation speed to the output shaft;
a second transmission mechanism capable of transmitting rotation of the input shaft to the output shaft at a speed faster than that of the first transmission mechanism,
the first transmission mechanism includes a two-way clutch capable of selectively transmitting, to the output shaft, rotation of the input shaft in a direction in which the vehicle moves forward and rotation of the vehicle moves backward;
the second speed change mechanism includes a clutch mechanism capable of transmitting the rotation of the input shaft in the forward direction to the output shaft by frictional engagement;
The input shaft and the output shaft are arranged on the same axis,
the first transmission mechanism includes a planetary gear mechanism including a sun gear, a plurality of planetary gears meshing with the sun gear, a planetary carrier supporting the plurality of planetary gears so as to be rotatable about their axes, and a ring gear meshing with the plurality of planetary gears;
The output shaft is connected to the planetary carrier,
the two-way clutch is provided between the input shaft and the planetary gear mechanism,
The clutch mechanism is provided between the input shaft and the planetary carrier,
The input shaft is formed in a cylindrical shape and constitutes an outer ring of the two-way clutch,
the ring gear constitutes an inner ring of the two-way clutch,
A plurality of teeth are formed at predetermined intervals in the circumferential direction on an outer periphery of the ring gear,
The two-way clutch includes a first pawl member that is held by the outer ring so as to be able to swing in the radial direction, and that, when it swings radially inward to mesh with the tooth portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves backward; a first elastic member that urges the first pawl member in the meshing direction with the tooth portion; a second pawl member that is held by the outer ring so as to be able to swing in the radial direction, and that, when it swings radially inward to mesh with the tooth portion, locks the relative rotation of the output shaft with respect to the outer ring in the direction in which the vehicle moves forward; and a second elastic member that urges the second pawl member in the meshing direction with the tooth portion .
The elastic force of the second elastic member is set to be smaller than the elastic force of the first elastic member,
A drive device characterized in that when a centrifugal force exceeding a predetermined magnitude acts on the first pawl member and the second pawl member due to rotation of the outer ring, the second elastic member is compressed by the second pawl member until the second pawl member is disengaged from the tooth portion, and the first elastic member is not compressed by the first pawl member and maintains engagement with the tooth portion . The drive unit according to claim 3, characterized in that the second pawl member swings radially outward due to centrifugal force acting due to rotation of the outer ring, and becomes disengaged from the tooth portion when the centrifugal force exceeds a predetermined magnitude. 6. The drive device according to claim 1, 2, 4, or 5, characterized in that when the second pawl member is in a disengaged state due to centrifugal force, when the second transmission mechanism is engaged, the first pawl member is in a disengaged state , thereby disengaging the first transmission mechanism and causing the second transmission mechanism to become a main transmission mechanism for the driving force.

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