JP3998932B2 - Four-wheel drive system for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a four-wheel drive device for a vehicle that transmits rotational driving force from a driving source (such as an engine) to front wheels and rear wheels to rotationally drive all four wheels, and more specifically, rotational driving force from a driving source. The present invention relates to a four-wheel drive device for a vehicle configured to divide and transmit to the front and rear wheels via a center differential mechanism.
[0002]
[Prior art]
Four-wheel drive vehicles that drive both front and rear wheels are generally known, and a center differential mechanism is provided between the front and rear wheels, and the rotational driving force of the engine is divided via the center differential mechanism. There are also known four-wheel drive vehicles configured to transmit to the front and rear wheels. Also in such a four-wheel drive vehicle, the front and rear wheels are each provided with an axle differential mechanism for absorbing the difference in rotation between the left and right wheels. For this reason, in this type of four-wheel drive vehicle, a center differential mechanism and front and rear axle differential mechanisms are required, and a total of three differential mechanisms must be provided.
[0003]
If such three differential mechanisms are separately provided, there is a problem that the configuration of the driving force transmission device of the vehicle increases in size and the number of parts increases, leading to an increase in cost. For this reason, it is proposed in, for example, Japanese Patent No. 2615086, Japanese Patent No. 3047016, Japanese Patent No. 2621680, etc., to integrally configure either the front or rear axle differential mechanism and the center differential mechanism. ing. According to the devices disclosed in these publications, it is considered that the configuration of the entire power transmission device can be reduced because the front wheel side axle differential mechanism and the center differential mechanism are integrally configured.
[0004]
[Problems to be solved by the invention]
However, in the apparatus disclosed in Japanese Patent No. 2615086, the center differential mechanism has a pair of double planetary gears and a bevel gear type axle differential mechanism is disposed adjacent to the center differential mechanism, which is very complicated. There is a problem that the structure is expensive. In addition, after the bevel gear type axle differential mechanism is assembled in the two-divided type casing that houses the center differential, the two-divided type casing is bolted to form an integrated device, and the number of components in each part is large. In addition, there is a problem that there are many places where shim adjustment is necessary, and the assemblability is poor. Further, the integrally configured device is rotatably supported by a transmission housing via a pair of left and right bearings, and includes an input gear member for the center differential mechanism and an output gear for the rear wheel side. It is necessary to support the acting force by the pair of bearings, and there is a problem that the bearing load becomes large.
[0005]
Further, the device of Japanese Patent No. 3047016 is provided with a hydraulic clutch for turning on and off the center differential mechanism, and there is a problem that a part of the device has a double shaft structure and the overall structure is complicated. . Further, the device of Japanese Patent No. 2621680 is configured by arranging two sets of planetary gear trains adjacent to each other, and the first planetary gear train provides rotational driving force from the engine to the left front wheel and the second planetary gear train. The rotational driving force transmitted to the second planetary gear train in this way is divided into the right front wheel and the rear wheel side by the second planetary gear train. There is a problem that it is necessary to set the same gear ratio for the left and right front wheels by the planetary gear train, and the degree of freedom in design is low, making it difficult to set the gear ratio.
[0006]
The present invention has been made in view of such problems, and an object of the present invention is to provide a simple, small and compact four-wheel drive device in which a center differential mechanism and any one of the front and rear axle differential mechanisms are integrally configured.
[0007]
[Means for Solving the Problems]
In order to achieve such an object, in the present invention, a center differential mechanism that transmits a rotational driving force from a driving source (for example, the engine E in the embodiment) to the front wheel side and the rear wheel side, and the center differential. A four-wheel drive device for a vehicle is configured including an axle differential mechanism that transmits the rotational driving force divided by the mechanism to the left and right wheels on one of the front wheel side and the rear wheel side. The center differential mechanism includes an input gear member (for example, the output driven gear 3 in the embodiment) that is rotationally driven by receiving a rotational driving force from a drive source, and a first carrier that is configured integrally with the input gear member. A member (for example, the first carrier 13 in the embodiment), a first sun gear member (for example, the first sun gear 11 in the embodiment), a first ring gear member (for example, the first ring gear 14 in the embodiment), and the first A single ring gear member that is integrally formed on the outer periphery of the ring gear member and that has an output gear member (for example, the rear wheel drive gear 15 in the embodiment) for transmitting rotational driving force to the other of the front wheel side and the rear wheel side. The first planetary gear unit of the pinion type is used, and the axle differential mechanism is configured integrally with the first sun gear member. A ring gear member (for example, the second ring gear 24 in the embodiment), a second sun gear member (for example, the second sun gear 21 in the embodiment) connected to one of the left and right wheels, and a second connected to the other of the left and right wheels. It comprises a double pinion type second planetary gear device having a carrier member (for example, the second carrier 23 in the embodiment). Furthermore, a cylindrical holding member is fitted and connected to a first carrier member configured integrally with the input gear member to form an input rotating member, and a second planetary gear device is disposed in the input rotating member, The right end portion and the left end portion of the input rotation member are rotatably supported by the housing via first and second bearings (for example, tapered roller bearings 61 and 62 in the embodiment), and are arranged on the outer periphery of the first ring gear member. An output rotation member configured integrally with the output gear member is rotatably supported by the input gear member via a third bearing (for example, the ball bearing 64 in the embodiment) on one end side and the other end side. Are supported rotatably by the housing via a fourth bearing (for example, the ball bearing 63 in the embodiment).
[0008]
In the four-wheel drive device having such a configuration, the rotational driving force is divided and transmitted to the front wheel side and the rear wheel side by the center differential mechanism, and the left and right wheels are divided by the axle differential mechanism. The structure for dividing and transmitting power is simple, and the structure for dividing and transmitting power is simple and easy to design. Further, by configuring the single pinion type first planetary gear train constituting the center differential mechanism and the double pinion type second planetary gear train constituting the axle differential mechanism by connecting the respective elements as described above, The connecting structure can be simplified and the entire configuration can be made compact and compact.
[0009]
In the present invention, in particular, a second planetary gear device is disposed in an input rotation member configured by fitting and connecting a cylindrical holding member to a first carrier member integral with the input gear member. By assembling sequentially, this structure can be assembled, the number of shim adjustment points can be reduced, and bolts for connecting the casing as in the prior art are unnecessary, and the assembly configuration is simplified.
[0010]
Further, the right end portion and the left end portion of the input rotation member are rotatably supported by the housing via the first and second bearings, and the force acting on the input gear member is received by these first and second bearings. Can do. On the other hand, the output rotation member configured integrally with the output gear member on the outer periphery of the ring gear member is rotatably supported by the input gear member via the third bearing on one end side, and the fourth on the other end side. Therefore, the force acting on the output gear member can be received by these third and fourth bearings, and the force acting on the input gear member and the output gear member is the second. It is possible to reduce the load on these bearings by receiving them distributed by the first to fourth bearings.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. A power transmission system having a vehicle four-wheel drive device according to a preferred embodiment of the present invention is schematically shown in FIG. 1, and this power transmission system will be described first. This power transmission system is configured to distribute and transmit the rotational driving force of the engine E to the left and right front wheels 5a, 5b and the left and right rear wheels 37a, 37b. The output of the engine E is changed by a transmission mechanism TM including a torque converter, a transmission gear, and the like, and then output from an output drive gear 2 coupled to the transmission output shaft 1 according to the present invention. It is transmitted to a power split device DF having a wheel drive device configuration. The power split device DF includes an output driven gear 3 that meshes with the output drive gear 2, and further includes a first planetary gear device 10 and a second planetary gear device 20 that are provided coaxially with the output driven gear 3. Composed.
[0012]
The first planetary gear device 10 includes a first sun gear 11 disposed coaxially with the output driven gear 3, and a first carrier 13 disposed coaxially with the first sun gear 11 and coupled to the output driven gear 3. A plurality of first pinion gears 12 that are rotatably held by the first carrier 13, mesh with the first sun gear 11 and revolve around the first sun gear 11, and inner teeth that surround the outer periphery of the first pinion gear 12. 12 and a first ring gear 14 that rotates coaxially with the first sun gear 11. As can be seen from this configuration, the first planetary gear device 10 is configured by a single pinion type planetary gear mechanism. The first sun gear 11 is configured integrally with the second ring gear 24 of the second planetary gear device 20. A rear wheel drive gear 15 is integrally formed on the outer periphery of the first ring gear 14 to transmit a driving force to the rear wheel side.
[0013]
The second planetary gear unit 20 includes a second sun gear 21 disposed coaxially with the output driven gear 3 and the first sun gear 11, a second carrier 23 disposed coaxially with the second sun gear 21, and a second carrier. A plurality of second inner pinion gears 22a that are rotatably held by the second sun gear 21 and revolve around the second sun gear 21, and a second inner pinion gear 22a that is rotatably held by the second carrier 23 and is engaged with the second sun gear 21a. A plurality of second outer pinion gears 22b revolving together with inner teeth surrounding the outer periphery of the second outer pinion gear 22b, meshing with the second outer pinion gear 22b and rotating coaxially with the second sun gear 21 And a ring gear 24. As can be seen from this configuration, the second planetary gear device 20 is constituted by a double pinion type planetary gear mechanism. And the 2nd ring gear 24 is comprised integrally with the 1st sun gear 11 as mentioned above, and is combined. The second sun gear 21 is connected to the right wheel 5a via the right axle shaft 4a, and the second carrier 23 is connected to the left wheel 5b via the left axle shaft 4b.
[0014]
On the other hand, the rear wheel drive gear 15 provided integrally on the outer periphery of the first ring gear 14 meshes with the rear wheel driven gear 31 formed on the rear wheel drive shaft 31a. A first bevel gear 32 is connected to the rear wheel drive shaft 31 a, and a propeller shaft 34 is connected to a second bevel gear 33 that meshes with the first bevel gear 32. The propeller shaft 34 is connected to the rear wheel side axle differential mechanism 35, and the rear wheel side axle differential mechanism 35 is connected to the left and right rear wheels 37a, 37b via the left and right axle shafts 36a, 36b.
[0015]
In the power transmission system configured as described above, the output rotation of the engine E is shifted by the speed change mechanism TM and transmitted from the output drive gear 2 coupled to the transmission output shaft 1 to the output driven gear 3. The output driven gear 3 is coupled to the first carrier 13 of the first planetary gear device 10, and the rotational driving force transmitted to the output driven gear 3 is transmitted as it is to the first carrier 13 and is freely rotatable by the first carrier 13. Are transmitted to the first sun gear 11 and the first ring gear 14 with which the first pinion gear 12 supported by the gears meshes. As can be seen from the above configuration, the first sun gear 11 is connected to the front wheel side and the first ring gear 14 is connected to the rear wheel side, and the first planetary gear device 10 is used as a center differential mechanism.
[0016]
First, the rotational driving force transmitted to the first sun gear 11 is transmitted as it is to the second ring gear 24 integrally coupled therewith, and the second outer pinion gear 22b and the second inner pinion gear 22a meshing with the second ring gear 24 are freely rotatable. The second carrier 23 and the second sun gear 21 meshed with the second inner pinion gear 22a are divided and transmitted. The rotational driving force transmitted to the second carrier 23 is transmitted to the left front wheel 5b via the left axle shaft 4b, and the rotational driving force transmitted to the second sun gear 21 is transmitted to the right front wheel 5a via the right axle shaft 4a. The left and right front wheels 5a and 5b are rotationally driven. As can be seen from this configuration, the second planetary gear unit 20 is used as a front wheel side axle differential mechanism.
[0017]
On the other hand, the rotational driving force transmitted to the first ring gear 14 is transmitted from the rear wheel driving gear 15 integrally provided on the outer periphery of the first ring gear 14 to the rear wheel driven gear 31 that meshes with the rear wheel driving gear 15, and the rear wheel driving shaft. 31 a, the first bevel gear 32, the second bevel gear 33, and the propeller shaft 34 are transmitted to the rear wheel side axle differential mechanism 35. Then, the rear wheel side axle differential mechanism 35 is divided into left and right axle shafts 36a and 36b and transmitted to the left and right rear wheels 37a and 37b, and the left and right rear wheels 37a and 37b are rotationally driven.
[0018]
The operation of the first planetary gear unit 10 as a center differential mechanism and the operation of the second planetary gear unit 20 as a front wheel axle differential mechanism in the above configuration will be described with reference to the velocity diagram of FIG. FIG. 2 shows the rotational speed relationship between the first sun gear 11, the first carrier 13 and the first ring gear 14 in the first planetary gear device 10, and the second sun gear 21, the second carrier 23 and the second gear in the second planetary gear device 20. The relationship between the rotational speeds of the two-ring gear 24 is shown.
[0019]
In this velocity diagram, the rotational speed of each of these rotating elements is represented by the length in the vertical direction, and the horizontal intervals a, b, c, d of each element are shown corresponding to the reciprocal of the number of teeth of the sun gear and ring gear. ing. Since the first planetary gear device 10 is of a single pinion type, the positional relationship of each element is the first sun gear 11, the first carrier 13, and the first ring gear 14 from the left as shown in the figure, and the first sun gear 11 and the first carrier 13 are located. The horizontal interval a = 1 / Ns1 of the vertical line indicating the vertical line, and the horizontal interval b = 1 / Nr1 of the vertical line indicating the first carrier 13 and the first ring gear 14 is shown. Further, since the second planetary gear device 20 is a double pinion type, the positional relationship of each element is different from that of the first planetary gear device 10 as shown in the figure, and the second carrier 23, the second ring gear 24, 2 is a horizontal distance c = 1 / Ns2 between the vertical lines indicating the second sun gear 21 and the second carrier 23, and a horizontal distance d = 1 between the vertical lines indicating the second carrier 23 and the second ring gear 24. / Nr2. However, Ns1, Nr1, Ns2, and Nr2 mean the number of teeth of the first sun gear 11, the first ring gear 12, the second sun gear 21, and the second ring gear 24, respectively.
[0020]
In this speed diagram, when the rotational driving force from the engine E is transmitted from the output driven gear 3 to the first carrier 13, it is divided into the first sun gear 11 and the first ring gear 14 and transmitted to the front wheel side and the rear wheel side. Is done. At this time, when the front wheels and the rear wheels are driven to rotate at the same speed, the entire first planetary gear device 10 is rotated integrally, and the front wheel side and the rear wheel side rotate at the same rotation as indicated by a solid line A in the diagram. Driven. On the other hand, for example, when the front wheel side tends to slip and the traveling load becomes smaller than the rear wheel side, the rotation of the first sun gear 11 connected to the front wheel side increases as shown by the broken line B, and the first ring gear 14 connected to the rear wheel side Rotation decreases. On the other hand, when the rear wheel side tends to slip and the traveling load becomes smaller than the front wheel side, the rotation of the first ring gear 14 connected to the rear wheel side increases as shown by the dashed line C, and the first sun gear 11 connected to the front wheel side Rotation is reduced. In this way, the center differential operation is performed in which the rotational difference between the front wheel side and the rear wheel side is allowed and the rotational driving force is divided and transmitted to both of them.
[0021]
The rotational driving force divided and transmitted to the first sun gear 11 by the first planetary gear device 10 as described above is transmitted to the second ring gear 24 formed integrally therewith. The rotational driving force transmitted to the second ring gear 24 in this way is divided into the second sun gear 21 and the second carrier 23 in the second planetary gear device 20 and transmitted to the left and right front wheels. At this time, when the left and right front wheels are driven to rotate at the same speed without slipping, the entire second planetary gear device 20 is rotated together, and the left and right front wheels are driven at the same rotation as shown by the solid line D in the diagram. The On the other hand, for example, when the left front wheel 5b becomes slippery and the traveling load is smaller than that of the right front wheel 5a, the rotation of the second carrier 23 connected to the left front wheel 5b increases as shown by the broken line E, and the second front wheel 5a 2 The rotation of the sun gear 21 decreases. Conversely, when the traveling load on the right front wheel 5a decreases, the rotation of the second sun gear 21 connected to the right front wheel 5a increases as indicated by the broken line F, and the rotation of the second carrier 23 connected to the left front wheel decreases. In this way, the front wheel side axle differential operation is performed in which the rotational driving force is divided and transmitted to both the left and right front wheels while allowing a difference in rotation between them.
[0022]
Next, a specific configuration of the power split device DF will be described with reference to FIG. The power split device DF is configured by rotatably supporting the output drive gear 3 and the first and second planetary gear devices 10 and 20 by a pair of left and right tapered roller bearings 61 and 62 in a housing HSG. The left boss portion 50e (see FIG. 5) of the output gear body 50 having the output drive gear 3 on the outer peripheral portion is rotatably supported by the left taper roller bearing 62 with respect to the housing HSG. This output gear body 50 is shown in FIG. 4, and has a wall surface 50a having a recessed portion opened rightward on the inner diameter side of the output drive gear 3, and a plurality of (four in this example) connecting arms 50b from the wall surface 50a. Protrudes rightward and a ring-shaped first holding portion 51 is integrally formed at the tip of the connecting arm 50b. Further, a pinion disposition space 50c for disposing the first pinion gear 22 is formed between the four connecting arms 50b. The output gear body 50 is made by molding using a lost wax casting method.
[0023]
The wall surface 50a and the first holding portion 51 are formed with four pin press-fit holes 50d and 51a extending in the axial direction and passing through the pinion arrangement space 50c and coaxially, and the pin press-fit holes 50d and 51a. The first carrier pin 13a is press-fitted inside. However, at this time, the first carrier pin 13a is press-fitted with the first pinion gear 12 arranged in the pinion arrangement space 50c, and the first pinion gear 12 is placed on the first carrier pin 13a as shown in FIG. It will be in the state supported rotatably. As can be seen from this configuration, the output carrier body 50, the first carrier pin 13 a, and the first holding portion 51 constitute the first carrier 13.
[0024]
A cylindrical second holding member 52 shown in FIG. 4 is coupled to the cylindrical outer peripheral surface 51 b of the first holding part 51. The second holding member 52 is formed in a cylindrical shape opened to the left side, and the inner peripheral surface 52a of the left cylindrical portion and the right outer peripheral surface 51b of the first holding portion 51 are press-fitted and shown in FIG. Thus, the input rotation member is configured integrally. In the input rotation member configured integrally as described above, the right end portion thereof, that is, the right end portion boss portion 52b of the second holding member 52 is rotatably supported by the right taper roller bearing 61 with respect to the housing HSG. As described above, the output gear body 50, the first carrier pin 13a, the first holding portion 51, and the second holding member 52 are integrally coupled to form an input rotating member, and the input rotating member is a left and right tapered roller bearing 61. , 62 are rotatably supported with respect to the housing HSG.
[0025]
On the other hand, a drive gear body 55 (which has a first ring gear 14 on the inner periphery and a rear wheel drive gear 15 formed on the outer periphery, is located on the outer periphery side of the input rotation member constructed integrally as described above. An output rotating member is also provided. The drive gear body 55 is rotatably held by a ball bearing 64 disposed in the output gear body 50 at the outer peripheral portion on the left end side, and is rotatable by a ball bearing 63 disposed in the housing HSG on the outer peripheral surface on the right end side. Is retained.
[0026]
A through hole is formed in the second holding member 52 supported rotatably by the right taper roller bearing 61 in the axial direction, and the end of the right axle shaft 4a is inserted into the through hole so as to be relatively rotatable. Yes. A second sun gear body 56 in which the second sun gear 21 is formed is attached to the tip of the right axle shaft 4a by spline connection.
[0027]
A through hole is formed in the output gear body 50 that is rotatably supported by the left taper roller bearing 62, and an end portion of the left axle shaft 4b is inserted into the through hole so as to be relatively rotatable. . A third holding member 53 constituting the second carrier 23 is spline-coupled at the tip of the left axle shaft 4b. A second inner carrier pin 23a that rotatably supports the second inner pinion gear 22a and a second outer carrier pin 23b that rotatably supports the second outer pinion gear 22b are press-fitted and attached to the third holding member 53. It has been. A fourth holding portion 54 is formed integrally with the second inner and second outer carrier pins 23a and 23b on the opposite side in the axial direction, and the third holding member 53, the second inner and second outer carrier pins 23a are formed. , 23b and the fourth holding part 54 constitute the second carrier 23. A connecting gear member 57 that integrally includes the first sun gear 11 and the second ring gear 24 is rotatably disposed on the outer peripheral surface of the third holding member 53.
[0028]
When assembling the power split device DF having the above configuration, first, the first carrier pin 13a is press-fitted into the pin press-fit holes 50d and 51a in a state where the first pinion gear 12 is arranged in the pinion arrangement space 50c of the output gear body 50. Then, the pinion gear 12 is rotatably supported on the first carrier pin 13a in the pinion disposition space 50c. Then, the connecting gear member 57 integrally having the first sun gear 11 and the second ring gear 24 is assembled in the recess of the output gear body 50 to mesh the first sun gear 11 and the first pinion gear 12. Further, the second holding pin 53a is rotatably held by the second inner carrier pin 23a and the third holding member 53 in a state where the second outer pinion gear 22b is rotatably held by the second outer carrier pin 23b is output from the left side. It is assembled in the recess of the gear body 50. As a result, the second outer pinion gear 22 b meshes with the second ring gear 24. Further, the second sun gear body 56 is assembled from the left side, and the second sun gear 21 is engaged with the second inner pinion gear 22a.
[0029]
Then, in the state where the connecting gear member 57, the third holding member 53, and the second sun gear body 56 are disposed in the recess of the output gear body 50 as described above, the cylindrical second holding member is covered so as to cover them. 52 is press-fitted and attached to the first holding portion 51 of the output gear body 50. Thereby, the input rotation member in a state in which the second planetary gear device 20 is housed therein is assembled.
[0030]
A drive gear body (output rotation member) 55 is attached to the outer peripheral side of the input rotation member while being rotatably supported by the output gear body 50 via a ball bearing 64 at the left end. Then, the assembly of the power split device DF is completed by allowing the device assembled in this way to be supported by the housing HSG so as to be rotatable by the ball bearing 63 and the pair of left and right tapered roller bearings 61 and 62.
[0031]
As described above, the power split device DF is configured only to require the work of assembling the respective components in order and the work of press-fitting the second holding member into the first holding part 51 of the output gear body 50. The conventional work of bolting the casing is unnecessary, and the assembling work is simple. In addition, since it is only necessary to assemble the components in such a manner that the components are stacked in the axial direction in this order, shim adjustment for adjusting the accumulated error in the stacked state may be performed last, and there are few shim adjustment points, and assembling work accordingly. Becomes easy.
[0032]
Further, in the power split device DF, the input rotation member formed by integrally connecting the output gear body 50, the first carrier pin 13a, the first holding portion 51, and the second holding member 52 is a tapered roller at the left and right ends. It is configured to be rotatably supported by the housing HSG via the bearings 61 and 62, and the radial force and the thrust force that act when the rotational driving force from the engine E is transmitted to the output driven gear 3 are tapered. It is received by the roller bearings 61 and 62. On the other hand, the radial direction which acts on the output rotating member (driving gear body 55) when the rotational driving force is transmitted from the rear wheel driving gear 15 to the rear wheel side by being divided by the first planetary gear device 10 constituting the center differential mechanism. The force and thrust force are received by the ball bearings 63 and 64. Thus, since the force acting on the input rotating member and the force acting on the output rotating member are supported by different bearings, the load on each bearing can be reduced, and the housing HSG that supports these bearings is necessary. The strength can be reduced.
[0033]
【The invention's effect】
As described above, according to the present invention, the center differential mechanism includes an input gear member, a first carrier member configured integrally with the input gear member, a first sun gear member, a first ring gear member, A single pinion type first planetary gear device having an output gear member integrally formed on the outer periphery of the first ring gear member, and the axle differential mechanism is configured integrally with the first sun gear member. A double pinion type second planetary gear device comprising a second ring gear member, a second sun gear member connected to one of the left and right wheels, and a second carrier member connected to the other of the left and right wheels. A second planetary gear device is disposed in an input rotation member formed by fitting and connecting a cylindrical holding member to a first carrier member integral with the gear member; The right and left ends of the force rotating member are rotatably supported by the housing via the first and second bearings, and the output rotating member integrally having the output gear member on the outer periphery of the first ring gear member is on one end side. Is supported by the input gear member via the third bearing and is rotatably supported by the housing via the fourth bearing at the other end, so that the front and rear wheels are supported by the center differential mechanism. The rotational driving force can be divided and transmitted to the side, and the divided rotational driving force can be divided and transmitted to the left and right wheels by the axle differential mechanism, and the structure for dividing and transmitting the power is simple It is easy to design. In addition, by configuring the single pinion type first planetary gear train constituting the center differential mechanism and the double pinion type second planetary gear train constituting the axle differential mechanism by connecting the respective elements as described above, The connecting structure can be simplified and the entire configuration can be made compact and compact.
[0034]
In the present invention, in particular, a second planetary gear device is disposed in an input rotation member configured by fitting and connecting a cylindrical holding member to a first carrier member integral with the input gear member. By assembling sequentially, this structure can be assembled, the number of shim adjustment points can be reduced, and bolts for connecting the casing as in the prior art are unnecessary, and the assembly configuration is simplified. Further, the force acting on the input gear member can be received by the first and second bearings, and the force acting on the output gear member can be received by the third and fourth bearings. The force acting on the output gear member is distributed and received by the first to fourth bearings, and the load on these bearings can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the configuration of a power transmission system having a vehicle four-wheel drive device according to the present invention.
FIG. 2 is a velocity diagram showing a rotational speed relationship of each rotary element in the first and second planetary gear devices constituting the four-wheel drive device.
FIG. 3 is a sectional view showing a configuration example of the four-wheel drive device.
FIG. 4 is a perspective view showing an output gear body constituting the four-wheel drive device and a second holding member fitted to the output gear body.
FIG. 5 is a perspective view showing a state in which the output gear body and a second holding member are fitted together.
[Explanation of symbols]
E Engine (drive source)
3 Output driven gear 10 1st planetary gear unit (center differential mechanism)
11 First sun gear 13 First carrier 14 First ring gear 15 Rear wheel drive gear (output rotating member)
20 Second planetary gear set (front wheel side axle differential mechanism)
21 Second sun gear 23 Second carrier 24 Second ring gear 5a, 5b Left and right front wheels 50 Output gear body (input rotation member)
51 1st holding | maintenance part (input rotation member)
52 Second holding member (input rotating member)
61, 62 Tapered roller bearings (first and second bearings)
63 Ball bearing (fourth bearing)
64 Ball bearing (third bearing)

Claims (1)

A center differential mechanism that divides and transmits the rotational driving force from the driving source to the front wheel side and the rear wheel side, and the rotational driving force divided by the center differential mechanism is transmitted to the left and right sides on one of the front wheel side and the rear wheel side. In a vehicle four-wheel drive device configured by disposing an axle differential mechanism that divides and transmits wheels into a housing,
The center differential mechanism is rotated by receiving a rotational driving force from the drive source, a first carrier member configured integrally with the input gear member, a first sun gear member, A single-pinion type first gear having a ring gear member and an output gear member that is integrally formed on the outer periphery of the first ring gear member and transmits rotational driving force to the other of the front wheel side and the rear wheel side. 1 planetary gear unit,
The axle differential mechanism includes a second ring gear member integrally formed with the first sun gear member, a second sun gear member connected to one of the left and right wheels, and a second carrier member connected to the other of the left and right wheels. A double pinion type second planetary gear device comprising:
A cylindrical holding member is fitted and connected to the first carrier member formed integrally with the input gear member to form an input rotating member, and the second planetary gear device is disposed in the input rotating member. ,
A right end portion and a left end portion of the input rotation member are rotatably supported by the housing via first and second bearings;
An output rotating member configured integrally with the output gear member on the outer periphery of the first ring gear member is rotatably supported by the input gear member via a third bearing on one end side and the other end side. The vehicle four-wheel drive device according to claim 1, wherein the four-wheel drive device is rotatably supported by the housing via a fourth bearing.

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