JP2019011826A - Drive device for vehicle - Google Patents

Abstract

To provide a drive device for a vehicle, applicable to an electrically-driven commercial vehicle while suppressing agitation resistance of lubrication oil in a speed reduction mechanism.SOLUTION: A housing structure comprises: a first housing which is provided so that a width in a second direction orthogonal to a first direction gradually decreases in the first direction from a first shaft gear to a second shaft gear, and a part of an inner wall part for storing a part of the second shaft gear becomes close to a part of the second shaft gear, and in which a first drain plug is provided in a part of an inner wall part for storing the first shaft gear; and a second housing which is provided so that a width in a fourth direction orthogonal to a third direction gradually decreases in the third direction from a differential gear to the second shaft gear, and a part of an inner wall part for storing the other part of the second shaft gear becomes closer to the other part of the second shaft gear, and in which a second drain plug is provided in a part of an inner wall part for storing the differential gear.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vehicle drive device that transmits a driving force of a motor to a differential gear.

  For example, in a vehicle that uses a motor as a drive source, such as an electric vehicle, a vehicle drive device that includes a motor and a speed reduction mechanism that includes a plurality of gears and that can transmit the drive force of the motor to a differential gear connected to drive wheels. Are known.

International Publication No. 2014/148410

  In recent years, electric commercial vehicles such as electric trucks without an internal combustion engine have been developed in the field of commercial vehicles such as trucks from the viewpoint of reducing environmental impact. However, since such an electric commercial vehicle requires a larger driving torque than a passenger vehicle, a larger gear ratio is also required for a reduction gear. Accordingly, the number of gear teeth increases and the speed reduction mechanism also increases in size, which increases the agitation resistance of the lubricating oil in the speed reduction mechanism, which may lead to deterioration in energy efficiency and an increase in the temperature of the lubricating oil.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a vehicle drive device that can be applied to an electric commercial vehicle while suppressing agitation resistance of lubricating oil in a speed reduction mechanism. Is to provide.

  The present invention can be realized as the following application examples. A vehicle drive device according to this application example includes a motor mounted on the vehicle, and a speed reduction mechanism that transmits a driving force of the motor to a differential gear of the vehicle. A housing structure that houses the speed reduction mechanism and the differential gear, wherein the speed reduction mechanism includes a first shaft gear coupled to the motor, a second shaft gear coupled to the differential gear, and the first shaft gear; A third shaft gear connecting the second shaft gear. The housing structure houses the first shaft gear, a part of the second shaft gear, and the third shaft gear, and in the first direction from the first shaft gear toward the second shaft gear, The width in the second direction orthogonal to the first direction is gradually reduced so that a part of the inner wall portion that accommodates a part of the second shaft gear is close to a part of the second shaft gear. A first housing in which a first drain plug is provided in a part of an inner wall portion that accommodates the first shaft gear, and other portions of the differential gear and the second shaft gear are accommodated from the differential gear. In the third direction toward the second shaft gear, the width in the fourth direction orthogonal to the third direction gradually decreases, and the second shaft gear A second housing in which a part of the inner wall part that accommodates the part is provided so as to be close to the other part of the second shaft gear, and a second drain plug is provided in a part of the inner wall part that accommodates the differential gear; Consists of.

  According to the above configuration, the vehicular drive device according to this application example has a shape in which the inner wall portion is close to the second shaft gear, and thus has a rectifying effect that keeps the fluid flow constant. Thereby, the stirring resistance of the lubricating oil in the speed reduction mechanism can be suppressed. However, when such a housing structure is adopted, there is a risk that two oil reservoirs of lubricating oil may be formed in the housing structure on both the first shaft gear side and the third shaft gear side. It cannot actually be mounted on a vehicle. However, in the vehicle drive device according to this application example, the first drain plug is provided in a part of the inner wall portion that accommodates the first shaft gear, and the second drain plug is provided in a part of the inner wall portion that accommodates the differential gear. Provided. Thereby, since it becomes possible to discharge | emit lubricating oil appropriately, a drive device can be applied to an electric commercial vehicle, suppressing the stirring resistance of the lubricating oil in a deceleration mechanism.

It is a figure which shows the drive device for vehicles which concerns on one Embodiment of this invention. It is sectional drawing along line (alpha)-(alpha) in FIG. It is sectional drawing along line (beta)-(beta) in FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(Constitution)
FIG. 1 is a diagram showing a vehicle drive device 1 according to an embodiment of the present invention. A vehicle drive device 1 shown in FIG. 1 is a device that is used in, for example, a vehicle that drives a motor 3 and transmits a driving force of the motor 3 to a differential gear 5 to which drive wheels are connected. The vehicle that drives the motor 3 in the present embodiment is, for example, an electric commercial vehicle such as an electric truck.

  As shown in FIG. 1, the vehicle drive device 1 includes a motor 3 and a speed reduction mechanism 7. The motor 3 is a vehicle drive source. The motor 3 is accommodated in the motor housing 31. The motor housing 31 is made of a metal such as aluminum, magnesium, or iron.

  For example, the speed reduction mechanism 7 reduces the rotational speed of the motor 3 with a gear or the like and outputs it to the differential gear 5. The speed reduction mechanism 7 in the present embodiment includes a first shaft gear 71, a second shaft gear 73, and a third shaft gear 75. Each of the plurality of gears provided in the speed reduction mechanism 7 has a substantially circular shape, and the diameter of each of the plurality of gears is different.

  The first shaft gear 71 is connected to the motor 3 via the motor shaft 9. The first shaft gear 71 may be called an input gear. The second shaft gear 73 is connected to the differential gear 5. The second shaft gear 73 is sometimes called an output gear. The third shaft gear 75 connects the first shaft gear 71 and the second shaft gear 73. The first shaft gear 71, the second shaft gear 73, and the third shaft gear 75 in the present embodiment are arranged in a line along a predetermined direction. Note that the predetermined direction is, for example, the front-to-rear direction of the vehicle.

  In the above configuration, the driving force output from the motor 3 is transmitted to the first shaft gear 71 connected via the motor shaft 9. Next, the driving force transmitted from the motor 3 to the first shaft gear 71 is transmitted to the second shaft gear 73 connected to the first shaft gear 71 via the third shaft gear 75. Further, the driving force transmitted from the first shaft gear 71 to the second shaft gear 73 is transmitted to the connected differential gear 5. Thereby, the vehicle drive device 1 according to the present embodiment can transmit the driving force output from the motor 3 to the differential gear 5.

  Here, the number of teeth of the gear provided in the reduction mechanism 7 increases in the order of the first shaft gear 71, the third shaft gear 75, and the second shaft gear 73, for example. That is, the rotational speed of the motor 3 may be reduced through the first shaft gear 71, the third shaft gear 75, and the second shaft gear 73. Although not shown, the third shaft gear 75 may be set to have the largest number of teeth. On the other hand, the diameter of the gear provided in the reduction mechanism 7 increases in the order of the first shaft gear 71, the third shaft gear 75, and the second shaft gear 73, for example. That is, the torque of the motor 3 increases via the first shaft gear 71, the third shaft gear 75, and the second shaft gear 73. The vehicle drive device 1 according to the present embodiment can generate torque necessary for driving the vehicle while reducing the rotational speed of the motor 3.

  Further, as shown in FIG. 1, the differential gear 5 and the speed reduction mechanism 7 are accommodated in a gear housing (housing structure) 11. The gear housing 11 is made of a metal such as aluminum, magnesium, or iron, like the motor housing 31.

  The gear housing 11 includes a first housing 13 and a second housing 15. The first housing 13 accommodates the first shaft gear 71, a part of the second shaft gear 73, and the third shaft gear 75. The part of the second shaft gear 73 is a part connected to the third shaft gear 75. The first housing 13 is provided with a breather 17 for adjusting the pressure inside the speed reduction mechanism 7. The first housing 13 has a shape corresponding to the first shaft gear 71, a part of the second shaft gear 73, and the third shaft gear 75.

  The second housing 15 accommodates the other portions of the differential gear 5 and the second shaft gear 73. The other part of the second shaft gear 73 is a part connected to the differential gear 5. The second housing 15 has a shape corresponding to the differential gear 5 and the other part of the second shaft gear 73. The specific shapes of the first housing 13 and the second housing 15 will be described later.

  The first housing 13 and the second housing 15 are spatially separated by respective inner walls except for the position of the hole for providing the second shaft gear 73.

  In addition, lubricating oil (gear oil) for smooth rotation of the differential gear 5, the first shaft gear 71, the second shaft gear 73, and the third shaft gear 75 is injected into the gear housing 11. Yes. The inside of the gear housing 11 does not need to be completely filled with the lubricating oil, and the amount of the lubricating oil injected into the gear housing 11 can be adjusted so that a part of each gear is immersed in the lubricating oil. preferable.

  Here, the 1st housing 13 and the 2nd housing 15 which concern on this embodiment are demonstrated with reference to FIG. 2 and FIG.

(Description of the first housing)
FIG. 2 is a cross-sectional view taken along line α-α in FIG. FIG. 2 shows a cross section of the first housing 13 in the speed reduction mechanism 7. As shown in FIG. 2, the first housing 13 has a shape in which a part of the inner wall 131 that accommodates a part of the second shaft gear 73 is close to a part of the second shaft gear 73. Specifically, as shown in FIG. 2, a part of the inner wall 131 of the first housing 13 has a shape along a part of the circumference of the second shaft gear 73.

The first housing 13 has a shape in which the width in the second direction orthogonal to the first direction gradually decreases in the first direction from the first shaft gear 71 to the second shaft gear 73. Have. For example, as shown in FIG. 2, the width w ₁ of the first housing 13 in the second direction at the position of the second shaft gear 73 is equal to the first housing in the second direction at the position of the first shaft gear 71. 13 narrower than the width _{w 2} of. Here, the 1st direction in this embodiment is a back direction from the front of a vehicle, for example. Further, assuming that the first direction is the front to the rear direction of the vehicle, the second direction is the vehicle height direction of the vehicle.

  Further, the first housing 13 is provided with a first drain plug 19 in a part of the inner wall portion 131. For example, the first drain plug 19 is provided at the lower portion of the first shaft gear 71 having the widest width in the second direction.

(Overview of the first housing)
According to the above configuration, in the vehicle drive device 1 according to the present embodiment, the first housing 13 has a shape in which the inner wall portion 131 is close to a part of the second shaft gear 73 as shown in FIG. Yes. Since the inner wall 131 is close to a part of the second shaft gear 73, the first housing 13 has a rectifying effect that regulates the fluid flow to be constant.

  The vehicle drive device 1 in this embodiment can reduce the stirring resistance of the lubricating oil by providing the first housing 13 with a shape having a rectifying effect. Further, the vehicle drive device 1 can suppress an increase in the temperature of the lubricating oil by reducing the stirring resistance by the first housing 13. Further, the vehicle drive device 1 can improve the fuel efficiency because the transmission efficiency of the driving force is improved by reducing the stirring resistance by the first housing 13.

  In the conventional vehicle drive device, the space for arranging the first shaft gear 71, the second shaft gear 73, and the third shaft gear 75 is wider than the space of the first housing 13 in the present embodiment. In order to obtain the rectifying effect, it is necessary to install a rectifying plate (baffle plate) in the vicinity of each gear. For example, in a conventional vehicle drive device, the rectifying plate is installed at the lower part of each gear and along the circumference of each gear.

  On the other hand, the vehicle drive device 1 according to the present embodiment does not need to install a rectifying plate by providing the first housing 13 with a shape having a rectifying effect. That is, the vehicle drive device 1 according to the present embodiment can reduce the number of parts and the weight.

  Moreover, according to the said structure, in the vehicle drive device 1 which concerns on this embodiment, the 1st housing 13 is the said 1st direction in the 1st direction which goes to the 2nd shaft gear 73 from the 1st shaft gear 71. The width in the second direction orthogonal to the width gradually decreases. Thereby, the space of the 1st housing 13 can be made smaller than the space which arrange | positions the 1st shaft gear 71, the 2nd shaft gear 73, and the 3rd shaft gear 75 in the conventional vehicle drive device. That is, the vehicle drive device 1 according to the present embodiment can save the space of the first housing 13.

  In the vehicle drive device 1 according to the present embodiment, it is assumed that the lubricating oil is collected on one side of the first housing 13 by the above-described configuration. For example, the lubricating oil may be collected from the second shaft gear 73 side to the first shaft gear 71 side.

  In the vehicle drive device 1 according to the present embodiment, the first drain plug 19 is provided in a part of the inner wall portion 131. Specifically, the vehicle drive device 1 is provided with a first drain plug 19 at a position where the lubricating oil in the first housing 13 is collected. Thereby, the vehicle drive device 1 can improve the discharge property of the lubricating oil in the replacement operation of the lubricating oil.

(Description of second housing)
FIG. 3 is a cross-sectional view taken along line β-β in FIG. FIG. 3 shows a cross section of the second housing 15 in the speed reduction mechanism 7. As shown in FIG. 3, the second housing 15 has a shape in which a part of the inner wall 151 that accommodates the other part of the second shaft gear 73 is close to the other part of the second shaft gear 73. Specifically, as shown in FIG. 3, a part of the inner wall portion 151 of the second housing 15 has a shape along a part of the circumference of the second shaft gear 73.

The second housing 15 has a shape in which the width in the fourth direction orthogonal to the third direction gradually decreases in the third direction from the differential gear 5 toward the second shaft gear 73. ing. For example, as shown in FIG. 3, the width w ₃ of the second housing 15 in the second direction at the position of the second shaft gear 73 is equal to the width of the second housing 15 in the second direction at the position of the differential gear 5. narrower than the width _{w 4.} Here, the 3rd direction in this embodiment is a front direction from the back of vehicles, for example. Assuming that the third direction is the front direction from the back of the vehicle, the fourth direction is the vehicle height direction as in the second direction.

  Further, the second housing 15 is provided with the second drain plug 21 in a part of the inner wall portion 151 that accommodates the other portion of the second shaft gear 73. For example, the second drain plug 21 is provided below the differential gear 5 having the widest width in the second direction.

(Overview of the second housing)
According to the above configuration, in the vehicle drive device 1 according to the present embodiment, the second housing 15 has a shape in which the inner wall portion 151 is close to the other portion of the second shaft gear 73 as shown in FIG. ing. Since the second housing 15 has the inner wall portion 151 close to the other portion of the second shaft gear 73, the second housing 15 has a rectifying effect that keeps the fluid flow constant, as in the first housing 13.

  The vehicle drive device 1 in the present embodiment can reduce the stirring resistance of the lubricating oil by providing the second housing 15 with a shape having a rectifying effect. Further, the vehicle drive device 1 can suppress an increase in the temperature of the lubricating oil by reducing the stirring resistance by the second housing 15. Furthermore, the vehicle drive device 1 can improve the fuel efficiency because the transmission efficiency of the driving force is improved by reducing the stirring resistance by the second housing 15.

  Moreover, according to the said structure, in the vehicle drive device 1 which concerns on this embodiment, the 2nd housing 15 is orthogonal to the said 3rd direction in the 3rd direction which goes to the 2nd shaft gear 73 from the differential gear 5. FIG. The width in the fourth direction is gradually reduced. Thereby, the space of the 2nd housing 15 can be made smaller than the space which arrange | positions the differential gear 5 and the 2nd shaft gear 73 in the conventional vehicle drive device. That is, the vehicle drive device 1 according to the present embodiment can save the space of the second housing 15.

  In the vehicle drive device 1 according to the present embodiment, it is assumed that the lubricating oil is collected on one side of the second housing 15 by the above-described configuration. For example, the lubricating oil may be collected from the second shaft gear 73 side to the differential gear 5 side.

  The vehicle drive device 1 is provided with a second drain plug 21 in a part of the inner wall portion 151. Specifically, the vehicle drive device 1 is provided with a second drain plug 21 at a position where the lubricating oil in the second housing 15 is collected. Thereby, the vehicle drive device 1 can improve the discharge property of the lubricating oil in the replacement operation of the lubricating oil.

  Thus, the vehicle drive device 1 according to the present embodiment can be applied to an electric commercial vehicle while suppressing the stirring resistance of the lubricating oil in the speed reduction mechanism 7.

  In the vehicle drive device 1 according to the present embodiment, a rectifying plate may be provided so as to be close to the first shaft gear 71. Further, a rectifying plate may be provided so as to be close to the third shaft gear 75. Further, a rectifying plate having a shape along a part of the circumference of the first shaft gear 71 and the third shaft gear 75 may be provided. Accordingly, the vehicle drive device 1 according to the present embodiment can obtain a rectifying effect also in the first shaft gear 71 and the third shaft gear 75 in addition to the second shaft gear 73.

  Moreover, in the vehicle drive device 1 according to the present embodiment, the housing structure constituted by only the first housing 13 and the second housing 15 is exemplified, but the first housing 13 and the first housing 13 are not limited thereto. The structure provided with the 3rd housing connected between 2 housings 15 may be sufficient.

DESCRIPTION OF SYMBOLS 1 Vehicle drive device 3 Motor 5 Differential gear 7 Reduction mechanism 9 Motor shaft 11 Gear housing (housing structure)
13 1st housing 15 2nd housing 17 breather 19 1st drain plug 21 2nd drain plug 31 motor housing 71 1st shaft gear 73 2nd shaft gear 75 3rd shaft gear 131 inner wall part 151 inner wall part

Claims (1)

A vehicle drive device comprising: a motor mounted on a vehicle; and a speed reduction mechanism that transmits a driving force of the motor to a differential gear of the vehicle,
A housing structure that houses the speed reduction mechanism and the differential gear;
The deceleration mechanism is
A first shaft gear coupled to the motor;
A second shaft gear coupled to the differential gear;
A third shaft gear connecting the first shaft gear and the second shaft gear;
With
The housing structure is
The first shaft gear, a part of the second shaft gear, and the third shaft gear are accommodated, and in the first direction from the first shaft gear to the second shaft gear, the first direction and The width in the second direction perpendicular to the second direction gradually decreases, and a part of the inner wall portion that accommodates a part of the second shaft gear is provided close to a part of the second shaft gear, A first housing in which a first drain plug is provided in a part of an inner wall portion that houses the first shaft gear;
The other part of the differential gear and the second shaft gear is accommodated, and the width in the fourth direction orthogonal to the third direction is gradually increased in the third direction from the differential gear toward the second shaft gear. A portion of the inner wall portion that accommodates the other portion of the second shaft gear is provided so as to be close to the other portion of the second shaft gear, and a portion of the inner wall portion that accommodates the differential gear A second housing provided with a second drain plug;
A vehicle drive device comprising:

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