WO2019244564A1

WO2019244564A1 - Vehicle drive device

Info

Publication number: WO2019244564A1
Application number: PCT/JP2019/020722
Authority: WO
Inventors: 昇悟竹田
Original assignee: ダイムラー・アクチェンゲゼルシャフト
Priority date: 2018-06-19
Filing date: 2019-05-24
Publication date: 2019-12-26
Also published as: JP2019218989A

Abstract

[Problem] To provide a vehicle drive device with which it is possible to ensure lubrication of a differential gear while restricting the number of components and the cost, and the lubricating oil stirring resistance in a speed reduction mechanism. [Solution]　This vehicle drive device is provided with a motor installed in a vehicle, and a speed reduction mechanism for transmitting a driving force from the motor, via a coupling gear, to an output gear coupled to a differential unit of the vehicle, wherein the vehicle drive device includes a housing for accommodating the speed reduction mechanism, and, in the housing, a lubricating oil supply path provided in such a way as to supply lubricating oil pulled upward by the coupling gear of the speed reduction mechanism inside the housing, to a bevel gear of the differential unit.

Description

Vehicle drive system

The present invention relates to a vehicle drive device for transmitting a driving force of a motor to a differential portion of a vehicle.

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

International Publication No. WO 2014/148410

In such a vehicle drive device, it is conceivable to design the inner wall surface of the housing so as to be close to the gear of the reduction mechanism from the viewpoint of ensuring lubricity while suppressing an increase in lubricating oil stirring resistance. Here, from the viewpoint of mountability of the vehicle drive device, there is a demand for arranging a gear arrangement including a differential gear along the vehicle longitudinal direction.

However, in a vehicle drive device in which the gear arrangement is arranged along the vehicle front-rear direction, sufficient lubricating oil cannot be supplied to the differential gear in the drive device due to oil level fluctuations caused by the running state of the vehicle. The differential gear may not be sufficiently lubricated. On the other hand, it is conceivable to increase the amount of the lubricating oil, but there is a risk that the stirring resistance of the lubricating oil in the speed reduction mechanism increases, resulting in deterioration of energy efficiency and an excessive rise in temperature of the lubricating oil. Further, if a design is adopted in which an oil pump is provided to forcibly lubricate the lubricating oil, the number of parts and the cost increase.

The present invention has been made in view of such a situation, and aims at ensuring the lubricity of a differential gear while suppressing the number of parts, cost, and agitation resistance of lubricating oil in a reduction mechanism. It is an object of the present invention to provide a vehicular drive device that can perform the above.

In order to achieve the above object, a vehicle drive device according to an aspect of the present invention includes a motor mounted on a vehicle and an output gear connected to a differential section of the vehicle, the output gear being connected to the motor via a connection gear. A drive mechanism for transmitting the driving force of the vehicle, comprising: a housing for accommodating the speed reduction mechanism; and a lubrication device in the housing, the lubrication being scraped up by the connection gear of the speed reduction mechanism in the housing. A lubricating oil supply passage provided to supply oil to the bevel gear of the differential section.

In the vehicle drive device, since a lubricating oil supply path for supplying the lubricating oil scraped up by the connecting gear to the bevel gear of the differential unit is provided, a device such as an oil pump for forcibly lubricating the lubricating oil is provided. At least, the lubricating oil can be supplied to the differential unit by rotating the coupling gear even in various running situations, and the lubrication of the differential unit can be ensured.

In the vehicle drive device, the lubricating oil supply path may be provided along a contact surface of a virtual circle formed by gear tooth end surfaces when the connection gear rotates. This makes it possible to introduce the scooped lubricating oil toward the lubricating oil supply path by utilizing the rotation and gravity of the connecting gear. Further, the lubricating oil can be efficiently supplied to the differential unit via the lubricating oil supply path, and the lubricity of the differential unit can be further improved.

1 is a top view of a vehicle drive device according to an embodiment of the present invention. It is a top view showing the composition inside the housing in the state where the housing of the drive system for vehicles concerning one embodiment of the present invention was cut up and down. It is a side view showing the relation between the gear of the drive device for vehicles concerning one embodiment of the present invention, and the internal space which stores a gear. 1 is a rear view of a vehicle drive device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the content described below, and can be arbitrarily changed and implemented without changing the gist. Further, the drawings used in the description of the embodiments each schematically show constituent members, and partial emphasis, enlargement, reduction, or omission is performed for better understanding. In some cases, the scale, shape, and the like are not accurately represented.

First, the schematic configuration of the vehicle drive device will be described with reference to FIG. Here, FIG. 1 is a top view of the vehicle drive device 1 according to the present embodiment. In FIG. 1, the vehicle length direction A is the front-back direction of the vehicle on which the vehicle drive device 1 is mounted, and the vehicle width direction B is the left-right direction of the vehicle on which the vehicle drive device 1 is mounted. It is. That is, each direction indicates a direction in a state where the vehicle drive device 1 is mounted on the vehicle.

In the present embodiment, the vehicle drive device 1 is a drive source that is mounted on an electric vehicle and converts supplied power into power for running the vehicle. In addition, the electric vehicle is, for example, an electric commercial vehicle such as an electric truck, but is not limited to this, and may be an electric passenger vehicle obtained by electrifying a general passenger vehicle. As shown in FIG. 1, the vehicle drive device 1 includes a motor 2, a speed reduction mechanism 3, a differential unit 4, and a housing 5 that houses these components.

The motor 2 converts electric power supplied from a battery (not shown) mounted on the vehicle together with the vehicle driving device 1 into a rotational motion and outputs the rotational motion. As shown in FIG. 1, the motor 2 includes a main body 2a and an output shaft 2b.

The reduction mechanism 3 includes an input unit 11 connected to the output shaft 2 b of the motor 2, a middle unit 12 connected to the input unit 11, and an output unit 13 located between the middle unit 12 and the differential unit 4. This is a two-stage reducer. In particular, the input unit 11, the middle unit 12, and the output unit 13 are connected to each other as a gear mechanism. Then, the speed reduction mechanism 3 reduces the rotational motion input from the motor 2 to the input unit 11 to a rotational speed suitable for traveling of the vehicle, and outputs the rotation from the output unit 13. In addition, more detailed configurations of the input unit 11, the middle unit 12, and the output unit 13 will be described later.

The differential unit 4 has a rotating shaft connected to an axle (not shown) of a driving wheel of the vehicle, and performs a rotational motion output from the output unit 13 while absorbing a difference in the number of revolutions during turning, for example, while driving the left and right driving wheels. , The drive wheels are rotated. Thereby, the vehicle drive device 1 can run the vehicle by rotating the drive wheels of the vehicle through the speed reduction mechanism 3 and the differential unit 4 with the drive force generated by the motor 2. Note that a more detailed configuration of the differential unit 4 will be described later.

The housing 5 includes a motor housing 5a that houses the motor 2, a speed reduction mechanism 3, and a gear housing 5b that houses the differential unit 4. The motor housing 5a protects and supports the motor 2 housed therein, and also prevents lubricating oil used for the motor 2 from leaking out. The motor housing 5a is connected to a predetermined position of the gear housing 5b so that the motor 2 and the speed reduction mechanism 3 are appropriately connected.

The gear housing 5b protects and supports the reduction mechanism 3 and the differential unit 4 housed therein, and also prevents the lubricating oil used for the reduction mechanism 3 and the differential unit 4 from leaking out. Although the speed reduction mechanism 3 and the differential unit 4 are housed in one gear housing 5b in the present embodiment, they may be housed individually in two housings as long as they are connected to each other.

Next, the configuration up to transmission of the driving force of the motor 2 to the differential unit 4 via the speed reduction mechanism 3 will be described in detail with reference to FIGS. Here, FIG. 2 is a top view showing the internal configuration of the housing 5 in a state where the housing 5 of the vehicle drive device 1 according to one embodiment of the present invention is cut vertically and the upper housing is removed. FIG. 3 is a side view showing the relationship between the gears of the vehicle drive device 1 according to the embodiment of the present invention and the internal space accommodating the gears. 2 and 3, similarly to FIG. 1, the vehicle length direction A is the front-rear direction of the vehicle on which the vehicle drive device 1 is mounted, and the vehicle width direction B is the vehicle drive direction 1. Is the left-right direction of the vehicle on which the vehicle is mounted, and the vehicle height direction C is the vertical direction of the vehicle on which the vehicle drive device 1 is mounted, and each direction is a state in which the vehicle drive device 1 is mounted on the vehicle. Shows the direction at. Further, in FIG. 3, only a part of the gear teeth is illustrated for convenience.

As can be seen from FIGS. 2 and 3, the middle portion 12 includes a connection gear 22 that meshes with the input portion 11 serving as an input gear, a connection gear 23 having a smaller diameter than the connection gear 22, and the connection gear 22 and the connection gear 23. It is composed of a shaft 24 which is connected to be a rotating shaft. The output unit 13 includes a connection gear 25 that meshes with the connection gear 23, an output gear 26 having a smaller diameter than the connection gear 25, and a shaft 27 that connects the connection gear 25 and the output gear 26 to be a rotating shaft. Have been. With such a configuration of the speed reduction mechanism 3, the rotation speed of the motor 2 is reduced in two stages and transmitted to the differential unit 4.

2 and 3, the differential unit 4 includes a final gear 31 that meshes with the output gear 26, and a differential case 32 integrally provided on the surface of the final gear 31. The differential section 4 includes a right differential side gear 33, a left differential side gear 34, and two differential pinion gears 35 and 36 housed in a differential case 32. Here, the right differential side gear 33, the left differential side gear 34, and the differential pinion gears 35 and 36 are general bevel gears. With these members, the differential section 4 constitutes a general differential gear.

分かる As can be seen from FIGS. 2 and 3, in the vehicle drive device 1 according to the present embodiment, the respective gears constituting the speed reduction mechanism 3 and the differential unit 4 are arranged along the vehicle length direction A. Therefore, the mountability of the vehicle drive device 1 in the electric vehicle is improved. That is, the vehicle drive device 1 according to the present embodiment can be easily mounted on a general electric truck, and can be used for various types of vehicles.

As shown in FIG. 3, the inner wall surface 5c of the housing 5 is close to the gears forming the speed reduction mechanism 3 and the differential unit 4 in the vehicle height direction C. For this reason, even if lubricating oil is not added in such an amount that most of the gear housing 5b is filled, each gear is easily immersed in the lubricating oil, and the increase in the stirring resistance of the lubricating oil is suppressed. As a result, lubricity for each gear is ensured.

Next, supply of lubricating oil to each gear will be described with reference to FIGS. Here, FIG. 4 is a rear view of the vehicle drive device 1 according to one embodiment of the present invention, in which a part of the speed reduction mechanism 3 and the differential unit 4 are visualized. Also in FIG. 4, similarly to FIGS. 1 to 3, the vehicle length direction A is the front-back direction of the vehicle on which the vehicle drive device 1 is mounted, and the vehicle height direction C is the vehicle drive device 1. Are the vertical directions of the vehicle on which the vehicle is mounted, and each direction indicates the direction in a state where the vehicle drive device 1 is mounted on the vehicle.

潤滑 As shown in FIG. 3, the lubricating oil is present in the internal space of the housing 5 so as to immerse a part of each of the connection gear 22, the connection gear 25, and the final gear 31. That is, the oil surface 40 of the lubricating oil is located higher than the lower end surfaces of the connection gear 22, the connection gear 25, and the final gear 31. Therefore, the rotation of the connection gear 22, the connection gear 25, and the final gear 31 ensures the lubricity of each tooth of the connection gear 22, the connection gear 25, and the final gear 31. On the other hand, the input unit 11, the connecting gear 23, and the output gear 26, which are input gears, are not immersed in the lubricating oil, but are engaged with the connecting gear 22, the connecting gear 25, and the final gear 31 immersed in the lubricating oil. The lubricating oil is supplied via the connection gear 22, the connection gear 25, and the final gear 31. Thereby, lubricity of each tooth of the input unit 11, the connecting gear 23, and the output gear 26 is ensured. Further, lubricating oil is supplied to each bevel gear accommodated in the differential case 32 via an opening (not shown) provided in the differential case 32.

2 and 4, the gear housing 5b is provided with a lubricating oil supply passage 41 extending from above the coupling gear 25 toward the differential portion 4. More specifically, the lubricating oil supply passage 41 extends from an opening (introduction port) provided in the wall of the gear housing 5 b located behind the top of the coupling gear 25 to the right central end of the differential unit 4. It is formed as a communication hole extending to an opening (discharge port) provided in the wall of the gear housing 5b located above. In particular, the opening serving as the discharge port of the lubricating oil supply passage 41 is located immediately above the right differential side gear 33 protruding from the differential case 32.

As can be seen from FIG. 3, the lubricating oil supply passage 41 is provided along a contact surface of a virtual circle (circumferential portion of the connection gear 25) formed by the gear tooth end surfaces when the connection gear 25 rotates. Have been. That is, on the side surface of the vehicle drive device 1, the lubricating oil supply path 41 is provided with its inlet port close to one point on the outer edge of the connection gear 25 so as to be in contact with one point on the outer edge. .

By providing such a lubricating oil supply passage 41, the lubricating oil around the connecting gear 25 is scraped up along the circumference of the connecting gear 25 as shown by an arrow D in FIG. 3 and the arrow E in FIG. 4, the oil reaches the right differential side gear 33 of the differential section 4 via the lubricating oil supply path 41. In other words, the lubricating oil scooped up by the connection gear 25 is transmitted through the inside of the wall of the gear housing 5b, and is supplied to the right differential side gear 33 which is a bevel gear.

The lubricating oil supplied to the right differential side gear 33 is transmitted from the right differential side gear 33 into the differential case 32, and is also supplied to the other bevel gears, that is, the left differential side gear 34 and the differential pinion gears 35 and 36. Therefore, the lubricating oil can be satisfactorily supplied to each bevel gear in the differential case 32 that is not immersed in the lubricating oil, and the lubricity of the differential section 4 can be improved. In particular, when the electric vehicle travels on a path having a predetermined gradient such as a downhill or an uphill, even when the lubricating oil is biased toward the speed reduction mechanism 3, the connecting gear 25 rotates to supply the lubricating oil. By scooping up, lubricating oil can be supplied to the differential unit 4.

As described above, in the vehicle drive device 1 according to the present embodiment, the lubricating oil is supplied to the differential portion 4 even in various driving situations without providing a device such as an oil pump for forcibly lubricating the lubricating oil. The lubrication of the differential section 4 can be ensured. Further, since the inner wall surface 5c of the housing 5 is close to the gears of the speed reduction mechanism 3 and the differential section 4, the resistance of the lubricating oil to stirring in the speed reduction mechanism is suppressed.

Further, in the present embodiment, when the connection gear 25 rotates, the lubricating oil supply path 41 is provided along the tangent surface of the virtual circle formed by the gear tooth end faces. The lubricating oil thus scooped can be introduced toward the inlet of the lubricating oil supply passage 41 using the lubricating oil. Thus, the lubricating oil can be efficiently supplied to the differential unit 4 via the lubricating oil supply path 41, and the lubricity of the differential unit 4 can be further improved. Specifically, since there is no need to forcibly lubricate the differential portion 4 using a lubricating oil supply pump or the like, the lubricity of the differential portion 4 can be improved without increasing the energy load.

DESCRIPTION OF SYMBOLS 1 Vehicle drive device 2 Motor 2a Main body part 2b Output shaft 3 Reduction mechanism 4 Differential part 5 Housing

5a Motor housing

5b Gear housing 5c Inner wall surface 11 Input part (input gear)
12 Middle part 13

Output part

22, 23, 25 Connecting

gear

24, 27 Shaft 26 Output gear 31 Final gear 32 Differential case 33 Right differential side gear (bevel gear)
34 Left differential side gear (bevel gear)
35, 36 differential pinion gear (bevel gear)
40 Oil level 41 Lubricating oil supply path A Vehicle length direction B Vehicle width direction C Vehicle height direction

Claims

A vehicle drive device comprising: a motor mounted on a vehicle, and a reduction mechanism that transmits a driving force from the motor via a connection gear to an output gear connected to a differential portion of the vehicle,
A housing for accommodating the speed reduction mechanism;
A lubricating oil supply passage provided in the housing to supply lubricating oil scooped up by the coupling gear of the speed reduction mechanism to the bevel gear of the differential unit in the housing;
A vehicle drive device, including:
The vehicle drive device according to claim 1, wherein the lubricating oil supply path is provided along a contact surface of an imaginary circle formed by gear tooth end surfaces when the connection gear rotates.
.