JP6725464B2 - Vehicle drive - Google Patents

Description

The present invention relates to a vehicle drive device.

For example, Patent Document 1 below discloses an in-wheel motor drive device, which is a type of vehicle drive device. This in-wheel motor drive device includes an electric motor unit, a wheel bearing unit that rotatably supports a wheel, a speed reducer unit that decelerates rotation of the electric motor unit and transmits the rotation to the wheel bearing unit, and an electric motor unit. A so-called parallel shaft gear reducer in which the reduction gear unit has a plurality of gears (gear shafts) and the rotation axes of the gears are arranged in parallel with each other. ing.

The speed reducer section is usually provided with a lubrication mechanism for lubricating and cooling each section (particularly, the gear section of the gear). Examples of this lubrication mechanism include one in which a part of a plurality of gears is placed in an oil bath state and the lubricating oil is splashed onto other gears as the gears rotate, as well as oil pipes extending from an oil pump. A nozzle is provided in the nozzle to inject lubricating oil toward a predetermined location from this nozzle (Patent Document 2), or an oil supply hole connected to the tooth bottom is provided in the gear shaft, and the lubricating oil is applied to the tooth bottom through the oil supply hole. (Patent Document 3) and the like. In particular, since the lubrication mechanisms of Patent Documents 2 and 3 can directly lubricate and cool the gear parts of the gears that form the parallel shaft gear reducer, in order to enhance the reliability and durability of the parallel shaft gear reducer. It can be said that it is preferable.

JP, 2017-65666, A JP, 2009-156368, A JP2012-82945A

From the viewpoint of enhancing the traveling stability and NVH characteristics of the vehicle as well as the mountability on the vehicle, the above vehicle drive device is required to be as light and compact as possible. Therefore, in the speed reducer (parallel shaft gear speed reducer) installed in the vehicle drive device, the components are densely arranged, and the gap width between the speed reducer and the casing accommodating the speed reducer is set to be as small as possible. Has become commonplace. Therefore, the lubrication mechanisms of Patent Documents 2 and 3 which are likely to cause the speed reducer, and eventually the in-wheel motor drive device to be large and complicated, and to be high in cost, are applied to the speed reducer of the vehicle drive device. Is not realistic.

In view of the above situation, the present invention relates to a vehicle drive device in which a parallel shaft gear reducer is applied to a reducer, without reducing the size and complexity of the entire device. The purpose is to enable efficient lubrication and cooling of gears that are located deep in the reducer.

The present invention devised to achieve the above object includes an electric motor unit, a speed reducer unit, and a casing accommodating the electric motor unit and the speed reducer unit, and the speed reducer unit has parallel rotating shafts. In a vehicle drive device including a parallel shaft gear reducer having an input gear, one or more intermediate gears, and an output gear that are arranged, a part of the gear portion of the output gear is in an oil bath state in a casing. An oil sump forming section is provided for forming an oil sump before the meshing point of the output gear and the intermediate gear by utilizing the lubricating oil filled with the lubricating oil and scraped up as the output gear rotates. It is characterized in that at least a part of the puddle forming portion is located inside (inner diameter side) of the maximum addendum circle of the intermediate gear that meshes with the output gear. The "tooth circle" referred to here means a circular orbit (trajectory) drawn by the tooth tips as the gear rotates about its rotation axis.

According to the above configuration, an oil sump in which a sufficient amount of lubricating oil intervenes can be formed before the meshing point (final meshing point) between the output gear and the intermediate gear as the output gear rotates. Lubricating oil can be successively supplied from the oil sump toward the final meshing point. As a result, the final meshing point (the gear part of the output gear and the gear part of the intermediate gear meshing with it) can be efficiently lubricated and cooled.

When the output gear is rotating, the lubricating oil supplied from the oil sump to the final meshing point is mainly along the tangent line of the final meshing point on the front side in the rotation direction of the output gear (that is, the final meshing point). Scatter on the side opposite to the oil sump). Therefore, the addendum circle of the first gear arranged before the intermediate gear that meshes with the output gear and the tangent line of the final meshing point intersect on the opposite side of the oil sump across the final meshing point. If so, the lubricating oil can be efficiently supplied to the one gear. Further, the lubricating oil supplied to the one gear is also supplied to the gear with which the one gear meshes as the one gear rotates. In addition, the above-mentioned "one gear arranged before the intermediate gear that meshes with the output gear" means that the reduction gear unit is a three-shaft type parallel shaft gear reduction gear consisting of an input gear, one intermediate gear and an output gear. Input gear, when the speed reducer section is composed of a parallel shaft gear reducer of four or more axes consisting of an input gear, a plurality of intermediate gears and an output gear, the input gear or It is an intermediate gear.

It is preferable that the first gear is arranged on the front side of the vehicle with respect to the final meshing point, and the oil sump forming portion is arranged on the rear side of the vehicle with respect to the final meshing point. With this configuration, it is possible to effectively enjoy the above-described operational effects when the vehicle equipped with the vehicle drive device moves forward.

It is preferable that the input gear and the intermediate gear are arranged so that a part of the gear portion of the output gear does not come into contact with the lubricating oil that makes the oil bath state. This is to avoid a reduction in efficiency of the reducer due to an increase in stirring resistance. For the same reason, the final meshing point is preferably located above the rotation axis of the output gear.

If the tooth width of the one gear is set to be larger than the tooth width of the gear that meshes with the one gear, the lubricating oil scattered in the tangential direction of the final meshing point is applied to the gear portion of the one gear. Can be efficiently supplied. At this time, if the tooth width of the one gear and the tooth width of the intermediate gear that meshes with the output gear overlap, the lubricating oil is easily supplied to the gear portion of the one gear.

In the above configuration, a control unit for controlling the flow of the lubricating oil may be provided on the tangent line of the final meshing point and between the final meshing point and the one gear. With this configuration, by appropriately setting the shape and arrangement of the control unit, it becomes possible to arbitrarily adjust the supply location and the supply amount of the lubricating oil, so that the intermediate gear that meshes with the output gear can be provided in the preceding stage. This is advantageous in increasing the lubrication efficiency of the gears arranged.

Further, in the above configuration, if the oil sump forming portion is provided so as to be able to divide the lubricating oil scraped up with the rotation of the output gear into two different directions, the lubricating oil scraped up by the output gear, It is possible to supply to a site other than the final meshing point.

From the above, according to the present invention, in a vehicle drive device in which a parallel shaft gear reducer is applied to the reducer, it is possible to efficiently lubricate and cool the reducer without causing an increase in size or complexity of the entire device. Is possible. As a result, it is possible to realize a lightweight, compact, and low-cost vehicle drive device.

It is a sectional view showing the whole structure of an in-wheel motor drive as a vehicle drive concerning one embodiment of the present invention. FIG. 2 is a schematic diagram showing an example of an arrangement mode (layout) of each gear forming the parallel shaft gear reducer shown in FIG. 1. It is a schematic diagram showing a modification of arrangement mode of each gear which constitutes a parallel axis gear reducer. It is a schematic diagram showing a modification of arrangement mode of each gear which constitutes a parallel axis gear reducer. It is a schematic diagram showing a modification of arrangement mode of each gear which constitutes a parallel axis gear reducer. It is a schematic diagram which expands and shows a part of parallel axis gear reducer. It is a schematic plan view of the electric vehicle carrying the in-wheel motor drive device. FIG. 8 is a rear sectional view of the electric vehicle shown in FIG. 7.

Embodiments of the present invention will be described below with reference to the drawings.

First, an outline of an electric vehicle 11 equipped with an in-wheel motor drive device, which is a type of vehicle drive device, will be described with reference to FIGS. 7 and 8. As shown in FIG. 7, an electric vehicle 11 drives a chassis 12, a pair of front wheels 13 that function as steered wheels, a pair of rear wheels 14 that function as drive wheels, and an in-vehicle drive wheel that drives each of the left and right rear wheels 14. The wheel motor drive device 21 is provided. As shown in FIG. 8, the rear wheel 14 is housed inside the wheel housing 15 of the chassis 12 and is fixed to the lower portion of the chassis 12 via a suspension device 16.

The suspension device 16 supports the rear wheel 14 by a suspension arm extending to the left and right, and absorbs the vibration received by the rear wheel 14 from the road surface by the strut including the coil spring and the shock absorber to suppress the vibration of the chassis 12. Stabilizers are provided at the connecting portions of the left and right suspension arms to suppress tilting of the vehicle body during turning. The suspension device 16 is of an independent suspension type in which the left and right wheels are independently moved up and down in order to improve the followability to the unevenness of the road surface and to efficiently transmit the driving force of the rear wheel 14 to the road surface.

In the electric vehicle 11, since the in-wheel motor drive device 21 that rotationally drives the left and right rear wheels 14 is incorporated inside the left and right wheel housings 15, a motor, a drive shaft, a differential gear mechanism, and the like are mounted on the chassis 12. There is no need to provide it. Therefore, the electric vehicle 11 has an advantage that a large passenger compartment space can be secured and the rotations of the left and right rear wheels 14 can be controlled respectively.

As described above, the in-wheel motor drive device 21 includes not only the rear-wheel drive type electric vehicle 11 in which the rear wheels 14 are drive wheels, but also the front-wheel drive type electric vehicle in which the front wheels 13 are drive wheels, It can also be applied to a four-wheel drive type electric vehicle having front wheels 13 and rear wheels 14 as driving wheels. Although the electric vehicle 11 employs the suspension device 16 of the independent suspension type, the suspension system of the suspension device 16 can be designed arbitrarily.

In order to improve the running stability and NVH characteristics of the electric vehicle 11, it is necessary to suppress the unsprung weight. Further, in order to expand the cabin space of the electric vehicle 11, it is necessary to downsize the in-wheel motor drive device 21. Therefore, the in-wheel motor drive device 21 as shown in FIG. 1 is adopted.

As shown in FIG. 1, an in-wheel motor drive device 21, which is a type of vehicle drive device, includes an electric motor unit A that generates a driving force, and a speed reducer unit B that decelerates and outputs the rotation of the electric motor unit A. , And a wheel bearing portion C for transmitting the output of the speed reducer portion B to a wheel (rear wheel 14 as a driving wheel: see FIG. 7). The electric motor portion A and the reduction gear portion B are housed in the casing 22, and the wheel bearing portion C is attached to the casing 22. In the following description, the sides that are the outer side in the vehicle width direction and the inner side in the vehicle width direction with the in-wheel motor drive device 21 mounted in the wheel housing 15 are also referred to as the outboard side and the inboard side, respectively. In FIG. 1, the left side of the paper is the outboard side, and the right side of the paper is the inboard side.

The casing 22 has a motor housing chamber 22A housing the electric motor unit A and a speed reducer housing chamber 22B housing the speed reducer unit B. The casing 22 in the illustrated example integrally includes the motor housing chamber 22A and the speed reducer housing chamber 22B, but in reality, the electric motor unit A and the speed reducer unit B to the chambers 22A and 22B are provided. In many cases, it is divided at an arbitrary position in consideration of embedding property and connected by an appropriate means.

The electric motor unit A includes a stator 23 fixed to the casing 22, a rotor 24 disposed inside the stator 23 so as to face each other with a radial gap therebetween, and a motor rotating shaft 25 having the rotor 24 mounted on the outer periphery thereof. It is composed of a radial gap type electric motor 26. The motor rotating shaft 25 is rotatably supported with respect to the casing 22 by rolling bearings 40 and 41 arranged at two positions separated from each other in the axial direction thereof, and rotates at a rotational speed of about 10,000 thousands per minute. It is possible.

As shown in FIG. 1, the reduction gear unit B includes a plurality of gears (gear shafts), so-called parallel shaft gear reduction gears 30, in which the rotation axes of the gears are arranged in parallel with each other. The parallel shaft gear reducer 30 of the present embodiment includes an input gear 31, an intermediate gear 32, and an output gear 33, and the rotation shafts (rotation centers) O1 to O3 of the gears 31 to 33 are, as shown in FIG. The straight lines connecting the respective rotation axes O1 to O3 are arranged so as to form a triangular shape. More specifically, the rotation shaft O3 of the output gear 33 is arranged at the lowermost side, the rotation shaft O2 of the intermediate gear 32 is arranged at the uppermost side, and the rotation shaft O1 of the input gear 31 is substantially the rotation shafts O2 and O3. It is located in the middle. By arranging the gears 31 to 33 in this manner, a compact speed reducer 30 can be realized.

The meshing point Mp between the output gear 33 and the intermediate gear 32, that is, the final meshing point between the gears in the reduction gear 30 is located above the rotation axis O3 of the output gear 33. This is to avoid a reduction in efficiency of the speed reducer 30 due to an increase in stirring resistance of the lubricating oil 70 filled in the speed reducer chamber 22B of the casing 22 for lubricating and cooling the speed reducer portion B.

In the parallel shaft gear reducer 30, the gear portion 34 of the input gear 31 and the large diameter gear portion 35 of the intermediate gear 32 mesh with each other, and the small diameter gear portion 36 of the intermediate gear 32 and the gear portion 37 of the output gear 33 are combined. Are in mesh. The number of teeth of the large-diameter gear portion 35 of the intermediate gear 32 is larger than the number of teeth of the gear portion 34 of the input gear 31 and the small-diameter gear portion 36 of the intermediate gear 32, and the number of teeth of the gear portion 37 of the output gear 33 is intermediate. The number of teeth is larger than the number of teeth of the small-diameter gear portion 36 of the gear 32. With such a configuration, the parallel shaft gear reducer 30 of the present embodiment decelerates the rotation of the motor rotation shaft 25 in two stages and outputs (transmits) the rotation to the wheel bearing portion C.

The input gear 31 is rotatably connected to the motor rotating shaft 25 by spline fitting, and is rotatably supported by the casing 22 by rolling bearings 42 and 43 arranged at two axially spaced positions. There is. The intermediate gear 32 is provided by rolling bearings 44, 45 arranged at two axial positions, and the output gear 33 is provided by rolling bearings 46, 47 arranged at two axial positions, respectively. It is rotatably supported by the casing 22.

Helical gears are used as the input gear 31, the intermediate gear 32, and the output gear 33 of this embodiment (see FIG. 6 ). The helical gear has many teeth that mesh at the same time and the tooth contact is dispersed, so that it has the advantages that the sound at the time of meshing is quiet and the torque fluctuation is small. Therefore, the use of the helical gear is advantageous in realizing the parallel shaft gear reducer 30 that is quiet and has excellent torque transmission efficiency.

As shown in FIG. 1, the wheel bearing portion C includes a so-called inner ring rotating type wheel bearing 50. The wheel bearing 50 is a double row angular contact ball bearing including an inner member 53 including a hub wheel 51 and an inner ring 52, an outer ring 54, balls 57, and a cage (not shown). Although detailed illustration is omitted, the internal space of the wheel bearing 50 is filled with grease as a lubricant. Sealing members are provided at both axial end portions of the wheel bearing 50 in order to prevent foreign matter from entering the bearing internal space and leaking grease to the outside of the bearing.

The hub wheel 51 is connected to the output gear 33 forming the parallel shaft gear reducer 30 by spline fitting so as to be rotatable integrally therewith. A flange portion 51a is provided on the outer periphery of the end portion of the hub wheel 51 on the outboard side, and wheels (brake discs and wheels) not shown are attached to the flange portion 51a. Further, a swaged portion 51b formed by swaging and fixing the inner ring 52 is formed at an end portion of the hub wheel 51 on the inboard side. The caulking portion 51b applies a preload to the wheel bearing 50.

An inner raceway surface 55 on the outboard side is formed on the outer circumference of the hub wheel 51, and an inner raceway surface 55 on the inboard side is formed on the outer circumference of the inner ring 52. On the inner circumference of the outer ring 54, double rows of outer raceway surfaces 56 corresponding to both inner raceway surfaces 55, 55 are formed, and a ball track formed by a pair of inner raceway surface 55 and outer raceway surface 56. A plurality of balls 57 are incorporated in the. The outer ring 54 integrally has a flange portion that extends outward in the radial direction from the end portion on the outboard side, and is bolted to the casing 22 via an attachment 58 bolted to this flange portion.

The overall operation mode of the in-wheel motor drive device 21 having the above configuration will be briefly described.

First, in the electric motor unit A, when an alternating current is supplied to the stator 23, the rotor 24 and the motor rotating shaft 25 rotate due to the electromagnetic force generated with the alternating current. The rotation of the motor rotary shaft 25 is reduced in speed by the parallel shaft gear reducer 30 (the input gear 31, the intermediate gear 32, and the output gear 33) in the reducer unit B, and then transmitted to the wheel bearing 50. In this way, the rotation of the motor rotating shaft 25 is transmitted to the wheel bearing 50 after being decelerated by the parallel shaft gear reducer 30. Therefore, even when the low torque, high speed rotating electric motor 26 is adopted, The required torque can be transmitted to the rear wheel 14 (see FIGS. 7 and 8) as a driving wheel.

In the present embodiment, a radial gap type electric motor is adopted as the electric motor 26 that constitutes the electric motor portion A. However, as the electric motor 26, the stator 23 and the rotor 24 are disposed with an axial gap therebetween. You may employ|adopt the so-called axial gap type electric motor arrange|positioned facing.

In the in-wheel motor drive device 21 described above, the reduction gear accommodating chamber 22B of the casing 22 is filled with the lubricating oil 70 (see FIG. 2), and the gears 31 to 33 are driven when the in-wheel motor drive device 21 is driven. The lubricating oil 70 is supplied to each part of the speed reducer section B in accordance with the rotation of the speed reducer section B, whereby the speed reducer section B is lubricated and cooled.

The in-wheel motor drive device 21 of the present embodiment has a main feature of a lubrication mechanism for lubricating and cooling the speed reducer section B, which will be described in detail below.

In order to realize the lightweight and compact in-wheel motor drive device 21, as shown in FIG. 2, the components (the gears 31 to 33, etc.) of the speed reducer section B are densely arranged and the speed reducer chamber 22B is small. It is effective to employ the simplified casing 22 and make the gap between the parallel shaft gear reducer 30 and the casing 22 as small as possible. However, if such a configuration is adopted, a lubrication mechanism that requires an oil pump, oil piping, or the like cannot be installed in the speed reducer section B due to space restrictions. Therefore, in the present embodiment, among the gears 31 to 33 configuring the parallel shaft gear reducer 30, a part of the gear portion 37 of the output gear 33 is constantly immersed in lubricating oil to be in an oil bath state, and the output gear 33 Lubricating oil scraped up by rotation is used to efficiently lubricate and cool the meshing point (final meshing point Mp) between the output gear 33 and the intermediate gear 32, and to lubricate the final meshing point Mp. Oil can be used efficiently to lubricate and cool other gears.

As shown in FIG. 2, the speed reducer chamber 22B of the casing 22 is filled with a predetermined amount of lubricating oil 70 (shown by dotted hatching). Here, the input gear 31, the intermediate gear 32, and the output gear 33 are filled. Of these, the lubricating oil 70 is filled to such an extent that a part of the gear portion 37 of the output gear 33 arranged at the lowermost side can be brought into an oil bath state. Therefore, from the above-mentioned arrangement of the gears 31 to 33, the gear portion 34 of the input gear 31, and the large diameter gear portion 35 and the small diameter gear portion 36 of the intermediate gear 32 are lubricated at the bottom of the reduction gear chamber 22B. Only the gear portion 37 of the output gear 33 does not come into contact with the oil 70, but comes into contact with the lubricating oil 70 accumulated at the bottom of the speed reducer chamber 22B. As a result, it is possible to avoid a decrease in the efficiency of the parallel shaft gear reducer 30 due to an increase in the stirring resistance of the lubricating oil 70.

As described above, from the viewpoint of downsizing the casing 22, the gap between the parallel shaft gear reducer 30 and the casing 22 is set as small as possible. Here, the output gear 33 is arranged in the speed reducer chamber 22B so that the tip of the output gear 33 faces the inner wall surface of the casing 22 via a gap (radial gap) 22Ba having a gap width d=3 to 20 mm. To be done. Further, the intermediate gear 32 is arranged above the output gear 33 so that the tooth tips of the large-diameter gear portion 35 of the intermediate gear 32 face the inner wall surface of the casing 22 through a gap having a gap width similar to the above. To be done. On the other hand, the input gear 31 is arranged on the front side of the vehicle with respect to the intermediate gear 32 and the output gear 33 so that the tip circle C ₁ thereof intersects with the tangent line T of the final meshing point Mp.

The reduction gear chamber 22B is provided with an oil sump forming portion 71 for forming an oil sump 72 before the final meshing point Mp by using the lubricating oil 70 scraped up by the rotation of the output gear 33. As a result, when the lubricating oil 70 stored at the bottom of the speed reducer chamber 22B is scraped up along the gap 22Ba between the output gear 33 and the casing 22 as the output gear 33 rotates, the output gear 33, By the cooperation of the intermediate gear 32 and the oil sump forming portion 71, an oil sump 72, which stores a sufficient amount of lubricating oil 70, is formed before the final meshing point Mp.

In the present embodiment, the casing 22 is integrally provided with a protrusion that protrudes toward the interior of the speed reducer chamber 22B, and the protrusion forms the oil sump formation portion 71. Since the oil sump forming portion 71 can appropriately form the oil sump 72 at a position before the final meshing point Mp, at least a part (in the present embodiment, a part on the free end side of the oil sump forming portion 71). ) Is located on the inner diameter side of the maximum addendum circle (addendum circle of the large diameter gear part 35) C ₂ of the intermediate gear 32. It should be noted that the oil sump forming portion 71 can be configured by a component other than the casing 22. The same applies to other embodiments described later. Examples of parts other than the casing 22 include a fastening member such as a bolt and an oil thermometer.

With the above configuration, when the in-wheel motor drive device 21 is driven (strictly speaking, when the electric motor 26 is rotationally driven in the direction of moving the electric vehicle 11 forward), the speed reducer section B operates as follows. Lubricated and cooled.

The input gear 31, the intermediate gear 32, and the output gear 33 rotate in response to the output of the motor rotation shaft 25 (see the solid arrows for the rotation directions of the gears 31 to 33 ), and the output gear 33 rotates to reduce the speed reducer chamber. When the lubricating oil 70 stored at the bottom of 22B is scraped up along the gap 22Ba between the output gear 33 and the casing 22 (see the white arrow in FIG. 2), the output gear 33, the intermediate gear 32, and By the cooperation of the oil sump forming portion 71, the oil sump 72 in which the sufficient lubricating oil 70 is interposed is formed before the final meshing point Mp. Then, as the output gear 33 continuously rotates, the final meshing point Mp is lubricated/cooled by the lubricating oil 70 successively supplied from the oil sump 72. The lubricating oil 70 supplied to the final meshing point Mp is the rolling bearing 45 (see FIG. 1) axially adjacent to the final meshing point Mp, as well as the rolling bearing on the outboard side that supports the output gear 33. 47 (see FIG. 1) to lubricate and cool the rolling bearings 45, 47.

The lubricating oil 70 supplied to the final meshing point Mp mainly scatters along the tangent line T of the final meshing point Mp to the front side in the rotational direction of the gears 33, 32. Therefore, when both gears 33, 32 rotate, the tip circle C _{1 of} the lubricating oil 70 that lubricates the final meshing point Mp is opposite to the oil sump 72 (in FIG. 2) with the final meshing point Mp interposed therebetween. Is scattered toward the input gear 31 arranged so as to intersect with the tangent line T at the left side of the final meshing point Mp (see the white arrow in FIG. 2) and becomes (the shaft portion of) the input gear 31. Supplied. The lubricating oil 70 successively supplied to the shaft portion of the input gear 31 is not only the meshing portion between the input gear 31 (the gear portion 34 thereof) and the intermediate gear 32 (the large diameter gear portion 35 thereof) but also the output of the input gear 31. It is also supplied to the rolling bearing 43 (see FIG. 1) that supports the end portion on the board side to lubricate them. The lubricating oil 70 supplied to the shaft portion of the input gear 31 scatters and flows down on the inner wall of the casing 22 near the shaft portion due to the rotation of the input gear 31, and the rolling bearing that supports the end portion of the input gear 31 on the inboard side. It is also supplied to 42. Further, if the outer diameters of the rolling bearings 42, 43 supporting the input gear 31 and the tangent line T of the final meshing point Mp intersect, the gear portion 34 of the input gear 31 can be efficiently lubricated/cooled.

As described above, the lubricating oil 70 is carried from the output gear 33 to the input gear 31, and the lubricating oil 70 is supplied to the gear portion 34 of the input gear 31 and the rolling bearings 42 and 43 to lubricate and cool them. As described above, in the present invention, the speed reducer is not required to be installed in the speed reducer section B, or the gears 31 to 33 forming the speed reducer 30 are not provided with the oil supply holes. An input gear 31 (gear portion 34) of the input gear 31, which is disposed at a recessed position of the lubricating oil 70, that is, away from the oil level of the lubricating oil 70 and the output gear 33 in the oil bath state, and which is difficult to sufficiently replenish only by splashing, The lubricating oil 70 can be efficiently supplied to the rolling bearings 42 and 43 that support the gear 31. Therefore, according to the present invention, it is possible to realize the in-wheel motor drive device 21 which is light and compact and which can efficiently lubricate and cool each part of the speed reducer part B and which is highly reliable.

The in-wheel motor drive device 21 according to the embodiment of the present invention has been described above, but the embodiment of the present invention is not limited to this.

For example, as shown in FIG. 3, in the speed reducer unit B, on the tangent line T of the final meshing point Mp, the final meshing point Mp and the input gear 31 (the intermediate gear 32 meshing with the output gear 33, the preceding stage A control unit 73 for controlling the flow of the lubricating oil 70 may be provided between the control unit 73 and the first gear). With this configuration, by appropriately setting the shape and the installation posture of the control unit 73, the supply location and the supply amount of the lubricating oil 70 with respect to the input gear 31 can be arbitrarily adjusted. It is advantageous in improving the lubrication efficiency. Similar to the oil sump forming unit 71, the control unit 73 may be integrally provided with the casing 22, or may be configured by a component other than the casing 22.

Further, as shown in FIG. 4, the oil sump forming portion 71 may be provided so as to be able to divide the lubricating oil 70 scraped up by the rotation of the output gear 33 into two different directions. In this case, the lubricating oil 70 scraped up by the output gear 33 can be used not only for forming the oil sump 72, but also for directly lubricating and cooling the large diameter gear portion 35 of the intermediate gear 32. Become. Thereby, the large-diameter gear portion 35 of the intermediate gear 32 can be efficiently lubricated and cooled. In this case, the lubricating oil 70 scattered above the speed reducer 30 easily adheres to the inner wall of the casing 22, and the lubricant oil 70 adhered to the inner wall of the casing 22 drops along the inner wall 22 of the casing 22 to the entire speed reducer 30. Therefore, the lubricating oil 70 can be not only concentratedly supplied to an arbitrary place but also dispersedly supplied to the entire speed reducer 30. The configuration shown in FIG. 4 has a gap 22Ba formed between the gear portion 37 of the output gear 33 and the casing 22 at the base of the oil sump forming portion 71 shown in FIGS. 2 and 3, and the intermediate gear 32. It is formed by providing a notch 74 for communicating the gap 22Bb formed between the large-diameter gear portion 35 and the casing 22.

Further, in the above, the parallel shaft gear reducer 30 (three shafts) that has the input gear 31, the intermediate gear 32, and the output gear 33, reduces the rotation of the motor rotation shaft 25 in two stages, and transmits the rotation to the wheel bearing portion C. The present invention is applied to a parallel shaft gear reducer 30) of a type, but the present invention relates to a parallel shaft gear having four or more axes, in which one or more intermediate gears are added between the input gear 31 and the intermediate gear 32. It can also be applied to the speed reducer 30. FIG. 5 shows an example thereof and shows a four-axis type parallel shaft gear reducer 30 in which one intermediate gear 39 is added between the input gear 31 and the intermediate gear 32. The intermediate gear 39 shown in FIG. 5 includes a rotary shaft O4 arranged in parallel with the rotary shafts O1 to O3 of the other gears 31 to 33, a large-diameter gear portion 39a meshing with the gear portion 34 of the input gear 31, and an intermediate gear. It has a large diameter gear part 35 of 32 and a small diameter gear part 39b which meshes. The characteristic configuration of the embodiment shown in FIG. 5 is the same as that of the parallel shaft gear reducer 30 according to the first embodiment of the present invention described with reference to FIG.

Further, in the above description, the tooth width of the gear portion 34 of the one gear (the input gear 31 in FIG. 2) arranged before the intermediate gear 32 that meshes with the output gear 33 and the intermediate width that meshes with the gear portion 34 of the input gear 31. Although the tooth width of the large-diameter gear portion 35 of the gear 32 is the same (see FIG. 1), the tooth width of the gear portion 34 of the input gear 31 is as shown in FIG. It may be larger than the tooth width of 35. With this configuration, the lubricating oil 70 mainly scattered in the direction along the tangent line T of the final meshing point Mp can be directly supplied to the gear portion 34 of the input gear 31, so that the input gear 31 It is advantageous in improving lubrication/cooling efficiency.

Further, in the above, the present invention is applied to the in-wheel motor drive device 21 including the electric motor portion A and the speed reducer portion B housed in the casing 22, and the wheel bearing portion C attached to the casing 22. According to the present invention, a vehicle driving device other than the in-wheel motor driving device 21, for example, a casing accommodating the electric motor unit A and the reduction gear unit B is attached to the vehicle body, and the output of the reduction gear unit B is passed through the drive shaft. It can also be applied to a so-called on-board type vehicle drive device that is transmitted to wheels (wheel bearings).

The present invention is not limited to the above-described embodiments, and can be carried out in various forms without departing from the gist of the present invention. That is, the scope of the present invention is defined by the claims, and includes equivalent meanings in the claims and all modifications within the scope.

21 in-wheel motor drive device 22 casing 22B reduction gear chamber 26 electric motor 30 parallel shaft gear reduction gear 31 input gear 32 intermediate gear 33 output gear 34 gear portion 35 large diameter gear portion 36 small diameter gear portion 37 gear portion 50 wheel bearing 70 Lubricating oil 71 Oil sump forming part 72 Oil sump 73 Control part A Electric motor part B Reduction gear part C Wheel bearing part C ₁ Tip circle of input gear C ₂ Maximum tip circle of intermediate gear Mp Engagement point O 1 Rotating shaft O2 rotation axis O3 rotation axis T tangent

Claims (8)

An electric motor unit, a speed reducer unit, and a casing accommodating the electric motor unit and the speed reducer unit, wherein the speed reducer unit is an input gear having rotation shafts arranged in parallel, and one or more intermediate gears. , And a vehicle drive device composed of a parallel shaft gear reducer having an output gear,
The casing is filled with a lubricating oil that places a part of the gear portion of the output gear in an oil bath state,
An oil sump forming portion for forming an oil sump is provided before the meshing point of the output gear and the intermediate gear by using the lubricating oil scraped up by the rotation of the output gear. At least a part of which is located inside a maximum addendum circle of the intermediate gear that meshes with the output gear. The addendum circle of one gear arranged in a stage preceding the intermediate gear that meshes with the output gear and the tangent line of the meshing point intersect on the opposite side of the oil sump across the meshing point. The vehicle drive device according to claim 1. One gear that is arranged in a stage preceding the intermediate gear that meshes with the output gear is arranged on the front side of the vehicle with respect to the meshing point, and the oil sump forming portion is behind the vehicle with respect to the meshing point. The vehicle drive device according to claim 1, wherein the vehicle drive device is disposed on the side. The vehicle drive device according to any one of claims 1 to 3, wherein the input gear and the intermediate gear do not come into contact with a lubricating oil that places a part of a gear portion of the output gear in an oil bath state. The vehicle drive device according to claim 1, wherein the meshing point is located above a rotation axis of the output gear. The tooth width of the gear portion of the one gear arranged at a stage preceding the intermediate gear that meshes with the output gear is larger than the tooth width of the gear portion of the gear that meshes with the one gear. The vehicle drive device according to one item. On the tangent line of the meshing point, between the meshing point and one gear arranged in a stage preceding the intermediate gear meshing with the output gear, for controlling the flow direction of the lubricating oil. The vehicle drive device according to claim 1, further comprising a control unit. The vehicle drive device according to any one of claims 1 to 7, wherein the oil sump formation portion is provided so as to be able to divide the lubricating oil scraped up by the rotation of the output gear into two different directions.

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