JP2019049338A - Vehicle driving device - Google Patents

Abstract

To efficiently lubricate and cool a reduction gear part provided to a vehicle driving device.SOLUTION: In an in-wheel motor driving device 21 as a vehicle driving device, a casing 22 housing a reduction gear part B is filled with lubrication oil 70 for making one part of a gear part 37 of an output gear 33 into an oil bath condition. The device is provided with an oil reservoir formation part 71 for forming an oil reservoir 72 in front of a meshing point Mp of an output gear 33 and an intermediate gear 32 using lubrication oil 70 scraped together with rotation of the output gear 33. At least one of the oil reservoir formation part 71 is positioned on an inner diameter side of a maximum gear tip circle Cof the intermediate gear 32 meshed with the output gear 33.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a vehicle drive system.

  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 portion, a wheel bearing portion rotatably supporting a wheel, a reduction gear portion decelerating the rotation of the electric motor portion and transmitting it to the wheel bearing portion, and the electric motor portion And a casing containing a reduction gear portion, and the reduction gear portion has a plurality of gears (gear shafts), and so-called parallel shaft gear reduction gears in which the rotation axes of the respective gears are arranged in parallel to each other ing.

  The reduction gear portion is usually provided with a lubrication mechanism for lubricating and cooling each portion (particularly, the gear portion of the gear). As this lubrication mechanism, for example, a part of one gear of a plurality of gears is made into an oil bath state, and besides splashing lubricating oil onto other gears as the gears rotate, oil piping extended from an oil pump The nozzle is provided with a nozzle, and the lubricating oil is injected from this nozzle toward a predetermined location (Patent Document 2), and the oil supply hole connected to the tooth bottom is provided in the gear shaft. (Patent Document 3) and the like. In particular, the lubricating mechanisms of Patent Documents 2 and 3 can directly lubricate and cool the gear portion of the gears constituting the parallel-shaft gear reducer, thereby improving the reliability and durability of the parallel-shaft gear reducer. It can be said that it is preferable.

Unexamined-Japanese-Patent No. 2017-65666 JP, 2009-156368, A JP 2012-82945 A

  From the viewpoint of enhancing the running stability of the vehicle, the NVH characteristics, and the like in addition to the mountability to the vehicle, the above-described vehicle drive device is required to be as light and compact as possible. Therefore, in the reduction gear (parallel shaft gear reduction gear) equipped in the vehicle drive apparatus, the component parts are closely arranged, and the gap width between the reduction gear and the casing accommodating the reduction gear is set as small as possible. It has become commonplace. Therefore, the lubricating mechanisms of Patent Documents 2 and 3 which are likely to cause increase in size and complexity of the reduction gear and hence the in-wheel motor drive and increase in cost etc. are applied to the reduction gear of the vehicle drive. Is not realistic.

  In view of the above situation, the present invention is a vehicle drive apparatus to which a parallel shaft gear reduction gear is applied to a reduction gear, and in particular, the reduction gear (of the reduction gear, without increasing the size and complexity of the entire device. It is an object of the present invention to efficiently lubricate and cool gears (gears disposed at a lower position of a reduction gear).

  The present invention invented to achieve the above object comprises an electric motor portion, a reduction gear portion, and a casing accommodating the electric motor portion and the reduction gear portion, and the reduction gear portions have parallel rotation axes. In a vehicle drive comprising a parallel shaft gear reducer having an input gear, one or more intermediate gears, and an output gear arranged, in the casing, a part of the gear portion of the output gear is oil bathed An oil reservoir forming portion for forming an oil reservoir is provided in front of the meshing point between the output gear and the intermediate gear using lubricating oil which is filled with lubricating oil and scraped up with the rotation of the output gear. It is characterized in that at least a part of the reservoir forming portion is located inside (inner diameter side) of the maximum tip circle of the intermediate gear meshed with the output gear. Here, the “tooth tip circle” refers to a circular path (trajectory) drawn by the tooth tip as the gear rotates around its rotation axis.

  According to the above configuration, it is possible to form an oil reservoir in which ample lubricating oil intervenes before the meshing point (final meshing point) of the output gear and the intermediate gear with the rotation of the output gear. From the oil sump, lubricating oil can be supplied one after another towards the final meshing point. Thereby, the final meshing point (the gear portion of the output gear and the gear portion of the intermediate gear meshed therewith) can be efficiently lubricated and cooled.

  When the output gear is rotating, the lubricating oil supplied from the oil reservoir to the final meshing point is mainly on the rotational direction front side of the output gear along the tangent of the final meshing point (ie, the final meshing point Splashes on the opposite side of the oil reservoir). Therefore, the tip line circle of one gear arranged on the front side of the intermediate gear meshing with the output gear and the tangent of the final meshing point intersect on the opposite side to the oil sump across the final meshing point For example, lubricating oil can be efficiently supplied to the one gear. Furthermore, the lubricating oil supplied to the one gear is also supplied to the gear with which it meshes as the one gear rotates. The "one gear arranged in front of the intermediate gear meshing with the output gear" mentioned above refers to a triaxial parallel-shaft gear reduction in which the reduction gear portion is composed of the input gear, one intermediate gear and the output gear. When it is configured as an input gear, and when the reduction gear unit is configured with a parallel shaft gear reducer with four or more axes consisting of an input gear, a plurality of intermediate gears and an output gear, an input gear or It is an intermediate gear.

  The one gear is preferably disposed forward of the final meshing point on the vehicle, and the oil reservoir forming portion is preferably disposed rearward of the final meshing point on the vehicle. According to this configuration, the above-described effects can be effectively obtained when the vehicle equipped with the vehicle drive device moves forward.

  The input gear and the intermediate gear are preferably arranged so as not to be in contact with the lubricating oil that brings a portion of the gear portion of the output gear into the oil bath state. This is to avoid the reduction in the efficiency of the reduction gear due to the increase in the 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 made larger than the tooth width of the gear meshing with the one gear, the lubricating oil splashing in the tangential direction of the final meshing point is made to the gear portion of the one gear. Can be supplied efficiently. At this time, when the tooth width of the one gear and the tooth width of the intermediate gear meshing 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 lubricating oil may be provided on the tangent of the final meshing point, between the final meshing point and the one gear. In this way, by appropriately setting the shape and arrangement of the control unit, it is possible to arbitrarily adjust the supply location and supply amount of the lubricating oil, so it is possible to adjust the position upstream of the intermediate gear that meshes with the output gear. It is advantageous in improving the lubricating efficiency of the gear that is disposed.

  Further, in the above configuration, if the oil reservoir forming portion is provided so that the lubricating oil scraped up with the rotation of the output gear can be divided in two different directions from each other, the lubricating oil scraped up by the output gear is It becomes possible to supply also to parts other than the final meshing point.

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

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the whole structure of the in-wheel motor drive device as a vehicle drive device which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of the arrangement | positioning aspect (layout) of each gear which comprises the parallel axis gear reduction gear shown in FIG. It is a schematic diagram showing the modification of the arrangement mode of each gear which constitutes a parallel axis gear reduction gear. It is a schematic diagram showing the modification of the arrangement mode of each gear which constitutes a parallel axis gear reduction gear. It is a schematic diagram showing the modification of the arrangement mode of each gear which constitutes a parallel axis gear reduction gear. It is a schematic diagram expanding and showing a part of parallel axis gear reduction gears. It is a schematic plan view of the electric vehicle carrying an in-wheel motor drive device. It is a back sectional view of the electric vehicle shown in FIG.

  Hereinafter, embodiments of the present invention will be described based on the drawings.

  First, based on FIG. 7 and FIG. 8, the outline | summary of the electric vehicle 11 which mounts the in-wheel motor drive device which is 1 type of a vehicle drive device is demonstrated. As shown in FIG. 7, the electric vehicle 11 includes a chassis 12, a pair of front wheels 13 functioning as steering wheels, a pair of rear wheels 14 functioning as drive wheels, and an inside for driving the left and right rear wheels 14. And a wheel motor drive device 21. As shown in FIG. 8, the rear wheel 14 is housed inside the wheel housing 15 of the chassis 12 and fixed to the lower part of the chassis 12 via a suspension device 16.

  The suspension device 16 supports the rear wheel 14 by suspension arms extending leftward and right, and absorbs a vibration that the rear wheel 14 receives from the road surface and suppresses a vibration of the chassis 12 by a strut including a coil spring and a shock absorber. At the connection portion of the left and right suspension arms, a stabilizer that suppresses the inclination of the vehicle body at the time of turning or the like is provided. 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 efficiently transmit the driving force of the rear wheel 14 to the road surface.

  In this electric vehicle 11, the in-wheel motor drive device 21 for rotationally driving each of the left and right rear wheels 14 is incorporated inside the left and right wheel housings 15, so the motor, drive shaft, differential gear mechanism, etc. There is no need to provide it. Therefore, the electric vehicle 11 has an advantage that the passenger compartment space can be widely secured, and furthermore, the rotation of the left and right rear wheels 14 can be controlled.

  As described above, the in-wheel motor drive device 21 is not only a rear wheel drive type electric car 11 with the rear wheel 14 as a drive wheel, but also a front wheel drive type electric car with the front wheel 13 as a drive wheel, The present invention can also be applied to a four-wheel drive type electric vehicle in which the front wheel 13 and the rear wheel 14 are drive wheels. Moreover, although the above-mentioned electric vehicle 11 adopts the independent suspension type suspension system 16, the suspension system of the suspension system 16 can also be designed arbitrarily.

  In order to improve the traveling stability and the NVH characteristics of the electric vehicle 11, it is necessary to reduce the unsprung weight. Moreover, in order to expand the passenger compartment space of the electric vehicle 11, it is necessary to miniaturize the in-wheel motor drive device 21. Then, the in-wheel motor drive device 21 as shown in FIG. 1 is employ | adopted.

  As shown in FIG. 1, an in-wheel motor drive device 21 which is a kind of vehicle drive device includes an electric motor unit A for generating a driving force, and a reduction gear unit B for decelerating and outputting rotation of the electric motor unit A. And a wheel bearing unit C for transmitting the output of the reduction gear unit B to the wheels (rear wheels 14 as drive wheels: see FIG. 7). The electric motor portion A and the reduction gear portion B are accommodated in the casing 22, and the wheel bearing portion C is attached to the casing 22. In the following description, when the in-wheel motor drive device 21 is attached to the inside of the wheel housing 15, the sides that are the outer side in the vehicle width direction and the inner side in the vehicle width direction are also referred to as the outboard side and the inboard side. In FIG. 1, the left side in the drawing is the outboard side, and the right side in the drawing is the inboard side.

  The casing 22 has a motor accommodating chamber 22A accommodating the electric motor unit A and a reduction gear accommodating chamber 22B accommodating the reduction gear unit B. Although the casing 22 of the illustrated example is provided integrally with the motor storage chamber 22A and the reduction gear storage chamber 22B, in actuality, the electric motor portion A and the reduction gear portion B to each chamber 22A, 22B are provided. It is often divided at an arbitrary position in consideration of incorporation and often linked by an appropriate means.

  The electric motor unit A includes a stator 23 fixed to the casing 22, a rotor 24 disposed opposite to the inside of the stator 23 with a radial gap therebetween, and a motor rotation shaft 25 having the rotor 24 mounted on the outer periphery thereof. A radial gap type electric motor 26 is configured. The motor rotation shaft 25 is rotatably supported on the casing 22 by rolling bearings 40 and 41 disposed at two places separated in the axial direction, and rotates at a rotational speed of about 10,000 times per minute. It is possible.

  As shown in FIG. 1, the reduction gear portion B includes a so-called parallel shaft gear reduction gear 30 having a plurality of gears (gear shafts), and rotation axes of the gears are arranged in parallel to each other. The parallel-shaft gear reducer 30 according to the present embodiment includes an input gear 31, an intermediate gear 32, and an output gear 33. The rotation axes (rotation centers) O1 to O3 of the gears 31 to 33 are as shown in FIG. The straight lines connecting the rotation axes O1 to O3 are arranged in a triangular shape. More specifically, the rotation axis O3 of the output gear 33 is disposed at the bottom, the rotation axis O2 of the intermediate gear 32 is disposed at the top, and the rotation axis O1 of the input gear 31 is substantially the same as the rotation axes O2 and O3. It is placed in the middle. By arranging the gears 31 to 33 in such a mode, a compact reduction gear 30 can be realized.

  Further, 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 the reduction in the efficiency of the reduction gear 30 due to the increase in the stirring resistance of the lubricating oil 70 filled in the reduction gear chamber 22B of the casing 22 in order to lubricate and cool the reduction gear portion B.

  In this parallel shaft gear reducer 30, the gear portion 34 of the input gear 31 meshes with the large diameter gear portion 35 of the intermediate gear 32, and the small diameter gear portion 36 of the intermediate gear 32 and the gear portion 37 of the output gear 33 It is engaged. The number of teeth of the large diameter gear portion 35 of the intermediate gear 32 is greater 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 More than the number of teeth of the small diameter gear portion 36 of the gear 32. From such a configuration, the parallel shaft gear reducer 30 of the present embodiment decelerates the rotation of the motor rotation shaft 25 in two steps and outputs (transmits) the same to the wheel bearing portion C.

  The input gear 31 is integrally and rotatably connected to the motor rotation shaft 25 by spline fitting, and is rotatably supported on the casing 22 by rolling bearings 42 and 43 which are disposed at two axial locations apart from each other. There is. The intermediate gear 32 is provided by rolling bearings 44 and 45 spaced apart at two axial positions, and the output gear 33 is separated by rolling bearings 46 and 47 spaced apart at two axial positions. The casing 22 is rotatably supported.

  A helical gear is used for the input gear 31, the intermediate gear 32, and the output gear 33 of this embodiment (see FIG. 6). The helical gear has an advantage that the noise at the time of meshing is quiet and the torque fluctuation is small because the number of teeth meshing simultaneously and the tooth contact is dispersed. Therefore, the use of a helical gear is advantageous in realizing a parallel shaft gear reducer 30 which is quiet and has excellent torque transmission efficiency.

  As shown in FIG. 1, the wheel bearing portion C is configured by a so-called inner ring rotation type wheel bearing 50. The wheel bearing 50 is a double-row angular contact ball bearing provided with an inner member 53 consisting of 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. Seal members are provided at both axial ends of the wheel bearing 50 in order to prevent foreign matter from entering the bearing internal space and grease leakage to the outside of the bearing.

  The hub wheel 51 is integrally rotatably connected to an output gear 33 constituting the parallel shaft gear reducer 30 by spline fitting. A flange portion 51a is provided on an outer periphery of an end portion of the hub wheel 51 on the outboard side, and a wheel (a brake disk and a wheel) (not shown) is attached to the flange portion 51a. Further, at an end portion on the inboard side of the hub wheel 51, a crimped portion 51b formed by crimping and fixing the inner ring 52 is formed. The crimped portion 51 b applies a preload to the wheel bearing 50.

  An inner raceway surface 55 on the outboard side is formed on the outer periphery of the hub wheel 51, and an inner raceway surface 55 on the inboard side is formed on the outer periphery of the inner ring 52. On the inner periphery of the outer ring 54, a double-row outer raceway 56 corresponding to both inner raceways 55, 55 is formed, and a ball track formed by a pair of the inner raceway 55 and the outer raceway 56 Have a plurality of balls 57 incorporated therein. The outer ring 54 integrally includes a flange portion extending radially outward from an end portion on the outboard side, and is bolted to the casing 22 via an attachment 58 bolted to the flange portion.

  The entire 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 rotation shaft 25 are rotated by the electromagnetic force generated accordingly. The rotation of the motor rotation shaft 25 is reduced by the parallel shaft gear reduction gear 30 (the input gear 31, the intermediate gear 32 and the output gear 33) in the reduction gear portion B and transmitted to the wheel bearing 50. As described above, since the rotation of the motor rotation shaft 25 is decelerated by the parallel shaft gear reducer 30 and transmitted to the wheel bearing 50, even when the low-torque, high-speed rotation type electric motor 26 is adopted, The necessary torque can be transmitted to the rear wheel 14 (see FIGS. 7 and 8) as a drive wheel.

  In the present embodiment, a radial gap type electric motor is employed as the electric motor 26 constituting the electric motor unit A, but as the electric motor 26, the stator 23 and the rotor 24 are separated via an axial gap A so-called axial gap type electric motor disposed oppositely may be adopted.

  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. As the lubricating oil 70 is supplied to each part of the reduction gear unit B with the rotation of the reduction gear unit B, the reduction gear unit B is lubricated and cooled.

  The in-wheel motor drive device 21 of the present embodiment is mainly characterized in the lubrication mechanism for lubricating and cooling the reduction gear portion B, and the details thereof will be described below.

  In order to realize a lightweight and compact in-wheel motor drive device 21, as shown in FIG. 2, the components (gears 31 to 33, etc.) of the reduction gear unit B are densely arranged, and the reduction gear chamber 22B is small. It is effective to adopt the integrated casing 22 and to make the clearance between the parallel shaft gear reducer 30 and the casing 22 as small as possible. However, if such a configuration is adopted, it is not possible to install a lubrication mechanism that requires an oil pump, oil piping or the like in the reduction gear portion B due to space limitations. Therefore, in the present embodiment, among the gears 31 to 33 constituting 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. Lubrication that efficiently lubricates and cools the meshing point (final meshing point Mp) between the output gear 33 and the intermediate gear 32 using lubricating oil scraped up with rotation, and lubricates the final meshing point Mp Oil can be used efficiently to lubricate and cool other gear parts etc.

  As shown in FIG. 2, the reduction gear chamber 22B of the casing 22 is filled with a predetermined amount of lubricating oil 70 (indicated by dotted hatching). Here, the input gear 31, the intermediate gear 32, and the output gear 33 Among them, the lubricating oil 70 is filled to such an extent that a part of the gear portion 37 of the output gear 33 disposed at the lowermost side can be brought into an oil bath state. Therefore, according to the arrangement of the gears 31 to 33 described above, the gear portion 34 of the input gear 31, and further, 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. It does not contact the oil 70, and only the gear portion 37 of the output gear 33 contacts the lubricating oil 70 accumulated at the bottom of the reduction gear chamber 22B. Thereby, the efficiency reduction of parallel axis gear reduction gear 30 by the increase in the agitation resistance of lubricating oil 70 can be avoided.

As described above, in order to make the casing 22 compact, 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 disposed in the reduction gear chamber 22B such that the tip of the output gear 33 faces the inner wall surface of the casing 22 via a gap (radial gap) 22Ba with a gap width d of about 3 to 20 mm. Be done. Further, the intermediate gear 32 is disposed above the output gear 33 so that the tip of the large diameter gear portion 35 of the intermediate gear 32 faces the inner wall surface of the casing 22 with a gap having the same gap width as the above. Be done. On the other hand, the input gear 31, the addendum circle C ₁ is as intersects the tangent T of the last meshing point Mp, is disposed on the front side of the vehicle than the intermediate gear 32 and the output gear 33.

  An oil reservoir forming portion 71 for forming an oil reservoir 72 in front of the final meshing point Mp is provided in the reduction gear chamber 22B by using the lubricating oil 70 scraped up with the rotation of the output gear 33. Thus, when the lubricating oil 70 stored at the bottom of the reduction gear 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, The cooperation of the intermediate gear 32 and the oil reservoir forming portion 71 forms an oil reservoir 72 formed by storing ample lubricating oil 70 before the final meshing point Mp.

In the present embodiment, the casing 22 is integrally provided with a projecting portion that protrudes to the indoor side of the reduction gear chamber 22B, and the projecting portion constitutes an oil reservoir forming portion 71. The oil reservoir forming portion 71 can at least partially (in the present embodiment, a portion on the free end side of the oil reservoir forming portion 71) in order to enable the oil reservoir 72 to be appropriately formed at a position before the final meshing point Mp. ) is provided to be located on the inner diameter side of the addendum circle) C ₂ up to the tip circle of the intermediate gear 32 (large-diameter gear portion 35. The oil reservoir forming portion 71 can also be configured with parts other than the casing 22. The same applies to the other embodiments described later. As parts other than casing 22, fastening members, such as a bolt, and an oil temperature gauge can be mentioned, for example.

  With the above configuration, when the in-wheel motor drive device 21 is driven (strictly, when the electric motor 26 is rotationally driven in the direction of moving the electric vehicle 11 forward), the reduction gear unit B is as follows It is 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 (the rotation directions of the gears 31 to 33 refer to the filling arrows), and the reduction gear chamber rotates with the rotation of the output gear 33. When lubricating oil 70 stored at the bottom of 22B is scraped up along gap 22Ba between output gear 33 and casing 22 (see the white arrow in FIG. 2), output gear 33, intermediate gear 32, and By the cooperation of the oil reservoir forming portion 71, an oil reservoir 72 in which a rich lubricating oil 70 intervenes is formed before the final meshing point Mp. Then, as the output gear 33 continues to rotate, the final meshing point Mp is lubricated and cooled by the lubricating oil 70 supplied one after another from the oil reservoir 72. The lubricating oil 70 supplied to the final meshing point Mp is a rolling bearing on the outboard side that supports the output gear 33, in addition to the rolling bearing 45 (see FIG. 1) disposed axially adjacent to the final meshing point Mp. 47 (see FIG. 1) to lubricate and cool these rolling bearings 45, 47.

The lubricating oil 70 supplied to the final meshing point Mp mainly scatters forward in the rotational direction of the gears 33 and 32 along the tangent T of the final meshing point Mp. Therefore, when the gears 33 and 32 rotate, the lubricating oil 70 that has lubricated the final meshing point Mp has a tip circle C ₁ opposite to the oil reservoir 72 across the final meshing point Mp (in FIG. 2 Is scattered toward the input gear 31 disposed so as to intersect the tangent T at the final meshing point Mp) (see the white arrow in FIG. 2), Supplied. The lubricating oil 70 supplied one after another to the shaft portion of the input gear 31 includes the meshing portion between (the gear portion 34 of) the input gear 31 and the (large diameter gear portion 35 of) the intermediate gear 32. The roller bearing 43 (see FIG. 1) supporting the board side end is also supplied to lubricate these. The lubricating oil 70 supplied to the shaft portion of the input gear 31 scatters and flows down to the inner wall of the casing 22 near the shaft portion by the rotation of the input gear 31, and the rolling bearing supports the inboard end of the input gear 31 42 are also supplied. Further, if the outer diameters of the rolling bearings 42 and 43 supporting the input gear 31 intersect the tangent T of the final meshing point Mp, the gear portion 34 of the input gear 31 can be efficiently lubricated and cooled.

  As described above, the lubricating oil 70 is conveyed 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 reduction gear unit B is not provided with the oil pump or the oil pipe, and the reduction gears are not provided with the oil supply holes or the like in the gears 31 to 33 constituting the reduction gear 30. The input gear 31 (the gear portion 34 of the gear 31), which is disposed away from the back surface of the 30, that is, away from the oil surface of the lubricating oil 70 and the output gear 33 in the oil bath state and sufficient splashing alone is difficult The lubricating oil 70 can be efficiently supplied to the rolling bearings 42 and 43 supporting the gear 31. Therefore, according to the present invention, it is possible to realize the highly reliable in-wheel motor drive device 21 capable of efficiently lubricating and cooling each part of the reduction gear unit B while being lightweight and compact.

  As mentioned above, although the in-wheel motor drive device 21 which concerns on one Embodiment of this invention was demonstrated, embodiment of this invention is not limited to this.

  For example, as shown in FIG. 3, the reduction gear portion B is on the tangent line T of the final meshing point Mp, and before the final meshing point Mp and the input gear 31 (the intermediate gear 32 meshing with the output gear 33). A control unit 73 for controlling the flow of the lubricating oil 70 may be provided between the first gear and the gear). In this way, by appropriately setting the shape and the installation attitude of the control unit 73, it becomes possible to arbitrarily adjust the supply location and supply amount of the lubricating oil 70 to the input gear 31. It is advantageous in increasing the lubrication efficiency. Similar to the oil reservoir forming portion 71, the control portion 73 may be provided integrally with the casing 22 or may be configured by parts other than the casing 22.

  Further, as shown in FIG. 4, the oil reservoir forming portion 71 can also be provided so that the lubricating oil 70 which is scraped up with the rotation of the output gear 33 can be divided in two different directions. In this case, the lubricating oil 70 scraped up by the output gear 33 can be used to form the oil reservoir 72, and can also be used to directly lubricate and cool 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. Further, in this case, the lubricating oil 70 scattered to the upper side of the reduction gear 30 easily adheres to the inner wall of the casing 22, and the lubricating oil 70 adhered to the inner wall of the casing 22 drops on the entire reduction gear 30 while traveling along the inner wall 22 of the casing 22. Therefore, the lubricating oil 70 can be distributed to the entire reduction gear 30 in addition to being concentratedly supplied to any place. In the configuration shown in FIG. 4, the gap 22Ba formed between the gear portion 37 of the output gear 33 and the casing 22 at the base of the oil reservoir forming portion 71 shown in FIGS. 2 and 3 and the intermediate gear 32. It forms by providing the notch 74 for making the clearance gap 22Bb formed between the large diameter gear part 35 and the casing 22 connect.

  Furthermore, in the above description, parallel-shaft gear reducer 30 (three-shaft having gear 31, intermediate gear 32 and output gear 33) for reducing the rotation of motor rotation shaft 25 in two stages and transmitting it to wheel bearing C The present invention is applied to a parallel shaft gear reducer 30) of the type, but the present invention is a four or more parallel shaft gear with one or more intermediate gears added between the input gear 31 and the intermediate gear 32. It is also possible to apply to the reduction gear 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 has a rotation axis O4 disposed parallel to the rotation axes 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 And a small diameter gear portion 39 b that meshes with the 32 large diameter gear portions 35. The characteristic configuration of the embodiment shown in FIG. 5 follows the parallel-shaft gear reducer 30 according to the first embodiment of the present invention described with reference to FIG.

  Further, in the above, the tooth width of the gear portion 34 of one gear (the input gear 31 in FIG. 2) disposed in the front stage of the intermediate gear 32 meshing with the output gear 33 and the intermediate gear meshing 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 the large diameter gear portion of the intermediate gear 32, as shown in FIG. It may be larger than the tooth width of 35. In this way, it is possible to directly supply the lubricating oil 70 that mainly scatters in the direction along the tangent line T of the final meshing point Mp to the gear portion 34 of the input gear 31. It is advantageous in improving the lubrication and cooling efficiency.

  Further, in the above, the present invention is applied to the in-wheel motor drive device 21 provided with the electric motor portion A and the reduction gear portion B accommodated in the casing 22 and the wheel bearing portion C attached to the casing 22. In the present invention, a vehicle drive device other than the in-wheel motor drive 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 through the drive shaft. The present invention can also be applied to a so-called on-board type vehicle drive device that is transmitted to the wheels (wheel bearings).

  The present invention is not limited to the embodiment described above, and may be embodied in various forms without departing from the scope of the present invention. That is, the scope of the present invention is indicated by the claims, and further includes the equivalent meaning described in the claims and all the modifications within the scope.

21 In-wheel motor drive device 22 casing 22B reducer 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 reservoir forming portion 72 Oil reservoir 73 Control portion A Electric motor portion B Reducer portion C Wheel bearing portion C ₁ Tooth top circle of input gear C ₂ Maximum tooth top circle of intermediate gear Mp Tooth point O 1 Rotational shaft O2 rotation axis O3 rotation axis T tangent

Claims (8)

An input gear including one or more intermediate gears, comprising: an electric motor portion; a reduction gear portion; and a casing accommodating the electric motor portion and the reduction gear portion, wherein the reduction gear portion is provided with parallel rotation axes. And a vehicle drive system comprising a parallel shaft gear reducer having an output gear,
The casing is filled with a lubricating oil that brings a portion of the gear portion of the output gear into an oil bath state,
An oil reservoir forming portion for forming an oil reservoir is provided in front of a meshing point between the output gear and the intermediate gear using lubricating oil scraped up with the rotation of the output gear, and the oil reservoir forming portion A vehicle drive system according to any one of the preceding claims, wherein at least a portion of the wheel is located inside the maximum tip circle of the intermediate gear meshing with the output gear.   The tooth tip circle of one gear arranged at the front stage of the intermediate gear meshing with the output gear and the tangent of the meshing point intersect at the opposite side to the oil reservoir across the meshing point The vehicle drive device according to claim 1.   One gear disposed in front of the intermediate gear meshing with the output gear is disposed forward of the meshing point on the front side of the vehicle, and the oil reservoir forming portion is disposed rearward of the vehicle on the meshing point The vehicle drive device according to claim 1 or 2 disposed on the side.   The vehicle drive system according to any one of claims 1 to 3, wherein the input gear and the intermediate gear do not come in contact with a lubricating oil that brings a part of the gear portion of the output gear into an oil bath state.   The vehicle drive system according to any one of claims 1 to 4, wherein the meshing point is positioned above a rotation axis of the output gear.   The tooth width of a gear portion of one gear disposed at a front stage with respect to the intermediate gear meshing with the output gear is larger than the tooth width of a gear gear portion meshing with the one gear. The vehicle drive device according to one item.   For controlling the flow direction of the lubricating oil between the meshing point and one gear arranged upstream of the intermediate gear meshing with the output gear, which is tangent to the meshing point The vehicle drive device as described in any one of Claims 1-6 which provided the control part.   The vehicle drive system according to any one of claims 1 to 7, wherein the oil reservoir forming portion is provided so as to be able to divide lubricating oil scraped up with the rotation of the output gear in two different directions.

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