JP2013040659A - Drive unit for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive unit for an in-wheel motor type electric vehicle which can rigidly fix a hub unit 15 and a housing 16 even if the thickness of the housing 16 is thinned and its axial length is shortened.SOLUTION: The drive unit for the electric vehicle comprises; an electric motor 11; a speed reduction unit 12 which is driven by an output of the electric motor 11; the hub unit 15 rotated by an output member 14 which is coaxial with an input shaft 13 of the speed reduction unit 12; and the housing 16 for accommodating the electric motor 11 and the speed reduction unit 12. A flange 22 is arranged at an outside member 21 of the hub unit 15, and the flange 22 is bolt-fastened to a ring gear 42 in the housing 16 with the wall face of the housing 16 therebetween, thus thinning the thickness of the housing itself by bolt-fastening, reducing weight and shortening the axial length.

Description

  The present invention relates to an electric vehicle drive device using an electric motor as a drive source, and more particularly to an in-wheel motor drive device for an electric vehicle.

  2. Description of the Related Art A conventionally known in-wheel motor drive device for an electric vehicle includes an electric motor, a reduction unit that receives the motor output, and a hub unit that is rotated by the reduction output of the reduction unit ( Patent Document 1).

  In the electric vehicle drive device disclosed in Patent Document 1, an electric motor is disposed on the radially outer side of the speed reduction unit, and the speed reduction unit is a planetary gear type that is arranged in two stages in the axial direction. The reason why the reduction units are arranged in two stages is to increase the reduction ratio.

  In a general configuration of a planetary gear type reduction unit, a sun gear is provided coaxially on an input shaft, and a ring gear is fixed coaxially around the input shaft. A plurality of pinion gears are interposed between the sun gear and the ring gear, and pinion pins that support the pinion gears are connected to a common carrier. The carrier is integrated with the output member.

  The deceleration unit revolves while the pinion gear rotates by the rotation of the input shaft. The rotational speed of the revolution is decelerated from the rotational speed of the input shaft, and the decelerated rotation is transmitted to the output member through the carrier. The reduction ratio in this case is Zs / (Zs + Zr). However, Zs is the number of teeth of the sun gear, and Zr is the number of teeth of the ring gear.

  The input shaft of the deceleration unit is supported by two bearings arranged in the axial direction, that is, an inboard side bearing and an outboard side bearing. The inboard side bearing is attached to the housing of the reduction unit, and the outboard side bearing is attached to the output member of the reduction unit. The housing is supported by the vehicle body via the suspension, and the output member is coupled and integrated with the inner member of the hub unit to drive the wheel.

  In the electric vehicle driving apparatus, the load acting on the input shaft of the speed reduction unit is supported by the housing on the inboard side via the inboard side bearing, and on the outboard side via the outboard side bearing. Supported by the output member of the deceleration unit.

JP 2001-32888 A

  By the way, in the in-wheel motor type electric vehicle drive device, in order to suppress the unsprung weight as much as possible, the housing that houses the electric motor and the speed reduction unit is made of a light alloy, for example, an aluminum alloy.

  The hub unit must be firmly fixed to the vehicle body side in order to receive a turning load from the tire.

  The hub unit and the housing are usually fastened by bolts. However, when fastening bolts to a housing formed of an aluminum alloy, it is necessary to set the bolt fastening length long in order to secure the strength. The housing part to be formed must be thick.

  As the thickness of the housing increases, the weight increases and the axial length also increases.

  An in-wheel motor type drive device for an electric vehicle must be accommodated in a wheel, so that the axial length needs to be shortened.

  Accordingly, the present invention provides an in-wheel motor type electric vehicle drive device that can firmly fix the hub unit and the housing even if the thickness of the housing is reduced and the axial length is reduced. To do.

  In order to solve the above-described problems, the present invention provides an electric motor, a reduction unit driven by the output of the electric motor, a hub unit rotated by an output member coaxial with the input shaft of the reduction unit, and an electric motor And a housing for housing the speed reduction unit, the outer member of the hub unit is provided with a flange, and the flange is sandwiched between the wall surfaces of the housing and bolted to the fixing member inside the housing. Is.

  According to the above configuration, since the fixing member for fastening the bolt is provided inside the housing, there is no need to provide a bolt hole in the housing itself, so the thickness of the housing itself can be reduced, and the weight reduction and axial length can be reduced. It is possible to reduce the thickness.

  When the reduction unit is a planetary gear type comprising a sun gear and a ring gear provided coaxially on the input shaft, a plurality of pinion gears provided equidistantly in the circumferential direction between the sun gear and the ring gear, and a carrier holding the pinion gear A bolt member can be formed in the ring gear to form a fixing member.

  When the ring gear is used as a fixing member, the ring gear is bolted to the housing, so that a key stopper for fixing the ring gear to the housing is not required, and the shape of the ring gear can be simplified and manufactured at low cost. be able to.

  As described above, in the present invention, the outer member of the hub unit is provided with a flange, and the flange is clamped to the fixing member inside the housing with the wall surface of the housing interposed therebetween. The thickness can be reduced, and the weight can be reduced and the axial length can be reduced.

FIG. 1 is a cross-sectional view of the first embodiment. 2A, 2B, and 2C are front views of ring gears that can be used in the first embodiment. FIG. 3 is a partially enlarged sectional view of the above. 4 is an enlarged cross-sectional view taken along line X1-X1 of FIG. FIG. 5 is a perspective view of the same spacer. 6 is a cross-sectional view taken along line X2-X2 of FIG. FIG. 7 is a cross-sectional view showing a part of the second embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
[Embodiment 1]

  As shown in FIG. 1, the electric vehicle drive device according to the first embodiment includes an electric motor 11, a speed reduction unit 12 driven by the output of the electric motor 11, and an output member coaxial with the input shaft 13 of the speed reduction unit 12. The main unit is a hub unit 15 that is rotated by the motor 14 and a housing 16 that houses the electric motor 11 and the speed reduction unit 12.

  The housing 16 has a cylindrical portion 17 and a front end portion 18 in the radial direction provided at the front end thereof (the end portion on the outboard side, the left end portion in the figure). The front end portion 18 is opened at the center portion, and the rear end portion of the outer member 21 of the hub unit 15 is fitted into the open portion 19, and the flange 22 is located inside the front end portion 18 with the front end portion 18 interposed therebetween. The bolt 23 is fixed to a bolt hole 41 formed in the ring gear 42. In this way, the bolt 23 that fixes the flange 22 of the outer member 21 of the hub unit 15 is fastened to the ring gear 42 that is located inside the front end 18 with the front end 18 sandwiched therebetween, so Since it is not necessary to form a bolt hole for fastening the bolt 23 on the wall surface of the front end portion 18 and only the insertion hole of the bolt 23 is formed, the wall surface of the front end portion 18 of the housing 16 is made to the minimum necessary thickness. Therefore, the weight can be reduced and the axial length can be reduced.

  The bolt holes 41 of the bolts 23 formed in the ring gear 42 are evenly provided so that the pitch circle diameter is positioned on the outer diameter side of the root diameter of the ring gear 42 as shown in FIG. ing.

  Further, in order to reduce the weight of the ring gear 42, as shown in FIG. 2B, the outer diameter side thickness of the ring gear 42 between the bolt holes 41 is made thin so that the whole is formed into a petal shape. Also good.

  Further, as shown in FIG. 2C, a bolt hole 68 for fixing the partition wall member 20 may be formed in the bolt hole 41 of the ring gear 42 and the ring gear 42.

  Between the flange 22 of the hub unit 15 and the front end 18 of the housing 16, in order to prevent leakage of the lubricating oil in the speed reduction unit 12 at the outer diameter position of the bolt insertion hole formed in the front end 18 of the housing 16. In addition, an O-ring 69 is fitted.

  Inside the front end 18 of the housing 16, a partition wall base 18 a having a larger diameter than the opening hole 19 is provided concentrically with the open hole 19. A dish-shaped partition member 20 is fixed to the partition base 18a by bolts 20a. A center hole 25 is provided at the center of the partition member 20. The center hole 25 faces the outer diameter surface of the input shaft 13 with a radial gap. A partition wall 24 is formed by the partition base 18a and the partition member 20 connected and fixed thereto. The partition wall 24 has a function of partitioning the housing 16 into a housing space for the electric motor 11 on the outer diameter side and a housing space for the reduction unit 12 on the inner diameter side.

  Suspension connecting portions 27 protruding in the axial direction are provided at two positions symmetrical with respect to the rear end edge of the cylindrical portion 17 of the housing 16. In the conventional automobile, the hub unit 15 is connected to the suspension via the knuckle of the vehicle body. However, in the case of the first embodiment, the suspension unit 27 which is a part of the housing 16 is connected to the suspension on the vehicle body side. Can be directly linked.

  Since the housing 16 functions as a knuckle, it can be said that the housing 16 has a structure in which the knuckle is integrated. In this case, when the outer member 21 of the hub unit 15 needs to be replaced, it is not necessary to remove the housing 16 from the suspension, and the replacement can be performed by simply removing the bolt 23.

  In the illustrated case, the electric motor 11 is a brushless DC motor of a radial gap type, and is arranged with a stator 28 fixed to the inner surface of the cylindrical portion 17 of the housing 16 and a radial gap on the inner surface of the stator 28. And the rotor 29. The rotor 29 is fitted and fixed to the input shaft 13 by a rotor support member 31.

  The rotor support member 31 includes a support member cylindrical portion 31a (see FIG. 3) fitted to the inner diameter portion of the rotor 29, and a support member disk portion 31b extending rearward along the partition wall 24 and bent in the inner diameter direction. Composed. A boss portion 31 c is provided on the inner diameter portion of the support member disk portion 31 b, the boss portion 31 c is fitted to the input shaft 13, and is fixed to the input shaft 13 by the key stopper 35.

  The boss portion 31c is inserted into the inner diameter side of the center hole 25 of the partition wall 24, and an oil seal member 36 is interposed between the center hole 25 and the boss portion 31c (see FIG. 2). By the partition wall 24 and the oil seal member 36, the storage portion of the electric motor 11 and the storage portion of the speed reduction unit 12 are partitioned and oil-sealed. As a result, the lubricating oil on the speed reduction unit 12 side is prevented from moving to the electric motor 11 side, the electric motor 11 side is kept dry, and the problem that the lubricating oil hinders the rotation of the rotor 29 is eliminated.

  The speed reduction unit 12 is of a planetary gear type. As shown in FIG. 3, the input shaft 13 and the output member 14, a sun gear 39 attached to the outer diameter surface of the input shaft by a key stopper 38, and the sun gear 39 The ring gear 42 disposed along the inner diameter surface of the boundary portion between the partition wall base 18a and the partition wall member 20 is provided at three locations at equal intervals in the circumferential direction between the ring gear 42 and the sun gear 39. And a pinion gear 43. The pinion gear 43 is supported by a pinion pin 45 through a needle roller bearing 44. Since the ring gear 42 is fixed by the bolts 23 that fasten and fix the flange 22 of the hub unit 15 as described above, the outer diameter surface of the ring gear 42 does not require a key-stop portion for preventing rotation, so the shape is simple. This is advantageous in terms of cost.

  The output member 14 has a coupling shaft portion 47 at an end portion on the outboard side. The coupling shaft portion 47 is splined to the inner member 46 of the hub unit 15 and fixed by the nut 50. On the inner end side of the coupling shaft portion 47, a bearing support portion 49 that is formed to have a larger diameter than that is provided.

  On the inboard side of the output member 14, a pair of flanges 52, 53 facing in the axial direction are provided with an interval slightly larger than the width of the pinion gear 43 in the axial direction. Bridges 54 for connecting the flanges 52 and 53 to each other in the axial direction are provided at three circumferentially equidistant positions. The flanges 52 and 53 have a carrier function in the planetary gear type reduction unit 12.

  By providing the bridges 54 at equidistant positions in the circumferential direction, the output member 14 is smoothly rotated, and as a result, the rotation accuracy of the rotor 29 of the electric motor 11 is improved through the output member 14 and the input shaft 13.

  A shaft hole 51 is provided at the center of the end surface of the flange 53 on the inboard side at the center coaxial with the coupling shaft portion 47. The shaft hole 51 has a length that reaches the bearing support portion 49.

  Three pinion gear storage portions 55 partitioned in the circumferential direction are provided by a pair of flanges 52 and 53 facing in the axial direction and three bridges 54 in the circumferential direction (see FIG. 4). The pinion gear 43 is housed in each pinion gear housing portion 55, and both end portions of the pinion pin 45 are inserted into the flanges 52 and 53 and fixed by set screws 56. It can be said that both the flanges 52 and 53 are coupled and integrated not only by the bridge 54 but also by the pinion pin 45.

  Since the flanges 52 and 53 are integrated by the bridge 54, the support rigidity at both ends of the pinion pin 45 is improved.

  A thrust plate 57 is interposed between both side surfaces of each pinion gear 43 and each flange 52, 53 in order to ensure smooth rotation of the pinion gear 43.

  A pair of rolling bearings 58 and 59 for supporting the input shaft 13 are provided on both sides of the sun gear 39 between the inner diameter surfaces of the flanges 52 and 53 and the outer diameter surface of the input shaft 13 facing the inner diameter surfaces. Provided. By adopting this configuration, the rolling bearings 58 and 59 are both supported by the same output member 14.

  Further, as shown in FIG. 3, the axial positional relationship between the rolling bearings 58 and 59 and the fitting portion between the support member disk portion 31b and the input shaft 13 is such that each of the rolling bearings 58 and 59 is out. The support structure for the input shaft 13 disposed on the board side is a so-called cantilever support structure.

  On the other hand, in the conventional case (Patent Document 1), the bearing on the outboard side is arranged on the outboard side from the fitting portion between the support member disk portion and the input shaft, whereas the bearing on the inboard side Since the bearing is attached to the housing, it is on the inboard side from the fitting portion. Therefore, the support structure of the input shaft is a so-called both-end support structure. The cantilevered support structure has a feature that the structure is simplified as compared with the both-end supported structure.

  In the rolling bearing 58 on the outboard side, the inner ring is engaged with the stepped portion 61 provided on the input shaft 13, and the outer ring is engaged with the stepped portion 62 provided on the inner diameter surface of the shaft hole 51. The inboard side rolling bearing 59 has its inner ring engaged with the boss 31c and the key stopper 35 of the rotor support member 31, and the outer ring engaged with the retaining ring 63.

  A sun gear 39 is interposed between the inner rings of the rolling bearings 58 and 59, and a spacer 64 is interposed between the outer rings. The spacer 64 prevents both rolling bearings 58, 59 from being displaced in a direction approaching each other.

  As shown in FIGS. 4 and 5, the spacer 64 is formed in a cylindrical state, and is provided with window holes 65 that match the shape of the pinion gear storage portion 55 at three locations in the circumferential direction. The 65 closed portions 66 are formed in a shape that follows the shape of the bottom surface of the bridge 54. The spacer 64 is interposed between the rolling bearings 58 and 59 on the inner diameter surface of the shaft hole 51 in a posture in which each window hole 65 matches the pinion gear housing portion 55 (see FIG. 4). The screw 67 is screwed into the positioning hole 60 (see FIG. 5) for positioning.

  By appropriately setting the axial length of the spacer 64, the bearing preload applied to both the rolling bearings 58 and 59 can be controlled, and a simple fixed position preload structure is obtained.

  When viewed in the radial direction, the speed reduction unit 12 is arranged in the radial direction accommodated on the inner diameter side of the electric motor 11 with the partition wall 24 interposed therebetween, and the axial direction can be made compact compared to the case where the reduction unit 12 is arranged in the axial direction.

  Here, the partition wall 24 will be described in more detail. The partition wall cylindrical portion 24b is interposed between the electric motor 11 arranged in the radial direction and the speed reduction unit 12, and the partition disk portion 24a is connected to the speed reduction unit 12. And the support member disk portion 31b. The peripheral edge of the center hole 25 faces the outer diameter surface of the boss 31c of the rotor support member 31 with a predetermined interval. The ring gear 42 of the speed reduction unit 12 is fitted to the inner diameter surface of the partition wall base 18 a and is fixed by a bolt 23 that fixes the flange 22 of the hub unit 15. As shown in FIG. 2C, a bolt hole 68 may be formed in the ring gear 42 and fixed to the wall surface of the front end portion 18 of the housing 16.

  An oil seal member 36 is interposed between the peripheral edge portion of the center hole 25 and the boss portion 31c. Due to the presence of the oil seal member 36 and the partition wall 24, the storage space for the electric motor 11 in the housing 16 and the storage space for the speed reduction unit 12 are partitioned. As a result, the lubricating oil on the speed reduction unit 12 side is prevented from moving to the electric motor 11 side, and the electric motor 11 side is kept dry, thereby preventing the lubricating oil from obstructing the rotation of the rotor 29. The

  In the above description, both the flanges 52 and 53 of the output member 14 have been described as being coupled and integrated by both the bridge 53 and the pinion pin 45. However, as shown in FIGS. Can be configured separately from the output member 14 and both can be coupled and integrated by a pinion pin 45.

  The deceleration unit 12 is filled with lubricating oil. The lubricating oil is sealed on the electric motor 11 side by the oil seal member 36, and the hub unit 15 side is interposed between the bearing support portion 49 of the output member 14 and the outer member 21 and is sealed by the oil seal member 70. Sealed.

  As shown in FIG. 1, the electric motor 11 and the speed reduction unit 12 are within the range of the axial length of the cylindrical portion 17 of the housing 16 except for the rear end portion (inboard side end portion) of the input shaft 13. Therefore, the rear cover 73 is fitted to the rear end portion of the cylindrical portion 17 via the seal member 60. A heat dissipation fin 74 is provided on the outer surface of the rear cover 73 so as to dissipate heat of the electric motor 11 to the outside.

  A rotation sensor 75 is provided between the center hole of the rear cover 73 and the input shaft 13 passing through the center hole, and the portion is closed by the sensor cover 77. The illustrated rotation sensor 75 is a resolver, and its sensor stator 75 a is fixed to the center hole of the rear cover 73, and the sensor rotor 75 b is attached to the input shaft 13.

  A lead wire 79 of the sensor stator 75 a is connected to a connector insertion portion 78 provided outside the sensor cover 77. As the rotation sensor 75, a Hall element or the like can be used in addition to the resolver. A connector (not shown) of a signal line cable is inserted into the connector insertion portion 78.

  The rotation angle of the input shaft 13 detected by the rotation sensor 75 is input to a control circuit (not shown) via the signal line cable and used for rotation control of the electric motor 11.

  A power supply terminal box 76 for supplying power to the stator 28 of the electric motor 11 is provided at a position eccentric to the outer peripheral edge of the rear cover 73 and at a 90-degree position different from that of the suspension connecting portion 27 ( (See FIG. 6).

  The power terminal box 76 is formed in a cylindrical shape penetrating the rear cover 73, and a work hole 80 is provided in the outer peripheral portion. The work hole 80 is normally closed by a lid 81. Inside, a power supply terminal 82 is provided at a position facing the work hole 80. A lead wire 83 connected to the winding of the stator 28 is connected to the power terminal 82, and a connection terminal of the power cable 84 is connected to the same power terminal 82. These are fixed by a tightening screw 85. A cable hole 84a is provided at the rear end of the power terminal box 76, and the power cable 84 is inserted through the cable hole 84a.

  As shown in FIG. 1, the hub unit 15 includes the inner member 46 in which the hub 86 is integrated, a pair of inner rings 87 fitted to the outer diameter surface of the inner member 46, and the flange 22. , An outer ring 88 fitted to the inner diameter surface of the outer member 21 and having a double-row track, and a double-row ball 89 to be interposed between the inner ring 87 and the outer ring 88. Is done. The wheels are attached to the hub 86 by hub bolts 90.

  The connecting shaft portion 47 of the output member 14 is splined to the inner diameter surface of the inner member 46, and the distal end portion of the connecting shaft portion 47 protruding outward from the inner member 46 is fixed by the nut 50 as described above. The Instead of the fixing means using the nut 50, fixing means such as press-cut joining, diameter expansion caulking, or rocking caulking can be employed.

  The hub unit 15 is a so-called first generation type, but a second generation or third generation type can be used.

  The electric vehicle drive device of Embodiment 1 is configured as described above, and the operation thereof will be described next.

  When the accelerator of the driver's seat is operated to drive the electric motor 11, the input shaft 13 is rotated integrally with the rotation of the rotor 29, and the motor output is input to the speed reduction unit 12. When the sun gear 39 rotates integrally with the input shaft 13, the reduction unit 12 revolves while the pinion gear 43 rotates. When the pinion pin 45 is decelerated and rotated at the revolution speed, the output member 14 is rotated at the deceleration output indicated by the reduction ratio.

  The inner member 46 of the hub unit 15 is rotated integrally with the coupling shaft portion 47 of the output member 14, and the wheel attached to the hub 86 is driven.

  The input shaft 13 is supported on both sides of the pinion gear 43 by an outboard side rolling bearing 58 and an inboard side rolling bearing 59 and rotates. These rolling bearings 58 and 59 are all attached to flanges 52 and 53 integrated with the output member 14 (in the case of FIG. 6, the flanges 52 and 53 integrated via the pinion pin 45). Therefore, the radial vibration and impact transmitted from the wheel to the output member 14 via the hub unit 15 are simultaneously applied to both rolling bearings 58 and 59 in the same manner.

  As a result, any rolling bearings 58 and 59 can be prevented from being subjected to an unbalanced load, so that the rotational accuracy and durability can be improved, and the noise of the rotating sound can be suppressed.

  Since both ends of the pinion pin 45 of the pinion gear 43 are supported by the flanges 52 and 53, the support rigidity is improved as compared with the conventional case where the pinion pin 45 is cantilevered.

  The rolling bearings 58 and 59 are arranged on the outboard side of the fitting portion between the support member 31 of the rotor 29 and the input shaft 13, that is, the keying portion 35, and compared to the conventional case arranged on both sides thereof. The support structure is simple and easy to assemble.

  Further, since the lubricating oil in the speed reduction unit 12 is sealed to the electric motor 11 side by the oil seal member 36 and to the hub unit 15 side by the oil seal member 70, the lubricating oil is supplied to the electric motor 11 side and the hub unit side. Leakage is prevented. As a result, the rotation of the rotor 29 is not hindered on the electric motor 11 side, and the lubricating oil is prevented from leaking outside through the hub unit 15 on the hub unit 15 side.

  The heat generated by driving the electric motor 11 is effectively radiated by the fins 74 of the rear cover 73.

The rotation angle of the input shaft 13 necessary for the rotation control of the electric motor 11 is detected by the rotation angle sensor 75 and input to the control device.
[Embodiment 2]

  In the second embodiment shown in FIG. 7, the configuration of the hub unit 15 is the third generation as compared with the case of the first embodiment. In the first embodiment, the oil seal member 70 provided between the hub unit 15 and the speed reduction unit 12 is omitted, and the hub unit 15 and the speed reduction unit 12 are lubricated with the same lubricating oil. Since other configurations are the same as those of the first embodiment, common portions are denoted by the same reference numerals, and description thereof is omitted.

DESCRIPTION OF SYMBOLS 11 Electric motor 12 Deceleration unit 13 Input shaft 14 Output member 15 Hub unit 16 Housing 17 Cylindrical part 18 Front end part 18a Bulkhead base 19 Open part 20 Bulkhead member 20a Bolt 21 Outer member 22 Flange 23 Bolt 24 Bulkhead 24a Bulkhead disk part 24b Bulkhead cylindrical portion 25 Center hole 27 Suspension connecting portion 28 Stator 29 Rotor 31 Rotor support member 31a Support member cylindrical portion 31b Support member disc portion 31c Boss portion 32 Flange cylindrical portion 35 Key stop portion 36 Oil seal member 38 Key stop portion 39 Sun gear 41 Bolt hole 42 Ring gear 43 Pinion gear 44 Needle roller bearing 45 Pinion pin 46 Inner member 47 Coupling shaft portion 49 Bearing support portion 50 Nut 51 Shaft hole 52, 53 Flange 54 Bridge 55 Pinion gear YA storage part 56 set screw 57 thrust plate 58, 59 rolling bearing 60 positioning hole 61, 62 stepped part 63 retaining ring 64 spacer 65 window hole 66 closing part 67 set screw 68 bolt hole 69 O-ring 70 oil seal member 71 groove 72 Closing screw 73 Rear cover 74 Fin 75 Rotation sensor 75a Sensor stator 75b Sensor rotor 76 Power supply terminal box 76a Power supply terminal 77 Sensor cover 78 Connector insertion part 79 Insertion hole 80 Work hole 81 Lid 82 Power supply terminal 83 Lead wire 84 Power supply cable 84a Cable Hole 85 Clamping screw 86 Hub 87 Inner ring 88 Outer ring 89 Ball 89a, 89b Hub bearing 90 Hub bolt

Claims (11)

  For an electric vehicle comprising: an electric motor; a reduction unit driven by the output of the electric motor; a hub unit rotated by an output member coaxial with an input shaft of the reduction unit; and a housing for housing the electric motor and the reduction unit A drive device for an electric vehicle, wherein a flange is provided on an outer member of the hub unit, and the flange is clamped to a fixing member inside the housing with a wall surface of the housing interposed therebetween.   The reduction gear unit is a planetary gear type comprising a sun gear and a ring gear provided coaxially on an input shaft, a plurality of pinion gears provided equidistantly in the circumferential direction between the sun gear and the ring gear, and a carrier holding the pinion gear. The drive device for an electric vehicle according to claim 1, wherein the fixing member is a ring gear in which a bolt hole is formed.   The drive device for an electric vehicle according to claim 2, wherein the bolt holes formed in the ring gear are arranged uniformly such that the pitch circle diameter is located on the outer diameter side of the root circle diameter.   The electric vehicle drive device according to claim 2 or 3, wherein the outer diameter side thickness of the ring gear between the bolt holes is reduced to form a petal shape as a whole.   The drive device for an electric vehicle according to any one of claims 2 to 4, wherein a bolt hole for fixing the partition wall member is formed in the ring gear.   The electricity according to any one of claims 1 to 6, wherein the speed reduction unit is disposed on an inner diameter side of the electric motor, and a housing portion for the speed reduction unit and the electric motor is partitioned by a partition wall provided in the housing. Driving device for automobiles.   The drive device for an electric vehicle according to claim 6, wherein the partition wall is configured by a partition base portion provided on the housing and a partition member connected and fixed to the partition base portion.   The drive device for an electric vehicle according to claim 7, wherein an oil seal member is disposed between a partition wall base provided in the housing and an input shaft of the speed reduction unit.   The O-ring is fitted between the flange of the outer member of the hub unit and the wall surface of the front end of the housing to prevent leakage of lubricating oil in the reduction unit. The drive device for electric vehicles as described.   The drive device for an electric vehicle according to any one of claims 1 to 9, wherein an oil seal member is provided between an outer member of the hub unit and an output member of the speed reduction unit.   The oil seal member between the outer member of the hub unit and the output member of the speed reduction unit is omitted, and the hub unit and the speed reduction unit are lubricated with the same lubricating oil. A drive device for an electric vehicle according to claim 1.

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