JP2016186320A - Motor drive device with automobile speed reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor drive device with an automobile speed reducer capable of reducing a number of press-in components of a dust cover and an oil seal installed between an opening portion of a speed reducer casing pulling out an output shaft and the output shaft.SOLUTION: A sealing portion 36 configuring a labyrinth seal is provided between an opening portion 35c of a speed reducer casing and an output shaft, thereby making the sealing portion 36 function as a dust cover. The sealing portion 36 is formed by a slinger 38 composed of a cylindrical externally fitting fixing portion 38a pressed in an outer surface of the output shaft, and a flange portion 38b opposing between an end surface of the opening portion 35c of the speed reducer casing and the flange portion 38b through a labyrinth clearance. A slide lip portion 40d of an oil seal 40 installed to a space portion between the opening portion 35c of the speed reducer casing and the output shaft is installed to the slinger 38, thereby reducing a number of seal components.SELECTED DRAWING: Figure 5

Description

  In this invention, a speed reducer that decelerates the power of a motor and transmits it to drive wheels is housed in a speed reducer casing, and an automobile having an output shaft lead-out port that connects the speed reducer and drive wheels is provided in the speed reducer casing. The present invention relates to a motor drive device with a speed reducer.

  Patent Documents 1 and 2 disclose a motor drive device with a reduction gear for an automobile that includes two electric motors and a reduction gear for independently driving left and right drive wheels.

  As shown in FIG. 11, this conventional motor drive device with a reduction gear for an automobile includes left and right electric motors 101 that individually drive left and right drive wheels, and two reduction gears 102 that reduce the rotation of the electric motor 101. The two reduction gears 102 are arranged in the center of the left and right electric motors 101.

  As shown in FIG. 11, the speed reducer 102 includes an input gear shaft 123 having an input gear to which power is transmitted from the motor shaft 112, a large-diameter gear that meshes with the input gear of the input gear shaft 123, and a small-diameter that meshes with the output gear. A plurality of intermediate gear shafts 124 having gears, and an output shaft having an output gear, which is pulled out from the reduction gear casing 128 and transmits a driving force to the drive wheels via a drive shaft including a constant velocity joint 126 and an intermediate shaft 127. 125 is a parallel gear reducer.

Japanese Patent Laid-Open No. 11-243664 US2012 / 0304790A1

  By the way, as shown in FIG. 11, the speed reducer casing 128 of the motor drive device with a speed reducer for an automobile is provided with an opening 130 for pulling out the output shaft 125, and between the opening 130 and the output shaft 125. In this space, an oil seal 131 is installed so that the lubricating oil sealed in the reduction gear casing 128 does not leak.

  This oil seal 131 is generally installed between the outer diameter surface of the outer joint member 126a of the constant velocity joint 126 provided on the output shaft 125 and the inner diameter surface of the opening 130 of the reduction gear casing 128, When the constant velocity joint 126 is replaced, if the constant velocity joint 126 is pulled out, the lubricating oil sealed in the reduction gear casing 128 leaks out.

  On the other hand, as shown in FIG. 12, a sealing function is provided between the outer joint member 126a of the constant velocity joint 126 and the opening 130 of the reduction gear casing 128 in order to prevent dust (water) from entering from the outside. Some dust covers 132 are provided.

  In the case where the dust cover 132 having a sealing function shown in FIG. 12 is provided, the output shaft 125 and the opening in the speed reducer casing 128 are further opened in order to prevent leakage of the lubricating oil when the constant velocity joint 126 is pulled out. An oil seal 131 is provided between the portion 130 and the dust cover 132.

  The dust cover 132 includes a slinger 132a that is press-fitted into the outer diameter portion of the outer joint member 126a of the constant velocity joint 126, and an annular seal plate 132b that is press-fitted into the inner peripheral surface of the opening 130 of the reduction gear casing 128. .

  In addition, an oil seal 131 that prevents leakage of lubricating oil when the constant velocity joint 126 is pulled out includes a core bar 131a that is press-fitted into the inner peripheral surface of the opening 130 of the reduction gear casing 128, and the core bar 131a. The seal member 131b is mounted on the inner peripheral surface and is in sliding contact with the outer peripheral surface of the output shaft 125.

  As shown in FIG. 12, in the conventional case where the dust cover 132 and the oil seal 131 are provided separately, the press-fitting parts (slinger 132a, seal plate 132b, cored bar 131a) are provided in three places with only the output shaft 125 on one side. Therefore, there is a problem that the assembly becomes complicated.

  Accordingly, the present invention provides a motor drive device with a reduction gear for an automobile that can reduce the number of press-fitted parts of a dust cover and an oil seal installed between an opening of a reduction gear casing that pulls out an output shaft and the output shaft. Is to provide.

  In order to solve the above-mentioned problems, the present invention accommodates a speed reducer that reduces the power of a motor and transmits it to a drive wheel in the speed reducer casing, and connects the speed reducer and the drive wheel to the speed reducer casing. In the motor drive device with a reduction gear for an automobile provided with an opening for drawing out the output shaft, a sealing portion constituting a labyrinth seal is provided between the opening of the reduction gear casing and the output shaft. .

  The sealing portion is formed by a slinger composed of a cylindrical outer fixing portion that is press-fitted into the outer surface of the output shaft, and a flange portion that faces the end surface of the opening of the reduction gear casing via a labyrinth gap. be able to.

  The flange portion of the slinger is formed with a plurality of annular portions extending in the end face direction of the opening portion of the reduction gear casing, and a concave portion into which the annular portion is fitted is formed on the end face of the opening portion of the reduction gear casing. A labyrinth gap may be formed between the recess and the recess.

  By forming a concave groove in the outer diameter end surface of the flange portion of the slinger, or forming a chamfer inclined to the drive wheel side, water adhering to the outer diameter end surface of the slinger flange portion is blown off by centrifugal force. Since it becomes easy, the penetration | invasion of the water to a labyrinth clearance gap can be prevented more effectively.

  The sealing portion includes an annular portion formed on an end surface of the opening of the reduction gear casing and extending to the outer diameter surface of the outer joint member of the constant velocity joint constituting the output shaft, and an inner diameter surface of the annular portion and a labyrinth gap. It can also be formed by the outer diameter surface of the constant velocity joint which opposes.

  It is preferable to install an oil seal in the space between the opening of the reduction gear casing and the output shaft.

  The oil seal can be provided with a side lip portion that is in sliding contact with the flange portion of the slinger, or a side lip portion that is in sliding contact with the outer joint member of the constant velocity joint.

  As described above, according to the present invention, since the sealing portion constituting the labyrinth seal is provided between the opening of the reduction gear casing and the output shaft, the labyrinth seal functions as a dust cover, and dust from the outside Intrusion of (water) can be prevented.

  The sealing part that functions as a dust cover is composed of a cylindrical outer fitting fixing part that is press-fitted into the outer surface of the output shaft, and a flange part that faces the end face of the opening of the reduction gear casing via a labyrinth gap. By attaching the side lip part of the oil seal that is formed by the slinger and installed in the space between the opening of the reducer casing and the output shaft to this slinger, the number of seal parts can be reduced and assembly is easy become.

It is a cross-sectional top view which shows embodiment of the motor drive device with a reduction gear for motor vehicles of the 2 motor type to which this invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view showing an example of an electric vehicle using a two-motor type motor drive device with a reduction gear for an automobile according to the present invention. It is the end elevation which looked at the gear train of the reduction gear of the embodiment of FIG. 1 from the axial direction. FIG. 2 is an enlarged cross-sectional plan view of the speed reducer of FIG. 1. FIG. 2 is an enlarged cross-sectional plan view showing a portion of an opening that pulls out an output shaft of the reduction gear of FIG. 1. It is an expanded transverse plane view which shows another example of the part of the opening part which pulls out the output shaft of the reduction gear to which this invention is applied. It is an expanded transverse plane view which shows another example of the part of the opening part which pulls out the output shaft of the reduction gear to which this invention is applied. It is an expanded transverse plane view which shows another example of the part of the opening part which pulls out the output shaft of the reduction gear to which this invention is applied. It is an expanded transverse plane view which shows another example of the part of the opening part which pulls out the output shaft of the reduction gear to which this invention is applied. It is an expansion cross-sectional top view which shows another example of the opening part which draws out the output shaft of the reduction gear to which this invention is applied. It is a cross-sectional top view which shows the motor drive device with a conventional motor type reduction gear for motor vehicles. It is an expansion cross-sectional top view which shows an example of the part of the opening part which pulls out the output shaft of the conventional reduction gear.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
A motor drive device A with a reduction gear for an automobile shown in FIG. 1 has a reduction gear casing 20 that houses two reduction gears 2L and 2R in parallel on the left and right sides, and two electric motors on the left and right sides of the reduction gear casing 20. 1L and 1R motor casings 3L and 3R are fixedly arranged.

  The electric vehicle B shown in FIG. 2 is a front-wheel drive system, and is a two-motor type vehicle deceleration that independently drives a chassis 41, front wheels 42 as drive wheels, rear wheels 43, and left and right drive wheels. The motor drive device A with a two-motor type automobile reduction gear is mounted on the chassis 41 at the center position of the left and right front wheels 42 which are drive wheels. The driving force of the motor drive device A with a reduction gear is transmitted to the front wheels 42 which are left and right driving wheels via a drive shaft composed of a constant velocity joint 15 and an intermediate shaft 16.

  As a mounting form of the two-motor type motor drive device A with a reduction gear for automobiles, a rear wheel drive system or a four wheel drive system may be used in addition to the front wheel drive system shown in FIG.

  As shown in FIG. 1, the left and right electric motors 1L and 1R in the two-motor type motor drive device A with a reduction gear for an automobile are accommodated in motor casings 3L and 3R.

  The motor casings 3L and 3R are cylindrical motor casing main bodies 3aL and 3aR, and outer walls 3bL and 3bR which close the outer surfaces of the motor casing main bodies 3aL and 3aR, and the speed reducer 2L inside the motor casing main bodies 3aL and 3aR. The inner wall 3cL and 3cR are separated from 2R. The inner walls 3cL and 3cR of the motor casing bodies 3aL and 3aR are provided with openings for drawing out the motor shaft 12a.

  As shown in FIG. 1, the electric motors 1L and 1R are of a radial gap type in which a stator 11 is provided on the inner peripheral surface of the motor casing bodies 3aL and 3aR, and a rotor 12 is provided at an interval from the stator 11. doing. Although not shown, the motor type may be an axial gap type.

  The rotor 12 has a motor shaft 12a in the center, and the motor shaft 12a is drawn from the openings of the inner side walls 3cL and 3cR of the motor casing bodies 3aL and 3aR to the speed reducers 2L and 2R, respectively. A seal member 13 is provided between the openings of the motor casing bodies 3aL and 3aR and the motor shaft 12a.

  The motor shaft 12a is rotatably supported by the rolling bearings 14a and 14b on the inner side walls 3cL and 3cR and the outer side walls 3bL and 3bR of the motor casing bodies 3aL and 3aR (FIG. 1).

  As shown in FIG. 1, a speed reducer casing 20 that accommodates two speed reducers 2L and 2R provided in parallel in the left and right is a central casing 20a and left and right side casings 20bL fixed to both side surfaces of the central casing 20a. , 20bR three-piece structure.

  By fixing the side surface of the side casings 20bL and 20bR of the reduction gear casing 20 on the outboard side and the inner side walls 3cL and 3cR of the motor casing bodies 3aL and 3aR of the electric motors 1L and 1R with a plurality of bolts 29, the reduction gears are obtained. Two electric motors 1L and 1R are fixedly arranged on the left and right sides of the casing 20 (FIG. 1).

  As shown in FIG. 1, a partition wall 21 is provided at the center of the center casing 20a. The reduction gear casing 20 is divided into right and left parts by the partition wall 21, and independent left and right accommodation chambers for accommodating the two reduction gears 2L, 2R are provided in parallel.

  As shown in FIGS. 1 and 4, the speed reducers 2L and 2R are provided symmetrically and have input gear shafts 23L and 23R having an input gear 23a to which power is transmitted from the motor shaft 12a, and the input gear 23a. Intermediate gear shafts 24L and 24R having a large diameter gear 24a meshing with the output gear 25a and a small diameter gear 24b meshing with the output gear 25a, and an output gear 25a, which are pulled out from the speed reducer casing 20 through the constant velocity joint 15 and the intermediate shaft 16. And a parallel gear reducer provided with output shafts 25L and 25R for transmitting a driving force to the drive wheels. The left and right input gear shafts 23L, 23R, intermediate gear shafts 24L, 24R, and output shafts 25L, 25R are arranged coaxially.

  Both ends of the input gear shafts 23L, 23R of the speed reducers 2L, 2R roll into bearing fitting holes 27a formed on both the left and right sides of the partition wall 21 of the central casing 20a and bearing fitting holes 27b formed in the side casings 20bL, 20bR. The bearings 28a and 28b are rotatably supported.

The end portions on the outboard side of the input gear shafts 23L and 23R are drawn outward from the opening portions 27c provided in the side casings 20bL and 20bR, and the openings 27c and the outer end portions of the input gear shafts 23L and 23R are connected to each other. An oil seal 31 is provided to prevent leakage of the lubricating oil sealed in the speed reducers 2L and 2R and intrusion of muddy water from the outside.
The input gear shafts 23L and 23R have a hollow structure, and the motor shaft 12a is inserted into the hollow input gear shafts 23L and 23R. The input gear shafts 23L and 23R and the motor shaft 12a are coupled to each other by a spline (including the serrations).

  The intermediate gear shafts 24L and 24R are stepped gears having a large-diameter gear 24a meshing with the input gear 23a and a small-diameter gear 24b meshing with the output gear 25a on the outer peripheral surface.

  At both ends of the intermediate gear shafts 24L and 24R, rolling bearings 34a and 34b are formed into bearing fitting holes 32a formed on both surfaces of the partition wall 21 of the central casing 20a and bearing fitting holes 32b formed on the side casings 20bL and 20bR. Is supported through.

  The output shafts 25L and 25R have large-diameter output gears 25a and roll into bearing fitting holes 35a formed on both surfaces of the partition wall 21 of the central casing 20a and bearing fitting holes 35b formed on the side casings 20bL and 20bR. It is supported by bearings 37a and 37b.

  Outboard-side ends of the output shafts 25L and 25R are drawn out of the reduction gear casing 20 through openings 35c formed in the side casings 20bL and 20ObR, and the outboard-side ends of the output shafts 25L and 25R are drawn out. The shaft portion 15b of the outer joint member 15a of the constant velocity joint 15 is splined to the outer peripheral surface of the portion (see FIGS. 1 and 5).

  The constant velocity joint 15 coupled to the output shafts 25L and 25R is connected to the drive wheels via the intermediate shaft 16 (FIG. 2).

The input gear shafts 23L and 23R, the intermediate gear shafts 24L and 24R, and the output shafts 25L and 25R of the left and right reduction gears 2L and 2R are coaxially arranged.
The arrangement of the gears of the input gear shafts 23L and 23R, the intermediate gear shafts 24L and 24R, and the output shafts 25L and 25R of the speed reducers 2L and 2R is as shown in FIG. FIG. 3 shows the right speed reducer 2R. The arrangement is the same for the left reduction gear 2L.

  As shown in FIGS. 1 and 5, the output shafts 25L and 25R end portions on the outboard side are pulled out from the openings 35c formed in the side casings 20bL and 20bR, and the output shafts 25L and 25R are pulled out from the openings 35c. The shaft portion 15b of the outer joint member 15a of the constant velocity joint 15 is splined to the end portion of 25R.

  A sealing portion 36 constituting a labyrinth seal is provided at the end of the opening 35c of the side casings 20bL and 20bR of the reduction gear casing 20 and the shaft portion 15b of the outer joint member 15a of the constant velocity joint 15. FIG. 5 partially shows the opening 35c of the right side casing 20bR.

As shown in FIG. 5, the sealing portion 36 includes a cylindrical outer fitting fixing portion 38a that is press-fitted into the outer surface of the shaft portion 15b of the outer joint member 15a of the constant velocity joint 15 that is splined to the outer surface of the output shaft 25R. The cross section formed by the flange portion 38b facing the end surface of the opening portion 35c via the labyrinth gap is formed by an L-shaped steel slinger 38.

  The flange portion 38b of the slinger 38 is formed with a plurality of annular portions 38c extending in the end surface direction of the opening portion 35c of the reduction gear casing 20, and the annular portion 38c is fitted to the end surface of the opening portion 35c of the reduction gear casing 20. A recess 38d is formed, and a gap between the annular portion 38c and the recess 38d forms a labyrinth gap.

  In the embodiment shown in FIG. 5, the shaft portion 15b of the outer joint member 15a of the constant velocity joint 15 attached to the outer surface of the output shaft 25R is enclosed in the speed reducer casing 20 when it is extracted from the output shaft 25R. An oil seal 40 is mounted between the inner diameter surface of the opening 35c of the reduction gear casing 20 and the outer diameter surface of the output shaft 25R so that the lubricating oil does not leak out.

  The oil seal 40 includes a metal core 40a and a seal member 40b that is vulcanized and bonded to the metal core 40a. The metal core 40a is formed in an L-shaped cross section including a cylindrical portion press-fitted into the inner diameter surface of the opening 35c and an annular portion facing the flange portion 38b of the slinger 38.

  The seal member 40b is provided with two radial lips 40c that contact the outer diameter surface of the output shaft 25R and side lips 40d that contact the flange portion 38b of the slinger 38. A garter spring is mounted on the inner side of the two radial lips 40c to improve the sealing performance.

  In the embodiment shown in FIG. 6, an extension portion 38 e extending to the outer diameter end surface side of the flange portion 38 b of the slinger 38 is provided on the outer diameter portion of the end portion 35 c of the speed reducer casing 20, and the extension portion 38 e and the slinger 38. A labyrinth gap is also formed between the outer diameter end surface of the flange portion 38b. The extension part 38e covers the flange part 38b of the slinger 38, and the sealing performance is further improved.

  The embodiment shown in FIG. 7 is a modification of the embodiment shown in FIG. 5, and is an example in which a concave groove 38 f is formed on the outer diameter end surface of the flange portion 38 b of the slinger 38. This embodiment is intended to prevent water from entering the labyrinth gap more effectively by collecting water in the concave groove 38f. The water collected in the concave groove 38f is caused by centrifugal force. Played away.

  The embodiment shown in FIG. 8 is a modification of the embodiment shown in FIG. 5, and by forming a chamfer 38 g inclined toward the drive wheel on the outer diameter end surface of the flange portion 38 b of the slinger 38, In this example, the labyrinth effect is further improved by preventing water adhering to the outer diameter end face from flowing toward the labyrinth gap. The chamfer 38g extends to the end surface of the opening 35c of the speed reducer casing 20.

  The embodiment shown in FIG. 9 is a modification of the embodiment shown in FIG. 5, and the annular portion 38 c provided on the flange portion 38 b of the slinger 38 and the end face of the opening portion 35 c of the reduction gear casing 20 are provided with an annular portion. This is an example in which the labyrinth effect is further improved by preventing the water adhering to the flange portion 38b from flowing in the direction of the labyrinth gap by making the concave portion 38d into which the 38c fits into an inclined surface inclined toward the drive wheel.

  FIG. 10 is an embodiment in which the end portion of the output shaft 25R is a hollow female hole, and the shaft portion 15b of the outer joint member 15a of the constant velocity joint 15 is a male shaft. In this embodiment, an annular portion 38h extending to the outer diameter surface of the outer joint member 15a of the constant velocity joint 15 is formed on the end surface of the opening 35c of the speed reducer casing, and the inner diameter surface of the annular portion 38h and the constant velocity joint 15 are formed. This is an example in which the sealing portion 36 is formed so as to face the outer diameter surface of the outer joint member 15a through a labyrinth gap.

  In the example of FIG. 10, the intrusion of water is more effectively prevented by forming a plurality of annular grooves 38 i on the outer diameter surface of the outer joint member 15 a of the constant velocity joint 15.

  The above embodiment has been described by taking the two-motor type motor drive device A with a reduction gear for an automobile as an example, but it can also be applied to a one-motor type motor drive device with a reduction gear for an automobile.

  The drive format is not limited to pure EV, but may be HV (hybrid vehicle) or PHV (plug-in hybrid vehicle).

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. The scope of the present invention is claimed. The equivalent meanings recited in the claims, and all modifications within the scope.

1L, 1R: Electric motor 2L, 2R: Reducer 3L, 3R: Motor casing 3aL, 3aR: Motor casing body 3bL, 3bR: Outer wall 3cL, 3cR: Inner wall 11: Stator 12: Rotor 12a: Motor shaft 13: Seal Members 14a, 14b: Rolling bearing 15: Constant velocity joint 15a: Outer joint member 15b: Shaft 16: Intermediate shaft 20: Reduction gear casing 20a: Central casing 20bL, 20bR: Side casing 21: Partition walls 23L, 23R: Input gear Shaft 23a: Input gear 24L, 24R: Intermediate gear shaft 24a: Large diameter gear 24b: Small diameter gear 25L, 25R: Output shaft 25a: Output gear 27a, 27b: Bearing fitting hole 27c: Openings 28a, 28b: Rolling bearing 29 : Bolt 31: Oil seals 32a and 32b: Receiving fitting hole 34a, 34b: Rolling bearing 35a, 35b: Bearing fitting hole 35c: Opening 36: Sealing part 37a, 37b: Rolling bearing 38: Slinger 38a: Outer fitting fixing part 38b: Flange part 38c: Ring part 38d: recess 38e: extension 38f: groove 38g: chamfer 38h: annular portion 38i: annular groove 40: oil seal 40a: core metal 40b: seal member 40c: radial lip 40d: side lip 41: chassis 42: front wheel 43 : Rear wheel A: Motor drive unit B with reduction gear for automobiles: Electric car

Claims (9)

  For automobiles in which a reduction gear that reduces the power of the motor and transmits it to the drive wheels is housed in the reduction gear casing, and an opening is provided in the reduction gear casing for drawing out the output shaft that connects the reduction gear and the drive wheels. A motor drive device with a reduction gear for an automobile, wherein a sealing portion constituting a labyrinth seal is provided between an opening of the reduction gear casing and an output shaft.   The sealing portion is formed by a slinger composed of a cylindrical outer fitting fixing portion that is press-fitted into the outer surface of the output shaft, and a flange portion that faces the end surface of the opening portion of the reduction gear casing through a labyrinth gap. The motor drive apparatus with a reduction gear for automobiles according to claim 1.   The flange portion of the slinger is formed with a plurality of annular portions extending in the end face direction of the opening portion of the reduction gear casing, and a concave portion into which the annular portion is fitted is formed on the end face of the opening portion of the reduction gear casing. The motor drive device with a reduction gear for an automobile according to claim 2, wherein a labyrinth gap is formed between the recess and the recess.   The motor drive device with a reduction gear for an automobile according to claim 2 or 3, wherein a concave groove is formed in an outer diameter end face of the flange portion of the slinger.   The motor drive device with a reduction gear for an automobile according to claim 2 or 3, wherein a chamfer inclined toward the drive wheel is formed on an outer diameter end face of the flange portion of the slinger.   The sealing portion is formed on the end face of the opening of the reduction gear casing and extends to the outer diameter surface of the outer joint member of the constant velocity joint constituting the output shaft, and the inner diameter surface of the annular portion and the labyrinth gap The motor drive device with a reduction gear for an automobile according to claim 1, comprising an outer diameter surface of a constant velocity joint facing each other.   The motor drive device with a reduction gear for an automobile according to any one of claims 1 to 6, wherein an oil seal is mounted in a space between the opening of the reduction gear casing and the output shaft.   The motor drive apparatus with a reduction gear for an automobile according to claim 2 or 3, wherein the oil seal is provided with a side lip portion that is in sliding contact with a flange portion of the slinger.   The motor drive apparatus with a reduction gear for an automobile according to claim 6, wherein the oil seal is provided with a side lip portion that is in sliding contact with an outer joint member of the constant velocity joint.

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