JP2017129178A - Motor drive unit for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor drive unit A for a vehicle which can replenish a lubricant to a lubricant tank 40 which is arranged at a bottom of a reduction gear housing 20 according to a rotational speed of a gear without losing the lubricant before the scooped-up lubricant drips down to a gear element, and also without enlarging the reduction gear housing 20.SOLUTION: A lubricant tank 40 is arranged at a bottom of a reduction gear housing 20 for accommodating a reduction gear 2, a lubricant in the lubricant tank 40 is scooped up by a gear of the reduction gear 2, a lubricant storage part 41 for storing the lubricant which has lubricated the gear is arranged in an upper position of the lubricant tank 40 in the reduction gear housing 20, and the lubricant which is stored in the lubricant storage part 41 is supplied to the lubricant tank 40 of the reduction gear housing 20 according to rotational speeds of output gear shafts 25L, 25R by the opening/closing of a valve 42 which is arranged at the lubricant storage part 41.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a vehicle motor drive device, and more particularly to a lubricating structure of a vehicle motor drive device for an electric vehicle.

  In a vehicle motor drive device that uses an electric motor as a drive source and decelerates the rotation of the electric motor by a speed reducer to rotate a drive wheel, the rotation of the output shaft of the speed reducer is applied to a hub wheel provided on the output shaft. In-wheel motor system that transmits and drives the drive wheel supported by the hub wheel, and the drive shaft is connected to the output shaft of the reducer through a joint, and the rotation of the drive shaft is transmitted to the hub wheel And there is an on-board system that drives the driving wheel.

  As a speed reducer for these vehicle motor drive devices, an input gear shaft that is rotated by the output torque of an electric motor, an output gear shaft that is output to a drive wheel, and an intermediate gear provided between the input gear shaft and the output gear shaft There is a gear drive reduction mechanism including a shaft, and the output torque of the electric motor is sequentially reduced to output a large output torque from the output gear shaft.

  Since the gear drive speed reduction mechanism of the vehicle motor drive device is driven at high rotation and high output, the gear drive speed reduction mechanism generally applies the rotational force of the speed reduction element (gear or pulley) for the purpose of lubrication and cooling. There is a splash system that uses a pump and a pump system that uses a pump for forced circulation.

  In a general splashing system that uses the rotational force of the speed reduction element (gear or pulley), either gear can use the oil level of the lubricating oil tank provided at the bottom of the speed reducer housing. What is set is common.

  Therefore, if the oil surface height of the lubricating oil tank is set high, the agitation resistance of the lubricating oil accompanying the rotation of each gear increases, and the efficiency of the gear drive device decreases. However, if the oil level is set to a low level, the amount of lubricating oil scraped down will be small, which may result in insufficient lubrication.

  On the other hand, the patent document discloses that the oil level in the lubricating oil tank at the bottom of the housing can be adjusted in order to increase the lubricity when lubrication is required while reducing the stirring resistance in the gear drive. 1 and 2.

JP 2008-39072 A JP 2008-51176 A

  However, since the techniques disclosed in Patent Document 1 and Patent Document 2 are provided with a second lubricating oil tank that collects the lubricating oil splashed on the upper part of the housing, it is necessary that the technique is originally dropped on the gear element. Certain lubricants may be taken away before dripping.

  Furthermore, in order to provide the second lubricating oil tank in the housing, a sufficient space is required in the housing, so that there is a problem that the drive device becomes large.

  In Patent Document 1, the oil level is controlled by a float type valve. However, since the oil level is not stable when the gear rotates at high speed, accurate control is considered difficult.

  Moreover, in patent document 2, since the control is based on the shift position, it is impossible to adjust the oil level by the rotation speed.

  Accordingly, the present invention provides a lubricating oil that is provided at the bottom of the reduction gear housing without removing the lubricating oil before the scraped lubricating oil drops on the gear element, without increasing the size of the reduction gear housing. An object of the present invention is to make it possible to replenish the tank with lubricating oil according to the rotational speed of the gear.

  In order to solve the above-described problems, the present invention includes an electric motor and a speed reducer that decelerates the power of the electric motor and transmits the power to the drive wheels, and the speed reducer is an input gear to which power is transmitted from the motor shaft. An input gear shaft having an output gear shaft having an output gear for transmitting a driving force to the drive wheel, and one or more intermediate gear shafts having an intermediate gear provided between the input gear shaft and the output gear shaft. In a vehicle motor drive device for providing a lubricating oil tank at the bottom of a reduction gear housing that houses the reduction gear, and lubricating and cooling the gears by scraping the lubricating oil in the lubricating oil tank by the gears of the reduction gear The lubricating oil storage part that stores the lubricating oil that has been scraped up by the gear and lubricated the gear is provided above the lubricating oil tank in the reducer housing, and the lubricating oil stored in the lubricating oil storage part. The lubricating oil storage The opening and closing of the valve provided in the section, and supplying the lubricating oil tank of the reducer housing according to the rotational speed of the output gear shaft.

  The lubricating oil reservoir is provided in the space of the speed reducer housing where the upper gear in the circumferential direction of the small gear provided on the intermediate gear shaft meshing with the output gear does not exist on the side of the input gear shaft in the axial direction of the input gear. As a result, an increase in size of the reduction gear housing can be prevented.

  By providing the bottom of the lubricating oil reservoir at a position lower than the center of the gear shaft closest to the vertical direction from the lubricating oil tank of the reduction gear housing, before the scraped lubricating oil drops on the gear element It is possible to prevent deprivation of lubricating oil.

  In the vehicle motor drive device according to the present invention, a lubricating oil storage portion that stores the lubricating oil that has been scraped up by the gears and lubricated the gears is provided at a position above the lubricating oil tank of the reduction gear housing, The lubricating oil stored in the lubricating oil reservoir can be supplied to the lubricating oil tank of the reducer housing according to the rotational speed of the output gear shaft by opening and closing the valve provided in the lubricating oil reservoir. The oil level of the lubricating oil tank can be adjusted, and the lubricity when lubrication is required can be improved while reducing the stirring resistance.

1 is a longitudinal front view of a vehicle motor drive device according to an embodiment of the present invention. 1 is a schematic plan view of an electric vehicle equipped with a vehicle motor drive device of the present invention. It is a schematic side view of the state at the time of the start which opened the valve provided in the bottom part of the lubricating oil storage part of a reduction gear housing. It is a schematic side view of the state where the valve provided in the bottom part of the lubricating oil storage part of the reduction gear housing was closed and the lubricating oil began to accumulate in the lubricating oil storage part. It is a schematic side view which shows the state which closed the valve provided in the bottom part of the lubricating oil storage part of the reduction gear housing, and the lubricating oil accumulated in the lubricating oil storage part. It is a schematic side view of the state which opened the valve provided in the bottom part of the lubricating oil storage part of the reduction gear housing, and returned the lubricating oil of the lubricating oil storage part to the lubricating oil tank. It is a schematic side view of the state which closed the valve in other embodiments of the valve provided in the bottom part of the lubricating oil storage part of a reduction gear housing. It is a schematic side view of the state which opened the valve in embodiment of FIG. It is a schematic side view of the state which closed the valve in other embodiments of the valve provided in the bottom part of the lubricating oil storage part of a reduction gear housing. It is a schematic side view of the state which opened the valve in embodiment of FIG.

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

  The electric vehicle shown in FIG. 2 is a front-wheel drive system, and is a two-motor vehicle drive device A that independently drives a chassis 51, front wheels 52 as drive wheels, rear wheels 53, and left and right drive wheels. The two-motor type vehicle drive device A is mounted on a chassis 51 at the center position of the left and right front wheels 52 as drive wheels, and the driving force of the two-motor type vehicle drive device A is constant velocity joint 15. And transmitted to the front wheel 52 which is the left and right drive wheels via the intermediate shaft 16.

  As a mounting form of the two-motor type vehicle driving device A, a rear wheel driving method or a four wheel driving method may be used in addition to the front wheel driving method shown in FIG.

  The left and right electric motors 1L, 1R in the two-motor type vehicle drive device A are housed in motor housings 3L, 3R as shown in FIG.

  The motor housings 3L and 3R include cylindrical motor housing bodies 3aL and 3aR, outer walls 3bL and 3bR that close the outer surfaces of the motor housing bodies 3aL and 3aR, and reduction gears on the inner surfaces of the motor housing bodies 3aL and 3aR. It consists of inner walls 3cL and 3cR separated from 2L and 2R. The inner walls 3cL and 3cR of the motor housing bodies 3aL and 3aR are provided with openings through which the motor shaft 12a is drawn.

  As shown in FIG. 1, the electric motors 1 </ b> L and 1 </ b> R are of a radial gap type in which a stator 11 is provided on the inner peripheral surface of the motor housing body 3 aL and 3 aR, and a rotor 12 is provided at an interval on the inner periphery of the stator 11. I am using something. The electric motors 1L and 1R may be axial gap types.

  The rotor 12 has a motor shaft 12a in the center, and the motor shaft 12a is drawn from the openings of the inner walls 3cL and 3cR of the motor housing bodies 3aL and 3aR to the speed reducers 2L and 2R, respectively. A seal member 13 is provided between the openings of the motor housing main 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 walls 3cL and 3cR and the outer walls 3bL and 3bR of the motor housing main bodies 3aL and 3aR (FIG. 1).

  As shown in FIG. 1, a speed reducer housing 20 that accommodates two speed reducers 2L and 2R provided in parallel on the left and right is a central housing 20a and left and right side housings 20bL fixed to both side surfaces of the central housing 20a. , 20bR three-piece structure. The left and right side housings 20bL and 20bR are fixed to the openings on both sides of the central housing 20a by a plurality of bolts (not shown).

  The side surfaces of the side housings 20bL and 20bR of the speed reducer housing 20 on the outboard side (outside the vehicle body) and the motor housing bodies 3aL and 3aR of the electric motors 1L and 1R are fixed to the inner walls 3cL and 3cR with a plurality of bolts 29. Thus, the two electric motors 1L and 1R are fixedly arranged on the left and right sides of the reduction gear housing 20 (FIG. 1).

  As shown in FIG. 1, the central housing 20a is provided with a partition wall 21 at the center. The speed reducer housing 20 is divided into left and right parts by the partition wall 21, and independent left and right accommodation chambers for accommodating the two speed reducers 2 </ b> L and 2 </ b> R are provided in parallel.

  As shown in FIG. 1, the speed reducers 2L and 2R are provided symmetrically and have large input gear shafts 23L and 23R each having an input gear 23a to which power is transmitted from the motor shaft 12a, and the input gear 23a. The intermediate gear shafts 24L and 24R having the small diameter gear 24b meshing with the diameter gear 24a and the output gear 25a, and the output gear 25a are pulled out from the speed reducer housing 20, and the constant velocity joint 15 and the intermediate shaft 16 (FIG. 2) are connected. It is a parallel shaft gear reducer provided with the output gear shafts 25L and 25R that transmit the driving force to the drive wheels via the shafts. The input gear shafts 23L and 23R, the intermediate gear shafts 24L and 24R, and the output gear shafts 25L and 25R of the two left and right speed reducers 2L and 2R are coaxially arranged.

  Both ends of the input gear shafts 23L, 23R of the speed reducers 2L, 2R are rolled into bearing fitting holes 27a formed on both the left and right sides of the partition wall 21 of the central housing 20a and bearing fitting holes 27b formed in the side housings 20bL, 20bR. The bearings 28a and 28b are rotatably supported. The bottoms of the bearing fitting holes 27a and 27b are stepped and are formed with a thinner thickness on the inner peripheral side than the wall part with which the outer rings of the rolling bearings 28a and 28b abut.

  The end portions on the outboard side of the input gear shafts 23L and 23R are drawn outward from openings 27c provided in the side housings 20bL and 20bR, and the openings 27c and the outer ends of the input gear shafts 23L and 23R are connected to each other. An oil seal 31 is provided between them to prevent leakage of lubricating oil sealed in the speed reducers 2L and 2R and intrusion of muddy water from the outside.

  The motor shaft 12a has a hollow structure, and the input gear shafts 23L and 23R are inserted into the hollow motor shaft 12a. 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 gear shafts 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 housing 20a and bearing fitting holes 32b formed on the side housings 20bL and 20bR. Is supported through. And the bottom part of the bearing fitting holes 32a and 32b is formed in a stepped shape with a thinner thickness on the inner peripheral side than the wall part with which the outer ring of the rolling bearings 34a and 34b abuts.

  The output gear shafts 25L and 25R have a large-diameter output gear 25a, and are formed in bearing fitting holes 35a formed on both surfaces of the partition wall 21 of the central housing 20a and bearing fitting holes 35b formed on the side housings 20bL and 20bR. It is supported by rolling bearings 37a and 37b. And the bottom part of the bearing fitting holes 35a and 35b is formed in a stepped shape in which the inner peripheral side is thinner than the wall part with which the outer ring of the rolling bearings 37a and 37b abuts.

  Outboard side ends of the output gear shafts 25L and 25R are pulled out to the outside of the reduction gear housing 20 through openings 35c formed in the side housings 20bL and 20bR, and the output gear shafts 25L and 25R are pulled out to the outboard side. The outer joint portion 15a of the constant velocity joint 15 is splined to the outer peripheral surface of the end portion.

  The constant velocity joint 15 coupled to the output gear shafts 25L and 25R is connected to the drive wheel (front wheel 52) via the intermediate shaft 16 (FIG. 2).

  An oil seal 39 is provided between the end of the output gear shafts 25L and 25R on the outboard side and the opening 35c formed in the side housings 20bL and 20bR, and leakage of the lubricating oil sealed in the speed reducers 2L and 2R. It also prevents the entry of muddy water from the outside.

  As shown in FIG. 3, a lubricating oil tank 40 is provided at the bottom of the reduction gear housing 20.

  As shown in FIG. 3, the oil level of the lubricating oil tank 40 is such that the large gear 24a of the intermediate gear shafts 24L and 24R and the output gear 25a of the output gear shafts 25L and 25R are sufficiently immersed. When the large-diameter gear 24a of the intermediate gear shafts 24L and 24R and the output gear 25a of the output gear shafts 25L and 25R rotate, the rotation causes the lubricating oil in the lubricating oil tank 40 to be scraped upward and scraped. The raised lubricating oil is dropped on each gear shaft, and the gears are lubricated.

  In FIG. 3, the flow of the lubricating oil is indicated by broken-line arrows. In the forward rotation direction of the output gear 25 a in which the drive wheel moves forward (the arrow direction in FIG. 3), the lubricating oil is scraped up, and the reduction gear housing 20 Flows toward the input gear shafts 23L and 23R.

  On the inner side in the axial direction of the input gear 23a of the input gear shafts 23L and 23R, there is a space where no gear is present in the reduction gear housing 20 above the circumferential direction of the small diameter gear 24b of the intermediate gear shafts 24L and 24R. There exists a lubricating oil reservoir 41 that receives the lubricating oil that is present and scraped up in this space. The intermediate gear shafts 24L and 24R have two large-diameter gears 24a and 24b, but the small-diameter gear 24b that meshes with the output gear 25a has a small diameter, so that there is a space above the small-diameter gear 24b. By utilizing this space, the lubricating oil reservoir 41 can be provided, so that the reduction gear housing 20 does not need to be enlarged.

  As shown in FIG. 3, the bottom of the lubricating oil reservoir 41 is positioned lower than the shaft center of the gear shaft (intermediate gear shafts 24L, 24R) closest to the vertical direction from the lubricating oil tank 40 of the speed reducer housing 20. The lubricating oil that is provided and scraped up along the upper surface of the speed reducer housing 20 and flows to the input gear shafts 23L and 23R is dropped on the input gear shafts 23L and 23R and then collected in the lubricating oil reservoir 41. The

  A valve 42 is installed at the bottom of the lubricating oil reservoir 41. The valve 42 is in an open state as shown in FIG. 3 in order to facilitate supply of lubricating oil at the time of starting.

  After starting, the valve 42 is closed as shown in FIG. 4, the lubricating oil is stored in the lubricating oil storage unit 41, and the oil level of the lubricating oil tank 40 is adjusted by the storage amount of the lubricating oil storage unit 41. Thus, the stirring resistance of the lubricating oil can be reduced.

  When the operation is continued with the valve 42 closed, the amount of lubricating oil stored in the lubricating oil reservoir 41 increases as shown in FIG. 5, and the oil level height of the lubricating oil tank 40 decreases. Although the agitation resistance of the lubricating oil can be reduced, if the oil surface height of the lubricating oil tank 40 becomes too low, the amount of the lubricating oil that is scraped is reduced, resulting in poor lubrication, as shown in FIG. In addition, the valve 42 is opened and the lubricating oil in the lubricating oil reservoir 41 is supplied to the lubricating oil tank 40 to increase the oil level of the lubricating oil tank 40.

  In addition, when performing high speed operation, in order to perform sufficient lubrication, the valve 42 is opened and the lubricating oil in the lubricating oil reservoir 41 is supplied to the lubricating oil tank 40, and the oil level of the lubricating oil tank 40 is increased. To increase.

  The valve 42 in the embodiment of FIGS. 3 to 6 uses a push solenoid valve with a spring that opens and closes by moving back and forth.

  7 and 8 use a spring solenoid valve with a spring that opens and closes as a valve 42, FIG. 7 shows a state in which the valve 42 is closed, and FIG. 8 shows a state in which the valve 42 is open. Is shown.

  9 and 10 use a rotary valve by a stepping motor as the valve 42, FIG. 9 shows a state in which the valve 42 is closed, and FIG. 10 shows a state in which the valve 42 is opened. ing.

  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 housing 3aL, 3aR: Motor housing body 3bL, 3bR: Outer wall 3cL, 3cR: Inner wall 11: Stator 12: Rotor 12a: Motor shaft 13: Seal Member 14a, 14b: Rolling bearing 15: Constant velocity joint 15a: Outer joint part 16: Intermediate shaft 20: Reduction gear housing 20a: Central housing 20bL, 20bR: Side housing 21: Partition walls 23L, 23R: Input gear shaft 23a: Input Gears 24L, 24R: Intermediate gear shaft 24a: Large diameter gear 24b: Small diameter gears 25L, 25R: Output gear shaft 25a: Output gears 27a, 27b: Bearing fitting holes 27c: Openings 28a, 28b: Rolling bearings 29: Bolts 31 : Oil seal 32a, 32b: Bearing fitting hole 3 4a, 34b: Rolling bearings 35a, 35b: Bearing fitting holes 35c: Openings 37a, 37b: Rolling bearings 39: Oil seal 40: Lubricating oil tank 41: Lubricating oil reservoir 42: Valve 51: Chassis 52: Front wheel 53: Rear wheel A: vehicle drive device

Claims (7)

  An electric motor and a speed reducer that decelerates the power of the electric motor and transmits the power to the drive wheel. The speed reducer includes an input gear shaft having an input gear to which power is transmitted from the motor shaft, and a driving force applied to the drive wheel. An output gear shaft having an output gear for transmitting the transmission gear, and one or more intermediate gear shafts having an intermediate gear provided between the input gear shaft and the output gear shaft. A lubricating oil tank is provided at the bottom, and the lubricating oil in the lubricating oil tank is scraped up by the gear of the speed reducer to lubricate and cool the gear, and the gear is lubricated by being scraped up by the gear. A lubricating oil storage part for storing the lubricating oil after the operation is provided at a position above the lubricating oil tank in the reducer housing, and the lubricating oil stored in the lubricating oil storage part is opened and closed by a valve provided in the lubricating oil storage part. By the output gear shaft The vehicle motor drive device and supplying the lubricating oil tank of the reducer housing in accordance with the rotational speed.   The lubricating oil reservoir is provided in the space of the reduction gear housing in the axial direction of the input gear shaft on the side in the axial direction of the input gear, where there is no gear in the circumferential direction of the small-diameter gear provided on the intermediate gear shaft meshing with the output gear. The vehicle motor drive device according to claim 1, wherein:   3. The vehicle according to claim 1, wherein a bottom portion of the lubricating oil storage portion is provided at a position lower than a shaft center of a gear shaft closest to a vertical direction from a lubricating oil tank of a reduction gear housing. Motor drive device.   The vehicle motor drive device according to any one of claims 1 to 3, wherein the valve provided in the lubricating oil storage unit is a solenoid valve that opens and closes by forward and backward movement.   The vehicle motor drive device according to any one of claims 1 to 3, wherein the valve provided in the lubricating oil reservoir is a solenoid valve that opens and closes by vertical movement.   The vehicle motor drive device according to any one of claims 1 to 3, wherein the valve provided in the lubricating oil reservoir is a rotary valve using a stepping motor.   The vehicle motor drive device according to any one of claims 1 to 6, wherein a valve provided in the lubricating oil reservoir opens when the output gear shaft is stopped.

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