JP2019194056A - In-wheel motor drive device - Google Patents

Abstract

To provide an in-wheel motor drive device which can achieve output performance and cooling performance of a three-phase induction motor.SOLUTION: An in-wheel motor drive device D includes: a seal member 35 which has a cylindrical part 35a for partitioning an outer case 31 from an inner member 32 and annular parts 35b, 35c for making fluid-tight sealing at both axial end parts of the cylindrical part 35a and cooperates with the outer case to form a housing chamber R which houses a stator 33; and a heat pipe 40 which can cool the stator 33 through a working fluid filling the housing chamber R. The heat pipe 40 includes: pipe-like recirculation passages 41, 42 which are arranged at an exterior of the in-wheel motor 5 so as to connect a lead-out part 34a formed at an end wall part 34 with an introduction part 34b and allow the working fluid to circulate therein; and a heat exchanger 43 which is provided at a middle part of the recirculation passages 41, 42 and can conduct heat exchange with outer air.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an in-wheel motor drive device in which a three-phase induction motor is accommodated in an inner circumferential space of a wheel rim.

2. Description of the Related Art Conventionally, an in-wheel motor driving device in which an electric motor for driving is housed in an inner peripheral space of a wheel rim has been known for the purpose of increasing the power transmission efficiency of a vehicle.
Among drive electric motors, a three-phase induction motor (also referred to as an SR motor) generates a rotating magnetic field by passing a three-phase alternating current through a stator coil (stator), while the rotor (rotor) has an electromagnetic induction action. An induced current is generated. An electromagnetic force is generated by the rotating magnetic field and the induced current, and the rotor is rotating. This three-phase induction motor is superior to the PM motor using permanent magnets in that it does not generate cogging torque and does not generate induced electromotive force during idle running. ing.

When the in-wheel motor drive device is operated under a high load or high rotation state, the temperature of the in-wheel motor (electric motor for driving), particularly the stator including the coil, rises rapidly. There are concerns about component damage and the like due to a decrease in oil viscosity.
In addition, a water-cooling type cooling mechanism that circulates water from the outside to a part to be cooled increases the size of equipment such as a heat exchanger and piping. Therefore, in general, an in-wheel motor cooling mechanism has a flow of air generated by traveling. The air cooling method using
However, since such an air cooling system is affected by the running state, there is a limit to the operation start timing and the cooling capacity.

The heat pipe, which is one form of the cooling mechanism, can be used for non-fluorocarbon refrigerants and has the advantage of not requiring power, so it is widely adopted for the cooling mechanism of in-wheel motors that are high heating elements. ing. The heat transport capability of this heat pipe is affected by five factors: viscosity limit, sound speed limit, capillary limit, scattering limit, and boiling limit.
Since hydrofluoroether (HFE), which is a halogenated hydrocarbon, has extremely low viscosity and high electrical insulation and thermal stability, it is a refrigerant capable of improving the heat transport capability of the heat pipe. It is.

The wheel drive device for vehicles of patent documents 1 has a rotor which drives a wheel, an outer case which accommodates this rotor and a stator, and was fixed to a knuckle member, and the 1st-3rd cooling device, The cooling device is constituted by a first heat pipe connected between the stator and a lid for closing the opening of the outer case, and the second cooling device is constituted by a second heat pipe connected between the stator and the outer case, 3 The cooling device is constituted by a third heat pipe in contact with the outer case.
The motor of Patent Document 2 includes a stator, an oil passage that supplies oil to the stator, and a heat pipe. The heat pipe is disposed between the motor outer periphery and the motor case and is in contact with or close to the stator. A heat receiving portion provided in the oil passage and a heat radiating portion provided outside the oil passage.

JP 2006-282158 A JP 2008-072881 A

By adopting the heat pipe using HFE as a refrigerant (working fluid) as described above, it is possible to increase the thermal reliability and operating efficiency of the in-wheel motor as compared with the conventional heat pipe.
However, even if the refrigerant performance of the hydraulic fluid used in the heat pipe is improved, the heat pipe itself possesses from the aspect of structural factors related to the capillary limit among the above five elements that affect the heat transport capability of the heat pipe. There is a possibility that the cooling performance cannot be sufficiently exhibited.

Since the vehicle wheel drive device of Patent Literature 1 physically contacts the stator, which is a cooling target, and the heat pipe, when cooling a wide range, the heat pipe may become large or complicated.
In addition, since the working fluid, which is a refrigerant, is in contact with the stator via the heat pipe components (the pipe connection portion and the heat pipe outer wall), the time required for heat exchange becomes longer, and the heat between the stator and the working fluid is increased. The exchange is not performed sufficiently, and there is concern about the diffusion of heat to the surroundings.
On the other hand, in the motor of Patent Document 2, since the heat receiving portion of the heat pipe is disposed in the oil passage of the oil supplied to the stator, the stator and the heat pipe are physically and spatially separated, and the cooled oil Drops (moves) and adheres to the stator, and as in Patent Document 1, heat exchange between the stator and the working fluid is indirect. Moreover, since the cooling performance of the heat pipe depends on the performance of the oil pump that circulates the oil, it is not easy to sufficiently exhibit the cooling performance of the heat pipe.

By the way, the induction motor includes an inner rotor type in which a rotor provided on a radially inner side of a stator that is a stator rotates, and an outer rotor type in which a rotor (outer case) provided on a radially outer side of the stator rotates. Existing.
In the case of motors of the same size, the outer rotor type can increase the rotor radius, so that a larger output torque can be ensured than the inner rotor type.
However, since the outer case that covers the periphery of the stator, which is a stator, rotates, there is a problem that various wirings and piping are complicated.
That is, it is desired that the output performance and the cooling performance be compatible in the in-wheel motor drive device.

  The objective of this invention is providing the in-wheel motor drive device etc. which can make output performance and cooling performance compatible.

  An in-wheel motor drive device according to claim 1 is a three-phase induction motor having an inner member supported by a knuckle member and having a stator, and a substantially cylindrical outer rotor that accommodates the inner member and is connected to a wheel. In the in-wheel motor drive device accommodated in the inner circumferential space of the rim of the wheel, a cylindrical portion that partitions between the outer rotor and the stator, and axial end portions of the cylindrical portion at both ends in the vehicle width direction of the inner member, respectively. A seal member having a ring portion that contacts and seals in a liquid-tight manner, and forms a storage chamber for storing the stator in cooperation with the outer rotor, and the hydraulic fluid filled in the storage chamber A heat pipe mechanism capable of cooling the stator, and the heat pipe mechanism is formed at one end of the inner member in the vehicle width direction. A pipe-like reflux passage that is routed outside the three-phase induction motor and connects the inside portion to the introduction portion formed at one end in the vehicle width direction of the inner member and through which the working fluid can flow. A heat exchanger provided in the middle of the reflux passage and capable of exchanging heat with outside air is provided.

In this in-wheel motor drive device, a cylindrical portion that partitions the outer rotor and the stator, and a circular portion that seals in a liquid-tight manner in contact with both end portions in the vehicle width direction of the inner member at both axial end portions of the cylindrical portion. A seal member having a ring portion and forming a housing chamber for housing the stator in cooperation with the outer rotor, and a heat pipe mechanism capable of cooling the stator through the working fluid filled in the housing chamber. Therefore, the stator can be entirely immersed in the hydraulic fluid of the heat pipe mechanism, and direct heat exchange between the stator and the hydraulic fluid can be performed.
The outside of the three-phase induction motor is configured so that the heat pipe mechanism connects a lead-out portion formed at one end portion in the vehicle width direction of the inner member and an introduction portion formed at one end portion in the vehicle width direction of the inner member. And a heat exchanger that is provided in the middle of the reflux passage and is capable of exchanging heat with the outside air. In the three-phase induction motor, the lead-out part and the introduction part can be arranged separately, and the working fluid in the storage chamber can be stirred by the refluxed working fluid.

According to a second aspect of the present invention, in the first aspect of the present invention, the power supply line of the three-phase induction motor is from a portion spaced radially inward from the lead-out portion and the introduction portion at one end portion in the vehicle width direction of the inner member. It is characterized by being taken out.
According to this configuration, the lead-out portion of the power supply line and the lead-out portion and the introduction portion of the heat pipe mechanism can be formed on the fixed side member.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the feeding wire of the three-phase induction motor is taken out from a portion that is spaced apart in the circumferential direction of each phase at one end in the vehicle width direction of the inner member. It is characterized by being.
According to this configuration, the power supply line can be taken out from the stationary member for each phase.

The invention of claim 4 is the invention of any one of claims 1 to 3, wherein the rotation shaft of the rotor is arranged coaxially with the wheel center, and the heat exchanger is in the front-rear direction with respect to the wheel center. In addition to being arranged on one side, the power supply line of the three-phase induction motor is routed on the other side in the front-rear direction with respect to the wheel center.
According to this configuration, it is possible to reduce the size and weight by omitting the speed reduction mechanism from the rim of the wheel, and to improve the handling of the power supply line.

The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the power supply line of the three-phase induction motor is connected to the vehicle body side power supply line via the movable power supply line, It is wired from the edge part of the said feeder to the vehicle width direction inner side and upper direction.
According to this structure, the displacement locus | trajectory of the feeder line accompanying steering can be made small.

  According to the in-wheel motor drive device of the present invention, both the output performance and the cooling performance of the three-phase induction motor can be achieved.

1 is a layout diagram of a hybrid vehicle according to a first embodiment. It is the perspective view which looked at the right front wheel from the left front. It is the perspective view which looked at the right front wheel from the left rear. It is a left view of a right front wheel. It is a longitudinal cross-sectional view of a right front wheel. It is the perspective view which looked at the in-wheel motor from the right front. It is the perspective view which looked at the in-wheel motor from the left front. It is a longitudinal cross-sectional view of an in-wheel motor. It is explanatory drawing of a heat pipe. It is another explanatory view of a heat pipe. It is explanatory drawing of the displacement locus | trajectory of the electric power feeding line accompanying steering.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its application, or its use.

Embodiment 1 of the present invention will be described below with reference to FIGS.
As shown in FIG. 1, the vehicle V of the present embodiment is a hybrid vehicle on which an in-wheel motor drive device D is mounted.
In the description of the in-wheel motor drive device D, the premise structure of the vehicle V will be described.
The vehicle V is an FR (Front engine Rear drive) vehicle in which an engine 3 that is an internal combustion engine is mounted at the front of a vehicle body and that drives a pair of left and right rear wheels 2 that are main drive wheels.
The rear wheels 2 of the main drive wheels are also driven by a main drive motor 4 instead of the engine 3, and the pair of left and right front wheels 1 that are sub drive wheels are in-wheel motors (hereinafter, IWM) that are sub drive motors. 5) is driven to a predetermined operation region.
The engine 3 and the main drive motor 4 are connected via a clutch (not shown) so that the fastening can be released.

The engine 3 is configured as a flywheel-less engine in which a flywheel is omitted, and drives the rear wheel 2 via a power transmission mechanism 6.
The power transmission mechanism 6 includes a propeller shaft 6a, a clutch 6b, a transmission 6c as a stepped transmission connected to the rear wheel 2 via an axle (not shown), and the like.
The main drive motor 4 is constituted by, for example, a 25 kW permanent magnet synchronous motor (PM motor) driven by 48V, and an inverter 7 for converting the current of a 48V battery 8 (for example, a 3.5 kWh lithium ion battery). Is supplied with alternating current.
The main drive motor 4 is connected in series with the engine 3, and the drive force generated by the main drive motor 4 is transmitted to the rear wheel 2 through the power transmission mechanism 6, similarly to the drive force of the engine 3.
The IWM 5 is configured by, for example, a 17 kW three-phase induction motor (SR motor) driven at 120 V, and an alternating current is supplied from an inverter 10 d that converts the current of the capacitor 10 a.

The control device 9 controls the engine 3, the main drive motor 4 and the IWM 5.
As shown in FIG. 1, a high-voltage DC / DC converter 10b and a low-voltage DC / DC converter 10c, which are voltage converters, are disposed in the vicinity of the capacitor 10a.
The capacitor 10a, the high voltage DC / DC converter 10b, the low voltage DC / DC converter 10c, and the inverter 10d are unitized to form an integrated unit 10.

When the EV mode is selected by a changeover switch (not shown), the control device 9 drives the vehicle V only by the main drive motor 4 at the time of start and at low speed travel, and at the time of acceleration travel in the high vehicle speed region, the IWM 5 The main drive motor 4 and the IWM 5 cooperate to drive the vehicle V.
Further, during deceleration, the main drive motor 4 and the IWM 5 function as a generator and regenerate kinetic energy to generate electric power. The electric power regenerated by the main drive motor 4 is accumulated in the battery 8, and the electric power regenerated by the IWM 5 is accumulated in the capacitor 10a.
When the charge of the capacitor 10a is insufficient, the voltage of the battery 8 is boosted to charge the capacitor 10a. When the voltage between the terminals of the capacitor 10a rises excessively, the charge of the capacitor 10a is lowered to charge the battery 8 Yes.

Next, the front wheel 1 and the front suspension device that supports the front wheel 1 will be described.
This front suspension device is accommodated on the outer side in the vehicle width direction of a wheel house (not shown) formed corresponding to each of the pair of front wheels 1.
As shown in FIGS. 2 and 3, the front suspension apparatus of the present embodiment is of a double wishbone type, and includes an upper arm 11 pivotally supported by an upper body member (not shown) so as to be pivotable up and down, and a subframe. A lower arm 12 pivotally supported by a front member (not shown) of the upper arm 11, a knuckle member 13 rotatably attached to the upper arm 11 and the lower arm 12, a shock absorber 14 extending in the vertical direction, and the like. Yes.
Since the front wheel 1 and the front suspension device that supports the front wheel 1 have a bilaterally symmetric structure, the structure on the right side will be mainly described below.
Also, in the figure, the arrow F direction is the forward direction, the arrow L direction is the left direction, and the arrow U direction is the upward direction.

As shown in FIGS. 2 to 5, the knuckle member 13 supports the front wheel 1, the brake disc 25, and the like so as to be rotatable around the virtual kingpin axis. The knuckle member 13 is formed in a substantially bowl shape opened to the inner side in the vehicle width direction, and an upper end portion and a lower end portion thereof are pivotally supported by the upper arm 11 and the lower arm 12, respectively. The shock absorber 14 includes a damper and a coil spring, the upper ends of which are fixed to a suspension tower (not shown), and the lower end of the damper is rotatably attached to the lower arm 12.
This front suspension device is attached via a steering gear unit (not shown) extending in the vehicle width direction and a rotatable connecting portion extending outward from the steering gear unit to the front side of the knuckle member 13. A tie rod 15 is provided.
By operating a steering wheel (not shown) linked to the steering gear unit, the tie rod 15 moves to the left and right, and the front wheel 1 is steered through the knuckle member 13.

As shown in FIGS. 4 and 5, the front wheel 1 includes a tire 21, a cylindrical rim 22 on which the tire 21 is mounted, and a substantially disc-shaped wheel disk disposed on the outer side in the vehicle width direction of the rim 22. 23 and a disc-shaped hub 24 fixed to a central portion of the wheel disk 23 via a plurality of fastening members. These rim 22, wheel disc 23, hub 24 and the like constitute the wheel of the front wheel 1.
A hollow disc-like brake disc 25 is fixed to the outer side of the hub 24 in the vehicle width direction.
The brake caliper 26 is disposed behind the IWM 5.
The brake caliper 26 is fixed to the rear portion of the knuckle member 13 and is configured to be able to brake the rear portion of the brake disc 25. Reference numeral 27 denotes a heat shielding protective cover provided on the inner side in the vehicle width direction of the brake disc 25.
As described above, the IWM 5, the brake disc 25, the brake caliper 26, and the like are accommodated in the radially inner space of the rim 22.

Next, the in-wheel motor drive device D will be described.
The in-wheel motor drive device D includes an IWM 5 provided on each front wheel 1, a heat pipe 40 (heat pipe mechanism) as a cooling mechanism provided corresponding to each IWM 5, and the like.

The IWM 5 is supported by the knuckle member 13 in a state where the right side portion is partially surrounded by the knuckle member 13 in the radially inner space of the rim 22.
As shown in FIGS. 6 to 8, the IWM 5 includes a substantially cylindrical outer case 31 whose right end is bottomed, an inner member 32 housed in the outer case 31, and a stator 33 that is a stator. The end wall portion 34 that closes the left end portion of the outer case 31 and the seal member 35 are the main components. The IWM 5 is an outer rotor type induction motor in which an outer case 31 provided on the radially outer side of the stator 33 rotates.
In the case of motors of the same size, the outer rotor type can increase the rotor radius, so that a larger output torque can be ensured than the inner rotor type.

As shown in FIG. 8, the outer case 31 includes a rotor coil 31a, a substantially cylindrical outer peripheral wall 31b, a seal portion 31c, a rotor shaft 31s, and the like.
The rotor coil 31a is attached to the inner periphery of the outer peripheral wall 31b by distributed winding.
The rotor coil 31a is disposed opposite the stator coil 33a so that an induced current is generated by a rotating magnetic field generated by a stator coil 33a described later.
The left end portion of the outer peripheral wall 31b is formed with a seal portion 31c having a larger diameter than the right side portion and extending leftward.

The rotor shaft 31 s is integrally formed coaxially with the axis of the outer case 31, and has a left half portion that extends into the outer case 31 (left side) and a right half portion that extends outside (right side) the outer case 31. is doing. The rotor shaft 31s is provided such that the center of the front wheel 1 is positioned on the axial extension line. The IWM 5 is assisted and driven only during specific acceleration travel, so that the IWM 5 is compact and the speed reduction mechanism is omitted.
The left half portion of the rotor shaft 31s is inserted into the inner member 32 and supported by the inner member 32 via a pair of left and right bearings b1.
The right half of the rotor shaft 31 s is connected to an inner race 24 a formed integrally with the hub 24. The inner race 24a is rotatably supported by the knuckle member 13 via the bearing b2 and the outer race 24b.

As shown in FIG. 8, the inner member 32 includes a substantially cylindrical stator 33 and a substantially annular end wall portion 34 projecting radially outward from the left end portion of the stator 33.
The stator 33 has a stator coil 33a composed of a U-phase coil, a V-phase coil, and a W-phase coil attached to the radially outer portion by distributed winding. The rotor coil 31a and the stator coil 33a are provided with an electrically insulating coating (for example, enamel coating).
The end wall portion 34 is formed with three electrode terminal extraction portions (not shown) spaced apart on the same circumference at positions corresponding to the imaginary kingpin axis on the radially inner portion. Are electrically extracted via the bus bars 36u, 36v, 36w, respectively (see FIG. 7).
A seal portion 34c that is bent rightward and faces the seal portion 31c is formed at the outer end portion of the end wall portion 34. The seal portion 34c and the seal portion 31c are sandwiched between dust seals 37 and held in a liquid-tight state. The two pairs of front and rear attachment portions 34d fix the end wall portion 34 (inner member 32) to the left side wall portion of the knuckle member 13 via a fastening member.

The seal member 35 is formed in a substantially hat shape in the longitudinal section, and forms a ring-shaped accommodation chamber R that accommodates the stator 33 in cooperation with a part of the inner member 32 including the end wall portion 34.
Specifically, the sealing member 35 includes a cylindrical portion 35a that partitions the outer case 31 (rotor coil 31a) and the stator 33 (stator coil 33a), and an inner wall surface of the end wall portion 34 at the left end portion of the cylindrical portion 35a. An annular portion 35b that contacts and seals in a liquid-tight manner, and an annular portion 35c that contacts the right end portion (the stator 33) of the inner member 32 at the right end portion of the cylindrical portion 35a and seals in a fluid-tight manner. is doing.
The seal member 35 is made of a non-magnetic material (aluminum, carbon, or the like), and seals between the stator coil 33a and the rotor coil 31a in a liquid-tight manner.
The accommodating chamber R is filled with a hydraulic fluid having electrical insulation properties, for example, hydrofluoroether (HFE) so as to immerse the stator coil 33a as a whole.
In this embodiment, the seal member 35 forms the radially outer end wall and the right end wall of the storage chamber R, and the inner member 32 forms the radial inner end wall and the left end wall of the storage chamber R.
In addition, stainless steel, which is a weak magnetic material, can be used as the seal member 35.

As shown in FIG. 8, a lead-out portion 34 a and an introduction portion 34 b penetrating the end wall portion 34 are provided in portions corresponding to the upper end vicinity position and the lower end vicinity position of the storage chamber R, respectively. The lead-out part 34a and the introduction part 34b are arranged so as to be spaced radially outward from the bus bars 36u, 36v, 36w.
The lead-out part 34a is formed so as to move upward on the left side, and the introduction part 34b is formed so as to move downward on the left side.
On the left side (in the vehicle width direction) of the end wall portion 34, a terminal box 38 that covers the periphery of the lead-out portion 34a, the introduction portion 34b, and the bus bars 36u, 36v, 36w is mounted.

Next, the heat pipe 40 as a cooling mechanism will be described.
As shown in FIGS. 4 and 9, the heat pipe 40 includes pipe-like upstream and downstream passages 41 and 42 (reflux passage), a heat exchanger 43 corresponding to a heat radiating portion to the outside, and a stator 33 (stator coil). 33a) is configured by a storage chamber R or the like corresponding to a heat receiving portion that receives heat from 33a).
In the heat pipe 40, the hydraulic fluid heated by the stator 33 takes the latent heat of vaporization and vaporizes, and a pressure difference is generated between the storage chamber R and the heat exchanger 43. And move to the heat exchanger 43. In the heat exchanger 43, the vaporized working fluid condenses and releases an equal amount of latent heat of condensation. The condensed hydraulic fluid flows through the downstream passage 42 by gravity and is returned to the storage chamber R. The cycle of evaporation and condensation is repeated in response to heating and cooling of the hydraulic fluid.

Since HFE has extremely low viscosity due to its nature, it enters between each stator coil 33a attached by distributed winding, and the infiltrated working fluid is vaporized by receiving heat from the entire surface of the stator coil 33a. The boiling point of HFE is about 40 ° C.
As shown in FIG. 10, the accommodation chamber R is formed with a minute gap between the stator coil 33a. For example, a gap of 3 mm is formed at the left end, the right end, and the radially outer end of the stator coil 33a, and the vaporized hydraulic fluid moves to the upper end portion of the storage chamber R through the gap.

As shown in FIGS. 4 and 8 to 10, the upstream passage 41 extends upward from the lead-out portion 34 a corresponding to the position near the upper end of the storage chamber R, and the downstream passage 42 is near the lower end of the storage chamber R. After extending from the introduction part 34b corresponding to the position to the lower rear side, it extends upward. By arranging the introduction part 34b in the vicinity of the lower end of the storage chamber R, the hydraulic fluid filled in the storage chamber R is stirred using the refluxed hydraulic fluid, and the heat exchange efficiency of the entire cooling mechanism is improved. Yes.
The passage length of the upstream passage 41 is shorter than the passage length of the downstream passage 42.
When the upstream passage 41 is long, the vaporized hydraulic fluid may condense before reaching the heat exchanger 43 and may flow backward in the upstream passage 41, so that the cooling cycle of the heat pipe 40 functions normally in the circulation direction. Because.

As shown in FIGS. 4 and 5, the heat exchanger 43 is disposed in the inner space of the rim 22, specifically, in the space between the outer periphery of the outer case 31 and the inner periphery of the rim 22.
The heat exchanger 43 is disposed in a region opposite to the brake caliper 26 with respect to the wheel center of the front wheel 1 (axial center of the rotor 34), specifically, in a front region and an upper region from the wheel center. This is for securing the arrangement space of the heat exchanger 43 and avoiding heat reception from the brake caliper 26.

As shown in FIGS. 4 and 9, the heat exchanger 43 communicates with the downstream end of the upstream passage 41 and communicates with the upper volume chamber 43 a extending in the front-rear direction in a substantially horizontal manner and the upstream end of the downstream passage 42. A lower volume chamber 43b extending in the front-rear direction in a substantially horizontal manner, a plurality of vertical passages 43c communicating between the upper volume chamber 43a and the lower volume chamber 43b and extending vertically, and a plurality of vertical passages 43c connected to the plurality of vertical passages 43c A cooling fin 43f is provided.
The upper volume chamber 43a is supported on the front upper portion of the knuckle member 13 by the upper bracket 44 (see FIG. 11), and the lower volume chamber 43b is supported on the front portion of the lid 32 by the lower bracket 45.

Next, the power feeding system will be described.
As shown in FIGS. 3, 4, and 11, the power supply system includes a motor-side power supply line 51, a vehicle body-side power supply line 52, a movable power supply line 53 that connects the motor-side power supply line 51 and the vehicle body-side power supply line 52, and the like. It is comprised so that electric power can be supplied to IWM5 from a vehicle-mounted power supply (not shown).
The motor-side power supply line 51 extends rearward from the bus bars 36u, 36v, 36w connected to the take-out portion, and 3 in the first connection portion 54 (motor-side connection portion) disposed in the vicinity of the rear end portion of the IWM 5. The two feeder lines are bundled into one to constitute a collective wire.

The vehicle body side power supply line 52 is connected to a second connecting portion 55 (vehicle body side connecting portion) that extends from the inner wall portion of the wheel house and is locked to the upper arm 11. The second connecting portion 55 is formed to be swingable at a height position equal to or higher than the position near the upper arm 11.
In the present embodiment, as shown in FIGS. 2 and 3, the second connecting portion 55 has a swing shaft formed coaxially with the swing shaft of the upper arm 11 and swings in the vehicle width direction. It is configured freely.
The movable power supply line 53 is formed of a flexible material and is configured as a collective electric wire that can be connected to the first and second connection portions 54 and 55. The movable power supply line 53 is formed in a substantially U-shape that extends rightward and downward from the second connection portion 55 and then curves toward the upper front, and is connected to the first connection portion 54.

  Since the bus bars 36u, 36v, 36w are arranged at positions corresponding to the virtual kingpin axis, even when the front wheel 1 is steered, the movement trajectory radius of the bus bars 36u, 36v, 36w is made as small as possible. Since the second connecting portion 55 is disposed coaxially with the swing axis of the upper arm 11, the first connecting portion 55 is swung in the vehicle width direction regardless of whether the vehicle V is bound or rebound. The separation distance between the second connecting portions 54 and 55 is maintained substantially constant.

As shown in FIG. 11A, when the front wheel 1 is steered to the left side, the first connection portion 54 (bus bars 36u, 36v, 36w) is farthest from the second connection portion 55 in plan view. Yes.
However, in the neutral state shown in FIG. 11 (b), the movable power supply line 53 is formed in a substantially U shape with respect to the vehicle width direction. Guarantee of steering tracking.
As shown in FIG. 11C, when the front wheel 1 is steered to the right side, the first connection portion 54 is closest to the second connection portion 55 in plan view.
However, since the first connection portion 54 is disposed on the side opposite to the tie rod 15 with respect to the wheel center, the lower end portion is displaced downward without causing interference between the movable power supply line 53 and the tie rod 15, and the movable power supply line 53. Guarantees the ability to follow the steering.

Next, the operation and effect of the in-wheel motor drive device D will be described.
In the in-wheel motor drive device D, the cylindrical portion 35a that partitions the outer case 31 and the inner member 32 (stator 33) and the axial end portions of the cylindrical portion 35a are in contact with both end portions in the vehicle width direction of the inner member 32, respectively. And a sealing member 35 having an annular portion 35b, 35c for sealing in a liquid-tight manner and forming a storage chamber R for storing the stator 33 in cooperation with the outer case, and a hydraulic fluid filled in the storage chamber R Therefore, the stator 33 can be entirely immersed in the working fluid of the heat pipe 40, and direct heat generated by the stator 33 and the working fluid can be obtained. Exchanges can be made.
The heat pipe 40 is routed outside the IWM 5 so as to connect the lead-out portion 34a formed in the end wall portion 34 that is the left end portion of the inner member 32 and the introduction portion 34b formed in the end wall portion 34, and Since it is provided with pipe-like reflux passages 41 and 42 through which the working fluid can flow and a heat exchanger 43 provided in the middle of the reflux passages 41 and 42 and capable of exchanging heat with the outside air, the outer rotor type In the IWM 5, the lead-out part 34 a and the introduction part 34 b can be spaced apart, and the working fluid in the storage chamber R can be stirred by the refluxed working fluid.

  Since the motor-side power supply line 51 of the IWM 5 is taken out from a portion separated radially inward from the lead-out part 34a and the introduction part 34b at the left end portion of the inner member 32, the take-out part (bus bar 36u) of the motor-side power supply line 51 , 36v, 36w) and the lead-out portion 34a and the introduction portion 34b of the heat pipe 40 can be formed on the fixed side member.

  Since the motor-side power supply line 51 of the IWM 5 is respectively taken out from the portion separated in the circumferential direction of each phase at the left end portion of the inner member 32, the motor-side power supply line 51 can be taken out from the fixed-side member for each phase. it can.

  The rotor shaft 31s of the outer case 31 is disposed coaxially with the wheel center, the heat exchanger 43 is disposed on the front side with respect to the wheel center, and the motor-side power supply line 51 of the IWM 5 is located on the rear side with respect to the wheel center. Therefore, the speed reduction mechanism can be omitted from the wheel rim 22 to reduce the size and weight, and the motor-side power supply line 51 can be favorably routed.

  The motor side power supply line 51 of the IWM 5 is connected to the vehicle body side power supply line 52 via the movable power supply line 53, and the movable power supply line 53 is routed from the end of the motor side power supply line 51 to the inside in the vehicle width direction and above. Therefore, the displacement trajectory of the power supply lines 51 and 52 accompanying the turning can be reduced.

Next, a modified example in which the embodiment is partially changed will be described.
1) In the above-described embodiment, the example in which the IWM is mounted on the front wheel of the FR vehicle has been described. However, the IWM may be mounted on the rear wheel of the FF vehicle. Further, although an example of an SR motor has been described as IWM, at least a three-phase induction motor may be used, and a PM motor may be employed.

2) In the above embodiment, an example of a heat exchanger composed of an upper volume chamber, a lower volume chamber, a vertical member, and fins has been described. However, it is sufficient that at least heat exchange with the outside air is possible, and a single volume chamber is required. It may be. Further, it is sufficient that at least the outlet passage and the introduction passage can be formed, and the passage and the heat exchanger may be used by extending the passage instead of the volume chamber.

3) In the above-described embodiment, the example in which the heat pipe is completely accommodated in the radially inner space of the rim has been described, but at least the heat pipe may be disposed on the radially inner side of the rim. The component member may partially protrude inward in the vehicle width direction from the rim.

4) In the above embodiment, an example of a double wishbone type suspension has been described. However, at least an upper support member and a lower support member may exist, and the present invention may be applied to a strut type suspension or the like.

5] In addition, those skilled in the art can implement the present invention in a form in which various modifications are added to the above-described embodiment or in a form in which each embodiment is combined without departing from the gist of the present invention. Various modifications are also included.

1 Front wheel 5 IWM
13 Knuckle member
22 Rim 31 Outer case 31s Rotor shaft 32 Inner member 33 Stator 34 End wall portion 34a Derived portion 34b Introducing portion 35 Seal member 35a Cylindrical portions 35b and 35c Annular portion 40 Heat pipe 41 Upstream passage 42 Downstream passage 43 Heat exchanger 51 Motor side power supply line 52 Car body side power supply line 53 Movable power supply line D In-wheel motor drive device R Storage chamber

Claims (5)

A three-phase induction motor having an inner member supported by a knuckle member and having a stator, and a substantially cylindrical outer rotor that accommodates the inner member and is connected to a wheel is accommodated in an inner circumferential space of the rim of the wheel. In the in-wheel motor drive device,
The outer rotor has a cylindrical portion that partitions the outer rotor and the stator, and an annular portion that contacts the both ends in the vehicle width direction of the inner member at both ends in the axial direction of the cylindrical portion and seals in a liquid-tight manner. A seal member that cooperates with and forms a storage chamber for storing the stator;
A heat pipe mechanism capable of cooling the stator via the hydraulic fluid filled in the storage chamber,
The outside of the three-phase induction motor is configured so that the heat pipe mechanism connects a lead-out portion formed at one end portion in the vehicle width direction of the inner member and an introduction portion formed at one end portion in the vehicle width direction of the inner member. And a heat exchanger that is provided in the middle of the reflux passage and can exchange heat with the outside air. Wheel motor drive device.   2. The power supply line of the three-phase induction motor is taken out from a portion spaced radially inward from the lead-out portion and the introduction portion at one end portion in the vehicle width direction of the inner member. In-wheel motor drive device.   3. The in-wheel according to claim 1, wherein a power supply line of the three-phase induction motor is taken out from a portion that is separated in the circumferential direction of each phase at one end portion in the vehicle width direction of the inner member. Motor drive device. The rotational axis of the rotor is arranged coaxially with the wheel center,
The heat exchanger is disposed on one side in the front-rear direction with respect to the wheel center,
The in-wheel motor drive device according to any one of claims 1 to 3, wherein a power supply line of the three-phase induction motor is wired on the other side in the front-rear direction with respect to the wheel center. The three-phase induction motor feed line is connected to the vehicle body side feed line via a movable feed line,
The in-wheel motor drive device according to any one of claims 1 to 4, wherein the movable feed line is routed inward and upward in the vehicle width direction from an end of the feed line.