JP2006248273A - Wheel drive device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more stably support a wheel on a wheel support part at a fixed side and to sufficiently cool a gear mechanism. <P>SOLUTION: The wheel drive device 20 for the vehicle incorporates an in-wheel motor 30 and the gear mechanism 50 for transmitting power of the in-wheel motor to a hub 14 of the wheel 10 into a rim 11 of the wheel. A rotation center Mc of a motor shaft 36 of the in-wheel motor is eccentric to a rotation center Wc of the wheel. The gear mechanism comprises a pinion 51 provided on the motor shaft; and an internal gear 52. The internal gear has a constitution that an outer peripheral surface 55a is rotatably supported by a motor housing 31 of the in-wheel motor and the hub is mounted. The hub is provided with a ventilation hole 14a penetrated on the rotation center of the hub. A central part of the internal gear can be cooled by outside air passing through the ventilation hole. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle wheel drive device in which an electric motor, a so-called in-wheel motor, and a gear mechanism for transmitting the power of the in-wheel motor to a wheel are arranged inside a rim of the vehicle wheel (wheel). The present invention relates to a technique for cooling the mechanism.

In recent years, in order to simplify a power transmission system from a power source to a wheel and increase transmission efficiency in a vehicle, development of a technique for arranging an in-wheel motor inside a rim in the wheel has been advanced. Since such a vehicle wheel drive device drives a wheel with a high load, the development of a technique for increasing the output torque by reducing the number of revolutions of the in-wheel motor with a gear mechanism is also possible. (See, for example, Patent Document 1-2).
JP-A-8-99538 JP 2004-90822 A

The conventional vehicle wheel driving device shown in Patent Document 1 and Patent Document 2 is said that an in-wheel motor and a gear mechanism for transmitting the power of the in-wheel motor to the wheel hub are incorporated in the rim of the wheel. Is.
The conventional gear mechanism shown in Patent Document 1 is a two-stage gear reduction mechanism housed in a motor housing of an in-wheel motor, and has a wheel hub bolted to its output shaft.
The conventional gear mechanism shown in Patent Document 2 is a one-stage gear reduction mechanism that is arranged adjacent to an in-wheel motor and is a combination of a pinion and an internal gear, and a wheel hub is bolted to the internal gear. Is.

As an example of a conventional vehicle wheel drive device, a conventional technique disclosed in Patent Document 2 will be described with reference to FIG. FIG. 8 is a schematic view of a conventional vehicle wheel drive device.
The conventional vehicle wheel drive device 100 is configured such that the rotation center Mt of the motor shaft 121 of the in-wheel motor 120 is decentered with respect to the rotation center Wh of the wheel 110, and the in-wheel motor is mounted on the fixed wheel support 131. 120 is attached, and the hub 112 of the wheel 110 is connected to the motor shaft 121 of the in-wheel motor 120 via the gear mechanism 132.

  More specifically, the gear mechanism 132 includes a pinion 133 attached to the motor shaft 121 and an internal gear 134 meshed with the pinion 133. The wheel 110 includes a hub 112 (disk 112) attached to the axle 111, a rim 113 fixed to the outer periphery of the hub 112, and a tire 114 attached to the rim 113. The wheel support portion 131 supports the axle 111 rotatably via the bearing 135 on the rotation center Wh of the wheel 110. Further, the axle 111 has a configuration in which an internal gear 134 is attached via a shallow dish-shaped disk 136.

  Incidentally, since a relatively large road surface reaction force acts on the wheel 110, it is required that the wheel 110 can be stably supported by the wheel support portion 131. Furthermore, since the gear mechanism that transmits the power of the in-wheel motor to the wheel is subjected to a high load, the heat generation amount is relatively large. In order to increase the durability of the gear mechanism, cooling is preferable.

  An object of the present invention is to provide a technique capable of supporting a wheel more stably by a wheel support portion on a fixed side and sufficiently cooling a gear mechanism.

The invention according to claim 1 is a vehicle wheel drive device in which an in-wheel motor and a gear mechanism for transmitting the power of the in-wheel motor to a wheel hub are incorporated in a rim of the wheel. In the vehicle wheel drive device in which the rotation center of the motor shaft of the in-wheel motor is eccentric with respect to the rotation center,
The gear mechanism is composed of a pinion provided on the motor shaft and an internal gear engaged with the pinion.
The outer peripheral surface of the internal gear is rotatably supported by the motor housing of the in-wheel motor, and the wheel hub is attached to the internal gear.
The hub is provided with a vent hole penetrating on the center of rotation of the hub, so that the internal gear is cooled by the outside air passing through the vent hole.

  According to a second aspect of the present invention, in the first aspect, the internal gear is integrally formed with a disk-shaped disk that closes one side, so that a hub is attached to the disk, and the disk is further connected to the disk. A cup-shaped heat radiating portion that bulges or is depressed facing the pores is provided.

According to a third aspect of the present invention, in the first or second aspect, the motor housing includes a gear storage chamber that stores the gear mechanism and stores electrically insulating lubricating oil.
The motor shaft protrudes from the motor housing into the gear housing chamber, and has a communication hole communicating from the gear housing chamber into the motor housing.
The internal gear includes an oil scooping portion that scoops up lubricating oil in the gear housing chamber and puts it into the communication hole.

In the invention according to claim 1, the gear mechanism for transmitting the power of the in-wheel motor to the wheel is constituted by a pinion provided on the motor shaft and an internal gear meshed with the pinion. The outer peripheral surface is rotatably supported by the motor housing, and the wheel hub is attached to the internal gear.
The wheel can be supported by the motor housing by rotatably supporting the outer peripheral surface of the internal gear to which the wheel is attached by the motor housing. For this reason, the motor housing can also serve as a wheel support portion on the fixed side that supports the wheel.
The wheel can be supported at a position away from the rotation center of the wheel by supporting the outer peripheral surface away from the rotation center of the internal gear by the wheel support portion. Therefore, the wheel can be supported more stably by the wheel support portion on the fixed side, and the support rigidity can be increased.

  Further, in the invention according to claim 1, since the through hole is provided at the center of rotation of the hub in the wheel, the internal gear can be efficiently cooled by the outside air that has passed through the hole. Since the gear mechanism can be sufficiently cooled, the durability of the gear mechanism can be further increased as a result.

  In the invention which concerns on Claim 2, the heat dissipation area of an internal gear is provided in the disk for attaching a hub among the internal gears by providing the cup-shaped heat radiation part which protruded or depressed facing the vent hole of the hub. Can be increased. Since the heat dissipating part is cup-shaped, the heat dissipating area is larger than a simple flat plate. Since the heat radiating part having a large heat radiating area is directly cooled by the outside air that has passed through the vent hole, the internal gear can be cooled more efficiently. As a result, the gear mechanism can be further sufficiently cooled.

In the invention according to claim 3, the lubricating oil in the gear housing chamber is scraped up by the oil scooping portion of the internal gear and put into the communication hole of the motor shaft, so that the lubricating oil is introduced into the motor housing from the communication hole. Can be put.
As described above, the gear mechanism is cooled while being lubricated with the lubricating oil in the gear housing chamber, and the in-wheel motor can also be cooled with the lubricating oil introduced from the gear housing chamber into the motor housing. That is, the lubricating oil in the gear housing chamber can be shared for the cooling of the gear mechanism and the cooling of the in-wheel motor.
Since the gear mechanism is cooled by the outside air and also by the lubricating oil, the gear mechanism can be cooled more efficiently and the cooling performance is improved. Moreover, the lubricating oil can be introduced from the gear housing chamber into the motor housing by the oil scraping portion of the internal gear. Therefore, the in-wheel motor can be efficiently cooled without providing a lubricating oil supply device composed of another member such as a pump.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view of a wheel provided with a vehicle wheel drive device according to the present invention. FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1 and shows a configuration of a wheel provided with a vehicle wheel drive device as viewed from the outside in the vehicle width direction.

  As shown in FIGS. 1 and 2, the vehicle wheel 10 is a wheel that is suspended from a vehicle body via a suspension (not shown) or directly, and includes a vehicle wheel drive device 20. The wheel 10 includes a cylindrical rim 11, a tire 12 attached to the rim 11, a hollow disk-shaped disk 13 formed integrally on the inner peripheral surface of the rim 11, and a hub formed integrally at the center of the disk 13. 14 and. The disk 13 and the hub 14 are arranged at positions outside the rim 11 in the vehicle width direction (right side in FIG. 1). Further, the hub 14 includes a vent hole 14a penetrating on the rotation center Wc of the hub 14 (that is, the rotation center Wc of the wheel 10).

  The vehicle wheel drive device 20 transmits the power of the in-wheel motor 30, which is a power source for driving the wheel 10, to the hub 14 of the wheel 10 in the rim 11 (inward diameter) of the wheel 10. The gear mechanism 50 and a disc brake 66 for braking the wheel 10 are incorporated.

  The rotation center Mc of the motor shaft 36 of the in-wheel motor 30 is eccentric by a certain distance Di with respect to the rotation center Wc of the wheel 10. As shown in FIG. 2, when the wheel 10 is viewed from the outside in the vehicle width direction, the rotation center Mc of the motor shaft 36 is on the front upper side or the rear upper side with respect to the rotation center Wc of the wheel 10.

FIG. 3 is a cross-sectional view of the vehicle wheel drive device according to the present invention and is shown corresponding to FIG.
As shown in FIG. 3, the in-wheel motor 30 includes a motor housing 31, an annular stator 32 fixed inside the motor housing 31, a plurality of coil portions 33 attached to the stator 32, and a stator 32. A three-phase brushless comprising a rotor 34 rotatably arranged inside, a plurality of permanent magnets 35 attached to the outer peripheral surface of the rotor 34, a motor shaft 36 attached to the center of the rotor 34, and a resolver 37. It is a motor.

The motor housing 31 is a member that also serves as a fixed wheel support portion that is attached to a vehicle body (not shown) and supports the wheel 10 (see FIG. 1), and is adjacent to each other via a partition wall 41. 42 and a gear storage chamber 43.
The motor storage chamber 42 is a space that opens on the opposite side to the gear storage chamber 43 and is closed by a lid 44, and includes a stator 32, a coil portion 33, a rotor 34, a permanent magnet 35,. -The motor shaft 36 and the resolver 37 can be accommodated. In the motor storage chamber 42, the motor housing 31 can be supported by rotating the motor shaft 36 via a bearing 45 and restricting movement in the axial direction.

  In the present invention, the lid 44 detachably attached to the motor housing 31 with a bolt or the like in order to close the motor housing chamber 42 is considered to be a part of the motor housing 31. The motor housing 31 and the lid 44 are made of a material having thermal conductivity.

The motor shaft 36 protrudes from the motor storage chamber 42 (in the motor housing 31) into the gear storage chamber 43 and includes a pinion 51 formed at the front end. That is, the motor shaft 36 extends from the motor storage chamber 42 into the gear storage chamber 43 through the through hole 41 a opened in the partition wall 41.
Further, the motor shaft 36 has a communication hole 36 a that communicates from the gear housing chamber 43 into the motor housing 31. That is, the communication hole 36 a is an oil circulation hole formed on the rotation center Mc of the motor shaft 36 and along the center line Mc. The communication hole 36 a has a discharge hole 36 b that opens radially outward in the motor storage chamber 42.

Each of the coil portions 33 is an electric element including an iron core 33a, a coil bobbin 33b, and a winding (coil) 33c.
The resolver 37 is a sensor that can perform magnetic pole position detection, speed detection, and rotational position detection.

  By the way, the in-wheel motor 30 is electrically insulated between the coil portions 33... And the lid 44 by a plurality of heat pipes 48. It is a connected configuration. The pipe connection portion 47 is a hollow disk-shaped heat transfer plate made of a material having thermal conductivity, such as a copper plate, and has a configuration in which the coil portion 33... Is closely attached to the side facing the lid 44. is there.

  Since the coil portions 33... And the motor housing 31 (including the lid 44) are connected while being electrically insulated by the heat pipes 48..., The heat generated in the coil portions 33. It is possible to quickly escape from the coil portions 33 to the motor housing 31 by the heat pipes 48 to dissipate from the motor housing 31 to the outside air. Therefore, the heat dissipation of the in-wheel motor 30 can be further improved.

  The lid 44 has a plurality of heat radiation fins 44a... On its outer surface, thereby increasing the heat radiation area. The heat transferred from the coil portions 33 to the lid 44 can be efficiently and quickly dissipated to the outside air.

  The gear storage chamber 43 is a space that opens on the opposite side of the motor storage chamber 42 and stores the gear mechanism 50 and stores lubricating oil. The gear mechanism 50 includes the pinion 51 and an internal gear 52 meshed with the pinion 51.

  4 is a perspective view in which a part of the internal gear according to the present invention is cut out, and FIG. 5 is a sectional view taken along line 5-5 of FIG. As shown in FIGS. 4 and 5, the internal gear 52 is a member disposed on the rotation center Wc of the wheel 10 (see FIG. 1), and includes a cup-shaped heat radiation portion 53 and internal teeth on the rotation center Wc. The ring-shaped gear part 55 which has 54, and the disk-shaped disk 56 which closes one side part so that the thermal radiation part 53 and the gear part 55 may be connected are integrally molded products.

  The heat dissipating part 53 is disposed sideways along the center of rotation Wc and the disk 56 side is opened. The heat dissipating part 53 has a loosely tapered cylindrical part 71 and a flat bottom plate 72 that closes the inner end of the cylindrical part 71. It is a bottomed cylindrical member consisting of The taper of the cylindrical portion 71 is configured to be tapered toward the bottom plate 72 side. The inner surface 73 of the heat radiating portion 53, that is, the inner peripheral surface of the cylindrical portion 71 and the inner surface of the bottom plate 72 are heat radiating surfaces that come into contact with the outside air.

  As shown in FIG. 3, in the gear housing chamber 43, the motor housing 31 can rotate the outer peripheral surface 55 a of the internal gear 52 through the bearing 57, that is, the outer peripheral surface 55 a of the gear portion 55 in the axial direction. It can be supported by restricting movement. The bearing 57 is prevented from coming off by a pressing member 58 bolted to the motor housing 31.

  As shown in FIG. 3, the disk 56 of the internal gear 52 has a hollow disk-like wheel mounting plate 61 superimposed on the outer surface in the vehicle width direction exposed from the gear storage chamber 43 (the right side surface in FIG. 3). , And a plurality of bolts 62... The wheel mounting board 61 includes a vent hole 61 a penetrating on the rotation center Wc of the wheel 10.

  As shown in FIGS. 1 and 3, the wheel mounting board 61 includes a plurality of bolts with a brake disk 67 and a hub 14 of the wheel 10 overlapped in this order on the outer surface in the vehicle width direction (right side in FIGS. 1 and 3). 63... And nuts 64. As a result, the hub 14 can be attached to the disk 56. In this way, the brake disk 67 and the hub 14 of the wheel 10 were attached to the internal gear 52.

  As shown in FIG. 1, the combined structure of the hollow disc-shaped brake disc 67 and the caliper 68 attached to the motor housing 31 forms a disc brake 66. The disc brake 66 is a hydraulic or pneumatic brake mechanism.

  As shown in FIG. 1, in the vehicle wheel drive device 20, the power generated by the in-wheel motor 30 is transmitted from the motor shaft 36 to the hub 14 through a path of the pinion 51 → the internal gear 52 → the wheel mounting board 61. , Transmitted to the wheel 10. In this way, the wheel 10 can be driven by the in-wheel motor 30.

  As shown in FIGS. 1 and 3, according to the vehicle wheel drive device 20, the motor housing 31 is configured such that the outer peripheral surface 55 a of the internal gear 52 to which the wheel 10 is attached is rotatably supported by the motor housing 31. The wheel 10 can be supported. For this reason, the motor housing 31 can also serve as a wheel support portion on the fixed side that supports the wheel 10.

  The wheel 10 can be supported at a position away from the rotation center Wc of the wheel 10 by supporting the outer peripheral surface 55a of the internal gear 52 away from the rotation center Wc by the wheel support portion 31. Therefore, the wheel 10 can be supported more stably by the wheel support portion 31 on the fixed side, and the support rigidity can be increased.

  Next, the heat radiation action of the internal gear 52 will be described. As shown in FIGS. 1 and 3, the inner surface 73 of the heat radiating portion 53 in the internal gear 52 is open to the outside air through the vent hole 61 a of the wheel mounting board 61 and the vent hole 14 a of the hub 14.

  Since the through hole 14a is provided at the rotation center Wc position of the hub 14 in the wheel 10, the internal gear 52 can be efficiently cooled by the outside air that has passed through the hole 14a. Since the gear mechanism 50 can be sufficiently cooled, the durability of the gear mechanism 50 can be further enhanced as a result.

  Furthermore, since the disk 56 for mounting the hub 14 of the internal gear 52 is provided with a cup-shaped heat radiating portion 53 bulging or recessed facing the vent hole 14 a of the hub 14, The heat radiation area can be increased. Since the heat radiating part 53 is cup-shaped, the heat radiating area is larger than that of a simple flat plate. Since the heat radiating portion 53 having a large heat radiating area is directly cooled by the outside air that has passed through the vent hole 14a, the internal gear 52 can be cooled more efficiently. As a result, the gear mechanism 50 can be further sufficiently cooled.

Next, a lubricating structure using lubricating oil accumulated in the motor storage chamber 42 and the gear storage chamber 43 will be described. As a matter of course, the lubricating oil has electrical insulation.
First, the lubricating structure of the motor housing 31 will be described.
As shown in FIG. 3, the motor housing 31 includes an oil reflecting plate 81 that repels the scattered lubricating oil in the upper part of the motor storage chamber 42. The bottom 42 a of the motor storage chamber 42 is higher than the bottom 43 a of the gear storage chamber 43. The partition wall 41 includes a side outflow hole 41 b through which lubricating oil collected at the bottom of the motor storage chamber 42 flows out to the gear storage chamber 43 through the auxiliary chamber 82. The height of the side outflow hole 41 b is set to such an extent that some lubricating oil is accumulated at the bottom of the motor storage chamber 42.

  FIG. 6 is a side view of the main part of the motor storage chamber viewed from the side with the lid removed from the motor housing according to the present invention. As shown in FIGS. 3 and 6, the motor housing 31 includes an oil partition plate 83 at a position slightly higher than the coil portion 33 disposed at the lowermost position in the bottom of the motor storage chamber 42. Even if the lubricating oil accumulated in the bottom of the motor storage chamber 42 scatters upward, it is rebounded by the oil partition plate 83, so that the lubricating oil can be prevented from scattering to the rotor 34.

  As shown in FIG. 3, the motor housing 31 further includes a small auxiliary chamber 82 that projects from the partition wall 41 to the gear storage chamber 43. The auxiliary chamber 82 is disposed below the heat dissipating portion 53 in the internal gear 52 and at a position that does not interfere with the internal teeth 54, and extends to the vicinity of the inner wall surface 56 a of the disk 56. Such an auxiliary chamber 82 communicates with the side outflow hole 41b, and has one or more small-diameter lower outflow holes 82a... Communicating with the bottom of the gear storage chamber 43 on the lower surface.

The combined structure of the space below the oil partition plate 83 in the motor storage chamber 42 and the auxiliary chamber 82 forms a motor-side oil reservoir chamber 84.
The arrangement and size of the lower outflow holes 82a are as follows: (1) From the inside of the auxiliary chamber 82 to the inner peripheral surface of the gear portion 55 below the auxiliary chamber 82 and the tooth surface of the inner teeth 54, an appropriate amount of lubricating oil And (2) a certain amount of lubricating oil can be stored in the motor-side oil reservoir chamber 84. The oil level of the lubricating oil collected in the motor side oil sump chamber 84 does not exceed the height of the oil partition plate 83. In this way, it is possible to minimize the range (immersion range) in which the coil portion 33 is immersed in the lubricating oil while accumulating a certain amount of lubricating oil.

  On the other hand, the space between the bottom 43 a of the gear storage chamber 43 and the lower surface of the auxiliary chamber 82 forms a gear-side oil reservoir chamber 85. The gear mechanism 50 and the bearing 57 can be lubricated by immersing the lower portion of the gear portion 55 and the lower portion of the bearing 57 in the lubricating oil accumulated in the gear-side oil reservoir chamber 85.

Next, the lubricating structure of the internal gear 52 will be described.
As shown in FIGS. 4 and 5, the cylindrical portions 71 in the heat radiating portion 53 of the internal gear 52 are arranged at a constant pitch in the circumferential direction of the outer peripheral surface 71a, that is, a plurality of first oil scooping grooves arranged radially. 74... Are formed. These first oil scooping grooves 74 are linear grooves extending in the longitudinal direction of the cylinder portion 71 along the outer peripheral surface of the cylinder portion 71, and one end of the groove is opened, The end extends to the inner wall surface 56a of the disk 56 and communicates with the second oil scraping grooves 75.

  As described above, the disk 56 has a plurality of second oil scooping grooves 75... Arranged radially on the inner wall surface 56a at a constant pitch with the rotation center Wc as a reference. These second oil scooping grooves 75... Are linear grooves extending from the end of the first oil scooping grooves 74. Thus, in the second oil scraping grooves 75... Extending radially outward of the disk 56, the radially outward ends are referred to as extended ends 75 a.

  The distance Lg from the rotation center Wc to the extended end 75a is smaller than ½ of the pitch diameter of the inner teeth 54. A more preferable distance Lg is slightly larger than a certain distance Di from the rotation center Wc of the wheel 10 to the rotation center Mc of the motor shaft 36. By doing so, the extended end 75a of the second oil scooping groove 75 or the vicinity of the extended end 75a faces the communication hole 36a of the motor shaft 36 indicated by an imaginary line.

  The extending ends 75a ... have a circular arc shape curved toward the communication hole 36a. This is because the lubricating oil flowing from the second oil scooping groove 75... To the extended end 75 a... Is guided to the communicating hole 36 a by the extended end 75 a.

These first and second oil scooping grooves 74, 75, ... are shaped and sized so that the lubricating oil in the gear housing chamber 43 can be scooped into the communication hole 36a. For example, it is a substantially U-shaped groove (including a V-shaped groove and a square groove) in a sectional view.
The combined structure of the first oil scooping grooves 74... And the second oil scooping grooves 75. In this way, the internal gear 52 includes the oil scooping portion 76 that scoops up the lubricating oil in the gear housing chamber 43 and puts it into the communication hole 36a.

  As shown in FIG. 3, the tip of the motor shaft 36 faces the inner wall surface 56 a of the disk 56 in the internal gear 52 with a slight gap Cr.

FIG. 7 is an operation diagram of the lubricating structure according to the present invention and is shown corresponding to FIG.
As shown in FIG. 7, since the lower part of the gear part 55 and the lower part of the bearing 57 are immersed in the lubricating oil Lu accumulated in the gear-side oil sump chamber 85, the internal gear 52 rotates so that the lubricating oil Lu The gear mechanism 50 and the bearing 57 can be lubricated and cooled.

  A part of the lubricating oil Lu after lubricating the gear mechanism 50 and the bearing 57 is dripped into the first oil scraping grooves 74... In the heat radiating portion 53 of the internal gear 52. The lubricating oil Lu that has entered the first oil scooping grooves 74... Is scattered around by the centrifugal force accompanying the rotation of the internal gear 52, or the second oil scooping grooves 74. It flows through the oil scraping grooves 75 to flow to the extended end 75a. The lubricating oil Lu that has flowed to the extended end 75a... Is scattered by centrifugal force to the tip of the motor shaft 36 facing the inner wall surface 56a of the disk 56 with a slight gap Cr. It enters into the communication hole 36a of the shaft 36. Since the clearance Cr is small, the lubricating oil Lu from the second oil scooping grooves 75... Is easily sucked into the communication hole 36 a of the motor shaft 36.

Furthermore, as the motor shaft 36 rotates, the lubricating oil Lu scatters from the discharge hole 36b to the motor storage chamber 42 by centrifugal force through the communication hole 36a. As a result, the scattered lubricating oil Lu contacts with each member of the in-wheel motor 30 housed in the motor housing chamber 42 and cools, and then drops and accumulates in the motor-side oil reservoir chamber 84.
Lubricating oil Lu accumulated in the motor side oil sump chamber 84 returns to the gear side oil sump chamber 85 through a path of the side outflow hole 41b → the auxiliary chamber 82 → the lower outflow hole 82a.

As is clear from the above description, according to the lubricating structure of the present invention, the lubricating oil Lu in the gear housing chamber 43 is scraped up by the oil scooping portion 76 of the internal gear 52, and the communication hole of the motor shaft 36. Lubricating oil Lu can be put into the motor housing 31 through the communication hole 36a by being put in 36a.
Thus, the gear mechanism 50 is lubricated and cooled by the lubricating oil Lu in the gear storage chamber 43, and the lubricating oil Lu introduced from the gear storage chamber 43 into the motor storage chamber 42 (in the motor housing 31) The in-wheel motor 30 can also be cooled. That is, the lubricating oil Lu in the gear housing chamber 43 can be shared for cooling the gear mechanism 50 and cooling the in-wheel motor 30.

  Since the gear mechanism 50 is cooled by the outside air and also by the lubricating oil Lu, the gear mechanism 50 can be cooled more efficiently, and the cooling performance is improved. Moreover, the lubricating oil Lu can be introduced from the gear housing chamber 43 into the motor housing 31 by the oil scooping portion 76 of the internal gear 52. Therefore, the in-wheel motor 30 can also be efficiently cooled without providing a lubricating oil supply device made of another member such as a pump.

  In the embodiment of the present invention, the disk 56 of the internal gear 52 only needs to have a cup-shaped heat radiating portion 53 that bulges or is depressed facing the vent hole 14 a of the wheel 10.

  The vehicle wheel drive device 20 of the present invention can simplify the power transmission system from the power source to the wheel 10 by disposing the in-wheel motor 30 as the power source inside the rim 11 of the wheel 10. Therefore, it is suitable for an electric vehicle.

It is sectional drawing of the wheel provided with the vehicle wheel drive device which concerns on this invention. FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1. It is sectional drawing of the wheel drive device for vehicles which concerns on this invention. It is the perspective view which notched some internal gears concerning the present invention. FIG. 5 is a sectional view taken along line 5-5 of FIG. It is the principal part side view of the motor storage chamber seen from the side in the state which removed the lid from the motor housing concerning the present invention. It is an effect | action figure of the lubricating structure which concerns on this invention. It is a schematic diagram of the conventional vehicle wheel drive device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Wheel, 11 ... Rim, 14 ... Hub, 14a ... Air hole, 20 ... Vehicle wheel drive device, 30 ... In-wheel motor, 31 ... Motor housing, 32 ... Stator, 34 ... Rotor, 36 ... Motor shaft, 36a ... Communication hole, 42 ... Inside motor housing (motor housing chamber), 43 ... Gear housing chamber, 50 ... Gear mechanism, 51 ... Pinion, 52 ... Internal gear, 53 ... Heat radiation part, 56 ... Disk, 76 ... Scraping Raised portion, Lu ... lubricating oil, Mc ... rotation center of motor shaft, Wc ... rotation center of wheel (rotation center of hub).

Claims (3)

An in-wheel motor and a gear mechanism for transmitting the power of the in-wheel motor to a wheel hub, wherein the vehicle wheel drive device is incorporated in a rim of the wheel. In the vehicle wheel drive device in which the rotation center of the motor shaft of the in-wheel motor is eccentric,
The gear mechanism includes a pinion provided on the motor shaft and an internal gear meshed with the pinion.
The internal gear is rotatably supported by the motor housing of the in-wheel motor on the outer peripheral surface, and the hub is attached.
The hub drive device according to claim 1, wherein the hub is provided with a vent hole penetrating on the center of rotation of the hub so that the internal gear is cooled by the outside air passing through the vent hole. The internal gear is configured such that the hub is attached to this disk by integrally forming a disk-shaped disk that closes one side.
The wheel drive device for a vehicle according to claim 1, wherein the disk includes a cup-shaped heat radiating portion that bulges or is depressed facing the vent hole. The motor housing includes a gear storage chamber that stores the gear mechanism and stores lubricating oil,
The motor shaft protrudes from the motor housing into the gear housing chamber and has a communication hole communicating from the gear housing chamber into the motor housing.
3. The vehicle wheel drive device according to claim 1, wherein the internal gear includes an oil scooping portion that scoops up lubricating oil in the gear housing chamber and puts the lubricating oil into the communication hole. 4.

Images