JP2006213182A - Electric type wheel driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric type wheel driving device capable of enhancing the durability of bearing for wheels, constructing the device lightweight and compact, and enhancing the ease of operation for disassembly and reassembly. <P>SOLUTION: The electric type wheel driving device is equipped with an epicyclic reduction gear 3 installed between a pair of bearings 1 and 2 for wheels and composed of a ring gear 16 as a first external member 8, a sun gear 4 as a supporting member 17, a plurality of planet gears 21 to mesh with them, and a carrier pin 20 to bear them on a carrier 19, and with a drive part 5 consisting of an electric motor M including a stator 25 attached fast to the inside circumferential surface of a drum 8b and a rotor 24 attached fast to the periphery of the supporting member 17 and the supporting member 17 to bear the rotor 24 on a shaft 14, and is configured so that a hub wheel 7 and an inner member 13 are coupled together through the shaft 14 in such a way as able to be uncoupled, wherein the carrier 19 is coupled with the hub wheel 7 through serration, whereby the rotation of the motor M is transmitted to the hub wheel 7 through the epicyclic reduction gear 3 so as to drive the wheels. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric wheel drive device that is used in a vehicle such as an electric vehicle, a golf cart, or a forklift, and in which a wheel bearing, a speed reducer, and an electric motor are integrated.

  The electric wheel drive device is proposed to increase the driving efficiency when the wheels are driven by an electric motor, and is used for driving wheels of an electric vehicle or the like, and directly rotates and drives the wheels by the electric motor. It is configured as follows. However, since this type of electric wheel drive device requires a large output torque for the electric motor, a large electric motor must be used. This not only increases the cost, but also increases the weight, making it difficult to ensure sufficient vehicle performance.

  On the other hand, an electric motor and a planetary gear speed reducer are arranged in the inner space portion of the wheel, and the rotation output of the electric motor is transmitted to the wheel via the planetary gear speed reducer. A drive device (in-wheel motor) has also been proposed (see, for example, Patent Document 1).

  However, when a planetary gear speed reducer is adopted as the speed reducer, the output shaft that transmits the rotational output of the rotor of the electric motor to the wheels via the planetary gear speed reducer is once divided in the axial direction of the electric wheel drive device. Since the output is extracted by aligning the shaft center, the structure is generally complicated and difficult to assemble, and the support span of the output shaft must be shortened, so the support strength against the falling of the wheel is low was there.

  As a solution to these problems, an electric wheel drive device as shown in FIG. 3 is known. The electric wheel drive device 51 includes an electric motor 54 and a gear reducer 55 inside a wheel 53 on which a tire 52 is mounted, and is configured to rotationally drive the wheel 53 by the rotation output of the electric motor 54. Has been.

  The electric motor 54 includes a stator 57 that is fixed to the case 56 disposed inside the wheel 53, a rotor 58 that is disposed opposite to the inside of the stator 57, and a rotational output of the rotor 58 that is used as a gear reducer 55. And an output shaft 59 that is transmitted to the wheel 53 via the. The stator 57 and the rotor 58 are fixed to the case 56 side while being sandwiched between the covers 60 and 61 to constitute the electric motor 54.

  The output shaft 59 is integrally formed with an attachment flange 62 at one end portion 59 a thereof, and a wheel 53 is fixed via a hub bolt 63. One end portion 59a of the output shaft 59 is rotatable via a rolling bearing 64 in the shaft insertion hole 56b of the case 56, and the other end portion 59b is rotatable via a rolling bearing 65 in the central recess 60a of the outer cover 60. It is supported.

  The gear reducer 55 accommodated in the case 56 is composed of a plurality of gears 55a, 55b, 55c and 55d. The first gear 55 a is integrally formed concentrically with the end portion of the rotor 58. The second and third gears 55b and 55c are fixed to the same support shaft 66 and rotate integrally with each other, and the second gear 55b and the first gear 55a are engaged with each other. One end 66a of the support shaft 66 is rotatably supported by the recess 61a of the inner cover 61 via the rolling bearing 67, and the other end 66b is rotatably supported by the recess 56a of the case 56 via the rolling bearing 68. Yes. The fourth gear 55d is fixed to the output shaft 59 and meshes with the third gear 55c.

With this configuration, the output shaft 59 of the electric motor 54 passes through the rotation center hole of the fourth gear 55d, which is the final stage of the gear reducer 55, and the shaft insertion hole 58a of the rotor 58. Since both ends are rotatably supported, the components of the gear reducer 55, the inner cover 61, the components of the electric motor 54, and the outer cover 60 are sequentially fitted and assembled with the output shaft 59 as a reference. be able to. Further, since the output shaft 59 is supported by substantially both ends of the electric wheel drive device 51 as a whole, the support span can be maximized so that sufficient support strength against the falling of the wheel 53 is obtained. (For example, refer to Patent Document 2).
Japanese Patent No. 3440082 JP-A-7-81436

  In such a conventional electric wheel drive device 51, this type of gear reducer 55 can easily assemble various components, but the electric motor 54 disposed inside the wheel 53 is downsized, and this In order to obtain a high rotational output with the electric motor 54, the space is inevitably increased, so that the installation space for the rolling bearings 64 and 65 for supporting the output shaft 59 is restricted. Therefore, the wheel 53 has fallen, that is, the load capacity with respect to the moment load is insufficient, and improvement has been demanded in terms of improving the durability of the rolling bearings 64 and 65.

  An object of the present invention is to solve such a conventional problem, and to provide an electric wheel drive device that improves the durability of wheel bearings, reduces the weight and size of the device, and improves disassembly and assembly. To do.

  In order to achieve such an object, the invention according to claim 1 of the present invention drives a pair of wheel bearings, a planetary speed reducer disposed between the wheel bearings, and the planetary speed reducer. An electric motor and a drive unit having a support member having a substantially U-shaped cross section for supporting the electric motor, and the wheel bearing on the outboard side of the pair of wheel bearings is provided at one end. A hub wheel having a wheel mounting flange, provided with an inner rolling surface on the outer periphery and formed with a small-diameter stepped portion extending in the axial direction from the inner rolling surface, a cup-shaped drum on the outer periphery, and a diameter of the drum A first outer member in which a cylindrical fixing element extending concentrically inward in the direction is integrally formed, and an outer rolling surface facing the inner rolling surface is provided on the inner periphery of the base, and both of these rolling members A plurality of rolling elements housed between the running surfaces so as to roll freely, Among the wheel bearings, the inboard wheel bearing has an inner rolling surface on the outer periphery, and an inner member integrally formed with a shaft portion extending from the inner rolling surface to the outboard side, and on the outer periphery. A second outer member integrally having a disc-shaped lid member for closing the opening of the drum, and provided with an outer rolling surface facing the inner rolling surface on the inner periphery of the base; A plurality of rolling elements housed in a rolling manner between the rolling surfaces, and the planetary reduction gear includes the fixed element, an input element provided on an outer peripheral surface of the inner cylinder of the support member, and these fixed elements. And a plurality of planetary elements respectively engaged with the input elements, and an output element that rotatably supports these planetary elements with respect to the carrier, and the drive unit is a stator fixed to the inner peripheral surface of the drum; And fixed to the outer peripheral surface of the outer cylinder of the support member, An electric motor comprising a rotor opposed to each other through a directional clearance; and a support member that rotatably supports the rotor with respect to a shaft portion of the inner member via a pair of rolling bearings; An inward member is detachably coupled via the shaft portion, and the carrier is detachably coupled to the hub wheel and capable of transmitting torque, and the rotation of the electric motor is transmitted via the planetary speed reducer. It was transmitted to the hub wheel to drive the wheel.

  The use of such a configuration makes it possible to reduce the weight and size of the device and reduce the unsprung weight, to ensure sufficient bearing space and improve durability, and to support planetary elements against moment loads. In addition, it is possible to suppress a biased load from acting on the input element, and it is possible to suppress noise generated by the engagement between the planetary element and the input element. Furthermore, a sufficient space for the bearing portion can be secured, and the carrier constituting the planetary speed reducer is connected to the hub wheel so as to be detachable and capable of transmitting torque. As a subunit, it can be easily separated and replaced, so that it is not necessary to replace the entire apparatus, and resource saving and maintenance cost can be reduced.

  According to a second aspect of the present invention, the planetary speed reducer includes a sun gear provided on the support member, a ring gear integrally formed with the outer member, and a plurality of gears meshing with the sun gear and the ring gear. Because it consists of planetary gears and these planetary gears rotatably supported and carrier pins fixed to the carrier, it can transmit power efficiently without sliding contact and be lubricated with the same oil as the wheel bearings. You can also.

  In the invention according to claim 3, serrations are formed on the outer periphery of the small-diameter step portion of the hub wheel, and serrations that engage with the serrations are formed on the inner periphery of the carrier. The planetary reduction gear can be easily handled as a subunit, and an electric wheel drive device with improved disassembly / assembly can be provided.

  Moreover, like the invention of Claim 4, the said inner side rolling surface may be integrally formed in the outer periphery of the said hub ring and an inner member, respectively, Moreover, the invention of Claim 5 is provided. Thus, the said outer side rolling surface may be integrally formed in the inner periphery of the said 1st and 2nd outer member, respectively. As a result, the device can be further reduced in weight and size.

  An electric wheel drive device according to the present invention supports a pair of wheel bearings, a planetary reduction gear disposed between the wheel bearings, an electric motor that drives the planetary reduction gear, and the electric motor. A driving part having a support member having a substantially U-shaped cross section, and the wheel bearing on the outboard side of the pair of wheel bearings has a wheel mounting flange at one end, A hub wheel provided with an inner rolling surface and formed with a small-diameter stepped portion extending in the axial direction from the inner rolling surface, a cup-shaped drum on the outer periphery, and a cylinder concentrically extending radially inward of the drum And a first outer member having an outer rolling surface opposed to the inner rolling surface on the inner periphery of the base, and accommodated in a freely rollable manner between these rolling surfaces. Of the pair of wheel bearings. The inner wheel bearing has an inner rolling surface on the outer periphery, an inner member integrally formed with a shaft portion extending from the inner rolling surface to the outboard side, and an opening of the drum on the outer periphery. A second outer member having a disc-like lid member that is integrally closed and having an outer rolling surface facing the inner rolling surface on the inner periphery of the base, and a rolling member between the two rolling surfaces. A plurality of rolling elements housed in a freely movable manner, and the planetary speed reducer includes the fixed element, an input element provided on an outer peripheral surface of the inner cylinder of the support member, and the fixed element and the input element, respectively. A plurality of planetary elements to be combined, and an output element that rotatably supports these planetary elements with respect to the carrier, and the drive unit includes a stator fixed to the inner peripheral surface of the drum, and an outer surface of the support member. It is fixed to the outer peripheral surface of the cylinder and is opposed to this stator via a predetermined radial clearance. And a support member that rotatably supports the rotor with respect to a shaft portion of the inner member via a pair of rolling bearings, the hub wheel and the inner member being the shaft. And the carrier is detachably coupled to the hub wheel and capable of transmitting torque, and the rotation of the electric motor is transmitted to the hub wheel via the planetary speed reducer. Since the wheel is driven, the weight and size of the device can be reduced and the unsprung weight can be reduced, the space of the bearing can be secured sufficiently, and the load on the planetary element and the input element is offset against the moment load. The action can be suppressed, and the noise generated by the engagement between the planetary element and the input element can be suppressed. Furthermore, sufficient space for the bearing portion is secured to improve durability, and the carrier constituting the planetary reduction gear is detachably connected to the hub wheel and capable of transmitting torque. The planetary speed reducer and the drive unit can be easily separated and replaced as a subunit, so that it is not necessary to replace the entire device, and resource saving and maintenance cost can be reduced.

  A pair of wheel bearings, a planetary speed reducer disposed between the wheel bearings, an electric motor that drives the planetary speed reducer, and a cross section that supports the electric motor are formed in a substantially U-shape. Of the pair of wheel bearings, the wheel bearing on the outboard side has a wheel mounting flange at one end, an inner rolling surface on the outer periphery, and the inner rolling surface. A hub wheel formed with a small-diameter step portion extending in the axial direction from the shaft, a cup-shaped drum on the outer periphery, and a ring gear concentrically extending inward in the radial direction of the drum are integrally formed, and the inner side on the inner periphery of the base portion A pair of wheel bearings, comprising: a first outer member formed with an outer rolling surface facing the rolling surface; and a plurality of rolling elements accommodated so as to roll between both rolling surfaces. The wheel bearings on the inboard side have an inner rolling surface on the outer periphery. An inner member integrally formed with a shaft portion extending from the rolling surface to the outboard side, and a disc-shaped lid member that closes the opening of the drum on the outer periphery, and the inner portion on the inner periphery of the base portion A second outer member formed with an outer rolling surface facing the rolling surface, and a plurality of rolling elements accommodated so as to roll between the two rolling surfaces, the planetary speed reducer, A ring gear; a sun gear formed on the outer peripheral surface of the inner cylinder of the support member; a plurality of planetary gears respectively meshing with the ring gear and the sun gear; and a carrier pin for rotatably supporting the planetary gears with respect to the carrier; The drive unit includes: a stator fixed to the inner periphery of the drum; and a rotor fixed to the outer peripheral surface of the outer cylinder of the support member and facing the stator via a predetermined radial clearance. Electric motor and the rotor in front A support member rotatably supported via a pair of rolling bearings with respect to the shaft portion of the inner member, the hub wheel and the inner member are detachably coupled via the shaft portion, and A carrier is connected to the hub wheel via a serration, and the rotation of the electric motor is transmitted to the hub wheel via the planetary speed reducer to drive the wheel.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of an electric wheel drive device according to the present invention, and FIG. 2 is a transverse sectional view taken along line II-II in FIG. In the following description, the side closer to the outside of the vehicle in the state assembled to the vehicle is referred to as the outboard side (left side in the drawing), and the side closer to the center is referred to as the inboard side (right side in the drawing).

  This electric wheel drive device is composed of a pair of wheel bearings 1 and 2, a planetary reduction gear 3 disposed between the wheel bearings 1 and 2, and a sun gear 4 constituting the planetary reduction gear 3. The drive unit 5 is mainly configured.

  The wheel bearing 1 on the outboard side integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion thereof, an inner rolling surface 7a on the outer periphery, and the inner rolling surface 7a. A hub wheel 7 formed with a cylindrical small-diameter stepped portion 7b extending to the inboard side, and a cup-shaped drum 8b on the outer periphery are integrally formed, and an outer rolling which faces the inner rolling surface 7a on a base inner periphery. A first outer member 8 having a surface 8a formed thereon, a plurality of rolling elements (balls) 9 accommodated in a freely rolling manner between the rolling surfaces 7a, 8a, and the rolling elements 9 around the circumference, etc. And a retainer 10 for holding the arrangement.

  The first outer member 8 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner rolling surface 8a is hardened to a surface hardness of 54 to 64 HRC. As the heat treatment, local heating is preferable, and quenching by high-frequency induction heating that can set the hardened layer depth relatively easily is preferable. A seal 11 is attached to the end portion of the first outer member 8 on the outboard side to prevent leakage of oil that lubricates the inside of the bearing and intrusion of rainwater and dust from the outside into the bearing. ing.

  The hub wheel 7 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the outer peripheral surface thereof has a small diameter from the inner rolling surface 7a including the seal land portion serving as the base of the wheel mounting flange 6. The surface hardness of the stepped portion 7b is set in the range of 54 to 64 HRC. As the heat treatment, local heating is preferable, and quenching by high-frequency induction heating that can set the hardened layer depth relatively easily is preferable. Here, serrations (or splines) 12 are formed on the outer periphery of the small-diameter step 7b.

  The wheel bearing 2 on the inboard side includes an inner rolling surface 13a on the outer periphery, an inner member 13 integrally formed with a shaft portion 14 extending from the inner rolling surface 13a to the outboard side, and the drum on the outer periphery. An outer rolling surface that closes the opening of 8b and integrally has a disc-like lid member 15b fixed to the drum 8b via a fixing bolt 15c, and that faces the inner rolling surface 13a on the inner periphery of the base. A second outer member 15 formed with 15a, a plurality of rolling elements 9 accommodated in a freely rolling manner between the rolling surfaces 13a and 15a, and the rolling elements 9 are held in a circumferentially equidistant manner. And a cage 10. The shaft portion 14 includes a spindle portion 14a on which a pair of rolling bearings 18 and 18 for supporting a support member 17 to be described later is fitted, a fitting portion 14b extending from the spindle portion 14a to the outboard side, and a screw portion at the tip portion. 14c is formed.

  The inner member 13 is made of medium carbon steel containing carbon 0.40 to 0.80 wt% such as S53C, and the outer peripheral surface of the inner member 13 extends from the inner rolling surface 13a to the spindle portion 14a and the fitting portion 14b of the shaft portion 14. Thus, the surface hardness is cured in the range of 54 to 64 HRC. As the heat treatment, local heating is preferable, and quenching by high-frequency induction heating that can set the hardened layer depth relatively easily is preferable. A seal 11 is attached to the end of the second outer member 15 on the inboard side to prevent leakage of oil that lubricates the inside of the bearing and intrusion of rainwater or dust from the outside into the bearing. ing.

  The second outer member 15 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner rolling surface 15a is hardened to a surface hardness of 54 to 64 HRC. As the heat treatment, local heating is preferable, and quenching by high-frequency induction heating that can set the hardened layer depth relatively easily is preferable.

  In addition, although the angular ball bearing which used the ball | bowl for the rolling element 9 was illustrated here, it is not restricted to this, The tapered roller bearing using a tapered roller may be sufficient. Further, the wheel bearings 1 and 2 exemplify a configuration in which rolling surfaces are directly formed on the outer periphery of the hub wheel 7 and the inner member 13 and the inner periphery of the first and second outer members 8 and 15. However, the present invention is not limited to this, and although not illustrated, a configuration in which separate inner rings and outer rings are press-fitted and fixed may be employed.

  A ring gear (fixed element) 16 that extends concentrically protrudes radially inward of the drum 8 b in the first outer member 8, and an inner tooth 16 a is formed on the inner periphery of the ring gear 16. . The support member 17 is integrally provided with an outer cylindrical portion 17a that covers the outer periphery of the ring gear 16, and is rotatably supported on the shaft portion 14 of the inner member 13 via a pair of rolling bearings 18 and 18. Is arranged. The support member 17 has an outer cylinder part 17a and an inner cylinder part 17b concentric with the outer cylinder part 17a, and has a substantially U-shaped cross section. The inner cylinder portion 17 b is configured as a sun gear (input element) 4. External teeth 4 a are formed on the outer periphery of the sun gear 4.

  A carrier 19 is disposed in an annular space formed between the ring gear 16 and the support member 17. The carrier 19 is formed in a crank shape including a base portion 19a, a cylindrical portion 19b extending in the axial direction from the base portion 19a, and a disk-shaped support portion 19c extending radially outward from the cylindrical portion 19b. Yes. A plurality (3 to 5) of carrier pins (output elements) 20 are fixed to the support portion 19c at equal intervals in the circumferential direction, and planetary gears (planetary elements) 21 are connected to these carrier pins 20 via rolling bearings 22. And is rotatably supported. The outer teeth 21 a of the planetary gear 21 mesh with the inner teeth 16 a of the ring gear 16 and the outer teeth 4 a of the sun gear 4 to constitute a planetary planetary speed reducer 3.

  A serration (or spline) 23 is formed on the inner periphery of the base portion 19a of the carrier 19, and is engaged with the serration 12 formed on the small-diameter step portion 7b of the hub wheel 7 so as to be able to transmit torque and connected to the hub wheel 7. Yes. In addition, although the ring gear 16 and the sun gear 4 illustrated what was directly formed in the drum 8b and the supporting member 17 of the 1st outer member 8, not only this but the separate ring gear and the sun gear were press-fit. It may be a thing.

  A rotor portion 24 is fixed to the outer peripheral surface of the outer cylinder portion 17a of the support member 17. This rotor part 24 consists of a plurality of permanent magnets. Further, a stator portion 25 is disposed opposite to the rotor portion 24 via a predetermined radial clearance (air gap). The stator portion 25 is fixed to the inner peripheral surface of the drum 8 b in the first outer member 8. The stator portion 25 includes a stator iron core 25a and a stator coil 25b wound around the stator iron core 25a. The rotor unit 24 and the stator unit 25 constitute an electric motor M. The drive unit 5 includes the electric motor M and the support member 17.

  Here, the hub wheel 7 is press-fitted and fixed to the fitting portion 14b of the inner member 13, and a fixing nut 26 is fastened to the screw portion 14c. The inner member 13 constituting the wheel bearing 2 on the inboard side, The hub wheel 7 constituting the wheel bearing 1 on the outboard side is integrally coupled.

  When the electric motor M is energized, the support member 17 is rotated, and the rotation of the support member 17 is transmitted to the planetary gear 21 via the sun gear 4, and the rotation of the planetary gear 21 is transmitted to the hub wheel via the carrier 19. 7 is transmitted to drive the wheel.

  In the present embodiment, a cover 27 is fixed to the end of the ring gear 16 serving as a fixing member, and a seal 28 is attached to the cover 27. The seal 28 is brought into sliding contact with the support member 17 serving as a rotating member, and the annular space formed between the ring gear 16 and the support member 17 is sealed. Further, a seal 29 is attached to the end portion of the second outer member 15 constituting the wheel bearing 2 on the inboard side. The seal 29 is brought into sliding contact with the support member 17 to seal the annular space formed between the second outer member 15 and the support member 17. As a result, the wheel bearings 1 and 2, the planetary speed reducer 3, and the pair of rolling bearings 18 and 18 that support the support member 17 can all be lubricated with the same oil. It is also possible to mount seals (not shown) on both sides of the wheel bearings 1 and 2 and the pair of rolling bearings 18 so that only these bearings are grease-lubricated and the planetary reduction gear 3 is oil-lubricated. .

  The reduction ratio of the planetary reduction gear 3 described above can be adjusted as appropriate by changing the ratio of the number of teeth of the planetary gear 21 and the number of teeth of the ring gear 16. For example, in an electric wheel drive device for an electric vehicle, When applied, the reduction ratio can be set in the range of 3-9. Furthermore, if a reduction ratio of this level is obtained, it can be sufficiently dealt with by reducing the outer diameter of the sun gear 4, and the planetary reduction gear 3 does not increase in size as the reduction ratio is increased. , Light weight, compactness and unsprung weight can be reduced.

  In this embodiment, since the planetary reduction gear 3 is disposed between the pair of wheel bearing devices 1 and 2, sufficient space for the bearing portion is ensured to improve durability, and the moment load is reduced. On the other hand, it is possible to suppress a biased load from acting on the planetary gear 21 and the sun gear 4, and it is possible to suppress a meshing sound generated by the meshing of the planetary gear 21 and the sun gear 4. Further, since the carrier 19 constituting the planetary speed reducer 3 is connected to the hub wheel 7 via the serrations 23 and 12, the wheel bearings 1 and 2, the planetary speed reducer 3 and the drive unit 5 are connected to the subunit at the time of repair. Can be easily separated and replaced, eliminating the need to replace the entire device, saving resources and reducing maintenance costs.

  In the present embodiment, the elements of the planetary speed reducer are illustrated in which the power is transmitted by the gear transmission means. However, the present invention is not limited to this, and power transmission (traction drive) may be performed by the friction means. In this case, noise and vibration generated during power transmission can be suppressed as much as possible.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The electric wheel drive device according to the present invention is a four-wheeled vehicle such as a fuel cell vehicle and an electric vehicle, a two-wheeled vehicle, a golf cart, a three-wheeled or four-wheeled cart for elderly people and persons with disabilities, and a construction site or a transportation industry. The present invention can be applied to an electric wheel drive device when various vehicles such as a hand-held type unicycle to a four-wheel vehicle to be used are electrically driven, or when auxiliary power is applied by electric drive.

1 is a longitudinal sectional view showing an embodiment of an electric wheel drive device according to the present invention. It is a transverse cross section along the II-II line same as the above. It is a longitudinal cross-sectional view which shows the conventional electric wheel drive device.

Explanation of symbols

1, 2, ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel bearing 3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Planar reducer 4 ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Sun gear 4a, 21a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ External teeth 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Driver 6 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flange 7 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ Hub wheel 7a, 13a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 7b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ Small diameter step 8 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ First outer member 8a, 15a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Outer rolling surface 8b ......... Drum 9 ......... Rolling element 10 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retainer 11, 28, 29 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal 12, 23 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・.... Serration 13 ..... Inner member 14 ...・ Shaft part 14a ... Spindle part 14b ... Fitting part 14c ... ............ Threaded part 15 ... 2nd outer member 15b ... ·········· Lid member 15c ... ... ring gear 16a ... internal teeth 17 ...・ ・ ・ ・ ・ ・ ・ ・ ・ Supporting member 17a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer cylinder 17b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ Inner cylinder parts 18, 22 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling bearing 19 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Carrier 19a・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Base 19b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Cylindrical part 19c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ Supporting part 20 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Carrier pin 21 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ Planetary gear 24 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rotor 25 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Stator 25a・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Stator core 25b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ Stator coil 26 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Fixing nut 27 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Cover 51・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Electric wheel drive device 52 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Tire 53・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel 54 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Electric motor 55 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... gear reducer 55a ... the first gear 55b ... 2nd gear 55c ... 3rd gear 55d ... 4th gear 56 · · · · · · · · · · · · · 56a, 60a, 61a ... .. Recess 56b ..... Insertion hole 57 .....・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rotor 59 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Output shaft 59a, 66a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... one end 59b, 66b ... the other end 60, 61 ... cover 62 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mounting flange 63 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub bolts 64, 65, 67, 68・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling bearing 66 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Support shaft M ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・..Electric motor

Claims (5)

A pair of wheel bearings, a planetary speed reducer disposed between the wheel bearings, an electric motor that drives the planetary speed reducer, and a cross section that supports the electric motor are formed in a substantially U-shape. A drive unit having a support member,
Of the pair of wheel bearings, the wheel bearing on the outboard side has a wheel mounting flange at one end, an inner rolling surface is provided on the outer periphery, and a small diameter step portion extending in the axial direction from the inner rolling surface. Is formed integrally with a hub-shaped wheel, a cup-shaped drum on the outer periphery, and a cylindrical fixing element that extends concentrically inwardly in the radial direction of the drum. A first outer member provided with an outer rolling surface, and a plurality of rolling elements accommodated so as to roll between these rolling surfaces,
Of the pair of wheel bearings, the wheel bearing on the inboard side is provided with an inner rolling surface on the outer periphery, and an inner member integrally formed with a shaft portion extending from the inner rolling surface to the outboard side. A second outer member integrally having a disc-like lid member for closing the opening of the drum on the outer periphery, and having an outer rolling surface facing the inner rolling surface on the inner periphery of the base portion; A plurality of rolling elements housed so as to be freely rollable between both rolling surfaces,
The planetary speed reducer includes the fixed element, an input element provided on an outer peripheral surface of the inner cylinder of the support member, a plurality of planet elements that respectively engage with the fixed element and the input element, and the planet elements as carriers. And an output element that is rotatably supported
An electric motor comprising: a stator fixed to an inner peripheral surface of the drum; and a rotor fixed to the outer peripheral surface of an outer cylinder of the support member and facing the stator via a predetermined radial clearance. A support member that rotatably supports the rotor with respect to the shaft portion of the inner member via a pair of rolling bearings,
The hub wheel and the inward member are detachably coupled via the shaft portion, and the carrier is detachably coupled to the hub wheel so as to be able to transmit torque, and the rotation of the electric motor is controlled by the planetary speed reducer. An electric wheel drive device for driving a wheel by transmitting to the hub wheel via a wheel.   The planetary reducer includes a sun gear provided on the support member, a ring gear integrally formed with the outer member, a plurality of planetary gears meshing with the sun gear and the ring gear, and the planetary gears being rotatable. The electric wheel drive device according to claim 1, comprising a carrier pin that is supported and fixed to the carrier.   The electric wheel drive device according to claim 1 or 2, wherein serrations are formed on an outer periphery of the small-diameter step portion of the hub wheel, and serrations that engage with the serrations are formed on an inner periphery of the carrier.   The electric wheel drive device according to any one of claims 1 to 3, wherein the inner rolling surface is integrally formed on the outer periphery of the hub wheel and the inner member.   The electric wheel drive device according to any one of claims 1 to 4, wherein the outer rolling surface is integrally formed on an inner periphery of each of the first and second outer members.

Images