JP2006149000A - Electromotive wheel driving unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromotive wheel driving unit which can improve the durability of a transmission, being able to prevent the abrasion of the coupling section between the outer ring of a frictional roller system of transmission and a wheel. <P>SOLUTION: In the electromotive wheel driving unit where an electric motor 5 and the frictional roller type transmission 6 are built in inside the wheel 1 of a wheel 3, the frictional roller system of transmission 6 is equipped with a retaining ring 33 which is arranged inside the outer ring 32 and is coupled with the wheel 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric wheel drive device, and in particular, a four-wheeled vehicle, a two-wheeled vehicle, a golf cart, a three-wheeled or four-wheeled cart for elderly people and persons with disabilities, a hand-held type used in the construction site and the transportation industry The present invention relates to an electric wheel drive device used when various vehicles such as a unicycle or a four-wheel vehicle are electrically driven (including a case where auxiliary power is applied by electricity).

  In an electric wheel drive device incorporating a prime mover such as an electric motor as a drive device, conventionally, a friction roller type transmission is assembled to the output part of the prime mover and used as a speed reducer to reduce the rotational motion of the prime mover and increase the torque. The structure to make is known (for example, refer patent documents 1-6).

  The friction roller type transmissions described in Patent Documents 1 to 6 are rotatably provided together with the output shaft in an eccentric state with respect to the outer peripheral surface of the rotational drive shaft driven by the electric motor and the rotational drive shaft. At least one guide roller and at least one movable roller that generates a pressing force by a wedge action are provided in an internal space between the inner peripheral surface of the outer ring. In this transmission, the contact pressure between the peripheral surfaces of the rollers is changed by friction engagement according to the magnitude of torque to be transmitted to ensure good transmission efficiency. Further, the outer ring and the output shaft are coupled by a claw such as a square spline, and a degree of freedom in the radial direction and the axial direction is provided therebetween.

  Moreover, as an electric wheel drive device, a structure is known in which an electric motor is incorporated on the inner diameter side of a wheel constituting the wheel and the driving force of the electric motor is transmitted to the wheel (see, for example, Patent Documents 7 and 8). .

The electric wheel drive device described in Patent Document 7 is configured to directly rotate and drive the wheel by an electric motor without using a transmission. On the other hand, the electric wheel drive device described in Patent Document 8 is configured to transmit the driving force of the electric motor to the wheel via a multistage gear transmission.
Japanese Patent Laid-Open No. 10-316081 Japanese Patent Laid-Open No. 10-252853 Japanese Patent Laid-Open No. 2002-13604 JP-A-10-281248 JP-A-10-281249 JP 2001-271897 A JP 7-131961 A Japanese Patent Laid-Open No. 9-23631

  By the way, the electric wheel drive devices described in Patent Documents 7 and 8 are large and heavy, and there is a risk of noise problems. For this reason, in these electric wheel drive devices incorporating an electric motor on the inner diameter side of the wheel, it is conceivable to employ a friction roller type transmission as means for transmitting the driving force from the electric motor to the wheel.

  In this case, the output shaft of the friction roller type transmission corresponds to a wheel, but since the wheel is generally made of aluminum, the outer ring using an iron-based material and the aluminum wheel are connected by a spline or the like. If they are joined, the joint part will be defective due to wear or the like.

  The present invention has been made in view of such circumstances, and an object of the present invention is to prevent wear at the coupling portion between the outer ring and the wheel of the friction roller type transmission and improve the durability of the transmission. An object of the present invention is to provide an electric wheel drive device that can be used.

The above object of the present invention can be achieved by the following constitution.
(1) An electric wheel drive device incorporating an electric motor and a friction roller type transmission on the inner diameter side of the wheel of the wheel,
The friction roller type transmission includes an outer ring provided around the tip of a rotary drive shaft driven by the electric motor and rotatably provided with the wheel in an eccentric state with respect to the rotary drive shaft. In an annular inner space that exists between a drive-side cylindrical surface that is the outer peripheral surface of the drive shaft and a driven-side cylindrical surface that is the inner peripheral surface of the outer ring and whose width in the radial direction is not the same in the circumferential direction At least one guide roller and at least one movable roller, each having an outer peripheral surface as a power transmission cylindrical surface,
The friction roller type transmission further includes a holding ring that is disposed on an inner diameter side of the outer ring and is coupled to the wheel.

  According to the electric wheel driving device of the present invention, the friction roller type transmission is disposed on the inner diameter side of the outer ring and further includes a holding ring coupled to the wheel. Therefore, the outer ring and the wheel of the friction roller type transmission are provided. Wear at the connecting portion can be prevented, and the durability of the transmission can be improved.

  Hereinafter, a friction roller transmission according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an internal structure of the electric wheel drive device according to the embodiment of the present invention, and is a cross-sectional view taken along the line II of FIG. FIG. 2 is a cross-sectional view taken along line II-II in FIG.

  An electric wheel drive device according to an embodiment of the present invention includes a wheel 3 formed by supporting a tire 2 around an aluminum wheel 1 and an inner diameter side of the wheel 1 for rotationally driving the wheel 3. And driving means provided in the above. The driving means is supported by a suspension device (not shown) and the wheel 1 is rotatably supported around the driving means, whereby the wheel 3 is rotatably supported by the suspension device.

  This driving means is formed by connecting an electric motor 5 and a friction roller type transmission 6 utilizing a wedge action in series with each other in the power transmission direction. Here, the friction roller type transmission using the wedge action is provided around the tip of the rotary drive shaft driven by the electric motor and is rotatable with the wheels in an eccentric state with respect to the rotary drive shaft. Between the outer ring and the driving-side cylindrical surface that is the outer peripheral surface of the rotary drive shaft and the driven-side cylindrical surface that is the inner peripheral surface of the outer ring, and the width in the radial direction is not the same in the circumferential direction A transmission including at least one guide roller and at least one movable roller, each of which is disposed in an annular inner space and has an outer peripheral surface as a cylindrical surface for power transmission. The movable roller is a roller that generates a pressing force by a wedge action, and refers to a roller that moves in a radial direction and a circumferential direction.

  The electric motor 5 has a bottomed cylindrical motor case 7. The motor case 7 has a bottomed cylindrical main body 9 having a bottom plate portion 8 at a base end portion (left end portion in FIG. 1), and a lid fixedly attached to a front end (right end in FIG. 1) opening portion of the main body 9. It is formed by combining with the plate 10. The central axis of the outer peripheral surface of the peripheral wall 11 of the main body 9 and the central axis of the inner peripheral surface are decentered from each other so that the thickness of the peripheral wall 11 is not the same in the circumferential direction. Screw holes (not shown) are formed at a plurality of locations on the base end surface of the main body 9, and a plurality of bolts (not shown) through which components of a suspension device (not shown) are inserted are also connected to the screw holes (not shown). The main body 9 can be coupled and fixed to the suspension device by being screwed onto and tightened. Further, on one side of the lid plate 10 (the left side in FIG. 1), an annular protrusion 13 is formed which can be fitted to the tip opening of the main body 9 without rattling. The center of the annular protrusion 13 and the center of the outer peripheral surface of the cover plate 10 are eccentric from each other in accordance with the eccentricity of the outer peripheral surface and the inner peripheral surface of the peripheral wall portion 11. Such a cover plate 10 is attached to the front end opening of the main body 9 with the annular protrusion 13 fitted inside the front end opening of the main body 9, and is further coupled to the main body 9 by a plurality of screws 14. It is fixed.

  In this manner, the main body 9 and the cover plate 10 are coupled and fixed to each other. Both end portions of the motor case 7 are respectively provided with support holes 15 and through holes 16 concentrically with each other and the peripheral wall portion 11. Concentric with the inner surface. Then, the base end portion (left end portion in FIG. 1) and the intermediate portion front end portion (right side in FIG. 1) of the rotary drive shaft 17 constituting the electric motor 5 are respectively rotated inside the support hole 15 and the through hole 16. Supports freely. Among these, inside the support hole 15 provided in the central portion of the bottom plate portion 8 of the main body 9, the base end portion of the rotary drive shaft 17 is arranged in both radial and axial directions such as a deep groove type or angular type ball bearing. The load is rotatably supported by a rolling bearing 18 that can be supported. On the other hand, inside the through hole 16 provided in the central portion of the cover plate 10, a portion near the tip of the intermediate portion of the rotary drive shaft 17 is arranged in both radial and axial directions such as a deep groove type or angular type ball bearing. Is supported by a rolling bearing 19 that can be freely supported.

  In this way, a rotor 20 composed of a permanent magnet or the like is rotationally driven between the pair of rolling bearings 18 and 19 at an intermediate portion of the rotational drive shaft 17 rotatably supported with respect to the motor case 7. It is externally supported in a state in which rotation with respect to the shaft 17 is prevented. On the other hand, the stator 21 is supported and fixed to a portion of the inner peripheral surface of the peripheral wall portion 11 that faces the outer peripheral surface of the rotor 20.

  Further, convex portions 25 are formed on the other surface of the lid plate 10 (the right surface in FIG. 1) in the radial intermediate portion and at three positions in the circumferential direction. 26 is coupled and fixed. The connecting plate 26 has protrusions 27 at three positions in the circumferential direction on one side (left surface in FIG. 1) opposite to the protrusions 25 on both side surfaces. In a state where the tip surfaces of the portions 25 are in contact with each other, the bolts are fixed to the lid plate 10 by three bolts 28. In the illustrated example, an inlay fitting portion is provided between the outer peripheral edge portion of each protrusion 27 and the inner peripheral edge portion of the convex portion 25 so as to position the connecting plate 26 with respect to the lid plate 10 in the radial direction. Yes. In this manner, with the connecting plate 26 being coupled and fixed to the lid plate 10, the three protruding portions 27 cover the periphery of the distal end portion of the rotary drive shaft 17. In addition, the tip of the rotary drive shaft 17 is in a state of loosely entering a concave hole 29 formed at the center of one side of the connecting plate 26.

  Further, a support shaft 30 protrudes from the center of the other surface of the connecting plate 26 (the right surface in FIG. 1) so as to protrude to the opposite side of the cover plate 10. A deep groove type or angular type ball bearing provided between the outer peripheral surface of the support shaft 30 and the outer peripheral surface of the tip end of the main body 9 of the motor case 7 and the inner peripheral surface of the wheel 1 is provided. The wheel 1 is rotatably supported with respect to a suspension device (not shown) by rolling bearings 31a, 31b, 31c that can support loads in both radial and axial directions. In this state, the wheel 1 is disposed concentrically with the outer peripheral surface of the main body 9. Therefore, the wheel 1 and the inner peripheral surface of the main body 9 are eccentric from each other.

  A friction roller type is provided at a radial intermediate portion between the inner peripheral surface of the intermediate portion of the wheel 1 and the tip end portion of the rotary drive shaft 17 that is rotatably supported by the main body 9 in such a positional relationship. An outer ring 32 made of an iron-based material for constituting the transmission 6 is disposed. The outer ring 32 is connected to the wheel 1 via a holding ring 33 disposed on the inner diameter side of the outer ring 32. As shown in FIG. 1 and FIG. 3, the inner peripheral surface of the holding ring 33 is formed in a stepped shape, and the holding ring 33 has a large-diameter inner peripheral surface 33 a on one side surface of the disk portion 1 a of the wheel 1 ( It is fitted and fixed by a plurality of bolts 34 by fitting with an inlay portion 1b protruding in the axial direction from the left side in FIG. The outer ring 32 is spline-engaged with a spline portion 33b formed on the outer peripheral surface of the holding ring 33, and is held at a predetermined position shown in FIG. The spline that engages the holding ring 33 and the outer ring 32 is provided with sufficient play, and the outer ring 32 can move freely in the radial direction and the axial direction by the amount of play of the spline with respect to the holding ring 33. Thus, machining tolerances, assembly tolerances, and deformation of parts during operation are allowed. In this state, the inner peripheral surface of the outer ring 32 is substantially concentric with the wheel 1 and is eccentric from the outer peripheral surface of the rotary drive shaft 17. Therefore, an annular inner space 36 having a radial width that is not the same in the circumferential direction is provided between the inner peripheral surface of the outer ring 32 and the outer peripheral surface of the distal end portion of the rotary drive shaft 17.

  In such an internal space 36, two guide rollers 37a and 37b and one movable roller 38 are installed to constitute the friction roller type transmission 6. In FIG. 2, the movable roller 38 is shown partially cut away. In order to install these rollers 37a, 37b, 38, three support shafts 39a, 39a, 39b are provided in the internal space 36 portion. Of these three support shafts 39a, 39a, 39b, the two support shafts 39a, 39a located on the lower right side of FIGS. 1 and 2 and the upper right side of FIG. It is press-fitted into the fitting holes 40, 40 formed in the No. 26, or fitted without rattling. Therefore, these two support shafts 39a and 39a are not displaced in the circumferential direction or the diametrical direction in the internal space 36. On the other hand, among the three support shafts 39a, 39a, 39b, the remaining one support shaft 39b located on the upper left side in FIG. 2 has both ends of the outer ring 32 with respect to the cover plate 10 and the connecting plate 26. Is supported so as to be slightly displaceable in the circumferential direction and the diameter direction. For this purpose, a support hole 41 having an inner diameter larger than the outer diameter of the support shaft 39b is formed in a part of the lid plate 10 and the connecting plate 26 that is aligned with both ends of one support shaft 39b. Both end portions of the support shaft 39b are loosely engaged with the support holes 41.

  The guide rollers 37a, 37b and the movable roller 38 are respectively provided around the intermediate portions of the support shafts 39a, 39a, 39b supported as described above, respectively, and bearings such as radial needle bearings 42, 42 (movable roller bearings). Is not shown) and is rotatably supported. In order to connect and fix the connecting plate 26 to the lid plate 10, each projecting portion 27 protruding from one side of the connecting plate 26 has guide rollers 37 a and 37 b and a movable portion in the circumferential direction of the connecting plate 26. Present between the rollers 38. In other words, the protrusions 27 and the guide rollers 37 a and 37 b or the movable rollers 38 are alternately present in the inner space 36 in the circumferential direction of the inner space 36. Further, the outer peripheral surface of each guide roller 37a, 37b or movable roller 38 and the circumferential side surface of each projection 27 do not interfere (rub against).

  In this way, the outer peripheral surfaces of the guide rollers 37a and 37b and the movable roller 38 are rotatably supported between the lid plate 10 and the connecting plate 26 by the support shafts 39a, 39a and 39b. The power transmission cylindrical surfaces 43 a, 43 a, and 43 b are brought into contact with the driving-side cylindrical surface 44 that is the outer peripheral surface of the tip of the rotary drive shaft 17 and the driven-side cylindrical surface 45 that is the inner peripheral surface of the outer ring 32. ing. As described above, the width in the radial direction of the internal space 36 in which the guide rollers 37a and 37b and the movable roller 38 are installed is not the same in the circumferential direction. In this way, the outer diameters of the guide rollers 37a and 37b and the movable roller 38 are made different from each other by making the width dimension of the internal space 36 the same in the circumferential direction. That is, among the guide rollers 37a and 37b and the movable roller 38, the movable roller 38 and the guide roller 37b located on the side where the tip of the rotational drive shaft 17 is eccentric with respect to the outer ring 32 (upper side in FIGS. 1 and 2). The outer diameters are the same as each other and are relatively small. On the other hand, the outer diameter of the guide roller 37a located on the opposite side (lower side in FIGS. 1 and 2) to the outer ring 32 where the tip of the rotational drive shaft 17 is eccentric is set to the movable roller 38 and the guide roller 37b. It is larger than the outer diameter. The power transmission cylindrical surfaces 43a, 43a, 43b, which are outer peripheral surfaces of the guide rollers 37a, 37b and the movable roller 38, are brought into contact with the driving side and driven side cylindrical surfaces 44, 45, respectively.

  Of the guide rollers 37a and 37b and the movable roller 38, both ends of the support shafts 39a and 39a that support the guide rollers 37a and 37b are connected to the cover plate 10 and the connecting plate 26 as described above (see FIG. It is fixed in the internal space 36). On the other hand, the support shaft 39b that supports the movable roller 38 can be slightly displaced in the circumferential direction and the diameter direction with respect to the lid plate 10 and the connecting plate 26 (inside the internal space 36) as described above. I support it. Therefore, the movable roller 38 can also be slightly displaced in the circumferential direction and the diameter direction in the internal space 36. Then, a movable roller, which is installed in the cylinder hole 46 of the lid plate 10 and the connecting plate 26, supports a support shaft 39b that supports the movable roller 38 by an elastic material 47 such as a compression spring, and rotatably supports the support shaft 39b. In order to move 38 toward the narrow portion of the internal space 36, it is pressed lightly elastically.

  In addition, traction oil or traction grease is sealed in the internal space 36 in which the rollers 37a, 37b, and 38 are disposed, and the rollers 37a, 37b, and 38, the rotary drive shaft 17, and the rollers 37a and 37b. , 38 and the outer ring 32 are lubricated at the contact portion, and efficient power transmission at the contact portion is enabled. The friction roller type transmission 6 includes sealing means 50, 51, 52 for preventing traction oil or traction grease existing in the internal space 36 from flowing out of the internal space 36. Specifically, the sealing means 50 is an oil seal provided between the cylindrical portion 53 extending in the axial direction from the other surface (the right surface in FIG. 1) of the lid plate 10 and the outer diameter surface 32a of the outer ring 32. The sealing means 51 is an O-ring provided between an annular groove 54 formed on one side surface (the left surface in FIG. 1) of the disk portion 1 a of the wheel 1 and the end surface 32 b of the outer ring 32. The sealing means 52 is an O-ring provided between the annular groove 55 formed in the through hole 16 of the lid plate 10 and the rolling bearing 19.

  When the wheel is driven to rotate by the electric wheel drive device of the present invention configured as described above, the rotation drive shaft 17 of the electric motor 5 is rotated clockwise in FIG. Rotate. The rotation of the rotary drive shaft 17 is transmitted to the outer ring 32 via the guide rollers 37a and 37b and the movable roller 38, and rotates the rollers 37a, 37b and 38 counterclockwise in FIG. Further, the rotation of each of the rollers 37a, 37b, 38 is transmitted to the outer ring 32, and the outer ring 32 is rotated together with the wheel 1 in the counterclockwise direction of FIG. Power transmission between the rotary drive shaft 17 and the guide rollers 37a and 37b and the movable roller 38, and power transmission between the guide rollers 37a and 37b and the movable roller 38 and the outer ring 32 are all performed by friction transmission. Therefore, noise and vibration generated during power transmission are low.

  Further, the movable roller 38 tends to bite into a portion where the width of the inner space 36 is narrow (the upper central portion in FIG. 2) with a force corresponding to the magnitude of torque transmitted from the rotary drive shaft 17 to the outer ring 32. For this reason, the contact portion between the drive-side cylindrical surface 44 that is the outer peripheral surface of the rotary drive shaft 17 and the power transmission cylindrical surfaces 43a, 43a, and 43b that are the outer peripheral surfaces of the guide rollers 37a and 37b and the movable roller 38, and The contact pressure between the power transmission cylindrical surfaces 43a, 43a, 43b and the driven-side cylindrical surface 45, which is the inner peripheral surface of the outer ring 32, increases as the torque increases. In other words, when the torque is small, the surface pressure of each contact portion is low. For this reason, the surface pressure of each contact portion is set to an appropriate value according to the torque to be transmitted, and torque transmission can be performed efficiently.

  That is, when the distal end portion of the rotational drive shaft 17 rotates clockwise in FIG. 2 and the outer ring 32 is rotated counterclockwise, the movable roller 38 is a drive that is the outer peripheral surface of the distal end portion of the rotational drive shaft 17. 2 receives a force in the same direction as the pressing force by the elastic material 47 from the driven cylindrical surface 45, which is the inner peripheral surface of the side cylindrical surface 44 and the outer ring 32, and thus a narrow portion of the internal space 36, that is, in FIG. It tends to move toward the upper center.

  As a result, the power transmission cylindrical surface 43 b, which is the outer peripheral surface of the movable roller 38, strongly presses the driving side cylindrical surface 44 and the driven side cylindrical surface 45. An inner diameter side contact portion 48 that is a contact portion between the power transmission cylindrical surface 43b and the driving side cylindrical surface 44, and a contact portion between the power transmission cylindrical surface 43b and the driven side cylindrical surface 45. The contact pressure of the outer diameter side contact portion 49 is increased. In this way, when the contact pressure of both the inner diameter side and outer diameter side contact portions 48 and 49 with respect to the movable roller 38 increases, the rotational drive is pressed by the power transmission cylindrical surface 43b which is the outer peripheral surface of the movable roller 38. The shaft 17 and the outer ring 32 are slightly displaced in the diametrical direction due to elastic deformation and an assembly gap. As a result, the contact pressure of the both inner diameter side and outer diameter side contact portions 48 and 49 with respect to the respective guide rollers 37a and 37b is increased. Then, based on the frictional engagement at the respective inner diameter side and outer diameter side abutting portions 48 and 49, the rotational force of the distal end portion of the rotary drive shaft 17 is transmitted through the guide rollers 37a and 37b and the movable roller 38 to the outer ring. 32 can be transmitted freely.

  As described above, the force for moving the movable roller 38 toward the narrow part of the internal space 36 depends on the magnitude of the rotational driving force transmitted from the tip of the rotational driving shaft 17 to the outer ring 32. Change. As the force increases, the contact pressures of both the inner diameter side and outer diameter side contact portions 48 and 49 increase. Therefore, based on such an action, the contact pressure corresponding to the rotational driving force to be transmitted can be automatically selected to ensure the transmission efficiency of the friction roller type transmission.

  In the case of this embodiment, the friction roller transmission 6 has a one-way clutch function, and the rotational speed of the outer ring 32 matches the rotational speed of the rotary drive shaft 17, that is, the rotational speed of the rotary drive shaft 17. Is faster than the speed divided by the reduction ratio of the friction roller transmission 6, the friction roller transmission 6 is disconnected. That is, in this case, the movable roller 38 is displaced to the wide side (lower left side in FIG. 2) of the internal space 36 against the elasticity of the elastic material 47. As a result, the contact portions of both the inner diameter side and outer diameter side contact portions 48 and 49 are lowered or lost, and the rotation of the outer ring 32 is not transmitted to the rotary drive shaft 17. Therefore, the structure of this embodiment is an appropriate structure when the wheel 3 is rotationally driven only in one direction.

  Note that the reduction ratio of the friction roller transmission 6 can be arbitrarily adjusted by changing the ratio of the outer diameter of the tip of the rotary drive shaft 17 to the inner diameter of the outer ring 32. When considering the friction roller type transmission 6 incorporated in the electric wheel drive device for an electric vehicle, the reduction ratio can be set in the range of about 3-9. Moreover, if a reduction ratio of this level is obtained, it is possible to cope with this problem by reducing the outer diameter of the tip of the rotary drive shaft 17, so that the friction roller type transmission is increased as the reduction ratio is increased. 6 does not increase in size. Therefore, the electric motor 5 can be a high-speed, small and lightweight one, and the entire electric wheel drive device can be reduced in size and weight. For this reason, it is possible to facilitate the design of an electric wheel drive device that must be installed in a limited space together with braking components such as a disk rotor. In addition, when incorporated in an automobile having a suspension system with a spring, the so-called unsprung load can be reduced, which can contribute to the improvement of the running performance of the electric automobile centered on the ride comfort and running stability. In addition, it is possible to realize an electric wheel drive device that can be configured in a small size and light weight, can easily obtain sufficient traveling performance, and has low noise generated during driving at low cost.

  As described above, according to the electric wheel drive device of the present embodiment, the friction roller transmission 6 is disposed on the inner diameter side of the outer ring 32 and includes the holding ring 33 coupled to the wheel 1. It is possible to avoid the direct sliding of the outer ring 32 using the iron-based material and the aluminum wheel 1 by a spline or the like, and to prevent wear at these connecting portions, thereby improving the durability of the transmission.

  Further, since the retaining ring 33 and the outer ring 32 are spline-engaged, the outer ring 32 can be moved relative to the retaining ring 33 in the radial direction and the axial direction. The deformation of the parts can be allowed.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

It is sectional drawing which shows the internal structure of the electrically driven wheel drive device which concerns on embodiment of this invention. It is sectional drawing along the AA line of FIG. (A) is a front view which shows a retaining ring, (b) is sectional drawing along the III-III line of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wheel 2 Tire 3 Wheel 4 Support cylinder part 5 Electric motor 6 Friction roller type transmission 7 Motor case 8 Bottom plate part 9 Main body 10 Cover plate 11 Peripheral wall part 13 Annular protrusion 14 Screw 15 Support hole 16 Through hole 17 Rotation drive shaft 18 Rolling bearing 19 Rolling bearing 20 Rotor 21 Stator 25 Annular convex portion 26 Connecting plate 27 Projection portion 28 Bolt 29 Recessed hole 30 Support shaft 31a, 31b, 31c Rolling bearing 32 Outer ring 33 Holding ring 34 Bolt 35 Retaining ring 36 Internal space 37a, 37b Guide roller 38 Movable rollers 39a, 39b Support shaft 40 Fitting hole 41 Support hole 42 Radial needle bearing 43 Power transmission cylindrical surface 44 Drive side cylindrical surface 45 Driven side cylindrical surface 46 Cylinder hole 47 Elastic material 48 Inner diameter side contact portion 49 Outer diameter side contact part 50 Oil seal (sealing means)
51 O-ring (sealing means)
52 O-ring (sealing means)

Claims (1)

An electric wheel drive device incorporating an electric motor and a friction roller transmission on the inner diameter side of the wheel of the wheel,
The friction roller type transmission includes an outer ring provided around the tip of a rotary drive shaft driven by the electric motor and rotatably provided with the wheel in an eccentric state with respect to the rotary drive shaft. In an annular inner space that exists between a drive-side cylindrical surface that is the outer peripheral surface of the drive shaft and a driven-side cylindrical surface that is the inner peripheral surface of the outer ring and whose width in the radial direction is not the same in the circumferential direction At least one guide roller and at least one movable roller, each having an outer peripheral surface as a power transmission cylindrical surface,
The friction roller type transmission further includes a holding ring that is disposed on an inner diameter side of the outer ring and is coupled to the wheel.

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