JP2017100610A - Driving device and bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easy handling of a driving device disposed in a wheel of a bicycle.SOLUTION: A driving device 54 is disposed on a bicycle wheel. The driving device 54 includes a motor 60, a speed reduction mechanism 62, a support member 64, and a housing 66. A driving force of the motor 60 is transmitted to the speed reduction mechanism 62. The support member 64 supports the motor 60 and the speed reduction mechanism 62. The housing 66 accommodates the motor 60 and the speed reduction mechanism 62. The driving force of the motor 60 is transmitted to the housing 66 through the speed reduction mechanism 62. The housing 66 rotates around an output shaft 74 of the motor 60 relative to the support member 64. A mounting shaft insertion hole 100A is formed in the support member 64. The mounting shaft insertion hole 100A allows a mounting shaft 136 attached to a vehicle body of the bicycle to be inserted from the outer side of the output shaft in an axial direction of the output shaft.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a drive device, and more particularly to a drive device disposed on a bicycle wheel.

  The bicycle travels using the pedaling force of the passenger. In recent years, electrically assisted bicycles have been proposed that assist an occupant's pedal effort with the driving force of a motor. There has also been proposed an electric bicycle that uses a driving force of a motor according to the amount of grip operation.

  In these bicycles, for example, the drive device is arranged on a wheel. Such a driving device is disclosed in, for example, Japanese Patent Application Laid-Open No. 2014-177265.

  The drive device described in the above publication includes a motor housing fixed to the axle and a motor disposed inside the motor housing. The motor has a stator, a rotor, and a rotor shaft. The rotation of the rotor shaft is transmitted to the hub via the first reduction gear and the second reduction gear. The hub is provided to be rotatable with respect to the motor housing.

  The drive device described in the above publication generates, for example, a drive force corresponding to the pedal effort. The wheels are rotated by transmitting the driving force to the hub.

  In the driving device described in the above publication, the axle is attached to the bicycle body. Specifically, when the drive device is disposed on the front wheel, the axle is attached to the front fork of the bicycle. If the drive is located on the rear wheel, the axle is attached to the bicycle frame.

JP 2014-177265 A

  As described above, in order for the axle to be attached to the bicycle body, the axle needs to protrude from the motor housing. Therefore, when handling the drive unit, it is necessary to pay attention to the axle. This is because, for example, the axle or the peripheral member may be damaged when the axle is in contact with the peripheral member.

  An object of the present invention is to facilitate handling of a drive device disposed on a bicycle wheel.

Means for Solving the Problems and Effects of the Invention

  The drive device by embodiment of this invention is arrange | positioned at the wheel of a bicycle. The drive device includes a motor, a speed reduction mechanism, a support member, and a housing. The driving force of the motor is transmitted to the speed reduction mechanism. The support member supports the motor and the speed reduction mechanism. The housing accommodates the motor and the speed reduction mechanism. The driving force of the motor is transmitted to the housing via a speed reduction mechanism. The housing rotates relative to the support member about the output shaft of the motor. A mounting shaft insertion hole is formed in the support member. The attachment shaft insertion hole allows the attachment shaft attached to the bicycle body to be inserted from the outside of the output shaft in the axial direction of the output shaft.

  The drive device does not include an attachment shaft. Therefore, for example, when carrying the drive device, it is possible to avoid the attachment shaft coming into contact with the peripheral members and damaging the attachment shaft and the peripheral members. Further, when the drive device is transported in a box, the space required for storage can be reduced by the amount that the mounting shaft does not exist. As a result, more drive devices can be transported at one time. As a result, handling of the drive device becomes easy.

  The attachment shaft may be inserted from the outside into the attachment shaft insertion hole when the drive device is attached to the bicycle body. Therefore, for example, it is not necessary to disassemble the drive device and provide the mounting shaft on the drive device. As a result, handling of the drive device becomes easy.

  The bicycle body includes not only the frame but also the front fork. That is, the vehicle body only needs to support the front wheels and the rear wheels.

  In the above drive device, the support member preferably includes a first support member, a second support member, and a third support member. The second support member supports the motor. The second support member is disposed away from the first support member in the axial direction. The third support member is disposed outside the output shaft in the radial direction of the output shaft. The third support member connects the first support member and the second support member. The third support member supports the speed reduction mechanism. The mounting shaft insertion hole preferably includes a first hole. The first hole is formed coaxially with the output shaft in one of the first support member and the second support member, and is positioned outside the output shaft in the axial direction.

  In the aspect in which the support member includes the first to third support members, the output shaft may be formed with a second hole. The second hole is positioned coaxially with the first hole and penetrates the output shaft in the axial direction. A third hole may be formed in the other member of the first support member and the second support member. The third hole is located coaxially with the output shaft, and is located on the opposite side of the first hole with respect to the output shaft in the axial direction. The attachment shaft is inserted from the same direction with respect to the first hole, the second hole, and the third hole.

  There is a through axle system as a mounting structure of the mounting shaft to the vehicle body. In the through axle system, the mounting shaft is inserted into the through hole formed in the vehicle body. Specifically, for example, an attachment shaft is inserted into a through hole formed in each front fork. In this state, the mounting shaft is fixed to the front fork.

  As described above, in the aspect in which the mounting shaft is inserted from the same direction with respect to the first hole, the second hole, and the third hole, the mounting shaft is inserted, for example, in the front fork before being inserted into the first hole. It is inserted into a through hole formed on one side. Moreover, the part which passed the 3rd hole among the attachment shafts is inserted in the through-hole formed in the other of the front fork, for example. That is, the aspect in which the mounting shaft is inserted from the same direction with respect to the first hole, the second hole, and the third hole can correspond to the through axle system.

  In the aspect in which the support member includes the first to third support members, the attachment shaft insertion hole may further include a second hole. The second hole is formed coaxially with the output shaft in the other member of the first support member and the second support member, and is positioned on the opposite side of the first hole with respect to the output shaft in the axial direction.

  In this case, the mounting shaft includes a first mounting shaft and a second mounting shaft. The first mounting shaft is inserted from the outside of the output shaft in the axial direction with respect to the first hole. Before the first mounting shaft is inserted into the first hole, for example, it is inserted into a through hole formed in one of the front forks. The second mounting shaft is disposed away from the first mounting shaft in the axial direction, and is inserted into the second hole from a direction opposite to the direction in which the first mounting shaft is inserted into the first hole. Before the second mounting shaft is inserted into the second hole, for example, it is inserted into a through hole formed in the other of the front forks. That is, even in an aspect in which the attachment shaft insertion hole further includes the second hole, the through axle system can be supported.

  In the aspect in which the mounting shaft includes the first mounting shaft and the second mounting shaft, the mounting shaft may not penetrate the output shaft. In this case, the diameter of the output shaft can be reduced as compared with the case where a hole penetrating the output shaft in the axial direction is formed. As a result, the reduction ratio of the reduction mechanism can be ensured without increasing the size of the drive device.

  In the aspect in which the mounting shaft includes the first mounting shaft and the second mounting shaft, a third hole may be formed in the output shaft. The third hole is located coaxially with the first hole and the second hole, and penetrates the output shaft in the axial direction. The second attachment shaft may be coupled to the first attachment shaft. In this case, the second mounting shaft may include a first shaft portion and a second shaft portion. The first shaft portion is located outside the output shaft in the axial direction. The second shaft portion extends in the axial direction from the first shaft portion, and is connected to the first shaft portion in a state of being inserted into the third hole.

  In such an aspect, if the diameter of the third hole is reduced, the diameter of the output shaft can be reduced. As a result, the reduction ratio of the reduction mechanism can be ensured without increasing the size of the drive device.

1 is a right side view showing an electric bicycle according to a first embodiment of the present invention. It is sectional drawing which shows the drive device with which the electric bicycle shown in FIG. 1 is provided. FIG. 3 is an enlarged cross-sectional view showing a part of the drive device shown in FIG. 2. It is sectional drawing which shows the drive device employ | adopted with the electric bicycle by the 2nd Embodiment of this invention. FIG. 5 is an enlarged cross-sectional view showing a part of the drive device shown in FIG. 4. It is sectional drawing which shows the drive device employ | adopted with the electric bicycle by the 3rd Embodiment of this invention. It is sectional drawing which expands and shows a part of drive device shown in FIG. It is sectional drawing which shows the application example of the attachment shaft employ | adopted with the drive device shown in FIG.

  In a conventional drive device, an attachment shaft for attaching the drive device to a bicycle body protrudes from a member constituting the drive device. Therefore, for example, when carrying the drive device, there is a possibility that the mounting shaft comes into contact with the peripheral members, and the peripheral members and the mounting shaft are damaged. Further, when the drive device is transported in a box, the space required for housing the drive device has been increased.

  In order to avoid such a problem, it is conceivable to carry the drive device in a disassembled state. In this case, it is possible to avoid the attachment shaft and the peripheral members from being damaged due to the attachment shaft coming into contact with the peripheral members.

  However, it is very troublesome to carry the drive unit in a disassembled state. For example, it is necessary not to lose each component constituting the driving device.

  In addition, the drive device needs to be assembled before the drive device is attached to the bicycle body. As a result, handling of the drive device becomes very troublesome.

  In recent years, a through axle system has been adopted as a structure for fixing a mounting shaft to a bicycle body. In the through axle system, the mounting shaft is inserted into the through hole formed in the vehicle body. Specifically, for example, an attachment shaft is inserted into a through hole formed in each front fork. In this state, the mounting shaft is fixed to the front fork.

  However, in the aspect in which the attachment shaft protrudes from the member constituting the drive device, it is difficult or impossible to insert the attachment shaft into the through hole formed in the vehicle body. Therefore, it was difficult to support the through axle system.

  The inventor of the present application has studied about providing the mounting shaft separately from the drive device. Thereby, when carrying a drive device, it can avoid that an attachment axis | shaft and a peripheral member are damaged. Further, when the drive device is transported in a box, it is easy to secure a space for storing the drive device. As a result, the drive device is easy to handle.

  However, simply providing the mounting shaft separately from the drive device is the same as allowing the drive device to be disassembled into a plurality of parts. That is, if the drive device is disassembled to assemble the mounting shaft, the drive device becomes difficult to handle.

  Therefore, the inventors of the present application have studied a configuration that facilitates the work of assembling the mounting shaft provided separately from the drive device to the drive device. As a result, a new finding was obtained that the mounting shaft only has to be inserted into the hole formed in the drive device from the outside. The present invention has been completed based on such findings.

  Hereinafter, a motorcycle according to an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an electric bicycle will be described as an example of a two-wheeled vehicle. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description of the members will not be repeated.

[First Embodiment]
FIG. 1 is a right side view of an electric bicycle 10 according to a first embodiment of the present invention. The electric bicycle 10 includes a human power drive system for driving the rear wheel 16 by human power.

  In the following description, front / rear / left / right means front / rear / left / right as viewed from a passenger seated on the saddle 30 of the electric bicycle 10. In FIG. 1, the arrow F indicates the forward direction of the electric bicycle 10, and the arrow U indicates the upward direction of the electric bicycle 10.

  The electric bicycle 10 includes a vehicle body 12, a front wheel 14, and a rear wheel 16. The vehicle body 12 supports the front wheel 14 and the rear wheel 16. In the present embodiment, the front wheel 14 and the rear wheel 16 have the same size.

  The vehicle body 12 includes a vehicle body frame 13. The vehicle body frame 13 includes a head pipe 18, an upper pipe 20, a front pipe 22, a seat pipe 24, a pair of left and right rear pipes 26 and 26, and a pair of left and right lower pipes 28 and 28.

  The upper pipe 20 extends rearward from the head pipe 18. The front pipe 22 is disposed below the upper pipe 20 and extends rearward and downward from the head pipe 18. The rear end of the front pipe 22 is connected to a bottom bracket (not shown). The seat pipe 24 extends upward from the bottom bracket. The rear end of the upper pipe 20 is connected to the seat pipe 24. A saddle 30 is attached to the upper end of the seat pipe 24. A battery 32 is attached to the seat pipe 24.

  The pair of left and right rear pipes 26, 26 extend rearward and downward from the seat pipe 24. The pair of left and right lower pipes 28 and 28 extend rearward from the bottom bracket. The rear ends of the pair of lower pipes 28, 28 are connected to the rear ends of the pair of rear pipes 26, 26. The rear wheel 16 is rotatably attached at a connection portion between the lower pipe 28 and the rear pipe 26. A rear sprocket 34 is fixed to the rear wheel 16. A drive device 36 is disposed on the hub of the rear wheel 16. The drive device 36 includes a motor and a speed reduction mechanism. The driving device 36 applies a driving force to the rear wheel 16.

  A crankshaft 38 is rotatably attached to the bottom bracket. Crank arms 44 are attached to both ends of the crankshaft 38. A pedal 46 is attached to the crank arm 44. When the occupant operates the pedal 46 (specifically, the pedal 46 is depressed), the crankshaft 38 rotates.

  A front sprocket 40 is attached to the crankshaft 38. An endless chain 42 is wound around the front sprocket 40 and the rear sprocket 34. The rotation of the crankshaft 38 is transmitted from the front sprocket 40 to the rear sprocket 34 via the chain 42.

  A steering shaft 50 is rotatably inserted into the head pipe 18. A front fork 52 is attached to the lower end of the steering shaft 50. The front wheel 14 is rotatably attached to the lower end of the front fork 52. A drive device 54 is disposed on the hub of the front wheel 14. The drive device 54 includes a motor and a speed reduction mechanism. The driving device 54 applies driving force to the front wheels 14. A handle 56 is attached to the upper end of the steering shaft 50. When the occupant rotates the handle 56, the steering shaft 50 rotates. Along with this, the front fork 52 and the front wheel 14 rotate. As a result, the traveling direction of the vehicle changes.

  An accelerator grip 58 is disposed on the handle 56. The accelerator grip 58 is disposed so as to be rotatable with respect to the handle 56. Based on the amount of operation of the accelerator grip 58, the output of the motor provided in the driving devices 36 and 54 is adjusted.

  The drive device 54 will be described with reference to FIG. FIG. 2 is a cross-sectional view showing a state in which the driving device 54 is attached to the front fork 52. Note that the structure of the driving device 54 can also be applied to the driving device 36. In the present embodiment, the drive device 36 has the same structure as the drive device 54. Therefore, detailed description of the drive device 36 is omitted. That is, the driving device of the present invention may be applied to a driving device for a front wheel or a driving device for a rear wheel.

  The drive device 54 includes a motor 60, a speed reduction mechanism 62, a support member 64, and a housing 66. The motor 60 includes a rotor 68 and a stator 70. The rotor 68 includes a rotor yoke 72 and a rotor shaft 74.

  In the following description, the axial direction refers to the axial direction of the rotor shaft 74. In the present embodiment, the one axial end side means the side of the front fork 52 where the right leg portion 52R is located, that is, the right side in FIG. The other end in the axial direction refers to the side of the front fork 52 where the left leg 52L is located, that is, the left side in FIG. The circumferential direction refers to a direction around the central axis L <b> 1 of the rotor shaft 74. The radial direction refers to the radial direction of the rotor shaft 74.

  The rotor yoke 72 has an annular shape. The rotor yoke 72 includes a permanent magnet. On the surface or inside of the rotor yoke 72, N poles and S poles are magnetized alternately in the circumferential direction. A rotor shaft 74 is inserted into a hole formed in the rotor yoke 72. In this state, the rotor shaft 74 is fixed to the rotor yoke 72. As a method of fixing the rotor shaft 74 to the rotor yoke 72, for example, there is a method of bonding the outer peripheral surface of the rotor shaft 74 and the inner peripheral surface of the rotor yoke 72, or the like.

  The rotor shaft 74 is fixed to the rotor yoke 72. As a result, the rotor shaft 74 rotates integrally with the rotor yoke 72 in the circumferential direction.

  A rotor gear 76 is formed on the rotor shaft 74. The rotor gear 76 is disposed at a position different from the rotor yoke 72 in the axial direction of the rotor shaft 74.

  As shown in FIG. 3, the rotor shaft 74 has a hole 74A. The hole 74A is formed so as to penetrate the rotor shaft 74 in the axial direction. The hole 74A has a cylindrical inner peripheral surface. That is, the opening shape of the hole 74A is circular. The hole 74A extends straight in the axial direction. The hole 74 </ b> A is located on the central axis of the rotor shaft 74. That is, the axis of the hole 74 </ b> A coincides with the axis of the rotor shaft 74. In other words, the hole 74 </ b> A is formed coaxially with the rotor shaft 74.

  The stator 70 has an annular shape. Stator 70 includes a core 78 and a coil 80 wound around core 78. The coil 80 extends to the outside of the housing 88 through a hole 100B formed in the support plate 100 of the housing 88 described later.

  The stator 70 is located on the central axis of the rotor shaft 74. That is, the axis of the stator 70 </ b> A coincides with the axis of the rotor shaft 74. In other words, the stator 70 is arranged coaxially with the rotor shaft 74. The stator 70 surrounds the rotor yoke 72.

  The speed reduction mechanism 62 includes a plurality (three in the present embodiment) of planetary gears 82. The plurality of planetary gears 82 are arranged at equal intervals in the circumferential direction around the central axis of the rotor shaft 74. The planetary gear 82 includes a gear 84 and a gear 86.

  The gear 84 meshes with the rotor gear 76. The gear 84 has a larger diameter than the rotor gear 76. The number of teeth of the gear 84 is larger than the number of teeth of the rotor gear 76. Therefore, the rotation speed of the gear 84 is slower than the rotation speed of the rotor gear 76.

  The gear 86 is disposed coaxially with the gear 84. The gear 86 is fixed to the gear 84. The gear 86 rotates integrally with the gear 84. The gear 86 has a smaller diameter than the gear 84. The number of teeth of the gear 86 is smaller than the number of teeth of the gear 84.

  The planetary gear 82 has a two-stage structure including the gear 84 and the gear 86, but may have a one-stage structure, for example. In this case, the gear 86 is eliminated, and the gear 84 meshes with a tooth 128A described later. Since the gear 86 is eliminated, the length of the support shaft 92 described later is shortened. As a result, the size of the drive device 54 (specifically, the size of the vehicle in the left-right direction) can be reduced.

  The support member 64 includes a housing 88, a support plate 90, and a plurality of (three in this embodiment) support shafts 92. Hereinafter, these will be described.

  The housing 88 accommodates the stator 70 and the rotor yoke 72. The housing 88 includes a housing main body 94 and a lid 96.

  The housing body 94 includes a cylindrical portion 98 and a support plate 100. The cylindrical portion 98 has a cylindrical shape and extends straight in the axial direction with a substantially constant outer diameter and inner diameter. The cylindrical portion 98 supports the stator 70. Specifically, the cylinder part 98 supports the core 78 in a state where the stator 70 is inserted. In this state, the stator 78 is fixed to the cylindrical portion 98. As a method of supporting the core 78 by the cylindrical portion 98, for example, there is a method of hooking a protrusion formed on one of the cylindrical portion 98 and the core 78 on a concave portion formed on the other.

  The support plate 100 is disposed at the right end (one end in the axial direction) of the cylindrical portion 98. The support plate 100 covers an opening on one end side in the axial direction of the cylindrical portion 98. The support plate 100 has a disc shape. The peripheral edge of the plate 100 is formed integrally with the right end (one axial end) of the cylindrical portion 98 over the entire periphery.

  A protrusion 102 is formed at the center of the support plate 100. The axis of the protrusion 102 coincides with the center of the support plate 100. The protrusion 102 protrudes from the right end surface (end surface located on one end side in the axial direction) of the support plate 100 toward the right side (one axial end side). The protrusion 102 has a cylindrical outer peripheral surface 102A. The outer peripheral surface 102A has a substantially constant diameter and extends straight in the axial direction.

  A concave portion 104 is formed in the central portion of the support plate 100. The recess 104 opens toward the left side (the other end side in the axial direction). The recess 104 has a cylindrical inner peripheral surface 104A. The inner peripheral surface 104A has a substantially constant diameter and extends straight in the axial direction. The axial center of the recess 104 coincides with the axial center of the support plate 100.

  A bearing 106 is accommodated in the recess 104. The bearing 106 rotatably supports the right end portion (one axial end portion) of the rotor shaft 74 with respect to the housing 88 (specifically, the support plate 100).

  As shown in FIG. 3, holes 100 </ b> A are formed in the support plate 100. The hole 100A has a cylindrical inner peripheral surface. That is, the opening shape of the hole 100A is circular. The hole 100A extends straight in the axial direction. The hole 100 </ b> A is formed in the central portion of the support plate 100. That is, the axis of the hole 100 </ b> A coincides with the axis of the support plate 100. The hole 100 </ b> A passes through the support plate 100. Specifically, the hole 100 </ b> A passes through the protrusion 102. The right end (one axial end) of the hole 100 </ b> A is open to the end face of the protrusion 102. The left end (the other end in the axial direction) of the hole 100 </ b> A opens into the recess 104. The axial center of the hole 100A coincides with the axial center of the hole 74A formed in the rotor shaft 74. That is, the hole 100A is formed coaxially with the hole 74A.

  The lid 96 has a disc shape. The lid 96 is disposed at the left end (the other end in the axial direction) of the cylindrical portion 98. The lid 96 covers the opening on the left side (the other end side in the axial direction) of the cylindrical portion 98. The lid 96 is fixed to the cylindrical portion 98. Examples of the method of fixing the lid 96 to the cylindrical portion 98 include a method of engaging a screw thread formed on the outer peripheral surface of the lid 96 with a screw groove formed on the inner peripheral surface of the cylindrical portion 98, There is a method of adhering the surface to the inner peripheral surface of the cylindrical portion 98. By fixing the lid 96 to the cylindrical portion 98, a space 110 for accommodating the rotor yoke 72 and the stator 70 is formed in the housing 88.

  A hole 96A is formed in the lid 96. The hole 96 </ b> A is formed in the central portion of the lid 96. The hole 96A has a cylindrical inner peripheral surface. That is, the opening shape of the hole 96A is circular. The hole 96A extends straight in the axial direction. The axial center of the hole 96A coincides with the axial center of the lid 96. That is, the hole 96 </ b> A is formed coaxially with the lid 96. The hole 96A penetrates the lid 96 in the axial direction. The axial center of the hole 96A coincides with the axial center of the hole 74A formed in the rotor shaft 74. That is, the hole 96A is formed coaxially with the hole 74A.

  In a state where the rotor yoke 72 and the stator 70 are accommodated in the space 99, the rotor shaft 74 is inserted into a hole 96A formed in the lid 96. That is, a part of the rotor shaft 74 is located outside the housing 88. A rotor gear 76 is formed on a portion of the rotor shaft 74 located outside the housing 88. That is, the rotor gear 76 is disposed outside the housing 88.

  The support plate 90 has a disk shape. The support plate 90 is disposed on the left side (the other end side in the axial direction) of the housing 88. The axis of the support plate 90 coincides with the axis of the housing 88. That is, the support plate 90 is positioned coaxially with the housing 88.

  A protrusion 112 is formed at the center portion of the support plate 90. The protrusion 112 has a cylindrical shape. The axis of the protrusion 112 coincides with the axis of the support plate 90. The protrusion 112 protrudes from the right end surface (end surface on one end side in the axial direction) of the support plate 90 toward the right side (one end side in the axial direction).

  A recess 114 is formed in the central portion of the support plate 90. The recess 114 is open to the end surface of the protrusion 112. The recess 114 has a cylindrical inner peripheral surface 114A. The inner peripheral surface 114A has a substantially constant diameter and extends straight in the axial direction. The axis of the recess 114 coincides with the axis of the support plate 90. That is, the recess 114 is formed coaxially with the protrusion 112.

  A bearing 116 is accommodated in the recess 114. The bearing 116 rotatably supports the left end portion (the other end portion in the axial direction) of the rotor shaft 74 with respect to the support plate 90.

  A protrusion 118 is formed at the central portion of the support plate 90. The protrusion 118 has a cylindrical shape. That is, the protrusion 118 has a circular cross section and extends straight in the axial direction. The protrusion 118 has a cylindrical outer peripheral surface 118A. The axis of the protrusion 118 coincides with the axis of the support plate 90. That is, the protrusion 118 is formed coaxially with the support plate 90.

  As shown in FIG. 3, holes 90 </ b> A are formed in the support plate 90. The hole 90A has a cylindrical inner peripheral surface. That is, the opening shape of the hole 90A is a circle. The hole 90A extends straight in the axial direction. The hole 90 </ b> A is formed in the central portion of the support plate 90. The axial center of the hole 90 </ b> A coincides with the axial center of the support plate 90. That is, the hole 90 </ b> A is formed coaxially with the support plate 90. The hole 90A penetrates the support plate 90 in the axial direction. Specifically, the hole 90A penetrates the protrusion 118 in the axial direction. The right end (one axial end) of the hole 90 </ b> A opens into the recess 114. The left end (the other end in the axial direction) of the hole 90 </ b> A opens to the end face of the protrusion 118. The axial center of the hole 90 </ b> A coincides with the axial center of the hole 74 </ b> A formed in the rotor shaft 74. That is, the hole 90A is formed coaxially with the hole 74A.

  A plurality of (three in this embodiment) support shafts 92 connect the support plate 90 and the housing 88 (specifically, the lid 96). Specifically, the right end portion (one axial end portion) of the support shaft 92 is fixed to the lid 96. The left end portion (the other end portion in the axial direction) of the support shaft 92 is fixed to the support plate 90. Examples of a method for fixing the support shaft 92 to the lid 96 and the support plate 90 include adhesion. The plurality of support shafts 92 are disposed radially outside the rotor shaft 74. The plurality of support shafts 92 are arranged at equal intervals in the circumferential direction. The support shaft 92 supports the planetary gear 82 rotatably.

  The housing 66 accommodates the motor 60 and a plurality of (three in this embodiment) planetary gears 82. The housing 66 includes a cylindrical portion 120, a support plate 122, and a support plate 124.

  The cylinder part 120 includes a first cylinder part 120A and a second cylinder part 120B having an inner diameter smaller than that of the first cylinder part 12A. 120 A of 1st cylinder parts are located in the right side (axial direction one end side) rather than the 2nd cylinder part 120B. The left end (the other end in the axial direction) of the first cylindrical portion 120A is connected to the right end (one end in the axial direction) of the second cylindrical portion 120B.

  The first cylindrical portion 120A has an inner peripheral surface 126 having a substantially constant diameter and extending straight in the axial direction. The second cylindrical portion 120B has an inner peripheral surface 128 having a substantially constant diameter and extending straight in the axial direction. The diameter of the inner peripheral surface 128 is smaller than the diameter of the inner peripheral surface 126. A tooth 128 </ b> A that meshes with the gear 86 is formed on the inner circumferential surface 128 over the entire circumference. That is, the 2nd cylinder part 120B forms the internal gear. All the planetary gears 82 (specifically, the gear 86) mesh with the internal gear. The number of teeth 128A is greater than the number of teeth of the gear 86. Therefore, the rotation of the housing 66 (that is, the internal gear) is slower than the rotation of the gear 86 (that is, the planetary gear 82). The internal gear may be formed of a member different from the second cylindrical portion 120B.

  A pair of support pieces 130 and 130 are formed on the outer peripheral surface of the cylindrical portion 120. Specifically, one support piece 130 is formed on the outer peripheral surface of the first cylindrical portion 120A. The other support piece 130 is formed on the outer peripheral surface of the second cylindrical portion 120B. Each support piece 130 is formed over the entire circumference. That is, the support piece 130 has an annular shape. A plurality of spokes are attached to each support piece 130. The plurality of spokes connect the housing 66 with the rim disposed on the radially outer side of the housing 66.

  The support plate 122 is disposed at the right end (one end in the axial direction) of the cylindrical portion 120. The support plate 122 extends radially inward from the inner peripheral surface 126 of the first cylindrical portion 120A. That is, the support plate 122 has an annular shape. The support plate 122 has a cylindrical inner peripheral surface 122A. The inner peripheral surface 122A has a substantially constant diameter and extends straight in the axial direction.

  The support plate 122 is formed separately from the cylindrical portion 120 and is fixed to the cylindrical portion 120. Examples of a method for fixing the plate 122 to the cylindrical portion 120 include adhesion and screwing.

  A bearing 132 is disposed between the inner peripheral surface 122 </ b> A of the support plate 122 and the outer peripheral surface 102 </ b> A of the protrusion 102. As a result, the right end portion (one axial end portion) of the housing 66 is rotatably supported with respect to the support member 64 (specifically, the housing 88).

  The support plate 124 is disposed at the left end (the other end in the axial direction) of the cylindrical portion 120. The support plate 124 extends radially inward from the inner peripheral surface 128 of the second cylindrical portion 120B. That is, the support plate 124 has an annular shape. The support plate 124 has a cylindrical inner peripheral surface 124A. The inner peripheral surface 124A has a substantially constant diameter and extends straight in the axial direction.

  The support plate 124 may be formed integrally with the cylindrical portion 120. Alternatively, the support plate 124 may be formed separately from the cylindrical portion 120 and fixed to the cylindrical portion 120. Examples of a method for fixing the support plate 124 to the cylindrical portion 120 include adhesion and screwing.

  A bearing 134 is disposed between the inner peripheral surface 124 </ b> A of the support plate 124 and the outer peripheral surface 118 </ b> A of the protrusion 118. Accordingly, the left end portion (the other end portion in the axial direction) of the housing 66 is rotatably supported with respect to the support member 64 (specifically, the support plate 90).

  Such a driving device 54 is attached to the front fork 52 via the attachment shaft 136. Specifically, it is as follows.

  When the drive device 54 is attached to the front fork 52, the attachment shaft 136 is assembled to the drive device 54. Specifically, the mounting shaft 136 has a hole 90A formed in the support plate 90, a hole 74A formed in the rotor shaft 74, and a hole 100A formed in the housing main body 94 on the right side (one axial end). From the side).

  The attachment shaft 136 is inserted into the hole 52A formed in the right leg portion 52R of the front fork 52 before being inserted into the hole 100A. A portion of the attachment shaft 136 that has passed through the hole 90 </ b> A, that is, a left end portion (the other end portion in the axial direction) of the attachment shaft 136 is inserted into a hole 52 </ b> B formed in the left leg portion 52 </ b> L of the front fork 52. That is, the attachment structure of the attachment shaft 136 to the front fork 52 is a through axle system. In the through axle system, the diameter of the hole 52A as the through hole and the hole 52B as the screw hole are different. Specifically, the diameter of the hole 52B is smaller than the diameter of the hole 52A.

  A thread groove is formed on the inner peripheral surface of the hole 52B. A thread is formed on the outer peripheral surface of the left end portion (the other end portion in the axial direction) of the mounting shaft 136. The left end portion (the other end portion in the axial direction) of the attachment shaft 136 is fixed to the left leg portion 52 </ b> L of the front fork 52 by meshing these screw threads and screw grooves. With the left end portion (the other end portion in the axial direction) of the mounting shaft 136 fixed to the left leg portion 52L of the front fork 52, the right end portion (the one end portion in the axial direction) of the mounting shaft 136 is located in the hole 52A. Yes.

  The attachment shaft 136 is not rotatable with respect to the support member 64 in a state where the attachment shaft 136 is assembled to the drive device 54. Specifically, as shown in FIG. 3, by tilting a lever 1361 provided at the right end (one axial end) of the mounting shaft 136, a pedestal 1362 provided at the right end (one axial end) of the mounting shaft 136 is moved. , Against the right leg 52R of the front fork 52. As a result, the right leg portion 52R is sandwiched between the base 1362 and the protrusion 102. As a result, the attachment shaft 136 is fixed to the right leg portion 52 </ b> R together with the support member 64. That is, the attachment shaft 136 cannot rotate with respect to the support member 64. In addition, the protrusion 102 may be fixed to the right leg portion 52R by using a separate anti-rotation member.

  As described above, the attachment shaft 136 cannot rotate with respect to the support member 64, but the housing 66 can rotate with respect to the support member 64. That is, the housing 66 is rotatable with respect to the mounting shaft 136 and the support member 64 in a state where the driving device 54 is mounted to the front fork 52 via the mounting shaft 136.

  As described above, the drive device 54 is attached to the front fork 52 via the attachment shaft 136 provided separately from the drive device 54. Here, the attachment shaft 136 is assembled to the drive device 54 after the drive device 54 is attached to the front fork 52. Therefore, even if the driving device 54 contacts the peripheral member before the mounting shaft 136 is assembled to the driving device 54, the mounting shaft 136 does not contact the peripheral member. As a result, it is possible to avoid the attachment shaft 136 from damaging the peripheral members due to the drive device 54 coming into contact with the peripheral members. Further, it is possible to avoid the attachment shaft 136 from being damaged by the attachment shaft 136 coming into contact with surrounding members.

  When the mounting shaft 136 is assembled to the drive device 54, the mounting shaft 136 may be inserted into the holes 74A, 90A, and 100A. That is, even if the drive device 54 is not disassembled, the attachment shaft 136 can be assembled to the drive device 54 by inserting the attachment shaft 136 from the outside. As a result, the work for assembling the mounting shaft 136 to the drive device 54 is facilitated.

  The attachment shaft 136 is provided separately from the drive device 54. Therefore, when the drive device 54 is transported in a box, the attachment shaft 136 may not be assembled to the drive device 54. That is, the drive device 54 can be put in the box in a state where the mounting shaft 136 does not protrude from the drive device 54. In other words, the space for housing the drive device 54 can be reduced. As a result, the number of drive devices 54 that can be put in the box increases, so that more drive devices 54 can be transported at one time.

  When the mounting shaft 136 is assembled to the drive device 54, the mounting shaft 136 may be inserted into the holes 74A, 90A, and 100A. Therefore, even if the mounting structure of the mounting shaft 136 to the front fork 52 is a through axle system, it can be handled.

[Second Embodiment]
Next, a drive device 54A employed in an electric bicycle according to the second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-sectional view showing the drive device 54A.

  The driving device 54A is different from the driving device 54 in that a hole 74B is formed instead of the hole 74A. The hole 74B differs from the hole 74A in that the diameter is smaller. Specifically, the diameter of the hole 74B is smaller than the diameter of the hole 100A. The axis of the hole 74B coincides with the axis of the hole 100A. That is, the hole 74B is formed coaxially with the hole 100A.

  The driving device 54A is different from the driving device 54 in that a hole 90B is formed instead of the hole 90A. As shown in FIG. 5, the hole 90B includes a hole 90B1 and a hole 90B2. The hole 90B1 is a part having a smaller diameter than the hole 90B2.

  The hole 90B1 has a cylindrical inner peripheral surface 901. That is, the opening shape of the hole 90B1 is a circle. The hole 90B1 extends straight in the axial direction. The hole 90B1 is formed in the central portion of the support plate 90. The axial center of the hole 90B1 coincides with the axial center of the support plate 90. That is, the hole 90B1 is formed coaxially with the support plate 90.

  The hole 90B2 has a cylindrical inner peripheral surface 902. That is, the opening shape of the hole 90B2 is a circle. The hole 90B2 extends straight in the axial direction. The diameter of the hole 90B2 is larger than the diameter of the hole 90B1. A thread groove is formed on the inner peripheral surface 902 of the hole 90B2. The hole 90B2 is formed in the central portion of the support plate 90. The axial center of the hole 90 </ b> B <b> 2 coincides with the axial center of the support plate 90. That is, the hole 90B2 is formed coaxially with the support plate 90.

  The hole 90B2 has an end surface 903. The end surface 903 is circular. The end surface 903 is formed at the right end (one axial end) of the hole 90B2. That is, the outer edge of the end surface 903 is connected to the right end (one axial end) of the inner peripheral surface 902.

  The hole 90B1 is connected to the hole 90B2. Specifically, the right end (one axial end) of the hole 90 </ b> B <b> 1 opens into the recess 114. The left end (the other end in the axial direction) of the hole 90B1 opens in the end surface 903 of the hole 90B2. That is, the right end (one axial end) of the hole 90B2 is connected to the left end (the other axial end) of the hole 90B1. The left end (the other end in the axial direction) of the hole 90B2 is open to the end face of the protrusion 118. That is, the hole 90B penetrates the support plate 90 in the axial direction. Specifically, the hole 90B penetrates the protrusion 118 in the axial direction.

  The drive device 54A is attached to the front fork 52 via an attachment shaft 136A. As shown in FIG. 5, the attachment shaft 136 </ b> A is different from the attachment shaft 136 in that it includes an attachment shaft 138 and an attachment shaft 140.

  The attachment shaft 138 has a cylindrical shape. A lever 138L and a base 138F are provided on the left end (the other end in the axial direction) of the mounting shaft 138. The outer peripheral surface 138A of the mounting shaft 138 extends straight in the axial direction with a substantially constant circular cross section. A screw thread is formed on the outer peripheral surface 138A.

  The attachment shaft 138 is inserted into the hole 90B from the left side (the other end side in the axial direction) to the right side (one end side in the axial direction). The screw thread formed on the outer peripheral surface 138A meshes with the screw groove formed on the inner peripheral surface 902. Thereby, the attachment shaft 138 is fixed to the support plate 90.

  When the mounting shaft 138 is inserted into the hole 90B, the mounting shaft 138 is from the left side (the other axial end side) to the right side (the one axial end side) with respect to the hole 52B formed in the left leg 52L of the front fork 52. ) Is inserted. At this time, the base 138F provided at the left end (the other end in the axial direction) of the attachment shaft 138 contacts the left leg 52L. In this state, the lever 138L is tilted. Thereby, the base 138F is pressed against the left leg 52L. As a result, the left leg 52L is sandwiched between the base 138F and the protrusion 118. The attachment shaft 138 is fixed to the left leg portion 52 </ b> L together with the support member 64. The diameter of the mounting shaft 138 is smaller than the diameter of the hole 52B. For this reason, when the mounting shaft 138 is inserted into the hole 52B, the thread formed on the outer peripheral surface 138A of the mounting shaft 138 does not mesh with the screw groove formed on the inner peripheral surface of the hole 52B. Therefore, in the present embodiment, a thread groove may not be formed on the inner peripheral surface of the hole 52B.

  The attachment shaft 140 includes a shaft portion 140A and a shaft portion 140B. The shaft portion 140A and the shaft portion 140B have a cylindrical shape. That is, the shaft portion 140A and the shaft portion 140B extend straight in the axial direction with a substantially constant circular cross section. The diameter of the shaft portion 140A is smaller than the diameter of the shaft portion 140B. The shaft portion 140A extends in the axial direction from the left end surface (the other end surface in the axial direction) of the shaft portion 140B. The shaft center of the shaft portion 140A coincides with the shaft center of the shaft portion 140B. That is, the shaft portion 140A is formed coaxially with the shaft portion 140B. The diameter of the shaft portion 140A is smaller than the diameter of the hole 74B and slightly smaller than the diameter of the inner peripheral surface 901 of the hole 90B. The diameter of the shaft portion 140B is larger than the diameter of the hole 74B and slightly smaller than the diameter of the hole 100B.

  The mounting shaft 140 is inserted from the right side (one axial end side) into the hole 74B formed in the rotor shaft 74 and the hole 100A formed in the housing body 94.

  The attachment shaft 140 is inserted into the hole 52A formed in the right leg portion 52R of the front fork 52 before being inserted into the hole 100A. The shaft portion 140A is inserted from the right side (one axial end side) into the hole 74B. The shaft portion 140A is inserted from the right side (one axial end side) into the hole 90B. That is, the shaft portion 140A is inserted into the hole 90B1 in the hole 90B. The left end portion (the other end portion in the axial direction) of the shaft portion 140A, that is, the portion of the shaft portion 140A that has passed through the hole 90B1 is on the right side (one axial end side) with respect to the hole 1381 formed in the mounting shaft 138. ) Is inserted. The hole 1381 has a cylindrical inner peripheral surface. That is, the opening shape of the hole 1381 is circular. The hole 1381 extends straight in the axial direction. A thread groove is formed on the inner peripheral surface of the hole 1381. A screw thread is formed on the outer peripheral surface of the left end portion (the other end portion in the axial direction) of the shaft portion 140A. By inserting the left end portion (the other end portion in the axial direction) of the shaft portion 140A into the hole 1381, a thread groove formed on the inner peripheral surface of the hole 1381 and a screw thread formed on the outer peripheral surface of the shaft portion 140A. Engage. As a result, the left end portion (the other end portion in the axial direction) of the shaft portion 140A is fixed to the right end portion (the one end portion in the axial direction) of the shaft portion 138.

  With the left end portion (the other end portion in the axial direction) of the shaft portion 140A being fixed to the right end portion (the one end portion in the axial direction) of the shaft portion 138, as shown in FIG. 5, the right end of the mounting shaft 140 (the shaft portion 140B) The lever 1361 provided at (one axial end) is tilted. At this time, the base 1362 provided at the right end (one axial end) of the mounting shaft 140 (shaft portion 140B) is pressed against the right leg portion 52R of the front fork 52. As a result, the right leg portion 52R is sandwiched between the base 1362 and the protrusion 102. As a result, the attachment shaft 140 is fixed to the right leg portion 52 </ b> R together with the support member 64.

  As described above, the drive device 54A is attached to the front fork 52 via the attachment shaft 136A (specifically, the attachment shaft 138 and the attachment shaft 140) provided separately from the drive device 54A. Here, the attachment shaft 136A is assembled to the drive device 54A after the drive device 54A is attached to the front fork 52. Therefore, even if the drive device 54A comes into contact with a peripheral member before the mounting shaft 136A is assembled to the drive device 54A, the attachment shaft 136A does not come into contact with the peripheral member. As a result, it is possible to avoid the attachment shaft 136A from damaging the peripheral members due to the drive device 54A coming into contact with the peripheral members. Further, it is possible to avoid the attachment shaft 136A from being damaged by the contact of the attachment shaft 136A with the surrounding members.

  When the mounting shaft 136A (the mounting shaft 138 and the mounting shaft 140) is assembled to the drive device 54A, the mounting shaft 138 may be inserted into the hole 90B and the mounting shaft 140 may be inserted into the hole 100A. That is, even if the drive device 54A is not disassembled, the attachment shaft 136A can be assembled to the drive device 54A by inserting the attachment shaft 138 and the attachment shaft 140 from the outside. As a result, the work for assembling the mounting shaft 136A to the drive device 54A is facilitated.

  The mounting shaft 136A (the mounting shaft 138 and the mounting shaft 140) is provided separately from the drive device 54A. Therefore, when the drive device 54A is transported in a box, the attachment shaft 138 and the attachment shaft 140 may not be assembled to the drive device 54A. That is, the drive device 54A can be put in the box in a state where the attachment shaft 138 and the attachment shaft 140 do not protrude from the drive device 54A. In other words, the space for housing the drive device 54A can be reduced. As a result, the number of drive devices 54A that can be put in the box increases, so that more drive devices 54A can be conveyed at one time.

  When the mounting shaft 136A (specifically, the mounting shaft 138 and the mounting shaft 140) is assembled to the drive device 54A, the mounting shaft 138 may be inserted into the hole 90B and the mounting shaft 140 may be inserted into the hole 100A. Therefore, even if the mounting structure of the mounting shaft 136A to the front fork 52 is a through axle system, it can be handled.

  The mounting shaft 140 assembled to the drive device 54A has a shaft portion 140A having a smaller diameter than the shaft portion 140B. The hole 74B into which the shaft portion 140A is inserted has a smaller diameter than the shaft portion 140B. Therefore, the outer diameter of the rotor shaft 74 can be reduced. As a result, the reduction ratio of the reduction mechanism 62, specifically, the reduction ratio between the rotor gear 76 and the gear 84 can be ensured. In order to ensure the reduction ratio of the speed reduction mechanism 62, it is possible to avoid an increase in the size of the drive device 54A.

[Third Embodiment]
Subsequently, a drive device 54B employed in an electric bicycle according to a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is a cross-sectional view showing the driving device 54B.

  The drive device 54B is different from the drive device 54 in that the hole 74A is not formed in the rotor shaft 74.

  The driving device 54B is different from the driving device 54 in that a hole 100C is formed instead of the hole 100A. The hole 100 </ b> C does not penetrate the support plate 100.

  As shown in FIG. 7, the hole 100 </ b> C includes a cylindrical inner peripheral surface 1001 and a circular end surface 1002. That is, the opening shape of the hole 100C is circular. The hole 100C extends straight in the axial direction. The axial center of the hole 100 </ b> C coincides with the axial center of the support plate 100. That is, the hole 100 </ b> C is formed coaxially with the support plate 100. A thread groove is formed on the inner peripheral surface 1001. The end surface 1002 defines the left end (the other end in the axial direction) of the hole 100C. That is, the end surface 1002 is connected to the left end (the other end in the axial direction) of the inner peripheral surface 1001. The hole 100 </ b> C opens at the end face of the protrusion 102. That is, the hole 100C opens toward the right side (one axial end side).

  The driving device 54B is different from the driving device 54 in that a hole 90C is formed instead of the hole 90A. The hole 90C does not penetrate the support plate 90.

  As shown in FIG. 7, the hole 90 </ b> C includes a cylindrical inner peripheral surface 904 and a circular end surface 905. That is, the opening shape of the hole 90C is circular. The hole 90C extends straight in the axial direction. The axial center of the hole 90C coincides with the axial center of the support plate 90. That is, the hole 90 </ b> C is formed coaxially with the support plate 90. A thread groove is formed on the inner peripheral surface 904. The end surface 905 defines the right end (one axial end) of the hole 90C. That is, the end surface 905 is connected to the right end (one axial end) of the inner peripheral surface 904. The hole 90 </ b> C opens at the end face of the protrusion 118. That is, the hole 90C opens toward the left side (the other end side in the axial direction).

  The drive device 54B is attached to the front fork 52 via an attachment shaft 136B. As shown in FIG. 7, the attachment shaft 136 </ b> B is different from the attachment shaft 136 in that it includes an attachment shaft 142 and an attachment shaft 144.

  The attachment shaft 142 has a cylindrical shape. The outer peripheral surface 142A of the mounting shaft 142 has a substantially constant circular cross section and extends straight in the axial direction. A screw thread is formed on the outer peripheral surface 142A.

  The attachment shaft 142 is inserted into the hole 100C from the right side (one axial end side) to the left side (the other axial end side). The screw thread formed on the outer peripheral surface 142A meshes with the screw groove formed on the inner peripheral surface 1001. Thereby, the attachment shaft 142 is fixed to the housing 88.

  When the mounting shaft 142 is inserted into the hole 100C, the mounting shaft 142 is positioned from the right side (one axial end side) to the left side (the other axial end side) with respect to the hole 52A formed in the right leg 52R of the front fork 52. ) Is inserted. As shown in FIG. 7, when the lever 1361 provided at the right end (one axial end) of the mounting shaft 142 is tilted, the pedestal 1362 provided at the right end (one axial end) of the mounting shaft 142 becomes the right leg 52R. Pressed against. As a result, the right leg portion 52R is sandwiched between the base 1362 and the protrusion 102. As a result, the attachment shaft 142 is fixed to the right leg portion 52R together with the support member 64.

  The attachment shaft 144 has a cylindrical shape. A lever 144L and a base 144F are provided on the left end (the other end in the axial direction) of the mounting shaft 144. The outer peripheral surface 144A of the mounting shaft 144 extends straight in the axial direction with a substantially constant circular cross section. A screw thread is formed on the outer peripheral surface 144A.

  The mounting shaft 144 is inserted into the hole 90C from the left side (the other end side in the axial direction) to the right side (one end side in the axial direction). The screw thread formed on the outer peripheral surface 144A meshes with the screw groove formed on the inner peripheral surface 904. As a result, the attachment shaft 144 is fixed to the support plate 90.

  When the mounting shaft 144 is inserted into the hole 90C, the mounting shaft 144 is positioned from the left side (the other end side in the axial direction) to the right side (the one end side in the axial direction) with respect to the hole 52B formed in the left leg 52L of the front fork 52. ) Is inserted. At this time, the pedestal 144F provided at the left end (the other end in the axial direction) of the attachment shaft 144 contacts the left leg 52L. In this state, the lever 144L is tilted. As a result, the base 144F is pressed against the left leg 52L. As a result, the left leg 52L is sandwiched between the base 144F and the protrusion 118. The attachment shaft 144 is fixed to the left leg portion 52 </ b> L together with the support member 64. Note that the diameter of the mounting shaft 144 is smaller than the diameter of the hole 52B. Therefore, when the mounting shaft 144 is inserted into the hole 52B, the thread formed on the outer peripheral surface 138A of the mounting shaft 144 does not mesh with the screw groove formed on the inner peripheral surface of the hole 52B. Therefore, in the present embodiment, a thread groove may not be formed on the inner peripheral surface of the hole 52B. In this case, for example, as shown in FIG. 8, an attachment shaft 142 may be used instead of the attachment shaft 144. That is, the two attachment shafts used for attaching the drive device 54B to the front fork 52 may have the same structure. In this case, productivity is improved as compared with the case where the mounting shaft 144 is used.

  As described above, the drive device 54B is attached to the front fork 52 via the attachment shaft 136B (specifically, the attachment shaft 142 and the attachment shaft 144) provided separately from the drive device 54B. Here, the attachment shaft 136B is assembled to the drive device 54B after the drive device 54B is attached to the front fork 52. Therefore, even if the driving device 54B contacts the peripheral member before the mounting shaft 136B is assembled to the driving device 54B, the mounting shaft 136B does not contact the peripheral member. As a result, it is possible to avoid the attachment shaft 136B from damaging the peripheral members due to the drive device 54B coming into contact with the peripheral members. Further, the attachment shaft 136B can be prevented from being damaged by the contact of the attachment shaft 136B with the peripheral members.

  When the mounting shaft 136B (the mounting shaft 142 and the mounting shaft 144) is assembled to the drive device 54B, the mounting shaft 144 may be inserted into the hole 90C and the mounting shaft 142 may be inserted into the hole 100C. That is, even if the drive device 54B is not disassembled, the attachment shaft 136B can be assembled to the drive device 54B by inserting the attachment shaft 142 and the attachment shaft 144 from the outside. As a result, the work for assembling the attachment shaft 136B to the drive device 54B is facilitated.

  The mounting shaft 136B (the mounting shaft 142 and the mounting shaft 144) is provided separately from the drive device 54B. Therefore, when the drive device 54B is transported in a box, the attachment shaft 142 and the attachment shaft 144 may not be assembled to the drive device 54B. That is, the drive device 54B can be put in the box in a state where the attachment shaft 142 and the attachment shaft 144 do not protrude from the drive device 54B. In other words, the space for housing the drive device 54B can be reduced. As a result, the number of drive devices 54B that can be put in the box is increased, so that a larger number of drive devices 54B can be conveyed at one time.

  When the attachment shaft 136B (specifically, the attachment shaft 142 and the attachment shaft 144) is assembled to the drive device 54B, the attachment shaft 144 may be inserted into the hole 90C and the attachment shaft 142 may be inserted into the hole 100C. Therefore, even if the mounting structure of the mounting shaft 136B to the front fork 52 is a through axle system, it can be handled.

  In the driving device 54B, the rotor shaft 74 has no hole 74A. Therefore, the outer diameter of the rotor shaft 74 can be reduced. As a result, the reduction ratio of the reduction mechanism 62, specifically, the reduction ratio between the rotor gear 76 and the gear 84 can be ensured. In order to ensure the reduction ratio of the speed reduction mechanism 62, it is possible to avoid an increase in the size of the drive device 54B.

  While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately modifying the above-described embodiment without departing from the spirit thereof.

  For example, in the first to third embodiments, the electric bicycle may not include a human power drive system.

  For example, in the first to third embodiments, the driving device 54 may not be disposed on the front wheel 14.

  For example, in the first to third embodiments, the electric bicycle may not include the accelerator grip 58.

DESCRIPTION OF SYMBOLS 10 Electric bicycle 53 Drive device 60 Motor 62 Deceleration mechanism 64 Support member 66 Housing 74 Rotor shaft 82 Planetary gear 88 Housing 90 Support plate 92 Support shaft

Claims (7)

A drive device arranged on a wheel of a bicycle,
A motor,
A speed reduction mechanism to which the driving force of the motor is transmitted;
A support member for supporting the motor and the speed reduction mechanism;
A housing that houses the motor and the speed reduction mechanism, and that rotates with respect to the support member around an output shaft of the motor by the driving force of the motor transmitted by the speed reduction mechanism;
The drive device, wherein the support member is formed with an attachment shaft insertion hole through which an attachment shaft attached to the bicycle body can be inserted from outside the output shaft in the axial direction of the output shaft. The drive device according to claim 1,
The support member is
A first support member;
A second support member disposed away from the first support member in the axial direction and supporting the motor;
A third support member that is disposed outside the output shaft in a radial direction of the output shaft, connects the first support member and the second support member, and supports the speed reduction mechanism;
The mounting shaft insertion hole is
One of the first support member and the second support member includes a first hole formed coaxially with the output shaft and positioned outside the output shaft in the axial direction. The drive device according to claim 2,
The output shaft is formed coaxially with the first hole and has a second hole penetrating the output shaft in the axial direction.
Of the first support member and the second support member, the other member is located on the same axis as the output shaft, and is located on the opposite side of the output shaft with respect to the output shaft in the axial direction. A third hole is formed,
The drive device in which the attachment shaft is inserted from the same direction with respect to the first hole, the second hole, and the third hole. The drive device according to claim 2,
The mounting shaft insertion hole further includes:
Of the first support member and the second support member, the other member is formed coaxially with the output shaft and is located on the opposite side of the output shaft with respect to the output shaft in the axial direction. A driving device including the second hole. The drive device according to claim 4,
The output shaft is formed coaxially with the first hole and the second hole, and has a third hole penetrating the output shaft in the axial direction.
The mounting shaft is
A first mounting shaft inserted from the outside of the output shaft in the axial direction with respect to the first hole;
A second mounting shaft that is inserted into the second hole from a direction opposite to the direction in which the first mounting shaft is inserted into the first hole, and is connected to the first mounting shaft in the axial direction;
The second mounting shaft is
A first shaft portion located outside the output shaft in the axial direction;
And a second shaft portion that extends in the axial direction from the first shaft portion and is connected to the first shaft portion while being inserted into the third hole. The drive device according to claim 4,
The mounting shaft is
A first mounting shaft inserted from the outside of the output shaft in the axial direction with respect to the first hole;
A second mounting shaft that is disposed away from the first mounting shaft in the axial direction and is inserted into the second hole from a direction opposite to the direction in which the first mounting shaft is inserted into the first hole; Including a driving device.   A bicycle comprising the drive device according to any one of claims 1 to 6.

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