CN-121990098-A - Power transmission device for bicycle

Abstract

A bicycle power transmission device improves the comfort of a bicycle on which the bicycle power transmission device is mounted. The power transmission device for a bicycle is provided with a first rotating body, a second rotating body, a friction member, and an elastic member. The second rotating body is configured to be rotatable relative to the first rotating body. The friction member is disposed between the first rotating body and the second rotating body. The friction member is configured to be rotatable relative to the first rotating body. The friction member is configured to rotate integrally with the second rotating body. The elastic member elastically connects the first rotating body and the second rotating body. The friction member includes a base portion, a claw portion, and a protruding portion. The base body part is annular. The claw portion extends from the base portion to a first side in an axial direction. The protruding portion is disposed radially inward of the claw portion. The protruding portion protrudes from the base portion toward the first side in the axial direction. The second rotating body is provided with an engagement hole and an engagement concave portion. The clamping hole is used for clamping the claw part. The engaging concave portion is engaged with the protruding portion.

Inventors

• HARIMA KENJI
• OSHIMA HIROSHI

Assignees

• 爱思帝股份有限公司

Dates

Publication Date

20260508

Application Date

20251105

Priority Date

20241106

Claims (8)

1. 1. A power transmission device for a bicycle is provided with: A first rotating body; A second rotating body configured to be rotatable relative to the first rotating body; a friction member disposed between the first rotating body and the second rotating body, the friction member being disposed so as to be rotatable relative to the first rotating body and configured to rotate integrally with the second rotating body, and An elastic member elastically connecting the first rotating body and the second rotating body, The friction member has: An annular base body portion; a claw portion extending from the base portion to a first side in an axial direction, and A protrusion portion which is disposed radially inward of the claw portion and protrudes from the base portion to a first side in an axial direction, The second rotating body has: An engaging hole for engaging the claw portion, and And an engaging recess for engaging the protruding portion.
2. 2. The power transmission device for a bicycle according to claim 1, wherein, The friction member has a plurality of the claw portions and a plurality of the protruding portions, Each of the claw portions and each of the protruding portions are alternately arranged in the circumferential direction.
3. 3. The power transmission device for a bicycle according to claim 1, wherein, The projection overlaps the resilient member under radial viewing.
4. 4. The power transmission device for a bicycle according to claim 1, wherein, The friction member has: A plurality of claw portions arranged at intervals in the circumferential direction, and An outer wall portion protruding from the base portion toward the first side in the axial direction and extending in the circumferential direction between a pair of the claw portions adjacent in the circumferential direction, The outer wall portion has: an inner side surface facing radially inward, and A concave portion formed on the inner side surface and recessed radially outward.
5. 5. The power transmission device for a bicycle according to claim 1, wherein, The friction member has: A plurality of claw portions arranged at intervals in the circumferential direction, and An outer wall portion protruding from the base portion toward the first side in the axial direction and extending in the circumferential direction between a pair of the claw portions adjacent in the circumferential direction, The outer wall portion is disposed at a distance from the claw portion in the circumferential direction.
6. 6. The power transmission device for a bicycle according to claim 1, wherein, The first rotating body has: A hub portion extending in an axial direction, and A flange portion extending radially outward from the hub portion, The second rotating body has: a first plate disposed on a first side in an axial direction with respect to the flange portion, and A second plate disposed on a second side in the axial direction with respect to the flange portion and configured to rotate integrally with the first plate, The friction member is disposed between the flange portion and the first plate in the axial direction, The first plate has the engagement hole and the engagement recess.
7. 7. The power transmission device for a bicycle according to claim 6, wherein, The bicycle power transmission device further includes a sprocket attached to the first plate.
8. 8. The power transmission device for a bicycle according to claim 1, wherein, The friction member has a cylindrical portion protruding from an inner peripheral end portion of the base portion toward a first side in an axial direction, The protruding portion is disposed radially outward of the cylindrical portion and is integrally formed with the cylindrical portion.

Description

Power transmission device for bicycle Technical Field The present invention relates to a power transmission device for a bicycle. Background The power transmission device for a bicycle includes a first rotating body and a second rotating body (for example, patent document 1). The first rotating body and the second rotating body are configured to be rotatable relative to each other. The first rotating body and the second rotating body are elastically coupled by a coil spring. When a torque is input to the first rotating body, the first rotating body rotates relative to the second rotating body, and the coil spring is compressed. When the torque input to the first rotating body becomes small, the input torque can be compensated by the restoring force of the coil spring. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2024-084007 Disclosure of Invention Technical problem to be solved by the invention The present invention aims to improve the comfort of a bicycle equipped with a bicycle power transmission device. Solution for solving the technical problems The power transmission device for a bicycle according to the first aspect includes a first rotating body, a second rotating body, a friction member, and an elastic member. The second rotating body is configured to be rotatable relative to the first rotating body. The friction member is disposed between the first rotating body and the second rotating body. The friction member is configured to be rotatable relative to the first rotating body. The friction member is configured to rotate integrally with the second rotating body. The elastic member elastically connects the first rotating body and the second rotating body. The friction member includes a base portion, a claw portion, and a protruding portion. The base body part is annular. The claw portion extends from the base portion to a first side in an axial direction. The protruding portion is disposed radially inward of the claw portion. The protruding portion protrudes from the base portion toward the first side in the axial direction. The second rotating body is provided with an engaging hole and an engaging concave portion. The clamping hole is used for clamping the claw part. The engaging concave portion is engaged with the protruding portion. According to this configuration, when the first rotating body and the second rotating body are rotated relatively by the restoring force of the elastic member, the friction member slides on the first rotating body, so that the relative rotation between the first rotating body and the second rotating body can be smoothly performed. As a result, the comfort of the bicycle in which the power transmission device for a bicycle is mounted can be improved. In the friction member, the claw portion is engaged with the engagement hole of the second rotating body, and the protruding portion disposed radially inward of the claw portion is engaged with the engagement recess of the second rotating body. Therefore, the mounting of the friction member to the second rotating body can be stabilized, so that the friction torque generated between the first rotating body and the friction member can be stabilized. As a result, the relative rotation between the first rotating body and the second rotating body can be made smoother, and the comfort of the bicycle can be further improved. The power transmission device for a bicycle according to the second aspect is configured as follows in the power transmission device for a bicycle according to the first aspect. The friction member has a plurality of claw portions and a plurality of protruding portions. The claw portions and the protruding portions are alternately arranged in the circumferential direction. The power transmission device for a bicycle according to the third aspect is the power transmission device for a bicycle according to the first or second aspect, configured as follows. The projection overlaps the elastic member when viewed in the radial direction. A power transmission device for a bicycle pertaining to a fourth aspect is the power transmission device for a bicycle pertaining to any one of the first to third aspects, which is configured as follows. The friction member has an outer wall portion and a plurality of claw portions. The claw portions are arranged at intervals in the circumferential direction. The outer wall portion protrudes from the base portion toward the first side in the axial direction. The outer wall portion extends in the circumferential direction between a pair of claw portions adjacent in the circumferential direction. The outer wall portion has an inner side surface and a recess. The inner side faces radially inward. A recess is formed on the inner side. The concave portion is recessed radially outward. A power transmission device for a bicycle according to a fifth aspect is the power transmission device for a bicycle according to any one of the first