CN-121990095-A - Power transmission device for bicycle

Abstract

A power transmission device for a bicycle improves the strength of a threaded portion. The power transmission device for a bicycle includes a first rotating body, a second rotating body, an elastic member, a stopper member, and a first nut. The first rotating body has a stop surface facing in the circumferential direction. The second rotating body is configured to be rotatable relative to the first rotating body. The elastic member elastically connects the first rotating body and the second rotating body. The stopper member is mounted to the second rotating body. The stopper member has a stopper portion and a first threaded portion. The stop portion is circumferentially opposite the stop surface. The first screw portion is integrally formed with the stopper portion and extends in the axial direction. The first nut is screwed with the first threaded portion.

Inventors

• HARIMA KENJI

Assignees

• 爱思帝股份有限公司

Dates

Publication Date

20260508

Application Date

20251031

Priority Date

20241106

Claims (9)

1. 1. A power transmission device for a bicycle is provided with: A first rotating body having a stop surface facing the circumferential direction; A second rotating body configured to be rotatable relative to the first rotating body; An elastic member elastically coupling the first rotating body and the second rotating body; A stopper member having a stopper portion and a first screw portion, and mounted to the second rotating body, the stopper portion being circumferentially opposed to the stopper surface, the first screw portion being integrally formed with the stopper portion and extending in an axial direction, and And a first nut screwed with the first threaded portion.
2. 2. The power transmission device for a bicycle according to claim 1, wherein, The second rotating body is provided with a first through hole, The stopper member has a first intermediate portion disposed between the stopper portion and the first threaded portion in an axial direction, The outer diameter of the first middle part is smaller than the outer diameter of the stop part, the outer diameter of the first middle part is larger than the outer diameter of the first thread part, The first intermediate portion is disposed in the first through hole.
3. 3. The power transmission device for a bicycle according to claim 2, wherein, The bicycle power transmission device further includes a sprocket having an engagement hole overlapping the first through hole when viewed in an axial direction and rotating integrally with the second rotating body, The first intermediate portion is disposed in the engagement hole.
4. 4. The power transmission device for a bicycle according to claim 2, wherein, The stopper member has a constricted portion disposed between the first intermediate portion and the first screw portion.
5. 5. The power transmission device for a bicycle according to claim 2, wherein, The stopper member has a constricted portion disposed between the stopper portion and the first intermediate portion.
6. 6. The power transmission device for a bicycle according to claim 1, wherein, The first nut is a flange nut.
7. 7. The power transmission device for a bicycle according to claim 1, wherein, The stopper member has an engagement portion configured to be engageable with a tool.
8. 8. The power transmission device for a bicycle according to claim 1, wherein, The power transmission device for a bicycle further includes a second nut, The second rotating body has a first plate disposed on a first side in an axial direction with respect to the first rotating body and a second plate disposed on a second side in the axial direction with respect to the first rotating body, The stopper is arranged axially between the first plate and the second plate, The first threaded portion is disposed on a first side in an axial direction with respect to the first plate, The stopper member has a second screw portion which is disposed on a second side in an axial direction with respect to the second plate and is integrally formed with the stopper portion, The second nut is screwed with the second threaded portion.
9. 9. The power transmission device for a bicycle according to claim 8, wherein, The first plate has a first through-hole, The second plate has a second through hole overlapping the first through hole when viewed in the axial direction, The stopper member has a first intermediate portion disposed axially between the stopper portion and the first threaded portion, and a second intermediate portion disposed axially between the stopper portion and the second threaded portion, The outer diameters of the first intermediate portion and the intermediate portion are smaller than the outer diameter of the stopper portion, the outer diameters of the first intermediate portion and the intermediate portion are larger than the outer diameter of the first threaded portion, The first intermediate portion is disposed in the first through hole, The second intermediate portion is disposed in the second through hole.

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 that are rotatably disposed relative to each other. The first rotating body and the second rotating body are elastically coupled by an elastic member. The range of the torsion angle of the first rotating body and the second rotating body is limited by the stopper member. In the power transmission device for a bicycle disclosed in patent document 1, the maximum torsion angle between the first rotating body and the second rotating body can be changed by changing the stopper member. The stopper member is mounted by a bolt for fastening the second rotating body. The bolt extends so as to penetrate through the stopper. Patent document 1 Japanese patent application laid-open No. 2024-084007 Disclosure of Invention For reasons such as firmly fastening the second rotating body, it is desirable to increase the strength of the threaded portion of the bolt. Therefore, the present invention has an object to improve the strength of a threaded portion. The power transmission device for a bicycle according to the first aspect includes a first rotating body, a second rotating body, an elastic member, a stopper member, and a first nut. The first rotating body has a stop surface facing in the circumferential direction. The second rotating body is configured to be rotatable relative to the first rotating body. The elastic member elastically connects the first rotating body and the second rotating body. The stopper member is mounted to the second rotating body. The stopper member has a stopper portion and a first threaded portion. The stop portion is circumferentially opposite the stop surface. The first screw portion is integrally formed with the stopper portion and extends in the axial direction. The first nut is screwed with the first threaded portion. According to this configuration, since the screw portion is integrally formed with the stopper portion, the screw portion can be thickened as compared with the screw portion of the bolt extending in the cylindrical stopper portion as in the related art. As a result, the strength of the screw portion can be improved. According to the power transmission device for a bicycle relating to the first aspect, the power transmission device for a bicycle relating to the second aspect is configured as follows. The second rotating body is provided with a first through hole. The stop member has a first intermediate portion. The first intermediate portion is disposed between the stopper portion and the first threaded portion in the axial direction. The outer diameter of the first intermediate portion is smaller than the outer diameter of the stopper portion, and the outer diameter of the first intermediate portion is larger than the outer diameter of the first threaded portion. The first intermediate portion is disposed in the first through hole. According to the power transmission device for a bicycle relating to the second aspect, the power transmission device for a bicycle relating to the third aspect further includes a sprocket. The sprocket rotates integrally with the second rotating body. The sprocket has a snap hole. The engagement hole overlaps the first through hole when viewed in the axial direction. The first intermediate portion is disposed in the engagement hole. According to the power transmission device for a bicycle relating to the second or third aspect, the power transmission device for a bicycle relating to the fourth aspect is configured as follows. The stopper member has a constricted portion. The constricted portion is disposed between the first intermediate portion and the first threaded portion. With this configuration, the stress of the stopper can be relaxed. The power transmission device for a bicycle according to any one of the second to fourth aspects, and the power transmission device for a bicycle according to the fifth aspect are configured as follows. The stopper member has a constricted portion. The constriction is arranged between the stop and the first intermediate portion. With this configuration, the stress of the stopper can be relaxed. The power transmission device for a bicycle according to any one of the first to fifth aspects, and the power transmission device for a bicycle according to the sixth aspect are configured as follows. The first nut is a flange nut. The power transmission device for a bicycle according to any one of the first to sixth aspects is configured as follows. The stopper member has an engagement portion configured to be engageable with the tool. The power transmission device for a bicycle according to the eighth aspect of the present invention is the power transmission device for a bicycle according to any one of the first to seventh aspects, further comprising a second nut. The second rot