CN-121990096-A - Power transmission device for bicycle

Abstract

The present invention relates to a power transmission device for a bicycle. The direction in which the coil spring protrudes is controlled. A power transmission device for a bicycle is provided with a first rotating body, a first plate, a second plate, and a coil spring. The first rotating body has a hub portion, a flange portion, and an accommodation hole. The hub portion extends in an axial direction. The flange portion extends radially outward from the hub portion. The receiving hole is formed in the flange portion. The first plate is disposed on a first side in the axial direction with respect to the flange portion. The first plate is configured to be rotatable relative to the flange portion. The second plate is disposed on a second side in the axial direction with respect to the flange portion. The second plate is configured to rotate integrally with the first plate. The coil spring is disposed in the accommodation hole. The coil spring elastically connects the first rotating body with the first and second plates. The flange portion is inclined in the axial direction.

Inventors

• HARIMA KENJI
• OSHIMA HIROSHI

Assignees

• 爱思帝股份有限公司

Dates

Publication Date

20260508

Application Date

20251104

Priority Date

20241106

Claims (7)

1. 1. A power transmission device for a bicycle is provided with: A first rotating body having a hub portion extending in an axial direction, a flange portion extending radially outward from the hub portion, and a receiving hole formed in the flange portion; a first plate disposed on a first side in an axial direction with respect to the flange portion, the first plate being disposed so as to be rotatable relative to the flange portion; A second plate disposed on a second side in an axial direction with respect to the flange portion, the second plate being configured to rotate integrally with the first plate, and A coil spring disposed in the accommodation hole and elastically connecting the first rotating body with the first plate and the second plate, The flange portion is inclined in the axial direction.
2. 2. The power transmission device for a bicycle according to claim 1, wherein, The power transmission device for a bicycle further includes a sprocket attached to the first plate, The flange portion is inclined to the second side in the axial direction.
3. 3. The power transmission device for a bicycle according to claim 1, wherein, The bicycle power transmission device further includes a crank arm attached to an end portion of the second side in the axial direction of the hub portion, The flange portion is inclined to the second side in the axial direction.
4. 4. The power transmission device for a bicycle according to claim 1, wherein, The flange portion has: A flange main body portion extending radially outward from the hub portion, and And an inclined portion extending radially outward from an outer peripheral end of the flange main body portion and inclined in an axial direction.
5. 5. The power transmission device for a bicycle according to claim 4, wherein, The receiving hole is formed across the flange main body portion and the inclined portion.
6. 6. The power transmission device for a bicycle according to claim 4, wherein, The end surface of the coil spring is in contact with the flange main body portion and the inclined portion.
7. 7. The power transmission device for a bicycle according to claim 1, wherein, The hub portion is in the shape of a cylinder, The first rotating body has: A plurality of protruding parts extending axially on the inner peripheral surface of the hub part, and And a plurality of clearance portions formed at least one end portion in an axial direction of each of the protruding portions.

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, a first plate, and a second plate (for example, patent document 1). The first and second plates are configured to rotate integrally with each other. The first rotating body, the first plate and the second plate are elastically connected by a coil spring. Specifically, the coil springs are disposed in the accommodation hole of the first rotating body, in the window of the first plate, and in the window of the second plate. 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 provides a power transmission device for a bicycle, which can control the protruding direction of a coil spring. Technical scheme for solving technical problems The power transmission device for a bicycle according to the first aspect includes a first rotating body, a first plate, a second plate, and a coil spring. The first rotating body has a hub portion, a flange portion, and an accommodation hole. The hub portion extends in an axial direction. The flange portion extends radially outward from the hub portion. The receiving hole is formed in the flange portion. The first plate is disposed on a first side in the axial direction with respect to the flange portion. The first plate is configured to be rotatable relative to the flange portion. The second plate is disposed on a second side in the axial direction with respect to the flange portion. The second plate is configured to rotate integrally with the first plate. The coil spring is disposed in the accommodation hole. The coil spring elastically connects the first rotating body with the first and second plates. The flange portion is inclined in the axial direction. According to this configuration, since the flange portion is inclined in the axial direction, the flange portion can be displaced from the center of the coil spring and can be brought into contact with the coil spring. Thus, when the coil spring is compressed by being pressed by the flange portion, a load in the axial direction opposite to the direction in which the flange portion is inclined is applied while adding a rotational direction to the coil spring. Therefore, by inclining the flange portion in the axial direction which is not preferable for the coil spring to protrude, the protruding direction of the coil spring can be controlled. The bicycle power transmission device according to the second aspect of the present invention is the bicycle power transmission device according to the first aspect of the present invention, further comprising a sprocket attached to the first plate. The flange portion is inclined to the second side in the axial direction. The power transmission device for a bicycle according to a third aspect is the power transmission device for a bicycle according to the first or second aspect, further including a crank arm attached to an end portion of the second side in the axial direction of the hub portion. The flange portion is inclined to the second side in the axial direction. With this configuration, the coil spring can be prevented from protruding toward the crank arm, that is, toward the driver of the bicycle. A power transmission device for a bicycle according to a fourth aspect is the power transmission device for a bicycle according to any one of the first to third aspects, configured as follows. The flange portion has a flange main body portion and an inclined portion. The flange main body portion extends radially outward from the hub portion. The inclined portion extends radially outward from an outer peripheral end of the flange main body portion. The inclined portion is inclined in the axial direction. A fifth aspect of the power transmission device for bicycles is the power transmission device for bicycles according to the fourth aspect, configured as follows. The receiving hole is formed across the flange main body portion and the inclined portion. A power transmission device for a bicycle relating to a sixth aspect is the power transmission device for a bicycle relating to the fourth or fifth aspect, configured as follows. The end face of the coil spring is in contact with the flange main body portion and the inclined portion. A seventh aspect of the power transmission device for a bicycle according to any one of the first to sixth aspects is configured as follows. The hub is cylindrical. The first rotating body has a plurality of protruding portions and a plurality of clearance portions. Each of the protrusions extends in the axial direction on the inner peripheral surface of the hub portion. Each of the clearance portions is formed at least at one end portion in the axial direction of each of the protruding portions. Eff