Bicycle transmission device

Patent metadata

Field	Value
Publication number	US-10994802-B2
Application number	US-201916513050-A
Country	US
Kind code	B2
Filing date	Jul 16, 2019
Priority date	Mar 25, 2015
Publication date	May 4, 2021
Grant date	May 4, 2021

Abstract

A bicycle transmission device basically includes an input rotational shaft, an output part, a transmission mechanism and a switching mechanism. The transmission mechanism includes a first rotating body configured to transmit rotation of the input rotational shaft and a fourth rotating body configured to transmit the rotation of the input rotational shaft. The switching mechanism is configured to selectively switch between a first state in which a ratio of a rotational speed of the output part to a rotational speed of the input rotational shaft is a first ratio and a second state in which the ratio is a second ratio that is different from the first ratio. The switching mechanism includes a one-way clutch and a switching unit.

First claim

What is claimed is:

1. A bicycle transmission device comprising:
an input rotational shaft;
an output part;
a transmission mechanism including a first rotating body configured to transmit rotation of the input rotational shaft and a fourth rotating body configured to transmit the rotation of the input rotational shaft, the fourth rotating body being different from the first rotating body; and
a switching mechanism configured to selectively switch between a first state in which a ratio of a rotational speed of the output part to a rotational speed of the input rotational shaft is a first ratio and a second state in which the ratio is a second ratio that is different from the first ratio,
a switching mechanism including:
a one-way clutch configured to switch between a third state in which rotation is not transmitted from the first rotating body to the output part, and a fourth state in which rotation is transmitted from the first rotating body to the output part; and
a switching unit configured to switch between a fifth state in which rotation is transmitted from the fourth rotating body to the output part, and a sixth state in which rotation is not transmitted from the fourth rotating body to the output part,

the first state including the third state and the fifth state, the second state including the fourth state and the sixth state.

2. The bicycle transmission device according to claim 1 , wherein
the one-way clutch is configured to permit relative rotation between the first rotating body and the output part so as to be in the third state when the rotational speed of the input rotational shaft in one direction is less than a rotational speed of the output part in one direction, and
the one-way clutch is configured to integrally rotate the first rotating body and the output part together so as to be in the fourth state when the rotational speed of the input rotation shaft in the one direction is greater than or equal to the rotational speed of the output part in the one direction.

3. The bicycle transmission device according to claim 1 , wherein
the one-way clutch is provided between the first rotating body and the output part with respect to a radial direction of the input rotational shaft.

4. The bicycle transmission device according to claim 1 , wherein
the one-way clutch is configured such that a radial distance between the input rotational shaft in the radial direction of the input rotational shaft is shorter than a radial distance between the switching unit and the input rotational shaft in the radial direction of the input rotational shaft.

5. The bicycle transmission device according to claim 1 , wherein
the transmission mechanism further comprises a transmission body that is configured to transmit the rotation of the input rotational shaft to the first rotating body, and
the one-way clutch is provided between the transmission body and the fourth rotating body in a direction along a center axis of the input rotational shaft.

6. The bicycle transmission device according to claim 5 , further comprising
a torque sensor provided on the transmission body.

7. The bicycle transmission device according to claim 1 , wherein
the output part has a first end portion provided with an attaching portion that is configured to be attached with a sprocket and a second end portion that is spaced from the first end portion in a direction along a center axis of the input rotational shaft,
the one-way clutch is provided at the second end portion.

8. The bicycle transmission device according to claim 1 , wherein
the first rotating body is configured to rotate around a center axis of the input rotational shaft,
the fourth rotating body is configured to rotate around a center axis of the output part.

9. The bicycle transmission device according to claim 1 , wherein
the first rotating body includes a first gear,
the fourth rotating body includes a fourth gear, and
the fourth gear has a total number of teeth that is fewer than a total number of teeth of the first gear.

10. The bicycle transmission device according to claim 1 , wherein
the switching unit is configured to be at least partially disposed between the fourth rotating body and the output part.

11. The bicycle transmission device according to claim 1 , wherein
the transmission mechanism further comprises a transmission shaft configured to transmit the rotation of the first rotating body to the fourth rotating body.

12. The bicycle transmission device according to claim 11 , wherein
the transmission mechanism further comprising a second rotating body provided between the transmission shaft and the first rotating body and a third rotating body provided between the transmission shaft and the forth rotating body, the second rotating body is configured to rotate around a center axis of the transmission shaft, and the third rotating body is configured to rotate around a center axis of the transmission shaft.

13. The bicycle transmission device according to claim 11 , further comprising
an assist motor operatively coupled to the transmission mechanism such that the transmission mechanism transmits torque of the motor to the output part via the transmission shaft.

14. The bicycle transmission device according to claim 13 , wherein
the transmission mechanism is configured to transmit the torque of the assist motor to the output part via the transmission shaft and the fourth rotating body while in the first state, and
the transmission mechanism is configured to transmit the torque of the assist motor to the output part via the first rotating body while in the second state.

15. The bicycle transmission device according to claim 1 , wherein
the first ratio is greater than the second ratio.

Assignees

• Shimano Kk

Inventors

• Yamamoto Takashi

Classifications

• F16H3/083

  with radially acting and axially controlled clutching members, e.g. sliding keys · CPC title

• B62M6/50 Primary

  characterised by detectors or sensors, or arrangement thereof · CPC title

• B62M6/55

  power-driven at crank shafts parts · CPC title

• B62M11/06

  with spur gear wheels (B62M11/14 takes precedence) · CPC title

• B62M11/02

  of unchangeable ratio · CPC title