Bicycle transmission apparatus

Patent metadata

Field	Value
Publication number	US-9623931-B2
Application number	US-201514640168-A
Country	US
Kind code	B2
Filing date	Mar 6, 2015
Priority date	Mar 6, 2015
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A bicycle transmission apparatus comprises a base member, an input shaft, a first transmission member, a second transmission member, and a first coupling member. The base member is configured to be attached to a bicycle frame as a separate member from the bicycle frame. The first transmission member is rotatable relative to the base member about a first rotational axis different from the input rotational axis. The second transmission member is rotatable relative to the base member about a second rotational axis different from each of the input rotational axis and the first rotational axis. The first coupling member is configured to couple the first transmission member to the second transmission member to transmit rotation of the first transmission member to the second transmission member at a variable speed stage.

First claim

What is claimed is:

1. A bicycle transmission apparatus comprising:
a base member configured to be attached to a bicycle frame as a separate member from the bicycle frame, the base member including an internal space;
an input shaft mounted to the base member to receive an input torque and rotatable relative to the base member about an input rotational axis in response to the input torque;
a first transmission member provided in the internal space of the base member and rotatable relative to the base member about a first rotational axis different from the input rotational axis;
a second transmission member provided in the internal space of the base member and rotatable relative to the base member about a second rotational axis different from each of the input rotational axis and the first rotational axis; and
a first coupling member having an annular shape to surround the first rotational axis and the second rotational axis when viewed from an axial direction parallel to the first rotational axis, the first coupling member being configured to couple the first transmission member to the second transmission member to transmit rotation of the first transmission member to the second transmission member at a variable speed stage, the variable speed stage being variable in accordance with at least one positional relationship among the first transmission member, the second transmission member, and the first coupling member in the axial direction.

2. The bicycle transmission apparatus according to claim 1 , further comprising:
an output shaft rotatable relative to the base member about the second rotational axis and coupled to the second transmission member to transmit rotation of the second transmission member to a bicycle wheel.

3. The bicycle transmission apparatus according to claim 2 , wherein
the input rotational axis and the second rotational axis are spaced apart from each other.

4. The bicycle transmission apparatus according to claim 2 , further comprising:
an input cogwheel configured to be coupled to the input shaft to rotate together with the input shaft relative to the base member about the input rotational axis; and
an output cogwheel configured to be coupled to the output shaft to rotate together with the output shaft relative to the base member about the second rotational axis, wherein
the input cogwheel is provided on a first side relative to the first transmission member in the axial direction, and
the output cogwheel is provided on the first side relative to the first transmission member in the axial direction.

5. The bicycle transmission apparatus according to claim 1 , further comprising:
an input coupling member having an annular shape to surround the input rotational axis and the first rotational axis when viewed from the axial direction, wherein
the input coupling member is configured to couple the input shaft to the first transmission member to transmit rotation of the input shaft to the first transmission member.

6. The bicycle transmission apparatus according to claim 5 , wherein
a value obtained by dividing a rotational speed of the first transmission member by a rotational speed of the input shaft is equal to 2 or 4.

7. The bicycle transmission apparatus according to claim 5 , wherein
the input coupling member is provided in the internal space of the base member.

8. The bicycle transmission apparatus according to claim 1 , further comprising:
a one-way clutch configured to transmit a first rotation of the input shaft to the first transmission member and configured to prevent a second rotation of the input shaft from being transmitted from the input shaft to the first transmission member, wherein
the second rotation is opposite to the first rotation about the input rotational axis.

9. The bicycle transmission apparatus according to claim 1 , wherein
the base member includes an internal space in which the first transmission member and the second transmission member are provided, and
the base member is configured to store lubricant in the internal space.

10. The bicycle transmission apparatus according to claim 9 , wherein
the base member includes a supply port through which the lubricant is to be supplied to the internal space.

11. The bicycle transmission apparatus according to claim 1 , wherein
the base member is configured to be clamped by the bicycle frame.

12. The bicycle transmission apparatus according to claim 11 , wherein
the base member includes
a base member body in which the first transmission member and the second transmission member are provided, and
an input shaft support including a support opening in which the input shaft is rotatable relative to the base member about the input rotational axis, the input shaft support extending from the base member body along the input rotational axis, and

the input shaft support is configured to be clamped by the bicycle frame.

13. The bicycle transmission apparatus according to claim 1 , wherein
the base member is configured to be mounted to a first frame of the bicycle frame and is pivotable relative to a second frame of the bicycle frame about the second rotational axis, the second frame being pivotably coupled to the first frame about the second rotational axis.

14. The bicycle transmission apparatus according to claim 13 , further comprising:
an output shaft rotatable relative to the base member about the second rotational axis and coupled to the second transmission member to transmit rotation of the second transmission member to a bicycle wheel rotatable relative to the second frame, wherein
the output shaft is configured to extend through a support opening of the bicycle frame along the second rotational axis.

15. The bicycle transmission apparatus according to claim 14 , further comprising:
an inner bearing unit configured to be provided in the support opening of the bicycle frame and configured to rotatably couple the output shaft to the bicycle frame about the second rotational axis via an outer bearing unit provided radially outward of the inner bearing unit, the outer bearing unit being configured to pivotably couple the second frame to the first frame about the second rotational axis.

16. The bicycle transmission apparatus according to claim 1 , further comprising:
an assist device configured to assist pedaling.

17. The bicycle transmission apparatus according to claim 16 , wherein
the assist device is configured to generate an assist torque inputted to the second transmission member to assist pedaling.

18. The bicycle transmission apparatus according to claim 16 , wherein
the assist device is provided on a front side of the base member in an attachment state where the bicycle transmission apparatus is attached to the bicycle frame.

19. The bicycle transmission apparatus according to claim 18 , further comprising:
an electrical power source configured to supply electrical power to the assist device and provided under the base member in the attachment state of the bicycle transmission apparatus.

20. The bicycle transmission apparatus according to claim 16 , further comprising:
a sensing device configured to sense a pedaling state of a bicycle; and
an assist controller configured to control the assist device to input the assist torque to the second transmission member based on the pedaling state sensed by the sensing device.

21. The bicycle transmission apparatus according to claim 1 , further comprising:
an input coupling member is configured to coupl

Assignees

• Shimano Kk

Inventors

• Emura Atsuhiro
• Yamaguchi Sota
• Oishi Toshinari
• Nishimoto Yusuke
• Koshiyama Kazuki

Classifications

• B62M9/132

  electrically or fluid actuated; Controls thereof · CPC title

• F16H57/035

  Gearboxes for gearing with endless flexible members · CPC title

• F16H57/05

  of chains · CPC title

• B62M2025/006

  with auxiliary shift assisting means · CPC title

• B62M25/08

  with electrical or fluid transmitting systems · CPC title