Bicycle derailleur, bicycle gear structure, bicycle motor unit, and front derailleur

1. A bicycle derailleur comprising:

a base member;

a linkage structure including a first link pin rotatably mounted to the base member about a first pivot axis; and

a motor unit configured to apply rotational force to the first link pin to rotate the first link pin relative to the base member about the first pivot axis, wherein

the motor unit includes an output structure coupled to the first link pin to be rotatable relative to the base member about the first pivot axis,

the output structure includes

an engagement body including a first engagement hole, and

a geared portion provided on the engagement body,

the engagement body includes a tubular part and a sleeve which is a separate member from the tubular part,

the sleeve includes the first engagement hole and a second engagement part,

the tubular part includes a second engagement hole, and

the second engagement part is provided in the second engagement hole to transmit the rotational force from the tubular part to the sleeve.

2. The bicycle derailleur according to claim 1 , wherein

the linkage structure includes a first link member coupled to the first link pin to be pivotable relative to the base member about the first pivot axis.

3. The bicycle derailleur according to claim 2 , further comprising

a chain guide pivotally coupled to the first link member to move relative to the base member in response to a pivotal movement of the first link member relative to the base member.

4. The bicycle derailleur according to claim 2 , wherein

at least one of the first link pin and the output structure includes a first coupling part,

the first link member includes a second coupling part, and

the first coupling part is engaged with the second coupling part to transmit the rotational force from the at least one of the first link pin and the output structure to the first link member.

5. The bicycle derailleur according to claim 4 , wherein

the first coupling part has a first profile other than a perfect circle as viewed along the first pivot axis, and

the second coupling part has a second profile other than a perfect circle as viewed along the first pivot axis.

6. The bicycle derailleur according to claim 5 , wherein

the first profile of the first coupling part has a polygonal shape, and

the second profile of the second coupling part has a polygonal shape.

7. The bicycle derailleur according to claim 4 , wherein

the first coupling part includes at least one first flat surface,

the second coupling part includes at least one second flat surface, and

the at least one first flat surface is contactable with the at least one second flat surface to transmit the rotational force from the at least one of the first link pin and the output structure to the first link member in a state where the first coupling part is engaged with the second coupling part.

8. The bicycle derailleur according to claim 4 , wherein

the first link pin includes a first engagement part, and

the first engagement part is provided in the first engagement hole to transmit the rotational force from the output structure to the first link pin.

9. The bicycle derailleur according to claim 8 , wherein

the first engagement part has an outer profile other than a perfect circle as viewed along the first pivot axis, and

the first engagement hole has an inner profile other than a perfect circle as viewed along the first pivot axis.

10. The bicycle derailleur according to claim 8 , wherein

the first engagement part frictionally engages with the first engagement hole.

11. The bicycle derailleur according to claim 9 , wherein

the outer profile of the first engagement part has a polygonal shape, and

the inner profile of the first engagement hole has a polygonal shape.

12. The bicycle derailleur according to claim 8 , wherein

the first engagement part includes at least one outer flat surface,

the first engagement hole includes at least one inner flat surface, and

the at least one outer flat surface is contactable with the at least one inner flat surface to transmit the rotational force from the output gear to the first link pin in a state where the first engagement part is provided in the first engagement hole.

13. The bicycle derailleur according to claim 8 , wherein

the second engagement part has an additional outer profile other than a perfect circle as viewed along the first pivot axis, and

the second engagement hole has an additional inner profile other than a perfect circle as viewed along the first pivot axis.

14. The bicycle derailleur according to claim 13 , wherein

the additional outer profile of the second engagement part has a polygonal shape, and

the additional inner profile of the second engagement hole has a polygonal shape.

15. The bicycle derailleur according to claim 8 , wherein

the second engagement part includes at least one additional outer flat surface,

the second engagement hole includes at least one additional inner flat surface, and

the at least one additional outer flat surface is contactable with the at least one additional inner flat surface to transmit the rotational force from the tubular part to the sleeve.

16. The bicycle derailleur according to claim 8 , wherein

the second engagement part frictionally engages with the second engagement hole.

17. The bicycle derailleur according to claim 1 , wherein

the base member includes a first support hole and a second support hole spaced apart from the first support hole along the first pivot axis, and

the first link pin includes

a first end provided in the first support hole, and

a second end provided in the second support hole.

18. The bicycle derailleur according to claim 1 , wherein

the linkage structure comprises

a second link member;

a second link pin configured to pivotally couple the second link member to the base member about a second pivot axis;

a third link pin configured to pivotally couple the first link member to the chain guide about a third pivot axis; and

a fourth link pin configured to pivotally couple the second link member to the chain guide about a fourth pivot axis.

19. A bicycle gear structure comprising:

a torque diode comprising:

an outer casing;

a first shaft rotatably mounted to the outer casing about a first rotational axis; and

a second shaft rotatably mounted to the outer casing about a second rotational axis;

a first transmitting gear attached to the first shaft; and

a first additional transmitting gear meshed with the first transmitting gear and rotatably mounted to the outer casing about a third rotational axis offset from the first rotational axis and the second rotational axis.

20. The bicycle gear structure according to claim 19 , further comprising

a support pin, wherein

the outer casing includes a gear support hole, and

the first additional transmitting gear is attached to the support pin, and

the support pin is rotatably provided in the gear support hole.

21. The bicycle gear structure according to claim 20 , wherein

the outer casing includes an outer casing body and a gear support part extending radially outwardly from the outer casing body with respect to the first rotational axis, and

the gear support part includes the gear support hole.

22. The bicycle gear structure according to claim 21 , wherein

the outer casing includes a securing part configured to be secured to another member, and

the securing part extends radially outwardly from the outer casing body with respect to the first rotational axis and includes a securing hole.

23. The bicycle gear structure according to claim 19 , further comprising

a second transmitting gear attached to the second shaft.

24. The bicycle gear structure according to claim 19 , wherein

an outer diameter of the first transmitting gear is larger than an outer diameter of the first additional transmitting gear.

25. The bicycle gear structure according to claim 19 , wherein

the first rotational axis is coincident with the second rotational axis.

26. A bicycle motor unit comprising:

a motor configured to generate rotational force; and

the bicycle gear structure according to claim 21 , the bicycle gear structure being configured to transmit the rotational force.

27. A bicycle derailleur comprising:

a base member;

a chain guide movable relative to the base member;

a linkage structure configured to movably couple the chain guide to the base member; and

the bicycle motor unit according to claim 26 , the bicycle motor unit being configured to apply rotational force to at least one of the chain guide and the linkage structure to move the chain guide relative to the base member.

28. A front derailleur comprising:

a base member;

a chain guide movable relative to the base member;

a linkage structure configured to movably couple the chain guide to the base member; and

a motor unit configured to apply rotational force to at least one of the chain guide and the linkage structure to move the chain guide relative to the base member, the motor unit comprising:

a motor configured to generate the rotational force; and

a gear structure including a plurality of spur gears configured to transmit the rotational force to the at least one of the chain guide and the linkage structure, the motor unit being free of gears other than the plurality of spur gears on a rotational-force transmission path provided from the motor to the at least one of the chain guide and the linkage structure, wherein

the motor includes an output shaft,

the plurality of spur gears includes

an input gear secured to the output shaft, and

an output gear coupled to the at least one of the chain guide and the linkage structure,

the reduction ratio is defined from the input gear to the output gear, and

the output gear includes a sector gear.

29. The front derailleur according to claim 28 , wherein

the gear structure has a reduction ratio equal to or lower than 1400.

30. A bicycle derailleur comprising:

a base member;

a chain guide movable relative to the base member;

a linkage structure configured to movably couple the chain guide to the base member; and

a motor unit configured to apply rotational force to at least one of the chain guide and the linkage structure to move the chain guide relative to the base member, the motor unit comprising:

a motor; and

a gear structure including a plurality of spur gears configured to transmit the rotational force to the at least one of the chain guide and the linkage structure, the gear structure having a reduction ratio equal to or lower than 1400, wherein

the motor unit is free of gears other than the plurality of spur gears on a rotational-force transmission path provided from the motor to the at least one of the chain guide and the linkage structure.

31. The bicycle derailleur according to claim 30 , further comprising

a rotation sensor configured to sense a rotational position of one of the plurality of spur gears.

32. The bicycle derailleur according to claim 31 , wherein

the plurality of spur gears includes a sensor gear, and

the rotation sensor is configured to sense the rotational position of the sensor gear.

33. A front derailleur comprising:

a base member;

a chain guide movable relative to the base member;

a linkage structure configured to movably couple the chain guide to the base member; and

a motor unit configured to apply rotational force to at least one of the chain guide and the linkage structure to move the chain guide relative to the base member, the motor unit comprising:

a motor configured to generate the rotational force;

a gear structure including a plurality of gears configured to transmit the rotational force to the at least one of the chain guide and the linkage structure; and

a gear support structure configured to rotatably support the plurality of gears,

the plurality of gears comprising:

a first gear rotatable relative to the gear support structure about a first gear axis;

a second gear rotatable relative to the gear support structure about a second gear axis;

a third gear rotatable relative to the gear support structure about a third gear axis;

a first pin configured to rotatably support the first gear about the first gear axis, the first pin including a first pin end and a first opposite pin end;

a second pin configured to rotatably support the second gear about the second gear axis, the second pin including a second pin end and a second opposite pin end;

a third pin configured to rotatably support the third gear about the third gear axis, the third pin including a third pin end and a third opposite pin end, and

the gear support structure comprising:

a first support configured to support the first pin end and the second pin end;

a second support configured to support the second opposite pin end and the third pin end, the second support being a separate member from the first support;

a third support configured to support the third opposite pin end; and

a fourth support configured to support the first opposite pin end.

34. The front derailleur according to claim 33 , wherein

the plurality of gears comprises a first additional gear rotatable relative to the gear support structure about the first gear axis, and

the first pin is configured to rotatably support the first gear and the first additional gear about the first gear axis.

35. The front derailleur according to claim 33 , wherein

the plurality of gears comprises a second additional gear rotatable relative to the gear support structure about the second gear axis, and

the second pin is configured to rotatably support the second gear and the second additional gear about the second gear axis.

36. The front derailleur according to claim 33 , wherein

the gear structure includes a torque diode including:

an outer casing;

a first shaft rotatably mounted to the outer casing about a first rotational axis; and

a second shaft rotatably mounted to the outer casing about a second rotational axis, and

the outer casing of the torque diode includes at least one of the first support, the second support, the third support, and the fourth support.