BICYCLE CRANK ASSEMBLY

• US 20150274253A1
• Filed: 07/22/2014
• Published: 10/01/2015
• Est. Priority Date: 03/26/2014
• Status: Active Grant

• Current Assignee: Shimano Inc
• Original Assignee: Shimano Inc
• Inventors: HARA, Nobukatsu, KODAMA, Michihiro
• Granted Patent: US 9,725,132 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B62M 1/105 using elastic elements
• CPC Class Codes: B62M 1/36 with rotary cranks, e.g. with pedal cranks B62M1/34 takes precedence; combined with reciprocating levers B62M1/26; cranks which can be immobilised as foot rests B62M5/00
• CPC Class Codes: B62M 3/00 Construction of cranks operated by hand or foot
• CPC Class Codes: B62M 3/003 Combination of crank axles and bearings housed in the bottom bracket bottom bracket frame details B62K19/34
• CPC Class Codes: B62M 3/16 Accessories
• CPC Class Codes: Y10T 74/2165 with attached gear

Abstract

A bicycle crank assembly having a rotational center axis is basically provided with a crank member and a sprocket member. The crank member includes a support portion that extends in the axial direction and an arm portion that is integrally rotatable around the rotational center axis with the support portion. The sprocket member includes a sliding portion that extends in the axial direction that is integrally rotatable with respect to the support portion and that is displaceable in the axial direction. The bicycle crank assembly is constructed to achieve high strength and to suppress the decrease in the efficiency of the rotation transmission from the crank member to the sprocket member in a crank assembly in which the sprocket member is movable in the axial direction.

Claims

1. A bicycle crank assembly having a rotational center axis, the bicycle crank assembly comprising:

a crank member having a support portion and an arm portion, the support portion extending from the arm portion in an axial direction, the arm portion being integrally rotatable around the rotational center axis with the support portion; and

a sprocket member having a sliding portion that extends in the axial direction, the sliding portion being integrally rotatable with the support portion, the sliding portion displaceably coupled to the support portion in the axial direction.

2. The bicycle crank assembly as recited in claim 1, wherein

the crank member has an axle mounting hole that is formed with the rotational center axis as a center, and

the support portion is formed around the axle mounting hole.

3. The bicycle crank assembly as recited in claim 1, wherein

the support portion is disposed radially inward of the sliding portion.

4. The bicycle crank assembly as recited in claim 1, further comprising

at least one rolling member that is disposed between the support portion and the sliding portion.

5. The bicycle crank assembly as recited in claim 1, further comprising

a plurality of rolling members disposed between the support portion and the sliding portion, and

a retaining member that retains the plurality of rolling members at intervals in a circumferential direction with resect to the rotational center axis.

6. The bicycle crank assembly as recited in claim 4, wherein

the rolling member is a sphere.

7. The bicycle crank assembly as recited in claim 5, further comprising

a reinforcing member that is installed in at least one of the support portion and the sliding portion and that slides so as to contact with the rolling member.

8. The bicycle crank assembly as recited in claim 7, wherein

the reinforcing member has a hardness that is greater than a hardness of the at least one of the support portion and the sliding portion, in which the reinforcing member is disposed.

9. The bicycle crank assembly as recited in claim 1, wherein

the crank member has an axle mounting hole that is arranged with the rotational center axis as its center, and further comprising

a crank axle coupled to the axle mounting hole to be integrally rotatable with the crank member.

10. The bicycle crank assembly as recited in claim 9, wherein

the crank axle is coupled to the axle mounting hole by press fitting.

11. The bicycle crank assembly as recited in claim 9, wherein

the crank axle is coupled to the axle mounting hole by adhesive.

12. The bicycle crank assembly as recited in claim 9, wherein

the crank axle is detachably coupled to the axle mounting hole.

13. The bicycle crank assembly as recited in claim 1, wherein

the support portion is integrally installed with the arm portion.

14. The bicycle crank assembly as recited in claim 1, wherein

the support portion is separately installed from the arm portion.

15. The bicycle crank assembly as recited in claim 1, further comprising

a dust cover covering a gap between the support portion and the sliding portion.

16. The bicycle crank assembly as recited in claim 1, further comprising

a movement amount adjusting mechanism arranged to adjust a movement amount of the sliding portion in the axial direction with respect to the support portion.

17. The bicycle crank assembly as recited in claim 1, further comprising

a backlash removing mechanism arranged to remove backlash between the support portion and the sliding portion in a radial direction with respect to the rotational center axis.

18. The bicycle crank assembly as recited in claim 1, wherein

the sprocket member further includes a sprocket main body that is coupled to the sliding portion to be integrally rotatable therewith as well as detachably coupled to the sliding portion.

19. The bicycle crank assembly as recited in claim 18, further comprising

a tool-free stopper member fixing the sprocket main body with respect to the sliding portion in the axial direction and with which the sprocket main body is manually detachably coupled to the sliding portion.

20. The bicycle crank assembly as recited in claim 19, wherein

the sliding portion has an outer peripheral surface with a mounting groove that extends in a circumferential direction on the outer peripheral surface, and

the tool-free stopper member includes:

an annular spring section that is mounted to the mounting groove and that has a smaller diameter than a mounting diameter of the mounting groove in a free state, and

a pair of operating handles that extends radially outward from both ends of the annular spring section for manually expanding a diameter of the annular spring section to be wider than the mounting groove.

21. A bicycle crank assembly having a rotational center axis, the bicycle crank assembly comprising:

a crank member rotatably arranged around the rotational center axis;

a sprocket member integrally and rotatably attached to the crank member;

a sliding mechanism movably coupling the sprocket member in an axial direction with respect to the crank member; and

a movement amount adjusting mechanism selectively adjusting an amount of movement of the sliding mechanism.

22. The bicycle crank assembly as recited in claim 21, wherein

the crank member has a axle mounting hole that is arranged with the rotational center axis as its center, and further comprising

an crank axle coupled to the axle mounting hole to be integrally rotatable with the crank member.

23. The bicycle crank assembly as recited in claim 22, wherein

the crank axle is coupled to the axle mounting hole by press fitting.

24. The bicycle crank assembly as recited in claim 22, wherein

the crank axle is coupled to the axle mounting hole by adhesive.

25. The bicycle crank assembly as recited in claim 22, wherein

the crank axle is detachably coupled to the axle mounting hole.

26. The bicycle crank assembly as recited in claim 21, wherein

a part of the sliding mechanism is integrally installed with the crank member.

27. The bicycle crank assembly as recited in claim 21, wherein

the sliding mechanism is separately installed from the crank member.

28. The bicycle crank assembly as recited in claim 21 further comprising

a dust seal covering both ends of the sliding mechanism in the axial direction.

29. The bicycle crank assembly as recited in claim 21, further comprising

a backlash removing mechanism arranged to remove backlash of the sliding mechanism in a radial direction with respect to the rotational center axis.

30. The bicycle crank assembly as recited in claim 21, wherein

the sprocket member is detachably coupled to the sliding mechanism, and further comprising

a tool-free stopper member fixing the sprocket member with respect to the sliding mechanism in an axial direction and with which the sprocket member is manually detachably coupled to the sliding mechanism.

31. The bicycle crank assembly as recited in claim 30, wherein

the sliding mechanism has an outer peripheral surface with a mounting groove that extends in a circumferential direction on the outer peripheral surface, and

the tool-free stopper member includes:

an annular spring section that is mounted to the mounting groove and that has a smaller diameter than a mounting diameter of the mounting groove in a free state, and

a pair of operating handles that extends radially outward from both ends of the annular spring section for manually expanding a diameter of the annular spring section to be wider than the mounting groove.

32. A bicycle crank assembly having a rotational center axis, the bicycle crank assembly comprising:

a crank member rotatably arranged around the rotational center axis;

a sprocket member integrally and rotatably attached to the crank member;

a sliding mechanism movably coupling the sprocket member in an axial direction with respect to the crank member; and

a dust cover covering both ends of the sliding mechanism in the axial direction.

33. The bicycle crank assembly as recited in claim 32, wherein

the crank member has a axle mounting hole that is arranged with the rotational center axis as its center, and further comprising

a crank axle coupled to the axle mounting hole to be integrally rotatable with the crank member.

34. The bicycle crank assembly as recited in claim 33, wherein

the crank axle is coupled to the axle mounting hole by press fitting.

35. The bicycle crank assembly as recited in claim 33, wherein

the crank axle is coupled to the axle mounting hole by adhesive.

36. The bicycle crank assembly as recited in claim 33, wherein

the crank axle is detachably coupled to the axle mounting hole.

37. The bicycle crank assembly as recited in claim 32, wherein

a part of the sliding mechanism is integrally installed with the crank member.

38. The bicycle crank assembly as recited in claim 32, wherein

the sliding mechanism is separately installed from the crank member.

39. The bicycle crank assembly as recited in claim 32, further comprising

a backlash removing mechanism arranged to remove backlash of the sliding mechanism in a radial direction with respect to the rotational center axis.

40. The bicycle crank assembly as recited in claim 32, wherein

the sprocket member is detachably coupled to the sliding mechanism, and further comprising

a tool-free stopper member fixing the sprocket member with respect to the sliding mechanism in the axial direction and with which the sprocket member is manually detachably coupled to the sliding mechanism.

41. The bicycle crank assembly as recited in claim 40, wherein

the sliding mechanism has an outer peripheral surface with a mounting groove that extends in a circumferential direction on the outer peripheral surface, and

the tool-free stopper member includes:

an annular spring section that is mounted to the mounting groove and that has a smaller diameter than a mounting diameter of the mounting groove in a free state, and

a pair of operating handles that extends radially outward from both ends of the annular spring section for manually expanding a diameter of the annular spring section to be wider than the mounting groove.

42. A bicycle crank assembly having a rotational center axis, the bicycle crank assembly comprising:

a crank member rotatably arranged around the rotational center axis;

a sprocket member integrally and rotatably attached to the crank member;

a sliding mechanism movably coupling the sprocket member in an axial direction with respect to the crank member; and

a backlash removing mechanism arranged to remove backlash of the sliding mechanism in the radial direction.

43. The bicycle crank assembly as recited in claim 42, wherein

the crank member has an axle mounting hole that is arranged with the rotational center axis as its center, and further comprising

a crank axle coupled to the axle mounting hole to be integrally rotatable with the crank member.

44. The bicycle crank assembly as recited in claim 43, wherein

the crank axle is coupled to the axle mounting hole by press fitting.

45. The bicycle crank assembly as recited in claim 43, wherein

the crank axle is coupled to the axle mounting hole by adhesive.

46. The bicycle crank assembly as recited in claim 43, wherein

the crank axle is detachably coupled to the axle mounting hole.

47. The bicycle crank assembly as recited in claim 42, wherein

a part of the sliding mechanism is integrally installed with the crank member.

48. The bicycle crank assembly as recited in claim 42, wherein

the sliding mechanism is separately installed from the crank member.

49. The bicycle crank assembly as recited in claim 42, wherein

the sprocket member is detachably coupled to the sliding mechanism, and further comprising

a tool-free stopper member fixing the sprocket member with respect to the sliding mechanism in the axial direction and with which the sprocket member is manually detachably coupled to the sliding mechanism.

50. The bicycle crank assembly as recited in claim 49, wherein

the sliding mechanism has an outer peripheral surface with a mounting groove that extends in a circumferential direction on the outer peripheral surface, and

the tool-free stopper member includes:

an annular spring section that is mounted to the mounting groove and that has a smaller diameter than a mounting diameter of the mounting groove in a free state, and

a pair of operating handles that extends radially outward from both ends of the annular spring section for manually expanding a diameter of the annular spring section to be wider than the mounting groove.

51. A bicycle crank assembly having a rotational center axis, the bicycle crank assembly comprising:

a crank member rotatably arranged around the rotational center axis;

a sprocket member integrally and rotatably attached to the crank member as well as detachably attached to the crank member; and

a tool-free stopper member fixing the sprocket member with respect to the crank member in an axial direction and with which the sprocket member is manually detachably coupled to the crank member.

52. The bicycle crank assembly as recited in claim 51, wherein

the crank member has a mounting groove that extends in a circumferential direction, and

the tool-free stopper member includes:

an annular spring section that is mounted to the mounting groove and that has a smaller diameter than a mounting diameter of the mounting groove in a free state, and

a pair of operating handles that extends radially outward from both ends of the annular spring section for manually expanding a diameter of the annular spring section to be wider than the mounting groove.

53. The bicycle crank assembly as recited in claim 51, wherein

the crank member has a axle mounting hole that is arranged with the rotational center axis as its center, and further comprising

a crank axle coupled to the axle mounting hole to be integrally rotatable with the crank member.

54. The bicycle crank assembly as recited in claim 53, wherein

the crank axle is coupled to the axle mounting hole by press fitting.

55. The bicycle crank assembly as recited in claim 53, wherein

the crank axle is coupled to the axle mounting hole by adhesive.

56. The bicycle crank assembly as recited in claim 53, wherein

the crank axle is detachably coupled to the axle mounting hole.

57. The bicycle crank assembly as recited in claim 51, further comprising

a sliding mechanism movably coupling the sprocket member in the axial direction with the crank member.

58. The bicycle crank assembly as recited in claim 57, wherein

a part of the sliding mechanism is integrally installed with the crank member.

59. The bicycle crank assembly as recited in claim 57, wherein

the sliding mechanism is separately installed separate the crank member.

60. A bicycle crank assembly having a rotational center axis, the bicycle crank assembly comprising:

a crank member rotatably arranged around the rotational center axis;

a sprocket member integrally and rotatably attached to the crank member;

a sliding mechanism movably coupling the sprocket member in an axial direction with respect to the crank member;

a first stopper member attached to the crank member;

a second stopper member attached to the sprocket member, and

a damping member attached to at least one of the first stopper member and the second stopper member and configured to contact the other of the first stopper member and the second stopper member while the sliding mechanism is in operation.

61. The bicycle crank assembly as recited in claim 60, wherein

the damping member is made of an elastic material.

62. The bicycle crank assembly as recited in claim 61, wherein

the damping member is made of urethane.

63. The bicycle crank assembly as recited in claim 61, wherein

the damping member is attached to the at least one of the first stopper member and the second stopper member by adhesive.

64. The bicycle crank assembly as recited in claim 60, wherein

the first stopper member and the second stopper member constitute a movement amount adjusting mechanism selectively adjusting an amount of movement of the sliding mechanism.