Bottom bracket assembly for man-powered vehicle

Abstract

To provide a bottom bracket assembly for a man-powered vehicle that enables a crankshaft of a man-powered vehicle to be appropriately mounted.SOLUTION: A bottom bracket assembly configured to be attached to a bottom bracket hanger of a man-powered vehicle has a central axis of rotation defining an axial direction, a radial direction, and a circumferential direction, and includes: a bearing unit including an inner race, an outer race, and a plurality of rolling elements disposed between the inner race and the outer race in the radial direction; a bearing support body configured to support the bearing unit; and a seal unit configured to be in contact with the crankshaft in the radial direction in a mounted state where the bottom bracket assembly is mounted on the man-powered vehicle. The seal unit is a separate member from the bearing support body and extends further radially outward than the inner race of the bearing unit in the radial direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a bottom bracket assembly for a human powered vehicle. [Background technology]

[0002] The bottom bracket assembly disclosed in Patent Document 1 includes, for example, a bearing that rotatably supports the crankshaft, and an O-ring that is disposed between the bearing and the crankshaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2022 / 0411011 Summary of the Invention [Problem to be solved by the invention]

[0004] In the bottom bracket assembly of Patent Document 1, there is a risk that the O-ring may become misaligned when attaching the crankshaft to the bottom bracket assembly. In the bottom bracket assembly of Patent Document 1, for example, if the O-ring becomes misaligned, the efficiency of the crankshaft attachment work decreases.

[0005] One object of the present disclosure is to provide a bottom bracket assembly that can suitably mount a crankshaft of a human-powered vehicle. [Means for solving the problem]

[0006] A bottom bracket assembly according to a first aspect of the present disclosure is a bottom bracket assembly configured to be attached to a bottom bracket hanger of a human-powered vehicle, the bottom bracket assembly having a central axis of rotation defining an axial direction, a radial direction, and a circumferential direction, and comprising: a bearing unit including an inner ring, an outer ring, and a plurality of rolling elements arranged between the inner ring and the outer ring in the radial direction; a bearing support configured to support the bearing unit; and a seal unit configured to contact a crankshaft in the radial direction when the bottom bracket assembly is attached to the human-powered vehicle, the seal unit being a separate member from the bearing support, and extending radially outward in the radial direction than the inner ring of the bearing unit. According to the bottom bracket assembly of the first aspect, since the seal unit extends radially outward beyond the inner ring of the bearing unit, the seal unit is less likely to shift when the crankshaft is attached to the bottom bracket assembly. Therefore, the crankshaft can be attached suitably to the bottom bracket assembly.

[0007] In the bottom bracket assembly of the second aspect according to the first aspect of the present disclosure, the seal unit is configured to be disposed between the bearing support and the crank arm in the axial direction. According to the bottom bracket assembly of the second aspect, the seal unit is less likely to become misaligned when the crankshaft is attached to the bottom bracket assembly.

[0008] In a bottom bracket assembly of a third aspect according to the first or second aspects of the present disclosure, the bearing support has an axial extension portion relating to the axial direction and a radial extension portion relating to the radial direction, and the bearing unit is configured to be disposed in the axial extension portion of the bearing support. According to the bottom bracket assembly of the third aspect, it is possible to easily remove backlash between the crankshaft and the bottom bracket assembly.

[0009] In a bottom bracket assembly of a fourth aspect according to the third aspect of the present disclosure, the seal unit is configured to be adjacent to the radial extension portion of the bearing support in the axial direction when the bottom bracket assembly is in an assembled state. According to the bottom bracket assembly of the fourth aspect, the seal unit is less likely to become misaligned when the crankshaft is attached to the bottom bracket assembly.

[0010] In a bottom bracket assembly of a fifth aspect according to any one of the first to fourth aspects of the present disclosure, the inner ring has an axial inner ring length measured in the axial direction and the outer ring has an axial outer ring length measured in the axial direction, the axial inner ring length being longer than the axial outer ring length. According to the bottom bracket assembly of the fifth aspect, the length of the inner ring in the axial direction is longer than the length of the outer ring in the axial direction, making it easy to arrange a seal member that slides on the inner ring.

[0011] In a bottom bracket assembly of a sixth aspect according to any one of the first to fifth aspects of the present disclosure, a rotating seal is further provided having a mounting end and a sliding end configured to slide against one of the inner ring and the outer ring of the bearing unit. According to the bottom bracket assembly of the sixth aspect, the rotational seal can prevent foreign matter from entering the inside of the bearing unit.

[0012] In a bottom bracket assembly of a seventh aspect according to the sixth aspect of the present disclosure, the sliding end of the rotating seal is configured to slide against the inner ring. According to the bottom bracket assembly of the seventh aspect, the sliding end slides against the inner ring having a smaller outer diameter than the outer ring, so that the rotational load caused by the sliding of the rotating seal can be reduced.

[0013] The bottom bracket assembly of an eighth aspect according to any one of the first to seventh aspects of the present disclosure further comprises an adapter member to which the outer ring of the bearing unit is attached. According to the bottom bracket assembly of the eighth aspect, a user can easily attach the bottom bracket assembly to a human-powered vehicle by using the adapter member.

[0014] In a bottom bracket assembly of a ninth aspect according to the eighth aspect of the present disclosure, the adapter member includes a small diameter tubular portion configured to be attached to the bottom bracket hanger of the human-powered vehicle, a large diameter tubular portion configured to hold the bearing unit, and a radially extending annular portion configured to connect the small diameter tubular portion to the large diameter tubular portion. According to the bottom bracket assembly of the ninth aspect, since the bearing unit different from the small diameter tubular portion configured to be attached to the bottom bracket hanger is held in the large diameter tubular portion, the bearing unit can be disposed outside the bottom bracket hanger, thereby improving the rigidity of the bottom bracket assembly.

[0015] In the bottom bracket assembly of a tenth aspect according to the ninth aspect of the present disclosure, the radially extending annular portion is configured to be adjacent to an axial end of the bottom bracket hanger of the human-powered vehicle in the mounted state. According to the bottom bracket assembly of the tenth aspect, the bearing unit can be suitably disposed outside the bottom bracket hanger, thereby improving the rigidity of the bottom bracket assembly.

[0016] In a bottom bracket assembly of an eleventh aspect according to any one of the first to tenth aspects of the present disclosure, the seal unit has a radially inner seal portion configured to seal between the bottom bracket assembly and the crankshaft in the radial direction. According to the bottom bracket assembly of the eleventh aspect, the radially inner seal portion can provide an appropriate seal between the crankshaft and the bottom bracket assembly.

[0017] In a bottom bracket assembly of a twelfth aspect according to an eleventh aspect of the present disclosure, further comprising an adapter member to which an outer ring of the bearing unit is attached, the seal unit having a radially outer seal portion configured to form a contactless seal between the radially outer seal portion and the adapter member. According to the bottom bracket assembly of the twelfth aspect, the radially outer seal portion can prevent foreign matter from entering the inside of the bearing unit, and can also prevent an increase in rotational load due to the radially outer seal portion.

[0018] In a bottom bracket assembly of a thirteenth aspect according to the eleventh aspect of the present disclosure, further comprising an adapter member to which an outer ring of the bearing unit is attached, the seal unit having a radially outer seal portion configured to contact the adapter member. According to the bottom bracket assembly of the thirteenth aspect, the radially outer seal portion can suppress the intrusion of foreign matter into the inside of the bearing unit.

[0019] In a bottom bracket assembly of a fourteenth aspect according to any one of the first to thirteenth aspects of the present disclosure, the seal unit includes a seal member configured to seal at least between the bottom bracket assembly and the crankshaft in the radial direction, and a seal core at least partially incorporated into the seal member. According to the bottom bracket assembly of the fourteenth aspect, it is possible to suppress the seal unit from becoming misaligned when attaching the crankshaft to the bottom bracket assembly.

[0020] In a bottom bracket assembly of a fifteenth aspect according to the fourteenth aspect of the present disclosure, the seal member has a radially inner seal portion configured to contact the crankshaft in the radial direction in the attached state. According to the bottom bracket assembly of the fifteenth aspect, the radially inner seal portion can provide an appropriate seal between the crankshaft and the bottom bracket assembly.

[0021] In a bottom bracket assembly of a sixteenth aspect according to the fifteenth aspect of the present disclosure, further comprising an adapter member to which an outer ring of the bearing unit is attached, the seal member having a radially outer seal portion configured to form a contactless seal between the radially outer seal portion and the adapter member. According to the bottom bracket assembly of the sixteenth aspect, the radially outer seal portion can prevent foreign matter from entering the inside of the bearing unit, and can also prevent an increase in rotational load due to the radially outer seal portion.

[0022] In a bottom bracket assembly of a seventeenth aspect according to the fifteenth aspect of the present disclosure, further comprising an adapter member to which an outer ring of the bearing unit is attached, the seal member having a radially outer seal portion configured to contact the adapter member. According to the bottom bracket assembly of the seventeenth aspect, the radially outer seal portion can prevent foreign matter from entering the inside of the bearing unit.

[0023] In a bottom bracket assembly of an 18th aspect according to any one of the 14th to 17th aspects of the present disclosure, the seal member is formed of a first material, and the seal core is formed of a second material harder than the first material of the seal member. According to the bottom bracket assembly of the eighteenth aspect, the seal unit is less likely to become misaligned when the crankshaft is attached to the bottom bracket assembly.

[0024] In a bottom bracket assembly of a 19th aspect according to any one of the 14th to 18th aspects of the present disclosure, the bearing support has a recess, and the seal member is configured to be at least partially disposed in the recess of the bearing support in the mounted state. According to the bottom bracket assembly of the nineteenth aspect, the seal unit can be suitably disposed.

[0025] In a bottom bracket assembly of a twentieth aspect according to any one of the first to nineteenth aspects of the present disclosure, the bearing support is formed from polybutylene terephthalate. According to the bottom bracket assembly of the twentieth aspect, deformation of the bearing support can be suppressed during use of the bottom bracket assembly. Effect of the Invention

[0026] The bottom bracket assembly for a human-powered vehicle of the present disclosure can suitably mount the crankshaft of the human-powered vehicle. [Brief description of the drawings]

[0027] [Figure 1] FIG. 2 is a front view of a bottom bracket assembly for a human-powered vehicle according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view of a bottom bracket assembly for the human-powered vehicle of FIG. 1. [Diagram 3] FIG. 2 is a cross-sectional view of the bottom bracket assembly for the human-powered vehicle in the mounted state of FIG. 1. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a bottom bracket assembly for the human-powered vehicle of FIG. [Diagram 5] FIG. 5 is a perspective view of the bearing support of FIG. 4. [Figure 6] FIG. 6 is a rear perspective view of the bearing support of FIG. 5. [Figure 7] FIG. 5 is a perspective view of the seal member of FIG. [Figure 8]FIG. 1 is an enlarged cross-sectional view of a bottom bracket assembly for a human-powered vehicle including a seal unit of a first modified example. [Figure 9] FIG. 11 is an enlarged cross-sectional view of a bottom bracket assembly for a human-powered vehicle including a seal unit of a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] <Embodiment> A bottom bracket assembly 30 for a human-powered vehicle will be described with reference to Figs. 1 to 7. A human-powered vehicle is a vehicle that has at least one wheel and can be driven at least by human-powered driving force. Human-powered vehicles include various types of bicycles, such as mountain bikes, road bikes, city bikes, cargo bikes, hand bikes, and recumbents. The number of wheels that a human-powered vehicle has is not limited. Human-powered vehicles also include, for example, one-wheeled vehicles and vehicles with two or more wheels. Human-powered vehicles are not limited to vehicles that can be driven only by human-powered driving force. Human-powered vehicles include E-bikes that use not only human-powered driving force but also the driving force of an electric motor for propulsion. E-bikes include electrically assisted bicycles whose propulsion is assisted by an electric motor. In the following, in each embodiment, a human-powered vehicle will be described as a bicycle.

[0029] In this specification, the following directional terms "front," "rear," "forward," "rearward," "left," "right," "sideways," "upward," and "downward," as well as any other similar directional terms, refer to those directions determined with reference to a rider in a reference position on the human-powered vehicle (e.g., on a saddle or seat) facing the handlebars.

[0030] 2 and 3, the human-powered vehicle 10 includes, for example, a frame 12. The human-powered vehicle 10 includes, for example, at least one wheel. The at least one wheel includes, for example, a front wheel and a rear wheel.

[0031] The frame 12 has, for example, a bottom bracket hanger 14. The bottom bracket hanger 14 is formed, for example, in a cylindrical shape. The bottom bracket hanger 14 is configured so that, for example, a bottom bracket assembly 30 can be attached thereto.

[0032] The bottom bracket hanger 14 has, for example, axial ends 14A and 14B. Female threads 14C and 14D for attaching a bottom bracket assembly 30 are formed on the inner circumferential surfaces of the axial ends 14A and 14B. If the bottom bracket assembly 30 is a press-fit type bottom bracket assembly, the bottom bracket hanger 14 does not have the female threads 14C and 14D.

[0033] The frame 12 has, for example, a down tube 16. The down tube 16 extends, for example, in front of the bottom bracket hanger 14. The frame 12 has, for example, a seat tube 18. The seat tube 18 extends, for example, above the bottom bracket hanger 14 and supports a saddle. The frame 12 has, for example, chain stays 20. The chain stays 20 extend, for example, rearward of the bottom bracket hanger 14 and to which a rear wheel is attached.

[0034] The human-powered vehicle 10 includes, for example, a crankshaft 22 and crank arms 24A, 24B. For example, a human-powered driving force is input to the crankshaft 22 and the crank arms 24A, 24B. For example, crank arms 24A, 24B are provided at the ends of the crankshaft 22. Pedals are connected to the crank arms 24A, 24B, respectively. The crankshaft 22 is attached to the frame 12, for example, so as to be rotatable relative to the frame 12. The crankshaft 22 is attached to the frame 12 via a bottom bracket assembly 30 so as to be rotatable relative to the frame 12.

[0035] The crank shaft 22 is disposed in the bottom bracket assembly 30, for example, in an attached state in which the bottom bracket assembly 30 is attached to the bottom bracket hanger 14. A spacer 26 for adjusting the positions of the crank arms 24A, 24B with respect to the frame 12 in the axial direction AD may be provided between the crank arms 24A, 24B and the bottom bracket assembly 30. The spacer 26 may be provided only between the crank arm 24A and the bottom bracket assembly 30, or only between the crank arm 24B and the bottom bracket assembly 30.

[0036] 1 to 3, the bottom bracket assembly 30 is configured to be attached to the bottom bracket hanger 14 of the human-powered vehicle 10. The bottom bracket assembly 30 has a central axis of rotation C that defines an axial direction AD, a radial direction RD, and a circumferential direction CD. The bottom bracket assembly 30 includes bearing units 32, 34, bearing supports 36, 38 configured to support the bearing units 32, 34, and seal units 40, 42.

[0037] The bearing unit 32 is provided at one end of the bottom bracket assembly 30 in the axial direction AD. The bearing unit 34 is provided at the other end of the bottom bracket assembly 30 in the axial direction AD. The bearing unit 32 includes, for example, an inner ring 32A, an outer ring 32B, and a plurality of rolling elements 32C arranged between the inner ring 32A and the outer ring 32B in the radial direction RD. The bearing unit 34 includes, for example, an inner ring 34A, an outer ring 34B, and a plurality of rolling elements 34C arranged between the inner ring 34A and the outer ring 34B in the radial direction RD.

[0038] The seal unit 40 is provided at one end of the bottom bracket assembly 30 in the axial direction AD. The seal unit 42 is provided at the other end of the bottom bracket assembly 30 in the axial direction AD. The seal units 40, 42 are configured to contact the crankshaft 22 in the radial direction RD, for example, when the bottom bracket assembly 30 is attached to the human-powered vehicle 10. The seal units 40, 42 are, for example, separate members from the bearing supports 36, 38, and extend radially outward from the inner rings 32A, 34A of the bearing units 32, 34 in the radial direction RD. The seal unit 40 is, for example, a separate member from the bearing support 36, and extends radially outward from the inner ring 32A of the bearing unit 32 in the radial direction RD. The seal unit 42 is, for example, a separate member from the bearing support 38, and extends radially outward from the inner ring 34A of the bearing unit 34 in the radial direction RD.

[0039] The bottom bracket assembly 30 further includes, for example, a dust tube 44. The dust tube 44 prevents foreign matter such as water and mud from entering the bottom bracket assembly 30 through the seat tube 18. The dust tube 44 is disposed, for example, in the bottom bracket hanger 14 in the attached state.

[0040] The dust tube 44 has, for example, annular grooves 44A, 44B on the outer circumferential surface of the end in the axial direction AD. The annular groove 44A is provided, for example, at one end in the axial direction AD of the dust tube 44. The annular groove 44B is provided, for example, at the other end in the axial direction AD of the dust tube 44. An O-ring 44C, for example, is disposed in the annular groove 44A. An O-ring 44D, for example, is disposed in the annular groove 44B.

[0041] The bottom bracket assembly 30 further includes adapter members 46, 48 to which, for example, the outer rings 32B, 34B of the bearing unit 32 are attached. For example, the outer ring 32B of the bearing unit 32 is attached to the adapter member 46. For example, the outer ring 34B of the bearing unit 32 is attached to the adapter member 48. The adapter members 46, 48 are, for example, tubular.

[0042] The adapter members 46, 48 include, for example, small diameter tubular portions 50, 56, large diameter tubular portions 52, 58, and radially extending annular portions 54, 60 configured to connect the small diameter tubular portions 50, 56 to the large diameter tubular portions 52, 58. The small diameter tubular portions 50, 56 are configured to be attached to, for example, the bottom bracket hanger 14 of the human-powered vehicle 10. The large diameter tubular portions 52, 58 are configured to hold, for example, the bearing units 32, 34. The radially extending annular portions 54, 60 are configured to connect, for example, the small diameter tubular portions 50, 56 to the large diameter tubular portions 52, 58. The adapter members 46 include, for example, the small diameter tubular portion 50, the large diameter tubular portion 52, and the radially extending annular portion 54 configured to connect the small diameter tubular portion 50 to the large diameter tubular portion 52. The small diameter tubular portion 50 is configured to be attached to, for example, the bottom bracket hanger 14 of the human-powered vehicle 10. The large diameter tubular portion 52 is configured to hold, for example, the bearing unit 32. The radially extending annular portion 54 is configured to connect, for example, the small diameter tubular portion 50 to the large diameter tubular portion 52. The adapter member 48 includes, for example, a small diameter tubular portion 56, a large diameter tubular portion 58, and a radially extending annular portion 60 configured to connect the small diameter tubular portion 56 to the large diameter tubular portion 58. The small diameter tubular portion 56 is configured to be attached to, for example, the bottom bracket hanger 14 of the human-powered vehicle 10. The large diameter tubular portion 58 is configured to hold, for example, the bearing unit 34. The radially extending annular portion 60 is configured to connect, for example, the small diameter tubular portion 56 to the large diameter tubular portion 58.

[0043] An external thread 50A is formed on the outer circumferential surface of the small diameter tubular portion 50 for attaching the adapter member 46 to the bottom bracket hanger 14. The external thread 50A engages with, for example, the internal thread 14C. In this embodiment, the bottom bracket assembly 30 is attached to the bottom bracket hanger 14 by a screw, but the bottom bracket assembly 30 may be a press-fit type bottom bracket assembly. When the bottom bracket assembly 30 is a press-fit type bottom bracket assembly, the external thread 50A is not formed on the outer circumferential surface of the small diameter tubular portion 50.

[0044] An external thread 56A is formed on the outer circumferential surface of the small diameter tubular portion 56 for attaching the adapter member 48 to the bottom bracket hanger 14. The external thread 56A engages with, for example, the internal thread 14D. When the bottom bracket assembly 30 is a press-fit type bottom bracket assembly, the external thread 56A is not formed on the outer circumferential surface of the small diameter tubular portion 56.

[0045] The radially extending annular portion 54 extends, for example, in the radial direction RD from the end of the small diameter tubular portion 50 opposite the dust tube 44 toward the large diameter tubular portion 52. The radially extending annular portion 54 is configured, for example, to be adjacent to the axial end portion 14A of the bottom bracket hanger 14 of the human-powered vehicle 10 in the attached state.

[0046] The radially extending annular portion 60 extends, for example, in the radial direction RD from an end of the small diameter tubular portion 56 opposite to the end on the dust tube 44 side, toward the large diameter tubular portion 58. The radially extending annular portion 60 is configured, for example, to be adjacent to the axial end portion 14B of the bottom bracket hanger 14 of the human-powered vehicle 10 in the attached state.

[0047] The bottom bracket assembly 30 further includes, for example, rotating seals 62, 64. The rotating seal 62 seals the crank arm 24A side of the bearing unit 32 to prevent foreign matter from entering the inside of the bearing unit 32, for example, in an assembled state. The rotating seal 64 seals the crank arm 24B side of the bearing unit 34 to prevent foreign matter from entering the inside of the bearing unit 34, for example, in an assembled state.

[0048] The bottom bracket assembly 30 further includes, for example, inner rotating seals 66, 68. The inner rotating seal 66 seals the side of the bearing unit 32 opposite to the rotating seal 62, for example, in the axial direction AD. The inner rotating seal 66 seals the bottom bracket hanger 14 side of the bearing unit 32 in the assembled state, for example, to prevent foreign matter from entering the inside of the bearing unit 32. The inner rotating seal 68 seals the side of the bearing unit 34 opposite to the rotating seal 64, for example, in the axial direction AD. The inner rotating seal 68 seals the bottom bracket hanger 14 side of the bearing unit 34 in the assembled state, for example, to prevent foreign matter from entering the inside of the bearing unit 34.

[0049] The bottom bracket assembly 30 includes, for example, a first seal structure. The first seal structure includes, for example, a bearing unit 32, a bearing support 36, and a seal unit 40. Preferably, the first seal structure further includes an adapter member 46, a rotating seal 62, and an inner rotating seal 66. The bottom bracket assembly 30 includes, for example, a second seal structure. The second seal structure includes, for example, a bearing unit 34, a bearing support 38, and a seal unit 42. Preferably, the second seal structure further includes an adapter member 48, a rotating seal 64, and an inner rotating seal 68. The first seal structure is configured similarly to the second seal structure, except that it is formed symmetrically in the axial direction AD. Therefore, in the following, the members included in the first seal structure will be described, but the members included in the second seal structure are also configured similarly to the members included in the first seal structure, except that it is formed symmetrically in the axial direction AD.

[0050] The bearing unit 32, for example, supports the crankshaft 22 rotatably with respect to the bottom bracket hanger 14. The inner ring 32A is configured to rotate integrally with the crankshaft 22. The inner ring 32A is attached to the crankshaft 22 via, for example, a bearing support 36. The outer ring 32B is configured to be non-rotatable relative to the bottom bracket hanger 14. The outer ring 32B is attached to the bottom bracket hanger 14 via, for example, an adapter member 48.

[0051] The inner ring 32A has an axial inner ring length L1 measured in the axial direction AD, for example. The outer ring 32B has an axial outer ring length L2 measured in the axial direction AD, for example. The axial inner ring length L1 is longer than the axial outer ring length L2, for example. The axial inner ring length L1 may be equal to or shorter than the axial outer ring length L2. The axial inner ring length L1 is, for example, 1.2 times or more and 2 times or less than the axial outer ring length L2. The crank arm 24A side end of the inner ring 32A is, for example, closer to the crank arm 24A than the crank arm 24A side end of the outer ring 32B. The bottom bracket hanger 14 side end of the outer ring 32B is, for example, closer to the bottom bracket hanger 14 than the bottom bracket hanger 14 side end of the inner ring 32A.

[0052] 3 to 6, the bearing support 36 supports the bearing unit 32. The bearing support 36 is attached, for example, to the outer circumferential surface of the crankshaft 22. The bearing support 36 is attached, for example, to the crankshaft 22 so as to rotate integrally with the crankshaft 22. An inner ring 32A of the bearing unit 32 is attached to the outer circumferential surface of the bearing support 36. The inner ring 32A of the bearing unit 32 is attached to the bearing support 36 so as to rotate integrally with the bearing support 36, for example.

[0053] The bearing support 36 has, for example, an axial extension portion 36A in the axial direction AD and a radial extension portion 36B in the radial direction RD. The bearing unit 32 is configured to be disposed, for example, on the axial extension portion 36A of the bearing support 36. The bearing support 36 is configured to rotate integrally with the bearing unit 32. The bearing support 36 is formed, for example, from polybutylene terephthalate. The bearing support 36 may also be formed from a metal material.

[0054] The axially extending portion 36A extends, for example, in the axial direction AD in parallel with the large diameter tubular portion 52 of the adapter member 46. The axially extending portion 36A is configured, for example, to contact the crankshaft 22 in an assembled state. The inner ring 32A is disposed, for example, radially outward of the axially extending portion 36A so as to contact the axially extending portion 36A.

[0055] The radial extension portion 36B has, for example, a first end portion 36C and a second end portion 36D. The first end portion 36C is closer to the large diameter tubular portion 52 of the adapter member 46 than the second end portion 36D in the radial direction RD. The axial extension portion 36A extends from the second end portion 36D toward the small diameter tubular portion 50 in the axial direction AD.

[0056] The bearing support 36 further includes, for example, an extension portion 36E. The outer periphery of the extension portion 36E is, for example, smoothly formed. The extension portion 36E extends, for example, in the axial direction AD from the first end portion 36C toward the bearing unit 32. The length of the extension portion 36E in the axial direction AD is, for example, shorter than the length of the axial extension portion 36A in the axial direction AD. The end portion of the extension portion 36E opposite to the radial extension portion 36B is, for example, disposed between the sliding end 62B of the rotary seal 62 and the mounting end 62A of the rotary seal 62 in the radial direction RD.

[0057] The bearing support 36 has, for example, a recess 36F. The recess 36F is configured to accommodate, for example, a portion of the seal unit 40. The recess 36F is provided, for example, at the second end 36D of the radial extension portion 36B. The recess 36F is provided, for example, continuously with the second end 36D of the radial extension portion 36B in the circumferential direction CD.

[0058] 4, the rotating seal 62 has, for example, a mounting end 62A and a sliding end 62B configured to slide against one of the inner ring 32A and the outer ring 32B of the bearing unit 32. The mounting end 62A is configured to rotate integrally with, for example, the other of the inner ring 32A and the outer ring 32B of the bearing unit 32.

[0059] The sliding end 62B of the rotary seal 62 of this embodiment is configured to slide against the inner ring 32A. The sliding end 62B is configured to slide against, for example, the outer peripheral surface of the inner ring 32A. The mounting end 62A of the rotary seal 62 of this embodiment is configured to be attached to the outer ring 32B. The mounting end 62A is configured to be attached to, for example, an end surface in the axial direction AD of the outer ring 32B. When the sliding end 62B is configured to slide against the inner ring 32A, the mounting end 62A may be attached to the inner peripheral surface of the adapter member 46. The mounting end 62A may be attached to the inner ring 32A, and the sliding end 62B may be configured to slide against the outer ring 32B.

[0060] The rotary seal 62 includes, for example, a rotary seal member 62C and a rotary seal core 62D. The rotary seal member 62C is configured to provide a seal between at least the inner ring 32A and the outer ring 32B in, for example, the axial direction AD. The rotary seal core 62D is, for example, at least partially disposed inside the rotary seal member 62C.

[0061] The material of the rotary seal core 62D is harder than the material of the rotary seal member 62C, for example. The material of the rotary seal member 62C is, for example, a rubber material. The rubber material is, for example, acrylonitrile butadiene rubber (NBR) or fluororubber (FKM). The material of the rotary seal core 62D is, for example, a metal material. The metal material is, for example, iron or aluminum. The rotary seal member 62C and the rotary seal core 62D are, for example, molded.

[0062] The inner rotating seal 66 has, for example, a mounting end 66A and a sliding end 66B. The sliding end 66B is configured to slide against, for example, one of the inner ring 32A and the outer ring 32B of the bearing unit 32. The mounting end 66A is configured to rotate integrally with, for example, the other of the inner ring 32A and the outer ring 32B of the bearing unit 32.

[0063] The sliding end 62B of the inner rotating seal 66 of this embodiment is configured to slide against the inner ring 32A. The sliding end 62B is configured to slide against, for example, an end face in the axial direction AD of the inner ring 32A. The mounting end 66A of the inner rotating seal 66 of this embodiment is configured to be attached to the outer ring 32B. The mounting end 66A is configured to be attached to, for example, an inner peripheral portion of the outer ring 32B. The mounting end 66A may be attached to, for example, the inner ring 32A, and the sliding end 62B may be configured to slide against the outer ring 32B.

[0064] As shown in Fig. 3, the seal unit 40 is configured to be disposed, for example, between the bearing support 36 and the crank arm 24A in the axial direction AD. As shown in Figs. 3 and 4, the seal unit 40 is configured, for example, to be adjacent to the radial extension portion 36B of the bearing support 36 in the axial direction AD in an assembled state of the bottom bracket assembly 30. The seal unit 40 is configured to be adjacent to the crank arm 24A in the axial direction AD in an assembled state. The seal unit 40 is disposed between the bearing support 36 and the crank arm 24A in an assembled state.

[0065] A spacer 26 may be disposed between the seal unit 40 and the crank arm 24A. When the spacer 26 is disposed between the seal unit 40 and the crank arm 24A, the seal unit 40 is configured to be adjacent to the spacer 26 in the axial direction AD in the assembled state.

[0066] 4, the seal unit 40 extends, for example, in the radial direction RD, from a position radially inward of the inner ring 32A of the bearing unit 32 to a position radially outward of the inner ring 32A of the bearing unit 32. The seal unit 40 extends, for example, in the radial direction RD, from a position radially inward of the inner ring 32A of the bearing unit 32 to a portion corresponding to the outer ring 32B of the bearing unit 32.

[0067] The seal unit 40 has a radial inner seal portion 40A configured to provide a seal between the bottom bracket assembly 30 and the crankshaft 22, for example, in the radial direction RD. The radial inner seal portion 40A is arranged in a recess 36F of the bearing support 36, for example, in the mounted state. The radial inner seal portion 40A includes, for example, a protrusion that protrudes in the axial direction AD. The protrusion of the radial inner seal portion 40A is configured to be at least partially positionable within the recess 36F.

[0068] The seal unit 40 has, for example, a radially outer seal portion 40B. The radially outer seal portion 40B is configured, for example, to form a non-contact seal 40C between the radially outer seal portion 40B and the adapter member 46. The radially outer seal portion 40B is configured, for example, to form a non-contact seal 40C between the radially outer seal portion 40B and the large diameter tubular portion 52 of the adapter member 46. The radially outer seal portion 40B is configured, for example, not to contact the large diameter tubular portion 52 of the adapter member 46. The radially outer seal portion 40B is provided, for example, on the outer periphery of the seal unit 40. The non-contact seal 40C is formed continuously, for example, in the circumferential direction CD. The seal unit 40 is configured, for example, so that the outer diameter of the radially outer seal portion 40B is slightly smaller than the inner diameter of the portion of the adapter member 46 where the seal unit 40 is disposed.

[0069] The seal unit 40 further includes, for example, a radially extending seal portion 40F that connects the radially inner seal portion 40A and the radially outer seal portion 40B. The radially extending seal portion 40F is continuous with, for example, an outer end portion in the radial direction RD of the radially inner seal portion 40A. The radially extending seal portion 40F is continuous with, for example, an inner end portion in the radial direction RD of the radially outer seal portion 40B. The radially outer seal portion 40B extends from a connection portion with the radially extending seal portion 40F toward the outer ring 32B of the bearing unit 32 in the axial direction AD.

[0070] 4 and 7, the seal unit 40 includes, for example, a seal member 40D and a seal core 40E. The seal member 40D is configured to provide a seal at least between the bottom bracket assembly 30 and the crankshaft 22 in the radial direction RD. The seal core 40E is at least partially assembled into the seal member 40D.

[0071] The seal member 40D is formed of, for example, a first material. The seal core 40E is formed of, for example, a second material harder than the first material of the seal member 40D. The first material is, for example, a rubber material. The rubber material is, for example, acrylonitrile butadiene rubber (NBR) or fluororubber (FKM). The second material is, for example, a metal material. The second material is, for example, iron or aluminum. The seal member 40D and the seal core 40E are, for example, molded.

[0072] The seal member 40D has a radially inner seal portion 40A configured to contact the crankshaft 22 in the radial direction RD in the attached state, for example. The radially inner seal portion 40A is provided continuously in the circumferential direction CD, for example. The seal unit 40 is configured such that the seal core 40E does not contact the crankshaft 22 in the attached state, for example.

[0073] The seal member 40D is configured, for example, to be at least partially disposed in the recess 36F of the bearing support 36 in the mounted state. In the mounted state, the portion of the seal member 40D that is at least partially disposed in the recess 36F of the bearing support 36 includes, for example, the radially inner seal portion 40A. For example, the portion of the seal member 40D that is at least partially disposed in the recess 36F is substantially entirely formed by the seal member 40D. For example, the portion of the seal member 40D that is at least partially disposed in the recess 36F is entirely formed by the seal member 40D.

[0074] The seal member 40D has, for example, a radially outer seal portion 40B. The radially outer seal portion 40B is configured to form a non-contact seal 40C between, for example, the radially outer seal portion 40B and the adapter member 46. A portion of the radially outer seal portion 40B that forms the non-contact seal 40C is, for example, entirely formed by the seal member 40D. A portion of the radially outer seal portion 40B that faces the adapter member 46 is, for example, entirely formed by the seal member 40D.

[0075] The seal core 40E is, for example, included in the radially outer seal portion 40B and the radially extending seal portion 40F. The seal core 40E is, for example, a plate-shaped member. The seal core 40E has, for example, a first seal core portion 40G. The first seal core portion 40G is included in the radially extending seal portion 40F. The first seal core portion 40G extends, for example, in the radial direction RD.

[0076] The seal core 40E further includes, for example, a second seal core portion 40H. The second seal core portion 40H is included in the radially outer seal portion 40B. The second seal core portion 40H extends, for example, in the axial direction AD. The second seal core portion 40H is continuous with the outer end portion of the first seal core portion 40G in the radial direction RD. The second seal core portion 40H extends, for example, from the connection portion with the first seal core portion 40G toward the outer ring 32B of the bearing unit 32 in the axial direction AD.

[0077] The first seal core portion 40G is disposed, for example, in a portion of the radially extending seal portion 40F close to the bearing support 36 in the axial direction AD. When the first seal core portion 40G is exposed to the outer surface of the seal unit 40, the first seal core portion 40G comes into contact with the radially extending portion 36B. The second seal core portion 40H is disposed, for example, in a portion of the radially outer seal portion 40B close to the radially extending portion 36B of the bearing support 36 in the radial direction RD. When the second seal core portion 40H is exposed to the outer surface of the seal unit 40, the second seal core portion 40H comes into contact with the radially extending portion 36B.

[0078] The seal unit 40 is formed, for example, so that the inner diameter of the radially outer seal portion 40B corresponds to the outer diameter of the radially extending portion 36B of the bearing support 36. The seal unit 40 is attached to the bearing support 36 by fitting the radially outer seal portion 40B into the radially extending portion 36B and disposing the radially inner seal portion 40A in the recess 36F.

[0079] The seal unit 40 is attached to the bearing support 36 so that, for example, movement relative to the bearing support 36 is restricted. The seal unit 40 is attached to the bearing support 36 by, for example, pressing the radially outer seal portion 40B into the radially extending portion 36B of the bearing support 36. When the seal member 40D is disposed on the inner periphery of the radially outer seal portion 40B, the seal unit 40 is attached to the bearing support 36 so that movement relative to the bearing support 36 is restricted by elastic deformation of the seal member 40D. The seal unit 40 may be attached to the bearing support 36 by an adhesive. The seal unit 40 may be simply disposed adjacent to the bearing support 36 without being attached to the bearing support 36 by pressing, adhesive, or the like.

[0080] For example, when a seal member such as an O-ring is provided between the crankshaft and the bearing unit, and when the crankshaft is attached to the bottom bracket assembly, there is a possibility that the O-ring may become misaligned, which reduces the efficiency of the attachment work. In the bottom bracket assembly 30 of this embodiment, the seal unit 40 extends in the radial direction RD, so that when the crankshaft 22 is attached to the bottom bracket assembly 30, the seal unit 40 is less likely to become misaligned. Therefore, the crankshaft 22 can be attached to the bottom bracket assembly 30 in an appropriate manner.

[0081] Since the outer periphery of the extension portion 36E is formed smoothly, when the radially outer seal portion 40B is fitted into the extension portion 36E, the radially outer seal portion 40B can move smoothly in the axial direction AD. Furthermore, if a convex portion is formed on the outer periphery of the extension portion 36E closer to the outer ring 32B than the radially outer seal portion 40B, it is necessary to reduce the dimensional tolerance of the seal unit 40 to avoid contact between the radially outer seal portion 40B and the convex portion. Since the outer periphery of the extension portion 36E in this embodiment is formed smoothly, it can contribute to improving the yield of the seal unit 40.

[0082] <Example of change> The description of the embodiments is merely an example of possible forms of a bottom bracket assembly for a human-powered vehicle, and is not intended to limit the forms. A bottom bracket assembly for a human-powered vehicle according to the present disclosure may take the form of, for example, a modified example of the embodiment shown below, or a combination of at least two modified examples that are not mutually contradictory. In the modified examples below, parts that are common to the embodiment are given the same reference numerals as the embodiment, and descriptions thereof are omitted.

[0083] As shown in FIG. 8, the seal unit 40 may have a radially outer seal portion 40K configured to contact the adapter member 46. In this modification, the seal member 40D may have a radially outer seal portion 40K configured to contact the adapter member 46. The radially outer seal portion 40K includes, for example, a contact portion 40M extending from the radially outer seal portion 40K toward the adapter member 46. The seal unit 40 of this modification is configured, for example, so that the outer diameter of the contact portion 40M is larger than the inner diameter of the portion of the adapter member 46 where the seal unit 40 is disposed. The contact portion 40M may be provided continuously or discontinuously in the circumferential direction CD at the outer periphery of the radially outer seal portion 40K.

[0084] 9, the radially outer seal portion 40B may include, for example, a labyrinth seal 40N. The labyrinth seal 40N may include, for example, a plurality of protrusions extending from the radially outer seal portion 40B toward the adapter member 46. The labyrinth seal 40N may be configured to form a contactless seal 40C between itself and the adapter member 46, or may be configured to contact the adapter member 46.

[0085] In the embodiment, in both the first seal structure and the second seal structure, the seal units 40, 42 are separate members from the bearing supports 36, 38 and are configured to extend radially outward from the inner rings 32A, 34A of the bearing units 32, 34 in the radial direction RD. However, in only one of the first seal structure and the second seal structure, the seal units 40, 42 may be separate members from the bearing supports 36, 38 and may extend radially outward from the inner rings 32A, 34A of the bearing units 32, 34 in the radial direction RD. In this modified example, the other of the first seal structure and the second seal structure may have an O-ring disposed on the outer circumferential surface of the crankshaft 22 instead of the seal units 40, 42. In this modified example as well, the movement of the seal unit 40 relative to the crankshaft 22 when the bottom bracket assembly 30 is attached to the crankshaft 22 is suitably restricted by one of the first seal structure and the second seal structure.

[0086] 8 and 9, the extension portion 36E may have a radial protrusion 36G. The radial protrusion 36G extends, for example, from the extension portion 36E in the radial direction RD. The radial protrusion 36G is provided, for example, on the outer periphery of the extension portion 36E, closer to the outer ring 32B than the radial outer seal portion 40B. The radial protrusion 36G can, for example, prevent foreign matter from entering the inside of the bottom bracket assembly 30.

[0087] The seal unit 40 may be entirely formed of one of the seal member 40D and the seal core 40E. When the seal unit 40 is entirely formed of the seal member 40D, the seal unit 40 is, for example, a resin seal. When the seal unit 40 is entirely formed of the seal core 40E, the seal unit 40 is, for example, a metal seal.

[0088] The seal unit 40 does not have to have the radially outer seal portions 40B, 40K. Even if the seal unit 40 does not have the radially outer seal portions 40B, 40K, the seal unit 40 is sandwiched between the crank arm 24A or the spacer 26 and the bearing support 36, so that movement of the seal unit 40 relative to the crankshaft 22 when the bottom bracket assembly 30 is attached to the crankshaft 22 is suitably restricted.

[0089] The term "at least one" as used herein means "one or more" of the desired options. As an example, the term "at least one" as used herein means "only one option" or "both of two options" if the number of options is two. As another example, the term "at least one" as used herein means "only one option" or "any combination of two or more options" if the number of options is three or more.

[0090] As used in this specification, ordinal numbers such as "first, second, and third" are used merely to distinguish between multiple elements having the same name and do not have any special meaning. [Explanation of symbols]

[0091] 10... human-powered vehicle, 14... bottom bracket hanger, 14A, 14B... axial end, 22... crankshaft, 24A, 24B... crank arm, 30... bottom bracket assembly, 32, 34... bearing unit, 32A, 34A... inner ring, 32B, 34B... outer ring, 32C, 34C... rolling elements, 36, 38... bearing support, 36A... axial extension, 36B... radial extension, 36 F...recess, 40, 42...seal unit, 40A...radially inner seal portion, 40B, 40K...radially outer seal portion, 40C...non-contact seal, 40D...seal member, 40E...seal core, 46, 48...adapter member, 50, 56...small diameter tubular portion, 52, 58...large diameter tubular portion, 54, 60...radially extending annular portion, 62, 64...rotating seal, 62A, 66A...mounting end, 62B, 66B...sliding end.

Claims

1. 1. A bottom bracket assembly configured to be attached to a bottom bracket hanger of a human-powered vehicle, comprising: the bottom bracket assembly has a central axis of rotation that defines an axial direction, a radial direction, and a circumferential direction; a bearing unit including an inner ring, an outer ring, and a plurality of rolling elements disposed between the inner ring and the outer ring in the radial direction; a bearing support configured to support the bearing unit; a seal unit configured to come into contact with the crankshaft in the radial direction when the bottom bracket assembly is attached to the human-powered vehicle; A bottom bracket assembly, wherein the seal unit is a separate member from the bearing support and extends radially outwardly beyond the inner ring of the bearing unit in the radial direction.

2. The bottom bracket assembly according to claim 1 , wherein the seal unit is configured to be disposed between the bearing support and a crank arm in the axial direction.

3. The bearing support has an axial extension portion extending in the axial direction and a radial extension portion extending in the radial direction, The bottom bracket assembly according to claim 1 , wherein the bearing unit is configured to be disposed on the axial extension of the bearing support.

4. The bottom bracket assembly according to claim 3 , wherein the seal unit is configured to be adjacent to the radial extension portion of the bearing support in the axial direction in an assembled state of the bottom bracket assembly.

5. the inner ring has an axial inner ring length measured in the axial direction; the outer ring has an axial outer ring length measured in the axial direction; The bottom bracket assembly according to claim 1 , wherein the inner axial length is greater than the outer axial length.

6. 2. The bottom bracket assembly of claim 1, further comprising a rotating seal having a mounting end and a sliding end configured to slide against one of the inner and outer races of the bearing unit.

7. The bottom bracket assembly of claim 6 , wherein the sliding end of the rotating seal is configured to slide against the inner race.

8. The bottom bracket assembly according to claim 1 , further comprising an adapter member to which the outer ring of the bearing unit is attached.

9. The adapter member includes: a small diameter tubular portion configured to be attached to the bottom bracket hanger of the human-powered vehicle; a large diameter tubular portion configured to hold the bearing unit; a radially extending annular portion configured to connect the smaller diameter tubular portion to the larger diameter tubular portion.

10. The bottom bracket assembly of claim 9 , wherein the radially extending annular portion is configured to abut an axial end of the bottom bracket hanger of the human-powered vehicle in the mounted state.

11. The bottom bracket assembly according to claim 1 , wherein the seal unit has a radially inner seal portion configured to seal between the bottom bracket assembly and the crankshaft in the radial direction.

12. an adapter member to which an outer ring of the bearing unit is attached; The seal unit has a radially outer seal portion, The bottom bracket assembly of claim 11 , wherein the radially outer seal is configured to provide a contactless seal between the radially outer seal and the adapter member.

13. an adapter member to which an outer ring of the bearing unit is attached; The bottom bracket assembly according to claim 11, wherein the seal unit includes a radially outer seal configured to contact the adapter member.

14. The seal unit includes: a seal member configured to seal at least between the bottom bracket assembly and the crankshaft in the radial direction; A bottom bracket assembly according to claim 1 , further comprising: a seal core at least partially embedded in said seal member.

15. The bottom bracket assembly according to claim 14 , wherein the seal member has a radially inner seal portion configured to contact the crankshaft in the radial direction in the attached state.

16. an adapter member to which an outer ring of the bearing unit is attached; The seal member has a radially outer seal portion, 16. A bottom bracket assembly according to claim 15, wherein the radially outer seal is configured to provide a contactless seal between the radially outer seal and the adapter member.

17. an adapter member to which an outer ring of the bearing unit is attached; The bottom bracket assembly of claim 15, wherein the seal member has a radially outer seal portion configured to contact the adapter member.

18. the seal member is formed of a first material; A bottom bracket assembly according to claim 14, wherein the seal core is formed from a second material harder than the first material of the seal member.

19. The bearing support has a recess; The bottom bracket assembly according to claim 14 , wherein the seal member is configured to be located at least partially in a recess in the bearing support in the mounted state.

20. A bottom bracket assembly according to any one of the preceding claims, wherein the bearing support is formed from polybutylene terephthalate.

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