Rear sprocket of human-powered vehicle and rear sprocket assembly of human-powered vehicle

Abstract

Provided is a human-powered vehicle rear sprocket capable of suppressing an increase in weight of a rear sprocket assembly and improving strength. A ninth rear sprocket (49) of a bicycle (1) includes a first outer ring body (57), a plurality of first sprocket teeth (59), an inner ring body (61), a plurality of link arms (63), and a plurality of first rivet holes (69). Each of the plurality of link arms (63) has a circumferential center line (CL) with respect to a rotation center axis (X). The plurality of first rivet holes (69) are at least partially provided in the first outer ring body (57). Each of the plurality of first rivet holes (69) has a hole center axis (HC). A total number of the plurality of link arms (63) is different from a total number of the plurality of first rivet holes (69). At least one of the plurality of hole center axes (HC) is circumferentially offset from each of the plurality of circumferential center lines (CL) with respect to the rotation center axis (X).

Description

Technical Field

[0001] This invention relates to a rear sprocket for a human-powered vehicle and a rear sprocket assembly for a human-powered vehicle. Background Technology

[0002] Patent Document 1 discloses a rear sprocket for a human-powered vehicle, such as a bicycle rear sprocket. Referring to Patent Document 1... Figure 4 It can be seen that the rear sprocket (12) for bicycles has an outer ring (50), multiple sprocket teeth (54), an inner ring (52), multiple connecting arms (62), and multiple fastening holes (64). Multiple sprocket teeth are located on the outer ring. The inner ring is mounted on the hub assembly. Multiple connecting arms (62) connect the outer ring and the inner ring.

[0003] Multiple fastening holes (64) are provided on multiple connecting arms (62). Fastening components are provided in the multiple fastening holes (64). The fastening components fasten the rear sprocket (12) to the adjacent rear sprocket (11). Specifically, the fastening components fasten the connecting arm (62) of the rear sprocket (12) to the inner part (42) of the adjacent rear sprocket (11) via the fastening holes (64).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: U.S. Patent Application Publication No. 2012 / 0225745. Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In recent years, various attempts have been made to improve the strength of bicycle rear sprockets. For example, in the aforementioned prior art, the strength of the rear sprocket is increased by adding more connecting arms. However, this approach results in an increase in the weight of the rear sprocket.

[0009] Furthermore, in this case, the number of multiple fastening holes increases in response to the increase in the number of multiple connecting arms. As a result, the number of inner portions adjacent to the rear sprocket increases, leading to an increase in the weight of the adjacent rear sprocket. That is, the weight of the rear sprocket assembly, including the rear sprocket and the adjacent rear sprocket, increases. Thus, in the prior art, it is difficult to simultaneously achieve both lightweighting of the rear sprocket assembly and increased strength of the rear sprocket.

[0010] The purpose of this invention is to provide a rear sprocket for a human-powered vehicle that can suppress the increase in weight of the rear sprocket assembly and improve its strength.

[0011] means for solving problems

[0012] Regarding a first aspect of the invention, a rear sprocket for a manually operated vehicle is used in a manually operated vehicle having an axial center plane. The rear sprocket of the manually operated vehicle has an axially outer surface and an axially inner surface. The axially inner surface is provided axially opposite to the axially outer surface about the axis of rotation. The axially inner surface is configured such that, in the mounted state of the rear sprocket in the manually operated vehicle, it is axially opposite to the axial center plane.

[0013] The rear sprocket of the manually driven vehicle has an outer ring, multiple sprocket teeth, an inner ring, multiple connecting arms, and multiple fastening holes. The multiple sprocket teeth extend radially outward from the outer ring about the axis of rotation. The inner ring is configured to connect to the sprocket support of the hub assembly in a manner capable of transmitting torque when the rear sprocket is mounted on the hub assembly.

[0014] Multiple connecting arms extend radially between an outer ring and an inner ring. Each of the multiple connecting arms has a circumferential centerline about the axis of rotation. The multiple connecting arms, together with the outer ring, multiple sprocket teeth, and the inner ring, form a single integral component. Multiple fastening holes are at least partially provided in the outer ring. Each of the multiple fastening holes is configured to receive a fastening component for fastening adjacent rear sprockets to each other.

[0015] The adjacent rear sprocket is abutted to the rear sprocket in such a manner that no other sprockets are disposed between the adjacent rear sprockets. Each of the plurality of fastening holes has a central axis. The total number of the plurality of connecting arms is different from the total number of the plurality of fastening holes. At least one of the plurality of central axes is offset circumferentially about the rotational central axis from each of the plurality of circumferential center lines.

[0016] According to the first aspect, the strength of the rear sprocket of the human-powered vehicle can be increased by increasing the number of multiple connecting arms. Furthermore, multiple fastening holes are at least partially provided on the outer annulus, and at least one of the central axes of the multiple holes is circumferentially offset from each of the multiple circumferential center lines about the rotational center axis.

[0017] According to this structure, the aforementioned problems arising from the increase in the number of multiple connecting arms can be solved. For example, the increase in weight of the adjacent rear sprocket can be suppressed. That is, according to the rear sprocket of the manually driven vehicle of the first aspect, the increase in weight of the rear sprocket assembly can be suppressed and the strength of the rear sprocket can be improved.

[0018] Regarding the second aspect of the invention, the rear sprocket of the manually driven vehicle of the first aspect is configured such that the inner annular body has a spline portion. The spline portion is configured such that, in the assembled state where the rear sprocket is mounted on the hub assembly, the spline portion engages with the sprocket support of the hub assembly.

[0019] In the second aspect, the rear sprocket of the human-powered vehicle can reliably transmit the driving torque to the hub assembly via the spline.

[0020] Regarding the third aspect of the present invention, the rear sprocket of the human-powered vehicle of the first or second aspect is configured such that the difference between the total number of the plurality of connecting arms and the total number of the plurality of fastening holes is 3 or less.

[0021] According to the third aspect of the rear sprocket of the human-powered vehicle, the increase in weight of the adjacent rear sprocket can be appropriately suppressed. That is, according to the third aspect of the rear sprocket of the human-powered vehicle, the increase in weight of the rear sprocket assembly can be appropriately suppressed and the strength of the rear sprocket can be improved.

[0022] Regarding the fourth aspect of the invention, the rear sprocket of the human-powered vehicle of the third aspect is configured such that the difference between the total number of the plurality of connecting arms and the total number of the plurality of fastening holes is 1.

[0023] According to the fourth aspect of the rear sprocket of the human-powered vehicle, the increase in weight of the adjacent rear sprocket can be appropriately suppressed. That is, according to the fourth aspect of the rear sprocket of the human-powered vehicle, the increase in weight of the rear sprocket assembly can be appropriately suppressed and the strength of the rear sprocket can be improved.

[0024] Regarding the fifth aspect of the invention, the rear sprocket of the human-powered vehicle of any one of the first to fourth aspects is configured such that the total number of the plurality of connecting arms is greater than the total number of the plurality of fastening holes.

[0025] According to the fifth aspect of the rear sprocket of the human-powered vehicle, the strength of the rear sprocket can be appropriately increased. That is, according to the fifth aspect of the rear sprocket of the human-powered vehicle, the weight increase of the rear sprocket assembly can be suppressed and the strength of the rear sprocket can be appropriately increased.

[0026] Regarding the sixth aspect of the present invention, the rear sprocket of the human-powered vehicle of any one of the first to fifth aspects is configured such that the central axis of the plurality of holes is offset circumferentially from the plurality of circumferential center lines.

[0027] According to the sixth aspect, the rear sprocket of the human-powered vehicle can appropriately suppress the increase in weight of the adjacent rear sprocket. That is, according to the sixth aspect, the rear sprocket of the human-powered vehicle can appropriately suppress the increase in weight of the rear sprocket assembly and improve the strength of the rear sprocket.

[0028] Regarding the seventh aspect of the invention, the rear sprocket of the human-powered vehicle of the sixth aspect is configured such that each of the central shafts of the holes is offset circumferentially from each of the circumferential center lines.

[0029] According to the seventh aspect of the rear sprocket of the human-powered vehicle, the increase in weight of the adjacent rear sprocket can be appropriately suppressed. That is, according to the seventh aspect of the rear sprocket of the human-powered vehicle, the increase in weight of the rear sprocket assembly can be appropriately suppressed and the strength of the rear sprocket can be improved.

[0030] Regarding the eighth aspect of the invention, the rear sprocket of the human-powered vehicle of any one of the first to seventh aspects is configured as follows: A plurality of connecting arms are arranged at equal intervals to each other in the circumferential direction about the axis of rotation. A plurality of fastening holes are arranged at equal intervals to each other in the circumferential direction.

[0031] According to the eighth aspect of the rear sprocket of the human-powered vehicle, the increase in weight of the adjacent rear sprocket can be appropriately suppressed, and the strength of the rear sprocket can be appropriately improved. That is, according to the eighth aspect of the rear sprocket of the human-powered vehicle, the increase in weight of the rear sprocket assembly can be appropriately suppressed, and the strength of the rear sprocket can be appropriately improved.

[0032] Regarding the ninth aspect of the present invention, the rear sprocket of the human-powered vehicle of any one of the first to eighth aspects is configured as follows.

[0033] The multiple sprocket teeth include multiple downshift actuating teeth. These multiple downshift actuating teeth are configured to facilitate a downshifting action that moves the drive chain from the adjacent small rear sprocket to the rear sprocket. The multiple downshift actuating teeth include downshift initiation teeth and downshift recessed teeth. The downshift initiation teeth are configured to engage with the drive chain first during the downshifting action.

[0034] The downshift recess tooth is arranged adjacent to the downshift initiation tooth on the downstream side of the downshift initiation tooth in the direction of drive rotation of the rear sprocket, such that no other sprocket teeth are arranged between the downshift initiation tooth and the downshift recess tooth in the circumferential direction. The downshift recess tooth has a downshift recess. The downshift recess is provided on the axial outer side of the downshift recess tooth in such a way that it is recessed from the axial outer side to the axial inner side in the axial direction.

[0035] According to the ninth aspect, the rear sprocket of the human-powered vehicle, since multiple sprocket teeth include the aforementioned multiple downshifting actuation teeth, can mitigate the impact during downshifting and can smoothly execute downshifting actions.

[0036] Regarding the tenth aspect of the present invention, the rear sprocket of the human-powered vehicle of any one of the first to ninth aspects is configured as follows.

[0037] The multiple sprocket teeth include multiple upshift actuating teeth. The multiple upshift actuating teeth are configured to facilitate the upshifting action that moves the drive chain from the rear sprocket to the adjacent small rear sprocket.

[0038] Multiple upshifting actuating teeth include upshift displacement teeth, upshift initiation teeth, and upshift recess teeth. The upshift displacement teeth are configured to displace the drive chain toward the adjacent small rear sprocket during the upshifting action. The upshift initiation teeth are configured to be the first to disengage from the drive chain during the upshifting action.

[0039] The upshift initiation tooth is arranged adjacent to the upshift displacement tooth on the upstream side of the upshift displacement tooth in the direction of drive rotation, such that no other sprocket teeth are arranged between the upshift initiation tooth and the upshift displacement tooth in the circumferential direction. The upshift initiation tooth has an upshift first recess. The upshift first recess is provided on the axial outer side of the upshift initiation tooth in such a way that it is recessed from the axial outer side to the axial inner side in the axial direction.

[0040] The upshift recess tooth is arranged adjacent to the upshift initiation tooth on the upstream side of the upshift initiation tooth in the direction of drive rotation, such that no other sprocket teeth are arranged between the upshift recess tooth and the upshift initiation tooth in the circumferential direction. The upshift recess tooth has a second upshift recess. The second upshift recess is provided on the axial outer side of the upshift recess tooth in such a way that it is recessed from the axial outer side to the axial inner side in the axial direction.

[0041] According to the tenth aspect, the rear sprocket of the human-powered vehicle, since multiple sprocket teeth include multiple upshift facilitating teeth, can mitigate the impact during upshifting and can smoothly execute upshifting actions.

[0042] Regarding the eleventh aspect of the invention, the rear sprocket of the manually driven vehicle of any one of the first to tenth aspects is configured as follows: Each of the plurality of sprocket teeth has a maximum radial length defined by the radial direction and a maximum axial length defined by the axial direction. The maximum radial length is longer than the maximum axial length.

[0043] According to the eleventh aspect, the rear sprocket of the human-powered vehicle can be easily multi-stage in terms of assembly.

[0044] Regarding the twelfth aspect of the present invention, the rear sprocket assembly includes the aforementioned rear sprocket and an adjacent rear sprocket. The rear sprocket has a first pitch circle diameter. The adjacent rear sprocket has a second pitch circle diameter larger than the first pitch circle diameter. The adjacent rear sprocket is coaxially arranged with the rear sprocket in the assembled state of the rear sprocket assembly.

[0045] According to the twelfth aspect of the rear sprocket assembly, the rear sprocket is a small sprocket, and the adjacent rear sprocket is a large sprocket. This structure can suppress the increase in weight of the rear sprocket assembly and improve its strength.

[0046] Regarding the thirteenth aspect of the present invention, the rear sprocket assembly of the twelfth aspect is configured as follows: An adjacent rear sprocket includes a sprocket body and a plurality of additional sprocket teeth. The plurality of additional sprocket teeth extend radially outward from the sprocket body. Each of the plurality of additional sprocket teeth has an additional maximum radial length defined by the radial direction and an additional maximum axial length defined by the axial direction. The additional maximum radial length is longer than the additional maximum axial length.

[0047] According to the rear sprocket assembly in aspect thirteen, the multi-stage nature of the rear sprocket assembly can be easily achieved.

[0048] Regarding the fourteenth aspect of the present invention, the rear sprocket assembly of the thirteenth aspect is configured as follows: The adjacent rear sprocket further includes a plurality of additional fastening holes. The plurality of additional fastening holes are at least partially provided in the sprocket body. The plurality of additional fastening holes are configured to receive fastening members for fastening the rear sprocket and the adjacent rear sprocket to each other. The total number of the plurality of fastening holes is equal to the total number of the plurality of additional fastening holes.

[0049] According to the fourteenth aspect of the rear sprocket of the human-powered vehicle, since multiple additional fastening holes are at least partially provided in the sprocket body, it is possible to suppress the increase in weight of the adjacent rear sprocket. According to this structure, it is possible to suppress the increase in weight of the rear sprocket assembly and improve the strength of the rear sprocket assembly.

[0050] Regarding the fifteenth aspect of the present invention, a rear sprocket for a manually operated vehicle is used in a manually operated vehicle having an axial center plane. The rear sprocket of the manually operated vehicle has an axial outer surface and an axial inner surface. The axial inner surface is provided axially opposite to the axial outer surface about the axis of rotation. The axial inner surface is configured such that, in the mounted state of the rear sprocket in the manually operated vehicle, it is axially opposite to the axial center plane.

[0051] The rear sprocket of the manually driven vehicle has an outer ring, multiple sprocket teeth, an inner ring, multiple connecting arms, and multiple fastening holes. The multiple sprocket teeth extend radially outward from the outer ring about the axis of rotation. The inner ring is configured to connect to the sprocket support of the hub assembly in a manner capable of transmitting torque when the rear sprocket is mounted on the hub assembly.

[0052] Multiple connecting arms extend radially between an outer annulus and an inner annulus. Each of the multiple connecting arms has a circumferential centerline about the axis of rotation. Multiple fastening holes are at least partially provided in the outer annulus. Each of the multiple fastening holes is configured to receive a fastening component for fastening adjacent rear sprockets to each other.

[0053] The adjacent rear sprocket is abutted axially, with no other sprockets positioned between the adjacent rear sprocket and the rear sprocket. Each of the plurality of fastening holes has a central axis. Each of the plurality of central axes is circumferentially offset from each of the plurality of circumferential center lines about the rotational central axis.

[0054] According to the fifteenth aspect of the rear sprocket of the human-powered vehicle, the strength of the rear sprocket can be increased by increasing the number of multiple connecting arms. Furthermore, multiple fastening holes are at least partially provided on the outer annular body, each of the central axes of the multiple holes being circumferentially offset from each of the multiple circumferential center lines about the rotational center axis.

[0055] According to this structure, the aforementioned problems arising from the increase in the number of multiple connecting arms can be solved. For example, the increase in weight of the adjacent rear sprocket can be suppressed. That is, according to the rear sprocket of the human-powered vehicle of aspect fifteen, the increase in weight of the rear sprocket assembly can be suppressed and the strength of the rear sprocket can be improved.

[0056] Furthermore, according to the fifteenth aspect of the rear sprocket of the human-powered vehicle, since each of the multiple hole center axes is circumferentially offset from each of the multiple circumferential center lines about the rotation center axis, the degree of freedom in the configuration of the speed-shifting actuating gears can be increased.

[0057] Regarding the sixteenth aspect of the present invention, the rear sprocket of the human-powered vehicle of the fifteenth aspect is configured such that the total number of the plurality of connecting arms is different from the total number of the plurality of fastening holes.

[0058] According to the sixteenth aspect of the rear sprocket of the human-powered vehicle, the strength of the rear sprocket can be appropriately increased. That is, according to the sixteenth aspect of the rear sprocket of the human-powered vehicle, the weight increase of the rear sprocket assembly can be suppressed and the strength of the rear sprocket can be appropriately increased.

[0059] Regarding the seventeenth, fifteenth, or sixteenth aspect of the present invention, the rear sprocket of the human-powered vehicle is configured such that the total number of the plurality of connecting arms is greater than the total number of the plurality of fastening holes.

[0060] According to the seventeenth aspect, the rear sprocket of the human-powered vehicle can appropriately increase the strength of the rear sprocket. That is, according to the seventeenth aspect, the rear sprocket of the human-powered vehicle can suppress the increase in weight of the rear sprocket assembly and appropriately increase the strength of the rear sprocket.

[0061] Regarding the eighteenth aspect of the present invention, the rear sprocket of a manually driven vehicle according to any one of aspects fifteen to seventeen is configured as follows: A plurality of sprocket teeth include a plurality of downshift actuating teeth. The plurality of downshift actuating teeth are configured to facilitate a downshifting action that moves the drive chain from an adjacent small rear sprocket to the rear sprocket. The plurality of downshift actuating teeth include a downshift initiating tooth and a downshift recessed tooth. The downshift initiating tooth is configured to engage with the drive chain first during the downshifting action.

[0062] The downshift recess tooth is arranged adjacent to the downshift initiation tooth on the downstream side of the downshift initiation tooth in the direction of drive rotation of the rear sprocket, such that no other sprocket teeth are arranged between the downshift initiation tooth and the downshift recess tooth in the circumferential direction. The downshift recess tooth has a downshift recess. The downshift recess is provided on the axial outer side of the downshift recess tooth in such a way that it is recessed from the axial outer side to the axial inner side in the axial direction.

[0063] According to the rear sprocket of the human-powered vehicle in the eighteenth aspect, since the multiple sprocket teeth include the aforementioned multiple downshifting actuation teeth, the impact during downshifting can be mitigated and the downshifting action can be performed smoothly.

[0064] Regarding the nineteenth aspect of the present invention, the rear sprocket of the manually driven vehicle of any one of the fifteenth to eighteenth aspects is configured as follows: A plurality of sprocket teeth include a plurality of upshift actuating teeth. The plurality of upshift actuating teeth are configured to facilitate an upshifting action that moves the drive chain from the rear sprocket to an adjacent small rear sprocket.

[0065] Multiple upshifting actuating teeth include upshift displacement teeth, upshift initiation teeth, and upshift recess teeth. The upshift displacement teeth are configured to displace the drive chain toward the adjacent small rear sprocket during the upshifting action. The upshift initiation teeth are configured to be the first to disengage from the drive chain during the upshifting action.

[0066] The upshift initiation tooth is arranged adjacent to the upshift displacement tooth on the upstream side of the upshift displacement tooth in the direction of drive rotation, such that no other sprocket teeth are arranged between the upshift initiation tooth and the upshift displacement tooth in the circumferential direction. The upshift initiation tooth has an upshift first recess. The upshift first recess is provided on the axial outer side of the upshift initiation tooth in such a way that it is recessed from the axial outer side to the axial inner side in the axial direction.

[0067] The upshift recess tooth is arranged adjacent to the upshift initiation tooth on the upstream side of the upshift initiation tooth in the direction of drive rotation, such that no other sprocket teeth are arranged between the upshift recess tooth and the upshift initiation tooth in the circumferential direction. The upshift recess tooth has a second upshift recess. The second upshift recess is provided on the axial outer side of the upshift recess tooth in such a way that it is recessed from the axial outer side to the axial inner side in the axial direction.

[0068] According to the nineteenth aspect, the rear sprocket of the human-powered vehicle, since multiple sprocket teeth include multiple upshift facilitating teeth, can mitigate the impact during upshifting and can smoothly execute upshifting actions.

[0069] Invention Effects

[0070] According to the present invention, it is possible to suppress the weight increase of the rear sprocket assembly of a manually driven vehicle and improve the strength of the rear sprocket of the manually driven vehicle. Attached Figure Description

[0071] Figure 1 This is a side view of a bicycle according to an embodiment of the present invention;

[0072] Figure 2 This is a diagram showing the bicycle as viewed from above.

[0073] Figure 3 This is a three-dimensional view of the front side of the rear sprocket assembly;

[0074] Figure 4 This is a three-dimensional view of the rear sprocket assembly.

[0075] Figure 5 This is a cross-sectional view of the rear sprocket assembly;

[0076] Figure 6A This is the front view of the ninth rear sprocket;

[0077] Figure 6B This is a view of the back of the ninth rear sprocket;

[0078] Figure 6C It is a partially enlarged cross-sectional view of the ninth and tenth rear sprockets;

[0079] Figure 7A This is the front view of the ninth sprocket, used to illustrate the structure related to the gear shifting action;

[0080] Figure 7B This is a back view of the ninth sprocket, used to illustrate the structure related to the shifting action;

[0081] Figure 8A This is the front view of the tenth rear sprocket;

[0082] Figure 8B This is a view of the back of the tenth rear sprocket. Detailed Implementation

[0083] like Figure 1As shown, in an embodiment of the present invention, the bicycle 1 is used as an example of a human-powered vehicle. The bicycle 1 has a drive chain 3, a frame 5, handlebars 7, a front wheel 9, a rear wheel 11, a gear shifting mechanism 13, a drive unit 15, and a front fork 17. The bicycle 1 also has a front derailleur 21 and a rear derailleur 23. Figure 2 As shown, bicycle 1 has an axial center plane P.

[0084] like Figure 1 As shown, the front fork 17 is rotatably mounted to the frame 5. The handlebars 7 are fixed to the front fork 17. The front wheel 9 is rotatably mounted to the front fork 17 via the front hub assembly 18. The rear wheel 11 is rotatably mounted to the rear of the frame 5 via the rear hub assembly 19. The front tire 9a is mounted to the front wheel 9. The rear tire 11a is mounted to the rear wheel 11.

[0085] The derailleur 13 is mounted on the handlebars 7. The derailleur 13 actuates the front derailleur 21 and the rear derailleur 23 via cables. For example, the rear derailleur 23 is mounted on the frame 5. The rear derailleur 23, through the derailleur 13, moves the drive chain 3 from one rear sprocket to other rear sprockets. The front derailleur 21 is mounted on the frame 5. The front derailleur 21, through the derailleur 13, moves the drive chain 3 from one front sprocket to other front sprockets.

[0086] The drive unit 15 mainly includes a rear hub assembly 19, a rear sprocket assembly 27, and a crank assembly 29. The drive unit 15 may include a drive chain 3. The rear hub assembly 19 is mounted on the frame 5.

[0087] The rear hub assembly 19 is connected to the rear wheel 11. A portion of the rear hub assembly 19 rotates integrally with the rear wheel 11. That is, a portion of the rear hub assembly 19 rotates relative to the frame 5. The rear hub assembly 19 is configured to rotate integrally with the rear sprocket assembly 27.

[0088] like Figure 1 and Figure 2 As shown, the rear sprocket assembly 27 has a rotation center axis X. Figure 2 The rear sprocket assembly 27 is schematically shown. The rear sprocket assembly 27 rotates about the rotation center axis X. For example, the rear sprocket assembly 27 rotates together with the rear hub assembly 19 via a hub axle (not shown). The driving force input from the rider of the bicycle 1 to the crank assembly 29 is transmitted to the rear sprocket assembly 27 and the rear hub assembly 19 via the drive chain 3.

[0089] like Figure 1As shown, the crank assembly 29 has a crank arm 31 and a front sprocket assembly 33. The crank arm 31 is rotatably supported on the lower part of the frame 5. The front sprocket assembly 33 is mounted on the crank arm 31 in a manner that allows it to rotate integrally with the crank arm 31. The front sprocket assembly 33 has at least one front sprocket.

[0090] like Figure 3 and Figure 4 As shown, the rear sprocket assembly 27 has multiple rear sprockets 41-51. Figure 4 The diagram shows multiple rear sprockets 46-51. (For example...) Figure 2 As shown, each of the plurality of rear sprockets 41-51 engages with the drive chain 3. The driving force transmitted from the crank assembly 29 to the drive chain 3 is transmitted to each of the plurality of rear sprockets 41-51.

[0091] like Figure 5 As shown, each of the plurality of rear sprockets 41 to 51 is mounted on the sprocket support 19a of the rear hub assembly 19 in such a way that it rotates integrally with the sprocket support 19a of the rear hub assembly 19.

[0092] In this embodiment, such as Figure 3 and Figure 5 As shown, an example of a configuration comprising 11 rear sprockets 41-51 is illustrated. The first rear sprocket 41 to the eleventh rear sprocket 51 are arranged coaxially about the rotational axis X. The first rear sprocket 41 to the eleventh rear sprocket 51 are arranged axially about the rotational axis X. Figure 5 As shown, among the third rear sprocket 43 to the ninth rear sprocket 49, shims 28a to 28f are arranged between two adjacent sprockets.

[0093] like Figure 4 and Figure 5 As shown, the seventh rear sprocket 47 to the ninth rear sprocket 49 are connected to each other by the first rivet 53a. The eighth rear sprocket 48 and the ninth rear sprocket 49 are connected to each other by the second rivet 53b. The ninth rear sprocket 49 and the tenth rear sprocket 50 are fastened to each other by the third rivet 53c. The third rivet 53c is an example of a fastening component.

[0094] The tenth rear sprocket 50 and the eleventh rear sprocket 51 are connected to each other by the fourth rivet 53d. The first rear sprockets 41 to the eleventh rear sprocket 51 are connected to each other by the washers 28a to 28f via the connecting component 53e. The washers 28a to 28f, the first rivet 53a, the second rivet 53b, the third rivet 53c, the fourth rivet 53d, and the connecting component 53e can be interpreted as the structure of the rear sprocket assembly 27.

[0095] In this embodiment, the ninth rear sprocket 49 and the tenth rear sprocket 50 have the characteristic structure of the present invention. The rear sprocket assembly 27 includes the ninth rear sprocket 49 and the tenth rear sprocket 50. The ninth rear sprocket 49 is an example of a rear sprocket. The tenth rear sprocket 50 is an example of an adjacent rear sprocket. The eighth rear sprocket 48 used in the following description is an example of an adjacent small rear sprocket.

[0096] ・Ninth rear sprocket

[0097] like Figure 6A and Figure 6B As shown, the ninth rear sprocket 49 has a rotation center axis X. The rotation center axis X is concentric with the rotation center axis of the rear sprocket assembly 27 described above.

[0098] The ninth rear sprocket 49 has a first axial outer surface 49a and a first axial inner surface 49b. The ninth rear sprocket 49 has a first pitch circle diameter PD1. (As follows...) Figure 6A As shown, the first axial outer surface 49a forms the outer surface of the ninth rear sprocket 49 in the axial direction about the rotation center axis X.

[0099] like Figure 6B As shown, the first axial inner surface 49b forms the inner surface of the ninth rear sprocket 49 in the axial direction about the rotation center axis X. The first axial inner surface 49b is located on the opposite side of the first axial outer surface 49a in the axial direction about the rotation center axis X. The first axial inner surface 49b is configured such that, in the mounted state of the ninth rear sprocket 49 mounted on the bicycle 1, in the axial direction about the rotation center axis X, it forms the inner surface of the ninth rear sprocket 49. Figure 2 The axial center plane P shown is set opposite to each other.

[0100] like Figure 6A and Figure 6B As shown, the first pitch circle diameter PD1 is defined with the rotation center axis X as the center. The first pitch circle diameter PD1 is the diameter of the pitch circle PC1 of the ninth rear sprocket 49. The pitch circle PC1 of the ninth rear sprocket 49 is formed by connecting the centers of the chain rollers when the chain rollers of the drive chain 3 are in contact with the plurality of first sprocket teeth 59 of the ninth rear sprocket 49.

[0101] like Figure 6A and Figure 6B As shown, the ninth rear sprocket 49 includes a first outer annular body 57, a plurality of first sprocket teeth 59, an inner annular body 61, a plurality of connecting arms 63, and a plurality of first rivet holes 69. In this embodiment, the first outer annular body 57, the plurality of first sprocket teeth 59, the inner annular body 61, and the plurality of connecting arms 63 are formed as a single integral component. The first outer annular body 57, the inner annular body 61, and the plurality of connecting arms 63 can be formed separately from each other.

[0102] A plurality of first sprocket teeth 59 extend radially outward from the first outer annulus 57 about the axis of rotation X. More specifically, the plurality of first sprocket teeth 59 extend radially outward from the outer periphery 57a of the first outer annulus 57 about the axis of rotation X. The outer periphery 57a of the first outer annulus 57 is defined by the root circle CB1 of the plurality of first sprocket teeth 59.

[0103] like Figure 6C As shown, each of the plurality of first sprocket teeth 59 has a first maximum radial length L1 and a first maximum axial length L2. The first maximum radial length L1 is defined radially about the rotation center axis X. For example, the first maximum radial length L1 is the length in the radial direction about the rotation center axis X from the outer periphery 57a of the first outer annulus 57 to the tooth tip 59a of the plurality of first sprocket teeth 59.

[0104] The first maximum axial length L2 is defined axially about the rotation center axis X. For example, the first maximum axial length L2 is the maximum length at the position of the outer periphery 57a of the first outer annulus 57 about the rotation center axis X. More specifically, the first maximum axial length L2 is the maximum axial length between the first axial outer surface 49a and the first axial inner surface 49b at the position of the tooth root circle CB1 of the plurality of first sprocket teeth 59. The first maximum radial length L1 is longer than the first maximum axial length L2.

[0105] like Figure 5 As shown, the inner ring 61 is configured to connect to the sprocket support 19a of the rear hub assembly 19 in a manner that can transmit torque when the rear sprocket assembly 27 is installed on the rear hub assembly 19.

[0106] like Figure 5 , Figure 6A and Figure 6B As shown, the inner annular body 61 has a spline portion 61a. The spline portion 61a forms the inner circumferential surface of the inner annular body 61. Figure 5 As shown, the spline portion 61a is configured to engage with the sprocket support 19a of the rear hub assembly 19 when the ninth rear sprocket 49 is mounted on the rear hub assembly 19. A spline is formed on the sprocket support 19a that engages with the spline portion 61a of the rear sprocket 49.

[0107] like Figure 6A and Figure 6BAs shown, a plurality of connecting arms 63 extend radially about the rotation center axis X between the first outer annulus 57 and the inner annulus 61. The plurality of connecting arms 63 are arranged at equal intervals around each other in the circumferential direction about the rotation center axis X. The plurality of connecting arms 63, together with the first outer annulus 57, the plurality of first sprocket teeth 59, and the inner annulus 61, form a single integral component. Each of the plurality of connecting arms 63 has a circumferential center line CL about the rotation center axis X.

[0108] Figure 6A and Figure 6B Each of the plurality of first rivet holes 69 shown is configured to receive Figure 4 and Figure 5 The third rivet 53c is shown. A plurality of first rivet holes 69 are at least partially provided on the first outer annulus 57. The first rivet holes 69 are an example of fastening holes.

[0109] In this embodiment, each of the plurality of first rivet holes 69 is at least partially provided on the first outer annulus 57. Each of the plurality of first rivet holes 69 may be partially provided on the first outer annulus 57 and partially provided on the connecting arm 63. The plurality of first rivet holes 69 are arranged at equal intervals to each other in the circumferential direction about the rotation center axis X. Figure 4 and Figure 5 The third rivet 53c shown is inserted into the first rivet hole 69.

[0110] Each of the plurality of first rivet holes 69 has a hole center axis HC. At least one of the plurality of hole center axes HC is offset circumferentially from each of the plurality of circumferential center lines CL about the rotation center axis X. That is, at least two hole center axes HC are offset circumferentially from the plurality of circumferential center lines CL about the rotation center axis X. In this embodiment, each of the plurality of hole center axes HC is offset circumferentially from each of the plurality of circumferential center lines CL about the rotation center axis X.

[0111] The total number of the plurality of connecting arms 63 is different from the total number of the plurality of first rivet holes 69. The total number of the plurality of connecting arms 63 is greater than the total number of the plurality of first rivet holes 69. For example, the difference between the total number of the plurality of connecting arms 63 and the total number of the plurality of first rivet holes 69 is 3 or less. In this embodiment, the total number of the plurality of connecting arms 63 is 7, and the total number of the plurality of first rivet holes 69 is 6. The difference between the total number of the plurality of connecting arms 63 and the total number of the plurality of first rivet holes 69 is 1.

[0112] The aforementioned ninth rear sprocket 49 is configured as follows to facilitate downshifting. For example... Figure 7AAs shown, the plurality of first sprocket teeth 59 include a plurality of downshift promoting teeth 59D1 and 59D2. The plurality of first sprocket teeth 59 may also include an additional downshift promoting tooth 59D3. The plurality of first sprocket teeth 59 may also include downshift engagement promoting teeth 59D4 and 59D5.

[0113] Multiple downshifting actuating teeth 59D1 and 59D2 constitute an actuating downshifting action. During the downshifting action, the drive chain 3 moves from the eighth rear sprocket 48, which is a small sprocket, to the ninth rear sprocket 49, which is a large sprocket.

[0114] like Figure 7A As shown, the multiple downshifting actuation teeth 59D1 and 59D2 include a downshift initiation tooth 59D1 and a downshifting recess tooth 59D2. The downshift initiation tooth 59D1 is configured to engage with the drive chain 3 first during the downshifting operation.

[0115] For example, when downshifting, with the outer link of the drive chain 3 in the position of the additional downshift promoting tooth 59D3 and the inner link of the drive chain 3 in the position of the downshift promoting tooth 59D2, the outer link of the drive chain 3 engages with the downshift initiation tooth 59D1 first.

[0116] Among the multiple downshift facilitator teeth 59D1, 59D2 and the additional downshift facilitator tooth 59D3, the downshift initiation tooth 59D1 is located on the upstream side of the drive rotation direction RD of the ninth rear sprocket 49.

[0117] like Figure 7B As shown, the downshift initiation tooth 59D1 has a first axial recess 59D1a. The first axial recess 59D1a is provided on the first axial inner surface 49b of the downshift initiation tooth 59D1. For example, the first axial recess 59D1a is provided on the first axial inner surface 49b of the downshift initiation tooth 59D1 in such a way that it is recessed from the first axial inner surface 49b toward the first axial outer surface 49a in the axial direction about the rotation center axis X. The first axial recess 59D1a can be a recess or an inclined portion.

[0118] like Figure 7A As shown, the downshift recess tooth 59D2 is arranged adjacent to the downshift start tooth 59D1 on the downstream side of the drive rotation direction RD of the ninth rear sprocket 49 in the circumferential direction about the rotation center axis X, such that no other first sprocket teeth 59 are arranged between the downshift start tooth 59D1 and the downshift recess tooth 59D2.

[0119] The downshifting recess tooth 59D2 has downshifting recesses (59D2a, 59D2b). The downshifting recesses (59D2a, 59D2b) are provided on the first axial outer surface 49a of the downshifting recess tooth 59D2. For example, the downshifting recesses (59D2a, 59D2b) are provided on the first axial outer surface 49a of the downshifting recess tooth 59D2 in such a way that they are recessed from the first axial outer surface 49a toward the first axial inner surface 49b in the axial direction about the rotation center axis X.

[0120] In detail, the downshift recesses (59D2a, 59D2b) have a first downshift recess 59D2a and a second downshift recess 59D2b. Each of the first downshift recess 59D2a and the second downshift recess 59D2b is provided on the first axial outer side 49a of the downshift recess tooth 59D2 in such a way that it is recessed from the first axial outer side 49a toward the first axial inner side 49b about the rotation center axis X.

[0121] The first downshift recess 59D2a and the second downshift recess 59D2b are arranged circumferentially about the rotation center axis X. The first downshift recess 59D2a and the second downshift recess 59D2b are arranged adjacent to each other such that no other recesses are arranged between them. The first downshift recess 59D2a and the second downshift recess 59D2b can be formed as a single recess.

[0122] like Figure 7A As shown, the additional downshifting actuating gear 59D3 is configured to facilitate the downshifting action that moves the drive chain 3 from the eighth rear sprocket 48 to the ninth rear sprocket 49.

[0123] The additional downshift facilitator tooth 59D3 includes an additional downshift recess tooth 59D3'. The additional downshift recess tooth 59D3' is located downstream of the downshift recess tooth 59D2 in the drive rotation direction RD of the ninth rear sprocket 49, and is disposed adjacent to the downshift recess tooth 59D2. In this embodiment, the downshift recess tooth 59D2 and the additional downshift recess tooth 59D3' are arranged in the drive rotation direction RD of the ninth rear sprocket 49.

[0124] The additional downshifting recess 59D3' has an additional downshifting recess 59D3a. The additional downshifting recess 59D3a is provided on the first axial outer surface 49a of the additional downshifting recess 59D3'. For example, the additional downshifting recess 59D3a is provided on the first axial outer surface 49a of the additional downshifting recess 59D3' in such a way that it is recessed from the first axial outer surface 49a toward the first axial inner surface 49b in the axial direction about the rotation center axis X.

[0125] like Figure 7AAs shown, the downshift engagement promoting teeth 59D4 and 59D5 are configured to promote the engagement of the drive chain 3 with respect to the downshift initiation tooth 59D1 during downshifting. The downshift engagement promoting teeth 59D4 and 59D5 are positioned upstream of the downshift initiation tooth 59D1 in the drive rotation direction RD with respect to the ninth rear sprocket 49.

[0126] With the outer link of the drive chain 3 first engaged with the downshift initiation tooth 59D1, the downshift engagement facilitator tooth 59D4 engages with the outer link of the drive chain 3, and the downshift engagement facilitator tooth 59D5 engages with the inner link of the drive chain 3.

[0127] like Figure 7B As shown, downshift engagement promoting teeth 59D4 and 59D5 respectively have downshift engagement recesses 59D4a and 59D5a. Downshift engagement recesses 59D4a and 59D5a are provided on the first axial inner surface 49b of downshift engagement promoting teeth 59D4 and 59D5.

[0128] For example, the downshift engagement recesses 59D4a and 59D5a are respectively provided on the first axial inner surface 49b of the downshift engagement promoting teeth 59D4 and 59D5 in such a way that they are recessed from the first axial inner surface 49b toward the first axial outer surface 49a in the axial direction about the rotation center axis X. The first axial recess 59D1a can be a recess or an inclined portion.

[0129] The aforementioned ninth rear sprocket 49 is configured as follows to facilitate upshifting. For example... Figure 7A As shown, the plurality of first sprocket teeth 59 include a plurality of upshift promoting teeth 59U1, 59U2, and 59U3. The plurality of first sprocket teeth 59 may include an additional upshift promoting tooth 59U0.

[0130] Multiple upshifting actuators 59U1, 59U2, and 59U3 constitute an upshifting action. Adding an additional upshifting actuator 59U0 constitutes an upshifting action.

[0131] The upshifting action is the movement of the drive chain 3 from the ninth rear sprocket 49, which is the large sprocket, to the eighth rear sprocket 48, which is the small sprocket.

[0132] like Figure 7A As shown, the multiple upshift promoting teeth 59U1, 59U2, and 59U3 include an upshift shifting tooth 59U1, an upshift initiation tooth 59U2, and an upshift recess tooth 59U3. An additional upshift promoting tooth 59U0 includes an additional upshift shifting tooth 59U0.

[0133] like Figure 7AAs shown, the upshift shifting tooth 59U1 is configured to shift the drive chain 3 toward the eighth rear sprocket 48 during the upshifting operation. The additional upshift shifting tooth 59U0 is configured to shift the drive chain 3 toward the eighth rear sprocket 48 during the upshifting operation.

[0134] For example, when upshifting, if the inner link of the drive chain 3 is located at the additional upshift shifting tooth 59U0 and the outer link of the drive chain 3 is located at the upshift shifting tooth 59U1, the drive chain 3 will be closer to the eighth rear sprocket 48 in both the additional upshift shifting tooth 59U0 and the upshift shifting tooth 59U1.

[0135] like Figure 7B As shown, the shifting gear 59U1 has a second axial recess 59U1a. The second axial recess 59U1a is provided on the first axial inner surface 49b of the shifting gear 59U1. For example, the second axial recess 59U1a is provided on the first axial inner surface 49b of the shifting gear 59U1 in such a way that it is recessed from the first axial inner surface 49b toward the first axial outer surface 49a in the axial direction about the rotation center axis X.

[0136] like Figure 7A As shown, the additional upshifting gear 59U0 is located downstream of the upshifting gear 59U1 in the drive rotation direction RD, and is configured adjacent to the upshifting gear 59U1. The additional upshifting gear 59U0 can be a regular drive gear that does not have the function of an upshifting gear.

[0137] like Figure 7B As shown, the additional shifting gear 59U0 has a third axial recess 59U0a. The third axial recess 59U0a is provided on the first axial inner surface 49b of the additional shifting gear 59U0. The third axial recess 59U0a is provided on the first axial inner surface 49b of the additional shifting gear 59U0 in a manner that it is recessed from the first axial inner surface 49b toward the first axial outer surface 49a in the axial direction about the rotation center axis X. The second axial recess 59U1a and the third axial recess 59U0a can be either recesses or inclined portions.

[0138] like Figure 7A As shown, the upshift initiation tooth 59U2 is configured to disengage from the drive chain 3 first during the upshift operation. For example, when the inner link of the drive chain 3 is located at the upshift initiation tooth 59U2 during the upshift operation, the drive chain 3 begins to disengage from the upshift initiation tooth 59U2.

[0139] The upshift initiation tooth 59U2 is located upstream of the upshift shift tooth 59U1 in the drive rotation direction RD of the ninth rear sprocket 49, and is configured adjacent to the upshift shift tooth 59U1.

[0140] For example, the upshift start tooth 59U2 is arranged adjacent to the upshift shift tooth 59U1 on the upstream side of the upshift shift tooth 59U1 about the drive rotation direction RD, in such a way that no other first sprocket teeth 59 are arranged between the upshift start tooth 59U2 and the upshift shift tooth 59U1 in the circumferential direction about the rotation center axis X.

[0141] The upshift initiation tooth 59U2 has an upshift first recess 59U2a. The upshift first recess 59U2a is provided on the first axial outer surface 49a of the upshift initiation tooth 59U2. For example, the upshift first recess 59U2a is provided on the first axial outer surface 49a of the upshift initiation tooth 59U2 in such a way that it is recessed from the first axial outer surface 49a toward the first axial inner surface 49b in the axial direction about the rotation center axis X.

[0142] like Figure 7A As shown, the upshift recessed tooth 59U3 is used to assist the drive chain 3 in disengaging from the ninth rear sprocket 49 during upshifting. For example, when the inner link of the drive chain 3 disengages from the upshift initiation tooth 59U2, the upshift recessed tooth 59U3 is configured such that the outer link of the drive chain 3 does not engage with the upshift recessed tooth 59U3.

[0143] The upshift recessed tooth 59U3 is located upstream of the upshift initiation tooth 59U2 in the drive rotation direction RD of the ninth rear sprocket 49, and is configured adjacent to the upshift initiation tooth 59U2.

[0144] For example, the upshift recess tooth 59U3 is arranged adjacent to the upshift start tooth 59U2 on the upstream side of the upshift start tooth 59U2 about the drive rotation direction RD, in such a way that no other first sprocket teeth 59 are arranged between the upshift recess tooth 59U3 and the upshift start tooth 59U2 in the circumferential direction about the rotation center axis X.

[0145] The shifting tooth 59U3 has a second shifting recess 59U3a. The second shifting recess 59U3a is provided on the first axial outer surface 49a of the shifting tooth 59U3. For example, the second shifting recess 59U3a is provided on the first axial outer surface 49a of the shifting tooth 59U3 in such a way that it is recessed from the first axial outer surface 49a toward the first axial inner surface 49b in the axial direction about the rotation center axis X.

[0146] • Tenth rear sprocket

[0147] like Figure 3 , Figure 4 as well as Figure 5As shown, the tenth rear sprocket 50 is coaxially configured with the ninth rear sprocket 49 in the assembled state of the rear sprocket assembly 27. The tenth rear sprocket 50 is adjacent to the ninth rear sprocket 49 in such a way that no other sprockets are configured between the tenth rear sprocket 49 and the ninth rear sprocket 49 in the axial direction about the rotation center axis X.

[0148] like Figure 8A and Figure 8B As shown, the tenth rear sprocket 50 has a rotation center axis X, a second axial outer surface 50a, and a second axial inner surface 50b. The tenth rear sprocket 50 has a second pitch circle diameter PD2.

[0149] The rotation center axis X is concentric with the rotation center axis of the aforementioned rear sprocket assembly 27. For example... Figure 8A As shown, the second axial outer surface 50a forms the outer surface of the tenth rear sprocket 50 in the axial direction about the rotation center axis X.

[0150] like Figure 8B As shown, the second axial inner surface 50b forms the inner surface of the tenth rear sprocket 50 in the axial direction about the rotation center axis X. The second axial inner surface 50b is located on the opposite side of the second axial outer surface 50a in the axial direction about the rotation center axis X. The second axial inner surface 50b is configured such that, in the mounted state on the bicycle 1, it is located axially about the rotation center axis X, opposite to... Figure 2 The axial center plane P shown is set opposite to each other.

[0151] Figure 8A and Figure 8B As shown, the second pitch circle diameter PD2 is larger than the first pitch circle diameter PD1 of the ninth rear sprocket 49. The second pitch circle diameter PD2 is defined with the rotation center axis X as the center. The second pitch circle diameter PD2 is the diameter of the pitch circle PC2 of the tenth rear sprocket 50. The pitch circle PC2 of the tenth rear sprocket 50 is formed by connecting the centers of the chain rollers of the drive chain 3 in contact with the multiple second sprocket teeth 67 described later.

[0152] like Figure 8A and Figure 8B As shown, the tenth rear sprocket 50 has a sprocket body 65 and a plurality of second sprocket teeth 67. The tenth rear sprocket 50 also has a plurality of second rivet holes 71. The plurality of second sprocket teeth 67 is an example of a plurality of additional sprocket teeth, and the plurality of second rivet holes 71 is an example of a plurality of additional fastening holes.

[0153] The sprocket body 65 has a second outer ring 73 and a plurality of radially inner portions 74. The second outer ring 73 and the plurality of radially inner portions 74 are formed as a single integral component.

[0154] The second outer annular body 73 is formed in an annular shape. A plurality of radially inner portions 74 are provided on the inner periphery of the second outer annular body 73. The plurality of radially inner portions 74 protrude radially inward from the inner periphery of the second outer annular body 73 about the rotation center axis X. The total number of the plurality of radially inner portions 74 is the same as the total number of the plurality of first rivet holes 69. For example, the total number of the plurality of radially inner portions 74 is 6.

[0155] Multiple second rivet holes 71 are configured to receive Figure 4 and Figure 5 The third rivet 53c is shown. As described above, the third rivet 53c secures the ninth rear sprocket 49 and the tenth rear sprocket 50 to each other. A plurality of second rivet holes 71 are at least partially provided in the sprocket body 65. For example, the plurality of second rivet holes 71 are respectively provided in a plurality of radially inner portions 74.

[0156] A plurality of second rivet holes 71 respectively penetrate a plurality of radially inner portions 74. The plurality of second rivet holes 71 are arranged at equal intervals in the circumferential direction. The total number of the plurality of second rivet holes 71 is equal to the total number of the plurality of first rivet holes 69.

[0157] like Figure 5 As shown, a plurality of second rivet holes 71 are arranged opposite to a plurality of first rivet holes 69 in the axial direction about the rotation center axis X. For example, the plurality of second rivet holes 71 are arranged opposite to the plurality of first rivet holes 69 in the axial direction about the rotation center axis X, such that the center axis of the plurality of second rivet holes 71 is concentric with the center axis HC of the plurality of first rivet holes 69. Each of the plurality of second rivet holes 71 is through which a third rivet 53c is inserted.

[0158] like Figure 8A and Figure 8B As shown, a plurality of second sprocket teeth 67 extend radially outward from the sprocket body 65 about the rotation center axis X. For example, a plurality of second sprocket teeth 67 extend radially outward from the second outer annular body 73 about the rotation center axis X.

[0159] In detail, a plurality of second sprocket teeth 67 extend radially outward from the outer periphery 73a of the second outer annulus 73 about the rotation center axis X. The outer periphery 73a of the second outer annulus 73 is defined by the root circle CB2 of the plurality of second sprocket teeth 67.

[0160] like Figure 6C As shown, each of the plurality of second sprocket teeth 67 has a second maximum radial length L3 and a second maximum axial length L4. The second maximum radial length L3 is an example of an additional maximum radial length. The second maximum axial length L4 is an example of an additional maximum axial length.

[0161] The second maximum radial length L3 is defined radially about the axis of rotation X. For example, the second maximum radial length L3 is the length in the radial direction about the axis of rotation X, from the outer periphery 73a of the second outer annulus 73 to the tooth tip 67A of the plurality of second sprocket teeth 67.

[0162] The second maximum axial length L4 is defined axially about the rotation center axis X. For example, the second maximum axial length L4 is the maximum length at the position of the outer periphery 73a of the second outer annulus 73 in the axial direction about the rotation center axis X.

[0163] Specifically, the second maximum axial length L4 is the maximum axial length between the second axial outer surface 50a and the second axial inner surface 50b at the position of the root circle CB2 of the plurality of second sprocket teeth 67. The second maximum radial length L3 is longer than the second maximum axial length L2.

[0164] Symbol explanation:

[0165] 1. Bicycle

[0166] 3 Drive chain

[0167] 19 Rear Hub Assembly

[0168] 19a Sprocket Support

[0169] 27 Rear sprocket assembly

[0170] 48 Eighth rear sprocket

[0171] 49 Ninth rear sprocket

[0172] 49a First axial outer surface

[0173] 49b First axial inner surface

[0174] 50 Tenth rear sprocket

[0175] 57 First outer ring body

[0176] More than 59 first sprocket teeth

[0177] 59D1, 59D2 downshift facilitator teeth

[0178] 59D1 Downshift Start Gear

[0179] 59D2 Downshift recessed teeth

[0180] 59D2a, 59D2b downshift recess

[0181] 59D3 Added downshift accelerator gear

[0182] 59D4, 59D5 downshift engagement facilitator gear

[0183] 59U0 Added upshift accelerator gear

[0184] 59U1, 59U2, 59U3 Upshift facilitator gears

[0185] 59U1 Upshift gear

[0186] 59U2 upshift start gear

[0187] 59U2a first recess of upshift

[0188] 59U3 Upshift Recessed Gear

[0189] 59U3a second recess of upshift

[0190] 61 Inner ring

[0191] 61a Spline section

[0192] More than 63 connecting arms

[0193] 65 Sprocket Body

[0194] 67 Second sprocket teeth

[0195] 69 First rivet hole

[0196] 71 Second rivet hole

[0197] CL circumferential centerline

[0198] HC hole center axis

[0199] L1 First maximum radial length

[0200] L2 First maximum axial length

[0201] L3 Second maximum radial length

[0202] L4 Second maximum axial length

[0203] P-axis center plane

[0204] PD1 First section circle diameter

[0205] PD2 Second section circle diameter

[0206] RD drive rotation direction

[0207] X is the axis of rotation.

Claims

1. A rear sprocket for a manually driven vehicle, for use in a manually driven vehicle having an axial center plane, and having an axial outer side and an axial inner side, the axial inner side being configured to be disposed on the opposite side of the axial outer side in an axial direction about a rotation center axis, and in a mounted state installed in the manually driven vehicle, being disposed opposite to the axial center plane in the axial direction, wherein, The rear sprocket has: Outer ring-shaped body; Multiple sprocket teeth extend radially outward from the outer annulus about the axis of rotation; The inner annular body is configured such that, in the assembled state where the rear sprocket is mounted on the hub assembly, it is connected to the sprocket support of the hub assembly in a manner that can transmit torque. Multiple connecting arms, extending radially between the outer and inner annular bodies, each having a circumferential centerline about the axis of rotation, and forming a single integral component together with the outer annular body, the multiple sprocket teeth, and the inner annular body; and Multiple fastening holes are configured to be at least partially provided on the outer annular body, and each receives a fastening component for fastening the adjacent rear sprocket to itself. The adjacent rear sprocket is abutted against the rear sprocket in the axial direction, such that no other sprockets are disposed between the adjacent rear sprocket and the rear sprocket. Each of the plurality of fastening holes has a central axis. The total number of the plurality of connecting arms is different from the total number of the plurality of fastening holes. At least one of the central axes of the plurality of holes is offset circumferentially from each of the plurality of circumferential center lines about the axis of rotation.

2. The rear sprocket of the human-powered vehicle according to claim 1, wherein, The inner annular body has a spline portion, which is configured to engage with the sprocket support of the hub assembly in the assembled state.

3. The rear sprocket of the human-powered vehicle according to claim 1, wherein, The difference between the total number of the plurality of connecting arms and the total number of the plurality of fastening holes is 3 or less.

4. The rear sprocket of the human-powered vehicle according to claim 3, wherein, The difference between the total number of the plurality of connecting arms and the total number of the plurality of fastening holes is 1.

5. The rear sprocket of the human-powered vehicle according to claim 1, wherein, The total number of the plurality of connecting arms is greater than the total number of the plurality of fastening holes.

6. The rear sprocket of the human-powered vehicle according to claim 1, wherein, The central axes of the plurality of holes are offset from the plurality of circumferential center lines in the circumferential direction.

7. The rear sprocket of the human-powered vehicle according to claim 6, wherein, Each of the central axes of the holes is offset circumferentially from each of the circumferential center lines.

8. The rear sprocket of the human-powered vehicle according to claim 1, wherein, The plurality of connecting arms are arranged at equal intervals with respect to each other in the circumferential direction about the axis of rotation. The plurality of fastening holes are arranged at equal intervals in the circumferential direction.

9. The rear sprocket of a human-powered vehicle according to claim 1, wherein, The plurality of sprocket teeth include a plurality of downshifting actuating teeth, which are configured to facilitate a downshifting action that moves the drive chain from the adjacent small rear sprocket to the rear sprocket. The plurality of downshift facilitators include: The downshift initiation gear is configured to engage with the drive chain first during the downshifting action; and Downshift recessed teeth, The downshift recessed teeth are configured as follows: In the circumferential direction, no other sprocket teeth are arranged between the downshift initiation tooth and the downshift recess tooth. The downshift initiation tooth is arranged adjacent to the downshift initiation tooth on the downstream side of the drive rotation direction with respect to the rear sprocket. It has a downshifting recess, which is provided on the outer side of the downshifting recess tooth in such a way that it is recessed from the outer side of the axial direction toward the inner side of the axial direction.

10. The rear sprocket of a human-powered vehicle according to claim 1, wherein, The plurality of sprocket teeth include a plurality of upshift actuating teeth, which are configured to facilitate an upshifting action that moves the drive chain from the rear sprocket to an adjacent small rear sprocket. The plurality of upshift facilitators include: The upshifting gear is configured to cause the drive chain to shift toward the adjacent small rear sprocket during the upshifting action. The upshift initiation gear is configured to be the first to disengage from the drive chain during the upshift action; as well as Upshift recessed teeth, The upshift initiation gear is configured as follows: In the circumferential direction, no other sprocket teeth are arranged between the upshift initiation tooth and the upshift shifting tooth. The upshift shifting tooth is arranged adjacent to the upshift shifting tooth on the upstream side of the drive rotation direction with respect to the rear sprocket. It has a first lifting recess, which is provided on the outer axial side of the lifting start tooth in such a way that it is recessed from the outer axial side toward the inner axial side in the axial direction. The gear-lifting recess teeth are configured as follows: In the circumferential direction, no other sprocket teeth are arranged between the upshift recess tooth and the upshift initiation tooth. The upshift initiation tooth is arranged adjacent to the upshift initiation tooth on the upstream side with respect to the drive rotation direction. It has a second lifting recess, which is provided on the outer side of the lifting recess tooth in such a way that it is recessed from the outer side toward the inner side in the axial direction.

11. The rear sprocket of a human-powered vehicle according to claim 1, wherein, Each of the plurality of sprocket teeth has a maximum radial length defined by the radial direction and a maximum axial length defined by the axial direction. The maximum radial length is longer than the maximum axial length.

12. A rear sprocket assembly, comprising: The rear sprocket according to any one of claims 1 to 11, having a first pitch circle diameter; and The adjacent rear sprocket has a second section diameter that is larger than the diameter of the first section circle. The adjacent rear sprocket is coaxially configured with the rear sprocket in the assembled state of the rear sprocket assembly.

13. The rear sprocket assembly according to claim 12, wherein, The adjacent rear sprocket includes: a sprocket body; and a plurality of additional sprocket teeth extending radially outward from the sprocket body. Each of the plurality of additional sprocket teeth has an additional maximum radial length defined by the radial direction and an additional maximum axial length defined by the axial direction. The additional maximum radial length is longer than the additional maximum axial length.

14. The rear sprocket assembly according to claim 13, wherein, The adjacent rear sprocket also has a plurality of additional fastening holes, which are at least partially located in the sprocket body. The plurality of additional fastening holes are configured to receive the fastening components that fasten the rear sprocket to the adjacent rear sprocket. The total number of the plurality of fastening holes is equal to the total number of the plurality of additional fastening holes.

15. A rear sprocket for a manually driven vehicle, for use in a manually driven vehicle having an axial center plane, and having an axial outer side and an axial inner side, the axial inner side being configured to be disposed on the opposite side of the axial outer side in an axial direction about a rotation center axis, and in an installed state mounted on the manually driven vehicle, being disposed opposite to the axial center plane in the axial direction, wherein... The rear sprocket has: Outer ring-shaped body; Multiple sprocket teeth extend radially outward from the outer annular body about the axis of rotation. The inner ring-shaped body is configured such that, in the assembled state where the rear sprocket is mounted on the hub assembly, it is connected to the sprocket support of the hub assembly in a manner capable of transmitting torque; Multiple connecting arms extend radially between the outer annulus and the inner annulus, and each has a circumferential centerline about the axis of rotation. as well as Multiple fastening holes are configured to be at least partially provided on the outer annular body, and each receives a fastening component for fastening the adjacent rear sprocket to itself. The adjacent rear sprocket is abutted against the rear sprocket in the axial direction, such that no other sprockets are disposed between the adjacent rear sprocket and the rear sprocket. Each of the plurality of fastening holes has a central axis. Each of the central axes of the holes is circumferentially offset from each of the circumferential center lines about the axis of rotation.

16. The rear sprocket of a human-powered vehicle according to claim 15, wherein, The total number of the plurality of connecting arms is different from the total number of the plurality of fastening holes.

17. The rear sprocket of a human-powered vehicle according to claim 15, wherein, The total number of the plurality of connecting arms is greater than the total number of the plurality of fastening holes.

18. The rear sprocket of a human-powered vehicle according to claim 15, wherein, The plurality of sprocket teeth include a plurality of downshifting actuating teeth, which are configured to facilitate a downshifting action that moves the drive chain from the adjacent small rear sprocket to the rear sprocket. The plurality of downshift facilitating teeth include: a downshift initiation tooth, configured to engage with the drive chain first during the downshifting action; and a downshift recess tooth. The downshift recessed teeth are configured as follows: In the circumferential direction, no other sprocket teeth are arranged between the downshift initiation tooth and the downshift recess tooth. The downshift initiation tooth is arranged adjacent to the downshift initiation tooth on the downstream side of the drive rotation direction with respect to the rear sprocket. It has a downshifting recess, which is provided on the outer side of the downshifting recess tooth in such a way that it is recessed from the outer side of the axial direction toward the inner side of the axial direction.

19. The rear sprocket of a human-powered vehicle according to claim 15, wherein, The plurality of sprocket teeth include a plurality of upshift actuating teeth, which are configured to facilitate an upshifting action that moves the drive chain from the rear sprocket to an adjacent small rear sprocket. The plurality of upshift facilitators include: The upshifting gear is configured to shift the drive chain toward the adjacent small rear sprocket during the upshifting action. The upshift initiation gear is configured to be the first to disengage from the drive chain during the upshift action; as well as Upshift recessed teeth, The upshift initiation gear is configured as follows: In the circumferential direction, no other sprocket teeth are arranged between the upshift initiation tooth and the upshift shifting tooth. The upshift shifting tooth is arranged adjacent to the upshift shifting tooth on the upstream side of the drive rotation direction with respect to the rear sprocket. It has a first lifting recess, which is provided on the outer axial side of the lifting start tooth in such a way that it is recessed from the outer axial side toward the inner axial side in the axial direction. The gear-lifting recess teeth are configured as follows: In the circumferential direction, no other sprocket teeth are arranged between the upshift recess tooth and the upshift initiation tooth. The upshift initiation tooth is arranged adjacent to the upshift initiation tooth on the upstream side with respect to the drive rotation direction. It has a second lifting recess, which is provided on the outer side of the lifting recess tooth in such a way that it is recessed from the outer side toward the inner side in the axial direction.

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