rear sprocket

Abstract

A rear sprocket includes a sprocket body, a plurality of sprocket teeth, a plurality of spline teeth, a maximum spline distance, and a radial tooth base distance. Each of the plurality of spline teeth has a spline tip. The maximum spline distance is defined from a rotational center axis to the spline tip. The radial tooth base distance is defined from the rotational center axis to one of a plurality of tooth base center points. The maximum spline distance is greater than the radial tooth base distance. The spline tip of each of the plurality of spline teeth is located radially inward from a tooth profile of each of the plurality of sprocket teeth in a radial direction.

Description

[0001] Cross-references to related applications

[0002] This application is a partial continuation-in-place of U.S. Patent Application No. 17 / 899,549, filed August 30, 2022. The contents of that application are incorporated herein by reference in their entirety. Technical Field

[0003] This invention relates to a rear sprocket. Background Technology

[0004] The human-powered vehicle includes a sprocket assembly configured to engage with a chain. The sprocket assembly includes multiple sprockets. Each sprocket includes a torque transmission component configured to engage with another torque transmission component of an adjacent sprocket to transmit torque between that sprocket and the adjacent sprocket. When the sprocket has a relatively small outer diameter, it is preferable to increase the strength of the torque transmission component of the sprocket.

[0005] The sprocket includes a shifting actuation mechanism configured to facilitate shifting operations of the chain between sprockets. Preferably, the shifting operation is smooth. Summary of the Invention

[0006] According to a first aspect of the invention, a rear sprocket is configured to be mounted to a rear hub assembly for a manually driven vehicle. The rear sprocket has a central axis of rotation defining an axial direction, a radial direction, and a circumferential direction. The rear sprocket includes a sprocket body, a plurality of sprocket teeth, a plurality of spline teeth, a maximum spline distance, and a radial tooth root distance. The plurality of sprocket teeth extend radially outward from the sprocket body in the radial direction. The plurality of sprocket teeth define a plurality of tooth root center points spaced apart from each other in the circumferential direction. Each of the plurality of sprocket teeth has a tooth profile extending circumferentially from a corresponding tooth root center point among the plurality of tooth root center points to an adjacent tooth root center point among the plurality of tooth root center points. The plurality of spline teeth are configured to transmit drive torque to an adjacent sprocket adjacent to the rear sprocket, while there is no additional sprocket between the rear sprocket and the adjacent sprocket in the axial direction. Each of the plurality of spline teeth has a spline crest. The maximum spline distance is defined from the central axis of rotation to the spline crest. The radial tooth root distance is defined from the central axis of rotation to one of the plurality of tooth root center points. The maximum spline distance is greater than the radial tooth root distance. The spline tip of each of the multiple spline teeth is located radially inward from the tooth profile of each of the multiple sprocket teeth.

[0007] By utilizing the rear sprocket according to the first aspect, the strength of the multiple spline teeth can be increased because the maximum spline distance is greater than the radial tooth root distance. Furthermore, a rear sprocket with multiple spline teeth can be manufactured by forging.

[0008] According to a second aspect of the invention, the rear sprocket of the first aspect is configured such that the sprocket body has a sprocket opening configured to receive the hub shaft of the rear hub assembly in a hub-mounted state where the rear sprocket is mounted to the rear hub assembly.

[0009] The rear sprocket, according to the second aspect, can be installed onto the rear hub assembly.

[0010] According to a third aspect of the invention, the rear sprocket according to the second aspect is configured such that the minimum diameter of the sprocket opening is smaller than the outermost diameter of the sprocket support of the rear hub assembly.

[0011] By utilizing the rear sprocket according to the third aspect, the total number of sprocket teeth can be less than 10.

[0012] According to a fourth aspect of the invention, the rear sprocket according to any one of the first to third aspects further includes an annular base from which a plurality of spline teeth extend radially outward in a radial direction.

[0013] The rear sprocket, according to the fourth aspect, makes it easier to arrange multiple spline teeth by using the annular base.

[0014] According to a fifth aspect of the invention, the rear sprocket according to the fourth aspect has an axially outward surface and an axially inward surface. The axially inward surface is disposed on the opposite side of the axially outward surface in the axial direction. The axially inward surface is configured to face the axial center plane of the manually driven vehicle in the axial direction when the rear sprocket is mounted to the vehicle in a vehicle mounting state. An annular base extends axially inward from the axially inward surface of the sprocket body in the axial direction.

[0015] Using the rear sprocket according to the fifth aspect, multiple spline teeth can be arranged to engage with adjacent sprockets located between the rear sprocket and the axial center plane of the manually driven vehicle.

[0016] According to a sixth aspect of the invention, the rear sprocket described in the fourth aspect is configured such that the sprocket body has a sprocket opening configured to receive the hub shaft of the rear hub assembly in a hub-mounted state where the rear sprocket is mounted to the rear hub assembly. An annular base is configured to surround the sprocket opening when viewed in the axial direction.

[0017] Using the rear sprocket according to the sixth aspect, multiple spline teeth can be arranged on the rear sprocket, which is easy to attach to the rear hub assembly.

[0018] According to a seventh aspect of the invention, the rear sprocket according to the first aspect is configured such that a plurality of spline teeth are spaced apart from a plurality of sprocket teeth in the axial direction.

[0019] By utilizing the rear sprocket according to the seventh aspect, interference between the drive chain and multiple spline teeth can be reduced, while simultaneously increasing the strength of the multiple spline teeth.

[0020] According to an eighth aspect of the invention, the rear sprocket according to the first aspect is configured such that at least two of the plurality of spline teeth are arranged to overlap with one of the plurality of sprocket teeth when viewed in the axial direction.

[0021] By utilizing the rear sprocket according to aspect eight, the total number of spline teeth can be increased. Therefore, the strength of multiple spline teeth can be further improved.

[0022] According to a ninth aspect of the invention, the rear sprocket according to the first aspect is configured such that the plurality of spline teeth include at least one positioning spline tooth, the at least one positioning spline tooth being different from the other spline teeth of the plurality of spline teeth in at least one aspect of size and shape.

[0023] Using the rear sprocket according to aspect nine, the rear sprocket can be circumferentially positioned relative to the adjacent sprocket at a predetermined position.

[0024] According to a tenth aspect of the invention, the rear sprocket according to the ninth aspect is configured such that the circumferential locating spline width of the at least one locating spline tooth is greater than each of the circumferential spline widths of the other spline teeth among the plurality of spline teeth.

[0025] Using the rear sprocket according to aspect ten, the rear sprocket can be reliably positioned circumferentially relative to the adjacent sprocket at a predetermined position.

[0026] According to an eleventh aspect of the invention, the rear sprocket according to the first aspect is configured such that the plurality of spline teeth include at least one tooth that is circumferentially symmetrical with respect to the axis of rotation.

[0027] By utilizing the rear sprocket according to aspect eleven, uneven wear of at least one circumferentially symmetrical tooth can be reduced.

[0028] According to a twelfth aspect of the invention, the rear sprocket according to the eleventh aspect is configured such that the plurality of spline teeth include a plurality of teeth circumferentially symmetrical with respect to the axis of rotation.

[0029] By utilizing the rear sprocket according to the twelfth aspect, uneven wear of at least one circumferentially symmetrical tooth can be reliably reduced.

[0030] According to a thirteenth aspect of the invention, the rear sprocket according to the first aspect is configured such that the plurality of spline teeth include at least one tooth that is circumferentially asymmetrical with respect to the axis of rotation.

[0031] By utilizing the rear sprocket according to aspect thirteen, interference between at least one circumferentially asymmetrical tooth and the shifting facilitation structure of the adjacent sprocket can be reduced.

[0032] According to the fourteenth aspect of the invention, the rear sprocket according to the first aspect is configured such that the total number of spline teeth of the plurality of spline teeth is in the range of 15 to 18.

[0033] Using the rear sprocket according to aspect fourteen, multiple spline teeth with the necessary and sufficient number can be set in the tooth profile of the rear sprocket.

[0034] According to the fifteenth aspect of the invention, the rear sprocket according to the first aspect is configured such that the total number of sprocket teeth of the plurality of sprocket teeth is equal to or less than 10.

[0035] By utilizing the rear sprocket according to aspect fifteen, the necessary and sufficient strength can be provided for multiple spline teeth, while the rear sprocket has a relatively small outer diameter.

[0036] According to a sixteenth aspect of the invention, the rear sprocket according to the fifteenth aspect is configured such that the total number of sprocket teeth of the plurality of sprocket teeth is 9.

[0037] By utilizing the rear sprocket according to the sixteenth aspect, the necessary and sufficient strength can be provided for multiple spline teeth, while the rear sprocket has a relatively small outer diameter.

[0038] According to a seventeenth aspect of the invention, a rear sprocket is configured to be mounted to a rear hub assembly of a manually driven vehicle. The rear sprocket has a central axis of rotation defining an axial direction, a radial direction, and a circumferential direction. The rear sprocket includes a sprocket body, a plurality of sprocket teeth, and a plurality of splined teeth. The plurality of sprocket teeth extend radially outward from the sprocket body in the radial direction. The plurality of sprocket teeth define a plurality of tooth root center points spaced apart from each other in the circumferential direction. The plurality of splined teeth are configured to transmit drive torque to an adjacent sprocket adjacent to the rear sprocket, with no additional sprocket between the rear sprocket and the adjacent sprocket in the axial direction. The plurality of splined teeth are arranged to be offset from the plurality of tooth root center points in the circumferential direction.

[0039] By utilizing the rear sprocket according to aspect seventeen, since the multiple spline teeth are arranged to be offset from the center points of the tooth roots in the circumferential direction, the size of at least one of the multiple spline teeth can be increased. Therefore, the strength of the multiple spline teeth can be improved. Furthermore, the rear sprocket having multiple spline teeth can be manufactured by forging.

[0040] According to the eighteenth aspect of the invention, the rear sprocket according to the seventeenth aspect is configured such that the total number of spline teeth of the plurality of spline teeth is in the range of 15 to 18.

[0041] Using the rear sprocket according to aspect eighteen, multiple spline teeth with the necessary and sufficient number can be set in the tooth profile of the rear sprocket.

[0042] According to the nineteenth aspect of the invention, the rear sprocket according to the seventeenth aspect is configured such that the total number of sprocket teeth of the plurality of sprocket teeth is equal to or less than 10.

[0043] By utilizing the rear sprocket according to the nineteenth aspect, the necessary and sufficient strength can be provided for multiple spline teeth, while the rear sprocket has a relatively small outer diameter.

[0044] According to the twentieth aspect of the invention, the rear sprocket of the nineteenth aspect is configured such that the total number of sprocket teeth of the plurality of sprocket teeth is 9.

[0045] By utilizing the rear sprocket according to aspect 20, the necessary and sufficient strength can be provided for multiple spline teeth, while the rear sprocket has a relatively small outer diameter.

[0046] According to a twenty-first aspect of the invention, a rear sprocket is configured to be mounted to a rear hub assembly for a manually driven vehicle. The rear sprocket has a rotational central axis defining an axial direction, a radial direction, and a circumferential direction. The rear sprocket has an axially outward surface and an axially inward surface. The axially inward surface is disposed on the opposite side of the axially outward surface in the axial direction. The axially inward surface is configured to face the axial center plane of the manually driven vehicle in the vehicle-mounted state. The rear sprocket includes a sprocket body and a plurality of sprocket teeth. The plurality of sprocket teeth extend radially outward from the sprocket body in the radial direction. The plurality of sprocket teeth includes a first upshift actuating tooth, a second upshift actuating tooth, a third upshift actuating tooth, and an upshift initiating tooth. The first upshift actuating tooth, the second upshift actuating tooth, and the third upshift actuating tooth are configured to facilitate an upshift operation in which the drive chain shifts from an adjacent larger sprocket toward the rear sprocket. The upshift initiating tooth is configured to engage the drive chain first during the upshift operation. The first upshift actuating tooth has a first recess disposed on the axially inward surface of the first upshift actuating tooth, recessed axially from the axially inward surface toward the axially outward surface. The second upshift actuating tooth has a second recess disposed on the axially inward surface of the second upshift actuating tooth, recessed axially from the axially inward surface toward the axially outward surface. The second upshift actuating tooth is adjacent to the first upshift actuating tooth upstream of the first upshift actuating tooth in the drive rotation direction relative to the rear sprocket, and there are no additional teeth between the first upshift actuating tooth and the second upshift actuating tooth in the circumferential direction. The third upshift actuating tooth has a third recess disposed on the axially inward surface of the third upshift actuating tooth, recessed axially from the axially inward surface toward the axially outward surface. The third upshift actuating tooth is adjacent to the second upshift actuating tooth upstream of the second upshift actuating tooth in the drive rotation direction relative to the rear sprocket, and there are no additional teeth between the second upshift actuating tooth and the third upshift actuating tooth in the circumferential direction. The upshift initiation tooth is adjacent to the third upshift facilitator tooth on the upstream side of the third upshift facilitator tooth in the direction of drive rotation relative to the rear sprocket, and there are no other teeth between the third upshift facilitator tooth and the upshift initiation tooth in the circumferential direction.

[0047] The first, second, and third recesses, utilizing the rear sprocket according to aspect twenty-one, allow the drive chain to move smoothly toward the rear sprocket during upshifting operations. The first, second, and third recesses also make the engagement of the upshift initiation teeth with the drive chain smoother during upshifting operations. Therefore, for example, when the difference between the total number of sprocket teeth and the total number of sprocket teeth of the adjacent larger sprocket is equal to or less than 2, the upshifting operation can be made smooth.

[0048] According to the twenty-second aspect of the invention, the rear sprocket according to the twenty-first aspect is configured such that the total number of sprocket teeth of the plurality of sprocket teeth is equal to or less than 10.

[0049] By utilizing the rear sprocket according to aspect twenty-two, the upshifting operation between two adjacent sprockets, each with a relatively small diameter, can be made smooth.

[0050] According to the twenty-third aspect of the present invention, the rear sprocket according to the twenty-second aspect is configured such that the total number of sprocket teeth of the plurality of sprocket teeth is 9.

[0051] By utilizing the rear sprocket according to aspect twenty-three, the upshifting operation between two adjacent sprockets, each with a relatively small diameter, can be made smooth.

[0052] According to a twenty-fourth aspect of the invention, the rear sprocket according to the twenty-first aspect is configured such that the first upshift actuating tooth has a first tooth tip, a first driving surface, and a first non-driving surface opposite to the first driving surface in the circumferential direction. A first recess reaches each of the first tooth tip, the first driving surface, and the first non-driving surface.

[0053] By using the rear sprocket according to aspect twenty-four, upshifting can be reliably made smooth, for example, when the difference between the total number of sprocket teeth and the total number of sprocket teeth of the adjacent larger sprocket is equal to or less than 2.

[0054] According to a twenty-fifth aspect of the invention, the rear sprocket according to the twenty-first aspect is configured such that the second upshift promoting tooth has a second tooth tip, a second driving surface, and a second non-driving surface opposite to the second driving surface in the circumferential direction. A second recess reaches each of the second tooth tip, the second driving surface, and the second non-driving surface.

[0055] By using the rear sprocket according to aspect 25, upshifting can be reliably made smooth, for example, when the difference between the total number of sprocket teeth and the total number of sprocket teeth of the adjacent larger sprocket is equal to or less than 2.

[0056] According to a twenty-sixth aspect of the invention, the rear sprocket according to the twenty-first aspect is configured such that the third upshift promoting tooth has a third tooth tip, a third driving surface, and a third non-driving surface opposite to the third driving surface in the circumferential direction. The third recess reaches each of the third tooth tip and the third non-driving surface, but does not reach the third driving surface.

[0057] By using the rear sprocket according to aspect twenty-six, the upshifting operation can be made smooth while providing the necessary and sufficient strength to the third upshifting facilitator tooth, for example, when the difference between the total number of sprocket teeth and the total number of sprocket teeth of the adjacent larger sprocket is equal to or less than 2. Attached Figure Description

[0058] A more complete understanding of the invention and its many accompanying advantages can be readily obtained and better understood when considered in conjunction with the accompanying drawings and by referring to the following detailed description.

[0059] Figure 1 This is a schematic diagram of a manually driven vehicle including a rear sprocket assembly according to one embodiment, the rear sprocket assembly including a rear sprocket.

[0060] Figure 2 yes Figure 1 An exploded rear view of the rear sprocket assembly and rear hub assembly of a human-powered vehicle.

[0061] Figure 3 yes Figure 2 The diagram shows a cross-sectional view of the rear sprocket assembly and the rear hub assembly.

[0062] Figure 4 yes Figure 2 The rear sprocket of the rear sprocket assembly shown is a side elevation view.

[0063] Figure 5 yes Figure 2 Partial cross-sectional view of the rear sprocket assembly and rear hub assembly shown.

[0064] Figure 6 yes Figure 2 Another side elevation view of the rear sprocket of the rear sprocket assembly shown.

[0065] Figure 7 yes Figure 6 The image shows a partially enlarged side elevation view of the rear sprocket.

[0066] Figure 8 yes Figure 6 The image shows a partially enlarged side elevation view of the rear sprocket.

[0067] Figure 9 yes Figure 6 A partial 3D view of the rear sprocket is shown.

[0068] Figure 10 yes Figure 6 A partial 3D view of the rear sprocket is shown.

[0069] Figure 11 It is along Figure 23 The cross-sectional view of the rear sprocket taken from line XI-XI.

[0070] Figure 12 It is along Figure 23 A cross-sectional view of the rear sprocket taken from line XII-XII.

[0071] Figure 13 It is along Figure 8 A cross-sectional view of the rear sprocket taken from line XIII-XIII.

[0072] Figure 14 It is along Figure 23 A cross-sectional view of the rear sprocket taken from line XIV-XIV.

[0073] Figure 15 yes Figure 2 The side elevation view of the adjacent sprockets in the rear sprocket assembly shown.

[0074] Figure 16 It is along Figure 5 A cross-sectional view of the rear sprocket taken along line XVI-XVI.

[0075] Figure 17 yes Figure 2 An exploded perspective view of the locking device assembly of the rear sprocket assembly shown.

[0076] Figure 18 yes Figure 2 Another exploded perspective view of the locking device assembly of the rear sprocket assembly shown.

[0077] Figure 19 yes Figure 2 The cross-sectional views of the rear sprocket assembly and rear hub assembly shown are used to illustrate the assembly process.

[0078] Figure 20 yes Figure 2 The cross-sectional views of the rear sprocket assembly and rear hub assembly shown are used to illustrate the assembly process.

[0079] Figure 21 yes Figure 2 The cross-sectional views of the rear sprocket assembly and rear hub assembly shown are used to illustrate the assembly process.

[0080] Figure 22 It is along Figure 24 A cross-sectional view of the rear sprocket taken from line XXII-XXII.

[0081] Figure 23 yes Figure 6 The image shows a partially enlarged side elevation view of the rear sprocket.

[0082] Figure 24 yes Figure 6 The image shows a partially enlarged side elevation view of the rear sprocket.

[0083] Figure 25 It is a three-dimensional view based on the first variant of the rear sprocket assembly.

[0084] Figure 26 It is along Figure 25 A cross-sectional view of the rear sprocket assembly taken from line XXVI-XXVI.

[0085] Figure 27 yes Figure 25 The side elevation view of the first rear sprocket of the rear sprocket assembly shown.

[0086] Figure 28 yes Figure 25 Side elevation views of the second and third rear sprockets of the rear sprocket assembly shown.

[0087] Figure 29 yes Figure 26 A partially enlarged cross-sectional view of the rear sprocket assembly shown.

[0088] Figure 30 yes Figure 28 The perspective view of the second and third rear sprockets shown.

[0089] Figure 31 It is along Figure 28 A cross-sectional view of the rear sprocket assembly taken along line XXXI-XXXI.

[0090] Figure 32 It is along Figure 28 A cross-sectional view of the rear sprocket assembly taken from line XXXII-XXXII.

[0091] Figure 33 It is a perspective view of the rear sprocket assembly based on the second variant.

[0092] Figure 34 It is along Figure 33 A cross-sectional view of the rear sprocket assembly taken from line XXXIV-XXXIV.

[0093] Figure 35 yes Figure 33 Side elevation views of the second, third, and fourth rear sprockets of the rear sprocket assembly shown.

[0094] Figure 36 yes Figure 34 A partially enlarged cross-sectional view of the rear sprocket assembly shown.

[0095] Figure 37 yes Figure 35 The three-dimensional view of the second, third, and fourth rear sprockets shown.

[0096] Figure 38 It is along Figure 35 A cross-sectional view of the rear sprocket assembly taken from line XXXVIII-XXXVIII.

[0097] Figure 39 It is along Figure 35 A cross-sectional view of the rear sprocket assembly taken from line XXXIX-XXXXIX. Detailed Implementation

[0098] Embodiments will now be described with reference to the accompanying drawings, wherein similar reference numerals in the various drawings denote corresponding or identical elements.

[0099] like Figure 1 As shown, the manually driven vehicle 2 includes a body 4 and a drivetrain 6. The drivetrain 6 includes a rear sprocket assembly 10 and a rear hub assembly 12. The rear hub assembly 12 is fixed to the body 4. The rear sprocket assembly 10 is configured to be mounted to the rear hub assembly 12 for the manually driven vehicle 2. The rear sprocket assembly 10 has a rotational central axis A1 to define an axial direction D1, a radial direction, and a circumferential direction D2 (see example...). Figure 4 The rear sprocket assembly 10 is rotatably supported relative to the vehicle body 4 by the rear hub assembly 12 about the rotation center axis A1. The manually driven vehicle 2 has an axial center plane CP. The axial center plane CP is defined at the lateral center position of the vehicle body 4 of the manually driven vehicle 2. The axial center plane CP is perpendicular to the rotation center axis A1.

[0100] The drivetrain 6 includes a crank assembly 6A, a front sprocket 6B, and a drive chain C. The crank assembly 6A is rotatably mounted to the vehicle body 4. The front sprocket 6B is fixed to the crank assembly 6A. The drive chain C engages with the front sprocket 6B and the rear sprocket assembly 10 to transmit pedaling force from the front sprocket 6B to the rear sprocket assembly 10. In this embodiment, the front sprocket 6B includes a single sprocket sprocket. However, the front sprocket 6B may include multiple sprocket sprockets.

[0101] In this application, the following directional terms "forward," "rear," "forward," "backward," "left," "right," "lateral," "upward," and "downward," as well as any other similar directional terms, refer to the direction determined based on a user (e.g., rider) in a standard user position (e.g., on a seat or saddle) and facing the handlebars or steering mechanism in the human-powered vehicle 2. Therefore, when used to describe the rear sprocket assembly 10, the rear hub assembly 12, or other components, these terms should be interpreted relative to a human-powered vehicle 2 equipped with the rear sprocket assembly 10, the rear hub assembly 12, or other components used in an upright riding position on a horizontal surface.

[0102] In this application, human-powered vehicles include various types of bicycles, such as mountain bikes, road bikes, city bikes, freight bikes, manual bikes, and recumbent bikes. Furthermore, human-powered vehicles include electric bicycles (E-bikes). Electric bicycles include electric-assisted bicycles, which are configured to use an electric motor to assist in the propulsion of the vehicle. However, the total number of wheels in a human-powered vehicle is not limited to two. For example, human-powered vehicles include vehicles with one wheel or three or more wheels. In particular, human-powered vehicles do not include vehicles that use only an internal combustion engine as their power source. Generally, light road vehicles (including vehicles that do not require a driver's license on public roads) are considered human-powered vehicles.

[0103] like Figure 2 As shown, the rear sprocket assembly 10 includes a plurality of rear sprockets SP. The plurality of rear sprockets SP are configured to engage with the drive chain C. The plurality of rear sprockets SP includes rear sprockets SP1 to SP11. Rear sprockets SP1 to SP11 may also be referred to as first sprockets SP1 to eleventh sprockets SP11, respectively. The total number of the plurality of rear sprockets SP is not limited to eleven.

[0104] The rear hub assembly 12 includes a hub shaft 14, a hub body 16, and a sprocket support 18. The hub shaft 14 is configured to be fixed to the body 4 of the manually driven vehicle 2 (see example...). Figure 1 The hub body 16 is rotatably mounted on the hub shaft 14 around the rotation center axis A1. The sprocket support 18 is rotatably mounted on the hub shaft 14 around the rotation center axis A1.

[0105] The rear sprocket assembly 10 is configured to be mounted to a sprocket support 18. The sprocket support 18 includes a plurality of external splines 18A. The rear sprocket assembly 10 is configured to engage with the plurality of external splines 18A of the sprocket support 18.

[0106] like Figure 3As shown, the rear hub assembly 12 includes a ratchet structure 20. The ratchet structure 20 is configured to allow the sprocket support 18 to rotate relative to the hub body 16 about the rotational axis A1 in only one rotational direction. The ratchet structure 20 is also configured to restrict the sprocket support 18 from rotating relative to the hub body 16 about the rotational axis A1 in another rotational direction.

[0107] For example, an upshift occurs when drive chain C moves from one sprocket along the upshift direction D41 to an adjacent smaller sprocket. A downshift occurs when drive chain C moves from one sprocket along the downshift direction D42 to an adjacent larger sprocket.

[0108] The rear sprocket SP1 is configured to be mounted to the rear hub assembly 12 for the manually driven vehicle 2. The second sprocket SP2 is configured to be mounted to the rear hub assembly 12 for the manually driven vehicle 2. The second sprocket SP2 is adjacent to the rear sprocket SP1, and there is no other sprocket between the rear sprocket SP1 and the second sprocket SP2. The second sprocket SP2 may also be referred to as the adjacent sprocket SP2 or the adjacent larger sprocket SP2.

[0109] The rear sprocket SP1 has a first sprocket outer diameter DM1. The second sprocket SP2 has a second sprocket outer diameter DM2 that is larger than the first sprocket outer diameter DM1. In the axial direction D1 relative to the rotation center axis A1, the second sprocket SP2 is adjacent to the rear sprocket SP1, and there are no other sprockets between the rear sprocket SP1 and the second sprocket SP2. In this embodiment, the first sprocket outer diameter DM1 is the smallest among the outer diameters of the first sprocket SP1 to the eleventh sprocket SP11. Therefore, the rear sprocket SP1 is the smallest sprocket in the rear sprocket assembly 10. The rear sprocket SP1 can also be referred to as the highest speed sprocket SP1.

[0110] The third sprocket SP3 has a third sprocket outer diameter DM3 that is larger than that of the second sprocket DM2. The third sprocket SP3 is adjacent to the second sprocket SP2 in the axial direction D1, and there is no other sprocket between the second sprocket SP2 and the third sprocket SP3.

[0111] The rear sprocket assembly 10 includes a sprocket bracket 22. Rear sprockets SP5 to SP11 are mounted on the sprocket bracket 22. In this embodiment, the rear sprockets SP5 to SP11 are secured to the sprocket bracket 22 by fasteners 24, such as rivets. However, the total number of sprockets secured to the sprocket bracket 22 is not limited to this. Figure 3 The embodiment shown. The sprocket carrier 22 is configured to contact the positioning surface 18C of the sprocket support 18. However, the structure of the sprocket carrier 22 is not limited to... Figure 3 The structure is shown. If needed and / or desired, the sprocket bracket 22 can be omitted from the rear sprocket assembly 10. In such an embodiment, all sprockets engage directly with the sprocket support 18.

[0112] like Figure 4 As shown, the rear sprocket SP1 has a rotational center axis A1, defining an axial direction D1, a radial direction, and a circumferential direction D2. The rear sprocket SP1 includes a sprocket body S11 and a plurality of sprocket teeth S12. The sprocket body S11 has a sprocket opening S13. The sprocket opening S13 has a minimum diameter DM11. The plurality of sprocket teeth S12 extend radially outward from the sprocket body S11 in the radial direction. The plurality of first sprocket teeth S12 define a first sprocket outer diameter DM1. The sprocket body S11 may also be referred to as the first sprocket body S11. The sprocket teeth S12 may also be referred to as the first sprocket teeth S12. The sprocket opening S13 may also be referred to as the first sprocket opening S13. The minimum diameter DM11 may also be referred to as the first minimum diameter DM11.

[0113] The plurality of sprocket teeth S12 have a total number of sprocket teeth, which is the total number of sprocket teeth S12. The total number of sprocket teeth of the plurality of sprocket teeth S12 is equal to or less than 10. In this embodiment, the total number of sprocket teeth of the plurality of sprocket teeth S12 is nine. However, the total number of sprocket teeth of the plurality of sprocket teeth S12 is not limited to the above total number and the above range.

[0114] like Figure 5 As shown, the sprocket opening S13 is configured to receive the hub shaft 14 of the rear hub assembly 12 in the hub-mounted state where the rear sprocket SP1 is mounted to the rear hub assembly 12. The minimum diameter DM11 is smaller than the outermost diameter DM6 of the sprocket support body 18 of the rear hub assembly 12.

[0115] The rear sprocket SP1 has an axially outward surface S14 and an axially inward surface S15. The axially inward surface S15 is disposed on the opposite side of the axially outward surface S14 in the axial direction D1. The axially inward surface S15 is configured to face the axial center plane CP of the manually driven vehicle 2 in the axial direction D1 when the rear sprocket SP1 is mounted to the vehicle in the vehicle mounting state. The axially outward surface S14 may also be referred to as the first axially outward surface S14. The axially inward surface S15 may also be referred to as the first axially inward surface S15.

[0116] like Figure 6 As shown, a plurality of sprocket teeth S12 define a plurality of tooth root center points S12A spaced apart from each other in the circumferential direction D2. Each sprocket tooth in the plurality of sprocket teeth S12 has a tooth profile OL extending from a corresponding tooth root center point in the plurality of tooth root center points S12A to an adjacent tooth root center point in the plurality of tooth root center points S12A in the circumferential direction D2. The plurality of tooth root center points S12A define a tooth root circle S12B. The tooth profile OL in Figure 6 The middle part is represented by a thick double dashed line.

[0117] The rear sprocket SP1 includes multiple splined teeth S16. These splined teeth S16 are configured to transmit drive torque to the adjacent sprocket SP2, which is adjacent to the rear sprocket SP1 in the axial direction D1 (see example...). Figure 5 There is no additional sprocket between the rear sprocket SP1 and the adjacent sprocket SP2.

[0118] The plurality of spline teeth S16 have a total number of spline teeth as the total number of spline teeth S16. The total number of spline teeth of the plurality of spline teeth S16 ranges from 15 to 18. In this embodiment, the total number of spline teeth of the plurality of spline teeth S16 is 16. However, the total number of spline teeth of the plurality of spline teeth S16 is not limited to the above total number and the above range.

[0119] The rear sprocket SP1 also includes an annular base S17, from which a plurality of spline teeth S16 extend radially outward. When viewed in the axial direction D1, the annular base S17 is configured to surround the sprocket opening S13.

[0120] like Figure 6 As shown, when viewed in the axial direction D1, at least two of the multiple spline teeth S16 are configured to overlap with one of the multiple sprocket teeth S12. The multiple spline teeth S16 are configured to be offset from the multiple tooth root center points S12A in the circumferential direction D2.

[0121] The plurality of spline teeth S16 includes at least one first spline tooth S16B and at least one second spline tooth S16C. The plurality of spline teeth S16 also includes at least two first spline teeth S16B and at least two second spline teeth S16C. The plurality of spline teeth S16 includes at least two pairs of first spline teeth S16B and second spline teeth S16C. In this embodiment, the total number of at least two pairs of first spline teeth S16B and second spline teeth S16C is seven. However, the total number of at least two pairs of first spline teeth S16B and second spline teeth S16C is not limited to seven.

[0122] In a pair of first spline teeth S16B and second spline teeth S16C, the second spline tooth S16C is adjacent to the first spline tooth S16B in the circumferential direction D2, while there are no other spline teeth between the first spline tooth S16B and the second spline tooth S16C in the circumferential direction D2. When viewed in the axial direction D1, the first spline tooth S16B and the second spline tooth S16C are configured to overlap with one of the plurality of sprocket teeth S12. If desired and / or expected, when viewed in the axial direction D1, three or more spline teeth in the spline tooth S16 can be configured to overlap with one of the plurality of sprocket teeth S12.

[0123] The plurality of spline teeth S16 includes at least one positioning spline tooth S16D and / or S16E. The at least one positioning spline tooth S16D and / or S16E differs from the other spline teeth in the plurality of spline teeth S16 in at least one aspect of size and shape. In this embodiment, the plurality of spline teeth S16 includes positioning spline teeth S16D and S16E. However, if desired and / or expected, the plurality of spline teeth S16 may include at least one positioning spline tooth.

[0124] A locating spline S16D is disposed in the circumferential direction D2 between one pair of at least two pairs of first spline teeth S16B and second spline teeth S16C and another pair of at least two pairs of first spline teeth S16B and second spline teeth S16C. A locating spline S16E is disposed in the circumferential direction D2 between one pair of at least two pairs of first spline teeth S16B and second spline teeth S16C and another pair of at least two pairs of first spline teeth S16B and second spline teeth S16C. When viewed in the axial direction D1, the locating spline S16D is configured to overlap with one of the plurality of sprocket teeth S12. When viewed in the axial direction D1, the locating spline S16E is configured to overlap with one of the plurality of sprocket teeth S12.

[0125] like Figure 7 and Figure 8 As shown, the first spline tooth S16B has a circumferential spline width W1 defined in the circumferential direction D2. The second spline tooth S16C has a circumferential spline width W2 defined in the circumferential direction D2. At least one locating spline tooth S16D and / or S16E has a circumferential locating spline width W3 and / or W4. Locating spline tooth S16D has a circumferential locating spline width W3. Locating spline tooth S16E has a circumferential locating spline width W4.

[0126] The circumferential positioning spline width W3 is greater than each of the circumferential spline widths W1 and W2 of the other spline teeth in the plurality of spline teeth S16. The circumferential positioning spline width W4 is greater than each of the circumferential spline widths W1 and W2 of the other spline teeth in the plurality of spline teeth S16. The circumferential positioning spline widths W3 and / or W4 of at least one positioning spline tooth S16D and / or S16E are greater than each of the circumferential spline widths W1 and W2 of the other spline teeth in the plurality of spline teeth S16. In this embodiment, the circumferential spline widths W1 and W2 are equal to each other. The circumferential positioning spline width W4 is different from the circumferential positioning spline width W3. The circumferential positioning spline width W4 is greater than the circumferential positioning spline width W3. However, if needed and / or desired, each of the circumferential positioning spline widths W3 and W4 may be equal to or less than at least one of the circumferential spline widths W1 and W2. If required and / or desired, the circumferential spline width W4 can be equal to or less than the circumferential spline width W3. If required and / or desired, the circumferential spline width W2 can be different from the circumferential spline width W1.

[0127] The circumferential spline widths W1 and W2 range from 1.5 mm to 3.0 mm. The circumferential locating spline width W3 ranges from 1.5 mm to 3.0 mm. The circumferential locating spline width W4 ranges from 3.0 mm to 6.0 mm. In this embodiment, the circumferential spline widths W1 and W2 are equal to 2.03 mm. The circumferential locating spline width W3 is equal to 2.42 mm. The circumferential locating spline width W4 is equal to 4.12 mm. However, the circumferential spline widths W1 and W2 are not limited to the above dimensions and ranges. The circumferential locating spline width W3 is not limited to the above dimensions and ranges. The circumferential locating spline width W4 is not limited to the above dimensions and ranges.

[0128] The sum of the circumferential spline widths W1 and W2 and the circumferential locating spline widths W3 and W4 of spline teeth S16B, S16C, S16D, and S16E is greater than or equal to 11.0 mm to achieve sufficient strength for the multiple spline teeth S16. The sum of the circumferential spline widths W1 and W2 and the circumferential locating spline widths W3 and W4 of spline teeth S16B, S16C, S16D, and S16E is less than or equal to 15.0 mm to increase the total number of spline teeth S16. Therefore, the range of the sum of the circumferential spline widths W1 and W2 and the circumferential locating spline widths W3 and W4 of spline teeth S16B, S16C, S16D, and S16E can be from 11.0 mm to 15.0 mm to achieve sufficient strength for the multiple spline teeth S16 and to increase the total number of spline teeth S16. In this embodiment, the sum of the circumferential spline widths W1 and W2 of spline teeth S16B, S16C, S16D, and S16E, and the sum of the circumferential positioning spline widths W3 and W4, is 13.92 mm. However, the sum of the circumferential spline widths W1 and W2 of spline teeth S16B, S16C, S16D, and S16E, and the sum of the circumferential positioning spline widths W3 and W4, is not limited to the above dimensions and ranges.

[0129] like Figure 7 and Figure 8 As shown, at least one of the first spline teeth S16B has a shape that is circumferentially symmetrical about the rotation center axis A1. The other of the first spline teeth S16B may have a shape that is circumferentially asymmetrical about the rotation center axis A1. At least one of the second spline teeth S16C has a shape that is circumferentially symmetrical about the rotation center axis A1. The other of the second spline teeth S16C may have a shape that is circumferentially asymmetrical about the rotation center axis A1. The positioning spline tooth S16D has a shape that is circumferentially asymmetrical about the rotation center axis A1. The positioning spline tooth S16E has a shape that is circumferentially symmetrical about the rotation center axis A1.

[0130] In this embodiment, each first spline tooth S16B has a shape circumferentially symmetrical about the rotation center axis A1. Six of the second spline teeth S16C have a shape circumferentially symmetrical about the rotation center axis A1. One of the second spline teeth S16C has a shape circumferentially asymmetrical about the rotation center axis A1. However, if desired and / or expected, at least one of the first spline teeth S16B may have a shape circumferentially asymmetrical about the rotation center axis A1. If desired and / or expected, at least two of the second spline teeth S16C may have a shape circumferentially asymmetrical about the rotation center axis A1. If desired and / or expected, the positioning spline tooth S16D may have a shape circumferentially symmetrical about the rotation center axis A1. If desired and / or expected, the positioning spline tooth S16E may have a shape circumferentially asymmetrical about the rotation center axis A1.

[0131] like Figure 7 and Figure 8 As shown, the first spline tooth S16B with a circumferentially symmetrical shape can also be called a circumferentially symmetrical tooth S16B. The second spline tooth S16C with a circumferentially symmetrical shape can also be called a circumferentially symmetrical tooth S16C. The second spline tooth S16C with a circumferentially asymmetrical shape can also be called a circumferentially asymmetrical tooth S16C. The locating spline tooth S16D with a circumferentially asymmetrical shape can also be called a circumferentially asymmetrical tooth S16D. The locating spline tooth S16E with a circumferentially symmetrical shape can also be called a circumferentially symmetrical tooth S16E.

[0132] That is, the plurality of spline teeth S16 includes at least one circumferentially symmetrical tooth S16B, S16C, S16D and / or S16E about the rotation center axis A1. The plurality of spline teeth S16 includes a plurality of circumferentially symmetrical teeth S16B, S16C and S16E about the rotation center axis A1. The plurality of spline teeth S16 includes at least one circumferentially asymmetrical tooth S16B, S16C, S16D and / or S16E about the rotation center axis A1. The plurality of spline teeth S16 includes a plurality of circumferentially asymmetrical teeth S16C and S16D about the rotation center axis A1.

[0133] like Figure 7 and Figure 8 As shown, each of the plurality of spline teeth S16 has a spline tip S16A. The spline tip S16A includes the radial outer end of the spline tooth S16. Therefore, the spline tip S16A can also be referred to as the radial outer end S16A. Each of the first spline tooth S16B, the second spline tooth S16C, the locating spline tooth S16D, and the locating spline tooth S16E includes a spline tip S16A.

[0134] The maximum spline distance DS1 is defined as the distance from the rotation center axis A1 to the spline tip S16A. The radial tooth root distance DS2 is defined as the distance from the rotation center axis A1 to one of the multiple tooth root center points S12A. The radial tooth root distance DS2 corresponds to the radius of the tooth root circle S12B of the rear sprocket SP1.

[0135] The maximum spline distance DS1 is greater than the radial tooth root distance DS2. The spline tip S16A of each of the plurality of spline teeth S16 is located radially inward from the tooth profile OL of each of the plurality of sprocket teeth S12. The spline tip S16A of each of the plurality of spline teeth S16 is located radially outward from the tooth root circle S12B of the rear sprocket SP1.

[0136] In this embodiment, the maximum spline distance DS1 of the first spline tooth S16B, the second spline tooth S16C, the positioning spline tooth S16D, and the positioning spline tooth S16E are all equal to each other. However, if needed and / or desired, at least one of the maximum spline distances DS1 of the first spline tooth S16B, the second spline tooth S16C, the positioning spline tooth S16D, and the positioning spline tooth S16E may be different from the other one of the maximum spline distances DS1 of the first spline tooth S16B, the second spline tooth S16C, the positioning spline tooth S16D, and the positioning spline tooth S16E.

[0137] like Figure 7 As shown, the first spline tooth S16B includes a driving spline surface S16B1 and a non-driving spline surface S16B2. The driving spline surface S16B1 faces the driving rotation direction D5. The driving spline surface S16B1 is configured to transmit driving torque from the rear sprocket SP1 to the adjacent sprocket SP2 during pedaling. The non-driving spline surface S16B2 is opposite to the driving spline surface S16B1 in the circumferential direction D2. The driving spline surface S16B1 can also be configured to transmit driving torque directly from the rear sprocket SP1 to the sprocket support 18 of the rear hub assembly 12 during pedaling.

[0138] The second spline tooth S16C includes a driving spline surface S16C1 and a non-driving spline surface S16C2. The driving spline surface S16C1 faces the driving rotation direction D5. The driving spline surface S16C1 is configured to transmit driving torque from the rear sprocket SP1 to the adjacent sprocket SP2 during pedaling. The non-driving spline surface S16C2 is opposite to the driving spline surface S16C1 in the circumferential direction D2. The driving spline surface S16C1 can also be configured to transmit driving torque directly from the rear sprocket SP1 to the sprocket support 18 of the rear hub assembly 12 during pedaling.

[0139] The positioning spline S16E includes a driving spline surface S16E1 and a non-driving spline surface S16E2. The driving spline surface S16E1 faces the driving rotation direction D5. The driving spline surface S16E1 is configured to transmit driving torque from the rear sprocket SP1 to the adjacent sprocket SP2 during pedaling. The non-driving spline surface S16E2 is opposite to the driving spline surface S16E1 in the circumferential direction D2. The driving spline surface S16E1 can also be configured to transmit driving torque directly from the rear sprocket SP1 to the sprocket support 18 of the rear hub assembly 12 during pedaling.

[0140] like Figure 8 As shown, the positioning spline S16D includes a driving spline surface S16D1 and a non-driving spline surface S16D2. The driving spline surface S16D1 faces the driving rotation direction D5. The driving spline surface S16D1 is configured to transmit driving torque from the rear sprocket SP1 to the adjacent sprocket SP2 during pedaling. The non-driving spline surface S16D2 is opposite to the driving spline surface S16D1 in the circumferential direction D2. The driving spline surface S16D1 can also be configured to transmit driving torque directly from the rear sprocket SP1 to the sprocket support 18 of the rear hub assembly 12 during pedaling.

[0141] like Figure 9 As shown, the driving spline surface S16B1 of the first spline tooth S16B has an axial length L1 and a radial length H1. The axial length L1 is defined in the axial direction D1. The radial length H1 is defined in the radial direction of the rear sprocket SP1. The axial length L1 ranges from 0.7 mm to 1.1 mm. The radial length H1 ranges from 0.27 mm to 0.4 mm. In this embodiment, the axial length L1 is equal to 0.87 mm. The radial length H1 is equal to 0.34 mm. However, the axial length L1 is not limited to the above dimensions and ranges. The radial length H1 is not limited to the above dimensions and ranges.

[0142] The driving spline surface S16C1 of the second spline tooth S16C has an axial length L2 and a radial length H2. The axial length L2 is defined in the axial direction D1. The radial length H2 is defined in the radial direction of the rear sprocket SP1. The axial length L2 ranges from 0.7 mm to 1.1 mm. The radial length H2 ranges from 0.27 mm to 0.4 mm. In this embodiment, the axial length L2 is equal to 0.87 mm. The radial length H2 is equal to 0.34 mm. However, the axial length L2 is not limited to the above dimensions and ranges. The radial length H2 is not limited to the above dimensions and ranges.

[0143] The driving spline surface S16E1 of the positioning spline tooth S16E has an axial length L4 and a radial length H4. The axial length L4 is defined in the axial direction D1. The radial length H4 is defined in the radial direction of the rear sprocket SP1. The axial length L4 ranges from 0.7 mm to 1.1 mm. The radial length H4 ranges from 0.27 mm to 0.4 mm. In this embodiment, the axial length L4 is equal to 0.87 mm. The radial length H4 is equal to 0.34 mm. However, the axial length L4 is not limited to the above dimensions and ranges. The radial length H4 is not limited to the above dimensions and ranges.

[0144] like Figure 10 As shown, the driving spline surface S16D1 of the positioning spline tooth S16D has an axial length L3 and a radial length H3. The axial length L3 is defined in the axial direction D1. The radial length H3 is defined in the radial direction of the rear sprocket SP1. The axial length L3 ranges from 0.7 mm to 1.1 mm. The radial length H3 ranges from 0.27 mm to 0.4 mm. In this embodiment, the axial length L3 is equal to 0.87 mm. The radial length H3 is equal to 0.34 mm. However, the axial length L3 is not limited to the above dimensions and ranges. The radial length H3 is not limited to the above dimensions and ranges.

[0145] The sum of the axial lengths L1, L2, L3, and L4 of the driving spline surfaces S16B1, S16C1, S16D1, and S16E1 in the plurality of spline teeth S16 is greater than 11.0 mm to achieve sufficient strength for the plurality of spline teeth S16. Preferably, the sum of the axial lengths L1, L2, L3, and L4 of the driving spline surfaces S16B1, S16C1, S16D1, and S16E1 in the plurality of spline teeth S16 is greater than 13.0 mm to achieve sufficient strength for the plurality of spline teeth S16. The range of the sum of the axial lengths L1, L2, L3, and L4 of the driving spline surfaces S16B1, S16C1, S16D1, and S16E1 in the plurality of spline teeth S16 can be from 11.0 mm to 16.0 mm to achieve sufficient strength for the plurality of spline teeth S16 and to save axial space for the plurality of spline teeth S16. In this embodiment, the sum of the axial lengths L1, L2, L3, and L4 of the driving spline surfaces S16B1, S16C1, S16D1, and S16E1 in the plurality of spline teeth S16 is 13.92 mm. However, the sum of the axial lengths L1, L2, L3, and L4 of the driving spline surfaces S16B1, S16C1, S16D1, and S16E1 in the plurality of spline teeth S16 is not limited to the above dimensions and ranges.

[0146] The sum of the radial lengths H1, H2, H3, and H4 of the driving spline surfaces S16B1, S16C1, S16D1, and S16E1 in the multiple spline teeth S16 is greater than 4.0 mm to achieve sufficient strength for the multiple spline teeth S16. Preferably, the sum of the radial lengths H1, H2, H3, and H4 of the driving spline surfaces S16B1, S16C1, S16D1, and S16E1 in the multiple spline teeth S16 is greater than 5.0 mm to achieve sufficient strength for the multiple spline teeth S16. The range of the sum of the radial lengths H1, H2, H3, and H4 of the driving spline surfaces S16B1, S16C1, S16D1, and S16E1 in the multiple spline teeth S16 can be from 4.0 mm to 7.0 mm to achieve sufficient strength for the multiple spline teeth S16 and save radial space in the multiple spline teeth S16. In this embodiment, the sum of the radial lengths H1, H2, H3, and H4 of the driving spline surfaces S16B1, S16C1, S16D1, and S16E1 in the plurality of spline teeth S16 is 5.44 mm. However, the sum of the radial lengths H1, H2, H3, and H4 of the driving spline surfaces S16B1, S16C1, S16D1, and S16E1 in the plurality of spline teeth S16 is not limited to the above dimensions and ranges.

[0147] like Figures 11 to 14 As shown, the annular base S17 extends axially inward from the axially inner surface S15 of the sprocket body S11 along the axial direction D1. A plurality of spline teeth S16 are spaced apart from a plurality of sprocket teeth S12 in the axial direction D1. However, if needed and / or desired, at least one of the spline teeth S16 can be directly engaged with a corresponding sprocket tooth among the plurality of sprocket teeth S12.

[0148] like Figure 11 As shown, the first spline tooth S16B extends radially outward from the annular base S17. The first spline tooth S16B is spaced apart from the plurality of sprocket teeth S12 in the axial direction D1. However, if needed and / or desired, the first spline tooth S16B can be directly engaged with a corresponding sprocket tooth among the plurality of sprocket teeth S12.

[0149] like Figure 12 As shown, the second spline tooth S16C extends radially outward from the annular base S17. The second spline tooth S16C is spaced apart from the plurality of sprocket teeth S12 in the axial direction D1. However, if needed and / or desired, the second spline tooth S16C can be directly engaged with a corresponding sprocket tooth among the plurality of sprocket teeth S12.

[0150] like Figure 13As shown, the locating spline S16D extends radially outward from the annular base S17. The locating spline S16D is spaced apart from multiple sprocket teeth S12 in the axial direction D1. However, if needed and / or desired, the locating spline S16D can be directly engaged with a corresponding sprocket tooth among the multiple sprocket teeth S12.

[0151] like Figure 14 As shown, the locating spline S16E extends radially outward from the annular base S17. The locating spline S16E is spaced apart from multiple sprocket teeth S12 in the axial direction D1. However, if needed and / or desired, the locating spline S16E can be directly engaged with a corresponding sprocket tooth among the multiple sprocket teeth S12.

[0152] like Figure 15 As shown, adjacent sprockets SP2 include a second sprocket body S21 and a plurality of second sprocket teeth S22. The second sprocket body S21 has a second sprocket opening S23. The second sprocket opening S23 has a second minimum diameter DM21. The plurality of second sprocket teeth S22 extend radially outward from the second sprocket body S21 in a radial direction relative to the rotation center axis A1. The plurality of second sprocket teeth S22 defines the outer diameter DM2 of the second sprocket. In this embodiment, the total number of second sprocket teeth S22 is eleven. However, the total number of second sprocket teeth S22 is not limited to eleven.

[0153] like Figure 5 As shown, the second sprocket opening S23 is configured to receive the hub shaft 14 of the rear hub assembly 12 in the hub-mounted state where the rear sprocket SP1 and the adjacent sprocket SP2 are mounted to the rear hub assembly 12. The second minimum diameter DM21 is smaller than the outermost diameter DM6 of the sprocket support body 18 of the rear hub assembly 12.

[0154] The rear sprocket SP2 also has a second axially outward surface S24 and a second axially inward surface S25. The second axially inward surface S25 is disposed on the opposite side of the second axially outward surface S24 in the axial direction D1. The second axially inward surface S25 is configured to face the axial center plane CP of the manually driven vehicle 2 in the axial direction D1 when the rear sprocket SP1 and the adjacent sprocket SP2 are mounted to the vehicle in the vehicle mounting state.

[0155] like Figure 15As shown, adjacent sprockets SP2 include a plurality of spline recesses S26. The plurality of spline recesses S26 are disposed on a second axially outward surface S24. The plurality of spline recesses S26 include at least one first spline recess S26B and at least one second spline recess S26C. The plurality of spline recesses S26 include at least two first spline recesses S26B and at least two second spline recesses S26C. The plurality of spline recesses S26 include at least two pairs of first spline recesses S26B and second spline recesses S26C. In this embodiment, the total number of at least two pairs of first spline recesses S26B and second spline recesses S26C is seven. The plurality of spline recesses S26 includes positioning spline recesses S26D and S26E. However, the total number of at least two pairs of first spline recesses S26B and second spline recesses S26C is not limited to seven.

[0156] In a pair of first spline recesses S26B and second spline recesses S26C, the second spline recesses S26C are adjacent to the first spline recesses S26B in the circumferential direction D2, while there are no other spline recesses between the first spline recesses S26B and the second spline recesses S26C in the circumferential direction D2.

[0157] The plurality of spline recesses S26 include at least one positioning spline recess S26D and / or S26E. At least one positioning spline recess S26D and / or S26E differs from the other spline recesses in the plurality of spline recesses S26 in at least one aspect of size and shape. In this embodiment, the plurality of spline recesses S26 include positioning spline recesses S26D and S26E. However, if desired and / or expected, the plurality of spline recesses S26 may include at least one positioning spline recess.

[0158] A positioning spline recess S26D is disposed in the circumferential direction D2 between one pair of at least two pairs of first spline recesses S26B and second spline recesses S26C and the other pair of at least two pairs of first spline recesses S26B and second spline recesses S26C. A positioning spline recess S26E is disposed in the circumferential direction D2 between one pair of at least two pairs of first spline recesses S26B and second spline recesses S26C and the other pair of at least two pairs of first spline recesses S26B and second spline recesses S26C.

[0159] like Figure 16As shown, a plurality of spline teeth S16 engage with a plurality of spline recesses S26 to transmit drive torque between the rear sprocket SP1 and the adjacent sprocket SP2. The spline teeth S16 are configured to be at least partially disposed in the spline recesses S26 in the hub-mounted state where the rear sprocket SP1 and the adjacent sprocket SP2 are mounted to the rear hub assembly 12. A first spline tooth S16B is configured to be at least partially disposed in the first spline recess S26B in the hub-mounted state where the rear sprocket SP1 and the adjacent sprocket SP2 are mounted to the rear hub assembly 12. A second spline tooth S16C is configured to be at least partially disposed in the second spline recess S26C in the hub-mounted state where the rear sprocket SP1 and the adjacent sprocket SP2 are mounted to the rear hub assembly 12. A positioning spline tooth S16D is configured to be at least partially disposed in the positioning spline recess S26D in the hub-mounted state where the rear sprocket SP1 and the adjacent sprocket SP2 are mounted to the rear hub assembly 12. The positioning spline tooth S16E is configured to be at least partially disposed in the positioning spline recess S26E when the rear sprocket SP1 and the adjacent sprocket SP2 are mounted to the rear hub assembly 12.

[0160] like Figure 5 As shown, the rear sprocket assembly 10 includes a locking device 26. The locking device 26 is configured to secure the rear sprocket assembly 10 to the sprocket support 18 of the rear hub assembly 12 in the hub-mounted state. The locking device 26 is configured to mount the rear sprocket SP1 and the adjacent sprocket SP2 to the rear hub assembly 12. The locking device 26 is configured to attach to the sprocket support 18 to retain the sprocket carrier 22 and the first sprockets SP1 to the fourth sprockets SP4 in the axial direction D1 on the positioning surfaces 18C of the locking device 26 and the sprocket support 18 (see, for example...). Figure 3 )between.

[0161] The locking device 26 includes an axially inward end portion 26A and an axially outward end portion 26B. The locking device 26 extends in the axial direction D1 between the axially inward end portion 26A and the axially outward end portion 26B. The axially outward end portion 26B is opposite to the axially inward end portion 26A in the axial direction D1. The locking device 26 includes a first locking member 28 and a second locking member 30. The first locking member 28 includes the axially inward end portion 26A. The second locking member 30 includes the axially outward end portion 26B.

[0162] The first locking member 28 is configured to detachably engage with the sprocket support 18 of the rear hub assembly 12 in the hub-mounted state. The second locking member 30 is configured to detachably engage with the first locking member 28 in the hub-mounted state so as to abut against the rear sprocket SP1 in the axial direction D1.

[0163] The first locking member 28 is configured to be detachably and reattachedly engaged with the axial end 18B of the sprocket support 18 in the hub-mounted state. The first locking member 28 is configured to be at least partially disposed in the second sprocket opening S23 in the hub-mounted state. The second locking member 30 is configured to be at least partially disposed in the first sprocket opening S13 and the second sprocket opening S23 in the hub-mounted state.

[0164] The term “removable ground” or “removable and reattachable ground” as used herein refers to a construction in which one element can be repeatedly detached from and attached to another element without causing substantial damage.

[0165] like Figure 5 As shown, the first locking member 28 includes a first axial end 28A and a second axial end 28B. The second axial end 28B is opposite to the first axial end 28A in the axial direction D1. The first axial end 28A is configured to be detachably attached to the sprocket support 18 of the rear hub assembly 12 in the hub-mounted state. The first axial end 28A is configured to be detachably and reattached to the sprocket support 18 of the rear hub assembly 12 in the hub-mounted state.

[0166] The first axial end portion 28A has a first thread 28D. The second axial end portion 28B has a second thread 28E. The axially inward end portion 26A has a first thread 28D. In this embodiment, the first thread 28D includes an external thread. The second thread 28E includes an internal thread. However, if desired and / or expected, the first thread 28D may include an internal thread. If desired and / or expected, the second thread 28E may include an external thread.

[0167] The first thread 28D is configured to thread into the thread 18D of the sprocket support 18 disposed on the rear hub assembly 12 in the hub-mounted state where the rear sprocket assembly 10 is mounted to the rear hub assembly 12. In this embodiment, the thread 18D includes an internal thread. However, if desired and / or expected, the thread 18D may include an external thread.

[0168] The first locking member 28 includes a first surface 28C. The first surface 28C extends radially outward relative to the rotation center axis A1. The first surface 28C is adjacent to a first thread 28D. The first thread 28D of the first locking member 28 extends radially outward from the first surface 28C. The first surface 28C extends from the first thread 28D in the axial direction D1. A second thread 28E is disposed radially inward on the first surface 28C.

[0169] like Figure 5As shown, the second locking member 30 includes a third axial end 30A and a fourth axial end 30B. The fourth axial end 30B is opposite to the third axial end 30A in the axial direction D1. The third axial end 30A is configured to be attached to the second axial end 28B of the first locking member 28 in an assembled state where the rear sprocket SP1 and the locking device 26 are assembled as a single unit. The third axial end 30A of the second locking member 30 is configured to be detachably attached to the second axial end 28B of the first locking member 28 in an assembled state where the rear sprocket SP1 and the locking device 26 are assembled as a single unit.

[0170] The third axial end portion 30A has a third thread 30D. The third thread 30D is configured to engage with the second thread 28E of the first locking member 28 in an assembled state where the rear sprocket SP1 and the locking device 26 are assembled as a unit. The fourth axial end portion 30B has at least one radial protrusion 30F. That is, the axially outward end portion 26B has at least one radial protrusion 30F. In this embodiment, the third thread 30D includes an external thread. However, if desired and / or expected, the third thread 30D may include an internal thread. Furthermore, the third axial end portion 30A of the second locking member 30 may be attached to the second axial end portion 28B of the first locking member 28 by a spline engagement via a press fit.

[0171] The second locking member 30 includes a second surface 30C. The second surface 30C is radially outward in the radial direction. The second surface 30C is adjacent to a third thread 30D. The second surface 30C is adjacent to at least one radial protrusion 30F in the axial direction D1. The second surface 30C is disposed between the third thread 30D and at least one radial protrusion 30F. The second surface 30C extends from the third thread 30D in the axial direction D1. The second surface 30C extends from at least one radial protrusion 30F in the axial direction D1. At least one radial protrusion 30F of the second locking member 30 extends radially outward from the second surface 30C in the radial direction. The first surface 28C is arranged radially outward from the second surface 30C relative to the rotation center axis A1 in the assembled state of the rear sprocket SP1 and the locking device 26 as a unit.

[0172] At least one radial protrusion 30F is configured to abut against the rear sprocket SP1 in the axial direction D1 when the rear sprocket assembly 10 is mounted to the rear hub assembly 12 in a hub-mounted state. At least one radial protrusion 30F has a flange shape. At least one radial protrusion 30F has an annular shape. However, if desired and / or expected, at least one radial protrusion 30F may include multiple radial protrusions. If desired and / or expected, at least one radial protrusion 30F may have a shape different from the flange shape and the annular shape. If desired and / or expected, an intermediate member, such as a washer, may be provided between at least one radial protrusion 30F and the rear sprocket SP1 in the axial direction D1.

[0173] like Figure 5 As shown, the first locking member 28 has an axial contact surface 28F disposed radially inward from the first surface 28C. The axial contact surface 28F is configured to contact the third axial end 30A of the second locking member 30 in an assembled state where at least two of the plurality of rear sprockets SP and the locking device 26 are assembled as a single unit. The axial contact surface 28F is configured to contact the third axial end 30A of the second locking member 30 in an assembled state where the rear sprocket SP1 and the locking device 26 are assembled as a single unit. The axial contact surface 28F is configured to contact the third axial end 30A of the second locking member 30 in an assembled state where the first locking member 28, the second locking member 30, and at least two of the plurality of rear sprockets SP are assembled as a single unit. The axial contact surface 28F is configured to contact the third axial end 30A of the second locking member 30 in an assembled state where the first locking member 28, the second locking member 30, and the rear sprocket SP1 are assembled as a single unit.

[0174] like Figure 5 As shown, the locking device 26 is configured such that, in the assembled state where the rear sprocket SP1 and the locking device 26 are assembled as a single unit, the rear sprocket SP1 is positioned in the axial direction D1 between the first thread 28D of the first locking member 28 and at least one radial protrusion 30F of the second locking member 30. The rear sprocket SP1 is configured such that, in the hub-mounted state, it is positioned in the axial direction D1 between at least one radial protrusion 30F of the second locking member 30 and the sprocket support 18 of the rear hub assembly 12. The first locking member 28 and the second locking member 30 are configured such that, in the assembled state where the first locking member 28, the second locking member 30, and the rear sprocket SP1 are assembled as a single unit, the rear sprocket SP1 is positioned in the axial direction D1 between the first thread 28D of the first locking member 28 and at least one radial protrusion 30F of the second locking member 30.

[0175] At least one radial protrusion 30F has a maximum radial protrusion diameter DM4. The first thread 28D has a first maximum thread diameter DM5. The first maximum thread diameter DM5 is the outer diameter of the first thread 28D. The first minimum diameter DM11 of the first sprocket opening S13 is smaller than each of the first maximum thread diameter DM5 of the first thread 28D and the maximum radial protrusion diameter DM4 of the at least one radial protrusion 30F. Therefore, the rear sprocket SP1 is positioned axially D1 between the first thread 28D and the at least one radial protrusion 30F without disengaging from the locking device 26.

[0176] The second minimum diameter DM21 of the second sprocket opening S23 is less than the maximum radial protrusion diameter DM4 of at least one radial protrusion 30F. The second minimum diameter DM21 of the second sprocket opening S23 is greater than the first maximum thread diameter DM5 of the first thread 28D. Therefore, the first thread 28D of the locking device 26 is configured to be inserted into the second sprocket opening S23 of the adjacent sprocket SP2 in an assembled state where the rear sprocket SP1 and the locking device 26 are assembled as a unit. However, if desired and / or desired, the second minimum diameter DM21 of the second sprocket opening S23 may be less than or equal to the first maximum thread diameter DM5 of the first thread 28D. In such an embodiment, the rear sprocket SP1 and the adjacent sprocket SP2 are disposed in the axial direction D1 between the first thread 28D and at least one radial protrusion 30F without dislodging from the locking device 26.

[0177] like Figure 17 and 18 As shown, the first axial end 28A of the first locking member 28 includes a first tool engagement profile 28G. In this embodiment, the first tool engagement profile 28G includes a plurality of first tool engagement recesses 28G1. The first tool engagement recesses 28G1 are arranged circumferentially at constant intervals. However, the structure of the first tool engagement profile 28G is not limited to the first tool engagement recesses 28G1.

[0178] The fourth axial end 30B of the second locking member 30 includes a second tool engagement profile 30G. In this embodiment, at least one radial protrusion 30F includes the second tool engagement profile 30G. The second tool engagement profile 30G includes a plurality of second tool engagement recesses 30G1. The second tool engagement recesses 30G1 are arranged circumferentially at constant intervals. However, the structure of the second tool engagement profile 30G is not limited to the second tool engagement recesses 30G1.

[0179] The first tool engagement profile 28G is configured to engage with the first tool. The second tool engagement profile 30G is configured to engage with the second tool. With the first tool engaged with the first tool engagement profile 28G and the second tool engaged with the second tool engagement profile 30G, the first locking member 28 and the second locking member 30 rotate relative to each other using the first and second tools. Therefore, the third thread 30D of the second locking member 30 is screwed into the second thread 28E of the first locking member 28.

[0180] like Figure 5 As shown, the adjacent sprocket SP2 includes an axially inward torque transmission profile S27 disposed on the second axially inward surface S25. The axially inward torque transmission profile S27 is configured to engage, in a torque transmission manner, with at least one of the torque transmission profile of the third sprocket SP3 and the plurality of external splines 18A disposed on the sprocket support 18.

[0181] In this embodiment, the axially inward torque transmission profile S27 is configured to engage with a plurality of external splines 18A of the sprocket support 18 in a torque transmission manner. However, if needed and / or desired, the axially inward torque transmission profile S27 may be configured to engage with a torque transmission profile provided on the third sprocket SP3 in a torque transmission manner.

[0182] like Figure 17 As shown, the axially inward torque transmission profile S27 includes a plurality of torque transmission recesses S27A. The plurality of torque transmission recesses S27A includes a plurality of torque transmission recesses S27A1 and a positioning recess S27A2. The positioning recess S27A2 has a different shape and / or size than another of the plurality of torque transmission recesses S27A1. In this embodiment, the circumferential width of the positioning recess S27A2 is greater than the circumferential width of the torque transmission recesses S27A1.

[0183] like Figure 18 As shown, the plurality of external spline teeth 18A includes a plurality of external spline teeth 18A1 and an external positioning tooth 18A2. The plurality of external spline teeth 18A includes at least two external spline teeth 18A1 and one external positioning tooth 18A2. The external positioning tooth 18A2 has a different shape and / or size than the other external spline teeth in the at least two external spline teeth 18A1. In this embodiment, the circumferential width of the external positioning tooth 18A2 is greater than the circumferential width of the external spline teeth 18A1.

[0184] like Figure 17 and Figure 18 As shown, the external spline teeth 18A of the sprocket support 18 are configured to engage with the torque transmission recesses S27A of the adjacent sprocket SP2 in a torque transmission manner. In this embodiment, the external spline teeth 18A1 of the sprocket support 18 are configured to engage with the torque transmission recesses S27A1 of the adjacent sprocket SP2. The external positioning teeth 18A2 of the sprocket support 18 are configured to engage with the positioning recesses S27A2 of the adjacent sprocket SP2. Since the circumferential width of the external positioning teeth 18A2 is greater than the circumferential width of the torque transmission recesses S27A1, the external positioning teeth 18A2 are configured not to engage with the torque transmission recesses S27A1. Therefore, the external positioning teeth 18A2 and the positioning recesses S27A2 define a unique circumferential position of the sprocket support 18 relative to the adjacent sprocket SP2.

[0185] The following will refer to Figure 3 , Figure 5 and Figures 19 to 21 The assembly process of assembling the rear sprocket assembly 10 into the rear hub assembly 12 is described.

[0186] like Figure 3As shown, before the adjacent sprockets SP2 and locking device assembly 50 are installed into the sprocket support 18, the third sprockets SP3 to eleventh sprockets SP11 and sprocket bracket 22 are installed into the sprocket support 18. After the third sprockets SP3 to eleventh sprockets SP11 and sprocket bracket 22 are installed into the sprocket support 18, the adjacent sprocket SP2 is installed into the sprocket support 18.

[0187] like Figure 19 As shown, for example, the user rotates the adjacent sprocket SP2 about the rotation center axis A1 relative to the sprocket support 18, so that the adjacent sprocket SP2 is positioned at a predetermined circumferential position relative to the sprocket support 18.

[0188] With adjacent sprockets SP2 in a predetermined circumferential position, the axially inward torque transmission profile S27 of the adjacent sprockets SP2 engages with a plurality of external splines 18A of the sprocket support 18. Specifically, with adjacent sprockets SP2 in a predetermined circumferential position, the torque transmission recess S27A1 of the axially inward torque transmission profile S27 (see, for example, see...) Figure 17 ) and the external spline 18A1 of the sprocket support 18 (see, for example, see Figure 18 ) engagement. With the adjacent sprocket SP2 in a predetermined circumferential position, the locating recess S27A2 of the axially inward torque transmission profile S27 (see, for example, see...) Figure 17 ) and the outer positioning tooth 18A2 of the sprocket support 18 (see, for example, see Figure 18 Therefore, the adjacent sprocket SP2 engages with the sprocket support 18 at a predetermined circumferential position around the rotation center axis A1.

[0189] like Figure 20 As shown, after the adjacent sprocket SP2 is mounted onto the sprocket support 18, the locking device assembly 50 is mounted onto the sprocket support 18. For example, the user rotates the rear sprocket SP1 relative to the sprocket support 18 and the adjacent sprocket SP2 about the rotation center axis A1, thereby positioning the rear sprocket SP1 at a predetermined circumferential position relative to the sprocket support 18 and the adjacent sprocket SP2. With the rear sprocket SP1 in the predetermined circumferential position, a plurality of spline teeth S16 of the rear sprocket SP1 engage with a plurality of spline recesses S26 of the adjacent sprocket SP2. With the rear sprocket SP1 in the predetermined circumferential position, the first spline tooth S16B, the second spline tooth S16C, the positioning spline tooth S16D, and the positioning spline tooth S16E engage with the first spline recess S26B, the second spline recess S26C, the positioning spline recess S26D, and the positioning spline recess S26E.

[0190] like Figure 21As shown, after the multiple spline teeth S16 of the rear sprocket SP1 engage with the multiple spline recesses S26 of the adjacent sprocket SP2, the user rotates the locking device 26 relative to the sprocket support 18 about the rotation center axis A1. When the user rotates the locking device 26 relative to the sprocket support 18 about the rotation center axis A1, the first thread 28D of the first locking member 28 is screwed into the thread 18D of the sprocket support 18.

[0191] The first thread 28D and thread 18D convert the rotation of the locking device 26 into axial movement of the locking device 26 relative to the sprocket support 18 in the axial direction D1. Therefore, when the first thread 28D is screwed into the thread 18D of the sprocket support 18, the locking device 26 moves relative to the sprocket support 18 in the first axial direction D11. When the first thread 28D is screwed into the thread 18D of the sprocket support 18, at least one radial protrusion 30F moves relative to the rear sprocket SP1 from the first end position P21 toward the second end position P22.

[0192] like Figure 5 As shown, the rear sprocket SP1 and the adjacent sprocket SP2 are held in the axial direction D1 between at least one radial protrusion 30F of the second locking member 30 and the sprocket support 18. Therefore, the rear sprocket assembly 10 is assembled onto the rear hub assembly 12.

[0193] like Figure 6 As shown, the plurality of sprocket teeth S12 include a first upshift promoting tooth S12C, a second upshift promoting tooth S12D, a third upshift promoting tooth S12E, and an upshift initiating tooth S12F. The first upshift promoting tooth S12C, the second upshift promoting tooth S12D, and the third upshift promoting tooth S12E are configured to facilitate an upshift operation in which the drive chain C shifts from the adjacent larger sprocket SP2 toward the rear sprocket SP1. The upshift initiating tooth S12F is configured to engage with the drive chain C first during the upshift operation. Specifically, the upshift initiating tooth S12F is configured to first insert into the space between a pair of opposing chain plates on the drive chain C during the upshift operation. The drive chain C shifts from the adjacent larger sprocket SP2 to the rear sprocket SP1 via a shifting device such as a derailleur.

[0194] The second upshift promoting tooth S12D is adjacent to the first upshift promoting tooth S12C upstream of it in the drive rotation direction D5 relative to the rear sprocket SP1. There are no additional teeth between the first upshift promoting tooth S12C and the second upshift promoting tooth S12D in the circumferential direction D2. The second upshift promoting tooth S12D is positioned upstream of the first upshift promoting tooth S12C in the drive rotation direction D5. During pedaling, the rear sprocket SP1 rotates about its rotation center axis A1 in the drive rotation direction D5.

[0195] The third upshift promoting tooth S12E is located upstream of the second upshift promoting tooth S12D in the drive rotation direction D5 relative to the rear sprocket SP1. There are no additional teeth between the second upshift promoting tooth S12D and the third upshift promoting tooth S12E in the circumferential direction D2. The third upshift promoting tooth S12E is positioned upstream of the second upshift promoting tooth S12D in the drive rotation direction D5.

[0196] The upshift initiating tooth S12F is adjacent to the third upshift promoting tooth S12E upstream of it in the drive rotation direction D5 relative to the rear sprocket SP1. There are no additional teeth between the third upshift promoting tooth S12E and the upshift initiating tooth S12F in the circumferential direction D2. The upshift initiating tooth S12F is located upstream of the third upshift promoting tooth S12E in the drive rotation direction D5.

[0197] like Figure 12 As shown, the first upshift promoting tooth S12C has a first recess S12C1. The first recess S12C1 is provided on the axially inward surface S15 of the first upshift promoting tooth S12C, so that it is recessed from the axially inward surface S15 toward the axially outward surface S14 in the axial direction D1.

[0198] like Figure 14 As shown, the second upshift promoting tooth S12D has a second recess S12D1. The second recess S12D1 is provided on the axially inward surface S15 of the second upshift promoting tooth S12D, so that it is recessed from the axially inward surface S15 toward the axially outward surface S14 in the axial direction D1.

[0199] like Figure 22 As shown, the third upshift promoting tooth S12E has a third recess S12E1, which is provided on the axially inner surface S15 of the third upshift promoting tooth S12E so that it is recessed from the axially inner surface S15 toward the axially outer surface S14 in the axial direction D1.

[0200] like Figure 23As shown, the first upshift facilitator tooth S12C has a first tooth tip S12C2, a first driving surface S12C3, and a first non-driving surface S12C4. The first non-driving surface S12C4 is opposite to the first driving surface S12C3 in the circumferential direction D2. The first tooth tip S12C2 includes the radially outer end of the first upshift facilitator tooth S12C. Therefore, the first tooth tip S12C2 can also be referred to as the first radially outer end S12C2. The first driving surface S12C3 is configured to receive driving force from the drive chain C during pedaling. The first driving surface S12C3 is located upstream of the first non-driving surface S12C4 in the driving rotation direction D5.

[0201] like Figure 12 and Figure 23 As shown, the first recess S12C1 reaches each of the first tooth tip S12C2, the first driving surface S12C3, and the first non-driving surface S12C4. However, if needed and / or desired, the first recess S12C1 may be configured not to reach at least one of the first tooth tip S12C2, the first driving surface S12C3, and the first non-driving surface S12C4.

[0202] like Figure 23 As shown, the second upshift facilitator tooth S12D has a second tooth tip S12D2, a second driving surface S12D3, and a second non-driving surface S12D4. The second non-driving surface S12D4 is opposite to the second driving surface S12D3 in the circumferential direction D2. The second tooth tip S12D2 includes the radially outer end of the second upshift facilitator tooth S12D. Therefore, the second tooth tip S12D2 can also be referred to as the second radially outer end S12D2. The second driving surface S12D3 is configured to receive driving force from the drive chain C during pedaling. The second driving surface S12D3 is located upstream of the second non-driving surface S12D4 in the driving rotation direction D5.

[0203] like Figure 14 and Figure 23 As shown, the second recess S12D1 reaches each of the second tooth tip S12D2, the second driving surface S12D3, and the second non-driving surface S12D4. However, if needed and / or desired, the second recess S12D1 may be configured not to reach at least one of the second tooth tip S12D2, the second driving surface S12D3, and the second non-driving surface S12D4.

[0204] like Figure 24As shown, the third upshift facilitator tooth S12E has a third tooth tip S12E2, a third driving surface S12E3, and a third non-driving surface S12E4. The third non-driving surface S12E4 is opposite to the third driving surface S12E3 in the circumferential direction D2. The third tooth tip S12E2 includes the radially outer end of the third upshift facilitator tooth S12E. Therefore, the third tooth tip S12E2 can also be referred to as the third radially outer end S12E2. The third driving surface S12E3 is configured to receive driving force from the drive chain C during pedaling. The third driving surface S12E3 is located upstream of the third non-driving surface S12E4 in the driving rotation direction D5.

[0205] like Figure 22 and Figure 24 As shown, the third recess S12E1 reaches each of the third tooth tip S12E2 and the third non-driving surface S12E4, but does not reach the third driving surface S12E3. However, if needed and / or desired, the third recess S12E1 may be configured not to reach at least one of the third tooth tip S12E2, the third driving surface S12E3, and the third non-driving surface S12E4.

[0206] The first recess S12C1, the second recess S12D1, and the third recess S12E1 allow the drive chain C to move smoothly toward the rear sprocket SP1 during upshifting. The first recess S12C1, the second recess S12D1, and the third recess S12E1 also make the engagement of the upshift initiation tooth S12F with the drive chain C smoother during upshifting. Therefore, the upshifting operation can be made smoother.

[0207] like Figure 3 As shown, the rear sprockets SP1 to SP11 are separate components. However, if required and / or desired, at least two rear sprockets can be integrally configured as a single, monolithic component. Components having substantially the same function as those in the rear sprocket assembly 10 and its variations will be numbered the same here, and for the sake of brevity, will not be described in detail or shown further.

[0208] Figure 25 A rear sprocket assembly 210 according to a first variant is shown. The rear sprocket assembly 210 has a structure substantially the same as that of the rear sprocket assembly 10. The rear sprocket assembly 210 for the manually driven vehicle 2 has a rotational central axis A1. The rear sprocket SP10 of the rear sprocket assembly 10 can also be referred to as the first rear sprocket SP10. The rear sprocket assembly 210 includes the first rear sprocket SP10, the second rear sprocket SP211, and the third rear sprocket SP212. In the rear sprocket assembly 210, the second rear sprocket SP211 and the third rear sprocket SP212 are formed as a single, integral component.

[0209] like Figure 26As shown, the second rear sprocket SP211 is adjacent to the first rear sprocket SP10 in the axial direction D1, and there is no other sprocket between the first rear sprocket SP10 and the second rear sprocket SP211. The third rear sprocket SP212 is adjacent to the second rear sprocket SP211 in the axial direction D1, and there is no other sprocket between the second rear sprocket SP211 and the third rear sprocket SP212. The first rear sprocket SP10 is a separate component from the second rear sprocket SP211 and the third rear sprocket SP212.

[0210] The rear sprockets SP1 to SP9 of the rear sprocket assembly 10 can also be referred to as additional rear sprockets SP1 to SP9. That is, the rear sprocket assembly 210 also includes a plurality of additional rear sprockets SP1 to SP9. The plurality of additional rear sprockets SP1 to SP9 are disposed on the opposite side of the second rear sprocket SP211 relative to the first rear sprocket SP10. Each of the plurality of additional rear sprockets SP1 to SP9 is a separate component from the second rear sprocket SP211 and the third rear sprocket SP212. The plurality of additional rear sprockets SP1 to SP9 are separate components from each other. However, if required and / or desired, the first rear sprocket SP10 and at least two of the plurality of additional rear sprockets SP1 to SP9 can be integrally configured as a single, integral component.

[0211] For example, the additional rear sprockets SP1 to SP9 are made of at least one of aluminum, titanium, and iron. The first rear sprocket SP10 is made of at least one of aluminum, titanium, and iron. The second rear sprocket SP211 and the third rear sprocket SP212 are made of aluminum. However, the materials of the first rear sprocket SP10 and the additional rear sprockets SP1 to SP9 are not limited to the examples described above. The materials of the second rear sprocket SP211 and the third rear sprocket SP212 are not limited to the examples described above.

[0212] like Figure 25 As shown, the rear sprocket assembly 210 includes a sprocket bracket 22. One of the second rear sprocket SP211 and the third rear sprocket SP212 has at least one connecting portion 225 that is connected to one of the first rear sprocket SP10 and the sprocket bracket 22, the sprocket bracket 22 being a separate component from the second rear sprocket SP211 and the third rear sprocket SP212. The at least one connecting portion 225 is connected to one of the first rear sprocket SP10 and the sprocket bracket 22 by at least one fastener 24. The fastener 24 includes a rivet 24A. Therefore, at least one connecting portion 225 is connected to one of the first rear sprocket SP10 and the sprocket bracket 22 by at least one rivet 24A.

[0213] In a first variation, the second rear sprocket SP211 has at least one connecting portion 225. This connecting portion 225 is connected to a sprocket carrier 22. The sprocket carrier 22 includes a plurality of arms 22A. The second rear sprocket SP211 has a plurality of connecting portions 225 connected to the plurality of arms 22A of the sprocket carrier 22. The connecting portions 225 are connected to the arms 22A of the sprocket carrier 22 by rivets 24A. However, if desired and / or expected, the connecting portions 225 can be connected to the arms 22A of the sprocket carrier 22 using components other than rivets 24A. The total number of connecting portions 225 is not limited to the variation shown. The total number of arms 22A of the sprocket carrier 22 is not limited to the variation shown. If desired and / or expected, the third rear sprocket SP212 may include at least one connecting portion 225. If desired and / or expected, at least one connecting portion 225 can be connected to the first rear sprocket SP10 by fasteners 24.

[0214] like Figure 27 As shown, the first rear sprocket SP10 has a rotational center axis A1 to define an axial direction D1, a radial direction, and a circumferential direction D2. The first rear sprocket SP10 includes a sprocket body S101 and a plurality of sprocket teeth S102. The plurality of sprocket teeth S102 extend radially outward from the sprocket body S101 in the radial direction. The plurality of sprocket teeth S102 define a sprocket outer diameter DM101. The first rear sprocket SP10 has a first total number of teeth. The first total number of teeth is the total number of sprocket teeth S102.

[0215] like Figure 28 As shown, the second rear sprocket SP211 has a rotation center axis A1 to define an axial direction D1, a radial direction, and a circumferential direction D2. The second rear sprocket SP211 includes a sprocket body S111 and a plurality of sprocket teeth S112. The plurality of sprocket teeth S112 extend radially outward from the sprocket body S111 in the radial direction. The plurality of sprocket teeth S112 define a sprocket outer diameter DM111. The second rear sprocket SP211 has a second total number of teeth. The second total number of teeth is the total number of sprocket teeth S112. The second total number of teeth is greater than the first total number of teeth. The sprocket outer diameter DM111 is greater than the sprocket outer diameter DM101 of the first rear sprocket SP10 (see example...). Figure 27 ).

[0216] The third rear sprocket SP212 has a rotational center axis A1, defining an axial direction D1, a radial direction, and a circumferential direction D2. The third rear sprocket SP212 includes a sprocket body S121 and a plurality of sprocket teeth S122. The plurality of sprocket teeth S122 extend radially outward from the sprocket body S121 in the radial direction. The plurality of sprocket teeth S122 defines a sprocket outer diameter DM121. The third rear sprocket SP212 has a third total number of teeth. The third total number of teeth is the total number of sprocket teeth S122. The third total number of teeth is greater than the second total number of teeth. The sprocket outer diameter DM121 is greater than the sprocket outer diameter DM111 of the second rear sprocket SP211.

[0217] like Figure 29 As shown, the connecting portion 225 extends radially inward from the sprocket body S111 of the second rear sprocket SP211. In this embodiment, the connecting portion 225 is integrally formed with the sprocket body S111. However, if desired and / or desired, the connecting portion 225 may be a component separate from the sprocket body S111. If desired and / or desired, the connecting portion 225 may be configured to extend radially inward from the sprocket body S121 of the third rear sprocket SP212.

[0218] like Figure 30 As shown, the third rear sprocket SP212 includes at least one connecting portion 227 extending radially inward from the sprocket body S121. The third rear sprocket SP212 includes a plurality of connecting portions 227 extending radially inward from the sprocket body S121. The connecting portions 227 extend radially inward from the sprocket body S121 of the third rear sprocket SP212 to the sprocket body S111 of the second rear sprocket SP211. The connecting portions 227 connect the sprocket body S111 of the second rear sprocket SP211 and the sprocket body S121 of the third rear sprocket SP212.

[0219] The plurality of connecting portions 227 include at least one first connecting portion 227A and at least one second connecting portion 227B. In a first variant, the plurality of connecting portions 227 include a plurality of first connecting portions 227A and a plurality of second connecting portions 227B. The plurality of first connecting portions 227A and the plurality of second connecting portions 227B are alternately arranged in the circumferential direction D2.

[0220] The first connecting portion 227A extends radially inward from the sprocket body S121 of the third rear sprocket SP212 toward the connecting portion 225. The second connecting portion 227B extends radially inward from the sprocket body S121 of the third rear sprocket SP212 toward the connecting portion 225. The first connecting portion 227A connects the sprocket body S111 of the second rear sprocket SP211 and the sprocket body S121 of the third rear sprocket SP212. The second connecting portion 227B connects the sprocket body S111 of the second rear sprocket SP211 and the sprocket body S121 of the third rear sprocket SP212. A pair of first connecting portions 227A and second connecting portions 227B correspond to the connecting portion 225. The arrangement of the connecting portions 227 is not limited to the variant shown.

[0221] like Figure 31 and 32 As shown, the connecting portion 227 and the sprocket body S111 of the second rear sprocket SP211 are integrally formed as a single component. The connecting portion 227 and the sprocket body S121 of the third rear sprocket SP212 are also integrally formed as a single component.

[0222] like Figure 31 As shown, the first connecting portion 227A and the sprocket body S111 of the second rear sprocket SP211 are integrally configured as a single, integrated component. The first connecting portion 227A and the sprocket body S121 of the third rear sprocket SP212 are also integrally configured as a single, integrated component.

[0223] like Figure 32 As shown, the second connecting portion 227B and the sprocket body S111 of the second rear sprocket SP211 are integrally formed as a single component. The second connecting portion 227B and the sprocket body S121 of the third rear sprocket SP212 are also integrally formed as a single component.

[0224] Figure 33A rear sprocket assembly 310 according to a second variation is shown. The rear sprocket assembly 310 has a structure substantially the same as that of the rear sprocket assembly 210. The rear sprocket assembly 310 for a manually driven vehicle 2 has a rotational central axis A1. The rear sprocket assembly 310 includes a first rear sprocket SP10, a second rear sprocket SP211, and a third rear sprocket SP212. The second rear sprocket SP211 and the third rear sprocket SP212 are formed as a single integral component. The rear sprocket assembly 310 also includes a fourth rear sprocket SP313. The second rear sprocket SP211, the third rear sprocket SP212, and the fourth rear sprocket SP313 are formed as a single integral component. In the above embodiment, the total number of rear sprockets formed as a single integral component in the rear sprocket assembly is two or three. However, the total number of rear sprockets formed as a single integral component in the rear sprocket assembly can be equal to or greater than four. Preferably, the rear sprocket assembly includes a plurality of rear sprockets formed as an integral single component and at least one rear sprocket, the at least one rear sprocket being a component separate from the plurality of rear sprockets formed as an integral single component.

[0225] like Figure 34 As shown, the fourth rear sprocket SP313 is adjacent to the third rear sprocket SP212 in the axial direction D1, and there is no other sprocket between the third rear sprocket SP212 and the fourth rear sprocket SP313. The first rear sprocket SP10 is a separate component from the second rear sprocket SP211, the third rear sprocket SP212 and the fourth rear sprocket SP313.

[0226] Rear sprockets SP1 to SP5 and SP7 to SP9 can also be referred to as auxiliary rear sprockets SP1 to SP5 and SP7 to SP9. That is, the rear sprocket assembly 310 also includes a plurality of auxiliary rear sprockets SP1 to SP5 and SP7 to SP9. The plurality of auxiliary rear sprockets SP1 to SP5 and SP7 to SP9 are disposed on the opposite side of the second rear sprocket SP211 relative to the first rear sprocket SP10. Each of the plurality of auxiliary rear sprockets SP1 to SP5 and SP7 to SP9 is a component separate from the second rear sprocket SP211 and the third rear sprocket SP212. Each of the plurality of auxiliary rear sprockets SP1 to SP5 and SP7 to SP9 is a component separate from the second rear sprocket SP211, the third rear sprocket SP212 and the fourth rear sprocket SP313. The plurality of auxiliary rear sprockets SP1 to SP5 and SP7 to SP9 are components separate from each other. However, if needed and / or desired, at least two of the first rear sprocket SP10 and the plurality of additional rear sprockets SP1 to SP5 and SP7 to SP9 can be configured as a single integral component.

[0227] For example, the additional rear sprockets SP1 to SP5 and SP7 to SP9 are made of at least one of aluminum, titanium, and iron. The first rear sprocket SP10 is made of at least one of aluminum, titanium, and iron. The second rear sprocket SP211 and the third rear sprocket SP212 are made of aluminum. The second rear sprocket SP211, the third rear sprocket SP212, and the fourth rear sprocket SP313 are made of aluminum. However, the materials of the first rear sprocket SP10 and the additional rear sprockets SP1 to SP5 and SP7 to SP9 are not limited to the examples described above. The materials of the second rear sprocket SP211, the third rear sprocket SP212, and the fourth rear sprocket SP313 are not limited to the examples described above.

[0228] like Figure 33 As shown, the rear sprocket assembly 310 includes a sprocket bracket 22. One of the second rear sprocket SP211, the third rear sprocket SP212, and the fourth rear sprocket SP313 has at least one connecting portion 225 that connects to one of the first rear sprocket SP10 and the sprocket bracket 22, the sprocket bracket 22 being a separate component from the second rear sprocket SP211, the third rear sprocket SP212, and the fourth rear sprocket SP313. At least one connecting portion 225 is connected to one of the first rear sprocket SP10 and the sprocket bracket 22 by at least one fastener 24. At least one connecting portion 225 is connected to one of the first rear sprocket SP10 and the sprocket bracket 22 by at least one rivet 24A.

[0229] In the second variation, the second rear sprocket SP211 has at least one connecting portion 225. This at least one connecting portion 225 is connected to the sprocket carrier 22. The second rear sprocket SP211 has multiple connecting portions 225 that are connected to multiple arms 22A of the sprocket carrier 22. The connecting portions 225 are connected to the arms 22A of the sprocket carrier 22 by rivets 24A. However, if desired and / or expected, the connecting portions 225 can be connected to the arms 22A of the sprocket carrier 22 by means other than rivets 24A. The total number of connecting portions 225 is not limited to the variation shown. The total number of arms 22A of the sprocket carrier 22 is not limited to the variation shown. If desired and / or expected, one of the third rear sprocket SP212 and the fourth rear sprocket SP313 may include at least one connecting portion 225. If desired and / or expected, at least one connecting portion 225 can be connected to the first rear sprocket SP10 by fasteners 24.

[0230] like Figure 35 As shown, the second rear sprocket SP211 includes a sprocket body S111 and a plurality of sprocket teeth S112. The second rear sprocket SP211 has a second total number of teeth. The second total number of teeth is greater than the first total number of teeth of the first rear sprocket SP10. The sprocket outer diameter DM111 is greater than the sprocket outer diameter DM101 of the first rear sprocket SP10 (see example...). Figure 27 ).

[0231] The third rear sprocket SP212 includes a sprocket body S121 and multiple sprocket teeth S122. The third rear sprocket SP212 has a third total number of teeth. The third total number of teeth is greater than the second total number of teeth. The sprocket outer diameter DM121 is greater than the sprocket outer diameter DM111 of the second rear sprocket SP211.

[0232] The fourth rear sprocket SP313 includes a sprocket body S131 and a plurality of sprocket teeth S132. The plurality of sprocket teeth S132 extend radially outward from the sprocket body S131 in the radial direction. The plurality of sprocket teeth S132 define the sprocket outer diameter DM131. The fourth rear sprocket SP313 has a fourth total number of teeth. The fourth total number of teeth is the total number of sprocket teeth S132. The fourth total number of teeth is greater than the third total number of teeth. The sprocket outer diameter DM131 is greater than the sprocket outer diameter DM121 of the third rear sprocket SP212.

[0233] like Figure 36 As shown, the connecting portion 225 extends radially inward from the sprocket body S111 of the second rear sprocket S211. In this embodiment, the connecting portion 225 is integrally formed with the sprocket body S111. However, if desired and / or desired, the connecting portion 225 may be a component separate from the sprocket body S111. If desired and / or desired, the connecting portion 225 may be configured to extend radially inward from the sprocket body S121 of the third rear sprocket SP212 and / or the sprocket body S131 of the fourth rear sprocket SP313.

[0234] like Figure 37 As shown, the fourth rear sprocket SP313 includes at least one connecting portion 327 extending radially inward from the sprocket body S121. The fourth rear sprocket SP313 includes a plurality of connecting portions 327 extending radially inward from the sprocket body S121. The connecting portions 327 extend radially inward from the sprocket body S131 of the fourth rear sprocket SP313 to the sprocket body S111 of the second rear sprocket SP211. The connecting portions 327 connect the sprocket body S121 of the third rear sprocket SP212 and the sprocket body S131 of the fourth rear sprocket SP313. Furthermore, the connecting portions 327 connect the sprocket body S111 of the second rear sprocket SP211 and the sprocket body S121 of the third rear sprocket SP212. That is, the connecting part 327 connects the sprocket body S131 of the fourth rear sprocket SP313, the sprocket body S121 of the third rear sprocket SP212, and the sprocket body S111 of the second rear sprocket SP211.

[0235] The plurality of connecting portions 327 include at least one first connecting portion 327A and at least one second connecting portion 327B. In this embodiment, the plurality of connecting portions 327 include a plurality of first connecting portions 327A and a plurality of second connecting portions 327B. The plurality of first connecting portions 327A and the plurality of second connecting portions 327B are alternately arranged in the circumferential direction D2.

[0236] The first connecting portion 327A extends radially inward from the sprocket body S131 of the fourth rear sprocket SP313 toward the connecting portion 225. The second connecting portion 327B extends radially inward from the sprocket body S131 of the fourth rear sprocket SP313 toward the connecting portion 225. The first connecting portion 327A connects the sprocket body S131 of the fourth rear sprocket SP313, the sprocket body S121 of the third rear sprocket SP212, and the sprocket body S111 of the second rear sprocket SP211. The second connecting portion 327B connects the sprocket body S131 of the fourth rear sprocket SP313, the sprocket body S121 of the third rear sprocket SP212, and the sprocket body S111 of the second rear sprocket SP211. A pair of first connecting portions 327A and second connecting portions 327B correspond to the connecting portion 225. The arrangement of the connecting portions 327 is not limited to the variant shown.

[0237] like Figure 38 and 39 As shown, the connecting portion 327 is integrally formed with the sprocket body S131 of the fourth rear sprocket SP313 as a single, integrated component. The connecting portion 327 is integrally formed with the sprocket body S121 of the third rear sprocket SP212 as a single, integrated component. The connecting portion 327 is integrally formed with the sprocket body S111 of the second rear sprocket SP211 as a single, integrated component.

[0238] like Figure 38 As shown, the first connecting portion 327A and the sprocket body S131 of the fourth rear sprocket SP313 are integrally formed as a single component. The first connecting portion 327A and the sprocket body S121 of the third rear sprocket SP212 are integrally formed as a single component. The first connecting portion 327A and the sprocket body S111 of the second rear sprocket SP211 are integrally formed as a single component.

[0239] like Figure 39 As shown, the second connecting portion 327B and the sprocket body S131 of the fourth rear sprocket SP313 are integrally formed as a single component. The second connecting portion 327B and the sprocket body S121 of the third rear sprocket SP212 are integrally formed as a single component. The second connecting portion 327B and the sprocket body S111 of the second rear sprocket SP211 are integrally formed as a single component.

[0240] In this application, the term "comprising" and its derivatives, as used herein, are intended to be open-ended terms that specify the presence of a described feature, element, component, group, whole, and / or step, but do not exclude the presence of other undescribed features, elements, components, groups, wholes, and / or steps. This concept also applies to words with similar meanings, such as the terms "comprising," "having," and their derivatives.

[0241] The terms “component,” “section,” “part,” “unit,” “element,” “body,” and “structure” can have a dual meaning of a single part or multiple parts when used in the singular.

[0242] The ordinal numbers “first” and “second” listed in this application are merely identifiers and do not have any other meaning, such as a specific order. Furthermore, for example, the term “first element” does not itself imply the existence of a “second element,” nor does the term “second element” itself imply the existence of a “first element.”

[0243] The term “paired” as used herein can include configurations in which, in addition to a configuration in which a pair of elements have the same shape or structure as each other, a pair of elements also have different shapes or structures from each other.

[0244] The terms “a” (or “one”), “one or more” and “at least one” are used interchangeably in this document.

[0245] As used in this disclosure, the phrase "at least one" means "one or more" of the desired choices. For example, if the number of choices is two, the phrase "at least one" as used in this disclosure means "only one single choice" or "two of the two choices." For example, if the number of choices is equal to or more than three, the phrase "at least one" as used in this disclosure means "only one single choice" or "any combination of equal to or more than two choices." For example, the phrase "at least one of A and B" includes (1) A alone, (2) B alone, and (3) both A and B. The phrase "at least one of A, B, and C" includes (1) A alone, (2) B alone, (3) C alone, (4) both A and B, (5) both B and C, (6) both A and C, and (7) all of A, B, and C. In other words, in this disclosure, the phrase "at least one of A and B" does not mean "at least one A and at least one B."

[0246] Finally, the degree terms used herein, such as “substantially,” “approximately,” and “approximately,” refer to a reasonable amount of deviation of the modified term such that the final result does not change significantly. All numerical values ​​described in this application can be interpreted as including terms such as “substantially,” “approximately,” and “approximately.”

[0247] Obviously, many modifications and variations of the invention are possible based on the above teachings. Therefore, it should be understood that the invention can be practiced in ways other than those specifically described herein, within the scope of the appended claims.

Claims

1. A rear sprocket configured to be mounted to a rear hub assembly for a manually driven vehicle, the rear sprocket having a central axis of rotation defining an axial direction, a radial direction, and a circumferential direction, the rear sprocket comprising: Sprocket body; A plurality of sprocket teeth, the plurality of sprocket teeth extending radially outward from the sprocket body along the radial direction, the plurality of sprocket teeth defining a plurality of tooth root center points spaced apart from each other along the circumferential direction, each of the plurality of sprocket teeth having a tooth profile extending from a corresponding tooth root center point among the plurality of tooth root center points along the circumferential direction to an adjacent tooth root center point among the plurality of tooth root center points. Multiple spline teeth are configured to transmit drive torque to an adjacent sprocket adjacent to the rear sprocket, while there are no other sprockets between the rear sprocket and the adjacent sprocket in the axial direction, each of the multiple spline teeth having a spline apex. The maximum spline distance is defined as the distance from the rotation center axis to the top of the spline. The radial tooth root distance is defined as the distance from the rotation center axis to one of the plurality of tooth root center points; The maximum spline distance is greater than the radial tooth root distance; and The spline tip of each of the plurality of spline teeth is located radially inward from the tooth profile of each of the plurality of sprocket teeth in the radial direction.

2. The rear sprocket according to claim 1, wherein The sprocket body has a sprocket opening configured to receive the hub shaft of the rear hub assembly in the hub-mounted state where the rear sprocket is mounted to the rear hub assembly.

3. The rear sprocket according to claim 2, wherein... The sprocket opening has a minimum diameter that is smaller than the outermost diameter of the sprocket support of the rear hub assembly.

4. The rear sprocket according to claim 1, further comprising: An annular base, wherein the plurality of spline teeth extend radially outward from the annular base along the radial direction.

5. The rear sprocket according to claim 4, wherein... The rear sprocket has an axially outward surface and an axially inward surface disposed on the opposite side of the axially outward surface in the axial direction. The axially inward surface is configured such that, in the vehicle mounting state where the rear sprocket is mounted to the manually driven vehicle, it faces the axial center surface of the manually driven vehicle in the axial direction. The annular base extends axially inward from the axial inner surface of the sprocket body along the axial direction.

6. The rear sprocket according to claim 4, wherein The sprocket body has a sprocket opening, which is configured to receive the hub shaft of the rear hub assembly in the hub-mounted state where the rear sprocket is mounted to the rear hub assembly. When viewed along the axial direction, the annular base is configured to surround the sprocket opening.

7. The rear sprocket according to claim 1, wherein... The plurality of spline teeth are spaced apart from the plurality of sprocket teeth in the axial direction.

8. The rear sprocket according to claim 1, wherein When viewed along the axial direction, at least two of the plurality of spline teeth are configured to overlap with one of the plurality of sprocket teeth.

9. The rear sprocket according to claim 1, wherein The plurality of splines includes at least one positioning spline, which differs from the other splines in at least one aspect of size and shape.

10. The rear sprocket according to claim 9, wherein The at least one positioning spline tooth has a circumferential positioning spline width that is greater than the circumferential spline width of each of the other spline teeth in the plurality of spline teeth.

11. The rear sprocket according to claim 1, wherein The plurality of spline teeth includes at least one tooth that is circumferentially symmetrical about the axis of rotation.

12. The rear sprocket according to claim 11, wherein The plurality of spline teeth include a plurality of teeth that are circumferentially symmetrical about the axis of rotation.

13. The rear sprocket according to claim 1, wherein The plurality of spline teeth includes at least one tooth that is circumferentially asymmetrical about the axis of rotation.

14. The rear sprocket according to claim 1, wherein The total number of spline teeth in the plurality of spline teeth ranges from 15 to 18.

15. The rear sprocket according to claim 1, wherein The total number of sprocket teeth is equal to or less than 10.

16. The rear sprocket according to claim 15, wherein The total number of sprocket teeth is 9.

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