SPROCKET ARRANGEMENT

Abstract

A sprocket assembly includes a carrier and a plurality of sprockets. The carrier has a central axis. Each sprocket has a different number of teeth and is formed with a central through-bore. The carrier extends into the central through-bore of each sprocket such that the sprockets are arranged on an outer periphery of the carrier and along the central axis. At least one of the sprockets is coupled to the carrier via a weld formed by a solid-state welding process.

Description

AREA

[0001] The disclosure relates to a sprocket assembly and, more particularly, to a sprocket assembly formed by a solid-state welding process. BACKGROUND

[0002] A sprocket set or cassette is used in a multi-speed bicycle and has a plurality of interconnected sprockets. According to one embodiment, the sprockets are formed individually and connected to one another by a plurality of pins. However, two adjacent sprockets must be formed with pin holes such that the pin holes in one of the two adjacent sprockets are each aligned with the pin holes in the other of the two adjacent sprockets, so that the pins can be inserted into the pin holes in the two adjacent sprockets. This process is cumbersome and time-consuming. According to another example, the sprockets are formed in one piece from a truncated cone using 5-axis machining. This process is costly and time-consuming. GENERAL SUMMARY

[0003] The object of the disclosure is therefore to provide a sprocket assembly which can eliminate at least one of the disadvantages of the prior art.

[0004] According to one aspect of the disclosure, the sprocket assembly includes a carrier and a plurality of sprockets. The carrier has a central axis. Each sprocket has a different number of teeth and is formed with a central through-bore. The carrier extends into the central through-bore of each sprocket such that the sprockets are arranged on an outer periphery of the carrier and along the central axis. At least one of the sprockets is coupled to the carrier via a weld formed by a solid-state welding process.

[0005] According to another aspect of the disclosure, the sprocket assembly comprises a carrier and at least one sprocket. The at least one sprocket is formed with a central through-bore. The carrier extends into the central through-bore of the at least one sprocket such that the at least one sprocket is arranged on an outer periphery of the carrier. The at least one sprocket is coupled to the carrier via a welded joint formed by a solid-state welding process. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Further features and advantages of the disclosure will become apparent from the following detailed description of the embodiment(s) taken in conjunction with the accompanying drawings. It should be noted that various features may not be drawn to scale. Fig. 1 is a side view of an exemplary bicycle. Fig. 2 is a perspective view of an exemplary sprocket assembly. Fig. 3 is a perspective sectional view of the exemplary gear assembly of Fig. 2. Fig. 4 is a perspective view of an exemplary sprocket assembly according to the disclosure. Fig. 5 is an exploded perspective view of the exemplary sprocket assembly of Fig. 4. Fig. 6 is a schematic view of an exemplary first sprocket mounted to an exemplary carrier. Fig. 7 is an enlarged view of the Fig. 6 circled area VII and shows a welding tool used to couple the exemplary first sprocket and the exemplary carrier. Fig. 8 is a fragmentary sectional view of a weld formed between the exemplary first sprocket and the exemplary carrier. Fig. 9 is a schematic view of an exemplary second sprocket mounted to the exemplary carrier. Fig. 10 is a sectional view of the exemplary sprocket assembly of Fig. 4. Fig. 11 is a schematic view of the exemplary sprocket assembly of Fig. 4, which is coupled with another sprocket arrangement. Fig. 12 is a side view of another exemplary sprocket assembly according to the disclosure. Fig. 13 is a schematic view illustrating the formation of the exemplary sprocket assembly of Fig. 12 illustrates. DETAILED DESCRIPTION

[0007] Before describing the invention in more detail, it is pointed out that, where appropriate, reference numerals or end portions of reference numerals are repeated in the figures to identify corresponding or analogous elements which may optionally have similar properties.

[0008] It is noted herein that, for clarity of description, spatially relative terms such as "above," "below," "upper," "lower," "on," "above," "over," "downward," "upward," and the like may be used throughout the disclosure while referring to the features illustrated in the drawings. The features may be oriented differently (e.g., rotated 90 degrees or in other orientations), and the spatially relative terms used herein may be interpreted accordingly.

[0009] Examples of a sprocket assembly disclosed herein are used in a drivetrain of a bicycle. An exemplary sprocket assembly disclosed herein includes a carrier and at least one sprocket coupled to the carrier via a weld formed by a solid-state welding process. For example, the carrier may have a carrier working surface, and the at least one sprocket may have a sprocket working surface flush with the carrier working surface and cooperating with the carrier working surface to form a boundary therebetween. A solid-state welding tool may be moved along the boundary to form the weld coupling the carrier and the at least one sprocket together.According to one embodiment, the carrier may have a carrier positioning structure and the at least one sprocket may have a sprocket positioning structure that engages the carrier positioning structure such that the sprocket working surface and the carrier working surface are flush with each other after the at least one sprocket has been attached to the carrier. According to one embodiment, the weld extends over the entire boundary line between the sprocket working surface and the carrier working surface. According to one embodiment, the carrier and the at least one sprocket are made of the same material. According to one embodiment, the carrier and the at least one sprocket are made of different materials.

[0010] An example of a solid-state welding process that can be used to weld the carrier and the at least one sprocket is friction stir welding. Friction stir welding is a process in which a non-consumable tool is used to join two metal pieces without melting the material of the metal pieces. The tool has a probe or bit extending from a shoulder of the tool. The tool is rotated at a relatively high speed and pushed toward a joint between the metal pieces until the probe penetrates the metal pieces and the shoulder contacts the metal pieces. Portions of both metal pieces adjacent to the probe are softened without melting by the heat generated by the friction between the rotating tool and the two metal pieces.The tool is moved along a boundary line formed at the junction between the two metal pieces, causing the two metal pieces to mechanically blend at the junction. The shoulder of the tool exerts mechanical pressure on the junction between the two metal pieces to form the heated and softened metal. After cooling, a solid-phase weld or joint is formed between the metal pieces. In friction stir welding, only the material of the two metal pieces present at the junction is mixed and formed. Therefore, the welded joint is formed only from the material of the two metal pieces, creating a strong bond that mechanically couples the two metal pieces.

[0011] Fig. 1 illustrates an exemplary bicycle 100 having a main frame 102, a front wheel 104, a rear wheel 106, and a drivetrain 108. The front wheel 104 and the rear wheel 106 are rotatably connected to the main frame 102. In the illustrated example, the bicycle 100 further includes a braking system having a front brake 110 and a rear brake 112 for braking the front wheel 104 and the rear wheel 106, respectively. In the illustrated example, the drivetrain 108 includes a chain 114, a spindle 116 rotatably mounted to the main frame 102, a front sprocket assembly 118 coaxially mounted to the spindle 116, and a rear sprocket assembly 120 coaxially mounted to the rear wheel 106. The front sprocket assembly 118 and the rear sprocket assembly 120 each include at least one sprocket. The direction of arrow (A) in Fig. 1 indicates a forward direction of movement for the bicycle 100.

[0012] In the illustrated example, the bicycle 100 includes a bottom bracket 122, a rear wheel hub 124, a headset 126, and a front wheel hub 128. The bottom bracket 122 is attached to a lower portion of the main frame 102 and supports the spindle 116 relative to the main frame 102. The rear wheel hub 124 is attached to a rear portion of the main frame 102 and supports the rear wheel 106 and the rear sprocket assembly 120 relative to the main frame 102. The headset 126 is attached to a front portion of the main frame 102. In the illustrated example, the front wheel 104 is coupled to the front portion of the main frame 102 via a front fork 130 rotatably attached to the headset 126. The front wheel hub 128 is attached to a lower portion of the front fork 130 and supports the front wheel 104 relative to the front fork 130. The bicycle 100 may further include a handlebar 132 rotatably connected to the front fork 130.The bottom bracket 122, the rear wheel hub 124, the headset 126, and the front wheel hub 128 may each include components that are rotatable relative to one another.

[0013] In the Fig. 1, the bicycle 100 may have a single-speed drivetrain or a multi-speed drivetrain with a shifting system. For example, the bicycle 100 may have a multi-speed drivetrain 108, which may include a front gear changer (hereinafter referred to as a front shifting system) and / or a rear gear changer mounted to the main frame 102. The gear changers may be, for example, electromechanical derailleurs including a front derailleur 140 and a front shifting system. The gear changers may be operable with one or more shift levers 144, which may be mounted on the handlebar 132. The shift levers 144 may initiate gear changes via wireless communication or via a physical connection to a mechanical shift cable or hydraulic line.Apart from the chainrings and the front gear system, the bicycle 100 described above is known state of the art and in . Fig. 1 is depicted as a full-suspension mountain bike with flat handlebars. Professionals should recognize that the type and style of bicycle may vary from the example shown. For example, a road bike with drop handlebars may be used in conjunction with a drivetrain with road gears instead of a mountain bike or other bicycle gear system, or an e-bike with an integrated electric motor for propulsion assistance.

[0014] In this embodiment, the bicycle 100 includes a braking system. The braking system includes at least one brake lever 134 movably connected to the handlebar 132. The brake lever 134 is configured to actuate components of the braking system of the bicycle 100. According to one embodiment, the braking system may include a hydraulically or cable-actuated front braking mechanism coupled to the front wheel 104 via a hydraulic line or a mechanical cable, and / or a hydraulically or cable-actuated rear braking mechanism (not shown) coupled to the rear wheel 106 via a hydraulic line or a mechanical cable. As previously mentioned, the braking system may be a hydraulically actuated system or a mechanically actuated system, and both are known in the art.

[0015] Fig. 2 is a perspective view of an exemplary sprocket assembly 200 configured for attachment to a hub assembly of a bicycle wheel and used as a rear sprocket assembly 120 of Fig. 1 can serve. Fig. 3 is a perspective, cut-away view of the exemplary sprocket pack. In the illustrated example, the sprocket pack 200 includes a first sprocket assembly 300 having a plurality of interconnected sprockets, a second sprocket assembly 302 having a plurality of sprockets interconnected by a plurality of pins 304, and a spacer sleeve 306 connected between the first sprocket assembly 300 and the second sprocket assembly 302. According to one embodiment, the largest sprocket 308 of the second sprocket assembly 302 may have internal teeth. According to one embodiment, the spacer sleeve 306 may have an internally threaded portion 310 in a central region and internal teeth at an end remote from the largest sprocket 308 of the second sprocket assembly 302. The spacer sleeve 306 may be threaded to a wheel hub shell (not shown) by means of the threaded portion 310.The internal teeth of the spacer sleeve 306 can be used to guide an axle or a hub portion when the gear set 200 is attached to a wheel hub assembly (not shown).

[0016] Fig. 4 is a perspective view of the Fig. 2 and Fig. 3. In the illustrated example, the sprocket assembly 300 includes a carrier 400 having a central axis (C) and a plurality of sprockets arranged on an outer periphery of the carrier 400 and along the central axis (C). Each sprocket of the exemplary sprocket assembly 300 has a different number of teeth. For example, the plurality of sprockets includes a first sprocket 402 mounted on the carrier 400, a second sprocket 404 disposed adjacent to the first sprocket 402 and having fewer teeth than the first sprocket 402, a third sprocket 406 disposed on a side of the second sprocket 404 opposite the first sprocket 402 and having fewer teeth than the second sprocket 404, and a fourth sprocket 408 disposed on a side of the third sprocket 406 opposite the second sprocket 404 and having fewer teeth than the third sprocket 406.

[0017] Fig. 5 is an exploded perspective view of the exemplary sprocket assembly 300. In the illustrated example, the carrier 400 has the shape of a stepped cone that tapers substantially in a taper direction (T) parallel to the central axis (C), a plurality of shoulder surfaces 500, 502, 504, 506, 508, 510, 512 spaced apart along the central axis (C) and facing in the taper direction (T), and an end surface 514 facing in the taper direction (T). The first sprocket 402 is formed with a central through-bore 542 into which the carrier 400 extends. The second sprocket 404 is formed with a central through-bore 544 into which the carrier 400 extends. The third sprocket 406 is formed with a central through-bore 546 into which the carrier 400 extends. The fourth sprocket 408 is formed with a central through-bore 548 into which the carrier 400 extends.According to one embodiment, at least one of the sprockets 402, 404, 406, 408 is coupled to the carrier 400 via a welded joint formed by a solid-state welding process. According to another embodiment, the sprockets 402, 404, 406, 408 are each coupled to the carrier 400 via a plurality of welded joints formed by a solid-state welding process. The solid-state welding process can be, for example, a friction stir welding process. According to one embodiment, the carrier 400 and the sprockets 402, 404, 406, 408 are made of the same material, e.g., aluminum, iron, copper, steel, or stainless steel. According to one embodiment, each sprocket 402, 404, 406, 408 can be made of a different material than the carrier 400. For example, the carrier 400 may be made of aluminum and each sprocket 402, 404, 406, 408 may be made of steel.According to further embodiments, the carrier 400 can be made of aluminum, iron, copper, steel, or stainless steel, and each sprocket 402, 404, 406, 408 can be made of a different material from aluminum, iron, copper, steel, or stainless steel. The sprockets 402, 404, 406, 408 can be made of the same material or different materials.

[0018] As in Fig. 6, during assembly of the exemplary sprocket assembly, the first sprocket 402 is moved relative to the carrier 400 in a direction opposite the taper direction (T) to attach to the carrier 400. According to one embodiment, the carrier 400 has a first carrier working surface 600 and the first sprocket 402 has a first sprocket working surface 602. The first carrier working surface 600 and the first sprocket working surface 602 are flush with each other after the first sprocket 402 is attached to the carrier 400 and together form an annular boundary line at a joint therebetween. According to one embodiment, the carrier 400 and the central through-bore 542 of the first sprocket 402 may be sized to form a transition fit or a sliding fit.According to one embodiment, the carrier 400 and the central through-bore 542 of the first sprocket 402 can be sized to form a clearance fit. According to one embodiment, the carrier 400 includes a first carrier positioning structure 604, and the first sprocket 402 includes a first sprocket positioning structure 608 that engages the first carrier positioning structure 604 to cause the first carrier working surface 600 and the first sprocket working surface 602 to be flush with each other after the first sprocket 402 is attached to the carrier 400. According to one embodiment, the first sprocket 402 includes a first surrounding inner surface 606 that defines the central through-bore 542 and includes a stepped structure (e.g., a shoulder surface facing away from the taper direction (T)) that serves as the first sprocket positioning structure 608. Back to . Fig. 5: According to one embodiment, one of the shoulder surfaces 502 of the carrier 400 serves as the first carrier working surface 600 and another of the shoulder surfaces 500 serves as the first carrier positioning structure 604.

[0019] According to Fig. 7, an exemplary friction stir welding tool 700 is operable to form a weld between the first sprocket 402 and the carrier 400 to couple the first sprocket 402 and the carrier 400 together. The friction stir welding tool 700 includes a shoulder surface 702 and a bit or probe 704 extending from the shoulder surface 702. The friction stir welding tool 700 may be part of an automated machine or a hand tool. After the first sprocket positioning structure 608 engages the first carrier positioning structure 604 and after the friction stir welding tool 700 is rotated to a relatively high speed, as indicated by the arrow in Fig. As indicated in Figure 7, the probe 704 pierces the boundary between the first carrier working surface 600 and the first sprocket working surface 602, and the shoulder surface 702 engages and exerts pressure on the first carrier working surface 600 and the first sprocket working surface 602. According to some embodiments, a pilot hole may be pre-drilled into the junction between the first carrier working surface 600 and the first sprocket working surface 602 to ensure that the probe 704 is centered. The high-speed rotation of the probe 704 generates high temperatures (which, however, are still below the melting point(s) of the material(s) of the first sprocket 402 and the carrier 400). Due to the high-speed rotation and high temperatures, the material of the first sprocket 402 and the carrier 400 melts and mixes at the junction.The friction stir welding tool 700 is moved along the boundary line between the first carrier working surface 600 and the first sprocket working surface 602 and then removed from the joint. This process creates a weld at the joint that couples the first sprocket 402 and the carrier 400. Various parameters of the friction stir welding tool 700 can be changed to influence (e.g., optimize) the weld, such as the profile of the probe 704, the material of the probe 704, the length and / or width of the probe 704, the rotational speed of the friction stir welding tool 700, the speed at which the friction stir welding tool 700 moves along the boundary line, and / or the pressure exerted by the shoulder surface 702.

[0020] As in Fig. As shown in Figure 8, a weld 800 is formed along the boundary line between the first carrier working surface 600 and the first sprocket working surface 602, such that the first sprocket 402 and the carrier 400 are firmly coupled to each other. According to one embodiment, the weld 800 is formed only from material of the carrier 400 and material of the first sprocket 402. According to some embodiments, one or more machining operations (e.g., grinding) may be performed to smooth the weld 800. According to one embodiment, the weld 800 may extend across the entire boundary line between the first carrier working surface 600 and the first sprocket working surface 602.According to one embodiment, friction stir welding tool 700 is operable to form a plurality of welds spaced apart along the boundary between first carrier working surface 600 and first sprocket working surface 602. Friction stir welding allows first sprocket 402 and carrier 400 to be welded together even though they are made of different materials. If first sprocket 402 and carrier 400 are made of the same material, weld 800 is formed from the materials of first sprocket 402 and carrier 400.If the first sprocket 402 and the carrier 400 are made of two different materials, one of the materials with a lower melting point is softened, while a surface of another material with a higher melting point is roughened by the probe 704 so that the two materials can be firmly bonded together.

[0021] According to some embodiments, the probe 704 requires a certain amount of time to heat up and soften the material(s) to allow the probe 704 to move after the probe 704 is inserted into the boundary between the first support working surface 600 and the first sprocket working surface 602. Furthermore, according to some embodiments, a small hole may remain after the probe 704 is removed at the end of the process. An additional structure or component may be used to assist in the initiation and / or completion of friction stir welding.

[0022] As in Fig. 9, according to one embodiment, the second sprocket 404 may be coupled to the carrier 400 similarly to the first sprocket 402 after the first sprocket 402 and the carrier 400 have been fixedly coupled together. For example, the carrier 400 has a second carrier working surface 900 and the second sprocket 404 has a second sprocket working surface 902. The second carrier working surface 900 and the second sprocket working surface 902 are flush with each other after the second sprocket 404 has been attached to the carrier 400 and together form an annular boundary line at a joint therebetween. According to one embodiment, the carrier 400 and the central through-bore 544 of the second sprocket 404 may be sized to form a transition fit or a sliding fit.According to one embodiment, the carrier 400 and the central through-bore 544 of the second sprocket 404 can be sized to form a clearance fit. According to one embodiment, the carrier 400 includes a second carrier positioning structure 904, and the second sprocket 404 includes a second sprocket positioning structure 908 that engages the second carrier positioning structure 904 to cause the second carrier working surface 900 and the second sprocket working surface 902 to be flush with each other after the second sprocket 404 is attached to the carrier 400. According to one embodiment, the second sprocket 404 includes a second surrounding inner surface 906 that defines the central through-bore 544 and includes a stepped structure (e.g., a shoulder surface facing away from the taper direction (T)) that serves as the second sprocket positioning structure 908. Back to . Fig. 5: According to one embodiment, one of the shoulder surfaces 506 of the carrier 400 serves as the second carrier working surface 900 and another of the shoulder surfaces 504 serves as the second carrier positioning structure 904. Likewise, the Fig. 7 is operable to form a weld between the second sprocket 404 and the carrier 400 to couple the second sprocket 404 and the carrier 400 together.

[0023] As in Fig. 10, according to one embodiment, the third sprocket 406 may be coupled to the carrier 400 similarly to the first sprocket 402 after the second sprocket 404 and the carrier 400 have been fixedly coupled together. For example, the carrier 400 has a third carrier working surface 1000 and the third sprocket 406 has a third sprocket working surface 1002. The third carrier working surface 1000 and the third sprocket working surface 1002 are flush with each other after the third sprocket 406 has been attached to the carrier 400 and together form an annular boundary line at a joint therebetween. According to one embodiment, the carrier 400 and the central through-bore 546 of the third sprocket 406 may be sized to form a transition fit or a sliding fit.According to one embodiment, the carrier 400 and the central through-bore 546 of the third sprocket 406 may be sized to form a clearance fit. Back to . Fig. 5: According to one embodiment, one of the shoulder surfaces 510 of the carrier 400 serves as the third carrier working surface 1000. The Fig. The friction stir welding tool 700 shown in Figure 7 is operable to form a weld joint between the third sprocket 406 and the carrier 400 to couple the third sprocket 406 and the carrier 400 together.

[0024] According to one embodiment, the fourth sprocket 408 may be coupled to the carrier 400 similarly to the first sprocket 402 after the third sprocket 406 and the carrier 400 have been fixedly coupled. For example, the carrier 400 has a fourth carrier working surface 1004 and the fourth sprocket 408 has a fourth sprocket working surface 1006. The fourth carrier working surface 1004 and the fourth sprocket working surface 1006 are flush with each other after the fourth sprocket 408 has been attached to the carrier 400 and together form an annular boundary line at a joint therebetween. According to one embodiment, the carrier 400 and the central through-bore 548 of the fourth sprocket 408 may be sized to form a transition fit or a sliding fit.According to one embodiment, the carrier 400 and the central through-bore 548 of the fourth sprocket 408 may be sized to form a clearance fit. Return to . Fig. 5: According to one embodiment, the end surface 514 of the carrier 400 pointing in the tapering direction (T) serves as the fourth carrier working surface 1004. The Fig. The friction stir welding tool 700 shown in Figure 7 is operable to form a weld joint between the fourth sprocket 408 and the carrier 400 to couple the fourth sprocket 408 and the carrier 400 together.

[0025] Fig. 11 is a schematic perspective view showing how the exemplary first sprocket assembly 300 is attached to the exemplary second sprocket assembly 302. For example, the exemplary second sprocket assembly 302 includes a plurality of connecting pins 1100 extending from the smallest of the sprockets. An end surface of the first sprocket 402 of the exemplary first sprocket assembly 300 that is opposite the fourth sprocket 408 may be formed with a plurality of connecting holes (not shown) that correspond positionally to the connecting pins 1100 of the second sprocket assembly 302, respectively.The first sprocket assembly 300 is moved toward the second sprocket assembly 302 such that the connecting pins 1100 are respectively inserted into the connecting holes of the first sprocket assembly 300 and that the first sprocket assembly 300 and the second sprocket assembly 302 are coupled to each other to form a sprocket assembly.

[0026] In summary, solid-state welding allows multiple sprockets to be assembled in a relatively short time and at a relatively low cost. Furthermore, the material(s) of the carrier and sprockets can be carefully selected, allowing various properties of the sprocket assembly, such as weight, structural strength, thermal conductivity, etc., to be optimized.

[0027] Fig. 12 illustrates another exemplary sprocket assembly. The illustrated sprocket assembly 1200 includes, for example, a carrier 1202 and a sprocket 1204 coupled to the carrier 1202 by solid-state welding. The exemplary sprocket 1204 has a plurality of teeth 1206 on its outer circumference. The exemplary sprocket assembly 1200 may include a plurality of attachment structures 1208 formed on the carrier 1202 and / or the sprocket 1204 such that the exemplary sprocket assembly 1200 may be coupled to another sprocket(s) or a hub component via the attachment structures 1208 to form a multiple sprocket assembly, as described in Fig. 1 or rear sprocket assembly 120. The solid-state welding process may be, for example, a friction stir welding process. According to one embodiment, the carrier 1202 and the sprocket 1204 are made of the same material, e.g., aluminum, iron, copper, steel, or stainless steel. According to one embodiment, the sprocket 1204 may be made of a different material than the carrier 1202. For example, the carrier 1202 may be made of aluminum and the sprocket 1204 may be made of steel. An aluminum carrier is relatively lightweight and can be easily machined through various surface treatments such as anodizing, polishing, coating, painting, etc. According to further embodiments, the carrier 1202 may be made of aluminum, iron, copper, steel, or stainless steel, and the sprocket 1204 may be made of another material selected from the group consisting of aluminum, iron, copper, steel, and stainless steel.

[0028] As in Fig. 13, is used in the production of the Fig. 12, an inner ring 1300 is inserted into a central through-bore of an outer ring 1302 to form an annular boundary line 1304 at a joint therebetween. According to one embodiment, the inner ring 1300 and the outer ring 1302 may be sized to form a transition fit or a sliding fit. According to one embodiment, the inner ring 1300 and the outer ring 1302 may be sized to form a clearance fit. The Fig. The exemplary friction stir welding tool 700 illustrated in Figure 7 is operable to pierce the inner ring 1300 and the outer ring 1302 and move along the boundary line 1304 to form a weld (not shown) between the inner ring 1300 and the outer ring 1302 such that the inner ring 1300 and the outer ring 1302 are fixedly coupled together. According to one embodiment, the weld may extend across the entire boundary line between the inner ring 1300 and the outer ring 1302. According to one embodiment, the exemplary friction stir welding tool 700 may be operated to form a plurality of welds arranged and spaced apart from one another along the boundary line between the inner ring 1300 and the outer ring 1302. After the inner ring 1300 and the outer ring 1302 have been firmly coupled together, the teeth 1206 and / or the attachment structures 1208 (see Fig. 12), for example, by means of stamping processes. According to further embodiments, the teeth 1206 and / or the attachment structures 1208 may be formed by means of CNC machining or other machining processes. According to the above-mentioned processes, the inner ring 1300 serves as the Fig. 12 illustrated exemplary carrier 1202 and the outer ring 1302 as the one in Fig. 12 sprocket 1204 shown.

[0029] In the production of the Fig.In the exemplary sprocket assembly 1200 shown in Figure 12, the materials of the carrier 1202 and the sprocket 1204 can be carefully selected so that the carrier 1202 is relatively lightweight and the sprocket 1204 has sufficient strength. According to some embodiments, the materials of the carrier 1202 and the sprocket 1204 can be carefully selected with different thermal conductivities so that the sprocket assembly 1200 can have better heat radiation properties.

[0030] The above description includes numerous specific details for explanation in order to provide a thorough understanding of the embodiment(s). However, it will be apparent to one skilled in the art that one or more other embodiments may be practiced without some of these specific details. Further, reference throughout this description to "an embodiment," an embodiment by number, etc., means that a particular feature, structure, or characteristic may be incorporated into the practice of the disclosure. Further, it should be noted that in the description, various features are sometimes grouped into a single embodiment, figure, or description thereof in order to simplify the disclosure and facilitate understanding of various inventive aspects; this does not imply that each of these features must be practiced with the presence of all other features.In other words, if the implementation of one or more features or specific details does not affect the implementation of one or more other features or specific details, the one or more features in any described embodiment may be singled out and implemented alone without the other features or specific details. Furthermore, it should be noted that one or more features or specific details of one embodiment may be used in conjunction with one or more features or specific details of another embodiment in implementing the disclosure.

[0031] Although the disclosure has been described in connection with the exemplary embodiment(s), it should be understood that this disclosure is not limited to the disclosed embodiment(s), but covers various arrangements, which are intended to include, within the broadest sense and scope of all such modifications and equivalent arrangements.

Claims

[1] Sprocket arrangement designed for a bicycle and comprising: a support with a central axis and a plurality of sprockets, each having a different number of teeth and formed with a central through-bore, wherein the carrier extends into the central through-bore of each sprocket such that the sprockets are arranged on an outer circumference of the carrier and along the central axis, wherein at least one of the sprockets is coupled to the carrier via a welded joint formed by a solid-state welding process. [2] The sprocket assembly of claim 1, wherein the carrier has at least one carrier working surface, wherein the at least one of the sprockets has a sprocket working surface flush with the at least one carrier working surface, wherein the welded joint is formed at a junction between the at least one carrier working surface and the sprocket working surface of the at least one of the sprockets. [3] The sprocket assembly of claim 2, wherein the carrier includes at least one carrier positioning structure, wherein the at least one of the sprockets includes a sprocket positioning structure engaging the at least one carrier positioning structure. [4] The sprocket assembly of claim 3, wherein the carrier has the shape of a stepped cone and a plurality of shoulder surfaces spaced apart along the central axis, one of the shoulder surfaces serving as the at least one carrier working surface and another of the shoulder surfaces serving as the at least one carrier positioning structure. [5] A sprocket assembly according to claim 3 or 4, wherein the outer periphery of the carrier has a stepped structure serving as the at least one carrier positioning structure, wherein a surrounding inner surface of the at least one of the sprockets defines the central through-bore of the at least one of the sprockets and has a stepped structure serving as the sprocket positioning structure. [6] Sprocket assembly according to one of claims 2 to 5, wherein the welded joint extends over the entire connection between the at least one support working surface and the sprocket working surface of the at least one of the sprockets. [7] A sprocket assembly according to any one of the preceding claims, wherein the carrier and the central through-bore of at least one of the sprockets are sized to form a transition fit. [8] Sprocket assembly according to one of the preceding claims, wherein the welded joint is formed only from material of the carrier and from material of at least one of the sprockets. [9] A sprocket assembly according to any one of the preceding claims, wherein the carrier and at least one of the sprockets are made of the same material. [10] Sprocket assembly according to one of the preceding claims, wherein the carrier and the at least one of the sprockets are made of different materials. [11] A sprocket assembly according to claim 10, wherein the carrier is made of aluminum and at least one of the sprockets is made of steel. [12] A sprocket assembly according to claim 10, wherein the carrier is made of aluminum, iron, copper, steel or stainless steel and the at least one of the sprockets is made of another of the materials aluminum, iron, copper, steel and stainless steel. [13] Sprocket assembly according to one of the preceding claims, wherein the sprockets are each coupled to the carrier via a plurality of welded joints formed by a solid-state welding process. [14] Sprocket arrangement adapted for a bicycle and comprising: a carrier and at least one sprocket formed with a central through-bore, wherein the carrier extends into the central through-bore of the at least one sprocket such that the at least one sprocket is arranged on an outer circumference of the carrier, wherein the at least one sprocket is coupled to the carrier via a welded joint formed by means of a solid-state welding process. [15] The sprocket assembly of claim 14, wherein the carrier has a carrier working surface, the at least one sprocket having a sprocket working surface flush with the carrier working surface, the weld being formed at a junction between the carrier working surface and the sprocket working surface of the at least one sprocket. [16] The sprocket assembly of claim 15, wherein the carrier includes a carrier positioning structure, wherein the at least one sprocket includes a sprocket positioning structure engaging the carrier positioning structure. [17] The sprocket assembly of claim 16, wherein the outer periphery of the carrier includes a stepped structure serving as a carrier positioning structure, wherein a surrounding inner surface of the at least one sprocket defines the central through-bore of the at least one sprocket and includes a stepped structure serving as a sprocket positioning structure. [18] Sprocket assembly according to one of claims 15 to 17, wherein the welded joint extends over the entire connection between the carrier working surface and the sprocket working surface of the at least one sprocket. [19] A sprocket assembly according to any one of claims 14 to 18, wherein the carrier and the central through-bore of the at least one sprocket are dimensioned to form a transition fit. [20] Sprocket assembly according to one of claims 14 to 19, wherein the welded joint is formed only from material of the carrier and from material of the at least one sprocket. [21] Sprocket assembly according to one of claims 14 to 20, wherein the carrier and the at least one sprocket are made of the same material. [22] Sprocket assembly according to one of claims 14 to 21, wherein the carrier and the at least one sprocket are made of different materials. [23] A sprocket assembly according to claim 22, wherein the carrier is made of aluminum and the at least one sprocket is made of steel. [24] A sprocket assembly according to claim 22, wherein the carrier is made of aluminum, iron, copper, steel or stainless steel and the at least one sprocket is made of another of the materials aluminum, iron, copper, steel and stainless steel. [25] Sprocket assembly according to one of claims 14 to 24, wherein the at least one sprocket has a plurality of teeth, wherein the teeth of the at least one sprocket are formed by means of stamping processes. [26] A sprocket assembly according to any one of claims 14 to 25, wherein the at least one sprocket has a plurality of teeth, the teeth of the at least one sprocket being formed after forming the welded joint between the at least one sprocket and the carrier.

Images