Chain wheel mechanism and bicycle

Abstract

The utility model discloses a chain wheel mechanism and a bicycle, and relates to the technical field of bicycles, the chain wheel mechanism comprises an assembly seat, a middle shaft, a shaft sleeve and a chain wheel, the assembly seat is used for being installed on a bicycle frame, an installation hole is formed in the assembly seat, the middle shaft is rotatably installed in the installation hole, and the shaft sleeve is arranged on the middle shaft in a sleeving mode and can move in the axial direction of the middle shaft; the shaft sleeve and the middle shaft are relatively fixed in the circumferential direction, and the chain wheel is arranged on the shaft sleeve and located outside one axial end of the assembly seat; a receding cavity is formed between the hole wall of the mounting hole and the peripheral wall of the middle shaft, and the shaft sleeve extends into the receding cavity. According to the chain wheel mechanism and the bicycle, the riding efficiency of a user can be improved, the situations of chain falling after returning, asymmetric abrasion of the tooth part, tooth part deformation and the like can be reduced, and therefore the riding experience of the user can be improved, and the service life of the bicycle is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of bicycle technology, and in particular to a chainring mechanism and a bicycle. Background Technology

[0002] In recent years, multi-speed bicycles have developed rapidly. Currently, when riding multi-speed bicycles, it has been found that some multi-speed bicycles experience changes in the angle between the chain and the chainring, and between the chain and the freewheel, due to the different levels of chain winding around the freewheel. This causes the chain to experience a slant pull, resulting in axial separation of the chain's driving force. Consequently, the chain cannot be used to maximize the rotation of the freewheel, affecting the rider's riding efficiency. In addition, it can also lead to uneven shifting, chain slippage, asymmetrical wear of the teeth, and tooth deformation. This not only affects the rider's riding experience but also reduces the lifespan of the bicycle. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a chainring mechanism that not only improves the user's riding efficiency but also reduces chain slippage, asymmetrical wear of the teeth, and tooth deformation, thereby improving the user's riding experience and extending the bicycle's lifespan.

[0004] This utility model also proposes a bicycle having the above-mentioned chainring mechanism.

[0005] According to a first aspect of the present invention, a crank mechanism includes an assembly base, a bottom bracket, a bushing, and a crank chain. The assembly base is used for mounting on a vehicle frame and has a mounting hole. The bottom bracket is rotatably mounted in the mounting hole. The bushing is sleeved on the bottom bracket and can move axially along the bottom bracket. The bushing and the bottom bracket are relatively fixed in the circumferential direction. The crank chain is disposed on the bushing and located outside one axial end of the assembly base. A clearance cavity is formed between the wall of the mounting hole and the outer peripheral wall of the bottom bracket, and the clearance cavity allows the bushing to extend into it.

[0006] The toothed disc mechanism according to the embodiments of the present utility model has at least the following beneficial effects:

[0007] In this invention, a movable bushing is installed on the bottom bracket, and a chainring is mounted on the bushing. When the bicycle freewheel shifts gears, the bushing moves axially along the bottom bracket, causing the chainring to move axially as well. This allows the chainring to adapt its position to the gear changes, effectively reducing the angles between the chain and chainring, and between the chain and freewheel, thus improving riding efficiency. Furthermore, the smaller angles allow for a wider engagement range between the chain and the chainring or freewheel teeth, reducing chain slippage, asymmetrical wear, and axial stress on the teeth, thus minimizing tooth deformation and extending service life. Furthermore, compared to bushings that can only move back and forth at one end of the assembly seat, in this application, a clearance cavity is formed between the wall of the mounting hole and the outer peripheral wall of the bottom bracket. The bushing can extend into the clearance cavity, which not only makes the movement path of the bushing longer, thus making the adjustment range of the chainring along the bottom bracket axis larger, but also allows the bushing to extend further along the bottom bracket axis, thereby making the bushing structure stronger and the installation stability of the bushing better, reducing chainring wobble, and thus further improving the riding experience.

[0008] According to some embodiments of the present invention, when the bushing is moved to any position, the end of the bushing away from the toothed disc is always located in the relief cavity.

[0009] According to some embodiments of the present invention, the crank mechanism further includes a first bearing and a second bearing. The first bearing is installed at the end of the mounting hole away from the crank, and the second bearing is installed at the end of the mounting hole close to the crank. The central shaft is rotatably installed in the first bearing and the second bearing.

[0010] According to some embodiments of the present invention, the second bearing is configured as a needle roller bearing and is sleeved on the outside of the bushing, and the bushing can move relative to the second bearing along the axial direction of the central shaft.

[0011] According to some embodiments of the present invention, the outer peripheral wall of the central shaft is provided with a limiting protrusion, the limiting protrusion abuts against the side of the first bearing near the crankset, and the outer peripheral wall of the central shaft is provided with a detachable axial locking structure, the axial locking structure abuts against the side of the first bearing away from the crankset.

[0012] According to some embodiments of the present invention, the length of the bushing along its own axial direction is 1.2 to 3 times the travel of the bushing.

[0013] According to some embodiments of the present invention, the gear chain mechanism further includes a drive mechanism, which is disposed on the central shaft or the assembly base, for driving the bushing to move axially along the central shaft.

[0014] According to some embodiments of the present invention, the driving mechanism includes a lead screw, a connecting member, and a driving unit. The lead screw is rotatably mounted on the central shaft or the assembly seat and extends axially along the central shaft. The connecting member has a threaded hole and is threadedly connected to the lead screw through the threaded hole. The connecting member is connected to the bushing and / or the gear plate. The driving unit is connected to the lead screw and is used to drive the lead screw to rotate, thereby causing the connecting member to move axially along the central shaft, so that the bushing moves axially along the central shaft.

[0015] According to some embodiments of the present invention, the central shaft is provided with a mounting cavity, the driving mechanism is installed in the mounting cavity, the outer peripheral wall of the central shaft is provided with a relief groove communicating with the mounting cavity, the relief groove extends along the axial direction of the central shaft, and the connecting member passes through the relief groove.

[0016] The bicycle according to a second aspect embodiment of the present invention includes the chainring mechanism described in the first aspect embodiment above.

[0017] The bicycle according to the embodiments of this utility model has at least the following beneficial effects:

[0018] The chainring mechanism of the first aspect of this utility model not only improves the cycling efficiency of cyclists but also reduces chain slippage, asymmetrical wear of the teeth, and tooth deformation, thereby enhancing the cycling experience and extending the lifespan of the bicycle. Furthermore, compared to bushings that can only move back and forth at one end of the assembly seat, in this application, a clearance cavity is formed between the wall of the mounting hole and the outer peripheral wall of the bottom bracket. The bushing can extend into this clearance cavity, which not only lengthens the bushing's movement path, thus increasing the chainring's axial adjustment range along the bottom bracket, but also allows the bushing to extend further along the bottom bracket's axial direction. This results in higher bushing structural strength and better installation stability, reducing chainring wobble and further improving the cycling experience.

[0019] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and some of these additional aspects and advantages will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0021] Figure 1 This is a schematic diagram illustrating the connection between a traditional chainring and a freewheel.

[0022] Figure 2 This is a schematic diagram illustrating the fit between the chainring and the freewheel of this utility model.

[0023] Figure 3 This is a schematic diagram of the overall structure of the toothed disc mechanism of this utility model;

[0024] Figure 4 This is a partial sectional view of the toothed disc mechanism of this utility model.

[0025] Icon labels:

[0026] Central shaft 100; mounting cavity 101; clearance groove 102; limiting protrusion 103;

[0027] Bushing 200;

[0028] Crankset 300;

[0029] Drive mechanism 400; lead screw 401; connector 402; drive unit 403; power supply 404; reducer 405; electronic control module 406;

[0030] First bearing 500; axial locking structure 501; first locking plug 502; first sealing ring 503;

[0031] Second bearing 600; Second locking plug 601; Second sealing ring 602;

[0032] Assembly base 700; mounting hole 701; clearance cavity 702;

[0033] Frame 800;

[0034] Crankshaft connecting shaft 900;

[0035] Flywheel 1000. Detailed Implementation

[0036] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0037] In the description of this utility model, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0038] In the description of this utility model, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features or their sequential relationship.

[0039] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0040] To better describe the chainring mechanism and bicycle of the embodiments of this application, a brief description is given here of the change in the 300° angle between the chain and the chainring during the conventional bicycle gear shifting process. (Reference) Figure 1 When the chain is in the highest gear (1000) on the cassette, there is a large angle θ between the chain and the chainring 300. Because of this angle θ, a significant axial component of the chain's driving force cannot be used to drive the cassette 1000, resulting in energy waste. Understandably, the larger the angle θ, the more energy is wasted. This embodiment reduces energy waste by decreasing the angle θ, thereby improving riding efficiency. (Reference) Figure 2 , Figure 2 The dashed rectangle can be understood as the position of the crankset 300 before it moves, and the solid rectangle can be understood as the position of the crankset 300 after it moves. The included angle after the movement is β, which is significantly smaller than the angle θ, thus effectively reducing the axial force component.

[0041] The following is for reference. Figure 3 and Figure 4 This invention describes a chainring mechanism and a bicycle according to an embodiment of the present invention.

[0042] like Figure 3 and Figure 4 As shown, the crank mechanism according to the first aspect of the present invention includes an assembly seat 700, a central shaft 100, a bushing 200, and a crank 300.

[0043] The assembly seat 700 is used to mount the frame 800. The assembly seat 700 is provided with a mounting hole 701. The bottom shaft 100 is rotatably mounted in the mounting hole 701. The bushing 200 is sleeved on the bottom shaft 100 and can move along the axial direction of the bottom shaft 100. The bushing 200 and the bottom shaft 100 are relatively fixed in the circumferential direction. The chain 300 is provided on the bushing 200 and is located outside one end of the axial direction of the assembly seat 700. A relief cavity 702 is formed between the hole wall of the mounting hole 701 and the outer peripheral wall of the bottom shaft 100, and the relief cavity 702 allows the bushing 200 to extend into it.

[0044] For example, the assembly base 700 can be detachably mounted on the frame 800. By placing the bottom bracket 100 in the assembly base 700, the entire crankset mechanism can be configured as a single assembly. This allows for quick installation and replacement of the entire crankset mechanism through the assembly base 700, providing a better user experience. The assembly base 700 has horizontally extending mounting holes 701, with both ends of the mounting holes 701 penetrating through.

[0045] The bottom bracket 100 can be mounted in the mounting hole 701 via a bearing system, allowing the bottom bracket 100 to rotate. A clearance cavity 702 is formed between the wall of the mounting hole 701 and the outer peripheral wall of the bottom bracket 100. In addition, both ends of the bottom bracket 100 can extend beyond both ends of the assembly seat 700 and can be respectively provided with crank connecting shafts 900 for connecting cranks. The cranks are used to mount pedals, and the bicycle user rotates the cranks by pedaling, thereby driving the bottom bracket 100 to rotate.

[0046] The bushing 200 is fitted onto the outer side of the central shaft 100 and can move axially along the central shaft 100. After the chainring 300 is fixed on the bushing 200, the chainring 300 can move axially along the central shaft 100, thereby adjusting the relative position of the chainring 300 and the central shaft 100. The bushing 200 and the central shaft 100 are relatively fixed in the circumferential direction so that when the central shaft 100 rotates, it can drive the bushing 200 to rotate, thereby driving the chainring 300 to rotate. The chainring 300 is located outside one axial end of the assembly seat 700 to avoid interference between the chainring 300 and the assembly seat 700.

[0047] The bushing 200 can be moved axially along the central shaft 100 to any position, with a portion of its structure extending into the relief cavity 702; alternatively, when the bushing 200 is moved to a partial position closer to the assembly seat 700, a portion of its structure extends into the relief cavity 702, and when the bushing 200 is moved to a partial position further away from the assembly seat 700, the entire bushing 200 is located outside one end of the assembly seat 700. The specific length of the bushing 200 can be flexibly adjusted according to actual needs, and will not be elaborated further here.

[0048] In this invention, a movable bushing 200 is provided on the bottom bracket 100, and a chainring 300 is provided on the bushing 200. When the bicycle freewheel 1000 changes gears, the bushing 200 can move axially along the bottom bracket 100, thereby causing the chainring 300 to move axially along the bottom bracket 100. This allows the chainring 300 to adaptively adjust its position according to the changes in bicycle gears, effectively reducing the angles between the chain and the chainring 300, and between the chain and the freewheel 1000, thus improving the cyclist's riding efficiency. Furthermore, because the angles are smaller, the meshing range between the chain and the chainring or freewheel teeth is wider, reducing chain slippage, asymmetrical wear of the teeth, and axial stress on the teeth, which helps reduce tooth deformation and extends service life. Furthermore, compared to the bushing 200, which can only move back and forth outside one end of the assembly seat 700, in this application, a relief cavity 702 is formed between the hole wall of the mounting hole 701 and the outer peripheral wall of the bottom bracket 100. The bushing 200 can extend into the relief cavity 702, which not only makes the movement path of the bushing 200 longer, thus making the adjustment range of the chainring 300 along the axial direction of the bottom bracket 100 larger, but also allows the bushing 200 to extend further along the axial direction of the bottom bracket 100, thereby making the structure of the bushing 200 stronger. At the same time, the installation stability of the bushing 200 is better, which can reduce the shaking of the chainring 300, thereby further improving the riding experience.

[0049] Understandably, if the bushing 200 can only move back and forth outside one end of the assembly seat 700, not only is the movement path of the bushing 200 short, but also, since the distance between the end of the bottom bracket 100 and the assembly seat 700 is fixed, in order for the bushing 200 to move a certain displacement along the axial direction of the bottom bracket 100, the length of the bushing 200 can only be set to be short. Thus, not only is the structural strength low, but the stability is also poor, and the chainring 300 is prone to shaking, affecting the riding experience. In this application, a relief cavity 702 for the bushing 200 to extend into is formed between the hole wall of the mounting hole 701 and the outer peripheral wall of the bottom bracket 100, which can effectively solve the above problems.

[0050] It should be noted that the chainring 300 can stop at multiple gears when it moves along the axial direction of the central axis 100, for example, it can be three. The gears of the chainring 300 on both sides can correspond to multiple gears on both sides of the freewheel 1000, and the gears of the chainring 300 in the middle can correspond to multiple gears in the middle of the freewheel 1000.

[0051] In some embodiments of this utility model, such as Figure 4 As shown, the toothed disc 300 can be installed on the end of the bushing 200 away from the assembly seat 700. When the bushing 200 moves to any position along the axial direction of the central shaft 100, the end of the bushing 200 away from the toothed disc 300 is always located in the relief cavity 702.

[0052] In this embodiment, this configuration not only makes the bushing 200 extend longer along the axial direction of the central shaft 100, thus making the bushing 200 structurally stronger, but also improves the installation stability of the bushing 200, reducing the shaking of the chainring 300 and further improving the riding experience. In addition, it can also avoid interference between the bushing 200 and the assembly seat 700 when the bushing 200 enters the clearance cavity 702, thus making the movement of the bushing 200 smoother.

[0053] In some embodiments of this utility model, such as Figure 4 As shown, the crank mechanism also includes a first bearing 500 and a second bearing 600. The first bearing 500 is installed in the end of the mounting hole 701 away from the crank 300, and the second bearing 600 is installed in the end of the mounting hole 701 close to the crank 300. The central shaft 100 is installed in the first bearing 500 and the second bearing 600.

[0054] In this embodiment, the rotation setting of the central shaft 100 can be achieved by using the first bearing 500 and the second bearing 600, which satisfies the rotation requirements of the central shaft 100 and makes the rotation of the central shaft 100 smoother.

[0055] In some embodiments of this utility model, such as Figure 4 As shown, a limiting protrusion 103 is provided on the outer peripheral wall of the central shaft 100, on the side of the first bearing 500 near the bushing 200, to provide a directional restriction. Simultaneously, an axial locking structure 501 is provided on the outer peripheral wall of the central shaft 100, on the side of the first bearing 500 away from the bushing 200, thereby restricting the first bearing 500 in another direction and also restricting the axial movement of the central shaft 100. For example, the axial locking structure 501 can be an axial locking nut, and the outer peripheral wall of the end of the central shaft 100 away from the bushing 200 can be provided with external threads, with the axial locking nut threadedly connected to the central shaft 100. Alternatively, the axial locking structure 501 can be a locking ring, and the outer peripheral wall of the end of the central shaft 100 away from the bushing 200 can be provided with a retaining ring, with the axial lock engaged within the retaining ring.

[0056] In some embodiments of this utility model, such as Figure 4 As shown, on the assembly seat 700 or the frame 800, a first locking plug 502 is provided on the side of the first bearing 500 away from the bushing 200. The first locking plug 502 is located on the outer periphery of the axial locking structure 501 to fix the first bearing 500. On the assembly seat 700 or the frame 800, a second locking plug 601 can be provided on the side of the second bearing 600 away from the first bearing 500. The second locking plug 601 can be located on the outer side of the bushing 200 to fix the second bearing 600.

[0057] It should be noted that when there is a gap between the first locking screw plug 502 and the axial locking structure 501, a first sealing ring 503 can be provided between the first locking screw plug 502 and the axial locking structure 501. When there is a gap between the second locking screw plug 601 and the bushing 200, a second sealing ring 602 can be provided between the second locking screw plug 601 and the bushing 200.

[0058] In some embodiments of this utility model, the first bearing 500 can be a ball bearing. In this embodiment, the ball bearing's strong axial bearing capacity can better withstand the axial force when the crankset 300 moves, and the ball bearing can better fix the central shaft 100.

[0059] It should be noted that the first bearing 500 can also be other suitable types of bearings, which will not be elaborated here.

[0060] In some embodiments of this utility model, such as Figure 4 As shown, the second bearing 600 is configured as a needle roller bearing and is sleeved on the outside of the bushing 200. The bushing 200 can move relative to the second bearing 600 along the axial direction of the central shaft 100. For example, the second bearing 600 can be a needle roller bearing without an inner ring, and the end of the bushing 200 away from the gear sprocket 300 can extend into the second bearing 600 as the inner ring of the second bearing 600.

[0061] In this embodiment, the bushing 200 extends into the second bearing 600 and can rotate relative to the second bearing 600, thereby reducing the circumferential friction force on the outer peripheral wall of the bushing 200, making the rotation of the bushing 200 smoother, and thus improving riding efficiency. In addition, since the second bearing 600 is set as a needle roller bearing, the bushing 200 can move axially relative to the second bearing 600 along the central shaft 100, thereby reducing the axial friction force on the outer peripheral wall of the bushing 200, making the axial movement of the bushing 200 along the central shaft 100 smoother, and the shifting of the chainring 300 smoother. Furthermore, the bushing 200 can also support the second bearing 600, making the installation of the second bearing 600 more stable.

[0062] It should be noted that the second bearing 600 can also be other suitable types of bearings, which will not be elaborated here.

[0063] In some embodiments of this utility model, such as Figure 4As shown, the length of the bushing 200 along its own axial direction is 1.2 to 3 times the travel of the bushing 200. For example, the length of the bushing 200 along its own axial direction can be 1.2, 2, 2.5, 3 times, or other suitable multiples of the travel of the bushing 200. This not only avoids the bushing 200 being too long, resulting in a too low travel of the bushing 200 and thus affecting the shifting effect of the gear sprocket 300, but also avoids the bushing 200 being too short, resulting in a decrease in structural strength and unstable installation.

[0064] In some embodiments of this utility model, such as Figure 4 As shown, the chainring mechanism also includes a drive mechanism 400, which is located on the central shaft 100 or the assembly seat 700 for driving the bushing 200 to move axially along the central shaft 100.

[0065] For example, when the bicycle's freewheel 1000 changes gears, the drive mechanism 400 can drive the bushing 200 to move, thereby adjusting the relative position of the chainring 300 and the bottom bracket 100, and consequently the relative position between the chainring 300 and the freewheel 1000, thus adjusting the angle between the chain and the chainring 300. The drive mechanism 400 can be located inside or outside the bottom bracket 100, for example, on the assembly mount 700. The specific location can be flexibly adjusted according to actual needs, as long as it enables the movement of the bushing 200.

[0066] Compared to the cassette 1000 where the chain drives the chainring 300 to move during gear shifting, this application uses a drive mechanism 400 to actively drive the chainring 300. The chainring 300 moves more smoothly and precisely, reducing the occurrence of jamming. Moreover, after moving to the corresponding position, the bushing 200 will not move passively due to the chain pull, thus improving riding stability.

[0067] It is understood that the aforementioned drive mechanism 400 can be either a mechanical or an electric drive mechanism. When configured as a mechanical drive mechanism, it can be connected to an external manual operating device, allowing for direct manual control of its operation. The specific position of the drive bushing 200 can be adjusted by the user based on their riding experience. When configured as an electric drive mechanism, it can also be connected to an external manual operating device. Furthermore, an electronic control module 406 can be installed within the drive mechanism 400 to automatically adjust the position of the bushing 200, ensuring that the chainring 300 and the freewheel 1000 are always in an optimal relative position.

[0068] It should be noted that in some other embodiments of this utility model, the drive mechanism 400 may not be provided, and the chain directly drives the bushing 200 to move when the flywheel 1000 shifts gears.

[0069] In some embodiments of this utility model, such as Figure 4 As shown, the drive mechanism 400 includes a lead screw 401, a connecting member 402, and a drive unit 403. The lead screw 401 is rotatably mounted on the central shaft 100 or the assembly seat 700 and extends along the axial direction of the central shaft 100. The connecting member 402 is provided with a threaded hole and is threadedly connected to the lead screw 401 through the threaded hole. The connecting member 402 is connected to the bushing 200. The drive unit 403 is connected to the lead screw 401 and is used to drive the lead screw 401 to rotate, thereby causing the connecting member 402 to move along the axial direction of the central shaft 100, so that the bushing 200 moves along the axial direction of the central shaft 100.

[0070] For example, the lead screw 401 can be installed inside or outside the central shaft 100, such as on the assembly seat 700. The connector 402 can be a nut or other structure with a threaded hole. The connector 402 achieves a threaded connection with the lead screw 401 through the engagement of the internal thread of the threaded hole with the external thread of the lead screw 401.

[0071] The drive unit 403 can be of various types, such as a servo motor. When the drive unit 403 is a servo motor, a power supply 404, a reducer 405, and an electronic control module 406 can be installed inside the central shaft 100. The power supply 404 supplies power to the drive unit 403, the reducer 405 is installed between the drive unit 403 and the lead screw 401, and the electronic control module 406 performs real-time control. Alternatively, when the lead screw 401 is rotatably mounted on the assembly 700, the drive unit 403 can also have other structures. For example, it can be a clutch located between the lead screw 401 and the central shaft 100. When the movement of the drive sleeve 200 is not required, the clutch disengages the lead screw 401 from the central shaft 100. When the movement of the drive sleeve 200 is required, the clutch engages the lead screw 401 with the central shaft 100. When the central shaft 100 rotates, the lead screw 401 rotates synchronously, thereby driving the sleeve 200 to move.

[0072] In this embodiment, operating the drive unit 403 controls the rotation of the lead screw 401. The lead screw 401, through its threaded engagement with the connecting member 402, drives the connecting member 402 to move axially along the central shaft 100. The connecting member 402 then drives the bushing 200 to move axially along the central shaft 100, thereby adjusting the position of the bushing 200 and achieving the purpose of adjusting the relative position of the chainring 300 and the freewheel 1000. The operation is simple and convenient. Furthermore, this drive method allows for precise control of the bushing 200's movement and also restricts its movement, preventing passive movement under chain traction and improving riding stability.

[0073] It should be noted that the drive mechanism 400 can also be other structures, such as an electric push rod, which controls the movement of the bushing 200 by extending and retracting the electric push rod.

[0074] In some embodiments of this utility model, such as Figure 4 As shown, the central shaft 100 is provided with a mounting cavity 101, the drive mechanism 400 is installed in the mounting cavity 101, the outer peripheral wall of the central shaft 100 is provided with a relief groove 102 that communicates with the mounting cavity 101, the relief groove 102 extends along the axial direction of the central shaft 100, and the connecting piece 402 passes through the relief groove 102.

[0075] For example, the mounting cavity 101 can extend along the axial direction of the central shaft 100. When the drive unit 403 is a servo motor, the mounting cavity 101 can be divided into two parts, including a first chamber and a second chamber. The first chamber can be located away from the crank sprocket 300, and the second chamber can be located close to the crank sprocket 300. The first chamber can house the servo motor, reducer 405, power supply 404, and electronic control module 406, etc., and the second chamber can house the lead screw 401 and connector 402.

[0076] A clearance groove 102 is provided on the outer peripheral wall of the central shaft 100 near the bushing 200. The clearance groove 102 is connected to the mounting cavity 101. The clearance groove 102 can be elongated, with its length direction aligned with the axial direction of the central shaft 100, so that the connecting piece 402 can be connected to the bushing 200. It can also guide the connecting piece 402, allowing it to slide along the axial direction of the central shaft 100. Furthermore, the clearance groove 102 effectively prevents relative rotation between the bushing 200 and the central shaft 100.

[0077] Multiple clearance grooves 102 can be formed on the outer peripheral wall of the central shaft 100 near the bushing 200. Providing multiple clearance grooves 102 can increase the connection stability between the connector 402 and the bushing 200. For example... Figure 4 As shown, the central shaft 100 has two relief grooves 102, and the upper and lower parts of the inner wall of the bushing 200 are connected to the connector 402 through the relief grooves 102.

[0078] In this embodiment, the mounting cavity 101 not only protects the drive mechanism 400 from being exposed and damaged, but also makes the drive mechanism 400 closer to the axis of the central shaft 100, resulting in less centrifugal force and less resistance to the rotation of the central shaft 100, making the rotation of the central shaft 100 smoother and further improving the riding efficiency of the bicycle user.

[0079] In some embodiments of this utility model, such as Figure 4As shown, the lead screw 401 is coaxial with the bottom bracket 100. That is, the center line of the lead screw 401 coincides with the center line of the bottom bracket 100. This makes the centrifugal force generated when the bottom bracket 100 rotates smaller, thus reducing the resistance to the rotation of the bottom bracket 100, making the rotation of the bottom bracket 100 smoother, and further improving the riding efficiency of the cyclist.

[0080] In some embodiments of this utility model, such as Figure 4 As shown, a key structure is installed between the central shaft 100 and the bushing 200, and the key structure restricts the relative rotation of the central shaft 100 and the bushing 200. For example, both the outer peripheral wall of the central shaft 100 and the inner peripheral wall of the bushing 200 may be provided with keyways, the keyways extending along the axial direction of the central shaft 100, and the key structure is installed in both keyways and can slide relative to the keyways along the axial direction of the central shaft 100. Alternatively, one of the outer peripheral wall of the central shaft 100 and the inner peripheral wall of the bushing 200 may be provided with a keyway, the keyway extending along the axial direction of the central shaft 100, and the key structure is installed in the other and extends into the keyway, the key structure being able to slide relative to the keyway along the axial direction of the central shaft 100.

[0081] In this embodiment, the key structure can restrict the relative rotation between the central shaft 100 and the bushing 200, thereby enabling the central shaft 100 to drive the toothed disc 300 on the bushing 200 to rotate.

[0082] The bicycle according to a second aspect embodiment of the present invention includes the chainring mechanism described in the first aspect embodiment.

[0083] The bicycle according to the embodiments of the present invention, by adopting the chainring mechanism of the first aspect of the present invention, can not only improve the riding efficiency of the cyclist, but also reduce issues such as chain slippage, asymmetrical wear of the teeth, and tooth deformation, thereby improving the riding experience and extending the service life of the bicycle. Furthermore, compared to the bushing 200, which can only move back and forth outside one end of the assembly seat 700, in this application, a clearance cavity 702 is formed between the wall of the mounting hole 701 and the outer peripheral wall of the bottom bracket 100. The bushing 200 can extend into the clearance cavity 702, which not only makes the movement path of the bushing 200 longer, thus allowing for a larger adjustment range of the chainring 300 along the axial direction of the bottom bracket 100, but also allows the bushing 200 to extend further along the axial direction of the bottom bracket 100, resulting in higher structural strength and better installation stability of the bushing 200, reducing chainring wobbling and further improving the riding experience.

[0084] It should be noted that since the bicycle can adopt all the technical solutions of the chainring mechanism of the first aspect embodiment, it has at least all the beneficial effects brought about by the technical solutions of the first aspect embodiment. These additional beneficial effects will not be elaborated here.

[0085] It is understood that other components and operations of the bicycle according to the embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0086] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A toothed disc mechanism, characterized in that, include: Assembly mount, for mounting to the vehicle frame, the assembly mount having mounting holes; The central shaft is rotatably mounted in the mounting hole; A bushing is fitted onto the central shaft and can move along the axial direction of the central shaft; the bushing and the central shaft are relatively fixed in the circumferential direction. The toothed plate is mounted on the bushing and located outside one end of the assembly seat in the axial direction; A clearance cavity is formed between the wall of the mounting hole and the outer peripheral wall of the central shaft, and the clearance cavity allows the bushing to extend into it.

2. The toothed disc mechanism according to claim 1, characterized in that, When the bushing moves to any position, the end of the bushing away from the toothed disc is always located in the clearance cavity.

3. The toothed disc mechanism according to claim 1, characterized in that, The toothed disc mechanism also includes: A first bearing is installed at the end of the mounting hole away from the toothed disc; The second bearing is installed at one end of the mounting hole near the toothed disc; The central shaft is rotatably mounted within the first bearing and the second bearing.

4. The toothed disc mechanism according to claim 3, characterized in that, The second bearing is configured as a needle roller bearing and is sleeved on the outside of the bushing, and the bushing can move relative to the second bearing along the axial direction of the central shaft.

5. The toothed disc mechanism according to claim 3, characterized in that, The outer peripheral wall of the central shaft is provided with a limiting protrusion, which abuts against the side of the first bearing near the crankcase. The outer peripheral wall of the central shaft is provided with a detachable axial locking structure, which abuts against the side of the first bearing away from the crankcase.

6. The toothed disc mechanism according to claim 1, characterized in that, The length of the bushing along its own axis is 1.2 to 3 times the travel of the bushing.

7. The toothed disc mechanism according to claim 1, characterized in that, The toothed disc mechanism also includes: A drive mechanism, located on the central shaft or the assembly base, is used to drive the bushing to move axially along the central shaft.

8. The toothed disc mechanism according to claim 7, characterized in that, The drive mechanism includes: A lead screw is rotatably mounted on the central shaft or the assembly base and extends axially along the central shaft; A connector is provided with a threaded hole and is threadedly connected to the lead screw through the threaded hole; the connector is connected to the bushing and / or the gear plate. A drive unit, connected to the lead screw, is used to drive the lead screw to rotate and drive the connecting member to move axially along the central shaft, so that the bushing moves axially along the central shaft.

9. The toothed disc mechanism according to claim 8, characterized in that, The central shaft has a mounting cavity, the drive mechanism is installed in the mounting cavity, the outer peripheral wall of the central shaft has a relief groove that communicates with the mounting cavity, the relief groove extends along the axial direction of the central shaft, and the connector passes through the relief groove.

10. A bicycle, characterized in that, Includes the toothed disc mechanism as described in any one of claims 1 to 9.

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