Bicycle hub assembly

Abstract

The present application relates to the field of bicycle, specifically relates to a bicycle hub assembly, which comprises a middle shaft, a tower base, a hub shell and a ratchet transmission mechanism, the ratchet transmission mechanism comprises a first ratchet ring and a second ratchet ring, the first ratchet ring is coaxially connected with the tower base and is provided with a first main spring, the second ratchet ring is coaxially connected with the hub shell and is provided with a second main spring, the middle shaft is provided with an auxiliary reset mechanism at the position corresponding to the ratchet transmission mechanism, the auxiliary reset mechanism comprises an elastic pressing piece, the first ratchet ring and the second ratchet ring are respectively provided with chamfered surfaces at the inner sides of the distal ends away from each other, and the chamfered surfaces are in abutment with the elastic pressing piece.The present application utilizes the cooperation of the chamfered surfaces at the inner sides of the first ratchet ring and the second ratchet ring and the elastic pressing piece to convert the radial force of the reset spring into axial component force by using the rolling contact of the ball, actively pushes the first ratchet ring and the second ratchet ring to fully engage, avoids slipping, and improves the transmission reliability.

Description

Technical Field

[0001] This invention relates to the field of bicycles, and more specifically to bicycle hub assemblies. Background Technology

[0002] In high-performance bicycle hub assemblies, to improve transmission rigidity and response speed, some designs employ a double-end-face ratchet ring axial engagement structure. Both the freehub base and the hub shell have annular ratchet rings with helical teeth. Under the preload of an axial spring, these two rings engage and transmit torque. When the freehub base is driven, the helical teeth mesh, causing the hub shell to rotate. When the wheel's inertial slippage causes the hub shell to rotate at a higher speed than the freehub base, the high-speed side ratchet pushes the low-speed side along the helical surface, causing axial separation and allowing the hub to idle.

[0003] However, existing technology relies on a single spring to provide axial preload. After long-term use, the spring is prone to fatigue and relaxation, resulting in insufficient clamping force between the two ratchet rings, reduced engagement depth, or even partial engagement. This not only causes slippage in power transmission but also exacerbates wear on the tooth surfaces. Furthermore, during repeated switching between disengagement and engagement, if the reset force is insufficient, the two ratchet rings cannot quickly and completely align and engage, affecting pedaling response.

[0004] Therefore, there is a need for a bicycle hub assembly with reliable engagement and retention capabilities, which can ensure the effectiveness of the reset action even after the main spring has become fatigued due to long-term use, so that the double ratchet ring is fully engaged during each drive and avoids partial engagement and slippage. Summary of the Invention

[0005] To address the problems existing in the prior art, a bicycle hub assembly is provided. Through the cooperation of the inner chamfered surfaces of the first and second ratchet rings with the elastic pressing member, the radial force of the return spring is converted into an axial component force by the rolling contact of the ball bearings. This actively pushes the first and second ratchet rings to fully engage, preventing slippage and improving transmission reliability.

[0006] To address the problems of existing technologies, this invention provides a bicycle hub assembly, including a bottom bracket for fixing to the frame, a freehub body fitted around the bottom bracket and rotatable around it, a hub shell fitted around the bottom bracket and axially adjacent to the freehub body, and a ratchet drive mechanism disposed between the opposite end faces of the freehub body and the hub shell, including a first ratchet ring and a second ratchet ring. The first ratchet ring is coaxially connected to the freehub body and has a first main spring, and the second ratchet ring is coaxially connected to the hub shell and has a second main spring. The first and second ratchet rings are arranged opposite each other and move towards each other under the action of the springs. The first and second ratchet rings are intermeshing, with a plurality of axial locking blocks evenly distributed around their outer peripheries in the circumferential direction. The hub base and hub shell are respectively provided with axial sleeves that cooperate with the axial locking blocks to transmit torque and restrict relative circumferential rotation. The central shaft is provided with an auxiliary reset mechanism at the position corresponding to the ratchet transmission mechanism. The auxiliary reset mechanism includes elastic pressing members arranged radially along the central shaft. The elastic pressing members are evenly distributed around the inner side of the first and second ratchet rings in the circumferential direction. The first and second ratchet rings are respectively provided with chamfered surfaces on the inner side of their opposite ends, and the chamfered surfaces abut against the corresponding elastic pressing members.

[0007] Preferably, the central shaft is fitted with an inner ring at the position of the auxiliary reset mechanism. Each elastic pressing member is provided with a guide sleeve on the inner ring. The elastic pressing member includes a pressing rod that is radially inserted into the guide sleeve and a reset spring. The pressing rod is provided with a pressing head that abuts against the chamfered surface. The reset spring is connected between the pressing head and the guide sleeve.

[0008] Preferably, the pressing head includes a ball-and-socket structure and a ball embedded therein, the ball-and-socket structure being fixedly connected to the pressing rod, and the ball forming rolling contact with the chamfered surface.

[0009] Preferably, the chamfered surface is a continuous annular slope with its height gradually increasing radially inward, used to convert the radial force of the ball into an axial component force that drives the corresponding ratchet ring to engage.

[0010] Preferably, an outer ring coaxial with the inner ring is fixedly provided on the outer periphery of the inner ring, and a magnetic attraction structure is provided between the outer ring and the ball-and-socket structure to provide auxiliary reset force when the pressure head returns to its original position.

[0011] Preferably, the magnetic attraction structure includes a fixed permanent magnet and a movable permanent magnet. The movable permanent magnet is fixedly connected to the ball-and-socket structure. The fixed permanent magnet is fixedly disposed on the outer ring at the position corresponding to the movable permanent magnet. The outer ring has a channel for the movable permanent magnet to move.

[0012] Preferably, the ball-and-socket structure is provided with an mounting groove for mounting a movable permanent magnet, and the mounting groove is in sliding contact with the inner wall of the channel.

[0013] Preferably, the fixed permanent magnet and the pressing head are in a clearance fit.

[0014] Preferably, a gap is left between the fixed permanent magnet and the movable permanent magnet during the full engagement stage of the ratchet ring.

[0015] Preferably, the outer ring is symmetrically fitted with annular washers located on both sides of the ball-and-socket structure, and the annular washers are engaged between the fixed permanent magnet and the movable permanent magnet to form a magnetic suction buffer structure.

[0016] The advantages of this application compared to the prior art are:

[0017] 1. This invention constructs an adaptive auxiliary reset mechanism by setting chamfered surfaces on the inner sides of the first and second ratchet rings and cooperating with the radially arranged elastic pressing members on the central shaft. When the force of the first and second main springs decreases due to long-term use, resulting in insufficient meshing depth of the first and second ratchet rings, the reset spring pushes the pressing head in the elastic pressing member back, so that its end contacts the chamfered surface. The inclined structure converts the radial thrust into an axial component pointing towards the central shaft, thereby actively driving the first and second ratchet rings to re-approach and restore full meshing. This ensures that reliable and complete transmission connection can be achieved in each driving action. Without interfering with the original gliding and idling function, it effectively suppresses transmission slippage caused by spring aging or load fluctuations, and improves the transmission reliability and durability of the hub assembly under high load conditions or after long-term use.

[0018] 2. The present invention sets a ball in the pressure head to form a rolling contact with the chamfered surface inside the first and second ratchet rings. During the process of the return spring pushing the pressure rod back to its original position, the ball rolls smoothly along the slope of the chamfered surface, efficiently and with low resistance converting the radial thrust into an axial component force pointing towards the axis, continuously and actively pushing the first and second ratchet rings toward the fully engaged position, reducing contact friction resistance and wear during long-term operation;

[0019] 3. This invention integrates a magnetic attraction structure into the auxiliary reset mechanism. Utilizing the non-contact magnetic force between the fixed and movable permanent magnets, the magnetic attraction naturally weakens as the distance increases when the first and second ratchet rings disengage, accommodating the separation action. During the reset process, as the distance decreases, the magnetic attraction rapidly increases, actively pulling the pressure head back to its original position and accelerating the engagement response. Without introducing additional friction or mechanical wear, the reset driving force is strengthened, ensuring that the first and second ratchet rings can reliably and promptly complete full engagement each time, thereby effectively improving the response accuracy of the hub assembly. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the bicycle hub assembly of the present invention.

[0021] Figure 2 This is a three-dimensional exploded view of the hub base and hub shell of the bicycle hub assembly of the present invention from a first perspective.

[0022] Figure 3 This is a three-dimensional exploded view of the hub base and hub shell of the bicycle hub assembly of the present invention from a second perspective.

[0023] Figure 4 This is a three-dimensional structural cross-sectional view of the bicycle hub assembly of the present invention.

[0024] Figure 5 This is a planar sectional view of the bicycle hub assembly of the present invention.

[0025] Figure 6 This is a three-dimensional structural diagram of the hub base and ratchet drive mechanism of the bicycle hub assembly of the present invention.

[0026] Figure 7 This is a three-dimensional exploded view of the freehub base and ratchet drive mechanism of the bicycle hub assembly of the present invention from a first perspective.

[0027] Figure 8 This is a three-dimensional exploded view of the freehub base and ratchet drive mechanism of the bicycle hub assembly of the present invention from a second perspective.

[0028] Figure 9 This is a three-dimensional structural cross-sectional view of the first and second ratchet rings and the auxiliary reset mechanism of the bicycle hub assembly of the present invention.

[0029] Figure 10 This is a planar sectional view of the first and second ratchet rings and the auxiliary reset mechanism of the bicycle hub assembly of the present invention.

[0030] Figure 11 This is an exploded three-dimensional structural diagram of the first and second ratchet rings and the auxiliary reset mechanism of the bicycle hub assembly of the present invention.

[0031] Figure 12 This is a three-dimensional structural cross-sectional view of the auxiliary reset mechanism of the bicycle hub assembly of the present invention.

[0032] Figure 13 This is a planar sectional view of the auxiliary reset mechanism of the bicycle hub assembly of the present invention.

[0033] The following components are labeled in the diagram: 1. Central shaft; 2. Base; 21. Axial locking block; 22. Axial sleeve; 3. Hub housing; 4. First ratchet ring; 41. First main spring; 42. Chamfered surface; 5. Second ratchet ring; 51. Second main spring; 6. Auxiliary reset mechanism; 61. Elastic pressing component; 611. Pressing rod; 612. Reset spring; 62. Pressing head; 621. Ball socket structure; 6211. Insert groove; 622. Ball; 63. Magnetic attraction structure; 631. Fixed permanent magnet; 632. Movable permanent magnet; 7. Inner ring; 71. Guide sleeve; 8. Outer ring; 81. Annular washer. Detailed Implementation

[0034] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0035] See Figures 1 to 10 As shown, a bicycle hub assembly includes a bottom bracket 1 for fixing to the frame. A freehub base 2 is fitted around the bottom bracket 1 and can rotate around it. A hub shell 3 is fitted around the bottom bracket 1 and is axially adjacent to the freehub base 2. A ratchet drive mechanism is disposed between the opposite end faces of the freehub base 2 and the hub shell 3, including a first ratchet ring 4 and a second ratchet ring 5. The first ratchet ring 4 is coaxially connected to the freehub base 2 and is provided with a first master spring 41. The second ratchet ring 5 is coaxially connected to the hub shell 3 and is provided with a second master spring 51. The first ratchet ring 4 and the second ratchet ring 5 are arranged opposite each other and mesh with each other under the action of the spring force. A plurality of axial locking blocks 21 are evenly distributed around the outer periphery of the first ratchet ring 4 and the second ratchet ring 5 in the circumferential direction. The freehub base 2 and the hub shell 3 are respectively provided with axial retaining sleeves 22 that cooperate with the axial locking blocks 21, for transmitting torque and restricting relative circumferential rotation. The central shaft 1 is provided with an auxiliary reset mechanism 6 at the position corresponding to the ratchet transmission mechanism. The auxiliary reset mechanism 6 includes elastic pressing members 61 arranged radially along the central shaft 1. The elastic pressing members 61 are evenly distributed circumferentially on the inner sides of the first ratchet ring 4 and the second ratchet ring 5. The first ratchet ring 4 and the second ratchet ring 5 are respectively provided with chamfered surfaces 42 on the inner sides of their opposite ends. The chamfered surfaces 42 abut against the corresponding elastic pressing members 61.

[0036] The axial locking block 21 is a trapezoidal boss that protrudes radially along the outer periphery of the ratchet ring, and the axial retaining sleeve 22 is an axial limiting groove corresponding to the end face of the base 2 and the hub shell 3.

[0037] During the assembly and operation of the bicycle hub assembly, the bottom bracket 1 is first fixed between the frame and the rear fork, serving as the static support core of the entire drivetrain. The freehub base 2 and the hub housing 3 are respectively sleeved on the outer periphery of the bottom bracket 1 via bearings. The two can rotate independently around the bottom bracket 1 and are arranged adjacent to each other along the axial direction, forming a compact end face fit structure.

[0038] Next, a ratchet drive mechanism is installed between the opposite end faces of the freehub base 2 and the hub shell 3. First, the first ratchet ring 4 is installed into the end face of the freehub base 2, so that several trapezoidal axial locking blocks 21 on its outer periphery are embedded in the pre-machined axial limiting grooves on the end face of the freehub base 2, achieving circumferential locking while allowing for slight axial movement. Similarly, the second ratchet ring 5 is installed into the end face of the hub shell 3, and its outer trapezoidal axial locking blocks 21 are also correspondingly embedded in the axial limiting grooves of the hub shell 3, completing the circumferential force transmission engagement.

[0039] Subsequently, a first main spring 41 is installed on the side of the first ratchet ring 4 away from the meshing surface, with one end abutting against the first ratchet ring 4 and the other end abutting against the inner step of the hub base 2. Similarly, a second main spring 51 is installed on the back side of the second ratchet ring 5, with one end abutting against the second ratchet ring 5 and the other end abutting against the inner wall of the hub housing 3. The two main springs are pre-compressed, continuously applying an axial force towards each other, pushing the first ratchet ring 4 and the second ratchet ring 5 to engage with each other, so that the helical teeth on their end faces are fully engaged, forming a transmission pair capable of transmitting torque.

[0040] When the rider pedals the chain, driving the freehub 2 to rotate forward, the freehub 2 drives the first ratchet ring 4 to rotate synchronously via the axial locking block 21. The helical tooth surface of the first ratchet ring 4 pushes against the corresponding tooth surface of the second ratchet ring 5, transmitting torque to the wheel through the second ratchet ring 5 and the hub housing 3, thus achieving drive. At this time, the two ratchet rings remain tightly engaged under the pressure of the main spring, with no relative slippage.

[0041] When pedaling stops and the vehicle enters a gliding state, the wheel inertia causes the hub housing 3 to rotate at a higher speed than the freehub 2, and the second ratchet 5 to rotate at a higher speed than the first ratchet 4. The helical tooth surface on the high-speed side slides along the tooth surface on the low-speed side, generating an axial separation force that overcomes the pressure of the main spring, causing the two ratchet sprockets to briefly disengage and achieve freewheeling. The freehub 2 is no longer dragged backward.

[0042] During this repeated engagement and disengagement process, if the main spring becomes fatigued due to long-term use and the preload weakens, the first ratchet ring 4 and the second ratchet ring 5 may not engage properly. In this case, since the first ratchet ring 4 and the second ratchet ring 5 are respectively provided with chamfered surfaces 42 on the inner side of their opposite ends, and the central shaft 1 is provided with elastic pressing members 61 arranged radially and evenly distributed circumferentially at the corresponding positions, these elastic pressing members 61 always remain in contact with the chamfered surfaces 42.

[0043] When the axial clearance of the ratchet ring increases due to insufficient spring force, the interaction between the chamfered surface 42 and the elastic pressing member 61 converts the radial support force of the elastic pressing member 61 into an axial component force pointing towards the center. This actively pushes the first ratchet ring 4 and the second ratchet ring 5 to re-engage, assisting in restoring the full engagement depth and ensuring reliable transmission. The entire process requires no external intervention, relying on structural self-adaptation to complete power transmission and reset assurance.

[0044] See Figure 2 , Figure 4 , Figure 5 and Figures 9 to 13 As shown, the central shaft 1 is fitted with an inner ring 7 at the position of the auxiliary reset mechanism 6. Each elastic pressing member 61 is provided with a guide sleeve 71 on the inner ring 7. The elastic pressing member 61 includes a pressing rod 611 that is radially inserted into the guide sleeve 71 and a reset spring 612. The pressing rod 611 is provided with a pressing head 62 that abuts against the chamfered surface 42. The reset spring 612 is connected between the pressing head 62 and the guide sleeve 71.

[0045] When the first ratchet ring 4 and the second ratchet ring 5 disengage during rotation, the chamfered surface 42 on their inner side moves outward, pushing the pressing head 62 to overcome the elastic force of the return spring 612, causing the pressing rod 611 to slide radially outward along the guide sleeve 71.

[0046] When the rider pedals again to restore engagement, the return spring 612 releases its stored energy, pushing the pressure head 62 back to its original position. During the return process, the pressure head 62 contacts the chamfered surface 42 and converts the radial return force into an axial component force pointing towards the center through the chamfered surface 42, thereby actively assisting the corresponding first ratchet ring 4 and second ratchet ring 5 to move in the engagement direction, ensuring that the first ratchet ring 4 and second ratchet ring 5 are fully engaged.

[0047] See Figure 4 , Figure 5 and Figures 9 to 13 As shown, the pressing head 62 includes a ball-and-socket structure 621 and a ball 622 embedded therein. The ball-and-socket structure 621 is fixedly connected to the pressing rod 611, and the ball 622 forms rolling contact with the chamfered surface 42.

[0048] During assembly, the ball socket structure 621 is first fixedly connected to the end of the pressure rod 611 facing the chamfered surface 42. The ball socket structure 621 has a spherical cavity inside. Then, the ball 622 is embedded in the spherical cavity, so that part of the ball 622 is exposed on the outer surface of the ball socket, forming a freely rotatable rolling end.

[0049] When the hub assembly is in operation, as the first ratchet ring 4 or the second ratchet ring 5 rotates and disengages axially, its inner chamfered surface 42 moves outward and contacts the ball bearing 622, forming rolling contact rather than sliding friction. During the return engagement of the first ratchet ring 4 or the second ratchet ring 5, the return spring 612 pushes the pressure rod 611 inward, and the ball bearing 622 rolls along the slope of the chamfered surface 42, smoothly converting the radial thrust into an axial component force. At the same time, the rolling contact reduces wear and resistance of the rotating first ratchet ring 4 or the second ratchet ring 5.

[0050] See Figure 4 , Figure 5 , Figure 9 and Figure 10 As shown, the chamfered surface 42 is an annular continuous slope, the height of which gradually increases radially inward, and is used to convert the radial force of the ball 622 into the axial component force that drives the corresponding ratchet ring to engage.

[0051] When the return spring 612 pushes the pressure rod 611 inward, the ball 622 at its end rolls along the chamfered surface 42 inside the first ratchet ring 4 or the second ratchet ring 5. As the ball 622 rolls inward along the chamfered surface 42, the radial thrust it experiences is guided by the inclined profile of the chamfered surface 42, continuously decomposing into an axial component force pointing towards the axis. This axial component force acts directly on the corresponding ratchet ring, pushing it to move axially toward the other ratchet ring, thereby actively prompting it to return to a fully engaged state. This ensures reliable transmission even when the main spring preload decreases.

[0052] See Figure 9 and Figure 10 As shown, an outer ring 8 coaxial with the inner ring 7 is fixedly provided on the outer periphery of the inner ring 7. A magnetic attraction structure 63 is provided between the outer ring 8 and the ball-and-socket structure 621 to provide auxiliary reset force when the pressure head 62 returns to its original position.

[0053] When the first ratchet ring 4 and the second ratchet ring 5 disengage and the pressing head 62 moves outward, the movable permanent magnet 632 moves away from the fixed permanent magnet 631, and the magnetic attraction weakens.

[0054] When the first ratchet ring 4 and the second ratchet ring 5 re-engage, the return spring 612 begins to push back the pressure rod 611. At the same time, the attraction force generated by the magnetic attraction structure 63 actively pulls the ball socket structure 621 inward, providing additional auxiliary return force for the pressure head 62 and accelerating its contact with the chamfered surface 42. This allows the first ratchet ring 4 and the second ratchet ring 5 to re-engage more quickly and reliably, improving the response performance.

[0055] See Figure 4 , Figure 5 and Figures 9 to 13As shown, the magnetic attraction structure 63 includes a fixed permanent magnet 631 and a movable permanent magnet 632. The movable permanent magnet 632 is fixedly connected to the ball-and-socket structure 621. The fixed permanent magnet 631 is fixedly disposed on the outer ring 8 at the position corresponding to the movable permanent magnet 632. The outer ring 8 has a channel for the movable permanent magnet 632 to move.

[0056] When the hub assembly is working, if the first ratchet ring 4 and the second ratchet ring 5 disengage, causing the pressure head 62 to move outward, the movable permanent magnet 632 will slide radially outward along the channel on the outer ring 8, increasing the distance between it and the fixed permanent magnet 631, and weakening the magnetic attraction.

[0057] When the first ratchet ring 4 and the second ratchet ring 5 are reset, the return spring 612 pushes the pressure head 62 to move inward, and the movable permanent magnet 632 slides inward synchronously in the channel, gradually approaching the fixed permanent magnet 631. The magnetic attraction between the two is thus enhanced, thereby superimposing a magnetic attraction auxiliary force on the spring force, which together pulls the ball socket structure 621 to quickly return to its original position, ensuring that the pressure head 62 contacts the chamfered surface 42 in time and effectively assists the first ratchet ring 4 and the second ratchet ring 5 to complete the engagement.

[0058] See Figure 4 , Figure 5 , Figure 12 and Figure 13 As shown, the ball-and-socket structure 621 is provided with an mounting groove 6211 for mounting a movable permanent magnet 632, and the mounting groove 6211 slides in contact with the inner wall of the channel.

[0059] When the hub assembly is working, if the first ratchet ring 4 and the second ratchet ring 5 are axially disengaged, the pressure head 62 drives the ball socket structure 621 and the movable permanent magnet 632 to move radially outward together. At this time, the outer peripheral wall of the mounting groove 6211 and the inner wall of the corresponding channel on the outer ring 8 form a sliding fit surface, guiding the movable permanent magnet 632 to slide smoothly in the channel.

[0060] Conversely, during the reset process, the mounting groove 6211 slides inward along the inner wall of the channel, which not only restricts the shaking of the movable permanent magnet 632, but also ensures that its movement trajectory is accurately aligned, making the magnetic attraction stable and reliable, while reducing friction and impact, and ensuring the smoothness and durability of the auxiliary reset action.

[0061] See Figures 9 to 13 As shown, the fixed permanent magnet 631 and the pressing head 62 are in a clearance fit.

[0062] When the pressing head 62 moves radially along with the axial movement of the first ratchet ring 4 and the second ratchet ring 5, the fixed permanent magnet 631 fixed on the outer ring 8 and the pressing head 62 always remain in a non-contact state.

[0063] Because the fixed permanent magnet 631 and the pressing head 62 are in a clearance fit, they will not make physical contact or rub against each other during relative movement. This allows the pressing head 62 and the movable permanent magnet 632 to slide freely within the channel, while ensuring the effective transmission of magnetic force, avoiding obstruction and wear of the pressing head 62, and maintaining a stable magnetic attraction-assisted reset function.

[0064] See Figure 5 , Figure 12 and Figure 13 As shown, a gap is left between the fixed permanent magnet 631 and the movable permanent magnet 632 during the full engagement stage of the ratchet ring.

[0065] When the hub assembly is in normal driving state and the first ratchet ring 4 and the second ratchet ring 5 are fully engaged, the pressure head 62 has moved back to the innermost position under the combined action of the return spring 612 and the magnetic attraction. At this time, the fixed permanent magnet 631 fixed on the outer ring 8 and the movable permanent magnet 632 installed on the ball socket structure 621 are close to each other, but still maintain a small non-contact gap.

[0066] The gap ensures that the fixed permanent magnet 631 and the movable permanent magnet 632 will not have a rigid impact due to direct contact when they are engaged, thereby effectively avoiding operating noise, risk of magnet breakage and additional frictional resistance, while maintaining sufficient magnetic attraction to prepare for rapid reset after the next disengagement.

[0067] See Figure 5 As shown, the outer ring 8 is symmetrically fitted with annular washers 81 located on both sides of the ball-and-socket structure 621. The annular washers 81 are engaged between the fixed permanent magnet 631 and the movable permanent magnet 632 to form a magnetic buffer structure.

[0068] When the movable permanent magnet 632 moves radially along the channel with the ball-and-socket structure 621, the two annular washers 81 are precisely positioned in the gap between the fixed permanent magnet 631 and the movable permanent magnet 632. When the pressing head 62 returns to its original position and the fixed permanent magnet 631 and the movable permanent magnet 632 approach each other, the annular washers 81 first come into contact and are compressed, using their elastic material to absorb the magnetic impact and restrict direct collision between the fixed permanent magnet 631 and the movable permanent magnet 632.

[0069] Meanwhile, the annular washers 81 are symmetrically distributed on both sides to ensure uniform force distribution, effectively buffer the vibration and noise caused by sudden changes in magnetic force, form a stable magnetic buffer structure, and improve the smoothness of the reset action.

[0070] This invention constructs an adaptive assisted reset mechanism by providing a chamfered surface 42 on the inner side of the first ratchet ring 4 and the second ratchet ring 5, and combining it with an elastic pressing member 61 arranged radially on the central shaft 1. This mechanism utilizes the rolling ball 622 on the pressing head 62 to form a rolling contact with the chamfered surface 42, and under the action of the reset spring 612, efficiently converts the radial force into an axial component force, actively pushing the first ratchet ring 4 and the second ratchet ring 5 to fully engage.

[0071] Simultaneously, a non-contact magnetic attraction structure 63 is integrated. Through the dynamic magnetic force changes of the fixed permanent magnet 631 and the movable permanent magnet 632, it adapts to separation when disengaging and provides additional auxiliary force when resetting. It also works with the channel, the mounting groove 6211, and the symmetrical annular washer 81 to achieve precise guidance and buffering. Without interfering with sliding or increasing friction, it avoids partial engagement and slippage between the first ratchet ring 4 and the second ratchet ring 5, improving the transmission reliability and durability of the hub assembly under high load or long-term use conditions.

[0072] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A bicycle hub assembly, characterized in that, include: The bottom bracket is used to fix the vehicle to the frame; The tower base is fitted around the outer periphery of the central axis and can rotate around the central axis; The hub shell is fitted around the outer circumference of the central shaft and is arranged adjacent to the base of the hub along the axial direction. A ratchet drive mechanism is provided between the opposite end faces of the freehub base and the hub housing, and includes a first ratchet ring and a second ratchet ring; The first ratchet ring is coaxially connected to the tower base and is provided with a first main spring; The second ratchet ring is coaxially connected to the hub housing and is equipped with a second main spring; The first and second ratchet rings are arranged opposite to each other and mesh with each other under the action of the spring force; The outer periphery of the first ratchet ring and the second ratchet ring are evenly distributed with a number of axial locking blocks along the circumferential direction. The base and the hub shell are respectively provided with axial sleeves that cooperate with the axial locking blocks, which are used to transmit torque and restrict relative circumferential rotation. The central shaft is provided with an auxiliary reset mechanism at the position corresponding to the ratchet transmission mechanism. The auxiliary reset mechanism includes an elastic pressing member arranged radially along the central shaft. The elastic pressing member is evenly distributed in the circumferential direction on the inner side of the first ratchet ring and the second ratchet ring. The first and second ratchet rings are respectively provided with chamfered surfaces on the inner side of their opposite ends, and the chamfered surfaces abut against the corresponding elastic pressing members.

2. The bicycle hub assembly according to claim 1, characterized in that, The central shaft is fitted with an inner ring at the position of the auxiliary reset mechanism. Each elastic pressing member is provided with a guide sleeve on the inner ring. The elastic pressing member includes a pressing rod that is radially inserted into the guide sleeve and a reset spring. The pressing rod is provided with a pressing head that abuts against the chamfered surface. The reset spring is connected between the pressing head and the guide sleeve.

3. The bicycle hub assembly according to claim 2, characterized in that, The pressure head includes a ball-and-socket structure and balls embedded therein. The ball-and-socket structure is fixedly connected to the pressure rod, and the balls form rolling contact with the chamfered surface.

4. The bicycle hub assembly according to claim 3, characterized in that, The chamfered surface is a continuous annular slope with its height gradually increasing radially inward, used to convert the radial force of the ball into an axial component force that drives the corresponding ratchet ring to engage.

5. The bicycle hub assembly according to claim 3, characterized in that, An outer ring coaxial with the inner ring is fixedly provided on the outer circumference of the inner ring, and a magnetic attraction structure is provided between the outer ring and the ball-and-socket structure to provide auxiliary reset force when the pressure head returns to its original position.

6. The bicycle hub assembly according to claim 5, characterized in that, The magnetic attraction structure includes a fixed permanent magnet and a movable permanent magnet. The movable permanent magnet is fixedly connected to the ball-and-socket structure. The fixed permanent magnet is fixedly disposed on the outer ring at the position corresponding to the movable permanent magnet. The outer ring has a channel for the movable permanent magnet to move.

7. The bicycle hub assembly according to claim 6, characterized in that, The ball-and-socket structure is provided with a mounting groove for mounting a movable permanent magnet, and the mounting groove slides in contact with the inner wall of the channel.

8. The bicycle hub assembly according to claim 6, characterized in that, The fixed permanent magnet and the pressure head are fitted with a clearance.

9. The bicycle hub assembly according to claim 6, characterized in that, A gap is left between the fixed permanent magnet and the movable permanent magnet during the full engagement of the ratchet ring.

10. The bicycle hub assembly according to claim 9, characterized in that, The outer ring is symmetrically fitted with annular washers on both sides of the ball-and-socket structure. The annular washers are engaged between the fixed permanent magnet and the movable permanent magnet to form a magnetic buffer structure.

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