Ratchet structure of a bicycle hub
Patent Information
- Application Number
- DE202024107491
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-03-06
- Estimated Expiration
- 2034-12-31
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
BACKGROUND OF THE INVENTION 1. Context of the invention
[0001] The present invention relates to a ratchet structure, in particular a ratchet structure used between a bicycle hub housing and a freewheel sleeve, which generates an intermittent one-way transmission by axially linearly engaging and disengaging the hub. 2. Description of the known design
[0002] When riding a bicycle, pedaling drives the rear hub assembly through the chainring and chain connected to the pedals, generating a driving force in the rear wheel and propelling the bicycle forward. When pedaling is stopped, the rear wheel and hub assembly continue to rotate, allowing the bicycle to continue moving forward. This transmission state is primarily achieved by the ratchet mechanism inside the bicycle's rear hub assembly, utilizing its structural property of producing an intermittent, one-way transmission motion.
[0003] The ratchet tooth structures commonly used in hub shells and sleeves can be broadly divided into two categories based on the different actuation methods of the intermittent transmission ratchets of the drive element: "swivel type" and "linear type." The "swivel type" refers to structural designs in which the engagement and disengagement processes between the driving and driven parts occur via an oscillating motion. Examples of this technology include the "bicycle hub system assembly structure" described in Utility Model Patent No. 111211577 from Taiwan and the "bicycle hub" described in Utility Model Patent No. 112206175 from Taiwan.
[0004] The “linear type” refers to structural designs in which the engagement and disengagement processes between the driving and driven parts are achieved through linear motion. This type of technology includes the technology described in utility model patent no.111146818 from Taiwan describes a “bicycle hub” comprising the following components: a hollow tube body with an inner toothed section formed at one end on the inner wall surface; a gear set positioned at one end of the body and engaging with the inner toothed part of the body; a chainring seat rotatably combined at the end of the body containing the gear set, with an internal ring gear that can mesh with the gear set installed in the chainring seat, the engagement between the ring gear and the gear set producing a one-way transmission; and two shock-absorbing seals, each attached to either side of the gear set.
[0005] Another “linear” bicycle hub ratchet structure, as described in Utility Model Patent No. 112207964 “Bicycle Gearbox with a Ratchet Tooth Structure” from Taiwan, comprises a first toothed ring with a circumferential surface and a side surface, the side surface having several ratchet teeth of the first surface arranged in a circular pattern, each ratchet tooth of the first surface being an inclined tooth with an adjacent section having a convex arc surface; and a second toothed ring with a circumferential surface and a side surface facing the first toothed ring, the side surface of the second toothed ring having several ratchet teeth arranged in a circular pattern; the first surface ratchet teeth and the second surface ratchet teeth interlocking.
[0006] In the two aforementioned known "linear" bicycle hub ratchet structures, both ratchet rings engage laterally, with each ratchet ring undergoing a linear displacement along the hub axis to switch between engaged and disengaged states. This directly causes the hub shell and sleeve seat to rotate synchronously. The first case focuses primarily on the structural features of related components that extend beyond the application of the ratchet ring technology. The second case focuses on the structural design of the engaging ratchet tooth shape between the two ratchet rings as a technical feature.
[0007] In the two aforementioned known "linear" bicycle hub ratchet structures, where the two interlocking ratchet rings directly drive the hub shell and the sleeve seat to rotate synchronously, both the inner diameter of the hub shell and the outer diameter of the ratchet ring, due to manufacturing limitations, feature circularly arranged, engageable drive gear structures with the larger inner diameter of the hub shell. This necessitates higher manufacturing precision, resulting in high production costs. Furthermore, the frequent and unavoidable linear reciprocating motion of the ratchet rings while riding, whether pedaling or not, easily leads to wear on the engaged gear structure.When repairs are needed, the entire hub shell must be replaced, resulting in excessive maintenance costs. When not pedaling, the two ratchet rings are in a disengaged position. Whether spring force or magnetic attraction is used to keep the two ratchet rings close together, the incompletely engaged ratchet teeth on both sides repeatedly touch and rub hard against each other during engagement and disengagement, producing clicking noises. This one-sided forced engagement, where the two ratchet rings are held tightly together, accelerates wear on the ratchet teeth and shortens the lifespan.
[0008] The present invention aims to create a ratchet structure for a bicycle hub in order to eliminate the aforementioned deficiencies. TASK OF INVENTION
[0009] The present invention relates to a ratchet mechanism for a bicycle hub located between a hub shell and a sleeve seat. One end of the sleeve seat is located in one end of the hub shell. The ratchet mechanism comprises a wheel axle assembly in which a wheel axle passes through an axis of the hub shell and an axis of the sleeve seat. At least one first bearing is installed between the wheel axle and the hub shell. At least one second bearing is installed between the wheel axle and the sleeve seat.
[0010] A ratchet clutch assembly is mounted around the wheel axle and generates linear actuation for engaging or disengaging the ratchet teeth along an axial direction of the hub housing and an axial direction of the sleeve seat. The ratchet clutch assembly comprises a first ratchet ring and a second ratchet ring made of magnetic materials. A first end face of the first ratchet ring has several radially arranged first ratchet teeth. A first end face of the second ratchet ring has several radially arranged second ratchet teeth. The second ratchet teeth are connected to the first ratchet teeth and are in a state of magnetic repulsion with each other. Two elastic elements are preloaded against a second end face of the first ratchet ring and a second end face of the second ratchet ring, respectively.The elastic elements provide a spring force that can move the first and second ratchet rings linearly in the direction of engagement of the first and second ratchet rings.
[0011] A first gear unit has a first gear seat that is mounted around the first ratchet ring. Multiple first gear teeth are formed on both an inner circumference of the first gear seat and an outer circumference of the first ratchet ring. The multiple first gear teeth of the first gear seat mesh with the multiple first gear teeth of the first ratchet ring to produce a synchronous rotary transmission. Multiple second gear teeth are formed on both an outer circumference of the second ratchet ring and an inner circumference of the sleeve seat. The multiple second gear teeth of the second ratchet ring mesh with the multiple second gear teeth of the sleeve seat to produce a synchronous rotary transmission.
[0012] A second gear unit has several projections formed on an inner circumference of the hub housing. The first gear seat has several grooves formed on its outer circumference. These grooves engage with the projections, thus securing the first gear seat within the hub housing and transmitting synchronous rotation. A second gear seat is mounted between the hub housing and the sleeve seat. The second gear seat has several limiting grooves formed on its outer circumference. These limiting grooves engage with the projections, thus securing the second gear seat within the hub housing and transmitting synchronous rotation. The limiting grooves are groove-shaped with a preset length to prevent inward displacement of the mounted sleeve seat and the second gear seat toward the hub housing.
[0013] The main objective of the present invention is to create a ratchet structure for a hub housing, wherein two magnetically repulsive ratchet rings are used to generate a separating force, combined with a proximity force created by elastic elements at the other ends of the ratchet rings, thereby holding the ratchet rings in a floating state. If the frictional force is greater than the spring force plus the instantaneous repulsive force, it can increase the separation distance between the two sides of the ratchet teeth to reduce friction and extend the service life of the ratchet teeth.
[0014] Another objective of the present invention is to create a ratchet structure for a bicycle hub with two magnetically repelling ratchet rings that achieve a faster and more sensitive disengagement effect when not pedaling.
[0015] A further objective of the present invention is to create a ratchet structure for a bicycle hub with a first gear seat arranged between the first ratchet ring and the hub housing, enabling the first ratchet ring to perform a reciprocating linear movement within the first gear seat. If the gear teeth are damaged, only the first gear seat needs to be replaced, rather than the entire hub housing, thus effectively reducing maintenance costs.
[0016] A further objective of the present invention is to create a ratchet mechanism for a bicycle hub, in which a first gear seat is arranged between the first ratchet ring and the hub housing, with gear teeth machined on its inner diameter. Since the inner diameter of the first gear seat is much smaller than the inner diameter of the hub housing, the manufacturing technology required for machining the gear teeth is less demanding and yet still meets the precision requirements, thereby effectively reducing manufacturing costs.
[0017] The present invention will become more obvious from the following description with reference to the accompanying drawings, which merely show a preferred embodiment according to the present invention for illustrative purposes. BRIEF DESCRIPTION OF THE DRAWINGS The Fig. Figure 1 shows a perspective view of a preferred embodiment of the present invention; The Fig. Figure 2 shows an exploded view of a preferred embodiment of the present invention; The Fig. Figure 3 shows a first sectional view of a preferred embodiment of the present invention; The Fig. Figure 4 shows a second sectional view of a preferred embodiment of the present invention; The Fig. Figure 5 shows a first operating scheme of a preferred embodiment of the present invention; The Fig. Figure 6 shows a second operating scheme of a preferred embodiment of the present invention, and The Fig. Figure 7 shows an enlarged partial view to illustrate the disengaged state of a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EXECUTION EXAMPLE
[0018] The Fig. Figures 1 to 4 show the ratchet mechanism for a bicycle hub between a hub shell 10, a sleeve seat 11, a wheel axle assembly 20, a clutch ratchet assembly 30, a first gear unit 40, and a second gear unit 50. One end of the sleeve seat 11 is positioned within one end of the hub shell 10. A cover 12 is provided between an end face section of the hub shell 10 and the sleeve seat 11 to secure the sleeve seat 11 to the hub shell 10 and prevent dust from entering the hub shell 10 and sleeve seat 11 assembly. A positioning groove 13 is axially recessed at a preset position within the hub shell 10.
[0019] The wheel axle assembly 20 has a wheel axle 21 that passes through an axis of the hub housing 10 and an axis of the sleeve seat 11. At least one first bearing 22 is installed between the wheel axle 21 and the hub housing 10, with at least one second bearing 23 being installed between the wheel axle 21 and the sleeve seat 11. Each of the first and second bearings 22, 23 comprises a concentrically fitted inner ring 221 / 231 and an outer ring 222 / 232, with several rolling elements 223, 233 arranged between the inner rings 221, 231 and the outer rings 222, 232. A bearing ring 24 is positioned between the first and second bearings 22, 23 and is mounted around the wheel axle 21. Two end faces of the bearing ring 24 each abut two inner ring end faces of the first and second bearings 22, 23. Another bearing ring 24 is placed between each of the first bearings 22 and mounted around the wheel axle 21.Two end faces of the bearing ring 24 each abut the inner ring end faces of the first bearings 22. Another bearing ring 24 is arranged between each of the second bearings 23 and mounted around the wheel axle 21. Two end faces of the bearing ring 24 each abut the inner ring end faces of the second bearing 23. A set of recessed mounting grooves 25 is pre-set inside the sleeve seat 11.
[0020] The clutch ratchet assembly 30 is mounted around the wheel axle 21 and generates a linear actuation for engaging or disengaging the ratchet teeth along an axial direction of the hub housing 10 and an axial direction of the sleeve seat 11. The clutch ratchet assembly 30 has a first ratchet ring 31 and a second ratchet ring 32, which are made of magnetic materials. A first end face of the first ratchet ring 31 has several radially arranged first ratchet teeth 33. A first end face of the second ratchet ring 32 has several radially arranged second ratchet teeth 34. The second ratchet teeth 34 engage with the first ratchet teeth 33 and are in a state of magnetic repulsion with each other. Two elastic elements 35 are each tensioned against a second end face of the first ratchet ring 31 and a second end face of the second ratchet ring 32.The elastic elements 35 provide a spring force that displaces the first and second ratchet rings 31, 32 linearly in the direction of engagement of the first and second ratchet rings 31, 32. The spring force of each elastic element 35 is greater than a magnetic field repulsion force between the first and second ratchet teeth 33, 34.
[0021] From the buttress sections of the first and second ratchet rings 31, 32, an abutting edge 311 / 321 projects radially. The abutting edges 311, 321 are located between the first and second ratchet rings 31, 32 and the elastic elements 35, in order to increase the contact area between the first and second ratchet rings 31, 32 and the elastic elements 35. Therefore, the inner diameter dimension 'D' of the elastic elements 35 is larger than the inner diameter dimension 'd' of the abutting edges 311, 321. The elastic elements abut the positioning groove 13 and the fastening groove 25 at their respective ends opposite the first and second ratchet rings 31, 32.
[0022] The elastic elements 35 are conical springs or applications for other types of springs, such as leaf springs, coil springs, disc springs, spiral springs or other elastic plastics.
[0023] The first gear unit 40 has a first gear seat 41, which is arranged around the first ratchet ring 31. Several first gear teeth 42 are formed on both an inner circumference of the first gear seat 41 and on an outer circumference of the first ratchet ring 31. The multiple first gear teeth 42 of the first gear seat 41 mesh with the multiple first gear teeth 42 of the first ratchet ring 31 to produce a synchronous rotary transmission. Multiple secondary gear sets 43 are formed on both an outer circumference of the second ratchet ring 32 and on an inner circumference of the sleeve seat 11. The multiple secondary gear teeth 43 of the second ratchet ring 32 mesh with the multiple secondary gear teeth 43 of the sleeve seat 11 to produce a synchronous rotary transmission.
[0024] The second gear unit 50 has several projections 51 formed on an inner circumference of the hub housing 10. The multiple projections 51 have a preset length. The first gear seat 41 has several grooves 52 formed on its outer circumference. The multiple grooves 52 engage with the projections 51 such that the first gear seat 41 is fitted into the hub housing 10 and transmits synchronous rotation. A second gear seat 53 is installed between the hub housing 10 and the sleeve seat 11. The second gear seat 53 has several limiting grooves 54 formed on its outer circumference. The multiple limiting grooves 54 engage with the projections 51, so that the second gear seat 53 is installed within the hub housing 10 and transmits synchronous rotation.The limiting grooves 54 are groove-shaped with a preset length to prevent the mounted sleeve seat 11 and the second gear seat 53 from shifting inwards towards the hub housing 10.
[0025] The components mentioned above cause the magnetically repulsive first and second ratchet rings 31, 32 to generate a separating force, combined with a proximity force provided by elastic elements 35 at the other ends of the first and second ratchet rings 31, 32, thus holding the first and second ratchet rings 31, 32 in a floating state. If the frictional force is greater than the spring force plus the instantaneous repulsive force, it can increase the separation distance between the first and second ratchet teeth 33, 34 on both sides to reduce friction and extend the service life of the ratchet teeth, thereby making the disengagement action during non-pedaling faster and more sensitive.Furthermore, the manufacturing technology required for machining the gear teeth of the first gear unit 40 is less demanding yet still meets the precision requirements, effectively reducing manufacturing costs. Additionally, if the gear teeth are damaged, only the first gear seat 41 or the first ratchet ring 31 needs to be replaced, not the entire hub housing, effectively reducing maintenance costs and making the overall structure practical and convenient to use.
[0026] During the pedaling state, when the bicycle frame moves forward (see Fig. 5) When the pedals drive the chain system and cause the sleeve seat 11 and the second gear seat 53 to rotate synchronously with the front of the bicycle frame, the first and second ratchet teeth 33, 34 are in a fully engaged state. This causes the first ratchet teeth 33 to rotate the first ratchet ring 31, the first gear seat 41, and the hub shell 10 in the same direction, with the wheel rolling forward synchronously.
[0027] During non-pedaling (see Fig. 6 and Fig.7) The sleeve seat 11 stops rotating, while the first ratchet ring 31, the first gear seat 41, and the hub shell 10 continue to rotate forward due to inertia. At this point, the first and second ratchet teeth 33 and 34 change from their initial engaged state. Since the second ratchet ring 32 is not rotating, the first ratchet teeth 33 move along the inclined surface of the second ratchet teeth 34 to the highest point of the tooth and then drop into the lowest point of the next ratchet tooth, causing the first and second ratchet teeth 33 and 34 to collide and produce a clicking sound. This back-and-forth movement between the highest and lowest points of the second ratchet teeth 34 represents the disengaged state of the first and second ratchet teeth 33 and 34, in which the bicycle hub is in a freewheeling state, performing no work, but the bicycle frame can still move forward.
[0028] The present invention uses a conical spring as an elastic element 35, utilizing the stackable compression properties of conical springs, in which all coils are stacked inwards when compressed and may even be stacked in a flat plane. When extended in its natural state, the width spacing is also reduced, thus achieving space-saving efficiency. The additional space facilitates the use of different shapes or sizes of other components.
[0029] The ratchet mechanism for a bicycle hub according to the present invention mainly uses the magnetic repulsion of the first and second ratchet rings 31, 32 to generate a separating force, combined with the elastic elements 35, which are arranged at the opposite ends of the first and second ratchet rings 31, 32, to generate a proximity force. The design of the indirect transmission through the first and second gear arrangement 40, 50 offers the following advantages:
[0030] The present invention uses magnetically repulsive first and second ratchet rings 31, 32 to generate a separating force, combined with elastic elements that generate a proximity force at the other ends of the first and second ratchet rings 31, 32, thereby holding the first and second ratchet rings 31, 32 in a floating state. During linear actuation, this results in force changes on both sides of the first and second ratchet rings 31, 32, thereby automatically balancing the repulsive and elastic forces on both sides at all times.During disengagement, when the frictional force is greater than the spring force plus the instantaneous repulsion force, it can automatically increase the separation distance between the first and second ratchet teeth 33, 34 on both sides to reduce friction and extend the service life of the ratchet teeth, thereby solving various problems caused by the continuous hard contact wear between ratchet teeth of the prior art.
[0031] Due to the magnetic repulsion between the first and second ratchet rings 31, 32 during the non-pedaling disengaged state, the repulsion force contributes to making the disengagement action faster and more sensitive.
[0032] With a first gear seat 41 located between the first ratchet ring 31 and the hub housing 10, and an indirect gear structure design in which gear teeth are arranged between the first ratchet ring 31 and the first gear seat 41, the first ratchet ring 31 performs a reciprocating linear displacement within the first gear seat 41. If the gear teeth are damaged, only the smaller and more cost-effective first gear seat 41 or the first ratchet ring 31 needs to be replaced, rather than the entire hub housing. This reduces wear on the hub housing and effectively lowers maintenance costs. This eliminates the problems of the prior art, which require replacing the entire hub housing when the gear teeth are damaged, and the associated high maintenance costs.
[0033] By arranging a first gear seat 41 between the first ratchet ring 31 and the hub housing 10, with gear teeth machined on its inner diameter, and because the inner diameter of the first gear seat 41 is much smaller than the inner diameter of the hub housing 10, the manufacturing technology required for machining the gear teeth is less demanding and easier to meet precision requirements, effectively reducing manufacturing costs. This solves the problems of the prior art regarding high manufacturing requirements and high processing costs due to the large inner diameter of the hub housing.
[0034] The second gear seat 53 is mounted between the sleeve seat 11 and the hub housing 10, employing an indirect gear structure design that prevents the frequently rotating sleeve seat 11 from directly contacting the hub housing 10, thus preventing the wear point from being transferred to the second gear seat 53. For maintenance, only the second gear seat 53 needs to be replaced, not the entire hub housing, thereby reducing wear on the hub housing and effectively lowering maintenance costs. This eliminates the problems associated with prior art, where the entire hub housing has to be replaced when the gear teeth are damaged, and the associated high maintenance costs.
[0035] The positioning groove 13 and the fastening groove 25, which are formed within the hub housing 10 and the sleeve seat 11, mainly provide positions at which the elastic elements 35 can be securely mounted within the hub housing 10 and the sleeve seat 11, thereby achieving a positioning effect.
[0036] The second gearbox seat 53 and the hub housing 1, which are interlocked by the projections 51 and the limiting grooves 54, not only position the two components but also ensure synchronous rotational transmission between them. Furthermore, the limiting groove 54 has an additional limiting function to prevent inaccurate positioning of the second gearbox seat (53) during assembly and thus simultaneously improve assembly accuracy.
[0037] The present invention features radially extending flanges of a certain height on the inner circumference of the contact surfaces between the first and second ratchet rings 31, 32 and the elastic elements 35. The inner diameter of these abutting edges 311, 321 is set to "d", while the inner diameter of the elastic elements is set to "D". Therefore, by setting the inner diameter "D" of the elastic elements 35 to a size larger than the inner diameter "d" of the abutting edges 311, 321, it is prevented that the elastic elements 35 fall into the first and second ratchet rings 31, 32, which would lead to failure of the linear drive spring force. At the same time, the abutting edges 311, 321 can increase the contact area with the elastic elements 35.Even if the elastic elements 35 wobble during operation, they can still effectively butt against the end faces of the abutting edges 311, 321, thereby reducing cases in which the elastic elements 35 detach.
[0038] In summary, the present invention aims to create a hub ratchet structure that reduces wear, achieves faster and more sensitive disengagement when not pedaling, and simultaneously lowers maintenance and manufacturing costs. It primarily utilizes magnetically repelling first and second ratchet rings to generate a disengaging force, combined with elastic elements at the other ends of the first and second ratchet rings, which provide a converging force and hold the first and second ratchet rings in a floating state.In combination with the structural design of the indirect transmission between the first and second gear seats, between the hub housing and the sleeve seat, it transfers wear and damage to smaller components such as the first and second gear seats and the first and second ratchet rings, thus eliminating the need to replace the entire hub housing. Meanwhile, the first and second ratchet rings are in a floating position with automatically balanced forces on both sides, resulting in smoother engagement and disengagement of the first and second ratchet rings.
[0039] Despite the presentation and description of the embodiment according to the present invention, it will be obvious to the person skilled in the art that further embodiments can be created without deviating from the scope of the present invention.
Claims
[1] A ratchet structure for a bicycle hub arranged between a hub shell (10) and a sleeve seat (11), one end of the sleeve seat (11) being positioned inside one end of the hub shell (10), the ratchet structure comprising the following components: a wheel axle assembly (20) in which a wheel axle (21) extends through an axis of the hub shell (10) and an axis of the sleeve seat (11), at least one first bearing (22) mounted between the wheel axle (21) and the hub shell (10), and at least one second bearing (23) mounted between the wheel axle (21) and the sleeve seat (11); a clutch ratchet assembly (30) mounted around the wheel axle (21) and producing a linear actuation for engaging or disengaging the ratchet teeth along an axial direction of the hub shell (10) and an axial direction of the sleeve seat (11), the clutch ratchet assembly (30) comprising a first ratchet ring (31) and a second ratchet ring (32) made of magnetic materials, a first end face of the first ratchet ring (31) having a plurality of radially arranged first ratchet teeth (33), a first end face of the second ratchet ring (32) having a plurality of radially arranged second ratchet teeth (34), the second ratchet teeth (34) engaging the first ratchet teeth (33) and being in a magnetic field repulsion state, two elastic elements (35) each biased against a second end face of the first ratchet ring (31) and a second end face of the second ratchet ring (32), the elastic elements (35),which generate a spring force for the first and second ratchet rings (31, 32) to move linearly in an engagement direction of the first and second ratchet rings (31, 32); , a first gear unit (40) having a first gear seat (41) mounted around the first ratchet ring (31), a plurality of first gear teeth (42) formed in both an inner periphery of the first gear seat (41) and an outer periphery of the first ratchet ring (31), the multiple first gear teeth (42) of the first gear seat (41) engaging with the multiple first gear teeth (42) of the first ratchet ring (31) to produce a synchronous rotary transmission, multiple second gear teeth (43) formed in both an outer periphery of the second ratchet ring (32) and an inner periphery of the sleeve seat (11), the multiple second gear teeth (43) of the second ratchet ring (32) engaging with the multiple second gear teeth (43) of the sleeve seat (11) to produce a synchronous rotary transmission, and a second gear unit (50) having a plurality of projections (51) formed in an inner periphery of the hub shell (10), the first gear seat (41) having a plurality of grooves (52) formed towards an outer periphery thereof, the multiple grooves (52) engaging with the projections (51) such that the first gear seat (41) is fitted into the hub shell (10) and transmits synchronous rotation, a second gear seat (53) disposed between the hub shell (10) and the sleeve seat (11), the second gear seat (53) having a plurality of limiting grooves (54) formed towards an outer periphery thereof, the multiple limiting grooves (54) engaging with the projections (51) such that the second gear seat (53) is fitted into the hub shell (10) and transmits synchronous rotation, the limiting grooves (54) are groove-shaped and have a preset length to preventthat the mounted sleeve seat (11) and the second gear seat (53) move inwards towards the hub shell (10). [2] The ratchet structure of a bicycle hub according to claim 1, wherein an inner diameter dimension (D) of each elastic member (35) at adjacent portions of the first and second ratchet rings (31, 32) is larger than an inner diameter dimension (d). [3] The ratchet structure of a bicycle hub according to claim 1, wherein an abutting edge (311 / 321) protrudes radially from the abutting portions of the first and second ratchet rings (31, 32), the abutting edge (311, 321) is located between the first and second ratchet rings (31, 32) and the elastic members (35) to increase a contact area between the first and second ratchet rings (31, 32) and the elastic members (35) and to make an inner diameter dimension (D) of the elastic members (35) larger than an inner diameter dimension (d) of the abutting edges (311, 321). [4] The ratchet structure of a bicycle hub according to claim 1, wherein each of the first and second bearings (22, 23) comprises a concentrically fitted inner ring (221 / 231) and an outer ring (222 / 232), with a plurality of rolling elements (223, 233) arranged between the inner rings (221, 231) and the outer rings (222, 232), a bearing ring (24) is placed between the first and second bearings (22, 23) and mounted around the wheel axle (21), two end surfaces of the bearing ring (24) abut against two respective inner ring end surfaces of the first and second bearings (22, 23). [5] The ratchet structure of a bicycle hub according to claim 1, wherein a bearing ring (24) is placed between each of the first bearings (22) and mounted around the wheel axle (21), two end surfaces of the bearing ring (24) abut against the inner ring end surfaces of the first bearings (22), another bearing ring (24) is placed between each of the second bearings (23) and mounted around the wheel axle (21), two end surfaces of the other bearing ring (24) abut against the inner ring end surfaces of the second bearing (23). [6] The ratchet structure of a bicycle hub according to claim 1, wherein a cover (12) is interposed between an end surface portion of the hub shell (10) and the sleeve seat (11) to fix the sleeve seat (11) to the hub shell (10). [7] The ratchet structure of a bicycle hub according to claim 1, wherein the elastic members (35) are conical springs. [8] The ratchet structure of a bicycle hub according to claim 1, wherein the spring force of each elastic member (35) is greater than a magnetic field repulsion force between the first and second ratchet teeth (33, 34). [9] The ratchet structure of a bicycle hub according to claim 1, wherein a set of fastening grooves (25) is formed in a depressed shape within the sleeve seat (11) allowing a position for mounting an end face of the elastic member (35). [10] The ratchet structure of a bicycle hub according to claim 1, wherein a positioning groove (13) is axially countersunk at a preset position within the hub shell (10) providing a position for mounting an end face of the elastic member (35).