Bicycle driving chain wheel capable of preventing chain falling, bicycle transmission assembly and bicycle
By designing arc-shaped hook teeth with a tooth height of 33.5-36.5mm and a chamfered structure, the problem of chain slippage from the bicycle drive sprocket was solved, achieving stable meshing between the chain and the sprocket and improving riding safety and comfort.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-21
- Publication Date
- 2026-04-21
AI Technical Summary
Existing bicycle drive chains are prone to slipping off during riding, leading to riding interruptions and safety hazards, especially on bumpy roads or when shifting gears.
Design a bicycle drive sprocket to prevent chain slippage. The tooth height is 33.5-36.5mm. It has an arc-shaped hook structure and an arc-shaped bevel to enhance the wrapping and limiting effect on the chain roller. An arc-shaped chamfer and a beveled chamfer are set at the top of the tooth to ensure stable meshing between the chain and the sprocket.
It effectively reduces chain slippage, improves riding stability and safety, extends component life, reduces the probability of chain jamming, and ensures smooth and reliable riding.
Smart Images
Figure CN224146107U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of bicycle technology, and in particular to a bicycle drive sprocket to prevent chain slippage, a bicycle transmission assembly, and a bicycle. Background Technology
[0002] See Figure 1 In the bicycle's drivetrain, the drive sprocket 100, drive chain 200, and drive sprocket 300 constitute the key power transmission structure. As a core component, the performance of the drive sprocket 100 in conjunction with the drive chain 200 directly affects the riding experience and safety. The bicycle's drivetrain principle is based on the interaction between the drive sprocket 100 and the links of the drive chain 200 through their teeth, and the transmission of force through chain rollers. When the rider pedals, the drive sprocket 100 rotates and transmits power to the drive chain 200, thereby driving the rear wheel and propelling the bicycle forward.
[0003] Currently, most bicycles on the market use a traditional drive sprocket structure, see [link / reference]. Figure 2 Typically, multiple teeth 120 are arranged on the circumference of the sprocket body 110. The load-bearing side of the teeth 120 is used to transmit the force on the teeth to the chain rollers. However, in actual use, this traditional drive sprocket has a prominent problem: chain slippage is prone to occur. Chain slippage not only interrupts the riding process, causing inconvenience to the rider, but may also occur suddenly during riding, causing the rider to lose balance and resulting in accidents such as falls.
[0004] A deeper analysis of why traditional drive sprockets are prone to chain slippage reveals two main reasons. Firstly, the existing drive sprocket tooth design has structural flaws. The shape and size of traditional teeth often fail to adequately consider the chain's stability requirements under complex road conditions and varying riding styles, resulting in limited restraint and limiting of the chain rollers. When riding on bumpy roads, shifting gears, or pedaling heavily, the chain is easily subjected to lateral or longitudinal forces. Because the teeth cannot effectively enclose and restrain the chain rollers, the chain may slip off the sprocket. Secondly, considering the tooth dimensions, the existing tooth height may not meet the requirements for stable chain engagement under various conditions. Inappropriate tooth height results in insufficient engagement depth between the chain and sprocket, making the engagement easily disrupted by external forces, leading to chain slippage.
[0005] In conclusion, there is an urgent need to design a new type of bicycle drive sprocket to solve the chain drop problem and improve the stability and reliability of the transmission system. Utility Model Content
[0006] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a bicycle drive sprocket, bicycle transmission assembly and bicycle to prevent chain drop, so as to solve the problem of chain drop in existing bicycles.
[0007] To achieve the above objectives, in a first aspect, this utility model provides a bicycle drive sprocket to prevent chain slippage. The drive sprocket engages with a drive chain, which has chain rollers. The drive sprocket includes a sprocket body and a plurality of teeth formed on the circumference of the sprocket body. Each tooth has a load-bearing side, configured to transmit force from the corresponding tooth to the chain roller. The tooth height is 33.5–36.5 mm, and the tooth has an arc-shaped hook structure facing the load-bearing side, so that when the drive chain engages with the sprocket, the teeth provide a certain degree of containment and restraint on the chain roller.
[0008] Furthermore, the tooth also has an arc-shaped inclined surface opposite to the load-bearing side, and the arc-shaped inclined surface bends in the same direction as the load-bearing side to form the arc-shaped hook structure.
[0009] Furthermore, the load-bearing side of the tooth includes a contact area and a limiting area, wherein the limiting area is arc-shaped and hook-shaped.
[0010] Furthermore, the transmission chain is also engaged with a transmission sprocket, the tooth height of which is 20.0 to 30.0 mm.
[0011] Furthermore, the tooth has a width direction along the circumference of the sprocket body and a thickness direction along the axial direction of the sprocket body. In the width direction, the tip of the tooth has an arc-shaped chamfer, and in the thickness direction, the tip of the tooth has a beveled chamfer.
[0012] Furthermore, the transmission chain includes alternating inner and outer links connected by the chain rollers. The inner link includes inner link plates respectively installed at both ends of the chain rollers, with a first receiving space defined between the two inner link plates. The outer link includes an outer link plate installed at the end of the chain rollers and located outside the inner link plates, with a second receiving space defined between the two outer link plates.
[0013] Furthermore, the thickness of the teeth is less than the width between the two inner link plates.
[0014] Furthermore, a left crank and a right crank are respectively installed on both sides of the sprocket, and the sprocket body has a mounting hole in the middle. The circumference of the mounting hole is provided with several spline grooves for mounting a spline shaft. The left crank and the right crank are respectively installed at both ends of the spline shaft.
[0015] Secondly, this utility model provides a bicycle transmission component to prevent chain slippage, including a drive sprocket, a transmission chain, and a transmission sprocket, wherein the drive sprocket is the drive sprocket described above.
[0016] Thirdly, this utility model provides a bicycle with anti-chain-dropping features, including a frame, a transmission assembly, and a crank assembly. The crank assembly is connected to the transmission assembly. The transmission assembly includes the aforementioned drive sprocket, transmission chain, and transmission sprocket. The crank assembly includes a left crank and a right crank respectively mounted on both sides of the drive sprocket.
[0017] Due to the adoption of the above technical solutions, this utility model has the following beneficial effects:
[0018] 1. In this invention, the tooth height of the drive sprocket teeth is set within a specific range of 33.5-36.5mm, and the teeth have an arc-shaped hook structure facing the load side. Compared to traditional drive sprockets, this structural design greatly enhances the teeth's containment and restraint of the chain rollers. During bicycle riding, especially when encountering bumpy roads, frequent gear changes, or heavy pedaling, the chain is subjected to external forces from various directions. In this invention, the arc-shaped hook structure can constrain the chain rollers between the teeth to a certain extent, reducing chain displacement space, maintaining stable meshing between the chain and the sprocket, and effectively reducing the occurrence of chain slippage. This not only avoids interruptions in the riding process, but more importantly, ensures the rider's safety, reduces the risk of the rider losing balance and falling due to chain slippage, and provides riders with more reliable riding protection.
[0019] 2. This utility model optimizes several structural parameters of the drive sprocket. For example, the teeth have an arc-shaped chamfer at the top in the width direction and a beveled chamfer at the top in the thickness direction, and the thickness of the teeth is less than the width between the two inner link plates. These designs ensure a precise fit between the drive sprocket and the drive chain. The arc-shaped and beveled chamfers not only reduce wear between the chain and the teeth, extending the service life of the components, but also make the engagement and disengagement of the chain and sprocket smoother, reducing the probability of chain jamming and other malfunctions. The fit between the tooth thickness and the width of the inner link plates makes the chain more stable during operation, preventing chain malfunctions caused by teeth that are too wide or too narrow. Attached Figure Description
[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only involve some embodiments of this utility model, and are not intended to limit this utility model.
[0021] Figure 1This is a schematic diagram of the structure of an existing bicycle transmission assembly in the background art of this utility model;
[0022] Figure 2 This is a schematic diagram of the structure of a conventional bicycle drive sprocket in the background art of this utility model;
[0023] Figure 3 This is a schematic diagram of the bicycle transmission assembly in an embodiment of the present invention;
[0024] Figure 4 This is a schematic diagram of the bicycle drive sprocket in an embodiment of the present invention;
[0025] Figure 5 This is a side sectional view of the bicycle drive chain wheel in an embodiment of this utility model.
[0026] Figure label:
[0027] 100. Drive sprocket; 110. Sprocket body; 111. Mounting hole; 112. Spline groove; 120. Tooth; 121. Load side; 1211. Contact area; 1212. Limiting area; 122. Curved bevel; 123. Curved chamfer; 124. Bevel chamfer;
[0028] 200. Drive chain; 210. Chain roller; 220. Inner link; 221. Inner link plate; 230. Outer link; 231. Outer link plate;
[0029] 300. Drive sprocket. Detailed Implementation
[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the utility model will be further described in detail below with reference to the accompanying drawings. The components of the embodiments of this utility model described and shown in the accompanying drawings can be arranged and designed in various different configurations. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.
[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0032] Unless otherwise defined, the technical or scientific terms used in this patent document shall have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model patent specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an," "a," or "the" do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" indicate that the element or object preceding "comprising" encompasses the element or object listed following "comprising" or its equivalents, and do not exclude other elements or objects. Terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are used only to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. 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, and therefore should not be construed as a limitation of this utility model.
[0033] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0034] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the features in the following embodiments can be combined with each other.
[0035] Example 1:
[0036] like Figure 3 and Figure 4As shown, the anti-chain slippage bicycle drive sprocket of this utility model, as a core component of the bicycle transmission system, meshes with the drive chain 200. The drive sprocket 100 includes a sprocket body 110 and multiple teeth 120 formed on the circumference of the sprocket body 110. The sprocket body 110 has a disc-shaped structure, and its material can be a high-strength metal material, such as aluminum alloy or steel, to ensure that the sprocket has sufficient strength and wear resistance to withstand the power transmitted during riding and various external forces. A mounting hole 111 is provided in the middle of the sprocket body 110, and several spline grooves 112 are provided on the circumference of the mounting hole 111. These spline grooves 112 are used to mate with a spline shaft for installation, thereby realizing the connection between the drive sprocket and the left crank and right crank, and transmitting the power generated by the rider pedaling to the drive sprocket.
[0037] In this embodiment, the tooth height of the tooth 120 is set in the range of 33.5-36.5mm. Compared with the tooth height of a traditional drive sprocket, this tooth height range can significantly increase the meshing depth between the chain and the sprocket. Furthermore, the tooth 120 also has an arc-shaped hook structure facing the load side 121, further forming a wrapping and limiting effect on the chain roller. During bicycle riding, a stable meshing relationship needs to be maintained between the chain and the sprocket to ensure effective power transmission. When the tooth height is within this range, the chain roller 210 can be more deeply embedded between the teeth, making it less likely for the chain to come off the sprocket when subjected to external forces such as bumps, vibrations, or heavy pedaling by the rider. For example, during mountain biking, frequent gear changes and bumps in complex road conditions place extremely high demands on the meshing stability of the chain and sprocket. The tooth height design of this invention can effectively cope with these situations, ensuring smooth and safe riding.
[0038] like Figure 4 As shown, the load-bearing side 121 of each tooth 120 is configured to transmit the force on the corresponding tooth to the chain roller 210. In some embodiments, the tooth 120 also has an arc-shaped inclined surface 122 opposite to the load-bearing side 121, and the arc-shaped inclined surface 122 and the load-bearing side 121 bend in the same direction, together forming an arc-shaped hook structure. This structure allows the tooth 120 to wrap around and limit the chain roller 210 when the drive chain 200 meshes with the sprocket. When the chain is subjected to external force, the arc-shaped hook structure can constrain the chain roller 210 between the teeth, limiting the displacement of the chain, thereby effectively preventing the chain from easily coming off the sprocket. In actual riding, when the bicycle goes over speed bumps or potholes, the chain will be subjected to a large impact force. At this time, the arc-shaped hook structure can play its limiting role, maintaining the stable meshing of the chain and the sprocket, and preventing the chain from falling off.
[0039] In some embodiments, the tooth height of the transmission sprocket 300 is designed to be 20.0-30.0 mm. This tooth height is reasonably matched with the tooth height of the drive sprocket, which can ensure that the transmission chain 200 can smoothly transmit between the drive sprocket and the transmission sprocket 300.
[0040] In some embodiments, the load-bearing side 121 of the tooth 120 is further subdivided into a contact area 1211 and a limiting area 1212, wherein the limiting area 1212 is arc-shaped. The contact area 1211 is mainly responsible for contacting the chain roller 210 and transmitting the power of the drive sprocket to the chain. The limiting area 1212, through its special arc-shaped hook structure, limits the chain roller 210 during chain operation. During the meshing process between the chain and the sprocket, when the chain roller 210 enters the tooth 120, the contact area 1211 first contacts the chain roller 210 and transmits power. As the chain rotates, the chain roller 210 gradually enters the limiting area 1212. The arc-shaped hook structure of the limiting area 1212 can further constrain the chain roller 210, ensuring that the chain always remains in the correct position during operation and preventing the chain from deviating or coming off.
[0041] In some embodiments, see Figure 4 and Figure 5 The tooth 120 has a width direction along the circumference of the sprocket body 110 and a thickness direction along the axial direction of the sprocket body 110. In the width direction, the tip of the tooth 120 has an arc-shaped chamfer 123; in the thickness direction, the tip of the tooth 120 has a beveled chamfer 124, preferably at an angle of 75 degrees. The arc-shaped chamfer 123 and the beveled chamfer 124 design have multiple advantages. On the one hand, they can effectively reduce friction and wear between the chain and the tooth. During the frequent engagement and disengagement of the chain and sprocket, if the tip of the tooth has a right-angle structure, it is easy to generate greater friction with the chain, leading to increased wear on the chain and teeth and reducing the service life of the transmission system. The arc-shaped chamfer 123 and the beveled chamfer 124 make the contact between the chain and the tooth smoother, reducing frictional resistance and extending the service life of the components. On the other hand, this chamfer design makes the engagement and disengagement process of the chain and sprocket smoother, reducing the probability of chain jamming and other malfunctions. During chain shifting, the chain needs to switch between sprockets of different sizes. At this time, the chamfer design can help the chain enter or leave the teeth more smoothly, improving the smoothness and reliability of shifting.
[0042] In some embodiments, the drive chain 200 includes alternating inner links 220 and outer links 230 connected by chain rollers 210. The inner link 220 includes inner link plates 221 respectively installed at both ends of the chain roller 210, defining a first receiving space between the two inner link plates 221; the outer link 230 includes an outer link plate 231 installed at the end of the chain roller 210 and located outside the inner link plates 221, defining a second receiving space between the two outer link plates 231. In this invention, the thickness of the teeth 120 is less than the width between the two inner link plates 221. This dimensional design ensures precise fit between the drive sprocket and the drive chain. The teeth 120 can smoothly embed into the first receiving space between the inner link plates 221, ensuring stable meshing between the chain and the sprocket while preventing chain obstruction due to excessively wide teeth and ensuring stable power transmission stability due to excessively narrow teeth. During chain operation, this fit relationship enables the chain to run smoothly on the drive sprocket, reducing chain swaying and jumping, and further improving the stability of the transmission system.
[0043] Example 2:
[0044] This utility model discloses an anti-chain-drop bicycle transmission assembly, comprising a drive sprocket 100, a drive chain 200, and a drive sprocket 300. The drive sprocket 100 is the anti-chain-drop bicycle drive sprocket described in Embodiment 1. During bicycle transmission, the drive sprocket 100 transmits power to the drive chain 200 through the meshing of its teeth 120. The chain then transmits the power to the drive sprocket 300, thereby driving the rear wheel of the bicycle to rotate. Because the drive sprocket employs an anti-chain-drop design, and the tooth height of the drive sprocket 300 is matched to that of the drive sprocket, the entire transmission assembly effectively prevents chain drop during operation. In various riding scenarios, such as urban road riding, highway riding, or mountain biking, this transmission assembly can operate stably and reliably, ensuring the normal operation of the bicycle.
[0045] During installation, first, install the drive sprocket onto the splined shaft through mounting holes 111 and spline grooves 112, ensuring a tight fit between the drive sprocket and the splined shaft. Then, engage the drive chain 200 with the drive sprocket and drive sprocket 300 sequentially, ensuring the chain rollers 210 align correctly with the teeth to allow the chain to move smoothly between the two sprockets. Finally, install the left and right cranks, fixing them to both ends of the splined shaft. By stepping on the left and right cranks, the drive sprocket will rotate, transmitting power.
[0046] Example 3:
[0047] This utility model discloses an anti-chain-drop bicycle, comprising a frame, a transmission assembly, and a crank assembly. The transmission assembly adopts the anti-chain-drop bicycle transmission assembly from Embodiment 2, and the crank assembly includes a left crank and a right crank respectively mounted on either side of the drive sprocket. The frame, as the main structure of the bicycle, provides support and a mounting base for other components. During bicycle assembly, the transmission assembly is first installed on the frame, ensuring the accurate positioning of the drive sprocket, drive chain 200, and drive sprocket 300, and that the chain tension is appropriate. Then, the left and right cranks are connected to the drive sprocket via splined shafts and tightened to ensure that there is no relative rotation between the crank assembly and the drive sprocket during riding.
[0048] During actual riding, the rider pedals the left and right cranks, driving the drive sprocket to rotate. The teeth of the drive sprocket mesh with the drive chain 200, transmitting power to the chain, which then transmits the power to the drive sprocket 300, thereby driving the rear wheel and propelling the bicycle forward. Because the drive sprocket employs an anti-chain-drop design, and the transmission and crank components fit tightly together, the bicycle maintains stable operation under various riding conditions, such as acceleration, deceleration, climbing, or descending, effectively preventing chain drop. Furthermore, this invention significantly improves comfort and reliability, providing riders with a better riding experience.
[0049] In summary, this invention effectively solves the problem of chain slippage in existing bicycles by optimizing the design of the bicycle's drive sprocket, transmission components, and overall bicycle structure. It improves the stability and reliability of the bicycle's transmission system, possessing high practical value and promising market prospects. In actual production and application, the dimensions and parameters of each component of this invention can be appropriately adjusted according to the needs of different types of bicycles to meet diverse market demands.
[0050] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.
Claims
1. A bicycle drive sprocket for preventing chain slippage, the drive sprocket engaging in a drive chain having chain rollers, the drive sprocket comprising a sprocket body and a plurality of teeth formed on the circumference of the sprocket body, each tooth having a load-bearing side configured to transmit force on the corresponding tooth to the chain rollers; characterized in that: The tooth height is 33.5 to 36.5 mm, and the tooth has an arc-shaped hook structure facing the load side, so that when the transmission chain meshes with the sprocket, the tooth forms a certain wrapping and limiting effect on the chain roller.
2. The active sprocket for a bicycle of claim 1, wherein, The tooth also has an arc-shaped inclined surface opposite to the load-bearing side, and the arc-shaped inclined surface bends in the same direction as the load-bearing side to form the arc-shaped hook structure.
3. The active sprocket for a bicycle of claim 1 wherein, The load-bearing side of the tooth includes a contact area and a limiting area, wherein the limiting area is arc-shaped and hook-shaped.
4. The active sprocket for a bicycle of claim 1 wherein, The transmission chain is also engaged with a transmission sprocket, the tooth height of which is 20.0 to 30.0 mm.
5. The active sprocket for a bicycle of claim 1 wherein, The tooth has a width direction along the circumference of the sprocket body and a thickness direction along the axial direction of the sprocket body. In the width direction, the top of the tooth has an arc-shaped chamfer, and in the thickness direction, the top of the tooth has a beveled chamfer.
6. The active sprocket for a bicycle of claim 1 wherein, The drive chain includes alternating inner and outer links connected by the chain rollers. Each inner link includes inner link plates respectively installed at both ends of the chain rollers, with a first receiving space defined between the two inner link plates. Each outer link includes an outer link plate installed at the end of the chain rollers and located outside the inner link plates, with a second receiving space defined between the two outer link plates.
7. The active sprocket for a bicycle of claim 6 wherein, The thickness of the tooth is less than the width between the two inner link plates.
8. The active sprocket for a bicycle of claim 1 wherein, The chain roller has a left crank and a right crank installed on both sides respectively. The sprocket body has a mounting hole in the middle. The circumference of the mounting hole is provided with several spline grooves for mounting a spline shaft. The left crank and the right crank are respectively installed at both ends of the spline shaft.
9. A drop chain prevention bicycle drive assembly comprising a drive sprocket, a drive chain and a drive sprocket, characterised in that, The drive sprocket is the drive sprocket according to any one of claims 1 to 8.
10. A chain drop prevention bicycle comprising a frame, a drive assembly and a crank assembly, the crank assembly connecting the drive assembly, characterised in that, The transmission assembly includes the drive sprocket, transmission chain, and transmission sprocket as described in any one of claims 1 to 8, and the crank assembly includes a left crank and a right crank respectively mounted on both sides of the drive sprocket.