TWI534038B - Bicycle rear sprocket assembly - Google Patents

Description

Bicycle rear sprocket assembly

The present invention relates to a bicycle, and more particularly to a rear sprocket assembly for a bicycle.

In modern society, cycling has become more popular and popular. Whether it is an amateur rider or a professional rider, the pursuit of speed has become more eager. Therefore, the number of shifts in the bicycle transmission mechanism is increasing, and the number of sprockets of the sprocket assembly mounted on the rear drum of the bicycle is also from the previous six. Increase to ten or more. As the number of sprockets increases, the radial dimension of the sprocket also increases, and the weight of the entire sprocket assembly is greatly increased. The strength requirements for a single sprocket, especially a sprocket with a large radial size, are also increased. In order to prevent the lateral deformation of the sprocket with a large number of teeth during use, it not only affects the shifting effect, but also causes damage to the entire assembly. At the same time, in order to reduce the overall weight of the assembly, the sprocket assembly is required to be redesigned to meet the needs of the market.

Patent CN101088851A discloses a similar design, but one disadvantage of this design is that the first sprocket and the second sprocket with the largest number of teeth are connected to the third sprocket by rivets, and the first and second sprocket are subjected to The force is also transmitted to the third sprocket by the rivet, and then transmitted by the third sprocket to the keyway of the bicycle rear drum, so that the torque of the third sprocket is very large, especially when used for mountain sports. The internal spline of the third sprocket and the hub is easily damaged; in addition, since the first sprocket and the second sprocket are not in direct contact with the rear hub of the bicycle, when the sprocket assembly is mounted on the rear hub When you must use a specific rear hub to Cooperate, or add a specific size of accessories to ensure the correct installation position of the sprocket assembly, which will inevitably increase the production cost of the bicycle.

U.S. Patent No. 5,194,051 discloses a frame-like sprocket structure which can well solve the lateral deformation of a large-sized sprocket during use, and at the same time, because each sprocket is connected by a plurality of fixing members in a lighter quality. The claw-shaped frame structure has an integral portion of the frame that engages with the rear drum of the bicycle. The weight of the overall assembly of the sprocket will be much reduced. However, this type of sprocket structure requires a very high processing requirement for the intermediate frame parts, and the number of parts required and the assembly time are correspondingly increased. Therefore, the cost of the sprocket assembly of this type is also very high.

SUMMARY OF THE INVENTION The object of the present invention is to overcome the deficiencies of the prior art and to provide a bicycle rear sprocket assembly which is structurally sound, low in production cost, light in weight, strong in torsional rigidity, and easy to produce and assemble.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solution: a bicycle rear sprocket assembly including at least three sprocket wheels arranged in parallel from large to small, wherein the largest and small sprocket are spoke sprocket At the center of the largest and small sprocket, there is a spline that can be sleeved outside the rear drum of the bicycle; and the middle sprocket is a hollow ring sprocket, that is, the center of the intermediate sprocket is not directly connected with the rear hub of the bicycle Contact; adjacent sprocket wheels are connected by a plurality of fasteners distributed at a circumferential interval, and the fastener is provided with a partition which separates adjacent sprockets in parallel.

In a modification of the bicycle rear sprocket assembly, the fastener is a screw or a rivet, which is riveted or screwed at one end of one of the adjacent sprockets, and the other end is To insert into the corresponding jack of the other wheel chain.

In a modification of the bicycle rear sprocket assembly described above, the splined end of the largest sprocket is just in contact with the splined end of the smallest sprocket.

Compared with the prior art, the beneficial effects of the present invention are: 1), because it is sleeved on the rear hub of the bicycle through the spline of the largest and small sprocket, and the intermediate sprocket does not overlap with the rear hub of the bicycle Therefore, the intermediate sprocket can be made into a hollow ring type, so that the weight of the intermediate sprocket can be greatly reduced, and the material is saved. When the number of sprocket wheels of the rear sprocket assembly is increased, the weight is reduced more obviously. After being applied to the bicycle transmission mechanism with more shifting numbers, the weight of the bicycle is still greatly reduced, and the speed of the rider is satisfied, so the invention can achieve weight reduction, reasonable structure and low production cost; 2) There is no need for a specific rear hub to cooperate with it, so that the production and assembly of the sprocket assembly is simple and easy; 3) at the same time, since the present invention is sleeved on the rear hub by the largest and small sprocket on both sides, The sprocket is simultaneously stressed, which ensures the torsional rigidity of the sprocket assembly and is less prone to deformation, thus ensuring the safety and reliability of the bicycle.

1,2‧‧‧Sprocket

11, 21‧‧‧ spline

3‧‧‧Intermediate sprocket

4‧‧‧fasteners

5‧‧‧ separate table

6‧‧‧ jack

1 is a perspective view of an embodiment of the present invention; and FIG. 2 is an assembled view of an embodiment of the present invention.

The present invention is a bicycle rear sprocket assembly, as shown in Figures 1 and 2, which includes at least three sprocket wheels arranged in parallel from large to small, wherein the largest and small sprocket wheels 1, 2 are spoke sprocket wheels, The center of the largest and small sprockets 1, 2 is provided with splines 11 and 21 which can be sleeved outside the rear drum of the bicycle; and the intermediate sprocket 3 is a hollow ring type sprocket, that is, the center of the intermediate sprocket 3 is not After the bike The hub is in direct contact; adjacent sprocket wheels are connected by a plurality of fasteners 4 distributed circumferentially, and the fastener 4 is provided with a partition 5 which separates adjacent sprockets in parallel. Since the present invention is sleeved on the rear hub of the bicycle through the splines 11, 21 of the largest and small sprocket 1, 2, and the intermediate sprocket 3 is not spliced with the rear hub of the bicycle, the intermediate sprocket can be made The hollow ring type can greatly reduce the weight of the intermediate sprocket and save material. When the number of sprocket wheels of the rear sprocket assembly increases, the weight is reduced, so when the invention is applied to the shifting quantity, After the bicycle transmission mechanism, the weight of the bicycle is still greatly reduced, and the speed of the rider is satisfied, so the invention can realize the weight reduction, the structure is reasonable, the production cost is low, and the specific rear hub is not required to cooperate with the bicycle. Thus, the production and assembly of the sprocket assembly is simple and easy; at the same time, since the present invention is sleeved on the rear hub by the largest and small sprockets 1, 2 on both sides, the two sprockets are simultaneously stressed, thus ensuring The torsional rigidity of the sprocket assembly is not easily deformed, thus ensuring the safety and reliability of the bicycle.

The fastener 4 is typically a screw or rivet structure that is riveted or screwed at one end of one of the adjacent sprockets and the other end of which can be inserted into a corresponding receptacle 6 of the other chain. In the present embodiment, as shown in FIG. 2, the fastener 4 is a rivet which is riveted to the larger sprocket between the adjacent two sprockets, and of course, can be riveted to the smaller sprocket. It can even be staggered on the large and small sprocket wheels, and then the corresponding jacks are alternately arranged on the large and small sprocket wheels.

In this embodiment, as shown in FIG. 2, the end of the spline 11 on the largest sprocket 1 is just in contact with the end of the spline 21 of the smallest sprocket 2, which can increase the sleeve area with the rear hub. Thereby enhancing the torsional stiffness of the entire sprocket assembly.

In the present embodiment, the partition 5 is a circle that is directly fitted over the fastener. Of course, it can also be formed with the fastener.

In the present embodiment, the rear sprocket assembly has three sprocket wheels, so that there is only one intermediate sprocket 3; when the sprocket assembly then has four or more sprockets, then the intermediate sprocket has two or more.

While the invention has been described with reference to the embodiments thereof, it is understood that various modifications can be made within the spirit and scope of the inventive concept. Therefore, the invention is not limited to the described embodiments, but rather the full scope of the claims.

1,2‧‧‧Sprocket

11, 21‧‧‧ spline

3‧‧‧Intermediate sprocket

Claims (3)

A bicycle rear sprocket assembly characterized by comprising at least three sprocket wheels arranged in parallel from large to small, wherein the largest and small sprocket wheels (1, 2) are spoke sprocket, at the largest and small sprocket (1, 2) is provided with a spline (11, 21) that can be sleeved outside the rear drum of the bicycle; and the intermediate sprocket (3) is a hollow ring sprocket, that is, the center of the intermediate sprocket (3) It is not in direct contact with the rear hub of the bicycle; adjacent sprocket wheels are connected by a plurality of fasteners (4) distributed at intervals, and the fasteners (4) are provided with parallel separation of adjacent sprocket wheels. Separator (5). The bicycle rear sprocket assembly according to claim 1, characterized in that the fastener (4) is a screw or a rivet, which is riveted or screwed at one end of one of the adjacent sprockets, and the other end. It can be inserted into the corresponding jack (6) of the other chain. The bicycle rear sprocket assembly according to claim 1 or 2, characterized in that the end of the spline (11) on the largest sprocket (1) is just at the end of the spline (21) of the smallest sprocket (2) Contact docking.