Motorcycle rear fork swing arm mounting structure

Abstract

The utility model relates to a mounting structure for a swing arm of a rear fork of a motorcycle, which is characterized in that a mounting seat is arranged on a box body of an engine assembly, and an output shaft of an engine is rotatably mounted on the mounting seat; shaft sleeves are respectively fixed on the left side and the right side of the mounting seat, and the shaft sleeves and the output shaft on the mounting seat are coaxially arranged; the first end of the rear bottom fork is rotatably mounted on the shaft sleeve, and the rear wheel shaft is mounted at the second end of the rear bottom fork; after installation is completed, the output shaft penetrates out of the shaft hole of at least one shaft sleeve, the rear fork on the same side is rotatably installed on the outer side of the shaft sleeve, and an installation gap exists between the output shaft and the shaft sleeve on the same side in the radial direction of the output shaft. According to the scheme, it can be guaranteed that the fit clearance between the chain (transmission belt) and the chain wheel is constant, and the transmission and riding stability is guaranteed.

Description

Technical Field

[0001] This utility model relates to the technical field of motorcycle rear wheel drive system, and in particular to a motorcycle rear swingarm mounting structure. Background Technology

[0002] Most motorcycles currently sold on the market use a three-axle system, namely the engine output shaft, the swingarm shaft, and the rear wheel axle. Figure 1 This transmission structure swings up and down with the swingarm. When the rear shock absorber compression is too large, the distance between the output shaft and the rear wheel axle decreases. Since the chain length does not change, this leads to an increase in the gap between the sprocket and the chain (drive belt). Figure 2 This transmission condition can affect the lifespan of the chain or drive belt, and in severe cases, may cause belt slippage, tooth skipping, and other problems, accelerating wear on the chain (drive belt) and sprockets. This creates safety hazards for riders and increases vehicle maintenance costs. Summary of the Invention

[0003] In order to solve the above problems, the purpose of this utility model is to provide a motorcycle rear swingarm mounting structure so that the output shaft of the engine gearbox is coaxial with the swingarm shaft.

[0004] The motorcycle rear swingarm mounting structure includes a mounting base on the engine assembly housing, on which the engine output shaft is rotatably mounted. Bushings are fixed to the left and right sides of the mounting base, coaxially arranged with the output shaft on the mounting base. The first end of the rear swingarm is rotatably mounted on the bushings, and the rear wheel axle is mounted on the second end of the rear swingarm. After installation, the output shaft passes through the shaft hole of at least one bushing, and the rear swingarm on the same side is rotatably mounted on the outside of the bushing. A radial installation gap exists between the output shaft and the bushing on the same side.

[0005] Preferably, the bushing has a T-shaped cross-section, including a radial protrusion and an axial protrusion. The radial protrusion is fixed to the mounting base, and the axial protrusion is located outside the shaft hole of the mounting base.

[0006] Preferably, at least one of the left and right sides of the first end of the rear swingarm is provided as a detachable connecting plate. One end of the connecting plate is detachably fixed to the rear swingarm, and the other end of the connecting plate is provided with a shaft hole. At least a portion of the bushing on the same side is rotatably installed in the shaft hole of the connecting plate.

[0007] Preferably, the first end of the output shaft extends out of one side of the mounting base, and the second end of the output shaft is located inside the mounting base; the same side of the rear horizontal fork and the first end of the output shaft is provided with a detachable connecting plate, and the other side of the rear horizontal fork is rotatably connected to the bushing on that side via a rotating shaft.

[0008] This invention employs the above-mentioned solution to achieve coaxiality between the engine output shaft and the rear swingarm, meaning the rear swingarm swings with the output shaft as its axis. Compared to traditional rear wheel drive systems, this invention ensures a constant clearance between the chain (drive belt) and sprocket under different road conditions or loads, guaranteeing transmission and riding stability and safety, reducing vehicle maintenance costs, and improving ease of installation. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the structure of a triaxial system in the prior art;

[0010] Figure 2 for Figure 1 Schematic diagram of chain length variation;

[0011] Figure 3 This is a schematic diagram of the structure of this application;

[0012] Figure 4 for Figure 3 Top view;

[0013] Figure 5 This is a schematic diagram of the assembly structure of the bushing and the connecting plate.

[0014] Figure label:

[0015] 1. Small sprocket, 2. Output shaft, 3. Chain, 4. Connecting plate, 5. Rear horizontal fork, 6. Mounting base, 7. Rear wheel assembly, 8. Large sprocket, 9. Rear wheel axle, 10. Right flange bushing, 11. Left flange bushing. Detailed Implementation

[0016] The embodiments of this utility model are described in detail below.

[0017] like Figure 3-4 As shown, this embodiment provides a swingarm structure for a motorcycle rear swingarm 5. A mounting base 6 is provided on the engine assembly housing. The output shaft 2 of the engine assembly is rotatably mounted on the mounting base 6. It should be noted that, generally, the output shaft 2 of the engine assembly is the output shaft 2 of the gearbox. The mounting base 6 can be detachably fixed to the engine assembly housing using bolts or other connecting parts, or it can be integrally formed on the engine assembly housing. Bushings are provided on the left and right sides of the mounting base 6. These bushings are used to mount the rear swingarm 5. The bushings are coaxially arranged with the output shaft 2 on the mounting base 6. The first end of the rear swingarm 5 is rotatably mounted on the bushing, and the rear wheel axle 9 is mounted on the second end of the rear swingarm 5. A small sprocket 1 is mounted on the output shaft 2, and a large sprocket 8 is mounted on the rear wheel axle 9. The small sprocket 1 and the large sprocket 8 are driven by a chain 3, realizing the power transmission from the engine to the motorcycle rear wheel assembly 7. In other embodiments, the output shaft 2 of the engine assembly and the rear wheel axle 9 can also be driven by a pulley and a belt.

[0018] With the above structural configuration, the engine's output shaft 2 is coaxially aligned with the rotation shaft of the rear swingarm 5, ensuring that the length of the chain 3 or drive belt remains consistent during the swinging of the rear swingarm 5. Furthermore, the bushing allows for rotatable connection between the bushing and the rear swingarm 5, without affecting the installation of the engine assembly's output shaft 2, resulting in a simple installation structure.

[0019] In the above structure, there is an installation gap in the radial direction between the bushing's shaft hole and the output shaft 2. With this configuration, the engine's output shaft 2 extends through the shaft hole of at least one side of the bushing, and the rear swingarm 5 on that side is rotatably mounted on the outer periphery of the bushing's shaft hole. The radial gap between the output shaft 2 and the shaft hole of the shaft head ensures that, after the rear swingarm 5 is installed, the external force driving the rear swingarm 5 to rotate will not be output to the engine assembly's output shaft 2, thus avoiding affecting the operation of the engine's output shaft 2.

[0020] In this embodiment, the bushing has a T-shaped cross-section, including a radial protrusion and an axial protrusion. The radial protrusion is fixed to the mounting base 6, and the axial protrusion is located outside the shaft hole of the mounting base 6. The bushing and the mounting base 6 are detachably installed, allowing them to be manufactured and assembled independently, which improves production efficiency. In this embodiment, the bushing is a flange bushing, divided into a left flange bushing 11 and a right flange bushing 10 based on their location on the left and right sides of the mounting base 6. The flange bushing has multiple connecting holes on its flange and is fixed to the mounting base 6 with bolts. This embodiment uses a flange bushing, which utilizes existing parts and eliminates the need for new molds, thus saving production costs.

[0021] like Figure 4 and Figure 5As shown, at least one of the left and right sides of the first end of the rear swingarm 5 is provided with a detachable connecting plate 4. One end of the connecting plate 4 is detachably fixed to the rear swingarm 5, and the other end of the connecting plate 4 is provided with a shaft hole. At least a portion of the bushing on the same side is rotatably installed in the shaft hole of the connecting plate 4. With the above-mentioned detachable connecting plate 4 structure, it is easy to align the output shaft 2 with the shaft hole during installation, making installation convenient. In a specific embodiment, the above-mentioned detachable connecting plate 4 can be provided only on the side where the output shaft 2 extends out of the mounting base 6. In this embodiment, the first end of the output shaft 2 extends out of the mounting base 6, and the second end of the output shaft 2 is located inside the mounting base 6; the detachable connecting plate 4 is provided on the same side as the first end of the rear swingarm 5 and the first end of the output shaft 2, and the other side of the rear swingarm 5 is rotatably connected to the bushing on that side through a rotating shaft. With the above configuration, during assembly, the bushing is first fixed to both sides of the mounting base 6, and then the connecting plate 4 is installed. After the connecting plate 4 and the bushing are aligned in place, the rear swingarm 5 is then installed, so that the output shaft 2 and the bushing will not obstruct the connection of the first end of the rear swingarm 5, and the installation structure is simple. In other embodiments, connecting plates 4 are provided on both sides of the mounting base 6 to connect with the rear swingarm 5, which also achieves a structure in which the output shaft 2 and the rotation shaft of the rear swingarm 5 are coaxially arranged. This ensures a constant clearance between the chain 3 and the sprocket, guarantees the stability and safety of transmission and riding, reduces vehicle maintenance costs, and improves the ease of component installation.

[0022] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A motorcycle rear swingarm mounting structure, characterized in that, The engine assembly housing is provided with a mounting base, and the output shaft of the engine assembly is rotatably mounted on the mounting base; bushings are provided on the left and right sides of the mounting base, and the bushings are coaxially arranged with the output shaft on the mounting base; the first end of the rear swingarm is rotatably mounted on the bushing, and the rear wheel axle is mounted on the second end of the rear swingarm; after installation, the output shaft passes through the shaft hole of at least one bushing, and the rear swingarm on the same side is rotatably mounted on the outside of the bushing, and there is an installation gap in the radial direction between the output shaft and the bushing on the same side.

2. The motorcycle rear swingarm mounting structure according to claim 1, characterized in that, The bushing has a T-shaped cross-section, including a radial protrusion and an axial protrusion. The radial protrusion is fixed to the mounting base, and the axial protrusion is located outside the shaft hole of the mounting base.

3. The motorcycle rear swingarm mounting structure according to claim 1, characterized in that, At least one of the left and right sides of the first end of the rear swingarm is provided as a detachable connecting plate. One end of the connecting plate is detachably fixed to the rear swingarm, and the other end of the connecting plate is provided with a shaft hole. At least a portion of the bushing on the same side is rotatably installed in the shaft hole of the connecting plate.

4. The motorcycle rear swingarm mounting structure according to claim 3, characterized in that, The first end of the output shaft extends out of one side of the mounting base, and the second end of the output shaft is located inside the mounting base; the rear horizontal fork is provided with a detachable connecting plate on the same side as the first end of the output shaft, and the other side of the rear horizontal fork is rotatably connected to the bushing on that side via a rotating shaft.

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