A mid-mounted continuously variable transmission engine

Abstract

This utility model relates to the field of automotive engine technology, specifically to a mid-mounted continuously variable transmission (CVT) engine. It includes an engine housing, a drive wheel, a driven wheel, a crankshaft assembly, and a driven wheel output shaft. The engine housing comprises a left housing and a right housing. The crankshaft assembly includes a crank and a drive sprocket. A reduction gear assembly is provided on the driven wheel output shaft and connected to the output shaft. A shaft hole is provided on the left housing, and the output shaft is installed in the shaft hole and located on the central axis of the engine housing. This utility model adopts a central shaft drive, which offers high transmission efficiency, smooth power transmission, and convenient maintenance. Furthermore, by moving the CVT from its usual left-side mounting to a reverse right-side mounting, the forces on both sides of the crankshaft are more balanced, effectively improving the service life of the crankshaft assembly. This solves the problems of complex shifting operation, slow response, and poor shifting comfort in existing mid-mounted engines.

Description

Technical Field

[0001] This utility model relates to the field of automotive engine technology, and in particular to a mid-mounted continuously variable transmission (CVT) engine. Background Technology

[0002] Current underbone motorcycles typically use mid-mounted, horizontally mounted, automatic clutch engines. In the engine's transmission structure, the rotational driving force of the crankshaft assembly is transmitted to the clutch via gears, and then from the clutch through the main shaft assembly and countershaft assembly to output rotational power to the wheels, thus driving the vehicle forward. To match the crankshaft's operating speed with the vehicle's speed and power, a stepped transmission is generally used. A multi-stage transmission consists of various gear pairs on the main shaft assembly and countershaft assembly, typically 4 to 6 pairs, with only one pair engaged during operation. When the vehicle speed needs adjustment, the driver usually manually releases the accelerator to reduce the engine speed. After the speed decreases, the engine automatically disengages from the clutch. Then, the driver uses their hand or foot to operate the gear lever, shifting between different gear ratios to match the engine crankshaft speed with the vehicle speed. However, underbone motorcycles using stepped transmissions experience strong jerking during operation, resulting in lower comfort. Utility Model Content

[0003] The purpose of this invention is to provide a mid-mounted continuously variable transmission (CVT) engine that solves the problems of complex shifting operation, slow response, and poor shifting comfort of existing mid-mounted engines.

[0004] To achieve the above objectives, this utility model provides a mid-mounted continuously variable transmission (CVT) engine, including an engine housing. The engine housing includes a left housing and a right housing connected to the left housing. The engine housing is provided with a drive wheel, a driven wheel, a crankshaft assembly, and a driven wheel output shaft.

[0005] The crankshaft assembly includes a crank and a drive sprocket. The two ends of the crank are connected to the left housing and the right housing, respectively. The drive sprocket is sleeved on the end of the crank connected to the right housing in the opposite direction. The drive sprocket is provided on the end of the crank connected to the left housing. The driven wheel output shaft is provided on the right housing. The driven wheel is sleeved on the driven wheel output shaft in the opposite direction. Both the drive wheel and the driven wheel are located inside the right housing.

[0006] A speed reduction assembly is provided on the driven wheel output shaft. The speed reduction assembly is located in the left housing and is connected to the output shaft.

[0007] The left housing has a shaft hole, and the output shaft is installed in the shaft hole and located on the central axis of the engine housing;

[0008] The driving wheel and the driven wheel are provided with V-shaped grooves, and a belt is provided between the driving wheel and the driven wheel, the belt being wrapped around the V-shaped grooves.

[0009] The driven wheel output shaft is provided with a driven wheel positioning bushing, and the driven wheel is fixed in the opposite direction on the driven wheel output shaft through the driven wheel positioning bushing and the first nut.

[0010] The drive wheel is fixed to the crank in the opposite direction by the drive wheel positioning bushing and the second nut.

[0011] The left housing contains a starter motor, which is connected to the crankshaft assembly via gear transmission.

[0012] The driving wheel is provided with a driving wheel washer on one side; the driven wheel is provided with a driven wheel washer on one side.

[0013] This utility model discloses a mid-mounted continuously variable transmission (CVT) engine. The output shaft is located on the central axis of the engine housing, employing a central shaft drive. This design offers high transmission efficiency, smooth power transmission, and convenient maintenance. Since only a drive wheel is fitted between the crankshaft and the right housing, the connection length between them is effectively shortened, resulting in better stress distribution on the crankshaft and reduced damage. Furthermore, moving the CVT from its usual left-side mounting to a reverse mounting on the right side balances the stress on both sides of the crankshaft, effectively extending the service life of the crankshaft assembly. The reverse mounting structure does not require altering the existing CVT structure, thus improving the versatility of the CVT mechanism, reducing manufacturing costs, and ultimately solving the problems of complex shifting operations, slow response, and poor shifting comfort in existing mid-mounted engines. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0015] Figure 1 This is a schematic diagram of the overall structure of the mid-mounted continuously variable transmission (CVT) engine of this utility model.

[0016] Figure 2 This is a schematic diagram of the internal structure of the mid-mounted continuously variable transmission (CVT) engine of this utility model.

[0017] Figure 3 This is a cross-sectional view of the mid-mounted continuously variable transmission (CVT) engine of this utility model.

[0018] In the diagram: 1-Engine housing, 101-Left housing, 102-Right housing, 2-Drive wheel, 3-Driven wheel, 302-Driven wheel washer, 4-Belt, 5-Starter motor, 6-Reduction gear assembly, 7-Crankshaft assembly, 701-Crank, 703-Drive sprocket, 8-Output shaft, 9-Driven wheel output shaft, 11-First nut, 12-Output shaft bushing, 13-Driven wheel positioning sleeve, 14-Sliding sleeve, 15-Driven wheel positioning sleeve, 16-Driven wheel washer, 17-Second nut, 18-O-ring seal, 19-Retaining ring. Detailed Implementation

[0019] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0020] like Figures 1 to 3 As shown, where Figure 1 This is a schematic diagram of the overall structure of a mid-mounted continuously variable transmission (CVT) engine. Figure 2 This is a schematic diagram of the internal structure of a mid-mounted continuously variable transmission (CVT) engine. Figure 3 This is a cross-sectional view of a mid-mounted continuously variable transmission (CVT) engine. The present invention provides a mid-mounted CVT engine comprising an engine housing 1, a drive wheel 2, a driven wheel 3, a crankshaft assembly 7, and a driven wheel output shaft 9. The engine housing 1 includes a left housing 101 and a right housing 102. The crankshaft assembly 7 includes a crank 701 and a drive sprocket 703. A reduction gear assembly 6 is mounted on the driven wheel output shaft 9 and connected to an output shaft 8. A shaft hole is formed in the left housing 101, and the output shaft 8 is installed in the shaft hole and located on the central axis of the engine housing 1. This solution solves the problems of complex shifting operation, slow response, and poor shifting comfort in existing mid-mounted engines. It is understood that the aforementioned solution can improve transmission efficiency and shifting comfort.

[0021] In this embodiment, the engine housing 1 includes a left housing 101 and a right housing 102 connected to the left housing 101, and the left housing 101 and the right housing 102 are assembled by bolt connection.

[0022] The crank 701 is connected at both ends to the left housing 101 and the right housing 102, respectively. The end of the crank 701 connected to the right housing 102 is fitted with the drive wheel 2 in a reverse manner. The end of the crank 701 connected to the left housing 101 is equipped with the drive sprocket 703. The right housing 102 is equipped with the driven wheel output shaft 9, and the driven wheel 3 is fitted in a reverse manner onto the driven wheel output shaft 9. Both the drive wheel 2 and the driven wheel 3 are located inside the right housing 102. The drive wheel 2 and the driven wheel 3 are fitted in a reverse manner. The installation method, where only the drive wheel 2 is fitted between the crank 701 and the right housing 102, effectively shortens the connection length between the crank 701 and the right housing 102. This results in better stress distribution on the crank 701, making it less prone to damage. Furthermore, moving the continuously variable transmission (CVT) from its usual left-side mounting to a reverse right-side mounting allows for more balanced stress distribution on both sides of the crankshaft assembly 7, effectively extending its service life. The reverse mounting structure does not require altering the existing CVT structure, thus improving the versatility of the CVT product and reducing manufacturing costs.

[0023] A speed reduction assembly 6 is provided on the driven wheel output shaft 9. The speed reduction assembly 6 is located inside the left housing 101 and is connected to the output shaft 8. The speed reduction assembly 6 is used for speed adjustment.

[0024] The left housing 101 has a shaft hole, and the output shaft 8 is installed in the shaft hole and located on the central axis of the engine housing 1. This structure realizes the central shaft drive of the engine, which has high transmission efficiency, smooth power transmission, and is easy to maintain.

[0025] The driving wheel 2 and the driven wheel 3 are provided with V-shaped grooves, and a belt 4 is arranged between the driving wheel 2 and the driven wheel 3, with the belt 4 wrapped around the V-shaped grooves. This structure facilitates stable transmission by the belt 4.

[0026] Secondly, a driven wheel positioning sleeve 13 is provided on the driven wheel output shaft 9, and the driven wheel 3 is fixed to the driven wheel output shaft 9 in the opposite direction by the driven wheel positioning sleeve 13 and the first nut 11. This structure facilitates the installation and fixation of the driven wheel 3.

[0027] Then, the drive wheel 2 is fixed to the crank 701 in the opposite direction by the drive wheel positioning bushing 15 and the second nut 17. This structure facilitates the installation and fixation of the drive wheel 2.

[0028] Furthermore, a starter motor 5 is provided inside the left housing 101, and the starter motor 5 is connected to the crankshaft assembly 7 via gear transmission.

[0029] Finally, a drive wheel washer 16 is provided on one side of the drive wheel 2; a driven wheel washer 302 is provided on one side of the driven wheel 3. The corresponding washer structures are used for installation and mating.

[0030] When using the mid-mounted continuously variable transmission (CVT) engine of this invention, the engine operation process is as follows: the output shaft of the starter motor 5 rotates, driving the crankshaft assembly 7 to rotate around its own axis. The drive pulley 2, fixed on the crankshaft assembly 7, rotates accordingly, driving the driven pulley 3 to rotate via the belt 4. The driven pulley 3, in turn, drives the driven pulley output shaft 9 to rotate via its own clutch device. The driven pulley output shaft 9 transmits power to the reduction assembly 6 and outputs power externally through the output shaft 8. The drive pulley 2, driven pulley 3, and belt 4 together form a transmission system. This transmission system automatically adjusts the working rotation radius between the drive pulley 2 and the driven pulley 3 as the speed of the drive pulley 2 increases or decreases, thereby adjusting the speed ratio between the drive pulley 2 and the driven pulley 3, thus achieving automatic speed change.

[0031] Furthermore, since the output shaft 8 described in this application is located on the central axis of the engine housing 1, central shaft transmission is achieved, which has high transmission efficiency, smooth power transmission, and convenient maintenance. Since only the drive wheel 2 is sleeved between the crank 701 and the right housing 102, the connection length between the crank 701 and the right housing 102 is effectively shortened, the crank 701 is better subjected to force and is not easily damaged. At the same time, moving the continuously variable transmission from the usual left-side installation to the right-side reverse installation makes the force on the left and right sides of the crankshaft assembly 7 more balanced, effectively improving the service life of the crankshaft assembly 7. The reverse installation structure does not require changing the existing continuously variable transmission structure, thereby improving the versatility of the continuously variable transmission mechanism product, reducing manufacturing costs, and thus solving the problems of complex shifting operation, slow response, and poor shifting comfort of the mid-mounted engine in the prior art.

[0032] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A mid-mounted continuously variable transmission (CVT) engine, comprising an engine housing, the engine housing including a left housing and a right housing connected to the left housing, characterized in that: The engine housing contains a drive wheel, a driven wheel, a crankshaft assembly, and a driven wheel output shaft. The crankshaft assembly includes a crank and a drive sprocket. The two ends of the crank are connected to the left housing and the right housing, respectively. The drive sprocket is sleeved on the end of the crank connected to the right housing in the opposite direction. The drive sprocket is provided on the end of the crank connected to the left housing. The driven wheel output shaft is provided on the right housing. The driven wheel is sleeved on the driven wheel output shaft in the opposite direction. Both the drive wheel and the driven wheel are located inside the right housing. A speed reduction assembly is provided on the driven wheel output shaft. The speed reduction assembly is located in the left housing and is connected to the output shaft. The left housing has a shaft hole, and the output shaft is installed in the shaft hole and located on the central axis of the engine housing; The driving wheel and the driven wheel are provided with V-shaped grooves, and a belt is provided between the driving wheel and the driven wheel, the belt being wrapped around the V-shaped grooves.

2. The mid-mounted continuously variable transmission engine as described in claim 1, characterized in that: A driven wheel positioning sleeve is provided on the driven wheel output shaft, and the driven wheel is fixed in the opposite direction on the driven wheel output shaft through the driven wheel positioning sleeve and the first nut.

3. The mid-mounted continuously variable transmission engine as described in claim 1, characterized in that: The drive wheel is fixed to the crank in the opposite direction by the drive wheel positioning bushing and the second nut.

4. The mid-mounted continuously variable transmission engine as described in claim 1, characterized in that: The left housing contains a starter motor, which is connected to the crankshaft assembly via gear transmission.

5. The mid-mounted continuously variable transmission engine as described in claim 1, characterized in that: A drive wheel washer is provided on one side of the drive wheel; a driven wheel washer is provided on one side of the driven wheel.

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