CVT speed change mechanism

Abstract

The invention discloses a CVT speed change mechanism which comprises a driving belt pulley assembly, a driven belt pulley assembly and a driving triangular belt. The driving belt wheel assembly comprises a driving disc and a moving wheel which are coaxially arranged, a box body is arranged on the side, back to the driving disc, of the moving wheel, a moving shaft is slidably connected to the box body in the axial direction of the moving wheel, a fixed shaft is rotationally connected into the box body, and the fixed shaft is in threaded fit with the moving shaft; the box body is connected with a motor used for driving the fixed shaft to rotate, a slope plate is arranged between the movable shaft and the movable wheel, a pulley ball is connected between the slope plate and the movable wheel, and the movable wheel is provided with an inclined sliding groove matched with the pulley ball. According to the scheme, the problem that in the prior art, a CVT speed change mechanism is poor in compatibility is solved.

Description

Technical Field

[0001] This invention relates to continuously variable transmissions, specifically a CVT transmission mechanism. Background Technology

[0002] CVT transmission mechanism, also known as continuously variable transmission mechanism or stepless transmission mechanism, is a transmission device that can continuously obtain any transmission ratio within the transmission range.

[0003] Chinese patent document CN102109032A discloses an electrically controlled V-belt continuously variable transmission mechanism, including a V-belt; a drive pulley having a fixed part fixed to the drive pulley support shaft and a movable part that can move axially on the drive pulley support shaft, the drive pulley being driven by the power source; a driven pulley connected to the drive pulley, having a fixed part fixed to the driven pulley support shaft and a movable part that can move axially and rotate on the driven pulley support shaft, the driven pulley being driven by the drive pulley via the V-belt; and a pulley drive system connected to the drive pulley to provide power to drive the movable part of the drive pulley to move axially on the drive pulley support shaft, the distance of which the axial movement is between the fixed part and the movable part of the drive pulley, and The movable part of the driven pulley responds to the change in the axial movement distance of the movable part of the driving pulley on the driving pulley support shaft, and accordingly performs axial movement and rotational movement on the driven pulley support shaft to change the rotational speed of the driven pulley; and a transmission housing base for accommodating the driving pulley, the driven pulley, and the pulley drive system; wherein the pulley drive system includes: a bearing housing disposed on the movable part of the driving pulley and slidably connected to the driving pulley support shaft on which the driving pulley is attached, and having at least one cam guide groove; a gearbox cover connected to the front end portion of the transmission housing base; and at least one cam guide device disposed between the gearbox cover and the cam guide groove of the bearing housing disposed on the movable part of the driving pulley to guide the bearing housing disposed on the movable part of the driving pulley to move axially. The electrically controlled V-belt continuously variable transmission mechanism includes a transmission housing base cover, which engages with the transmission housing base to cover the drive pulley and the driven pulley; the pulley drive system includes: a motor for providing power; a gear system disposed between the motor and the drive pulley for transmitting the power output by the motor to the movable part of the drive pulley, and having a lead screw connected to a bearing seat disposed on the movable part of the drive pulley; and a sealing unit disposed between the gear housing cover and the bearing seat disposed on the movable part of the drive pulley to prevent the wet-lubricated gear system from leaking lubricating oil.

[0004] In this prior art, the motor directly drives the outer and inner lead screws to move the sliding pulley through the gear mechanism. However, due to the motor's fast response speed, the transmission ratio of the speed change mechanism is easily switched too quickly, resulting in power transmission fluctuations. This reduces the smooth speed change performance of the speed change mechanism, making it difficult for the speed change mechanism to meet conventional power transmission requirements. Furthermore, this speed change mechanism requires constant adjustment via the motor during use, increasing the complexity of its use and thus increasing the difficulty of operation. Summary of the Invention

[0005] The purpose of this invention is to provide a CVT transmission mechanism to solve the problem of poor compatibility of existing CVT transmission mechanisms.

[0006] To achieve the above objectives, the basic solution of the present invention provides a CVT transmission mechanism, including a driving pulley assembly, a driven pulley assembly, and a drive V-belt; the driving pulley assembly includes a drive disc and a movable wheel coaxially arranged, a housing is provided on the side of the movable wheel opposite to the drive disc, a movable shaft is slidably connected to the housing along the axial direction of the movable wheel, a fixed shaft is rotatably connected inside the housing, the fixed shaft is threadedly engaged with the movable shaft, a motor for driving the fixed shaft to rotate is connected to the housing, a ramp plate is provided between the movable shaft and the movable wheel, a jacking ball is connected between the ramp plate and the movable wheel, and the movable wheel is provided with an inclined groove that engages with the jacking ball.

[0007] The beneficial effects of this basic scheme are as follows: By using a motor to control the fixed and moving shafts to adjust the force between the ramp and the jacks, thereby changing the force and positional relationship between the moving wheel and the drive V-belt, the CVT transmission mechanism can better meet the requirements of sudden power changes (such as during start-up and acceleration), and the gear shifting is smoother, less prone to power fluctuations. When the motor is not used, the CVT transmission mechanism can be routinely adjusted using the jacks to meet conventional power transmission requirements. Compared with existing technologies, the CVT transmission mechanism in this scheme is compatible with various power demands, improving its versatility.

[0008] Preferably, a slider that slides along the axial direction of the moving wheel is connected between the ramp plate and the moving wheel. This arrangement helps to avoid sliding wear of the ramp plate and increases its stability, thereby improving structural reliability.

[0009] Preferably, the moving shaft and the ramp plate are rotatably fitted by a deep groove ball bearing. This arrangement helps reduce wear on the ramp plate, thereby improving structural reliability.

[0010] Preferably, the fixed shaft is connected to the motor via a gear transmission mechanism, which is located inside the housing. This arrangement facilitates lubrication of the gear transmission mechanism, thereby reducing wear and maintenance costs.

[0011] Preferably, an oil seal is provided at the mating surface between the moving shaft and the housing. This arrangement helps to prevent lubricating oil inside the housing from flowing out from the mating surface between the moving shaft and the housing, thus affecting the operation of the transmission mechanism.

[0012] Preferably, a support bearing is connected between the outer side of the fixed shaft and the housing. This arrangement allows the fixed shaft to be positioned directly on the outside of the housing, thus facilitating the assembly of the fixed shaft. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of an embodiment of a CVT transmission mechanism according to the present invention; Figure 2 for Figure 1 Schematic diagram of the central drive pulley assembly; Figure 3 for Figure 1 A schematic diagram of the driven pulley assembly. Detailed Implementation

[0014] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings include: drive disc 1, moving wheel 2, drive V-belt 3, housing 4, displacement sensor 5, motor 6, fixed disc shaft assembly 7, moving disc shaft assembly 8, slider 9, ramp 10, deep groove ball bearing 11, support bearing 12, crankshaft 13, moving shaft 14, fixed shaft 15, plenum beads 16, inclined slide 17, oil seal 18, gear transmission mechanism 19, speed regulating spring 20, and drive spindle 21.

[0015] The basic implementation examples are as follows: Figure 1 , Figure 2 and Figure 3The diagram shows a CVT transmission mechanism, including a drive pulley assembly, a driven pulley assembly, and a drive V-belt 3. The drive V-belt 3 connects the drive pulley assembly and the driven pulley assembly. The drive pulley assembly includes a drive disc 1 and a movable pulley 2 coaxially arranged. In this embodiment, a ramp 10 is provided between the movable shaft 14 and the movable pulley 2. A jacking ball 16 connects the ramp 10 and the movable pulley 2. The movable pulley 2 is provided with an inclined groove 17 that cooperates with the jacking ball 16. Under the action of the ramp 10, the jacking ball 16 is confined within the inclined groove 17. When the movable pulley 2 rotates, the jacking ball 16 can overcome the force of the ramp 10 and move radially along the movable pulley 2 according to the rotational speed of the movable pulley 2. A slider 9 that slides along the axial direction of the movable pulley 2 connects the ramp 10 and the movable pulley 2, thereby enabling the ramp 10 and the movable pulley 2 to slide together through the slider 9, which can reduce the performance degradation of the ramp 10 due to wear. In this embodiment, the moving shaft 14 and the ramp plate 10 are rotatably coupled through a deep groove ball bearing 11, so that the moving shaft 14 and the ramp plate 10 can rotate relative to each other while transmitting a large thrust, thereby reducing frictional resistance.

[0016] In this embodiment, a housing 4 is provided on the side of the ramp plate 10 opposite to the moving wheel 2. A moving shaft 14 is slidably connected to the housing 4 along the axial direction of the moving wheel 2. A fixed shaft 15 is rotatably connected inside the housing 4. The fixed shaft 15 and the moving shaft 14 are threadedly engaged, so that the rotation of the fixed shaft 15 can drive the moving shaft 14 to move axially. In this embodiment, a support bearing 12 is connected between the outer side of the fixed shaft 15 and the housing 4, so that the housing 4 supports and positions the fixed shaft 15 through the support bearing 12. An oil seal 18 is provided at the mating surface between the moving shaft 14 and the housing 4. A motor 6 for driving the fixed shaft 15 to rotate is connected to the housing 4. Preferably, the fixed shaft 15 and the motor 6 are connected by a gear transmission mechanism 19, which is located inside the housing 4. Specifically, the motor 6 and the fixed shaft 15 are connected by a two-stage reduction gear transmission mechanism 19. In this embodiment, a displacement sensor 5 for monitoring the movement displacement of the moving wheel 2 is installed on the housing 4. The displacement sensor 5 is electrically connected to the controller of the motor 6, thereby facilitating and better realizing the automated operation of the motor 6 control.

[0017] In this embodiment, the driven pulley assembly includes a fixed disc shaft assembly 7 and a movable disc shaft assembly 8 arranged coaxially. A speed regulating spring 20 is connected to the fixed disc shaft assembly 7 to drive the movable disc shaft assembly 8 to move axially, so that the movable disc shaft assembly 8 clamps the drive V-belt 3 with the fixed disc shaft assembly 7 under the elastic force of the speed regulating spring 20.

[0018] The specific implementation process is as follows: In use, the drive pulley assembly is mounted on the crankshaft 13, and the driven pulley assembly is mounted on the drive spindle 21, so that the power of the crankshaft 13 is transmitted to the drive spindle 21 through the CVT transmission mechanism. Taking a motorcycle equipped with a CVT transmission mechanism as an example, when the motorcycle starts, the fixed shaft 15 is rotated by controlling the motor 6. The fixed shaft 15 drives the moving shaft 14 to move away from the ramp 10, so that when the moving wheel 2 rotates, it drives the jacks 16 to rotate, which reduces the compression on the drive V-belt 3. This prolongs the time that the CVT transmission mechanism is in a high transmission ratio state, and thus the driven pulley always outputs a large driving force through the drive spindle 21 and maintains it for a longer time, enabling the motorcycle to overcome greater resistance and quickly increase speed, achieving a rapid start. After the speed increases, the ramp 10 is returned to its initial position by controlling the motor 6, and the CVT transmission mechanism returns to its normal operating state. When a rapid increase in vehicle speed is required during operation, the motor 6 drives the fixed shaft 15 to move the movable shaft 14 towards the ramp 10. The ramp 10 then compresses the ball bearings 16. Under the pressure of the ramp 10, the ball bearings 16 move towards the center of the movable wheel 2. However, due to centrifugal force, they also move away from the center of the movable wheel 2, causing the movable wheel 2 to compress the drive V-belt 3. This shifts the transmission ratio of the CVT transmission to a smaller ratio, thus achieving a faster speed increase. After the speed increase is complete, the motor 6 returns the ramp 10 to its initial position, restoring the CVT transmission to its normal operating state. This design allows the transmission ratio of the CVT transmission to be adjusted as needed to meet different power requirements.

[0019] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics in the solutions is not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A CVT transmission mechanism, comprising a driving pulley assembly, a driven pulley assembly, and a drive V-belt; the driving pulley assembly includes a drive disc and a movable pulley coaxially arranged, a housing is disposed on the side of the movable pulley opposite to the drive disc, a movable shaft is slidably connected to the housing along the axial direction of the movable pulley, a fixed shaft is rotatably connected inside the housing, the fixed shaft is threadedly engaged with the movable shaft, and a motor for driving the fixed shaft to rotate is connected to the housing, characterized in that: A ramp is provided between the moving shaft and the moving wheel, and a boulders are connected between the ramp and the moving wheel. The moving wheel is provided with an inclined groove that cooperates with the boulders.

2. The CVT transmission mechanism according to claim 1, characterized in that: A slider that slides along the axial direction of the moving wheel is connected between the ramp plate and the moving wheel.

3. A CVT transmission mechanism according to claim 2, characterized in that: The moving shaft and the ramp plate are rotated together by a deep groove ball bearing.

4. A CVT transmission mechanism according to claim 3, characterized in that: The fixed shaft is connected to the motor via a gear transmission mechanism, which is located inside the housing.

5. A CVT transmission mechanism according to claim 4, characterized in that: An oil seal is provided at the mating surface between the moving shaft and the housing.

6. A CVT transmission mechanism according to claim 5, characterized in that: A support bearing is connected between the outer side of the fixed shaft and the housing.

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