CVT speed change mechanism

Abstract

The utility model discloses a CVT (continuously variable transmission) speed change mechanism which comprises a box provided with a driving belt pulley assembly and a driven belt pulley assembly. The driving belt wheel assembly comprises a conical driving fixed disc and a driving movable disc, a movable shaft is coaxially and rotatably connected to the side, back to the driving fixed disc, of the driving movable disc, the movable shaft is in sliding fit with the box body in the axial direction, and a fixed shaft is coaxially and rotatably arranged on the movable shaft; the fixed shaft and the movable shaft are connected through a cylindrical cam mechanism, the fixed shaft is connected with a worm and gear mechanism, and a motor connected with the worm and gear mechanism is installed on the box body. According to the scheme, the problem that in the prior art, a CVT speed change mechanism is single in performance is solved, and the CVT speed change mechanism can meet different use performance requirements such as dynamic performance, economical efficiency and balance.

Description

Technical Field

[0001] The utility model relates to a continuously variable transmission device, in particular to a CVT transmission mechanism. Background Art

[0002] CVT transmission mechanism is a stepless transmission mechanism that can obtain any transmission ratio within the speed range. The traditional CVT transmission mechanism is controlled by a purely mechanical structure, and the same transmission mechanism can only meet one requirement, either good power, low fuel consumption, or a balance between the two.

[0003] Chinese patent document CN205371498U discloses a metal belt type continuously variable transmission that uses a motor to control mechanical transmission speed regulation, comprising: a driving shaft, which is rotatably supported on a transmission housing and is used to receive the rotational power of an engine or a motor; a driven shaft, which is rotatably supported on the transmission housing and is used to output the rotational power; and a first screw shaft, which is hollow inside, has threads on its outer surface, and is rotatably fixed on the driving shaft; a second screw shaft, which is hollow inside, has threads on its outer surface, and is rotatably fixed on the driven shaft; a first speed regulating mechanism, which is rotatably supported on an active cone disc, and is sleeved with the first screw shaft and threadedly matched; and can drive the active cone disc to move along the axial direction of the active shaft; a second speed regulating mechanism, which is rotatably supported on a driven cone disc, and is sleeved with the second screw shaft and threadedly matched; and can drive the driven cone disc to move along the axial direction of the driven shaft; a first motor, which drives the first screw shaft to rotate; and a second motor, which drives the second screw shaft to rotate. The effects of the prior art are as follows: the pressurized speed regulating mechanism using a motor-controlled mechanical transmission method can reduce hydraulic components and reduce maintenance difficulty, and adopts multi-screw transmission to improve transmission efficiency; the brake clutch of the speed regulating motor output shaft is coaxial with the speed regulating motor to achieve a fixed speed ratio output, prevent the motor from stalling, and extend the service life of the motor; the clutch power input shaft is coaxial with the transmission power input shaft to achieve the switching of the transmission forward gear and reverse gear.

[0004] Although the above-mentioned prior art can also realize the adjustment of the transmission ratio, its structure is complex and the manufacturing cost is high, which is not conducive to promotion and application. Utility Model Content

[0005] The utility model aims to provide a CVT speed change mechanism to solve the problem of single performance of the CVT speed change mechanism in the prior art.

[0006] In order to achieve the above-mentioned purpose, the basic scheme of the utility model provides a CVT transmission mechanism, including a housing, wherein the housing is provided with a driving pulley assembly and a driven pulley assembly; the driving pulley assembly includes a conical active fixed plate and an active movable plate, and the active movable plate is coaxially connected to a movable shaft on the side opposite to the active fixed plate, and the movable shaft slides with the housing along the axial direction, and the movable shaft is coaxially provided with a fixed shaft, and the fixed shaft and the movable shaft are connected by a torsion cam mechanism, and the fixed shaft is connected to a worm gear mechanism, and a motor connected to the worm gear mechanism is installed on the housing.

[0007] The beneficial effect of this basic scheme is that the worm is driven to rotate by controlling the motor, and the worm drives the worm wheel to rotate, so that the worm wheel drives the fixed shaft to rotate, so that the fixed shaft and the movable shaft rotate relative to each other, so that the fixed shaft drives the movable shaft to move axially through the torque cam mechanism, and then the movable shaft drives the active movable disk to move. When the active movable disk moves toward the active fixed disk, the active pulley assembly squeezes the belt, so that the effective rotation radius of the active pulley assembly increases, while the total length of the belt remains unchanged, so the effective rotation radius of the driven pulley assembly decreases, so that the transmission ratio of the CVT transmission mechanism changes from large to small. And the worm gear mechanism has a self-locking function, so that the transmission ratio of the CVT transmission mechanism can be stabilized at the corresponding position. The adoption of this scheme makes the structure of the CVT transmission mechanism simple, and makes the adjustment of the transmission ratio convenient and reliable, so that the CVT transmission mechanism can meet different performance requirements such as power, economy, and balance, which is conducive to improving the practicality of the CVT transmission mechanism.

[0008] Preferably, the movable shaft sleeve is arranged outside the fixed shaft. Such an arrangement is beneficial to both enhancing structural stability and reducing space occupation.

[0009] Preferably, the torque cam mechanism includes a guide pin extending in the radial direction of the fixed shaft, the guide pin is connected to the fixed shaft, and the torque cam mechanism also includes a slide groove provided on the movable shaft, the slide groove and the guide pin are slidably matched. With such a setting, the setting of the torque cam mechanism is relatively simple, which is conducive to improving the transmission reliability between the movable shaft and the fixed shaft, thereby reducing maintenance operations.

[0010] Preferably, the box body comprises a guide rod arranged parallel to the moving shaft, and the moving shaft is slidably connected to the guide rod. With such an arrangement, the sliding fit between the moving shaft and the box body is simple and reliable, thereby facilitating improving structural reliability.

[0011] Preferably, the active moving disk is connected to the moving shaft via a bearing. With such an arrangement, the active moving disk can move axially together with the moving shaft, and the wear between them can be reduced, thereby improving the structural reliability.

[0012] Preferably, an oil shield is mounted on the outer side of the movable shaft, and both ends of the oil shield are sealed with the movable shaft, and an oil seal is arranged between the movable shaft and one end of the fixed shaft close to the worm gear mechanism. With such an arrangement, lubricating oil is filled between the movable shaft and the fixed shaft, and the oil shield and the oil seal are used for sealing, so that the wear between the movable shaft and the fixed shaft can be reduced, which is conducive to extending the service life and reducing maintenance operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of an embodiment of a CVT transmission mechanism of the utility model;

[0014] Figure 2 for Figure 1 A cross-sectional view of the middle driving pulley assembly;

[0015] Figure 3 for Figure 2 Schematic diagram of the active movable plate of the middle active pulley assembly after it moves toward the active fixed plate. DETAILED DESCRIPTION

[0016] The following is further described in detail through specific implementation methods:

[0017] The figure marks in the drawings of the specification include: driven pulley assembly 1, transmission belt 2, active fixed disk 3, active movable disk 4, motor 5, housing 6, guide rod 7, worm 8, slide groove 9, guide pin 10, worm wheel 11, bearing 12, oil shield 13, movable shaft 14, fixed shaft 15, distance cylinder 16, displacement sensor 17, controller 18.

[0018] The embodiment is basically as shown in the attached Figures 1 to 3 As shown: a CVT transmission mechanism includes a housing 6, the housing 6 is provided with a driving pulley assembly and a driven pulley assembly 1, and the driving pulley assembly and the driven pulley assembly 1 are connected to each other through a transmission belt 2. The driving pulley assembly includes a conical active fixed disk 3 and an active movable disk 4, a distance cylinder 16 is provided between the active fixed disk 3 and the active movable disk 4, and the active movable disk 4 and the distance cylinder 16 are slidably matched.

[0019] The active movable disk 4 is coaxially rotatably connected with a movable shaft 14 on the side facing away from the active fixed disk 3. In the present embodiment, the active movable disk 4 is connected to the movable shaft 14 through a bearing 12. The movable shaft 14 is slidably matched with the housing 6 along the axial direction. In the present embodiment, the housing 6 includes a guide rod 7 arranged in parallel with the movable shaft 14, and a sliding hole matched with the guide rod 7 is arranged on the movable shaft 14, so that the guide rod 7 passes through the sliding hole and is slidably connected with the movable shaft 14. A fixed shaft 15 is coaxially rotatably arranged on the movable shaft 14. In the present embodiment, the movable shaft 14 is sleeved on the outer side of the fixed shaft 15. The fixed shaft 15 is connected to the movable shaft 14 through a torsion cam mechanism. In the present embodiment, the torsion cam mechanism includes a guide pin 10 extending along the radial direction of the fixed shaft 15, and the guide pin 10 is connected to the fixed shaft 15; the torsion cam mechanism also includes a slide groove 9 arranged on the movable shaft 14, and the slide groove 9 is slidably matched with the guide pin 10.

[0020] The fixed shaft 15 is connected to a worm gear mechanism, and a motor 5 connected to the worm gear mechanism is installed on the housing 6. Specifically, the fixed shaft 15 is coaxially connected and fixed to the worm wheel 11, and the motor 5 is connected and fixed to the worm 8, so that the motor 5 drives the worm wheel 11 to rotate through the worm 8. An oil shield 13 is mounted on the outer side of the movable shaft 14, and both ends of the oil shield 13 are sealed with the movable shaft 14, and an oil seal is arranged between the movable shaft 14 and one end of the fixed shaft 15 close to the worm gear mechanism. A displacement sensor 17 for detecting the moving distance of the active movable disk is arranged on the housing 6. The motor 5 is connected to a controller 18, so as to facilitate the precise control of the motor 5.

[0021] The specific implementation process is as follows: by controlling the motor 5 to drive the worm 8 to rotate, the worm 8 drives the worm wheel 11 to rotate, so that the worm wheel 11 drives the fixed shaft 15 to rotate, so that the fixed shaft 15 and the movable shaft 14 rotate relative to each other, so that the fixed shaft 15 drives the movable shaft 14 to move axially through the torsion cam mechanism, and then the movable shaft 14 drives the active movable disk 4 to move. When the active movable disk 4 moves toward the active fixed disk 3, the active pulley assembly squeezes the belt at this time, so that the effective rotation radius of the active pulley assembly increases, while the total length of the belt remains unchanged, so the effective rotation radius of the driven pulley assembly 1 decreases, so that the transmission ratio of the CVT transmission mechanism changes from large to small. And the worm gear mechanism has a self-locking function, so that the transmission ratio of the CVT transmission mechanism can be stabilized at the corresponding position. The adoption of this scheme makes the structure of the CVT transmission mechanism simple, and makes the adjustment of the transmission ratio convenient and reliable, so that the CVT transmission mechanism can meet different performance requirements such as power, economy, and balance, which is conducive to improving the practicality of the CVT transmission mechanism.

[0022] When the CVT transmission mechanism of the utility model is used in a vehicle, the whole vehicle can have a sports mode, an economic mode, a balanced mode and an autonomous control mode. For example, the controller 18 is used to control the motor 5 to adjust the transmission ratio of the CVT transmission mechanism. When the sports mode is adopted, the controller 18 sets the engine speed when the motor controls the CVT transmission mechanism to a high speed, such as when the speed is higher than the torque point speed of 1000rpm, the speed is changed, and the whole vehicle has strong power when starting and accelerating; when the economic mode is adopted, the controller 18 sets the engine speed when the motor 5 controls the CVT transmission mechanism to a low speed, such as when the speed is lower than the torque point speed of 1000rpm, the speed is changed, and the starting and acceleration power of the whole vehicle is weak, but the fuel consumption is low; when the balanced mode is adopted, the controller sets the engine speed when the motor controls the CVT transmission mechanism to a moderate speed, such as when the speed is the torque point speed, the power and fuel consumption of the whole vehicle are relatively balanced; when the autonomous control mode is adopted, the operator can autonomously adjust the engine speed when the motor controls the CVT transmission mechanism to change speed according to his or her preferences.

[0023] The above is only an embodiment of the utility model, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the utility model, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent.

Claims

1. A CVT transmission mechanism, comprising a housing, wherein the housing is provided with a driving pulley assembly and a driven pulley assembly; the driving pulley assembly comprises a conical active fixed disc and an active movable disc, characterized in that: The active movable disk is coaxially connected to a movable shaft on the side facing away from the active fixed disk. The movable shaft slides with the box body along the axial direction. The movable shaft is coaxially provided with a fixed shaft. The fixed shaft and the movable shaft are connected by a torsion cam mechanism. The fixed shaft is connected to a worm gear mechanism. A motor connected to the worm gear mechanism is installed on the box body.

2. A CVT transmission mechanism according to claim 1, characterized in that: The movable shaft sleeve is arranged on the outer side of the fixed shaft.

3. A CVT transmission mechanism according to claim 2, characterized in that: The torque cam mechanism includes a guide pin extending radially along the fixed shaft, the guide pin is connected to the fixed shaft, and the torque cam mechanism also includes a slide groove arranged on the movable shaft, the slide groove is slidably matched with the guide pin.

4. A CVT transmission mechanism according to claim 3, characterized in that: The box body comprises a guide rod which is arranged parallel to the moving shaft, and the moving shaft is slidably connected to the guide rod.

5. A CVT transmission mechanism according to claim 4, characterized in that: The active moving disk is connected to the moving shaft through a bearing.

6. A CVT transmission mechanism according to claim 5, characterized in that: An oil shield is sleeved on the outer side of the movable shaft, and both ends of the oil shield are sealed with the movable shaft. An oil seal is arranged between the movable shaft and one end of the fixed shaft close to the worm gear mechanism.

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