Stepless hydraulic transmission of bicycle

Abstract

The utility model relates to the field of bicycle transmissions, in particular to a bicycle stepless hydraulic transmission which comprises a driving wheel, a driven wheel, a transmission body, a spring piece and the like. A driving wheel on a pedal shaft is matched with a driven wheel on a rear wheel shaft, a frame oil cylinder and a gear pump in the transmission are used for driving an oil cylinder piston piece to act, cooperative adjustment of the rotating radius of the driving wheel and the rotating radius of the driven wheel is achieved, and meanwhile a spring piece is used for providing reset force, and the stepless speed change effect is achieved. Cooperative adjustment of the rotating radius of the driving wheel and the rotating radius of the driven wheel can be achieved, the transmission efficiency of stepless speed change is improved, and then efficient and reliable riding experience is provided for a user.

Description

Technical Field

[0001] This application relates to the field of sludge drying equipment technology, and in particular to a continuously variable hydraulic transmission for bicycles. Background Technology

[0002] The bicycle derailleur is a key component of the bicycle's drivetrain. Its main function is to adjust the gear ratio to adapt to different riding environments, thereby improving riding efficiency and comfort. With people's pursuit of environmentally friendly travel and healthy lifestyles, bicycles have been widely used and developed as a green mode of transportation. Against this backdrop, continuous advancements in bicycle derailleur technology are of great significance for improving the riding experience, reducing energy consumption, and meeting diverse needs. In recent years, derailleur technology has evolved from stepped gears to continuously variable transmissions (CVTs), providing riders with a smoother and more convenient way to adjust speed, greatly promoting technological innovation and market expansion in the bicycle industry.

[0003] In existing technologies, several conventional methods are typically used to achieve gear shifting: one is the traditional stepped transmission, which uses multiple gear combinations to switch between different transmission ratios, such as using a chain to jump between sprockets of different sizes; another is the friction-type continuously variable transmission (CVT), which uses the relative position change between a conical pulley and a drive belt to continuously adjust the transmission ratio; and yet another is the hydraulically driven CVT, which uses hydraulic cylinders to drive the transmission components to change the transmission radius, thereby achieving continuous gear shifting. In addition, there are gear shifting schemes based on magnetic coupling or electronic control, but these schemes usually involve complex structural designs or additional energy supplies.

[0004] However, the aforementioned existing technologies generally have some shortcomings, particularly in terms of structural complexity and ease of operation. For example, traditional stepped transmissions require frequent manual shifting and suffer from uneven shifting; friction-type continuously variable transmissions (CVTs), while capable of continuous gear changes, have low transmission efficiency and are prone to wear after prolonged use; and existing hydraulically driven transmissions, although possessing certain advantages, have limitations in bidirectional linkage adjustment, failing to achieve synchronized radius adjustment between the driving and driven pulleys, resulting in less than ideal gear shifting performance. Therefore, designing a device that is simple in structure, easy to operate, and capable of achieving efficient continuously variable transmission has become an urgent technical problem to be solved. Utility Model Content

[0005] The purpose of this application is to overcome the above-mentioned technical problems and provide a continuously variable hydraulic transmission for bicycles, which adopts the following solution:

[0006] A continuously variable hydraulic (CVT) gearbox for bicycles includes: a drive wheel, sleeved on one end of a pedal axle, and comprising a fixed drive disc and a movable drive disc, wherein a trapezoidal belt is fitted between the fixed drive disc and the movable drive disc, wherein the movable drive disc is movably mounted on the pedal axle relative to the fixed drive disc, and is used to move the trapezoidal belt to adjust the rotation radius of the drive wheel, wherein both ends of the pedal axle are used to connect pedals; a gearbox, sleeved on the other end of the pedal axle, and comprising a pedal axle sleeve, a frame cylinder, and a gear pump, wherein the pedal axle sleeve is sleeved on the pedal axle, the frame cylinder is sleeved outside the pedal axle sleeve, and one end of the frame cylinder is provided with a piston abutting against the movable drive disc; the gear... A gear pump is mounted on the frame cylinder and connected to the frame cylinder via an oil outlet pipe and a return pipe. A first gear is provided on the end of the gear pump away from the drive wheel, and a second gear is provided on the pedal shaft away from the drive wheel, meshing with the first gear and rotating with the pedal shaft. A driven wheel is mounted on one end of the rear wheel axle, and is connected to the drive wheel via the trapezoidal belt. The driven wheel includes a driven fixed disc and a driven movable disc. The driven movable disc is movably mounted on the rear wheel axle relative to the driven fixed disc and is used to drive the trapezoidal belt to move to adjust the rotation radius of the driven wheel. A spring is mounted on the other end of the rear wheel axle and is used to spring against the driven movable disc.

[0007] By adopting the above technical solution, the combination of the drive wheel, driven wheel, and derailleur achieves continuously variable transmission (CVT) on the bicycle. Specifically, the movable arrangement of the drive wheel's moving sprocket relative to the fixed drive sprocket allows it to move the trapezoidal belt, thereby adjusting the drive wheel's rotation radius and achieving gear shifting. The derailleur, through the cooperation of a gear pump and a frame cylinder, utilizes the rotation of the pedal axle to drive the gear pump, which in turn controls the hydraulic pressure within the frame cylinder, pushing the piston to move and precisely adjusting the position of the moving sprocket. The movable arrangement of the driven wheel's moving sprocket relative to the fixed driven sprocket allows it to work in conjunction with the drive wheel to adjust the position of the trapezoidal belt, further optimizing gear shifting. A spring abuts against the driven sprocket, providing a stable restoring force and ensuring good contact between the driven sprocket and the drive wheel in different gear shifting states, improving transmission efficiency and stability.

[0008] Optionally, it further includes: one end of the trapezoidal belt member is movably fitted between the active fixed disc and the active moving disc, and the other end is movably fitted between the driven fixed disc and the driven moving disc; wherein, when the trapezoidal belt member adjusts the rotation radius of the active wheel to increase, the rotation radius of the driven wheel decreases accordingly; when the trapezoidal belt member adjusts the rotation radius of the active wheel to decrease, the rotation radius of the driven wheel increases accordingly.

[0009] By adopting the above technical solution, the two ends of the trapezoidal belt are movably fitted between the fixed and movable discs of the driving and driven pulleys, respectively, achieving coordinated adjustment of the rotation radii of the driving and driven pulleys. When the rotation radius of the driving pulley is increased by adjusting the trapezoidal belt, the rotation radius of the driven pulley decreases accordingly, and vice versa. This design ensures continuous adjustment of the transmission ratio, thereby achieving stepless speed change and improving the rider's adaptability and comfort.

[0010] Optionally, the frame cylinder is also connected to a drain pipe, and a control valve is installed on the drain pipe.

[0011] By adopting the above technical solution, a drain pipe is connected to the frame cylinder and a control valve is installed on the drain pipe, which enables precise control of the hydraulic oil in the frame cylinder, thereby adjusting the speed range.

[0012] Optionally, a first end face ball bearing is provided on the end face of the cylinder piston away from the second gear to abut against the active moving disk.

[0013] By adopting the above technical solution, a first end-face ball bearing is installed on the contact surface between the cylinder piston and the active moving disc, which can significantly reduce the frictional resistance between the two and improve the transmission efficiency. At the same time, the installation of the first end-face ball bearing can also enhance the stability of the structure, avoid wear caused by direct contact, and extend the service life.

[0014] Optionally, a second end-face ball bearing is provided on one end of the spring member near the driven moving disk to abut against the driven moving disk.

[0015] By adopting the above technical solution, the inclusion of a second end-face ball bearing effectively reduces the friction between the spring and the driven moving disc, thus allowing the driven moving disc to move more smoothly under the action of the spring. This improvement not only enhances the accuracy of the driven wheel's rotation radius adjustment but also extends the service life of the component.

[0016] Optionally, one end of the pedal shaft is provided with a first spline for the active moving disc to be fitted.

[0017] By adopting the above technical solution, a first spline is provided at one end of the pedal axle for the active moving disc to be fitted. This structure can effectively limit the axial position of the active moving disc, ensuring that its movement range on the pedal axle is precisely controllable, thereby improving the stability and reliability of the adjustment of the active wheel's rotation radius.

[0018] Optionally, one end of the rear wheel axle is provided with a second spline for the driven moving disc to be fitted.

[0019] By adopting the above technical solution, the second spline set at one end of the rear wheel axle can axially limit the driven moving disc, preventing it from axially disengaging or moving excessively on the rear wheel axle, thereby ensuring the stability of the driven moving disc when adjusting the rotation radius of the driven wheel.

[0020] Optionally, it also includes: a spring adjusting nut, for sleeved on one end of the rear wheel axle and located at the end of the spring member away from the driven moving disc.

[0021] By adopting the above technical solution, the spring adjusting nut allows for adjustment of the preload of the spring components, thereby achieving precise control over the radius variation range of the driven wheel. Combined with the overall solution, the rotation radii of the driving and driven wheels can be adjusted through the linkage of the hydraulic system and mechanical structure, thus achieving continuously variable transmission (CVT) and improving the riding experience and transmission efficiency. The specific function of the spring adjusting nut is to provide adjustable support force, optimize the working state of the spring components, and ensure stable operation of the driven wheel under different working conditions.

[0022] In summary, this application includes at least one of the following beneficial technical effects:

[0023] 1. By cooperating with the gear pump and the frame cylinder, the rotation of the pedal shaft drives the hydraulic system to achieve automatic adjustment of the rotation radius of the drive wheel, which solves the problems of inconvenient operation and uneven shifting of traditional gearboxes and improves the riding experience;

[0024] 2. The driving wheel and the driven wheel are linked by a trapezoidal belt. The displacement of the driving disc can drive the driven disc to adjust its rotation radius in the opposite direction, thus realizing the synchronous and coordinated adjustment of the driving wheel and the driven wheel, improving the speed change efficiency and transmission stability.

[0025] 3. The spring component provides a restoring force to the driven moving disc, ensuring stable operation of the driven wheel under different working conditions, while simplifying the overall structure and reducing maintenance costs. Attached Figure Description

[0026] Figure 1 This is a three-dimensional structural schematic diagram of the continuously variable hydraulic transmission for bicycles disclosed in an embodiment of this application;

[0027] Figure 2 This is a three-dimensional structural schematic diagram of the continuously variable hydraulic transmission for bicycles disclosed in an embodiment of this application;

[0028] Figure 3 for Figure 1 A partial structural schematic diagram of a continuously variable hydraulic (CVT) transmission for bicycles, publicly disclosed in China;

[0029] Figure 4 for Figure 1 An exploded schematic diagram of part of the structure of a continuously variable hydraulic (CVT) transmission for bicycles, publicly disclosed in China.

[0030] Figure 5 for Figure 1 An exploded view of the drive wheel and transmission structure in a continuously variable hydraulic transmission for bicycles, published in China.

[0031] Figure 6 for Figure 1 An exploded view of the drive wheel and transmission structure in a continuously variable hydraulic transmission for bicycles, as publicly disclosed in China.

[0032] Explanation of reference numerals in the attached figures:

[0033] 10. Drive wheel; 11. Pedal axle; 111. Second gear; 112. First spline; 12. Drive fixed disc; 13. Drive moving disc; 14. Trapezoidal belt component; 20. Gearbox; 21. Pedal bushing; 22. Frame cylinder; 221. Cylinder piston component; 222. First end face ball bearing; 23. Gear pump; 231. Oil outlet pipe; 232. Oil return pipe; 233. First gear; 234. Drain pipe; 30. Driven wheel; 31. Rear wheel axle; 311. Second spline; 32. Driven fixed disc; 33. Driven moving disc; 40. Spring component; 50. Second end face ball bearing; 60. Spring adjusting nut. Detailed Implementation

[0034] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0035] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0036] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0037] See Figure 1 The continuously variable hydraulic transmission 20 for bicycles disclosed in this application includes a drive wheel 10, a transmission 20, a driven wheel 30, and a spring member 40.

[0038] The drive wheel 10 and the gearbox 20 are mounted on the pedal shaft 11, and the driven wheel 30 and the spring 40 are mounted on the rear wheel axle 31. The radius adjustment of the drive wheel 10 and the driven wheel 30 is achieved through the hydraulic system of the gearbox 20, thereby achieving the effect of continuously variable transmission.

[0039] For details, see Figure 2 and Figure 3 The drive wheel 10 includes a fixed drive disc 12 and a movable drive disc 13, with a trapezoidal belt 14 fitted between them. The fixed drive disc 12 and the movable drive disc 13 are tapered at an angle of 10° to 15°. When the movable drive disc 13 moves along the pedal shaft 11, it drives the trapezoidal belt 14 to move radially along the axis of the drive wheel 10, thereby adjusting the effective rotation radius of the drive wheel 10.

[0040] See Figure 4 The active fixed plate 12 is fixed to one end of the pedal shaft 11, and the active moving plate 13 is sleeved on the pedal shaft 11 through a keyway or spline structure. Specifically, a first spline 112 is provided at one end of the pedal shaft 11 for the active moving plate 13 to be sleeved, so that the active moving plate 13 can move axially but does not rotate relative to it, that is, to limit the range of movement of the active moving plate 13 and prevent it from falling off.

[0041] See Figure 2 and Figure 4 The transmission 20 includes a pedal bushing 21, a frame cylinder 22, and a gear pump 23. The pedal bushing 21 has a cylindrical structure with an inner diameter slightly larger than the outer diameter of the pedal shaft 11 to ensure a stable connection. The frame cylinder 22 is fitted onto the outside of the pedal bushing 21, with a cylinder piston 221 at one end. A first end-face ball bearing 222 is installed at the end of the cylinder piston 221 for moving and abutting against the drive moving disc 13. The external structure of the frame cylinder 22 can be described as follows... Figure 5 As shown, the interior is used to hold liquid oil.

[0042] See Figure 2 and Figure 6 The gear pump 23 is mounted on the frame cylinder 22 and is connected to the frame cylinder 22 via an oil outlet pipe 231 and an oil return pipe 232 to allow for the inflow and outflow of liquid oil. A first gear 233 is mounted on the end of the gear pump 23 furthest from the drive wheel 10, and a second gear 111 meshing with the first gear 233 is mounted on the end of the pedal shaft 11 furthest from the drive wheel 10. The second gear 111 is mounted on the pedal shaft 11 via a keyway or spline structure and, as the pedal shaft 11 rotates, drives the first gear 233 to rotate, thereby driving the gear pump 23 to operate. This allows liquid oil to flow between the gear pump 23 and the frame cylinder 22, thus regulating the oil pressure in the frame cylinder 22.

[0043] See Figure 2 , Figure 3 and Figure 4 The driven wheel 30 includes a driven fixed disc 32 and a driven movable disc 33. One end of the trapezoidal belt 14 is fitted with a driving wheel, while the other end is fitted with the driven wheel 30, fitting between the driven fixed disc 32 and the driven movable disc 33. The driven fixed disc 32 and the driven movable disc 33 are set with a conical slope of 10°~15°. When the driven movable disc 33 moves along the rear wheel axle 31, it drives the second trapezoidal member 34 to move radially along the axis of the driven wheel 30, thereby adjusting the effective rotation radius of the driven wheel 30. One end of the rear wheel axle 31 is provided with a second spline 311 to limit the axial movement range of the driven movable disc 33.

[0044] In this embodiment, the trapezoidal belt component 14 is simultaneously attached between the active fixed disc 12 and the active moving disc 13, and between the driven fixed disc 32 and the driven moving disc 33, so as to realize the linkage adjustment of the rotation radius of the active wheel 10 and the driven wheel 30, that is, to adjust the transmission ratio to achieve the speed adjustment.

[0045] For example, when a user wants to accelerate, they can increase the rotation frequency of the pedal shaft 11, i.e., the pedal frequency, by using the foot pedal. This increases the rotation speed of the first gear 233 and the second gear 111. In conjunction with the oil outlet pipe 231 and the oil return pipe 232, hydraulic oil is generated (flowing into the frame cylinder 22), thereby increasing the oil pressure inside the frame cylinder 22. This indirectly drives the cylinder piston 221 to push the active moving disc 13, increasing the rotation radius of the trapezoidal belt 14 relative to the drive wheel 10. Since the length of the trapezoidal belt 14 is fixed, the rotation radius of the trapezoidal belt 14 relative to the driven wheel 30 is also reduced, making it larger at the front and smaller at the back, increasing the transmission ratio, and thus increasing the speed.

[0046] Correspondingly, when the user wants to slow down, they can reduce the rotation frequency of the pedal shaft 11, i.e., the pedal frequency, by using the foot pedal. This reduces the rotation speed of the first gear 233 and the second gear 111. With the oil outlet pipe 231 and the oil return pipe 232, the hydraulic oil flows back to the gear pump 23 to reduce the oil pressure in the frame cylinder 22. This causes the piston of the drive cylinder 221 to retract. In conjunction with the trapezoidal belt 14 sliding down towards the axis of the drive wheel 10, the rotation radius of the trapezoidal belt 14 relative to the drive wheel 10 is reduced. Since the length of the trapezoidal belt 14 is fixed, the rotation radius of the trapezoidal belt 14 relative to the driven wheel 30 is also increased, making it smaller at the front and larger at the back, thus reducing the transmission ratio and slowing down the speed.

[0047] In addition, to meet the user's needs for different speed adjustment ranges, a drain pipe 234 is connected to the frame cylinder 22. A control valve is installed on the drain pipe 234. The user can open the control valve to allow liquid oil to flow out from the frame cylinder 22 through the drain pipe 234 to adjust the oil pressure of the frame cylinder 22, thereby adjusting the vehicle's speed range.

[0048] A spring element 40 is sleeved on the other end of the rear wheel axle 31 to abut against the driven moving disc 33. A second end face ball bearing 50 is provided on the end face of the spring element 40 near the driven moving disc 33 to abut against the driven moving disc 33, reducing friction and improving service life. In addition, a spring adjusting nut 60 is provided on one end of the rear wheel axle 31 to adjust the preload of the spring element 40, thereby adjusting the initial rotation radius of the driven wheel 30.

[0049] The implementation principle of this embodiment is as follows: by optimizing the structural design of the hydraulic system corresponding to the drive wheel 10, driven wheel 30, and gearbox 20, a smooth and efficient continuously variable transmission (CVT) effect is achieved. When the rider pedals the pedal shaft 11, based on the increase in pedal frequency, the pedal shaft 11 continuously drives the gear pump 23 to work, continuously pressing hydraulic oil into the frame cylinder 22, increasing the oil pressure to push the cylinder piston 221 to move, thereby driving the drive moving disc 13 to move along the pedal shaft 11 to adjust the rotation radius of the drive wheel 10. At the same time, the trapezoidal belt 14 moves accordingly, adjusting the rotation radius of the driven wheel 30, thereby realizing the change of the transmission ratio between the drive wheel 10 and the driven wheel 30. This solution has the advantages of simple structure, convenient operation, and high transmission efficiency, which can meet the rider's gear shifting needs under different road conditions and significantly improve the riding experience.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A continuously variable hydraulic transmission for bicycles, characterized in that, include: The drive wheel (10) is sleeved on one end of the pedal shaft (11) and includes a drive fixed plate (12) and a drive moving plate (13). A trapezoidal belt (14) is sleeved between the drive fixed plate (12) and the drive moving plate (13). The drive moving plate (13) is movably arranged on the pedal shaft (11) relative to the drive fixed plate (12) to drive the trapezoidal belt (14) to move and adjust the rotation radius of the drive wheel (10). The two ends of the pedal shaft (11) are used to connect the pedal. The gearbox (20) is sleeved on the other end of the pedal shaft (11) and includes a pedal shaft sleeve (21), a frame cylinder (22) and a gear pump (23). The pedal shaft sleeve (21) is sleeved on the pedal shaft (11). The frame cylinder (22) is sleeved on the outside of the pedal shaft sleeve (21) and has a cylinder piston (221) at one end that abuts against the active moving disc (13). The gear pump (23) is sleeved on the frame cylinder (22) and is connected to the frame cylinder (22) through an oil outlet pipe (231) and an oil return pipe (232). A first gear (233) is provided on the end of the gear pump (23) away from the drive wheel (10). A second gear (111) is provided on the end of the pedal shaft (11) away from the drive wheel (10) that meshes with the first gear (233) and rotates with the pedal shaft (11). Driven wheel (30) is sleeved on one end of rear wheel axle (31). Driven wheel (30) is sleeved on trapezoidal belt (14) and linked with driving wheel (10). Driven wheel (30) includes driven fixed disc (32) and driven moving disc (33). Driven moving disc (33) is movably arranged on rear wheel axle (31) relative to driven fixed disc (32) to drive trapezoidal belt (14) to move in order to adjust the rotation radius of driven wheel (30). A spring element (40) is sleeved on the other end of the rear wheel axle (31) for spring abutting against the driven moving disc (33).

2. The continuously variable hydraulic transmission for bicycles according to claim 1, characterized in that, One end of the trapezoidal belt component (14) is movably attached between the active fixed disc (12) and the active moving disc (13), and the other end is movably attached between the driven fixed disc (32) and the driven moving disc (33); wherein, when the trapezoidal belt component (14) adjusts the rotation radius of the active wheel (10) to increase, the rotation radius of the driven wheel (30) decreases accordingly, and when the trapezoidal belt component (14) adjusts the rotation radius of the active wheel (10) to decrease, the rotation radius of the driven wheel (30) increases accordingly.

3. The continuously variable hydraulic transmission for bicycles according to claim 1, characterized in that, The frame cylinder (22) is also connected to a drain pipe (234), and a control valve is provided on the drain pipe (234).

4. The continuously variable hydraulic transmission for bicycles according to claim 1, characterized in that, The piston component (221) of the hydraulic cylinder is provided with a first end face ball bearing (222) on the end face away from the second gear (111) to abut against the active moving disk (13).

5. The continuously variable hydraulic transmission for bicycles according to claim 1, characterized in that, The spring (40) is provided with a second end face ball bearing (50) on one end near the driven moving disk (33) to abut against the driven moving disk (33).

6. The continuously variable hydraulic transmission for bicycles according to claim 1, characterized in that, One end of the pedal shaft (11) is provided with a first spline (112) for the active moving disc (13) to be fitted.

7. The continuously variable hydraulic transmission for bicycles according to claim 1, characterized in that, One end of the rear wheel axle (31) is provided with a second spline (311) for the driven moving disk (33) to be fitted.

8. The continuously variable hydraulic transmission for bicycles according to claim 1, characterized in that, Also includes: A spring adjusting nut (60) is used to be sleeved on one end of the rear wheel axle (31) and located at the end of the spring member (40) away from the driven moving disk (33).

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