Speed control system of pedal motorcycle

Abstract

The invention belongs to the technical field of pedal motorcycles, and relates to a speed change system of a pedal motor.The speed change system comprises a driving wheel assembly driven by an engine crankshaft, the driving wheel assembly is in transmission connection with a driven wheel assembly through a belt, and the driving wheel assembly comprises an axially-positioned fixed disc and an axially-slidable movable disc; the engine crankshaft is sequentially sleeved with a lining, a movable disc and a compression spring, the lining is in transmission connection with the engine crankshaft through an involute spline, the movable disc is in sliding connection with the lining, and the compression end of the compression spring is rotationally connected with the movable disc through a thrust bearing. A radial disc pin is arranged on the lining, and a spiral line sliding groove matched with the disc pin is formed in the sliding sleeve of the movable disc. Compared with a traditional pulley ball speed control system, the speed control system of the pedal motorcycle has better speed control performance.

Description

Technical Field

[0001] The invention belongs to the technical field of scooters and relates to a speed change system of a scooter. Background Art

[0002] The CVT transmission system of scooters mainly uses a V-belt with front and rear discs as a speed change and transmission mechanism. In traditional transmission systems, the drive disc group generally includes a pulley disc, a pulley bead and a fan disc. When the engine is at a low speed, the pulley bead does not have enough centrifugal force to throw it out, so the gap between the two discs is larger, and the belt is closer to the axis to simulate a low gear and a high reduction ratio. During the acceleration process, when the engine speed increases, the pulley bead will be thrown outward, and at the same time, the pulley disc will be stretched outward, shortening the distance between the two discs. After the distance between the two discs is shortened, the V-belt is also squeezed outward by the two discs, simulating a high gear and a low reduction ratio, so that the vehicle speed can be increased.

[0003] The traditional Pulley-based speed change structure has many disadvantages, such as poor transmission efficiency, easy wear, risk of speed change failure, difficult processing, high cost, etc. Specifically, its disadvantages are:

[0004] 1. The engine speed change depends on the centrifugal force of the puli bead. The greater the mass of the puli bead, the greater the centrifugal force. The higher the speed, the greater the centrifugal force. The puli bead has sliding friction. The transmission efficiency of this structure is relatively low. At the same time, the size and material requirements of the speed change belt are relatively harsh, the controllable accuracy is relatively low, and the belt has a poor cost performance.

[0005] 2. Since the driving wheel is driven by the centrifugal force of the puli beads, the puli beads are severely worn. The sliding friction will also generate a lot of heat, causing the speed change mechanism to overheat, which is not conducive to the life of the entire engine. For example, a scooter engine using this structure generally needs to replace the puli beads after about 10,000 kilometers. At the same time, this structure cannot withstand heavy loads (motorcycle engines above 350CC do not use this structure). After the puli beads are worn, a large amount of dust will be generated in the belt chamber, aggravating the wear of the belt and causing the speed change mechanism to fail. At present, as long as the left cover of the domestic scooter engine is opened, a large amount of dust pollutants will be found.

[0006] 3. When the centrifugal force is insufficient, the belt will slip, resulting in the engine torque not being output normally and the engine starting to shake. Excessive centrifugal force will aggravate the abnormal wear of the belt, thus causing the engine speed change failure.

[0007] 4. The casting and processing of the active movable disk is relatively difficult, and the stamping precision of the Pulizhu plate is high. The processing cost of this structure is relatively high, which is not conducive to market competition.

[0008] In view of this, it is necessary to develop a new speed change system for scooters to abandon the traditional pulizhu structure and avoid its shortcomings. Summary of the invention

[0009] In view of the deficiencies in the prior art, the present invention provides a speed change system for a scooter, which has better speed change performance than the traditional Pulleyball speed change system.

[0010] In order to solve the above technical problems, the purpose of the present invention is achieved through the following technical solutions:

[0011] A speed change system for a scooter comprises a driving wheel assembly driven by an engine crankshaft, the driving wheel assembly is connected to the driven wheel assembly by a belt drive, the driving wheel assembly comprises an axially positioned fixed plate and an axially slidable movable plate, the engine crankshaft is sequentially provided with a bushing, a movable plate and a compression spring, the bushing is connected to the engine crankshaft by an involute spline drive, the movable plate is slidingly connected to the bushing, the compression end of the compression spring is rotationally connected to the movable plate by a thrust bearing, a radial disk pin is provided on the bushing, a helical groove cooperating with the disk pin is provided in the sliding sleeve of the movable plate, the output torque of the engine crankshaft drives the movable plate to move in a direction away from the fixed plate after being transmitted by the disk pin and the helical groove, and the compression spring drives the movable plate to move in a direction close to the fixed plate.

[0012] In the above-mentioned speed change system of a scooter, the disc pins are provided in plurality and are evenly distributed along the circumference, and the helical slide grooves are provided in one-to-one correspondence with the disc pins. Preferably, the disc pins and the helical slide grooves are provided in three.

[0013] In the above-mentioned speed change system of a scooter, the disc pin includes a pin shaft and a roller, the pin shaft is fixedly connected to the bushing, and the roller is assembled in the spiral groove and rollingly connected thereto.

[0014] In the above-mentioned speed change system of a scooter, the compression spring includes a spring fixing seat, a spring moving seat and a compression spring, the two ends of the compression spring are respectively assembled on the spring fixing seat and the spring moving seat, the spring fixing seat is fixedly connected to the gearbox body, the spring moving seat is sleeved outside the sliding sleeve of the movable disk and is clearance-matched therewith, the thrust bearing is arranged between the spring moving seat and the movable disk, and when the spring moving seat presses the movable disk, the movable disk can still automatically rotate relative to the spring moving seat.

[0015] In the above-mentioned speed change system of a scooter, the engine crankshaft passes through the driving wheel assembly and is locked by a locking nut, and the engine crankshaft is connected to the fixed plate by an involute spline transmission.

[0016] In the above-mentioned speed change system of a scooter, the involute internal spline on the bushing is arranged at one end close to the fixed plate, the involute internal spline on the fixed plate is arranged through, the involute internal spline on the bushing and the involute internal spline on the fixed plate form a continuous involute internal spline, and the involute external spline on the engine crankshaft is arranged correspondingly and meshed with the continuous involute internal spline.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention provides a new speed change system for a scooter, which no longer uses a puli-bead structure, thereby avoiding the disadvantages of the puli-bead speed change. The driving wheel of the present invention is not driven by centrifugal force, but by the output torque of the engine crankshaft. The rotation of the crankshaft will drive the bushing to rotate. When the bushing rotates, the movable disk is driven to move axially through the disk pin and the spiral groove, thereby realizing the change of the belt pitch circle and realizing the speed change function. The speed change system uses the engine crankshaft to directly output torque, with large starting torque and good acceleration performance. It also has a simple structure, is easy to process, and mostly uses common parts on the market, which is more cost-effective.

[0019] 2. The engine crankshaft of the present invention drives the bushing through the involute spline. This structure can bear large torque and has high transmission efficiency. It will not generate extra heat and will not wear out during long-term use, thereby extending the service life of the engine. In addition, the speed change structure of the involute spline and the helical groove has a more stable transmission and will not cause sliding friction, slipping, shaking, etc. during the speed change of the puli beads.

[0020] 3. The present invention changes speed through the axial displacement generated by the spiral slideway, and its speed change is more accurate, the speed change is more in line with the output torque of the rear wheel, and the riding comfort is better. When the engine is at low speed, the large torque output of the speed change system slows down the driving wheel, and when the engine is at high speed, the small torque output actively increases the speed, which fully meets the torque output requirements of the whole vehicle, the sliding distance of the whole vehicle will be very long, and the fuel consumption will be very low. The Pulizhu structure relies on the crankshaft speed output and cannot match the torque output of the whole vehicle well. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is an axial cross-sectional view of the present invention;

[0022] Figure 2 yes Figure 1 A magnified image of point A;

[0023] Figure 3 is an exploded view of some components of the present invention;

[0024] Figure 4 is a perspective view of an engine crankshaft of the present invention;

[0025] Figure 5 is a three-dimensional diagram of the bushing of the present invention;

[0026] Figure 6 is a three-dimensional diagram of the movable disk of the present invention;

[0027] Figure 7 is a three-dimensional diagram of a fixed disk of the present invention;

[0028] Figure 8 is a three-dimensional diagram of a compression spring of the present invention;

[0029] Figure numerals: 1. engine crankshaft; 2. belt; 3. fixed plate; 4. movable plate; 5. bushing; 6. compression spring; 7. thrust bearing; 8. disc pin; 9. sliding sleeve; 10. helical groove; 11. pin shaft; 12. roller; 13. spring fixing seat; 14. spring moving seat; 15. compression spring; 16. gearbox body; 17. locking nut; 18. involute internal spline; 19. involute external spline. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to specific embodiments of the present invention. Figure 1-8 :

[0031] A speed change system for a scooter comprises a driving wheel assembly driven by an engine crankshaft 1, wherein the driving wheel assembly is connected to the driven wheel assembly via a belt 2, the driving wheel assembly comprises an axially positioned fixed plate 3 and an axially slidable movable plate 4, the engine crankshaft 1 is sequentially provided with a bushing 5, a movable plate 4 and a compression spring 6, the bushing 5 is connected to the engine crankshaft 1 via an involute spline transmission, the movable plate 4 is slidingly connected to the bushing 5, the compression end of the compression spring 6 is rotationally connected to the movable plate 4 via a thrust bearing 7, a radial disk pin 8 is provided on the bushing 5, a helical groove 10 cooperating with the disk pin 8 is provided in a sliding sleeve 9 of the movable plate 4, the output torque of the engine crankshaft 1 is transmitted via the disk pin 8 and the helical groove 10 to drive the movable plate 4 to move in a direction away from the fixed plate 3, and the compression spring 6 drives the movable plate 4 to move in a direction close to the fixed plate 3.

[0032] The speed change principle of this embodiment is: the engine crankshaft 1 acts on the movable disk 4 through the output torque, and the movable disk 4 is made to slide by the transmission of the disk pin 8 and the spiral groove 10. When the movable disk 4 slides axially, the pitch circle of the belt 2 is changed, and then acts on the driven wheel assembly to change the reduction ratio to achieve the purpose of speed change. The driven wheel assembly and the belt 2 connection structure of this embodiment are the same as those in the prior art, and the principle and process of producing the speed change effect after the movable disk 4 slides are also the same as those in the prior art; when the force of the output torque on the movable disk 4 is equal to the force of the clamping spring 6 on the movable disk 4, the movable disk 4 is in a relatively static state, and the engine crankshaft 1, the bushing 5, the movable disk 4 and the fixed disk 3 rotate synchronously. At this time, the scooter runs in a state of a certain fixed reduction ratio; different torques are output by the engine crankshaft 1 to achieve the effect of continuously variable transmission (CVT).

[0033] The speed change process of this embodiment is: when the engine is started, the engine crankshaft 1 starts to rotate, and the bushing 5 rotates accordingly. When the scooter starts, the engine crankshaft 1 outputs a large output torque, which acts on the movable disk 4 through the disk pin 8 and the spiral groove 10 of the bushing 5. The movable disk 4 slides axially relative to the bushing 5 and compresses the clamping spring 6. Due to the large output torque, the movable disk 4 will move to the maximum distance. At this time, the pitch circle of the belt 2 is the largest, forming a low gear and high reduction ratio state, thereby obtaining the maximum starting torque and achieving rapid acceleration. When the speed increases, the output torque of the engine crankshaft 1 gradually decreases, and the force on the movable disk 4 also decreases. Under the action of the clamping spring 6, the movable disk 4 gradually approaches the fixed disk 3. When the output torque of the engine crankshaft 1 is the smallest, the clamping spring 6 presses the movable disk 4 to the nearest place of the fixed disk 3, and the pitch circle of the belt 2 is the smallest, forming a high gear and low reduction ratio state, so that the vehicle speed can be increased to the maximum.

[0034] When the present embodiment is working, it can well match the torque output of the whole vehicle. When the engine is working at a low speed, the transmission system outputs a large torque and the driving wheel slows down. When the engine is working at a high speed, the transmission system outputs a small torque and actively increases the speed.

[0035] Compare with Figure 5 and attached Figure 6 In order to better drive the movable disk 4 to slide, the disk pins 8 are provided with a plurality of disk pins 8 and are evenly distributed along the circumference, and the spiral grooves 10 are provided in a one-to-one correspondence with the disk pins 8. In this embodiment, the disk pins 8 and the spiral grooves 10 are both provided with three.

[0036] Compare with Figure 2 In this embodiment, the specific structure of the disc pin 8 is: the disc pin 8 includes a pin shaft 11 and a roller 12, the pin shaft 11 is fixedly connected to the bushing 5, and the roller 12 is assembled in the spiral groove 10 and rollingly connected thereto. Through the action of the roller 12, the speed change can be made smoother.

[0037] Compare with Figure 2 and attached Figure 8 In this embodiment, the specific structure of the compression spring 6 is: the compression spring 6 includes a spring fixing seat 13, a spring moving seat 14 and a compression spring 15, the two ends of the compression spring 15 are respectively assembled on the spring fixing seat 13 and the spring moving seat 14, the spring fixing seat 13 is fixedly connected to the gearbox body 16, the spring moving seat 14 is sleeved outside the sliding sleeve 9 of the movable disk 4 and is clearance-matched therewith, the thrust bearing 7 is arranged between the spring moving seat 14 and the movable disk 4, and when the spring moving seat 14 presses the movable disk 4, the movable disk 4 can still automatically rotate relative to the spring moving seat 14.

[0038] Compare with Figure 1-5 And attached Figure 7 In this embodiment, the specific transmission structure of the engine crankshaft 1, the bushing 5 and the fixed plate 3 is: the engine crankshaft 1 passes through the driving wheel assembly and is locked by the locking nut 17, the engine crankshaft 1 is connected to the fixed plate 3 by involute spline transmission, further, the involute internal spline 18 on the bushing 5 is arranged at one end close to the fixed plate 3, the involute internal spline 18 on the fixed plate 3 is arranged through, the involute internal spline 18 on the bushing 5 and the involute internal spline 18 on the fixed plate 3 form a continuous involute internal spline 18, the involute external spline 19 on the engine crankshaft 1 is arranged correspondingly and meshed with the continuous involute internal spline 18, when the engine crankshaft 1 rotates, the involute external spline 19 can simultaneously drive the bushing 5 and the involute internal spline 18 on the fixed plate 3 to obtain a more stable transmission effect.

[0039] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A speed change system for a scooter, comprising a driving wheel assembly driven by an engine crankshaft (1), the driving wheel assembly being connected to a driven wheel assembly via a belt (2), the driving wheel assembly comprising an axially positioned fixed disc (3) and an axially slidable movable disc (4), characterized in that: The engine crankshaft (1) is sequentially provided with a bushing (5), a movable disk (4) and a compression spring (6); the bushing (5) is connected to the engine crankshaft (1) via an involute spline transmission; the movable disk (4) is slidingly connected to the bushing (5); the compression end of the compression spring (6) is rotationally connected to the movable disk (4) via a thrust bearing (7); a radial disk pin (8) is provided on the bushing (5); a helical groove (10) matching the disk pin (8) is provided in a sliding sleeve (9) of the movable disk (4); the output torque of the engine crankshaft (1) is transmitted via the disk pin (8) and the helical groove (10) to drive the movable disk (4) to move in a direction away from the fixed disk (3); and the compression spring (6) drives the movable disk (4) to move in a direction close to the fixed disk (3).

2. A speed change system for a scooter according to claim 1, characterized in that: A plurality of the disk pins (8) are provided and are evenly distributed along the circumferential direction, and the spiral sliding grooves (10) are provided in one-to-one correspondence with the disk pins (8).

3. A speed change system for a scooter according to claim 1, characterized in that: The disc pin (8) comprises a pin shaft (11) and a roller (12), wherein the pin shaft (11) is fixedly connected to the bushing (5), and the roller (12) is assembled in the spiral line slide groove (10) and is rollingly connected thereto.

4. A speed change system for a scooter according to claim 1, characterized in that: The compression spring (6) comprises a spring fixing seat (13), a spring moving seat (14) and a compression spring (15); two ends of the compression spring (15) are respectively mounted on the spring fixing seat (13) and the spring moving seat (14); the spring fixing seat (13) is fixedly connected to a gearbox body (16); the spring moving seat (14) is sleeved outside a sliding sleeve (9) of a movable disk (4) and is clearance-matched therewith; and the thrust bearing (7) is arranged between the spring moving seat (14) and the movable disk (4).

5. The speed change system of a scooter according to claim 1, characterized in that: The engine crankshaft (1) passes through the driving wheel assembly and is locked by a locking nut (17); the engine crankshaft (1) is connected to the fixed plate (3) by involute spline transmission.

6. A speed change system for a scooter according to claim 5, characterized in that: The involute internal spline (18) on the bushing (5) is arranged at one end close to the fixed disk (3), the involute internal spline (18) on the fixed disk (3) is arranged through, the involute internal spline (18) on the bushing (5) and the involute internal spline (18) on the fixed disk (3) form a continuous involute internal spline (18), and the involute external spline (19) on the engine crankshaft (1) is arranged correspondingly and meshes with the continuous involute internal spline (18).

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