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CN-116946300-B - Speed variator for bicycle

CN116946300BCN 116946300 BCN116946300 BCN 116946300BCN-116946300-B

Abstract

The invention relates to a bicycle speed changing device, which comprises an axle center, a plurality of planetary gear modules, a plurality of one-way clutches and a gear shifting mechanism. The planetary gear modules are connected in series and arranged at the axle center. The shift mechanism includes a shift actuator and a plurality of control pawls. The control pawls are respectively movably arranged at different positions of the axle center. The concave part of the gear shifting actuator is used for controlling the opening and closing of the control end of one control pawl of the control pawls, so as to control the sun gears corresponding to the planetary gear modules to be fixed on the axle center. When shifting from a high gear to a low gear, the direction of rotation of the shift actuator is the same as the direction of rotation in which the control pawl is closed.

Inventors

  • CAI MINGZHI

Assignees

  • 日驰企业股份有限公司

Dates

Publication Date
20260505
Application Date
20230213
Priority Date
20220425

Claims (11)

  1. 1. A bicycle shifting device, comprising: An axle center; The at least two planetary gear modules are respectively and sequentially arranged on the axle center, wherein the at least two planetary gear modules are connected in series, each of the at least two planetary gear modules comprises a planet carrier, a gear ring and a sun gear, the sun gear is arranged in the planet carrier, and the gear ring is meshed with a planetary gear in the planet carrier; at least two one-way clutches connecting the corresponding planet carrier and the gear ring; A gear shifting mechanism comprising a gear shifting actuator and at least two control pawls, the gear shifting actuator is arranged at the axle center, the at least two control pawls are respectively movably arranged at different positions of the axle center, the at least two control pawls respectively comprise a control end, the gear shifting actuator comprises a plurality of concave parts corresponding to the control end, the gear shifting actuator is rotated to provide a plurality of speed increasing ratios according to the number of at least two planetary gear modules, the gear shifting is carried out between a low gear and a high gear according to the plurality of speed increasing ratios, the concave parts are used for controlling the opening and closing of the control end of one of the at least two control pawls during each gear shifting, and further controlling at least two sun gears corresponding to the at least two planetary gear modules to be fixed at the axle center, wherein when the gear shifting from the high gear to the low gear, a rotation direction of the gear shifting actuator is the same as a closing direction of the corresponding control pawl, and The gear shifting actuator is connected between the transmission member and the at least two planetary gear modules, wherein when the gear shifting actuator is switched from the high gear to the low gear, the control pawl corresponding to the position of the planetary gear module is closed by the plurality of concave parts in the sequence from the planetary gear module farthest from the transmission member to the planetary gear module closest to the transmission member, so that the sun gear corresponding to the at least two planetary gear modules is not fixed on the axle center, and the control end of only one control pawl is controlled to be opened or closed each time when the gear shifting is carried out to the adjacent gear.
  2. 2. The bicycle shifting device according to claim 1, further comprising a shift gate, wherein the transmission member is disposed between the shift gate and the at least two planetary gear modules.
  3. 3. The bicycle shifting device according to claim 1, further comprising an electrical shifting unit and an inner guide pulley, wherein a slot on an outer periphery of the inner guide pulley is engaged with a slot of the electrical shifting unit.
  4. 4. The bicycle transmission according to claim 3, further comprising a return spring and a spring seat, wherein the spring seat is fixed to the hub, and the return spring is connected to the shift actuator and the spring seat.
  5. 5. The bicycle shifting device according to claim 1, wherein the ring gear of each of the planetary gear modules constitutes the planet carrier of the next planetary gear module from the planetary gear module closest to the transmission member to the planetary gear module furthest from the transmission member.
  6. 6. The bicycle transmission according to claim 1, further comprising a hub shell, wherein the hub, the driving member, the at least two planetary gear modules and the shifting mechanism are disposed in the hub shell, and the gear ring of the planetary gear module furthest from the hub shell is fixedly connected to the hub shell.
  7. 7. The bicycle transmission according to claim 1, wherein one of the at least two planetary gear modules is a compound planetary gear train comprising the planet carrier, the gear ring, two or more layers of compound planetary gears, and at least two sun gears corresponding to the positions of the two or more layers of compound planetary gears.
  8. 8. The bicycle transmission according to claim 1, wherein the at least two control pawls have different lengths along an axial direction of the axial center, the lengths of the at least two control pawls being a distance from the control end of the shift actuator to a position of the at least two control pawls corresponding to the sun gear of the at least two planetary gear modules.
  9. 9. The bicycle shifting device according to claim 1, wherein the sun gear includes a gear body, an external tooth and an internal ratchet tooth, the internal ratchet tooth is provided in the gear body, and the external tooth is formed by one side of the gear body.
  10. 10. The bicycle shifting device according to claim 1, wherein an outer tooth of the sun gear furthest from the transmission member is offset from an inner tooth of the sun gear.
  11. 11. The bicycle transmission according to claim 1, wherein the step-up ratio can range to more than 1.33 Nth power, where N is the number of planetary gear modules.

Description

Speed variator for bicycle Technical Field The present invention relates to a bicycle shifting device. Background Bicycle shifting devices that utilize a planetary gear system to achieve a variety of different speed ratios are known in the art. For example, EP1289827B2 discloses a series connection of three different planetary gear modules, wherein each planetary gear module has two speed ratios of on and off to achieve 8 speed ratios, and each planetary gear module controls the sun gear to be fixed on the shaft through the on control pawl to provide a speed increasing ratio greater than 1 to achieve the speed increasing effect, and conversely, closes the control pawl to make the sun gear not fixed on the shaft to enable the sun gear to rotate freely to provide a 1:1 speed ratio. For four-stage transmission provided by two planetary gear modules, the first gear is that two axial pawls are closed to provide a 1:1 speed ratio, and the axial pawls need to be opened and closed between the second gear and the third gear, although the axial pawls provide a speed ratio greater than 1, which axial pawls need to be opened and closed, and one axial pawl is simultaneously opened and one axial pawl is closed, the control of the mechanism is complex, the mechanism is closed in the opened state of the axial pawls, the control is not easy, and the mechanism is easy to damage. And the fourth gear is that the two axle center pawls are opened, so that the highest speed ratio is provided. More importantly, when shifting from third gear to second gear, the closing direction of the control end of the control pawl is different from the rotation direction of the shift actuator, and the control pawl must be reversely closed. Therefore, it would be desirable to provide a bicycle shifting device that ameliorates the above-mentioned problems. Disclosure of Invention The invention aims to provide a bicycle speed changing device which can save labor when a high gear is shifted to a low gear. The present invention provides a bicycle transmission, characterized by comprising: An axle center; The at least two planetary gear modules are respectively and sequentially arranged on the axle center, wherein the at least two planetary gear modules are connected in series, each of the at least two planetary gear modules comprises a planet carrier, a gear ring and a sun gear, the sun gear is arranged in the planet carrier, and the gear ring is meshed with one planetary gear in the planet carrier; at least two one-way clutches connecting the corresponding planet carrier and the gear ring; A gear shifting mechanism comprising a gear shifting actuator and at least two control pawls, the gear shifting actuator being disposed at the axle center, the at least two control pawls being movably disposed at different positions of the axle center, the at least two control pawls each comprising a control end, the gear shifting actuator comprising a plurality of recesses corresponding to the control ends, the gear shifting actuator being rotated to provide a plurality of increasing speed ratios according to the number of the at least two planetary gear modules, the plurality of recesses being used to control opening and closing of the control ends of one of the at least two control pawls during each gear shifting, thereby controlling the sun gear corresponding to the at least two planetary gear modules to be fixed at the axle center, wherein a rotation direction of the gear shifting actuator is the same as a closing direction of the corresponding control pawl when the gear shifting from the high gear to the low gear, and The gear shifting actuator is connected between the transmission member and the at least two planetary gear modules, wherein when the gear shifting actuator is switched from the high gear to the low gear, the control pawl corresponding to the position of the planetary gear module is closed by the plurality of concave parts in the sequence from the planetary gear module farthest from the transmission member to the planetary gear module closest to the transmission member, so that the sun gear corresponding to the at least two planetary gear modules is not fixed on the axle center, and the control end of only one control pawl is controlled to be opened or closed each time when the gear shifting is carried out to the adjacent gear. The bicycle speed changing device further comprises a speed changing guide wheel, and the transmission piece is arranged between the speed changing guide wheel and the at least two planetary gear modules. The bicycle speed changing device further comprises an electronic speed changing unit and an inner guide wheel, wherein a bolt groove around the inner guide wheel is clamped in a bolt groove of the electronic speed changing unit. The bicycle speed changing device further comprises a return spring and a spring seat, wherein the spring seat is fixed on the axle center, and the return spring is connected with the gear shif