Automatic control system of planetary gear transmission and 3-speed automatic transmission in bicycle hub

Abstract

An automatic control system of a planetary gear transmission and a 3-speed automatic transmission in a bicycle hub. The 3-speed automatic transmission in the bicycle hub uses the automatic control system of a planetary gear transmission at the input end, and the automatic control system of a planetary gear transmission is achieved by means of automatic transformation of a high-speed input end and a low-speed input end of a planetary gear. A driven part of the high-speed input end is connected to a slip clutch having set torque, and a driving part is connected to a controllable one-way clutch. A driven part of the low-speed input end is connected to a one-way clutch, and the driven part is connected to the driving part by means of a one-way clutch seat and an elastic element and has a set rotation angle relative to the driving part. When the output torque is less than the set torque of the slip clutch, the automatic transmission is in a high-speed input state. When the output torque is greater than the set torque of the slip clutch, slip occurs at the high-speed input end, the low-speed input end enters a power input state, and the automatic transmission is in a low-speed input state, thereby achieving downshift speed change.

Description

Planetary gear transmission automatic control system and 3-speed automatic transmission in bicycle hub

[0001] Technical field: The present invention belongs to the field of pure mechanical automatic control of planetary gear transmissions, and its three-speed automatic transmission in a bicycle hub belongs to the field of bicycle internal transmissions.

[0002] Background technology: The existing planetary gear transmission automatic control system requires the use of more complex electrical and electronic control systems. Its purely mechanical control method for the transmission in the bicycle hub only uses centrifugal pawl speed control technology, which has three problems: it can only shift up but not down at the initially set gear, which has certain limitations; it is easy to shift up but difficult to shift out of gear, especially when riding an uphill bicycle; the centrifugal pawl is set on the active part, and the gear is disengaged when the bicycle is coasting, and there is a feeling of stepping on air when pedaling again.

[0003] Summary of the invention: The planetary gear transmission automatic control system of the present invention is a purely mechanical control and has the control function of a torque sensor. Downshifting can be achieved at the initial setting gear. The 3-speed automatic transmission in the bicycle hub adopts the planetary gear transmission automatic control system of the present invention in combination with the existing centrifugal pawl control technology. Upshifting and downshifting can be achieved at the initial setting gear. The centrifugal pawl is set on the passive component, and the centrifugal pawl is provided with a torque disengagement mechanism, which completely solves the problems existing in the automatic transmission in the existing bicycle hub. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 is a cross-sectional view of the assembly diagram of a 3-speed automatic transmission in a bicycle hub.

[0005] FIG2 is an axonometric view of a 3-speed automatic transmission flywheel assembly within a bicycle hub.

[0006] FIG3 is an exploded view of a 3-speed automatic transmission flywheel seat assembly within a bicycle hub.

[0007] FIG4 is an axonometric view of a 3-speed automatic transmission hub end cap assembly within a bicycle hub.

[0008] FIG5 is an exploded view of a 3-speed automatic transmission hub end cover assembly within a bicycle hub.

[0009] FIG6 is an isometric view of a 3-speed automatic transmission clutch assembly within a bicycle hub.

[0010] FIG7 is an exploded view of a 3-speed automatic transmission clutch assembly within a bicycle hub.

[0011] FIG8 is an axonometric view of a planetary gear carrier of a 3-speed automatic transmission in a bicycle hub.

[0012] FIG9 is an exploded view of a planetary gear carrier of a 3-speed automatic transmission in a bicycle hub. Specific implementation method:

[0013] Naming and functional description of each part and component in the accompanying drawings:

[0014] Figure 1 is a cross-sectional view of the overall diagram of a 3-speed automatic transmission in a bicycle hub:

[0015] Part 1 is the transmission gear shaft, which functions as the central gear of the planetary gear system. It is connected to the bicycle rear fork via threads and attachments (not shown) at both ends of the shaft. It supports the entire weight of the bicycle's rear wheel and restricts shaft rotation. It also supports the hub's rotation through bearings and restricts axial displacement of the hub and its internal components. Part 2 is the nut, which locks the bearing. Part 3 is the bearing, which supports the flywheel seat at its right end. Assembly 4 is the flywheel seat assembly, supported between the shaft and the hub by inner and outer bearings and free to rotate. It is responsible for inputting power to the transmission and is a key component of the planetary gear transmission's automatic control system. Part 5 is the hub, whose right end is supported by a bearing on the flywheel seat. Its left end is bolted to the hub end cap. It is supported on the shaft via the hub end cap and bearings, and connected to the wheel rim via spokes (not shown). Part 6 is the ring gear. Its right end has an internal ratchet that receives unidirectional power input from the flywheel seat via an outer pawl on the flywheel seat. The ring gear, with an internal gear in the center, serves as the main transmission component. Its right end also has an internal ratchet that outputs power to the hub via a centrifugal pawl on the hub end cap. Component 7 is the planetary gear carrier assembly. Its right end features a tooth profile and is integrated into the clutch assembly for power input. The center assembly houses the planetary gear assembly, supported by the planetary gear shaft. The outer ring of the planetary gear meshes with the ring gear and the inner ring with the gear shaft. A one-way bearing is mounted on the left end of the planetary gear carrier and connected to the hub end cap, providing one-way power output. The planetary gear carrier is mounted on the gear shaft and can rotate freely in the circumferential direction, but has an axial limit. Component 8 is the hub bolt, connecting the hub to the hub end cap. Component 9 is the hub end cap. The outer ring is connected to the hub via hub bolts. The left end of the inner ring is supported on the shaft via a bearing. The right end of the inner ring is connected to the planetary gear carrier via a one-way bearing, receiving the one-way power output from the planetary gear carrier. The center ring is equipped with a centrifugal pawl, receiving the one-way power output from the ring gear. Component 10 is a one-way bearing. Component 11 is a bearing. Component 12 is a bearing nut. Component 13 is a planetary gear carrier retaining spring, which limits the axial position of the planetary gear carrier. Component 14 is the clutch assembly. Its left end is engaged with the planetary gear carrier via a toothed connection, and its right end is connected to the flywheel carrier via the flywheel carrier's internal pawl. The middle section of the clutch assembly, through a butterfly spring, lock nut, clutch shaft, and friction post, provides a slip clutch function for the power transmission path from the flywheel carrier to the planetary gear carrier. The set torque can be adjusted using the lock nut. Component 15 is a thin-walled bearing. Component 16 is a thin-walled bearing retaining spring. Component 17 is a clutch assembly retaining spring. Component 18 is a sprocket, which transmits the bicycle chain's power to the flywheel carrier. Component 19 is a sprocket adjustment ring. Component 20 is a sprocket retaining spring.

[0016] Figures 2 and 3 are the axonometric and exploded views of the flywheel seat assembly (the part numbers are universal)

[0017] Part 401 is the inner pawl of the flywheel seat, part 402 is the torsion spring of the flywheel seat, part 403 is the flywheel seat, part 404 is the inner pawl spring, part 405 is the pawl seat, part 406 is the outer pawl of the flywheel seat, and part 407 is the outer pawl retaining spring. The pawl seat is mounted in the groove of the outer ring at the left end of the flywheel seat, and can have a circumferential rotation angle relative to the flywheel seat. The C-shaped hook of the pawl seat is located at the left end, and the torsion spring is mounted on the outer periphery of the C-shaped hook at the left end of the pawl seat, and the flywheel seat and the pawl seat are connected through the two protruding ends of the torsion spring. One protruding end of the torsion spring is inserted into the hole of the flywheel seat, and the other protruding end is inserted into the pawl seat hole, so that the pawl seat is in the extreme position of forward rotation relative to the flywheel seat, the outer pawl is installed in the outer periphery of the pawl seat and limited by the retaining spring, so that the outer pawl is in an open state, and the inner pawl is installed in the inner periphery of the left end of the flywheel seat and limited by the pawl spring, so that the inner pawl is in an open position toward the inner periphery. The flywheel seat assembly can transmit power to the ring gear through the outer pawl, and can also transmit power to the clutch assembly through the inner pawl.

[0018] Figures 4 and 5 are the axonometric and exploded views of the hub end cap (the part numbers are universal).

[0019] Part 901 is the hub end cover, part 902 is the centrifugal pawl, part 903 is the pawl shaft, part 904 is the centrifugal pawl disengagement pin, part 905 is the centrifugal pawl seat, part 906 is the centrifugal pawl rubber spring, and part 907 is the centrifugal pawl torsion spring; the centrifugal pawl is connected to the centrifugal pawl seat in the form of a thread through the pawl shaft, the centrifugal pawl seat is installed in the circumferential groove of the hub end cover, and the rubber spring is pressed into it, and the initial position of the centrifugal pawl is limited by the pawl torsion spring, which can be adjusted by adjusting the torsion of the torsion spring and the centrifugal pawl The weight of the pawl is used to set the appropriate centrifugal torque. The initial position is the retracted position of the centrifugal pawl, and no power is transmitted. The power transmission of the centrifugal pawl is to the hub end cover through the compressed rubber spring. The compression force of the rubber spring can set the transmission torque of the centrifugal pawl. When the transmission torque of the centrifugal pawl is greater than the set torque, the rubber spring is further compressed, causing the centrifugal pawl seat to rotate circumferentially relative to the hub end cover. This rotational displacement causes the centrifugal pawl to disengage from the gear through the centrifugal pawl disengagement pin, thereby solving the problem of difficulty in disengaging the centrifugal pawl.

[0020] Figures 6 and 7 are the axial and exploded views of the clutch assembly (the part numbers are universal)

[0021] Part 1401 is the clutch shaft, part 1402 is the clutch output plate, part 1403 is the clutch pressure plate, part 1404 is the butterfly spring, part 1405 is the clutch small pressure plate, part 1406 is the clutch input plate, part 1407 is the clutch lock nut, and part 1408 is the clutch friction column. The clutch assembly's function is to receive power from the pawl inside the flywheel seat via the outer ratchet teeth of the clutch input plate, and transmit this power to the clutch engagement plate through the friction generated by the clutch pressure plate and the clutch shaft pressing against the friction column. The clutch engagement plate then transmits the power to the planetary gear carrier. The clutch's transmission torque can be adjusted by tightening the lock nut. The clutch's initial position is the power transmission state. When the transmission torque exceeds the clutch's set torque, the clutch will slip.

[0022] Figures 8 and 9 are the axonometric and exploded views of the planetary gear carrier assembly (part numbers are universal)

[0023] Part 701 is the planetary gear carrier, part 702 is the planetary gear, and part 703 is the planetary gear shaft. The planetary gear assembly's function is to connect to the clutch assembly's output plate via face gear at the right end, receiving clutch power. At the right end, a one-way bearing, sleeved outside the planetary gear carrier and press-fitted into the hub end cap, transmits one-way power to the hub end cap. In the middle section, the planetary gear shaft supports the inner circumference of the planetary gear, which meshes with the central gear on the shaft, and the outer circumference of the planetary gear meshes with the ring gear.

[0024] Implementation plan for a 3-speed automatic transmission in a bicycle hub:

[0025] The initial gear of this plan is 2nd gear (also direct gear, starting gear), 1st gear is deceleration gear (climbing gear, low speed gear), and 3rd gear is speed increase gear (flat road and downhill gear, high speed gear).

[0026] This bicycle starts in second gear; the power transmission route is from sprocket to flywheel seat, pawl inside the flywheel seat, clutch input plate, clutch shaft, clutch pressure plate, clutch engagement plate, planetary gear carrier, one-way bearing, hub end cap, and hub. At this point, the output torque is less than the clutch's set torque, and the clutch is engaged. The ring gear is rotating at a high speed, exceeding the speed of the flywheel seat. The centrifugal pawl is in its initial position and has not yet opened due to the low hub speed.

[0027] After starting, the bicycle accelerates or when traveling downhill, and is in third gear. The power transmission route is: sprocket - flywheel seat - pawl inside the flywheel seat - clutch input plate - clutch shaft - clutch pressure plate - clutch engagement plate - planetary gear carrier - planetary gear - ring gear - centrifugal pawl - centrifugal pawl shaft - hub end cap - hub. At this point, the transmitted torque is less than the clutch's set torque, the clutch is in operation, the ring gear rotates beyond the flywheel seat, and the centrifugal pawl, due to the increased centrifugal force of the increased hub speed, overcomes the restraining force of the pawl's torsion spring and remains open. The hub end cap's speed is higher than the planetary gear carrier, and it overtakes the planetary gear carrier via the one-way bearing.

[0028] When going uphill, the bicycle is in first gear; the power transmission path is from sprocket to flywheel carrier, outer pawl to ring gear, planetary gears, planetary gear carrier, one-way bearing, hub end cap, and finally hub. At this point, the bicycle's speed decreases, increasing the transmitted torque. Due to the reduced hub speed, the centrifugal force on the centrifugal pawl is less than the limiting torque of the centrifugal pawl torsion spring, causing it to retract. At the same time, due to the high torque exerted on the centrifugal pawl and the high friction between the ratchet teeth, disengagement becomes difficult. This is because the transmitted torque of the centrifugal pawl exceeds the set torque of the rubber spring, causing the rubber spring to further compress. The centrifugal pawl, under the pressure of the centrifugal pawl disengagement pin, disengages the gear. Because the transmitted torque exceeds the set torque, the clutch slips. The outer pawl of the flywheel carrier, under the reaction force of the ring gear, pushes the pawl carrier backward by a defined angle relative to the flywheel carrier, overcoming the torque of the torsion spring. The pawl carrier's C-shaped claw retracts the inner pawl of the flywheel carrier, disengaging the clutch.

[0029] When the bicycle completes the climb and the output torque decreases, as long as the cyclist pauses pedaling, the pawl seat on the flywheel seat returns to its initial position under the action of the torsion spring, the pawl inside the flywheel seat opens, the clutch starts to work, and the gear returns to 2nd gear. When the bicycle speed increases, the hub speed increases, the centrifugal pawl opens, and the gear shifts to 3rd gear.

Claims

1. An automatic control system for a planetary gear transmission, wherein the high-speed end is connected to the passive part by a slip clutch with settable torque, and is connected to the active part by a controllable one-way clutch, and the low-speed end is connected to the passive part by a one-way clutch, which is connected to the active part through a one-way clutch seat and an elastic element and can have a settable rotation angle relative to the active part, and the torque and displacement generated by this relative rotation are used to control the controllable one-way clutch at the high-speed end.

2. The 3-speed automatic transmission in the bicycle hub adopts the planetary gear automatic control system of claim 1) at the input end, which belongs to the torque control system.

3. The 3-speed automatic transmission in the bicycle hub adopts a centrifugal pawl and ratchet centrifugal force speed-up control system at the output end, and a pawl seat and a rubber spring are arranged between the centrifugal pawl and the passive part. The transmission torque of the centrifugal pawl can be set by the spring, and it has a torque disengagement control mechanism. The ratchet teeth are arranged on the inner side of the gear ring. The centrifugal pawl seat is connected to the hub end cover through a rubber spring, and the torque is output through the hub end cover, which belongs to the speed control system.

4. By using the planetary gear automatic control system and the ratchet pawl speed-up control system to form an intermediate adapter plate, system cascading can be achieved, thereby realizing the design of a 5-speed automatic transmission and a 7-speed automatic transmission in a bicycle hub.

5. The basic principles of claims 1), 2), 3) and 4) can be used to design an automatic transmission in a bicycle bottom bracket.

6. The planetary gear transmission control system described in claim 1) can be used on the input side as well as the output side.

7. By utilizing the relative rotation between the one-way clutch seat and the active member described in claim 1), a trigger-type wireless transmitter can be set to control the power-assisting motor system, thereby realizing the torque-controlled motor power-assisting function.

8. By using the technology of claim 1), it is possible to design automatic transmissions for electric bicycles, motorcycles, automobiles and other vehicles that require automatic speed control of planetary gears.

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