Bicycle gear mechanism and use thereof

Abstract

The application discloses a bicycle gear transmission mechanism and application thereof, and the transmission mechanism comprises a rear axle flywheel gear set and a variable speed gear set; the rear axle flywheel gear set comprises coaxial rear axle flywheel gear A and rear axle flywheel gear B, and the size of the rear axle flywheel gear A is larger than that of the rear axle flywheel gear B; the variable speed gear set comprises coaxial variable speed gear A and variable speed gear B, and the size of the variable speed gear A is smaller than that of the variable speed gear B; an active connecting sleeve set is arranged between the variable speed gear A and the variable speed gear B, the active connecting sleeve set comprises a male part and a female part, and a certain fixed force exists between the male part and the female part when the male part and the female part are in a connecting position; the rear axle flywheel gear A is engaged with the variable speed gear A, and the rear axle flywheel gear B is engaged with the variable speed gear B. The bicycle gear transmission mechanism has reasonable structural design, can realize automatic switching of two energy transmission paths, and realizes good compromise of high durability, low cost, high transmission efficiency and high speed.

Description

Technical Field

[0001] This invention relates to the field of bicycle transmission technology, specifically to a bicycle gear transmission mechanism and its application, and more particularly to a two-speed automatic shifting bicycle gear transmission mechanism and a bicycle using the gear transmission mechanism. Background Technology

[0002] A bicycle, also known as a pedal bike or cyclist, is typically a small, two-wheeled land vehicle. Riders power it by pedaling, making it a green and environmentally friendly mode of transportation. In cities where traffic congestion is increasingly severe, more and more people are using bicycles for short-distance travel. Besides its function as a means of transportation, it is also widely used as fitness equipment (cycling for exercise).

[0003] Modern bicycles are mainly divided into driveshaft bicycles and chain-driven bicycles. Chain-driven bicycles use a chain to connect the front chainring and the rear freewheel to transmit power, while driveshaft bicycles use a driveshaft for power transmission. Although the driveshaft system of chain-driven bicycles is inexpensive, it has poor durability and is prone to failure. Although the driveshaft system of bicycles is compact and durable, it is more expensive. In addition, the driveshaft needs to work with bevel gears to transmit power, and bevel gears have low transmission efficiency, which makes riding more strenuous.

[0004] CN202201122U discloses a chainless gear transmission bicycle, which provides a planar gear transmission system. Compared with the drive shaft transmission system, it is cheaper and has higher transmission efficiency. However, it only has one set of gears and a single transmission ratio. In order to ensure sufficient torque during starting / hill / rapid acceleration, the transmission ratio cannot be designed to be too high. This results in a slower top speed and slower commuting speed for this type of bicycle.

[0005] Therefore, it is of great practical significance to develop a bicycle gear transmission mechanism that has a reasonable structural design, good durability, low cost, high transmission efficiency, and can meet the needs of higher commuting speeds. Summary of the Invention

[0006] Due to the aforementioned deficiencies in the existing technology, the present invention provides a bicycle gear transmission mechanism with reasonable structural design, good durability, low cost, high transmission efficiency, and the ability to meet the needs of higher commuting speeds, thereby overcoming the shortcomings of existing bicycle transmission mechanisms that cannot simultaneously achieve a good balance of high durability, low cost, high transmission efficiency, and high commuting speed.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A bicycle gear transmission mechanism includes a rear axle freewheel gear set and a speed-changing gear set;

[0009] The rear axle freewheel gear set includes a coaxial rear axle freewheel gear A and a rear axle freewheel gear B. The size of the rear axle freewheel gear A is larger than that of the rear axle freewheel gear B. The rear axle freewheel gear A and the rear axle freewheel gear B are respectively fixed to the rear axle of the bicycle via the rear axle of the bicycle.

[0010] The gear set includes coaxial gears A and B, which are mounted on a gear shaft fixedly connected to the bicycle. Gears A and B can rotate independently around the gear shaft. Gear A is smaller than gear B. A movable connecting assembly is provided between gears A and B. The movable connecting assembly includes a male and a female component. When the male and female components are in the connected position, there is a certain fixing force between them. When the force between the male and female components exceeds their force limit, gears A and B rotate relative to each other. Gear A rotates, and the movable connecting assembly changes from the disengaged position to the connected position. At this time, the male and female components are... Under a certain fixed force, gear A transmits energy to gear B (driving gear B). If the force between the male and female parts still exceeds their force limits, as gear A rotates continuously, gear B gradually accelerates, and the relative angular velocity between gear A and gear B gradually decreases until the force between the male and female parts is less than or equal to their force limits. The active connecting kit then reconnects gear A and gear B into one unit. When the force between the male and female parts is less than or equal to their force limits, the active connecting kit connects gear A and gear B into one unit, meaning that at this time, the angular velocities (rotational speeds) of gear A and gear B are the same.

[0011] The rear axle flywheel gear A meshes with the transmission gear A, and the rear axle flywheel gear B meshes with the transmission gear B.

[0012] The bicycle gear transmission mechanism includes two energy transmission paths: gear A (small wheel) to rear axle freewheel gear A (large wheel) and gear B (large wheel) to rear axle freewheel gear B (small wheel). The transmission ratios of the two are different, with the transmission ratio of gear B (large wheel) to rear axle freewheel gear B (small wheel) being larger.

[0013] The state of the movable coupling kit depends on the resistance of the bicycle's rear wheel. When the rear wheel resistance is too high (uphill / starting / rapid acceleration), torque is transmitted to the movable coupling kit, which may become overwhelmed and disengage. At this point, gears A and B slip, and power is transmitted via the energy transmission path from gear A to rear axle freewheel gear A (small gear ratio, large torque). When the rear wheel resistance is low (flat road / constant speed), the torque is low, and the movable coupling kit connects gears A and B, allowing power to be transmitted via the energy transmission path from gear B to rear axle freewheel gear B (small gear ratio, large torque). (Higher speed, faster speed) Transmits power. At this time, gear A still drives the rear axle freewheel gear A to rotate. However, because the speed of the rear axle freewheel gear B is higher than that of the rear axle freewheel gear A, due to the specific structure of the rear axle freewheel gear and the rear axle freewheel, the rotation of the rear axle freewheel gear in a certain direction can drive the rear axle freewheel to rotate, but the rotation of the rear axle freewheel will not affect the rear axle freewheel gear. The angular velocity of the bicycle's rear axle is determined by the faster-rotating rear axle freewheel gear B. At this time, the rear axle freewheel gear A does not drive the rear wheel to rotate, that is, the rear axle freewheel gear A is in an idle state. When the user is riding, the active connection component will automatically switch its state according to the external resistance.

[0014] When the bicycle starts, the movable connecting assembly connects gear A and gear B as one unit. Gear A (small wheel) drives rear axle freewheel gear A (large wheel), which in turn drives rear axle freewheel A. Gear B (large wheel) drives rear axle freewheel gear B (small wheel), which in turn drives rear axle freewheel B. At the start, the torque between gear A (small wheel) and gear B (large wheel) is relatively high (gear A rotates, gear B does not rotate, and their relative angular velocity is high), exceeding the force limit of the movable connecting assembly. The movable connecting assembly disengages, and gear A and gear B slip. Gear A (small wheel) then drives rear axle freewheel gear A (large wheel), which is... In the starting / upshifting gear position, the movable connecting kit moves from the engaged position to the disengaged position. Gear A transfers energy to gear B. Because gear A has a greater angular velocity than gear B, as gear A rotates, the movable connecting kit re-engages, driving gear B. Gear B gradually accelerates, and the relative angular velocity between gears A and B gradually decreases (the torque between them decreases) until the force on the movable connecting kit is less than its limit. The movable connecting kit then reconnects gears A and B. Gear A (smaller gear) drives rear axle flywheel gear A (larger gear), and gear B (larger gear) drives the rear axle flywheel gear... Due to size issues, the transmission speed ratio of gear A (small wheel) to rear axle freewheel gear A (large wheel) is much smaller than that of gear B (large wheel) to rear axle freewheel gear B (small wheel). Therefore, the angular velocity of rear axle freewheel gear B is necessarily greater than that of rear axle freewheel gear A. Furthermore, since the rear axle freewheel gear (external gear) is fixedly connected to the bicycle's rear axle via the rear freewheel, the rear axle freewheel gear and the rear axle freewheel are in a semi-independent state. Rotation of the rear axle freewheel gear in a specific direction can drive the rotation of the rear axle freewheel, but the rotation of the rear axle freewheel will not affect the rear axle freewheel gear. In other words, the rotations of rear axle freewheel gears A and B do not interfere with each other. The angular velocity of the bicycle's rear axle is controlled by the faster angular velocity of the rear axle freewheel. Gear B determines that at this time, the rear axle freewheel gear A does not drive the rear wheel to rotate, that is, the rear axle freewheel gear A is in an idle state. The gear B-rear axle freewheel gear B is the main drive wheel set. This state (large wheel to small wheel transmission) is a high speed compared to gear A-rear axle freewheel gear A (small wheel to large wheel transmission). It allows the user to maintain a higher speed with a lower pedaling frequency, ensuring that the bicycle can have a higher commuting speed. If the bicycle accelerates again or is in an uphill situation (the bicycle rear wheel has greater resistance, and the torque between gear A and gear B is greater), the situation is similar to the bicycle when it is just starting. The bicycle uses gear A-rear axle freewheel gear A as the drive wheel set.The bicycle gear transmission mechanism of this invention will automatically adjust the transmission wheel set according to actual needs during use, and can achieve the effect of stepless speed change to a certain extent. This invention uses a planar gear as the transmission component, which has higher transmission efficiency than the currently common bevel gear transmission form. Bicycles using the bicycle gear transmission mechanism of this invention are easy to ride, have a simple overall structure, good durability and low cost, and have good application prospects.

[0015] As a preferred technical solution:

[0016] The bicycle gear transmission mechanism described above also includes a chainring and multiple intermediate transmission gears;

[0017] The toothed sprocket meshes with either speed change gear A or speed change gear B via multiple intermediate transmission gears.

[0018] As described above, in a bicycle gear transmission mechanism, the chainring, multiple intermediate transmission gears, a gear set, and a rear axle freewheel are arranged in a row. The intermediate transmission gears are mounted on an intermediate transmission gear shaft that is fixedly connected to the bicycle. All intermediate transmission gear shafts, gear sets, chainring shafts, and the bicycle rear axle are located on the same plane.

[0019] In the bicycle gear transmission mechanism described above, there are two intermediate transmission gears;

[0020] The chainring meshes with intermediate drive gear A, intermediate drive gear A meshes with intermediate drive gear B, and intermediate drive gear B meshes with gear A. This is merely one feasible technical solution; of course, those skilled in the art can select the number or size of the intermediate drive gears according to actual needs to meet the requirements of bicycle structure and gear ratio design.

[0021] In the bicycle gear transmission mechanism described above, the active connecting kit is a magnetic connecting kit, and both the male and female parts are magnetic blocks;

[0022] The male and female components are fixed to gear A and gear B respectively, and their positions correspond. The near ends of the male and female components attract each other. During operation of the transmission mechanism, the magnetically connected components will not collide, there is no energy loss due to friction between the opposing parts, and no noise is generated.

[0023] As described above, in a bicycle gear transmission mechanism, a plurality of male components are mounted on the gear A, which are evenly distributed around the circumference of the gear A.

[0024] The variable speed gear B is equipped with multiple female parts evenly distributed around its circumference.

[0025] The male and / or female parts are installed inside the externally threaded hollow cylinder. The outer wall of the externally threaded hollow cylinder is provided with an externally threaded structure I. The gear A and / or gear B have internally threaded holes I that match the externally threaded structure I. The externally threaded hollow cylinder is connected to gear A and / or gear B by threads. By rotating the externally threaded hollow cylinder, the minimum distance between the male and female parts can be adjusted to adjust the stress limit of the male and female parts.

[0026] In the bicycle gear transmission mechanism described above, the active connection kit is a flexible connection kit;

[0027] The male component is a spring plunger (positioning bead / pillar), and the female component is a spring plunger fixing hole that matches the moving head of the spring plunger and corresponds to the position of the spring plunger. During operation of the transmission mechanism, the elastic connecting components will collide, and the parts will rub against each other, resulting in energy loss and noise, affecting the rider's user experience.

[0028] As described above, in a bicycle gear transmission mechanism, a plurality of spring plungers are mounted on the gear A, which are evenly distributed around the circumference of the gear A.

[0029] The gear B has multiple spring plunger fixing holes evenly distributed around its circumference.

[0030] The outer wall of the spring plunger is provided with an external thread structure II, and the gear A has an internal thread hole II that matches the external thread structure II. That is, the spring plunger and the gear A are connected by threads and the position of the spring plunger can be finely adjusted (i.e., the force limit of the male and female parts is adjusted).

[0031] The movable head of the spring plunger is spherical or hemispherical, and other smooth arc-shaped structures are also applicable, ensuring that the spring plunger can be disengaged from the spring plunger fixing hole.

[0032] The present invention also provides a chainless bicycle, including the bicycle gear transmission mechanism described above.

[0033] As a preferred technical solution:

[0034] As described above, in a chainless bicycle, two drive shaft mounting plates are installed between the chainring axle and the rear wheel axle, with the two drive shaft mounting plates located on both sides of the chainring and the rear freewheel, respectively.

[0035] The speed change gear shaft and all intermediate transmission gear shafts are fixed on the two transmission shaft mounting plates.

[0036] The above technical solution is only one feasible technical solution of the present invention. The scope of protection of the present invention is not limited thereto. Those skilled in the art can reasonably adjust the specific design according to actual needs.

[0037] The above invention has the following advantages or beneficial effects:

[0038] (1) The bicycle gear transmission mechanism of the present invention has a reasonable structural design and uses a planar gear as a transmission component, which has higher transmission efficiency than the currently common bevel gear transmission form;

[0039] (2) The bicycle gear transmission mechanism of the present invention is designed with two energy transmission paths and the two energy transmission paths can be adjusted according to the real-time state of the bicycle (the function of the active connection kit). When starting / accelerating / going uphill, energy is transmitted through the energy transmission path with a small transmission ratio to ensure a larger torque to provide a larger acceleration. When riding smoothly / at a constant speed, energy is transmitted through the energy transmission path with a large transmission ratio, so that the user can maintain a higher speed with a lower pedal frequency, which can improve the commuting speed of the bicycle.

[0040] (3) The bicycle gear transmission mechanism of the present invention is easy to ride, has a simple overall structure, good durability and low cost, and has great application prospects. Attached Figure Description

[0041] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings, the emphasis being on illustrating the gist of the invention.

[0042] Figure 1 This is a schematic diagram of the chainless bicycle in Example 2;

[0043] Figure 2 and 3 These are schematic diagrams of the bicycle gear transmission mechanism of Example 1 from different perspectives;

[0044] Figure 4 and 5 These are the front view and top view of the chainless bicycle in Example 4, respectively;

[0045] Figure 6 and 7 These are the front view and top view of the bicycle gear transmission mechanism in Example 3, respectively.

[0046] Among them, 1. Rear axle freewheel gear A; 2. Rear axle freewheel gear B; 3. Rear axle freewheel A; 4. Bicycle rear axle; 5. Shift gear A; 6. Shift gear B; 7. Shift gear shaft; 8. Intermediate drive gear B; 9. Intermediate drive gear A; 10. Chainring; 11. Spring plunger; 12. Chainring shaft; 13. Crank; 14. Pedal; 15. Drive shaft mounting plate; 16. Intermediate drive gear shaft A; 17. Intermediate drive gear shaft B; 18. Male magnetic block; 19. Female magnetic block. Detailed Implementation

[0047] The structure of the present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0048] Example 1

[0049] A bicycle gear transmission mechanism, such as Figure 2 and 3 As shown, it includes a row of chainrings 10, intermediate drive gear A9, intermediate drive gear B8, rear axle flywheel gear set, and speed change gear set;

[0050] Intermediate transmission gears A9 and B8 are respectively mounted on intermediate transmission gear shafts A and B, which are fixedly connected to the bicycle.

[0051] The gear set includes coaxial gears A5 and B6, which are mounted on a gear shaft 7 fixedly connected to the bicycle. Gears A5 and B6 can rotate independently around the gear shaft 7. Gear A5 is smaller than gear B6. A magnetic connection kit is provided between gears A5 and B6, including a male magnetic block 18 and a female magnetic block 19. The male and female magnetic blocks 18 are respectively fixed to gears A5 and B6. (Gear A5 has multiple male magnetic blocks 18 evenly distributed around its circumference.) Multiple female magnetic blocks 19 are evenly distributed around the circumference of the gear B6. Male magnetic blocks 18 and / or female magnetic blocks 19 are installed inside an externally threaded hollow cylinder. The outer wall of the externally threaded hollow cylinder has an external thread structure I. The gear A5 and / or gear B6 have internal thread holes I that match the external thread structure I. The externally threaded hollow cylinder is threaded to the gear A5 and / or gear B6. By rotating the externally threaded hollow cylinder, the minimum distance between the male magnetic blocks 18 and female magnetic blocks 19 can be adjusted, thereby adjusting the force limit of the male magnetic blocks 18 and female magnetic blocks 19. At position 9, the male magnetic block 18 and female magnetic block 19 attract each other at their close ends. When the force between the male and female magnetic blocks 18 and 19 exceeds their force limit, gears A5 and B6 rotate relative to each other. Gear A5 rotates, and the magnetic connection kit changes from the disengaged position to the connected position. At this time, there is a certain fixing force between the male and female magnetic blocks 18 and 19. Gear A5 transmits energy to gear B6 (driving gear B6). If the force between the male and female magnetic blocks 18 and 19 still exceeds their force limit, As gear A5 rotates continuously, gear B6 gradually accelerates. The relative angular velocity between gear A5 and gear B6 gradually decreases until the force between male magnetic block 18 and female magnetic block 19 is less than or equal to their force limits. The magnetic connection kit then reconnects gear A5 and gear B6 into one unit. When the force between male magnetic block 18 and female magnetic block 19 is less than or equal to their force limits, the magnetic connection kit connects gear A5 and gear B6 into one unit. At this point, the angular velocity (rotation speed) of gear A5 and gear B6 is the same.

[0052] The rear axle freewheel gear set includes coaxial rear axle freewheel gear A1 and rear axle freewheel gear B2. The size of rear axle freewheel gear A1 is larger than that of rear axle freewheel gear B2. Rear axle freewheel gear A1 and rear axle freewheel gear B2 are fixed to the rear axle 4 of the bicycle by rear axle freewheel A3 and rear axle freewheel B respectively (rear axle freewheel A is fixed on the outer ring of rear axle freewheel A and the inner ring of rear axle freewheel A is fixed on the rear axle of the bicycle, and rear axle freewheel gear B is the same as rear axle freewheel A).

[0053] The chainring 10 meshes with the intermediate transmission gear A9, the intermediate transmission gear A9 meshes with the intermediate transmission gear B8, and the intermediate transmission gear B8 meshes with the speed change gear A9.

[0054] Intermediate drive gear shaft A, intermediate drive gear shaft B, gear shift shaft 7, chainring shaft 12, and bicycle rear axle 4 are located on the same plane.

[0055] The specific states of each component during the operation of the aforementioned bicycle gear transmission mechanism are as follows:

[0056] When the bicycle starts moving, the magnetic attraction between the male and female parts connects gear A and gear B together. Gear A (small wheel) drives the rear axle freewheel gear A (large wheel), which in turn drives the rear axle freewheel A. Gear B (large wheel) drives the rear axle freewheel gear B (small wheel), which in turn drives the rear axle freewheel B. At the start, the torque between gear A (small wheel) and gear B (large wheel) is relatively high (gear A rotates while gear B does not, resulting in a high relative angular velocity), exceeding the magnetic attraction between the male and female parts. This causes the magnetic connection to detach, and gear A and gear B to slip. The small gear A drives the large gear A on the rear axle flywheel, which is the starting / accelerating gear. The magnetic connector changes from the connected position to the disengaged position, and gear A transfers energy to gear B. Since the angular velocity of gear A is greater than that of gear B, as gear A rotates, the male and female magnetic blocks re-enter the connected position (at which point the attraction is at its maximum). Gear A drives gear B to gradually accelerate, and the relative angular velocity between gears A and B gradually decreases (the torque between them decreases) until the force on the male and female magnetic blocks is less than the attraction between them. The magnetic connector then... The kit reconnects gears A and B into a single unit. Gear A (small wheel) drives rear axle freewheel gear A (large wheel), and gear B (large wheel) drives rear axle freewheel gear B (small wheel). Due to size issues, the speed ratio of gear A (small wheel) to rear axle freewheel gear A (large wheel) is much smaller than that of gear B (large wheel) to rear axle freewheel gear B (small wheel). Therefore, the angular velocity of rear axle freewheel gear B is necessarily greater than that of rear axle freewheel gear A. Due to the design of the rear axle freewheel, the rotation of rear axle freewheel gears A and B will not interfere with each other. The angular velocity of the bicycle's rear axle is determined by the faster angular velocity of rear axle freewheel gear B. At this point, the rear axle freewheel... Gear A does not drive the rear wheel to rotate, meaning the rear axle freewheel gear A is in an idle state. Gear B—rear axle freewheel gear B is the main drive wheel assembly. This state (large wheel to small wheel transmission) is a higher speed compared to gear A—rear axle freewheel gear A (small wheel to large wheel transmission). This allows the user to maintain a higher speed with a lower pedaling frequency, ensuring the bicycle can achieve a higher commuting speed. If the bicycle accelerates again or is going uphill (the rear wheel resistance is greater, and the torque between gear A and gear B is greater), the situation is similar to when the bicycle is just starting. In this case, the bicycle uses gear A—rear axle freewheel gear A as the drive wheel assembly.

[0057] Example 2

[0058] A type of chainless bicycle, such as Figure 1 As shown, it includes the bicycle gear transmission mechanism as described in Embodiment 1;

[0059] Two drive shaft mounting plates 15 are installed between the chainring axle 12 and the rear wheel axle 4. The two drive shaft mounting plates 15 are located on both sides of the chainring 10 and the rear freewheel, respectively.

[0060] The speed change gear shaft 7, intermediate transmission gear shaft A16 and intermediate transmission gear shaft B17 are fixed on the two transmission shaft mounting plates 15.

[0061] Example 3

[0062] A bicycle gear transmission mechanism, such as Figures 6-7 As shown, it includes a row of chainrings 10, intermediate drive gear A9, intermediate drive gear B8, rear axle flywheel gear set, and speed change gear set;

[0063] Intermediate transmission gears A9 and B8 are respectively mounted on intermediate transmission gear shafts A and B, which are fixedly connected to the bicycle.

[0064] The gear set includes coaxial gears A5 and B6, which are mounted on a gear shaft 7 fixedly connected to the bicycle. Gears A5 and B6 can rotate independently around the gear shaft 7. Gear A5 is smaller than gear B6. A flexible connecting element (i.e., spring plunger 11 and spring plunger fixing hole) is provided between gears A5 and B6. The movable head of spring plunger 11 is spherical or hemispherical, and its outer wall has an external thread structure II. Gear A5 has an internal thread hole II that matches the external thread structure II. Spring plunger 11 is threaded onto gear A5, and its position can be finely adjusted by rotating it. Gear B6 has a spring plunger fixing hole that matches the movable head of spring plunger 11 and corresponds to its position. Multiple spring plungers 11 and multiple spring plunger fixing holes are mounted on gear A5. The spring plunger 11 is evenly distributed around the circumference of the gear A5. The gear A5 and gear B6 can be connected as one unit through the spring plunger 11. At this time, the angular velocity (rotation speed) of the gear A5 and gear B6 is the same. When the force on the spring plunger 11 exceeds the bearing limit of the spring plunger 11, the spring plunger 11 disengages from the hole on the gear B6, that is, the gear A5 and gear B6 rotate relative to each other. The gear A5 rotates, and the spring plunger 11 changes from a disengaged state to a contact state. The gear A5 transmits energy to the gear B6 (driving the gear B6). If the force on the spring plunger 11 still exceeds the bearing limit of the spring plunger 11, as the gear A5 continues to rotate, the gear B6 gradually accelerates, and the relative angular velocity between the gear A5 and gear B6 gradually decreases until the force on the spring plunger 11 is less than the bearing limit of the spring plunger 11. The spring plunger 11 then reconnects the gear A5 and gear B6 as one unit.

[0065] The rear axle freewheel gear set includes coaxial rear axle freewheel gear A1 and rear axle freewheel gear B2. The size of rear axle freewheel gear A1 is larger than that of rear axle freewheel gear B2. Rear axle freewheel gear A1 and rear axle freewheel gear B2 are fixed to the rear axle 4 of the bicycle by rear axle freewheel A3 and rear axle freewheel B respectively (rear axle freewheel A is fixed on the outer ring of rear axle freewheel A and the inner ring of rear axle freewheel A is fixed on the rear axle of the bicycle, and rear axle freewheel gear B is the same as rear axle freewheel A).

[0066] The chainring 10 meshes with the intermediate transmission gear A9, the intermediate transmission gear A9 meshes with the intermediate transmission gear B8, and the intermediate transmission gear B8 meshes with the speed change gear A9.

[0067] Intermediate drive gear shaft A, intermediate drive gear shaft B, gear shift shaft 7, chainring shaft 12, and bicycle rear axle 4 are located on the same plane.

[0068] The specific states of each component during the operation of the aforementioned bicycle gear transmission mechanism are as follows:

[0069] When the bicycle starts, the spring plunger connects gear A and gear B as one unit. Gear A (small wheel) drives the rear axle freewheel gear A (large wheel), which in turn drives the rear axle freewheel A. Gear B (large wheel) drives the rear axle freewheel gear B (small wheel), which in turn drives the rear axle freewheel B. At the very beginning of the start, the torque between gear A (small wheel) and gear B (large wheel) is relatively large (gear A rotates, gear B does not rotate, and their relative angular velocity is relatively large), exceeding the spring plunger's bearing limit. The elastic connecting component disengages, and gear A and gear B slip. The smaller gear drives the rear axle flywheel gear A (larger gear), which is the starting / accelerating gear. The flexible connecting assembly moves from the contact position to the disengagement position. Gear A transmits energy to gear B. Because the angular velocity of gear A is greater than that of gear B, as gear A rotates, the spring plunger will re-engage in its hole. Gear A drives gear B to gradually accelerate, and the relative angular velocity between gears A and B gradually decreases (the torque between them decreases) until the force on the spring plunger is less than its bearing limit. The flexible connecting assembly then reconnects gears A and B as a single unit. Wheel A (small wheel) drives rear axle freewheel gear A (large wheel), and gear B (large wheel) drives rear axle freewheel gear B (small wheel). Due to size issues, the transmission speed ratio of gear A (small wheel) → rear axle freewheel gear A (large wheel) is much smaller than that of gear B (large wheel) → rear axle freewheel gear B (small wheel). Therefore, the angular velocity of rear axle freewheel gear B is necessarily greater than that of rear axle freewheel gear A. Due to the design of the rear axle freewheel, the rotation of rear axle freewheel gears A and B will not interfere with each other. The angular velocity of the bicycle's rear axle is determined by the faster angular velocity of rear axle freewheel gear B. At this point, rear axle freewheel gear A is not driving the rear wheel to rotate. With the rear axle freewheel gear A in an idle state, gear B—rear axle freewheel gear B is the main drive wheel assembly. This state (large wheel to small wheel drive) is a higher speed compared to gear A—rear axle freewheel gear A (small wheel to large wheel drive), allowing the user to maintain a higher speed with a lower cadence. This ensures the bicycle can achieve a higher commuting speed. If the bicycle accelerates again or is going uphill (the rear wheel resistance is higher, and the torque between gear A and gear B is greater), the situation is similar to when the bicycle is just starting. In this case, gear A—rear axle freewheel gear A is used as the drive wheel assembly.

[0070] Of course, those skilled in the art can adjust the number and arrangement of intermediate transmission gears according to actual needs to meet those needs.

[0071] Example 4

[0072] A type of chainless bicycle, such as Figures 4-5 As shown, it includes the bicycle gear transmission mechanism as described in Embodiment 3;

[0073] Two drive shaft mounting plates 15 are installed between the chainring axle 12 and the rear wheel axle 4. The two drive shaft mounting plates 15 are located on both sides of the chainring 10 and the rear freewheel, respectively.

[0074] The speed change gear shaft 7, intermediate transmission gear shaft A, and intermediate transmission gear shaft B are fixed on the two transmission shaft mounting plates 15.

[0075] Those skilled in the art should understand that variations can be implemented by combining existing technology with the above embodiments, which will not be elaborated here. Such variations do not affect the essence of the present invention, and will not be elaborated here either.

[0076] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A bicycle gear drive mechanism characterised in that: The rear axle flywheel gear set and the variable gear set are included. The rear axle flywheel gear set includes coaxial rear axle flywheel gear A and rear axle flywheel gear B, the size of rear axle flywheel gear A is larger than that of rear axle flywheel gear B, and rear axle flywheel gear A and rear axle flywheel gear B are fixed on the rear axle of the bicycle through rear axle flywheel A and rear axle flywheel B respectively. The variable gear set includes coaxial variable gear A and variable gear B, variable gear A and variable gear B are sleeved on the variable gear shaft fixedly connected with the bicycle and can rotate independently around the variable gear shaft, the size of variable gear A is smaller than that of variable gear B, and an active connection set is arranged between variable gear A and variable gear B, the active connection set includes a male part and a female part, when the male part and the female part are in the connected position, there is a certain fixed force between the male part and the female part, when the force between the male part and the female part exceeds the force limit of the male part and the female part, variable gear A and variable gear B rotate relatively, and when the force between the male part and the female part is less than or equal to the force limit of the male part and the female part, the active connection set connects variable gear A and variable gear B into one. The rear axle flywheel gear A is engaged with the variable gear A, and the rear axle flywheel gear B is engaged with the variable gear B.

2. A bicycle gear transmission mechanism according to claim 1, characterised in that, The toothed disc and a plurality of intermediate transmission gears are further included. The toothed disc is engaged with the variable gear A or the variable gear B through the plurality of intermediate transmission gears.

3. A bicycle gear transmission mechanism according to claim 2, wherein The toothed disc, the plurality of intermediate transmission gears, the variable gear set and the rear axle flywheel set are arranged in a row, the intermediate transmission gears are sleeved on the intermediate transmission gear shaft fixedly connected with the bicycle, and all the intermediate transmission gear shafts, the variable gear shaft, the toothed disc shaft and the rear axle of the bicycle are located on the same plane.

4. A bicycle gear transmission mechanism according to claim 3, wherein The intermediate transmission gears are two in total. The toothed disc is engaged with the intermediate transmission gear A, the intermediate transmission gear A is engaged with the intermediate transmission gear B, and the intermediate transmission gear B is engaged with the variable gear A.

5. A bicycle gear transmission mechanism according to claim 1, wherein The active connection set is a magnetic attraction connection set, and the male part and the female part are both magnetic attraction blocks. The male part and the female part are fixed on the variable gear A and the variable gear B respectively and the positions of the male part and the female part correspond, and the mutually approaching ends of the male part and the female part attract each other.

6. A bicycle gear mechanism as claimed in claim 5, wherein A plurality of male parts are evenly distributed around the circumference of the variable gear A and fixed on the variable gear A. A plurality of female parts are evenly distributed around the circumference of the variable gear B and fixed on the variable gear B. The male part and / or the female part are installed in an outer threaded hollow cylinder, an outer wall of the outer threaded hollow cylinder is provided with an outer thread structure I, an inner threaded hole I matched with the outer thread structure I is formed on the variable gear A and / or the variable gear B, and the outer threaded hollow cylinder is connected with the variable gear A and / or the variable gear B through threads.

7. A bicycle gear transmission mechanism according to claim 1, wherein The active connection set is an elastic connection set. The male part is a spring plunger, and the female part is a spring plunger fixed hole matched with the movable head of the spring plunger and corresponding in position to the spring plunger.

8. A bicycle gear mechanism as claimed in claim 7, wherein, A plurality of spring plungers are evenly distributed around the circumference of the variable gear A and fixed on the variable gear A. A plurality of spring plunger fixed holes are evenly distributed around the circumference of the variable gear B and formed on the variable gear B. The outer wall of the spring plunger is provided with an external thread structure II, and the variable gear A is provided with an internal thread hole II matched with the external thread structure II, that is, the spring plunger is connected with the variable gear A through thread connection and the position of the spring plunger can be finely adjusted. The movable head of the spring plunger is spherical or semi-spherical.

9. A chainless bicycle, characterized in that Bicycle gear transmission mechanism comprising a bicycle gear transmission mechanism according to any one of claims 1 to 8.

10. A chainless bicycle according to claim 9, characterized in that Two transmission shaft mounting plates are arranged between the toothed disc shaft and the rear wheel shaft, and the two transmission shaft mounting plates are respectively located on the two sides of the toothed disc and the rear freewheel. The variable gear shaft and all the intermediate transmission gear shafts are fixed on the two transmission shaft mounting plates. The variable gear shaft and all the intermediate transmission gear shafts are fixed on the two transmission shaft mounting plates.

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