Mechanical structure for automatic speed change and stepless speed change of bicycle

Abstract

The invention relates to a mechanical structure for automatic speed change and stepless speed change of a bicycle, which comprises a driving wheel mechanism and a driven wheel mechanism, and is characterized in that the driving wheel mechanism and the driven wheel mechanism are connected through a transmission belt to transmit torque, and a torque sensor is mounted on the driving wheel mechanism; an output signal of the torque sensor is connected with an adjusting motor installed on the driven wheel mechanism, and the adjusting motor is connected with a driven wheel driving adjusting mechanism on the driven wheel mechanism. The automatic speed changing device has the advantages that the automatic speed changing function of the bicycle according to road conditions can be achieved, the speed changing ratio of the speed changer can be adjusted through the pedal torque applied by a driver, and therefore the most suitable speed changer gear is achieved, and the force transmission efficiency of the driver is improved. Compared with a traditional bicycle transmission, the bicycle transmission is smaller in size and occupied space and simpler in structure, and the risk that a chain of a traditional bicycle is separated from a chain wheel is avoided.

Description

Technical Field

[0001] The invention relates to a mechanism principle and a mechanical structure used in a bicycle speed changing device to realize automatic speed changing and stepless speed changing. Background Art

[0002] Bicycles are widely used as one of the simplest, most convenient and most environmentally friendly modes of travel. In the process of using bicycles, due to changes in road conditions, in order to achieve higher kinetic energy conversion efficiency and greater ease for users, transmission devices for bicycles have evolved. The basic principle is to change the transmission ratio between the human input end and the driving wheel of the bicycle, so that riders can adjust the most appropriate transmission ratio according to their own needs based on different passengers.

[0003] Among bicycle transmissions, most on the market are manual transmission structures, usually two independent transmissions respectively control the driving wheel connected to the pedals and the driven wheel connected to the bicycle wheel. The speed change principle is that there are multiple sets of sprockets with graduated circle diameters from small to large on the driving wheel and the driven wheel. After adjusting the transmission, the chain will cooperate with sprockets of different sizes according to the gear adjusted by the transmission, thereby realizing the speed change principle. Usually, the driving wheel has one to three gear sprockets, and the driven wheel has one to nine gear sprockets. Therefore, most of the speed change mechanisms on the market have gears below 27 gears.

[0004] In the manual transmission of bicycles currently on the market, the gear change can be clearly felt during the gear shifting process, and due to the fixed gear combination, it is sometimes impossible to find the right gear combination. When faced with complex road conditions, the driver needs to change gears frequently to adapt, resulting in problems such as reduced efficiency and delayed response.

[0005] The existing transmission requires the driver to adjust the gear by himself according to the road condition experience. When the driver is inexperienced or the road condition is complicated, the most suitable transmission gear combination cannot be obtained.

[0006] The existing transmission gears are fixed and the most suitable speed ratio cannot be obtained under some special road conditions.

[0007] When the existing transmission shifts gears, the chain and sprocket need to be realigned, and the driver can clearly feel the sense of frustration during the speed change process, which affects the driving experience, and the speed change process is slow. Summary of the invention

[0008] The present invention aims at the above-mentioned problems existing in the bicycle transmission in the prior art, and provides a mechanism principle and mechanical structure used in a bicycle transmission device to realize automatic speed change and stepless speed change. The present invention designs a mechanical structure for automatic speed change and stepless speed change of a bicycle, including a driving wheel mechanism and a driven wheel mechanism, characterized in that the driving wheel mechanism and the driven wheel mechanism are connected to transmit torque through a transmission belt, a torque sensor is installed on the driving wheel mechanism, and the output signal of the torque sensor is transmitted to the adjustment motor installed on the driven wheel mechanism, and the adjustment motor is connected to the driven wheel on the driven wheel mechanism to drive the adjustment mechanism. The driving wheel mechanism is composed of a driving pulley, a small driving wheel bearing, a driving wheel shaft, and a large driving wheel bearing. The driving wheel shaft is connected and fixed to the bicycle frame by the small driving wheel bearing and the large driving wheel bearing, and the driving wheel shaft is connected to the pedal of the bicycle by a torque sensor. The driven wheel mechanism is composed of a driven wheel small bearing, a driven wheel shaft, a driven wheel large bearing, a first driven wheel, a second driven wheel and an adjusting motor. The driven wheel shaft is connected and fixed to the bicycle frame by the driven wheel small bearing and the driven wheel large bearing. The driven wheel shaft and the adjusting motor are fixed to each other and the driven wheel small bearing is locked. The external thread structure on the adjusting motor and the internal thread structure in the inner hole of the second driven wheel are meshed with each other to form a driven wheel drive adjustment mechanism, so that the adjusting motor can adjust the axial position of the second driven wheel. The driven wheel shaft and the first driven wheel are fixed to each other and the driven wheel large bearing is locked. The first driven wheel and the second driven wheel cooperate with each other through the internal spline of the first driven wheel and the external spline of the second driven wheel to achieve synchronous rotation and mutual radial fixation. A speed sensor is installed on the second driven wheel. The thread structure includes but is not limited to welding fixation and riveting fixation, and the spline structure includes but is not limited to sliding bearing connection and pin connection. The advantages of the present invention are: it can realize the function of automatic speed change of the bicycle according to the road conditions, and can use the pedal torque applied by the driver to adjust the speed ratio of the transmission, so as to achieve the most suitable transmission gear and improve the driver's force transmission efficiency. It can realize the stepless speed change function of the bicycle, and adjust the diameter change of the driving wheel and the driven wheel after judging the working conditions according to the vehicle speed and the torque applied by the driver to the pedal, so as to achieve the purpose of stepless speed change. Automatic stepless speed change is realized during the bicycle driving process, which reduces the driving difficulty, saves the driver's energy to judge the road conditions, and improves the driving safety performance. Compared with the transmission of the transmission bicycle, the size occupies a smaller space, the structure is simpler, and the risk of the chain and sprocket detaching of the traditional bicycle is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural schematic diagram of the present invention.

[0010] Figure 2 It is a schematic diagram of the structural cross-section of the present invention.

[0011] Figure 3It is a schematic cross-sectional view of the structure of the driven wheel mechanism of the present invention.

[0012] Figure 4 It is an exploded schematic diagram of the driven wheel mechanism structure of the present invention.

[0013] Figure 5 It is a schematic diagram of the low speed ratio structure of the driven wheel mechanism of the present invention.

[0014] Figure 6 It is a schematic diagram of the high speed ratio structure of the driven wheel mechanism of the present invention. Implementation

[0015] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. The described embodiments are obviously only embodiments of the present invention, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0016] The figure shows a mechanical structure for automatic speed change and stepless speed change of a bicycle, including a driving wheel mechanism and a driven wheel mechanism, characterized in that the driving wheel mechanism and the driven wheel mechanism are connected to transmit torque through a transmission belt 1, a torque sensor 2 is installed on the driving wheel mechanism, the output signal of the torque sensor is connected to an adjustment motor 3 installed on the driven wheel mechanism, and the adjustment motor 3 is connected to the driven wheel on the driven wheel mechanism to drive the adjustment mechanism. The driving wheel mechanism is composed of a driving pulley 4, a small driving wheel bearing 5, a driving wheel shaft 6, and a large driving wheel bearing 7. The driving wheel shaft is connected and fixed to the bicycle frame by the small driving wheel bearing and the large driving wheel bearing, and the driving wheel shaft is connected to the pedal 8 of the bicycle by a torque sensor. The driven wheel mechanism is composed of a driven wheel small bearing 9, a driven wheel shaft 10, a driven wheel large bearing 11, a first driven wheel 12, a second driven wheel 13 and an adjusting motor. The driven wheel shaft is connected and fixed to the bicycle frame by the driven wheel small bearing and the driven wheel large bearing. The driven wheel shaft and the adjusting motor are fixed to each other and the driven wheel small bearing is locked. The external thread structure 16 on the adjusting motor and the internal thread structure 17 in the inner hole of the second driven wheel are meshed with each other to form a driven wheel drive adjustment mechanism, so that the adjusting motor can adjust the axial position of the second driven wheel. The driven wheel shaft and the first driven wheel are fixed to each other and the driven wheel large bearing is locked. The first driven wheel and the second driven wheel cooperate with each other through the internal spline 18 of the first driven wheel and the external spline 19 of the second driven wheel to achieve synchronous rotation and mutual radial fixation. A speed sensor 15 is installed on the second driven wheel. The thread structure includes but is not limited to welding fixation and riveting fixation, and the spline structure includes but is not limited to sliding bearing connection and pin connection.

[0017] In actual use, when the driver steps on the pedal to start the bicycle: When the driver steps on the pedal, the torque sensor 2 senses a large torque signal and transmits the signal to the regulating motor. At this time, the bicycle is not started, so the speed sensor 15 installed on the second driven wheel obtains a speed signal of 0 and transmits it to the regulating motor. The regulating motor adjusts the relative axial distance between the second driven wheel and the first driven wheel by adjusting the rotation of the motor according to the signal of the sensor through the spline cooperation and the thread cooperation. At this time, the relative axial distance between the second driven wheel and the first driven wheel should be the maximum, that is, Figure 5 From D1 and L1 in the figure, it can be seen that the diameter of the transmission belt of the second driven wheel becomes larger, while the diameter of the driving pulley remains unchanged. Therefore, the speed change between the driving wheel and the driven wheel is relatively small at this time, and the driver can easily start the bicycle.

[0018] When the driver is riding a bicycle at high speed: When the bicycle is moving forward at high speed, the torque applied by the driver to the pedal is low, and the vehicle speed obtained by the vehicle speed signal is high, that is, the signal transmitted by the torque sensor 2 to the regulating motor is low torque, and the signal transmitted by the speed sensor 15 to the regulating motor is high speed. At this time, the regulating motor adjusts the relative axial position of the second driven wheel and the first driven wheel, that is, Figure 6 From D2 and L2 in the figure, it can be seen that the diameter of the transmission belt of the second driven wheel becomes smaller, while the diameter of the driving pulley remains unchanged. Therefore, the speed change between the driving wheel and the driven wheel is relatively large at this time, and the driver can easily keep the bicycle at a high speed.

[0019] When the rider slows the bicycle to a stop: When the bicycle starts to slow down and stops, the torque applied by the driver to the pedals is very low or no torque, so the signal transmitted to the regulating motor by the torque sensor 2 is low torque or no torque, and the signal transmitted to the regulating motor by the speed sensor 15 is that the vehicle speed is gradually decreasing. At this time, the regulating motor adjusts the relative axial distance between the second driven wheel and the first driven wheel from large to small, that is, Figure 5 , 6 In the process, D2 is adjusted to D1 and L2 is adjusted to L1. After the vehicle stops, the belt rotation diameter of the driven wheel is the largest, and the axial relative distance between the second driven wheel and the first driven wheel is the smallest. Therefore, the vehicle speed ratio is the smallest after stopping, which is convenient for the driver to start next time.

[0020] When the torque sensor fails or the transmitted signal is invalid, the motor will automatically adjust to the D1, L1 state to improve the drivability in the failure state; When the motor or wheel speed sensor fails, an alarm sound will be issued and the motor position will be maintained. The vehicle will lose the function of automatically adjusting the speed ratio, but can still drive normally.

Claims

1. A mechanical structure for automatic speed change and stepless speed change of a bicycle, comprising a driving wheel mechanism and a driven wheel mechanism, characterized in that: The driving wheel mechanism and the driven wheel mechanism are connected to transmit torque through a transmission belt. A torque sensor is installed on the driving wheel mechanism. The output signal of the torque sensor is transmitted to the adjusting motor installed on the driven wheel mechanism. The adjusting motor is connected to the driven wheel on the driven wheel mechanism to drive the adjusting mechanism.

2. A mechanical structure for automatic speed change and stepless speed change of a bicycle according to claim 1, characterized in that: The driving wheel mechanism is composed of a driving pulley, a small driving wheel bearing, a driving wheel shaft, and a large driving wheel bearing. The driving wheel shaft is connected and fixed to the bicycle frame by the small driving wheel bearing and the large driving wheel bearing. The driving wheel shaft is connected to the pedal of the bicycle by a torque sensor.

3. A mechanical structure for automatic speed change and stepless speed change of a bicycle according to claim 1, characterized in that: The driven wheel mechanism is composed of a small driven wheel bearing, a driven wheel shaft, a large driven wheel bearing, a first driven wheel, a second driven wheel and an adjusting motor. The driven wheel shaft is connected and fixed to the bicycle frame by the small driven wheel bearing and the large driven wheel bearing. The driven wheel shaft and the adjusting motor are fixed to each other and the small driven wheel bearing is locked. The external thread structure on the adjusting motor and the internal thread structure in the inner hole of the second driven wheel are meshed with each other to form a driven wheel drive adjusting mechanism, so that the adjusting motor can adjust the axial position of the second driven wheel. The driven wheel shaft and the first driven wheel are fixed to each other and the large driven wheel bearing is locked. The first driven wheel and the second driven wheel cooperate with each other through the internal spline of the first driven wheel and the external spline of the second driven wheel to achieve rotation synchronization and mutual radial fixation. A speed sensor is installed on the second driven wheel.

4. A mechanical structure for automatic speed change and stepless speed change of a bicycle according to claim 3, characterized in that: The threaded structure includes but is not limited to welding fixation and riveting fixation, and the spline structure includes but is not limited to sliding bearing connection and pin connection.

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