Power module for an electrically assisted bicycle

Abstract

The power module of the electric power-assisted bicycle comprises a pedal shaft, a toothed disc output shaft, a speed reducer, a motor, a first sensor, a housing, a second sensor and a drive controller. The toothed disc output shaft, the speed reducer output shaft and the speed reducer fixed shaft are arranged in parallel with the pedal shaft in the axial direction and concentrically around the pedal shaft. The motor drives the speed reducer to rotate the toothed disc output shaft through the speed reducer input shaft. The first sensor is arranged on the speed reducer fixed shaft to detect the first torque of the speed reducer output shaft acting on the speed reducer fixed shaft. The speed reducer fixed shaft is connected to the housing. The frame fixing member protrudes outward from the housing to assemble the power module to the frame. The second sensor is arranged on the frame fixing member to detect the second torque of the power module acting on the frame. The drive controller controls the motor according to the first torque and the second torque.

Description

Technical Field

[0001] This disclosure relates to a power module, and more particularly to a coaxially configured mid-mounted electric assist bicycle power module, which, without increasing the external dimensions, separates two sensors to improve the overall output accuracy of the power module and achieves optimal control of the motor's assist force. Background Technology

[0002] Electric-assisted bicycles, also known as e-bikes, are bicycles with an integrated motor and gearbox to provide electric power for propulsion. There are many types of electric bicycles on the market, but they generally fall into two main categories: electric-assisted bicycles that detect and assist the rider's pedaling force, and regular electric bicycles that are driven solely by an electric motor. Because electric-assisted bicycles must integrate both human power and electric motor assistance, and meet the need for both power sources (human power and electric motor assistance) to optimize the performance of the power module in different usage scenarios, the accuracy of force sensing is even more crucial.

[0003] Traditional electric-assist bicycles use human input via the pedal axle to control the motor's auxiliary force input, thus requiring a torque sensor to be placed in the central pedal axle. However, due to the small diameter of the central pedal axle, adding a torque sensor is difficult to manufacture, and the torque sensor integrated into traditional power modules has poor accuracy and high cost. Furthermore, the pedal axle with the torque sensor already has a fairly complex surface structure, which is not conducive to the concentric fitting of the motor's auxiliary force output shaft. Therefore, the motor's auxiliary force output shaft and the pedal axle must be designed as separate shafts, making it difficult to reduce the size of the power module.

[0004] On the other hand, traditional electric-assist bicycles, after controlling the input of the motor's auxiliary force, only use the rotational speed to monitor the overall power output (human power combined with motor assistance), without separately monitoring the output of the motor's auxiliary force. Therefore, it is impossible to grasp the actual output of the motor's auxiliary force in real time. Since the pedal shaft with the torque sensor is already not conducive to the concentric integration of the motor's auxiliary force, if another torque sensor is added to monitor the actual output of the motor's auxiliary force, the overall size needs to be increased to separately measure the pedaling force of the rider and the output of the motor's assistance, making the design of the power module more complex.

[0005] In view of this, it is necessary to provide a power module for an electric-assisted bicycle that, without increasing the size and space of the external dimensions, uses a simple method to combine a torque sensor to simultaneously measure the pedaling force and the motor's auxiliary force, and uses the pedaling force and the motor's auxiliary force to provide torque feedback, thereby improving the overall output accuracy of the power module and achieving optimal control of the motor's auxiliary force, thus solving the shortcomings of the existing technology. Summary of the Invention

[0006] The purpose of this disclosure is to provide a power module for an electric-assisted bicycle that, without increasing the external dimensions, uses a simple method to combine a torque sensor to simultaneously measure the pedaling force and the motor's auxiliary force, and uses the pedaling force and the motor's auxiliary force to provide torque feedback, thereby improving the overall output accuracy of the power module and achieving optimal control of the motor's auxiliary force.

[0007] Another objective of this disclosure is to provide a power module for an electric-assisted bicycle. By respectively mounting a first sensor and a second sensor on the reducer's fixed shaft and the power module's housing, the drive controller can control the motor based on a first torque measured by the first sensor and a second torque measured by the second sensor. When the rider is not pedaling, neither the first nor the second sensor generates any signal. By comparing the difference between the second torque and the first torque to a predetermined value, the drive controller can control the timing and range of the motor's auxiliary force activation, while simultaneously providing torque feedback for the motor's auxiliary output, improving the overall output accuracy of the power module, and achieving optimal control of the motor's auxiliary force.

[0008] To achieve the aforementioned objectives, this disclosure provides a power module for an electric-assisted bicycle, including a pedal axle, a sprocket output shaft, a reducer, a motor, a first sensor, a housing, a second sensor, and a drive controller. The pedal axle is axially oriented. The sprocket output shaft is axially parallel to the pedal axle and concentrically fitted radially onto the pedal axle. The reducer has a reducer output shaft and a reducer fixed shaft, both axially parallel to the pedal axle, and the reducer output shaft is concentrically fitted radially onto the sprocket output shaft. The motor is mechanically connected to the reducer and drives the reducer via the reducer input shaft. The first sensor is mounted on the reducer fixed shaft to detect a first torque exerted by the reducer output shaft on the reducer fixed shaft. The housing includes a frame fixing member and a receiving space, which accommodates the pedal axle, the sprocket output shaft, the reducer, and the motor. Both ends of the pedal axle penetrate the housing, the reducer fixed shaft is connected to the housing, and the frame fixing member protrudes outward from the housing to fix the power module to the frame. The second sensor is mounted on the frame fixture to detect the second torque applied to the frame by the power module. The drive controller is electrically connected to the motor, the first sensor, and the second sensor, and controls the motor based on the difference between the first torque and the second torque.

[0009] In one embodiment, when the difference between the second torque and the first torque is greater than or equal to a predetermined value, the drive controller starts the motor to output the motor output torque. In another embodiment, when the difference between the second torque and the first torque is less than a predetermined value, the drive controller shuts down the motor.

[0010] In one embodiment, the first torque is the output torque of a speed reducer, which acts on a tangential direction perpendicular to the axial direction on the pipe diameter of the fixed shaft of the speed reducer.

[0011] In one embodiment, the second torque includes the output torque of the speed reducer and the output torque of a human foot pedal, wherein the output torque of the human foot pedal acts on a tangential direction perpendicular to the axial direction on the housing.

[0012] In one embodiment, the geared disc output shaft is concentrically mounted on the pedal shaft in a radial direction via a first one-way bearing, wherein the pedal shaft is driven to rotate via the first one-way bearing when subjected to force.

[0013] In one embodiment, the reducer output shaft is concentrically mounted on the gear disk output shaft in a radial direction via a second one-way bearing, wherein when the motor drives the reducer to rotate the reducer output shaft, the reducer output shaft drives the gear disk output shaft to rotate via the second one-way bearing.

[0014] In one embodiment, the housing includes a front fixing plate and a rear fixing plate, which are respectively disposed on opposite sides of the housing along the axial direction, wherein the foot pedal shaft passes through the front fixing plate and the rear fixing plate along the axial direction.

[0015] In one embodiment, the fixed end of the reducer fixed shaft is connected to the rear fixed plate, and the reducer fixed shaft is concentrically fitted to the foot pedal shaft through a first bidirectional bearing.

[0016] In one embodiment, the torsional stiffness of the rear fixed plate is greater than the torsional stiffness of the reducer fixed shaft.

[0017] In one embodiment, the side edge of the gear sprocket output shaft is connected to the front fixing plate via a second bidirectional bearing, and the side edge is concentrically fitted onto the pedal shaft via a third bidirectional bearing.

[0018] In one embodiment, the reducer further includes an output gear and a fixed gear respectively disposed on the reducer output shaft and the reducer fixed shaft. The output gear and the fixed gear are connected to each other, and transmit a first torque when the reducer output shaft drives the gear disk output shaft to rotate.

[0019] The power module of the electric-assisted bicycle provided by this invention features a coaxial design for its pedal axle, sprocket output shaft, and reducer output shaft, all housed within the power module's housing. A first sensor and a second sensor are respectively mounted on the reducer's fixed shaft and the power module's frame mounting component. Compared to the current mainstream design that places the complex torque sensor on the central pedal axle, with the pedal axle and reducer output shaft being parallel and non-coaxial, this design reduces sensor installation difficulty, saves assembly space, and decreases the overall size of the device. Since the sensor installation is not affected by the small diameter of the pedal axle, thus improving sensor accuracy, reducing costs, and increasing space utilization, the invention also enhances sensor accuracy. Furthermore, by configuring sensors at different positions to detect the reducer's output torque and the torque output from the human pedal, the timing and range of the motor's starting assist force can be controlled. Simultaneously, torque feedback of the motor's assist output force is provided, improving the overall output accuracy of the power module and optimizing the control of the motor's assist force. Attached Figure Description

[0020] Figure 1 This is a structural diagram of the power module of an electric-assisted bicycle according to a preferred embodiment of the present disclosure.

[0021] Figure 2 This is a cross-sectional view of the power module of an electric-assisted bicycle according to a preferred embodiment of the present disclosure.

[0022] Figure 3 This is a schematic diagram of a preferred embodiment of the present disclosure, showing the first sensor disposed on the fixed shaft of the reducer.

[0023] Figure 4 This is a schematic diagram showing the location of each sensor and its corresponding measuring force in the power module of an electric-assisted bicycle according to a preferred embodiment of the present disclosure.

[0024] Figure 5 This is a flowchart illustrating the operation of the power module of an electric-assisted bicycle according to a preferred embodiment of the present disclosure.

[0025] Figure 6 This is a schematic diagram of the measured force corresponding to the second sensor in the power module of the electric-assisted bicycle of the preferred embodiment of the present disclosure when the motor auxiliary output is not applied.

[0026] Figure 7 This is a schematic diagram showing the measured forces corresponding to the second sensor and the first sensor in the power module of the electric-assisted bicycle according to a preferred embodiment of the present disclosure when the motor assists in the output.

[0027] Figure 8 This is a schematic diagram showing the correspondence between the total output torque measured by the second sensor and the output torque of the human pedal in the power module of the electric-assisted bicycle according to a preferred embodiment of the present disclosure.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1: Power Module

[0030] 10: Foot pedal axle

[0031] 20: Gearbox output shaft

[0032] 21: Lateral edge

[0033] 30: Gearbox

[0034] 31: Reducer output shaft

[0035] 32: Output gear

[0036] 33: Reducer fixed shaft

[0037] 330: Outer ring wall

[0038] 331: Fixed end

[0039] 34: Fixed gear

[0040] 35: Input shaft of the reducer

[0041] 40: Electric motor

[0042] 41: Motor output shaft

[0043] 50: First Sensor

[0044] 60: Shell

[0045] 61: Chassis fasteners

[0046] 610: Sidewall

[0047] 62: Storage space

[0048] 63: Front fixing plate

[0049] 64: Rear fixing plate

[0050] 70: Second sensor

[0051] 71a, 71b: Strain gauges

[0052] 80: Drive Controller

[0053] 81: First one-way bearing

[0054] 82: Second one-way bearing

[0055] 83: First double-sided bearing

[0056] 84: Second double-direction bearing

[0057] 85: Third double-acting bearing

[0058] 90: Chain sprocket

[0059] C: Axial

[0060] T A First torque

[0061] T B Second torque

[0062] T PRESET : Preset value

[0063] S01~S04: Steps

[0064] X, Y, Z: Axes Detailed Implementation

[0065] Some typical embodiments embodying the features and advantages of this disclosure will be described in detail in the following description. It should be understood that this disclosure can be varied in different implementations without departing from the scope of this disclosure, and the descriptions and drawings therein are for illustrative purposes only and not for limiting the scope of this disclosure.

[0066] In this embodiment, the power module of the electric-assisted bicycle (hereinafter referred to as power module 1) is, for example, applied to a mid-mounted architecture. Power module 1 includes a pedal axle 10, a sprocket output shaft 20, a reducer 30, a motor 40, a first sensor 50, a housing 60, a second sensor 70, and a drive controller 80. The aforementioned mid-mounted architecture refers to the power module 1 being located between the front and rear wheels of the electric-assisted bicycle, typically used to distinguish it from a hub-and-spoke architecture where the power module is directly mounted on the wheel. The pedal axle 10 is positioned along the axial direction C, which is, for example, parallel to the X-axis and perpendicular to the Y and Z axes, with the direction of gravity opposite to the Z-axis. The sprocket output shaft 20 is cylindrical and parallel to the pedal axle 10 along the axial direction C. The inner surface of the sprocket output shaft 20 is concentrically sleeved radially onto the outer surface of the pedal axle 10 via a first one-way bearing 81, which is perpendicular to the aforementioned axial direction C. In this embodiment, when the pedal shaft 10 bears the rider's pedaling force and rotates in the forward direction, it drives the geared disc output shaft 20 to rotate via the first one-way bearing 81. In this embodiment, the reducer 30 includes, for example, a reducer output shaft 31, an output gear 32, a reducer fixed shaft 33, a fixed gear 34, and a reducer input shaft 35. The reducer output shaft 31, the reducer fixed shaft 33, and the reducer input shaft 35 are respectively arranged parallel to the pedal shaft 10 along the axial direction C, and the pedal shaft 10 passes through the reducer output shaft 31, the reducer fixed shaft 33, and the reducer input shaft 35 to form a coaxial structure. The reducer output shaft 31 is concentrically sleeved on the geared disc output shaft 20 in the radial direction and is connected to the outer surface of the geared disc output shaft 20 via the second one-way bearing 82. It should be noted that the first one-way bearing 81 is a one-way clutch. Through the first one-way bearing 81, the pedal shaft 10 can only drive the geared output shaft 20 in a single rotational direction. That is, only pedaling in one direction can transmit pedaling force to drive the geared output shaft 20 and propel the vehicle forward. If pedaling in the opposite direction, the geared output shaft 20 cannot be driven. In this embodiment, the motor 40 is mechanically connected to the reducer 30. The motor output shaft 41 of the motor 40 is mechanically connected to and drives the reducer 30 through the reducer input shaft 35. This causes the reducer 30 to rotate through the reducer output shaft 31 and drive the geared output shaft 20 to rotate through the second one-way bearing 82. Similarly, the second one-way bearing 82 is a one-way clutch. Through the second one-way bearing 82, the reducer output shaft 31 can only drive the geared output shaft 20 in a single rotational direction. That is, only rotation in one direction can transmit reducer torque output to drive the geared output shaft 20 and propel the vehicle forward. In other words, in this embodiment, the first one-way bearing 81 and the second one-way bearing 82 can be enabled in the same single rotation direction, so that the human output force of the pedal shaft 10 and the motor auxiliary force transmitted by the reducer output shaft 31 can be input separately and added to each other. Of course, this disclosure is not limited thereto.

[0067] In this embodiment, the output gear 32 is mounted on the output shaft 31 of the reducer, and the fixed gear 34 is mounted on the fixed shaft 33 of the reducer. The output gear 32 and the fixed gear 34 are arranged along the axial direction C and are mated to each other, so as to transmit a first torque T when the output shaft 31 of the reducer drives the gear disk output shaft 20 to rotate. A The first sensor 50 is, for example, disposed on the outer ring wall 330 of the reducer fixed shaft 33, so as to detect the first torque T exerted by the reducer output shaft 31 on the reducer fixed shaft 33 when the reducer output shaft 31 drives the gear disk output shaft 20 to rotate. A .

[0068] In this embodiment, the housing 60 is a cylindrical assembly arranged along the axial direction C, and includes a frame fixing member 61 and a receiving space 62. The receiving space 62 is configured to accommodate the pedal axle 10, the geared sprocket output shaft 20, the reducer 30, and the motor 40. Both ends of the pedal axle 10 extend through both sides of the housing 60 along the axial direction C, exposing the two opposite ends of the pedal axle 10. The reducer fixing shaft 33 is housed in the receiving space 62, and one fixed end 331 of the reducer fixing shaft 33 is connected to the housing 60. The frame fixing member 61 protrudes outward from the housing 60 and has a height difference with the surface of the housing 60, for assembling and fixing the power module 1 to a frame (not shown). Additionally, in this embodiment, the second sensor 70 is, for example, disposed on one side wall 610 of the frame fixing member 61 to detect a second torque T exerted by the power module 1 on the frame. B In this embodiment, the second torque T B Greater than or equal to the first torque T A The first torque T A and the second torque T B It is used to control the output torque of motor 40.

[0069] In this embodiment, the drive controller 80 is electrically connected to the motor 40, the first sensor 50, and the second sensor 70. In this embodiment, the first sensor 50, for example, includes a strain gauge disposed axially C on the outer ring wall 330 of the reducer fixed shaft 33, for sensing, for example, a first torque T, which is the output torque of the reducer. A The first torque T A Furthermore, the force acts on a tangential direction perpendicular to the axial direction C on the pipe diameter outside the reducer fixed shaft 33. This tangential direction is, for example, parallel to the vehicle travel direction, but this disclosure is not limited thereto. In this embodiment, the second sensor 70 includes, for example, strain gauges 71a and 71b, which are radially disposed on one side wall 610 of the frame fixing member 61 and spaced apart from each other. The strain gauges 71a and 71b are used to sense a second torque T acting on the frame by the power module 1. B The second torque T BFurthermore, it acts on all tangential directions perpendicular to the axial direction C on the frame fixing member 61, such as parallel to the driving direction, but this disclosure is not limited thereto. In this embodiment, the drive controller 80 acts based on the second torque T. B With the first torque T A The difference control motor 40. The operation process of the power module 1 will be explained in more detail later.

[0070] In this embodiment, the housing 60 is a cylindrical structure arranged along the axial direction C, and includes a front fixing plate 63 and a rear fixing plate 64, which are respectively arranged along the axial direction C on two opposite sides of the housing 60. The accommodating space 62 is defined between the front fixing plate 63 and the rear fixing plate 64. The two opposite ends of the pedal shaft 10 pass through the front fixing plate 63 and the rear fixing plate 64 along the axial direction C, respectively. In this embodiment, the fixing end 331 of the reducer fixing shaft 33 is connected to the rear fixing plate 64, and the fixing end 331 is concentrically fitted onto the pedal shaft 10 through a first double-direction bearing 83. It should be noted that this disclosure does not limit the combination of the front fixing plate 63 and the rear fixing plate 64. In this embodiment, the frame fixing member 61 protrudes radially outward from the outer edge of the rear fixing plate 64, for example. In other embodiments, the frame fixing member 61 may extend directly outward from the outer periphery of the housing 60, for example, without protruding through the rear fixing plate 64, and this disclosure is not limited thereto. In this embodiment, the first sensor 50 is mounted on the reducer fixed shaft 33, and the second sensor 70 is mounted on the frame fastener 61 on the outer edge of the rear fixed plate 64. The second sensor 70 measures the second torque T. B The first torque T is greater than that measured by the first sensor 50. A To meet the requirements, the torsional rigidity of the rear fixing plate 64 is preferably greater than that of the reducer fixing shaft 33. In addition, in this embodiment, one side edge 21 of the gear plate output shaft 20 is connected to the front fixing plate 63 through a second double-acting bearing 84, and the side edge 21 is concentrically fitted to the pedal shaft 10 through a third double-acting bearing 85.

[0071] In this embodiment, the power module 1 further includes a chain toothed disc 90, which is concentrically fitted radially onto the side edge 21 of the toothed disc output shaft 20 and adjacent to the outer surface of the toothed disc output shaft 20. When the foot pedal shaft 10 is manually stepped on and rotates the toothed disc output shaft 20 in the forward direction, it provides a second torque T. B The output is transmitted to the rear wheel (not shown) via, for example, the chain of an electric-assisted bicycle, thus propelling the electric-assisted bicycle forward. It should be noted that the second torque T of the sprocket output shaft 20 or the chain sprocket 90... BThe output can be provided, for example, simply by human pedaling, through the pedal shaft 10 driving the geared output shaft 20 to rotate clockwise via the first one-way bearing 81; or simultaneously by the motor output shaft 41 of the motor 40 driving the reducer output shaft 31 to rotate, which in turn drives the geared output shaft 20 to rotate clockwise via the second one-way bearing 82, thus providing additional motor auxiliary force. In other words, when the motor auxiliary force is not applied, the first torque T... A =0, at this time the torque output of the sprocket output shaft 20 is simply generated by the human pedaling force through the pedal shaft 10 via the first one-way bearing 81. However, in the case of motor-assisted force, the pedaling torque generated by the human pedaling force through the first one-way bearing 81 and the motor-assisted force generated by the motor output shaft 41 and the reducer output shaft 31 through the second one-way bearing 82 simultaneously provide torque output, which is transmitted to the rear wheel through the chain, propelling the electric-assisted bicycle forward. At this time, the first torque T can be measured. A .

[0072] It should be noted that the sprocket output shaft 20 and chain sprocket 90 of this disclosure can be configured near the rider's right or left foot side. The aforementioned forward rotation refers to the rotation direction of the pedal shaft 10 that drives the electric-assisted bicycle forward when the sprocket output shaft 20 rotates in a rotational direction, causing the chain sprocket 90, chain, and rear wheel to rotate. This rotational direction can be defined as clockwise or counterclockwise depending on whether the sprocket output shaft 20 and chain sprocket 90 are configured near the rider's right or left foot side, or when viewed from different sides. These rotational directions, in conjunction with the one-way bearings 81 and 82, can be used to determine whether the electric-assisted bicycle is driven forward, avoiding damage to the components due to incorrect pedaling posture, rather than being used to limit this disclosure.

[0073] refer to Figures 1 to 5 When the rider is not pedaling, neither the first sensor 50 nor the second sensor 70 will detect any signal. At this time, the first torque T... A and the second torque T B All are zero. When the rider begins pedaling, as in step S01, the second sensor 70 can sense the second torque T. B The torque T measured by the first sensor 50 is greater than 0, but the motor 40 is not started. A =0. In this embodiment, the drive controller 80 determines the torque T based on the second torque T. B With the first torque T A The difference between the torque output and the starting / stopping timing of the motor 40 is used to control the torque output when the motor 40 is turned on. In one embodiment, the drive controller 80 may first provide a predetermined value T for determining the torque required to turn on the motor 40. PRESET First torque T A and the second torque T B The initial values ​​are all zero. When the rider begins to pedal, the second torque T...B The torque begins to increase and is no longer zero. At this point, as in step S02, the drive controller 80 determines the second torque T. B With the first torque T A The difference is not zero, but it is still less than the predetermined value T. PRESET Since the system is in its initial stage, the drive controller 80 has not yet determined whether the motor 40 needs to be activated to provide auxiliary force. In this embodiment, when the power module 1 is not activated by the auxiliary output of the motor 40, the reducer 30 will not be driven, the first sensor 50 will not generate a signal, and the strain gauges 71a and 71b of the second sensor 70 will measure the second torque T provided by human footing. B ,like Figure 6 As shown. Then, as in step S03, when the drive controller 80 determines the second torque T... B With the first torque T A The difference is greater than or equal to the predetermined value T PRESET At this time, the drive controller 80 starts the motor 40, causing the motor output shaft 41 of the motor 40 to output torque. Specifically, the motor 40 drives the reducer 30, causing the reducer output shaft 31 to rotate, which in turn rotates the gear disc output shaft 20. At this time, the strain gauge of the first sensor 50 can correspondingly measure the first torque T exerted by the reducer output shaft 31 on the reducer fixed shaft 33. A >0, while the strain gauges 71a and 71b of the second sensor 70 can correspondingly measure the second torque T acting on the frame by the power module 1. B ,like Figure 7 As shown. The second torque T B That is, including the output torque of the reducer (first torque T) A The total output torque is the sum of the rider's pedal output torque and the motor's auxiliary output torque. This total output torque acts on all tangential directions of the housing 60, i.e., on all tangential directions perpendicular to the axis C. These tangential directions are, for example, parallel to the direction of travel, and are not intended to limit this disclosure. Furthermore, under the combined output torque of the rider's pedal output force and the motor's auxiliary output force, the drive controller 80 controls the motor 40 to stably output torque. At this time, the first torque T measured by the first sensor 50 is... A Maintaining a constant value, that is, the motor 40 maintains a constant output. Once the rider reduces the pedaling force, the second torque T measured by the second sensor 70 will be released. B Decrease. When the drive controller 80 determines the second torque T B With the first torque T A The difference is again less than the predetermined value T. PRESET At that time, for example as shown in step S04, the drive controller 80 determines that the motor 40 needs to be turned off in order to stop the output torque of the motor.

[0074] like Figure 8As shown, the second torque T output by the toothed sprocket output shaft 20 or the chain toothed sprocket 90 is... B The output can be sensed onto the strain gauges 71a and 71b of the second sensor 70. Specifically, when the motor assists, the second torque T... B The output sources include the torque output from the human-powered foot pedal and the torque output from the reducer. The first torque T measured by the first sensor 50... A This is equal to the output torque of the speed reducer; therefore, the torque output by manual foot pedal can be equal to the second torque T. B With the first torque T A The difference represents the torque output by the human foot pedal, which equals the second torque T. B —First Torque T A .

[0075] In summary, this disclosure provides a power module for an electric-assisted bicycle. Without increasing the overall size and space, it utilizes a simple method to simultaneously measure the pedaling force and motor assist force using a torque sensor. Torque feedback is then provided based on these two forces, improving the overall output accuracy of the power module and optimizing the control of the motor assist force. Furthermore, by respectively mounting a first sensor and a second sensor on the reducer's fixed shaft and the power module's frame mounting component, the drive controller can control the motor to output torque based on the first torque measured by the first sensor and the second torque measured by the second sensor. When the rider is not pedaling, neither the first nor the second sensor generates any signal. When the rider begins pedaling, by comparing the difference between the second and first torques using a predetermined torque value, the drive controller can control the timing and range of the motor's assist force activation, simultaneously providing torque feedback for the motor assist force, thus improving the overall output accuracy of the power module and optimizing the control of the motor assist force.

[0076] This disclosure is open to various modifications by those skilled in the art, but all such modifications shall not depart from the protection sought by the appended claims.

Claims

1. A power module for an electric-assisted bicycle, comprising: One foot pedal axle, set along one axis; A toothed disc output shaft is arranged parallel to the foot pedal shaft along the axial direction and concentrically sleeved on the foot pedal shaft along a radial direction; A speed reducer has a speed reducer output shaft and a speed reducer fixed shaft respectively arranged parallel to the foot pedal shaft along the axial direction, and the speed reducer output shaft is concentrically sleeved on the gear plate output shaft along the radial direction, and the fixed end of the speed reducer fixed shaft is concentrically sleeved on the foot pedal shaft. An electric motor is mechanically connected to the reducer and drives the reducer through a reducer input shaft; A first sensor is disposed on the fixed shaft of the reducer to detect a first torque exerted by the output shaft of the reducer on the fixed shaft of the reducer; A housing includes a frame fixing member and an accommodating space, the accommodating space being configured to accommodate the pedal axle, the geared sprocket output shaft, the reducer and the motor, wherein both ends of the pedal axle pass through the housing, the reducer fixing shaft is connected to the housing through the fixing end, and the frame fixing member protrudes outward from the housing to fix the power module to a frame. A second sensor, mounted on the frame mounting member, detects a second torque exerted by the power module on the frame; and A drive controller is electrically connected to the motor, the first sensor, and the second sensor. The drive controller controls the motor based on the difference between the second torque and the first torque. The reducer further includes an output gear and a fixed gear respectively disposed on the reducer output shaft and the reducer fixed shaft. The output gear and the fixed gear are arranged along the axial direction and mesh with each other to transmit the first torque when the reducer output shaft drives the geared disc output shaft to rotate. The toothed disc output shaft is concentrically mounted on the foot pedal shaft along the radial direction via a first one-way bearing. When the foot pedal shaft is rotated under force, the toothed disc output shaft is driven to rotate via the first one-way bearing. The reducer output shaft is concentrically mounted on the toothed disc output shaft along the radial direction via a second one-way bearing. When the motor drives the reducer to rotate the reducer output shaft, the reducer output shaft drives the toothed disc output shaft to rotate via the second one-way bearing.

2. The power module of the electric-assisted bicycle as claimed in claim 1, wherein when the difference between the second torque and the first torque is greater than or equal to a predetermined value, the drive controller starts the motor to output a motor output torque; wherein when the difference between the second torque and the first torque is less than the predetermined value, the drive controller shuts down the motor.

3. The power module of the electric-assisted bicycle as described in claim 1, wherein the first torque is the output torque of a reducer, acting on a tangential direction perpendicular to the axis on the diameter of the fixed shaft of the reducer.

4. The power module of the electric-assisted bicycle as claimed in claim 3, wherein the second torque includes the output torque of the reducer and the output torque of a human pedal, wherein the output torque of the human pedal acts on a tangential direction perpendicular to the axis on the housing.

5. The power module of the electric-assisted bicycle as claimed in claim 1, wherein the housing includes a front fixing plate and a rear fixing plate, respectively disposed on two opposite sides of the housing along the axial direction, wherein the pedal axle passes through the front fixing plate and the rear fixing plate along the axial direction.

6. The power module of the electric-assisted bicycle as described in claim 5, wherein a fixed end of the reducer fixed shaft is connected to the rear fixed plate, and the reducer fixed shaft is concentrically fitted to the pedal shaft through a first bidirectional bearing, wherein the torsional rigidity of the rear fixed plate is greater than the torsional rigidity of the reducer fixed shaft.

7. The power module of the electric-assisted bicycle as claimed in claim 6, wherein one side edge of the sprocket output shaft is connected to the front fixing plate via a second bidirectional bearing, and the side edge is concentrically fitted to the pedal shaft via a third bidirectional bearing.

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