Power module of electric power-assisted bicycle

Abstract

The invention provides a power module of an electric power-assisted bicycle. The power module comprises a pedal shaft, a shell, a motor, a speed reducer, a fluted disc output shaft, a pedal shaft first bidirectional bearing and a sensor assembly. An interval part of the shell divides the inner space into a motor containing part and a speed reducer containing part in the axial direction, and the motor containing part and the speed reducer containing part are used for containing a motor and a speed reducer respectively. A stator of the motor and fixed teeth of the speed reducer are fixed to the first side and the second side, opposite to each other, of the interval part respectively. The two ends of the speed reducer input shaft are connected to the motor and the speed reducer respectively, and the input shaft body part between the motor and the speed reducer is connected with the third side of the interval part. By means of the configuration mode that the three sides of the interval part are connected respectively, the space utilization rate of the power module can be optimized, the torque sensor is attached to the pedal shaft, and meanwhile the structure is strong, the rotation axis of the input shaft of the speed reducer is stable, and the stator heat dissipation effect is achieved.

Description

Technical Field

[0001] This case involves a power module, and in particular, a power module for a mid-mounted electric power-assisted bicycle. Background Art

[0002] An electric assisted bicycle, also known as an e-Bike, is a bicycle with an integrated motor and a reducer to provide motor power to assist propulsion. There are many types of electric bicycles on the market, but they are generally divided into two categories: electric assisted bicycles that detect and assist the rider's pedaling force and general electric bicycles that only use motors to drive the wheel hub. Since electric assisted bicycles must integrate both human and motor assistance, reducing the size of the space has always been an important issue in the design of the power module. In addition, the power module must also meet the needs of dual power (human and motor assistance) at the same time, so that the power module can perform optimally in different usage scenarios. Therefore, the power module of an electric assisted bicycle is quite difficult to design.

[0003] The power module of an electric power-assisted bicycle mainly includes a motor and a reducer, which are arranged in a housing of the power module. The existing power module is radially arranged to connect the motor and the reducer from the central pedal axis outward, and the fixed teeth of the reducer are connected to the housing. The fixed point is not easy to install and increases the radial thickness of the power module.

[0004] In addition, due to space limitations, the existing power module also includes a torque sensor connected between the inner diameter of the module housing and the bidirectional bearing of the pedal shaft, and the pedal force is transmitted through the pedal shaft bearing. Since the torque sensor is not connected in series in the force flow transmission path, the pedal torque needs to be calculated by the pedal pressure when sensing the torque, and the real pedal torque is not sensed. The sensing error is large, and due to the configuration position, only the single-side pedal force can be measured.

[0005] In view of this, it is necessary to provide a power module for a mid-mounted electric power-assisted bicycle with an axially arranged motor and reducer, which can optimize the radial space, meet the requirements of miniaturization and achieve optimal measurement of pedal torque to address the deficiencies of the prior art. Summary of the invention

[0006] The purpose of this case is to provide a power module for a mid-mounted electric power-assisted bicycle in which the motor and the reducer are axially arranged, which can optimize the radial space, meet the requirements of miniaturization and achieve optimal measurement of pedal torque.

[0007] Another object of the present invention is to provide a power module for an electric power-assisted bicycle. The internal space of the housing is divided into a motor accommodating portion and a reducer accommodating portion arranged axially by a partition extending radially inwardly from the middle frame of the housing. When the motor and the reducer are axially sleeved on the pedal shaft, the stator of the motor and the fixed teeth of the reducer can be fixedly connected to the two opposite sides of the partition respectively, so as to achieve alignment installation, improve assembly efficiency, enhance heat dissipation of the stator, and strengthen the structure. Furthermore, when the axially arranged motor and reducer can transmit the power of the motor to the speed sensor through a reducer input shaft, one end of the reducer input shaft constitutes an input shaft rotor portion connected to the rotor (output shaft) of the motor or the motor output shaft, and the other end constitutes an input shaft eccentric portion connected to the movable teeth of the reducer, and the input shaft body portion between the input shaft rotor portion and the input shaft eccentric portion can be further radially connected to the third side of the partition portion through a bearing shaft, so that the reducer input shaft is close to the partition portion. On the other hand, the reducer input shaft can also extend axially to bear against the end cover of the housing. As a result, when the motor drives the reducer to operate, the rotation axis of the reducer input shaft can run stably. In other words, the stator of the motor is axially attached to one side of the spacer, which can increase the contact area between the stator and the housing and improve the heat dissipation efficiency. The fixed teeth of the reducer are axially attached to the other side of the spacer, which not only facilitates positioning and installation and strengthens the structure, but also can further reduce the radial space of the power module.

[0008] Another purpose of the present invention is to provide a power module for an electric power-assisted bicycle. The motor and the reducer are axially arranged on two opposite sides of the partition of the shell. Compared with the radial stacking design, the volume in the axial direction is only slightly increased. The additional size increase can be absorbed by changing the design of the bicycle frame, so that the overall volume of the power module is further reduced and suitable for mounting on the bicycle frame. The configuration method of connecting the reducer fixed teeth, the motor stator and the reducer input shaft body on three sides of the shell partition can optimize the space utilization of the entire power module, so that the torque sensor has space to be connected to the pedal shaft to realize accurate double pedal force sensing, and at the same time meet the above-mentioned structural strength, stable rotation axis of the reducer input shaft and stator heat dissipation effect.

[0009] To achieve the above-mentioned purpose, the present invention provides a power module for an electric power-assisted bicycle, including a pedal shaft, a housing, a motor, a reducer, a gear output shaft, a first bidirectional bearing of the pedal shaft, and a sensor assembly. The housing defines a radial direction and an axial direction, and has a middle frame and a spacer, the spacer extends radially from the middle frame to the inside of the housing, and the spacer divides the internal space of the housing into a motor accommodating portion and a reducer accommodating portion along the axial direction. The pedal shaft is accommodated in the housing and extends axially. The motor is accommodated in the motor accommodating portion, and a stator of the motor is fixed to a first side of the spacer. The reducer is accommodated in the reducer accommodating part, and includes a reducer input shaft, a movable tooth, a fixed tooth and a reducer output shaft, the fixed tooth is sleeved with the movable tooth in the radial direction, the fixed tooth is fixed to the second side of the interval part, the first side and the second side are opposite to each other, the reducer output shaft is connected to the movable tooth in the axial direction, the reducer input shaft has an input shaft body, an input shaft rotor part and an input shaft eccentric part, the movable tooth is sleeved with the input shaft eccentric part in the radial direction, the input shaft rotor part is connected to the motor output shaft of the motor in the radial direction, the input shaft body part is connected to the third side of the interval part, and the third side is connected between the first side and the second side. The toothed disc output shaft is accommodated in the housing. The reducer output shaft is sleeved with the toothed disc output shaft in the radial direction through the first one-way bearing of the toothed disc output shaft, and the toothed disc output shaft is sleeved with the first end of the pedal shaft in the radial direction through the second one-way bearing of the toothed disc output shaft. The first bidirectional bearing of the pedal shaft is accommodated in the housing, and is sleeved with the second end of the pedal shaft in the radial direction. The sensor assembly is attached to the pedal shaft and is axially arranged on one side of the first bidirectional bearing of the pedal shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The cross-sectional schematic diagram is a diagram showing a power module of an electric power-assisted bicycle according to a first preferred embodiment of the present invention.

[0011] Figure 2 A schematic diagram showing the connection between the reducer input shaft and the corresponding components for transmitting the motor power source to the reducer.

[0012] Figure 3 To reveal Figure 2 Exploded view of the reducer input shaft and corresponding components.

[0013] Figure 4 A schematic diagram showing the torque force flow path of the power module of the first preferred embodiment of the present invention when the right pedal torque is input.

[0014] Figure 5 A schematic diagram showing the torque force flow path of the power module of the first preferred embodiment of the present invention when the left pedal torque is input.

[0015] Figure 6 The cross-sectional schematic diagram is a diagram showing a power module of an electric power-assisted bicycle according to a second preferred embodiment of the present invention.

[0016] Figure 7The cross-sectional schematic diagram is a diagram showing a power module of an electric power-assisted bicycle according to a third preferred embodiment of the present invention.

[0017] Figure 8 The present invention discloses a cross-sectional schematic diagram of a power module of an electric power-assisted bicycle according to a fourth preferred embodiment of the present invention.

[0018] Description of Reference Numerals

[0019] 1. 1a, 1b, 1c: Power module

[0020] 10: Pedal shaft

[0021] 20: Shell

[0022] 201: Motor housing

[0023] 202: Reducer housing

[0024] 21: Left end cover

[0025] 22: Middle frame

[0026] 23: Right end cap

[0027] 24: Interval

[0028] 30: Motor

[0029] 31: Stator

[0030] 32: Magnet

[0031] 33: Input shaft rear bearing

[0032] 40: Reducer

[0033] 41: Reducer input shaft

[0034] 411: Input shaft body

[0035] 412: Input shaft rotor

[0036] 413: Eccentric part of input shaft

[0037] 414: Extension

[0038] 42: Movable teeth

[0039] 43: Fixed teeth

[0040] 44: Reducer output shaft

[0041] 50: Toothed disc shaft

[0042] 51: Chain sprocket

[0043] 60: Sensor components

[0044] 61: Rotating part

[0045] 62, 62a: Sensing part

[0046] 70: Drive

[0047] 81: Pedal shaft first double-direction bearing

[0048] 82: First double-direction bearing of input shaft body

[0049] 83: Second double-direction bearing of input shaft body

[0050] 84: First double-direction bearing of the eccentric part of the input shaft

[0051] 85: First double-direction bearing of the gear shaft

[0052] 86: Second double-direction bearing of the gear shaft

[0053] 87: The first one-way bearing of the gear shaft

[0054] 88: Second one-way bearing of the gear shaft

[0055] 89: First double-direction bearing of the reducer output shaft

[0056] A: Reducer stress point

[0057] B: Bearing force point

[0058] C: Axial

[0059] L: force span

[0060] M: force fulcrum

[0061] S1: First side

[0062] S2: Second side

[0063] S3: Third side DETAILED DESCRIPTION

[0064] Some typical embodiments that embody the features and advantages of this case will be described in detail in the following description. It should be understood that this case can have various changes in different implementations, which do not deviate from the scope of this case, and the description and drawings therein are essentially used for illustration purposes rather than for limiting this case. For example, different embodiments of the present disclosure may use repeated reference symbols and / or marks. These repetitions are for the purpose of simplicity and clarity, and are not used to limit the relationship between each embodiment and / or the appearance structure. Furthermore, in order to facilitate the description of the relationship between a component or feature component and another (plural) component or (plural) feature component in the drawings, space-related terms such as "right", "left", "inside", "outside" and similar terms can be used. In addition to the orientation shown in the drawings, space-related terms are used to cover different orientations of the device in use or operation. In addition, it is understood that although the terms "first", "second", "third" and the like can be used in the claims to describe different components, these components should not be limited by these terms, and the components described in the embodiments are represented by different component symbols. These terms are for different components. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component without departing from the scope of the embodiment. As used herein, the term "and / or" includes any or all combinations of one or more of the associated listed items.

[0065] Figures 1 to 5To disclose the power module of the electric power-assisted bicycle of the first preferred embodiment of the present case. In this embodiment, the power module (hereinafter referred to as the power module) 1 of the electric power-assisted bicycle is applied to a mid-mounted structure, for example, and includes a pedal shaft 10, a housing 20, a motor 30, a reducer 40, a gear output shaft 50, a first bidirectional bearing 81 of the pedal shaft, and a sensor assembly 60. The aforementioned mid-mounted structure refers to that the power module 1 is arranged between the front wheel and the rear wheel of the electric power-assisted bicycle, for example, at the position of the bottom bracket, which is usually used to distinguish it from the hub motor design directly arranged on the wheel. In this embodiment, the housing 20 defines a radial direction and an axial direction C, and has a left end cover 21, a middle frame 22, a right end cover 23 and a spacer 24. The left end cover 21, the middle frame 22 and the right end cover 23 are connected to each other and define the internal space of the housing 20. The spacer 24 extends radially from the inner wall of the middle frame 22 to the inside of the housing 20. In this way, the partition portion 24 extending radially toward the inside of the housing 20 further axially divides the internal space of the housing 20 into a motor accommodating portion 201 (the left space as shown in the accompanying drawings) and a reducer accommodating portion 202 (the right space). The pedal shaft 10 is accommodated in the housing 20, and passes through the left end cover 21, the middle frame 22 and the right end cover 24 along the axial direction C. The motor 30 is, for example, an outer stator inner rotor structure and is accommodated in the motor accommodating portion 201. In this embodiment, the stator 31 of the motor 30 is fixed to the first side S1 of the partition portion 24 (the left side as shown in the accompanying drawings). In addition, the reducer 40 is accommodated in the reducer accommodating portion 202, and includes a reducer input shaft 41, movable teeth 42, fixed teeth 43 and a reducer output shaft 44. The reducer input shaft 41 has an input shaft body portion 411, an input shaft rotor portion 412 and an input shaft eccentric portion 413. The input shaft rotor portion 412 and the input shaft eccentric portion 413 are respectively arranged at two opposite ends of the reducer input shaft 41, and the input shaft body portion 411 is located between the input shaft rotor portion 412 and the input shaft eccentric portion 413. The outer diameter of the input shaft rotor portion 412 is greater than the outer diameter of the input shaft body portion 411, and the outer diameter of the input shaft body portion 411 is greater than the outer diameter of the input shaft eccentric portion 413. Of course, the present case is not limited to this. In this embodiment, the input shaft rotor portion 412 is radially connected to a rotor or a motor output shaft (not shown) of the motor 30. In some embodiments, the input shaft rotor portion 412 and the motor output shaft can be a common component, that is, the two can be the same component to further reduce the device volume, strengthen the structure and reduce the cost. For example, the magnet 32 ​​of the rotor is arranged on the outer ring wall of the input shaft rotor portion 412 to form the motor output shaft. Of course, the present case is not limited to this. In this embodiment, the movable tooth 42 is radially sleeved with the input shaft eccentric portion 413. The fixed teeth 43 are radially sleeved with the movable teeth 42 and fixed to the second side S2 (right side) of the partition 24 . The reducer output shaft 44 is connected to the movable teeth 42 along the axial direction C. The input shaft body 411 is connected to the third side S3 (inner side) of the partition 24 .The first side S1 and the second side S2 are two opposite sides of the spacer 24, and the third side S3 is connected between the first side S1 and the second side S2. The sprocket shaft 50 is accommodated in the housing 20. The reducer output shaft 44 is radially sleeved on the sprocket shaft 50 through a first one-way bearing 87 of the sprocket shaft, and the sprocket shaft 50 is radially sleeved on the first end (right end) of the pedal shaft 10 through a second one-way bearing 88 of the sprocket shaft. The first two-way bearing 81 of the pedal shaft is accommodated in the housing 20 and radially sleeved on the second end (left end) of the pedal shaft 10. For example, the sensor assembly 60 of the torque sensor is attached to a portion of the surface of the pedal shaft 10 and is arranged on one side (right side) of the first two-way bearing 81 of the pedal shaft along the axial direction C.

[0066] It is worth noting that the motor 30 and the reducer 40 of this case are axially arranged and accommodated in the housing 20, and the stator of the motor 30 and the fixed teeth 43 of the reducer 40 are respectively fixed to the first side S1 and the second side S2 opposite to the partition 24. In this embodiment, the housing 20 of the power module 1 is extended from the outside to the inside in the radial direction through the partition 24, and the interior of the housing 20 is divided into two accommodating spaces arranged along the axial direction C, one is the motor accommodating portion 201 on the left side of the partition 24, and the other is the reducer accommodating portion 202 on the right side of the partition 24. The first side S1 (left side) of the partition 24 is connected to the stator 31 of the motor 30, the second side S2 (right side) of the partition 24 is connected to the fixed teeth 43 (or inner ring teeth) of the reducer 40, and the third side S3 (inner side) of the partition 24 is connected to the input shaft body 411 between the motor 30 and the reducer 40. Since the spacer 24 extends a portion of the middle frame 22 of the housing 20, a mechanism can be provided for the motor components and the reducer components to be supported on the housing 20. Furthermore, one end (left end) of the reducer input shaft 41 is the input shaft rotor part 412, and the other end (right end) is the input shaft eccentric part 413. In this embodiment, the end surface of the input shaft rotor part 412 is connected to the rotor output shaft of the motor 30 and the encoder rotating part 61, and the first bidirectional bearing 82 of the input shaft body part and the second bidirectional bearing 83 of the input shaft body part are arranged between the middle input shaft body part 411 and the third side S3 of the spacer 24. In detail, the first bidirectional bearing 82 of the input shaft body part and the second bidirectional bearing 83 of the input shaft body part are connected to the input shaft body part 411 on one side, and connected to the third side S3 (inner side) of the spacer 24 of the housing 20 of the power module 1 on the other side to fix the input shaft body part 411, so that the reducer 40 has a stable rotation axis when operating. Furthermore, the second side S2 of the spacer 24 is connected to the fixed teeth 43 of the reducer 40 along the axial direction C, which can further reduce the radial space of the power module 1 compared to the embodiment of the prior art in which the fixed teeth are connected to the shell along the radial direction. The stator 31 of the motor 30 is abutted against the inner wall of the middle frame 22 and the first side S1 of the spacer 24. In addition to a stable connection, more shell contact area can be obtained to improve the heat dissipation efficiency. The configuration method of connecting the stator 31 of the motor 30, the fixed teeth 43 of the reducer 40 and the input shaft body 411 of the reducer 40 through the three sides S1, S2, and S3 of the shell spacer 24 can optimize the space utilization of the entire power module 1. Therefore, for example, the sensor assembly 60 of the torque sensor has space to be connected to the surface of the pedal shaft 10, so that the power module 1 can simultaneously meet the requirements of structural strength, stable rotation axis of the reducer input shaft and stator heat dissipation effect.

[0067] In this embodiment, the power module 1 further includes a chain sprocket 51, which is concentrically sleeved on the outer surface of the sprocket shaft 50 in the radial direction, and is assembled to transmit the auxiliary torque output of the sprocket shaft 50, or provide the pedaling torque output when it is rotated in the forward direction by human pedaling, for example, the torque output is transmitted to the rear wheel (not shown) through the chain of the electric power-assisted bicycle, so that the electric power-assisted bicycle moves forward. The torque output of the sprocket shaft 50 or the chain sprocket 51 can be provided by human pedaling, or by the motor 30 driving the reducer 40 to rotate and drive the sprocket shaft 50 to rotate, or by both providing torque at the same time. Of course, the sprocket shaft 50 and the chain sprocket 51 of this case can be arranged near the right foot side or the left foot side of the rider, and the electric power-assisted bicycle moves forward when the chain and the rear wheel rotate. Of course, this case is not limited to this, and will not be repeated.

[0068] In this embodiment, the power module 1 includes a first bidirectional bearing 82 of the input shaft body and a second bidirectional bearing 83 of the input shaft body, which are arranged in the axial direction C and are respectively radially sleeved between the input shaft body 411 and the third side S3 of the spacer 24, and the second bidirectional bearing 83 of the input shaft body is connected to one end (right end) of the input shaft rotor part 412 along the axial direction C. In addition, in this embodiment, the power module 1 also includes a first bidirectional bearing 84 of the input shaft eccentric part, which is radially sleeved between the input shaft eccentric part 413 and the movable tooth 42. The power module 1 also includes a first bidirectional bearing 85 of the gear output shaft and a second bidirectional bearing 86 of the gear output shaft, wherein the first bidirectional bearing 85 of the gear output shaft is radially sleeved between the gear output shaft 50 and the right end cover 23 of the housing 20, and is adjacent to the first one-way bearing 87 of the gear output shaft along the axial direction C. The second two-way bearing 86 of the gear output shaft is sleeved between the gear output shaft 50 and the pedal shaft 10 in the radial direction, and is adjacent to the second one-way bearing 88 of the gear output shaft in the axial direction C. In this embodiment, the first two-way bearing 85 of the gear output shaft and the second two-way bearing 86 of the gear output shaft limit the movement of the gear output shaft 50 in the axial direction C. In this embodiment, the power module 1 also includes a first two-way bearing 89 of the reducer output shaft, which is sleeved between the reducer output shaft 44 and the inner wall of the housing 20 in the radial direction, and in this embodiment, the inner wall is located at the right end cover 23.

[0069] In this embodiment, the configuration of the three sides S1, S2, and S3 of the spacer 24 of the housing 20, which are respectively connected to the stator 31 of the motor 30, the fixed teeth 43 of the reducer 40, and the input shaft body 411 of the reducer 40, can optimize the space utilization of the entire power module 1, so that the sensor assembly 60 is spatially configured in the housing 20 and connected to the surface of the pedal shaft 10. In this embodiment, the power source of the reducer 40 is transmitted to the movable teeth 42 of the reducer 40 via the input shaft eccentric portion 413 from the input shaft rotor portion 412 connected to the motor rotor or the motor output shaft. When the movable teeth 42 have rotational power, the movable teeth 42 generate revolution and rotation motions through the gear meshing of the movable teeth 42 and the fixed teeth 43 and the driving of the input shaft eccentric portion 413. When the movable tooth 42 generates revolution and rotation, the indexing hole 421 of the movable tooth 42 drives the reducer output shaft fixing column 46 through the movable tooth bidirectional bearing 45, so that the reducer output shaft 44 obtains the final rotational power and outputs it.

[0070] In this embodiment, the power module 1 further includes an encoder assembly having a rotating portion 61 and a sensing portion 62. The rotating portion 61 is connected to one end (left end) of the input shaft rotor portion 412 along the axial direction C. The sensing portion 62 is spatially relative to the rotating portion 61, and is assembled to measure the speed and angle information of the input shaft 41 when it rotates. In this embodiment, the power module 1 further includes a driver 70, which is arranged in the housing 20 along the axial direction C, located between the motor 30 and the left end cover 21, and is electrically connected to the encoder assembly and the sensor assembly 60.

[0071] It should be noted that, if the conventional motor and reducer are radially arranged, the axial width can be reduced, but the outer diameter space is relatively large. The motor 30 and reducer 40 arranged along the axial direction C in this case only slightly increase the volume in the axial direction C compared to the radial stacking design, and the additional size increase can be absorbed by changing the design of the bicycle frame, so that the overall volume of the power module 1 is further reduced and suitable for mounting on the bicycle frame, and the appearance does not appear abrupt. Of course, this case is not limited to this.

[0072] On the other hand, in order to meet the requirements of miniaturization of the overall volume and optimization of bilateral (pedaling) sensing of the left and right feet, the sensor assembly 60 of the torque sensor is centrally configured. For example, it is arranged on the right side of the pedal shaft bidirectional bearing 81 but does not contact the pedal shaft bidirectional bearing 81, and is connected to the pedal shaft 10. Therefore, based on this design, the reducer 40 moves along the axial direction C (to the right as shown in the figure) to make way for the sensor assembly 60, thereby forming an axial configuration of the reducer 40 and the motor 30. Compared with the existing motor and reducer radial design, the reducer 40 can reduce part of the radial space after making way along the axial direction C, and can cooperate with the central design of the sensor assembly 60 (for example, a torque sensor). Since the sensor assembly 60 is connected to the surface of the pedal shaft 10 and is centrally configured, it is connected in series in the torque force flow (transmission) path, so the requirements for optimizing bilateral (pedaling) sensing can be met.

[0073] In this embodiment, when the rider steps on the pedal with his right foot, the right pedal torque is input to the pedal shaft 10. Figure 4 As shown, the force flow is transmitted from the right side of the pedal shaft 10 to the left side of the pedal shaft 10, then returns to the right side of the pedal shaft 10 through the sensor assembly 60 on the surface of the pedal shaft 10, and finally continues to be transmitted to the right side and output by the sprocket output shaft 50 and the chain sprocket 51. Since the sensor assembly 60 is connected in series in the torque force flow transmission path, it is located between the torque input and torque output points and directly bears the transmitted torque, so the measurement accuracy is high.

[0074] In this embodiment, when the rider steps on the left foot to input the left pedal torque to the pedal shaft 10, Figure 5 As shown, the force flow transmission mode is transmitted from the left side of the pedal shaft 10 to the right side of the pedal shaft 10, and then continuously transmitted to the right through the sensor assembly 60 on the surface of the pedal shaft 10 and output by the toothed disc output shaft 50 and the chain toothed disc 51. Since the sensor assembly 60 in this embodiment is also connected in series in the torque force flow transmission path, located between the torque input and torque output points, it directly bears the transmitted torque, so the measurement accuracy is high. Of course, the present case is not limited to this.

[0075] Figure 6 The power module of the electric power-assisted bicycle of the second embodiment of the present invention is disclosed. In this embodiment, the power module 1a and Figures 1 to 5The power module 1 shown is similar, and the same component numbers represent the same components, structures and functions, which will not be repeated here. In this embodiment, the reducer input shaft 41 also includes an extension portion 414, which is connected to one side (left side) of the input shaft rotor portion 412, extends along the axial direction C to the left end cover 21, and is connected to the left end cover 21 of the housing 20 through the input shaft rear bearing 33. In this embodiment, through the setting of the extension portion 414, the force span L formed by the bearing force point B of the input shaft rear bearing 33 to the force fulcrum M is increased and greater than the distance from the reducer force point A to the force fulcrum M, so as to increase the support strength of the reducer input shaft 41, improve the stability of the operation of the reducer input shaft 41 when the reducer 40 is subjected to force, and reduce the vibration and noise of the overall power module 1a. Of course, the present case is not limited to this.

[0076] Figure 7 The third embodiment of the present invention discloses a power module of an electric power-assisted bicycle. In this embodiment, the power module 1b and Figures 1 to 6 The power modules 1 and 1a shown are similar, and the same element numbers represent the same elements, structures and functions, which will not be repeated here. In this embodiment, the reducer input shaft 41 also includes Figure 6 An extension portion 414 is shown extending to the left end cover 21 along the axial direction C, and is connected to the left end cover 21 of the housing 20 through the input shaft rear bearing 33 to increase the force span of the input shaft rear bearing 33. In this embodiment, the power module 1b further includes an encoder component, such as a magnetic inductive encoder, having a sensing portion 62a spatially relative to the magnet 32 ​​of the motor 30 rotor, for sensing the magnetic field of the motor magnet surface, so as to sense the speed and angle information of the motor 30 when rotating.

[0077] Figure 8 The fourth embodiment of the present invention discloses a power module of an electric power-assisted bicycle. In this embodiment, the power module 1c and Figures 1 to 6 The power modules 1 and 1a shown are similar, and the same element numbers represent the same elements, structures and functions, which will not be repeated here. In this embodiment, the reducer input shaft 41 also includes Figure 6An extension portion 414 is shown, extending along the axial direction C to the left end cover 21, and is connected to the left end cover 21 of the housing 20 through the input shaft rear bearing 33 to increase the force span of the input shaft rear bearing 33. In this embodiment, the power module 1c also includes an encoder component, such as a rotary sensing encoder, having a rotating portion 61 and a sensing portion 62. The rotating portion 61 is disposed on the reducer input shaft 41 and sleeved on the extension portion 414. The rotating portion 61 and the sensing portion 62 are arranged radially so that the rotating portion 61 on the reducer input shaft 41 is relative to the sensing portion 62 in space to realize the sensing of the speed and angle information of the reducer 40 when it is running. In other embodiments, the type and configuration position of the encoder component can be adjusted according to the actual application requirements. This case is not limited to this and will not be repeated.

[0078] In summary, the present invention provides a power module for a mid-mounted electric power-assisted bicycle in which a motor and a reducer are axially arranged, which can optimize the radial space, meet the requirements of miniaturization and realize the optimal measurement of pedal torque. The internal space of the housing is divided into an axially arranged motor accommodating portion and a reducer accommodating portion by a spacer extending radially inwardly from the middle frame of the housing. When the motor and the reducer are axially sleeved on the pedal shaft, the stator of the motor and the fixed teeth of the reducer can be respectively fixedly connected to the two opposite sides of the spacer, so as to achieve alignment installation, improve assembly efficiency, enhance stator heat dissipation, and strengthen the structure. Furthermore, when the axially arranged motor and reducer can transmit the power of the motor to the speed-sensitive machine through a reducer input shaft, one end of the reducer input shaft constitutes an input shaft rotor portion connected to the rotor (output shaft) of the motor or the motor output shaft, and the other end constitutes an input shaft eccentric portion connected to the movable teeth of the reducer, and the input shaft body portion between the input shaft rotor portion and the input shaft eccentric portion can be further radially connected to the third side of the spacer portion through a bearing shaft, so that the reducer input bearing is close to the spacer portion. On the other hand, the reducer input shaft can also extend axially to bear against the end cover of the housing. Thus, when the motor drives the reducer to operate, the rotation axis of the reducer input shaft can run stably. In other words, the stator of the motor is axially attached to one side of the spacer, which can increase the contact area between the stator and the housing and improve the heat dissipation efficiency. The fixed teeth of the reducer are axially attached to the other side of the spacer, which is convenient for positioning and installation and strengthening the structure, and can further reduce the radial space of the power module. The motor and the reducer are axially arranged on the two opposite sides of the spacer of the housing. Compared with the radial stacking design, the volume in the axial direction is only slightly increased. The additional size increase can be absorbed by the change design of the bicycle frame, so that the overall volume of the power module is further reduced and suitable for mounting on the bicycle frame. The configuration method of connecting the reducer fixed teeth, the motor stator and the reducer input shaft body on three sides of the housing spacer can optimize the space utilization of the entire power module, so that the torque sensor has space to be connected to the pedal shaft to realize accurate double pedal force sensing, and at the same time meet the above-mentioned structural strength, stable rotation axis of the reducer input shaft and stator heat dissipation effect.

[0079] The present invention can be modified in various ways by those skilled in the art, but all of them are within the protection scope of the attached claims.

Claims

1. A power module for an electric power-assisted bicycle, comprising: A housing, which defines a radial direction and an axial direction, and has a middle frame and a partition, wherein the partition extends from the middle frame toward the interior of the housing along the radial direction, and divides the interior space of the housing into a motor accommodating portion and a reducer accommodating portion along the axial direction; A pedal shaft, accommodated in the housing and extending along the axial direction; A motor is accommodated in the motor accommodating portion, and a stator of the motor is fixed to a first side of the spacing portion; A reducer, accommodated in the reducer accommodating portion, and comprising a reducer input shaft, a movable tooth, a fixed tooth and a reducer output shaft, wherein the fixed tooth is sleeved with the movable tooth along the radial direction, the fixed tooth is fixed to the second side of the spacing portion, the first side and the second side are opposite to each other, the reducer output shaft is connected to the movable tooth along the axial direction, the reducer input shaft comprises an input shaft body portion, an input shaft rotor portion and an input shaft eccentric portion, the movable tooth is sleeved with the input shaft eccentric portion along the radial direction, the input shaft rotor portion is connected to the motor output shaft of the motor along the radial direction, the input shaft body portion is connected to the third side of the spacing portion, and the third side is connected between the first side and the second side; The gear output shaft is accommodated in the housing, wherein the reducer output shaft is sleeved with the gear output shaft along the radial direction through the first one-way bearing of the gear output shaft, and the gear output shaft is sleeved with the first end of the pedal shaft along the radial direction through the second one-way bearing of the gear output shaft; A first bidirectional bearing of the pedal shaft is accommodated in the housing and sleeved with the second end of the pedal shaft along the radial direction; and The sensor component is attached to the pedal shaft and is arranged on one side of the first bidirectional bearing of the pedal shaft along the axial direction. 2 . The power module of the electric power-assisted bicycle according to claim 1 , further comprising an encoder assembly having a rotating portion connected to the input shaft rotor portion along the axial direction.

3. The power module of the electric assisted bicycle according to claim 1, wherein the input shaft body is located between the input shaft rotor and the input shaft eccentric portion, the outer diameter of the input shaft rotor is larger than the outer diameter of the input shaft body, and the outer diameter of the input shaft body is larger than the outer diameter of the input shaft eccentric portion.

4. The power module of the electric assisted bicycle according to claim 1 further includes a first bidirectional bearing of the input shaft body and a second bidirectional bearing of the input shaft body, which are arranged along the axial direction and are respectively sleeved between the input shaft body and the third side of the spacer along the radial direction, and the second bidirectional bearing of the input shaft body is connected to the input shaft rotor part along the axial direction.

5. The power module of the electric power-assisted bicycle according to claim 1 further includes a first bidirectional bearing of the reducer output shaft and a first bidirectional bearing of the eccentric portion of the input shaft, wherein the first bidirectional bearing of the reducer output shaft is sleeved between the reducer output shaft and the housing along the radial direction, and the first bidirectional bearing of the eccentric portion of the input shaft is sleeved between the eccentric portion of the input shaft and the movable tooth along the radial direction.

6. The power module of the electric power-assisted bicycle according to claim 1 further includes a first bidirectional bearing of the sprocket shaft and a second bidirectional bearing of the sprocket shaft for limiting the movement of the sprocket shaft along the axial direction, wherein the first bidirectional bearing of the sprocket shaft is sleeved between the sprocket shaft and the housing along the radial direction, and is adjacent to the first unidirectional bearing of the sprocket shaft along the axial direction, and the second bidirectional bearing of the sprocket shaft is sleeved between the sprocket shaft and the pedal shaft along the radial direction, and is adjacent to the second unidirectional bearing of the sprocket shaft along the axial direction.

7. The power module of the electric power-assisted bicycle according to claim 1, further comprising a driver disposed in the housing, located between the motor and an end cover of the housing, and electrically connected to an encoder assembly and the sensor assembly.

8. The power module of the electric power-assisted bicycle according to claim 1, wherein the reducer input shaft further has an extension portion extending along the axial direction to the end cover of the housing and connected to the end cover via an input shaft rear bearing. 9 . The power module of the electric assist bicycle according to claim 8 , further comprising an encoder assembly having a rotating portion and a sensing portion arranged along the radial direction, wherein the rotating portion is disposed at the extending portion of the reducer input shaft. 10 . The power module of the electric power-assisted bicycle according to claim 1 , further comprising an encoder assembly having a sensing portion and a magnet spatially relative to the rotor of the motor.

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