Coaxial middle motor and electric power-assisted bicycle

Abstract

The present disclosure relates to a coaxial middle motor and an electric power-assisted bicycle. The coaxial middle motor comprises a box body, a central shaft, a driving assembly, a control board, an output assembly and a sleeve type torque detection device, which comprises a torque sleeve, a torque sensor and a wireless signal collector. The torque sleeve is sleeved on the outer side of the central shaft, the first end of the torque sleeve is torsionally connected with the central shaft, and the second end of the torque sleeve is drivingly connected with the output assembly. The wireless signal collector is sleeved on the first end of the torque sleeve and is electrically connected with the control board. The torque sensor is arranged on the first end of the torque sleeve and wirelessly transmits the detected human power torque signal to the wireless signal collector. The torque sensor and the wireless signal collector are integrated on the same end of the central shaft, and the signal interaction between the torque sensor and the wireless signal collector is realized through wireless transmission. The coaxial middle motor not only omits the need for wire harness and improves the signal transmission reliability, but also realizes the compact structure requirement of the central shaft.

Description

Technical Field

[0001] This utility model relates to the field of electric power assist technology, and in particular to a coaxial mid-mounted motor and an electric power assist bicycle. Background Technology

[0002] Electric-assist bicycles (also known as e-bikes) are equipped with a power assist system (PAS), which can be categorized into different types of motor configurations based on its installation location. A common configuration is the mid-drive motor, which is mounted on the pedals of the frame and connected to the rear wheel via links and a chain to transmit power. Pedals are located on either side of the mid-drive motor, allowing riders to continue pedaling even when the motor is not powered.

[0003] Mid-drive motors are mainly divided into two types: parallel mid-drive motors and coaxial mid-drive motors. A parallel mid-drive motor means that the motor shaft, pedal input shaft (also called the center shaft), and final output shaft are arranged parallel to each other, but not on the same axis. A coaxial mid-drive motor means that the motor shaft, pedal input shaft, and final output shaft are arranged coaxially. Therefore, parallel mid-drive motors occupy more space, resulting in a larger and heavier overall bicycle size. Coaxial mid-drive motors better solve the space-consuming problem of parallel mid-drive motors, enabling a lighter and more compact design for electric-assist bicycles.

[0004] Nevertheless, coaxial mid-drive motors still face some technical challenges, particularly in the structural layout and signal transmission of the controller, output module (chain link), and torque sensor.

[0005] The output module (chain link) of the coaxial mid-drive motor is located on one side of the assist motor's axial direction, while the controller is typically located on the other side. In related technologies, a torque sensor is usually mounted near the chain link to detect the torque along the path from the pedal input shaft to the chain link, and then the torque data is transmitted via a signal harness to the controller located on the other side of the assist motor's axial direction.

[0006] Considering that the chain links, foot pedal input shaft, and reducer are constantly rotating during operation and there is a speed difference, in order to avoid tangling or connection failure of the signal harness, the signal harness can only be arranged inside the rotor shaft of the boost motor. The internal arrangement of the harness significantly increases the complexity of the system, including wiring difficulty and maintenance costs. In addition, to accommodate the internal harness, the inner diameter of the rotor shaft needs more space, which limits the effective volume of the boost motor and may result in a decrease in boost motor power. Utility Model Content

[0007] To overcome the problems existing in the related technologies, this disclosure provides a coaxial mid-drive motor and an electric-assisted bicycle.

[0008] According to a first aspect of the present disclosure, a coaxial mid-drive motor is provided, comprising: a housing; a central shaft, both ends of which are rotatably supported within the housing; a drive assembly located within the housing and coaxially arranged with the central shaft; a control board fixed within the housing and located on a first axial side of the drive assembly; an output assembly located on a second axial side of the drive assembly and respectively connected to the central shaft and the drive assembly; a sleeve-type torque detection device, comprising a torque sleeve sleeved outside the central shaft, a first end of the torque sleeve being close to the control board and anti-torsively connected to the central shaft, and a second end of the torque sleeve being connected to the output assembly; a wireless signal collector sleeved on the first end of the torque sleeve and electrically connected to the control board; and a torque sensor disposed on the first end of the torque sleeve and wirelessly transmitting the detected human torque signal to the wireless signal collector.

[0009] In some embodiments, the axial length of the torque sleeve is greater than the axial length of the drive assembly, and the first end of the torque sleeve extends axially beyond the first axial side of the drive assembly, wherein the wireless signal collector is arranged coaxially and axially overlapping with the control board.

[0010] In some embodiments, the torque sleeve has a strain region near the first end for mounting the torque sensor, and the thickness of the strain region is less than the thickness of the torque sleeve.

[0011] In some embodiments, the central shaft consists of a first shaft and a second shaft; wherein the first shaft extends axially through the drive assembly, and the second shaft is torsionally connected to the second end of the first shaft on the second axial side of the drive assembly.

[0012] In some embodiments, a radially protruding convex ring is provided at the first end of the first shaft, and the two axial ends of the torque sleeve are respectively defined between the axial end face of the convex ring and the axial end face of the second shaft.

[0013] In some embodiments, the coaxial center motor further includes a cadence magnetic ring, which is fixed on the convex ring of the first shaft and together with the wireless signal collector forms a cadence detection device for detecting the cadence data of the center shaft.

[0014] In some embodiments, the torque sleeve has a radially protruding baffle ring on the outer wall of the first end, and the wireless signal collector is located axially between the baffle ring and the protruding ring.

[0015] In some embodiments, the drive assembly includes: an assist motor, including a stator and a rotor, the stator being fixed in the housing, the first axial side of the stator being electrically connected to the control board via a wiring harness, and the rotor being located radially inside the stator; a reducer being located on the second axial side of the assist motor; and a rotor sleeve, the rotor sleeve being rotatably supported outside the torque sleeve by a bearing, and the rotor of the assist motor being drively connected to the reducer through the rotor sleeve.

[0016] In some embodiments, the output component includes: a toothed plate bracket, the radial inner wall of the first end of the toothed plate bracket being drive-connected to the second end of the torque sleeve via a first one-way clutch, and the radial outer wall of the first end of the toothed plate bracket being drive-connected to the output shaft of the reducer via a second one-way clutch; and a toothed plate, which is torque-connected to the second end of the toothed plate bracket.

[0017] According to a second aspect of the present disclosure, an electric-assisted bicycle is provided, comprising: a left pedal; a right pedal; and a coaxial central motor as described in the first aspect, located axially between the left pedal and the right pedal, wherein a first end of the central shaft is torsionally connected to the left pedal, and a second end of the central shaft is torsionally connected to the right pedal.

[0018] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: a sleeve-type torque sensing device is used, the torque sensor and the wireless signal acquisition device are integrated and set on the same end of the central shaft near the control board, and the signal interaction between the torque sensor and the wireless signal acquisition device is realized through wireless transmission, which eliminates the need to arrange the wiring harness inside the central shaft. The short axial distance greatly improves the reliability of signal transmission of the coaxial central motor, while achieving the structural requirement of compact central shaft. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0020] Figure 1 This is a cross-sectional view of a coaxial mid-drive motor according to an exemplary embodiment. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0022] In this invention, unless otherwise specified, axial A and radial R refer to the axial A and radial R of the coaxial centrally mounted motor 100, respectively; the axial first side or first end refers to... Figure 1 The left side (e.g., the side where the left pedal is located), the axial second side or second end refers to Figure 1 The right side (e.g., the side where the right pedal is located); radially outer refers to the side that is radially away from... Figure 1 The side of the central axis O in the diagram refers to the radially inner side, which is closer to the central axis O in the radial direction. Furthermore, "transmission connection" refers to the ability to transmit driving force / torque between two components, which can be directly connected or achieved through various transmission mechanisms or connection structures. The term "torsional connection" refers to a connection between two elements that does not rotate relative to each other, which can be achieved via a press fit (i.e., interference fit) or by integrally forming the two components. Those skilled in the art will understand the specific meaning of the above terms in this invention as appropriate.

[0023] To address the aforementioned technical problems, this disclosure provides a coaxial mid-drive motor 100, which is commonly used in electric-assist bicycles. In the electric-assist bicycle, the left and right pedals are located on opposite sides of the coaxial mid-drive motor 100 and are torque-transmitted to both ends of the central shaft 20 of the coaxial mid-drive motor 100. During riding, the pedaling force applied by the rider to the left and / or right pedals is transmitted to the central shaft 20. The coaxial mid-drive motor 100 converts this pedaling force into a corresponding human torque signal and outputs it to the control board 40. After processing these human torque signals, the control board 40 precisely controls the power output of the assist motor 31, thereby providing intelligent auxiliary power to the electric-assist bicycle and significantly reducing the rider's pedaling force.

[0024] Specifically, such as Figure 1 As shown, the coaxial mid-drive motor 100 includes at least a housing 10, a central shaft 20, a drive assembly 30, a control board 40, an output assembly 50, a sleeve-type torque detection device 60, and a cadence magnetic ring 70.

[0025] The coaxial mid-drive motor 100 can be fixed to the frame of an electric-assist bicycle (not shown) via a housing 10. The housing 10 can be composed of a shell 11 and a cover 12, facilitating assembly and disassembly. In this embodiment, the cover 12 can be axially connected to the shell 11 via fasteners 105, welding, or interference fit to form the housing 10, giving the housing 10 a closed cavity for accommodating other components of the coaxial mid-drive motor 100 and effectively preventing the intrusion of external contaminants.

[0026] The central shaft 20 includes a first end and a second end along axial direction A. In an exemplary embodiment, the first end of the central shaft 20 can be torque-transmittingly connected to the left pedal, and the second end of the central shaft 20 can be torque-transmittingly connected to the right pedal. Figure 1 As shown, the first and second ends of the central shaft 20 are rotatably supported in the housing 10 by bearings 101 and 102, respectively.

[0027] The drive assembly 30 is located within the receiving cavity of the housing 10. The drive assembly 30 includes an auxiliary motor 31, a reducer 32, and a rotor sleeve 33, all arranged coaxially with the central shaft 20. Figure 1 As shown, the drive assembly 30 is approximately fitted around the center of the central shaft 20 along its axial direction. The assist motor 31 is located at... Figure 1 As shown on the left. The reducer 32 is located on the left side. Figure 1 As shown on the right. The power assist motor 31 transmits torque to the reducer 32 through the rotor sleeve 33.

[0028] Furthermore, the power assist motor 31 includes a stator 311 and a rotor 312. The stator 311 is fixed inside the housing 10, while the rotor 312 is located radially inside the stator 311. The radially inner wall of the rotor sleeve 33 is rotatably supported outside the torque sleeve 61 described below by a bearing 106. The two ends of the radially outer wall of the rotor sleeve 33 are respectively anti-torsively connected to the rotor 312 of the power assist motor 31 and the output shaft of the reducer 32, ensuring that the power of the power assist motor 31 can be transmitted to the reducer 32 through the rotor sleeve 33.

[0029] The control panel 40 is fixed inside the housing 10 and located in Figure 1 As shown on the left, the stator 311 of the boost motor 31 is connected to the stator 311 via wiring harness 104, allowing the control board 40 to supply power to the stator 311 based on received signals, thereby driving the rotor 312 to rotate. It can be seen that the control board 40 is located on the first axial side of the entire drive assembly 30. The output assembly 50 needs to be connected to the reducer 32 to output torque; therefore, the output assembly 50 is also located on the first axial side of the drive assembly 30. Figure 1 As shown on the right, the output component 50 is located on the second axial side of the entire drive assembly 30. Therefore, it can be seen that the control board 40 and the output component 50 are located on opposite axial sides of the drive assembly 30.

[0030] Furthermore, the output component 50 can be connected to the central shaft 20 and the drive component 30 respectively, enabling the electric-assisted bicycle to have three riding modes: manual riding mode, electric-assisted riding mode, and electric riding mode. In manual riding mode, the rider's pedaling force provides torque to the output component 50 through the central shaft 20. In electric-assisted riding mode, if the drive component 30 also provides torque to the output component 50, it is in electric riding mode. In electric riding mode, if only the drive component 30 provides torque to the output component 50, it is in electric riding mode.

[0031] Output assembly 50 may include a toothed plate bracket 51, a toothed plate 52, and a chain (not shown). The radial inner wall of the first end of the toothed plate bracket 51 is connected to the second end of the central shaft 20 via a first one-way clutch 80. Figure 1 (As shown on the right) The transmission connection is as follows: The radial outer wall of the first end of the toothed plate bracket 51 is connected to the output shaft of the reducer 32 via a second one-way clutch 90. The toothed plate 52 is torque-transmittingly connected to the second end of the toothed plate bracket 51. The toothed plate 52 rotates relative to the housing 11 via a bearing 103. One end of the chain is sleeved on the toothed plate 52, and the other end of the chain is connected to the wheel (not shown) via other transmission connectors. It can be seen that the torque obtained from the central shaft 20 or the drive assembly 30 from the first end of the toothed plate bracket 51 is transmitted to the wheel through the toothed plate 52 and the chain, thereby driving the wheel to rotate.

[0032] In the embodiments disclosed herein, such as Figure 1 As shown, the sleeve-type torque detection device 60 includes a torque sleeve 61, a wireless signal collector 62, and a torque sensor. The torque sleeve 61 is sleeved on the outside of the central shaft 20 and has a first end 611 and a second end 612.

[0033] The first end 611 of the torque sleeve 61 is close to the control plate 40 located on the first axial side of the drive assembly 30 (i.e. Figure 1 (as shown on the left) and is torsionally connected to the central shaft 20. Optionally, the first end 611 of the torque sleeve 61 is torsionally connected to the central shaft 20 via a spline; the second end 612 of the torque sleeve 61 is located near the axial second side of the drive assembly 30 (i.e., the left side of the drive assembly 30). Figure 1 (as shown on the right), and is drivenly connected to the gear plate bracket 51 of the output assembly 50 via the second one-way clutch 90.

[0034] Furthermore, a torque sensor is mounted on the outer wall of the torque sleeve 61 near the first end 611 for measuring the manual torque applied to the central shaft 20. Alternatively, the torque sensor may be a strain gauge and is adhered to the surface of the strain region 613 at the first end 611 of the torque sleeve 61.

[0035] When the rider applies pedaling force to the left or right pedal, it causes the central shaft 20 to rotate. Since the first end 611 of the torque sleeve 61 is torsionally connected to the central shaft 20, and the second end 612 of the torque sleeve 61 is torsionally connected to the toothed plate bracket 51 of the output assembly 50, when the central shaft 20 rotates, the first end 611 of the torque sleeve 61 rotates relative to the second end 612 of the torque sleeve 61, causing the torque sleeve 61 to undergo rotational torsion. During this process, the torque sleeve 61 undergoes slight torsional deformation, causing the strain gauge torque sensor mounted on its strain area 613 to also deform accordingly, generating a human torque signal.

[0036] Furthermore, the wireless signal collector 62 is sleeved on the outer periphery of the first end 611 of the torque sleeve 61, indicating that the wireless signal collector 62 and the torque sensor are integrated on the same end of the torque sleeve 61. The wireless signal collector 62 is fixedly installed inside the housing 10 and electrically connected to the control board 40, maintaining relative fixation, that is, there is no circumferential relative rotation between the wireless signal collector 62 and the control board 40.

[0037] The wireless signal collector 62 is configured to wirelessly receive the human torque signal detected by the torque sensor, reducing the possibility of wire tangling or connection failure, and improving the flexibility and maintenance convenience of the coaxial mid-drive motor 100. Simultaneously, the wireless signal collector 62 is also configured to form a non-contact cadence detection device with the cadence magnetic ring 70 fixed on the central shaft 20, ensuring accurate capture of each rotation of the central shaft 20, used to detect the cadence frequency of the central shaft 20 and provide cadence data to the control board 40.

[0038] It is known that the wireless signal collector 62 can transmit the human torque signal applied to the central shaft 20 and the acquired cadence data to the control board 40 in real time. After receiving the human torque signal and cadence data, the control board 40 calculates the auxiliary power required by the power assist motor 31 based on the magnitude of the human torque signal and cadence data and through the built-in program. Based on the calculation result, the control board 40 transmits the instruction to the power assist motor 31, so that the power assist motor 31 can adjust its output power in real time, provide appropriate auxiliary power, and provide the best riding experience.

[0039] As shown above, the control board 40 is located outside the drive assembly 30 on one axial side. The first end 611 of the torque sleeve 61 is torsionally connected to the central shaft 20 on the first axial side near the drive assembly 30. The torque sensor and the wireless signal acquisition unit 62 are both integrated on the same end of the central shaft 20 near the control board 40, and the torque sensor and the wireless signal acquisition unit 62 achieve signal interaction through wireless transmission. This layout makes the axial distance between the torque sensor and the control board 40 very short, enabling the transmission of the detected torque sleeve 61's manual torque signal and pedal frequency data to the control board 40 within a very short axial distance. This reduces potential problems in the signal transmission path and improves signal transmission reliability. At the same time, it also eliminates the need to arrange wiring harnesses inside the central shaft 20, achieving the structural requirement of a compact central shaft.

[0040] In some embodiments, the axial length of the torque sleeve 61 is greater than the axial length of the drive assembly 30, and the first end 611 of the torque sleeve 61 can extend axially beyond the first axial side of the drive assembly 30 (i.e., Figure 1 (As shown on the left), furthermore, the first end 611 of the torque sleeve 61 is also located outside the axial first side of the drive assembly 30 at the anti-torsional connection point with the central shaft 20.

[0041] The longer axial length makes the first end 611 of the torque sleeve 61 more prone to deformation when generating torque compared to the second end 612, thereby improving the accuracy and sensitivity of the torque sensor in detecting torque. The position where the first end 611 of the torque sleeve 61 is anti-torsionally connected to the central shaft 20 is located outside the first axial side of the drive assembly 30. The control board 40 and the wireless signal acquisition unit 63 are arranged coaxially and overlap in the axial direction, which allows the coaxial central motor 100 to make full use of the axial space, making the axial space more compact. The torque sensor can also be closer to the control board 40, shortening the connection path and signal transmission path between the two.

[0042] In some embodiments, the torque sleeve 61 has a strain region 613 near the first end 611 for mounting a torque sensor, and the thickness of the strain region 613 is less than the thickness of the torque sleeve.

[0043] The relatively thin strain region 613 ensures that the torque sleeve 61 undergoes significant deformation only within this strain region, thereby improving the sensitivity and detection accuracy of the torque sensor to stress changes. The strain region 613 also ensures that the rest of the torque sleeve 61 maintains sufficient thickness and strength, guaranteeing effective torque transmission and preventing overall structural failure due to localized weaknesses. Because the strain region 613 is close to the first end 611 of the torque sleeve 61, the torque sensor mounted here is also closer to the control board 40, shortening the signal transmission distance.

[0044] In some embodiments, the central shaft 20 is composed of a first shaft 21 and a second shaft 22; wherein the first shaft 21 extends axially through the drive assembly 30, and the second shaft 22 is torsionally connected to the second end of the first shaft 21 on the second axial side of the drive assembly 30.

[0045] The central shaft 20 is divided into a first shaft 21 and a second shaft 22, which facilitates the independent manufacturing and assembly of each component, reduces production difficulty, and improves assembly efficiency. Depending on the axial length requirements of different coaxial mid-drive motors 100 for the central shaft 20, a specific shaft segment, such as the first shaft 21, can be individually replaced or adjusted during production and maintenance without disassembling or replacing the entire central shaft 20. This adapts to various application scenarios and increases the versatility and market competitiveness of the coaxial mid-drive motor 100.

[0046] In addition, the first shaft 21 has a long axial length and runs through the entire drive assembly 30, ensuring that the power transmission in the manual riding mode and the power transmission in the assist mode of the motor 31 both occur on the same shaft. There are no connection points on the same shaft used for power transmission. Especially under long-term use or high-intensity riding conditions, this avoids the problem of power transmission failure caused by loosening of the connection parts during the transmission torque process.

[0047] In some embodiments, a radially protruding convex ring 211 is provided at the first end of the first shaft 21, and the axial ends of the torque sleeve 61 are respectively defined between the axial end face of the convex ring 211 and the axial end face of the second shaft 22. Through the combined action of the convex ring 211 on the first shaft 21 and the axial end face of the second shaft 22, the axial ends of the torque sleeve 61 are firmly defined in a fixed axial position, ensuring that the torque sleeve 61 will not undergo axial displacement or movement during operation.

[0048] In some embodiments, the tread frequency magnetic ring 70 is fixed on the protruding ring 211 of the first shaft 21.

[0049] Furthermore, the torque sleeve 61 is provided with a radially protruding baffle ring 614 on the outer wall of the first end 611. The baffle ring 614 is located on the first axial side of the drive assembly 30. The wireless signal collector 62 is located between the baffle ring 614 and the protruding ring 211 along the axial direction A. This not only restricts the axial position of the wireless signal collector 62, but also prevents the wireless signal collector 62 from moving along the axial direction A.

[0050] The following is a detailed explanation of the torque transmission path in manual riding mode, electric-assisted riding mode, and electric riding mode:

[0051] Human-powered riding mode

[0052] When the rider is in manual riding mode, the rider's pedaling force is transmitted to the central shaft 20 through the left or right pedal, causing the central shaft 20 to rotate. The rotation of the central shaft 20 causes the torque sleeve 61 to rotate coaxially. The first end 611 of the torque sleeve 61 rotates with the central shaft 20 relative to the second end 612 of the torque sleeve 61, resulting in the torque sleeve 61 being subjected to rotational torsion. At the same time, the second end 612 of the torque sleeve 61 drives the toothed plate bracket 51 and the toothed plate 52 to rotate through the first one-way clutch 80, thereby driving the chain and realizing manual riding.

[0053] Electric riding mode

[0054] The first one-way clutch 80 disengages the second end 612 of the torque sleeve 61 from the toothed plate bracket 51, while the second one-way clutch 90 connects the second end 612 of the torque sleeve 61 to the output shaft of the reducer 32. The toothed plate bracket 51 and the toothed plate 52 receive electric power solely from the drive assembly 30. Specifically, the power assist motor 31 transmits electric power to the output shaft of the reducer 32 via the reducer 32. The output shaft of the reducer 32 directly drives the toothed plate bracket 51 and the toothed plate 52 to rotate via the second one-way clutch 90, thereby causing the chain to drive the wheels and achieving electric drive. In this mode, the rider does not need to apply pedaling force; the entire bicycle relies entirely on electric drive, providing a convenient electric riding experience.

[0055] Electric assist riding mode

[0056] This is a combination of human-powered and electric-powered riding modes. The rider's pedaling force is transmitted to the central shaft 20 through the left or right pedal, causing the central shaft 20 to start rotating. The rotation of the central shaft 20 causes the first end 611 of the torque sleeve 61 to rotate with the central shaft 20 relative to the second end 612 of the torque sleeve 61. The first one-way clutch 80 is closed, and the second end 612 of the torque sleeve 61 drives the toothed bracket 51 and the toothed plate 52 to rotate through the first one-way clutch 80.

[0057] Simultaneously, the torque sleeve 61 is subjected to rotation and torsion, resulting in slight torsional deformation. This causes the torque sensor mounted on it to deform accordingly, generating a manual torque signal. This manual torque signal is transmitted to the control board 40 via the wireless signal acquisition unit 62. Upon receiving the manual torque signal, the control board 40 determines that the power assist motor 31 can adjust its output power in real time to provide appropriate auxiliary power.

[0058] The assist motor 31 transmits appropriate torque to the reducer 32, and the output shaft of the reducer 32 transmits torque to the sprocket carrier 51 and the sprocket 52 via the second one-way clutch 90. In this mode, the sprocket carrier 51 and the sprocket 52 simultaneously receive both human and electric power, achieving a superposition of their power and providing additional auxiliary power to the rider.

[0059] It is further understood that the terms "first," "second," etc., are used to describe various structures, but these structures should not be limited to these terms. These terms are only used to distinguish structures of the same type from one another and do not indicate a specific order or degree of importance. In fact, the expressions "first," "second," etc., are completely interchangeable. For example, without departing from the scope of this disclosure, a first structure can also be called a second structure, and similarly, a second structure can also be called a first structure.

[0060] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0061] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A coaxial mid-drive motor (100), characterized in that, include: Box (10); A central shaft (20) is rotatably supported at both ends within the housing (10); The drive assembly (30) is located inside the housing (10) and arranged coaxially with the central axis (20); The control panel (40) is fixed inside the housing (10) and located on the first axial side of the drive assembly (30); The output component (50) is located on the second axial side of the drive component (30) and is connected to the central shaft (20) and the drive component (30) respectively. A sleeve-type torque detection device (60) includes: A torque sleeve (61) is sleeved outside the central shaft (20). The first end (611) of the torque sleeve (61) is close to the control plate (40) and is anti-torsional connected to the central shaft (20). The second end (612) of the torque sleeve (61) is drive-connected to the output assembly (50). A wireless signal collector (62) is fitted onto the first end (611) of the torque sleeve (61) and electrically connected to the control board (40); as well as A torque sensor is located at the first end (611) of the torque sleeve (61) and wirelessly transmits the detected human torque signal to the wireless signal collector (62).

2. The coaxial mid-mounted motor (100) according to claim 1, characterized in that, The axial length of the torque sleeve (61) is greater than the axial length of the drive assembly (30), and the first end (611) of the torque sleeve (61) extends axially beyond the first axial side of the drive assembly (30). The wireless signal collector (62) and the control board (40) are arranged coaxially and axially overlapped.

3. The coaxial mid-mounted motor (100) according to claim 1, characterized in that, The torque sleeve (61) has a strain region (613) near the first end (611) for mounting the torque sensor, and the thickness of the strain region (613) is less than the thickness of the torque sleeve (61).

4. The coaxial mid-mounted motor (100) according to claim 1, characterized in that, The central axis (20) is composed of a first axis (21) and a second axis (22); The first shaft (21) extends axially through the drive assembly (30), and the second shaft (22) is anti-torsionally connected to the second end of the first shaft (21) on the second axial side of the drive assembly (30).

5. The coaxial mid-mounted motor (100) according to claim 4, characterized in that, The first end of the first shaft (21) is provided with a radially protruding convex ring (211), and the two axial ends of the torque sleeve (61) are respectively defined between the axial end face of the convex ring (211) and the axial end face of the second shaft (22).

6. The coaxial mid-mounted motor (100) according to claim 5, characterized in that, The coaxial central motor (100) also includes a cadence magnetic ring (70), which is fixed on the convex ring (211) of the first shaft (21) and together with the wireless signal collector (62) forms a cadence detection device for detecting the cadence data of the central shaft (20).

7. The coaxial mid-mounted motor (100) according to claim 6, characterized in that, The torque sleeve (61) has a radially protruding baffle ring (614) on the outer wall of the first end (611), and the wireless signal collector (62) is located axially between the baffle ring (614) and the protruding ring (211).

8. The coaxial mid-mounted motor (100) according to claim 1, characterized in that, The driving component (30) includes: The power assist motor (31) includes a stator (311) and a rotor (312). The stator (311) is fixed inside the housing (10). The first axial side of the stator (311) is electrically connected to the control board (40) via a wiring harness. The rotor (312) is located on the radial inner side of the stator (311). The reducer (32) is located on the second axial side of the power assist motor (31); The rotor sleeve (33) is rotatably supported outside the torque sleeve (61) by a bearing, and the rotor (312) of the power assist motor (31) is connected to the reducer (32) through the rotor sleeve (33).

9. The coaxial mid-mounted motor (100) according to claim 8, characterized in that, The output component (50) includes: The toothed plate bracket (51) has its first end radial inner wall connected to the second end of the torque sleeve (61) via a first one-way clutch (80), and its first end radial outer wall connected to the output shaft of the reducer (32) via a second one-way clutch (90). The toothed plate (52) is torsionally connected to the second end of the toothed plate bracket (51).

10. An electric-assisted bicycle, characterized in that, include: Left pedal; Right pedal; as well as The coaxial center motor (100) as described in any one of claims 1-9 is located axially between the left pedal and the right pedal, with the first end of the central shaft (20) being torque-transmittingly connected to the left pedal and the second end of the central shaft (20) being torque-transmittingly connected to the right pedal.

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