Assist unit and assisted bicycle

Abstract

This application relates to the field of electric bicycles and discloses an assist unit and an electric bicycle. The assist unit includes a first shaft, an output shaft, a transmission device, and a measuring component. The output shaft is connected to the power unit of the assist unit and is arranged substantially parallel to the first shaft. The transmission device is used to drive the first shaft and the output shaft, and includes a transmission component with a suspended portion located between the first shaft and the output shaft. The measuring component is arranged substantially along a first direction and is used to detect the pressure applied by the transmission component to the measuring component and / or a first parameter corresponding to the pressure, so as to determine the torque of the first shaft. The measuring component is fixed inside the assist unit and pressed against the suspended portion, so that the first angle formed by the extension direction of the transmission component on the pressed side and the first direction remains substantially unchanged. The first direction is the pressure direction in which the transmission component applies pressure to the measuring component. The assist unit of this application is small in size, has high measurement accuracy, and strong anti-interference ability.

Description

Technical Field

[0001] This application relates to the field of electric bicycle technology, and more particularly to an assist unit and an electric bicycle. Background Technology

[0002] A torque sensor is typically installed in the assist unit of an electric bicycle. The torque sensor is used to detect the torque applied by the rider when pedaling in real time. The assist unit dynamically adjusts the amount of assistance based on the torque measured by the torque sensor.

[0003] In related technologies, the elastic element of a torque sensor is typically located on the crankshaft or its drive wheel to detect strain caused by pedaling torque, thereby measuring the user's pedaling torque for dynamic adjustment of the power assist unit. However, this approach increases the radial dimension of the crankshaft or its drive wheel, significantly increasing the size of the power assist unit and hindering its miniaturization. Furthermore, in these technologies, the location of the torque sensor and the position it detects may change constantly, resulting in low measurement accuracy and poor interference resistance. Utility Model Content

[0004] The purpose of this application is to provide a power assist unit and a power assist vehicle that address at least one of the problems mentioned above.

[0005] To achieve the above objectives, in a first aspect, this application provides an assist unit, comprising: a first shaft; an output shaft connected to a power device of the assist unit and disposed substantially parallel to the first shaft; a transmission device for drivingly connecting the first shaft and the output shaft, the transmission device including a transmission member sleeved on the first shaft and the output shaft, including a suspended portion located between the first shaft and the output shaft; and a measuring component disposed substantially along a first direction, for detecting the pressure applied by the transmission member to the measuring component and / or a first parameter corresponding to the pressure, so as to determine the torque of the first shaft; wherein the measuring component is fixed inside the assist unit and pressed against the suspended portion, so that the first angle formed by the extension direction of the side of the transmission member pressed against and the first direction remains substantially unchanged, the first direction being the pressure direction in which the transmission member applies pressure to the measuring component.

[0006] Secondly, this application provides a power-assisted vehicle, including: a vehicle body; and a power-assisting unit according to the above embodiments, wherein the power-assisting unit is connected to the vehicle body.

[0007] In the power assist unit and power-assisted vehicle provided in this application, a measuring component is fixedly installed inside the power assist unit, and the measuring component presses against the transmission component of the transmission device. The measuring component can detect the pressure applied to it by the transmission component, thereby determining the torque of the first shaft. Since the measuring component is located in the suspended portion between the first shaft and the output shaft of the power assist unit, it does not increase the radial dimensions of the first shaft and the output shaft, which is beneficial for the miniaturization design of the power assist unit. Furthermore, because the position of the measuring component is fixed and the first included angle remains approximately constant, the detected pressure applied to it by the transmission component and the torque of the first shaft obtained from it are more accurate and have stronger anti-interference capabilities. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0009] Figure 1 This is one of the structural block diagrams of the assist unit provided in the embodiments of this application; Figure 2 This is a partial structural schematic diagram of the assist unit provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the measuring component pressing against the transmission component in the assist unit provided in the embodiment of this application; Figure 4 This is the second structural block diagram of the assist unit provided in the embodiments of this application; Figure 5 This is a partially exploded view of the assist unit provided in the embodiments of this application; Figure 6 This is one of the structural schematic diagrams of the measurement component of the assist unit provided in the embodiments of this application; Figure 7 This is a second schematic diagram of the structure of the measurement component of the assist unit provided in this application embodiment; Figure 8 This is a structural block diagram of the electric bicycle provided in the embodiments of this application.

[0010] Explanation of icon numbers: 1000: Electric bicycle; a: First direction; 100: Assist unit; 10: First axis; 20: Output shaft; 30: Transmission device; 31: Transmission component; 311: Suspended part; 32: First transmission wheel; 321: First gear; 322: First gear component; 33: Second transmission wheel; 331: Second gear; 332: Second gear component; 40: Measuring component; 401: First included angle; 41: Fixing component; 411: First connecting hole; 42: First wheel; 43: First bracket; 431: Support member; 4311: Support part; 4312: Movable end; 432: Base; 4321: Slide groove; 4322: Sliding sleeve; 44: Connecting shaft; 45: Detection component; 451: Strain gauge; 50: Computing components; 60: Controller; 70: Power unit; 200: Body; 201: Pedal; 202: Drive wheel assembly. Detailed Implementation

[0011] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0012] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0013] It should also be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.

[0014] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0015] In related technologies, the power assist unit places the elastic element of the torque sensor at the crankshaft or its drive wheel. When the user pedals to output torque to the crankshaft, the elastic element of the torque sensor deforms, and the user's pedaling torque is obtained based on the detected strain. Placing the elastic element at the crankshaft or its drive wheel increases the radial dimension of the crankshaft or its drive wheel, requiring additional space to accommodate this increased size. This significantly increases the size of the power assist unit, hindering its miniaturization design. In addition, some related technologies place torque sensors on the drive belt of the power assist unit to obtain the user's pedaling torque by detecting the tension of the drive belt. However, this method relies on the tension pulley of the power assist unit to calculate the tension of the drive belt. During detection, the tension pulley changes position with the drive belt or chain, causing the placement and detection position of the torque sensor to constantly change. This results in low measurement accuracy and poor anti-interference capability of the torque sensor. Other technologies use external torque sensors to detect pressure or tension applied by the user, such as directly detecting the chain pressure between the chainring and the rear wheel to obtain chain tension. However, in this method, chain vibration and chain engagement fluctuations during vigorous riding can affect the accuracy of chain pressure detection. Furthermore, the tension conversion may already include the assist torque of the power assist unit, resulting in low measurement accuracy and poor anti-interference capability.

[0016] To this end, this application provides an assist unit and an assist vehicle that, while meeting the requirements of miniaturization, also ensure that the measuring components have high measurement accuracy and strong anti-interference capability.

[0017] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0018] like Figure 1 As shown in the embodiment of this application, an assistive unit 100 includes a first shaft 10, an output shaft 20, a transmission device 30, and a measuring component 40. The output shaft 20 is connected to the power device 70 of the assistive unit 100 and is arranged substantially parallel to the first shaft 10. The transmission device 30 is used to drive the first shaft 10 and the output shaft 20, and the transmission device 30 includes a transmission element 31. Figure 2 As shown, the transmission component is fitted with a first shaft 10 and an output shaft 20, including a suspended portion 311 located between the first shaft 10 and the output shaft 20. Figure 3As shown, the measuring component 40 is arranged along the first direction a and is used to detect a first parameter corresponding to the pressure applied by the transmission member 31 to the measuring component 40, so as to determine the torque of the first shaft 10. The measuring component 40 is fixed within the assist unit 100 and pressed against the suspended portion 311, so that the first angle formed by the extension direction of the transmission member 31 on the pressed side and the first direction a remains approximately unchanged. The first direction a is the pressure direction in which the transmission member 31 applies pressure to the measuring component 40.

[0019] In the assist unit 100 of this embodiment, a measuring component 40 is fixedly installed inside the assist unit 100. The measuring component 40 presses against the transmission member 31 of the transmission device 30. The measuring component 40 can detect the pressure applied to the measuring component 40 by the transmission member 31 and / or the first parameter corresponding to the pressure, thereby determining the torque of the first shaft 10. Since the measuring component 40 is placed in the suspended portion 311 between the first shaft 10 and the output shaft 20 of the assist unit 100, the radial dimensions of the first shaft 10 and the output shaft 20 are not increased, which is beneficial for the miniaturization design of the assist unit 100. Furthermore, since the position of the measuring component 40 is fixed, the first included angle 401 remains approximately unchanged, resulting in higher measurement accuracy and stronger anti-interference capability. Therefore, this assist unit 100 can meet the requirements of miniaturization design while ensuring that the measuring component 40 has high measurement accuracy and anti-interference capability. Furthermore, since the measuring component is set independently of the first shaft 10, the output shaft 20 and the transmission device 30, it does not need to be connected to the first shaft 10, the output shaft 20 and the transmission device 30 in a complex structure. Therefore, the complexity of the internal structure of the assist unit 100 can be reduced, the number of parts can be reduced, and the cost can be reduced.

[0020] It is understandable that the first shaft 10 can be used to receive externally input torque, which can be the user's pedaling torque. Therefore, the first shaft 10 is generally the crankshaft or bottom bracket of the electric bicycle 1000, and the torque of the first shaft 10 is the user's pedaling torque. Of course, the externally input torque can also be the torque input from other power structures, without limitation. It should be noted that after obtaining the torque of the first shaft 10, that is, obtaining the user's pedaling torque, the user's control intention on the power assist unit 100 can be known, thereby enabling the power assist unit 100 to provide assistance to the user according to the user's pedaling torque. In some embodiments, by detecting the user's pedaling torque, the system can accurately identify the rider's force intensity, thereby reducing assistance when pedaling lightly on flat roads and increasing assistance when pedaling heavily uphill. This dynamic adjustment can avoid the defect of traditional speed sensors that "only look at the rotation speed and not the force," making the assistance more natural and energy-saving. In some embodiments, the torque detected by the first shaft 10, i.e., the user's pedaling torque, can sense the rider's force application intention in real time, avoiding ineffective assistance (such as frequent light pedaling) and prioritizing the allocation of electrical energy to scenarios requiring greater power (such as climbing hills and accelerating). This intelligent allocation can significantly improve range. In some embodiments, detecting the torque of the first shaft 10 helps to instruct the electric bicycle 1000 equipped with the assist unit 100 to trigger the anti-runaway protection mechanism when abnormal pedaling torque (such as sudden hard pedaling) is detected, thus avoiding the risk of loss of control due to excessive assistance.

[0021] The transmission device 30 is used to drively connect the first shaft 10 and the output shaft 20. When the first shaft 10 rotates, torque can be transmitted to the output shaft 20 through the transmission member 31 of the transmission device 30. Since the transmission member 31 is sleeved on the first shaft 10 and the second shaft 20, the torque of the first shaft 10 can be detected through the transmission member 31. It should be noted that since the transmission member of this application constitutes an endless structure, "sleeved" means that the first shaft 10 and the output shaft 20 are both located within the enclosed area formed by the transmission member, and are respectively set on one side close to the transmission member, so that the transmission member can drively connect the first shaft 10 and the output shaft, rather than the transmission member being sleeved on the first shaft alone or the output shaft alone. In some embodiments, the output shaft 20 can receive the torque transmitted by the first shaft 10 through the transmission device 30, and can also receive the torque of the power device 70 to output power to the outside. For example, the output shaft 20 provides propulsion power to the electric bicycle 1000. In some embodiments, the output shaft 20 can apply the user's pedaling torque and the torque provided by the power unit 70 to the rear wheel of the electric bicycle through a chainring, an external chain, etc., so that the electric bicycle 1000 can move forward. Those skilled in the art can also set other feasible embodiments for the torque to be transmitted to the rear wheel as needed, and this application does not limit this.

[0022] In some implementations, combined Figure 2 , Figure 3 As shown, the suspended portion 311 is the part of the transmission member 31 that is suspended during transmission operation. That is, during transmission operation, the transmission member 31 has portions that contact other structures in the transmission device 30, and portions that do not contact other structures in the transmission device 30. The suspended portion 311 is the portion of the transmission member 31 that does not contact other structures in the transmission device 30. The portions of the transmission member 31 that contact other structures in the transmission device 30 can then achieve power transmission. For example, the transmission device 30 includes a first transmission wheel 32 and a second transmission wheel 33, and the suspended portion 311 is the portion of the transmission member 31 that does not contact the first transmission wheel 32 or the second transmission wheel 33.

[0023] Understandably, in order for the suspended portion 311 of the transmission component 31 to be pressed against the measuring component 40 at a certain angle, the transmission component 31 is a non-rigid transmission structure. It can deform when pressed, making it a flexible transmission structure. This flexible transmission structure saves internal space and reduces the complexity of the assist unit 100 structure. Furthermore, since the suspended portion 311 is located between the first shaft 10 and the output shaft 20, and the measuring component 40 is also located between the first shaft 10 and the output shaft 20, which is the space required by the assist unit 100 itself, this space is redundant space within the assist unit 100 and does not increase the spatial dimensions of the assist unit 100.

[0024] like Figure 3As shown, the first direction a is the pressure direction in which the transmission member 31 applies pressure to the measuring component 40 (for example, the pressure direction in which the suspended portion 311 of the transmission member 31 applies pressure to the measuring component 40; more specifically, for example, the pressure direction in which the pressed position of the suspended portion 311 of the transmission member 31 applies pressure to the measuring component 40). The extension direction of the side of the transmission member 31 at the pressed position is the extension direction of the portion of the transmission member 31 at the pressed position that is not in contact with the measuring component 40. This portion is not affected by the shape of the measuring component 40 and can remain approximately unchanged after being pressed. Therefore, when the fixed position of the measuring component 40 remains approximately unchanged, the first angle 401 formed by the extension direction of the side of the transmission member at the pressed position and the first direction a remains approximately unchanged. It can be understood that the extension direction of the side of the transmission member 31 at the pressed position is the tension direction of the transmission member 31, and the first direction a is the pressure direction in which the transmission member 31 (for example, the position on the suspended portion 311 pressed by the measuring component 40) applies pressure to the measuring component 40. It is understood that the pressed position will vary depending on the size of the pre-set first angle 401. For example, when designing the assist unit 100 according to the concept of this application, those skilled in the art can decide on the size of the first angle 401. When the first angle 401 is relatively large, a larger portion of the pressed position will contact the measuring component 40 along the extension direction of the transmission member 31. When the first angle 401 is relatively small, a smaller portion of the pressed position will contact the measuring component 40 along the extension direction of the transmission member 31. It is understood that the transmission member 31 mainly applies pressure to the measuring component 40 by relying on the center point of the pressed position of the transmission member 31, and this pressure can be used to measure the tension of the transmission member 31.

[0025] In some embodiments, the first direction a is substantially perpendicular to the axial direction of the first shaft 10 and the axial direction of the output shaft 20 to ensure that the measuring component 40 can stably press against the suspended portion 311, further improving the measurement accuracy of the measuring component 40 and enhancing its anti-interference capability. The measuring component 40 is generally arranged along the first direction a. It is understood that in some embodiments, the measuring component 40 is arranged along the first direction a and presses against the suspended portion 311; in some embodiments, a small angular deviation, such as ±5°, is allowed between the setting direction of the measuring component 40 and the first direction a.

[0026] like Figure 1As shown, in some embodiments, the assist unit 100 is an integrated device, which also includes a housing (not shown). The first shaft 10 and the output shaft 20 both pass through the housing. The first shaft 10 is rotatable about its axis, and the output shaft 20 is rotatable about its axis. The first shaft 10 and the output shaft 20 are arranged approximately parallel to each other. The positions of the first shaft 10 and the output shaft 20 relative to the housing remain constant. Since the transmission device 30 is connected to the first shaft 10 and the output shaft 20, the position of the transmission device 30 relative to the housing also remains constant. Thus, the positions of the first shaft 10, the output shaft 20, the transmission device 30, and the measuring component 40 relative to the housing remain constant, and the first included angle 401 remains approximately constant. When determining the torque of the first shaft 10 by detecting pressure through the measuring component 40, compared to a measuring structure where the detection position of the measuring component 40 changes constantly, this method has stronger anti-interference capabilities and higher detection accuracy. It is understood that those skilled in the art will know that in order for the assist unit to function properly, the macroscopic relative positions (e.g., the relative distance between their central axes) of the first shaft 10 as a whole and the output shaft 20 as a whole relative to the assist unit 100 or the housing of the assist unit 100 must remain unchanged, and the rotation of the first shaft 10 or the output shaft 20 relative to the assist unit 100 will not cause the position of the first shaft 10 or the output shaft 20 relative to the assist unit 100 to change.

[0027] like Figure 1 As shown, in some embodiments, the assist unit 100 further includes a calculation component 50, which is used to determine the tension of the transmission member 31, especially the tension at the pressed position of the transmission member 31, by measuring the pressure detected by the measuring component 40, and to determine the torque of the first shaft 10 based on the tension. The torque of the first shaft 10 can be quickly obtained through the calculation component 50, and the assist unit 100 can then adjust the assist magnitude according to the torque of the first shaft 10. In some embodiments, the torque of the first shaft 10 can also be obtained using a first parameter corresponding to the pressure detected by the measuring component 40. For example, the first parameter corresponding to the pressure is related to the pressure. For example, the first parameter corresponding to the pressure is an electrical signal corresponding to the pressure, or a change in resistance, magnetic flux, optical path, micro-displacement, or deformation corresponding to the pressure, etc. This application does not limit this. Preferably, the first parameter is an electrical signal corresponding to the pressure.

[0028] The tension at the pressed position of the transmission component 31 is the same as the tension at the taut position. With the first included angle 401 unchanged, the pressure detected by the measuring component 40 is positively correlated with the tension at the pressed position of the transmission component 31, and the tension at the pressed position of the transmission component 31 is also positively correlated with the torque of the first shaft 10. Thus, after the measuring component 40 detects the pressure, the torque of the first shaft 10 can be calculated using the function relationship set by the calculation component 50.

[0029] In some embodiments, the torque of the first shaft 10 is ,in, The tension of the transmission component 31 being pressed against one side. The tension on the side of the suspended portion 311 of the transmission component 31 that is not pressed against remains approximately constant and is considered a fixed value. The radius of the transmission wheel connected to the transmission component 31 on one side of the first shaft 10 is, for example, Let be the radius of the first transmission wheel 32, which is a definite value. In the above relationship, the tension of the transmission member 31 pressed against one side... ,in, To measure the pressure detected by component 40, The first included angle is 40°. Therefore, the torque of the first shaft 10 can be obtained. It can be determined that the torque of the first shaft 10... and the pressure detected by the measuring component 40 The relationship is a linear function; the measuring component 40 obtains the pressure by detection. Then, the torque of the first shaft 10 can be calculated using this formula. The calculation component 50 can set this functional relationship in the processor. After the measuring component 40 detects the pressure, the torque of the first shaft 10 can be calculated through the functional relationship set by the calculation component 50.

[0030] In some embodiments, the assist unit 100 further includes a calculation component 50, which is used to obtain the torque of the first shaft 10 based on a first preset relationship and the pressure detected by the measuring component 40. In some embodiments, the first preset relationship can be obtained by calibration, which characterizes the relationship between the pressure measured by the measuring component 40 and the torque of the first shaft 10. Specifically, when the measuring component 40 detects pressure, it applies different torques to the first shaft 10, resulting in different pressures detected by the measuring component 40. The torque of the first shaft 10 and the recorded pressure detected by the measuring component 40 are calibrated. After calibration, these data are fitted into a first preset relationship. The calculation component 50 can set this first preset relationship in the processor. After the measuring component 40 detects pressure, the torque of the first shaft 10 can be calculated using the first preset relationship set by the calculation component 50.

[0031] In some embodiments, the assist unit 100 further includes a calculation component 50, which is used to obtain the torque of the first shaft 10 based on a first preset relationship and a first parameter corresponding to the pressure detected by the measuring component 40. The first preset relationship can be obtained through calibration, and it characterizes the relationship between the first parameter corresponding to the pressure measured by the measuring component 40 and the torque of the first shaft 10. Specifically, the measuring component 40 generates a first parameter during pressure detection. By applying different torques to the first shaft 10, the measuring component 40 generates corresponding first parameters. The torque of the first shaft 10 and the recorded first parameters of the measuring component 40 are calibrated. After calibration, these data are fitted into a first preset relationship. The calculation component 50 can set this first preset relationship in the processor. After the measuring component 40 detects pressure and generates the corresponding first parameter, the torque of the first shaft 10 can be calculated using the first preset relationship set by the calculation component 50. It is understood that in embodiments where the first parameter is an electrical signal corresponding to pressure, the pressure may not be calculated; only the first parameter may be measured and then combined with the first preset relationship (the mapping relationship between the first parameter and the torque of the first shaft) to obtain the torque of the first shaft. Here, the term "electrical signal corresponding to pressure" is used to indicate that the first parameter is a pressure-related value.

[0032] like Figure 1 As shown, in some embodiments, the assist unit 100 further includes a controller 60. The controller 60 is the core control component of the assist unit 100 and can control the power output according to the torque of the first shaft 10 to adjust the assist size.

[0033] like Figure 4 As shown, in some embodiments, the calculation component 50 is disposed within the measurement component 40. That is, after the measurement component 40 detects pressure or a first parameter corresponding to the pressure, it can calculate the torque of the first shaft 10 through the built-in calculation component 50. The measurement component 40 can then send the torque information to the controller 60, which controls the adjustment of the assist magnitude.

[0034] like Figure 1 As shown, in some embodiments, the calculation component 50 is disposed outside the measurement component 40. That is, after the measurement component 40 detects pressure or a first parameter corresponding to the pressure, it can send the corresponding pressure information or the first parameter corresponding to the pressure to the calculation component 50. The calculation component 50 calculates the torque of the first shaft 10, and then sends the torque information to the controller 60, which controls the adjustment of the assist level. Exemplarily, the calculation component 50 can be integrated into the controller 60. After the controller 60 calculates the torque of the first shaft 10, it can control the power output to adjust the assist level.

[0035] For example, the computing component 50 and the measuring component can be electrically connected or wirelessly connected to achieve a communication connection between them, thereby enabling information transmission.

[0036] like Figure 3 As shown, in some embodiments, the first included angle 401 ranges from 45° to 85°. The first included angle 401 can be selected from a preset angle range to ensure that the measuring component 40 stably presses against the suspended portion 311 of the transmission component 31. The transmission component 31 is in a tensioned state at the pressed position, and the first included angle 401 is a roughly constant angle. This results in higher detection accuracy and stronger anti-interference capability for the measuring component 40. It should be noted that "the first included angle 401 is roughly constant" means that it remains unchanged during the process of designing the assist unit and using it to measure torque. Those skilled in the art can also determine whether the first included angle 401 remains constant by observing whether the measuring component is fixedly installed on the assist unit.

[0037] For example, but not restrictively, the first included angle 401 is a range of values ​​of 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, or any two of these values.

[0038] In some embodiments, the first included angle 401 is an acute angle. When the measuring component 40 presses against the transmission member 31, the suspended portion 311 of the transmission member 31 deforms, so that the first included angle 401 can form an acute angle. In this way, the measuring component 40 can occupy part of the space originally occupied by the transmission member 31, so as to avoid increasing the space size of the assist unit 100, which is conducive to the miniaturization of the assist unit 100. In addition, based on the miniaturization, the assist and speed change functions of the assist unit can be integrated together, which is helpful for the integrated design of the assist unit.

[0039] like Figure 2 As shown, in some embodiments, the transmission component includes a flexible transmission component, for example, transmission component 31 includes a synchronous belt, belt, or chain. Synchronous belts, belts, and chains are all flexible transmission structures. When the torque of the first shaft 10 is transmitted to the output shaft 20 via the synchronous belt, belt, or chain, it can ensure that the first shaft 10 and the output shaft 20 rotate synchronously. Compared to a rigid transmission structure, this design is simpler and reduces the space required, facilitating the placement of the measuring component 40 using redundant space. Specifically, if the transmission component 31 is a rigid structure, such as a gear set, at least two gears are needed to achieve synchronous rotation of the first shaft 10 and the output shaft 20, inevitably requiring more space and increasing structural complexity. Furthermore, the synchronous belt, belt, or chain can be pressed against the measuring component 40, allowing it to deform after being pressed. The measuring component 40 can then occupy the space originally occupied by the synchronous belt, belt, or chain, avoiding additional space requirements for the assist unit 100.

[0040] like Figure 2 As shown, in some embodiments, the measuring component 40 is located on the outer side of the transmission member 31 along the radial direction of the first shaft 10. It should be noted that the transmission member 31 is an endless structure. The inner side of the transmission member 31 refers to the area enclosed by the transmission member 31, and the outer side refers to the area outside the area enclosed by the transmission member 31. Specifically, the area referred to here is the area of ​​the transmission member 31 along the radial direction of the first shaft 10. For example, the first shaft 10 and the output shaft 20 are located on the inner side of the transmission member 31. When the transmission member 31 is not deformed, its inner side has redundant space. Specifically, there is redundant space between the suspended portions 311 on both sides of the transmission member 31 and the first transmission wheel 32 and the second transmission wheel 33. By positioning the measuring component 40 on the outside of the transmission member 31, the transmission member 31 can deform inward when pressed against the measuring component 40. This allows the measuring component 40 to occupy the redundant space inside the transmission member 31 when it is not deformed, thus avoiding the need to increase the spatial dimensions of the assist unit 100 and facilitating its miniaturization and integrated design. Furthermore, positioning the measuring component 40 on the outside of the transmission member 31 also facilitates its fixed connection with the housing of the assist unit 100, reducing the structural complexity of the assist unit 100.

[0041] In some other embodiments, the measuring component 40 is located on the inner side of the transmission member 31 along the radial direction of the first axis 10. By placing the measuring component 40 on the inner side of the transmission member 31, the measuring component 40 can directly occupy the redundant space on the inner side of the transmission member 31, thus avoiding the need to increase the space size of the assist unit 100, which is beneficial for the miniaturization and integrated design of the assist unit 100.

[0042] like Figure 3 As shown, in some embodiments, the measuring component 40 includes a fixing component 41 and a detection component 45. The fixing component 41 is fixedly disposed with the housing of the assist unit 100 and presses against the suspended portion 311. The detection component 45 is disposed on the fixing component 41 and is used to detect the pressure applied to the fixing component 41 by the transmission member 31. By fixing the fixing component 41 with the housing and pressing it against the suspended portion 311, it can ensure that the first included angle 401 is a relatively constant angle. When determining the torque of the first shaft 10 by detecting the pressure through the detection component 45, it can ensure high measurement accuracy and strong anti-interference ability.

[0043] like Figure 2 As shown, in some embodiments, the fixing component 41 is provided with a first connecting hole 411, the housing is provided with a second connecting hole (not shown), and the fastener (not shown) connects the first connecting hole 411 and the second connecting hole to stably fix the fixing component 41 inside the housing.

[0044] For example, the first connecting hole is a through hole 411, the second connecting hole is a threaded hole, the fastener is a fastening screw, the fastening screw passes through the first connecting hole 411 and is fastened to the second connecting hole.

[0045] For example, both the first connecting hole 411 and the second connecting hole extend along the axial direction of the first shaft 10. When the fastener connects the first connecting hole and the second connecting hole, it securely connects the fixing component 41 and the housing along the axial direction of the first shaft 10. In this way, the fixing component 41 can achieve a fixed connection with the housing whenever it is positioned according to design requirements. Preferably, the fixing component 41 is located on the outer side of the transmission member 31 in the radial direction of the first shaft 10, the inner wall of the housing has a connecting portion (not shown), the connecting portion and the fixing component 41 are arranged along the axial direction of the first shaft 10, the second connecting hole is located in the connecting portion, and the fastener connects the first connecting hole 411 and the second connecting hole to securely connect the fixing component 41 and the connecting portion.

[0046] In other examples, the first and second connecting holes may also extend in a direction substantially perpendicular to the axial direction of the first shaft 10. The fixing component 41 is disposed on the outer side of the transmission member 31 in the radial direction of the first shaft 10 to abut against the housing, and fasteners can connect the first and second connecting holes.

[0047] like Figure 3 As shown, in some embodiments, the fixing component 41 includes a first bracket 43 and a first wheel 42. The first bracket 43 is fixedly disposed with the housing of the assist unit 100, and the first wheel 42 is rotatably connected to the first bracket 43 and presses against the suspended portion 311. The detection component 45 is disposed on the first bracket 43. When the user applies torque to the first shaft 10, the torque of the first shaft 10 can be transmitted to the output shaft 20 through the transmission device 30. The transmission component 31 will move around the first shaft 10 and the output shaft 20 as the first shaft 10 rotates to transmit torque. Since the first wheel 42 can rotate relative to the first bracket 43 and presses against the suspended portion 311, the first wheel 42 will rotate with the transmission component 31 when it moves, ensuring that the transmission component 31 can smoothly transmit torque and avoiding interference from the measuring component 40 to the operation of the transmission component 31.

[0048] For example, the transmission component 31 is a belt or a timing belt, and the measuring component 40 is located on the outer side of the transmission component 31 in the radial direction along the first shaft 10. The first wheel 42 is a flat pulley, which is used to contact the outer surface of the timing belt. Under the action of friction, the first wheel 42 will rotate as the transmission component 31 moves.

[0049] For example, the transmission member 31 is a synchronous belt, and the measuring component 40 is located on the inner side of the transmission member 31 in the radial direction along the first shaft 10. The first wheel 42 is a toothed wheel, which is used to contact the inner surface of the synchronous belt and mesh with the teeth on the inner side of the synchronous belt. The first wheel 42 rotates as the transmission member 31 moves.

[0050] For example, the transmission component 31 is a chain, and the first wheel 42 is a toothed wheel that meshes with the tooth grooves of the chain. The first wheel 42 rotates as the transmission component 31 moves.

[0051] like Figure 5 As shown, in some embodiments, the first bracket 43 includes a support member 431, which has two spaced-apart support portions 4311. A first wheel 42 is disposed between the two support portions 4311, and both sides of the first wheel 42 are rotatably connected to the two support portions 4311 respectively. It should be noted that the support portions 4311 extend radially along the first shaft 10, and the two sides of the first wheel 42 are axially aligned along the first shaft 10. The two support portions 4311 are spaced apart along the axial direction of the first shaft 10 and are arranged approximately parallel, so that when the first wheel 42 is placed between the two support portions 4311, it can rotate with the movement of the transmission member 31. The two support portions 4311 stably support the first wheel 42, enabling it to rotate stably. A portion of the first wheel 42 extends out of the two support portions 4311 so that it can press against the transmission member 31 and rotate with the movement of the transmission member 31.

[0052] For example, the first bracket 43 further includes a connecting shaft 44, both support portions 4311 are provided with a third connecting hole (not shown), and the first wheel 42 is provided with a fourth connecting hole (not shown). The connecting shaft 44 passes through the third connecting hole and the fourth connecting hole of the two support portions 4311. The first wheel 42 can rotate relative to the support member 431 through the connecting shaft 44.

[0053] In some other examples, each support portion 4311 has a support post (not shown) protruding toward the other support portion 4311, and the first wheel 42 is provided with fifth connecting holes (not shown) on both sides. The support posts of the two support portions 4311 are respectively placed in the fifth connecting holes on both sides of the first wheel 42 to realize the rotational connection of the first wheel 42 relative to the support member 431.

[0054] like Figure 6As shown, in some embodiments, the detection component 45 includes a strain gauge 451 disposed on the support portion 4311 to detect the deformation of the support portion 4311. The support portion 4311 serves as a structure to support the rotation of the first wheel 42. When the first wheel 42 is subjected to pressure applied by the transmission member 31, the pressure is transmitted to the support portion 4311. Since the support portion 4311 extends radially along the first shaft 10, it also undergoes slight deformation under pressure. The strain gauge 451 deforms along with the deformation of the support portion 4311, resulting in a significant change in the resistivity of the strain gauge 451. The detection component 45 can then convert the resistance change into a voltage signal output through a Wheatstone bridge circuit. This detection component 45 has a simple configuration, simplifying the structure of the measurement component 40 and reducing the overall cost of the assist unit 100.

[0055] For example, strain gauge 451 is disposed on the side of support portion 4311 away from transmission member 31. Furthermore, support portion 4311 has a position corresponding to the rotation center of first wheel 42, and strain gauge 451 is located on the side of this position away from transmission member 31. Thus, when support portion 4311 is subjected to force, strain gauge can undergo more significant deformation, thereby improving detection sensitivity.

[0056] like Figure 7 As shown, in some embodiments, the first support 43 further includes a base 432, which is fixedly disposed with the housing of the assist unit 100. The support member 431 has a movable end 4312 away from the support portion 4311, which is slidably connected to the base 432. The detection component 45 is disposed on the base 432 and configured to face the movable end 4312. When the first wheel 42 is subjected to pressure applied by the transmission member 31, the pressure is transmitted to the support member 431. Since the base 432 and the movable end 4312 of the support portion 4311 can slide relative to each other, the movable end 4312 of the support member 431 can therefore undergo a slight displacement relative to the base 432. The detection component 45 detects this slight displacement to detect the pressure. This pressure detection method is accurate and has strong anti-interference ability. It should be noted that the support member 431 only undergoes a slight displacement relative to the base 432, and the overall position of the fixing component 41 does not change significantly. When the fixing component 41 presses against the suspended part 311 of the transmission member 31, the angle of the first included angle 401 remains approximately unchanged. Therefore, when the measuring component 40 determines the torque of the first shaft 10 by detecting the pressure, the detection accuracy is higher and the anti-interference ability is stronger.

[0057] For example, the movable end 4312 is centered on the two support portions 4311 of the support member 431. In this way, the first wheel 42 and the movable end 4312 are spaced apart along the direction of the pressure. When the first wheel 42 is subjected to pressure by the transmission member 31, the movable end 4312 slides relative to the base 432 along the direction of the pressure. This makes the pressure detected by the detection component 45 more accurate and further improves the detection accuracy.

[0058] For example, the base 432 is provided with a groove 4321, the bottom of the groove 4321 is provided with a detection component 45, the side wall of the groove 4321 is provided with a sliding sleeve 4322, the movable end 4312 and the sliding sleeve 4322 are slidably connected, the end of the movable end 4312 away from the first wheel 42 contacts the detection component 45, when the movable end 4312 slides relative to the sliding sleeve 4322, the detection component 45 will detect the pressure through the small displacement of the movable end 4312.

[0059] For example, the base 432 and the outer shell are fixedly connected. The specific connection method can be referred to the connection method between the aforementioned fixing component 41 and the outer shell, which will not be repeated here.

[0060] In some embodiments, the detection component 45 includes at least one of the following: a strain gauge pressure sensor, a capacitive pressure sensor, an electromagnetic sensor, a laser sensor, or a piezoelectric sensor. In this application, the detection component 45 may be configured with one or more of the above, as long as accurate pressure detection is achieved.

[0061] In a strain gauge pressure sensor, there are metal or semiconductor strain gauges that are attached or integrated onto an elastic element. When the elastic element is subjected to pressure, it will deform (strain), and the strain gauges on it will deform accordingly, causing a significant change in its resistivity. The pressure sensor can then convert the resistance change into a voltage signal and output it through a Wheatstone bridge circuit.

[0062] like Figure 6 As shown, for example, the detection component 45 is a strain gauge pressure sensor. The strain gauge 451 of the strain gauge pressure sensor is disposed on the support portion 4311. The strain gauge deforms with the deformation of the support portion 4311, thereby generating a corresponding electrical signal to detect pressure.

[0063] For example, the detection component 45 is a strain gauge pressure sensor. The strain gauge of the strain gauge pressure sensor is disposed on the base 432 and is in direct or indirect contact with the end of the movable end 4312. The strain gauge deforms as the movable end 4312 is displaced, thereby generating a corresponding electrical signal to detect pressure.

[0064] A capacitive pressure sensor includes a variable capacitor, which typically consists of two parallel electrode plates, one of which is a pressurized, movable elastic diaphragm. When pressure is applied to the diaphragm, it displaces (deforms), causing a change in the distance between the two electrode plates, which in turn causes a change in the capacitance between them. The capacitance value is then converted into an electrical signal by a measuring circuit.

[0065] For example, the detection component 45 is a capacitive pressure sensor. The capacitive pressure sensor is disposed on the base 432, and its elastic diaphragm and the end of the movable end 4312 are in direct or indirect contact. The elastic diaphragm is displaced (deformed) as the movable end 4312 is displaced, thereby generating a corresponding electrical signal to detect pressure.

[0066] Electromagnetic sensors include a movable iron core or magnet, which is attached or integrated onto an elastic element. When the elastic element is subjected to pressure, it deforms, and the iron core or magnet on it moves accordingly, thereby changing the magnetic field or magnetic circuit, causing a change in voltage or inductance, which is then converted into an electrical signal and output.

[0067] For example, the detection component 45 is an electromagnetic sensor. The iron core or magnet of the electromagnetic sensor is disposed on the support portion 4311. The iron core or magnet deforms with the deformation of the support portion 4311, thereby generating a corresponding electrical signal to detect pressure.

[0068] For example, the detection component 45 is an electromagnetic sensor. The iron core or magnet of the electromagnetic sensor is disposed on the base 432 and is in direct or indirect contact with the end of the movable end 4312. The iron core or magnet deforms as the movable end 4312 is displaced, thereby generating a corresponding electrical signal to detect pressure.

[0069] In laser sensors, the principle of laser interference is used to measure the minute displacement produced when an elastic element is compressed, and then convert it into an electrical signal to calculate the pressure.

[0070] For example, the detection component 45 is a laser sensor, which is disposed on the base 432. Its measuring beam is positioned toward the movable end 4312, and the laser sensor measures the displacement caused by the light speed passing through the movable end 4312, thereby generating a corresponding electrical signal to detect pressure.

[0071] In a piezoelectric sensor, a piezoelectric material is included. When the piezoelectric material is subjected to pressure, polarization occurs inside it, and opposite charges are generated on two opposing surfaces of the material. The amount of charge is proportional to the applied pressure. The pressure can be calculated by outputting an electrical signal (charge signal).

[0072] For example, the detection component 45 is a piezoelectric sensor. The piezoelectric sensor is disposed on the base 432, and its piezoelectric material is in direct or indirect contact with the end of the movable end 4312. The piezoelectric material generates a corresponding electrical signal according to the magnitude of the charge to detect pressure.

[0073] like Figure 1 As shown, in some embodiments, the transmission device 30 includes a first transmission wheel 32 and a second transmission wheel 33. The first transmission wheel 32 is connected to the first shaft 10, and the second transmission wheel 33 is connected to the output shaft 20. A transmission member 31 connects the first transmission wheel 32 and the second transmission wheel 33. When the user applies pedal torque, the first shaft 10 rotates accordingly, and the first transmission wheel 32 rotates with the rotation of the first shaft 10. The first transmission wheel 32 then transmits the torque to the second transmission wheel 33 through the transmission member 31, and the second transmission wheel 33 can then transmit the torque to the output shaft 20, which can then output power.

[0074] For example, the first transmission wheel 32 is sleeved on the first shaft 10, and the second transmission wheel 33 is sleeved on the output shaft 20. In this way, on the one hand, a stable transmission connection between the first shaft 10 and the output shaft 20 can be ensured, and on the other hand, no extra space is required for setting the first transmission wheel 32 and the second transmission wheel 33, ensuring that the power assist unit 1000 can achieve a miniaturized design.

[0075] like Figure 2 As shown, in some embodiments, the first transmission wheel 32 is provided with a first stop member 321. The first stop member 321 is used to prevent the transmission member 31 from disengaging from the first transmission wheel 32 along the axial direction of the first shaft 10. The first stop member 321 can ensure a stable connection between the transmission member 31 and the first transmission wheel 32, ensuring stable torque transmission. Furthermore, it can also ensure that the position of the transmission member 31 remains approximately unchanged. When the measuring component 40 detects pressure to determine the torque of the first shaft 10, the detection accuracy is higher and the anti-interference ability is stronger.

[0076] For example, the first stop member 321 is a protruding ring of the first transmission wheel 32 to prevent the transmission member 31 from disengaging from the first transmission wheel 32. like Figure 2 As shown, in some embodiments, the second transmission wheel 33 is provided with a second stop member 331. The second stop member 331 is used to prevent the transmission member 31 from disengaging from the second transmission wheel 33 along the axial direction of the output shaft 20. The second stop member 331 ensures a stable connection between the transmission member 31 and the second transmission wheel 33, ensuring stable torque transmission. Furthermore, it also ensures that the position of the transmission member 31 remains approximately unchanged, resulting in higher detection accuracy and stronger anti-interference capability when the measuring component 40 detects pressure to determine the torque of the first shaft 10.

[0077] For example, the first stop member 321 is a protruding ring of the second transmission wheel 33 to prevent the transmission member 31 from disengaging from the second transmission wheel 33.

[0078] In some embodiments, the first stop members 321 are respectively disposed on both sides of the first transmission wheel 32 along the axial direction of the first shaft 10. In this way, the first stop members 321 on the first transmission wheel 32 can prevent the transmission member 31 from disengaging from either side of the first transmission wheel 32 along the axial direction of the first shaft 10, thereby further improving the stability of the connection between the transmission member 31 and the first transmission wheel 32.

[0079] In some embodiments, the second stop members 331 are respectively disposed on both sides of the second transmission wheel 33 along the axial direction of the output shaft 20. In this way, the second stop members 331 on the second transmission wheel 33 can prevent the transmission member 31 from disengaging from either side of the second transmission wheel 33 along the axial direction of the output shaft 20, thereby further improving the stability of the connection between the transmission member 31 and the second transmission wheel 33.

[0080] like Figure 2 As shown, in some embodiments, the first stop member 321 is disposed on one side of the first transmission wheel 32 along the axial direction of the first shaft 10, and the second stop member 331 is disposed on the other side of the second transmission wheel 33 along the axial direction of the first shaft 10. Thus, by combining the first stop member 321 and the second stop member 331, the transmission member 31 can be prevented from disengaging from the first transmission wheel 32 on either side of the axial direction of the first shaft 10, and the transmission member 31 can be prevented from disengaging from the second transmission wheel 33 on either side of the axial direction of the output shaft 20, further improving the stability of the connection between the transmission member 31 and the first and second transmission wheels 32 and 33. Furthermore, compared to the structure of placing the first stop member 321 on both sides of the first transmission wheel 32 and the structure of placing the second stop member 331 on both sides of the second transmission wheel 33, this arrangement avoids the need for additional structures to occupy space in the assist unit 100, which is beneficial for the miniaturization design of the assist unit 100.

[0081] like Figure 2 As shown, in some embodiments, the first transmission wheel 32 is provided with a first toothed component 322, the second transmission wheel 33 is provided with a second toothed component 332, and the transmission member 31 is provided with a third toothed component (not shown) on its inner side along the radial direction of the first shaft 10. The third toothed component meshes with the first toothed component 322, and the third toothed component meshes with the second toothed component 332. Compared to the method of transmitting torque solely through friction, transmitting torque through the meshing between toothed components ensures that the torque of the first shaft 10 can be stably transmitted to the output shaft 20.

[0082] In some embodiments, the number of teeth of the first toothed component 322 of the first transmission wheel 32 and the number of teeth of the second toothed component 332 of the second transmission wheel 33 can be designed according to requirements to adjust the transmission ratio and the user's pedaling force. For example, the number of teeth of the first toothed component 322 of the first transmission wheel 32 is greater than the number of teeth of the second toothed component 332 of the second transmission wheel 33.

[0083] like Figure 1 As shown, in some embodiments, the assist unit 100 further includes a power device 70, which is drive-connected to the output shaft 20. The power device 70 can provide additional torque to the output shaft 20. In practical use, in addition to receiving torque from the first shaft 10 via the transmission device 30, the output shaft 20 can also transmit torque to itself via the power device 70, thereby providing additional power to the output shaft 20 and achieving output assistance. Exemplarily, the power device 70 includes a motor.

[0084] like Figure 8 As shown in the embodiments of this application, an electric bicycle 1000 is also provided, including a frame 200 and an assist unit 100. The assist unit 100 is connected to the frame 200. The electric bicycle 1000 can achieve assisted riding through the assist unit 100.

[0085] In this embodiment, since the measuring component 40 is placed in the suspended portion 311 between the first shaft 10 and the output shaft 20 of the assist unit 100, the radial dimensions of the first shaft 10 and the output shaft 20 are not increased, which is beneficial for the miniaturization design of the assist unit 100. When the assist unit 100 is applied to the electric bicycle 1000, its space occupation on the body 200 of the electric bicycle 1000 can be reduced, thus making it easier to place the assist unit 100 in different positions on the body 200. Furthermore, the small size of the assist unit 100 also means that the assist unit 100 is lighter, which can also reduce the overall weight of the electric bicycle 1000. In this way, the stability and handling of the electric bicycle 1000 can be improved.

[0086] In some embodiments, the first shaft 10 of the assist unit 100 is connected to the pedal 201, and the output shaft 20 of the assist unit 100 is connected to the drive wheel set 202. When the user presses the pedal 200, torque can be transmitted to the first shaft 10, which in turn transmits torque to the output shaft 20 via the transmission device 30. The measuring component 40 can determine the torque of the first shaft 10, i.e., the user's pedaling torque, by detecting the pressure applied by the transmission component 31. The controller 60 within the assist unit 100 can then determine the additional torque required based on the torque of the first shaft 10. The controller 60 controls the power device 70 to provide additional torque to the output shaft 20, so that the total torque provided by the output shaft 20 to the drive wheel set 202 can meet the travel requirements.

[0087] In a more specific embodiment: a pressure measurement module (sensor (e.g., strain gauge pressure sensor, capacitive pressure sensor, electromagnetic sensor, laser sensor, or piezoelectric sensor) or strain gauge 451) is provided on the belt or timing belt (e.g., transmission component 31). The pressure measurement module can be a pressure sensor (e.g., strain gauge pressure sensor, capacitive pressure sensor, electromagnetic sensor, laser sensor, or piezoelectric sensor) or strain gauge 451, capable of measuring the pressure applied to the pressure measurement module by the belt or timing belt (deformation of the idler pulley (e.g., first pulley 42), bracket (e.g., first bracket 44), or strain gauge 451). This pressure is converted into the tension of the belt or timing belt, and then the torque of the crankshaft (e.g., first shaft 10) is obtained through this tension. The measured torque is more direct and has stronger anti-interference ability. In addition, a pressure sensor is added at the idler pulley of the belt drive to achieve a simpler structural stacking. Due to the reduction in the number of parts, the cost is also reduced accordingly. It should be noted that the idler pulley in this embodiment is a driven pulley and is not used to change the transmission ratio of the transmission component, nor does it change the position of the transmission component. It is neither a tensioning wheel nor a guide wheel in the relevant technology.

[0088] The above description is merely a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the content of this application's specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A power assist unit, characterized in that, include: First axis; The output shaft is connected to the power unit of the assist unit and is arranged approximately parallel to the first shaft; A transmission device for drivingly connecting the first shaft and the output shaft, the transmission device including a transmission component, the transmission component being sleeved on the first shaft and the output shaft, including a suspended portion located between the first shaft and the output shaft; as well as A measuring component, generally arranged along a first direction, is used to detect the pressure applied by the transmission member to the measuring component and / or a first parameter corresponding to the pressure, so as to determine the torque of the first shaft; wherein, The measuring component is fixed inside the assist unit and pressed against the suspended part, so that the first angle formed by the extension direction of the pressed side of the transmission member and the first direction remains approximately unchanged, where the first direction is the pressure direction in which the transmission member applies pressure to the measuring component.

2. The assist unit as described in claim 1, characterized in that, The assist unit also includes a calculation component, which is used to determine the tension of the transmission component by means of the pressure detected by the measurement component, and to determine the torque of the first shaft based on the tension. And / or, The calculation component is used to obtain the torque of the first shaft according to the first preset relationship and the pressure detected by the measurement component, and / or to obtain the torque of the first shaft according to the first parameter corresponding to the pressure detected by the measurement component and the first preset relationship.

3. The assist unit as described in claim 1, characterized in that, The first included angle is in the range of 45°-85°.

4. The assist unit as described in claim 1, characterized in that, The transmission component includes a flexible transmission component.

5. The assist unit as described in claim 1, characterized in that, The measuring component includes a fixing component and a detection component. The fixing component is fixedly disposed with the housing of the assist unit and presses against the suspended part. The detection component is disposed on the fixing component and is used to detect the pressure applied to the fixing component by the transmission component.

6. The assist unit as described in claim 5, characterized in that, The fixing component includes a first bracket and a first wheel. The first bracket is fixedly disposed to the housing of the assist unit. The first wheel is rotatably connected to the first bracket and presses against the suspended part. The detection component is disposed on the first bracket.

7. The assist unit as described in claim 6, characterized in that, The first bracket includes a support member, which has two spaced-apart support portions. The first wheel is located between the two support portions, and both sides of the first wheel are rotatably connected to the two support portions respectively.

8. The assist unit as described in claim 7, characterized in that, The detection component includes a strain gauge disposed on the support portion to detect the deformation of the support portion.

9. The assist unit as described in claim 7, characterized in that, The first bracket further includes a base, which is fixedly disposed with the housing of the assist unit. The support member has a movable end away from the support portion, which is slidably connected to the base. The detection component is disposed on the base and configured to face the movable end.

10. The assist unit as described in claim 5, characterized in that, The detection component includes at least one of the following: a pressure sensor, a resistance sensor, an electromagnetic sensor, a laser sensor, or a piezoelectric sensor.

11. The assist unit as described in claim 1, characterized in that, The measuring component is located on the outer side of the transmission member in the radial direction along the first axis.

12. The assist unit as described in claim 1, characterized in that, The transmission device includes a first transmission wheel and a second transmission wheel. The first transmission wheel is connected to the first shaft, and the second transmission wheel is connected to the output shaft. The transmission component connects the first transmission wheel and the second transmission wheel.

13. The assist unit as described in claim 12, characterized in that, The first transmission wheel is provided with a first stop, which is used to prevent the transmission member from disengaging from the first transmission wheel along the axial direction of the first shaft, and / or the second transmission wheel is provided with a second stop, which is used to prevent the transmission member from disengaging from the second transmission wheel along the axial direction of the output shaft.

14. The assist unit as described in claim 12, characterized in that, The first transmission wheel is provided with a first tooth component, the second transmission wheel is provided with a second tooth component, and the transmission component is provided with a third tooth component on its inner side along the radial direction of the first axis. The third tooth component meshes with the first tooth component and the second tooth component.

15. A power-assisted bicycle, characterized in that, include: Body; as well as The power assist unit as described in any one of claims 1 to 14, wherein the power assist unit is connected to the vehicle body.

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