Middle motor for bicycle and bicycle

Abstract

The invention relates to a middle motor (100) used for a bicycle and the bicycle, the middle motor (100) used for the bicycle comprises a machine shell (10), a motor body and a detection device (40), the motor body is arranged in the machine shell (10) and is configured to output first torque used for assisting the bicycle, the motor body comprises a driving part and an output part (20), and the detection device (40) is arranged in the machine shell (10) and is configured to output first torque used for assisting the bicycle. The driving part is configured to drive the output part (20) to rotate relative to the machine shell (10), and the output part (20) is used for being connected with a crank set (30) of the bicycle so as to transmit first torque to the crank set (30); the detection device (40) is fixedly connected to the machine shell (10), the detection device (40) and the output part (20) can be installed on the output part (20) in a relative rotation mode, and the detection device (40) is configured to detect the magnitude of second torque applied to the output part (20) by the crank set (30). The bicycle comprises the middle motor (100) for the bicycle.

Description

Technical Field

[0001] The invention relates to the technical field of bicycles, and in particular to a mid-mounted motor for a bicycle and a bicycle. Background Art

[0002] The mid-mounted motor is one of the important power systems of electric power-assisted bicycles. It is installed near the middle of the vehicle and can transmit power efficiently. The mid-mounted motor is usually used in conjunction with a torque sensor, which senses the rider's pedaling force and adjusts the power level of the mid-mounted motor. The torque sensor and the mid-mounted motor in the related technology are installed separately on the power system of the bicycle, which has problems such as complex structure, heavy weight, and large installation space, which brings challenges to the design, production and daily use of electric power-assisted bicycles.

[0003] It should be noted that the information disclosed in the background technology section of the present invention is only intended to increase the understanding of the overall background of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0004] The present invention provides a mid-mounted motor for a bicycle and a bicycle. A torque detection device is integrated into the mid-mounted motor, which helps to achieve a compact and lightweight design of the bicycle.

[0005] According to one aspect of the present invention, there is provided a mid-mounted motor for a bicycle, comprising:

[0006] chassis;

[0007] a motor body, disposed in the housing, configured to output a first torque for assisting the bicycle, the motor body comprising a driving part and an output part, the driving part being configured to drive the output part to rotate relative to the housing, the output part being used to connect to a crank set of the bicycle to transmit the first torque to the crank set; and

[0008] The detection device is fixedly connected to the housing and is mounted on the output part so as to be rotatable relative to the output part. The detection device is configured to detect the magnitude of the second torque applied by the crank group to the output part.

[0009] In some embodiments, the mid-mounted motor for a bicycle further includes a control device, which is signal-connected to the motor body and the detection device, and is configured to control the magnitude of the first torque output by the motor body according to the magnitude of the second torque detected by the detection device.

[0010] In some embodiments, the detection device includes a strain structure and a torque sensor. The strain structure is provided with a mounting hole, and the mounting hole cooperates with the output part so that the strain structure is sleeved on the outer periphery of the output part. The strain structure is configured to deform when the output part is subjected to a second torque. The torque sensor is connected to the strain structure, and the torque sensor is configured to obtain the magnitude of the torque applied to the strain structure based on the deformation of the strain structure, and use the magnitude of the torque applied to the strain structure as the magnitude of the second torque.

[0011] In some embodiments, the torque sensor includes a strain gauge and a processing unit electrically connected to the strain gauge. The strain gauge is attached to the strain structure. When the output part is subjected to the second torque, the strain gauge is configured to deform together with the strain structure and input a strain signal to the processing unit. The processing unit is configured to obtain the magnitude of the torque applied to the strain structure based on the strain signal.

[0012] In some embodiments, the torque sensor includes two strain gauges. In a direction perpendicular to the rotation axis of the output part, the strain structure is subjected to a resultant force F, and the two strain gauges are arranged along the direction of the resultant force F.

[0013] In some embodiments, the torque sensor includes multiple strain gauges, and the processing unit is configured to perform differential processing on strain signals input by the multiple strain gauges, and obtain the magnitude of the torque exerted on the strain structure based on the multiple strain signals obtained after differential processing.

[0014] In some embodiments, the strain structure includes a first strain ring, a second strain ring coaxially spaced apart from the first strain ring, and a strain bridge connected between the first strain ring and the second strain ring, the first strain ring is arranged on the outer circumference of the second strain ring, the inner ring of the second strain ring is constructed as a mounting hole, and the strain gauge is attached to the strain bridge.

[0015] In some embodiments, a connection between the strain bridge and the first strain ring has a rounded transition structure, and / or a connection between the strain bridge and the second strain ring has a rounded transition structure.

[0016] In some embodiments, the strain structure includes two or more strain bridges, and the two or more strain bridges are arranged along the circumference of the first strain ring.

[0017] In some embodiments, at least a portion of the strain bridge is bent relative to a radial direction of the first strain ring and / or the second strain ring.

[0018] In some embodiments, the mid-mounted motor for a bicycle further includes a bearing assembly, wherein the bearing assembly is disposed between an outer periphery of the output portion and the mounting hole.

[0019] In some embodiments, the detection device further includes an end cover, the strain structure is fixedly connected to the housing, the end cover is fixedly connected to a side of the strain structure facing away from the housing, and the torque sensor is located between the strain structure and the end cover.

[0020] According to another aspect of the present invention, a bicycle is provided, comprising a crank set and the above-mentioned mid-mounted motor for a bicycle, wherein an output portion of the mid-mounted motor is connected to the crank set to transmit a first torque to the crank set.

[0021] In some embodiments, the crankset includes a crankset and a crank arm, and the output portion of the mid-mounted motor of the bicycle is connected to the crankset.

[0022] In some embodiments, the crankset includes a disc body and a rotating shaft, the rotating shaft is connected between the disc body and the crank arm, the mid-mounted motor for the bicycle is mounted on the rotating shaft, and the output part of the mid-mounted motor for the bicycle is connected to the disc body.

[0023] Based on the above technical solution, the present invention installs the detection device on the output part of the motor body, so that the detection device can quickly and instantly detect the second torque applied to the output part by the crank group; and the output part of the mid-mounted motor is connected to the crank group of the bicycle, so that the first torque can be directly transmitted to the crank group to achieve efficient power assistance. In addition, compared with the solution in the related art that the detection device and the motor are set as two independent components and are installed on the bicycle respectively, the present invention couples the detection device in the mid-mounted motor, thereby saving the space occupied by the power assistance system on the bicycle, which helps to achieve a compact and lightweight design of the bicycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 An exploded view of a crankset and a mid-mounted motor mounting structure in one embodiment of a bicycle according to the second aspect of the present invention is shown.

[0026] Figure 2 An exploded view of an embodiment of a mid-mounted motor for a bicycle according to the first aspect of the present invention is shown.

[0027] Figure 3 An exploded view of a detection device in one embodiment of a mid-mounted motor for a bicycle according to the first aspect of the present invention is shown.

[0028] Figure 4 A schematic structural diagram of a strain structure in an embodiment of a mid-mounted motor for a bicycle according to the first aspect of the present invention is shown.

[0029] Figure 5 A schematic diagram of the forces acting on a detection device in one embodiment of a mid-mounted motor for a bicycle according to the first aspect of the present invention is shown.

[0030] Figure 6 The diagram shows the stress distribution on the strain structure of an embodiment of a mid-mounted motor for a bicycle according to the first aspect of the present invention.

[0031] Figure 7 A cross-sectional view showing a strain structure in one embodiment of a mid-mounted motor for a bicycle according to the first aspect of the present invention.

[0032] Figure 8 A first angle view of a housing of an embodiment of a mid-mounted motor for a bicycle according to the first aspect of the present invention is shown.

[0033] Fig. 9 A second angled cross-sectional view of a housing in an embodiment of a mid-mounted motor for a bicycle according to the first aspect of the present invention is shown.

[0034] In the figure:

[0035] 100, mid-mounted motor; 10, housing; 11, threaded hole; 20, output part; 21, clutch assembly; 22, connecting sleeve; 30, crank set; 31, toothed disc; 311, disc body; 312, rotating shaft; 32, crank arm; 40, detection device; 41, strain structure; 41, strain structure; 41a, mounting hole; 411, first strain ring; 411a, countersunk screw hole; 412, second strain ring; 412a, screw hole; 413, strain bridge; 42, torque sensor; 421, strain gauge; 422, processing unit; 423, fastening screw; 43, end cover; 431, reinforcing rib; 50, bearing assembly; 51, first bearing; 52, second bearing; 60, chain; 70, gearbox toothed disc. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0038] According to a first aspect of the present invention, a mid-mounted motor 100 for a bicycle is provided.

[0039] refer to Figure 1 As shown, in some embodiments, the mid-mounted motor 100 for a bicycle includes a housing 10, a motor body, and a detection device 40. The motor body is disposed in the housing 10 and is configured to output a first torque for assisting the bicycle. The motor body includes a driving portion and an output portion 20, the driving portion being configured to drive the output portion 20 to rotate relative to the housing 10, and the output portion 20 being used to connect with a crank set 30 of the bicycle to transmit a first torque to the crank set 30. The detection device 40 is fixedly connected to the housing 10 and is mounted on the output portion 20 so as to be relatively rotatable with the output portion 20. The detection device 40 is configured to detect the magnitude of a second torque applied to the output portion 20 by the crank set 30.

[0040] Here, the magnitude of the second torque is helpful to determine whether the rider needs assistance or how much assistance should be provided to the rider, and thus can be used as a reference for controlling the magnitude of the first torque output by the mid-mounted motor 100 .

[0041] The crankset 30 of a bicycle is usually installed in the middle of the bicycle and is the component to which the rider directly applies force during riding. The detection device 40 is installed on the output part 20, so that the detection device 40 can quickly and instantly detect the second torque applied to the output part 20 by the rider through the crankset 30. The output part 20 is connected to the crankset 30 of the bicycle and outputs torque, so that the torque output by the mid-mounted motor 100 can be conveniently transmitted directly to the crankset 30, which helps to provide efficient assistance to the rider.

[0042] In addition, compared with the solution in the related art in which the detection device and the motor are set as two independent components and installed separately on the bicycle, the present invention realizes the coupling setting of the detection device 40 in the mid-mounted motor 100, thereby effectively saving the space occupied by the power-assisting system on the bicycle and contributing to the compact and lightweight design of the bicycle.

[0043] Furthermore, in some embodiments, the mid-mounted motor 100 for a bicycle also includes a control device, which is signal-connected to the motor body and the detection device 40 , and the control device is configured to control the magnitude of the first torque output by the motor body according to the magnitude of the second torque detected by the detection device 40 .

[0044] By providing a control device in the mid-mounted motor 100, the mid-mounted motor 100 itself integrates the function of controlling the first torque output, avoiding the inconvenience of providing a separate motor control component on the bicycle, and contributing to achieving a compact and lightweight design of the bicycle as a whole.

[0045] The control device controls the magnitude of the first torque output by the motor body according to the magnitude of the second torque detected by the detection device 40, that is, it can adjust the output of the motor body based on the magnitude of the rider's real-time pedaling force. The mid-mounted motor 100 can provide a natural and smooth sense of assistance, which helps to improve the riding experience under different road conditions.

[0046] The magnitude relationship between the first torque and the second torque can be adjusted according to design requirements, user experience, etc. For example, the first torque can be set to 30% to 50% of the second torque, which can help the rider save effort while retaining a certain riding experience.

[0047] refer to Figure 2 As shown, in some embodiments, the detection device 40 includes a strain structure 41 and a torque sensor 42. The strain structure 41 is provided with a mounting hole 41a. The mounting hole 41a cooperates with the output part 20 so that the strain structure 41 is sleeved on the outer periphery of the output part 20. The strain structure 41 is configured to deform when the output part 20 is subjected to the second torque. The torque sensor 42 is connected to the strain structure 41. The torque sensor 42 is configured to obtain the magnitude of the torque applied to the strain structure 41 according to the deformation of the strain structure 41, and use the magnitude of the torque applied to the strain structure 41 as the magnitude of the second torque.

[0048] The strain structure 41 is sleeved on the outer periphery of the output part 20 so that it can have a close spatial connection with the output part 20. On the one hand, it realizes the integrated design of the strain structure 41 and the output part 20, which helps to reduce the volume of the entire mid-mounted motor 100. On the other hand, it also helps the strain structure 41 to quickly sense the second torque from the crank group 30 received by the output part 20 and deform, thereby helping to improve the response speed and accuracy of torque detection.

[0049] Furthermore, the torque sensor 42 obtains the magnitude of the second torque according to the deformation of the strain structure 41, and the control device can respond promptly according to the magnitude of the second torque and control the mid-mounted motor 100 to output a first torque of appropriate magnitude to match the actual needs of the rider.

[0050] refer to Figure 3 As shown, in some embodiments, the torque sensor 42 includes a strain gauge 421 and a processing unit 422 electrically connected to the strain gauge 421. The strain gauge 421 is attached to the strain structure 41. When the output part 20 is subjected to the second torque, the strain gauge 421 is configured to deform together with the strain structure 41 and input a strain signal to the processing unit 422. The processing unit 422 is configured to obtain the magnitude of the torque applied to the strain structure 41 according to the strain signal. Specifically, the magnitude of the torque to be detected can be obtained by combining the collected strain signal with the mechanical structure of each component.

[0051] Here, when the output part 20 is subjected to the second torque, the second torque is transmitted to the strain structure 41, causing the strain structure 41 to deform slightly, and the strain gauge 421 is also deformed accordingly. The position where the strain gauge 421 is attached can be selected based on the detection sensitivity requirements or the shape structure of the strain structure 41. For example, the strain gauge 421 can be attached to the key force position of the strain structure 41 to ensure that an accurate strain signal can be collected. Alternatively, the strain gauge 421 can be attached to the position on the strain structure 41 that is most likely to deform to improve the collection sensitivity of the strain signal.

[0052] The processing unit 422 may be configured in the form of a printed circuit board (PCB). The strain gauge 421 and the PCB may be connected by welding to transmit the strain signal. By adaptively designing the PCB, the processing unit 422 may quickly and accurately obtain the magnitude of the torque on the strain structure 41 based on the strain signal input by the strain gauge 421.

[0053] refer to Figure 4 and Figure 5 As shown, in some embodiments, the torque sensor 42 includes two strain gauges 421 . The strain structure 41 is subjected to a resultant force F in a direction perpendicular to the rotation axis of the output portion 20 . The two strain gauges 421 are arranged along the direction of the resultant force F.

[0054] Specifically, the crankset 30 of the bicycle generally includes a chainring 31 and a crank arm 32, and the crank arm 32 is used to connect with the pedal of the bicycle. When the rider steps on the pedal of the bicycle to ride, the pedal is subjected to the pedaling force of the rider and drives the chainring 31 of the bicycle to rotate through the crank arm 32, and the chainring 31 further drives the chain 60 of the bicycle matched therewith to pull the gearbox chainring 70 to rotate, thereby driving the wheel of the bicycle to rotate. In this process, the chain 60 has tension, so the crankset 30 of the bicycle is also subjected to the force from the chain 60.

[0055] In some embodiments of the present invention, the output portion 20 of the mid-mounted motor 100 is directly connected to the crankset 31 of the bicycle, so that the force applied to the crankset 31 is transmitted to the output portion 20 and then to the strain structure 41. Figure 5 As shown, the resultant force acting on the center O of the strain structure 41 is shown as F, and the strain structure 41 undergoes a slight deformation under the action of the resultant force F.

[0056] In some specific examples, the tension on the upper side of the chain 60 is greater than the tension on the lower side thereof, Figure 5 As shown, the direction of the resultant force F is tilted downward relative to the connecting line OP, and has an angle with OP. Point O is the center of the strain structure 41 and the center of the bicycle chainring 31, and point P is the center of the bicycle gearbox chainring 70. The size of the angle θ is related to the overall structural design of the bicycle and can be calculated by finite element analysis and other methods.

[0057] Arranging the two strain gauges 421 along the direction of the resultant force F can reduce the influence of environmental factors on the deformation process of the strain gauge 421, thereby reducing the error of the collected strain signal and facilitating further processing of the strain signal.

[0058] In some embodiments, the torque sensor 42 includes multiple strain gauges 421, and the processing unit 422 is configured to perform differential processing on the strain signals input by the multiple strain gauges 421, and obtain the magnitude of the torque exerted on the strain structure 41 based on the multiple strain signals obtained after differential processing.

[0059] Differential processing helps to filter out some external interference in the process of strain signal generation, such as changes in strain signals caused by temperature, so that the torque magnitude result obtained is more accurate. The collected strain signal can also be amplified by differential processing to more accurately capture the deformation information of the strain structure 41 and improve the sensitivity of torque detection.

[0060] In some embodiments, the strain structure 41 includes a first strain ring 411, a second strain ring 412 coaxially spaced apart from the first strain ring 411, and a strain bridge 413 connected between the first strain ring 411 and the second strain ring 412. The first strain ring 411 is disposed on the outer periphery of the second strain ring 412, the inner ring of the second strain ring 412 is constructed as a mounting hole 41a, and the strain gauge 421 is attached to the strain bridge 413.

[0061] The structure of connecting the strain bridge 413 between the two strain rings has a higher response sensitivity, and the strain bridge 413 itself can deform under a slight torque change, which helps to improve the sensitivity of torque detection. In addition, compared with the whole plate-shaped strain structure, the design of two strain rings can obtain a lower dead weight, which helps to achieve a lightweight design of the mid-mounted motor 100.

[0062] refer to Figure 3 As shown, in some embodiments, a screw hole 412 a is provided on the second strain ring 412 , and the torque sensor 42 further includes a fastening screw 423 , which is used to cooperate with the screw hole 412 a to connect the strain structure 41 with the processing unit 422 .

[0063] In some embodiments, a connection between the strain bridge 413 and the first strain ring 411 has a rounded transition structure, and / or a connection between the strain bridge 413 and the second strain ring 412 has a rounded transition structure.

[0064] refer to Figure 6 As shown, the rounded transition structure can effectively reduce the concentration of stress at the connection, so that the stress is concentrated at the main position of the strain bridge 413 (for example Figure 6 The strain bridge 413 is located at the lower part of the strain structure 41 in the figure). By such an arrangement, on the one hand, the probability of damage to the connection after multiple stresses can be reduced and the fatigue resistance of the strain structure 41 can be improved; on the other hand, the stress of the strain structure 41 can be concentrated on the main part of the strain bridge 413. Therefore, attaching the strain gauge 421 to the main part of the strain bridge 413 is conducive to the deformation of the strain gauge 421 when the strain bridge 413 is stressed, which can accurately reflect the actual stress of the strain structure 41, thereby outputting an effective and accurate strain signal.

[0065] In some embodiments, the strain structure 41 includes two or more strain bridges 413 , and the two or more strain bridges 413 are arranged along the circumference of the first strain ring 411 .

[0066] In the embodiment of the present invention, there is no restriction on the number and specific circumferential position of the strain bridges 413. During the design process, the arrangement of the strain bridges 413 can be adjusted according to the overall stress condition of the strain structure 41 or the accuracy requirement of torque detection.

[0067] In some embodiments, at least a portion of the strain bridge 413 is bent relative to a radial direction of the first strain ring 411 and / or the second strain ring 412 .

[0068] When the output portion 20 transmits force to the strain structure 41 , the strain bridge 413 with a curved structure is more likely to deform, such as bend, so that the strain structure 41 has a higher force response sensitivity.

[0069] In a specific example, refer to Figure 7 As shown, it can be seen from the cross-sectional shape of the strain bridge 413 that the strain bridge 413 has a radially curved structure relative to the first strain ring 411 and the second strain ring 412 (the right edge of the cross-sectional shape of the strain bridge 413 in the figure has an arc).

[0070] In some embodiments, the mid-mounted motor 100 for a bicycle further includes a bearing assembly 50 , which is disposed between the outer periphery of the output portion 20 and the mounting hole 41 a .

[0071] In a specific example, Figure 2 As shown, the bearing assembly 50 includes a first bearing 51 and a second bearing 52. The two bearings are connected as shown in FIG. Figure 7 The step structure of the mounting hole 41 a shown in the figure cooperates to realize the rotatable installation of the detection device 40 on the output part 20, while ensuring the installation stability of the detection device 40.

[0072] refer to Figure 2 and Figure 3 As shown, in some embodiments, the detection device 40 also includes an end cover 43, the strain structure 41 is fixedly connected to the housing 10, the end cover 43 is fixedly connected to the side of the strain structure 41 facing away from the housing 10, and the torque sensor 42 is located between the strain structure 41 and the end cover 43.

[0073] refer to Figure 8 and Fig. 9 As shown, the housing 10 is provided with a threaded hole 11 corresponding to the countersunk screw hole 411 a on the first strain ring 411 , so that the strain structure 41 can be mounted on the housing 10 by fasteners such as screws.

[0074] The end cap 43 can provide protection for the strain structure 41 and the torque sensor 42 , such as dust and water resistance, and helps to increase the service life of the detection device 40 .

[0075] Furthermore, for a mid-mounted motor that has been provided with a cover structure, the detection device 40 can also be obtained by modifying the existing cover structure of the mid-mounted motor. Specifically, the main body of the existing cover structure can be used as the strain structure 41 of the detection device 40, and the end cover part of the existing cover structure can be used as the end cover 43 of the detection device 40, and a torque sensor 42 is added to the space between the main body (strain structure 41) and the end cover part (end cover 43), so that the detection device 40 in the embodiment of the present invention can be formed.

[0076] In this way, the detection device 40 is integrally fixedly connected to the housing 10, and together with the housing 10, forms an installation space for accommodating the motor body. The detection device 40 as a whole can serve as a cover structure of the central motor 100, and the cover structure can provide protection for the components inside the central motor 100. Figure 3 As shown, reinforcing ribs 431 may also be provided on the end cover 43 of the detection device 40 to further enhance the strength of the cover structure.

[0077] Through the above arrangement, the detection device 40 and the cover structure of the central motor 100 are integrated and designed in an integrated manner, which effectively saves installation space and helps to achieve a miniaturized design of the central motor 100.

[0078] According to a second aspect of the present invention, a bicycle is provided. The bicycle comprises a crank set 30 and the mid-mounted motor 100 for a bicycle provided in the first aspect of the present invention.

[0079] In some embodiments, the output portion 20 of the mid-mounted motor 100 is connected to a crankset 30 of a bicycle to transmit a first torque to the crankset 30 .

[0080] refer to Figure 1 As shown, in some embodiments, the crank set 30 includes a crankset 31 and a crank arm 32 , and the output portion 20 of the mid-mounted motor 100 for a bicycle is connected to the crankset 31 .

[0081] Specifically, refer to Figure 2 As shown, the output part 20 includes a clutch assembly 21 and a connecting sleeve 22 connected to the clutch assembly 21. The clutch assembly 21 is selectively connected to the driving part, for example, selectively through meshing, or through electromagnetic attraction. The end of the connecting sleeve 22 away from the clutch assembly 21 is connected to the chainring 31, and the chainring 31 is provided with a positioning and mounting hole that cooperates with the connecting sleeve 22. When the bicycle needs power assistance, the driving part is connected to the clutch assembly 21 to output a first torque, and further transmits the first torque to the chainring 31 through the connecting sleeve 22.

[0082] refer to Figure 1 As shown, in some embodiments, the crankset 31 includes a disc body 311 and a rotating shaft 312, the rotating shaft 312 is connected between the disc body 311 and the crank arm 32, the mid-mounted motor 100 for the bicycle is mounted on the rotating shaft 312, and the output part 20 of the mid-mounted motor 100 for the bicycle is connected to the disc body 311.

[0083] As an example, the mid-mounted motor 100 of the bicycle is a hollow shaft motor, so the mid-mounted motor 100 is sleeved and mounted on the rotating shaft 312 through its hollow shaft structure.

[0084] Based on this, the bicycle of the present invention can provide assistance to the rider when the rider needs it, and the degree of assistance depends on the magnitude of the first torque output by the mid-mounted motor 100. The magnitude of the first torque is controlled based on the magnitude of the second torque detected by the detection device 40 of the mid-mounted motor 100. The magnitude of the second torque is related to the strength of the rider's pedaling of the bicycle. Therefore, the bicycle of the present invention can reduce the rider's fatigue, especially in scenes such as climbing and accelerating, and under the power-assist function of the mid-mounted motor 100, the bicycle can achieve a higher smoothness of movement.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that without departing from the principles of the present invention, the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents, and these modifications and equivalent replacements should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A mid-mounted motor (100) for a bicycle, characterized in that: include: Housing (10); a motor body, arranged in the housing (10), configured to output a first torque for assisting the bicycle, the motor body comprising a driving part and an output part (20), the driving part being configured to drive the output part (20) to rotate relative to the housing (10), the output part (20) being used to connect to a crank set (30) of the bicycle to transmit the first torque to the crank set (30); and A detection device (40) is fixedly connected to the housing (10) and is mounted on the output part (20) so as to be rotatable relative to the output part (20). The detection device (40) is configured to detect the magnitude of a second torque applied by the crank group (30) to the output part (20).

2. The mid-mounted motor (100) for a bicycle according to claim 1, characterized in that: It also includes a control device, which is connected to the motor body and the detection device (40) by signal, and is configured to control the magnitude of the first torque output by the motor body according to the magnitude of the second torque detected by the detection device (40).

3. The mid-mounted motor (100) for a bicycle according to claim 1, characterized in that: The detection device (40) comprises a strain structure (41) and a torque sensor (42); the strain structure (41) is provided with a mounting hole (41a); the mounting hole (41a) cooperates with the output part (20) so that the strain structure (41) is sleeved on the outer periphery of the output part (20); the strain structure (41) is configured to deform when the output part (20) is subjected to the second torque; the torque sensor (42) is connected to the strain structure (41); the torque sensor (42) is configured to obtain the magnitude of the torque applied to the strain structure (41) based on the deformation of the strain structure (41), and use the magnitude of the torque applied to the strain structure (41) as the magnitude of the second torque.

4. The mid-mounted motor (100) for a bicycle according to claim 3, characterized in that: The torque sensor (42) comprises a strain gauge (421) and a processing unit (422) electrically connected to the strain gauge (421); the strain gauge (421) is attached to the strain structure (41); when the output portion (20) is subjected to the second torque, the strain gauge (421) is configured to deform together with the strain structure (41) and input a strain signal to the processing unit (422); and the processing unit (422) is configured to obtain the magnitude of the torque applied to the strain structure (41) based on the strain signal.

5. The mid-mounted motor (100) for a bicycle according to claim 4, characterized in that: The torque sensor (42) comprises two strain gauges (421); in a direction perpendicular to the rotation axis of the output portion (20), the strain structure (41) is subjected to a resultant force F; and the two strain gauges (421) are arranged along the direction of the resultant force F.

6. The mid-mounted motor (100) for a bicycle according to claim 4, characterized in that: The torque sensor (42) comprises a plurality of strain gauges (421), and the processing unit (422) is configured to perform differential processing on the strain signals input by the plurality of strain gauges (421), and obtain the magnitude of the torque exerted on the strain structure (41) based on the plurality of strain signals obtained through the differential processing.

7. The mid-mounted motor (100) for a bicycle according to claim 4, characterized in that: The strain structure (41) comprises a first strain ring (411), a second strain ring (412) coaxially arranged with the first strain ring (411) and spaced apart therefrom, and a strain bridge (413) connected between the first strain ring (411) and the second strain ring (412); the first strain ring (411) is arranged on the outer periphery of the second strain ring (412); the inner ring of the second strain ring (412) is configured as the mounting hole (41a); and the strain gauge (421) is attached to the strain bridge (413).

8. The mid-mounted motor (100) for a bicycle according to claim 7, characterized in that: A connection between the strain bridge (413) and the first strain ring (411) has a rounded transition structure, and / or a connection between the strain bridge (413) and the second strain ring (412) has a rounded transition structure.

9. The mid-mounted motor (100) for a bicycle according to claim 7, characterized in that: The strain structure (41) comprises two or more strain bridges (413), and the two or more strain bridges (413) are arranged along the circumference of the first strain ring (411).

10. The mid-mounted motor (100) for a bicycle according to claim 7, characterized in that: At least a portion of the strain bridge (413) is bent relative to the radial direction of the first strain ring (411) and / or the second strain ring (412).

11. The mid-mounted motor (100) for a bicycle according to claim 3, characterized in that: It also includes a bearing assembly (50), wherein the bearing assembly (50) is arranged between the outer periphery of the output portion (20) and the mounting hole (41a).

12. The mid-mounted motor (100) for a bicycle according to claim 3, characterized in that: The detection device (40) further comprises an end cover (43), the strain structure (41) is fixedly connected to the housing (10), the end cover (43) is fixedly connected to a side of the strain structure (41) facing away from the housing (10), and the torque sensor (42) is located between the strain structure (41) and the end cover (43).

13. A bicycle, characterized in that: The invention comprises a crank set (30) and a mid-mounted motor (100) for a bicycle according to any one of claims 1 to 12, wherein the output portion (20) of the mid-mounted motor (100) for a bicycle is connected to the crank set (30) to transmit the first torque to the crank set (30).

14. The bicycle according to claim 13, characterized in that The crank set (30) comprises a crankset (31) and a crank arm (32), and the output portion (20) of the mid-mounted motor (100) for a bicycle is connected to the crankset (31).

15. The bicycle according to claim 14, characterized in that The crankset (31) comprises a crankset body (311) and a rotating shaft (312); the rotating shaft (312) is connected between the crankset body (311) and the crank arm (32); the mid-mounted motor (100) for a bicycle is mounted on the rotating shaft (312); and the output portion (20) of the mid-mounted motor (100) for a bicycle is connected to the crankset body (311).

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