Middle motor transmission module based on fluctuation cycloid speed reduction and electric power-assisted bicycle

Abstract

The utility model discloses a mid-motor transmission module based on fluctuation cycloid speed reduction and an electric power-assisted bicycle, the mid-motor transmission module comprises a central shaft, an outer rotor motor and a harmonic speed reduction assembly, the outer rotor motor comprises a stator and a rotor which are coupled with each other, the harmonic speed reduction assembly surrounds the center shaft and is arranged in the axial direction of the outer rotor motor. The harmonic speed reduction assembly comprises an input shaft tube, an inner gear and an outer gear, one end of the input shaft tube is connected with the rotor, the input shaft tube is sleeved with the inner gear, the input shaft tube can drive the inner gear to periodically swing or periodically deform in the rotating process, a first gear ring is arranged on the inner gear, and a second gear ring surrounding the outer side of the first gear ring is arranged on the outer gear; the tooth number of the second gear ring is larger than that of the first gear ring. By arranging the outer rotor motor and the harmonic speed reduction assembly, the transmission structure can be simplified, the occupied space can be reduced, miniaturization and light weight of the middle motor transmission module can be achieved, and arrangement of the middle motor transmission module is facilitated.

Description

Technical Field

[0001] The utility model relates to the field of electric power-assisted bicycles, in particular to a mid-mounted motor transmission module based on wave cycloid deceleration and an electric power-assisted bicycle. Background Art

[0002] Electric power-assisted bicycles, also known as smart electric bicycles, are a type of riding tool between bicycles and electric vehicles. The motor is directly responsible for mechanical transmission, acting on the pedaling force of the vehicle to complete the conversion of electrical energy into kinetic energy, and is the ultimate tool for providing auxiliary power.

[0003] The motor power-assist system of electric power-assisted bicycles can be roughly divided into mid-mounted and hub-mounted types. The mid-mounted motor system is installed at the five-way position of the frame, and the center of gravity of the vehicle body is reasonably distributed. The motor is connected to the vehicle body and connected to the rear wheel through a chain to transmit power. In the related art, the mid-mounted motor system is large in size, which is not conducive to layout and there is room for improvement. Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a mid-mounted motor transmission module based on wave cycloid deceleration, the mid-mounted motor transmission module is small in size and easy to arrange.

[0005] The utility model also provides an electric power-assisted bicycle with the above-mentioned centrally mounted motor transmission module.

[0006] According to the first aspect of the utility model, a mid-mounted motor transmission module based on cycloid deceleration includes: a central shaft; an outer rotor motor, the outer rotor motor includes a stator and a rotor coupled to each other, the stator is arranged around the central shaft, and the rotor is spaced around the outside of the stator; a harmonic reduction component, the harmonic reduction component surrounds the central shaft and is axially arranged with the outer rotor motor, the harmonic reduction component includes: an input shaft tube, an internal gear and an external gear, one end of the input shaft tube is connected to the rotor, the internal gear sleeve is on the input shaft tube, the input shaft tube is configured to drive the internal gear to swing or deform periodically during rotation, a first gear ring is provided on the internal gear, and a second gear ring is provided on the outer gear surrounding the first gear ring, the number of teeth of the second gear ring is greater than the number of teeth of the first gear ring, and each tooth of the first gear ring is periodically engaged and disengaged with the second gear ring to drive the internal gear or the external gear to rotate at a reduced speed.

[0007] According to the central motor transmission module of the utility model, by arranging an outer rotor motor and a harmonic reduction assembly, the transmission structure can be simplified and the occupied space can be reduced, thereby realizing the miniaturization and lightness of the central motor transmission module and facilitating the arrangement of the central motor transmission module.

[0008] In some embodiments, the mid-mounted motor transmission module further includes: a connecting disk, which is arranged around the central axis, the outer edge of the connecting disk is connected to the rotor, and the inner edge of the connecting disk is connected to the input shaft tube.

[0009] In some embodiments, the outer edge of the connecting disk is bent axially toward the rotor to connect to the rotor; the connecting disk is tightly attached to the end surface of the input shaft tube and is connected via a threaded fastener.

[0010] In some embodiments, the mid-mounted motor transmission module also includes: a support ring, which is arranged around the central axis, and one end of the support ring is connected to the stator; a first support bearing, the first support bearing is sleeved on the support ring, and one end of the input shaft tube is sleeved and connected to the first support bearing.

[0011] In some embodiments, the harmonic reduction assembly also includes: an output wheel, which is arranged around the central axis, and the output wheel is connected to the rotating internal gear or the external gear to rotate synchronously; the mid-mounted motor transmission module also includes: a second support bearing, the second support bearing is sleeved on the output wheel, and the other end of the input shaft tube is sleeved and connected to the second support bearing.

[0012] In some embodiments, a cam is provided on the input shaft tube; the inner gear is a flexible wheel and is mounted on the cam, the outer gear is a rigid wheel, and the rigid wheel is fixed relative to the stator; the harmonic reduction assembly also includes an elastic bearing connected between the flexible wheel and the cam.

[0013] In some embodiments, a first annular track groove is provided on the outer circumferential surface of the cam; the elastic bearing includes: a bearing outer ring and a plurality of rolling elements, the bearing outer ring is an elastic member and surrounds the outer side of the cam, a second annular track groove corresponding to the first annular track groove is provided on the inner circumferential surface of the bearing outer ring, and the plurality of rolling elements are distributed at intervals along the circumferential direction, and the rolling elements roll in cooperation with the first annular track groove and the second annular track groove.

[0014] In some embodiments, the inner gear is a plastic wheel.

[0015] In some embodiments, an eccentric wheel is provided on the input shaft tube; the inner gear is a rigid wheel and the outer sleeve swings periodically on the eccentric wheel, and the outer gear is a rigid wheel and is rotatably arranged.

[0016] In some embodiments, the rotating internal gear or the external gear is dynamically connected to the central shaft; or, the mid-mounted motor transmission module further includes: an output shaft tube disposed on the central shaft, and the rotating internal gear or the external gear is dynamically connected to the output shaft tube.

[0017] In some embodiments, the mid-mounted motor transmission module includes the output shaft tube; the mid-mounted motor transmission module also includes: a first one-way clutch, which is sleeved between the center shaft and the output shaft tube to transmit the power of the center shaft to the output shaft tube in one direction; a second one-way clutch, which is connected to the rotating internal gear or the external gear and is connected to the output shaft tube to transmit the power of the harmonic reduction assembly to the output shaft tube in one direction.

[0018] The electric power-assisted bicycle according to the second aspect of the utility model comprises a mid-mounted motor transmission module based on cycloid deceleration according to the first aspect of the utility model.

[0019] According to the electric power-assisted bicycle of the utility model, by setting the mid-mounted motor transmission module based on the cycloid deceleration of the first aspect mentioned above, the volume of the mid-mounted motor transmission module is small, which is conducive to the user's force, and at the same time reduces the windward area, which can reduce wind resistance and improve sports performance.

[0020] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a mid-mounted motor transmission module according to an embodiment of the utility model.

[0022] Reference numerals:

[0023] Mid-mounted motor transmission module 100;

[0024] Central axis 1;

[0025] External rotor motor 2; stator 21; rotor 22;

[0026] Harmonic reduction assembly 3; input shaft tube 31; internal gear 32; external gear 33; output wheel 34; elastic bearing 35;

[0027] Connecting plate 4; threaded fastener 41;

[0028] Support ring 5;

[0029] A first support bearing 6;

[0030] A second support bearing 7;

[0031] Shell 8. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0033] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the utility model can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the applicability of other processes and / or the use of other materials.

[0034] The following describes a mid-mounted motor transmission module 100 based on cycloid deceleration according to an embodiment of the present invention with reference to the accompanying drawings.

[0035] According to the central motor transmission module 100 of the embodiment of the present utility model, Figure 1 As shown, it includes: a central shaft 1, an outer rotor motor 2 and a harmonic reduction assembly 3, the outer rotor motor 2 includes a stator 21 and a rotor 22 coupled to each other, the stator 21 is arranged around the central shaft 1, and the rotor 22 is spaced around the outside of the stator 21. The harmonic reduction assembly 3 surrounds the central shaft 1 and is axially arranged with the outer rotor motor 2. The harmonic reduction assembly 3 includes: an input shaft tube 31, an internal gear 32 and an external gear 33. One end of the input shaft tube 31 is connected to the rotor 22, and the internal gear 32 is sleeved on the input shaft tube 31. The input shaft tube 31 is configured to drive the internal gear 32 to swing or deform periodically during rotation. The internal gear 32 is provided with a first gear ring, and the external gear 33 is provided with a second gear ring surrounding the outside of the first gear ring. The number of teeth of the second gear ring is greater than the number of teeth of the first gear ring. Each tooth of the first gear ring is periodically engaged and disengaged with the second gear ring to drive the internal gear 32 or the external gear 33 to reduce the rotation.

[0036] The mid-mounted motor transmission module 100 of the embodiment of the utility model is used for an electric power-assisted bicycle. The mid-mounted motor transmission module 100 is installed at the five-way position of the bicycle frame, and the center of gravity is reasonably distributed. The mid-mounted motor transmission module 100 is connected to the vehicle body and is connected to the rear wheel through a chain to transmit power.

[0037] The axial ends of the central shaft 1 are connected to pedals. When the user steps on the pedals, the pedals directly act on the central shaft 1 and transmit the rotational power to the wheels of the electric power-assisted bicycle through the central shaft 1, thereby driving the electric power-assisted bicycle to travel.

[0038] In addition to being able to drive the electric power-assisted bicycle by human power, the electric power-assisted bicycle can also be driven by the outer rotor motor 2 and the harmonic reduction assembly 3. The outer rotor motor 2 provides power, the harmonic reduction assembly 3 transmits power, and converts the high speed and low torque generated by the outer rotor motor 2 into low speed and high torque, which can provide the electric power-assisted bicycle with stronger climbing ability and acceleration performance.

[0039] The harmonic reduction assembly 3 and the outer rotor motor 2 are both arranged around the central axis 1. The harmonic reduction assembly 3 is coaxially arranged. Compared with the reduction assembly using a coaxial arrangement in the related art, the harmonic reduction assembly 3 of the embodiment of the utility model occupies a smaller space in the radial direction, which can realize the miniaturization and lightweight of the mid-mounted motor transmission module 100.

[0040] The input shaft tube 31 of the harmonic reduction assembly 3 is a power input part, and the input shaft tube 31 is connected to the rotor 22 to be driven to rotate. The rotation of the input shaft tube 31 drives the internal gear 32 to undergo controllable periodic swing or periodic deformation. The internal gear 32 meshes with the external gear 33 during the swing or deformation process. Since the number of teeth of the first gear ring of the internal gear 32 is less than the number of teeth of the second gear ring of the external gear 33, the meshing of the internal gear 32 and the external gear 33 is a cross-over non-full-tooth meshing. Every time the input shaft tube 31 rotates 360 degrees, the internal gear 32 generates a gear tooth of the difference between the second gear ring and the first gear ring relative to the external gear 33 during rotation. This movement is the output movement of the harmonic reduction assembly 3.

[0041] Through the continuous rotation of the input shaft tube 31, the internal gear 32 continuously undergoes controllable periodic swing or periodic deformation, and the external gear 33 also continuously changes the meshing state with the internal gear 32 to produce staggered tooth movement. This staggered tooth movement can convert the input high-speed rotation into the output low-speed rotation to achieve a deceleration effect.

[0042] One of the inner gear 32 and the outer gear 33 is fixed relative to the stator 21 of the outer rotor motor 2, and the other of the inner gear 32 and the outer gear 33 rotates relative to the outer rotor motor 2, thereby serving as a power output member to transmit power.

[0043] Compared with the coaxial reduction assembly using a planetary gear structure in the related art, the harmonic reduction assembly 3 of the embodiment of the utility model only needs an input shaft tube 31, an internal gear 32 and an external gear 33 to achieve the reduction effect, which can reduce the space occupied by the harmonic reduction assembly 3 in the axial and radial directions, and can realize the miniaturization and lightweight of the central motor transmission module 100. In addition, the harmonic reduction assembly 3 is a single-machine transmission form, and compared with the multi-stage transmission, the transmission efficiency of the harmonic reduction assembly 3 is higher.

[0044] Furthermore, by providing an outer rotor motor 2, the connection between the rotor 22 and the input shaft tube 31 is relatively simple, which can simplify the transmission structure, reduce the space occupied by the outer rotor motor 2 and the harmonic reduction assembly 3, and help reduce the volume of the central motor transmission module 100.

[0045] In addition, by providing an outer rotor motor 2, the stator 21 is located inside the rotor 22, and the rotor 22 surrounds the outside of the stator 21. Compared with the inner rotor 22 motor, the outer rotor motor 2 can generate a greater driving force under the same volume, which is also conducive to reducing the volume of the central motor transmission module 100 and improving the driving output.

[0046] According to the central motor transmission module 100 of the embodiment of the utility model, by providing the outer rotor motor 2 and the harmonic reduction assembly 3, the transmission structure can be simplified and the occupied space can be reduced, so that the central motor transmission module 100 can be miniaturized and lightweight, and the arrangement of the central motor transmission module 100 is convenient.

[0047] In some embodiments of the present invention, Figure 1 As shown, the mid-mounted motor transmission module 100 also includes: a connecting disk 4, the connecting disk 4 is arranged around the central axis 1, the outer edge of the connecting disk 4 is connected to the rotor 22, and the inner edge of the connecting disk 4 is connected to the input shaft tube 31. The connecting disk 4 is connected between the rotor 22 and the input shaft tube 31, and transmits the power of the outer rotor motor 2 to the harmonic reduction assembly 3, driving the input shaft tube 31 to rotate. The structure of the connecting disk 4 is simple. By arranging the connecting disk 4 to transmit between the outer rotor motor 2 and the harmonic reduction assembly 3, the structure can be simplified and the volume of the mid-mounted motor transmission module 100 can be reduced.

[0048] Here, the inside and outside are based on the central axis 1. In the radial direction of the central axis 1, the side close to the central axis 1 is the inside, and the side away from the central axis 1 is the outside. The rotor 22 of the outer rotor motor 2 is located on the inside of the stator 21, and the input shaft tube 31 is located on the inside of the rotor 22, so the outer edge of the connecting disk 4 is connected to the rotor 22, and the inner edge of the connecting disk 4 is connected to the input shaft tube 31.

[0049] Furthermore, in some embodiments of the present invention, Figure 1As shown, the outer edge of the connection disk 4 is bent toward the rotor 22 in the axial direction to connect the rotor 22. The outer edge of the connection disk 4 is located outside the inner edge of the connection disk 4, and the connection disk 4 is bent from the outer edge to the inner edge toward the inner side to connect the rotor 22.

[0050] In some embodiments of the present invention, Figure 1 As shown, the connecting plate 4 is closely attached to the end surface of the input shaft tube 31 and is connected via a threaded fastener 41 .

[0051] The connecting disc 4 is bent and extends radially along the central axis 1 to reduce the axial size of the connecting disc 4. The connecting disc 4 connects the outer rotor motor 2 and the harmonic reduction assembly 3 in a compact structure, which is conducive to reducing the volume of the central motor transmission module 100. In addition, the side surface of the connecting disc 4 extending in the radial direction is in close contact with the end surface of the input shaft tube 31, increasing the contact area. The end surfaces of the connecting disc 4 and the input shaft tube 31 are connected by threaded fasteners 41, which can improve the power transmission stability of the connecting disc 4 and the input shaft tube 31, and have strong working reliability.

[0052] In some embodiments of the present invention, Figure 1 As shown, the axial end surface of the input shaft tube 31 facing the connecting disc 4 forms a step portion, and the connecting disc 4 is supported on the step surface of the step portion, thereby improving the connection stability between the connecting disc 4 and the input shaft tube 31. In addition, the cooperation between the connecting disc 4 and the step portion can also play a role in axially positioning the connecting disc 4, and improve the dynamic transmission reliability of the connecting disc 4 and the input shaft tube 31.

[0053] In some embodiments of the present invention, Figure 1 As shown, the mid-mounted motor transmission module 100 also includes: a support ring 5 and a first support bearing 6. The support ring 5 is arranged around the central axis 1, one end of the support ring 5 is connected to the stator 21, the first support bearing 6 is outer sleeved on the support ring 5, and one end of the input shaft tube 31 is outer sleeved on the first support bearing 6.

[0054] The support ring 5 is fixedly connected to the stator 21 and is used to support the input shaft tube 31 . The support ring 5 can play a supporting and fixing role, thereby improving the movement stability of the input shaft tube 31 .

[0055] The first support bearing 6 is used to support and cooperate with the rotation of the input shaft tube 31. The input shaft tube 31 is connected to the support ring 5 through the first support bearing 6. This can reduce the impact of direct load on the central shaft 1, while providing smoother rotational movement and improving the movement stability of the input shaft tube 31.

[0056] In some embodiments of the present invention, Figure 1As shown, the harmonic reduction assembly 3 further includes: an output wheel 34, which is arranged around the central axis 1, and the output wheel 34 is connected to the rotating internal gear 32 or the external gear 33 to rotate synchronously. The central motor transmission module 100 further includes: a second support bearing 7, the second support bearing 7 is outer-coated on the output wheel 34, and the other end of the input shaft tube 31 is outer-coated and connected to the second support bearing 7.

[0057] The output wheel 34 transmits the output torque of the harmonic reduction assembly 3, and the output wheel 34 drives the electric power-assisted bicycle to travel. One axial side of the input shaft tube 31 is supported on the support ring 5 through the first support bearing 6, and the other axial side of the input shaft tube 31 is supported on the output wheel 34 through the second bearing. The second support bearing 7 can reduce the direct load on the output wheel 34, and the output wheel 34 can support the input shaft tube 31, thereby improving the motion stability of the input shaft tube 31.

[0058] The first support bearing 6 and the second support bearing 7 respectively support the two axial ends of the input shaft tube 31 to realize double bearing support, which can effectively reduce the vibration caused by the rotor 22 and make the transmission of the rotor 22 to the input shaft tube 31 more stable. In addition, the first support bearing 6 and the second support bearing 7 are arranged at intervals along the axial direction of the input shaft tube 31 to improve the deformation problem of the input shaft tube 31, reduce the uneven contact caused by the deformation of the input shaft tube 31, and extend the service life of the input shaft tube 31.

[0059] In some embodiments of the utility model, the connecting plate 4, the input shaft tube 31, the external gear 33, and the output wheel 34 in the central motor transmission module 100 of the embodiments of the utility model are all coaxially arranged with the central axis 1, which can make the various parts in the central motor transmission module 100 more compact, thereby reducing the axial dimension and reducing the volume of the central motor transmission module 100.

[0060] In some embodiments of the utility model, a cam is provided on the input shaft tube 31, the inner gear 32 is a flexible wheel and is outerly mounted on the cam, the outer gear 33 is a rigid wheel, the rigid wheel is fixed relative to the stator 21, and the harmonic reduction assembly 3 also includes an elastic bearing 35 connected between the flexible wheel and the cam.

[0061] In the embodiment of the utility model, the input shaft tube 31 and the elastic bearing 35 are constructed as a wave generator. By setting the elastic bearing 35, the rotational coordination of the cam and the internal gear 32 can be satisfied, and the stress integration generated by the internal gear 32 can be improved, thereby enhancing the deformation effect of the internal gear 32. The internal gear 32 is constructed as a flexible wheel, and the external gear 33 is constructed as a steel wheel.

[0062] The inner gear 32 of the flexible wheel is mounted on the input shaft tube 31, and the inner gear 32 is deformed from the original circular shape to an elliptical shape. The input shaft tube 31 rotates continuously, and the inner gear 32 is continuously deformed in a controllable periodic manner. The teeth near the two ends of the long axis of the deformed inner gear 32 are fully meshed with the outer gear 33, and the gold-plated teeth at the two ends of the short axis of the inner gear 32 are completely disengaged from the outer gear 33. The teeth in other sections of the circumference are in a transitional state of meshing and disengagement.

[0063] Through the continuous rotation of the input shaft tube 31, the internal gear 32 continuously undergoes controllable periodic deformation, and the external gear 33 also continuously changes the meshing state with the internal gear 32 to produce staggered tooth movement. This staggered tooth movement can convert the input high-speed rotation into the output low-speed rotation to achieve a deceleration effect.

[0064] The external gear 33 is a fixed part, and the input shaft tube 31 drives the internal gear 32 to rotate at a reduced speed, and the internal gear 32 is a torque output part.

[0065] In some embodiments of the utility model, a first annular track groove is provided on the outer circumferential surface of the cam, and the elastic bearing 35 includes: a bearing outer ring and a plurality of rolling elements, the bearing outer ring is an elastic member and is surrounded by the outer side of the cam, and a second annular track groove corresponding to the first annular track groove is provided on the inner circumferential surface of the bearing outer ring, and the plurality of rolling elements are distributed at intervals along the circumferential direction, and the rolling elements roll in cooperation with the first annular track groove and the second annular track groove.

[0066] The inner ring of the elastic bearing 35 is eliminated, and the multiple rolling elements in the elastic bearing 35 roll directly in the first annular track groove on the outer circumferential surface of the cam and between the second annular track groove on the inner circumferential surface of the bearing outer ring, so that the input shaft tube 31 and the inner gear ring can also rotate with each other. By eliminating the inner ring of the elastic bearing 35 and integrating the elastic bearing 35 and the input shaft tube 31, the axial size of the harmonic reduction assembly 3 can be reduced, which is conducive to reducing the volume of the mid-mounted motor transmission module 100.

[0067] In some embodiments of the present invention, the inner gear 32 is a plastic wheel.

[0068] The inner gear 32 is a plastic wheel, which can reduce the weight of the inner gear 32 and facilitate the elastic deformation of the inner gear 32 . In addition, the meshing noise of the inner gear 32 and the outer gear 33 of the plastic wheel is low, which can reduce the working noise of the harmonic reduction assembly 3 .

[0069] In other embodiments of the present invention, an eccentric wheel is provided on the input shaft tube 31, the inner gear 32 is a rigid wheel and is outerly mounted on the eccentric wheel to swing periodically, and the outer gear 33 is a rigid wheel and is rotatably arranged.

[0070] An eccentric wheel is arranged on the input shaft tube 31, and the input shaft tube 31 rotates continuously, and the internal gear 32 continuously swings in a controllable periodic manner. The input shaft tube 31 drives the internal periodic swing, and the external gear 33 rotates at a reduced speed, and the external gear 33 is a torque output member.

[0071] By setting the harmonic reduction assembly 3 of the embodiment of the utility model, since both the inner gear 32 and the outer gear 33 are rigid wheels, the energy efficiency loss caused by material elasticity can be reduced, and the failure caused by material fatigue can be reduced. The harmonic reduction assembly 3 can achieve efficient and reliable reduction transmission and improve working reliability.

[0072] In some embodiments of the present invention, the rotating inner gear 32 or outer gear 33 is connected to the central shaft 1. The outer rotor motor 2 outputs power to the harmonic reduction assembly 3, and the harmonic reduction assembly 3 reduces speed and increases torque, driving the central shaft 1 to rotate, and then driving the electric power-assisted bicycle to travel.

[0073] In other embodiments of the present invention, the central motor transmission module 100 further includes: an output shaft tube outer sleeved on the central shaft 1, and a rotating internal gear 32 or external gear 33 is connected to the output shaft tube. The outer rotor motor 2 outputs power to the harmonic reduction assembly 3. After the harmonic reduction assembly 3 reduces speed and increases torque, the rotating internal gear 32 or external gear 33 drives the output shaft tube to rotate, thereby driving the electric power-assisted bicycle to travel.

[0074] In some embodiments of the present invention, the mid-mounted motor transmission module 100 includes an output shaft tube, which transmits the rotational power to the wheels of the electric power-assisted bicycle, thereby driving the electric power-assisted bicycle to travel.

[0075] The mid-mounted motor transmission module 100 also includes: a first one-way clutch and a second one-way clutch, the first one-way clutch is sleeved between the central shaft 1 and the output shaft tube to transmit the power of the central shaft 1 to the output shaft tube in one direction; the second one-way clutch is connected to the rotating internal gear 32 or the external gear 33, and is connected to the output shaft tube to transmit the power of the harmonic reduction assembly 3 to the output shaft tube in one direction.

[0076] When the user drives the central shaft 1 to rotate manually, the first one-way clutch connects the central shaft 1 and the output shaft tube, and the power of the central shaft 1 is transmitted to the output shaft tube, while the second one-way clutch separates the output end of the harmonic reduction assembly 3 from the output shaft tube to avoid interference between the harmonic reduction assembly 3 and the output shaft tube. When the outer rotor motor 2 outputs power, the first one-way clutch separates the central shaft 1 and the output shaft tube, while the second one-way clutch connects the output end of the harmonic reduction assembly 3 and the output shaft tube to transmit power to the output shaft tube to avoid interference between the output shaft tube and the central shaft 1.

[0077] The first one-way clutch and the second one-way clutch are provided to eliminate the phenomenon of magnetic resistance or mechanical resistance to the output shaft tube when the outer rotor motor 2 stops running, thereby ensuring that no additional burden is imposed on the rider when the outer rotor motor 2 is not assisting. In addition, the human power output and the power of the outer rotor motor 2 can be separated without affecting each other, thereby preventing human pedaling from driving the motor to rotate, protecting the outer rotor motor 2, and extending the service life of the outer rotor motor 2.

[0078] In some embodiments of the present invention, Figure 1 As shown, the mid-mounted motor transmission module 100 also includes: a housing 8, the outer rotor motor 2 and the harmonic reduction assembly 3 are both arranged in the housing 8, the inner gear 32 or the outer gear 33 is fixedly connected in the housing 8, and the housing 8 can play a supporting role. The housing 8 can also play a protective role, reducing external pollutants from entering the housing 8 and contacting the outer rotor motor 2 and the harmonic reduction assembly 3, thereby improving the working reliability of the mid-mounted motor transmission module 100.

[0079] The electric power-assisted bicycle according to the second aspect of the utility model comprises the mid-mounted motor transmission module 100 based on cycloid deceleration according to the first aspect of the utility model.

[0080] According to the electric power-assisted bicycle of the present invention, by setting the mid-mounted motor transmission module 100 based on the cycloid deceleration of the first aspect mentioned above, the volume of the mid-mounted motor transmission module 100 is small, which is conducive to the user's force, and at the same time reduces the windward area, which can reduce wind resistance and improve sports performance.

[0081] In the description of the present invention, it is necessary to understand that the terms "center", "up", "down", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating orientations or positional relationships, are 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, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0082] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0083] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0084] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0085] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0086] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A mid-mounted motor transmission module based on cycloid deceleration, characterized in that: include: Central axis; An outer rotor motor, the outer rotor motor comprising a stator and a rotor coupled to each other, the stator being arranged around the central axis, and the rotor being spaced apart and surrounding the outer side of the stator; A harmonic reduction assembly, the harmonic reduction assembly surrounds the central axis and is axially arranged with the outer rotor motor, the harmonic reduction assembly includes: an input shaft tube, an internal gear and an external gear, one end of the input shaft tube is connected to the rotor, the internal gear sleeve is on the input shaft tube, the input shaft tube is configured to drive the internal gear to swing or deform periodically during rotation, a first gear ring is provided on the internal gear, and a second gear ring is provided on the external gear surrounding the first gear ring, the number of teeth of the second gear ring is greater than the number of teeth of the first gear ring, and each tooth of the first gear ring is periodically engaged and disengaged with the second gear ring to drive the internal gear or the external gear to reduce rotation.

2. The mid-mounted motor transmission module according to claim 1, characterized in that: Also includes: A connecting disk is arranged around the central axis, an outer edge of the connecting disk is connected to the rotor, and an inner edge of the connecting disk is connected to the input shaft tube.

3. The mid-mounted motor transmission module according to claim 2, characterized in that: The outer edge of the connecting plate is bent toward the rotor in the axial direction to connect with the rotor; The connecting plate is closely attached to the end surface of the input shaft tube and is connected via a threaded fastener.

4. The mid-mounted motor transmission module according to claim 2, characterized in that: Also includes: A support ring, the support ring is arranged around the central axis, and one end of the support ring is connected to the stator; A first support bearing, wherein the first support bearing is sleeved on the support ring, and one end of the input shaft tube is sleeved and connected to the first support bearing.

5. The mid-mounted motor transmission module according to claim 4, characterized in that: The harmonic reduction assembly further includes: an output wheel, the output wheel is arranged around the central axis, the output wheel is connected to the rotating internal gear or the external gear to rotate synchronously; The central motor transmission module also includes: a second support bearing, the second support bearing is sleeved on the output wheel, and the other end of the input shaft tube is sleeved and connected to the second support bearing.

6. The mid-mounted motor transmission module according to any one of claims 1 to 5, characterized in that: The input shaft tube is provided with a cam; The inner gear is a flexible wheel and is mounted on the cam, and the outer gear is a rigid wheel, which is fixed relative to the stator; The harmonic reduction assembly further includes an elastic bearing connected between the flexible wheel and the cam.

7. The mid-mounted motor transmission module according to claim 6, characterized in that: A first annular track groove is provided on the outer peripheral surface of the cam; The elastic bearing includes: a bearing outer ring and a plurality of rolling elements. The bearing outer ring is an elastic member and surrounds the outer side of the cam. A second annular track groove corresponding to the first annular track groove is provided on the inner circumferential surface of the bearing outer ring. The plurality of rolling elements are distributed at intervals along the circumferential direction. The rolling elements roll in cooperation with the first annular track groove and the second annular track groove.

8. The mid-mounted motor transmission module according to claim 6, characterized in that: The inner gear is a plastic wheel.

9. The mid-mounted motor transmission module according to any one of claims 1 to 5, characterized in that: An eccentric wheel is arranged on the input shaft tube; The inner gear is a rigid wheel and the outer sleeve swings periodically on the eccentric wheel, and the outer gear is a rigid wheel and is rotatably arranged.

10. The mid-mounted motor transmission module according to any one of claims 1 to 5, characterized in that: The rotating internal gear or the external gear is dynamically connected to the central shaft; Alternatively, the central motor transmission module further comprises: an output shaft tube which is sleeved on the central shaft, and the rotating internal gear or the external gear is dynamically connected to the output shaft tube.

11. The mid-mounted motor transmission module according to claim 10, characterized in that: The mid-mounted motor transmission module includes the output shaft tube; The mid-mounted motor transmission module also includes: A first one-way clutch, wherein the first one-way clutch is sleeved between the central shaft and the output shaft tube to transmit the power of the central shaft to the output shaft tube in one direction; A second one-way clutch is connected to the rotating internal gear or the external gear and is connected to the output shaft tube to transmit the power of the harmonic reduction assembly to the output shaft tube in one direction.

12. An electric power-assisted bicycle, characterized in that: A mid-mounted motor transmission module based on cycloid deceleration comprising any one of claims 1-11.

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