Middle motor transmission module based on end face tooth transmission and electric power-assisted bicycle

Abstract

The utility model discloses a mid-motor transmission module based on end face tooth transmission and an electric power-assisted bicycle with the mid-motor transmission module, the mid-motor transmission module comprises a central shaft, a motor assembly and a speed reduction assembly, the motor assembly comprises a stator and a rotor which are coupled with each other, the speed reduction assembly comprises a fixed fluted disc, an eccentric movable fluted disc and an output fluted disc which are sequentially arranged in the axial direction, the eccentric movable fluted disc is in power connection with the rotor, the axis of the eccentric movable fluted disc and the axis of the rotor are arranged in parallel at intervals, and the output fluted disc forms the output end of the speed reduction assembly. End face tooth structures are formed between the end faces, facing each other, of the fixed fluted disc and the eccentric movable fluted disc and between the end faces, facing each other, of the output fluted disc and the eccentric movable fluted disc respectively. Through the end face transmission cooperation of the fixed fluted disc, the eccentric movable fluted disc and the output fluted disc, the space occupied by the speed reduction assembly in the radial direction can be reduced, and therefore 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 face gear transmission 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 face gear transmission, which has a small volume and is easy to arrange.

[0005] The utility model also provides an electric power-assisted bicycle having the above-mentioned mid-mounted motor transmission module based on end face gear transmission.

[0006] According to the first aspect of the utility model, a mid-mounted motor transmission module based on face gear transmission comprises: a central shaft; a motor assembly, the motor assembly is arranged around the central shaft and comprises a stator and a rotor coupled to each other; a reduction assembly, the reduction assembly is arranged around the central shaft and comprises a fixed toothed disc, an eccentric movable toothed disc and an output toothed disc arranged in sequence along the axial direction, the eccentric movable toothed disc is dynamically connected to the rotor, the axis of the eccentric movable toothed disc is arranged parallel to the axis of the rotor, and the output toothed disc constitutes the output end of the reduction assembly; wherein, face gear structures are formed between the end faces of the fixed toothed disc and the eccentric movable toothed disc facing each other, and between the end faces of the output toothed disc and the eccentric movable toothed disc facing each other, respectively; the face gear structure comprises: a ball socket formed on one end face, an annular groove formed on the other end face, and a ball located in the ball socket, and is configured so that when the eccentric movable toothed disc rotates, the ball rolls along the annular groove, and the number of balls in the two face gear structures is not equal.

[0007] According to the mid-mounted motor transmission module of the utility model, the space occupied by the reduction assembly in the radial direction can be reduced by the end face transmission cooperation of the fixed gear plate, the eccentric movable gear plate and the output gear plate, thereby realizing the miniaturization and lightness of the mid-mounted motor transmission module and facilitating the arrangement of the mid-mounted motor transmission module.

[0008] In some embodiments, on each of the end face tooth structures, the ball sockets are multiple and circumferentially spaced, and a ball is assembled in each of the ball sockets; the annular groove includes multiple steering sockets and multiple arc grooves, and the multiple steering sockets are circumferentially spaced and the number is not equal to the ball sockets, and an arc groove is connected between every two adjacent steering sockets; on one of the end face tooth structures, the midpoint of the arc groove is closer to the axis of the eccentric movable toothed disc than the two ends, and on the other end face tooth structure, the midpoint of the arc groove is farther away from the axis of the eccentric movable toothed disc than the two ends.

[0009] In some embodiments, in the end face tooth structure between the fixed tooth plate and the eccentric movable tooth plate, the number of the ball sockets is Z1, the number of the arc grooves is Z2, and the following conditions are satisfied: Z2=Z1-1; in the end face tooth structure between the output tooth plate and the eccentric movable tooth plate, the number of the ball sockets is Z3, the number of the arc grooves is Z4, and the following conditions are satisfied: Z4=Z3+1.

[0010] In some embodiments, the motor assembly is an outer rotor motor.

[0011] In some embodiments, the mid-mounted motor transmission module also includes an input eccentric sleeve, which is arranged outside the center axis and is spaced apart. The input eccentric sleeve includes: a first sleeve, which is connected to the rotor and is coaxially arranged; a second sleeve, which is connected to the first sleeve, and the axis of the second sleeve is parallel to the axis of the first sleeve and is spaced apart, and the eccentric movable gear disc is outside the second sleeve.

[0012] In some embodiments, the inner diameter of the input eccentric sleeve is supported by two bearings, the two bearings are arranged at intervals along the axial direction of the input eccentric sleeve, and one of the bearings is arranged on the output gear disc.

[0013] In some embodiments, the mid-mounted motor transmission module also includes a housing, wherein at least a portion of the central shaft, the motor assembly, and the reduction assembly are at least partially disposed within the housing; and the stator and the fixed gear are connected to the housing.

[0014] In some embodiments, the central motor transmission module further includes an elastic clamping assembly, which connects the housing and the output gear disc to push the output gear disc toward the fixed gear disc.

[0015] In some embodiments, the elastic clamping assembly includes: a bearing cover, which is arranged around the central axis and is located on the side of the output gear disc away from the fixed gear disc; a compression spring, one end of which is connected to the housing and the other end is connected to the bearing cover; and a compression support bearing, which is arranged between the bearing cover and the output gear disc.

[0016] In some embodiments, the shell includes: an end cover, a first center hole is provided at the center of the end cover, one end of the center shaft is rotatably disposed in the first center hole, an assembly ring is formed on the end cover around the first center hole, and the stator sleeve is fixed on the assembly ring; a first cylinder body, the first cylinder body surrounds the outside of the rotor, and one end of the first cylinder body is connected to the end cover; a second cylinder body, a second center hole is provided at the center of the second cylinder body, and the other end of the center shaft is rotatably disposed in the second center hole, the edge of the fixed gear disc is clamped between the first cylinder body and the second cylinder body, and the eccentric movable gear disc and the output gear disc are located in the second cylinder body.

[0017] The electric power-assisted bicycle according to the second aspect of the utility model comprises the mid-mounted motor transmission module based on face gear transmission according to the first aspect of the utility model.

[0018] According to the electric power-assisted bicycle of the utility model, by setting the mid-mounted motor transmission module based on end face gear transmission of the first aspect, the weight of the electric power-assisted bicycle is reduced, and the reduction ratio of the electric power-assisted bicycle can be increased, thereby improving the sports performance.

[0019] 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

[0020] Figure 1 It is a structural schematic diagram of a central motor transmission module according to an embodiment of the utility model;

[0021] Figure 2 It is a side structural schematic diagram of an eccentric movable toothed disc according to an embodiment of the utility model;

[0022] Figure 3 It is another side structural schematic diagram of an eccentric movable toothed disc according to an embodiment of the utility model.

[0023] Reference numerals:

[0024] Mid-mounted motor transmission module 100;

[0025] Central axis 1;

[0026] Motor assembly 2; stator 21; rotor 22;

[0027] Speed ​​reduction assembly 3; fixed toothed disc 31; eccentric movable toothed disc 32; output toothed disc 33; annular groove 3a; ball 3b; ball socket 3c; steering socket 34; arc groove 35; first ball 36; second ball 37;

[0028] Input eccentric sleeve 4; first sleeve 41; second sleeve 42; bearing 43;

[0029] Shell 5; end cover 51; first cylinder body 52; second cylinder body 53;

[0030] Elastic clamping assembly 6; bearing cover 61; clamping spring 62; clamping support bearing 63;

[0031] Outer rotor connection structure 7. 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 face gear transmission 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 1As shown, it includes: a central axis 1, a motor assembly 2 and a reduction assembly 3. The motor assembly 2 is arranged around the central axis 1, and includes a stator 21 and a rotor 22 that are coupled to each other. The reduction assembly 3 is arranged around the central axis 1, and includes a fixed gear disc 31, an eccentric movable gear disc 32 and an output gear disc 33 that are arranged in sequence along the axial direction. The eccentric movable gear disc 32 is dynamically connected to the rotor 22. The axis of the eccentric movable gear disc 32 is arranged parallel to the axis of the rotor 22 and spaced apart. The output gear disc 33 constitutes the output end of the reduction assembly 3.

[0036] Among them, end face tooth structures are formed between the end faces of the fixed gear plate 31 and the eccentric movable gear plate 32 facing each other, and between the end faces of the output gear plate 33 and the eccentric movable gear plate 32 facing each other. The end face tooth structure includes: a ball socket 3c formed on one end face, an annular groove 3a formed on the other end face, and a ball 3b located in the ball socket 3c, and is constructed so that the ball 3b rolls along the annular groove 3a when the eccentric movable gear plate 32 rotates, and the number of balls 3b in the two end face tooth structures is not equal.

[0037] 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.

[0038] 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.

[0039] 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 motor assembly 2 and the reduction assembly 3. The motor assembly 2 provides power, the reduction assembly 3 transmits power, and the high-speed low-torque generated by the motor assembly 2 is converted into low-speed high-torque, which can provide the electric power-assisted bicycle with stronger climbing ability and acceleration performance.

[0040] The reduction assembly 3 and the motor assembly 2 are both arranged around the central axis 1. The reduction assembly 3 is coaxially arranged. Compared with the coaxially arranged reduction assembly in the related art, the 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 central motor transmission module 100.

[0041] The deceleration assembly 3 of the embodiment of the utility model is to transmit by using the end face tooth structure between the end faces of the fixed toothed disc 31 and the eccentric movable toothed disc 32 facing each other, and the end face tooth between the end faces of the output toothed disc 33 and the eccentric movable toothed disc 32 facing each other. The end face tooth structure includes a ball socket 3c, an annular groove 3a and a ball 3b, and the ball 3b is rotatably arranged between the ball socket 3c and the annular groove 3a and the ball 3b can roll along the annular groove 3a.

[0042] A ball socket 3c is provided on one of the end faces opposite to each other between the fixed toothed disc 31 and the eccentric movable toothed disc 32, and an annular groove 3a is provided on the other end faces opposite to each other between the fixed toothed disc 31 and the eccentric movable toothed disc 32; a ball socket 3c is provided on one of the end faces opposite to each other between the output toothed disc 33 and the eccentric movable toothed disc 32, and an annular groove 3a is provided on the other end faces opposite to each other between the output toothed disc 33 and the eccentric movable toothed disc 32.

[0043] The balls 3b are rollably arranged between the ball socket 3c and the annular groove 3a, and the number of balls 3b in the two end face tooth structures is not equal. The end face tooth structure between the fixed toothed disc 31 and the eccentric movable toothed disc 32 and the end face tooth structure between the output toothed disc 33 and the eccentric movable toothed disc 32 generate differential tooth motion, and the rotation speed of the output toothed disc 33 is reduced to achieve a deceleration effect.

[0044] The central motor transmission module 100 of the embodiment of the utility model is transmitted by using the end face tooth structure between the end faces of the fixed toothed disc 31 and the eccentric movable toothed disc 32 facing each other, and the end face teeth between the end faces of the output toothed disc 33 and the eccentric movable toothed disc 32 facing each other. Compared with the coaxial reduction assembly using the planetary gear structure in the related art, the reduction assembly in the related art still requires the outer teeth of the gear and the inner gear ring to mesh in the radial direction. The central motor transmission module 100 of the embodiment of the utility model uses the tooth end faces to transmit each other, which can further reduce the space occupied by the reduction assembly 3 in the radial direction, and can realize the miniaturization and lightweight of the central motor transmission module 100.

[0045] In addition, compared with the coaxial arrangement reduction assembly in the related art, the end face gear structure has high transmission efficiency and large reduction ratio. Moreover, compared with the coaxial arrangement reduction assembly in the related art, the end face gear structure has low wear, which is conducive to extending the service life and reducing the operating noise.

[0046] According to the central motor transmission module 100 of the embodiment of the utility model, the space occupied by the reduction assembly 3 in the radial direction can be reduced by the end face transmission cooperation of the fixed gear plate 31, the eccentric movable gear plate 32 and the output gear plate 33, 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 3 As shown, on each end face gear structure, there are multiple ball sockets 3c distributed at intervals in the circumferential direction, and each ball socket 3c is equipped with a ball 3b, that is, the ball 3b and the ball socket 3c are arranged in a one-to-one correspondence. Figure 2 As shown, the annular groove 3a includes a plurality of steering sockets 34 and a plurality of arcuate grooves 35. The plurality of steering sockets 34 are spaced apart along the circumferential direction and the number thereof is not equal to that of the ball socket 3c. An arcuate groove 35 is connected between every two adjacent steering sockets 34.

[0048] On one of the end face tooth structures, the midpoint of the arc groove 35 is closer to the axis of the eccentric movable toothed disc 32 than the two ends, and multiple arc grooves 35 are connected so that the annular groove 3a of this end face tooth structure is constructed as an inner cycloidal groove; on the other end face tooth structure, the midpoint of the arc groove 35 is farther from the axis of the eccentric movable toothed disc 32 than the two ends, and multiple arc grooves 35 are connected so that the annular groove 3a of this end face tooth structure is constructed as an outer cycloidal groove.

[0049] In some embodiments of the utility model, a ball socket 3c is provided on the end surface of the fixed toothed disc 31 facing the eccentric movable toothed disc 32, an annular groove 3a is provided on the end surface of the eccentric movable toothed disc 32 facing the fixed toothed disc 31, and the annular groove 3a is configured as an epicycloidal groove, and the ball 3b between the fixed toothed disc 31 and the eccentric movable toothed disc 32 is a first ball 36. An annular groove 3a is provided on the end surface of the output toothed disc 33 facing the eccentric movable toothed disc 32, and the annular groove 3a is configured as an hypocycloidal groove, a ball socket 3c is provided on the end surface of the eccentric movable toothed disc 32 facing the output toothed disc 33, and the ball 3b between the output toothed disc 33 and the eccentric movable toothed disc 32 is a second ball 37.

[0050] The number of balls 3b between the fixed gear plate 31 and the eccentric movable gear plate 32 is less than the number of balls 3b between the output gear plate 33 and the eccentric movable gear plate 32. Correspondingly, the number of ball sockets 3c on the fixed gear plate 31 is less than the number of ball sockets 3c on the eccentric movable gear plate 32.

[0051] The transmission process of the reduction assembly 3 in one embodiment of the utility model is briefly described below.

[0052] The fixed toothed disc 31 is fixed, and the end faces of the fixed toothed disc 31 and the eccentric movable toothed disc 32 facing each other form an end face tooth structure. The eccentric movable toothed disc 32 is driven to make eccentric circular motion. At this time, the first ball 36 located between the fixed toothed disc 31 and the eccentric movable toothed disc 32 rolls in the outer cycloidal groove, and the eccentric movable toothed disc 32 stably makes eccentric circular motion. At the same time, during the eccentric rotation of the eccentric movable toothed disc 32, the second ball 37 located between the eccentric movable toothed disc 32 and the output toothed disc 33 rolls in the inner cycloidal groove. The second ball 37 acts as an engagement medium to achieve engagement with the end face of the output toothed disc 33, driving the output toothed disc 33 to rotate.

[0053] The differential tooth motion is generated by the hypocycloidal groove and the epicycloidal groove, so that the output gear disc 33 has a lower rotation speed than the eccentric movable gear disc 32, thereby achieving a deceleration effect, improving the transmission efficiency, and increasing the speed ratio. Compared with the transmission method of tooth meshing, it can reduce wear and loss, reduce transmission errors, and improve working reliability.

[0054] In some embodiments of the present invention, in the end face tooth structure between the fixed toothed disc 31 and the eccentric movable toothed disc 32, the number of ball sockets 3c is Z1, the number of arc grooves 35 is Z2, and the following conditions are satisfied: Z2=Z1-1; in the end face tooth structure between the output toothed disc 33 and the eccentric movable toothed disc 32, the number of ball sockets 3c is Z3, the number of arc grooves 35 is Z4, and the following conditions are satisfied: Z4=Z3+1.

[0055] The number of arc grooves 35 and ball sockets 3c is different to realize the reduction transmission of the reduction assembly 3. The number of ball sockets 3c and arc grooves 35 in the end face tooth structure between the fixed tooth plate 31 and the eccentric movable tooth plate 32, and the number of ball sockets 3c and arc grooves 35 in the end face tooth structure between the tooth plate and the eccentric movable tooth plate 32 directly affect the reduction ratio of the reduction assembly 3.

[0056] The reduction ratio calculation formula of the reduction component 3 is as follows:

[0057] I=1 / {1-[(Z2×Z4) / (Z1×Z3)]}(1)

[0058] Wherein, I is the reduction ratio of the reduction assembly 3.

[0059] Let Z1 = n, Z2 = n-1, Z3 = n+k and Z4 = n+k+1, where n and k are both positive integers, and apply them to formula (1) to obtain the reduction ratio.

[0060] Let Z1=k+1, Z2=k, Z3=k+k+1 and Z4=k+k+2, where k is a positive integer, and apply it to formula (1) to obtain the reduction ratio I=2*k+1.

[0061] The utility model can actually select the number of ball sockets 3c and arc grooves 35 in the end face tooth structure between the fixed toothed disc 31 and the eccentric movable toothed disc 32, as well as the number of ball sockets 3c and arc grooves 35 in the end face tooth structure between the output toothed disc and the eccentric movable toothed disc 32 according to the reduction ratio required by the reduction assembly 3.

[0062] It can be understood that in the above-mentioned end face tooth structure between the fixed toothed disc 31 and the eccentric movable toothed disc 32, the number of ball sockets 3c is one more than the number of arc-shaped grooves 35, which is only for the purpose of illustration. In the end face tooth structure between the fixed toothed disc 31 and the eccentric movable toothed disc 32, the number of ball sockets 3c is two more than the number of arc-shaped grooves 35, or the number of ball sockets 3c is one less than the number of arc-shaped grooves 35, which all fall within the protection scope of the present utility model.

[0063] Similarly, in the above-mentioned end face tooth structure between the output gear plate 33 and the eccentric movable gear plate 32, the number of ball sockets 3c is one less than the number of arc grooves 35, which is only for illustrative purposes. In the end face tooth structure between the output gear plate 33 and the eccentric movable gear plate 32, the number of ball sockets 3c is two less than the number of arc grooves 35, or the number of ball sockets 3c is one more than the number of arc grooves 35, which all fall within the protection scope of the present utility model.

[0064] In some embodiments of the present invention, Figure 1 As shown, the motor assembly 2 is an outer rotor motor. The rotor 22 is located outside the stator 21, and the rotor 22 rotates relative to the stator 21 to output power.

[0065] In other embodiments of the present invention, the motor assembly 2 is an inner rotor motor.

[0066] In some embodiments of the present invention, Figure 1 As shown, the central motor transmission module 100 also includes an input eccentric sleeve 4, which is arranged outside the central shaft 1 and is arranged at intervals. The power of the motor is transmitted to the eccentric movable toothed disc 32 through the input eccentric sleeve 4, and the output eccentric sleeve is outside the central shaft 1 and can rotate relative to the central shaft 1.

[0067] The input eccentric sleeve 4 includes: a first sleeve 41 and a second sleeve 42. The first sleeve 41 is connected to the rotor 22 and is coaxially arranged. The second sleeve 42 is connected to the first sleeve 41. The axis of the second sleeve 42 is parallel to the axis of the first sleeve 41 and is spaced apart. The eccentric movable gear disc 32 is sleeved on the second sleeve 42.

[0068] When the rotor 22 drives the input eccentric sleeve 4 to rotate, the first sleeve 41 and the rotor 22 rotate coaxially, and there is an eccentric distance between the axis of the first sleeve 41 and the axis of the second sleeve 42. The second sleeve 42 rotates eccentrically relative to the rotor 22 to drive the eccentric movable toothed disc 32 mounted on the second sleeve 42 to rotate eccentrically.

[0069] In some embodiments of the present invention, Figure 1 As shown, the inner diameter of the input eccentric sleeve 4 is supported by two bearings 43 , and the two bearings 43 are arranged at intervals along the axial direction of the input eccentric sleeve 4 .

[0070] The input eccentric sleeve 4 is supported by double bearings, which can effectively reduce the vibration caused by the outer rotor 22, making the transmission of the rotor 22 to the input eccentric sleeve 4 more stable. In addition, the two bearings 43 are arranged at intervals along the axial direction of the input eccentric sleeve 4, which improves the deformation problem of the input eccentric sleeve 4, reduces the uneven contact caused by the deformation of the input eccentric sleeve 4, and prolongs the service life of the input eccentric sleeve 4.

[0071] like Figure 1 As shown, the inner diameter of the input eccentric sleeve 4 is supported by two bearings 43, one of which is disposed on the output gear disc 33, so as to avoid interference between the input eccentric sleeve 4 and the output gear disc 33 and improve the working stability of the reduction assembly 3. In addition, the bearing 43 supporting the input eccentric sleeve 4 is disposed on the output gear disc 33, so as to reduce the axial dimension of the reduction assembly 3 and further reduce the volume of the central motor transmission module 100.

[0072] In some embodiments of the present invention, the central motor transmission module 100 further includes an outer rotor connection structure 7, which is connected between the rotor 22 and the first sleeve 41 of the input eccentric sleeve 4 to drive the input eccentric sleeve 4 to rotate.

[0073] In some embodiments of the present invention, the outer rotor connection structure 7 is fixedly connected to the first shaft sleeve 41 by fasteners such as bolts.

[0074] In some embodiments of the utility model, the first sleeve 41 forms a step portion on the shaft end surface facing the motor assembly 2, and the outer rotor connection structure 7 is supported on the step surface of the step portion and connected to the first sleeve 41, thereby improving the connection stability between the outer rotor connection structure 7 and the input eccentric sleeve 4. In addition, the cooperation between the outer rotor connection structure 7 and the step portion can also play a role in axially positioning the outer rotor connection structure 7, improving the transmission reliability of the outer rotor connection structure 7, and thus improving the working stability of the reduction assembly 3.

[0075] In some embodiments of the present invention, Figure 1 As shown, the mid-mounted motor transmission module 100 also includes a housing 5 , wherein at least a portion of the central shaft 1 , the motor assembly 2 , and the reduction assembly 3 are at least partially disposed in the housing 5 , and the stator 21 and the fixed gear disc 31 are connected to the housing 5 .

[0076] The housing 5 is the outer contour part of the central motor transmission module 100. The housing 5 can support the motor assembly 2 and the reduction assembly 3 arranged in the housing 5. The stator 21 and the fixed gear plate 31 are fixedly mounted on the housing 5, and the input eccentric sleeve 4 is supported on the housing 5 through the bearing. The housing 5 can also play a protective role, reducing external pollutants from entering the housing 5 and contacting the motor assembly 2 and the reduction assembly 3, thereby improving the working reliability of the central motor transmission module 100.

[0077] In some embodiments of the present invention, Figure 1 As shown, the central motor transmission module 100 further includes an elastic pressing assembly 6 , which connects the housing 5 and the output gear disc 33 to push the output gear disc 33 toward the fixed gear disc 31 .

[0078] By providing the elastic clamping assembly 6, the elastic clamping assembly 6 applies an axial force to the output toothed disc 33, so that the end surface clearance between the fixed toothed disc 31 and the eccentric movable toothed disc 32, and the end surface clearance between the output toothed disc 33 and the eccentric movable toothed disc 32 can be adjusted to compensate for the processing error and assembly error of the housing 5. The ball 3b can roll stably between the ball socket 3c and the annular groove 3a, achieving a good transmission effect, improving the rigidity of the device, reducing the operating noise, improving the guiding accuracy, extending the working life, and compensating for the wear during operation.

[0079] In some embodiments of the present invention, Figure 1 As shown, the elastic clamping assembly 6 includes: a bearing cover 61, a clamping spring 62 and a clamping support bearing 63. The bearing cover 61 is arranged around the central axis 1. The bearing cover 61 is located on the side of the output gear disc 33 away from the fixed gear disc 31. One end of the clamping spring 62 is connected to the housing 5 and the other end is connected to the bearing cover 61. The clamping support bearing 63 is arranged between the bearing cover 61 and the output gear disc 33.

[0080] The bearing cover 61 is used to install a compression support bearing 63, which can withstand axial force. The compression support bearing 63 is arranged between the bearing cover 61 and the output gear disc 33, and the output gear disc 33 can rotate relative to the bearing cover 61. The compression spring 62 is compressed between the bearing cover 61 and the housing 5 to apply a preload force to the output gear disc 33 and adjust the end surface clearance between the fixed gear disc 31 and the eccentric movable gear disc 32.

[0081] Optionally, the compression support bearing 63 is a thrust bearing.

[0082] In some embodiments of the present invention, Figure 1 As shown, a spring mounting seat is provided on the housing 5 , one end of the compression spring 62 is mounted in the spring mounting seat, and the other end of the compression spring 62 is abutted against the bearing cover 61 .

[0083] In some embodiments of the present invention, Figure 1 As shown, the housing 5 includes: an end cover 51, a first cylinder body 52 and a second cylinder body 53. The center of the end cover 51 is provided with a first center hole, one end of the center shaft 1 is rotatably arranged in the first center hole, and a mounting ring is formed on the end cover 51 around the first center hole, and the stator 21 is sleeved and fixed on the mounting ring. The first cylinder body 52 surrounds the outside of the rotor 22, and one end of the first cylinder body 52 is connected to the end cover 51. The center of the second cylinder body 53 is provided with a second center hole, and the other end of the center shaft 1 is rotatably arranged in the second center hole. The edge of the fixed toothed disc 31 is clamped between the first cylinder body 52 and the second cylinder body 53, and the eccentric movable toothed disc 32 and the output toothed disc 33 are located in the second cylinder body 53.

[0084] Along the axial direction of the central axis 1, the shell 5 is divided into three parts: an end cover 51, a first cylinder body 52 and a second cylinder body 53. The axial ends of the central axis 1 pass through the shell 5. One end of the central axis 1 passes through the first center hole of the end cover 51, and the other end of the central axis 1 passes through the second center hole of the second cylinder body 53.

[0085] The end cover 51, the first cylinder body 52 and the second cylinder body 53 separate the housing 5 into two chambers. The motor assembly 2 and the reduction assembly 3 are arranged separately, which can reduce the difficulty of arrangement and installation and reduce interference between components.

[0086] In some embodiments of the present invention, the output gear disc 33 is connected to the central shaft 1. The motor assembly 2 outputs power to the reduction assembly 3. After the reduction assembly 3 reduces speed and increases torque, the output gear disc 33 drives the central shaft 1 to rotate, thereby driving the electric power-assisted bicycle to travel.

[0087] In other embodiments of the present invention, the central motor transmission module 100 further includes: an output shaft tube mounted on the central shaft 1, and an output gear plate 33 is connected to the output shaft tube. The motor assembly 2 outputs power to the reduction assembly 3. After the reduction assembly 3 reduces speed and increases torque, the output gear plate 33 drives the output shaft tube to rotate, thereby driving the electric power-assisted bicycle to travel.

[0088] 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.

[0089] 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 sleeved between the output shaft tube and the output gear plate 33 to transmit the power of the output gear plate 33 to the output shaft tube in one direction.

[0090] 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 gear plate 33 from the output shaft tube to avoid interference between the output gear plate 33 and the output shaft tube. When the motor assembly 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 gear plate 33 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.

[0091] By setting the first one-way clutch and the second one-way clutch, the phenomenon of magnetic resistance or mechanical resistance to the output shaft tube when the motor assembly 2 stops running is eliminated, thereby ensuring that no additional burden is imposed on the rider when the motor assembly 2 is not assisting.

[0092] In other embodiments of the present invention, the mid-mounted motor transmission module 100 includes an output shaft tube, and the mid-mounted motor transmission module 100 is only provided with a second one-way clutch, and the second one-way clutch is sleeved between the output shaft tube and the output gear plate 33 to transmit the power of the output gear plate 33 to the output shaft tube in one direction.

[0093] When the user drives the central shaft 1 to rotate manually, the power of the central shaft 1 is transmitted to the output shaft tube, and the second one-way clutch separates the output gear plate 33 and the output shaft tube to avoid interference between the output gear plate 33 and the output shaft tube. When the motor assembly 2 outputs power, the output shaft tube rotates to drive the central shaft 1 to rotate, and the user can remove his feet from the pedals, which can also avoid interference with the user. In addition, this design method can save the second one-way clutch, which is conducive to the miniaturization and lightweight of the central motor transmission module 100.

[0094] The electric power-assisted bicycle according to the embodiment of the second aspect of the utility model comprises the mid-mounted motor transmission module 100 based on face gear transmission according to the first aspect of the utility model.

[0095] According to the electric power-assisted bicycle of the second embodiment of the utility model, by setting the mid-mounted motor transmission module 100 based on end face gear transmission of the first aspect of the utility model, the weight of the electric power-assisted bicycle can be reduced, and the reduction ratio of the electric power-assisted bicycle can be increased, thereby improving the sports performance.

[0096] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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 face gear transmission, characterized in that: include: Central axis; A motor assembly, the motor assembly is arranged around the central axis and includes a stator and a rotor coupled to each other; A reduction assembly, the reduction assembly is arranged around the central axis and comprises a fixed toothed disc, an eccentric movable toothed disc and an output toothed disc arranged in sequence along the axial direction, the eccentric movable toothed disc is dynamically connected to the rotor, the axis of the eccentric movable toothed disc is arranged parallel to the axis of the rotor and spaced apart, and the output toothed disc constitutes an output end of the reduction assembly; Wherein, end face tooth structures are formed between the end faces of the fixed toothed disc and the eccentric movable toothed disc facing each other, and between the end faces of the output toothed disc and the eccentric movable toothed disc facing each other; The end face tooth structure includes: a ball socket formed on one end face, an annular groove formed on the other end face, and a ball located in the ball socket. The structure is such that when the eccentric movable toothed disc rotates, the ball rolls along the annular groove, and the number of balls in the two end face tooth structures is not equal.

2. The mid-mounted motor transmission module according to claim 1, characterized in that: On each of the end face gear structures, the ball sockets are multiple and circumferentially spaced, and a ball is mounted in each of the ball sockets; The annular groove includes a plurality of steering sockets and a plurality of arcuate grooves, the plurality of steering sockets are spaced apart along the circumferential direction and the number of the plurality of steering sockets is not equal to the number of the ball sockets, and an arcuate groove is connected between every two adjacent steering sockets; On one of the end face tooth structures, the midpoint of the arc groove is closer to the axis of the eccentric movable toothed disc than the two ends, and on the other end face tooth structure, the midpoint of the arc groove is farther away from the axis of the eccentric movable toothed disc than the two ends.

3. The mid-mounted motor transmission module according to claim 2, characterized in that: In the face tooth structure between the fixed toothed disc and the eccentric movable toothed disc, the number of the ball sockets is Z1, the number of the arc grooves is Z2, and the following conditions are satisfied: Z2 = Z1-1; In the end face tooth structure between the output gear disc and the eccentric movable gear disc, the number of the ball sockets is Z3, the number of the arc grooves is Z4, and the following condition is satisfied: Z4=Z3+1.

4. The mid-mounted motor transmission module according to claim 1, characterized in that: The motor assembly is an outer rotor motor.

5. The mid-mounted motor transmission module according to claim 1, characterized in that: It also includes an input eccentric sleeve, the input eccentric sleeve is arranged outside the central shaft and is arranged at intervals, and the input eccentric sleeve includes: A first sleeve, the first sleeve is connected to the rotor and is coaxially arranged; The second sleeve is connected to the first sleeve, the axis of the second sleeve is parallel to the axis of the first sleeve and is spaced apart from the first sleeve, and the eccentric movable toothed disc is sleeved on the second sleeve.

6. The mid-mounted motor transmission module according to claim 5, characterized in that: The inner diameter of the input eccentric sleeve passes through two bearings, the two bearings are arranged at intervals along the axial direction of the input eccentric sleeve, and one of the bearings is arranged on the output gear disc.

7. The mid-mounted motor transmission module according to any one of claims 1 to 6, characterized in that: It also includes a housing, wherein at least a portion of the central shaft, the motor assembly, and the reduction assembly are at least partially disposed within the housing; The stator and the fixed gear disc are connected to the housing.

8. The mid-mounted motor transmission module according to claim 7, characterized in that: It also includes an elastic pressing assembly, which connects the housing and the output gear disc to push the output gear disc toward the fixed gear disc.

9. The mid-mounted motor transmission module according to claim 8, characterized in that: The elastic pressing component comprises: A bearing cover, the bearing cover is arranged around the central axis, and the bearing cover is located on a side of the output gear disc away from the fixed gear disc; A compression spring, one end of which is connected to the housing and the other end of which is connected to the bearing cover; A compression support bearing is arranged between the bearing cover and the output gear disc.

10. The mid-mounted motor transmission module according to claim 7, characterized in that: The housing comprises: An end cover, wherein a first center hole is provided at the center of the end cover, one end of the center shaft is rotatably disposed in the first center hole, an assembly ring is formed on the end cover around the first center hole, and the stator jacket is fixed on the assembly ring; A first cylinder body, the first cylinder body surrounds the outer side of the rotor, and one end of the first cylinder body is connected to the end cover; A second cylinder body, wherein a second center hole is provided at the center of the second cylinder body, the other end of the center shaft is rotatably disposed in the second center hole, the edge of the fixed gear plate is clamped between the first cylinder body and the second cylinder body, and the eccentric movable gear plate and the output gear plate are located in the second cylinder body.

11. An electric power-assisted bicycle, characterized in that: It comprises a mid-mounted motor transmission module based on end face gear transmission as described in any one of claims 1-10.

Images