A mid-mounted motor and electric power-assisted bicycle

Abstract

The present invention discloses a mid-mounted motor and an electric power-assisted bicycle, and relates to the field of electric bicycles. The mid-mounted motor includes a housing, a stator, a rotor assembly, a sun gear, a planetary gear assembly, a first clutch assembly, a second clutch assembly, and a central shaft, wherein the stator is fixedly connected to the housing; the rotor is coaxially and rotatably arranged inside the stator; the sun gear is fixedly penetrated through the rotor and is rotatably connected to the housing; the planetary gear assembly includes an inner gear ring, a double-linked planetary gear meshed with the inner gear ring, and a planetary carrier connected to the double-linked planetary gear, the inner gear ring is fixedly connected to the housing, the double-linked planetary gear meshes with the sun gear, the planetary carrier is rotatably connected to the sun gear and fixed to the double-linked planetary gear; the first clutch assembly is fixedly connected to the planetary carrier; the second clutch assembly is transmission-connected to the first clutch assembly; the central shaft extends along the axial direction of the sun gear and is connected to the second clutch assembly. By adopting the planetary gear assembly, the mid-mounted motor is light in weight and small in size, and can increase the motor torque while reducing the motor speed.

Description

Technical Field

[0001] The present invention relates to the field of electric bicycles, and in particular to a mid-mounted motor and an electric power-assisted bicycle. Background Art

[0002] As an auxiliary means of transportation, power-assisted bicycles are equipped with motors and power-assisted systems, which can realize the integration of human riding and motor assistance. At present, power-assisted bicycles have increasingly become an important means of transportation for people to travel, and the motor of power-assisted bicycles is particularly important as the main power source in the power-assisted device. In the prior art, the primary reduction gears of traditional motors used in power-assisted bicycles mostly use parallel teeth and nylon teeth, resulting in low working efficiency, narrow motor high-efficiency platform, large tooth slot torque, small torque, high temperature rise, poor reliability and low strength of nylon teeth. Summary of the invention

[0003] The object of the present invention is to provide a mid-mounted motor and an electric power-assisted bicycle. The mid-mounted motor is light in weight and small in size and can increase the torque of the motor while reducing the motor speed.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] A mid-mounted motor, comprising:

[0006] chassis;

[0007] A stator, the stator being fixedly connected to the casing;

[0008] A rotor assembly, the rotor assembly is coaxially and rotatably disposed inside the stator;

[0009] A sun gear, the sun gear is fixedly disposed through the rotor assembly and is rotatably connected to the casing;

[0010] A planetary gear assembly, comprising an inner gear ring, duplex planetary gears meshing with the inner gear ring, and a planet carrier connected to the duplex planetary gears, wherein the inner gear ring is fixedly connected to the housing, the duplex planetary gears meshing with the sun gears, and the planet carrier is rotatably connected to the sun gears and fixedly connected to the duplex planetary gears;

[0011] a first clutch assembly, wherein the first clutch assembly is fixedly connected to the planet carrier;

[0012] a second clutch assembly, the second clutch assembly being drivingly connected to the first clutch assembly;

[0013] A middle shaft extends along the axial direction of the sun gear and is connected to the second clutch assembly.

[0014] Optionally, the planetary gear assembly further includes a connecting pin and a support frame, wherein the connecting pin is rotatably inserted into the double-linked planetary gear and has two ends respectively fixedly connected to the planetary frame and the support frame, and the support frame is fixedly connected to the first clutch assembly.

[0015] Optionally, the central motor further includes a first housing, the housing and the inner gear ring are respectively fixed on two sides of the first housing, and the planet carrier and the central shaft are both rotatably connected to the first housing.

[0016] Optionally, the first clutch assembly includes a gear and a first inner wheel coaxially arranged inside the gear, a plurality of first rollers are evenly spaced along the circumferential direction of the first inner wheel between the first inner wheel and the inner wall of the gear, and the first rollers can roll between the first inner wheel and the gear; the first inner wheel is fixedly connected to the planetary carrier, and the gear is transmission-connected to the second clutch assembly.

[0017] Optionally, the first clutch assembly further includes a first bearing, which is coaxially disposed between the first inner wheel and the gear and is capable of abutting against the plurality of first rollers along an axial direction of the first inner wheel.

[0018] Optionally, the second clutch assembly includes an output gear and a second inner wheel coaxially arranged inside the output gear, a plurality of second rollers are evenly spaced along the circumferential direction of the second inner wheel between the second inner wheel and the inner wall of the output gear, and the second rollers can roll between the second inner wheel and the output gear; the second inner wheel is keyed to the center shaft, and the output gear is meshed with the gear and is rotationally connected to the center shaft.

[0019] Optionally, a plurality of third rollers are evenly spaced apart along the circumferential direction of the second inner wheel between the second inner wheel and the inner wall of the output gear, the third rollers are capable of rolling between the second inner wheel and the output gear, the third rollers are alternately arranged with the second rollers and the diameter of the third rollers is smaller than the diameter of the second rollers.

[0020] Optionally, the rotor assembly includes a rotor core and a plurality of magnets embedded in the rotor core, the plurality of magnets being evenly spaced along the circumference of the rotor core; a plurality of buckling points are arranged on one end surface of the rotor core along the axial direction, the plurality of buckling points are evenly spaced along the circumference of the rotor core, one buckling point is arranged between each adjacent two magnets, and a plurality of grooves are arranged on the other end surface of the rotor core along the axial direction, the plurality of grooves corresponding one-to-one to the positions of the plurality of buckling points.

[0021] Optionally, the rotor core is provided with a plurality of circular through holes evenly spaced apart along the axial direction, and the plurality of circular through holes all extend along the axial direction of the rotor core.

[0022] An electric power-assisted bicycle comprises the above-mentioned mid-mounted motor.

[0023] Beneficial effects of the present invention: The mid-mounted motor and electric power-assisted bicycle provided by the present invention, when powered on, the rotor can rotate relative to the stator, and then the rotor can drive the sun gear to rotate, the sun gear drives the double-linked planetary gear to rotate in the inner gear ring, and at the same time the double-linked planetary gear can drive the planetary carrier to rotate, and finally power is transmitted through the first clutch assembly and the second clutch assembly. By adopting the cooperation of the double-linked planetary gear and the inner gear ring, the structure of the planetary gear assembly is compact, and at the same time the inner gear ring has a large load-bearing capacity and can accommodate the double-linked planetary gear inside, so that the mid-mounted motor can be light in weight and small in size. At the same time, compared with the reduction gear in the traditional motor, the use of the planetary gear assembly for power transmission can improve the transmission efficiency of the motor, and can increase the torque of the motor while reducing the motor speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a cross-sectional view of a mid-mounted motor provided in Embodiment 1 of the present invention;

[0025] Figure 2 is an exploded view of a portion of the structure of the mid-mounted motor provided in the first embodiment of the present invention;

[0026] Figure 3 is a cross-sectional view of a planetary gear assembly of a mid-mounted motor provided in Embodiment 1 of the present invention;

[0027] Figure 4 1 is a schematic diagram of the installation of the inner gear ring of the planetary gear assembly of the mid-mounted motor provided in the first embodiment of the present invention;

[0028] Figure 5 is a cross-sectional view of a first clutch assembly of a mid-mounted motor provided in Embodiment 1 of the present invention;

[0029] Figure 6 is an exploded view of a first clutch assembly of a mid-mounted motor provided in Embodiment 1 of the present invention;

[0030] Figure 7 is a cross-sectional view of a second clutch assembly of a mid-mounted motor provided in Embodiment 1 of the present invention;

[0031] Figure 8 is an exploded view of the second clutch assembly of the mid-mounted motor provided in the first embodiment of the present invention;

[0032] Fig. 9 is a schematic structural diagram of a rotor assembly of a mid-mounted motor provided in Embodiment 1 of the present invention;

[0033] Fig.10 is a cross-sectional view of a first clutch assembly of a mid-mounted motor provided in Embodiment 2 of the present invention;

[0034] Fig.11 It is an exploded view of the first clutch assembly of the mid-mounted motor provided in the second embodiment of the present invention.

[0035] In the figure:

[0036] 1- housing; 2- stator;

[0037] 3- rotor assembly; 31- rotor core; 311- buckle point; 312- circular through hole; 313- through hole; 32- magnetic steel;

[0038] 4-Sun gear;

[0039] 5-planetary gear assembly; 51-inner ring gear; 52-double planetary gear; 53-planet carrier; 54-connecting pin; 55-support frame;

[0040] 6-first clutch assembly; 61-gear; 62-first inner wheel; 621-first arc groove; 622-semi-arc groove; 63-first roller; 64-first bearing; 65-baffle;

[0041] 7-second clutch assembly; 71-output gear; 72-second inner wheel; 73-second roller; 74-second roller; 75-cage;

[0042] 8-middle shaft; 9-first housing; 10-sprocket; 11-second housing; 12-bearing seat; 13-controller; 14-circuit board; 15-bracket; 16-oil seal. DETAILED DESCRIPTION

[0043] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0044] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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 or an electrical connection; 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.

[0045] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0046] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0047] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0048] Embodiment 1

[0049] like Figure 1-Figure 3As shown, the central motor includes a casing 1, a stator 2, a rotor assembly 3, a sun gear 4, a planetary gear assembly 5, a first clutch assembly 6, a second clutch assembly 7 and a central shaft 8, wherein the stator 2 is fixedly connected to the casing 1; the rotor assembly 3 is coaxially and rotatably arranged inside the stator 2; the sun gear 4 is fixedly penetrated through the rotor assembly 3 and is rotatably connected to the casing 1; the planetary gear assembly 5 includes an inner ring gear 51, a double planetary gear 52 meshing with the inner ring gear 51 and a planet carrier 53 connected to the double planetary gear 52, the inner ring gear 51 is fixedly connected to the casing 1, the double planetary gear 52 is meshed with the sun gear 4, the planet carrier 53 is rotatably connected to the sun gear 4 and fixed to the double planetary gear 5; the first clutch assembly 6 is fixedly connected to the planet carrier 53; the second clutch assembly 7 is transmission-connected to the first clutch assembly 6; the central shaft 8 extends along the axial direction of the sun gear 4 and is connected to the second clutch assembly 7. It can be understood that when power is turned on, the rotor assembly 3 can rotate relative to the stator 2, and then the rotor assembly 3 can drive the sun gear 4 to rotate, and the sun gear 4 drives the double planetary gear 52 to rotate in the inner ring gear 51, and at the same time, the double planetary gear 52 can drive the planet carrier 53 to rotate, and finally the power is transmitted through the first clutch assembly 6 and the second clutch assembly 7. By adopting the cooperation of the double planetary gear 52 and the inner ring gear 51, the structure of the planetary gear assembly 5 is compact, and at the same time, the inner ring gear 51 has a large load-bearing capacity and can accommodate the double planetary gear 52 inside, so that the mid-mounted motor can be light in weight and small in size. At the same time, compared with the reduction gear in the traditional motor, the use of the planetary gear assembly 5 for power transmission can improve the transmission efficiency of the motor, and can increase the torque of the motor while reducing the motor speed.

[0050] Specifically, Figure 1-Figure 3 As shown, in order to reduce the rotational friction, one end of the sun gear 4 is rotatably connected to the housing 1 through a bearing, and a gasket is provided between the bearing and the housing 1, and the axial clearance between the sun gear 4 and the housing 1 can be adjusted through the gasket, and the planet carrier 53 is rotatably matched with the sun gear 4 through a deep groove ball bearing. In other embodiments, other structures besides bearings can also be used.

[0051] In this embodiment, the mid-mounted motor is applied to an electric power-assisted bicycle, such as Figure 2 As shown, the electric power-assisted bicycle further includes a toothed disc 10, which is connected to the middle shaft 8, and the toothed disc 10 is connected to the wheel of the electric power-assisted bicycle through a chain; at the same time, cranks are installed at both ends of the middle shaft 8, and pedals are installed on the cranks, that is, the electric power-assisted bicycle can also rotate the middle shaft 8 through the pedals to drive the wheels to rotate. In other embodiments, the mid-mounted motor can also be applied to other electric bicycles.

[0052] Alternatively, if Figure 1 and Figure 3As shown, the planetary gear assembly 5 further includes a connecting pin 54 and a support frame 55. The connecting pin 54 is rotatably inserted into the double-linked planetary gear 52 and its two ends are respectively fixedly connected to the planetary frame 53 and the support frame 55. The support frame 55 is fixedly connected to the first clutch assembly 6. It can be understood that when the sun gear 4 is meshed with the double-linked planetary gear 52 for transmission, the double-linked planetary gear 52 can drive the planetary frame 53 to rotate synchronously while rotating in the inner gear ring 51. The planetary frame 53 drives the support frame 55 to rotate through the connecting pin 54, and then the support frame 55 can transmit power to the first clutch assembly 6. In this embodiment, the sun gear 4 is inserted into the planetary frame 53, and the connecting pin 54 extends along the length direction of the sun gear 4, and is rotatably connected to the double planetary gear 52 through two deep groove ball bearings, the two deep groove ball bearings are arranged at intervals and a gasket is arranged in the middle, and the two deep groove ball bearings can be limited by the gasket, and the two sides of the two deep groove ball bearings are respectively abutted against the planetary frame 53 and the support frame 55; in addition, in order to ensure the reliable connection between the planetary frame 53 and the support frame 55, in addition to the connecting pin 54, the planetary frame 53 and the support frame 55 are also fixed by screws. In other embodiments, the planetary frame 53 and the support frame 55 can also be fixed by other means.

[0053] In this embodiment, the inner gear ring 51 and the duplex planetary gears 52 are both made of steel, which has better heat dissipation capacity and strength than the common nylon material, and can extend the service life of the inner gear ring 51 and the duplex planetary gears 52. In other embodiments, the inner gear ring 51 and the duplex planetary gears 52 can also be made of other materials with better heat dissipation and greater strength.

[0054] Alternatively, if Figure 1 and Figure 3 As shown, the central motor further includes a first housing 9, the housing 1 and the inner gear ring 51 are fixed on both sides of the first housing 9, and the planet carrier 53 and the middle shaft 8 are both rotatably connected to the first housing 9. Specifically, the sun gear 4 is passed through the first housing 9, one end of the middle shaft 8 is also passed through the first housing 9 and rotatably cooperates with the first housing 9 through a bearing, and the planet carrier 53 is also rotatably cooperated with the first housing 9 through a bearing. Specifically, as Figure 4As shown, the inner gear ring 51 is fixed to the first housing 9 by six stepped screws. In this embodiment, the central motor also includes a circuit board 14, which is fixed to the first housing 9 and connected to the stator 2. It also includes a second housing 11, the other end of the central axis 8 is passed through the second housing 11, the first housing 9 and the second housing 11 are fixedly connected by screws, the planetary gear assembly 5, the first clutch assembly 6 and the second clutch assembly 7 are all located between the first housing 9 and the second housing 11, and the planetary gear assembly 5, the first clutch assembly 6 and the second clutch assembly 7 can be sealed and protected by the first housing 9 and the second housing 11 to avoid damage; at the same time, the end of the sun gear 4 away from the housing 1 is rotatably connected to the second housing 11 through a bearing, and the second clutch assembly 7 is rotatably matched with the second housing 11 through a bearing. In other embodiments, the inner gear ring 51 can also be fixedly connected to the first housing 9 by a pin and a retaining spring.

[0055] Optionally, the central motor further comprises a detection element, which is fixedly connected to the central shaft 8 and is used to detect the torque of the central shaft 8. Figure 1 As shown, the central motor also includes a controller 13, which is fixed to the first box body 9 by screws, and the detection element is a torque sensor, which is electrically connected to the controller 13. The torque of the central shaft 8 is detected by the torque sensor and fed back to the controller 13. The controller 13 can automatically control the central motor, and the control is simple and convenient. As for the specific structure of the controller 13, it is already a prior art and will not be described here. In other embodiments, the detection element can also be other structures.

[0056] Alternatively, if Figure 1 , Figure 5 and Figure 6As shown, the first clutch assembly 6 includes a gear 61 and a first inner wheel 62 coaxially arranged inside the gear 61. A plurality of first rollers 63 are evenly spaced between the first inner wheel 62 and the inner wall of the gear 61 along the circumferential direction of the first inner wheel 62. The first rollers 63 can roll between the first inner wheel 62 and the gear 61. The first inner wheel 62 is fixedly connected to the planet carrier 53, and the gear 61 is transmission-connected to the second clutch assembly 7. Specifically, the first inner wheel 62 is connected to the support frame 55 through an A-type flat key. A plurality of first arc grooves 621 are spaced apart on the outer circumference of the first inner wheel 62, and the first rollers 63 can roll in the first arc grooves 621. When the sun gear 4 rotates and drives the double planetary gear 52 to rotate, the first inner wheel 62 can be driven to rotate synchronously through the rotation of the planet carrier 53 and the support frame 55. At this time, the first clutch assembly 6 is in a coupled state, and the first roller 63 can be pressed between the first inner wheel 62 and the gear 61, driving the gear 61 to rotate, thereby transmitting power to the second clutch assembly 7; conversely, when the gear 61 rotates, the first clutch assembly 6 is in a disengaged state, that is, the first roller 63 can roll in the first arc groove 621 on the outer periphery of the first inner wheel 62, and power cannot be transmitted between the first inner wheel 62 and the gear 61. It can be understood that the power transmission between the first inner wheel 62 and the gear 61 is carried out through the first roller 63, with high transmission efficiency, stable operation and low noise.

[0057] Alternatively, if Figure 5 and Figure 6 As shown, the first clutch assembly 6 further includes a first bearing 64, which is coaxially disposed between the first inner wheel 62 and the gear 61 and can abut against a plurality of first rollers 63 along the axial direction of the first inner wheel 62. It can be understood that the two ends of the first roller 63 abut against the limiting step of the gear 61 and the first bearing 64, respectively, and the first roller 63 can be limited in the axial direction of the first inner wheel 62 by the first bearing 64 to prevent the first roller 63 from coming out in the axial direction of the first inner wheel 62. In other embodiments, other structures can also be used instead of the first bearing 64.

[0058] Alternatively, if Figure 1 , Figure 7 and Figure 8As shown, the second clutch assembly 7 includes an output gear 71 and a second inner wheel 72 coaxially arranged inside the output gear 71. A plurality of second rollers 73 are evenly spaced between the second inner wheel 72 and the inner wall of the output gear 71 along the circumferential direction of the second inner wheel 72. The second rollers 73 can roll between the second inner wheel 72 and the output gear 71. The second inner wheel 72 is keyed to the middle shaft 8. The output gear 71 is meshed with the gear 61 and is rotationally connected to the middle shaft 8. Specifically, the output gear 71 is rotationally connected to the second housing 11 through a bearing. The output end of the output gear 71 is inserted through the second housing 11 and connected to the toothed disc 10. The output gear 71 is rotationally connected to the middle shaft 8 through a needle bearing. At the same time, an oil seal 16 is also arranged outside the needle bearing. The oil seal 16 is sleeved on the middle shaft 8 to protect the needle bearing. It can be understood that when the output gear 71 rotates, it can drive the toothed disc 10 to rotate, and then drive the wheel to rotate, so as to achieve the purpose of electric riding.

[0059] Specifically, Figure 7 and Figure 8 As shown, a plurality of third rollers 74 are evenly spaced between the second inner wheel 72 and the inner wall of the output gear 71 along the circumferential direction of the second inner wheel 72, and the third rollers 74 can roll between the second inner wheel 72 and the output gear 71. The third rollers 74 and the second rollers 73 are alternately arranged, and the diameter of the third rollers 74 is smaller than the diameter of the second rollers 73. In this embodiment, a plurality of second arc grooves are evenly spaced on the outer periphery of the second inner wheel 72, and the third rollers 74 and the second rollers 73 can roll in the second arc grooves. When the first clutch assembly 6 is in an engaged state, that is, the first inner core wheel 62 can drive the gear 61 to rotate, and the gear 61 can drive the output gear 71 to rotate. At this time, the second clutch assembly 7 is in a disengaged state, that is, the third roller 74 and the second roller 73 can roll in the second arc groove, and the power cannot be transmitted to the second inner core wheel 72; when the pedal is stepped on and the middle shaft 8 is rotated by the crank, the middle shaft 8 drives the second inner core wheel 72 to rotate. At this time, the second clutch assembly 7 is in an engaged state, that is, the third roller 74 and the second roller 73 can be pressed between the second inner core wheel 72 and the output gear 71 to transmit power, thereby driving the output gear 71 to rotate, and then transmitting the power to the wheel through the sprocket 10, driving the wheel to rotate.

[0060] Specifically, the second clutch assembly 7 further includes a retainer 75, which is coaxially disposed between the second inner wheel 72 and the output gear 71 and can abut against the plurality of second rollers 73 and the plurality of third rollers 74 along the axial direction of the second inner wheel 72. It can be understood that the two ends of the second roller 73 and the plurality of third rollers 74 abut against the output gear 71 and the retainer 75 respectively, and the second roller 73 and the third roller 74 can be limited in the axial direction of the second inner wheel 72 by the retainer 75 to prevent the second roller 73 and the third roller 74 from coming out in the axial direction of the second inner wheel 72. The second clutch assembly 7 adopts the cooperation mode of the second roller 73 and the third roller 74, which can ensure high transmission efficiency, stable operation and low noise between the second inner wheel 72 and the output gear 71.

[0061] In this embodiment, Figure 1 As shown, the central motor further includes a bracket 15, which is sleeved on the central axis 8 and can abut against the first box body 9. The bracket 15 can limit the central axis 8 axially to prevent the central axis 8 from axially moving and affecting the use effect of the central motor; and also includes a bearing seat 12, which is sleeved on the central axis 8 and fixed to the first box body 9, and is rotatably connected to the output gear 71 through a bearing. In this embodiment, in order to reduce the weight of the central motor, the bracket 15 is made of plastic. In other embodiments, the bracket 15 can also be made of other materials.

[0062] Alternatively, if Fig. 9 As shown, the rotor assembly 3 includes a rotor core 31 and a plurality of magnetic steels 32 embedded in the rotor core 31, and the plurality of magnetic steels 32 are evenly spaced along the circumference of the rotor core 31; a plurality of buckle points 311 are arranged on one end face of the rotor core 31 in the axial direction, and the plurality of buckle points 311 are evenly spaced along the circumference of the rotor core 31, and a buckle point 311 is arranged between two adjacent magnetic steels 32. Specifically, a plurality of grooves are arranged on the other end face of the rotor core 31 in the axial direction, and the plurality of grooves correspond to the positions of the plurality of buckle points 311 one by one. It can be understood that when the plurality of rotor cores 31 are superimposed on each other, the buckle point 311 of one rotor core 31 can be buckled in the groove of another rotor core 31 to form a self-buckle, so that the structure is firm and stable. At the same time, the magnetic steel 32 is embedded in the rotor core 31, which can reduce the loss of the central motor and improve the motor efficiency, and can also save costs. In this embodiment, the buckle point 311 is rectangular, and the groove is also rectangular. In other embodiments, the buckle point 311 and the groove may also be in other shapes such as a circle.

[0063] In this embodiment, multiple buckle points 311 are evenly spaced along the circumferential direction of the rotor core 3 and near the axis position, and correspondingly, multiple grooves are also arranged at the same position on the other end surface of the rotor core 31 to correspond thereto. Through the above arrangement, the structural stability of multiple rotor cores 31 can be ensured when they are stacked on each other. In other embodiments, the positions and numbers of the buckle points 311 and the grooves can also be changed according to different usage requirements.

[0064] In this embodiment, a certain air gap is provided between one end of the magnetic steel 32 and the rotor core 31 , and the magnetic leakage of the magnetic steel 32 can be reduced through the air gap. The shape and size of the air gap are not limited herein.

[0065] Alternatively, if Fig. 9 As shown, the rotor core 31 is evenly spaced along the circumferential direction and is provided with a plurality of circular through holes 312, and the plurality of circular through holes 312 extend along the axial direction of the rotor core 31. Specifically, two circular through holes 312 are provided between two adjacent magnetic steels 32. The circular through holes 312 can reduce the cogging torque of the motor, thereby improving the performance of the motor. As for the size of the circular through holes 312, there is no limitation. In other embodiments, the number of the circular through holes 312 can be appropriately increased or decreased according to different usage requirements.

[0066] In this embodiment, Fig. 9 As shown, the rotor core 31 is also provided with a plurality of through holes 313 arranged at intervals. The plurality of through holes 313 are arranged along the circumferential direction of the rotor core 31 and extend along the axial direction of the rotor core 31. The through holes 313 are provided at one end of the magnet 32 ​​away from the air gap. The magnet slot where each magnet 32 ​​is located is connected to two through holes 313. The through holes 313 can further reduce the magnetic leakage of the magnet 32 ​​and improve the service life of the motor.

[0067] This embodiment also provides an electric power-assisted bicycle, which has three usage modes: electric mode, riding mode and power-assisted mode. When in the electric mode, after the motor is powered on, the rotor assembly 3 drives the sun gear 4 to rotate, the sun gear 4 drives the double planetary gear 52 to rotate, and then drives the planetary frame 53 and the support frame 55 to rotate, and the support frame 55 can drive the first inner core wheel 612 to rotate synchronously. At this time, the first clutch assembly 6 is in a coupled state, the first inner core wheel 62 drives the gear 61 to rotate through the first roller 63, and the gear 61 drives the output gear 71 to rotate. At this time, the second clutch assembly 7 is in a disengaged state, the third roller 73 and the fourth roller 74 will not transmit power, the second inner core wheel 62 will not generate movement, and the output gear 71 drives the toothed disc 10 to rotate, thereby driving the wheel to rotate. When in riding mode, the motor is not powered and the rotor assembly 3 does not rotate. At this time, the middle shaft 8 is rotated by pedaling the foot and the crank, and the middle shaft 8 drives the second inner wheel 72 to rotate. At this time, the second clutch assembly 7 is in a coupled state, and the second inner wheel 72 drives the output gear 71 to rotate through the second roller 73 and the third roller 74, and the output gear 71 drives the gear 61 to rotate. At this time, the first clutch assembly 6 is in a disengaged state. Therefore, the first roller 63 will not transmit power, and the first inner wheel 62 will not move. The output gear 71 then drives the sprocket 10 to rotate, thereby driving the wheel to rotate. When in the power-assist mode, the middle shaft 8 is rotated by pedaling the foot and the crank, and the middle shaft 8 drives the second inner core wheel 72 to rotate. At this time, the second clutch assembly 7 is in a coupled state, and the second inner core wheel 72 drives the output gear 71 to rotate through the second roller 73 and the third roller 74. At this time, the controller 13 processes the torque of the middle shaft 8 collected by the detection element, and controls the motor to start and work through power distribution. The rotor assembly 3 drives the sun gear 4 to rotate, and then drives the double planetary gear 52 to rotate, drives the planetary carrier 53 and the support frame 55 to rotate, and drives the first inner core wheel 62 to rotate. At this time, the first clutch assembly 6 is in a coupled state, and the first inner core wheel 62 drives the gear 61 to rotate, and at the same time transmits power to the output gear 71. In this mode, the pedal and the motor act on the output gear 71 at the same time to drive the sprocket 10 to rotate, thereby driving the wheel to rotate, which can achieve the effect of saving effort.

[0068] Embodiment 2

[0069] The difference between this embodiment and the first embodiment is that Fig.10 and 11 As shown, the outer periphery of the first inner wheel 62 is also provided with a plurality of semi-arc grooves 622 at intervals, the first arc grooves 621 and the semi-arc grooves 622 are alternately arranged, and when the first roller 63 rolls in the first arc groove 621, the semi-arc grooves 622 can cooperate with the inner wall of the gear 61 to ensure the free rolling of the first roller 63, thereby improving the transmission efficiency of the first clutch assembly 6 and ensuring silent operation.

[0070] In this embodiment, a baffle 65 is used in the first clutch assembly 6 to replace the first bearing 64. The first roller 63 is respectively in contact with the limiting step of the gear 61 and the baffle 65 at both ends in the axial direction. The baffle 65 can limit the first roller 63 in the axial direction of the first inner wheel 62 to prevent the first roller 63 from coming out in the axial direction of the first inner wheel 62. By using the baffle 65 instead of the first bearing 64, the structure of the first clutch assembly 6 can be simplified, ensuring a smoother operation.

[0071] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A mid-mounted motor, characterized in that: include: Housing (1); A stator (2), the stator (2) being fixedly connected to the casing (1); A rotor assembly (3), the rotor assembly (3) being coaxially and rotatably arranged inside the stator (2); A sun gear (4), the sun gear (4) being fixedly disposed through the rotor assembly (3) and rotatably connected to the casing (1); A planetary gear assembly (5), comprising an inner gear ring (51), duplex planetary gears (52) meshing with the inner gear ring (51), and a planet carrier (53) connected to the duplex planetary gears (52), wherein the inner gear ring (51) is fixedly connected to the housing (1), the duplex planetary gears (52) are meshing with the sun gear (4), and the planet carrier (53) is rotationally connected to the sun gear (4) and is fixedly connected to the duplex planetary gears (52); A first clutch assembly (6), the first clutch assembly (6) being fixedly connected to the planet carrier (53); a second clutch assembly (7), the second clutch assembly (7) being transmission-connected to the first clutch assembly (6); a middle shaft (8), the middle shaft (8) extending along the axial direction of the sun gear (4) and connected to the second clutch assembly (7); The rotor assembly (3) comprises a rotor core (31) and a plurality of magnetic steels (32) embedded in the rotor core (31), the plurality of magnetic steels (32) being evenly spaced along the circumference of the rotor core (31), and an air gap being provided between one end of the magnetic steel (32) and the rotor core (31); The rotor core (31) is further provided with a plurality of through holes (313) arranged at intervals, the plurality of through holes (313) being arranged along the circumferential direction of the rotor core (31) and extending along the axial direction of the rotor core (31), the through holes (313) being arranged at one end of the magnetic steel (32) away from the air gap, and each magnetic steel slot where the magnetic steel (32) is located is connected to two through holes (313).

2. The mid-mounted motor according to claim 1, characterized in that: The planetary gear assembly (5) further comprises a connecting pin (54) and a support frame (55); the connecting pin (54) is rotatably inserted into the double-linked planetary gear (52) and has two ends fixedly connected to the planetary frame (53) and the support frame (55) respectively; the support frame (55) is fixedly connected to the first clutch assembly (6).

3. The mid-mounted motor according to claim 1, characterized in that: The central motor further comprises a first housing (9), the housing (1) and the inner gear ring (51) are respectively fixed on two sides of the first housing (9), and the planet carrier (53) and the central shaft (8) are both rotatably connected to the first housing (9).

4. The mid-mounted motor according to claim 1, characterized in that: The first clutch assembly (6) comprises a gear (61) and a first inner wheel (62) coaxially arranged inside the gear (61); a plurality of first rollers (63) are evenly spaced between the first inner wheel (62) and the inner wall of the gear (61) along the circumferential direction of the first inner wheel (62); the first rollers (63) are capable of rolling between the first inner wheel (62) and the gear (61); the first inner wheel (62) is fixedly connected to the planet carrier (53); and the gear (61) is transmission-connected to the second clutch assembly (7).

5. The mid-mounted motor according to claim 4, characterized in that: The first clutch assembly (6) further comprises a first bearing (64), the first bearing (64) being coaxially arranged between the first inner wheel (62) and the gear (61) and being capable of abutting against the plurality of first rollers (63) along the axial direction of the first inner wheel (62).

6. The mid-mounted motor according to claim 4, characterized in that: The second clutch assembly (7) comprises an output gear (71) and a second inner wheel (72) coaxially arranged inside the output gear (71); a plurality of second rollers (73) are evenly spaced between the second inner wheel (72) and the inner wall of the output gear (71) along the circumferential direction of the second inner wheel (72); the second rollers (73) are capable of rolling between the second inner wheel (72) and the output gear (71); the second inner wheel (72) is key-connected to the center shaft (8); the output gear (71) is meshed with the gear (61) and is rotationally connected to the center shaft (8).

7. The mid-mounted motor according to claim 6, characterized in that: A plurality of third rollers (74) are evenly spaced between the second inner wheel (72) and the inner wall of the output gear (71) along the circumferential direction of the second inner wheel (72); the third rollers (74) are capable of rolling between the second inner wheel (72) and the output gear (71); the third rollers (74) and the second rollers (73) are alternately arranged and the diameter of the third rollers (74) is smaller than the diameter of the second rollers (73).

8. The mid-mounted motor according to any one of claims 1 to 7, characterized in that: A plurality of buckling points (311) are arranged on one end surface of the rotor core (31) in the axial direction, the plurality of buckling points (311) are evenly spaced along the circumference of the rotor core (31), one buckling point (311) is arranged between each of two adjacent magnetic steels (32), and a plurality of grooves are arranged on another end surface of the rotor core (31) in the axial direction, the plurality of grooves corresponding to the positions of the plurality of buckling points (311) one by one.

9. The mid-mounted motor according to claim 8, characterized in that: The rotor core (31) is provided with a plurality of circular through holes (312) at even intervals along a circumferential direction, and the plurality of circular through holes (312) all extend along an axial direction of the rotor core (31).

10. An electric power-assisted bicycle, characterized in that: Comprising a mid-mounted motor as described in any one of claims 1-9.

Images