CN111846102A - A mid-mounted motor and electric assist bicycle - Google Patents

Abstract

The invention discloses a mid-mounted motor and an electric power-assisted bicycle, and relates to the field of electric bicycles. The central motor includes a casing, 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 fixed to the casing; the rotor is coaxially and rotatably arranged inside the stator ; The sun gear is fixed through the rotor and is rotatably connected with the casing; the planetary gear assembly includes an inner gear, a double planetary gear meshing with the inner gear and a planet carrier connected with the double planetary gear, the inner gear and the casing Fixed connection, the double planetary gear is meshed with the sun gear, the planet carrier is rotatably connected with the sun gear and is fixedly connected with the double planetary gear; the first clutch assembly is fixedly connected with the planet carrier; the second clutch assembly is drive-connected with the first clutch assembly; The center shaft extends in the axial direction of the sun gear and is connected with the second clutch assembly. By adopting the planetary gear assembly, the mid-mounted motor is light in weight and small in size, and the motor torque can be increased while reducing the rotational speed of the motor.

Description

A mid-mounted motor and electric assist bicycle

technical field

The invention relates to the field of electric bicycles, in particular to a mid-mounted motor and an electric power-assisted bicycle.

Background technique

As an auxiliary means of transportation, the power-assisted bicycle is equipped with a motor and has a power assist system, which can realize the integration of human riding and motor-assisted driving. At present, the power-assisted bicycle has increasingly become an important means of transportation for people to travel, and the power-assisted bicycle motor is particularly important as the main power source in the power-assisted device. In the prior art, the first-stage reduction gears of traditional motors used in power-assisted bicycles mostly use parallel teeth and nylon teeth, resulting in low working efficiency, low motor efficiency platform, large cogging torque, low torque, and temperature rise. High, poor reliability and low strength of nylon teeth.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a mid-mounted motor and an electric power-assisted bicycle. The central-mounted motor is light in weight and small in size, and can increase the torque of the motor while reducing the rotational speed of the motor.

For this purpose, the present invention adopts the following technical solutions:

A mid-mounted motor comprising:

chassis;

a stator, which is fixedly connected to the casing;

a rotor assembly, which is coaxially and rotatably disposed inside the stator;

a sun gear, which is fixedly penetrated through the rotor assembly and is rotatably connected with the casing;

The planetary gear assembly includes an inner gear, a double planetary gear meshed with the inner gear, and a planet carrier connected with the double planetary gear, the inner gear is fixedly connected with the casing, and the double planetary gear is The coupled planetary gear is meshed with the sun gear, and the planet carrier is rotatably connected with the sun gear and is fixedly connected with the double-coupled planetary gear;

a first clutch assembly, the first clutch assembly is fixedly connected with the planet carrier;

a second clutch assembly, the second clutch assembly is drivingly connected with the first clutch assembly;

a center shaft extending in the axial direction of the sun gear and connected with the second clutch assembly.

Optionally, the planetary gear assembly further includes a connecting pin and a support frame, the connecting pin is rotatably penetrated through the double planetary gear and two ends are respectively fixed to the planetary frame and the support frame, the The support frame is fixedly connected with the first clutch assembly.

Optionally, the mid-mounted motor further includes a first casing, the casing and the inner gear are respectively fixed on both sides of the first casing, and the planet carrier and the central shaft are The first box is rotatably connected.

Optionally, the first clutch assembly includes a gear and a first inner wheel coaxially arranged inside the gear, and the first inner wheel and the inner wall of the gear are along the circumference of the first inner wheel. A plurality of first rollers are evenly spaced in the direction, and the first rollers can roll between the first inner wheel and the gear; the first inner wheel and the planet carrier are fixedly connected, so The gear is in driving connection with the second clutch assembly.

Optionally, the first clutch assembly further includes a first bearing, the first bearing is coaxially disposed between the first inner wheel and the gear and can be along the axial direction of the first inner wheel abuts against the plurality of first rollers.

Optionally, the second clutch assembly includes an output gear and a second inner wheel coaxially disposed inside the output gear, and the second inner wheel is along the second inner wheel between the second inner wheel and the inner wall of the output gear. A plurality of second rollers are evenly spaced in the circumferential direction of the wheel, and the second rollers can roll between the second inner wheel and the output gear; the second inner wheel and the middle shaft keyed connection, the output gear meshes with the gear and is rotatably connected with the central shaft.

Optionally, a plurality of third rollers are evenly spaced between the second inner wheel and the inner wall of the output gear along the circumferential direction of the second inner wheel, and the third rollers can Rolling between the second inner wheel and the output gear, the third roller and the second roller are alternately arranged, and the diameter of the third roller is smaller than the diameter of the second roller.

Optionally, the rotor assembly includes a rotor iron core and a plurality of magnetic steels embedded in the rotor iron core, and the plurality of magnetic steels are evenly spaced along the circumference of the rotor iron core; the rotor iron One end face of the core along the axial direction is provided with a plurality of buckle points, and the plurality of buckle points are arranged evenly spaced along the circumference of the rotor core, and a plurality of buckle points are arranged between two adjacent magnetic steels. For the buckle points, the other end surface of the rotor core along the axial direction is provided with a plurality of grooves, and the plurality of grooves correspond to the positions of the plurality of buckle points one-to-one.

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

An electric power-assisted bicycle includes the above-mentioned mid-mounted motor.

Beneficial effects of the present invention: In the mid-mounted motor and electric power-assisted bicycle provided by the present invention, when the power is turned on, the rotor can rotate relative to the stator, and then the rotor can drive the sun gear to rotate, and the sun gear drives the double planetary gear to rotate in the ring gear At the same time, the double planetary gear can drive the planet carrier to rotate, and finally the power is transmitted through the first clutch assembly and the second clutch assembly. The ring gear has a large carrying capacity and can accommodate double planetary gears inside, thereby making the mid-mounted motor light in weight and small in volume. The transmission efficiency of the motor can be reduced while the torque of the motor can be increased.

Description of drawings

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

2 is an exploded view of a partial structure of a mid-mounted motor provided in Embodiment 1 of the present invention;

3 is a cross-sectional view of a planetary gear assembly of a central motor provided in Embodiment 1 of the present invention;

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

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

6 is an exploded view of the first clutch assembly of the mid-mounted motor provided in the first embodiment of the present invention;

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

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

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

10 is a cross-sectional view of the first clutch assembly of the mid-mounted motor provided in the second embodiment of the present invention;

FIG. 11 is an exploded view of the first clutch assembly of the mid-mounted motor provided in the second embodiment of the present invention.

In the picture:

1-chassis; 2-stator;

3-rotor assembly; 31-rotor core; 311-buckle point; 312-round through hole; 313-through hole; 32-magnetic steel;

4- sun tooth;

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

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 plate ;

7-Second clutch assembly; 71-Output gear; 72-Second inner wheel; 73-Second roller; 74-Second roller; 75-Cage;

8-Central shaft; 9-First case; 10-Curve; 11-Second case; 12-Bearing seat; 13-Controller; 14-Circuit board; 15-Bracket; 16-Oil seal.

Detailed ways

In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved more clearly, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only the present invention. Some examples, but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, unless otherwise expressly specified and limited, the terms "connected", "connected" and "fixed" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integrated ; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may include the first and second features in direct contact, or may include the first and second features Not directly but through additional features between them. Also, the first feature being "above", "over" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature is "below", "below" and "below" the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this embodiment, the terms "up", "down", "left", "right" and other azimuth or positional relationships are based on the azimuth or positional relationship shown in the accompanying drawings, which are only for the convenience of description and simplifying operations. It is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention. In addition, the terms "first" and "second" are only used for distinction in description, and have no special meaning.

The technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments.

Example 1

As shown in FIGS. 1-3 , 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 , The stator 2 is fixedly connected with 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 with the casing 1; the planetary gear assembly 5 includes an inner gear 51 , the double planetary gear 52 meshing with the ring gear 51 and the planet carrier 53 connected with the double planetary gear 52, the ring gear 51 is fixedly connected to the casing 1, the double planetary gear 52 meshes with the sun gear 4, the planet carrier 53 is rotatably connected with the sun gear 4 and is fixedly connected with the double planetary gear 5; the first clutch assembly 6 is fixedly connected with the planet carrier 53; the second clutch assembly 7 is drivingly connected with the first clutch assembly 6; It extends axially and is connected with the second clutch assembly 7 . It can be understood that when the 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 ring gear 51. The planetary gears 52 can drive the planetary carrier 53 to rotate, and finally the power is transmitted through the first clutch assembly 6 and the second clutch assembly 7. By using the cooperation of the double planetary gears 52 and the ring gear 51, the structure of the planetary gear assembly 5 is compact. At the same time, the bearing capacity of the ring gear 51 is large and the double planetary gears 52 can be accommodated inside, thereby making the central motor light in weight and small in size. The power transmission can improve the transmission efficiency of the motor, and can reduce the rotation speed of the motor while increasing the torque of the motor.

Specifically, as shown in FIG. 1-FIG. 3, in order to reduce the rotational friction, one end of the sun gear 4 is rotatably connected to the casing 1 through a bearing, and a gasket is arranged between the bearing and the casing 1, and the gasket can The axial gap between the sun gear 4 and the casing 1 is adjusted, and the planet carrier 53 is rotatably matched with the sun gear 4 through the deep groove ball bearing. In other embodiments, structures other than bearings may also be used.

In this embodiment, the central motor is applied to an electric power-assisted bicycle. As shown in FIG. 2 , it also includes a chainring 10, which is connected to the central shaft 8, and the chainring 10 is connected to the wheel of the electric-assisted bicycle through a chain; At the same time, cranks are installed on both ends of the central shaft 8, and pedals are installed on the cranks, that is, the electric power-assisted bicycle can also rotate the central 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.

Optionally, as shown in FIG. 1 and FIG. 3 , the planetary gear assembly 5 further includes a connecting pin 54 and a support frame 55 . The connecting pin 54 rotates through the double planetary gear 52 and is connected to the planetary frame 53 and the support frame at both ends. 55 is fixedly connected, and the support frame 55 is fixedly connected with the first clutch assembly 6 . It can be understood that when the sun gear 4 meshes with the double planetary gear 52 for transmission, the double planetary gear 52 can drive the planet carrier 53 to rotate synchronously while rotating in the inner ring gear 51, and the planet carrier 53 drives the support through the connecting pin 54. The frame 55 is rotated, and the support frame 55 can transmit power to the first clutch assembly 6 . In this embodiment, the sun gear 4 passes through the planet carrier 53, the connecting pin 54 extends along the length direction of the sun gear 4, and is rotatably connected with the double planetary gear 52 through two deep groove ball bearings. The spacers are arranged at intervals and there are spacers in the middle. The spacers can limit the two deep groove ball bearings. The connection between the frame 53 and the support frame 55 is reliable. In addition to the connecting pins 54, the planetary frame 53 and the support frame 55 are also fixed by screws. In other embodiments, the planet carrier 53 and the support frame 55 may also be fixed in other ways.

In this embodiment, the inner gear 51 and the double planetary gears 52 are both made of steel, which has better heat dissipation capability and strength than common nylon materials, and can prolong the service life of the inner gear 51 and the double planetary gears 52 . In other embodiments, the ring gear 51 and the double planetary gears 52 may also be made of other materials with better heat dissipation and higher strength.

Optionally, as shown in FIGS. 1 and 3 , the mid-mounted motor further includes a first casing 9 , the casing 1 and the ring gear 51 are respectively fixed on both sides of the first casing 9 , the planet carrier 53 and the middle The shafts 8 are all rotatably connected with the first box body 9 . Specifically, the sun gear 4 passes through the first casing 9, and one end of the central shaft 8 also passes through the first casing 9 and rotates with the first casing 9 through a bearing. A box body 9 is rotatably matched. Specifically, as shown in FIG. 4 , the ring gear 51 is fixed on the first casing 9 by six stepped screws. In this embodiment, the central motor further includes a circuit board 14 , and the circuit board 14 is fixed on the first box body 9 and connected to the stator 2 . It also includes a second casing 11, the other end of the central shaft 8 is penetrated through the second casing 11, the first casing 9 and the second casing 11 are fixedly connected by screws, the planetary gear assembly 5, the first clutch assembly 6 and The second clutch assembly 7 is located between the first case 9 and the second case 11 , and the planetary gear assembly 5 , the first clutch assembly 6 and the second clutch assembly can be connected to the planetary gear assembly 5 , the first clutch assembly 6 and the second clutch assembly through the first case 9 and the second case 11 . 7 is closed and protected to avoid damage; at the same time, the end of the sun gear 4 away from the casing 1 is rotatably connected to the second casing 11 through a bearing, and the second clutch assembly 7 is rotatably matched with the second casing 11 through the bearing. In other embodiments, the ring gear 51 may also be fixedly connected to the first box body 9 through the cooperation of pins and retaining springs.

Optionally, the central motor further includes a detection element, the detection element is fixedly connected with the central shaft 8 , and the detection element is used to detect the torque of the central shaft 8 . In this embodiment, as shown in FIG. 1 , the central motor further includes a controller 13, the controller 13 is fixed on the first box 9 by screws, the detection element is a torque sensor, and the torque sensor 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, and 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 in the prior art, and will not be repeated here. In other embodiments, the detection element may also have other structures.

Optionally, as shown in FIG. 1 , FIG. 5 and FIG. 6 , the first clutch assembly 6 includes a gear 61 and a first inner wheel 62 coaxially arranged inside the gear 61 , and the first inner wheel 62 and the inner wall of the gear 61 are connected. A plurality of first rollers 63 are evenly spaced along the circumferential direction of the first inner wheel 62, and the first rollers 63 can roll between the first inner wheel 62 and the gear 61; the first inner wheel 62 and the planet carrier 53 is fixedly connected, and the gear 61 is drivingly connected with the second clutch assembly 7 . Specifically, the first inner wheel 62 is connected with the support frame 55 through an A-type flat key. The outer circumference of the first inner wheel 62 is provided with a plurality of first arc-shaped grooves 621 at intervals, and the first rollers 63 can roll in the first arc-shaped grooves 621 . When the sun gear 4 rotates and drives the double planetary gear 52 to rotate, the rotation of the planet carrier 53 and the support frame 55 can drive the first inner wheel 62 to rotate synchronously. At this time, the first clutch assembly 6 is in a combined state, and the first roller The column 63 can be tightly pressed between the first inner wheel 62 and the gear 61 to drive the gear 61 to rotate, thereby transmitting power to the second clutch assembly 7; on the contrary, 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 cannot transmit power 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, and the transmission efficiency is high, the operation is stable, and the noise is low.

Optionally, as shown in FIGS. 5 and 6 , the first clutch assembly 6 further includes a first bearing 64 , the first bearing 64 is coaxially disposed between the first inner wheel 62 and the gear 61 and can be along the first inner wheel The axial direction of 62 is in contact with the plurality of first rollers 63 . It can be understood that the two ends of the first roller 63 are in contact with the limiting step of the gear 61 and the first bearing 64 respectively, and the first bearing 64 can meet the first roller in the axial direction of the first inner wheel 62 . 63 is limited to prevent the first roller 63 from coming out in the axial direction of the first inner wheel 62 . In other embodiments, other structures may also be used in place of the first bearing 64 .

Optionally, as shown in FIG. 1 , FIG. 7 and FIG. 8 , the second clutch assembly 7 includes an output gear 71 and a second inner wheel 72 coaxially arranged inside the output gear 71 , and the second inner wheel 72 is connected to the output gear 71 . A plurality of second rollers 73 are evenly spaced between the inner walls of the second inner wheel 72 along the circumferential direction of the second inner wheel 72, and the second rollers 73 can roll between the second inner wheel 72 and the output gear 71; the second inner wheel 72 is connected with the central shaft 8 by a key, and the output gear 71 is meshed with the gear 61 and is rotatably connected with the central shaft 8 . Specifically, the output gear 71 is rotatably connected to the second casing 11 through a bearing, and the output end of the output gear 71 passes through the second casing 11 and is connected to the gear plate 10 ; the output gear 71 rotates with the central shaft 8 through a needle bearing At the same time, an oil seal 16 is provided outside the needle roller bearing, and the oil seal 16 is sleeved on the central shaft 8, which can protect the needle roller bearing. It can be understood that, when the output gear 71 rotates, it can drive the toothed plate 10 to rotate, which in turn can drive the wheels to rotate, so as to realize the purpose of electric riding.

Specifically, as shown in FIGS. 7 and 8 , 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 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 roller 74 is smaller than that of the second roller 73 . In this embodiment, a plurality of second arc-shaped grooves are evenly spaced at the outer circumference of the second inner wheel 72, and the third roller 74 and the second roller 73 can roll in the second arc-shaped grooves. When the first clutch assembly 6 is in the engaged state, that is, when the first inner wheel 62 can drive the gear 61 to rotate, the gear 61 can drive the output gear 71 to rotate. At this time, the second clutch assembly 7 is in the disengaged state, that is, the third roller The column 74 and the second roller 73 can roll in the second arc-shaped groove, and cannot transmit power to the second inner 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 wheel When the wheel 72 rotates, the second clutch assembly 7 is in a combined state, that is, the third roller 74 and the second roller 73 can be tightly pressed between the second inner wheel 72 and the output gear 71 for power transmission, so as to drive the The output gear 71 rotates, and then the power is transmitted to the wheel through the chainring 10, and the wheel is driven to rotate.

Specifically, the second clutch assembly 7 further includes a cage 75 , which is coaxially disposed between the second inner wheel 72 and the output gear 71 and capable of connecting with a plurality of second rollers along the axial direction of the second inner wheel 72 . The column 73 is in contact with the plurality of third rollers 74 . It can be understood that the two ends of the second roller 73 and the plurality of third rollers 74 are in contact with the output gear 71 and the cage 75 respectively, and the cage 75 can be used for the axial direction of the second inner wheel 72. The second rollers 73 and the third rollers 74 are limited to prevent the second rollers 73 and the third rollers 74 from coming out in the axial direction of the second inner wheel 72 . The second clutch assembly 7 adopts the manner in which the second roller 73 and the third roller 74 cooperate, which can ensure high transmission efficiency, stable operation and low noise between the second inner wheel 72 and the output gear 71 .

In this embodiment, as shown in FIG. 1 , the central motor further includes a bracket 15 . The bracket 15 is sleeved on the central shaft 8 and can abut with the first box 9 , and the central shaft 8 can be pivoted through the bracket 15 . To limit the position to prevent the axial movement of the central shaft 8 and affect the use effect of the central motor; it also includes a bearing seat 12, which is sleeved on the central shaft 8 and is fixed to the first box 9. At the same time, through The bearing is rotatably connected to the output gear 71 . In this embodiment, in order to reduce the weight of the central motor, the bracket 15 is made of plastic material. In other embodiments, the bracket 15 may also be made of other materials.

Optionally, as shown in FIG. 9 , the rotor assembly 3 includes a rotor iron core 31 and a plurality of magnetic steels 32 embedded in the rotor iron core 31 , and the plurality of magnetic steels 32 are evenly spaced along the circumference of the rotor iron core 31 ; One end face of the rotor iron core 31 in the axial direction is provided with a plurality of buckle points 311 , and the plurality of buckle points 311 are evenly spaced along the circumferential direction of the rotor core 31 , and a pair of adjacent magnetic steels 32 are provided between each other. Deduction point 311. Specifically, the other end surface of the rotor core 31 in the axial direction is provided with a plurality of grooves, and the plurality of grooves correspond to the positions of the plurality of buckle points 311 one-to-one. It can be understood that when a plurality of rotor cores 31 are stacked on each other, the buckle points 311 of one rotor core 31 can be buckled in the grooves of the other rotor core 31 to form self-buckling, so that the structure is firm and stable. At the same time, the magnetic steel 32 is embedded in the rotor iron core 31, which can reduce the loss of the central motor, improve the motor efficiency, and save costs. In this embodiment, the buckle point 311 is rectangular, and the groove is also rectangular. In other embodiments, the buckle points 311 and the grooves may also be in other shapes such as circles.

In this embodiment, a plurality of buckle points 311 are evenly spaced along the circumferential direction of the rotor core 3 and close to the axis. corresponding grooves. Through the above arrangement, the structural stability when the plurality of rotor cores 31 are stacked on each other can be ensured. In other embodiments, the positions and numbers of the buckle points 311 and the grooves can also be changed according to different usage requirements.

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

Optionally, as shown in FIG. 9 , the rotor core 31 is provided with a plurality of circular through holes 312 evenly spaced along the circumferential direction, and the plurality of circular through holes 312 all 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 hole 312 can reduce the cogging torque of the motor, thereby improving the performance of the motor. The size of the circular through hole 312 is not limited. In other embodiments, the number of circular through holes 312 may be appropriately increased or decreased according to different usage requirements.

In this embodiment, as shown in FIG. 9 , the rotor iron core 31 is further provided with a plurality of through holes 313 arranged at intervals, and the plurality of through holes 313 are arranged along the circumferential direction of the rotor iron core 31 and along the axis of the rotor iron core 31 . Extending in the direction, the through hole 313 is arranged at the end of the magnetic steel 32 away from the air gap, and the magnetic steel slot where each magnetic steel 32 is located is communicated with the two through holes 313, and the through holes 313 can further reduce the magnetic leakage of the magnetic steel 32. Increase the service life of the motor.

This embodiment also provides an electric power-assisted bicycle, which has three use 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 planet carrier 53 and the support frame 55 to rotate, and the support frame 55 can drive the first inner wheel. 612 rotates synchronously. At this time, the first clutch assembly 6 is in a combined state, the first inner 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 do not transmit power, the second inner wheel 62 does not move, and the output gear 71 drives the toothed plate 10 to rotate, thereby driving the wheels to rotate. When in the riding mode, the motor is not energized, and the rotor assembly 3 will not rotate. At this time, the central shaft 8 is rotated by the pedals and the crank, and the central shaft 8 drives the second inner wheel 72 to rotate. At this time, the second inner wheel 72 rotates. The clutch assembly 7 is in a combined state, 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 does not transmit power, the first inner wheel 62 does not move, and the output gear 71 further drives the toothed plate 10 to rotate, thereby driving the wheels to rotate. When in the boost mode, the central shaft 8 is rotated by the pedals and the crank, and the central shaft 8 drives the second inner wheel 72 to rotate. At this time, the second clutch assembly 7 is in a combined state, and the second inner wheel 72 passes through the first inner wheel The second roller 73 and the third roller 74 drive the output gear 71 to rotate. At this time, the controller 13 processes the torque of the central shaft 8 collected by the detection element, and controls the motor to start and work through the power distribution. 3. Drive the sun gear 4 to rotate, and then drive the double planetary gear 52 to rotate, drive the planet carrier 53 and the support frame 55 to rotate, and drive the first inner wheel 62 to rotate. At this time, the first clutch assembly 6 is in a combined state, and the first inner wheel 62 drives the gear 61 to rotate, and transmits power to the output gear 71 at the same time. In this mode, the pedals and the motor act on the output gear 71 at the same time to drive the gear plate 10 to rotate, thereby driving the wheels to rotate, which can save effort.

Embodiment 2

The difference between this embodiment and the first embodiment is that, as shown in FIGS. 10 and 11 , the outer circumference of the first inner wheel 62 is further provided with a plurality of semi-arc grooves 622 at intervals, the first arc groove 621 and the semi-arc groove 622 Alternately arranged, and when the first roller 63 rolls in the first arc groove 621, the semi-arc groove 622 can cooperate with the inner wall of the gear 61 to ensure the free rolling of the first roller 63 and improve the first clutch assembly. 6 transmission efficiency and can ensure quiet operation.

In this embodiment, the baffle plate 65 is used in the first clutch assembly 6 to replace the first bearing 64, and the two ends of the first roller 63 in the axial direction are respectively abutted with the limit step of the gear 61 and the baffle plate 65, The plate 65 can limit the position of the first roller 63 in the axial direction of the first inner ring 62 to prevent the first roller 63 from coming out in the axial direction of the first inner ring 62 . By using the baffle plate 65 instead of the first bearing 64, the structure of the first clutch assembly 6 can be simplified, and the operation is more stable.

Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the embodiments of the present invention. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (10)

1. A mid-motor, comprising:

a housing (1);

the stator (2), the said stator (2) is affixed to the said chassis (1);

the rotor assembly (3) is coaxially arranged inside the stator (2) in a rotating mode;

the sun gear (4) is fixedly arranged in the rotor component (3) in a penetrating mode and is in rotating connection with the machine shell (1);

the planetary gear assembly (5) comprises an inner gear ring (51), duplex planet gears (52) meshed with the inner gear ring (51) and a planet carrier (53) connected with the duplex planet gears (52), the inner gear ring (51) is fixedly connected with the machine shell (1), the duplex planet gears (52) are meshed with the sun gear (4), and the planet carrier (53) is rotationally connected with the sun gear (4) and fixedly connected with the duplex planet gears (52);

the first clutch component (6), the first clutch component (6) is fixedly connected with the planet carrier (53);

a second clutch assembly (7), wherein the second clutch assembly (7) is in transmission connection with the first clutch assembly (6);

a central shaft (8), wherein the central shaft (8) extends along the axial direction of the sun gear (4) and is connected with the second clutch component (7).

2. The centrally-mounted motor according to claim 1, wherein the planetary gear assembly (5) further comprises a connecting pin (54) and a supporting frame (55), the connecting pin (54) is rotatably inserted into the double planetary gear (52) and two ends of the connecting pin are fixedly connected with the planet carrier (53) and the supporting frame (55), respectively, and the supporting frame (55) is fixedly connected with the first clutch assembly (6).

3. The centrally-mounted motor according to claim 1, further comprising a first box (9), wherein the casing (1) and the ring gear (51) are respectively fixed on two sides of the first box (9), and the planet carrier (53) and the middle shaft (8) are both rotationally connected with the first box (9).

4. The centrally placed electric machine according to any one of claims 1-3, characterised in that the first clutch assembly (6) comprises a gear wheel (61) and a first inner core wheel (62) coaxially arranged inside the gear wheel (61), a plurality of first rollers (63) are arranged between the first inner core wheel (62) and the inner wall of the gear wheel (61) at even intervals in the circumferential direction of the first inner core wheel (62), and the first rollers (63) can roll between the first inner core wheel (62) and the gear wheel (61); the first inner core wheel (62) is fixedly connected with the planet carrier (53), and the gear (61) is in transmission connection with the second clutch component (7).

5. The centrally placed electric machine according to claim 4, characterised in that the first clutch assembly (6) further comprises a first bearing (64), the first bearing (64) being coaxially arranged between the first core wheel (62) and the gear wheel (61) and being capable of abutting with the plurality of first rollers (63) in the axial direction of the first core wheel (62).

6. The centrally-mounted motor according to claim 4, characterized in that the second clutch assembly (7) comprises an output gear (71) and a second inner core wheel (72) coaxially arranged inside the output gear (71), a plurality of second rollers (73) are uniformly arranged between the second inner core wheel (72) and the inner wall of the output gear (71) at intervals along the circumferential direction of the second inner core wheel (72), and the second rollers (73) can roll between the second inner core wheel (72) and the output gear (71); the second inner core wheel (72) is in key connection with the middle shaft (8), and the output gear (71) is meshed with the gear (61) and is in rotary connection with the middle shaft (8).

7. The centrally-mounted motor according to claim 6, characterized in that a plurality of third rollers (74) are provided between the second inner core wheel (72) and the inner wall of the output gear (71) at regular intervals in the circumferential direction of the second inner core wheel (72), the third rollers (74) are capable of rolling between the second inner core 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 that of the second rollers (73).

8. The centrally-mounted motor according to any one of claims 1 to 7, wherein the rotor assembly (3) comprises 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 uniformly arranged at intervals along the circumferential direction of the rotor core (31); rotor core (31) are provided with a plurality of knot points (311) on the terminal surface along axial direction, and are a plurality of knot point (311) are followed the even interval arrangement of circumference of rotor core (31), adjacent two all be provided with one between magnet steel (32) knot point (311), rotor core (31) are provided with a plurality of recesses, and are a plurality of on another terminal surface along axial direction the recess is with a plurality of the position one-to-one of knot point (311).

9. The centrally-mounted motor according to claim 8, characterized in that the rotor core (31) is provided with a plurality of circular through holes (312) at regular intervals in a circumferential direction, and each of the plurality of circular through holes (312) extends in an axial direction of the rotor core (31).

10. An electrically assisted bicycle, characterized in that it comprises a mid-motor according to any of claims 1-9.

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