CN112660293A

CN112660293A - High-inertia outer rotor air cooling middle motor with gear wheel and middle shaft sensor different shafts

Info

Publication number: CN112660293A
Application number: CN202110173671.8A
Authority: CN
Inventors: 钟德斌
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-02-06
Filing date: 2021-02-06
Publication date: 2021-04-16
Also published as: CN114379696B; CN114379695A; CN114379696A; CN114379695B

Abstract

The invention discloses a middle motor with a chain wheel and a middle shaft sensor which are not coaxial, a motor structure with high rotating speed, high inertia and gyro stability, and a middle shaft sensor for detecting the displacement of a repellent magnet by adopting a Hall IC. The pedal torque is transmitted to the chain wheel after being accelerated and decelerated by the three gears, and the motor torque is transmitted to the chain wheel through the needle roller clutch after being decelerated and decelerated by the planet. The middle shaft sensor adopts steel balls to radially roll and extrude the conical surface of the slip ring to transmit torque, the slip ring axially compresses the single disc spring to push the inner ring of the bearing, and the outer ring of the bearing drives the repulsive magnet to axially displace. The center of the stator is provided with an exhaust hole, the rotor drives a turbine, and cold air isolates the magnetic steel from a heating winding.

Description

High-inertia outer rotor air cooling middle motor with gear wheel and middle shaft sensor different shafts

Technical Field

The invention relates to the technical field of electric bicycles, in particular to a middle-mounted motor with a chain wheel and a middle shaft sensor which are not coaxial and a sensor for measuring pedal torque on a middle shaft.

Background

In the electric bicycle field, the design of putting the motor in is the same with traditional bicycle, directly acts on the chain wheel with pedal moment of torsion, and the chain wheel number of teeth is higher than about 2 times the flywheel number of teeth, will speed up the transmission, and the motor revolution is high, must slow down and pass to the chain wheel again, has wasted the speed reduction ratio of motor.

The built-in motor commonly uses an inner rotor, has high rotating speed and high reduction ratio, and has small rotor inertia. In the motor closed-loop control, the ratio of the moment of inertia of the load to the moment of inertia of the rotor cannot be too large, and the moment of inertia of the wheels is very large due to the fact that the moment of inertia is in direct proportion to the square of the radius, so that the electric bicycle is usually controlled in an open-loop mode to prevent vibration or squeak, and the bicycle chain is flexibly connected, so that the speed is difficult to acquire for closed-loop control. If the inertia of the rotor is increased, the control of the motor can be improved, and the rotor with high rotating speed and high inertia has the axis-fixing performance of a gyroscope and runs more stably.

The middle shaft sensor mostly adopts a magnetic flux or strain gauge mode for measuring the torque, belongs to micro-deformation, rigid connection, quick response and sensitivity, large bicycle starting pedal torque, large motor power assistance, quick response, strong power assistance and difficult mastering. From the safety consideration, the boosting needs to be slow and smooth when starting, the mechanical torque measurement can be adopted to compensate, the stepping on the disc spring with small displacement can generate force to accelerate linearly, the motor boosting is linear, the dead point of the pedal is delayed by high inertia, perfect coupling is realized, and the riding is smooth.

Disclosure of Invention

In order to improve the waste of the reduction ratio of the middle motor, the closed-loop control of the motor and improve the stability and comfort of the running of the bicycle, the invention adopts the scheme that the small chain wheel and the chain wheel are not coaxial with the middle shaft, and the rotary inertia of the motor is increased.

The chain wheel is not arranged on the middle shaft, the pedal torque is transmitted to the chain wheel after being accelerated and decelerated by the gear, and the large chain wheel of the middle shaft is replaced by the chain wheel with small tooth number, so that the waste of the speed ratio of the motor is avoided, the length of a chain is shortened, the diameter of the chain wheel box is reduced, and the weight of the whole vehicle is reduced.

The pedal torque on the middle shaft sensor is transmitted to the primary gear through the pawl clutch, the intermediate gear is transmitted to the final gear backwards, the toothed disc and the final gear are coaxial, the toothed disc is arranged on the tower footing, and the tower footing and the final gear are connected into a whole through reverse threads.

The primary gear, the carrier gear and the final gear are symmetrically arranged in parallel, two ends of the primary gear, the carrier gear and the final gear are respectively arranged on the front shell and the clamping plate through bearings and gear shafts, and screws are arranged to fix the clamping plate in the front shell.

To increase the inertia moment, it is preferable to increase the outer diameter of the rotor according to the inertia formula J = m (R + R), so that with the outer rotor brushless motor structure, the rotor can share the outer rotor of the existing hub motor, preferably with an outer diameter of 88 mm.

The compact appearance is required, the motor adopts a first-stage planetary speed reduction, the gear ring is fixed, the sun gear is input, the planet carrier is output, and the speed reduction ratio is maximum and in the same direction.

To improve the speed reduction ratio, a motor shaft or a rotor shaft is eliminated, the number of the teeth of the sun is selected as small as possible, preferably 10 teeth with the modulus of 1.0 and a square key are fixedly connected to the rotor to form a whole.

Further, to save space, the outer diameter of the gear ring is similar to the outer diameter of the rotor, and the modulus of 78 teeth is preferably 1.0.

Further, to achieve high speed and low noise, helical teeth are used, and the strength of the teeth is enhanced.

Furthermore, if the rotor and the chain wheel rotate in the same direction and can only rotate clockwise, the sun gear adopts a right spiral, the axial force applied to the rotor presses the rear shell to limit the axial movement of the rotor, the corresponding gear ring is a left spiral, the outer circle of the gear ring is provided with a key groove which is in transition fit with the front shell, and the axial force on the gear ring compresses the front shell tightly.

Further, to reduce the weight of the stator core, the center of the core is designed into a through hole, the center of the core is replaced by a die-cast aluminum core, and the core is sleeved on the outer circle of the aluminum core in an interference manner.

Furthermore, to facilitate production and assembly, the aluminum core is locked on the rear shell into a whole by adopting a positioning pin and a screw.

Furthermore, two 6804 rotor bearings are arranged in the inner cavity of the aluminum core and the center of the rotor to support the rotor, and the rotor cantilever is singly chosen from the outer end of the aluminum core.

Furthermore, a needle roller clutch and two clutch bearings are arranged on the axis of the final gear, the planet carrier shaft is inserted in the middle, the cantilever of the planet carrier is singly selected from the inner end of the final gear, and the torque of the motor is transmitted to the final gear through the planet carrier shaft and the needle roller clutch.

Furthermore, a planet carrier bearing is arranged at the outer ends of the sun gear and the counter bore in the center of the planet carrier flange, and when the front shell and the rear shell are assembled, the coaxiality of the planet carrier, the sun gear and the rotor is ensured.

In the motor which works with continuous heavy current, the temperature of a winding coil exceeds 110 ℃, and the structure of the outer rotor is unfavorable for heat dissipation, so that air cooling or water cooling is added to avoid high-temperature demagnetization. To realize the internal air flow of the motor, the motor shell is provided with an air exhaust hole and an air inlet hole, and a waterproof and breathable film is attached.

Further, the exhaust hole is formed in the center of the stator on the motor casing at a high-temperature position.

Further, to discharge high-temperature gas outside the shell, the turbine is arranged between rotor bearings, the rotor drives the turbine, air flows between air gaps of the iron core and the magnetic steel, cold air is used for isolating high-temperature heating components, and the temperature-resistant grade of the magnetic steel is reduced.

The motor frame is adopted to replace a motor hanging frame, and the middle-mounted motor can realize any mounting angle; the motor frame is extruded by aluminum profiles, the whole frame is cut after holes are drilled, the cost is low, and the motor frame can also be bent and welded by steel plates and is suitable for a steel frame vehicle.

The displacement measurement of the center shaft sensor of patent 2018110464918 is improved, and a single disc spring is adopted to replace a three-disc spring group, so that the elasticity is the same, the compression displacement is shortened to one third, and the pedal empty feeling is eliminated. The rotation of the repulsion magnetic ring is replaced by the rotation of the bearing, the repulsion magnetic ring is replaced by the repulsion magnet, rare earth is saved, the repulsion magnet only moves along with the axial direction of the outer ring of the bearing, so that the repulsion magnet and the Hall IC do not rotate, and the zero voltage does not change along with the rotation of the middle shaft.

A positioning steel ball is arranged between the middle shaft and the half shaft to limit the axial movement of the middle shaft and the half shaft and only can rotate mutually, the displacement steel ball rolls in the radial direction to transmit the torque of the middle shaft to the half shaft, the displacement steel ball extrudes the conical surface of the slip ring, and the slip ring generates axial component force to compress the single disc spring.

Two single-pole axially magnetized magnets are respectively arranged in the grooves of the magnet base and the magnet cover, the two magnets repel each other and are coaxial, and a displacement IC is inserted between the magnets and is close to one end, which is the zero voltage of the torque voltage signal.

The multistage magnetic ring is sleeved on the magnetic ring frame, and two ends of the magnetic ring frame are respectively propped against the end face of the sliding ring and the inner ring of the displacement bearing.

The magnet seat and the magnet cover are connected into a whole and sleeved on the outer ring of the displacement bearing, and the magnet seat is provided with a lug which is positioned in an open slot of the PCB support to limit rotation.

The magnetic ring frame, the multistage magnetic ring and the inner ring of the displacement bearing rotate and move axially along with the sliding ring, and the outer ring, the magnet seat, the magnet cover and the magnet of the displacement bearing only move axially.

The wave spring is located the PCB support inner chamber, and one end is withstand voltage magnet lid, and one end is withstand voltage PCB support bottom, is whole measuring component's reset spring.

A pawl clutch or one-way bearing is provided between the half shaft and the gear hub. The middle shaft is provided with an adjusting thread, and the nut adjusts the size error and the pre-pressure of the disc spring.

Drawings

FIG. 1 is a schematic view of the back of a mid-motor;

FIG. 2 is a cross-sectional view of a mid-motor;

FIG. 3 is an exploded view of a mid-motor;

FIG. 4 is a schematic diagram of a mid-motor assembly arrangement;

FIG. 5 is an exploded view of the motor assembly planetary reduction;

FIG. 6 is a schematic view of the assembly of the mid-motor front shell assembly;

FIG. 7 is a schematic view of the mid-motor backshell assembly;

FIG. 8 is a schematic view of the mounting of a mid-motor to a motor frame;

FIG. 9 is a cross-sectional view of the bottom bracket sensor;

FIG. 10 is an exploded view of the bottom bracket sensor;

fig. 11 is a 3D schematic of an aluminum core.

In the drawings, the reference numbers:

1 middle shaft sensor, 101 saw gear ring, 102 pawl, 103 bow line, 104 half shaft, 105 middle shaft, 106 positioning steel ball, 107 displacement steel ball, 108 PCB plate, 109 magnet, 110 displacement IC, 111 tread frequency IC, 112 slip ring, 113 disc spring, 114 nut, 115 magnetic ring frame, 116 multi-stage magnetic ring, 117 displacement bearing, 118 magnet base, 119 magnet cover, 120 wave spring, 121 PCB frame, 122 limit bearing, 123 frame base,

2 motor components, 201 aluminum cores, 202 iron cores, 203 rotors, 204 rotor bearings,

205 sun gear, 206 planet carrier bearing, 207 turbine, 208 magnetic steel,

3 drivers, 301 heat dissipation aluminum bars, 4 rear shells, 4a exhaust holes, 5 front shells, 6 motor frames, 7 cranksets,

801 primary gear, 802 intermediate gear, 803 final gear, 804 gear ring, 805 planet gear, 806 planet carrier, 807 needle roller clutch, 808 tower foundation, 809 gear hub, 810 clutch bearing, 811 ventilated membrane, 820 aluminum core screw, 821 aluminum strip screw, 822 frame screw,

And 9, clamping the plate.

Detailed Description

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the scope of the present invention will be more clearly and clearly defined.

As shown in FIG. 1, the bottom bracket sensor 1 is not coaxial with the crankset 7, and the number of teeth of the crankset 7 is less than 22. The rear case 4 has a discharge hole 4a formed at the center of the rotor 203. An aluminum core screw 820 and an aluminum bar screw 821 are both located at the rear of the shell.

As shown in fig. 2, 3 and 5, there is no motor shaft or rotor shaft that penetrates the stator core 202 and the rotor 203 and the carrier 806. The aluminum core 201 is locked on the rear case 4, and the heat dissipation aluminum bar 310 is locked on the rear case 4. The iron core 202 is sleeved on the outer circle of the aluminum core 201.

The rotor 203 is made of 'mountain' shaped integral die-casting aluminum alloy with a through hole at the axis, the through hole is provided with a square key slot, and the cantilever is singly cantilevered on the end surface of the aluminum core 201 and supported by two rotor bearings 204 in the inner cavity of the aluminum core 201. One end of the sun gear 205 is located in a through hole in the axis of the rotor 203, and the other end is fixed with a planet carrier bearing 206 which is located in a central counter bore of a flange plate of a planet carrier 806.

Two clutch bearings 810 and a needle roller clutch 807 are arranged on the shaft extension of the planet carrier 806, and are positioned in the shaft center through hole of the final stage gear 803, and the cantilever of the planet carrier 806 is cantilever on the end face of the final stage gear 803.

The shoulders of the final gear 803 have a bearing respectively, which are mounted on the clamping plate 9 and the front housing 5. The primary gear 801 is sleeved on a gear hub 809 in an interference manner, and bearings are arranged at two ends of the gear hub 809 and fixed on the clamping plate 9 and the front shell 5. The gear hub 809 is threadedly coupled with the serration ring 101 in a reverse thread.

The turbine 207 is located between the two rotor bearings 204. The clamping plate 9 is a flat plate.

The sun gear 205 is a right-handed 10 gear, the planet gear 805 is a left-handed gear, and the ring gear 804 is a left-handed gear.

The pedal torque on the middle shaft sensor is transmitted to a primary gear 801, a carrier gear 802 and a final gear 803 through a pawl clutch, a tower footing 808 is in thread connection with the final gear 803 in a reverse mode, and a chain wheel 7 is arranged on the tower footing 808.

As shown in fig. 4, 6 and 7, the bottom bracket sensor 1 is located between the motor assembly 2 and the driver 3, and the three are arranged in parallel on the rear housing 4.

The primary gear 801, the carrier gear 802 and the final gear 803 are symmetrically arranged side by side on the clamping plate 9. The gearing is mounted on the front housing 5.

The driver 3 is rectangular, the COB board is rectangular, and six MOS tubes are arranged in a row and locked on the heat dissipation aluminum strip 301.

The assembly is modular thanks to the cantilever beam structure of the rotor 203 and the planet carrier 806.

The end face of the rotor 203 is not provided with heat dissipation holes, and rotates clockwise, so that cold air must flow into the aluminum core 201 from an air gap, and heat generating components are isolated.

As shown in fig. 8, the middle motor is axially inserted into the motor frame 6, and frame screws 822 fix the middle motor in the motor frame 6 from the bottom, side and front surfaces, respectively. The motor frame (6) is a section bar stretching aluminum alloy.

As shown in fig. 9 and 10, the positioning steel ball 106 is located in an annular groove formed by the middle shaft 105 and the half shaft 104, the middle shaft 105 is a quarter-arc annular groove, and the half shaft 104 is a half-arc annular groove.

The displacement steel ball 107 is positioned among the middle shaft 105, the half shaft 104 and the slip ring 112, the displacement steel ball 107 is in arc surface semicircular line contact with the half shaft 104, is in inclined surface point contact with the middle shaft 105 and is in conical surface point contact with the slip ring 112.

The large end face of the disc spring 113 abuts against the slide ring 112 and the small end face abuts against the nut 114.

The multistage magnetic ring 116 is sleeved on the magnetic ring frame 115, and two ends of the magnetic ring frame 115 respectively prop against the end face of the slip ring 112 and the inner ring of the displacement bearing 117.

Two magnets 109 are respectively fitted in the recesses of the magnet holder 118 and the magnet cover 119, the two magnets 109 are mutually repulsive and coaxial, and the displacement IC110 is interposed between them and near one end. The tread frequency IC (111) is arranged above the multistage magnetic ring (116).

The magnet base 118 and the magnet cover 119 are connected to form a whole body and are sleeved on the outer ring of the displacement bearing 117, and the convex block on the magnet base 118 is positioned in the open slot of the PCB support 121.

The wave spring 120 is located in the inner cavity of the PCB support 121, one end of the wave spring abuts against the magnet cover 119, and the other end of the wave spring abuts against the bottom of the PCB support 121, and is a return spring of the whole measuring assembly.

The magnetic ring frame 115, the multi-stage magnetic ring 116 and the inner ring of the displacement bearing 117 rotate and move axially together with the slip ring 112, and the outer ring of the displacement bearing 117, the magnet base 118, the magnet cover 119 and the magnet 109 only move axially.

A pawl clutch or one-way bearing is provided between the half shaft 104 and the gear hub 809.

The middle shaft 105 is provided with an adjusting thread, and a nut 114 is arranged to adjust the size error and the pre-pressure of the disc spring 113. The central axis 105 is provided with steel ball grooves which are uniformly distributed on the excircle and are composed of inclined planes and arc surfaces.

The half shaft 104 is provided with semicircular tooth grooves uniformly distributed at the left end, and a pawl groove and a slingshot wire ring groove which are symmetrical are arranged on the excircle at the right end.

As shown in fig. 11, two screw holes 201a and two positioning pin holes 201b are symmetrically arranged on the step surface of the aluminum core 201, the connecting line of the two is vertical, and a plurality of L-shaped grooves 201c are arranged in the inner cavity of the aluminum core 201 to serve as air circulation channels between the rotor bearing 204 and the inner cavity wall.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. An air-cooled centrally-mounted motor applied to an electric power-assisted bicycle, comprising: the middle shaft motor comprises a middle shaft sensor (1), a motor component (2), a driver (3), a rear shell (4), a front shell (5), a motor frame (6), a toothed disc (7), a clamping plate (9), a primary gear (801), a carrier gear (802), a final gear (803), a gear ring (804), planetary teeth (805), a planet carrier (806), a needle roller clutch (807), a tower foundation (808), a saw gear ring (101) and the like, wherein the motor component (2) comprises an aluminum core (201), an iron core (202), a rotor (203), a rotor bearing (204), a sun gear (205), a planet carrier bearing (206), a turbine (207), magnetic steel (208) and the like;

the middle motor is characterized in that: the pedal torque and the pedal frequency can be detected, the pedal torque is transmitted to the chain wheel (7) after being accelerated by the three gears, and the motor torque is transmitted to the chain wheel (7) through the needle roller clutch (807) after being planetary decelerated;

the middle motor is characterized in that: the chain wheel (7) and the middle shaft sensor (1) are not coaxial, the axial leads of the chain wheel and the middle shaft sensor are parallel to each other, and the chain wheel (7) is a 15T-21T single-piece clamping type flywheel disc;

the middle motor is characterized in that: the middle shaft sensor (1) is positioned between the motor component (2) and the driver (3), the motor component, the driver and the driver are arranged in parallel and are arranged on the rear shell (4), and the clamping plate (9) and the transmission gear are arranged on the front shell (5);

the middle motor is characterized in that: a reversing carrier gear (802) is arranged between the primary gear (801) and the final gear (803) to ensure that the rotation directions of the pedal and the chain wheel (7) are the same, and the three gears are symmetrically fixed side by side between the front shell (5) and the clamping plate (9);

the middle motor is characterized in that: the tower foundation (808) is in reverse threaded connection with the final-stage gear (803), and the chain wheel (7) is clamped on the tower foundation (808);

the motor assembly (2) is characterized in that: the iron core (202) is used as a stator, is hollow and lightened, and is sleeved on the excircle of the aluminum core (201) in an interference manner, and the iron core (202) is provided with 18 slots and corresponds to 20 pieces of magnetic steel (208).

2. The center motor according to claim 1, characterized in that: a rotor (203) with high inertia is adopted, the outer diameter exceeds 87mm, the rated rotating speed exceeds 2000rpm, and a motor assembly (2) with high rotating speed and high inertia has gyro shafting property;

the middle motor is characterized in that: a motor shaft or a rotor shaft which does not penetrate through the stator, the rotor (203) and the planet carrier (806) is arranged, the cantilever of the rotor (203) is singly arranged at the outer end of the aluminum core (201), and two rotor bearings (204) are arranged in the inner cavity of the aluminum core (201) to support the rotor (203);

the middle motor is characterized in that: the cantilever of the planet carrier (806) is singly arranged at the inner end of the final gear (803), and a needle roller clutch (808) and two clutch bearings (810) are arranged in a shaft center through hole of the final gear (803) to support the planet carrier (806).

3. The center motor according to claim 1, characterized in that: the aluminum core screw (820) locks the aluminum core (201) on the rear shell (4) from the outside of the shell to fix the iron core (202);

the aluminum bar screw (821) locks the heat dissipation aluminum bar (301) on the rear shell (4) from the outside of the shell to fix the driver (3);

the middle motor is characterized in that: the rotor (203) rotates clockwise, the gear ring (804) is a left helical tooth and is arranged on the front shell (5);

the sun gear (205) is a right helical gear and is pressed into the axis of the rotor (203) to be integrated with the same.

4. The center motor according to claim 1, characterized in that: an exhaust hole (4a) and a breathable film (811) are arranged in a high-temperature area at the center of the stator of the rear shell (4), and air inlet holes are arranged at other non-heating positions;

the middle motor is characterized in that: the turbine (207) is positioned between the two rotor bearings (204), the rotor (203) drives the turbine (207) to rotate, low pressure is formed between the turbine (207) and the breathable film (811), high-temperature gas is pressed out of the shell, a negative pressure area is formed on the other surface of the turbine (207), cold air is sucked into the shell from the air inlet, the cold air flows through an air gap between the iron core (202) and the magnetic steel (208), and the coil, the iron core (202) and the aluminum core (201) are isolated from the rotor (203) and the magnetic steel (208) by the cold air.

5. The bottom bracket sensor (1) according to claim 1, comprising: the spring assembling device comprises a pawl (102), a spring bow line (103), a half shaft (104), a middle shaft (105), a positioning steel ball (106), a displacement steel ball (107), a PCB (108), a magnet (109), a displacement IC (110), a tread frequency IC (111), a slip ring (112), a disc spring (113), a nut (114), a magnetic ring frame (115), a multi-stage magnetic ring (116), a displacement bearing (117), a magnet base (118), a magnet cover (119), a wave spring (120), a PCB support (121), a limiting bearing (122) and a support base (123);

the middle shaft sensor (1) is characterized in that: a positioning steel ball (106) is arranged between the middle shaft (105) and the half shaft (104) to limit the axial movement of the middle shaft (105) and the half shaft (104) and only can rotate mutually, the displacement steel ball (107) radially rolls to transmit the torque on the middle shaft (105) to the half shaft (104), the displacement steel ball (107) extrudes the conical surface of the slip ring (112), and the slip ring (112) generates axial component force to compress the single disc spring (113);

the middle shaft sensor (1) is characterized in that: two unipolar axially magnetized magnets (109) are respectively arranged in the grooves of the magnet base (118) and the magnet cover (119), the two magnets (109) repel each other and are coaxial, a displacement IC (110) is inserted between the magnets and is close to one end, and the position is the zero voltage of the torque voltage signal; the tread frequency IC (111) is arranged above the multistage magnetic ring (116);

the middle shaft sensor (1) is characterized in that: the multistage magnetic ring (116) is sleeved on the magnetic ring frame (115), two ends of the magnetic ring frame (115) respectively prop against the sliding ring (112) and the inner ring of the displacement bearing (117), and the magnet seat (118) and the magnet cover (119) are buckled into a whole and sleeved on the outer ring of the displacement bearing (117);

the middle shaft sensor (1) is characterized in that: the magnetic ring frame (115), the multi-stage magnetic ring (116) and the inner ring of the displacement bearing (117) rotate and move axially along with the sliding ring (112), and the outer ring of the displacement bearing (117), the magnet base (118), the magnet cover (119) and the magnet (109) only move axially;

the middle shaft sensor (1) is characterized in that: a return spring, preferably a wave spring (120), is provided between the magnet cover (119) and the bottom of the PCB bracket (121).

6. The mid-motor installation according to claim 1, characterized in that: the motor frame (6) can be welded at the five-way position of the frame at any angle, the installation angle of the middle-placed motor is not limited, the middle-placed motor is axially placed into the motor frame (6), and frame screws (822) are used for fixing the middle-placed motor in the motor frame (6) from the bottom surface, the side surface and the front surface respectively.

7. The aluminum core (201) of claim 1, characterized by: the step surface of the rotor bearing is symmetrically provided with two screw holes (201a) and two positioning pin holes (201b), the two screw holes and the positioning pin holes are mutually vertical, and the inner cavity of the rotor bearing is provided with a plurality of L-shaped grooves (201c) which are used as air circulation channels between the rotor bearing (204) and the wall of the inner cavity;

the sun tooth (206) is characterized in that: tooth number 10, modulus 1.0, dextrorotation;

the final stage gear (803) is characterized in that: the axis is a through hole and is used for accommodating a needle roller clutch (807) and a clutch bearing (810), the straight teeth are shaft shoulders, two ends of the bearing are fixed, and the shaft extension is provided with reverse threads;

the clamping plate (9) is characterized in that: the aluminum alloy plate is formed by punching an aluminum alloy plate with the thickness of 4.0 mm;

the driver (2) is characterized in that: the appearance is the cuboid, and its COB board is the rectangle, and six MOS pipes are arranged into a line and are locked on heat dissipation aluminium bar (301).