CN111224527A

CN111224527A - Axial magnetic field hub motor

Info

Publication number: CN111224527A
Application number: CN202010105355.2A
Authority: CN
Inventors: 眭华兴; 眭重兴; 高波; 高峰
Original assignee: Hui Huaxing
Current assignee: Hui Huaxing
Priority date: 2019-08-16
Filing date: 2020-02-20
Publication date: 2020-06-02
Anticipated expiration: 2040-02-20
Also published as: CN111769709A; CN212627615U; CN212627617U; CN111756207A; CN111756206A; CN212627619U; CN212627614U; CN111224527B; CN111835172A; CN212627616U; WO2021031973A1; CN110350749A; CN111756205A

Abstract

The invention discloses an axial magnetic field hub motor, which comprises a main shaft, a hub and an end cover, wherein the hub and the end cover enclose an inner space, and the axial magnetic field hub motor also comprises a motor and a planetary reduction mechanism; the motor is an axial magnetic field motor with a single air gap structure, a rotor disc of the motor is sleeved on a main shaft through a bearing unit which comprises an angular contact bearing and is provided with two rows of rolling bodies, a stator core is connected with a fixed groove on a support disc through fixed teeth of the stator core and is welded or riveted by punching, and the support disc is fixedly connected with the main shaft or is fixedly connected with the main shaft through a shaft sleeve. The hub motor has the advantages of low cost, high efficiency and wide high-efficiency interval, and can greatly improve the continuous mileage of the electric bicycle.

Description

Axial magnetic field hub motor

Technical Field

The invention relates to the technical field of hub motors of electric bicycles, in particular to an axial magnetic field hub motor with a single air gap structure.

Background

The existing electric bicycle motors mainly comprise two types, one type is a middle motor arranged on a middle shaft of the bicycle, and the other type is a hub motor arranged on a wheel and integrated with a hub. The middle motor is an inner rotor high-speed motor, and after the speed of the planetary gear mechanism is reduced, the bicycle is driven by the power transmitted by the chain.

The hub motor is mainly adopted by the electric bicycle on the market, the traditional electric bicycle is provided with the gear hub motor, generally, the hub and the end cover are sleeved on the main shaft, the driving motor, the planetary reduction mechanism and the one-way clutch are arranged in the inner space of the hub and the end cover, for example, Chinese patents CN03127256.8 and CN201510104597.9 of the through-shaft structure outer rotor motor, and for example, U.S. patent US20050176542A1 of the half-shaft structure inner rotor motor, the driving motor with the gear hub motor is a direct current permanent magnet motor with a radial magnetic field, the efficiency of the motor is not high, the high-efficiency section is deviated to the high-power section, the driving motor usually runs in the low-efficiency section when the vehicle normally runs.

The driving motor of the electric bicycle requires frequent starting/stopping, accelerating/decelerating, requires high torque during low speed or climbing, requires low torque during normal flat driving, has a large speed change range, and can keep stable performance during driving under various different road conditions. For example, the disc type coreless direct current motor disclosed in ZL 201620995774.7, but the axial magnetic field motor with the coreless structure has a double-air gap structure, needs to consume more rare earth permanent magnets, and has obvious shortage in economy in the face of great increase in price of the rare earth permanent magnets; the axial magnetic field motor with the iron core has the obvious advantages of electric performance in the hub motor due to small magnetic leakage and high electromagnetic density, and particularly, the axial magnetic field motor with the single air gap structure has the characteristic of small permanent magnet consumption and better economical efficiency as long as the influence of unilateral magnetic pull force can be effectively overcome. Therefore, the axial magnetic field direct current motor with the single air gap structure is the best technical path for meeting the requirement of increasing the continuous mileage.

Because the axial magnetic field motor has axial magnetic pull force, a common technician can avoid the axial magnetic field motor with a single air gap structure and a larger overturning moment, and the axial magnetic field motor with a double air gap structure in the prior art is of a rotating shaft structure, so that the hub motor of the electric bicycle cannot have a structural form of a fixed shaft and a through shaft.

Disclosure of Invention

The invention aims to provide a geared hub motor with a through shaft structure, wherein a driving motor of the geared hub motor is an axial magnetic field motor with a stator core, in particular to an axial magnetic field hub motor with a single air gap structure, so that the application of the axial magnetic field motor in the field of electric bicycles is realized at low cost, and the requirement of people on the increase of the driving mileage is met.

In order to achieve the purpose, the invention provides the following scheme:

the invention discloses an axial magnetic field hub motor, which comprises a main shaft, a hub and an end cover, wherein the hub and the end cover are sleeved on the main shaft in a rolling manner, the hub is detachably and fixedly connected with the end cover, the hub and the end cover enclose an inner space, the axial magnetic field hub motor also comprises a motor and a planetary reduction mechanism, a wire hole is formed in the main shaft, a leading-out wire of the motor penetrates through the wire hole and is connected with an external controller, the motor is an axial magnetic field motor with a single air gap structure and comprises a rotor disc, a stator core, a supporting disc, a plurality of coil windings and a plurality of permanent magnets; the stator core is formed by winding a silicon steel sheet winding tape through a continuous punching process and then adding a pre-stressed tension, and comprises a plurality of wire slots, a plurality of stator teeth, a stator yoke and a plurality of fixed teeth, wherein magnetic pole surfaces of the stator teeth are vertical to the main shaft, and a coil winding is wound on the stator teeth through the wire slots; the permanent magnet is fixed on one surface of the rotor disc opposite to the stator core, and the rotor disc is rotationally connected with the main shaft through a bearing unit which comprises an angular contact bearing and is provided with two rows of rolling bodies; the supporting plate is provided with a plurality of fixing grooves which are connected with the fixing teeth of the stator core in a sleeved mode, and the supporting plate is fixedly connected with the main shaft or fixedly connected with the main shaft through a shaft sleeve; the planetary reduction mechanism comprises a planetary carrier, a plurality of planet wheels, a central wheel and a sun gear ring, wherein the planetary carrier is fixedly sleeved on the main shaft and provided with a one-way clutch, the plurality of planet wheels are rotatably arranged on the planetary carrier, the central wheel is fixed on the inner surface of the hub, the sun gear ring is fixed on the rotor disc, and the motor transmits torque to the hub through the planetary reduction mechanism.

Preferably, the axial magnetic field hub motor is a brushless motor, three mounting grooves for mounting the hall position sensors are formed between the stator teeth, the hall position sensors are connected with a PCB board mounted on the supporting plate, and the PCB board is connected with the outgoing line.

Preferably, the axial magnetic field hub motor with a single air gap structure has a structure in which the magnetic pulling force borne by the rotor disc and the overturning force generated due to unbalanced magnetic pulling force are supported by the bearing unit, and the bearing unit is a double-row angular contact ball bearing, or a series combination of a deep groove ball bearing and a single-row angular contact ball bearing, or a series combination of two single-row angular contact ball bearings.

Preferably, the slot edge of the fixed slot of the supporting disk, which is located on the other side of the stator core, is a chamfered edge, and the fixed teeth are inserted into the fixed slot and are welded at the joint with the chamfered edge by hot melt, or are riveted by punching, so that the stator core is stably connected with the supporting disk.

Preferably, the shaft sleeve is provided with a radial extending edge, a plurality of first threaded holes are circumferentially arranged on the extending edge, the supporting plate is provided with through holes corresponding to the first threaded holes, and first adjusting screws are screwed in the through holes and the first threaded holes so as to connect the supporting plate and the shaft sleeve; a second threaded hole is formed between the adjacent through holes on the supporting plate, and a second adjusting screw is screwed in the second threaded hole and abuts against the extending edge; and adjusting the first adjusting screw and the second adjusting screw to adjust the parallelism of the permanent magnet magnetic pole surface and the stator tooth magnetic pole surface and adjust the length of an air gap between the two magnetic pole surfaces.

Preferably, the stationary teeth of the stator core are disposed at the other sides of the stator teeth and the slot of the stator yoke, the stationary teeth correspond to the slot at an inner circumference of the stator core, and adjacent sides of adjacent two stationary teeth are parallel to each other.

Preferably, the rotor disc and/or the support disc are provided with ventilation openings, and cold air is introduced into the motor through the ventilation openings by the air pressure difference generated by the rotation of the rotor disc, so that hot air is discharged out of the motor.

Preferably, the bearing unit is a series combination of a deep groove ball bearing and a single-row angular contact ball bearing, the single-row angular contact ball bearing is positioned on one side of the stator core, and the diameter of the outer ring of the single-row angular contact ball bearing is larger than that of the outer ring of the deep groove ball bearing.

Preferably, in the series combination of the deep groove ball bearing and the single-row angular contact ball bearing, the diameters of the outer rings of the deep groove ball bearing and the single-row angular contact ball bearing are the same, and a gasket is arranged between the outer rings of the two bearings.

Preferably, in the series combination of two single-row angular contact ball bearings, the two single-row angular contact ball bearings are arranged in the same direction, an elastic washer is arranged between inner rings of the two bearings, and the magnetic pulling force applied to the rotor disc is shared by the two single-row angular contact ball bearings through the elastic washer.

Compared with the prior art, the invention has the following technical effects:

firstly, the axial magnetic pull force is supported by the angular contact bearing, and the overturning moment of the rotor disc is supported by the bearing unit provided with the double-row rolling bodies, so that the axial magnetic field motor with the iron core and the single air gap structure is successfully applied to the field of low-power electric bicycles, and the purpose of improving the continuous mileage of the electric bicycle is realized: secondly, the torque for driving the electric vehicle mainly acts on the planet carrier through the speed reduction of the planetary gear speed reducing mechanism, and the axial magnetic field motor with high speed and low torque has less permanent magnet materials, thereby reducing the magnetic tension, having strong motor reliability and realizing low cost; thirdly, the stator core is connected with a supporting disk which is arranged on one side of the motor in an offset mode through fixed teeth, so that the space layout of the hub motor with the fixed-shaft structure is compact, and the structure is simple and reasonable; fourthly, the rotary inertia of the rotor disc of the motor is small, and the failure rate of the brake tooth breaking of the planet wheel is low; fifthly, the wheel hub motor has small no-load current, a high-efficiency interval is wide, and the performance advantage of a low-power section is very obvious, so that the wheel hub motor is particularly suitable for application of light electric bicycles.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an axial magnetic field hub motor according to this embodiment;

fig. 2 is a schematic view of a stator core;

FIG. 3 is a schematic structural view of a support plate;

FIG. 4 is a schematic view of a combination structure of a support plate and a shaft sleeve;

FIG. 5 is a schematic view of a bearing unit;

FIG. 6 is another schematic structural view of the bearing unit;

FIG. 7 is another schematic structural view of the bearing unit;

FIG. 8 is a diagram showing the positional relationship between stator core slots and stationary teeth;

FIG. 9 is a power-efficiency curve diagram of a 48V340W prototype axial magnetic field hub motor of the present embodiment;

FIG. 10 is an exploded view of the axial field hub motor of this embodiment;

description of reference numerals: 1, a main shaft; 2, a hub; 3, end cover; 4 wire holes; 5 leading-out wires; 6 a rotor disk; 7 a stator core; 8, supporting the disc; 9 a coil winding; 10 a permanent magnet; 11 wire grooves; 12 stator teeth; 13 a stator yoke; 14, fixing teeth; 15 fixing the grooves; 16 shaft sleeves; 17 a planet carrier; 18 planet wheels; 19 a central wheel; 20 sun gear ring gear; 21 a hall position sensor; 22, mounting grooves; 23PCB board; 24 double-row angular contact ball bearings; 25 deep groove ball bearings; 26 single-row angular contact ball bearings; 27 air gap; 28 a gasket; 29 an elastic washer; 30 an extending edge; 31 a first threaded hole; 32 through holes; 33 a first adjusting screw; 34 a second threaded hole; 35 a second adjusting screw; 36 air vents.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide an axial magnetic field hub motor, which is used for applying the axial magnetic field hub motor with high efficiency and wide high-efficiency interval to the field of electric bicycles and meets the requirement of people on the increase of the driving mileage.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1-10, the present embodiment provides an axial magnetic field hub motor, which includes a main shaft 1, a hub 2, and an end cover 3, wherein the hub 2 and the end cover 3 are rotatably sleeved on the main shaft 1, the hub 2 and the end cover 3 are detachably and fixedly connected, and the motor and a planetary reduction gear are further included in an internal space enclosed by the hub 2 and the end cover 3. The main shaft 1 is provided with a wire hole 4, and an outgoing wire 5 of the motor is used for passing through the wire hole 4 and is connected with an external controller. The motor is an axial magnetic field motor with a single air gap structure and comprises a rotor disc 6, a stator core 7, a supporting disc 8, a plurality of coil windings 9 and a plurality of permanent magnets 10. The stator iron core 7 is formed by winding a silicon steel sheet winding tape through a continuous punching process and then adding a pre-stressed tension, and comprises a plurality of wire slots 11, a plurality of stator teeth 12, a stator yoke 13 and a plurality of fixed teeth 14, wherein magnetic pole surfaces of the stator teeth 12 are vertical to the main shaft 1, so that an axial magnetic field is formed; the coil winding 9 is wound on the stator teeth 12 through the slots 11; the permanent magnets 10 are fixed to a surface of the rotor disk 6 facing the stator core 7, the rotor disk 6 is rotatably connected to the main shaft 1 via a bearing unit having two rows of rolling elements including an angular contact bearing, an axial magnetic pulling force applied to the rotor disk 6 acts on the angular contact bearing of the bearing unit, and an overturning moment applied to the rotor disk 6 due to non-uniformity of the axial magnetic pulling force is supported by the bearing unit. The supporting disk 8 is provided with a plurality of fixing grooves 15 to be connected with the fixing teeth 14 of the stator core 7, and the supporting disk 8 is fixedly connected with the main shaft 1, or the supporting disk 8 is fixedly connected with the main shaft 1 through a shaft sleeve 16. The planetary reduction mechanism comprises a planet carrier 17 fixedly sleeved on the main shaft 1 and provided with a one-way clutch, a plurality of planet wheels 18 rotatably installed on the planet carrier 17, a central wheel 19 fixed on the inner surface of the hub 2, and a sun gear ring 20 fixed on the rotor disc 6.

When the axial magnetic field hub motor of the embodiment is used, after the axial magnetic field motor with the single air gap structure is powered through the outgoing line 5, the main shaft 1 does not rotate, the rotor disc 6 rotates to drive the sun gear ring 20 to rotate, the sun gear ring 20 drives the planet gear 18 to rotate, and the planet gear 18 drives the central wheel 19 to rotate, so that the torque of the motor is transmitted to the hub 2. The planet carrier 17 has a one-way clutch, so that the electric bicycle still has good sliding capacity when in unpowered input, and is not influenced by hysteresis resistance of a motor when riding without power.

The axial magnetic field hub motor of this embodiment is a brushless motor, and three mounting grooves 22 for mounting the hall position sensors 21 are provided between the stator teeth 12, the hall position sensors 21 are connected 23 with a PCB board mounted on the support plate 8, and the PCB board 23 is connected with the outgoing line 5.

The axial magnetic field hub motor of the present embodiment is of a single air gap structure, and needs to overcome the magnetic pulling force generated by the permanent magnet 10 on the stator core 7, and also needs to overcome the overturning force generated by the unbalanced magnetic pulling force, and those skilled in the art can select a specific form of the bearing unit according to actual needs, for example, the bearing unit may be a double-row angular contact ball bearing 24, as shown in fig. 6; or a series combination of a deep groove ball bearing 25 and a single row angular contact ball bearing 26, as shown in fig. 5; or a series combination of two single row angular contact ball bearings 26 as shown in fig. 7.

The form of the bearing unit is determined according to the magnetic energy product of the permanent magnet 10, the length of the air gap 27 between the permanent magnet 10 and the stator teeth 12 and the diameter of the rotor disc 6. In the series combination of the deep groove ball bearing 25 and the single-row angular contact ball bearing 26, the single-row angular contact ball bearing 26 is positioned on one side of the stator core 12, the diameter of the outer ring of the single-row angular contact ball bearing is larger than that of the outer ring of the deep groove ball bearing 25, and magnetic pulling force acts on a bearing stop of the single-row angular contact ball bearing 26, as shown in fig. 5; the deep groove ball bearing 25 has the same diameter as the single-row angular contact ball bearing 26, a gasket 28 is arranged between the outer rings, and magnetic pulling force is transmitted to a bearing stop of the deep groove ball bearing 25 through the gasket 28. When the magnetic tension is large, the bearing unit selects the series combination of two single-row angular contact ball bearings 26, the two single-row angular contact ball bearings 26 are arranged in the same direction, and an elastic washer 29 is arranged between the inner rings of the two single-row angular contact ball bearings 26, as shown in fig. 7, the elastic washer 29 adopts a waveform lamination, and the magnetic tension causes the elastic washer 29 to generate compression deformation and is shared by the two single-row angular contact ball bearings 26; when the diameters of the outer rings of the two single-row angular contact ball bearings 26 are different, magnetic pull force acts on the bearing stops of the two single-row angular contact ball bearings 26 respectively, and when the diameters of the outer rings of the two single-row angular contact ball bearings 26 are the same, a gasket 28 is arranged between the outer rings of the two single-row angular contact ball bearings.

The stator teeth 12 of the stator core 7 and the stator yoke 13 on the other side of the slot 11 are provided with fixed teeth 14, the supporting disk 8 is provided with a fixed slot 15 matched with the fixed teeth 14, and the slot edge of the fixed slot 15 on the other side of the stator core 7 is chamfered; after the fixed teeth 14 are inserted into the fixed slots 15, the connection portions are fixed by hot melt welding or the fixed teeth 14 are pressed and riveted, thereby realizing the stable connection between the stator core 7 and the support plate 8. The supporting disk 8 is offset at one side of the stator core 7, an axial space of the bearing unit on the main shaft 1 is reserved, and the bearing chamber part of the rotor disk 6 is positioned at the inner ring of the stator core 7, so that the arrangement of the motor and the planetary gear speed reducing mechanism in the scheme of the embodiment in the hub space is more compact and reasonable.

The influence of air gap magnetic flux density on the rotating speed of an axial magnetic field motor is obvious, in order to realize the consistency of the rotating speed of the motor in batch production, the shaft sleeve 16 is arranged between a supporting plate 8 and a main shaft 1 and is used for adjusting the parallel and air gap length of a rotor magnetic pole surface, the shaft sleeve 16 is provided with a radial extending edge 30, a plurality of first threaded holes 31 are circumferentially arranged on the extending edge 30, the supporting plate 8 is provided with through holes 32 corresponding to the first threaded holes 31, and first adjusting screws 33 are screwed in the through holes 32 and the first threaded holes 31 to connect the supporting plate 8 and the shaft sleeve 16; a second threaded hole 34 is formed between the adjacent through holes 32 on the supporting disk 8, and a second adjusting screw 35 is screwed in the second threaded hole and tightly abuts against the extending edge 30; the first adjusting screw 33 and the second adjusting screw 35 are adjusted to adjust the parallelism of the pole faces of the permanent magnet 10 and the stator teeth 12 and to adjust the length of the air gap 27 between the two pole faces.

As shown in fig. 2 and 8, the fixed teeth 14 are formed simultaneously with the winding slots 11, the stator teeth 12 and the stator yoke 13 when the silicon steel sheet tape is continuously stamped and wound with a pre-stressed tension, the fixed teeth 14 correspond to the winding slots 11 at the inner circle of the stator core 7, and adjacent edges of two adjacent fixed teeth 14 are parallel to each other.

Because the sealing performance of the hub motor is better, the heat dissipation capability of the hub motor is improved in a relatively sealed environment, the performance stability of the hub motor can be effectively improved, and the phenomenon of 'magnetic loss' of a permanent magnet caused by temperature rise is eliminated. In this embodiment, the vent 36 is provided on the rotor disk 6 and/or the support disk 8, and the rotor disk 6 and the support disk 8 rotate relatively to each other, so that the air in the air gap 27 is driven to flow along with the rotor disk 6, and the flow rate of the air at the edge of the rotor disk 6 is greater than that of the air at the inner side, so that the outer side air pressure is smaller than the inner side air pressure, a "pumping effect" is formed, cold air enters the air gap 27 from the vent 36, and the fluidity of the air in the hub 2 is.

As shown in figures 1 and 10, the geared hub motor prototype with the structure of the embodiment is designed to have a rated voltage of 48V and a rated power of 340W, an axial magnetic field driving motor no-load rotation speed of 2190rpm/min and a hub 2 no-load rotation speed of 308rpm/min, an axial magnetic field direct current motor adopts an 18-slot 20-pole fractional-slot synchronous direct current motor type, the inner diameter and the outer diameter of a stator core 7 are respectively equal to that of a stator core 7

And

armature winding using

And in a parallel winding mode, the number of parallel branches is 1, and the magnetic pole position sensor is a Hall element.

The test result of a prototype is shown in fig. 9, the maximum efficiency reaches 89%, the efficiency within the power range of 118W-582W is over 80%, and compared with the low-speed hub motor of 48V350W which is mainstream in the market, the motor of the invention has obvious advantages. A sample car with 20-inch 1.75-wide tires and an axial magnetic field hub motor of the embodiment is configured, a 48V14Ah lithium battery is used as a power source, the average current of riding is about 3.5A, and the continuous mileage reaches 100Km according to the pure electric riding test with the average speed per hour of 24Km/h on a flat road surface with three grades and four grades of wind power, and the purpose of the invention is achieved.

The principle and the implementation mode of the present invention are explained by applying specific examples in the present specification, and the above descriptions of the examples are only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims

1. The utility model provides an axial magnetic field in-wheel motor, includes main shaft, wheel hub and end cover roll cup joint on the main shaft, wheel hub with the detachable fixed connection of end cover, its characterized in that:

the motor is an axial magnetic field motor with a single air gap structure and comprises a rotor disc, a stator core, a supporting disc, a plurality of coil windings and a plurality of permanent magnets; the stator core is formed by winding a silicon steel sheet winding tape through a continuous punching process and then adding a pre-stressed tension, and comprises a plurality of wire slots, a plurality of stator teeth, a stator yoke and a plurality of fixed teeth, wherein magnetic pole surfaces of the stator teeth are vertical to the main shaft, and a coil winding is wound on the stator teeth through the wire slots; the permanent magnet is fixed on one surface of the rotor disc opposite to the stator core, and the rotor disc is rotationally connected with the main shaft through a bearing unit which comprises an angular contact bearing and is provided with two rows of rolling bodies; the supporting plate is provided with a plurality of fixing grooves which are connected with the fixing teeth of the stator core, and the supporting plate is fixedly connected with the main shaft, or the supporting plate is fixedly connected with the main shaft through a shaft sleeve; the planetary reduction mechanism comprises a planetary carrier, a plurality of planet wheels, a central wheel and a sun gear ring, wherein the planetary carrier is fixedly sleeved on the main shaft and provided with a one-way clutch, the plurality of planet wheels are rotatably arranged on the planetary carrier, the central wheel is fixed on the inner surface of the hub, the sun gear ring is fixed on the rotor disc, and the motor transmits torque to the hub through the planetary reduction mechanism.

2. The axial magnetic field in-wheel motor of claim 1, wherein three mounting slots for mounting the hall position sensor are formed between the stator teeth, the hall position sensor is connected with a PCB board mounted on the supporting plate, and the PCB board is connected with the lead-out wire.

3. The axial field in-wheel motor of claim 1, wherein the bearing unit is a double row angular contact ball bearing, or a series combination of a deep groove ball bearing and a single row angular contact ball bearing, or a series combination of two single row angular contact ball bearings.

4. The axial magnetic field hub motor of claim 1, wherein a slot edge of the fixing slot on the other side of the stator core is a chamfered edge, and the fixing teeth are inserted into the fixing slot on the support disk and are welded at a joint by hot melt or are riveted by punching, so that the stator core is firmly connected with the support disk.

5. The axial magnetic field hub motor of claim 1, wherein the shaft sleeve has a radially extending edge, a plurality of first threaded holes are circumferentially formed on the extending edge, the support plate has through holes corresponding to the first threaded holes, and first adjusting screws are screwed into the through holes and the first threaded holes to connect the support plate and the shaft sleeve; a second threaded hole is formed between the through holes adjacent to the supporting plate, and a second adjusting screw is screwed in the second threaded hole and abuts against the extending edge; and adjusting the first adjusting screw and the second adjusting screw to adjust the parallelism of the permanent magnet magnetic pole surface and the stator tooth magnetic pole surface and adjust the length of an air gap between the two magnetic pole surfaces.

6. The axial field in-wheel motor of claim 1, wherein said stationary teeth correspond to said slots at an inner circumference of said stator core, and adjacent sides of two adjacent stationary teeth are parallel to each other.

7. The axial magnetic field hub motor of claim 1, wherein the rotor disc and/or the support disc is provided with a vent, and cold air is introduced into the interior of the motor through the vent by an air pressure difference generated by rotation of the rotor disc, and hot air is discharged out of the motor.

8. The axial magnetic field in-wheel motor of claim 3, wherein the bearing unit is a series combination of a deep groove ball bearing and a single row angular contact ball bearing, the single row angular contact ball bearing is located on one side of the stator core and has an outer ring diameter larger than that of the deep groove ball bearing, or the deep groove ball bearing and the single row angular contact ball bearing have the same outer ring diameter and a washer is arranged between the outer rings of the two bearings.

9. The axial magnetic field in-wheel motor according to claim 3, wherein the bearing unit is a series combination of two single-row angular contact ball bearings, the two single-row angular contact ball bearings are arranged in the same direction, an elastic washer is arranged between the two inner rings with bearings, and the magnetic pulling force applied to the rotor disc is shared by the two single-row angular contact ball bearings through the elastic washer.