WO2021031973A1

WO2021031973A1 - Axial-flux geared hub motor having unit module-combined stator

Info

Publication number: WO2021031973A1
Application number: PCT/CN2020/108896
Authority: WO
Inventors: 眭华兴
Original assignee: 眭华兴
Priority date: 2019-08-16
Filing date: 2020-08-13
Publication date: 2021-02-25
Also published as: CN111756207A; CN111224527B; CN111224527A; CN212627614U; CN212627617U; CN111769709A; CN212627616U; CN111756206A; CN111835172A; CN111756205A; CN212627619U; CN110350749A; CN212627615U

Abstract

Disclosed in the present invention is an axial-flux geared hub motor having a unit module-combined stator, comprising a spindle, a hub, an end cover, a motor, and a planetary gear reduction mechanism. The motor is an axial-flux motor having a single air gap fixed shaft structure, and comprises a rotor assembly and a stator assembly; a rotor disc in the rotor assembly is in rolling connection to the spindle by means of a bearing unit comprising an angular contact bearing and having rolling elements arranged side by side in the axial direction; the stator assembly comprises multiple unit stators with coils wound thereon and one stator supporting disc; the unit stator is formed of "I"-shaped silicon steel sheets of different widths stacked in the radial direction and connected as a whole; the unit stators are connected to the stator supporting disc by means of fixing pins to form a unit module-combined stator structure; the stator supporting disc is fixedly connected to the spindle. The motor provided by the present invention has low cost, high efficiency, and a wide high-efficiency interval, and can greatly increase the riding range of an electric bicycle.

Description

Unit module combined stator axial magnetic field geared hub motor

Technical field

The invention relates to the technical field of hub motors for electric bicycles, in particular to a geared hub motor with axial magnetic field.

Background technique

There are two main types of existing electric bicycle motors. One is a mid-mounted motor installed on the central axis of the bicycle, and the other is a hub motor integrated with the hub. The hub motor is divided into low-speed hub motors and planetary gear reduction motors. There are two types of gear hub motors. Due to the hysteresis resistance of electric bicycles with low-speed hub motors, the riding function of bicycles is severely weakened. Geared hub motors are equipped with drive motors, planetary gear reduction mechanisms and one-way clutches in the inner space of the hub and end cover, which are more suitable Light electric bicycles with good riding function and sliding ability, such as the Chinese patents CN03127256.8 and CN201510104597.9 for the through-shaft structure outer rotor motor, and the US patent US20050176542A1 for the half-shaft structure inner rotor motor. For the above two types of in-wheel motors, the drive motors are all DC permanent magnet motors with radial magnetic field. The high efficiency range is biased towards the high power range. When the vehicle is running normally, the drive motor usually runs in the low efficiency range and has a short driving range.

The drive motor of the electric bicycle requires frequent start/stop, acceleration/deceleration, high torque at low speed or climbing, low torque when driving on normal flat ground, wide speed range, and can maintain under various road conditions Stable performance, compared with the characteristics of general industrial motors that can usually be optimized at the rated operating point, the requirements for electric bicycle drive motors are higher. Ordinary hub motors cannot meet the general requirements of people to increase the mileage of electric bicycles. The field DC motor itself can meet this requirement. For example, ZL 201620995774.7 discloses "a disc-type coreless DC motor", but the coreless axial field motor has a dual-rotor structure, which consumes more rare earth permanent magnets, and its economy is obviously insufficient.

The axial magnetic field motor with iron core, due to its small magnetic leakage, high electromagnetic density, and wide high efficiency range, its electrical performance is reflected in the in-wheel motor and has obvious advantages. Due to the axial magnetic pulling force, ordinary technicians will avoid the simultaneous There is also an axial magnetic field motor with a single air gap structure with overturning moment. Therefore, the prior art axial magnetic field motor has a double air gap structure, and the stator components are all connected to the casing. There is no fixed shaft structure that can be installed. The axial field motor technology with iron core in the hub space that meets the through-shaft requirements of the in-wheel motor. The realization of this technology is the best technical path to greatly increase the mileage of electric bicycles and achieve leap-forward technological progress in this field .

Summary of the invention

The purpose of the present invention is to provide a unit-module combined stator axial magnetic field geared hub motor, which is used to apply an axial magnetic field motor with high efficiency and a wide range of high efficiency to electric motors at low cost under the existing production technology conditions. The bicycle field meets people's requirements for increased mileage.

The technical idea is: the drive motor adopts an axial magnetic field motor with a single air gap structure and an iron core, and has a fixed shaft structure, which reduces the space occupation inside the hub; adopts a planetary gear reduction mechanism to reduce speed, so that the axial magnetic field motor has high speed The characteristics of low torque greatly reduce the amount of permanent magnets, thereby greatly reducing the magnetic pulling force and greatly reducing the cost of the motor; the motor rotor overcomes the axial magnetic pulling force through the bearing unit with the axially aligned rolling elements including the angular contact bearing And the overturning force of the rotor disc; the unit stator of independent modules is used to overcome the existing production conditions lacking high-efficiency punching and winding equipment, and the stator core is manufactured by the mature high-speed continuous die punching process and laser welding process. Realize the automation of coil winding.

To this end, the present invention provides the following solutions:

The invention discloses a unit module combined stator axial magnetic field geared hub motor, which includes a main shaft, a hub, an end cover, a motor and a planetary gear reduction mechanism. The motor is decelerated by the planetary gear reduction mechanism to drive the hub Rotation; The motor is an axial field motor with a single air gap fixed-shaft structure, including a rotor assembly and a stator assembly, the rotor assembly includes a rotor disk and a plurality of permanent magnets mounted on the rotor disk, so The rotor disk is rotatably connected with the main shaft through a bearing unit including an angular contact bearing and having axially aligned rolling elements; the stator assembly includes a plurality of unit stators, a plurality of coils and a stator tray, and the stator tray is fixed Connected to the main shaft, the unit stators are "I"-shaped silicon steel sheets of different widths stacked in the radial direction and connected as a whole, and the coils are in the form of concentrated windings and are wound on the unit stators, so The unit stators are arranged concentrically and connected to the stator tray by fixing pins to form a unit module combined stator.

Preferably, the unit stator and the coil are insulated and blocked by an insulated coil bobbin or an insulating coating layer.

Preferably, the axial length of the unit stator yoke laminations is greater than the axial length of the laminations on one side of the magnetic pole surface, and there is a gap between the circumferential lamination surfaces of the adjacent unit stator yokes, so that there is a second Air gap.

Preferably, the unit stator is formed into an integral structure through a superposition welding process or a bonding process, and the welding surface or the bonding surface at least includes the end surface of the yoke.

Preferably, the fixed pin is a dovetail pin of the unit stator yoke and integrated with the unit stator, and a first dovetail groove is provided on the stator tray in cooperation with the fixed pin, and the fixed pin is inserted into the The first dovetail slot realizes the fixed connection between the unit stator and the stator tray.

Preferably, the fixing pin has a dovetail shape on both sides or a dovetail shape on one side and a "T" shape on the other side. The unit stator yoke is provided with a second dovetail groove that matches the fixing pin, corresponding to the The second dovetail groove is provided with a first dovetail groove or "T" shaped groove on the stator tray, and the fixing pin is inserted into the second dovetail groove and the first dovetail groove or "T" shaped groove, thereby The fixed connection between the unit stator and the stator tray is realized.

Preferably, the fixed pin is cylindrical, the yoke of the unit stator is provided with a first mounting hole that matches with the fixed pin, and the stator tray is provided with an outer ring and an axial cylinder. The ring ring and the axial cylinder are formed on the stator tray with a ring groove covering the unit stator, and a second installation is provided on the outer ring and the axial cylinder corresponding to the first mounting hole Hole and third mounting hole, insert the fixing pin from the second mounting hole, the first mounting hole and the third mounting hole, so as to realize the fixed connection of the unit stator and the stator tray.

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

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 located on one side of the unit stator, and the outer ring diameter is larger than that of the deep groove ball bearing. The outer ring diameter, or the outer ring diameter of the deep groove ball bearing and the single row angular contact ball bearing are the same, and a washer is arranged between the outer rings of the two bearings.

Preferably, 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, and an elastic washer is arranged between the inner rings of the two bearings, the rotor The magnetic pulling force received by the disk is shared by the two single row angular contact ball bearings through the elastic washer.

Preferably, the rotor disc and/or the stator tray are provided with vents, and cold air is introduced into the motor from the vents through the air pressure difference generated by the rotation of the rotor disc, and hot air is discharged out The motor.

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

The invention applies the axial magnetic field motor, especially the axial magnetic field motor with a single air gap structure, to the hub motor of the electric bicycle. Compared with the traditional radial magnetic field motor, the amount of permanent magnet is reduced by 20%, the silicon steel sheet material consumption is reduced by 40%, and the efficiency is high. The interval is advanced and the width is greatly increased, which greatly increases the continuous mileage of the electric bicycle, and enables low-cost mass production under the existing manufacturing technology conditions.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, without creative work, other drawings can be obtained from these drawings.

FIG. 1 is a schematic diagram of the structure of a unit-module combined stator axial magnetic field geared hub motor of this embodiment;

Figure 2 is a 3D exploded view of the unit-module combined stator axial magnetic field geared hub motor of this embodiment;

Figure 3 is a schematic diagram of the connection between a unit stator and a stator tray;

Figure 4 is a schematic diagram of the unit stator structure of the embodiment;

Figure 5 is a schematic diagram of the structure of the stator tray of this embodiment;

Figure 6 is a schematic diagram of a structure of the bearing unit;

Figure 7 is a schematic diagram of another structure of the bearing unit;

Figure 8 is a schematic diagram of another structure of the bearing unit.

Description of Reference Signs: 1 main shaft; 2 hub; 3 end cover; 4 rotor disc; 5 permanent magnet; 6 rolling element; 7 unit stator; 8 coil; 9 stator tray; 10 coil bobbin; 11 fixing pin; 12 first gas Gap; 13 second air gap; 14 first dovetail groove; 15 second dovetail groove; 16 "T" groove; 17 first mounting hole; 18 outer ring; 19 axial cylinder; 20 ring groove; 21 second Mounting holes; 22 third mounting holes; 23 double row angular contact ball bearings; 24 deep groove ball bearings; 25 single row angular contact ball bearings; 26 washers; 27 elastic washers; 28 vents.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

As shown in Figures 1-8, this embodiment provides a unit-module combined stator axial magnetic field geared hub motor, which includes a main shaft 1, a hub 2, an end cover 3, a motor, and a planetary gear reduction mechanism. The planetary gear reduction mechanism drives the hub to rotate after deceleration; the motor is an axial field motor with a single air gap fixed shaft structure, and includes a rotor assembly and a stator assembly. The rotor assembly includes a rotor with 4 disks and A plurality of permanent magnets 5 on the rotor disc 4, the rotor disc 4 is rotatably connected with the main shaft 1 through a bearing unit including angular contact bearings with axially aligned rolling elements 6; the stator assembly includes a plurality of unit stators 7, multiple There are two coils 8 and one stator tray 9. The stator tray 9 is fixedly connected to the main shaft 1. The unit stator 7 is made of "I"-shaped silicon steel sheets of different widths laminated in the radial direction, and formed into a whole through a lamination welding process or a bonding process Structure, its welding surface or bonding surface includes at least the end surface of its yoke, as shown in Figure 4, the coil 8 is in the form of concentrated winding and is wound on the unit stator 7, and the unit stator 7 and the coil 8 pass through the insulated coil The frame 10 or the insulation coating layer is used for insulation barrier. The unit stators 7 are arranged concentrically and connected to the stator tray 9 by fixing pins 11 to form a unit module combined stator. The axial length of the yoke laminations of the unit stator 7 is greater than the magnetic pole face side For the axial length of the laminations, a gap is left between the circumferential overlapping surfaces of the yokes of the adjacent unit stators 7 and thus has a second air gap 13.

In the invention of the above solution, the space in the hub is compact and reasonable, the hub motor has a stable structure with a "through shaft" feature, and the unique "pumping effect" of the disc-shaped rotor disk 4 can generate circulation in the hub space. Airflow is conducive to cooling the motor.

The axial magnetic field motor needs to overcome the axial magnetic pulling force between the rotor assembly and the stator assembly, and because the axial magnetic pulling force will not be theoretically uniform in the circumferential direction, it also needs to overcome the resulting overturning force. The technology is based on the double air gap structure to balance the axial magnetic tension. The wheel hub motor of this embodiment has low rated power. Due to the planetary gear reduction mechanism, the axial field motor has the characteristics of high speed and low torque. The magnetic pulling force of the single air gap structure is limited and controllable. "Angular contact ball bearing + two parallel rolling elements The 6" bearing unit connects the rotor disc 4 to the main shaft 1 in a rotating manner. Its effectiveness and stability have been verified by experiments; multiple unit stators 7 are arranged coaxially and circumferentially to form a ring composed of multiple unit stator poles The magnetic pole plane corresponds to the magnetic pole faces of a plurality of permanent magnets 5, and the permanent magnet flux passes through "N pole of permanent magnet 5~first air gap 12~unit stator 7~second air gap 13~adjacent unit stator 7 ～First air gap 12～S poles of adjacent permanent magnets 5", forming a closed magnetic circuit. The purpose of setting the second air gap 13 in the yoke of the unit stator 7 is to prevent the adjacent unit stator 7 from contacting and eliminate the combined type The eddy current loss of the stator due to the conduction between the plates.

Those skilled in the art need to adopt an appropriate structure according to the magnitude of the magnetic pull and electromagnetic torque of the axial field motor to ensure the reliability of the unit and module combined stator assembly, the structure and connection of the unit stator 7 and the stator tray 9 It can be selected according to the following three examples of this embodiment, but not limited to the three examples.

Example one:

The fixed pin 11 is a dovetail pin integrated with the yoke of the unit stator 7 and integrated with the unit stator 7. As shown in Figure 4, the fixed pin 11 is provided with a first dovetail slot 14 on the stator tray 9 and the fixed pin 11 is inserted into the first dovetail slot 14, so as to realize the fixed connection between the unit stator 7 and the stator tray 9.

Embodiment two:

The fixing pin 11 has a dovetail shape on both sides or a dovetail shape on one side and a "T" shape on the other side. The yoke of the unit stator 7 is provided with a second dovetail slot 15 that is matched with the fixing pin 11, corresponding to the second dovetail slot 15 in the stator The pallet 9 is provided with a first dovetail slot 14 or "T"-shaped slot 16, and a fixing pin 11 is inserted into the second dovetail slot 15 and the first dovetail slot 14 or "T"-shaped slot 16, thereby realizing the unit stator 7 and the stator tray 9 fixed connection.

Example three:

The fixed pin 11 is cylindrical, the yoke of the unit stator 7 is provided with a first mounting hole 17 that is matched with the fixed pin 11, and the stator tray 9 is provided with an outer ring 18 and an axial cylinder 19, consisting of the outer ring 18 and the axial The cylinder 19 is formed on the stator tray 9 with a ring groove 20 for the unit stator 7, corresponding to the first mounting hole 17, the outer ring 18 and the axial cylinder 19 are provided with a second mounting hole 21 and a third mounting hole 22, such as As shown in FIG. 4 and FIG. 5, the fixing pin 11 is inserted from the second mounting hole 21, the first mounting hole 17 and the third mounting hole 22 to realize the fixed connection between the unit stator 7 and the stator tray 9.

Those skilled in the art can select the specific form of the bearing unit according to actual needs, as long as the bearing unit contains angular contact ball bearings that can bear axial magnetic tension, and the bearing unit has axially parallel rolling elements 6 that bear the overturning moment. can. For example, the bearing unit can be a double row angular contact ball bearing 23, as shown in Figure 7, or a series combination of a deep groove ball bearing 24 and a single row angular contact ball bearing 25, as shown in Figures 1 and 6; or two single row The series combination of angular contact ball bearings 25 is shown in FIG. 8.

The bearing unit is a series combination of a deep groove ball bearing 24 and a single row angular contact ball bearing 25. The single row angular contact ball bearing 25 is located on the side of the unit module combined stator, and its outer ring diameter is larger than that of the deep groove ball bearing 24 The diameter, the magnetic tension acts on the bearing stop of the single row angular contact ball bearing 25, as shown in Figure 6; the outer ring diameter of the deep groove ball bearing 24 and the single row angular contact ball bearing 25 are the same, and a washer 26 is arranged between the outer rings, The magnetic pulling force is transmitted through the washer 26 and acts on the bearing stop of the deep groove ball bearing 24, as shown in FIG. 8.

When the magnetic tension is large, the bearing unit chooses a series combination of two single row angular contact ball bearings 25, the two single row angular contact ball bearings 25 are arranged in the same direction, and an elastic washer 27 is arranged between the inner rings, as shown in Figure 8. The elastic washer 27 adopts a wave lamination. The magnetic tension causes the elastic washer 27 to compress and deform and is shared by the two single row angular contact ball bearings 25; when the outer ring diameters of the two single row angular contact ball bearings 25 are different, the magnetic tension acts on the When the outer rings of the two single row angular contact ball bearings 25 have the same diameter on the bearing stop, a washer 26 is arranged between the outer rings.

In this embodiment, the rotor disk 4 and/or the stator tray 9 are provided with vents 28. Since the rotor disk 4 and the unit module combined stator rotate relative to each other, the air in the first air gap 12 will be driven to flow with the rotor disk 4. The flow rate of the air at the edge of the rotor disk 4 is greater than the flow rate of the inner air, so the outer air pressure is lower than the inner air pressure, forming a "pumping effect". Cold air enters the first air gap 12 from the vent 28, and hot air is discharged from the motor, thereby increasing Heat dissipation capacity.

In this specification, specific examples are used to describe the principles and implementation of the present invention. The descriptions of the above examples are only used to help understand the methods and core ideas of the present invention; at the same time, for those skilled in the art, according to this The idea of the invention will change in the specific implementation and the scope of application, and the unit-module combined stator axial magnetic field geared hub motor of the invention can also be realized. In summary, the content of this specification should not be construed as limiting the present invention.

Claims

A unit module combined stator axial magnetic field geared hub motor includes a main shaft, a hub, an end cover, a motor, and a planetary gear reduction mechanism. The motor drives the hub to rotate after being reduced by the planetary gear reduction mechanism. Yes: The motor is an axial field motor with a single air gap fixed shaft structure, and includes a rotor assembly and a stator assembly. The rotor assembly includes a rotor disk and a plurality of permanent magnets mounted on the rotor disk, so The rotor disk is rotatably connected with the main shaft through a bearing unit including an angular contact bearing and having axially aligned rolling elements; the stator assembly includes a plurality of unit stators, a plurality of coils and a stator tray, and the stator tray is fixed Connected to the main shaft, the unit stators are "I"-shaped silicon steel sheets of different widths stacked in the radial direction and connected as a whole, and the coils are in the form of concentrated windings and are wound on the unit stators, so The unit stators are arranged concentrically and connected to the stator tray by fixing pins to form a unit module combined stator.
The unit-module combined stator axial magnetic field geared hub motor according to claim 1, wherein the axial length of the unit stator yoke lamination is greater than the axial length of the lamination on the side of the magnetic pole face. A gap is left between the circumferential superimposed surfaces of the adjacent unit stator yokes and thus has a second air gap.
The unit module combined stator axial magnetic field geared hub motor according to claim 1, wherein the unit stator is formed into an integral structure through a lamination welding process or a bonding process, and the welding surface or the bonding surface at least includes The end face of its yoke.
The unit-module combined stator axial magnetic field geared hub motor according to claim 1, wherein the fixed pin is a dovetail pin of the unit stator yoke and integral with the unit stator, which cooperates with the fixed A pin is provided with a first dovetail slot on the stator tray, and the fixing pin is inserted into the first dovetail slot, so as to realize a fixed connection between the unit stator and the stator tray.
The unit-module combined stator axial magnetic field geared hub motor according to claim 1, wherein the fixed pin has a dovetail shape on both sides or a dovetail shape on one side and a "T" shape on the other side. The stator yoke of the unit is provided with a second dovetail slot that is matched with the fixed pin, a first dovetail slot or a "T"-shaped slot is provided on the stator tray corresponding to the second dovetail slot, and the second dovetail slot And the first dovetail slot or the "T"-shaped slot is inserted into the fixing pin, so as to realize the fixed connection between the unit stator and the stator tray.
The unit-module combined stator axial magnetic field geared hub motor according to claim 1, wherein the fixed pin is cylindrical, and the yoke of the unit stator is provided with a first cooperating with the fixed pin. Mounting hole, the stator tray is provided with an outer ring and an axial cylinder, and the outer ring and the axial cylinder form a ring groove that covers the unit stator on the stator tray, corresponding to the first A mounting hole is provided with a second mounting hole and a third mounting hole on the outer ring and the axial cylinder, and the second mounting hole, the first mounting hole and the third mounting hole are inserted into the Fixing pins, so as to realize the fixed connection between the unit stator and the stator tray.
The unit module combined stator axial magnetic field geared hub motor according to 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.
The unit module combined stator axial magnetic field geared hub motor according to claim 7, wherein the bearing unit is a series combination of a deep groove ball bearing and a single row angular contact ball bearing, and the single row angular contact ball The bearing is located on one side of the unit stator, and its outer ring diameter is larger than the outer ring diameter of the deep groove ball bearing, or the outer ring diameter of the deep groove ball bearing and the single row angular contact ball bearing are the same and are in two bearings A washer is arranged between the outer ring of the
The unit module combined stator axial magnetic field geared hub motor according to claim 7, wherein the bearing unit is a series combination of two single row angular contact ball bearings, and the two single row angular contact ball bearings They are arranged in the same direction, and elastic washers are arranged between the inner rings of the two bearings, and the magnetic pulling force received by the rotor disk is shared by the two single row angular contact ball bearings through the elastic washers.
The unit module combined stator axial magnetic field geared hub motor according to claim 1, wherein the rotor disk and/or the stator tray are provided with vents, which are generated by the rotation of the rotor disk Due to the difference in air pressure, cold air is introduced into the motor from the vent, and hot air is discharged from the motor.