CN111756206A - An axial magnetic field hub motor - Google Patents

Abstract

The invention discloses an axial magnetic field hub motor, comprising a motor connected with a main shaft in a hub space and a planetary gear reduction mechanism, the motor is an axial magnetic field motor with a single air gap structure, and the motor rotor assembly passes through a motor including an angular contact ball bearing. The bearing unit with juxtaposed rolling elements is rotatably connected to the main shaft. The stator assembly includes a stator iron core, a coil, a stator yoke disk and a stator frame. The stator iron core is made of silicon steel sheets of different widths superimposed in the radial direction. The iron core is connected with the stator yoke disk and the stator frame, or the stator iron core is connected with the stator frame through the stator yoke disk, and the stator frame is fixedly connected with the main shaft. High-efficiency and low-cost mass production of axial magnetic field in-wheel motors.

Description

An axial magnetic field hub motor

technical field

The invention relates to the technical field of in-wheel motors of electric bicycles, in particular to an axial magnetic field geared in-wheel motor stator.

Background technique

Existing electric bicycles mainly use low-speed hub motors, and there are also geared hub motors that use planetary gear reduction mechanisms. In the US patent US20050176542A1, the above-mentioned in-wheel motors are all DC permanent magnet motors with radial magnetic field. Such motors are not efficient, and 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 the continuation mileage is relatively long. Short; axial magnetic field motor with iron core, the disclosed technology is to use silicon steel sheet tape to wind the stator iron core through continuous punching. The slot pitch is compensated and corrected on the ground, the stator core is manufactured with high efficiency and low cost, and the coil winding can only be done manually at present.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a low-cost axial magnetic field motor with excellent performance that meets the requirements of GB 17761-2018 "Technical Specifications for Electric Bicycle Safety" and is used in the field of electric bicycles at low cost under the existing production technology conditions. Requirements for increased mileage.

The technical idea is: single air-gap structure axial magnetic field motor, the stator assembly is fixedly connected to the main shaft, and the gear hub motor is the through-shaft structure to achieve the optimal space utilization and the lowest manufacturing cost, combined with the existing production technical conditions, to The technical solution of "independent module stator core + stator yoke disk + concentrated coil winding" realizes high-efficiency and low-cost mass production of stator components, and the initial cost of the in-wheel motor is the same as that of the existing technology in-wheel motor.

For this reason, the present invention provides the following scheme:

The invention discloses an axial magnetic field wheel hub motor, comprising a motor connected to a main shaft in a hub space and a planetary gear reduction mechanism, the motor drives the wheel hub to rotate through the planetary gear reduction mechanism, and the motor is a single air gap structure Axial field motor, comprising a rotor assembly and a stator assembly, the rotor assembly being rotatably connected to the main shaft through a bearing unit including angular contact ball bearings with parallel rolling elements, the stator assembly including a plurality of stator irons A core, a plurality of coils, a stator yoke disk and a stator frame, the stator iron core is a plurality of sheets of silicon steel material of different widths superimposed and connected as a whole in the radial direction, and the axial height of the coil is smaller than all the The axial length of the stator core, the coil is sleeved on the end of the stator core close to the rotor assembly, the stator yoke is provided with a plurality of first tongue grooves in a circumferential array, the stator is erected There is a radial tray, and one end of the stator core that is inserted into the first tongue and groove and not sleeved with the coil extends beyond the stator yoke disk and is connected with the radial tray, or the stator yoke disk is inserted into the The stator core of the first tongue and groove is connected and connected with the radial tray, and the stator frame is fixedly connected with the main shaft.

Preferably, 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 stator yoke disc is made of high magnetic permeability material, which is formed by stacking a plurality of disc sheets of silicon steel material in the axial direction, or is made of SMC composite soft magnetic material by molding and sintering.

Preferably, the stator iron core is formed into an integral structure through a lamination welding process, and its welding surface at least includes its end face away from one end of the rotor assembly. The stator iron core is connected to the stator yoke disk or to the stator yoke disk. It is connected with the stator frame in a tenon-and-mortise structure.

Preferably, the axial height of the coil is smaller than the axial length of the stator iron core, and the coil and the stator iron core are connected by an insulated coil bobbin or by coating an insulating material on the stator iron core. Insulation barrier.

Preferably, the stator core is provided with at least one second tongue groove on two radially superimposed surfaces perpendicular to the rotating surface of the rotor assembly on the side away from the rotor assembly, and the second tongue groove is " U"-shaped groove, the radial tray of the stator frame is disposed on the side away from the rotor assembly, the radial tray is provided with a third tongue groove corresponding to the first tongue groove, the The first tongue groove and the third tongue groove are open grooves, and the solid part of the stator core located in the second tongue groove is radially inserted into the first tongue groove and the third tongue groove, and the second tongue groove is inserted into the second tongue groove. The groove edges of the first tongue groove and the third tongue groove are clamped in the tongue groove, so that the stator iron core is connected with the stator yoke plate and the stator frame in a tongue and groove structure.

Preferably, the stator core is provided with at least one second tongue groove on two radially superimposed surfaces perpendicular to the rotating surface of the rotor assembly on the side away from the rotor assembly, and the second tongue groove is " U"-shaped groove, the first tongue groove of the stator yoke plate is an open groove, and a plurality of first connecting holes are also provided on the proximal side thereof, and the radial tray of the stator frame is arranged close to the On one side of the rotor assembly, the radial tray is provided with a second connection hole corresponding to the first connection hole, and the stator yoke plate and the stator frame pass through the first connection hole and the second connection hole The connection hole is riveted or bolted, the solid part of the stator core located in the second tongue-and-groove section is radially inserted into the first tongue-and-groove, and the first tongue-and-groove is clamped in the second tongue-groove. groove edge, so that the stator iron core and the stator yoke are connected in a tenon-and-mortise structure.

Preferably, the stator core is provided with at least one second tongue groove on two radially superimposed surfaces perpendicular to the rotating surface of the rotor assembly on the side away from the rotor assembly, and the second tongue groove is " L"-shaped slot, the proximal side of the stator yoke is also provided with a number of first connecting holes, the radial tray of the stator frame is arranged on the side close to the rotor assembly, the radial tray There is a second connection hole corresponding to the first connection hole, the stator yoke plate and the stator frame are riveted or bolted through the first connection hole and the second connection hole, and the stator iron The solid part of the core located in the second tongue-and-groove section is inserted into the first tongue-and-groove, so that the stator iron core and the stator yoke are connected in a tenon-and-mortise structure, and then the stator iron is realized by welding or riveting. The fixed connection of the core to the stator yoke disk.

Preferably, a plurality of first connecting holes are provided on the proximal side of the stator yoke, the radial tray of the stator frame is provided on the side close to the rotor assembly, and the radial tray is provided with a second connection hole corresponding to the first connection hole, the stator yoke disk and the stator frame are riveted or bolted through the first connection hole and the second connection hole, and the stator iron core is not covered The end connected to the coil is inserted into the first tenon and groove, so that the stator iron core and the stator yoke plate form a tenon and tenon structure connection, and then the stator iron core and the stator yoke are realized by welding or riveting. Fixed connection of the disc.

The present invention has achieved the following technical effects with respect to the prior art:

The axial magnetic field hub motor of the present invention is used to carry out comparative tests on different types of electric bicycles such as wheel diameter, tire width, vehicle weight, solid tires, pneumatic tires, etc. The continuation mileage is increased by 25-50% compared with the prior art electric bicycles ; The stator core can be processed by high-speed continuous die punching process, and its manufacturing cost is only 35% of the stator core of the overall structure manufactured by the continuous punching and winding process, thanks to the sorting and stacking of the stator core punching Simultaneous research and development of automatic equipment for pressure welding process, centralized coil winding is produced by existing automatic winding process, and the consumption of the three main materials of the motor "permanent magnet, silicon steel sheet, enameled copper wire" has been reduced to varying degrees. The initial cost is close to the cost of the prior art wheel hub motor; the single air gap structure axial magnetic field motor with iron core of the present invention, combined with the planetary gear reduction mechanism and the bicycle wheel hub, creatively realizes the axial magnetic field motor in the field of wheel hub motors. practical application.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is an axial arrangement diagram of an axial magnetic field hub motor in the hub space of the present embodiment;

FIG. 2 is a schematic structural diagram of a stator assembly of an axial magnetic field hub motor according to the present embodiment;

Figure 3 is a schematic structural diagram of a bearing unit;

Figure 4 is a schematic structural diagram of another bearing unit;

Figure 5 is a schematic diagram of the stator core structure;

6 is a schematic diagram of the connection of a stator core, a stator yoke disk and a stator frame;

FIG. 7 is a schematic diagram of the connection of the stator iron core, another kind of stator yoke disk and another kind of stator frame.

Description of reference numerals: 1 main shaft; 2 hub; 3 planetary gear reduction mechanism; 4 rotor assembly; 5 stator assembly; 6 rolling body; 7 stator core; 8 coil; 9 stator yoke disk; 10 stator frame; 11 welding surface; 12 first tongue and groove; 13 radial tray; 14 double row angular contact ball bearing; 15 deep groove ball bearing; 16 single row angular contact ball bearing; 17 pole piece; 18 coil bobbin; 19 second tongue and groove; 20 third tenon slot; 21 the first connection hole; 22 the second connection hole.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and appropriate descriptions will be made in conjunction with the connection and installation solutions of the geared hub motor in the electric bicycle of the present invention, so as to help Understanding of the technical solutions of the present invention.

As shown in FIGS. 1 to 7 , an axial magnetic field hub motor in this embodiment includes a motor connected to the main shaft 1 in the space of the hub 2 and a planetary gear reduction mechanism 3 , and the motor drives the hub through the planetary gear reduction mechanism 3 2 rotation, the motor is an axial magnetic field motor with a single air gap structure, including a rotor assembly 4 and a stator assembly 5. The rotor assembly 4 is connected to the main shaft 1 through a bearing unit with parallel rolling elements 6 including an angular contact ball bearing. Rotatingly connected, the stator assembly 5 includes a plurality of stator iron cores 7, a plurality of coils 8, a stator yoke disk 9 and a stator frame 10. The stator iron core 7 is a plurality of sheets of silicon steel material with different widths stacked in the radial direction. Welded as a whole, its welding surface 11 at least includes its end face away from the rotor assembly 4, the axial height of the coil 8 is less than the axial length of the stator core 7, and the coil 8 is sleeved on the stator core 7 close to the rotor assembly 4. At one end, the stator yoke disc 9 is made of high magnetic permeability material, which is formed by stacking a plurality of disc sheets of silicon steel material in the axial direction, or is made of SMC composite soft magnetic material by molding and sintering. The stator yoke disc 9 is provided with a plurality of The stator frame 10 is provided with a radial tray 13. One end of the stator core 7 of the unsleeved coil 8 inserted into the first tenon groove 12 extends beyond the stator yoke 9 and is connected to the radial tray. 13 connection, or the stator yoke disc 9 is connected with the stator iron core 7 inserted into the first tongue groove 12 and connected with the radial tray 13 , and the stator frame 10 is fixedly connected with the main shaft 1 .

In the present invention of the above scheme, the space in the hub is used compactly and reasonably, the hub motor has a stable structure with the characteristics of "through shaft", and the unique "pumping effect" of the disc rotor assembly 4 can generate circulation in the hub space. The airflow is beneficial to the cooling of the motor.

Those skilled in the art can select the specific form of the bearing unit according to actual needs, as long as the bearing unit includes an angular contact ball bearing capable of bearing the axial magnetic pulling force, and the bearing unit has parallel rolling elements 6 bearing the overturning moment. For example, the bearing unit may be a double row angular contact ball bearing 14, as shown in Figure 3, or a series combination of a deep groove ball bearing 15 and a single row angular contact ball bearing 16, as shown in Figures 1 and 4, or two single row A series combination of angular contact ball bearings 16 arranged in the same direction.

As shown in Figures 2 and 5, in order to weaken the cogging effect of the axial field motor with a single air gap structure, the end of the stator core 7 close to the rotor assembly 4 has a pole piece 17, the coil 8 is in the form of concentrated winding, and its axial height is Less than the axial length of the stator core 7, sleeved between the pole piece 17 and the stator yoke disk 9, between the coil 8 and the stator core 7 through the insulated coil bobbin 18 or coating the stator core 7 with insulating material For insulation and isolation, a plurality of stator iron cores 7 are arranged coaxially and circumferentially to form an annular armature magnetic pole plane composed of a plurality of stator iron core magnetic poles.

There are many factors affecting the magnetic pulling force of the axial magnetic field motor. Therefore, according to the magnitude of the magnetic pulling force and electromagnetic torque, an appropriate structural form should be adopted to ensure the stability of the stator structure. The stator iron core 7, the stator yoke disk 8 and the stator frame 9. As for the connection mode of the three, those skilled in the art can make specific applications according to the following four examples of connection based on the tenon and mortise structure of this embodiment, but are not limited to these four examples.

Example 1:

The stator core 7 is provided with at least one second tongue groove 19 on the side away from the rotor assembly 4 on the two radial superimposed surfaces perpendicular to the rotating surface of the rotor assembly 4. As shown in FIG. 5, the second tongue groove 19 is " As shown in FIG. 6 , the radial tray 13 on the stator frame 10 is arranged on the side away from the rotor assembly 4 , and the radial tray 13 is provided with a third tongue groove 20 corresponding to the first tongue groove 12 , the first tongue groove 12 and the third tongue groove 20 are open grooves, the groove shapes of the first tongue groove 12 and the third tongue groove 20 correspond to the solid part of the second tongue groove 19 of the stator core 7, and the second tongue groove The slot width of the tongue groove 19 is consistent with the sum of the axial lengths of the stator yoke disk 9 and the stator frame 10. The stator core 7 of the coil 8 is sheathed, and its solid part located in the interval of the second tongue groove 19 is inserted into the first tongue radially. The groove 12 and the third tongue groove 20, the second tongue groove 19 holds the groove edges of the first tongue groove 12 and the third tongue groove 20, so that the stator iron core 7, the stator yoke plate 9 and the stator frame 10 form a tongue Socket structure connection.

In this embodiment, the magnetic pulling force and electromagnetic torque of the motor are directly acted on the stator frame 10 by the stator iron core 7, and the most economical axial stacking thickness of the stator yoke disk 9 can be adopted.

Embodiment 2:

The stator core 7 is provided with at least one second tongue groove 19 on the two radial superimposed surfaces on the side away from the rotor assembly 4 and perpendicular to the rotating surface of the rotor assembly 4. The second tongue groove 19 is a "U"-shaped groove. The first tongue groove 12 of the yoke plate 9 is an open slot, the proximal side of the stator yoke plate 9 is also provided with a number of first connecting holes 21, the radial tray 13 of the stator frame 10 is arranged on the side close to the rotor assembly 4, The radial tray 13 is provided with a second connection hole 22 corresponding to the first connection hole 21, the stator yoke 9 and the stator frame 10 are riveted or bolted through the first connection hole 21 and the second connection hole 22, and the second tenon and groove The width of the slot 19 is consistent with the axial length of the stator yoke plate 9. The solid part of the stator core 7 located in the second tongue groove 19 is radially inserted into the first tongue groove 12, and the second tongue groove 19 clamps the first tongue groove 19. The groove edges of the tenon and groove 12 form a tenon-and-mortise structure connection between the stator core 7 and the stator yoke 9 .

In this embodiment, the magnetic pull force and electromagnetic torque of the motor are transmitted to the stator frame 10 by the stator yoke disc 9 , for this purpose, the number of laminations of the stator yoke disc 9 can be appropriately increased to increase its strength.

Embodiment three:

The stator core 7 is provided with at least one second tongue groove 19 on the side away from the rotor assembly 4 on the two radial superimposed surfaces perpendicular to the rotating surface of the rotor assembly 4, and the second tongue groove 19 is an "L"-shaped groove, such as As shown in FIG. 5; the proximal side of the stator yoke disk 9 is also provided with a number of first connecting holes 21, the radial tray 13 of the stator frame 10 is arranged on the side close to the rotor assembly 4, and the radial tray 13 is provided with The first connection hole 21 corresponds to the second connection hole 22 , the stator yoke plate 9 and the stator frame 10 are riveted or bolted through the first connection hole 21 and the second connection hole 22 , and the stator core 7 is located in the second tongue groove 19 section. The solid part is inserted into the first tenon groove 12, so that the stator iron core 7 and the stator yoke plate 9 form a tenon and tenon structure connection, and then the fixed connection between the stator iron core 7 and the stator yoke plate 9 is realized by welding or riveting. The axial length of the stator core 7 is small, and the material consumption of the silicon steel sheet is small.

Embodiment 4:

The proximal side of the stator yoke plate 9 is provided with several first connection holes 21 , the radial tray 13 of the stator frame 10 is provided on the side close to the rotor assembly 4 , and the radial tray 13 is provided with corresponding first connection holes 21 The second connection hole 22 of the stator yoke plate 9 and the stator frame 10 are riveted or bolted through the first connection hole 21 and the second connection hole 22, and the end of the stator core 7 that is not sleeved with the coil 8 is not provided with a tongue and groove, and the stator iron The tenon and mortise structure of the core 7 and the stator yoke 9 adopts the simplest form. The stator iron core 7 is directly inserted into the first tenon groove 12, and then the fixed connection between the two is realized by welding or riveting. The axial length of 7 is small, and the consumption of silicon steel sheet material is small.

In this specification, specific examples are used to illustrate the principles and implementations of the present invention, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention; The idea of the invention will have changes in the specific implementation manner and application range. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (9)

1. an axial magnetic field hub motor, comprising a motor and a planetary gear reduction mechanism connected with the main shaft in the hub space, the motor drives the wheel hub to rotate by the planetary gear reduction mechanism, and it is characterized in that: the motor is a single gas A gap structure axial magnetic field motor includes a rotor assembly and a stator assembly, the rotor assembly is rotatably connected to the main shaft through a bearing unit with parallel rolling elements including an angular contact ball bearing, and the stator assembly includes a plurality of A stator iron core, a plurality of coils, a stator yoke disk and a stator frame, the stator iron core is a plurality of sheets of silicon steel material of different widths superimposed and connected as a whole in the radial direction, and the coils are sleeved on the The stator core is close to one end of the rotor assembly, the stator yoke is provided with a plurality of first tongue grooves in a circumferential array, the stator frame is provided with a radial tray, and the stator inserted into the first tongue grooves The iron core extends beyond the stator yoke disk and is connected with the radial tray, or the stator yoke disk is connected with the stator iron core inserted into the first tongue and groove and connected with the radial tray, the stator The frame is fixedly connected with the main shaft. 2 . The axial magnetic field 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 two single row angular contact ball bearings. 3 . Tandem combination of angular contact ball bearings. 3 . The axial magnetic field hub motor according to claim 1 , wherein the stator yoke disk is formed by stacking a plurality of silicon steel disc sheets in the axial direction, or the stator yoke disk is made of SMC composite soft plate. 4 . Magnetic material is molded and sintered. 4 . The axial magnetic field hub motor according to claim 1 , wherein the stator iron core is formed into an integral structure through a lamination welding process, and the welding surface thereof at least includes the end surface of the end face away from the rotor assembly, and the The stator iron core is connected with the stator yoke disk or with the stator yoke disk and the stator frame in a tenon-and-mortise structure. 5 . The axial magnetic field hub motor according to claim 1 , wherein the axial height of the coil is smaller than the axial length of the stator iron core, and insulation is provided between the coil and the stator iron core. 6 . The coil bobbin or the stator core is coated with insulating material for insulation barrier. 6 . The axial magnetic field hub motor according to claim 1 , wherein the stator core is at least two radial superimposed surfaces perpendicular to the rotating surface of the rotor assembly on the side away from the rotor assembly. 7 . A second tongue groove is provided, the second tongue groove is a "U"-shaped groove, the radial tray of the stator frame is arranged on the side away from the rotor assembly, and the radial tray is provided with a third tongue groove corresponding to the first tongue groove, the first tongue groove and the third tongue groove are open grooves, and the solid part of the stator core located in the second tongue groove section is radially inserted The first tongue groove and the third tongue groove, the second tongue groove are clamped with the groove edges of the first tongue groove and the third tongue groove, so that the stator iron core and the stator The yoke plate and the stator frame are connected in a tenon-and-mortise structure. 7 . The axial magnetic field hub motor according to claim 1 , wherein the stator core is at least two radial superimposed surfaces perpendicular to the rotating surface of the rotor assembly on the side away from the rotor assembly. 8 . There is a second tongue groove, the second tongue groove is a "U"-shaped groove, the first tongue groove of the stator yoke plate is an open groove, and a number of first connection holes are also provided on the proximal side , the radial tray of the stator frame is arranged on the side close to the rotor assembly, the radial tray is provided with a second connection hole corresponding to the first connection hole, the stator yoke plate and the The stator frame is riveted or bolted through the first connection hole and the second connection hole, and the solid part of the stator core located in the second tongue and groove section is radially inserted into the first tongue and groove, so The groove edges of the first tenon groove are clamped in the second tenon groove, so that the stator iron core and the stator yoke are connected in a tenon-and-mortise structure. 8 . The axial magnetic field hub motor according to claim 1 , wherein the stator core is at least two radial superimposed surfaces perpendicular to the rotating surface of the rotor assembly on the side away from the rotor assembly. 9 . There is a second tongue and groove, the second tongue and groove is an "L"-shaped groove, the proximal side of the stator yoke is also provided with a number of first connecting holes, the radial tray of the stator frame It is arranged on the side close to the rotor assembly, the radial tray is provided with a second connection hole corresponding to the first connection hole, and the stator yoke plate and the stator frame pass through the first connection hole and the second connecting hole is riveted or bolted, and the solid part of the stator core located in the second tongue and groove section is inserted into the first tongue and groove, so that the stator core and the stator yoke are formed The tenon-and-mortise structure is connected, and then the stator core and the stator yoke are fixedly connected by welding or riveting. 9 . The axial magnetic field hub motor according to claim 7 , wherein the groove depth of the second tongue and groove is 0, that is, the second tongue and groove is not provided, and the stator iron core is not sleeved. 10 . One end of the coil is inserted into the first tenon and groove, so that the stator iron core and the stator yoke plate form a tenon and tenon structure connection, and then the stator iron core and the stator yoke plate are realized by welding or riveting. fixed connection.

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