CN111884364B

CN111884364B - Stator-rotor assembly and axial magnetic field motor

Info

Publication number: CN111884364B
Application number: CN201911158236.7A
Authority: CN
Inventors: 李树才; 张文晶; 彭维利; 刘国华
Original assignee: Shandong Jingchuang Technology Research Institute Of Magnetoelectrics Industry Co ltd
Current assignee: Shandong Jingchuang Technology Research Institute Of Magnetoelectrics Industry Co ltd
Priority date: 2019-11-22
Filing date: 2019-11-22
Publication date: 2021-05-07
Anticipated expiration: 2039-11-22
Also published as: CN111884364A

Abstract

The invention discloses a stator-rotor assembly and an axial magnetic field motor, and belongs to the field of motors. The stator-rotor assembly includes a rotor assembly, a front stator assembly, and a rear stator assembly. The rotor assembly comprises a rotor disc, a plurality of magnetic steel assemblies are arranged on the rotor disc, each magnetic steel assembly comprises inner magnetic steel arranged on the inner side of the rotor disc and outer magnetic steel arranged on the outer side of the rotor disc, and the magnetic poles of the inner magnetic steel and the outer magnetic steel of the same magnetic steel assembly are opposite in direction; the front stator assembly and the rear stator assembly respectively comprise a plurality of stator units which are annularly arranged, each stator unit comprises a U-shaped magnetic core, the end face of the inner side of each U-shaped magnetic core is aligned with the annular shape of the inner magnetic steel, the end face of the outer side of each U-shaped magnetic core is aligned with the annular shape of the outer magnetic steel, and the U-shaped magnetic cores are provided with coil windings. The invention reduces the weight and iron loss of the stator yoke part; the weight of the rotor is reduced, and the rotational inertia of the rotor is reduced; the axial size of the motor can be greatly shortened; the chute is easier to be made to be matched, and the torque pulsation is reduced.

Description

Stator-rotor assembly and axial magnetic field motor

Technical Field

The invention relates to the field of motors, in particular to a stator-rotor assembly and an axial magnetic field motor.

Background

An axial magnetic field motor, also called an axial flux motor or a disc motor, has a stator assembly and a rotor assembly in a disc structure. The air gap of the axial magnetic field motor is planar, the air gap magnetic field is axial, and the axial magnetic field motor has the advantages of compact structure, small volume, light weight, high torque density and small rotor moment of inertia.

Axial field motors generally have several configurations: 1. single rotor and single stator: a stator assembly and a rotor assembly (single sided air gap); 2. double-rotor single-stator: two rotor assemblies, one stator assembly in between (double-sided air gap); 3. single rotor double stator: two stator assemblies, one rotor assembly in the middle (double-sided air gap); 4. multi-rotor multi-stator: a plurality of stator assemblies and a plurality of rotor assemblies are interleaved (multi-faceted air gap).

Fig. 1 shows a typical configuration of a single rotor dual stator axial field machine with one rotor assembly in the middle and two stator assemblies on either side. The rotor assembly comprises a rotor disc 1 'and a circle of permanent magnets (magnetic steel) 2' arranged on the rotor disc 1 ', the stator assembly comprises a stator yoke part 3' and a circle of stator cores 4 'arranged on the stator yoke part 3', all the stator cores 4 'share one common stator yoke part 3', and the stator cores 4 'are provided with coil windings 5'.

Fig. 2 shows the magnetic circuit of the single-rotor double-stator axial field machine shown in fig. 1, and the machine with this structure can arrange the rotor disks to be non-magnetic materials, that is, the rotor has no yoke part, because the rotor disks do not participate in magnetic conduction. However, the stator yoke portion of the motor participates in magnetic conduction, and the stator yoke portion is required to be made of a magnetic conduction material such as an iron yoke, so that iron loss is generated on the stator yoke portion when the motor runs, and the weight of the motor is increased on the stator yoke portion.

Chinese patent document CN107408875A discloses an axial flux machine without a yoke segmented armature, which omits the stator yoke and significantly reduces weight and iron loss. However, the patent is an axial magnetic field motor with double rotors and single stators, and is not suitable for the axial magnetic field motor with single rotor and double stators. In addition, the rotor yoke part of the patent participates in magnetic conduction, so that the weight can not be further reduced, the iron loss can not be further eliminated, and the rotor yoke part-free axial magnetic field motor with the single rotor and the double stators is also not suitable for the rotor yoke-free axial magnetic field motor with the single rotor and the double stators.

Therefore, for the single-rotor double-stator axial magnetic field motor with no rotor yoke, how to reduce the iron loss and the weight of the stator yoke is not solved in the prior art.

Disclosure of Invention

In order to solve the technical problems, the invention provides a stator-rotor assembly and an axial magnetic field motor, which reduce the weight and iron loss of a stator yoke part; the weight of the rotor is reduced, and the rotational inertia of the rotor is reduced; the axial size of the motor can be greatly shortened; the chute is easier to be made to be matched, and the torque pulsation is reduced.

The technical scheme provided by the invention is as follows:

a stator-rotor assembly comprising a rotor assembly and a front stator assembly and a rear stator assembly disposed on a front side and a rear side of the rotor assembly, respectively, wherein:

the rotor assembly comprises a rotor disc, a plurality of magnetic steel assemblies are arranged on the rotor disc, each magnetic steel assembly comprises inner magnetic steel arranged on the inner side of the rotor disc and outer magnetic steel arranged on the outer side of the rotor disc, the inner magnetic steel and the outer magnetic steel are respectively arranged on the rotor disc in a ring shape, the centers of the inner magnetic steel and the outer magnetic steel of the same magnetic steel assembly are positioned on the same radius of the rotor disc, and the magnetic pole directions of the inner magnetic steel and the outer magnetic steel of the same magnetic steel assembly are opposite;

the front stator assembly and the rear stator assembly respectively comprise a plurality of stator units which are annularly arranged, each stator unit comprises a U-shaped magnetic core, the inner side end face of each U-shaped magnetic core is aligned with the annular shape of the inner magnetic steel, the outer side end face of each U-shaped magnetic core is aligned with the annular shape of the outer magnetic steel, and the U-shaped magnetic cores are provided with coil windings.

Further, the rotor disc comprises an inner support ring, a circular ring rib plate, an outer fixing ring and a plurality of radial rib plates, the radial rib plates are arranged on the inner support ring and extend outwards, the outer fixing ring is arranged at the tail end of each radial rib plate, and the circular ring rib plate is arranged between the inner support ring and the outer fixing ring and connected with all the radial rib plates;

the inner support ring, the ring rib plates and the plurality of radial rib plates form a first group of mounting positions, and the inner magnetic steel is mounted on the first group of mounting positions; the outer fixing ring, the ring rib plates and the plurality of radial rib plates form a second group of mounting positions, and the outer magnetic steel is mounted on the second group of mounting positions.

Furthermore, a first positioning groove is formed in the outer side face of the inner magnetic steel, positioning steps are arranged on the inner side face of the inner magnetic steel, the front side face of each positioning step and the front side face of the inner magnetic steel form a step shape, and the rear side face of each positioning step and the rear side face of the inner magnetic steel form a step shape;

a first positioning bulge is arranged on the inner side surface of the circular ring rib plate, and a groove is formed in the front side surface of the inner support ring and positioned on the outer side surface of the inner support ring; the first positioning groove is matched with the first positioning bulge, the rear side face of the positioning step is matched with the groove, and the front side face of the positioning step is pressed by the rotor shaft or a circular ring-shaped part arranged on the rotor shaft.

Furthermore, second positioning grooves are formed in the left side face and the right side face of the external magnetic steel, second positioning bulges are arranged on the parts, located on the outer sides of the annular rib plates, of the radial rib plates, the external magnetic steel is inserted into the second group of mounting positions from the outer sides, the second positioning grooves are matched with the second positioning bulges, and the external fixing rings are sleeved at the tail ends of the radial rib plates.

Furthermore, the tail end of the radial rib plate is provided with a limiting step, the inner side of the outer fixing ring is provided with a limiting groove, and the limiting step is matched with the limiting groove.

Furthermore, the inner magnetic steel and the outer magnetic steel are in fan-ring shapes, the thicknesses of the inner magnetic steel and the outer magnetic steel are the same as the thickness of the rotor disc, and the joints of the inner magnetic steel and the outer magnetic steel and the rotor disc are filled with glue.

Furthermore, the first positioning groove and the second positioning groove are both V-shaped grooves, and the first positioning bulge and the second positioning bulge are both V-shaped edge bulges.

Furthermore, the U-shaped magnetic core is formed by laminating silicon steel sheets, pole shoes made of soft magnetic composite materials are arranged on the end faces of the outer sides of the U-shaped magnetic core, the shape and the area of the end faces of the pole shoes are matched with those of the outer magnetic steel, and the shape and the area of the end faces of the inner sides of the U-shaped magnetic core are matched with those of the inner magnetic steel.

Furthermore, an insulating layer is arranged at the position where the U-shaped magnetic core is contacted with the coil winding, and an insulating layer is arranged between the pole shoe and the coil winding; the positioning device is characterized in that a positioning boss is arranged on the end face of the outer side of the U-shaped magnetic core, a positioning port is arranged on the pole shoe, the positioning port is sleeved on the positioning boss, and the pole shoe is fixed with the end face of the outer side of the U-shaped magnetic core through glue.

An axial magnetic field motor comprises the stator-rotor assembly.

The invention has the following beneficial effects:

1. the inner magnetic steel and the outer magnetic steel are distributed along the radial direction, so that the space can be more fully utilized, the inner magnetic steel and the outer magnetic steel are more easily made into chutes to be matched, and the front stator component and the rear stator component or the rotor component deflect at an angle in the circumferential direction to reduce torque pulsation.

2. The arrangement mode of the stator and the rotor ensures that the stator component is modularized, a plurality of stator units do not have a common yoke part any more, the iron loss generated by the yoke part of the stator is reduced, the utilization rate of magnetic field energy is high, and the weight of the motor is reduced.

3. The rotor of the invention adopts a disc structure to save silicon steel sheets or steel structures, thereby greatly reducing the weight of the rotor, reducing the rotational inertia of the rotor and improving the response speed of the motor. In addition, compared with a double-rotor motor, the rotor disc is made of a non-magnetic conducting material, a magnetic conducting structure of a yoke part of the rotor is omitted, and the weight of a supporting structure is reduced.

4. The front stator component and the rear stator component are formed by arranging a plurality of U-shaped stator units in a circle, and a part of space is reserved in the inner circles of the front stator component and the rear stator component after the stator units are assembled, and the space can be utilized: a brake such as a servo motor may be installed in an inner circle of the front stator assembly, and an encoder, a resolver, etc. may be installed at the rear stator assembly. For the motor needing to be provided with the accessories, the axial size of the motor can be greatly shortened.

Drawings

FIG. 1 is a schematic structural diagram of a single-rotor double-stator axial field motor in the prior art;

FIG. 2 is a schematic magnetic circuit diagram of a prior art single rotor dual stator axial field machine;

FIG. 3 is a schematic structural view of a stator-rotor assembly (with coil windings) of the present invention;

FIG. 4 is a schematic structural view of a stator-rotor assembly (without coil windings) of the present invention;

FIGS. 5-6 are schematic views of the construction of the rotor assembly;

FIG. 7 is a schematic structural view of a forward side of a rotor disk;

FIG. 8 is a structural schematic view of a rear side of a rotor disk;

FIG. 9 is a schematic structural view of a stator unit;

FIG. 10 is an exploded view of the stator unit;

FIG. 11 is a schematic magnetic circuit of the stator-rotor assembly of the present invention;

FIG. 12 is a schematic structural view of an inner support ring, annular rib and radial rib of a rotor disc;

FIG. 13 is a schematic structural view of an outer securing ring of a rotor disk;

FIGS. 14-16 are schematic structural diagrams of internal magnetic steels;

FIGS. 17 to 18 are schematic structural views of the external magnet;

FIG. 19 is an assembly schematic of a rotor disk.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.

Before describing the present invention in detail, the following definitions are provided for the various aspects of the present invention:

1. the "inner" and "outer" in the present invention are determined based on the distance from the motor rotation shaft (i.e. the rotor shaft) in the radial direction, the "inner" is close to the motor rotation shaft in the radial direction, the "outer" is far from the motor rotation shaft in the radial direction, and the directions related to the "inner" and the "outer" in the present invention are defined in this item.

2. The "front" and "rear" according to the present invention are determined based on the distance from the load of the electric machine in the axial direction, the side close to the load is the "front side" and the side far from the load is the "rear side", for example, fig. 7 shows the "front side" of the rotor disc, fig. 8 shows the "rear side" of the rotor disc, and the orientation of the present invention relating to "front" and "rear" is defined in this paragraph.

3. The terms "left" and "right" in the present invention refer to the left and right in fig. 17, which is a relative orientation, corresponding to the clockwise direction from left to right in fig. 7, and the orientation related to "left" and "right" in the present invention is defined by the present article.

An embodiment of the present invention provides a stator-rotor assembly, as shown in fig. 3 to 10, including a rotor assembly 100, and a front stator assembly 200 and a rear stator assembly 300 respectively disposed on a front side surface and a rear side surface of the rotor assembly 100, wherein:

the rotor assembly 100 includes a rotor disc 1 and a rotor shaft 2, the rotor disc 1 is connected with the rotor shaft 2, the material of the rotor disc 1 is a non-magnetic material, so that the rotor has no magnetic yoke, and the material of the rotor disc 1 is preferably an aluminum alloy.

The rotor disc 1 is provided with a plurality of magnetic steel assemblies 3, each magnetic steel assembly 3 comprises an inner magnetic steel 4 arranged on the inner side of the rotor disc 1 and an outer magnetic steel 5 arranged on the outer side of the rotor disc 1, namely, the invention is provided with two pieces of magnetic steel in the radial direction on the rotor disc. Two surfaces (namely the front side surface and the back side surface of the internal magnetic steel) of the internal magnetic steel 4, which are vertical to the motor rotating shaft (namely the rotor shaft 2), are magnetic poles of the internal magnetic steel 4, and two surfaces (namely the front side surface and the back side surface of the external magnetic steel) of the external magnetic steel 5, which are vertical to the motor rotating shaft, are magnetic poles of the external magnetic steel 5.

The inner magnet 4 and the outer magnet 5 are each arranged in a ring on the rotor disk 1, wherein: all the internal magnets 4 are arranged in a first ring on the rotor disc 1 and all the external magnets 5 are arranged in a second ring on the rotor disc 4, the radius of the first ring being smaller than the radius of the second ring, since the internal magnets 4 are on the inside and the external magnets 5 are on the outside.

The centers of the inner magnetic steel 4 and the outer magnetic steel 5 of the same magnetic steel assembly 3 are positioned on the same radius of the rotor disc 1, the magnetic pole directions of the inner magnetic steel 4 and the outer magnetic steel 5 of the same magnetic steel assembly 3 are opposite, and the inner magnetic steel 4 and the outer magnetic steel 5 of the same magnetic steel assembly 3, the front stator assembly 200 and the rear stator assembly 300 form a magnetic loop.

The front stator assembly 200 and the rear stator assembly 300 each include a plurality of stator units 400 arranged in a ring shape, each stator unit 400 includes a U-shaped magnetic core 6, a coil winding 7 is disposed on the U-shaped magnetic core 6, an inner side end surface 8 (i.e., an inner magnetic pole of the stator unit) of the U-shaped magnetic core 6 is aligned with a ring shape formed by the inner magnetic steel 4 and is matched with the inner magnetic steel 4 to form an air gap, and an outer side end surface 9 (i.e., an outer magnetic pole of the stator unit) of the U-shaped magnetic core 6 is aligned with a ring shape formed by the outer magnetic steel 5 and is matched with the outer magnetic.

The single-rotor double-stator axial magnetic field motor in the prior art has the advantages that the stator is provided with the common stator yoke, the yoke is thick, the magnetic poles and the yoke are complex to install and fix, the flatness of the stator surface is not easy to guarantee, the stator yoke generates iron loss when the motor operates, the utilization rate of magnetic field energy is low, and the stator yoke can increase the weight of the motor.

The stator-rotor assembly mainly comprises a front stator component, a rear stator component and a rotor component, wherein the front stator component and the rear stator component are formed by U-shaped stator units. Each stator unit is provided with a stator coil winding, and the coil windings are connected with each other to finally form a three-phase lead-out wire to provide an external interface for the motor or the generator. The stator unit is supported and fixed by a supporting structure.

The rotor assembly is located in the middle of the two stator assemblies, two pieces of magnetic steel of inner magnet steel and two pieces of magnetic steel of outer magnet steel are arranged in the radial direction of the rotor disc, the U-shaped stator units enable two areas which are aligned with the inner magnet steel and the outer magnet steel of the rotor to exist in the radial direction, the outer magnetic poles and the inner magnetic poles of the U-shaped stator units of the front stator assembly and the rear stator assembly are respectively matched with the inner magnet steel and the outer magnet steel, and a formed magnetic. When the three-phase outgoing line of the stator is electrified, the magnetic steel on the rotor disc generates traction under the action of electromagnetic force, and the rotor shaft can be driven to rotate.

The invention has the following beneficial effects:

4. The existing permanent magnet motor is generally a one-piece solid stator and rotor, the stator and rotor parts need to occupy special axial space, and the installation of other parts, such as bearings and brakes and encoders required to be used in some occasions, needs to continuously occupy new space in the axial direction, so that the axial length of the motor is increased. The front stator component and the rear stator component are formed by arranging a plurality of U-shaped stator units in a circle, and a part of space is reserved in the inner circles of the front stator component and the rear stator component after the stator units are assembled, and the space can be utilized: a brake such as a servo motor may be installed in an inner circle of the front stator assembly, and an encoder, a resolver, etc. may be installed at the rear stator assembly. For the motor needing to be provided with the accessories, the axial size of the motor can be greatly shortened.

The invention does not limit the fixing mode of the inner magnetic steel and the outer magnetic steel on the rotor disc, and can adopt various fixing modes such as glue bonding fixation, screw connection fixation, embedded fixation and the like. As shown in fig. 5-8, 12-19, one preferred example is as follows:

the rotor disc 1 comprises an inner support ring 10, a circular ring rib plate 11, an outer fixing ring 12 and a plurality of radial rib plates 13, wherein the plurality of radial rib plates 13 are arranged on the inner support ring 10 and extend towards the outer side, the outer fixing ring 12 is arranged at the tail ends of the radial rib plates 13, and the circular ring rib plate 11 is arranged between the inner support ring 10 and the outer fixing ring 12 and is connected with all the radial rib plates 13.

Preferably, the inner support ring, the annular rib plate and the plurality of radial rib plates are of an integrally formed structure, and can be integrally cast and formed or can be obtained by cutting the whole disc-shaped structure. The outer fixing ring, the integrally formed inner support ring, the circular ring rib plate and the plurality of radial rib plates are of split structures and are assembled together.

The inner support ring 10 is used for being connected with the rotor shaft 2 and providing the most basic support for the rotor disc 1, the circular ring rib plates 11 and the radial rib plates 13 provide the support for the rotor disc 1 and provide the installation base for the inner magnet steel 4, the inner support ring 10, the circular ring rib plates 11 and the plurality of radial rib plates 13 form a first group of installation positions 14, and the inner magnet steel 4 is installed on the first group of installation positions 14; the outer fixing ring 12, the ring rib plates 11 and the plurality of radial rib plates 13 form a second group of mounting positions 15, and the outer magnetic steel 5 is mounted on the second group of mounting positions 15.

The outer side surface 16 of the inner magnetic steel 4 is provided with a first positioning groove 17, the inner side surface 18 of the inner magnetic steel 4 is provided with a positioning step 19, the front side surface 20 of the positioning step 19 and the front side surface 21 of the inner magnetic steel 4 form a step shape, and the rear side surface 40 of the positioning step 19 and the rear side surface 22 of the inner magnetic steel 4 form a step shape.

Corresponding to the structure of the inner magnetic steel 4, the inner side surface of the circular ring rib plate 11 is provided with a first positioning bulge 24, and the front side surface 25 of the inner support ring 10 is provided with a groove 27 at the outer side surface 26 of the inner support ring 10.

When the inner magnetic steel 4 is installed, the inner magnetic steel 4 is obliquely inserted into the first group of installation positions 14 from the front side surface of the rotor disc 1 to enable the first positioning groove 17 of the inner magnetic steel 4 to be in butt joint fit with the first positioning protrusion 24 of the annular rib plate 11. Because the inner magnet steel is obliquely inserted into the rotor disc, a certain space is left between the rotor disc and the left side and the right side of the inner magnet steel, and a gap is formed after the inner magnet steel is assembled.

Similarly, in order to ensure that the inner side of the inner magnet steel 4 can be smoothly mounted on the rotor disc 1, a gap is formed between the inner side of the inner magnet steel 4 and the rotor disc after mounting, the inner magnet steel 4 can be positioned by the positioning step 19, the rear side 21 of the positioning step 19 is matched with the groove 27, and the rotor shaft 2 or the annular part 28 mounted on the rotor shaft 2 tightly presses the front side 20 of the positioning step 19, so that complete positioning is completed.

When the front side surface of the positioning step is pressed by using the rotor shaft, the rotor shaft is provided with a protruding annular step (the annular step and the rotor shaft are integrated), and the annular step presses the front side surface of the positioning step. When the front side face of the positioning step is pressed tightly by using the annular part arranged on the rotor shaft, the annular part and the rotor shaft are two split parts, the annular part is sleeved on the rotor shaft after being heated, and the annular part shrinks after being cooled to form interference fit with the rotor shaft.

The gap can be filled with glue, and the solidified glue can also prevent the inner magnetic steel from moving and reduce the impact of the electromagnetic force of the inner magnetic steel on the rotor disc in the rotating direction. The inner supporting ring 10 of the rotor disc 1 is provided with a mounting hole 29 for connecting with the rotor shaft 2, the rotor shaft 2 with the ring-shaped part 28 and the threaded hole is fixed by bolts, and the rotor shaft 2 compresses the inner magnetic steel 4 to play a main fixing role.

The inner magnetic steel is mainly fixed by a mechanical structure and filled with glue in an auxiliary mode, and compared with the method that the inner magnetic steel is mainly fixed by glue, the inner magnetic steel is more reliable, higher in safety coefficient, convenient to assemble and higher in production efficiency.

The left side 30 and the right side 31 of the external magnet 5 are provided with second positioning grooves 33, and the front side 41 and the back side 42 of the external magnet 5 are magnetic poles of the external magnet 5. The part of the radial rib plate 13, which is positioned at the outer side of the circular rib plate 11, is provided with a second positioning bulge 23, the outer magnetic steel 5 is inserted into the second group of mounting positions 15 from the outer side, the second positioning groove 33 is matched with the second positioning bulge 23, and then the outer fixing ring 12 is sleeved at the tail end of the radial rib plate 13.

The second positioning grooves on the left side and the right side of the external magnetic steel are conveniently connected with the second positioning bulges protruding from the radial rib plates of the rotor disc and used for axially positioning the external magnetic steel. The outer fixing ring is used for radially positioning the outer magnetic steel, and the tension of the outer fixing ring can buffer the extrusion force of the outer magnetic steel on the second positioning boss on the whole rotor disc, so that the problem of stress concentration is solved. The joint of the outer magnetic steel and the rotor disc can be filled with glue, and the solidified glue can also prevent the outer magnetic steel from moving and reduce the impact of the outer magnetic steel on the rotor disc due to the electromagnetic force in the rotating direction.

The outer magnetic steel is mainly fixed by a mechanical structure and filled with glue in an auxiliary mode, and compared with the outer magnetic steel which is mainly fixed by glue, the outer magnetic steel is more reliable, higher in safety coefficient, convenient to assemble and higher in production efficiency.

Preferably, the inner side surface 32 of the external magnet 5 is also provided with a second positioning groove 33, and the outer side surface of the annular rib plate 11 is also provided with a second positioning protrusion 23. The rotor disc positioning device has the main effects that more space in the radial direction of the rotor disc is provided by the second positioning protrusions on the outer side face of the circular rib plate, the structural strength of the rotor disc is improved, and meanwhile, a certain axial positioning effect on external magnetic steel is achieved.

The tail end of the radial rib plate 13 is provided with a limiting step 34, the inner side of the outer fixing ring 12 is provided with a limiting groove 35, and the limiting step 34 is matched with the limiting groove 35.

The outer fixing ring is in interference fit with the radial rib plate, and the outer fixing ring is sleeved at the tail end of the radial rib plate after being heated, so that the limiting groove of the outer fixing ring is matched with the limiting step of the radial rib plate. The outer fixing ring shrinks after being cooled, interference fit is formed between the outer fixing ring and the radial rib plate, and meanwhile, the glue also plays a role in assisting in fixing the outer fixing ring. The outer fixing ring is fixed in a manner of interference fit and glue fixation, and a screw fixing manner is not adopted. Because the space of the tail end of the radial rib plate is extremely limited, the screw fixation is difficult to realize, and the screw is made of ferromagnetic materials, the sine of a magnetic field can be influenced, and harmonic waves are generated. The fixing mode of the invention is simple and convenient, is easy to realize, and can not influence the magnetic field.

The inner magnetic steel and the outer magnetic steel of the invention are both in fan ring shapes, and the thickness of the inner magnetic steel and the thickness of the outer magnetic steel are the same as the thickness of the rotor disc.

The invention does not limit the structure of the first positioning groove, the second positioning groove, the first positioning bulge and the second positioning bulge, and preferably, the first positioning groove and the second positioning groove are both V-shaped grooves, and the first positioning bulge and the second positioning bulge are both V-shaped edge bulges.

The rotor disc is provided with raised edges (a first positioning bulge and a second positioning bulge) at positions for mounting the inner magnetic steel and the outer magnetic steel, and the raised edges are matched with the V-shaped groove so as to fix the inner magnetic steel and the outer magnetic steel. And a positioning step is designed at the mounting position of the inner magnetic steel, and an additional disc-shaped structure (a rotor shaft or a circular ring-shaped part) is used for pressing the positioning step. And after the inner magnetic steel and the outer magnetic steel are completely fixed, the gap is supplemented by glue to be used as auxiliary fixation.

Specifically, the process of mounting the internal magnet steel and the external magnet steel on the rotor disk is as follows:

1. and inserting the external magnetic steel into the second group of mounting positions from the outer side, so that the second positioning groove is matched with the second positioning bulge.

2. And sleeving the heated outer fixing ring at the tail end of the radial rib plate, so that the limiting groove of the outer fixing ring is matched with the limiting step of the radial rib plate. The outer fixing ring shrinks after being cooled and forms interference fit with the radial rib plate. Thus, the positioning of the external magnetic steel is completed.

3. And inserting the inner magnetic steel into the first group of mounting positions from the oblique outer side of the front side surface of the rotor disc, so that the first positioning groove is matched with the first positioning bulge, and the rear side surface of the positioning step is matched with the groove.

4. And glue is coated at the contact positions of the inner magnetic steel and the outer magnetic steel with the rotor disc.

5. And (3) clamping the rotor disc and the magnetic steel together by using two plane tools, leveling the flatness of the magnetic steel, and heating to cure the glue.

6. When the whole motor is assembled, the front side surface of the positioning step is pressed tightly through the rotor shaft or the annular part arranged on the rotor shaft. Thus, the positioning of the internal magnetic steel is completed.

After the rotor disc adopts the structure and the assembly mode, the rotor disc has the following advantages:

1) the inner magnetic steel and the outer magnetic steel are mainly fixed by a mechanical structure and are filled and fixed with glue in an auxiliary mode, the position of the magnetic steel can be located more quickly and accurately in industrial production, and rotor disc assembly is achieved more easily.

2) Even if glue falls off in the running process of the motor, the relative positions of the inner magnetic steel, the outer magnetic steel and the rotor disc cannot be influenced, the motor accidents such as sweeping and the like cannot be caused, and the safety factor of the motor is improved.

3) Under the condition of ensuring the magnetic flux provided by each piece of magnetic steel, the V-shaped edge protrusions can leave more space in the radial direction of the rotor disc, and the structural strength of the rotor disc is improved.

4) When the magnetic steel positioning device is installed, the joint surfaces of the V-shaped groove and the rotor disc are in extrusion fit, redundant tools are not needed, and the flatness of the inner magnetic steel and the outer magnetic steel can be well positioned by using two tools capable of ensuring the flatness.

5) In limited space, the thickness of the inner and outer magnetic steels is the same as that of the rotor disc, and the rotor structure has greater advantages than a rotor structure attached to a steel plate: the thickness of the rotor assembly is reduced; the magnetic energy provided by the magnetic steel is increased, so that the permanent magnet magnetic steel is not easy to demagnetize; magnetic flux leakage is reduced; the non-magnetic conductive material of the aluminum alloy of the rotor disc surrounds the magnetic steel, so that the damping coefficient is increased, and the motor has certain asynchronous starting capability.

6) The rotor disc assembled by the invention can achieve better planeness, and the verticality can be well ensured when the rotor disc is assembled on the rotor shaft.

In the invention, the magnetic pole directions of two adjacent inner magnetic steels can be the same or opposite, and the magnetic pole directions of two adjacent outer magnetic steels can be the same or opposite, which is related to the winding mode of the stator component. Preferably, the magnetic poles of two adjacent internal magnetic steels are opposite in direction, and the magnetic poles of two adjacent external magnetic steels are opposite in direction.

As an improvement of the present invention, as shown in fig. 9 and 10, the U-shaped magnetic core 6 is laminated by silicon steel sheets, a pole shoe 36 made of soft magnetic composite material is arranged on the outer side end face 9 of the U-shaped magnetic core 6, the shape and area of the end face of the pole shoe 36 are adapted to the external magnetic steel 5, and the shape and area of the inner side end face 8 of the U-shaped magnetic core 6 are adapted to the internal magnetic steel 4. The term "adapted" as used herein means substantially the same shape and area.

From the foregoing, the present invention solves the problem of the common stator yoke portion by the U-shaped stator units independent of each other, but there are also the following problems:

the existing stator is mostly made of silicon steel sheets, and for some special structures, the laminated form of the silicon steel sheets is difficult to manufacture, even cannot be manufactured, so that the U-shaped stator unit disclosed by the invention has the problems.

Because the outer magnetic steel is a large sector ring surface, the inner magnetic steel is a small sector ring surface, and the area of the outer magnetic steel is larger than that of the inner magnetic steel, in order to enable the stator unit to be matched with the inner magnetic steel and the outer magnetic steel, the outer side end face of the U-shaped magnetic core is preferably a large sector ring shape, and the inner side end face of the U-shaped magnetic core is preferably a small sector ring shape (or not a sector ring shape as long as the area of the U-shaped magnetic core can cover the inner magnetic steel), namely the area of the outer side end face of the U-shaped magnetic core is larger. However, due to the property that the silicon steel sheets can only conduct magnetism in two dimensions, a U-shaped magnetic core with the area of the outer end face (large sector ring shape) larger than that of the inner end face cannot be manufactured in the form of silicon steel sheet lamination.

In order to solve the problem, the invention arranges pole shoes made of SMC on the outer side end surface of a U-shaped magnetic core in the form of silicon steel sheet lamination, wherein the shape and the area of the pole shoes are adaptive to the outer magnetic steel and are larger than the area of the outer side end surface of the U-shaped magnetic core. The SMC has the characteristic of three-dimensional magnetic permeability and can be pressed into any shape, so that the SMC with a larger area is matched with the external magnetic steel, and the magnetic lines of force of the external magnetic steel are collected and converged on the U-shaped magnetic core by utilizing the three-dimensional magnetic permeability of the SMC.

The SMC has the characteristic of three-dimensional magnetic conductivity, can be pressed into any shape, and theoretically can also be used for manufacturing the stator unit of the invention completely, but the magnetic conductivity of the SMC is not good as that of a silicon steel sheet, and the total use of the SMC can cause the magnetic density to be too low, so that the motor is difficult to meet the requirement of the motor. Therefore, the invention does not use SMC to make stator units, but uses silicon steel sheets to make U-shaped magnetic cores, uses the high magnetic permeability of the silicon steel sheets to make pole shoes, and uses the three-dimensional magnetic permeability of the SMC to collect magnetic lines. The magnetic density in the stator pole shoe is smaller than that of other stator magnetic conduction parts, so the SMC pole shoe used in the invention can completely function even if the magnetic conduction performance is not good than that of a silicon steel sheet.

Therefore, the structure of the stator unit of the invention fully utilizes the high magnetic permeability of the silicon steel sheet and the three-dimensional magnetic permeability of the SMC, solves the problem of area change in the radial direction, and ensures that the stator unit can have two end surfaces with different areas in the radial direction to be aligned with the inner and outer magnetic steels with different areas of the rotor.

In the present invention, an insulation treatment is required between the coil winding 7 and the U-shaped magnetic core 6, and therefore, an insulation layer is provided at a position where the U-shaped magnetic core 6 contacts the coil winding 7, and preferably, the positions where the U-shaped magnetic core 6 contacts the coil winding 7 are all wrapped with insulation. The invention firstly winds the enameled wire into a coil winding, and then the coil winding is sleeved on the U-shaped magnetic core wrapped with the insulating layer after the coil winding is fixed and molded.

The pole piece 36 cannot contact the coil winding 7, and therefore an insulating layer is provided between the pole piece 36 and the coil winding 7.

In order to fix the U-shaped magnetic core 6 and the pole shoe 36, a positioning protrusion 37 is arranged on the outer end face 9 of the U-shaped magnetic core 6, a positioning hole 38 is arranged on the pole shoe 36, the positioning hole 38 is sleeved on the positioning protrusion 37, and the pole shoe 36 is fixed with the outer end face 9 of the U-shaped magnetic core 6 through glue. The positioning and fixing mode is simple and convenient. The positioning projection 37 and the positioning opening 38 are preferably rectangular in shape.

Of course, the SMC pole shoe can be made into a whole without a positioning opening and can be directly attached to the U-shaped magnetic core by glue.

The coil windings 7 are provided on the arms outside the U-shaped magnetic core 6 in order not to hinder the installation of brakes and the like in the inner circle of the stator assembly.

The pole shoe 36 can be adjusted in size according to the shape and size of the external magnet 5, and the shape of the pole shoe 36 is preferably fan-shaped and matched with the shape of the external magnet 5.

Part or all of the edges 39 of the U-shaped magnetic core 6 of the present invention are chamfered, particularly the portions where the coil windings 7 are mounted, the chamfer preventing the coil windings 7 from being scratched.

In the front stator assembly and the rear stator assembly, the coil windings of the stator units can be divided into a forward winding method and a reverse winding method according to design requirements, namely clockwise winding and anticlockwise winding.

The embodiment of the invention also provides an axial magnetic field motor which comprises the stator-rotor assembly, is a single-rotor double-stator axial magnetic field motor and is particularly suitable for a servo motor.

The axial magnetic field motor comprises the stator and rotor assembly, and naturally has the beneficial effects of the stator and rotor assembly, and the details are not repeated herein.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A stator-rotor assembly comprising a rotor assembly and a front stator assembly and a rear stator assembly disposed on a front side and a rear side of the rotor assembly, respectively, wherein:

the front stator assembly and the rear stator assembly respectively comprise a plurality of stator units which are annularly arranged, each stator unit comprises a U-shaped magnetic core, the inner side end face of each U-shaped magnetic core is aligned with the annular shape of the inner magnetic steel, the outer side end face of each U-shaped magnetic core is aligned with the annular shape of the outer magnetic steel, and the U-shaped magnetic cores are provided with coil windings;

the rotor disc comprises an inner support ring, a circular ring rib plate, an outer fixing ring and a plurality of radial rib plates, the radial rib plates are arranged on the inner support ring and extend outwards, the outer fixing ring is arranged at the tail end of the radial rib plates, and the circular ring rib plates are arranged between the inner support ring and the outer fixing ring and are connected with all the radial rib plates;

the inner support ring, the ring rib plates and the plurality of radial rib plates form a first group of mounting positions, and the inner magnetic steel is mounted on the first group of mounting positions; the outer fixing ring, the ring rib plates and the plurality of radial rib plates form a second group of mounting positions, and the outer magnetic steel is mounted on the second group of mounting positions;

the inner support ring, the circular ring rib plates and the plurality of radial rib plates are of an integrally formed structure, and the integrally formed inner support ring, the circular ring rib plates and the plurality of radial rib plates and the outer fixing ring are of a split structure;

the outer side surface of the inner magnetic steel is provided with a first positioning groove, the inner side surface of the inner magnetic steel is provided with a positioning step, the front side surface of the positioning step and the front side surface of the inner magnetic steel form a step shape, and the rear side surface of the positioning step and the rear side surface of the inner magnetic steel form a step shape;

a first positioning bulge is arranged on the inner side surface of the circular ring rib plate, and a groove is formed in the front side surface of the inner support ring and positioned on the outer side surface of the inner support ring; the inner magnetic steel is obliquely inserted into the first group of mounting positions from the outer side of the front side surface of the rotor disc, so that the first positioning groove is matched with the first positioning bulge, the rear side surface of the positioning step is matched with the groove, and the front side surface of the positioning step is pressed by the rotor shaft or a circular ring-shaped part arranged on the rotor shaft;

second positioning grooves are formed in the left side face and the right side face of the external magnetic steel, second positioning bulges are arranged on the parts, located on the outer sides of the circular rib plates, of the radial rib plates, the external magnetic steel is inserted into the second group of mounting positions from the outer sides, the second positioning grooves are matched with the second positioning bulges, the external fixing ring is sleeved at the tail end of the radial rib plates after being heated, and shrinks after being cooled, and forms interference fit with the radial rib plates;

the tail end of the radial rib plate is provided with a limiting step, the inner side of the outer fixing ring is provided with a limiting groove, and the limiting step is matched with the limiting groove;

the joints of the inner magnetic steel and the outer magnetic steel and the rotor disc are filled with glue;

the U-shaped magnetic core is formed by laminating silicon steel sheets, pole shoes made of soft magnetic composite materials are arranged on the end faces of the outer sides of the U-shaped magnetic core, the shape and the area of the end faces of the pole shoes are matched with those of outer magnetic steel, and the shape and the area of the end faces of the inner sides of the U-shaped magnetic core are matched with those of inner magnetic steel.

2. The stator-rotor assembly according to claim 1, wherein the inner and outer magnets are each sector-ring shaped, and have a thickness equal to a thickness of the rotor disk.

3. The stator-rotor assembly of claim 1 wherein the first and second positioning grooves are V-shaped grooves and the first and second positioning protrusions are V-shaped edge protrusions.

4. The stator-rotor assembly according to claim 1, wherein an insulating layer is arranged at a position where the U-shaped magnetic core is contacted with the coil winding, and an insulating layer is arranged between the pole shoe and the coil winding; the positioning device is characterized in that a positioning boss is arranged on the end face of the outer side of the U-shaped magnetic core, a positioning port is arranged on the pole shoe, the positioning port is sleeved on the positioning boss, and the pole shoe is fixed with the end face of the outer side of the U-shaped magnetic core through glue.

5. An axial field electric machine comprising the stator-rotor assembly of any one of claims 1-4.