CN210744991U

CN210744991U - Electric machine

Info

Publication number: CN210744991U
Application number: CN201922259656.6U
Authority: CN
Inventors: 何章; 梁宏常
Original assignee: Changzhou Golden Motor Technology Co ltd
Current assignee: Changzhou Golden Motor Technology Co ltd
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2020-06-12
Anticipated expiration: 2029-12-17

Abstract

The utility model relates to a motor, concretely relates to motor. Including rotor and stator mutually supporting, the rotor includes: a rotor support; the neodymium iron boron permanent magnets are circumferentially distributed on the rotor bracket; the ferrite magnet covers the axial side face, close to the stator, of the neodymium iron boron permanent magnet; and the pole shoes are arranged on the rotor bracket and separate two adjacent neodymium iron boron permanent magnets. The ferrite magnet is arranged on the axial side face of the neodymium iron boron permanent magnet, so that the neodymium iron boron permanent magnet is far away from a stator core, and an air gap magnetic field at the position of the neodymium iron boron permanent magnet is relatively uniform, so that the generation of eddy current is reduced; in addition, the position close to the motor stator core is replaced by a ferrite magnet, and the ferrite magnet has good insulation and hardly generates eddy current loss even in a high-frequency rotating magnetic field. The problem that the rotor of the disc type motor in the prior art is easy to generate eddy current in a magnetic field, so that the rotor is demagnetized is solved; the salient pole rate is low.

Description

Electric machine

Technical Field

The utility model relates to a motor, concretely relates to motor.

Background

In the rotor structure of the existing permanent magnet disc type motor, the position of a magnet in a magnetic circuit is mostly in a surface-mounted structure. As shown in fig. 1-2, the rotor 1 ' and the stator 2 ' are matched, the rotor 1 ' includes a rotor support 11 ' and permanent magnets 12 ', the stator 2 ' includes a stator core 21 ', the end surface of the stator core 21 ' facing the permanent magnets 12 ' is provided with stator slots 211 ', the permanent magnets 12 ' are directly exposed in the air gap, and this structure can bring advantages such as high torque coefficient and back electromotive force coefficient, but has many defects: such as large cogging, large torque ripple, poor low speed stability, etc.

As shown in fig. 2, due to the arrangement of the stator slots 211 ', the air gap field at the position of the permanent magnet 12' is not uniform, which is specifically represented by: the weaker the magnetic field is closer to the notch of the stator slot 211 'and the higher the unevenness of the magnetic field is closer to the surface of the stator core 21', the center of the air gap is relatively uniform. The material adopted by the permanent magnet has good conductivity, so that eddy current loss of the permanent magnet is seriously increased, and the temperature of the permanent magnet is greatly increased so as to be demagnetized. When the motor needs high rotating speed and high power density operation, particularly in a structure that the rotor is clamped between the two stators by the double stators or the multiple stators, the demagnetization phenomenon is more obvious, and the motor can not normally operate. In addition, because of the reason of the rotor structure, the disc motor cannot realize the IPM (interior permanent magnet) rotor structure of the traditional motor, and is basically an SPM (permanent magnet surface mounted) structure at present, so that the d-axis and q-axis inductances of the motor are almost equal (Ld ═ Lq), and the flux weakening speed expansion control cannot be realized.

SUMMERY OF THE UTILITY MODEL

The rotor is used for solving the problem that the rotor of the disc type motor in the prior art is easy to generate eddy current in a magnetic field, so that the rotor is demagnetized; the technical problem that the salient pole rate is low, the utility model provides a motor has solved above-mentioned technical problem. The technical scheme of the utility model as follows:

an electric machine comprising a rotor and a stator cooperating with each other, the rotor comprising: a rotor support; the neodymium iron boron permanent magnets are circumferentially distributed on the rotor bracket; the ferrite magnet covers the axial side face, close to the stator, of the neodymium iron boron permanent magnet; and the pole shoe is arranged on the rotor bracket and separates two adjacent neodymium iron boron permanent magnets.

The ferrite magnet is arranged on the axial side face of the neodymium iron boron permanent magnet, so that on one hand, the neodymium iron boron permanent magnet is far away from a stator core, and an air gap magnetic field at the position of the neodymium iron boron permanent magnet is relatively uniform, so that the generation of eddy current is reduced; on the other hand, the position close to the stator core of the motor is replaced by ferrite magnets, and the ferrite magnets have good insulation and hardly generate eddy current loss even in a high-frequency rotating magnetic field; in addition, the ferrite magnet has magnetism, and can compensate the loss of air gap magnetic field intensity brought by air gap increase.

The pole shoes are arranged on the rotor support and separate two adjacent neodymium iron boron permanent magnets, so that the q-axis flux linkage reluctance of the motor is greatly reduced, the q-axis inductance is increased, namely Lq is increased, and the salient pole rate is increased. In addition, the increase of the air gap can reduce the d-axis inductance and increase the salient pole rate, thereby improving the dynamic field weakening performance of the motor.

Further, neodymium iron boron permanent magnet circumference distributes on rotor support's same axial side, ferrite magnet covers on the axial side of keeping away from rotor support of neodymium iron boron permanent magnet.

Further, the stator is one, and the stator is located on the axial outer side of the rotor close to the ferrite magnet.

Further, the circumference of rotor support distributes there is the mounting hole, the neodymium iron boron permanent magnet inlays to be established in the mounting hole, the axial both sides of neodymium iron boron permanent magnet all cover have ferrite magnet.

Further, the mounting holes are filled with ferrite magnets on two sides of the neodymium iron boron permanent magnet in a matching mode.

Furthermore, the number of the stators is two, and the two stators are respectively positioned on two axial sides of the rotor.

Further, the pole shoe is made of high magnetic permeability soft magnetic material, and the pole shoe penetrates through the rotor support.

Furthermore, the stator comprises a stator core, a stator slot is formed in one end, facing the ferrite magnet, of the stator core, and a stator winding is arranged on the stator core.

Based on the technical scheme, the invention can realize the following technical effects:

1. according to the motor, the ferrite magnet is arranged on the axial side face of the neodymium iron boron permanent magnet, on one hand, the neodymium iron boron permanent magnet is far away from a stator core, and an air gap magnetic field at the position of the neodymium iron boron permanent magnet is relatively uniform, so that the generation of eddy current is reduced; on the other hand, the position close to the stator core of the motor is replaced by ferrite magnets, and the ferrite magnets have good insulation and hardly generate eddy current loss even in a high-frequency rotating magnetic field; in addition, the ferrite magnet has magnetism, and can compensate the loss of the air gap magnetic field intensity caused by the increase of the air gap;

2. according to the motor, the neodymium iron boron permanent magnet and the ferrite magnet can be arranged on one axial side surface of the rotor support, and the formed rotor can be matched with one stator; a neodymium iron boron permanent magnet can be embedded on the rotor support, the two circumferential sides of the neodymium iron boron permanent magnet are covered with ferrite magnets, and the formed rotor can be axially clamped between the two stators and is matched with the two stators; pole shoes are further arranged to separate two adjacent neodymium iron boron permanent magnets, and the q-axis flux linkage reluctance of the motor can be greatly reduced through the pole shoe structure, so that the q-axis inductance Lq is increased, and the salient pole effect is realized; the inductance Ld of the d axis is reduced by matching with the increase of the air gap, the salient pole ratio p is Lq/Ld, and the salient pole ratio is increased, so that the dynamic field weakening performance of the motor can be improved;

3. according to the motor, the length of the air gap between the stator and the rotor is increased, the generation of eddy current can be reduced, the air gap magnetic field at the position of the neodymium iron boron permanent magnet is uniform, and the power loss is small.

Drawings

Fig. 1 is a schematic structural diagram of a rotor and a single stator of a motor in the prior art;

FIG. 2 is a schematic view of a rotor and a double stator of a prior art motor;

fig. 3 is a schematic structural diagram of a motor according to a first embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a rotor according to the first embodiment;

FIG. 5 is a cross-sectional view A-A of FIG. 4;

FIG. 6 is a schematic view of a magnetic field distribution of a rotor and a stator of an electric machine when mated;

FIG. 7 is a cross-sectional view B-B of FIG. 4;

FIG. 8 is a schematic view of a rotor of an electric machine in cooperation with a stator;

fig. 9 is a schematic structural view of a rotor according to a second embodiment of the present invention;

FIG. 10 is a cross-sectional view C-C of FIG. 9;

FIG. 11 is a cross-sectional view D-D of FIG. 9;

fig. 12 is a schematic view of a rotor and a stator of a motor according to a second embodiment;

wherein: 1-a rotor; 11-a rotor support; 111-mounting holes; 112-central shaft hole; 12-a neodymium iron boron permanent magnet; 13-a ferrite magnet; 14-pole shoe; 2-a stator; 21-a stator core; 211-stator slots; 22-a stator winding; 3-a machine shell; 4-end cover; 5-a rotating shaft; 6-a fan; 7-cover plate; 1' -a rotor; 11' -a rotor spider; 12' -a permanent magnet; 2' -a stator; 21' -a stator core; 211' -stator slots.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

Unless specifically stated otherwise, the relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the orientation words such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of description, and in the case of not making a contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be interpreted as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and if not stated otherwise, the terms have no special meaning, and therefore, the scope of the present invention should not be construed as being limited.

Example one

As shown in fig. 3 to 8, the present embodiment provides a motor, in particular, a disk motor, including two stators 2 and two rotors 1, and the two stators 2 are axially sandwiched between the two rotors 1. Specifically, the motor includes shell 3 and end cover 4, and shell 3 and end cover 4 fixed connection form the cavity that has accommodation space, and rotor 1 and stator 2 are all arranged in the cavity, and two stators 2 are fixed respectively and are set up on the inner wall of shell 3 and the inner wall of end cover 4, and rotor 1 rotationally sets up between two stators 2, and rotor 1 rotates the setting through pivot 5, and the bearing is passed through respectively rotationally to the both ends of pivot 5 and is set up on shell 3 and end cover 4.

Rotor 1 includes rotor support 11, neodymium iron boron permanent magnet 12 and ferrite magnet 13, and neodymium iron boron permanent magnet 12 sets up on rotor support 11, and ferrite magnet 13 covers on at least one axial side of neodymium iron boron permanent magnet 12. The rotor support 11 is circular, a central shaft hole 112 is formed in the center of the rotor support 11 so as to be conveniently connected with the rotating shaft 5, and a mounting hole 111 is formed in the rotor support 11 along the circumferential direction so as to mount the neodymium iron boron permanent magnet 12. Specifically, the mounting holes 111 are a plurality of holes, and are uniformly distributed along the circumferential direction of the rotor holder 11, and the mounting holes 111 are through holes.

The ndfeb permanent magnet 12 is disposed in the mounting hole 111, and specifically, the ndfeb permanent magnet 12 is embedded in the mounting hole 111, and two axial sides of the ndfeb permanent magnet 12 do not protrude out of the mounting hole 111. Preferably, ndfeb permanent magnet 12 is fan-shaped or trapezoidal. The neodymium iron boron permanent magnet 12 is covered with ferrite magnets 13 on both axial sides. The shape of the ferrite magnet 13 is adapted to the shape of the ndfeb permanent magnet 12, two ferrite magnets 13 and the ndfeb permanent magnet 12 therebetween form a laminated structure, and the mounting hole 111 is filled with the whole laminated structure. As shown in fig. 6, in the structure of the rotor 1 of this embodiment, the ndfeb permanent magnet 12 is far away from the stator 2, and the air gap magnetic field at the position of the ndfeb permanent magnet 12 is more uniform than that of the prior art, so that the generation of eddy current is reduced; in addition, the position close to the stator core of the motor is replaced by ferrite magnets, and the ferrite magnets have good insulation and hardly generate eddy current loss even in a high-frequency rotating magnetic field; the ferrite magnet has magnetism, and can compensate the loss of air gap magnetic field intensity brought by air gap increase.

The rotor 1 further comprises pole shoes 14 arranged on the rotor support 11, and the pole shoes 14 separate two adjacent neodymium iron boron permanent magnets 12. Specifically, a receiving hole is formed between two adjacent mounting holes 111 of the rotor support 11, the pole shoe 14 is placed in the receiving hole, preferably, the receiving hole is a through hole penetrating through the rotor support 11, the receiving hole is adapted to the shape of the pole shoe 14, the pole shoe 14 just fills the receiving hole, and the plurality of pole shoes 14 and the ndfeb permanent magnet 12 are located on the same circumference. Preferably, the pole pieces 14 are made of a magnetically highly permeable soft magnetic material. By arranging the pole shoe 14 between the adjacent neodymium iron boron permanent magnets of the motor rotor, the q-axis flux linkage reluctance of the motor is greatly reduced, so that the q-axis inductance Lq is increased, and the salient pole effect is realized. The pole shoe 14 is provided such that Lq increases, the inductance Ld of the d-axis decreases due to an increase in the air gap δ, and the saliency p is Lq/Ld, and therefore, the saliency increases greatly.

Simulation shows that the rotor of the embodiment has the advantages that the salient pole rate p is smaller and smaller along with the increase of the air gap, but the q-axis inductance is hardly changed, so that the salient pole rate is increased, and the effect is better when the rotor is used in a mixed permanent magnet disc type motor rotor. Through ansys simulation results, after pole shoes are added, the saliency of the common disc type motor rotor can be expanded to 2-3 times, but for a mixed type rotor structure, the saliency can be expanded to 5-6 times.

The stator 2 comprises a stator core 21 and a stator winding 22, a stator slot 211 is opened on the end surface of the stator core 21 close to the rotor 1, the notch of the stator slot 211 faces the rotor 1, and the stator winding 22 is arranged on the stator core 21. As shown in fig. 6, the rotor 1 is matched with the stators 2 at two sides, and the ferrite magnets 13 are arranged at two sides of the ndfeb permanent magnet 12 of the rotor 1, so that the ndfeb permanent magnet 12 is far away from the stator core 21 compared with the prior art, the air gap length delta from the ndfeb permanent magnet 12 to the stator core 21 is increased, the magnetic field at the position of the ndfeb permanent magnet 12 is more uniform compared with the magnetic field in the prior art, the generation of eddy current is reduced, the position close to the stator core of the motor is replaced by the ferrite magnets, and because the ferrite has very good insulation, eddy current loss is hardly generated even in a high-frequency rotating magnetic.

Preferably, the outer terminal surface of end cover 4 is formed with and holds the chamber, and pivot 5 stretches into and holds intracavity connection fan 6, and pivot 5 drives fan 6 and rotates in order to play the radiating effect to the motor promptly. More preferably, the external fixed cover of the housing is provided with a cover plate 7 to protect the fan 6.

Based on the structure, the motor of the embodiment has the following advantages in the actual use process:

(1) the rotor temperature is greatly reduced: in the motor in the prior art, 20KW is output at 2000RPM for one hour, the rotor temperature reaches 180 ℃, 20KW is output at 3200RPM for 12 minutes, the rotor temperature is 220, and the rear rotor is permanently demagnetized; the motor of this embodiment, 20KW operation is exported to 2000RPM of rotational speed, and rotor temperature is to 90 degrees, and 20KW operation is exported to 3200RPM for an hour, and rotor temperature 100 degrees, the rotor does not have the demagnetization.

(2) The cost is reduced: because the temperature of the rotor is greatly reduced, the neodymium iron boron material adopted by the permanent magnet can be reduced from the original UH to SH or even H, the cost of the neodymium iron boron material is greatly reduced, although the material of the ferrite is added, the cost of the ferrite material is simply and directly negligible in front of the UH neodymium iron boron material, the prices of the UH neodymium iron boron and the ferrite with the same size are about 25 times more than the current purchase price, and the cost is saved by the integral structure.

(3) The cogging is greatly reduced: the cogging torque of the motor is reduced from the original 3.5NM to 0.5NM, and the low-speed stability is also greatly improved.

(4) The efficiency is greatly improved.

Example two

As shown in fig. 9 to 12, the present embodiment is substantially the same as the first embodiment, except that in the rotor 1 of the present embodiment, the ndfeb permanent magnet 12 is distributed on only one axial side surface of the rotor support 11, and the axial side surface of the ndfeb permanent magnet 12 away from the rotor support 11 is covered with the ferrite magnet 13. Specifically, the mounting hole 111 and the receiving hole are not required to be formed in the rotor holder 11, and the ndfeb permanent magnets 12 may be attached to one axial side surface of the rotor holder 11 and circumferentially distributed. The pole shoe 14 is attached to the same axial side of the rotor bracket 11, and the pole shoe 14 is located between two adjacent ndfeb permanent magnets 12.

The motor of this embodiment, rotor 1 and the cooperation of a stator 2, stator 2 sets up in one side of rotor 1 that is close to magnetic oxygen body magnet 13, and through setting up magnetic oxygen body magnet 13, neodymium iron boron permanent magnet 12 increases to stator core 21's air gap length delta, can play the magnetic field even, reduces the effect of vortex.

The embodiments of the present invention have been described in detail with reference to the drawings, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.

Claims

1. An electric machine comprising a rotor (1) and a stator (2) cooperating with each other, characterized in that the rotor (1) comprises:

a rotor support (11);

the neodymium iron boron permanent magnets (12), and the neodymium iron boron permanent magnets (12) are circumferentially distributed on the rotor bracket (11);

a ferrite magnet (13), wherein the ferrite magnet (13) covers the axial side surface of the neodymium iron boron permanent magnet (12) close to the stator (2);

the pole shoes (14), pole shoes (14) set up on rotor support (11), pole shoes (14) separate two adjacent neodymium iron boron permanent magnet (12).

2. An electric machine according to claim 1, characterized in that the neodymium iron boron permanent magnets (12) are circumferentially distributed on the same axial side of the rotor support (11), the ferrite magnets (13) covering the axial side of the neodymium iron boron permanent magnets (12) remote from the rotor support (11).

3. An electric machine according to claim 2, characterized in that the stator (2) is one, the stator (2) being located axially outside the rotor (1) near the ferrite magnets (13).

4. The motor according to claim 1, wherein mounting holes (111) are distributed in the circumferential direction of the rotor support (11), the neodymium iron boron permanent magnet (12) is embedded in the mounting holes (111), and the ferrite magnets (13) are covered on two axial sides of the neodymium iron boron permanent magnet (12).

5. An electric machine according to claim 4, characterized in that the neodymium-iron-boron permanent magnet (12) is fitted with ferrite magnets (13) on both sides to fill the mounting hole (111).

6. An electric machine according to claim 4, characterized in that the pole shoes (14) are made of magnetically highly conductive soft magnetic material, the pole shoes (14) extending through the rotor support (11).

7. An electric machine according to claim 4, characterized in that the number of stators (2) is two, the two stators (2) being located on either axial side of the rotor (1).

8. An electric machine according to any of claims 1-7, characterized in that the stator (2) comprises a stator core (21), in that the end of the stator core (21) facing the ferrite magnets (13) is provided with stator slots (211), and in that the stator core (21) is provided with stator windings (22).