CN110971031A

CN110971031A - Rotor and motor

Info

Publication number: CN110971031A
Application number: CN201811150146.9A
Authority: CN
Inventors: 王飞; 朱嘉东; 孙权贵
Original assignee: Guangdong Welling Motor Manufacturing Co Ltd; Midea Welling Motor Technology Shanghai Co Ltd
Current assignee: Guangdong Welling Motor Manufacturing Co Ltd; Midea Welling Motor Technology Shanghai Co Ltd
Priority date: 2018-09-29
Filing date: 2018-09-29
Publication date: 2020-04-07

Abstract

The invention relates to the field of motors and discloses a rotor and a motor. The rotor includes rotor core (1) and permanent magnet (3), be provided with a plurality of mounting grooves (2) that set up along the circumference interval of rotor core (1) on rotor core (1), permanent magnet (3) set up in mounting groove (2), every mounting groove (2) all have the first edge that is close to rotor core (1) outer fringe, the transition edge at the second edge of the center of orientation rotor core (1) and connection first edge and second edge, the transition edge is multistage structure (6), the part that is connected with first edge of multistage structure (6) sets up to the inboard protrusion towards mounting groove (2). The invention increases the distance between the permanent magnet and the outer edge of the rotor core by arranging the multi-section structure, and reduces the magnetic density, so that a magnetic bridge formed between the permanent magnet and the outer edge of the rotor core can protect the permanent magnet from the action of a stator magnetic field, and the local demagnetization resistance of the permanent magnet is effectively improved.

Description

Rotor and motor

Technical Field

The invention relates to the field of motors, in particular to a rotor and a motor.

Background

In the prior art, the problem of demagnetization of a permanent magnet needs to be considered in the design of an embedded permanent magnet motor, and particularly, the permanent magnet is positioned at a part close to the edge of a rotor core, and the part is easily subjected to a local demagnetization phenomenon because the core of the part is thinner and is more strongly influenced by a stator magnetic field.

At present, in order to overcome the problem of local demagnetization of the permanent magnet, methods of increasing the thickness of the permanent magnet or selecting a higher-level permanent magnet are generally adopted, but the designs all increase the manufacturing cost of the motor.

Disclosure of Invention

The invention aims to solve the problem that a rotor iron core is easy to partially demagnetize in the prior art, and provides a rotor which can protect an internal permanent magnet from the action of a stator magnetic field and effectively improve the local demagnetization resistance of the permanent magnet.

In order to achieve the above object, an aspect of the present invention provides a rotor including a rotor core and permanent magnets, the rotor core being provided with a plurality of mounting grooves spaced apart along a circumferential direction of the rotor core, the permanent magnets being disposed in the mounting grooves, each of the mounting grooves having a first edge near an outer edge of the rotor core, a second edge facing a center of the rotor core, and a transition edge connecting the first edge and the second edge, the transition edge being a multi-segment structure, a portion of the multi-segment structure connected to the first edge being configured to protrude toward an inner side of the mounting groove.

Preferably, a stepped magnetic bridge is formed between the multi-section structure and the outer edge of the rotor core.

Preferably, the multistage structure includes consecutive first section and second section, the second section with first edge links to each other, the second section along the orientation the inboard protrusion of mounting groove and with the permanent magnet contacts.

Preferably, the first edge is disposed in parallel with the second edge, and the permanent magnet is disposed in parallel with an axial direction.

Preferably, the outer edge of the rotor core includes a plurality of circular arc portions connected in sequence, and a concave portion is formed between adjacent circular arc portions.

Preferably, it is a plurality of the mounting groove respectively with a plurality of the circular arc portion one-to-one sets up, every the mounting groove is along connecting the correspondence the straight line direction setting at the both ends of circular arc portion, the multistage structure of mounting groove corresponds the depressed part setting.

Preferably, each circular arc group includes a first arc line, a second arc line and a third arc line that are connected in sequence, the second arc line and the rotor core are concentrically arranged, and the first arc line and the third arc line and the rotor core are non-concentrically arranged.

Preferably, the first arc line and the third arc line of each arc portion are symmetrical about a centre line of the second arc line, and the third arc line of each arc portion is connected to the first arc line of the adjacent arc portion and forms the recess.

Preferably, the rotor is of a radial strip-shaped magnetic shoe structure.

A second aspect of the invention provides an electrical machine comprising a stator and a rotor as described in any of the above aspects.

Through the technical scheme, the end part of the mounting groove for mounting the permanent magnet is arranged into a multi-section structure, the form of the traditional single-section structure is changed, the distance between the permanent magnet and the outer edge of the rotor core is increased, and the magnetic density is reduced, so that a magnetic bridge formed between the permanent magnet and the outer edge of the rotor core can protect the permanent magnet from the action of a stator magnetic field, and the local demagnetization resistance of the permanent magnet is effectively improved.

Drawings

Fig. 1 is a schematic structural view of a rotor core according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of a rotor according to an embodiment of the present invention;

fig. 3 is a partially enlarged view of fig. 2.

Description of the reference numerals

1-rotor core, 2-mounting groove, 3-permanent magnet, 4-arc portion, 41-second pitch arc, 42 first pitch arc, 43-third pitch arc, 5-depressed part, 6-multistage structure, 61-first section, 62-second section.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

With reference to fig. 1 and 2, according to an aspect of the present invention, a rotor is provided, which includes a rotor core 1 and permanent magnets 3, wherein a plurality of mounting grooves 2 are disposed on the rotor core 1 at intervals in a circumferential direction of the rotor core 1, the permanent magnets 3 are disposed in the mounting grooves 2, each mounting groove 2 has a first edge close to an outer edge of the rotor core 1, a second edge facing a center of the rotor core 1, and a transition edge connecting the first edge and the second edge, the transition edge is a multi-segment structure 6, and a portion of the multi-segment structure 6 connected to the first edge is disposed to protrude toward an inner side of the mounting groove 2.

Since the transition edge of the permanent magnet end of the prior art rotor is usually provided as a single-segment structure, i.e. the transition edge is not provided with any corrugated design, the distance between the transition edge and the edge of the rotor core is constant. Generally, the distance is smaller, so that the part of the transition edge, which is far away from the edge of the rotor core, of the core is thinner, the action of the stator magnetic field is stronger, and the local demagnetization phenomenon is easy to occur.

According to the technical scheme, the end transition edge of the mounting groove of the rotor is arranged to be of a multi-section structure, the form of a traditional single-section structure is changed, and the part, connected with the first edge, of the multi-section structure 6 is arranged to protrude towards the inner side of the mounting groove 2, so that compared with the prior art, the distance between the permanent magnet and the outer edge of the rotor iron core is increased by the design mode of the invention, the magnetic density is reduced, and therefore a magnetic bridge formed between the permanent magnet and the outer edge of the rotor iron core can protect the permanent magnet from the action of a stator magnetic field, and the local demagnetization resistance of the permanent magnet is effectively improved. The mounting groove 2 may be a magnetic steel groove in the prior art.

The multi-segment structure 6 may be provided in any suitable form, such as bending toward the outer edge of the rotor core 1 or toward the center of the rotor for multiple times, as long as the distance between the multi-segment structure 6 and the outer edge of the rotor core 1 can be increased compared to the design in the prior art.

It should be noted that, the form of arrangement of the multi-stage structure 6 will directly affect the shape of the magnetic bridge between the transition edge and the outer edge of the rotor core, in this embodiment, a step-shaped magnetic bridge is formed between the multi-stage structure 6 and the outer edge of the rotor core 1, so that the distance between the permanent magnet and the outer edge of the rotor core is increased, and the magnetic density is reduced, thereby protecting the permanent magnet 3 from demagnetization caused by the action of the stator magnetic field.

Specifically, the multi-segment structure 6 may be provided as two or more segments, and a multi-layer stepped magnetic bridge may be formed between the corresponding multi-segment structure 6 and the outer edge of the rotor core 1, so that the distance between the permanent magnet and the outer edge of the rotor core is significantly increased, and the magnetic density is reduced. In the present embodiment, as shown in fig. 3, the multi-stage structure 6 includes a first stage 61 and a second stage 62 connected in sequence, the first stage 61 is connected to the second edge, the second stage 62 is connected to the first edge, and the second stage 62 protrudes toward the inner side of the mounting groove 2 and contacts with the permanent magnet 3. The contact is understood to be that the permanent magnet 3 is limited in the mounting groove 2 through the convex part so as to prevent the permanent magnet 3 from being damaged due to the relative displacement between the permanent magnet 3 and the mounting groove 2 when the rotor rotates.

Further, because the both sides of mounting groove 2 all are connected with the transition edge, two promptly in the multistage structure 6 second section of thick bamboo 62 all follows the orientation the inboard protrusion of mounting groove 2 and with permanent magnet 3 contacts, consequently under the limiting displacement in the time of both sides bulge, can with establish the firm card of permanent magnet 3 in mounting groove 2 to the stability of installation has effectively been guaranteed.

As described above with reference to fig. 3, in the multi-stage structure 6, the distance between the first stage 61 and the outer edge of the rotor core 1 is narrow, and the distance between the second stage 62 and the outer edge of the rotor core 1 is wide, so that a stepped magnetic bridge can be formed between the multi-stage structure 6 and the outer edge of the rotor core 1.

It should be noted that the design of the multi-segment structure 6 is particularly suitable for the case of radial magnetic fields, and therefore, in order to generate a radial magnetic field, it is considered to arrange the permanent magnets 3 in parallel with the axial direction of the rotor, and accordingly, since the permanent magnets 3 are arranged in the mounting groove 2, the first edge of the mounting groove 2 is arranged in parallel with the second edge. Of course, the first edge and the second edge of the mounting groove 2 are not limited to the above design, and may be configured to protrude toward the center of the rotor at the same time, for example, without being limited thereto.

In the present embodiment, the outer edge of the rotor core 1 includes a plurality of circular arc portions 4 connected in series, and a concave portion 5 is formed between the adjacent circular arc portions 4. It should be noted here that the outer edge of the conventional rotor core is generally circular and has no concave design, and the purpose of providing the concave portion 5 on the outer edge in the present invention is mainly to improve the air gap waveform between the rotor and the stator, so as to achieve the purpose of reducing the operating noise.

To take into account and accommodate conventional design approaches, the rotor structure is typically designed symmetrically. Particularly, it is a plurality of mounting groove 2 respectively with a plurality of arc portion 4 one-to-one sets up, every mounting groove 2 is along connecting the correspondence the rectilinear direction setting at arc portion 4's both ends, the multistage structure 6 of mounting groove 2 corresponds depressed part 5 sets up.

Further, each of the arc groups 4 includes a first arc line 42, a second arc line 41, and a third arc line 43 connected in sequence, the second arc line 41 is disposed concentrically with the rotor core 1, and the first arc line 42 and the third arc line 43 are disposed non-concentrically with the rotor core 1, so that a recess 5 can be formed between two adjacent arc groups 4; to explain, if the first arc line 42 and the third arc line 43 are also arranged concentrically with the rotor core 1, the outer edge of the rotor core 1 will be a complete circular structure, and the recess 5 cannot be formed, which also cannot bring about the effect of reducing the operating noise.

It will be appreciated that, in order to ensure uniform magnetic field distribution, the first arc line 42 and the third arc line 43 of each arc portion 4 are symmetrical about the centre line of the second arc line 41, and the third arc line 43 of each arc portion 4 is connected to the first arc line 42 of the adjacent arc portion 4 and forms the recess 5. The second arc line 41 of each arc portion 4 is tangent to the junction of the first arc line 42 and the third arc line 43 at two ends thereof, so as to ensure that a smooth arc line structure can be formed.

In this embodiment, the rotor is a common radial strip magnetic shoe structure so as to adapt to the design of this application to form a magnetic bridge that resists demagnetization.

The invention also provides a motor which comprises a stator and the rotor in any scheme. The motor has all the advantages of the rotor in the scheme, and the local demagnetization resistance of the permanent magnet in the rotor can be effectively improved.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, numerous simple modifications can be made to the technical solution of the invention, including combinations of the individual specific technical features in any suitable way. The invention is not described in detail in order to avoid unnecessary repetition. Such simple modifications and combinations should be considered within the scope of the present disclosure as well.

Claims

1. The utility model provides a rotor, its characterized in that, includes rotor core (1) and permanent magnet (3), be provided with the edge on rotor core (1) a plurality of mounting grooves (2) that the circumference interval of rotor core (1) set up, permanent magnet (3) set up in mounting groove (2), every mounting groove (2) all have and are close to the first edge of rotor core (1) outer fringe, orientation the second edge at the center of rotor core (1) and connect the transition edge at first edge and second edge, the transition edge is multistage structure (6), the part of multistage structure (6) with first edge is connected sets up to the orientation the inboard protrusion of mounting groove (2).

2. The rotor according to claim 1, characterized in that a stepped magnetic bridge is formed between the multi-segment structure (6) and the outer edge of the rotor core (1).

3. The rotor according to claim 2, characterized in that the multi-segment structure (6) comprises a first segment (61) and a second segment (62) connected in series, the second segment (62) being connected to the first edge, the second segment (62) projecting along the inside towards the mounting groove (2) and being in contact with the permanent magnet (3).

4. The rotor according to claim 2, characterized in that the first edge is arranged parallel to the second edge, and the permanent magnets (3) are arranged in a direction parallel to the axial direction.

5. The rotor according to claim 1, characterized in that the outer edge of the rotor core (1) comprises a plurality of successively connected circular arc portions (4), with recesses (5) being formed between adjacent circular arc portions (4).

6. The rotor as recited in claim 5, characterized in that a plurality of the mounting grooves (2) are respectively provided in one-to-one correspondence with a plurality of the circular arc portions (4), each mounting groove (2) is provided along a straight line direction connecting both ends of the corresponding circular arc portion (4), and the multi-stage structure (6) of the mounting groove (2) is provided in correspondence with the recessed portion (5).

7. The rotor according to claim 6, characterized in that each arc group (4) comprises a first arc line (42), a second arc line (41) and a third arc line (43) connected in sequence, the second arc line (41) being arranged concentrically with the rotor core (1), the first arc line (42) and the third arc line (43) being arranged non-concentrically with the rotor core (1).

8. The rotor according to claim 7, characterized in that the first arc line (42) and the third arc line (43) of each circular arc portion (4) are symmetrical with respect to the centre line of the second arc line (41), the third arc line (43) of each circular arc portion (4) being connected to the first arc line (42) of the adjacent circular arc portion (4) and forming the recess (5).

9. The rotor of claim 1 wherein the rotor is a radial bar magnet shoe structure.

10. An electrical machine comprising a stator and a rotor according to any one of claims 1 to 9.