WO2022048169A1

WO2022048169A1 - Magnetic steel, motor rotor, and permanent magnet motor

Info

Publication number: WO2022048169A1
Application number: PCT/CN2021/090438
Authority: WO
Inventors: 郭伟林; 张芳; 张前亮; 李广海; 梁建东; 张勐
Original assignee: 珠海格力电器股份有限公司
Priority date: 2020-09-03
Filing date: 2021-04-28
Publication date: 2022-03-10
Also published as: CN112039238A

Abstract

The present invention provides a magnetic steel, a motor rotor, and a permanent magnet motor. The magnetic steel comprises a main body (1). The main body (1) comprises a magnetic pole surface. A first groove (4) and a second groove (5) are provided on at least one magnetic pole surface. The first grooves (4) and the second grooves (5) overlap each other. According to the magnetic steel of the present invention, the eddy current loss of a permanent magnet can be reduced, and the efficiency of the permanent magnet motor is improved.

Description

Magnets, Motor Rotors and Permanent Magnet Motors

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on the CN application number 202010915769.1 and the filing date is September 3, 2020, and claims its priority. The disclosure content of this CN application is hereby incorporated into this application as a whole.

technical field

The present disclosure relates to the technical field of motors, in particular to a magnetic steel, a motor rotor and a permanent magnet motor.

Background technique

The permanent magnet motor has the advantages of good torque and speed characteristics, higher efficiency than other types of motors, and convenient control, which makes many traditional electric excitation motors replaced by permanent magnet motors, so that the traditional electric excitation motors can be difficult to achieve. of high performance.

Permanent magnet motors are divided into surface-mounted permanent magnet motors and built-in permanent magnet motors according to the different magnetic pole positions. Permanent magnet motors have the advantages of simple structure, small size, high torque density and high efficiency, and are widely used in various occasions. However, the permanent magnet motor generates a large amount of eddy current loss due to the magnetic field of the armature winding during operation, and the rotor has poor heat dissipation, and the eddy current loss generated by the permanent magnet cannot be effectively dissipated, resulting in high rotor heat and high temperature. If the increase is large, the permanent magnet will be irreversibly demagnetized, which will seriously affect the operation reliability of the permanent magnet motor. The poor heat dissipation of the permanent magnet motor rotor leads to a decrease in the motor efficiency, and the irreversible demagnetization of the permanent magnet restricts the further development of the permanent magnet motor.

The magnetic poles of the permanent magnet motor in the related art usually use axial segmentation and radial segmentation to block the eddy current path, thereby reducing the eddy current loss. However, there is still a certain eddy current loss between the single magnetic poles after segmentation. In addition, due to the skin effect, large eddy currents accumulate on the surface of the magnetic pole, which is easy to cause irreversible demagnetization of the magnetic pole.

SUMMARY OF THE INVENTION

In view of this, the embodiments of the present disclosure provide a magnetic steel, a motor rotor and a permanent magnet motor, which can reduce the eddy current loss of the permanent magnet and improve the efficiency of the permanent magnet motor.

According to one aspect of the present disclosure, there is provided a magnetic steel including a body including at least one magnetic pole surface, and at least one magnetic pole surface is provided with a first slot and a second slot, and the first slot and the second slot intersect each other.

In some embodiments, the first groove penetrates the body along the first direction, and the second groove penetrates the body along the second direction; or, the first groove penetrates the body along the first direction, or the second groove penetrates the body along the second direction.

In some embodiments, the first slot and the second slot are perpendicular to each other.

In some embodiments, the depths of the first groove and the second groove are different.

In some embodiments, the width of the first slot and the second slot are different.

In some embodiments, the width of the first groove is greater than the width of the second groove, and the depth of the first groove is greater than the depth of the second groove.

In some embodiments, the first direction is the axial direction of the magnetic steel, and the second direction is the circumferential direction of the magnetic steel.

In some embodiments, at least one of the first groove and the second groove is filled with thermally conductive glue.

In some embodiments, the body is provided with a ventilation hole, and the ventilation hole penetrates the body along the first direction.

In some embodiments, at least one magnetic pole surface is provided with a plurality of first grooves and a plurality of second grooves, the plurality of first grooves are arranged in parallel and spaced apart from each other, and the plurality of second grooves are arranged in parallel with each other and spaced apart from each other.

In some embodiments, the magnets are built-in magnets.

In some embodiments, the width L1 of the first groove satisfies L1≤0.6 mm, and the depth H1 of the first groove satisfies H1≤20%H, where H is the thickness of the magnetic steel; or, the width L1 of the first groove satisfies L1≤0.6 mm, or the depth H1 of the first groove satisfies H1≤20%H, where H is the thickness of the magnetic steel.

In some embodiments, the width L2 of the second slot satisfies L2≤0.6mm, and the depth H2 of the second slot satisfies H2≤20%H, where H is the thickness of the magnetic steel; or, the width L2 of the second slot satisfies L2≤0.6 mm, , or the depth H2 of the second groove satisfies H2≤20%H, where H is the thickness of the magnetic steel.

In some embodiments, the distance between adjacent first slots is D1, the width of the magnetic steel is L, where D1≥5%L, the distance between adjacent second slots is D2, and the width of the magnetic steel is L , where D2≥5%L; or, the distance between adjacent first slots is D1, the width of the magnetic steel is L, where D1≥5%L, or the distance between adjacent second slots is D2, the magnetic The width of the steel is L, where D2≥5%L.

In some embodiments, the magnet is a surface mount magnet.

In some embodiments, the magnetic steel is arc-shaped, the arc length between adjacent first slots is a1, the arc length of the magnetic steel is a, and a1≥5%a.

In some embodiments, the magnetic steel is arc-shaped, the depth H1 of the first groove satisfies H1≤30%H, and the depth H2 of the first groove satisfies H2≤30%H, where H is the thickness of the magnetic steel; or, the first groove The depth H1 satisfies H1≤30%H, or the depth H2 of the first groove satisfies H2≤30%H, where H is the thickness of the magnetic steel.

According to another aspect of the present disclosure, a motor rotor is provided, comprising a rotor iron core and the above-mentioned magnetic steel, the magnetic steel being mounted on the rotor iron core.

In some embodiments, the magnetic steel is a built-in magnetic steel, which is installed in a magnetic steel slot opened in the rotor core, at least one magnetic pole surface includes a radially inner side surface of the magnetic steel adjacent to the central axis of the rotor, and the magnetic steel is far away from the central axis of the rotor. At least one of the radially outer surface, the radially inner surface and the radially outer surface on one side of the rotor central axis is provided with a first groove and a second groove that intersect with each other.

In some embodiments, the motor rotor includes a plurality of magnetic steels, and the plurality of magnetic steels are surface-mounted magnetic steels, and the plurality of magnetic steels are mounted on the outer surface of the rotor core to form annular magnetic steels.

In some embodiments, the annular magnetic steel outer casing is provided with a protective cover; the adjacent magnetic steels, between the multiple magnetic steels and the protective cover, and between the multiple magnetic steels and the rotor core are bonded and fixed by magnetic steel glue, The protective sleeve and the annular magnetic steel are in interference fit; or, between adjacent magnetic steels, between multiple magnetic steels and the protective sleeve, and between multiple magnetic steels and the rotor core, they are fixed by magnetic steel glue, or the protective sleeve is Interference fit with ring magnets.

According to another aspect of the present disclosure, a permanent magnet motor is provided, including the above-mentioned magnetic steel or the above-mentioned motor rotor.

The magnetic steel provided by the embodiment of the present disclosure includes a body, and the body includes at least one magnetic pole surface, and at least one magnetic pole surface is provided with a first slot and a second slot, and the first slot and the second slot intersect each other. Crossed grooves are formed on the surface of the magnetic steel, the surface of the magnetic steel can be cut by using the intersecting grooves, the eddy current path on the surface of the magnetic steel can be blocked, and the eddy current loss can be reduced. By reducing the eddy current loss of the magnetic steel, the heat generated by the magnetic steel is also reduced accordingly, thereby avoiding the demagnetization of the magnetic steel due to excessive temperature.

Description of drawings

The accompanying drawings, which form a part of the specification, illustrate embodiments of the present disclosure and together with the description serve to explain the principles of the present disclosure.

The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, wherein:

1 is a schematic three-dimensional structural diagram of a first embodiment of a magnetic steel according to the present disclosure;

2 is a schematic three-dimensional structural diagram of a second embodiment of a magnetic steel according to the present disclosure;

FIG. 3 is a partial structural schematic diagram of the first embodiment of the motor rotor according to the present disclosure;

FIG. 4 is a partial structural schematic diagram of a second embodiment of a motor rotor according to the present disclosure.

It should be understood that the dimensions of the various parts shown in the drawings are not to actual scale. Furthermore, the same or similar reference numerals denote the same or similar components.

Reference numerals are indicated as:

1. Main body; 2. Radial inner surface; 3. Radial outer surface; 4. First slot; 5. Second slot; 6. Ventilation hole; 7. Rotor core; 8. Protective sleeve.

detailed description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and in no way limits the disclosure, its application or uses in any way. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that unless specifically stated otherwise, the relative arrangements of parts and steps, compositions of materials, numerical expressions and numerical values set forth in these embodiments are to be interpreted as illustrative only and not as limiting.

As used in this disclosure, "first," "second," and similar words do not denote any order, quantity, or importance, but are merely used to distinguish the different parts. "Comprising" or "comprising" and similar words mean that the element preceding the word covers the elements listed after the word, and does not exclude the possibility that other elements are also covered. "Up", "Down", "Left", "Right", etc. are only used to represent the relative positional relationship, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

In the present disclosure, when a specific device is described as being located between the first device and the second device, there may or may not be an intervening device between the specific device and the first device or the second device. When it is described that a specific device is connected to other devices, the specific device may be directly connected to the other device without intervening devices, or may not be directly connected to the other device but have intervening devices.

All terms (including technical or scientific terms) used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, general-purpose dictionaries should be construed to have meanings consistent with their meanings in the context of the related art, and not to be construed in an idealized or highly formalized sense, unless explicitly stated herein. Defined like this.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification.

1 to 4 , according to an embodiment of the present disclosure, the magnetic steel includes a body 1 , the body 1 includes at least one magnetic pole surface, and at least one magnetic pole surface is provided with a first slot 4 and a second slot 5 . The grooves 4 and the second grooves 5 cross each other.

The first groove 4 and the second groove 5 are formed on the surface of the magnetic steel. The intersecting grooves can be used to cut the surface of the magnetic steel, so that the surface area of the magnetic steel is divided into a plurality of independent blocks that are separated from each other. The eddy current path on the surface of the magnetic steel reduces the eddy current loss. By reducing the eddy current loss of the magnetic steel, the heat generated by the magnetic steel is also reduced accordingly, so as to avoid the demagnetization of the magnetic steel due to excessive temperature.

When the magnetic steel is applied to the rotor of the motor, the magnetic pole surface includes the radial inner side surface 2 on the side of the magnetic steel adjacent to the central axis of the rotor, and the radial outer side surface 3 on the side of the magnetic steel away from the central axis of the rotor, the radial inner side surface 2 and/ Or the radially outer side surface 3 is provided with a first groove 4 and a second groove 5 that cross each other.

The first groove 4 and the second groove 5 are provided on at least one of the radially inner side surface 2 and the radially outer side surface 3 extending in the axial direction, and the first groove 4 extends in the rotor axial direction, and the second groove 5 extends in the rotor circumferential direction. Therefore, the grooves on the surface of the magnetic steel can also form a diversion channel, so that during the operation of the motor rotor, the air flow can flow through the surface of the magnetic steel under the diversion effect of the first groove 4 to dissipate heat to the magnetic steel, so that the magnetic steel can be dissipated. The heat can be dissipated in time to improve the heat dissipation performance of the magnetic steel and improve the efficiency of the motor.

In this embodiment, the relative position of the magnetic steel is determined based on the position where the magnetic steel is applied to the motor rotor, the relative position of the magnetic steel is defined based on the central axis of the motor rotor, and the radial direction of the motor rotor is defined. The direction is the radial direction of the magnetic steel, the axial direction of the motor rotor is the axial direction of the magnetic steel, and the circumferential direction of the motor rotor is the circumferential direction of the magnetic steel.

In some embodiments, the first slot 4 runs through the body 1 along the first direction (ie, the rotor axial direction), so that the air can flow through the entire magnetic steel along the guide of the first slot 4 to take away the heat of the magnetic steel and improve the magnetic properties. The heat dissipation capacity of steel.

In some embodiments, the second slot 5 runs through the body 1 in the second direction (ie, the rotor circumferential direction), so that the airflow can flow from the first slot 4 along the second slot 5 to other positions of the body 1 , and to the body 1 . The other positions of the device also form good heat dissipation.

In some embodiments, the second groove 5 extends to the edges of both sides of the body 1 in the circumferential direction, but does not penetrate the body 1 in the circumferential direction.

In some embodiments, the first slot 4 and the second slot 5 are perpendicular to each other, which makes it easier for the airflow entering the first slot 4 to be evenly distributed into the second slot 5, thereby improving the heat dissipation effect for the magnetic steel. In other embodiments, the first grooves 4 and the second grooves 5 may not be vertical, but are arranged obliquely and intersecting.

In some embodiments, the depths of the first grooves 4 and the second grooves 5 are different.

Specifically, the depth of the first groove 4 is greater than the depth of the second groove 5 . For the magnetic steel, since the first groove 4 extends along the axial direction, the heat of the magnetic steel is mainly discharged through the first groove 4. The greater the depth of the first groove 4, the higher the heat discharge efficiency, and the magnetic steel The cooling effect is better.

In other embodiments, the depths of the first groove 4 and the second groove 5 may also be the same.

In some embodiments, the widths of the first slot 4 and the second slot 5 are different.

Specifically, the width of the first groove 4 is greater than the width of the second groove 5 . For the magnetic steel, since the first slot 4 extends along the axial direction, the heat of the magnetic steel is mainly discharged through the first slot 4. The cooling effect is better.

In other embodiments, the widths of the first groove 4 and the second groove 5 may also be the same.

In some embodiments, the width of the first slot 4 is greater than the width of the second slot 5, and the depth of the first slot 4 is greater than the depth of the second slot 5, and the deeper and wider first slot 4 extends along the axial direction of the magnetic steel , the heat dissipation efficiency is higher, and the magnetic steel heat dissipation effect is better.

In some embodiments, one of the first groove 4 and the second groove 5 is filled with thermally conductive glue. The slotted position on the surface of the magnetic steel is filled with a thermally conductive adhesive with good thermal conductivity. After the thermally conductive adhesive is cured, the heat generated in the magnetic steel can be quickly transferred out, which can enhance the heat dissipation capacity of the magnetic steel and prevent the magnetic steel from accumulating heat due to eddy current loss. inside the magnet. In addition, after the thermal conductive adhesive is cured, the overall strength of the magnetic steel can be enhanced to prevent the magnetic steel from being damaged by centrifugal force during operation. The thermally conductive adhesive is, for example, epoxy resin.

In some embodiments, the body 1 is provided with a ventilation hole 6 , and the ventilation hole 6 penetrates the body 1 along the first direction (ie, the axial direction of the rotor). There are ventilation holes 6 in the interior of the magnetic steel along the axial direction of the motor rotor. After the magnetic steel is installed in the rotor core 7, when the motor is running, the air can flow from the internal ventilation holes 6 of the magnetic steel in the axial direction of the rotor, thereby bringing the Take away the heat generated by the magnet. By adding axially penetrating ventilation holes 6 on the magnetic steel, the eddy current loss of the motor can be effectively reduced, and the cooling channel of the motor can be increased, so that the permanent magnet motor has better anti-demagnetization ability and high temperature resistance performance.

In this embodiment, the grooves on the surface of the magnetic steel and the axially penetrating ventilation holes 6 are essentially different in the realization principle of reducing the heat of the magnetic steel. The grooves on the surface of the magnetic steel effectively suppress the generation of eddy current loss. The method reduces the heat of the magnetic steel, and the axially open ventilation holes 6 can quickly dissipate the heat generated by the eddy current loss and enhance the cooling effect of the motor. The combination of the two can effectively dissipate the magnetic steel from various aspects. , play a better heat dissipation effect.

In this embodiment, the magnetic steel includes a plurality of first grooves 4 and a plurality of second grooves 5, the plurality of first grooves 4 are arranged parallel to each other and spaced apart, and the plurality of second grooves 5 are arranged parallel to each other and spaced apart. A plurality of first grooves 4 and a plurality of second grooves 5 are formed on the surface of the magnetic steel, so that the blocks separated by the surface area of the magnetic steel are smaller, and eddy currents are less likely to be generated, thereby further reducing the eddy current loss.

The material of the above-mentioned magnetic steel can be a permanent magnet material suitable for a permanent magnet motor, such as SmCo samarium cobalt, NdFeB neodymium iron boron, etc.

Referring to FIG. 1 and FIG. 3 in combination, according to the first embodiment of the magnetic steel and the motor rotor of the present disclosure, the magnetic steel is a built-in magnetic steel.

In this embodiment, the radial inner side 2 of the main body 1 is provided with a first groove 4 and a second groove 5, the first groove 4 and the second groove 5 intersect with each other, and are also formed on the radial inner side 2 of the magnetic steel The crossed groove structure forms a cross segment on the radial inner side of the magnetic steel, which further blocks the eddy current path on the surface of the magnetic steel and reduces the eddy current loss. The first groove 4 and the second groove 5 of the radial inner side surface 2 of the body 1 may also be filled with thermally conductive adhesive.

In this embodiment, the block magnetic steel is taken as an example to describe the structural design of the magnetic steel.

For the magnetic steel in this embodiment, the width L1 of the first slot 4 satisfies L1≤0.6mm, and the width L2 of the second slot 5 satisfies L2≤0.6mm, so that the widths of the first slot 4 and the second slot 5 are both less than or equal to 0.6mm, it can avoid that the width of the slot is too large to affect the coercivity and magnetic density of the magnetic steel, and ensure the working performance of the magnetic steel.

In the magnetic steel in this embodiment, the depth H1 of the first groove 4 satisfies H1≤20%H, and the depth H2 of the second groove 5 satisfies H2≤20%H, where H is the thickness of the magnetic steel, so as to avoid the depth of the groove being too deep , to avoid a greater impact on the structural strength of the magnetic steel, and ensure the overall structural strength of the magnetic steel.

In the magnetic steel in this embodiment, the distance between adjacent first slots 4 is D1, the width of the magnetic steel is L, where D1≥5%L; the distance between adjacent second slots 5 is D2, Among them, D2≥5%L, which can effectively limit the spacing between adjacent grooves, and avoid the problem that the spacing between adjacent grooves is too small, which leads to the deterioration of the integrity of the magnetic steel structure.

The cross-section of the above-mentioned magnetic steel can be rectangular, fan-shaped, or trapezoidal, etc., and the magnetic steel can also be of other shapes having the above-mentioned features of the present disclosure.

Referring to FIG. 2 and FIG. 4 in combination, according to the second embodiment of the magnetic steel and the motor rotor of the present disclosure, the magnetic steel is a surface-mounted magnetic steel.

In some embodiments, a first groove 4 and a second groove 5 are provided on the radial inner side 2 of the magnetic steel, and the first groove 4 and the second groove 5 intersect each other.

In some embodiments, the magnetic steel is arc-shaped, the arc length between adjacent first slots 4 is a1, and the arc length of the magnetic steel is a, a1≥5%a, so as to avoid the spacing between adjacent slots of the magnetic steel If it is too small, it will affect the integrity of the magnetic steel structure.

In some embodiments, the magnetic steel is arc-shaped, the depth H1 of the first groove 4 satisfies H1≤30%H, and the depth H2 of the first groove 4 satisfies H2≤30%H, where H is the thickness of the magnetic steel, so as to avoid The groove depth is too large and affects the structural strength of the magnetic steel.

The above-mentioned magnetic steel shape is not limited to an arc shape, and can also be other surface-mounted magnetic steel structures.

Referring to FIGS. 1 to 4 in combination, according to an embodiment of the present disclosure, the motor rotor includes a rotor iron core 7 and the aforementioned embodiments of the magnetic steel, and the magnetic steel is installed on the rotor iron core 7 .

For the motor rotor of the built-in permanent magnet motor, a plurality of magnetic steel grooves are opened inside the rotor iron core 7, and the magnetic steel is installed in the magnetic steel grooves.

The manufacturing process of the motor rotor of the built-in permanent magnet motor is as follows: the first slot 4 and the second slot 5 on the surface of the magnetic steel can be processed on the surface of the magnetic steel by wire cutting, etc., and then the first slot 4 on the surface of the magnetic steel can be processed. And the second groove 5 is filled with thermally conductive adhesive. The rotor iron core 7 is formed by laminating silicon steel sheets. A ventilation hole 6 is opened in the block magnetic steel along the axial direction of the rotor iron core 7, and then the block magnetic steel is loaded into the magnetic steel slot of the rotor iron core 7. , so as to obtain the motor rotor of the built-in permanent magnet motor.

When the magnetic steel is a surface-mounted magnetic steel, there are multiple magnetic steels, and the magnetic steels are sequentially installed on the outer surface of the rotor core 7 in the circumferential direction, and spliced into a complete ring, thereby forming a ring-shaped magnetic steel.

In the embodiment of the present disclosure, a segmented sector-shaped magnetic steel is used, and a plurality of magnetic steel segments arranged in sequence in the circumferential direction are spliced into a ring-shaped magnetic steel. Compared with the integral ring-shaped magnetic steel, it has the following advantages: First, the motor rotor When rotating, it is easy to be damaged due to the centrifugal force, and the magnetic steel is divided into fan-shaped blocks and then spliced together. Compared with the integral ring magnetic steel, its structural strength is higher and it is not easy to be damaged. Secondly, the magnetization methods of sector magnets are more extensive, either parallel magnetization or radial magnetization can be adopted; while integral ring magnets can only be magnetized in parallel. Also, the separate sector magnets can form multiple pairs of magnetic pole structures, such as 2 poles, 4 poles, 6 poles, 8 poles, etc., which can be applied to a wider range of motor structures, while the integral ring magnet can only form 2 poles. Pole pole structure.

The annular magnetic steel outer casing is provided with a protective sleeve 8, and the adjacent magnetic steels, between the magnetic steel and the protective sleeve 8, and between the magnetic steel and the rotor core 7 are bonded and fixed by magnetic steel glue. The protective cover 8 can be made of high-strength alloy materials such as nickel-based alloys and titanium alloys, or high-strength fiber materials such as carbon fiber and glass fiber.

In some embodiments, the protective cover 8 may also be an interference fit with the ring magnet.

Taking arc-shaped magnetic steel as an example, the production process of the motor rotor of the surface-mounted permanent magnet motor is as follows: a number of vertical and horizontal small grooves are evenly cut on the surface of the magnetic steel by wire cutting to form the first groove 4 and the second groove 5, Then fill the first groove 4 and the second groove 5 on the surface of the magnetic steel with thermally conductive adhesive.

A ventilation hole 6 is opened inside the arc-shaped magnetic steel along the axial direction of the arc-shaped magnetic steel. The contact surfaces of the steels are closely attached to each other and can be fixed with magnetic steel glue. There is an interference fit between the protective sleeve 8 and the magnetic steel, which can reduce the stress generated by the internal structure (especially the magnetic steel) and protect the safe operation of the motor rotor. The motor rotor of the surface mount permanent magnet motor of the present disclosure can be obtained from the above process.

According to an embodiment of the present disclosure, the permanent magnet motor includes the above-mentioned magnetic steel embodiment or the above-mentioned motor rotor embodiment.

So far, the various embodiments of the present disclosure have been described in detail. Some details that are well known in the art are not described in order to avoid obscuring the concept of the present disclosure. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein according to the above description. It can be easily understood by those skilled in the art that, on the premise of no conflict, the above advantageous manners can be freely combined and superimposed.

The above are only preferred embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present disclosure should be included within the protection scope of the present disclosure. Inside. The above are only the preferred embodiments of the present disclosure. It should be pointed out that for those skilled in the art, without departing from the technical principles of the present disclosure, several improvements and modifications can also be made, and these improvements and modifications should also be It is regarded as the protection scope of the present disclosure.

Claims

A magnetic steel, comprising a main body (1), the main body (1) comprising at least one magnetic pole surface, the at least one magnetic pole surface being provided with a first groove (4) and a second groove (5), the first The grooves (4) and the second grooves (5) cross each other.
The magnetic steel according to claim 1, wherein the first groove (4) penetrates the body (1) along a first direction, and the second groove (5) penetrates the body (1) along a second direction );

Alternatively, the first groove (4) penetrates the body (1) along a first direction, or the second groove (5) penetrates the body (1) along a second direction.
The magnetic steel according to claim 1 or 2, wherein the first slot (4) and the second slot (5) are perpendicular to each other.
The magnetic steel according to any one of claims 1 to 3, wherein the depths of the first groove (4) and the second groove (5) are different.
The magnetic steel according to any one of claims 1 to 4, wherein the widths of the first groove (4) and the second groove (5) are different.
The magnetic steel according to claim 5, wherein the width of the first slot (4) is greater than the width of the second slot (5), and the depth of the first slot (4) is greater than that of the second slot (4) Depth of slot (5).
The magnetic steel according to any one of claims 1 to 6, wherein the first direction is an axial direction of the magnetic steel, and the second direction is a circumferential direction of the magnetic steel.
The magnetic steel according to any one of claims 1 to 7, wherein at least one of the first groove (4) and the second groove (5) is filled with thermally conductive glue.
The magnetic steel according to any one of claims 1 to 8, wherein the main body (1) is provided with a ventilation hole (6), and the ventilation hole (6) penetrates the main body (1) along the first direction .
The magnetic steel according to any one of claims 1 to 9, wherein a plurality of first grooves (4) and a plurality of second grooves (5) are provided on the surface of the at least one magnetic pole, and the plurality of first grooves (5) are provided on the surface of the at least one magnetic pole. The grooves (4) are arranged parallel to each other and spaced apart, and the plurality of second grooves (5) are arranged parallel to each other and spaced apart.
The magnetic steel according to any one of claims 1 to 10, wherein the magnetic steel is a built-in magnetic steel.
The magnetic steel according to claim 11, wherein the width L1 of the first groove (4) satisfies L1≤0.6mm, and the depth H1 of the first groove (4) satisfies H1≤20%H, where H is Magnet thickness;

Alternatively, the width L1 of the first groove (4) satisfies L1≤0.6 mm, or the depth H1 of the first groove (4) satisfies H1≤20%H, where H is the thickness of the magnetic steel.
The magnetic steel according to claim 11 or 12, wherein the width L2 of the second groove (5) satisfies L2≤0.6mm, and the depth H2 of the second groove (5) satisfies H2≤20%H, wherein H is the thickness of the magnetic steel;

Alternatively, the width L2 of the second groove (5) satisfies L2≤0.6 mm, or the depth H2 of the second groove (5) satisfies H2≤20%H, where H is the thickness of the magnetic steel.
The magnetic steel according to any one of claims 11 to 13, wherein the distance between adjacent first grooves (4) is D1, the width of the magnetic steel is L, wherein D1≥5%L, adjacent The distance between the second grooves (5) is D2, and the width of the magnetic steel is L, wherein D2≥5%L;

Alternatively, the distance between adjacent first slots (4) is D1, the width of the magnetic steel is L, where D1≥5%L, or the distance between adjacent second slots (5) is D2, so The width of the magnetic steel is L, where D2≥5%L.
The magnetic steel according to any one of claims 1 to 10, wherein the magnetic steel is a surface-mounted magnetic steel.
The magnetic steel according to claim 15, wherein the magnetic steel is arc-shaped, the arc length between adjacent first slots (4) is a1, and the arc length of the magnetic steel is a, a1≥5% a.
The magnetic steel according to claim 15, wherein the magnetic steel is arc-shaped;

The depth H1 of the first groove (4) satisfies H1≤30%H, and the depth H2 of the second groove (5) satisfies H2≤30%H, wherein H is the thickness of the magnetic steel;

Alternatively, the depth H1 of the first groove (4) satisfies H1≤30%H, or the depth H1 of the first groove (4) satisfies H1≤30%H, or the depth of the second groove (5) H2 satisfies H2≤30%H, where H is the thickness of the magnetic steel.
A motor rotor, comprising a rotor iron core (7) and the magnetic steel according to any one of claims 1 to 17, wherein the magnetic steel is mounted on the rotor iron core (7).
The motor rotor according to claim 18, wherein the magnetic steel is a built-in magnetic steel and is installed in a magnetic steel slot opened in the rotor iron core (7), and the at least one magnetic pole surface includes the magnetic steel. The radial inner side (2) on the side of the steel adjacent to the central axis of the rotor, and the radial outer side (3) on the side of the magnetic steel away from the central axis of the rotor, the radial inner side (2) and the radial At least one of the outer side surfaces (3) is provided with a first groove (4) and a second groove (5) that cross each other.
The motor rotor according to claim 18, wherein the motor rotor comprises a plurality of magnetic steels, and the plurality of magnetic steels are surface-mounted magnetic steels, and the plurality of magnetic steels are installed on the rotor core ( 7) The outer surface of the ring magnet is formed.
The motor rotor according to claim 20, wherein a protective cover (8) is provided on the outer side of the annular magnetic steel;

Adjacent magnetic steels, between the plurality of magnetic steels and the protective sleeve (8), and between the plurality of magnetic steels and the rotor core (7) are bonded and fixed by magnetic steel glue, so The protective cover (8) is in interference fit with the annular magnetic steel;

Or, between adjacent magnetic steels, between the plurality of magnetic steels and the protective sleeve (8), and between the plurality of magnetic steels and the rotor core (7), they are fixed by magnetic steel glue , or the protective sleeve (8) and the annular magnetic steel are in an interference fit.
A permanent magnet motor, comprising the magnetic steel described in any one of claims 1 to 17 or the motor rotor described in any one of claims 18 to 21 .