CN110022011B

CN110022011B - High-speed motor sheath structure

Info

Publication number: CN110022011B
Application number: CN201910371636.XA
Authority: CN
Inventors: 曹继伟; 李立毅; 王金耀; 张成明; 刘家曦; 王明义
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2019-05-06
Filing date: 2019-05-06
Publication date: 2021-04-13
Anticipated expiration: 2039-05-06
Also published as: CN110022011A

Abstract

The invention provides a high-speed motor sheath structure which is a cylindrical structure and is arranged on the surface of a permanent magnet and comprises a sheath cylinder, wherein a plurality of arc-shaped cutting slits which are cut along the radial direction are uniformly formed in the surface of the sheath cylinder, the plurality of arc-shaped cutting slits are coaxially arranged and are arranged on the sheath cylinder in a staggered mode, the sheath cylinder is axially divided by the plurality of arc-shaped cutting slits to form a segmented and connected sheath structure, two adjacent sheath sections are connected through an intersegment connecting area, eddy current directions in the two adjacent sheath sections are opposite, generated magnetic fields are opposite and offset, the arc length of each arc-shaped cutting slit accounts for 80-90% of the circumference of a circle where the arc-shaped cutting slit is located, and the sheath cylinder which is cut by the plurality of arc-. The sheath structure of the high-speed motor reduces the eddy current loss of the sheath, thereby reducing the temperature rise of a rotor, and can be used in the high-speed high-power motor to improve the running stability of the motor.

Description

High-speed motor sheath structure

Technical Field

The invention belongs to the field of motors, and particularly relates to a high-speed motor sheath structure.

Background

At the present stage, most of sheaths of the high-speed permanent magnet synchronous motors are surface-mounted type magnetic poles, and the surface-mounted type magnetic poles receive the action of a magnetic field of a stator armature winding when running at high speed, so that a large amount of eddy current loss is generated by the sheaths; the heat dissipation condition of the rotor is poor, eddy current loss generated by the sheath cannot be effectively dissipated, the heat quantity of the rotor is high, the temperature rise is large, and the operation reliability of the high-speed motor is seriously influenced.

At present, the existing sheath is generally concentrated on the material of the motor sheath, high-strength non-magnetic alloy steel is adopted as the sheath, but the metal material has stronger conductivity and can cause larger loss; recently, with the rise of the rechecking material, a non-conductive composite material such as carbon fiber or glass fiber is adopted as a sheath, so that the loss of the sheath is reduced; however, this method causes the permanent magnet to directly face the armature reaction magnetic field, and a large amount of eddy current loss is generated in the permanent magnet, which affects the reliability of the permanent magnet. Moreover, the alloy steel sheath will exert a partial pre-stress on the rotor magnets, which will improve the reliability of the permanent magnets at high speed operation, whereas composite materials do not. In some researches, the sheath is formed by splicing multiple sections, and although the blocked current flows axially, the eddy current loss on the rotor sheath cannot be reduced, so that the problem of the eddy current loss of the metal sheath is urgently needed to be solved in the high-speed high-power motor.

Disclosure of Invention

In view of this, the present invention is directed to a sheath structure of a high-speed motor, which reduces the eddy current loss of the sheath, thereby reducing the temperature rise of a rotor, and the sheath structure can be used in a high-speed high-power motor to improve the operation stability of the motor.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a high-speed motor sheath structure is a cylindrical structure and is arranged on the surface of a permanent magnet and comprises a sheath cylinder, wherein a plurality of arc-shaped cutting seams which are cut along the radial direction are uniformly formed in the surface of the sheath cylinder, the arc-shaped cutting seams are coaxially arranged and are arranged on the sheath cylinder in a staggered mode, the sheath cylinder is axially divided by the arc-shaped cutting seams to form a segmented and connected sheath structure, two adjacent sheath sections are connected through an intersegment connecting area, eddy currents in the two adjacent sheath sections are opposite in direction, generated magnetic fields are opposite and offset, the arc length of each arc-shaped cutting seam accounts for 80% -90% of the circumference of a circle where the arc-shaped cutting seam is located, and the sheath cylinder with the cut arc-shaped cutting seams still keeps in a.

Furthermore, the width of each circular arc-shaped cutting seam is smaller than 0.5mm, and the width of each jacket section is larger than 1 mm.

Furthermore, the cutting positions of the adjacent circular-arc-shaped cutting slits on the surface of the sheath cylinder are different, and the angle interval of the cutting positions of the adjacent circular-arc-shaped cutting slits on the surface of the sheath cylinder is 0-180 degrees, preferably 180 degrees.

Furthermore, all the circular-arc-shaped cutting seams are filled with epoxy resin glue for enhancing the integrity of the magnetic pole.

Furthermore, the material of the material is conductive and non-conductive stainless steel.

Compared with the prior art, the high-speed motor sheath structure has the following advantages:

the sheath structure of the high-speed motor is different from the traditional one-piece sheath, and the sheath structure is cut along the radial direction to form a multi-section structure. The sheath cut along the radial direction does not cut the sheath completely, and the cutting positions of adjacent cutting surfaces are different, so that the integral structure of the sheath is not damaged.

The high-speed motor rotor sheath structure is of a sheath structure which is distributed in multiple sections along the axial direction, can effectively cut off the eddy current path of the sheath, and forces eddy current to flow between the sections through the connection region between the sections, so that the resistance of the eddy current path is increased, the eddy current loss and temperature rise of the sheath are reduced, the permanent magnet is prevented from being demagnetized due to overhigh temperature, and the permanent magnet is protected.

The sheath structure of the invention has simple structure and is convenient for processing and manufacturing.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic perspective view of a high-speed motor sheath structure when the cut-in angle interval of adjacent circular-arc-shaped cutting slits is 180 degrees;

FIG. 2 is a schematic diagram of the eddy current path of a high speed motor sheath structure of FIG. 1;

fig. 3 is a schematic perspective view of a high-speed motor sheath structure when the cutting angle interval of adjacent circular-arc-shaped cutting slits is 150 degrees;

FIG. 4 is a schematic diagram of the eddy current path of a high speed motor sheath configuration of FIG. 3;

description of reference numerals:

1-sheath cylinder, 2-arc-shaped cutting seam, 3-sheath section and 4-intersegmental connection area.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1 and 3, a high-speed motor sheath structure is a cylindrical structure, is arranged on the surface of a permanent magnet, and includes a sheath cylinder 1, wherein a plurality of arc-shaped slits 2 cut along a radial direction are uniformly formed on the surface of the sheath cylinder 1, the plurality of arc-shaped slits 2 are coaxially arranged, the plurality of arc-shaped slits 2 are arranged on the sheath cylinder 1 in a staggered manner, the sheath cylinder 1 is axially divided by the plurality of arc-shaped slits 2 to form a segmented and connected sheath structure, two adjacent sheath segments 3 are connected by an intersegment connecting region 4, eddy currents in the two adjacent sheath segments 3 have opposite directions and generate opposite magnetic fields, the generated magnetic fields are offset with each other, the arc length of each arc-shaped slit 2 accounts for 80% -90% of the circumference of a circle where the arc-shaped slit 2 is located, and the sheath cylinder 1 with.

The width of each circular arc-shaped cutting seam 2 is smaller than 0.5mm, so that the mechanical strength of the sheath is not influenced, the width of each sheath section 3 is larger than 1mm, and the integrity of the sheath is deteriorated due to undersize.

The cutting positions of the adjacent circular-arc-shaped cutting slits 2 on the surface of the sheath cylinder 1 are different, the angle interval of the cutting positions of the adjacent circular-arc-shaped cutting slits 2 on the surface of the sheath cylinder 1 is 0-180 degrees, preferably 180 degrees, and the angle interval of the cutting positions of the adjacent circular-arc-shaped cutting slits 2 on the surface of the sheath cylinder 1 refers to the included angle of the radius of a circle at the cutting starting point of each two adjacent circular-arc-shaped cutting slits 2 on the radial projection plane.

The spacing is 180 ° in fig. 1, 150 ° in fig. 3, and the minimum cutting angle of the adjacent circular-arc-shaped slits is such that the connection regions 3 between the segments of the cylindrical magnet do not communicate with each other.

All the circular-arc-shaped cutting seams 2 are filled with epoxy resin glue for enhancing the structural integrity of the sheath, and the integrity of the sheath is further ensured by using the glue adhesion.

The sheath is made of conductive and non-magnetic stainless steel, eddy current can be generated under the action of a harmonic magnetic field, eddy current can inhibit eddy current loss generated by current harmonic on the permanent magnet, the eddy current loss generated in the sheath is large, the sheath is tightly attached to the permanent magnet, and the temperature rise of the permanent magnet is directly influenced by the loss.

The sheath structure is beneficial to reducing eddy current loss and saving materials, and as can be seen from eddy current schematic diagrams shown in fig. 2 and 4, the two cutting modes increase the length of an eddy current path under the condition of ensuring the integrity of the sheath; and adjacent eddy current directions are opposite, and the directions of the generated magnetic fields are opposite and mutually offset, so that the eddy current loss on the sheath is reduced to the maximum extent, and the reliable operation of the rotor is effectively ensured.

In some researches, the sheath is formed by splicing multiple sections, and although the blocked current flows axially, the eddy current loss on the rotor sheath cannot be reduced, because the sections of the multi-section spliced sheath are insulated, a small eddy current path can still be formed on each section of the sheath, and because the length of the sheath is shortened, the eddy current formed in the sheath section is mostly 'radial eddy current' forming a closed loop, only the length of the axial path is reduced, and the eddy current path is meaningless for reducing the eddy current loss.

Although the sheath in the application is also divided into a multi-section structure, the sections are connected by sections, and the multi-section sheath sections are not insulated, so that the multi-section sheath sections still form an eddy path in the same form before splicing, and the sections are connected by sections, so that the length of the eddy path is increased; and the directions of adjacent eddy currents are opposite, the directions of generated magnetic fields are opposite and mutually offset, and the eddy current loss on the sheath is reduced to the maximum extent.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The utility model provides a high-speed motor sheath structure which characterized in that: the magnetic shield sleeve is of a cylindrical structure and is arranged on the surface of a permanent magnet and comprises a sheath cylinder (1), wherein a plurality of arc-shaped cutting seams (2) which are cut along the radial direction are uniformly formed on the surface of the sheath cylinder (1), the plurality of arc-shaped cutting seams (2) are coaxially arranged, the plurality of arc-shaped cutting seams (2) are arranged on the sheath cylinder (1) in a staggered mode, the sheath cylinder (1) is axially divided into segmented and connected sheath structures by the plurality of arc-shaped cutting seams (2), two adjacent sheath sections (3) are connected through an intersegment connecting area (4), eddy currents in the two adjacent sheath sections (3) are opposite in direction, generated magnetic fields are opposite and offset, the arc length of each arc-shaped cutting seam (2) accounts for 80-90% of the circumference of a circle where the arc-shaped cutting seam is located, and the sheath cylinder (1) which cuts the;

the sheath cut along the radial direction does not cut the sheath completely, and the cut-in positions of adjacent cutting surfaces are different; the connection areas between the sections of the cylindrical sheath are not communicated;

the width of each circular-arc-shaped joint seam (2) is smaller than 0.5mm, and the width of each sheath section (3) is larger than 1 mm;

the cutting-in position angle interval of the adjacent arc-shaped cutting seams on the surface of the sheath cylinder (1) is 180 degrees;

the jacket structure is distributed along the axial direction in a multi-section manner, so that the eddy path of the jacket can be effectively cut off, and the eddy is forced to flow between sections through the section connecting area; the sections are provided with intersegmental connecting areas, so that the length of the eddy current path is increased;

epoxy resin glue for enhancing the structural integrity of the sheath is filled in all the arc-shaped cutting seams (2);

the material of the material is conductive and non-magnetic stainless steel.