CN-122001119-A - Magnetic conduction controllable high-speed permanent magnet motor rotor sheath and assembly method thereof

CN122001119ACN 122001119 ACN122001119 ACN 122001119ACN-122001119-A

Abstract

The invention discloses a magnetic conduction controllable high-speed permanent magnet motor rotor sheath which adopts a three-layer concentric lamination structure, wherein the thickness of an inner layer high magnetic permeability material is changed along the circumferential direction, the magnetic flux distribution of a permanent magnet is guided and regulated, the thickness of an intermediate layer low magnetic permeability material is complemented with the thickness of the inner layer high magnetic permeability material, the equivalent magnetic permeability of the sheath is changed in a sine and periodic manner to form a magnetic flux modulation area, the harmonic wave is restrained from the source, and the outer layer rigid material is coated to provide anti-centrifugal strength. According to the invention, the sheath is updated from a pure mechanical part to an electromechanical coupling functional element, so that the waveform of an air gap magnetic field is effectively improved, the torque pulsation is reduced, and the efficiency and the stability of the motor are improved on the premise of ensuring the high-speed rotation safety. The invention has flexible structure, material and process can be adjusted according to the requirements of power, rotation speed and cost, is suitable for the fields of high-performance permanent magnet motors with rotation speeds of more than or equal to 15000r/min, such as electric automobiles, aviation power generation, high-speed electric spindles and the like, and has remarkable economic and engineering application values.

Inventors

QIU HONGBO
JIA SHAOFENG
Zhao Zien
LI YIJIE
YI RAN
LIU ANYANG
CAO QINGYU
JIA WANYING
LIU XIAOMEI
WU XUANDONG
XING YIN
QIAO JIANWEI

Assignees

郑州轻工业大学

Dates

Publication Date: 20260508
Application Date: 20260204

Claims (8)

1. A rotor sheath of a high-speed permanent magnet motor with controllable magnetic conductivity is characterized by comprising a three-layer laminated structure, a high-magnetic conductivity material structure (3), a low-magnetic conductivity material structure (2) and a rigid material structure (1) from inside to outside, wherein the high-magnetic conductivity material structure (3) is located on the inner layer of the sheath, distributed along the circumferential direction and closely adjacent to a permanent magnet (4), has non-uniformly distributed geometric characteristics and is used for guiding and regulating magnetic flux distribution generated by the permanent magnet (4), the low-magnetic conductivity material structure (2) is laminated on the outer side of the high-magnetic conductivity material structure (3) and matched with the non-uniformly distributed high-magnetic conductivity material structure (3), so that a magnetic flux modulation area with periodically changed equivalent magnetic conductivity is formed in the circumferential direction of the sheath and is used for inhibiting air gap magnetic field harmonics, and the rigid material structure (1) is coated on the outer periphery of the low-magnetic conductivity material structure (2) and is used for providing the whole anti-centrifugal load capacity of the sheath so as to realize functional integration of mechanical strength and electromagnetic optimization.
2. The magnetically permeable high-speed permanent magnet motor rotor sheath according to claim 1, wherein the thickness of the high magnetic permeability material structure (3) in the circumferential direction changes regularly, and the thickness of the low magnetic permeability material structure (2) and the thickness of the high magnetic permeability material structure (3) change complementarily to each other, so that the total thickness of the sheath is kept constant.
3. The rotor sheath of the high-speed permanent magnet motor with controllable magnetic conductivity according to claim 2, wherein the thickness of the high-magnetic permeability material structure (3) changes along the circumferential direction in a sine law, and the thickness of the low-magnetic permeability material structure (2) correspondingly changes along the opposite trend, and the two materials are complementary to each other, so that the equivalent magnetic conductivity of the sheath is in sine distribution along the circumferential direction.
4. The rotor sheath of the high-speed permanent magnet motor with controllable magnetic conductivity according to claim 1, wherein the high-magnetic conductivity material structure (3) is made of silicon steel sheets or permalloy, the low-magnetic conductivity material structure (2) is made of stainless steel, titanium alloy or carbon fiber reinforced composite materials, and the rigid material structure (1) is made of alloy steel or carbon fiber winding layers.
5. The rotor sheath of the high-speed permanent magnet motor with controllable magnetic conductivity according to claim 1, wherein the rigid material structure (1) is coated on the periphery of the low-permeability material structure (2) in a shrink fit or structural adhesive bonding mode to form an anti-centrifugal strength coating layer.
6. The magnetically controllable high speed permanent magnet motor rotor jacket of claim 1 wherein the non-uniformly distributed geometric features are configured such that the jacket equivalent permeability varies sinusoidally periodically along the circumferential direction to improve air gap field waveforms and suppress torque ripple.
7. A method of assembling a flux-controlled rotor sheath for a high-speed permanent magnet motor according to any one of claims 1 to 6, comprising the steps of: s1, fixing a permanent magnet (4) on the excircle of a rotor core, and finishing an excircle reference surface; S2, processing the high magnetic permeability material into an annular structure with the thickness changing along the circumferential direction in a sine rule, namely a high magnetic permeability material structure (3); S3, processing the low magnetic permeability material into a ring structure which is complementary with the high magnetic permeability material structure (3), namely a low magnetic permeability material structure (2); S4, aligning and laminating the high magnetic permeability material structure (3) and the low magnetic permeability material structure (2) according to a circumferential positioning reference to form a magnetic flux modulation sheath main body; S5, assembling a rigid material structure (1) outside the sheath main body to form a strength coating layer; And S6, press-fitting the assembled sheath assembly to an area covering the permanent magnet (4), and finishing the outer circle and performing balance correction.
8. The assembly method according to claim 7, wherein the step S4 is performed by bonding or interference fit, and the step S5 is performed by curing and forming by a shrink-fit process or a carbon fiber winding process.

Description

Magnetic conduction controllable high-speed permanent magnet motor rotor sheath and assembly method thereof Technical Field The invention relates to the technical field of high-speed permanent magnet motors, in particular to a magnetic conduction controllable rotor sheath with mechanical protection and electromagnetic optimization functions and an assembly method thereof. Background In a high-speed permanent magnet motor, the peripheral line speed of a rotor is high, a surface-mounted or embedded permanent magnet bears remarkable centrifugal load when rotating at a high speed, and the permanent magnet and a bonding/positioning structure thereof are easy to loose, crack and even throw out, so that serious safety risks and failure results are brought. Therefore, a rotor sheath is usually arranged on the outer side of the permanent magnet in engineering, and radial pretightening force is applied through hot sleeve, interference fit or winding so as to realize restraint and protection of the permanent magnet. The main objective of the traditional jacket design is to meet the strength, rigidity and centrifugal force resistance, and a non-magnetic/weak magnetic material scheme such as high-strength metal or fiber reinforced composite materials is often adopted, so that the risk of 'flying' of the permanent magnet is reduced from the mechanical aspect. However, the above-mentioned conventional sheath scheme mostly uses "mechanical constraint" as a core, which often has insufficient consideration on the electromagnetic effect of the sheath, and under the selection of certain materials and structures, the sheath may introduce additional loss (such as eddy current loss and temperature rise of the metal sheath), change the air-gap magnetic circuit condition or aggravate the air-gap magnetic field distortion, thereby causing the distortion of back electromotive force waveform, the increase of torque pulsation and the rise of noise vibration. Particularly, for a high-speed permanent magnet motor pursuing high efficiency, low harmonic and high stability, a rotor sheath structure capable of optimizing an air gap magnetic field waveform and reducing harmonic content while guaranteeing mechanical strength and high-speed reliability is needed. Disclosure of Invention The invention aims to solve the technical problems of overcoming the defects in the prior art and providing the high-speed permanent magnet motor rotor sheath with controllable magnetic conductance. The technical scheme adopted by the invention for solving the technical problems is as follows: The rotor sheath of the high-speed permanent magnet motor with controllable magnetic conductivity is of a three-layer laminated structure, sequentially comprises a high-magnetic-conductivity material structure, a low-magnetic-conductivity material structure and a rigid material structure from inside to outside, wherein the high-magnetic-conductivity material structure is located on the inner layer of the sheath, distributed along the circumferential direction and is adjacent to a permanent magnet, has non-uniformly distributed geometric characteristics and is used for guiding and regulating magnetic flux distribution generated by the permanent magnet, the low-magnetic-conductivity material structure is laminated on the outer side of the high-magnetic-conductivity material structure and is matched with the non-uniform distribution of the high-magnetic-conductivity material structure, so that the sheath forms a magnetic flux modulation area with equivalent magnetic conductivity periodically changing along the circumferential direction and is used for inhibiting air gap magnetic field harmonic waves, and the rigid material structure is coated on the periphery of the low-magnetic-conductivity material structure and is used for providing the integral anti-centrifugal load capacity of the sheath and realizing functional integration of mechanical strength and electromagnetic optimization. Further, the thickness of the high magnetic permeability material structure along the circumferential direction changes regularly, and the thickness of the low magnetic permeability material structure and the thickness of the high magnetic permeability material structure change complementarily to each other, so that the total thickness of the sheath is kept constant. Further, the thickness of the high magnetic permeability material structure changes along the circumferential direction in a sine law, and the thickness of the low magnetic permeability material structure correspondingly changes along the opposite trend, and the two materials are complementary, so that the equivalent magnetic permeability of the sheath is distributed along the circumferential direction in a sine way. Further, the high magnetic permeability material structure adopts silicon steel sheet or permalloy, the low magnetic permeability material structure adopts stainless steel, titanium alloy or carbon fiber reinforced comp