EP-4738656-A1 - MOTOR ROTOR AND MOTOR

EP4738656A1EP 4738656 A1EP4738656 A1EP 4738656A1EP-4738656-A1

Abstract

The present application discloses a motor rotor and a motor. The motor rotor includes a rotor core provided with a plurality of first magnet slots uniformly distributed along a circumferential direction of the rotor core; the first magnet slots extend in a radial direction, and a tangentially magnetized main permanent magnet is provided in the first magnet slot; a second magnet slot is provided between any two adjacent first magnet slots on the rotor core, and an auxiliary permanent magnet module is provided in the second magnet slot; the auxiliary permanent magnet module includes at least two first auxiliary permanent magnet units, and closest surface magnetic poles of any two adjacent main permanent magnets are identical; a magnetization direction of the first auxiliary permanent magnet unit includes a radial magnetization component; the magnetization direction of the first auxiliary permanent magnet unit comprises a tangential magnetization component, and the tangential magnetization component of the first auxiliary permanent magnet unit is identical to a magnetization direction of the main permanent magnet adjacent to the first auxiliary permanent magnet unit.

Inventors

WU, Bocheng
DU, Xinming
ZHENG, JUN
DUAN, Shiying
PANG, Yilong
CHU, Wenqiang
ZHU, Xiaoyong

Assignees

Suzhou Inovance Technology Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20240628

Claims (14)

A motor rotor, characterized by comprising: a rotor core provided with a plurality of first magnet slots uniformly distributed along a circumferential direction of the rotor core, wherein: the first magnet slots extend in a radial direction, and a tangentially magnetized main permanent magnet is provided in the first magnet slot; a second magnet slot is provided between any two adjacent first magnet slots on the rotor core, and an auxiliary permanent magnet module is provided in the second magnet slot; the auxiliary permanent magnet module comprises at least two first auxiliary permanent magnet units, and closest surface magnetic poles of any two adjacent main permanent magnets are identical; a magnetization direction of the first auxiliary permanent magnet unit comprises a radial magnetization component; a direction of the radial magnetization component of the first auxiliary permanent magnet unit located between two main permanent magnets provided with magnetization directions facing each other is directed toward a stator along a radial direction of the rotor core, and a direction of the radial magnetization component of the first auxiliary permanent magnet unit located between two main permanent magnets provided with magnetization directions diverging from each other is directed toward a rotor axis along the radial direction of the rotor core; and the magnetization direction of the first auxiliary permanent magnet unit comprises a tangential magnetization component, and the tangential magnetization component of the first auxiliary permanent magnet unit is identical to a magnetization direction of the main permanent magnet adjacent to the first auxiliary permanent magnet unit; the magnetization direction of the main permanent magnet and the tangential magnetization direction of the first auxiliary permanent magnet unit both are tangential directions of a circle centered on the axis of the rotor core.
The motor rotor according to claim 1, wherein the at least two first auxiliary permanent magnet units comprise at least two auxiliary permanent magnets provided with at least one magnetization direction, or one auxiliary permanent magnet provided with at least two magnetization directions.
The motor rotor according to claim 1, wherein an angle between all magnetization directions or opposite directions of the magnetization directions in the auxiliary permanent magnet module and a center line of the second magnet slot along the radial direction of the rotor core is defined as α, and α is greater than or equal to 0° and less than or equal to 90°.
The motor rotor according to claim 2, wherein an angle between all magnetization directions or opposite directions of the magnetization directions in the auxiliary permanent magnet module and a center line of the second magnet slot along the radial direction of the rotor core is defined as α, and α is greater than or equal to 0° and less than or equal to 40°.
The motor rotor according to claim 2, wherein the auxiliary permanent magnet modules are symmetrically distributed about a center line of the second magnet slot along the radial direction of the rotor core, and an angle α of each of the first auxiliary permanent magnet units located on one side of the center line decreases gradually from a side distant from the center line toward a side adjacent to the center line.
The motor rotor according to claim 1, wherein the auxiliary permanent magnet module further comprises a second auxiliary permanent magnet unit located between the first auxiliary permanent magnet units, and an angle α between a magnetization direction of the second auxiliary permanent magnet unit and a center line of the second magnet slot along the radial direction of the rotor core is 0°.
The motor rotor according to claim 1, wherein the auxiliary permanent magnet module is provided adjacent to an inner edge of the rotor core.
The motor rotor according to claim 7, wherein a side wall of the auxiliary permanent magnet module adjacent to the inner edge of the rotor core and a side wall of the main permanent magnet adjacent to the inner edge of the rotor core are located on a same circle centered on the axis of the rotor core.
The motor rotor according to claim 1, wherein a length of the auxiliary permanent magnet module along the radial direction of the rotor core is L2, and a length of the main permanent magnet along the radial direction of the rotor core is L1; L2/L1 is greater than 0 and less than 1.
The motor rotor according to claim 9, wherein L2/L1 is greater than or equal to 0.1 and less than or equal to 0.5.
The motor rotor according to claim 1, wherein in adjacent main permanent magnets and auxiliary permanent magnet modules, a side surface of the main permanent magnet facing the auxiliary permanent magnet module is parallel to or in contact with a side surface of the auxiliary permanent magnet module facing the main permanent magnet module.
The motor rotor according to claim 1, wherein a distance D is provided between a side surface of the main permanent magnet facing the auxiliary permanent magnet module and a side surface of the auxiliary permanent magnet module facing the main permanent magnet, and D is greater than or equal to 0 mm and less than or equal to 0.5 mm.
The motor rotor according to any one of claims 1 to 12, wherein: the rotor core comprises a plurality of stacked first silicon steel sheets, and the main permanent magnet and the auxiliary permanent magnet module both pass through the first silicon steel sheets; and/or the rotor core comprises a plurality of stacked first silicon steel sheets, and at least one second silicon steel sheet is stacked between at least two adjacent first silicon steel sheets; the main permanent magnet and the auxiliary permanent magnet module both pass through the first silicon steel sheet and the second silicon steel sheet; the second silicon steel sheet is provided with a hollow portion, and the main permanent magnet and the auxiliary permanent magnet module are at least partially located in the hollow portion.
A motor, characterized by comprising: a stator assembly; and the motor rotor according to any one of claims 1 to 13, wherein the stator assembly is disposed around a periphery of the motor rotor.

Description

The present application claims priority to Chinese Patent Application No. 202310797571.1, entitled "MOTOR ROTOR AND MOTOR," filed with the China National Intellectual Property Administration on June 30, 2023, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD The present application relates to the technical field of motor, and in particular to a motor rotor and a motor. BACKGROUND Permanent magnet motors are widely used in industrial servo systems as actuators due to their advantages such as high dynamic response capability, high power density, and high control accuracy. They receive position, speed, and torque commands from an higher-level controller and accurately drive a load, featuring strong overload capacity, good linearity, and fast dynamic response. Therefore, they have been extensively applied in the industrial field. With the development of industry, various application scenarios have put forward higher requirements on the power density and torque density of industrial motors. However, in a conventional spoke-type built-in permanent magnet motor, magnetic leakage often occurs near the shaft surface inside the rotor, resulting in a decrease in the back electromotive force of the motor and a reduction in power density. SUMMARY TECHNICAL PROBLEM The main purpose of the present application is to provide a motor rotor and a motor, aiming to solve the problem of excessive magnetic leakage occurring near the shaft surface inside the rotor core of conventional spoke-type motors, which leads to a decrease in back electromotive force and power density, thereby improving the motor torque and power density and reducing torque ripples. TECHNICAL SOLUTION In order to achieve the above purpose, the present application provides a motor rotor, which includes a rotor core provided with a plurality of first magnet slots uniformly distributed along a circumferential direction of the rotor core. The first magnet slots extend in a radial direction, and a tangentially magnetized main permanent magnet is provided in the first magnet slot. A second magnet slot is provided between any two adjacent first magnet slots on the rotor core, and an auxiliary permanent magnet module is provided in the second magnet slot; the auxiliary permanent magnet module includes at least two first auxiliary permanent magnet units, and closest surface magnetic poles of any two adjacent main permanent magnets are identical. A magnetization direction of the first auxiliary permanent magnet unit includes a radial magnetization component, a direction of the radial magnetization component of the first auxiliary permanent magnet unit located between two main permanent magnets provided with magnetization directions facing each other is directed toward a stator along a radial direction of the rotor core, and a direction of the radial magnetization component of the first auxiliary permanent magnet unit located between two main permanent magnets provided with magnetization directions diverging from each other is directed toward a rotor axis along the radial direction of the rotor core. The magnetization direction of the first auxiliary permanent magnet unit includes a tangential magnetization component, and the tangential magnetization component of the first auxiliary permanent magnet unit is identical to a magnetization direction of the main permanent magnet adjacent to the first auxiliary permanent magnet unit. The magnetization direction of the main permanent magnet and the tangential magnetization direction of the first auxiliary permanent magnet unit both are tangential directions of a circle centered on the axis of the rotor core. In an embodiment, the at least two first auxiliary permanent magnet units include at least two auxiliary permanent magnets provided with at least one magnetization direction, or one auxiliary permanent magnet provided with at least two magnetization directions. In an embodiment, an angle between all magnetization directions or opposite directions of the magnetization directions in the auxiliary permanent magnet module and a center line of the second magnet slot along the radial direction of the rotor core is defined as α, and α is greater than or equal to 0° and less than or equal to 90°. In an embodiment, an angle between all magnetization directions or opposite directions of the magnetization directions in the auxiliary permanent magnet module and a center line of the second magnet slot along the radial direction of the rotor core is defined as α, and α is greater than or equal to 0° and less than or equal to 40°. In an embodiment, the auxiliary permanent magnet modules are symmetrically distributed about a center line of the second magnet slot along the radial direction of the rotor core, and an angle α of each of the first auxiliary permanent magnet units located on one side of the center line decreases gradually from a side distant from the center line toward a side adjacent to the ce