Permanent magnet for motor, rotor assembly having same, motor, and compressor
AssigneeAnhui Meizhi Precision Manufacturing Co., Ltd.
InventorsZhengzhong Qiao, Liyu Zheng, Xiaohua Qiu
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Abstract
A permanent magnet for a motor, a rotor assembly having the permanent magnet, a motor, and a compressor are disclosed. The permanent magnet has a Nd—Fe—B-based main phase. The main phase has a grain size of smaller than or equal to 4 micrometers. The mass ratio of dysprosium and/or terbium in the permanent magnet is less than or equal to 0.5%. The intrinsic coercivity Hcj of the permanent magnet at 25° C. satisfies Hcj≥1500 kA/m. The permanent magnet according to embodiments of the present disclosure can have fewer or no heavy rare-earth elements, and meanwhile exhibit excellent performance, which improves the cost performance.
Claims11
A permanent magnet for a motor, comprising:
- a main phase of neodymium iron boron, and
- dysprosium and/or terbium elements,
- wherein the main phase has a grain size of smaller than or equal to 1 micron, and the mass ratio of the dysprosium and/or terbium elements in the permanent magnet is equal to 0.5%, and
- wherein the permanent magnet has intrinsic coercivity Hcj at 25° C. that satisfies:
- Hcj≥1500 kA/m,
- wherein the permanent magnet further comprises gadolinium and/or holmium elements and the mass ratio of the gadolinium and/or holmium elements in the permanent magnet is equal to 0.5%, and
- wherein an area of a working surface of the permanent magnet is less than or equal to a product of a maximum length and a maximum width of the working surface of the permanent magnet.
Dependencies are inferred from the claim text.