Permanent magnet motor and electric tool and mower utilizing the same

Abstract

The invention relates to a permanent magnet motor. The permanent magnet motor comprises a stator and a rotator arranged in the stator, wherein the rotator comprises a plurality of permanent magnets which are arranged at intervals along the circumferential direction of the rotator, the permanent magnets are made of ferrite materials and are polarized along the circumferential direction of the rotator, the cross section of each permanent magnet is trapezoid, the edge, close to the center of the rotator, of each permanent magnet is the short edge of the trapezoid, and the edge, far away from the center of the rotator, of each permanent magnet is the long edge of the trapezoid. The motor is an 8-pole 9-groove motor, and is in a multi-pole built-in-type magnetic concentrating structure, so that the gap flux density of the motor is larger than the flux density of the surfaces of the permanent magnets, the gap flux density of the motor is largely improved, and therefore the motor with high power density and high torque density is obtained through the ferrite materials. A fragmentation rotator structure is adopted, so that magnetic flux leakage of a magnetic bridge is eliminated, the torque density of the motor is further improved, and the torque density of the ferrite motor reaches or approaches to the torque density of a surface mounted rare earth permanent magnet motor. The invention further provides an electric tool and a mower utilizing the permanent magnet motor.

Description

technical field [0001] The invention relates to a permanent magnet motor, in particular to a permanent magnet motor applied to occasions such as electric tools and lawn mowers with relatively high speed. Background technique [0002] The electric tool product is a portable or mobile production tool that is driven by an electromagnetic rotary or reciprocating small-capacity motor through a transmission mechanism to drive the operating device (working head). Power tools are easy to carry, easy to operate, versatile, safe and reliable, etc., can greatly reduce labor intensity, improve work efficiency, and realize manual mechanization, so they are widely used in construction, housing decoration, automobiles, machinery, electricity, bridges, Horticulture and other departments. [0003] Motors for electric tools pursue small size, light weight, and high output power, that is, high power density and high torque density. To achieve this purpose, existing electric tools generally a...

AI Technical Summary

Problems solved by technology

However, with the straight-up price of rare earth materials, the cost of the motor is unacceptable

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