Magnetic path structure of outer rotor permanent magnet brushless motor and assembly method of outer rotor permanent magnet brushless motor

Abstract

The invention discloses a magnetic path structure of an outer rotor permanent magnet brushless motor. The magnetic path structure comprises a stator and a rotor, wherein the stator comprises a stator core, a winding and a shaft, wherein the shaft and the stator core are in tight fit for supporting the stator; the rotor comprises a rotor core, magnetic steel and a machine case; the machine case and the rotor core are in tight fit for mechanical output; the magnetic path structure is characterized in that the rotor core comprises a plurality of symmetrical magnetic steel tanks; and a bump is reserved between two adjacent magnetic steel tanks and is used for positioning the magnetic steel.

Description

technical field [0001] The invention relates to an outer rotor permanent magnet brushless motor, in particular to a magnetic circuit structure and an assembly method of the outer rotor permanent magnet brushless motor. Background technique [0002] Existing outer rotor permanent magnet brushless motors generally use the motor casing as the mechanical output end, such as electric bicycle hub motors, traction machines, fan motors, and electric actuators. Staggered and pasted on the inner circle of the casing, but due to the limitation of processing technology, the size of the magnetic steel has a certain tolerance range, and there will be a certain gap between two adjacent magnetic steels, because the polarity of the adjacent two magnetic steels is opposite , when installing, two adjacent magnets will be attracted together, and there will be no gap between the end faces, resulting in a relatively large gap between the last magnet and the first magnet, then the last magnet and ...

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Problems solved by technology

[0002] Existing outer rotor permanent magnet brushless motors generally use the motor casing as the mechanical output end, such as electric bicycle hub motors, traction machines, fan motors, and electric actuators. Staggered and pasted on the inner circle of the casing, but due to the limitation of processing technology, the size of the magnetic steel has a certain tolerance range, and there will be a certain gap between two adjacent magnetic steels, because the polarity of the adjacent two magnetic steels is opposite , when installing, two adjacent magnets will be attracted together, and there will be no gap between the end faces, resulting in a relatively large gap between the last magnet and the first magnet, then the last magnet and the first The electrical deviation of a piece of magnetic steel reaches the maximum. For occasions that require high control position accuracy, such as servo, electric execution, etc., it will greatly affect the control accuracy and system performance. This processing technology can no longer meet the use requirements; At the same time, since the casing is used as the rotor yoke, the material of the casing is usually required to be a material with high magnetic permeability such as electrical pure iron, No. 10 steel or No. 20 steel, and the mechanical strength and processability of these materials are not very good. , which is not conducive to the processing of the casing and the output and utilization of motor power

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