Brushless motor rotor magnetic steel structure

Abstract

The invention discloses a brushless motor rotor magnetic steel structure. The brushless motor rotor magnetic steel structure comprises a rotating shaft, a rotor core and magnetic steel which are coaxially arranged. The rotating shaft passes through the shaft hole of the rotor core. Magnetic steel sleeved outside rotor core is annular, a magnetic steel cover is arranged between the magnetic steel and the rotating shaft; the magnetic steel cover is in clearance fit with the magnetic steel; the magnetic steel cover is in close fit with the rotating shaft, steps are arranged at the positions wherethe rotor core and the magnetic steel cover are in contact with the magnetic steel to fix the magnetic steel, the ends, not in contact with the magnetic steel, of the rotor core and the magnetic steel cover are connected with the bearing, the rotating shaft is sleeved with the bearing, and the brushless motor rotor magnetic steel structure is stable in magnetic field, high in matching precision,convenient to assemble and more durable.

Description

technical field [0001] The invention relates to the technical field of motors, in particular to a brushless motor rotor magnetic steel structure. Background technique [0002] Brushless motors use semiconductor switching devices to achieve electronic commutation, that is, electronic switching devices are used to replace traditional contact commutators and brushes. It has the advantages of high reliability, no commutation spark, low mechanical noise, etc. It is widely used in high-end recording sets, video recorders, electronic instruments and automated office equipment. As a part of the magnetic circuit of the brushless motor, the magnet steel is supplied with variable frequency power to the coil by the controller to generate a magnetic field to drive the motor to run. [0003] In the prior art, the magnetic steel adopts an assembled structure, which requires injection molding. During injection molding, the magnetic steel is easy to crack due to high temperature. When assem...

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Problems solved by technology

[0003] In the prior art, the magnetic steel adopts an assembled structure, which requires injection molding. During injection molding, the magnetic steel is easy to crack due to high temperature. When assembling, it needs to be pasted on the rotor core with glue. The glue is a chemical and has a pungent smell. There are certain hazards to the human body, and there are many processes. It is necessary to fix the magnetic steel with a clamp, so that the outer circumference of the magnetic steel should be on the same circumference as possible to ensure that the stator and rotor have a uniform air gap, and the rotor components (rotor core, magnetic Steel) placed in the oven at high temperature for 30 minutes to 1 hour to speed up the adhesion of the glue

In addition, when the complete machine of the brushless motor is subjected to the cold and thermal shock reliability test, because the magnet steel and the rotor core are tightly bonded together, the thermal expansion coefficients of the magnet steel and the rotor core are different, and the temperature drops or rises, and the magnet steel is prone to damage. cracking phenomenon

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