A permanent magnet DC motor

Abstract

The invention relates to a permanent magnet direct current motor comprising: the inside of a shell of the motor is provided with a stator and a rotor, a stator core is provided with a winding coil, a rotor rotating shaft is provided with a magnetic core folded by discoid copper sheets. The periphery of the magnetic core is fixed with a rotor magnetic tile and the motor is provided with sensor magnetic steel and a position sensing element of a hall element. The sensor magnetic steel is arranged in a magnetic steel seat which is fixed on the motor rotating shaft extending out of an end cover and the sensor magnetic steel and the hall element are arranged in a cavity consisting of the end cover and a dust cover. As the magnetic steel seat is fixed on the motor rotating shaft extending out of the end cover, the permanent magnet DC motor is not interfered by the outside, so an electronic reversing signal of the motor is not interfered by the machining precision of the rotor and the armature current. The position sensing element is only influenced by the environment temperature, thereby leading the motor to work more stably.

Description

Technical field: [0001] The invention relates to a permanent magnet DC motor. Background technique: [0002] At present, there are many structures of various permanent magnet brushless DC motors. For example, Chinese Patent No. 03249962.0 proposes an "inner rotor permanent magnet brushless DC motor". The inner rotor permanent magnet brushless DC motor includes: a motor stator, a rotor, an end cover and a position sensing element. The above-mentioned stator includes a stator core, an end ring, a rivet and a winding, wherein the stator core and the end ring are connected by a rivet. The outer circle of the stator iron core is the shell of the motor; the rotor is composed of the motor shaft and the rotor magnetic tile to form the inner rotor, wherein the rotor magnetic tile is fixed on the outer circle of the motor shaft, and the rotor magnetic tile outer circle is wound with a latitude-free tape. But there are following deficiencies: [0003] 1. Since the position sensing e...

AI Technical Summary

Problems solved by technology

[0003] 1. Since the position sensing element is located in the casing, the electronic commutation signal of the motor is easily affected by the machining accuracy of the rotor, the interference of the armature current, and the temperature in the casing, which makes the working stability of the motor unsatisfactory.

[0004] 2. The sensor magnetic steel in the position sensing element adopts an integral structure, and the boundary lines of each magnetic field are not clear, which may easily cause inaccurate commutation of the motor and affect the working performance of the motor

[0005] 3. Since the magnetic pole of the motor adopts the integral magnetic pole, the eddy current generated by the integral magnetic pole in the working process is large, which makes the temperature rise of the rotor large

When the overall magnetic pole volume is large, the mechanical strength of the magnetic pole is not ideal

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