What are the construction and classification of DC motors?
time：2012/12/27 click：7843
What are the construction and classification of DC motors?
1. Brushless DC motor: Brushless DC motor exchanges the stator and rotor of an ordinary DC motor. Its rotor is a magnet to generate an air gap flux: the stator is an armature and consists of a multiphase winding group. Structurally, it is similar to a permanent magnet synchronous motor. The structure of the stator of the brushless DC motor is the same as that of an ordinary synchronous motor or induction motor. A multi-phase winding(three-phase, four-phase, five-phase, etc.) is embedded in the core. The winding can be connected to a star or triangle and is connected to each power tube of the inverter. For a proper phase change. Rotors mostly use rare earth materials such as cobalt or neodymium iron boron, which are highly rigid and have high residual magnetic density. Due to the different positions of magnetic materials in the magnetic poles, they can be divided into surface magnetic poles, embedded magnetic poles, and circular magnetic poles. Since the motor body is a permanent magnet motor, it is customary to call a brushless DC motor also a permanent magnet brushless DC motor.
2. Brush-DC motor: The two brushes(copper brush or carbon brush) with a brush motor are fixed on the rear cover of the motor through an insulating seat to directly introduce the positive and negative poles of the power supply to the phase changer of the rotor, and the phase changer Connects the coil on the rotor, The alternating polarity of the three coils rotates with the force of the two magnets fixed on the shell. Since the phase changer is fixed with the rotor and the brush is fixed with the housing(stator), the constant friction between the brush and the phase changer during the motor rotation produces a lot of resistance and heat. Therefore, the efficiency of the brush motor is very low and the loss is very large. However, he also has the advantages of simple manufacturing, cost and low cost!
Linear motor