1, magnetic field properties. The permanent magnet motor can maintain the magnetic field without external energy after it is made; Ordinary motors need current to generate magnetic fields.
2. Rotor structure. A permanent magnet pole is arranged on the rotor of the permanent magnet motor; The excitation coil is installed on the rotor of a common motor.
3. Applicable occasions. Permanent magnet motors are usually used in low power occasions; Ordinary motors, especially excitation motors, are often used in high-power occasions.
Features:
Permanent magnet motor is a kind of rectangular pulse wave, sine wave current and hybrid permanent magnet motor. Simple structure, high reliability and high efficiency.
Ordinary motors have fast response and large starting torque, and can provide rated torque from zero speed to rated speed.
Brief introduction of permanent magnet motor;
Permanent magnet DC motor is also composed of stator pole, rotor, brush and shell. The stator poles are permanent magnets (permanent magnet steel) made of ferrite, Al-Ni-Co, NdFeB and other materials. According to its structural form, it can be divided into cylinder type and tile type. Most of the electric motors used in tape recorders are cylindrical magnets, while most of the motors used in electric tools and automobile appliances are special block magnets.
The rotor is generally made of silicon steel sheets laminated, which has fewer slots than the rotor of electromagnetic DC motor. Most of the low-power motors used in tape recorders have three slots, and the high-end ones have five slots or seven slots. The enameled wire is wound between two slots of the rotor core (three slots have three windings), and its joints are welded on the metal sheet of the commutator respectively. Brush is a conductive component connecting power supply and rotor winding, which has both conductive and wear-resistant properties. The brush of permanent magnet motor adopts neutral metal sheet or metal graphite brush and electrochemical graphite brush.