1. Permanent magnet DC motor:
It is composed of stator poles, rotor, brushes, housing, etc.
The stator poles use permanent magnets (permanent magnetic steel), including ferrite, AlNiCo, NdFeB and other materials. According to its structure, it can be divided into cylinder type and tile type.
The rotor is generally made of laminated silicon steel sheets, and the enameled wire is wound between the two slots of the rotor core (three slots means three windings), and its joints are respectively welded to the metal sheets of the commutator.
The brush is a conductive part that connects the power supply and the rotor winding. It has both conductive and wear-resistant properties. The brushes of permanent magnet motors use single-sex metal sheets, metal graphite brushes, and electrochemical graphite brushes.
2. Brushless DC motor:
The position sensor commutates the current of the stator winding in a certain order according to the change of the rotor position (that is, detects the position of the rotor pole relative to the stator winding, and generates a position sensing signal at a certain position, which is processed by the signal conversion circuit. Control the power switch circuit and switch the winding current according to a certain logical relationship).
3. High-speed permanent magnet brushless motor:
It is composed of stator core, magnetic steel rotor, sun gear, deceleration clutch, hub shell, etc.
There are three types of position sensors: magnetic sensitive, photoelectric and electromagnetic.
For brushless DC motors using magnetic-sensitive position sensors, the magnetic-sensitive sensor components (such as Hall elements, magneto-sensitive diodes, magneto-sensitive pole tubes, magneto-sensitive resistors or application-specific integrated circuits, etc.) are installed on the stator assembly. To detect the change of the magnetic field generated when the permanent magnet and the rotor rotate. Hall elements are commonly used in electric vehicles.
The working voltage of the stator winding is provided by an electronic switch circuit controlled by the output of the position sensor.