The Structure Of Electric Bicycle Motor

The structure of the Electric Bicycle Motor


1. Permanent magnet DC motor:

It consists of stator poles, rotors, brushes, shells, etc.

The stator poles are made of permanent magnets (permanent magnet steel), including ferrite, AlNiCo, NdFeB, and other materials. According to its structure, it can be divided into cylindrical type and tile types.

The rotor is generally made of laminated silicon steel sheets, and the enameled wire is wound between two slots of the rotor core (three slots have three windings), and each joint is welded to the metal sheet of the commutator.

The brush is a conductive part that connects the power supply and the rotor winding, and has both electrical conductivity and wear resistance.

The brushes of the permanent magnet motor use single metal sheets or metal graphite brushes and electrochemical graphite brushes.

2. Brushless DC motor:

It consists of a permanent magnet rotor, multi-pole winding stator, position sensor, etc. The brushless DC motor is characterized by brushless, which uses semiconductor switching devices (such as Hall elements) 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 sparks, and low mechanical noise.

According to the change of the rotor position, the position sensor commutates the current of the stator winding along a certain order (that is, detects the position of the rotor magnetic pole relative to the stator winding and generates a position sensing signal at the determined 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 consists of a stator iron core, magnetic steel rotor, sun gear, reduction clutch, hub shell, etc.
A hall sensor can be installed on the motor cover to measure the speed.

There are three types of position sensors: magnetic, photoelectric, and electromagnetic.

A brushless DC motor using a magneto-sensitive position sensor, its magneto-sensitive sensor devices (such as Hall elements, magneto-sensitive diodes, magneto-sensitive pole tubes, magneto-sensitive resistors or special integrated circuits, etc.) To detect changes in the magnetic field generated by the rotation of permanent magnets and rotors. Electric vehicles mostly use Hall elements.

The brushless DC motor using the photoelectric position sensor is equipped with photoelectric sensor devices at a certain position on the stator assembly, the rotor is equipped with a shading plate, and the light source is a light-emitting diode or a small light bulb. When the rotor rotates, due to the action of the shading plate, the photosensitive components on the stator will intermittently generate pulse signals at a certain frequency.

The brushless DC motor with an electromagnetic position sensor is equipped with electromagnetic sensor components (such as a coupling transformer, proximity switch, LC resonance circuit, etc.) on the stator assembly. When the position of the permanent magnet rotor changes, the electromagnetic effect will make the electromagnetic sensor A high-frequency modulated signal is generated (the amplitude of which varies with rotor position).

The operating voltage of the stator winding is provided by an electronic switching circuit controlled by the output of the position sensor.