The structure and working principle of hub motor

Working principle of hub motor:
The in-wheel motor is a motor embedded in the wheel, the stator is fixed on the tire, and the rotor is fixed on the axle. When the power is turned on, the stator and rotor move relative to each other. The electronic commutator (switching circuit) controls the order and time of energizing the stator windings according to the signal of the position sensor, generates a rotating magnetic field, and drives the rotor to rotate.
The structure of the hub motor:
1. Stator core
The stator core is the part of the motor's magnetic circuit on which the stator windings are placed.
*Semi-closed slot: The efficiency and power factor of the motor are high, but it is difficult to inlay and insulate the winding.
*Semi-open slot: It can be embedded with formed windings, generally used for large and medium-sized low-voltage motors.
*Open slot: used to embed the formed winding, the insulation method is convenient, and it is mainly used in high-voltage motors.
2. Stator winding
The stator winding is the circuit part of the motor, which is fed with three-phase alternating current to generate a rotating magnetic field. It consists of three identical windings that are spaced apart from each other by an electrical angle of 120° and arranged in teams.
*Ground insulation: the insulation between the stator winding as a whole and the stator core.
*Interphase insulation: the insulation between the stator windings of each phase.
*Turn-to-turn insulation: the insulation between the turns of each phase of the stator winding.
3. Base
The frame is usually made of cast iron, the frame of large asynchronous motor is generally welded with steel plate, the frame of micro motor is made of cast aluminum, and the stator core and front and rear end covers are fixed to support the rotor, and play the role of protection and heat dissipation.
4. Rotor core
The rotor core of the three-phase asynchronous motor is used as a part of the magnetic circuit of the motor and the rotor winding is placed in the core slot. The material used is the same as that of the stator. The outer circle of the silicon steel sheet is punched with evenly distributed holes for the placement of the rotor winding. Usually, the stator core is punched. The inner circle of the backward silicon steel sheet is used to punch the rotor core.
5. Rotor winding
The rotor winding of the three-phase asynchronous motor cuts the rotating magnetic field of the stator to generate induced electromotive force and current, and forms an electromagnetic torque to make the motor rotate. Divided into squirrel-cage rotors and wound-type rotors, wound-type motors have a more complex structure and are not as widely used as squirrel-cage motors.
*Squirrel-cage rotor: The rotor winding consists of multiple guide bars inserted into the rotor slots and two circular end rings.
*Wound rotor: The wound rotor winding is similar to the stator winding, and it is also a symmetrical three-phase winding. It is generally connected in a star shape. Circuit connection.