Stator (stationary part)
1. Stator core
Function: a part of the magnetic circuit of the motor, and the stator winding is placed on it.
Structure: stator core is usually made by punching and stacking the silicon steel sheet with insulation layer on the surface of 0.35~0.5 millimeter thick, and punching evenly distributed slot inside the core, so as to embed the stator windings.
The stator core groove type has the following several kinds:
Half closed groove: the efficiency and power factor of the motor are high, but the winding and insulation of the winding are difficult. It is generally used in small low voltage motor.
Half open slot: can be embedded and formed winding, generally used for large and medium low voltage motor. The so-called forming windings, that is, can be placed in the slot in advance after the insulation is treated.
Open slot: it is used to inlay the forming winding, and the insulation method is convenient. It is mainly used in the high voltage motor.
2. Stator windings
Function: it is the circuit part of the motor, which passes into the three-phase alternating current and produces the rotating magnetic field.
The structure is made up of three identical structures with the same structure in the space of 120 degrees, which are arranged in the same space. The coils of these windings are embedded in each slot of the stator according to certain rules.
There are three main insulation projects for stator windings: (ensuring reliable insulation between the conductive parts of the winding and the core and reliable insulation between the winding itself).
(1) to the ground insulation: the insulation between the stator winding and the stator core.
(2) interphase insulation: the insulation between the stator windings of each phase.
(3) interturn insulation: insulation between each phase of the stator winding in each phase.