Application of Insulating Material in Electric Machine
- By : Insulation Materials
Application of insulating material in electric machine:
1. Insulating material in the motor: the material that can prevent the current from passing through. The volume resistivity is usually greater than 109 Ω. Cm
2. Function of insulating material: isolate the live part from the uncharged part or the part with different potential, so that the current can flow in a certain path.
3. Motor: electromagnetic mechanical equipment for energy conversion
4. Motor classification: transformer, DC motor, AC motor, control motor, pulse current motor
5. Basic structure of motor: static part (stator): generate magnetic field, form magnetic circuit, mechanical support. Clearance (air gap): an important part of the magnetic circuit to ensure the safe operation of the motor, the rotating part (rotor): induction potential, electromagnetic torque, energy conversion.
Stator structure: frame, main magnetic pole, commutator, end cover, brush device. Rotor structure: shaft, armature core, armature winding, commutator.
6. Armature winding: it is composed of a certain number of armature coils connected according to certain rules; it is the circuit part of DC motor, and also the part that generates electromotive force and electromagnetic torque for electromechanical energy conversion.
7. Main insulation materials used for manufacturing the motor: conductive materials (winding, commutator, brush), insulating materials (separating the live parts from the grounding parts such as iron core, machine base and the live parts with different potential electrically), magnetic conducting materials (manufacturing various parts of the magnetic system such as iron core, machine base, etc.).
8. Insulation structure of motor: turn to turn insulation, layer to layer insulation, ground insulation, outsourcing insulation. There are also three, filled insulation, pad insulation, commutator insulation.
Turn to turn insulation: turn to turn insulation of main pole coil and reversing pole coil, turn to turn insulation of armature coil, reversing piece, piece to piece insulation, and insulation between wire turns of the same coil.
Interlayer insulation: the insulation between the layers of the main pole coil, the front and rear end sections of the armature winding, the upper and lower layers of the inner part of the slot, and the upper and lower layers of the coil.
Insulation to ground: refers to the insulation between each winding of the motor and the base and other uncharged parts, the insulation between the commutation pole coil of the main pole coil and the ground, the insulation between the armature winding and the ground, and the insulation between the commutator and the live parts of the motor and the base, iron core and other uncharged parts, so as to avoid breakdown to the ground.
External insulation: the insulation wrapped outside the ground insulation is mainly used to protect the ground insulation from mechanical damage and make the whole coil solid and flat, which also plays a reinforcing role in the ground insulation.
Filling insulation: fill the gap of the coil, make the whole coil form a whole firmly, reduce the vibration, and make the coil forming regular and flat, so as to facilitate the binding of the insulation to the ground and the heat dissipation
Pad insulation: protect the insulation structure from mechanical damage during process operation.
Commutator insulation: Commutator insulation commutator, commutator group to ground insulation, V-shaped mica ring and mica sleeve between commutator group and compression ring, multi-layer high-quality shellac plastic mica.
9. Stator bar conductor insulation: row insulation, transposition insulation, transposition filling.
10. Rotor insulation of Hydrogenerator: turn to turn insulation, pole plate, pole body insulation.