Insulating materials in motors

Definition of insulating materials: materials that can prevent the passage of current, whose volume resistivity is usually more than 109ΩNaN.

Types of insulating materials: Insulation boards, Insulated processed parts, Insulation Paper products etc...

The function of insulating materials: separate the charged part and the uncharged part or parts with different potentials from each other, so that the current can flow according to a certain path.

Motor: Electromagnetic mechanical equipment for energy conversion

The main materials used in motors: conductive materials (windings, commutators, brushes), insulating materials (electrically separate the charged parts from the grounding parts such as iron cores and chassis, and charged parts with different potentials) magnetic conductive materials (various parts of the magnetic system such as iron core, machine base, etc.).

Motor insulation structure: turn-to-turn insulation, inter-layer insulation, ground insulation, and wrapping insulation, filled insulation, liner insulation, commutator insulation.

1. Turn-to-turn insulation: inter-turn insulation of main pole coil and commutation pole coil, inter-turn insulation of armature coil, commutator sheet, inter-sheet insulation, insulation between turns of the same coil

2. Interlayer insulation: insulation between the layered flat-wound main pole coil, insulation between the front and rear end sections of the armature winding, the upper and lower layers in the slot, and the insulation between the upper and lower layers of the coil

3. Ground insulation: the insulation between the windings of the motor to the base and other non-charged parts, the ground insulation of the main pole coil commutation pole coil, the armature winding ground insulation, and the commutator ground insulation, which means to isolate the charged parts in the motor from the non-charged parts such as the base and iron core, so as to avoid breakdown to the ground.

4. Wrapping insulation: the insulation wrapped on the ground insulation, which is mainly used to protect the ground insulation from mechanical damage and also make the entire coil strong and smooth

5. Filled insulation: is used to fill the gap of the coil, making the whole coil more firm, reducing vibration, and making the coil well-shaped and smooth, so as to facilitate the  ground insulation and the heat dissipation.

6. Liner insulation: protect the insulation structure from mechanical damage during operation

Commutator insulation: insulation between the commutator segments, insulation between the commutator segments and the ground, V-shaped mica ring and mica sleeve between the commutator segments and the pressure ring, multi-layer high-quality shellac plastic mica

Insulation structure of stator bar conductor: row insulation, transposition insulation, transposition filling.

Insulation structure of hydro-generator rotor: turn-to-turn insulation, magnetic pole support plate, pole body insulation.