Commutator Insulation

Commutator Insulation

The micanite insulation between the commutator bars is to be recessed either by sawing out by hand or by using a commutator under-cutting machine. With older and small-sized motors used for hand tools or in household appliances, this under-cutting is not required  when using hard carbon or resin bonded grades due to it’s polishing action. The lamina edges of copper are to be chamfered in an angle of 45◦ to reach a trouble free commutation and a low brush abrasion. It is necessary to pay special attention to the laminas to prevent fine mica foils from clinging to them and standing out from the commutator surface.

 

Incorrect

Correct