Motor & Generator Commutator Segments

Lower quality Block Mica (Heavily Stained and Below) is used extensively as insulators between the copper commutator segments of all direct current and universal motors, especially those used in electric motor locomotives. The function of the commutator is to rectify the alternating current resulting from the rotating armature and to change it into direct current of a different frequency. Every direct current motor and generator requires 24 to 30 Mica segment insulating pieces in its commutator.This creates a market for millions of small Mica segment insulators in automotive, industrial, generator and motor applications each year. Many substitute materials have been tried as insulators for this application, but none have proved successful.Mica is the only known material with ample electrical resistance, dielectric strength and hardness capable of meeting the required insulating qualities under the great heat and pressure needed in the manufacture and operation of motors and generators.