Electric motor with contra:rotating rotor and field magnetic system - has separate commutators for rotor and field system

摘要

The contra-rotating motor has a means of making the field system rotate in the opposite direction to the rotor. Both the field system and rotor has a commutating arrangement to selectively apply current to the excitation currents. The commutating arrangement consists of a ring on the field system allowing given windings to receive excitation current and a ring on the rotor allowing certain of its windings to be excited. The commutating arrangement can be adjusted manually by two rings that alter the phase shift between windings.