Rotating electric machine having a coil coaxial with rotating shaft

Abstract

A starter-generator of an automobile is disclosed which comprises a stationary field coil wound and disposed coaxially around the rotational axis. The rotor comprises a pair of field pole forming members on which circumferentially alternating field poles are excited by the magnetic flux generated by the field coil. Armature coils connected in Y-connection are disposed around the rotor, and the terminals of the armature coils are coupled to the inputs of a three-phase rectifier circuit (used when the starter-generator acts as a starting motor) and the outputs of a armature current switching circuit (used when the starter-generator acts as a charging generator) which controls the flow of current through the armature coils so that a rotating magnetic field is formed. The starter-generator further comprises a pair of auxiliary coils which are wound and disposed around the rotational axis at both sides of the armature in the neighborhood of the rotor. A current is supplied to these auxiliary coils in a direction opposite to that of the current supplied to the field coil. The current supplied to the auxiliary coils are regulated in response to the magnetic flux density detected by Hall elements positioned near the rotational axis, to minimize the flux in the neighborhood of the rotational axis.

Dependencies are inferred from the claim text.