Patent ID: 7030532

Claim:
A variable reluctance resolver wherein angular position is determined by detection of permeance between a rotor pole and a stator pole, the resolver comprising: a rotor and a stator wherein the rotor includes a noncircular core of magnetic material which is rotatably supported inside the stator with a magnetic gap therebetween, said noncircular core including a central circular portion having a circular inner periphery, and a plurality of salient poles protruding from the central circular portion, wherein each salient pole of the rotor has a center which is offset by a prescribed offset distance in the radial direction from the center of the rotor, and the outer peripheral shape of each salient pole comprises an arc of a circle of radius r which is centered on the center of the salient pole and which does not extend to the inner peripheral surface of the stator, wherein a shape of said rotor is such that a permeance of the magnetic gap varies according to a sine function for the rotational angle and said offset distance.