Patent ID: 7034524

Claim:
A device for measuring the angle of rotation of a rotating member of a machine, comprising a signal transmitting rotor which includes a magnet rim consisting of magnets having alternatingly arranged south poles and north poles and being moved with respect to a stationary measuring sensor, characterized in that each magnet has a thickness which varies substantially sinusoidally in a circumferential direction, and where each magnet has its maximum thickness at its pole center, wherein the magnet rim is mounted on a peripheral surface of a support ring of the signal transmitting rotor, and that the measuring sensor is disposed radially with respect to the magnet rim, wherein the magnet rim is adhered to a substantially sinusoidally undulated peripheral surface of the support ring, and that the variation in thickness of the magnets is achieved by bulging of the magnets into a plurality of wave troughs formed by the undulated peripheral surface of the support ring.