Patent ID: 7341321
Filing Date: 2008-03-11
Classification: B60T,F16C,G01P

Abstract:
1. A rotation detecting device which comprises: an electric power generator including a stator and a rotor, said rotor having a plurality of opposite magnetic poles alternating in a direction circumferentially of the rotor; at least a first magnetic sensor mounted on either the stator or a support member for supporting the stator and operable to detect the alternating magnetic poles of the opposite magnetic poles of said rotor, thereby forming a to-be-detected member; and an electric power supply circuit for utilizing an electric power generated by the electric power generator as an electric power source for the at least first magnetic sensor, wherein the stator includes a ring member made of a magnetic material and a coil accommodated in the ring member, said ring member having two sets of a plurality of claws provided at a portion of the ring member that confronts the rotor, the claws of the two sets extending in respective directions opposite to each other to be interleaved relative to each other while alternating one after another in a direction circumferentially of the ring member, the neighboring claws being spaced in the circumferential direction with a gap defined therebetween, and the ring member has a sensor window defined in a portion the circumference of the ring member accommodating the first magnetic sensor, said sensor window being defined by depleting some of the claws in the ring member.