Revolving speed detecting device with reduced eddy current loss

摘要

A revolving speed detecting device for use with a rolling contact bearing having a rotary ring and a fixed ring. It has a magnetic ring provided on the peripheral surface thereof with a plurality of teeth at equal pitches and mounted on the rotary bearing ring. A sensor made of soft ferrite or by laminating a plurality of silicon steel plates is mounted on the fixed bearing ring opposite to the teeth of the magnetic ring. A coil is wound around the sensor. A high-frequency voltage generator is connected to the coil. A detecting device for detecting the output voltage of the coil is also connected to the coil.