Anti-friction bearing with speed measuring devices having an active

Abstract

An anti-friction bearing with a speed measuring device includes a transmitter for directing high frequency waves toward a side of the bearing and the transmitter being spaced from the bearing. A coding disk at the side of the bearing is arranged on the relatively rotatable ring. The coding disk has parts around the bearing at which the disk reflects the waves and other parts not reflecting or permitting passage of the waves. The waves are alternately reflected off the coding disk and not reflected off the disk to a receiver arranged outside the bearing. The resulting pulses may be fed to a signal processor. Variations include the coding disk having various constructional design features permitting or blocking the reflection of waves. Alternatively, a circuit at the stationary part of the bearing seal between the bearing rings is alternately impinged upon or protected from being impinged upon by waves due to the coding disk on the relatively movable part of the ring. Arrangements of a plurality of transmitters and/or receivers help detect the direction of rotation.