Patent ID: 7216551
Filing Date: 2007-05-15
Classification: F16C,G01L,G01P

Abstract:
1. A sensor-equipped antifriction bearing unit comprising: an antifriction bearing having a fixed-side raceway member; a rotation-side raceway member; rolling bodies arranged between the two members; and a sensor device provided on the antifriction bearing, wherein the sensor device includes a magnetostrictive sensor provided on the fixed-side raceway member configured to detect at least one variation in a gap between the sensor and the rotation-side raceway member, and a processor configured to process the output of the magnetostrictive sensor, the processor comprising a rotation detecting unit configured to determine the speed of rotation of the rotation-side raceway member from the number of repetitions of at least one variation in the output of the magnetostrictive sensor, the at least one variation in the gap are due to the eccentricity of the rotation-side raceway member relative to the fixed-side raceway member.