PHYSICAL QUANTITY MEASURING DEVICE OF ROLLING BEARING UNIT

PROBLEM TO BE SOLVED: To easily ensure positioning accuracy of an encoder 4a and sensors 8a, 8b while suppressing the replacement cost of the faulty sensors 8a, 8b, and realize a structure in which the diameter of an outer peripheral surface of an encoder body 10 of the encoder 4a which is a surface to be detected can be enlarged.SOLUTION: A sensor unit 12b in which both sensors 8a, 8b are held by a sensor holder 11b is detachably supported on a sensor support member 18 bonded and fixed onto the axial direction inner end part of an outer ring 1 which is a stationary ring. A sensor holding part 29 constituting the sensor unit 12b is arranged inside a cutout 21 formed in a supporting cylindrical part 19 configuring the sensor support member 18, so that the projection amount of the sensor holding part 29 from the inner peripheral surface of the supporting cylindrical part 19 is zero. Thereby, the diameter of the outer peripheral surface of the encoder body 10 is enlarged by making this diameter close to the diameter of the inner peripheral surface of the supporting cylindrical part 19.