SENSOR HOLDER, AND BEARING DEVICE ADAPTED FOR USE FOR WHEEL, HAVING ROTATION SPEED DETECTION DEVICE, AND INTEGRAL WITH THE SENSOR HOLDER

摘要

[PROBLEMS] A sensor holder capable of detecting a desired rotation speed with an air gap between an encoder and a rotation speed sensor maintained for a long period. [MEANS FOR SOLVING PROBLEMS] A rotary encoder (19) for detecting the rotation speed of a wheel is constructed from a rubber magnet formed by mixing magnetic powder in an elastomer and is circumferentially alternately magnetized by magnetic poles (N, S). A rotation speed sensor (20) has a magnetism detection element whose characteristics vary depending on the direction of flow of magnetic flux. The sensor holder (10) is constructed from a fitting ring (11) formed by press-forming a corrosion-resistant steel plate and from a holding section (12) formed of an injection-moldable synthetic resin and integrally molded with the fitting ring (11). The rotation speed sensor (20) is embedded in the holding section (12). At least that surface of the fitting ring (11) that is joined to the holding section (12) is roughened by shot blasting, and the roughness Ra of the surface is 0.8 or more.