Abstract: A rolling bearing unit has a rotational speed detection device which is comprised of a sensor having a yoke, a pair of permanent magnets and coil, and a tone wheal which is made by press-forming a magnetic metal plate so as to comprise a cylindrical support base secured onto an end portion of the bearing unit, a ring-shaped first detecting part which is bent radially outward from the inner rim of the cylindrical support base, and a cylindrical shaped second detecting part which extends axially from the outer peripheral rim of the first detecting part the first and second detecting parts having a ferro-magnetic first portion and a non-magnetic second portion, and the yoke having opposite ends to be faced to the first and second portions, and the permanent magnets being faced to each other so that magnetic fluxes flow alternatively through the yoke corresponding the rotation of the tone wheel.

Abstract: A rolling bearing unit has a rotational speed detection device which has a sensor having a yoke, a pair of permanent magnets, a coil, and a tone wheel. The tone wheel is made by press-forming a magnetic metal plate so as to form a cylindrical support base secured onto an end portion of the bearing unit. The tone wheel has a ring-shaped first detecting part which is bent radially outward from the inner rim of the cylindrical support base, and a cylindrical shaped second detecting part which extends axially from the outer peripheral rim of the first detecting part. The first and second detecting parts have a ferro-magnetic first portion and a non-magnetic second portion, and the yoke has opposite ends which are faced to the first and second portions. The permanent magnets have like poles faced toward each other so that magnetic fluxes flow alternately through the yoke corresponding to the rotation of the tone wheel.

Abstract: A rolling bearing unit with a rotating speed sensor comprising a hub having a flange for mounting a vehicle wheel and an inner ring raceway, an outer ring having a mount portion for supporting a suspension apparatus and an outer ring raceway, a plurality of rolling members between the inner ring raceway and the outer ring raceway, a sensor supported by the outer ring, a tone wheel mounted to the hub so as to be faced to the sensor, an annular support frame having a cylindrical mount portion, a flanged portion and a support portion, the cylindrical mount portion fitted onto the outer ring, the flanged portion bent inwards at right angles at an edge of the mount portion and having a side face, the support portion having a circumferential end face and projected from the side face of the flanged portion, and a conductive member projected from the circumferential end face of the support portion to output signals from the sensor, the circumferential end face of the support portion and part of the flanged portion co

Abstract: An electromagnetic rotation sensor for detecting a rotational speed of a rotating member includes a sensor portion and a connector portion which are molded of a resin to provide a resin-molded structure. The resin-molded structure is received in a cover, with the connector portion extending outwardly from the cover through a sensor portion-positioning hole formed through a wall of the cover. In order to prevent a positional displacement of the sensor portion with respect to a detection gear, connected to the rotating member, when fixedly mounting the cover on the resin-molded structure, a primary molded portion is molded to provide the sensor portion, and then the primary molded portion is inserted into the cover, and then a secondary molded portion is molded to form the connector portion on the primary molded portion in such a manner that a peripheral edge portion of the sensor portion-positioning hole is fixedly held between the primary molded portion and the secondary molded portion.