Rolling bearing unit with rotating speed detector

A rolling bearing unit with rotating speed detector comprising a non-rotating outer ring member having an opening end and an inner peripheral face formed with an outer raceway, a rotating inner ring member made of a magnetic material and having an end face and an outer peripheral face formed with an inner raceway, a plurality of rolling bodies provided between the outer raceway and the inner raceway, a cover securely fitted over the opening end of the outer ring member, an annular sensor supported inside the cover, and a rotating tone wheel made of a magnetic material and supported by the inner ring member,

• the cover provided with a cylinder portion having an end opening portion and a base end portion securely fitted over the opening end of the outer ring member,
• the sensor comprising a magnetic pole piece having a central portion and supported by the cover in a coaxial relationship with the inner ring member, a permanent magnet axially magnetized for magnetic flux and having a first end face in magnetic orientation close to the central portion of the pole piece and a second end face in magnetic orientation magnetically connected to the end face of the inner ring member so as to provide a closed magnetic circuit loop of lowest magnetic resistance, and a coil enclosed by said closed magnetic circuit loop and having a smaller diameter than the tone wheel, the tone wheel having a first cutout section with a plurality of first cutouts circumferentially formed with a pitch, and the pole piece having a second cutout section with a plurality of second cutouts with the same pitch to that of the first cutouts.

A rolling bearing unit with rotating speed detector comprising a non-rotating outer ring member having an opening end and an inner peripheral face formed with an outer raceway, a rotating inner ring member made of a magnetic material and having an end face and an outer peripheral face formed with an inner raceway, a plurality of rolling bodies provided between the outer raceway and the inner raceway, a cover securely fitted over the opening end of the outer ring member, an annular sensor supported inside the cover, and a rotating tone wheel made of a magnetic material and supported by the inner ring member,

• the cover provided with a cylinder portion having an end opening portion and a base end portion securely fitted over the opening end of the outer ring member,
• the sensor comprising a magnetic pole piece having a central portion and supported by the cover in a coaxial relationship with the inner ring member, a permanent magnet axially magnetized for magnetic flux and having a first end face in magnetic orientation in contact with the central portion of the pole piece and a second end face in magnetic orientation magnetically connected to the end face of the inner ring member so as to provide a closed magnetic circuit loop of lowest magnetic resistance, and a coil enclosed by said closed magnetic circuit loop and having a smaller diameter than the tone wheel, the tone wheel having a first cutout section with a plurality of first cutouts circumferentially formed with a pitch, and the pole piece having a second cutout section with a plurality of second cutouts with the same pitch to that of the first cutouts.

A rolling bearing unit with rotating speed detector comprising a non-rotating outer ring member having an opening end and an inner peripheral face formed with an outer raceway, a rotating inner ring member made of a magnetic material and having an end face and an outer peripheral face formed with an inner raceway, a plurality of rolling bodies provided between the outer raceway and the inner raceway, a cover securely fitted over the opening end of the outer ring member, an annular sensor supported inside the cover, and a rotating tone wheel made of a magnetic material and supported by the inner ring member,

• the cover provided with a cylinder portion having an end opening portion and a base end portion securely fitted over the opening end of the outer ring member,
• the sensor comprising at least one magnetic pole piece having a central portion and supported by the cover in a coaxial relationship with the inner ring member, a permanent magnet of a disc shape located spaced away from the inner ring member, magnetized for magnetic flux and having a first end face in magnetic orientation magnetically connected to the pole piece and a second end face in magnetic orientation magnetically connected to the tone wheel so as to provide a closed magnetic circuit loop of lowest magnetic resistance, and a coil enclosed by said closed magnetic circuit loop and having a smaller diameter than the tone wheel, the tone wheel having a first cutout section with a plurality of first cutouts circumferentially formed with a pitch, and at least one pole piece having a second cutout section with a plurality of second cutouts with the same pitch to that of the first cutouts.

A rolling bearing unit with rotating speed detector comprising a non-rotating outer ring member having an opening end and an inner peripheral face formed with an outer raceway, a rotating inner ring member made of a magnetic material and having an end face and an outer peripheral face formed with an inner raceway, a plurality of rolling bodies provided between the outer raceway and the inner raceway, a cover securely fitted over the opening end of the outer ring member, an annular sensor supported inside the cover, and a rotating tone wheel made of a magnetic material and supported by the inner ring member,

• the cover comprising a cylinder portion and a bottom plate portion, the cylinder portion having an end opening portion and a base end portion securely fitted over the opening end of the outer ring member, and the bottom plate portion adapted to cover the end opening portion of the cylinder portion,
• the sensor comprising a magnetic pole piece having a central portion and supported by the bottom plate portion in a coaxial relationship with the inner ring member, a permanent magnet axially magnetized for magnetic flux and having a first end face in magnetic orientation in contact with the central portion of the pole piece and a second end face in magnetic orientation magnetically connected to the end face of the inner ring member so as to provide a closed magnetic circuit loop of lowest magnetic resistance, and a coil enclosed by said closed magnetic circuit loop and having a smaller diameter than the tone wheel, the tone wheel having a first cutout section with a plurality of first cutouts circumferentially formed with a pitch, and the pole piece having a second cutout section with a plurality of second cutouts with the same pitch to that of the first cutouts.

A rolling bearing unit with rotating speed detector comprising a non-rotating outer ring member having an opening end and an inner peripheral face formed with an outer raceway, a rotating inner ring member made of a magnetic material and having an end face and an outer peripheral face formed with an inner raceway, a plurality of rolling bodies provided between the outer raceway and the inner raceway, a cover securely fitted over the opening end of the outer ring member, an annular sensor supported inside the cover, and a rotating tone wheel made of a magnetic material and supported by the inner ring member,

• the cover comprising a cylinder portion and a bottom plate portion, the cylinder portion having an end opening portion and a base end portion securely fitted over the opening end of the outer ring member, and the bottom plate portion adapted to cover the end opening portion of the cylinder portion,
• the sensor comprising at least one magnetic pole piece having a central portion and supported by the bottom plate portion in a coaxial relationship with the inner ring member, a permanent magnet of a disc shape located axially spaced from the inner ring member, magnetized for magnetic flux and having a first end face in magnetic orientation magnetically connected to the pole piece and a second end face in magnetic orientation magnetically connected to the tone wheel so as to provide a closed magnetic circuit loop of lowest magnetic resistance, and a coil enclosed by said closed magnetic circuit loop and having a smaller diameter than the tone wheel, the tone wheel having a first cutout section with a plurality of first cutouts circumferentially formed with a pitch, and at least one pole piece having a second cutout section with a plurality of second cutouts with the same pitch to that of the first cutouts.

A rolling bearing unit with rotating speed detector comprising a non-rotating outer ring member having an opening end and an inner peripheral face formed with an outer raceway, a rotating inner ring member made of magnetic material and having an end face and an outer peripheral face formed with an inner raceway, a plurality of rolling bodies provided between the outer raceway and the inner raceway, a cover securely fitted over the opening end of the outer ring member, an annular sensor supported inside the cover, and a rotating tone wheel made of magnetic material and supported by the inner ring member,

• the sensor comprising at least one magnetic pole piece positioned coaxially with the inner ring member, a permanent magnet in the form of a closed disk positioned coaxially with the inner ring member and axially magnetized for magnetic flux with a first axial end face in magnetic orientation positioned adjacent the pole piece and a second axial end face in magnetic orientation magnetically connected to the tone wheel so as to provide a closed magnetic circuit loop of lowest magnetic resistance, and a coil positioned adjacent said permanent magnet and enclosed by said closed magnetic circuit loop and having a smaller diameter than the tone wheel, the tone wheel having a first cutout section with a plurality of first cutouts circumferentially formed with a pitch, and the pole piece having a second cutout section with a plurality of second cutouts with the same pitch to that of the first cutouts.