Bearing rotary speed sensor with concentric multipole magnetic rings axially aligned with collector branches

A roller bearing comprising a rotating race, a non-rotating race, and bearing elements between said races;

• said roller bearing being equipped with a sensor device for sensing a speed of rotation of the rotating race relative to the non-rotating race, said sensor device comprising:
• a coder element which is rigid with said rotating race of the bearing, said coder element having two axially magnetized concentric multipole rings which are means for producing an alternating magnetic field while rotating, and
• a sensor element which is rigid with said non-rotating race of the bearing, said sensor element having a magnetic flux concentrator and an induction coil which is coaxial with the multipole rings, said magnetic flux concentrator having two collector branches for concentrating magnetic flux generated by the multipole rings to the induction coil, said collector branches having diameters which are substantially the same as their respective multipole rings, said collector branches each axially facing a respective one of said multipole rings and being spaced therefrom by an air gap.

A roller bearing comprising a rotating race, a non-rotating race, and bearing elements between said races;

• said roller bearing being equipped with a sensor device for sensing a speed of rotation of the rotating race relative to the non-rotating race, said sensor device comprising:
• a coder element which is rigid with said rotating race of the bearing, said coder element having two axially magnetized concentric multipole rings which are means for producing an alternating magnetic field while rotating, said coder element including an annular flange with fastening areas for the multipole rings and a tubular part fitted onto the rotating race of the bearing, said multipole rings being formed of a molded material loaded with particles of a magnetizable material which is molded over the flange,
• a sensor element which is rigid with said non-rotating race of the bearing, said sensor element having a magnetic flux concentrator and an induction coil which is coaxial with the multipole rings, said magnetic flux concentrator having two collector branches for concentrating magnetic flux generated by the multipole rings to the induction coil, said collector branches having diameters which are substantially the same as their respective multipole rings, said collector branches each axially facing a respective one of said multipole rings and being spaced therefrom by an air gap.