Rolling bearing with rotation sensor

Abstract

A compact rolling bearing with a rotation sensor is proposed which has a shortened axial length of a housing for mounting the rotation sensor. The rolling bearing comprises a rotating bearing ring and a fixed bearing ring, and the rotation sensor comprises a rotating element mounted to the rotating bearing ring and a detecting element mounted on the fixed bearing ring so as to oppose the rotating element, and an electric circuit board. The electric circuit board has a flexibility. With this arrangement, it is possible to mount the electric circuit board in a curved state in a limited space on a peripheral wall of the sensor housing, and thus to shorten the axial length of the sensor housing. This provides a compact rolling bearing with the rotation sensor. Another embodiment has a magnetic encoder, the binder for which is heat-resistant nitrile rubber, fluorine rubber or silicone rubber.

What is claimed is:  
     
         1 . A rolling bearing with a rotation sensor, said rolling bearing comprising a rotating bearing ring and a fixed bearing ring, said rotation sensor comprising a rotating element mounted to said rotating bearing ring, a detecting element mounted on said fixed bearing ring so as to oppose said rotating element, and an electric circuit board, characterized in that said electric circuit board has a flexibility.  
     
     
         2 . A rolling bearing with a rotation sensor as claimed in  claim 1  wherein said electric circuit board is formed of a plastic film.  
     
     
         3 . A rolling bearing with a rotation sensor as claimed in  claim 1  or  2  wherein said electric circuit board is mounted in a curved state to the inner peripheral surface of an annular sensor housing fixed to an end of the fixed bearing ring of said bearing.  
     
     
         4 . A rolling bearing with a rotation sensor as claimed in  claim 1  or  2  wherein said annular sensor housing comprises a peripheral wall and a flange extending radially inwardly therefrom, and said electric circuit board is mounted to said flange so that its board surface is perpendicular to the axis of said bearing.  
     
     
         5 . A rolling bearing with a rotation sensor as claimed in any of claims  1 - 4  wherein said detecting element is mounted so as to be adjacent to and oppose radially said rotating element.  
     
     
         6 . A rolling bearing with a rotation sensor as claimed in any of claims  1 - 4  wherein said detecting element is mounted so as to be adjacent to and oppose axially said rotating element.  
     
     
         7 . A rolling bearing with a rotation sensor, said rolling bearing comprising an inner ring, an outer ring, a plurality of rolling elements rollably mounted between said inner ring and said outer ring, one of said inner ring and said outer ring forming a rotating bearing ring and the other forming a fixed bearing ring, a first core metal fixedly mounted on said fixed bearing ring, a sensor element, a sensor housing including said sensor element and fixedly mounted on said first core metal, a second core metal fixedly mounted on said rotating bearing ring, a magnetic encoder magnetized and fixedly mounted on said second core metal so as to oppose said sensor element, said sensor element detecting the rotation of said rotating bearing ring by sensing magnetic change of said magnetic encoder, characterized in that said magnetic encoder is made of a magnetic material, the binder for which is a heat-resistant rubber.  
     
     
         8 . The rolling bearing with a rotation sensor as claimed in  claim 7  wherein said heat-resistant rubber is selected from the group consisting of heat-resistant nitrile rubber, fluorine rubber and silicone rubber.