Sealing Device with an Integrated Encoder for Bearings

Abstract

A sealing device is to be fitted at a side of a bearing unit in order to seal a gap ( 15 ) between a stationary race ( 11 ) and a rotatable race ( 10 ) of the bearing unit. The device includes a relatively rigid reinforcing insert ( 16 ) of disc-annular shape, and a gasket ( 17 ) of relatively soft rubber or elastomeric material, over-moulded or vulcanized onto the insert ( 16 ). The gasket forms two opposite peripheral sealing portions ( 18, 19 ) intended to perform a static sealing action against the rotatable race ( 10 ) and a dynamic sealing action on the stationary race ( 11 ), respectively. The insert ( 16 ) includes magnetized or magnetizable material for forming, at predetermined angular zones or fields, a sequence of alternate and/or spaced north/south poles, in order to act as an encoder.

1 . A sealing device for bearings, configured to be fitted at a side of a bearing unit to seal laterally a gap between a stationary race and a rotatable race of the bearing unit, the sealing device comprising:
 a rigid reinforcing insert of disc-annular shape, and   a gasket of rubber or elastomeric material, over-moulded or vulcanized onto the reinforcing insert, the gasket forming two opposite peripheral sealing portions configured to perform a static sealing action against one of the races and a dynamic sealing action against the other of the races,   
       wherein the opposite peripheral sealing portions comprise:
 a first peripheral portion forming a seal against the rotatable race and 
 a second peripheral portion forming a dynamic seal on the stationary race, and wherein the insert comprises magnetized or magnetizable material for forming, at predetermined angular zones or fields, a sequence of alternate and/or spaced north/south poles, to act as an encoder. 
 
     
     
         2 . A sealing device according to  claim 1 , wherein the insert comprises a matrix of plastic material loaded with a powder of magnetized or magnetizable material. 
     
     
         3 . A sealing device according to  claim 2 , wherein the matrix comprises thermoplastic material having a softening temperature exceeding 180° C. 
     
     
         4 . A sealing device according to  claim 3 , wherein the thermoplastic matrix is a material chosen from the group consisting of: polyamide (Nylon 66), polyimide, polyethylene-ether-sulphonate, polyetheretherketone (PEEK). 
     
     
         5 . A sealing device according to  claim 1 , wherein the first peripheral portion is radially outer and the second peripheral portion is radially inner. 
     
     
         6 . A sealing device according to  claim 1 , wherein the first peripheral portion is radially inner and the second peripheral portion is radially outer. 
     
     
         7 . A sealing device according to  claim 1 , further comprising fixing means for fixing the device to the rotatable race of a bearing unit.