BEARING DEVICE FOR WHEEL

摘要

According to the present invention, there is provided a bearing apparatus for a wheel of vehicle comprising a hub wheel integrally formed therewith a wheel mounting flange on the periphery at one end thereof, and a double row rolling bearing, the double row rolling bearing comprising an outer member integrally formed therewith a body mounting flange on the periphery thereof and also formed therewith double row outer raceway surfaces, an inner member including said hub wheel and formed therewith double row inner raceway surfaces each arranged opposite to each of said double row outer surfaces, and double row rolling elements freely rotatably contained between said double row outer and second raceway surfaces, said double row rolling bearing being adapted to be applied a predetermined preload characterized in that : there are arranged a separate outer or inner ring on at least one of said outer and inner members, and a preload varying means arranged at an abutting portion between said outer and inner members for varying the preload applied to the bearing, said preload varying means can be extended or contracted based on an output signal from a detecting sensor for detecting the running condition of vehicle.