METHOD FOR MANUFACTURING WHEEL SUPPORTING ROLLER BEARING UNIT, AND METHOD FOR TESTING DOUBLE-RACE ROLLER BEARING UNIT

摘要

Provided is a wheel supporting roller bearing unit, which is different in the pitch circle diameters of balls (6a and 6b) between an outer race and an inner race but which is identical in contact angles (αOUT and αIN) when the balls (6a and 6b) of the two races are completed. The initial contact angles (βOUT and βIN) are smaller than those predetermined contact angles (αOUT and αIN). The degree 'αIN - βIN', at which the initial contact angle (βIN) of the balls (6b and 6b) of the inner race is made smaller than the predetermined contact angle (αIN) of the balls (6b and 6b), is made larger ('αIN - βIN' 'αOUT - βOUT') than the degree 'αOUT - βOUT', at which the initial contact angle (βOUT) of the balls (6a and 6a) of the outer race is made smaller than the predetermined contact angle (αOUT) of the balls (6a and 6a). In this constitution, the predetermined contact angles (αOUT and αIN) are given to the balls (6a and 6b) of the two races in the completed state so that the pre-pressure and contact angle of the balls (6a and 6b) of the two races are made proper.