Method for measuring axial clearance of bearing device for vehicle wheel

A method for measuring axial clearance of a bearing device for a vehicle wheel which includes:

• an outer member having a plurality of rows of outer raceway surfaces on an inner periphery;
• an inner member including a hub ring having a small-diameter step portion axially extending on an outer periphery and an inner ring press-fitted into the small-diameter step portion of the hub ring, the inner member having a plurality of rows of inner raceway surfaces facing the plurality of rows of outer raceway surfaces;
• and
• a plurality of rows of rolling elements rollably accommodated between both raceway surfaces of the outer member and the inner member,
• the method comprising:
• press-fitting the inner ring into the small-diameter step portion of the hub ring to a position where the inner ring abuts on the hub ring in an axial direction;
• measuring a first negative axial clearance between the inner ring and the hub ring after the press-fitting;
• swaging an inner-side end portion of the small-diameter step portion to the inner ring after the measuring of the first negative axial clearance;
• measuring an inner ring press-in amount that is a press-in amount of the inner ring in the axial direction from after the press-fitting to after the swaging;
• measuring a first inner ring outer diameter enlarged amount that is an enlarged amount of an outer diameter of the inner ring from after the press-fitting to after the swaging;
• calculating a second inner ring outer diameter enlarged amount from the inner ring press-in amount measured in the measuring of the inner ring press-in amount, and a relationship between the press-in amount of the inner ring in the axial direction and an outer-diameter enlarged amount of the inner ring;
• calculating an outer diameter enlarged amount difference which is a difference between the first inner ring outer diameter enlarged amount and the second inner ring outer diameter enlarged amount;
• calculating a first axial clearance reduced amount from the outer diameter enlarged diameter amount difference calculated in the calculating of the outer diameter enlarged diameter amount difference, and a relationship between an outer diameter enlarged amount of the inner ring and an axial clearance reduced amount that is a reduced amount of an axial clearance between the inner ring and the hub ring;
• calculating a second axial clearance reduced amount from the inner ring press-in amount, and a relationship between the press-in amount of the inner ring in the axial direction and an axial clearance reduced amount that is a reduced amount of an axial clearance between the inner ring and the hub ring;
• calculating a third axial clearance reduced amount by adding the first axial clearance reduced amount calculated in the calculating of the first axial clearance reduced amount to the second axial clearance reduced amount calculated in the calculating of the second axial clearance reduced amount;
• and
• calculating a second negative axial clearance by adding the third axial clearance reduced amount to the first negative axial clearance measured in the measuring of the first axial clearance.