Wheel bearing device

A wheel bearing device comprising:

• a wheel bearing including:
• an outer member having double-row outer raceway surfaces in an inner circumference;
• an inner member including a hub wheel to be mounted to a wheel and having double-row inner raceway surfaces, which opposed to the double-row outer raceway surfaces of the outer member, in an outer circumference;
• and
• double-row rolling elements intervening between the double-row outer raceway surfaces of the outer member and the double-row inner raceway surfaces of the inner member,
• wherein the hub wheel has a hole portion, an inner wall, and an end portion, the inner wall protruding in an inner diameter direction and having a cylindrical inner circumferential surface, and the end portion being toward an inboard side of the hub wheel and being caulked to form a caulking portion, the caulking portion precompressing the wheel bearing;
• a bolt member;
• and
• a constant velocity universal joint having an outer joint member including a shaft portion with a bolt hole, wherein
• one of the shaft portion of the outer joint member and the hole portion of the hub wheel has projections extending in an axial direction that are press-fitted into another of the shaft portion of the outer joint member and the hole portion of the hub wheel to form recesses therein by the projections, the recesses and the projections forming a recess-projection fitting structure where an entire area of fitting sites of the projections and the recesses is brought into close contact,
• the bolt member is screwed into the bolt hole and fastens the hub wheel to the outer joint member via the inner wall of the hub wheel,
• when the bolt member is detached, a drawing force applied in the axial direction separates the recess-projection fitting structure,
• if a seating surface outer diameter of the bolt member is d1, a shaft diameter of the bolt member is d2, and an inner diameter size of the inner wall of the hub wheel is d3, the bolt member satisfies relational expressions of 2.3≦(d1/d2)2≦4.9 and 0.05 mm<d3−d2<0.5 mm, and
• an end surface of the caulking portion and an end surface of the outer joint member, which are opposed to each other, are in contact while an end surface of the shaft portion of the outer joint member and an end surface of the inner wall of the hub wheel, which are opposed to each other, are free from contact, and the hub wheel is sandwiched between the bolt member and the outer joint member in the axial direction.