Bearing device for a wheel

A bearing device for a wheel, the bearing device comprising:

• a bearing comprising:
• an outer member having double row outer raceway surfaces at an inner periphery of the outer member;
• an inner member having at an outer periphery thereof double row inner raceway surfaces opposed to the double row outer raceway surfaces, and including a hub having a hole and a flange for mounting the wheel, the hub having a step portion on an outer peripheral surface thereof with an inner ring fit-engaged with the step portion;
• and
• a plurality of rolling elements provided between the double row outer raceway surfaces of the outer member and the double row inner raceway surfaces of the inner member;
• and
• a constant velocity universal joint having an outer joint member, the outer joint member having a shaft portion that is fitted into the hole of the hub and connected to the hub through a recess/projection fit-engagement structure of a recess and a projection,
• wherein the projection extends in an axial direction and is provided on one of the shaft portion of the outer joint member and the hole of the hub, and the recess is formed in another of the shaft portion of the outer joint member and the hole of the hub by press-fitting the projection, to thereby form the recess/projection fit-engagement structure in which the projection and the recess are held in contact with each other over an entire fit-engagement region to integrate the hub and the outer joint member with each other,
• wherein the projection has a press-fitting start side end surface and a corner portion that cuts into the other of the shaft portion of the outer joint member and the hole of the hub to form the recess, the corner portion being provided at an edge of the press-fitting start side end surface,
• wherein a press-fitting margin Δd of the projection with respect to the other of the shaft portion of the outer joint member and the hole of the hub in which the recess is formed and a height h of the projection are in the following relationship:
• 0.3<Δd/2h<0.86,
• wherein, in a pitch circle diameter of the projection, an angle θ2 made by a radial line and a side surface of the projection satisfies the following relationship:
• 20°<θ2<35°, and
• wherein, when the pitch circle diameter of the projection is PCD, a number of projections is Z, and P=PCD/Z, P satisfies the following relationship:
• 0.33<P<0.7.