Patent ID: 7988365

Claim:
A ring-shaped cage for use in a ball bearing assembly, the cage comprising: a circumferentially extending body forming a bore defined therein and having inner and outer peripheral surfaces opposite to each other, the circumferentially extending body having a plurality of pockets defined therein to hold a corresponding number of balls, the radius of the bore measured from the geometric center of the bore to an outer peripheral surface area of the circumferentially extending body is uniform, and the radius of the bore measured from the geometric center of the bore to a whole inner peripheral surface area of the circumferentially extending body aligned with each of the pockets being greater than the radius measured from the geometric center of the bore to a different whole inner peripheral surface area of the circumferentially extending body intermediate the neighboring pockets so that recessed portions are formed in the inner peripheral surface extending the whole length of the pockets in the circumferential direction, respectively.