Patent ID: 7722257

Claim:
A roller bearing cage comprising a resin and having a tapered tubular shape as a whole, the roller bearing cage comprising: a large-diameter annular portion and a small-diameter annular portion that are concentrically arranged in an axial direction; a plurality of pillar portions that extend between the large-diameter annular portion and the small-diameter annular portion at a plurality of positions in a circumferential direction; pockets that are defined between the pillar portions, tapered rollers being forcibly fitted to the pockets while elastically deforming the pillar portions at a side of the small-diameter annular portion; and stress alleviating portions provided on at least an outer circumferential side of an end of the pillar portion at a side of the small-diameter annular portion for alleviating stress occurring in the pillar portion when a tapered roller is forcibly fitted to a pocket, wherein the stress alleviating portions are provided on both sides of the pillar portions in the circumferential direction, wherein the stress alleviating portions are formed so that a portion of the pillar portion from a crossing portion between the pillar portion and the small-diameter annular portion to a side of the large-diameter annular portion is linearly cut, and wherein a diameter at an edge portion of a small-end portion is less than a distance between adjacent crossing portions between the pillar portions and the small-diameter portions.