Patent ID: 7832943

Claim:
A cage for a roller bearing comprising: a pair of annular portions disposed coaxially each other; a plurality of pillar portions interconnecting the pair of annular portions; a plurality of pockets defined by the pair of annular portions and the plurality of pillar portions for holding rollers, respectively; roller retaining portions formed respectively on circumferentially-opposed wall surfaces of each of the pocket portions; and a concave groove extending axially in a back surface of the pillar portion and back surfaces of the annular portions, a width of the concave groove being smaller than a width of the pillar portion defined between the circumferentially-opposite side surfaces, wherein the concave groove includes separation groove portions formed respectively at circumferentially opposite sides of the concave groove at the opposite ends of the pillar portion, the separation groove portions extending respectively to the corresponding circumferentially-opposed wall surfaces of the pillar portion for separating the corresponding roller retaining portion and the corresponding annular portion from each other.