Käfig für Wälzlager

In a synthetic resin roller-bearing cage 1, axially separated annular bodies 4 are connected by columnar portions 3 arranged in the circumferential direction in order to define pockets for rollers R. The radially outer surface of the columnar portion forms a portion of a cylindrical surface whose radius is smaller than that of the outer circumferential surfaces of the annular bodies, thus forming a flow surface for lubrication oil. The radially inner surface of the columnar portion is flush with that of the inner circumferential surfaces of the annular bodies 4 and has a diameter greater than that of a shaft on which the roller bearing is mounted by at least 30% that of the roller. Recessed portions 7 are formed in the side surfaces 6 of the columnar portion at axially opposite end regions adjacent to the respective annular bodies 4. An outer roller-retaining portion 8 having a pawl-like section is formed on each circumferential edge of the radially outer surface of the columnar portion over the central region between the opposite recessed portions 7. Inner roller-retaining portions 9 are formed on the circumferential edges of the radially inner surface 5 of the columnar portion at axially opposite end regions located inwardly adjacent to the respective opposite recessed portions 7, so that a central unobstructed region 10 is formed between the inner roller-retaining portions 9. This improves the oil flow through the cage.