BALL BEARING

To provide a ball bearing capable of suppressing the occurrence of seizure or wear by suppressing the shortage of an oil amount on a rolling surface during high speed rotation.SOLUTION: A ball bearing 102 includes an inner ring 10, an outer ring 12, a plurality of rolling elements 14, and a cage 19, the inner ring 10 and the outer ring 12 being relatively rotatable around a central axis. The cage 19 has pockets each consisting of an upstream side claw part 19a provided on the revolution upstream side of the cage 19 and a downstream side claw part 19b provided on the downstream side for holding the rolling elements 14, and at least one of the upstream side claw part 19a and the downstream side claw part 19b includes a slit groove 19c linked with the pocket along the revolution direction to satisfy predetermined conditions.SELECTED DRAWING: Figure 5 【課題】高速で回転しても、転動面における油量不足を抑制し、焼き付きや摩耗の発生を抑制できる玉軸受を提供する。【解決手段】内輪１０、外輪１２、複数の転動体１４、保持器１９を備え、内輪１０及び外輪１２が回転軸を中心に相対的に回転可能な玉軸受１０２であって、保持器１９は、保持器１９の公転の上流側に設けられた上流側爪部１９ａと下流側に設けられた下流側爪部１９ｂで構成されたポケットによって転動体１４を保持し、上流側爪部１９ａ及び下流側爪部１９ｂの少なくとも１つは、公転の方向に沿ってポケットに繋がり、所定の条件を満たすスリット溝１９ｃを備える。【選択図】図５