Roller bearing

A roller bearing comprising:

• an inner ring having an inner-ring raceway surface on an outer periphery of the inner ring;
• an outer ring arranged concentric with and peripherally outside the inner ring and having, on an inner periphery of the outer ring, an outer-ring raceway surface that faces the inner-ring raceway surface;
• a plurality of rollers interposed between the inner-ring raceway surface and the outer-ring raceway surface in a rollable manner;
• and
• a cage that holds the rollers at predetermined intervals along a circumferential direction, the cage being provided with a plurality of cage bars, wherein
• at least one end portion of the outer-ring raceway surface in an axial direction serves as a guide surface on which rotation of the cage is guided, and on an outer periphery of the cage, a slidable contact surface is formed which slidably contacts the guide surface and which is arranged to face the guide surface across a labyrinth clearance,
• axially opposite end portions of the outer-ring raceway surface respectively serve as a first guide surface and a second guide surface on which rotation of the cage is guided, an axially-first-side slidable contact surface of the cage slidably contacting the first guide surface, and an axially-second-side slidable contact surface of the cage slidably contacting the second guide surface,
• a recessed portion that is recessed inward in the radial direction is formed on a radially outer side of each of the plurality of cage bars, and
• a diameter of a radially outer surface of at least one of the plurality of cage bars expands axially from the axially-first-side slidable contact surface to the axially-second-side slidable contact surface,
• crowning is applied to the outer-ring raceway surface, and
• the guide surface is formed away from a crowning center on the outer-ring raceway surface in the axial direction.