Cage for cylindrical roller bearing

A cage for a cylindrical roller bearing, the bearing comprising:

• an inner ring having an inner ring raceway formed on an outer circumferential side thereof;
• an outer ring having a larger diameter than the inner ring and having an outer ring raceway formed on an inner circumferential side thereof;
• and a plurality of rollers arranged in a circumferential direction between the inner ring raceway and the outer ring raceway,
• wherein the cage is provided between the inner ring and the outer ring and comprises:
• annular portions spaced apart in an axial direction;
• a plurality of column portions extending in the axial direction, having both ends connected to the annular portions, and spaced apart from each other in the circumferential direction;
• and a plurality of pockets 175, each defined by adjacent column portions and the annular portions on both sides, and arranged in the circumferential direction,
• wherein each column portion includes pocket surfaces formed on both circumferential sides thereof, and
• wherein each pocket surface includes:
• an outer inclined pocket surface formed to be inclined radially outward such that a distance from the opposing pocket surface of the adjacent column portion increases in the radially outward direction;
• an inner inclined pocket surface formed radially inward;
• and a concave pocket surface formed between the inner inclined pocket surface and the outer inclined pocket surface.