Split cage and roller bearing

A split cage comprising a plurality of cage segments, each of the cage segments having a pair of rim portions that face each other at a prescribed distance in an axial direction of the split cage, and a pair of cage bar portions disposed between the rim portions to connect the rim portions to each other, the cage bar portions and the rim portions defining a single pocket that accommodates a single roller, the pocket having an insertion opening through which the roller is inserted into the pocket from one of a radially outside and a radially inside, wherein:

• turning of each of the cage segments is guided by the roller, the cage segments being arranged in a circular pattern along a circumferential direction of the split cage, in an annular space between an inner ring and an outer ring;
• each of the cage segments has projections formed so as to project toward the other one of the radially outside and the radially inside, the projections being formed at both the rim portions and the cage bar portions, or at the rim portions or the cage bar portions;
• and
• a projecting length of each of the projections is set to such a length that the projections are brought into contact with an outer peripheral side portion of the inner ring or an inner peripheral side portion of the outer ring, which is located on the other one of the radially outside and the radially inside, before the cage segment is detached from the roller when the cage segment is displaced to the other one of the radially outside and the radially inside.