Needle roller bearing and bearing structure

摘要

A needle roller bearing comprises an outer ring having a plurality of outer ring members split by a parting line extending in the axial direction of the bearing, a plurality of needle rollers rotatably arranged on the raceway surface of the outer ring, and a retainer retaining the plurality of needle rollers. A curvature radius r1 of the outer ring member and a curvature radius r2 of the outer diameter of the retainer has a relation such that 1