Sheath=type needle roller bearing and manufacturing method

摘要

The bearing has needle rollers (2) arranged with radially bent downwards ends within an outer ring (1). Each needle roller has a nitrogen rich surface bearing section where the austenitic or non-austenitic contents are 20% by volume or greater than 20% by volume respectively. The thickness of the roller end hardened layer may be 0.1mm or more. The surface hardness of the ends may be at least 750 Hv. The hardnesses of the roller bearing ends and the housing bearing surfaces can be roughly the same. Manufacturing can involve hardening and tempering one end of the needle bearing and housing together in the assembled condition.