Rocker arm bearing
A rocker arm bearing comprising a support shaft in which end faces of shaft end portions of the support shaft are crimped to inner circumferential edges of shaft end inserting holes in opposed side walls and an outer ring which is rotatably supported on a raceway portion at a shaft intermediate portion of the support shaft via a plurality of rollers or directly, wherein an external surface of the raceway portion at the shaft intermediate portion of the support shaft is surface hardened by virtue of quenching, and as a wear-resistant hard coating, a DLC coating is formed on at least the external surface of the raceway portion which is surface hardened.
1 . A rocker arm bearing comprising:
a support shaft that includes end faces of shaft end portions, respectively, fitted to inner circumferential edges of shaft end inserting holes, respectively, formed through opposed side walls which constitute a rocker arm body, and a raceway portion at a shaft intermediate portion thereof; and
an outer ring which is rotatably supported on the raceway portion via a plurality of rollers or directly,
wherein the raceway portion is surface hardened by quenching, and a wear-resistant hard coating is formed on at least an external surface of the raceway portion which is surface hardened.
2 . The rocker arm bearing according to claim 1 , wherein
the wear-resistant hard coating is formed on external surfaces of the shaft end portions, and
the external surfaces of the shaft end portions including the wear-resistant hard coating is fitted in the inner circumferential edges of the shaft end inserting holes.
3 . The rocker arm bearing according to claim 1 , wherein the wear-resistant hard coating is a type of coating selected from DLC coating, chrome nitride coating and titanium nitride coating.
4 . The rocker arm bearing according to claim 1 , wherein a thickness of the wear-resistant hard coating is in a range from 1/500 to 1/5000 of the diameter of the support shaft.