Abstract
The cam-tappet of an I. C. engine is a rubbing pair with high load and severe lubrication condition. In order to raise the anti-scuffing capacity of the cam-tappet, a laser microprecision treatment was adopted to make the topography with artificial regular asperities on the working surface of tappets. It was proved by experiment rising a full-scale engine rig that the tappets treated by laser microprecision had an obvious antiscuffing effect.