MAIN MOTION MECHANISM OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To reduce the abrasion of both of a crankshaft and a sliding bearing in a rotation mechanism of an internal combustion engine formed by including a micro alloying steel crankshaft treated by neither high frequency hardening nor surface hardening and having a structure comprising perlite and pro-eutectoid ferrite, or the perlite, and the sliding bearing installed in the outer circumference of the crankshaft and composed of an aluminum bearing alloy. SOLUTION: The area fraction of pro-eutectoid perlite is 3% or less and the surface roughness of the crankshaft of the surface sliding with the sliding bearing is Rz 5μm or less. Hard substances composed of Si or including Si, having the hardness of Hv 900 or more, and being 6μm or less are distributed in the matrix for the aluminum bearing alloy. COPYRIGHT: (C)2004,JPO