BEAT SOUND PREVENTING STRUCTURE IN CRANKSHAFT SUPPORT BEARING FOR MOTORCYCLE

摘要

PROBLEM TO BE SOLVED: To restrict generation of beat sound at a bearing structure part comprising a holding bushing cast in a crank case to support a crankshaft through a ball bearing by reducing change of clearance due to thermal effects.;SOLUTION: Outer race parts 1b₂ and 1c₂ of ball bearings 1b and 1c are held by a bushing Bu to provide a bearing structure to support the crankshaft 1. The structure of the bushing Bu is composed of a bushing Bu₁ directly cast in the crank case C and a bushing Bu₂ engaged in the bushing Bu₁. The bushing Bu₁ and the bushing Bu₂ have similar thickness, and they comprise cast iron of almost similar material.;COPYRIGHT: (C)2005,JPO&NCIPI