Patent ID: 6332435
Filing Date: 2001-12-25
Classification: F02B

Abstract:
A crank journal support portion structure, disposed in a horizontal opposed type engine provided with mutually opposed crank cases and a plurality of horizontally opposed adjacent cylinders, each cylinder having a piston, comprising:a rotatable crank journal; anda crank journal support wall, between adjacent cylinders upon which the crank journal rotates, and which crank journal support wall is substantially perpendicular to a longitudinal axis of the crank journal, the crank journal support wall further being divided into approximately equal quadrants, two diagonally opposed quadrants of the crank journal support wall quadrants having a hole portion passing therethrough, such that each hole portion communicates with adjacent cylinders, wherein each hole portion is so located that during a period from an explosion stroke to an exhaust stroke, and at a rotating angle of the crank journal where the cylinder inner pressure becomes higher than the cylinder inner pressures in other strokes, at diagonally opposed positions, that are other than the quadrants to which the maximum stress by the combustion load is transmitted via the crank journal and the diagonally opposed quadrants where a reaction force of maximum stress is received.