MAIN BEARING FOR CRANKSHAFT OF INTERNAL COMBUSTION ENGINE

摘要

PURPOSE: A main bearing for a crank shaft of an internal combustion engine is provided to prevent a leakage of lubricating oil from an axial groove of the main bearing by the separating inner periphery being extended between a circumferential end portion of an oil groove and the axial groove. CONSTITUTION: A main bearing(19) for a crank shaft of an internal combustion engine comprises a pair of semi-cylindrical bearings(17,18). The main bearing supports a journal portion(10) of the crank shaft to be freely operated. The journal portion includes lubricating oil passages and an inlet opening thereof. One side of the semicircular bearing includes an oil groove(17a) formed in the inner periphery. The oil groove passes through at least the central portion of a circumferential direction of the semicircular bearing and extended in the circumferential direction. The center of the oil groove is arranged to be matched up the center of the inlet opening. An end portion of the circumferential direction of the oil groove is not extended to a cross section of the circumferential direction of the semicircular bearing.