Patent ID: 6722864
Filing Date: 2004-04-20
Classification: F02M,F04B,F16C,Y10T

Abstract:
A fuel injection pump comprising:a drive shaft rotatable; a cam formed eccentrically and integrally with the drive shaft; a cam ring; a bush whose outer circumference is fixed to inner circumference of the cam ring and whose inner circumference is slidably fitted to outer circumference of the cam shaft so that sliding contact portions of the eccentric cam and the bush are formed; a housing provided with a cylindrical bore; a plunger axially and reciprocatingly movable in the cylindrical bore via the cam, the bush and the cam ring by the drive shaft, axial end of the plunger being in slidable contact with outer circumference of the cam ring so that another axial end thereof and the cylindrical bore form a pressure chamber; an accommodation chamber formed in the housing for accommodating the plunger, the bush, the cam ring and the cam; a feed pump whose outlet side communicates with the pressure chamber for supplying fuel to the pressure chamber according to rotation of the drive shaft; and a communication path through which the outlet side of the feed pump also communicates with the accommodation chamber for supplying a part of the fuel discharged from the feed pump to the accommodation chamber, wherein at least one of the inner circumference of the bush and the outer circumference of the cam gradually protrudes radially toward the other one of the inner circumference of the bush and the outer circumference of the cam from the axial opposite ends to the axial center thereof.