PISTON PUMP FOR HIGH PRESSURE FUEL SUPPLY

A piston pump of the roller tappet type for high-pressure fuel delivery in fuel injection systems of internal combustion engines, particularly in common rail injection systems. A drive shaft that is supported in the pump housing and has a number of cam-like projections in the circumference direction. At least one tappet that is disposed in a cylinder chamber radially with regard to the drive shaft and in its radially inner end region has a rotatable roller which is supported so that it can roll in the circumference direction against the drive shaft in the region of its projections in order to reduce the wear in the region of the roller bearing. The pump is embodied so that a lubricant supply opening that leads from the circumference of the tappet and feeds into the radially inner tappet end region supporting the roller and at least during a part of the stroke, communicates with a lubricant supply line of the housing, which line feeds into the cylinder chamber.