Abstract: A piston pump as a high-pressure fuel pump of a common rail system includes: a pump cylinder; a pump piston moveably mounted in a recess of the pump cylinder, the pump piston being moveable up and down in the recess; and a leakage groove arranged in the pump cylinder in a region of the recess, the leakage groove being coupled with a leakage line configured to discharge a fuel leakage. Between the pump cylinder and the pump piston a different size pairing clearance is formed in first and second portions of the pump cylinder.

Abstract: A piston pump as a high-pressure fuel pump of a common rail system includes: a pump cylinder; a pump piston moveably mounted in a recess of the pump cylinder, the pump piston being moveable up and down in the recess; and a leakage groove arranged in the pump cylinder in a region of the recess, the leakage groove being coupled with a leakage line configured to discharge a fuel leakage. Between the pump cylinder and the pump piston a different size pairing clearance is formed in first and second portions of the pump cylinder.

Abstract: An internal combustion engine (1) has a plurality of combustion cylinders at each of which a fuel injection device (120) is provided. Every combustion cylinder is provided with its own pilot unit (10c-10f) with a fuel accumulator which is integrated therein and which is connected by one of a plurality of first fuel lines (110) to the fuel injection device associated with the respective combustion cylinder for supplying fuel to the latter. A fuel pump which can be connected to a fuel source for supplying a predetermined fuel pressure is integrated in at least one of the pilot units (10d). The fuel accumulator of every pilot unit is so adapted that it ensures that fuel delivered by the fuel pump is supplied to the respective associated fuel injection device in a pressure-stable manner.

Abstract: An internal combustion engine (1) has a plurality of combustion cylinders at each of which a fuel injection device (120) is provided. Every combustion cylinder is provided with its own pilot unit (10c-10f) with a fuel accumulator which is integrated therein and which is connected by one of a plurality of first fuel lines (110) to the fuel injection device associated with the respective combustion cylinder for supplying fuel to the latter. A fuel pump which can be connected to a fuel source for supplying a predetermined fuel pressure is integrated in at least one of the pilot units (10d). The fuel accumulator of every pilot unit is so adapted that it ensures that fuel delivered by the fuel pump is supplied to the respective associated fuel injection device in a pressure-stable manner.