Patent ID: 8256400

Claim:
Piston pump for supplying high-pressure fuel to a direct-injection internal combustion engine, comprising a pump housing and a drive shaft for activating at least one pump plunger that is oriented in a radial direction in the pump housing relative to the drive shaft, wherein the drive shaft is rotatably mounted by at least one bearing that extends between a shaft inlet opening of the pump housing and a rear housing wall opposite the shaft inlet opening, the at least one bearing extends between an internal lateral surface of a hollow cylindrical section of the drive shaft and an external lateral surface of a bearing journal starting from the rear housing wall and extending into the hollow cylindrical section, the drive shaft is rotationally connected coaxially to a camshaft used for activating intake or exhaust valves of the internal combustion engine, wherein the drive shaft has a continuous longitudinal opening, wherein the hollow cylindrical section and internal longitudinal teeth adjacent to the hollow section extend in the longitudinal opening, wherein the internal teeth engage with external longitudinal teeth on an end section of the camshaft facing the piston pump.