Patent ID: 8038079

Claim:
An injection system for injecting fuel with a predetermined fuel pressure comprising: a) a housing, which has a housing interior space, which comprises the fuel, a first housing aperture and a second housing aperture; b) a piezo actuator arranged in the housing interior space, which comprises: b1) a face plate, which comprises a first face plate aperture and a second face plate aperture, b2) a controllable piezo stack which is arranged between the face plate and a base plate, b3) a sealed casing which laterally surrounds at least the piezo stack and is arranged between the face plate, and the base plate and b4) a transmission means which is arranged in an actuator interior space, said transmission means comprising at least one fluid with a fluid pressure; c) a first contact device, which is guided through the first housing aperture and the first face plate aperture; d) a second contact device, which is guided through the second housing aperture and the second face plate aperture; e) a first sealing device, which surrounds the contact devices in the region of the housing apertures and provides a seal between the housing interior space and an exterior space with a predetermined exterior space pressure; and with f) a second sealing device comprising a first sealing element which surrounds the first contact device in the region of the face place aperture and a second sealing element which surrounds the second contact device in the region of the face place aperture and wherein the second sealing device provides a seal between the housing interior space and the actuator interior space, wherein at least one of the first and second sealing element consist of a glass; wherein with the transmission of the fuel pressure to the piezo stack a pressure difference between the fuel pressure and the fluid pressure in the actuator interior space is produced, which is less than or equal to 200 bar.