Patent ID: 8167577

Claim:
A fuel pump device comprising: a fuel pump comprising a chamber for receiving fuel, a first pressure-generating component movable in and with respect to the chamber, the first component having a pressure-generating surface which comprises a delineating surface of the chamber such that movement of the pressure generating surface of the first component changes the volume of the chamber, a second pressure-generating component passing around the first component and defining a space in the chamber in which the pressure-generating component is movable, the first and second components being dimensioned to define a clearance between the second pressure-generating component and the first component as the first component moves through the space defined by the second component, a force applying device operable to impart a force to the first component to move the first component reciprocally in the space to pressurize the fuel in the chamber during movement of the first component in a first direction, a temperature-regulator operable to maintain a temperature within a predetermined temperature range in a region of the fuel pump which includes the clearance and includes at least portions of the first and second pressure-generating components which portions of the pressure generating components may be affected by generated heat in the region of the fuel pump.