Abstract: A transfer pump for the injection of fuel under high pressure of the type comprising a piston (10) providing the hydraulic liquid to a deformable bellows (14), the deformations of said bellows (14) in a cylindrical chamber (20) filled with fuel giving rise to a high pressure pumping effect of said fuel; a cam (5) provided with lugs (6) carried by a drive shaft (1), is characterized in that the oil portion of the pump comprises: the portion of the drive shaft (1) bearing the cam (5); the cam (5) and its lugs (6); the roller (7) with its shaft (8) and its roller bearing (9) carried by a bearing member (12), by which roller the cam(5) bears on the piston (10); as well as the upper portion of said piston (10); such that all the mechanical drive portion and angle change are bathed in the oil of the oil portion.

Abstract: The invention concerns a safety device for preventing overpressure occurring in the oil part (3) of a transfer pump supplying a fuel such as high-pressure gasoline to an engine characterized in that it consists of a rotary sealing joint (10) separating the oil part (3) of the pump and the oil part (7) of said engine.

Abstract: Transfer pump of the type in which the moving part for pumping is a bellows (4) that is alternately filled with and emptied of hydraulic liquid at high pressure by a piston (1) that is driven by a cam (2), whereby the amount of fuel allowed into the chamber (5) into which the bellows (4) moves is determined, upstream, by a solenoid valve (8) that is driven by the computer for monitoring the engine, characterized by the fact that it comprises at least two pumping units (piston 1/bellows 4) that are supplied by a single intake system (6) that is common to the units on which the flow-monitoring solenoid valve (8) is placed and that have a conveyor circuit (10) that may be unique and common, or specific to each pumping unit.

Abstract: The invention concerns a method for controlling high pressure fuel supply of a set of injectors connected to a common high pressure chamber, called common rail C in a direct injection fuel circuit, through a high pressure pump (P), by acting on the low pressure supply of said pump (P) through an electromagnetic slide valve (E), controlled by the computer managing the operating conditions of the engine which consists in providing, inside the electromagnetic valve (E) one or more internal leakage flows, either from high pressure to low pressure, or from low pressure upstream of the electromagnetic valve (E) to the low pressure downstream thereby solving the specific problems related to the three operating modes of the engine: engine brake, engine shutdown, idle speed.