GB571501A - Improvement in fuel injection apparatus - Google Patents

Abstract

571,501. Fuel-injection pumps. BENDIX AVIATION CORPORATION. Sept. 22, 1943, No. 15570. Convention date, Sept. 22, 1942. [Class 102 (i)] In a fuel-injection pump, a film of lubricant is established, between the working surfaces of a plunger and cylinder by means of one or more grooves in the surface of the plunger provided with an escape passage independent of the passage, and dilution of the film by fuel is prevented by means of a circumferential relief channel in the cylinder bore between the film and the metering groove and having continuous direct connection with the fuel supply line. Additional relief channels may also be provided in the surface of the plunger. In the form shown, a shaft 42 drives a cam 36 in engagement with rollers 35 to reciprocate plungers 14 in cylinders 8. A metering groove 15 in each plunger cooperates with by-pass port 12 in each cylinder, and the plungers are adjusted angularly by sleeves 20 gearing with a central control gear 27 rotatable by a hollow shaft 28. The latter rotates around a stationary hollow spindle 30 connected to a supply of lubricating oil and formed with ducts 49 and an annular groove 48. This groove opens into passages 50 each of which is connected by an axial slot 51, a radial passage 52, a central passage 53, and radial ducts 56 to a pair of diametrically opposite helical lubricating grooves 55 in the surface of each plunger 14. Any air trapped in the lubricating passages may escape through a relatively small bleed hole 57 connecting one of the grooves 55 to an axial passage 58 leading to a fitting 59 with a removable cap 60. Fuel seeping down between the plunger and cylinder is'trapped in an annular relief groove 61 between the ducts 56 and the groove 15, the groove 61 being connected by passages 62, 63 to the fuel inlet 13 The application of the invention to a single cylinder pump is described and illustrated in the Specification.