GB191416528A - Improvements in and relating to Pumps. - Google Patents

Abstract

16,528. British Thomson-Houston Co., [General Electric Co.]. July 10. Auxiliary actuating -gear; lever - actuated pumps; stroke, varying; air traps; multipledelivery piston pumps; single-acting piston pumps; single-acting suction-valveless pumps; priming; regulating delivery by by-passes; suction reservoirs; valves, arrangement of.- In a suction-valveless fuel pump for internalcombustion engines, the delivery is adjusted to the load by the engine governor by varying the region of reciprocation of the plunger while the length of stroke remains constant. The plungers 27 are actuated against the action of the springs 28 by a cross-head 26 linked to a lever 30, which is connected at one end to a movable fulcrum 31 and at the other end to the connecting-rod 32 of a crank on the engine shaft. The fulcrum 31 is carried by a block attached to a hollow piston 40 in a cylinder 39. The piston 40 is attached to a tube 42 closed at the lower end and provided with one or more orifices 43 through which fluid is continually forced in varying amount by an auxiliary pump, of which the plunger 38 is actuated by the cross-head 26, and the cylinder 38<a> is connected by a pipe 46 to the cylinder 39. This pump draws lubricating-oil through the suction valves 44 from the reservoir 65, and forces it through delivery valves 45 to the pipe 46. A sleeve valve 49 connected to the governor by a rod 50 moves over the tube 42 as the load on the engine varies, and throttles more or less, according to its position, the passage of fluid through the orifices 43. With an increase of load, this throttling action creates fluid pressure which in the cylinder 39 forces the piston 40 and fulcrum 31 downwards and, by thus varying the region of reciprocation of the pump plunger, varies the delivery in accordance with the load. For motor-car work, the sleeve 49 and rod 50 may be moved by hand. The reservoir 65 is divided by a partition 66 into two chambers, of which the upper contains oil for lubricating the working parts and feeding the fulcrum-adjusting pump 38. The lower chamber 59 contains fuel, which enters the pump cylinders 27<a> through ports 58. The partition 66 is inclined to prevent air which may have entered the chamber 59 from passing into the pumps. The pipe 46 has a by-pass 48 controlled by a valve 47, by opening which the delivery of the pump 38 is returned to the reservoir and the fuel pump is brought tu no-load condition, thus stopping the engine. The pumps may be primed by means of handactuated rods 55 passing through the crosshead and engaging 'the plungers; by-pass valves on the delivery pipes 24 are opened for this purpose. The sensitiveness of the governing- mechanism is reduced at light load by means of an adjustable spring surrounding the rod 50 in a casing 62. This spring is normally inactive. There may be as many pumps as there are cylinders to the engine, or one pump may supply all the cylinders. The governor is driven from the main shaft by spiral gearing, and its shaft is in two parts connected by a spring to prevent or reduce the transmission of sudden irregular motions of the governor. The governor may be adjusted by an adjustable extension spring connected at one end to a lever in the transmitting-mechanism and at the other to the engine frame.