Patent GB-862339-A (GB)
Title: Turbine-driven pump
IPC: F04D13/04
Filed: 1959-03-05
Abstract: 862,339. Centrifugal pumps; gas turbine jetpropulsion plant. RUPPEL, C. D. March 5, 1959 [March 17, 1958], No. 7697/59. Classes 110 (1) and 110 (3). A turbine rotor comprises two parts 24, 26 bolted together, the part 24 being machined to form convolute passages 25. A centrifugal pump impeller 23 is screw-threaded at 29 to an upstanding boss 28 formed on the part 26 and secured thereto by a locking-pin. A sleeve 44 is splined at 77 and 45 to the impeller 23 and a cylinder 40, respectively. All these parts rotate together on bearings 39, 66. A sleeve valve 51 is screw-threaded to the spindle 54 of a poppet valve 55, the spindle being journalled in a bearing 57 carried by the sleeve 44 and in a stationary bearing 59. On operation of a solenoid 89 to move valves 94, 95 to the open position shown in Fig. 2, high-pressure fuel from the fuel system of a gas turbine engine is admitted through valve 95 to the space within the cylinder 40 and pushes the sleeve 44 downwards against the action of a spring 50 from the position shown in Fig. 1 to that shown in Fig. 2. A plate 70, slotted to engage a neck 62 on the valve spindle 54, is pushed downwardly by sleeve 44 against the action of a spring 76 to bring the valves 51, 55 into the positions shown in Fig. 2, so that valve 51 retains the same position relative to the sleeve 44 as in Fig. 1 and valve 55 opens to admit compressed air (bled from the compressor of the gas turbine engine) to drive the turbine rotor 24, 26. The driving air is exhausted through circumferential ports 69. Overspeeding is prevented by flaps 104, Fig. 8, which are moved by centrifugal force and air pressure against the action of springs 111 to close the inner ends of the passages 25. When a predetermined speed is reached, centrifugal force on a weight 71 moves the slotted plate 70 against the action of a spring 74 to disengage the neck 62, whereupon the spindle 54 is moved upwardly by means of a spring 63 to return the valves 51, 55 to their former positions. The supply of driving air is now shut off by valve 55, and the rotating parts begin to slow down, being kept rotating by inertia only. Valve 51 is now in the position shown in Fig. 1, while the sleeve 44 is still in the position shown in Fig. 2, so that ports 52 in the valve 51 are aligned with ports 47 in the sleeve 44. Low-pressure fuel admitted by valve 94 can now pass through the ports 47, 52 into the sleeve 44 and thence through ports 48 into the pump impeller 23. The pumped fuel is delivered through a non-return valve 85, which closes to stop the delivery when the delivery pressure has fallen below a predetermined value, a drain valve 81 opening at the same time to by-pass any remaining fuel through a pipe 83, On de-energization of solenoid 89, valves 94, 95 close, and the sleeve 44 returns to its original position. The pump is used to deliver single brief shots of additional fuel to separate jets in one of the combustion chambers of the gas turbine engine, for the purpose of lighting the reheat burner. The drops of fuel in the quantity delivered are sufficiently large that, after being ignited in the combustion chamber and passing through the gas turbine, they are still burning when they reach the reheat burner. An alternative use is to provide high-pressure fluid for a very short time to operate the jacks which actuate variable propulsive nozzles of the engine.