From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Developments in aircraft fuel feed systems, hydraulic controls, accumulators, and steering.
| Identifier | ExFiles\Box 178\2\ img005 | |
| Date | 24th April 1940 guessed | |
| -2- as experimental development to get rid of noise and pressure failures. On the West Coast it is being applied to aircraft for fuel feed, using a series of three pumps, one on the engine, pumping oil in a closed system, one under the fuel tank operating as a motor driven by the first, and driving the third pump, which pumps fuel from tank to carburetter. Claimed to get rid of vapor lock at high altitude. I expect to see Frank Mock soon at South Bend and will ask him about it. This is difficult to believe. The injector construction shown in the sketch is said to raise the cavitation speed from 4500 to over 8000 r.p.m., working at 800 lbs. pressure in the system. The tendency appears to be to overcharge the suction side from the reserve tank. Davis says the success of this device was instantaneous. He claims a clear basis patent. Hydraulic Control. For controlling all forms of large vehicles (notably to replace air-brakes on large trucks and buses and more recently for braking high speed train) systems of stored hydraulic pressure are coming into favor. In trains, although the air pressure brake is being retained, it is proposed to control it by hydraulic servo means. (As you will have read, the common wheel-brake is being replaced by disc-brakes.) These systems contain oil pressure accumulators of various types in which the pressure is maintained by a small oil pump driven by electric motor, which is operated by a pressure-sensitive microswitch. Pressures are held at about 800 lbs. Many of these accumulators contain mechanical pistons which give the usual amount of leakage trouble. Compressed air or nitrogen cannot be exposed directly to the oil, as it absorbs very rapidly and becomes dissolved in the oil. Attached sketch shows 'Davis' description of a new type accumulator made in Chicago which avoids these troubles. The oil in the outer chamber, which is used simply to fill up space, is isolated from the working oil in the middle chamber, by glycerine, which is impervious to compressed nitrogen. The possibility of using such systems in large aircraft is under consideration. Steering. The Davis steering gear, even after all these years of delay, is quite likely to be applied soon on large vehicles, but, instead of getting its hydraulic energy by interrupting the flow of a circulating oil system, it will use a hydraulic pressure-storage system as described | ||