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).
Tests carried out on a fluid transfer fuel pump supplied by Messrs Fluid Transfer Ltd.
| Identifier | ExFiles\Box 149\3\ scan0151 | |
| Date | 28th October 1940 guessed | |
| FLUID TRANSFER FUEL PUMP. Tests have been carried out on a fuel pump supplied by Messrs Fluid Transfer Ltd., to investigate the advantages claimed for this type of pump, which incorporates a patent bye-pass valve, as compared with existing RR types. The following advantages were claimed:- (a) Weight is lighter for any given performance (b) Starts pumping at 100 r.p.m. (c) Pumps gaseous fuel (d) Lifts dry (e) 23" Hg. vacuum against 23 lbs/sq.in. delivery pressure. (f) No lubrication required. (g) High volumetric efficiency. Points (e), (d) and (f) also apply, of course, to our gear type fuel pumps. Before describing the tests a brief description of the principles of operation of the pump is given. Description of Pump. The pump is essentially a rotary type, consisting of an oscillating displacement member driven by an eccentric rotor running in plain bearings; this member is located by a vane pivoting about a fulcrum in the pump casing; to prevent back leakage the inlet side of the oscillating piece carries a small projection which forms a seal by sliding into a mating recess in the casing. The general shape of the inlets and outlets is considered good. The attached diagram MT.199 illustrates a single rotor type but the method of operation is exactly the same as in the twin rotor pump on which the tests were carried out; this diagram does not show the sealing projection. The working parts of the pump are lubricated by petrol only, no external lubrication being considered necessary. In addition to a spring-loaded release valve that protects the mechanism against excess pressures the pump is provided with a spring-loaded bye-pass valve between the suction and delivery branches. It is claimed that this device permits the inertia of the moving column of liquid in the delivery pipe to draw liquid straight through the pump whenever the piston is decelerating, due to the resulting fall of pressure on the delivery side. It is claimed that by this means it is possible to obtain a volumetric efficiency exceeding 100% P.T.O. | ||