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).
Delivery performance of different Merlin engine oil pumps.
| Identifier | ExFiles\Box 149\2\ scan0215 | |
| Date | 28th April 1941 | |
| To - Rm.{William Robotham - Chief Engineer} MERLIN OIL PUMPS. In reply to Rm.{William Robotham - Chief Engineer}26/ML.25.4.41. I attach curves showing the delivery of Merlin pressure oil pumps when using DTD.109 oil at the normal maximum operating temperature of 90°C. The curves are for (a) the standard pump as originally fitted to Merlin III, X, etc. (b) the present standard (increased capacity) pump to BY.49 as fitted to Merlin XX, XLV, etc. and to repair engines of earlier marks. The curves are averages of a number of pumps under rig test conditions. The delivery will be sensibly the same under test bed conditions, but reduced under aircraft installation conditions by 15%-20% owing to aeration, the exact amount of the reduction depending on the particular installation considered. In addition, curves are shown for the corresponding scavenge pumps; these are only estimates, since the actual capacity is not usually measured. It has been assumed that the ratio of actual deliveries of the scavenge and pressure pumps is equal to the ratio of the theoretical deliveries, i.e. the ratio of the lengths of the gears. The power required to drive the complete BY.49 pressure and scavenge pump unit under rig test conditions is about 4 H.P. at 2600 e.r.p.m. with 150 lb/sq.in. pressure pump delivery pressure, and 40 lb/sq.in. scavenge pump delivery pressure. Lov{Mr Lovesey}/RCP. R C Plumb | ||