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).
Technical evaluation and summary of an air-driven reciprocating pump and regulator valve system for petrol feed.
| Identifier | ExFiles\Box 61\3\ scan0282 | |
| Date | 30th October 1931 | |
| -4- Hs{Lord Ernest Hives - Chair}/Aln.8/KT.30.10.31.contd. in the petrol constitutes an objection to the device. the more so as it also introduces elasticity in the lift line causing delay in the response of the regulator valve. The main reason, we presume, why the air and petrol both act on the same pistons is to avoid taking the connecting rod out through glands. Petrol does not seem to get into the exhaust air, though on one occasion we though there was a small amount after standing overnight, but we have never repeated this. Running without petrol, the pump operates at about 400 cycles per minute at 60 lbs.sq.in. of air. This is reduced a little by inserting a 1.5 mm. restriction washer in the air line to the pump without affecting normal performance. We believe, however, that the limited opening of the regulator valve helps to restrict the free flow of air and we see no reason why it should not be used so. The weight of the pump is 6.5 lbs. and of the regulator 1.0 lb. In working, oil for the trip valve was introduced through a screw down grease cup as shown in the diagram. In an installation, sufficient oil might be conveyed by feeding the air bottles at the bottom through the charge of oil kept in them for sealing the compressor, and taking the supply from the top. The Herzwark compressor however, may not be found to retain its own lubricant when delivering air over long periods as distinct from merely charging the bottles for starting and then releasing back into itself. This can only be ascertained by a prolonged trial. Summarizing, we would say that the system of reciprocating air driven pump combined with the regulator valve represents a good principle and promises, with a little development, to provide a reliable petrol feed of no great weight though we doubt whether it would ever obtain acceptance amongst pilots as an exclusive means of feed without a hand pump or other reserve device. Hs{Lord Ernest Hives - Chair}/Aln. | ||