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).
Typed document discussing issues with air in an oil system, pressure maintenance, and potential leaks.
| Identifier | ExFiles\Box 27\1\ Scan069 | |
| Date | 14th February 1929 guessed | |
| contd :- -2- (3) We have had a pressure gauge on the system and the pump seems to maintain a high pressure equally well all over the system, provided the maximum pressure is reached. We find, however, that a certain amount of air in the system renders the oil slightly compressible, and on the first strokes we are doing work in compressing oil instead of sending it through the drip plugs. We realise that the system should be thoroughly pumped clear of air in the first case, under high pressure with open ended pipes. We should be grateful to know what precautions you adopt in manufacture to ensure the system being air-clear. (4) The question of air in the oil itself may also be rather serious. It is evident that a customer will not realise his oil is not getting through if the system has air in it, as it will not necessarily make an appreciable difference in the time the plunger takes to return home. What instructions do you issue, if any, with regard to this? Has your oil been chosen in regard to this? Of course, 2 strokes of the plunger will always compensate for any air in the system, but we do not wish to adopt this precaution if the pump can be guaranteed to reach and maintain max. pressure on the first stroke. We are now calling for a pump which delivers 20 ccs. instead of 14 and we believe this will greatly help matters. (5) As a guarantee against no air in the system the joint should not leak oil on undoing any one drip-plug. Up to now we have always had an appreciable quantity escape. How does your chassis behave? contd :- | ||