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).
Raising questions about the design of an indicator diagram apparatus, specifically concerning the rotary valve and oil system.
| Identifier | ExFiles\Box 79\3\ scan0009 | |
| Date | 1st March 1917 | |
| R.R. 285 A (400A) (S C. 586 15-2-16) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1546. Copy from EFC. c. to Na.{Mr Nadin} X.2981 EFC1/T27. 3. 17. X.2981 - INDICATOR DIAGRAM APPARATUS. In connection with the above, there are one or two points we would like to mention. We do not quite see why the rotary valve with staggered passage, should be better than one with a straight through bore. Is it because of the additional resistance to flow producing a damping effect? We do not see that any damping effect is necessary when the apparatus is registering the correct instantaneous pressure, unless you mean that the successive instantaneous pressure corresponding to one point of the stroke may be rather variable. Should the relief valve be placed in the position shown on the original sketch, or is Mr. Royce's pencilling between the oil pump and the air vessel intended to represent the relief valve in another position? As far as we can see the air vessel shown is to act as a reservoir of oil under pressure without the oil pump running all the time, and in working upwards from low pressure to higher, we assume that some oil would be admitted from this air vessel into the pipe between the gauge and the engine, on account of superior pressure. In working downwards from a high pressure to a lower, there would seem no necessity to use the valve at the bottom of the air vessel open, as any oil which was discharged from the pipe could run into the engine. Would it not be a good scheme to put a second Contd. | ||