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 conducted on a thermostat for controlling extra cylinder lubrication.
| Identifier | ExFiles\Box 39\4\ Scan286 | |
| Date | 10th October 1932 | |
| E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} X3499. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}12/KT.10.10.32. X5980 EXTRA CYLINDER LUBRICATION CONTROLLED BY THERMOSTAT. We have now conducted tests on the latest thermostat supplied by Messrs Smith & Sons. This thermostat is the largest possible size which can be put into the relief valve, and is filled with liquid having the lowest vapour pressure which Smiths recommend. They indicate that even with this fluid there was a danger of the thermostat failing if temperatures over 100°C were attained. Testing the thermostat in still air we obtain the following results :- Starts to move 13°C. .055" movement for 25°C. .150 movement for 35°C. .250" movement for 46°C. It is therefore clear that considering the oil pressure that will be on the valve head and the limitations of size of bellows, the stroke cannot be more than about .100", which we think is too little for passing cold oil, or alternatively an internal spring fitted to the bellows to counteract the resistance of the case. Possibly we may get better results with the incubator capsules which are on order. We ourselves feel that, with regard to the thermostat element itself, more consistent results would be obtained by using the heat of the cooling water to cut off at a fixed point. However, it would probably be simpler from your point of view, if the dimensions of the bellows could be increased slightly. We know that if this is done we can make the existing scheme work immediately. Any other arrangement will definitely require development before we can say what is going to happen. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||