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).
Challenges in developing and silencing J.III type shock absorbers.
| Identifier | ExFiles\Box 105\3\ scan0247 | |
| Date | 13th June 1932 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} c. to SS.{S. Smith} Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to Ry. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}3/KT.13.6.32. J.III SHOCK ABSORBERS. We have not yet succeeded in getting these consistently quiet. We have tried a number of masks as you suggested in your memo. 11/5/32, so far without success. Our great difficulty is to co-relate rig and road tests. We have obtained results on the rig that were excellent. To hear anything, it was necessary to listen to the shock damper with a rod. The indicator diagrams showed no waves. On the road the dampers were audible under most conditions. We are therefore, in future, going to concentrate on road tests. We have had the best results from Type 1 mask. The oil passes through the centre of the valve and is released under the head. The difficulty is to get sufficient oil under the head to damp the chatter without getting pressure built up at this point, apparently when "fluttering" the valve only moves about .025". One peculiar feature is the wide range of frequencies over which the valve will "flutter". These vary between oil hot and cold. We can alter the frequencies with various mask modifications. Another feature is the inconsistency. We built four dampers up with the same type of valve. Two were almost silent, two very noisy. So far we have tried to silence the dampers without using the external oil pressure, we shall now utilize it for helping to supply the mask with oil. We admit we have done insufficient road testing to establish anything definite about the R.R. type valve. We have now got some J.III type dampers on a 40/50 which will help us. We shall concentrate on this job for the next few weeks. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} | ||