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).
Experiments with rubber engine mountings for the Phantom, exploring the possibility of avoiding drilling the rubbers.
| Identifier | ExFiles\Box 65\4\ scan0112 | |
| Date | 28th December 1928 | |
| To BY.{R.W. Bailey - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} X5005 c. to MX.{John H Maddocks - Chief Proving Officer} Wor.{Arthur Wormald - General Works Manager} Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}6/LG4.12. 28. RUBBER ENGINE MOUNTING. F.78146. X5005 (X7005 strikethrough) We have been carrying out experiments with the rubber engine mounting on the Phantom in order to determine whether it is not possible to avoid drilling the rubbers. It will be remembered that it was found necessary to drill these rubbers on production because their rating was too high. Also some inconvenience has been experienced in getting rubbers to 'pair up'. We find that the length of the rubber block under compression can vary .015" due to the limits on the detail of the engine foot. Additionally, if its length is judged by the distance apart of the lips of the recesses into which the rubber fits, there can be a further apparent variation of .010". It is clearly very difficult to make these rubber blocks with no variation in elasticity, we therefore suggest that the limits of the steel pieces that determine the compressed length of these rubbers should be cut down as far as possible so that the only variable to affect the engine alignment will be the rubber. Tests we have carried out shew that a rubber giving .150 deflection under 750 lbs. load is satisfactory for eliminating engine vibrations. This is approx. the rating of the rubbers at present supplied by Messrs. Dunlop for the 40/50 in an undrilled condition. We therefore recommend that contd :- | ||