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).
Test on the rubber silencer suspension for a Bentley vehicle.
| Identifier | ExFiles\Box 86\3\ scan0019 | |
| Date | 26th July 1933 | |
| X223 To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. Wor.{Arthur Wormald - General Works Manager} By.{R.W. Bailey - Chief Engineer} BENTLEY SILENCER SUSPENSION. We have carried out a test on the rubber silencer suspension to see if we can discover any reason for the failure on the car in France. The results are shewn in the attached curve Hs.{Lord Ernest Hives - Chair} 1085. The results indicate that this system is capable of moving a total of 2.8" fore and aft, and just over 1/2" sideways. It will be noticed that the flexible mounting is six times as rigid sideways as it is fore and aft. We feel that in this particular case it may be the stiffness of the sideways movement of the silencer suspension which is the cause of the trouble. This movement is continuous and may reach a high frequency when the car is run over bad roads. Furthermore, to move the mounting in this direction the intermediate pipe is acting as a cantilever, as you pointed out, and the maximum bending moment comes at the hottest point. We believe the success of the flexible mounting on 18.G.IV. rigged up by the Expl. was due to it being free to move transversely as it was longitudinally. We shew results obtained with more flexible rubbers but we fear perishing if we use a very soft grade.(Hs{Lord Ernest Hives - Chair}1093) Whilst trying to measure the actual movement of the power unit at the bottom of the downtake, we noted that the pedal shaft restrains the diamond engine mounting to a certain extent. Actually the engine oscillates considerably under torque in spite of this restraint. We will let you have further information re. this pedal shaft very shortly. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||