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 and proposals for engine mounting to manage torque and vibrations.
| Identifier | ExFiles\Box 25\3\ Scan308 | |
| Date | 4th February 1928 | |
| R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} c. to BJ. Hs.{Lord Ernest Hives - Chair} Rn.{Mr Robinson} √634 E1/M4.2.28. EAC.10 ENGINE MOUNTING. X.7380 X.7005 X.634 X.7830 In discussing recent experiments on engine mount-ings during visits to Derby, we arrived at the conclusions that so far as the low speed reactions were concerned it was difficult to obtain the requisite amount of damping owing to our inability to anchor the damping device with sufficient rigidity to the mass of the chassis. SEE ORIGINAL FOR SKETCH AND X.7005 These conclusions (which are embodied in experiment al report Hs{Lord Ernest Hives - Chair}/Rnl/LG30.1.28) have led us to consider if it would be possible to utilize the major portion of the mass of the frame and body for damping purposes, without spoiling the insulation of the body from engine and road vibrations, torsion of chassis frame etc. As shewn in the sketch the body carried on a subframe might be rigidly anchored to the middle of the chassis frame opposite the cross member at the front end of the 'X'. The subframe would then be flexibly supported elsewhere from the chassis frame as required. The engine clutch and gearbox are in one single unit and a part or the whole of the torque re-action from the power unit could be taken through rubber, with additional damping in the form of solid friction if required from the rear end of the gearbox to the cross member opposite the rigid mounting for the body. There should be no difficulty in carrying the power unit so that it remains otherwise torsionally free, yet triangulates the frame in the plan view, utilising the flexible plate scheme you devised for EAC.10 A peculiarity of this scheme is that the first speed and reverse torque is fed off direct and the clutch case only carries engine torque. It seems somewhat frightful to tell the body to go to the engine and hold it, after we have been trying to keep the two apart, but the chassis frame alone, even at the front end of the 'X' may not have sufficient inertia for the purpose. We advance these few notes in all diffidence, knowing that the pitfalls surrounding this problem are many, and some remedies are worse than the disease. E.{Mr Elliott - Chief Engineer} | ||