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).
Causes of transmission rattles, referencing historical context from the Silver Ghost and potential solutions like rubber couplings.
| Identifier | ExFiles\Box 179b\1\ img229 | |
| Date | 12th December 1932 | |
| HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} TRANSMISSION RATTLES. With reference to the above, which seem to exist somewhat on all our cars, this as you know is an old fault, and worried us on the Silver Ghost in 1912., especially when we had the brake drum round the transmission. We all know that it is the inertia masses of the universal joints, wheels, and propeller shaft, lying between the flexibility of the front end of the drive and the back axle shaft. We also know that the source of the vibration is from the speed variation of the flywheel, caused by the difference of kinetic energy in the pistons set up by the angularity of the con. rods, much the same source that puts the crankshaft in a state of torsional vibration. Since we cannot entirely avoid this with 6 cyls., one would think that the most efficient way is to cut it off as close as possible to the flywheel, as we are attempting to do with the rubber block coupling. It is very doubtful what would happen if we put another rubber coupling behind the gearbox. One would expect at least some good from it though it may not be the most efficient place. You pointed out that we had given you one to try on the 25H.P., and we shall await the results with interest. You will find that on the Silver Ghost we fitted some form of spring damped drive between the flywheel and the gearbox. I hardly remember what pattern this took, but believe that it proved effective, though it might not with the present great range and high revs. of the transmission shaft. I will ask D.A. to go into this matter and see whether we can design something that will fit into the present space, of the metal type, as our experience with the rubber type seems to suggest that it is not altogether satisfactory, in spite of the precautions we have taken to keep the heat of the clutch away from the rubber. I will write further after D.A. has gone into the matter. R.{Sir Henry Royce} | ||