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).
Issues with crankshaft damper stiction, a 'galloping' knock, and potential solutions including different materials and designs.
| Identifier | ExFiles\Box 25\3\ Scan301 | |
| Date | 14th January 1928 | |
| R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} c. to Hs.{Lord Ernest Hives - Chair} X634 E1/M14.1.28. RE. CRANKSHAFT DAMPERS. X.8010 X.4012 X.634 X.8300 X.4117 I understand from Hs.{Lord Ernest Hives - Chair} that nothing gives as good results as woven cotton. This remains to be confirmed officially. There appears to be too much stiction in our present production friction dampers which apparently gives rise to a periodic swing between the front and rear flywheels (the front acting as a solid flywheel) at 22 - 23 m.p.h. even under light conditions. This is CWB's 'galloping' knock which has come up load/as a complaint on one or two customers' cars. The knock can be cured by slacking off the damper wheel, and we shall hear from Hs.{Lord Ernest Hives - Chair} if woven cotton gives better results, as one anticipates it should. Chrysler uses an external damper split flywheel, and the two halves on his latest model are pushed apart by an inverted 'V' shaped rubber ring, the rubber being loaded with a lead compound to make it heavy. As the speed of the engine increases the rubber ring grows larger, tends to spread the flywheels, and apply more pressure in proportion to the increase in the intensity of the torsional vibration. We have always had the idea of variable friction, but until recent times as you have pointed out, we have had satisfaction with a fixed damper. Fibre appeared once to fulfil the requirements until the flywheels were bolted too closely together for it to swell. Our latest experimental flywheels are made and suitable for fibre and we are supposed to be trying this material as well as others. There is not much doubt that as the engine output increases crankshaft damping becomes a more difficult matter. E.{Mr Elliott - Chief Engineer} | ||