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).
Engine flywheel experiments concerning inertia, vibration, and performance.
| Identifier | WestWitteringFiles\U\August1930-November1930\ Scan091 | |
| Date | 2nd October 1930 guessed | |
| (2) flywheel therefore lag 90° on No.6 crank. Experiments were also carried out on engine 1Y-G3 giving an out of truth at right angles to axis = .020" / 2 } at * parallel to axis = .012" / 2 } 3100 R.P.M. Arrangements are being made so that a drive can be taken direct from the crankshaft to the gearbox; the lever plate of the flywheel, driven member, and serrated pressure plate can therefore be removed greatly reducing the inertia. With the direct drive to the crankshaft, the lever plate, pressure plate, and driven member having been removed, the period at 3100 R.P.M. had vanished, the engine being smooth up to 3610 R.P.M. at which speed it became very noisy. This noise we shall try to remove by stronger valve springs. The moment of inertia of existing flywheel is 0.70 slugs ft^2. We removed approximately 0.10 or 14% of the inertia. The car was now tried with a flywheel of 32% less inertia (GL.{G. Linnett}235). This broadened the flywheel period but left its maximum at 3100 R.P.M. The half torsional vibration at 2160 R.P.M. was more pronounced. If we assume flywheel whirling about the back bearing we should expect w_c^2 ∝ 1/mx{John H Maddocks - Chief Proving Officer}^3 where w_c = whirling speed x = distance of C.G. of flywheel from crankshaft bearing. For Standard flywheel = mx{John H Maddocks - Chief Proving Officer}^3 = 560 (approx.) * 32% less inertia flywheel mx{John H Maddocks - Chief Proving Officer}^3 = 610 = increase of 9%. | ||