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-gearbox alignment, piston design, and a proposed test rig for engine vibrations.
| Identifier | ExFiles\Box 25\3\ Scan047 | |
| Date | 21th February 1912 guessed | |
| FHR 184/12 (6) X639 between the engine and the gear box. I hope to send you a sketch of an apparatus which I think will test this alignment more conveniently than anything they have at present, and it should also be realised that both the deepening of the frame or the trussing of the frame should make this alignment more constant. It is evident from the reports I receive that an extremely light Piston would be a very desirable feature for the engine. This makes the resistance of the engine more constant when the throttle is closed, though it makes turning under full load rather worse. It has a second advantage, as observed by Mr Platford, of leaving the engine steadier when turning at high speeds. It appears to me that this feature is now well explained by the fact that at high speeds, the variation of kinetic energy in the pistons is a considerable amount, and probably causes some of the vibrations of the engine at high speeds which cannot be accounted for by any want of balance. This could be proved by the rig arranged some time ago by me to run in a crank chamber a crankshaft with connecting rods and pistons as desired by a steady running belt drive and through universal joints. This apparatus should show that the crankshaft is perfectly steady until the connecting rods and pistons are put on. A flywheel should be put upon the crankshaft and no gas pressure allowed to occur in the cylinders. This is best avoided by having a | ||