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).
Flywheel vibrations, their causes, and comparisons to similar phenomena.
| Identifier | ExFiles\Box 14\2\ Scan065 | |
| Date | 1st November 1939 | |
| -14- SECTION 2. FLYWHEEL. (Contd). are large amplitude vibrations when the rear half of the flywheel is removed, and these are reduced in amplitude and frequency by refitting the flywheel. (6) The mode of vibration was such that the flywheel appeared to vibrate laterally about a diameter, in a similar way to the propellor vibration experienced on R.R. Aero Engines during the War. With regard to these flywheel vibrations, we do not think they are anything new, but merely another case of the early propeller vibrations which gave us so much trouble during the War. In the latter case, the disturbing force was the alternating gyroscopic couple experienced by the propeller during a turn. Another instance of this type of vibration is found in marine steam turbines. In certain installations the turbines vibrate when the ship is pitching or yawing badly in a rough sea, and the explanation is lateral vibration or 'fluttering' of the turbine discs due to the gyroscopic couple set up during a turn. In our case we think the disturbing forces are due to (a) the unsteadiness of the rear journal due to distortion, and possibly (b) the cumulative effect of the slightly overhanging weight of the S.S. flywheel and clutch. It should be realised that the above is merely our best explanation to date; we have barely commenced experiments on this new vibration, and would have to fit a | ||