Practical Experiences with Devices for Damping Torsional Vibrations

EARLY troubles experienced with torsional vibration in the shafting of marine and Diesel engines are mentioned, following which the various types of torsional-vibration damper are listed. Comments on the different ones are presented with particular reference to a damper with hydraulic coupling for a 3000-hp. 10-cylinder Diesel engine.

The operation of this damper is described at some length, the text being supplemented by illustrations. Results of tests with this device are presented graphically, and the conclusion is drawn that the damping flywheel with hydrostatic coupling permits (a) damping of vibration of shafting even when running in the most dangerous speed-ranges of the largest engines and (b) running at all speeds without regard to vibration and without resorting to hand operation of the damping device.

One of the written discussions* submitted is a critical review of the vibration-damping problem, the principal points being that the Lanchester type is both cheap and efficient and that performance variations can be completely eliminated by lubricating the friction plates. Such procedure would require heavier loading springs due to a lowered coefficient of friction. In the other written discussion, damping vibration is said to be merely a question of energy dissipation and emphasis is laid on the point that the design of a vibration damper should be such that no auxiliary devices are required to assure its satisfactory operation.