Some Early Experiences of Mechanical Vibration in Marine Engine Systems

Abstract

Everything which is struck rings; everything has a particular ring.—Pythagoras of Samos (582-507 B.C.) The lecture is divided into the following sections. Introduction. Early days. Camshaft drives. Camshaft drive at free end and after end of crankshaft; later developments. Mass balancing of internal-combusion engines. Single-piston assemblies; unbalanced centrifugal and inertia forces. Mass balancing opposed-piston engines. Ship vibration; scavenge-crank balance weights; scavenge-pump reciprocating parts; crankshaft-coupling-bolt failures; change of firing order; results and conclusions from vibration tests. Differential-stroke (mass-balanced) opposed-piston engines; first fully balanced opposed-piston engines; lever-driven scavenge pumps. Transverse (rolling) vibration of engine frame. Experimental determination of the natural frequency of transverse (rolling) vibration of opposed-piston engines; transverse vibration of engine frame in twin-screw ships and its control. Torsional vibration. Investigation of side-connecting-rod failures; investigation of torsional vibration; retiming the crankshaft system; general; marine steam reciprocating engine. Devices for controlling torsional vibration. Tuned and damped vibration absorbers; dynamic vibration absorbers in opposed-piston-engine propulsion systems; Bibby peripheral grid springs; vibration absorbers at free ends of crankshafts; experimental absorber with peripheral helical springs; Doxford-Bibby absorber. Later history. Large six-cylinder opposed-piston engines; alternative viscous-friction dampers; modified vibration absorber; stiffer crankshafts; P-type engines; J-type engines.

Viscosity Approximation of PDMS Using Weibull Function

“…In order to eliminate vibrations, and thus limit damage to multi-cylinder engines, torsional vibration dampers are used. They were used for the first time at the beginning of the 20th century in the USA to damp vibrations of torsional camshafts in submarine engines [ 1 , 2 ]. Viscous torsional vibration dampers ( Figure 1 ) consist of a housing, a cover, and an inertia ring immersed in the fluid filling the housing.…”