Analysis of Vibrations of Reciprocating Engine Shaftings by the Transfer Matrix Method

The authors investigate the characteristics of torsional vibration displacement and stress of a crankshaft with a viscous fluid damper from the experimental and analytical viewpoints.The obtained results in this paper are as follows:1) The phase angle between the inertia ring and the case of the viscous fluid damper is considerably large, so the phase angle on the mode of torsional vibration cannot be neglected in this kind of the vibration systems.2) The engine speed of the maximum torsional vibration stress at one point of the crankshaft is different from that at the other point of the crankshaft.3) The engine speed of the maximum torsional vibration displacement does not necessarily correspond with that of the maximum torsional vibration stress.4) The torsional vibration displacement and stress in a crankshaft with a viscous fluid damper can be approximately calculated by using the 3 dimensional analysis of forced vibration by the transfer matrix method, in which the values of the complex viscous damping coefficient obtained with the experiment of a vibro-viscometer are adopted.