Abstract
Due to the increase in comfort demanded by the car market, all the major car competitors have focused a great part of 2000s challenge on this field.
A large contribution to the car internal comfort is due to the vibro-acoustical behaviour of the engine.
This paper describes an experimental study about the influence on the vibrational behaviour of the crankshaft due to several balancing degrees of the rotating forces acting on each own crank.
An assessment about different distribution of the counterweights, with the same total balancing degree, is also described.
All the tests have been performed on a baseline engine with a special crankshaft that allows to vary the balanc ing degree of the rotating forces without dismounting it from the engine block.
The study analysed the vibrational behaviour of the crankshaft itself and of the whole powertrain.
The results show that there is a very strong influece on the vibrational beha viour of the crankshaft due to the balancing degree of the rotating forces acting on it.
This dependence is not so remarkable in the other parts of the powertrain investigated.