Experimental vibration analysis of an automatic machine for plastic cap assembly.

The case study presented in this paper concerns vibration measurements performed on an industrial automatic machine for assembling plastic caps. The final purpose of the activity is increasing the machine working speed of 50% (and thus the productivity), by making only limited modifications to the current machine design. Since elastodynamic issues may occur for operation at higher working velocity, an experimental campaign was carried out for assessing the vibrations characterizing the machine functioning at different regimes. The investigation permitted to identify the functional groups exhibiting significant elastodynamic phenomena induced by the speed increment. The results concerning two of these groups, namely a unit for the orientation of the parts to be assembled and a power transmission chain, are presented and discussed.