Studies of retrofit and new designs for reducing the shaking force of a can body-making machine

The work described provides analytical tools that aid the task of reducing shaking effects caused by the inertia of high speed machines. The motivation arises from work being carried out in the Department to design a retrofit package for existing two piece can body-making machines in collaboration with the manufacturer with support from SERC. In addition to the SERC supported work design studies are provided for new body-making machines. A description of the existing body-making machine and the specification of the new retrofit package are provided. The shaking force created by a planar mechanism and a method of estimating instantaneous values of this force are described. Strategies for balancing are surveyed and relevant literature reviewed. Those balancing strategies suitable for the retrofit package are selected and are applied. The specification for a family of new .. machines is also described and again balancing strategies are selected and applied to meet this new specification. The following claims are made for contributions to knowledge. 1. Kinetostatic analysis is combined with the Fast Fourier Transform (FFT) analysis to provide new ways of representing the cyclic shaking force in terms of pairs of contrarotating force vectors. 2. New applications are found for numerical optimisation techniques, in combination with kinematic, kinetostatic and the FFf analysis. 3. The uses of auxiliary mechanisms to create the partial balance are explored and one such mechanism is studied in depth. In this work the point is made that too much attention has been paid by .other researchers to balancing techniques (described here collectively as mass redistribution methods) wherein moving parts are shaped in such a way that the masses and mass centre locations cause the shaking force to be minimised. The work described here concentrates on balancing by rotating balance masses or auxiliary mechanisms thereby minimising the loads carried by the parts that have to withstand process forces.