Some Experiments on the Deflections and Vibrations of Drilling Machines

Abstract

The experiments described in this paper are part of a series of researches being carried out to obtain data for improving the design, construction, and utilization of production equipment, having regard to the increasing demand for such development which will be occasioned by the growth of automation. Research techniques and equipment were developed for examining the deflection and vibration characteristics of various drilling machines. Some comparisons were made between radial-drilling machines, vertical-drilling machines, and portal-frame drilling machines, the latter type being included particularly because of the increased possibilities for its employment in unit construction automated lines. An account is given of the general experimental procedure and the special apparatus used. An analysis is made of the deflection characteristics of each type of machine, and examples are given of the magnitudes of the deflections. The principal natural frequencies of vibration of the machines were determined, and the vibration characteristics of the machines in drilling and facing operations were examined. Recommendations are made for the reduction of machine deflections and vibrations, and a basis for some machine design calculations is developed.