A simplified calculation of the intermittent periodic operating regime of an electromagnetic impact drive

Abstract

This paper considers an intermittent periodic operating regime of an electromagnetic cyclic impact drive, in which the power fed from the supply source can substantially exceed that in its continuous operating regime. These investigations are important because of the need to improve the methods of designing electromagnetic impact drives characterized by various operating regimes in 10-min operating cycles and various cooling conditions during on and off periods. Calculations are carried out on the basis of the solution of Newton’s law of a heating equation for the maximum overheating for any nth cycle on the assumption that the electric drive is a homogeneous body with a uniformly distributed heat source, ideal heat conductivity, and constant heat generation rate. For a given operating regime, approximate expressions are obtained for the impact energy and frequency permissible from the standpoint of maximum heating conditions, depending on the thermophysical and geometrical parameters of the electric drive and allowing for various conditions of its cooling during on and off periods. An example is presented of a simplified calculation of the useful impact power of an electromagnetic impact drive for various cooling conditions and operating regimes.