Analysis of the Pressure Increase in the Hydraulic Cylinder of the Longwall Powered Roof Support during Use

Abstract

This paper presents the results of lab-simulated tests on longwall powered supports under dynamic loading conditions. The tests were carried out on a test site, where the tested prop was subjected to a dynamic load using a controlled mass falling under gravity onto the support. The loading on the support was therefore determined based on the weight used and the distance of freefall before impact. The operating characteristics of the valve were determined, specifying temporary changes in the pressure and the prop’s dynamic yield rate and total deformation. The research aimed to determine the operational parameters of the valve to be used in new and improved components for powered roof supports. One of the most essential elements of the powered roof support hydraulic system is the safety valve. The results confirm the validity of the concept and the possibility of applying the tested valve to the developed control system of the prop of the powered roof support. The forged safety valve has been designed to significantly improve the safety and efficiency of the powered roof support, especially in conditions of safety hazards.