Substantiation of Rational Choice of Thickness of Shell and Plate for Rope Drum

Abstract

Double-ended lifting is often used in the mining industry. To change the horizon (hoisting height), it is necessary to change the working length of one of the ropes. The two-drum machines with a separate drum for each of the ropes are used for this purpose. One drum (jammed) is rigidly fixed to the shaft, and the second one (adjustable) is mounted on the bearings and is connected to the shaft by the decoupling device. Each drum is equipped with an individual braking device. We consider a two-rope mine hoist with a split drum, which performs the same functions as a two-drum machine. In this mine hoist, the drum consists of two parts – a wide jammed part and a narrow adjustable part, with a clearance of 3 to 5 mm between them. The jammed part of the drum is used for winding and unwinding both ropes. This design allows a significant reduction of the physical dimensions and the metal capacity of the mine hoist. At the same time, it raises requirements for the rigidity of the drum, as during the operation of the machine, one of the ropes passes the split between the parts of the drum. The rigidity of the drum should be such that its deformation due to the force of the coiled rope could not lead to an increase in the clearance beyond the defined norm. The purpose of the study is to improve the stability and safety of the mine hoist with a split drum by ensuring the rigidity of the drum, which prevents possible pinching of the rope in the gap between its parts. At the same time, the mass of the drum should be kept as low as possible. In the article, we propose an analytical model for determining the plate flexure of a drum under the action of a spread load of a coiled rope. The model is constructed based on the theory of elasticity. Using the presented analytical model, we build a graph of the relation of the plate flexure and the drum mass to the thickness of the shell (the thickness of the plate is constant) and a graph of the relation of the plate flexure and the drum mass to the thickness of the plate (the thickness of the shell is constant). Based on the analysis of the graphs, we conclude that in order to increase the rigidity of the drum from the point of view of the plate flexure (caused by the force of the coiled rope), it is necessary to first of all increase the thickness of the shell. Keywords: rope drum, shell, plate, rigidity, deformation, flexure, elasticity theory.