Factors Determining the Size of Sealing Clearance in Hydraulic Legs of Powered Supports

Abstract

Abstract. The factors that directly influence the formation of a sealing clearance between the piston and the working cylinder in hydraulic legs of powered supports are considered in this article, the size thereof has a direct effect on the tightness of the legs and, as a result, on the safety of work at the production face. A detailed description of these factors is given, which is supported by the dependencies obtained from the results of finite element modeling of various types of legs under various strength and geometric parameters, external load types and locations in the support section. The problems of formation of radial deformations of a working cylinder loaded with working fluid pressure are considered, and their dependence on the level of this pressure and extension. Based on the simulation results, the mechanisms for the formation of additional clearances due to rod and cylinder misalignments are described, and the conditions and causes of the resonant phenomena development are given. The classification of these factors according to the degree of generalization and the functional interaction between each other is proposed.

The Role and Relevance of a Double Block in the Hydraulic System of a Powered Roof Support

“…Для того, чтобы разработать двойной блок, команда конструкторов проанализировала современное состояние уровня техники в данной области. Основываясь на собственном опыте работы, обзоре литературы [1,5,6,7], исследовательских проблемах [8,11,12,13,15] и проблемах, возникающих на практике [11], были приняты следующие технические предположения:…”

Untitled

“…Чаще всего негерметичность небольшая, но с течением времени и очередных циклов работы секции увеличивается. Отсутствие системы контроля несущей способности секции приводит к тому, что с временем такая негерметичность может вызвать то, что секция перестанет переносить нагрузки [1,5,6,7], исследовательских проблемах [8,11,12,13,15] и проблемах, возникающих на практике [11], были приняты следующие технические предположения:…”

Development of a Hydraulic System for the Automatic Expansion of Powered Roof Support

“…In order to meet the previously mentioned requirements and constantly improve the production efficiency and safety of the crew, it is necessary to search for new solutions in the field of coal-bed selection [28][29][30][31][32][33], improve working conditions and minimize hazards [34,35] as well as conduct research aimed at improving the reliability of machines [36,37]. A key element influencing the increase in efficiency of the mining process and the increase in safety is automation of the longwall complex [38][39][40][41][42][43].…”