| Hydraulic support is the key equipment in fully mechanized coal face. Its main function is supporting roof, protecting workers and fully mechanized equipment. Large mining hydraulic support develops with the emersion of large mining fully mechanized technology. Although after years of development, large mining hydraulic support has become comparatively mature, it still has some problems, such as poor capacity of resistance rock burst, low stability, poor capacity of wall protection. In order to effectively deal those problems, large mining hyper-static hydraulic support is designed by mining machinery research institute of CUMT. Hyper-static structure is applied to this kind of hydraulic support instead of four-bar linkage which is also applied in traditional hydraulic support. It has eight roots column with a distribution of “X” to realize full timbering. Hyper-static hydraulic support features in higher stability, shorter production cycle and higher safety factor.Based on structure characteristics, design requirements and working environment of large mining hydraulic support, an overall structure design and parameter determination of hyper-static hydraulic support is conducted in this paper. Using bottom-up modeling approach in Pro/E, a 3D model of hyper-static hydraulic support is established and virtually assembled.According to “Powered support for coal mine-Part 1: General specification” and adopting internal loading method, intensity checking of hyper-static hydraulic support is conducted in AWB. After analyzing the result of simulation and getting stress and deformation contour figure, those areas which lack intensity is conducted improved design. Strength of connecting pin is calculated and checked, which is to verify the reliability of connection between column, top beam and base.Under carrying load condition, fatigue life analysis of hyper-static hydraulic support is conducted. By analyzing fatigue life of top beam, base, shield beam and connecting rod, and improving the design those parts or structure which have minor fatigue life, it can finally meets the requirement of durability test and provides a reliable guarantee for hydraulic support regular work.Under static state, the lateral and longitudinal force condition of hyper-static hydraulic support are analyzed and then stability analysis is conducted, which is to get dumping and slip critical conditions of hydraulic support in coal face. By discussing the influence of friction factor and coal face angle on support stability, this paper offers the relationship between these factors and support stability in the lateral and longitudinal.Taking advantage of MATLAB optimization toolbox, and taking plate size of top beam as design variable, the weight of hydraulic support as design objective, the structure strength of support and plate size range as limiting conditions, top beam of hyper-static hydraulic support is conducted optimal design. Then the plate size is obtained when top beam possess minimum weight and thus reduces the cost of hyper-static hydraulic support. |
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