Parametric Design And Structural Optimization Of Large Mining Excavator’s Indexing Platform

According to the Ministry of Land and Resources’ data, at the end of 2014, China has proven reserves reaching 1.53 trillion tons of coal resources, ranking first in the world.Technology level and mechanization degree will directly affect the cost of coal mining and decide the firm competitiveness in the market. In recent years, more and more mines use strip mining technology and this trend needs more large mining excavators. Therefore, market put forward higher requirements about technology and performance of the mechanical excavator.Large mining excavator includes boom, stick, bucket, indexing platform, A frame, track frame and other parts. Indexing platform bearing the weight of the boom, A frame, balance weight, cab, drum, and other components, plays an important role on excavator’s overall performance. At present, the research on mine excavator are mainly concentrated on the boom, stick, bucket and bucket teeth, such as working parts.The study on indexing platform is quite lesser and the understanding of the stress and displacement distribution of indexing platform is not intensive enough.This paper supported by the national high technology research and development plan(863 program)-“Development of 75m3 Large Scale Open Pit Mining Excavator”(No.2012AA062001), studies on the WK-75 large mine excavator’s indexing platform which is independently developed by Taiyuan Heavy Industry Co., Ltd. First of all, analyze the drawings of indexing platform to determine the overall control parameters of indexing platform according to the structural characteristics. Combined with indexing platform users’ expectations of parametric function and the structure of indexing platform, we decide to use flat plan. In this paper, using the development plan of flat, WAVE module and PTS module based on UG were used to establish parametric design model and human-computer interaction interface of WK-75 mining excavator’s indexing platform and A frame.What’s more, outputing the engineering drawing which satisfied the requirements of the enterprise, and guide the production.Secondly, reasonably simplify the indexing platform model, and use Workbench for static structural analysis and convergence verify, obtained the stress cloud and displacement cloud of indexing platform. The analysis results show that the stress and displacement of indexing platform in the middle are smaller, displacement of the back plate which is connected with balance weight is the largest,as big as 3.5627mm; Stress of connection support of boom is the largest, as big as 227.1Mpa. But the strength of the structure is satisfied. Through modal analysis and harmonic response analysis of indexing platform, demonstrates the reasonability of indexing platform’s structure design.Finally, support of boom’s parameterized model is established in the Workbench, the thickness about the stress influence factors were analyzed, the Design Exploration module were used for optimization design.After optimization, under the satisfy of the structure strength condition, the thickness of the steel plate is reduced largely, reduced the weight of the supporting as much as 15.76%, and the using of materials saved.In this paper, the parametric modeling and human-computer interaction interface of WK-75 mining excavator’s indexing platform and A frame were established, outputing the engineering drawing which satisfied the requirements of the enterprise. Through analyzing the structure of the indexing platform, the weakness position of the indexing platform were comfirmed.Comparing with the actual working conditions, the analysis results were verified. Through optimizing design, the target of the equipment design of whole life and lower usage and maintenance’s cost were achieved, which had important practical significance.