Underground Loader Working Device Performance Upgrading And Structural Optimization

Scraper is one of the key equipments used in underground trackless mines. It has three functions of load, haul and dump with the motions of its arm system, Therefore, the structure and performance parameters of the arm system could affect the scraper directly on the size and performance parameters. The design of the arm system includes structural parameters design of linkage and structural design of all components. The study in this paper was based on some scraper arm system, the work that studied include optimization design of linkage structural parameters, the development of linkage digital design software which based on the structural characteristics of Z style inversion six-bar linkage, the multi-rigid-body kinematic and dynamic analysis that did before and after the arm system optimization, and the finite element analysis of force condition at the state of static. The main content included:1. Some predigest treatments were made to the 3D geometric model of the arm system, before it was turned into plane frame structures. By extracting the basic relationships from the geometric structure, the linkage mathematic model for optimization design was established. And the optimization to structural parameters of linkage was executed by adopt the improved algorithm of constrained complex method.The performance of power and dump,by the different degree,was improved.2. Combined with the Six-bar linkage characteristics of arm system, by using GUIDE (Graphics User Interface Design Environment) platform of MATLAB, a scraper arm system digital design system was developed, which assembled some functions into one, these functions include the simulation and dynamic display of arm system, trajectories of cusp automatically drawing and the curve and data of performance automatically generation. The correctness and reliability of the optimize model was verified by the simulation of motion analysis before optimization.3. The virtual prototype digital model of scraper was built. The movement and dynamic characteristic of important poles and hinge points of arm system, which obtained from multi-body kinematic and dynamic simulation that did before and after the arm system optimization, accurately reflected the motion and force condition of the scraper arm system, and provided an important basis for a more rational components' mass distribution and strength calculation.4. The finite element analysis model of the scraper arm system was made. The maximum stress value and the stress concentration positions were found through static analysis of typical condition. And the best scheme of dynamic modification of arm system was confirmed by modifying, modeling and calculating again and again, so that the state of the stress could be in the best state.