| China's coal mines,iron ore and other mineral resources are rich,most of the mining methods used in the open pit mining,according to statistics,accounting for the proportion of 50 to 89%,while other minerals such as bauxite,limestone almost all open mining.In the large open pit stripping engineering,the most important step is to excavate the loading process.Mining excavator is the main equipment in the open air,its performance determines the overall economic benefits of the open pit mining industry,which puts forward higher requirements on the technology and performance of the excavator.Therefore,how to optimize and develop high efficiency mining machinery is of great significance.With the development and application of large mining machinery in mining engineering as the research background,combined with the National 863 project "75 cubic meters of large opencast mine excavator development"(No.2012AA062001),the Taiyuan group independent research and production of WK-75 large excavator as the specific research object,application of UG software to the excavator slewing platform and A frame the parametric modeling,using ANSYS Workbench computer software to calculate the A type excavator frame and rotary platform,according to the results found that the stress and deformation characteristics of the model,through the Workbench modal analysis of rotary platform and A type frame fatigue analysis and structure optimization,and provide a scientific basis for the design and optimization of the structure of large mining excavator WK-75.The main conclusions include the following:(1)according to the design and production drawings of the excavator,the flat model is used to realize the correlation between the model and the parameters.The parameters of the model are linked together by the expression,and the model is controlled by the modification of the parameters,so as to establish the model of the rotating platform and the A frame.The parametric model and engineering drawing of rotary platform and A frame of WK-75 type mining excavator based on UG can be set up and output.(2)the 3D model of UG is built into the rotary platform and the A frame,and then it is introduced into the ANSYS Workbench software to analyze the static strength,and then the stress nephogram and displacement nephogram of the rotary platform and A frame are obtained.The data show that the front rotary platform of the stress level is higher than the back end,overall stress most are within 90 MPa,the maximum stress is 218.37 MPa,the maximum displacement is 4.61mm;the A frame,the maximum stress position for A frame top pin sleeve and the connecting piece is connected,the maximum stress is 219.69 MPa,the maximum displacement is 0.60 mm.The yield limit of material is less than that of material,which satisfies the strength and stability of the structure.(3)on the basis of the parametric model and structure analysis of the rotary platform and the A frame,the modal analysis of the rotary platform and the A frame is carried out by using ANSYS Workbench.The results show that the working frequency of the excavator is between 5HZ and 15 HZ,and the minimum vibration frequency of the rotating platform is 28.799 HZ,which is far away from the resonance.The maximum displacement is twelfth,which is 0.84237 mm,compared with the size of the whole rotating platform,the displacement is smaller,the structural design is safe.(4)on the basis of the analysis of the structure of the ANSYS Workbench platform and the A frame,the fatigue analysis of the rotary platform and the A frame is carried out.The analysis showed that the front end of the rotary table is slightly lower than the minimum life back,but the fatigue life of parts in reinforcing plate parts under the arm,its service life is 53582 times,the safety coefficient is 0.39475;the A frame is in the top part of the minimum fatigue life of pin sleeve and the connecting part,the minimum fatigue working condition should be number of cycles for 17661 times,the minimum safety coefficient is 0.38844,less than the design life,so there may be fatigue failure,should be concerned. |
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