| The mechanical mining excavator has the advantages of high production efficiency,stable working performance and strong adaptability to the environment,and is widely used in large-scale open-pit mines.The tracked walking device is the bottom support member of the mechanical mine excavator,and not only bears the weight of the whole machine,but also receives various resistances during driving,and the load is greatly influenced by the driving conditions and the terrain.There are many components that make up the crawler device.It is difficult to calculate the force of each component of the key component through traditional mechanics under special conditions such as steering or climbing.Therefore,it is necessary to perform multi-body dynamic analysis on the crawler device and study the force conditions of the key components.On this basis to explore the mechanical properties of crawler components and optimize the track frame structure.The project was funded by the National High-tech Research and Development Program(863 Program)project “Development of a 75m3 Large Open-pit Mining Excavator”(NO.2012AA062001).In this paper,the multi-body dynamics analysis of WK-75 mining excavator crawler travelling device independently developed,and the finite element analysis of the key components of crawler walking is carried out,as well as the optimized design of the track frame.The main research contents are as follows:1 ? On the basis of reviewing a large number of related literatures,the development of crawler track theory,the influence of ground slip,center of gravity shift and other factors on the stress of the walking device are reviewed.The main research methods and optimization design methods of key components stiffness and strength are studied..2?This analysis not only the main factors considered in the design of the key components of crawler travelling device,but also the main types of resistance encountered by the Driving walking.According to the track driving theory,four working conditions are calculated.Lower drive torque and drive power values.3?The multi-body dynamics software RecurDyn was used to establish the dynamic model of the crawler walking device.The simulation analysis was carried out on four typical working conditions.The driving torque and driving power of each working condition were compared with the theoretical values to determine the reasonable simulation results.The load variation curve of the support roller in each direction under four working conditions was extracted to determine the most dangerous installation position of the support roller under various working conditions.4?The caterpillar frame and support wheel which is the key components of the crawler walking device are analyzed in ANSYS,and the stiffness and strength changes are studied.The maximum strain and stress position and value of the key components are determined.The natural frequency of the caterpillar frame is extracted,and the easy occurrence of the support wheel in the steering is analyzed.Wear types and improvement methods.5?The size of the track frame structure is optimized,and the thickness of the main support plate that constitutes the track frame is selected as a design variable.The minimization of the track frame volume is set as an objective function,and the track frame is optimized so that the track frame can increase the utilization rate of the material under the requirements of structural strength and rigidity,reduce the use of steel materials,reduce the weight,and improve the overall performance.In this paper,the multi-body dynamic analysis method,finite element analysis method,structural optimization analysis method are used to study which force analysis,stiffness strength analysis and structural optimization of crawler travelling device and key components.The research results can also provide a certain reference for the invention and optimization of other sizes of mining excavator crawler devices. |
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