Analysis and synthesis of vibration isolation system of a grinding machine with account of the operational reliability of its elements
Introduction. A feature of the grinding machine operation under the floating workshop conditions is the vibration that reduces the accuracy and increases the roughness of the machined surfaces. The scatter of output quality indicators is caused by disturbing influences, some of which are not controlled during machining and lead to instability of the product’s properties. Therefore reducing the level of machine-forced vibrations by the vibration isolation efficiency, with regard to the machining features, is the crucial task with its solution leading to the industrial process indicators increasing. The purpose of the work: develop the ways of improving the reliability of the vibration isolation systems of the grinding machine under the under the floating workshop conditions. The structural modifications of the machine vibration isolation devices were investigated in the paper to determine their operational reliability and to identify the weak points through determining their failures probability to reduce the influence of vibration effects from the outside environment and internal factors on the processing quality. The methods of investigation. The used research techniques are morphological analysis, structural-layout and parametric synthesis based on the elements reliability assessment using homogeneous Markov chains. Results and discussion. Possibility of rational structural design of vibration-isolating devices for grinding machine placed in a floating workshop at the stages of analysis and synthesis at the structural and layout optimization level according to aggregated quality indicators is presented. It is shown that parametric synthesis and additional theoretical and practical studies of real vibration-insulating devices allows new design of the vibration-insulating device of a floating workshop machine. The research of the operational reliability with regard to the failure and restoration rates of subsystems using the marked state graph and the equations of final probabilities allows us to determine the operational reliability of vibration-insulating device (reliability function, P0=0,96), as well subsystems’ reliability by means of computer experiment. It is exposed that the new design of the support and vibration isolation device created as a result of parametric synthesis increases the reliability of the machine vibration protection. The presented results and subsequent tests proved the better quality of ground parts produced with new devices under external equipment vibration effects as well as under the sea swell, on the floating base of the workshop (not exposed in the paper). The presented results verify the prospects of the developed approach for the modernization of floating workshops machine tools that perform complex operation of high-precision parts manufacturing in the aquatic and offshore areas.