RESEARCH OPPORTUNITIES TO IMPROVE THE HEALTH OF THE BOLTED JOINTS OF GAS TURBINE ENGINE

Abstract

The article considers the choice of the lubricants for using in the bolted joints of the serial gas-turbine engine AL-31. In a modern gas turbine engine complex bolted joints operating in various conditions are used. They are subject to demolition in the repair process, in which they break as the result of burning and thus the increase of the breakaway moment. On the basis of maintenance conditions analysis there were determined the most characteristic defects in bolted joints, as well as the reasons for their occurrence. It was established that the main cause of failure of bolted joints is the increase breakaway moment of bolted joint. To reduce the breakaway moment one should choose such lubricants as to reduce the thermal influence on the bolt and prevent it from being destroyed in the disassembly process. For choosing lubrications the analysis of the requirements for lubricants for bolted joints used at high temperatures was conducted. Lubricants choice was made based on the results of a comparative study of various compositions of lubricant application in the process of field testing. This research work is aimed to improve the efficiency of bolted connections in a wide operating range and to prevent the increase breakaway moments in gas-turbine engine repair. Obtained in the process of field testing results allow to suggest a lubricant that can be used in the bolt connection operating at high temperatures and to reduce the break-away moment compared to the commercially used one.