| Abstract [eng] |
With the rapid expansion of industry and the introduction of automated processes in production lines in Lithuania, there is an increasing need to use special industrial devices. One of the most commonly used components in such devices is threaded connections. These are general purpose connectors that allow certain assembly units to be easily disassembled, serviced and reassembled. However, the operating device can cause various external reactions, such as dynamic loads, vibrations, temperature spikes, etc., which can significantly affect the efficiency of the threaded connections and, at the same time, the performance and utilization of the devices. In order to maintain a high level of reliability of threaded connections, additional measures are often used that prevent the threaded connection from loosening easily and spontaneously. One such tool is the adhesive for fixing threaded connections. In this final master's project, the main strength characteristics of the adhesives for threaded joints supplied to Lithuanian market and their resistance to external influences affecting the joint were explained. During the preparation of this paper, alternatives to such adhesives as, for example, nuts with a nylon ring or toothed flange were reviewed and their advantages and disadvantages were evaluated. Analyzing the research conducted with adhesives for fixing threaded connections, researchers found interesting and useful insights about the effect of adhesives on the coefficient of friction between threaded surfaces, about the resistance of adhesives to high levels of humidity and temperature. However, there was found a lack of research on the variety of adhesives used and their comparison, and the different types of threading coatings and their influence on the adhesive properties were not evaluated, so it was decided to conduct three studies with adhesives from three manufacturers and different threading coatings: a verification study to determine the breakaway torque, the effect of the maximum operating temperature on the breakaway torque and the investigation of the adhesive resistance to dynamic shock loads. Both verification and maximum temperature tests were carried out using M10 size bolts. The results of the tests showed that “A brand” and “B brand” brand adhesives showed the most reliable properties to maintain threading performance. The single biggest difference between these brands is the price, which differs by as much as 93%. The test of resistance to dynamic loads was carried out based on the NASM 1312-7 standard. According to this standard, the effectiveness of threaded connections is evaluated by subjecting them to shock loads in a special test bench on a vibration bench. The obtained results showed that “A brand” glue has the highest load resistance, and “B brand” has a slightly lower, but also sufficient, load resistance. In the conducted studies, the use of third-party adhesives - "C brand" - showed unsatisfactory results in most cases, and this adhesive is not recommended for use in any case. |
