Application Research on Anti-loosening of OCS Structure and Equipment in Rail Transit

Research purposes：The development degree of rail transit has become a symbol of modernization and plays a key role in national economic development and social stability. Among them，the safety and reliability of traction power supply systems have gradually become the focus of public attention. The dynamic matching of catenary and pantograph in the power supply system is the key to ensure the smooth current collection of the locomotive. However，the high-frequency vibration caused by frequent alternating contact force can loosen components of the catenary，especially in high-speed railway operation，coupled with mechanical vibration and wind-induced vibration of trains. Therefore，the anti-loosening of equipment and components is an essential requirement for safety and reliability. The purpose of this paper is to analyze the comprehensive ability of catenary structure，equipment，connection mode between parts，failure mode of threaded connection，and matrix collapse. Through qualitative investigation，quantitative test，theoretical calculation，and finite element comparative simulation calculation，the technical performance of thread fastening and anti-loosening is compared and analyzed，and the anti-loosening ability is evaluated and the new technology for simple，long-term，and controllable thread connection is proposed. Research conclusions：（1）The proportion of carbon steel or carbon steel M16 and above bolts and nuts with added elements used in the overhead contact system is about 40%，but the control of tightening torque and the evaluation of anti-loosening performance are often ignored.（2）The anchor bolts of the inverted cone must be tightened accurately to allow the adhesive to detach from the body and produce expansion and compression，to better play their role. Therefore，precise control of tightening torque is an important safety indicator.（3）Through the analysis of the relationship between loosening torque and tightening torque，it is concluded that it is not necessary to completely prevent loosening as long as the loosening torque is greater than the tightening torque. Improper handling can lead to thread adhesion and jamming. Accurate control of tightening torque is the key to truly preventing loosening.（4）Precision torque control type anti-loosening nut achieves the most precise torque value with the simplest operation，ensuring reliable connection，controllable indicators，energy saving，and efficiency enhancement，and is more suitable for high-altitude operations on high altitudes.（5）The research results are mainly applied to bolt tightening and anti-loosening of contact network equipment，structures，and components. © 2024 Editorial Department of Journal of Railway Engineering Society. All rights reserved.