Study on pre-tightening force formation and tightening process characteristics of self-locking nut

收口螺母下预紧力形成及拧紧工艺特性研究

School of Mechanical Engineering, Dalian University of Technology, Dalian 116024, China

Received: 11 April 2025

Abstract

The self-locking nut has good seismic and anti-loosening performance and is widely used in the assembly of aero-engine rotor structures. The control accuracy of the pre-tightening force is crucial to the performance of the engine. However, the influence of the self-locking nut on the tightening process is less studied at present. First, the tightening process of the self-locking nut under the machining error is analysed, and the theory and error analysis of the bolt assembly process are carried out. The self-locking nut is closed by means of node offset. The influence of the self-locking nut on the tightening process is simulated and analysed. The results show that the closing nut makes the stress redistribution of the thread and the end face of the nut, from uniform distribution to symmetrical distribution, resulting in stress concentration. Finally, the single bolt tightening test is carried out to explore the influence of the number of tightening cycles on the tightening process parameters, and to provide guidance for the existing tightening process.

摘要

自锁螺母具有很好的抗震防松性能, 广泛应用于航空发动机转子结构装配中, 预紧力的控制精度对于发动机的整机性能至关重要, 而目前自锁螺母对拧紧工艺的影响研究较少。对加工误差下的自锁螺母拧紧过程进行分析, 对螺栓装配工艺进行理论和误差分析; 自锁螺母采用节点偏移的方式实现收口, 仿真分析了自锁螺母对拧紧过程的影响, 结果表明收口螺母使得螺纹及螺母端面应力重分布, 由均匀分布变为对称分布, 出现应力集中; 开展单螺栓拧紧试验, 探究拧紧次数对拧紧工艺参数的影响规律, 为现有的拧紧工艺提供指导。