振动条件下楔形垫圈的防松性能研究

Screw-thread looseness is one of important factors to affect reliability and safety of mechanical products. Wedge washers are a type of anti-loosening products with a special structure to receive more and more attentions in industry. However, its anti-loosening mechanism is not fully revealed. Here, the method of finite element simulation combined with test analysis was used to evaluate the anti-loosening performance of wedge washers under vibration. The wedge washers' anti-loosening mechanism was analyzed from views of positive feedback adjustment and negative one. The effects of wedge angle, washer outer diameter, friction coefficient and material properties on wedge washers' anti-loosening performance were systematically investigated. The results showed that wedge washers have a good anti-loosening performance under vibration because the use of wedge washer causes increase in preload, decrease in slip area on flank of thread and looseness-weakening, and this is a process of negative feedback adjustment to make loosening be stopped and preload be unchanged; the larger the wedge angle, washer outer diameter and material stiffness, the better the anti-loosening performance of wedge washers; friction coefficient on upper and lower radial tooth surface is also an important factor to affect wedge washers' anti-loosening performance; to ensure wedge washers' anti-loosening performance, the friction coefficient on upper and lower radial tooth surface is 0.06 larger at least than the friction coefficient of upper and lower washers be; the reliability of the simulation results is verified with transverse vibration tests.