Simulation And Experimental Study Of Rubber Oil Seal Performance

Nowadays,dynamic seals are one of the most commonly used mechanical components.The rotating shaft lip seal,also known as oil seal,is the most common dynamic seal.The failure of oil seals can lead to leakage of the sealed medium,causing serious economic losses or safety accidents,and may also cause environmental pollution.Therefore,it is of great significance to study the performance of oil seals.The sealing function of the oil seal is achieved through continuous contact between the oil seal lip and the rotating shaft.Therefore,the contact pressure and contact width of the oil seal lip determine the sealing performance of the oil seal.In addition,the heat generated by the friction of the oil seal lip cannot be ignored as it can affect the performance and service life of the oil seal.This article aims to address the drawback of the single performance evaluation index in the current design of oil seal structures.By comprehensively considering the highest temperature,maximum contact pressure,and contact width of the oil seal lip,the structure of the oil seal is optimized.Secondly,a reliable oil seal wear model is obtained by combining numerical simulation and experimental research to predict the wear of the oil seal lip.In addition,the finite element models established in the literature are based on the hyperelastic constitutive equation at room temperature.However,this article also considers the temperature dependence of rubber materials and fits the Yeoh model with rubber temperature dependence.The main work is as follows:Firstly,the influences of the main structural parameters(oil side lip angle α,spring offset R,air side lip angle β)of the rotating single-lip oil seal on the highest temperature,maximum contact pressure,and contact width of the oil seal lip under dry friction and good lubrication conditions are studied.The optimal structure is obtained according to the optimization target,which is α=50 °,R=0.4 mm,and β=23 °.The performance of the optimized oil seal is better than that of the original structure,decreasing the temperature of the oil seal lip and prolonging the service life of the oil seal.Secondly,combining the Archard wear equation,a finite element wear model of the rotating double-lip oil seal is established to simulate the wear of the oil seal lip after504 hours under dry friction and good lubrication conditions.The predicted profile of the oil seal lip under good lubrication conditions agrees well with the experimental profile,verifying the reliability of the wear model.The wear of the oil seal lip after 5years under good lubrication conditions is also predicted,and it is concluded that the sealing performance of the oil seal is still reliable after wear.Finally,the thermal-structural coupling finite element simulations of the rotating double-lip oil seal under dry friction and good lubrication conditions are conducted.The simulated temperature rise curve is compared with the experimental temperature rise curve,verifying the correctness of the thermal-structural coupling model of the rotating double-lip oil seal.The influences of speed and spring force on the highest temperature and maximum contact pressure of the lip are studied,and the material parameters are fitted according to the variable temperature tensile data to establish the Yeoh model with rubber temperature dependence for further exploration of the effect of speed and spring force.The results show that the consideration of the temperature dependence of rubber has a significant impact on the simulation results,so it is necessary to establish a finite element model considering the temperature dependence of rubber materials in the future.