Reliability Study On Lip Oil Seal Of Rotating Shaft

Due to its excellent sealing performance,high cost performance and long service life,oil seal has gradually become the most common seal in various fields,especially in the mechanical field.The reliability of rotary shaft lip seal directly affects the performance and operation reliability of the supporting mechanical equipment.However,the design of lip-shaped oil seal of rotary shaft mainly relies on the design experience of engineers.Its reliability can only rely on experimental measurement,which makes the reliability operation of oil seal very uncertain and unpredictable.The reliability research of rotary shaft lip seal has important theoretical significance and application value for improving the reliability of oil seal design and operation and improving the performance of mechanical equipment.Based on the finite element analysis and numerical calculation model,with the aid of response surface method and orthogonal test design,the structural parameters of oil seal are optimized and combined with the pump suction and friction torque as reliability indexes.The primary and secondary order of the influence of structural parameters on the reliability of oil seal was obtained by range analysis.Based on the experimental design and response surface method,the explicit and implicit conversion of the limit state function of the oil seal reliability index is carried out.According to the limit state function under the explicit state,the reliability sensitivity of the oil seal based on structural parameters is analyzed.The results show that the sensitivity of each factor to the suction rate of oil seal pump is in the order of oil side lip angle > theoretical contact width > air side lip angle > waist thickness >interference amount > waist length > spring stiffness coefficient.The sensitivity of each factor to friction torque is in the order of oil side lip angle > theoretical contact width >waist thickness > spring stiffness coefficient > interference amount > air side lip angle >waist length;the reliability of oil seal increases with the increase of the mean value of interference,oil side lip angle and air side lip angle,and decreases with the increase of the mean value of other influencing factors.The reliability decreases with the increase of variance of each factor.Based on the optimization model,combined with the analysis mode of structural parameters,the influence of operating parameters such as rotational speed,oil pressure,friction coefficient and roughness on the reliability of oil seal is studied and analyzed.Because the temperature has a great influence on the reliability of the oil seal,this paper takes the temperature related index as the reliability index of the oil seal to calculate the reliability.The results show that the maximum temperature is the best index to study the reliability of oil seal.Based on the three principles,the oil seal reliability is 1,and based on the actual use temperature of the main material of the oil seal,the oil seal reliability is0.4597;the sensitivity of friction coefficient to the maximum temperature is the highest;the increase in the average roughness will increase the reliability of the oil seal;the increase in the mean of other factors will reduce the reliability of the oil seal;the variance of each random variable increases,and the reliability of the oil seal decreases.