Efficiency -Reinforcement Study On Oil Seal Based On Numerical Calculation

Oil seal is an important component in mechanical equipment, and its sealing performance can directly affect the usage results as well as service life of the equipment.While in static state, as a result of the oil seal lip for surplus, oil seal lip tightly holds shaft surface, ensuring lubricating oil from leaking; When in dynamic state, between the sealing lip and axis, a very thin layer of fluid dynamic pressure oil film is usually formed to lubricate the oil film and to seal the medium in the cavity. This paper integrated finite element modeling and the numerical model of mixed elastohydrodynamic lubrication which is established on seal area. The analyses of the sealing performance of oil seal can achieve synergistic design of oil seal quickly and efficiently.The sealing performance of rotary shaft lip seal under both static and dynamic states were simulated and analyzed by ABAQUS software. The two-dimensional finite element model for oil seal under static conditions was established, and the effect of the interference fit, the spring stiffness coefficient and the theory contact width with or without spring on the static sealing index such as contact pressure and contact width were also analyzed. The three-dimensional finite element model for oil seal under dynamic conditions was established, and the influences of the rotational speed and the friction coefficient between the lip and the shaft on the friction force and friction torque of oil seal were analyzed.Analysis results shown that with the same interference fit, the sealing performance of oil seal with spring was higher than that without spring, and sealing performance improved along with the increase of spring stiffness coefficient, but reduced with the theory contact width increasing; the friction torque for seal increased with the increase of friction coefficient, but was not affected by the changing shaft speed.The mixed lubrication seal area numerical model is established based on flow factor statistics, and coupling oil film of fluid mechanics, lip rough peak contact mechanics analysis and the analysis of sealing lip elastic deformation. The above coupled iterative processes were all computed by MATLAB programming. Apart from mapping the fluid pressure distribution and that of oil film thickness, the two evaluation indexes on the properties of oil seal: pumping rate and the friction torque were further measured. The author analyzed how the lip roughness, axis of rotation speed, work pressure and the initial interference quantity of fluid parameters affect fluid pressure, oil film thickness, pump suction rate and friction torque, optimized oil seal structure and working parameters, as well as provided theoretical basis for synergistic design and practical application of oil seal.