Experimental Study And Theoretical Analysis Of Oil Seal Performance Operating At Medium-low Pressure Conditions

Rotary shaft oil seals have been widely used,because of its simple structure,low cost and easy installation.However,they are extremely vulnerable in higher pressure situations,and the experimental and theoretical studies of oil seals are mainly focus on the no pressure difference condition,while the selection criteria and theories in higher pressure situation are extremely scare at present.Special pressure oil seals mainly depend on import,severely restricting the use of oil seals in many important equipment.Therefore,it is quite important to carry out researchs on the performance of oil seals in the medium-low pressure situations in order to design pressure oil seals and improve the reliability of seal.First,TC,TCG,TCV and TCGZ oil seals which have different structures while all of them have been used in oil pumps were chosen to conduct experiments.The friction torque and temperature of the matching shaft end face where near sealing area under different pressure and different speed were tested by self-built experimental platform.By comparing the change rule of above tested performance under different oil pressure,we found that,even if the oil pressure is not higher than 0.2MPa,performances of above oil seals may be greatly affected,TCV oil seal possess the most stable performance under different pressure,and the supporting ring can improve the pressure-resistant properties of oil seal to a certain extent,thus reducing the influence of oil pressure on seal's tribological properties and temperature.Then,an axisymmetric contact model is established.After comparing the numerical value with experimental data of radial force of above four kinds of oil seals,the effects of pressure of sealed fluid and structure parameters on contact performance were discussed.Results showed that the waist length,waist thickness,atmospheric side angle and interference are the main factors affecting contact performances and stability of oil seals.Based on the Taguchi method,a robustness optimization design was carried out in order to improve the stability of the contact area,a set of optimized design parameters were obtained.Finally,considering the effect of pressure on the thermal boundary,the friction performance and the viscosity-temperature effect,an axisymmetric thermal-structure coupling analysis model of oil seal has been developmented with the help of secondary development of ANSYS.The results further proved that oil pressure have a significant influence on temperature field of oil seals,and need to carefully choose oil seal even in medium-low pressure situations.Whlie,by reasonably designing the structure of oil seal,the stability can be improved,the deformation can be controlled,and the influence of oil pressure on the temperature field can be reduced.This paper combined with the experimental test and theoretical analysis,the influence of oil pressure and oil seal's structure on the contact properties,temperature field and stability of oil seal is explored.It has to be proposed,even if it's used in medium-low pressure,it's necessary to focus on stability of oil seals.Yet theoretical models ignored the micron oil film,the influence rule of oil pressure on the formation of liquid film located in seal area and lubrication state can not be obtained,so a multi-scale thermal-fluid-solid coupling analysis model remains to be established in futher work.