Analysis Of Eyring Non-newtonian Fluid Thermal Elastohydrodynamic Lubrication With Spinning

Four problems are studied in this thesis: Effects of the heat convection on point contact thermal elastohydrodynamic lubrication(EHL)with single velocity direction;Analysis of thermal effects on EHL considering spinning;A numerical method of the Eyring non-Newtonian fluid and its application;Measurement of optical interference oil film with spinning.Firstly,for the adaptability of the Reynolds equation,a general Reynolds equation of a non-Newtonian fluid was derived and verified and it can reflect the running status of the two contact solids.Taking a non-Newtonian fluid point contact EHL model with a single velocity direction as an example,effects of the heat convection on the temperature and the shear stress in the thermal EHL was discussed,and the distribution of the shear stress was given.Results show that,with or without the heat convection,effects of the slide-roll ratio and the load on the distribution of the film thickness,the pressure,the temperature and the shear stress are nearly the same.However,when the entrainment velocity increases to a certain value,the influence of the heat convection on the film thickness and the temperature is different while considering or neglecting the heat convection.Secondly,the mathematic model of non-Newtonian thermal EHL considering spinning was established,and comparison with the Newtonian fluid model was made.In addition,effects of the angular velocity,the load,and the spinning factor on the performance of thermal EHL with spinning were discussed.Results show that,compared with the non-Newtonian fluid,the oil film temperature and the friction coefficient obtained with Newtonian fluid are much higher when the load is moderate or heavy,so the non-Newtonian effect can not be neglected.The symmetry of the distribution of the film thickness and the temperature disappears because of the spinning.With the increase of the spinning factor,the asymmetry of the distribution of the film thickness and the temperature increases;Moreover,the highest temperature rises,and its position moves to one side.Thirdly,a new method for solving the equivalent viscosity was presented,and was applied to the thermal EHL model with single velocity direction and the spinning thermal EHL model in which the velocity varies with coordinates.The influence factors of the oil film shear stress and the temperature were analyzed,and the friction power curve was given,too.Results show that,the new method can be widely used in non-Newtonian point or line contact thermal EHL model under the complex velocity conditions.As the slide-roll ratio is small,the spinning has a significant effect on the oil film characteristics.The friction power is no longer a constant,and changes with the coordinate while considering the spinning.Finally,based on the theoretical model,an optical interference EHL test rig with spinning was designed and built.Effects of the velocity,the load and the spinning factor on the oil film thickness and shape were analyzed,and the phenomenon of the inlet starvation was observed.Results show that,the classical horseshoe shaped symmetry is not existed both for the condition of the spinning-rolling and the spinning-sliding.When the viscosity of the lubricant reaches a certain value,a dimple is much more easily generated under the spinning-sliding condition.The dimple is formed in the joint action of the load and the speed.When the speed or the load increases to a certain value,the dimple appears near the center of the contact region,and moves towards the entrance.Effects of the position of the inlet starvation are different in spinning EHL.