Research On Thermal Elastohydrodynamic Lubrication For Cylindrical Gear Pair With Non-Newtonian Fluid

Cylindrical gear is widely used in ship, automobile, aerospace and other fields, with its advantages of high transmission efficiency, compact structure, large carrying capacity. Lubrication failure is one of the main forms of cylindrical gear transmission failure. The oil film fracture leads to the direct contact of metal, which produces local high temperature, the tooth surface wear, scuffing failure, etc.Nowadays, friction,wear and lubrication have been new hot research field.Based on finite line contact model for cylindrical gear pair, this paper researches non-Newtonian thermal elastohydrodynamic lubrication characteristics and provides tribology theory basis for the parameter design of gear, which has certain theoretical significance and practical application value.It is mainly devided into the following five aspects:1) Elastohydrodynamic lubrication numerical research for tapered roller. Ultilizing tapered roller and a rigid plane contact model as the research object, the distribution of the pressure, film thickness and temperature is studied, friction coefficient rule is analyzed under different working conditions, which provides theoretical basis for lubrication analysis of helical gear transmission.2) Non-Newtonian thermal elastohydrodynamic lubrication numerical research for spur gear pair. For spur gear pair elastohydrodynamic lubrication model, considering the characteristics of non-Newtonian fluid, the time-varying and heat effect, the influence of working parameters on the coefficient of friction is discussed.3) Newtonian isothermal elastohydrodynamic lubrication numerical study for helical gear pair. Viewing the helical gear meshing as the contact between two reverse tapers, the changing law of curvature radius, entrainment speed, sliding–rolling ratio and load distribution are obtained.The lubrication characteristics of helical gear pair in different contact and mesh position are investigated and the influences of working parameters on lubrication performance are researched.4) Non-Newtonian thermal elastohydrodynamic lubrication numerical research for helical gear pair. On the basis of Newton Fluid for helical gear, non-Newtonian fluid and heat affecting on the performance of helical gear pair lubrication, multigrid methods is used to solve the problem and the influence of working conditions on the friction coefficient are analyzed.5) Experimental verification of finite line cantact. The friction coefficient of the contact between tapered roller and plate is measured by UMT,and compared with the results of theory to prove the validity of the theory of finite line contact.