Gearing Elasto-Hydrodynamic Lubrication Based On The Ideal Model

With the mechanical parts requirements growing of carrying capacity and speed, lubricating the parts becomes particularly important. In the design of gears transmission, ensuring that the gears have sufficient thickness of lubrication film in the mating area, completely separated from the friction surface, which can be avoided the lubrication failure to the gear's tooth so as to extend the service life, but also make the gear's tooth withstand high pressure and increase the carrying capacity of gear. Then Elasto-Hydrodynamic Lubrication is one of basic lubrication states, and the author has addressed the EHL make studies.The paper based on the premise that fluid performs Newton performance, the author has made full use of Elasto-Hydrodynamic Lubrication theory, deducted the Reynolds equation, the thickness geometric equation of isotherm EHL line contact, setted up the corresponding mathematical model to make the theoretical research about the EHL issues; Through the calculate program development and calculating, the author has obtained fully numerical solutions, gained the curves of the EHL film pressure distribution and film shape; This paper has made a detailed analysis about nodes influences on the EHL film pressure and the shape, and furthermore made EHL numerical analysis under the water lubrication; Then using isotherm EHL line contact theory, the author has made numerical solution to the gear EHL, discussed the parameters of load, operation speed, lubrication oil viscosity effects on itself; and made the EHL research between PEEK plastic and steel gears meshing. In the same load, speed circumstances, the author has compared and analyzed the numerical results under the oil lubrication with under water lubrication. Finally give an example of the meshing of gears to judge the state of lubrication.The numerical analysis showed that: In the calculating regional the more nodes have, gain the numerical results more slowly; Under the water lubrication, the pressure of water film does not appear second-pressure, the shape of the water film does also not have shrink phenomenon obviously, which is different from the EHL characteristics under the oil lubrication; load and speed changes will cause changes in water film thickness, as the speed increases, the water film thickness also increases, then influence on the water film pressure very small; Then load, speed and lubricating oil's viscosity has different varying degrees impact on gear EHL, the load mainly affects in the film pressure, the speed of gear is an important factor in film thickness, the viscosity of lubrication oil has the greater impact on film thickness; In the same load and speed, plastic/steel gears meshing produce the greater film pressure under the oil lubrication than one under the water lubrication, the biggest oil/water film pressure increases up to 20 percent and forms film stability than the water film in the contact regional.