The Effect of High Gas Temperature on the Steady State Behavior of Non-Circular Two-Lobe Gas-Lubricated Micro-Bearings

Document Type : Research Article

Authors

1 Faculty of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran

2 صنعتی شاهرود، مهندسی مکانیک

10.22060/ajme.2021.18654.5910

Abstract

In this paper, the molecular gas lubrication (MGL) model is used to analyze the steady state behavior of two-lobe non-circular gas lubricated micro bearings. In this way, the effects of increasing temperature and gas rarefaction can be considered and then examined and analyzed. Behavior characteristics of two-lobe non-circular bearings with very small sizes differ from conventional sizes, especially at high temperatures and / or high rotational speeds. At high temperatures, in addition to diluting the gas, its viscosity and friction also change, and slippage may occur at the boundaries. The nonlinear equation governing the behavior of the gas is discretized using the finite element method and then solved together with the static equations of the rotor. Then the effects of temperature increase and gas rarefaction on gas pressure profile, load bearing capacity, angle of attitude, eccentricity ratio and frictional power loss have been studied and analyzed. The results show that the temperature rise and the gas rarefaction have significant effects on the steady state behavior of micro gas bearings. Among the results is that with increasing gas rarefaction, the gas pressure and consequently the load carrying capacity decrease more, and the attitude angle also increases more.

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