Static Characteirstics Research And Experiment Research On Oil-Film Flow Regime Of Step Bearing

The step bearing with deep and shallow pockets is widely used because it canincrease carrying capacity significantly and reduce friction coefficient. Almost all thecalculation is based on the hypothesis that the oil film is under laminar state, butbecause of the different oil-film thickness between deep and shallow pockets, theoil-film flow states would change from laminar to turbulent on high speed. This papernot only sets up a theory model of the oil-film in laminar flow and mixed pattern, butalso explores an experiment scheme about oil-film flow states visualization of stepbearing.First, the laminar and turbulent Reynolds equations have been deduced and themixed pattern consists of the two equations. The five point difference method hasbeen used to calculate the oil-film press distribution and the main static characteristicsin different flow states. The calculation indicates that the frictionforce\moment\power-loss is increased and the oil flow is decreased when turbulenceinvolves in the oil-film states.Then, the experiment based on Similar Principles is set up. Bubble tracer methodis used to observe the oil-film flow states and high-speed camera records the changingprocess. This paper sums up the oil-film flow images of laminar, turbulent and mixedflow regimes and depicts the curves. The experiment finds that the flow states hasrelationship with the velocity, clearance and viscosity. Turbulence is easier to appearin the deep pocket and the mixed pattern would easily show up at the boundary. Theflow lines in shallow pocket would transpire because of influence of the Press Flow.This paper has analyzed the oil-film flow states of step bearing in theoretical andexperimental fields, and came to some explorative conclusions. These all results canset up foundation for further research.