Research on Static Characteristics of Deep/shallow Pockets Hybrid Bearing under Lamin6ar and Turbulent Mixed Regimes

摘要

For high speed hybrid journal bearing with deep/shallow pockets, film thickness and film Reynolds number vary considerably in different position. Laminar flow and turbulent flow exist simultaneously in the bearing film. This paper establishes the laminar and turbulent mixed film control equations and the pressure boundary conditions together with the restrictor flow equation for a deep/shallow pockets journal hybrid bearing compensated by interior restrictor. The static characteristics such as attitude angle, load carrying capacity, friction power loss and flow volume rate are given by solving the equations with Finite Element Method. By comparing the laminar, turbulent and mixed flow results, it can be seen that the coefficients are proximity under journal speed 5000 rpm (only part of deep pockets is turbulent flow). But the characteristics coefficients of three flow models contrast evidently under journal speed 50000 rpm (deep and shallow pockets are turbulent flow, part of bearing land is laminar flow). Laminar and turbulence mixed flow lubrication theory is more accurate to high speed hybrid bearing with deep/shallow pockets.