ADIABATIC APPROXIMATE SOLUTION FOR STATIC AND DYNAMIC CHARACTERISTICSOF TURBULENT PARTIAL JOURNAL BEARINGS WITH SURFACE-ROUGHNESS

Hydrodynamic bearings are generally used for a long term, so the beari ng surfaces may be roughened for many reasons such as wear, impulsive damage, foreign particles, cavitation erosion, rust, and so on. Under the turbulent operating conditions of high speed bearings, the surface roughness may result in considerable increase in both film pressure a nd temperature. This paper describes an adiabatic approximate solution for the static and dynamic characteristics of 180 deg partial journal bearings with homogeneous surface roughness. Applying the modified lu brication equation and energy equation, considering the combined effec ts of turbulence and surface roughness, to the finite width 180 deg pa rtial journal bearings, the static and dynamic characteristics such as pressure and temperature distributions, Sommerfeld number, attitude a ngle, spring and damping coefficients and whirl onset velocity are obt ained numerically. In the numerical analysis of the temperature distri bution, adiabatic boundary conditions are assumed and then the heat tr ansfer effect to the journal and bearing-bush surfaces is omitted. The numerical results are indicated in graphic form for various relative roughness under the mean Reynolds number of Re = 5000 and 10,000. More over, some numerical results of static characteristics are compared wi th the experimental results.