Rarefaction Effects of Gas-Lubricated Bearings in a Magnetic Recording Disk File

The load versus spacing characteristics of a self-acting, gas-lubricated slider bearing similar to that used in a magnetic recording disk file have been investigated experimentally under sub-atmospheric ambient conditions. Interferometric techniques are used to measure the steady spacing between a rotating glass disk and the slider over a wide range of ambient pressures and disk speeds. For local Knudsen number less than 0.1, excellent agreement is found to exist between experimental data and numerical solutions of the Reynolds lubrication equation taking into account the velocity-slip boundary conditions. Effects of rarefaction on the bearing performance for a range of pertinent bearing parameters (i.e., bearing number and inlet-to-outlet ratio) are presented.