Pneumatic Hammer in a Gas Lubricated Externally Pressurized Annular Thrust Bearing

Abstract

An experimental study was conducted on the occurrence of pneumatic hammer in a gas lubricated externally pressurized annular thrust bearing. The bearing, which was orifice compensated, was fed by sets of three approximately equal orifices having nominal diameters 0.040, 0.020, 0.015, 0.010, and 0.005 in. Instability was most marked for the supply orifices of nominal diameter 0.020 in. The employment of orifices which had nominal diameters greater or smaller than 0.020 in. tended to make the bearing more stable. Experimental results were compared with the predictions of the simple, lumped parameter analysis.