Investigation of grooved hybrid air bearing performance

Abstract

Herringbone grooves machined into aerodynamic bearings are well known to produce improvements in bearing stiffness and stability at high operating speeds. In this investigation the effect of herringbone grooves on the performance of an externally pressurized bearing is examined. A mathematical model based on previous research has been developed and used to optimize the design of an air bearing suitable for use in ultrahigh-speed machining spindles. Experimental results show the spindle to run satisfactory at speeds in excess of 3.0 × 106 DN (bearing diameter in mm x shaft speed in r/min), being limited only by the maximum speed of its drive rotor.