Swing characteristic of pads in four-pad tilting pad bearing

Swing characteristic of pads in four-pad tilting pad bearing has been studied systematically with the guide bearing for canned pump motor in fourth generation nuclear power units as object. Theoretical derivation reveals that dimensionless pad pendulum angle depends on structural parameters, preload ratio and eccentricity ratio of the bearing, but is unrelated to viscosity of lubrication oil, shaft rotating speed and clearance. Numerical analysis shows that pad pendulum angle is determined by pad circumferential position, preload ratio and eccentricity ratio. Pad pendulum angle has significant influence on minimum oil film thickness. Pad pendulum angle maybe negative and leads to minimum oil film thickness greater than that of fixed pad. Results of this paper provide basic analysis for safety operation of the canned pump motor in fourth generation nuclear power units.