Influence of pad compliance on nonlinear dynamic characteristics of tilting pad journal bearings

The effect of pad compliance on the dynamic response of tilting pad journal bearings is investigated. Pad compliance is varied by changing pivot geometry and Young′s modulus of pad backing and pad liner. Two pad support configurations are considered: one that allows only circumferential tilt and another one that allows both circumferential and axial tilts. Journal orbits, oil film pressure and oil film thickness are compared and discussed. It is shown that higher pad backing compliance significantly increases the journal orbit size and results in an increase in oil film pressure while oil film thickness is decreased. With a compliant liner, oil film pressure is decreased while oil film thickness is increased. Tapers at the pad edges are essential to increase the global minimum oil film thickness in compliant liner bearings.

► Compliant liner increases oil film thickness.
► Pad tapers are essential to increase oil film thickness.
► Maximum oil film pressure is significantly reduced by the compliant liner.
► Higher pad backing compliance decreases oil film thickness and increases pressure.
► Liner properties determine dynamic response of line and ball–socket pivot pads.