Waukesha Bearings Horizontal Type Self Equalizing Tilting Pad Thrust Bearings with Forced Lubrication - Manual (Page 2)

I. GENERAL DESCRIPTION
This is a tilting pad type thrust bearing consisting of a number of load carrying thrust pads retained
within a base ring and incorporating a means of load equalization among the thrust pads. The bearing
is designed to transmit rotor axial thrust from a collar (either integral to the rotor shaft or a separate
piece secured to the shaft) to the machine stator. At the interface of rotating collar and stationary
thrust pads, the thrust load is carried by and transmitted through a hydrodynamic oil film, thus
avoiding solid rubbing contact and providing for extended bearing life.
The thrust load may be in either direction in which case a double (e.g. 6 x 6) bearing is used. Even
with no thrust load in one direction a double bearing is common on horizontal shaft machines to
maintain rotor position.
The number of thrust pads used is commonly six but may be most any number from two up. For two
pad bearings equalization of load is obtained simply by pivoting the supporting base ring on a central
rocker, thus achieving a “teeter-totter” effect. For three pad bearings a spherical seat finds some use
for limited equalization. For four or more pads the “equalizing link” arrangement is common. Here,
each thrust pad rests on an “upper leveling link.” These upper leveling links are positioned between
and bear upon “lower leveling links,” which in turn transmit the thrust load to the base ring. The
leveling links are each individual levers, which, acting together in their circular arrangement, result in
the transmitted thrust load being equally shared by all the pads.
This arrangement of parts and their interaction can be visualized in the diagram below.
II. DETAILED DESCRIPTION