INSTRUCTIONS FOR INSTALLING & OPERATING TILTING PAD TYPE JOURNAL BEARINGS WITH FORCED LUBRICATION WAUKESHA BEARINGS CORPORATION WAUKESHA, WISCONSIN 53186 U.S.A.
I. GENERAL DESCRIPTION This is a tilting pad type journal bearing consisting of a number (generally five) of arcuate journal pads retained within an annular shell and associated end plates. The bearing will accept radial load in any direction and is particularly useful under high speed, light load conditions where bearing instability may be encountered with other types of journal bearings. Several basic types are produced, all based around the same journal pads. (These variations are shown on page 4.
Preload in a tilting pad journal bearing is normally defined as follows: preload m 1 Cb Cp The preload used for a particular bearing will depend on the application. Preload values are generally between 0.0 and 0.5, with values of 0.2 to 0.3 common. Negative values are undesirable. Design clearance values are given on the bearing assembly drawing. The journal pads are retained loosely in the bearing shell by pins or dowels which prevent circumferential movement.
IMPORTANT Cleanliness and burr-free surfaces are vital to the proper performance of the bearing. Remove any burrs or raised edges on the pad faces with a scraper. Remove any light burrs or fine rust on the collar with a fine oil stone. Deep rust or bruising will require refinishing. Prior to installation of the bearing assembly, inspect the bearing cavity and cover for cleanliness. Remove any debris or dirt from the journal area, the bearing fit and the oil sump areas of the bearing case.
Observe the indicator on the bearing as the shaft is slowly lifted. Once the bearing lifts, as indicated by the dial indicator, stop lifting the shaft. The lift is the difference between the two indicator readings. Note that the lift with tilt pad bearings will always be more than the actual bearing set clearance due to shaft movement between pads.
