Tilt pad bearing assembly

Abstract

The invention provides a radial tilt pad bearing assembly comprising: an outer carrier (12); a plurality of tilt pads (14) retained within the outer carrier; and a corresponding plurality of retaining pins (50) to retain the tilt pads in given circumferential positions, each fixed in the bearing assembly outer carrier so as to abut a side face (38) of a cavity (28) in the corresponding tilt pad. At least one retaining pin (50) and the corresponding cavity (28) are respectively shaped such that, when in use, a clearance (c) in a plane transverse to the axes of the bearing assembly and the tilt pad between the retaining pin (50) and the side face (38) is lesser at a first location (54) which lies substantially at the inner surface of the carrier (12), than at all corresponding locations at radially inner portions of the side face, with respect to the first location. A contact point (54, 54') between the retaining pin (50) and the tilt pad (14) when in use, lies substantially at the inner surface of the outer carrier (12). The tilt pad (14) is accordingly able to tilt without being substantially displaced circumferentially about the outer carrier (12).

Description

technical field [0001] This invention relates to bearings such as those used to support engine rotors within gas turbines. In particular, the present invention relates to mechanical components for securing a tilting pad in a tilting pad radial bearing. Background technique [0002] Gas turbine engine rotor bearing assemblies may be of the plain bearing type, segmented (radially self-aligning) fixed in outer bearing housings, oil pressure lubricated and referred to as tilting pad bearings. The bearings are subjected to high speeds and loads when the engine is running, and even a small out of limit wear in the bearings can have a catastrophic effect on the engine. It can cause the engine to shut down, which is often a costly affair for such engines. Reliable bearing operation is therefore critical to acceptable engine life. [0003] In such segmented plain bearing arrangements, the circular movement of each segment is typically limited by the use of stop pins which are fixe...

AI Technical Summary

Problems solved by technology

[0013] Consequences of pad and / or housing wear include increased bearing clearance, which results in reduced bearing stiffness and damping, and reduced tolerance to unbalance and other exciting forces

Increased bearing clearance can cause shaft vibration in the housing

Pad and / or housing wear will also result in increased maintenance costs and increased downtime

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