Double acting, self-equalizing 1

[PAN]

In case of the data sheet shows "tilting pad" bearing. However, the supplier propose double acting, self-equalizing bearing.

Is this the same? Please also advise me if there are the difference.

Am I correct to say that double acting, self-equalizing bearing is tilt pad thrust bearing?

Is it possible to use double acting, self equalizing bearing for radial bearing?

Our appliation is centrifugal compressor.

 

[TPL]

The follwing is general:

Double acting, self equalising bearings are tilting pad thrust bearings.

The term ‘self equalising’ means that each pad can adopt a slightly different level of tilt or rotation to accommodate varying loads: this term can be applied to both radial and thrust tilting pad bearings.
The term ‘double acting’ applies to thrust bearing assemblies and describes their ability to accommodate movement/load applied in either axial direction.

Radial tilting pad bearings and thrust/axial tilting pads bearings, work on the same basic operating principles, but are of completely different design and cannot be interchanged

In plan, thrust bearing pads are roughly the shape of an isosceles triangle (with the sharp point removed) and arranged in a circle: with one set facing each surface of the thrust disc. When fitted to their retainer/carrier each pad can tilt individually along the centre line allowing an oil wedge to develop to counteract axial thrust/load.
A single thrust bearing assembly needs two sets of pads (one for each thrust disc face) to accommodate both loading in the normal direction and the change in thrust that can occur when normal load is (suddenly?) removed as in a shutdown/trip.

In plan, radial tilt pads are rectangular in shape but, in section are curved: these are able to pivot about the mid point of the curve, again to allow an oil wedge to develop to support the shaft. A single radial bearing assembly is typically made up of 5 or 7 pads arranged to form a cylinder (held in place by a carrier or retainer assembly) around the journal bearing surface. One radial bearing assembly (containg several pads) is needed for each compressor bearing.

In both radial and thrust bearings – individual pads can be replaced, although it is better practice to replace all the pads in a thrust bearing.
Radial bearings are usually loaded in one particular region and out of a set of say 7 pads, maybe only 3 will show signs of wear and it is possible to swap obviously worn pads with those that have not shown such signs of wear.

 

[Mendit]

A self equalizing bearing has a series of links or tipplers that allow uneven loads to be distributed evenly, example if one pad were 0,005" thicker than all the others, the equalizing links woud make this work OK. There is no such thing as an equalizing radial tilting pad bearing (not that I have heard of anyway). Radial tilt pad bearing shoes are contolled within very small tolerances typical 0.0003" from back pad radius to babbitt surface. and are supported on a precision machined base ring.