Plain bearings — Hydrodynamic plain thrust pad bearings under steady-state conditions — Part 1: Calculation of thrust pad bearings

The aim of this part of ISO 12131 is to achieve designs of plain bearings that are reliable in operation, by the

application of a calculation method for oil-lubricated hydrodynamic plain bearings with complete separation of the

thrust collar and plain bearing surfaces by a film of lubricant [1].

This part of ISO 12131 applies to plain thrust bearings with incorporated wedge and supporting surfaces having

any ratio of wedge surface length lwed to length of one pad L. It deals with the value lwed/L = 0,75 as this value

represents the optimum ratio [2]. The ratio of width to length of one pad can be varied in the range B/L = 0,5 to 2.

The calculation method described in this part of ISO 12131 can be used for other incorporated gap shapes, e.g.

plain thrust bearings with integrated baffle, when for these types the numerical solutions of Reynolds' differential

equation are known.

The calculation method serves for designing and optimizing plain thrust bearings e.g. for fans, gear units, pumps,

turbines, electrical machines, compressors and machine tools. It is limited to steady-state conditions, i.e. load and

angular speed of all rotating parts are constant under continuous operating conditions. Dynamic operating

conditions are not included.