Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

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This document was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 8, Calculation methods for plain bearings and their applications.

This third edition cancels and replaces the second edition (ISO 12131-2:2016), which has been technically revised.

The main changes are as follows:

Formula (1) has been corrected;
Table 1 has been added;
some editorial corrections have been made.

A list of all parts in the ISO 12131 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

Assuming hydrodynamic conditions with full lubrication, the functions of the type covered by this document are necessary for the calculation of oil-lubricated pad thrust bearings in accordance with ISO 12131-1. They are based on the premises and boundary conditions specified. The values necessary for the calculation can be determined by means of the given formulae, as well as from diagrams and tables. The formulae in this document are approximations of the numerically determined values traced as curves according to Reference [2]. The explanation of the symbols, as well as examples for the calculation, are included in ISO 12131-1.

1 Scope

This document specifies functions for thrust pad bearings. It also covers the effect of dynamic viscosity on lubricant film temperature.

2 Normative references

3 Terms and definitions

4 Symbols, terms and units

5 Functions for the thrust pad bearing

5.1 Load carrying capacity

5.2 Friction for thrust pad bearings

5.3 Relative lubricant flow rates

6 Effective dynamic viscosity of the lubricant, η_eff, as a function of the effective lubricant film temperature, T_eff

Bibliography