ISO/TC 123 - Plain bearings

This document specifies tribological tests of metallic bearing materials for plain bearings under conditions of boundary lubrication.

This document specifies the characteristic values for selected two-, three- and four-lobe bearings.

This document specifies the general principles, assumptions and preconditions for the calculation of multi-lobed and tilting-pad journal bearings by means of an easy-to-use calculation procedure based on numerous simplifying assumptions. The calculation method applies to the design and optimisation of plain bearings, for example in turbines, compressors, generators, electric motors, gears and pumps. It is restricted to steady-state operation, i.e. in continuous operating states the load according to size and direction and the angular velocity of the rotor are constant.

This document establishes the permissible operational parameters in terms of guide values for the calculation of selected multi-lobed and tilting-pad journal bearings.

This document specifies the characteristic values for selected tilting-pad journal bearings with four or five centrally or eccentrically supported tilting pads, and with angular spans of pad sliding surfaces of Ω = 80°, 60° and 45°.

This document specifies requirements and guidance on the storage, transportation, handling, installation, operation and replacement of plain bearings and related parts.

This document specifies dimensions and tolerances for cylindrical and flanged bushes with inside diameter, d1, in the range 6 mm to 200 mm. This document applies to solid mono-metal copper alloy bushes to be used as plain bearings with and without oil holes and oil grooves.

This document specifies a system of fits applicable to metallic plain bearings used in general engineering for mean relative bearing clearances, ψm, of 0,56 ‰ up to 3,15 ‰. Other clearance ranges can be used depending upon the requirements in specific applications. This system of fits is not applicable to half-bearings and bushes which, due to their special characteristics, are not measured by diameter but by wall thickness, and which are dimensionally changed on assembly. It is not applicable to profile bore or tilting pad bearings, or to cases where specific tolerances have been established by consideration of the bearing performance at both extremes of clearance. This document is applicable preferably to bearings in rotating machines or transmissions, but it can be used similarly in other ranges of application.

This document specifies a method for compression testing of bearing materials. It is applicable for both bulk materials and coatings. Compression testing within the meaning of this document serves for the determination of the behaviour of bearing materials under uniaxial compression loading which is uniformly distributed over the cross-section. For this purpose, a cylindrical specimen or a setup of two such specimen, with an original cross-section, A0, is loaded at constant crosshead speed and the resulting compressive stress and compressive strain are recorded.

This document specifies the most commonly used terms relating to design, bearing materials and their properties of plain bearings with their definitions and classification. For some terms and word combinations, their short forms are given, which can be used where they are unambiguous.

This document specifies the most commonly used terms relating to friction and wear of plain bearings with their definitions and classification. For some terms and word combinations, their short forms are given, which can be used where they are unambiguous.

This document specifies the most commonly used terms relating to lubrication of plain bearings with their definitions and classification. For some terms and word combinations, their short forms are given, which can be used where they are unambiguous.

This document specifies requirements for the selection and use of water-lubricated plain bearing materials used in different equipment and plants under various lubrication conditions, such as — fluid-film lubrication condition, — mixed lubrication condition, and — condition comprising a non-lubrication condition which shifts to a fluid-film lubrication condition. In addition, this document also specifies requirements for mating (shaft) material, the lubrication method and for items to consider during the design of water-lubricated plain bearing materials. The water used as a lubricant is pure water, tap water, river water or seawater. This document does not apply to the water solution of chemicals, refrigerants, liquid fuels, etc.

This document specifies how to effectively utilize material resources when recycling and reusing plain bearing materials. This document also specifies how to reduce the environmental impact of disposing of plain bearings.

This document specifies the test data for outside and inside diameters of wrapped bushes made of mono and multi-layer bearing material for plain bearing applications. It also specifies test designations. Since the wall thickness of the bush is measured in the free condition, no special test data are required for this on the drawing (see ISO 3547‑5 and ISO 3547‑6). NOTE Depending on the manufacturing method, the back of the bushes can show isolated light depressions and, similarly, bushes with lubrication holes, grooves and bore indentations can show distortion. It is therefore suggested to measure the wall thickness away from these areas.

This document specifies the calculation procedures to calculate and assess a given bearing design, as well as to design a bearing as a function of some optional parameters. This document contains the design of the required lubrication system including the calculation of the restrictor data. This document applies to hydrostatic plain journal bearings under steady-state conditions.

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

This document specifies, according to ISO 12301, the checking of the peripheral length of thin-walled half bearings with or without flange, and describes the necessary checking methods and measuring equipment. Thin-walled half bearings are flexible and, in the free condition, do not conform to a cylindrical profile. This is one reason the peripheral length of the half bearings can only be measured under a constraining load by use of specialized measuring equipment. In addition, measuring equipment different from that illustrated in this document can be used, provided the measuring accuracy of the equipment is consistent with the specifications given in Clause 17. This document does not include the measurement of the parting line taper. This document applies to thin-walled half bearings, the specifications of which are given in ISO 3548‑1.

This document specifies the method of surface modification that improves the friction characteristics of plain bearings, by press fitting a solid lubricant onto the bearing metal surface mechanically in combination with processing a lot of micro dimples on the surface.

This document specifies a calculation procedure for the maximum bearing temperature and effective dynamic viscosity in the lubricant film of oil-lubricated and statically loaded hydrodynamic plain journal bearings with a circular cylindrical shape, angular span Ω of 360° and width ratio B* of 0,5 to 1,5 under fluid lubrication regime. The bearing characteristics are obtained by design charts from four dimensionless numbers which are calculated from bearing dimensions, operating conditions and viscosity characteristics of the lubricant.

This document specifies tolerances, design features and test methods for thin-walled half bearings with integral flange up to an outside diameter of Do = 250 mm and without flange up to an outside diameter of Do = 500 mm. Due to the variety of design, it is, however, not possible to standardize the dimensions of the half bearings. Half bearings according to this document are predominantly used in reciprocating machinery and consist of a steel backing and one or more bearing metal layers on the inside. In reciprocating machinery, flanged half bearings can be used in connection with half bearings without flange. Alternatively, to serve as a flanged half bearing, it is possible to use a half bearing without flange together with two separate half thrust washers according to ISO 6526, or a half bearing with assembled flanges. NOTE All dimensions and tolerances are given in millimetres.

This document specifies the characteristics, materials, dimensions, assembly and surface finish for a bearing containing dispersed solid lubricants which is used as a solid lubricant bearing. NOTE In the solid lubricant bearing among self-lubricating bearings there is a solid type, a coated type, an embedded type and a dispersed type, which is specified by this document.

This document specifies a method for the determination of the endurance limit in fatigue of half-bearings of a multilayer bearing material.

This document specifies a procedure to measure the adhesion strength of diamond-like carbon (DLC) coatings specified in ISO 20523 by detecting acoustic emission signals using ball-on-disk method under the lubricated condition. DLC is normally coated on metal or ceramic. The test results are not applicable when the DLC coated parts operate in an unlubricated environment.

This document specifies the material compositions and the required properties of fluid film bearings used for vehicular turbochargers.

This document specifies parameters for the hardness testing of solid materials for plain bearings made from cast and wrought copper and aluminium alloys by machining and forming, of their wrought products and ingots, and of tin-based ingots. This document is a supplement to existing International Standards on hardness testing and, therefore, includes only the extensions and restrictions for observation compared to those publications. Owing to the heterogeneous structural composition of the majority of these bearing metals, a Brinell test is used.

This document specifies а method for the determination of the endurance limit in fatigue of bearing materials alone (not attached to steel backing).

This document specifies requirements for wrought copper alloys for use in solid plain bearings, particularly for bushes. This document provides a limited selection of alloys currently available for general purposes.

This document specifies requirements for cast copper alloys for use in solid and multilayer thick-walled plain bearings. It gives a limited selection of alloys currently available for general purposes.

This document specifies a classification and designation system for a selection of the most common unfilled thermoplastic polymers for plain bearings. The unfilled thermoplastic polymers are classified on the basis of appropriate levels of distinctive properties, additives and information about their application for plain bearings. The designation system does not include all properties; thermoplastic polymers having the same designation cannot therefore be interchanged in all cases. It also provides an outline of the properties and applications of the most common unfilled thermoplastic polymers as well as listing some of the fundamental parameters that influence the selection of thermoplastic polymers for use for plain bearings. NOTE In the further course of the work, it is intended to prepare standards on “thermosetting polymers” and “mixed polymers” for plain bearings.

This document specifies a bearing with embedded solid lubricants, which has been widely used as a solid lubricant bearing.

This document specifies requirements for some commonly used pad lining materials utilized on tilting pad bearings. The requirements in this document are expressed by specifying the chemical composition of the lining materials. Other lining materials can be used if they have been proven to be equally suitable at the required operating conditions. Descriptive characteristics of the lining materials are given along with the appropriate selection of pad backing and pivot materials.

This document specifies a method of improving test result comparability by evaluating the stresses in the bearing layers leading to fatigue (see Annex A). A similar evaluation is required in practical applications. Because the stresses are the result of pressure build-up in the hydrodynamic film, it is essential to fully state the conditions of operation and lubrication. In addition to dynamic loading, dimensional and running characteristics, the inclusion of the following adequately defines the fatigue system: a) under conditions of dynamic loading the minimum bearing oil film thickness as a function of time and location to ensure no excessive local overheating or shearing as a result of mixed lubrication when running in; b) the distribution of pressure circumferentially and axially with time under dynamic loading; c) from this the resulting stresses in the bearing layers as a function of time and location, especially the maximum alternating stress. Furthermore, bearing fatigue can be affected by mixed lubrication, wear, dirt, tribochemical reactions and other effects encountered in use thus complicating the fatigue problem. This document is therefore restricted to fatigue under full hydrodynamic separation of the bearing surfaces by a lubricant film. This document applies to oil-lubricated plain cylindrical bearings, in test rigs and application running in conditions of full hydrodynamic lubrication. It comprises dynamic loading in bi-metal and multilayer bearings. NOTE The number of practical applications with different requirements has led to the development of many bearing test rigs. If the conditions of lubrication employed on these test rigs are not defined in detail, test results from different rigs are generally neither comparable nor applicable in practice. Different test rigs can yield inconsistent ranking among equal materials.

This document specifies a calculation method for oil-lubricated hydrodynamic plain bearings with complete separation of the thrust collar and tilting pad thrust bearing surfaces by a film of lubricant. This document applies to plain thrust bearings with tilting-type sliding blocks (tilting pads), where a wedge-shaped lubrication clearance gap is automatically formed during operation. The ratio of width to length of one pad can be varied in the range B/L = 0,5 to 2. This document is not applicable to heavily loaded tilting pad thrust bearings. NOTE Equivalent calculation procedures exist that enable operating conditions to be estimated and checked against acceptable conditions. The use of them is equally admissible.

This document specifies the dimensions and tolerances for inserted thermoplastic bushes used as plain bearings with or without lubrication grooves in accordance with ISO 12128. These thermoplastic bushes are dimensionally exchangeable to wrapped bushes according to ISO 3547-1. This document is not applicable to reinforced plastics.

This document specifies, in graphic form, characteristic values used in the calculation of oil-lubricated plain journal bearings with drainage grooves.

This document specifies the requirements for an engine bearing test rig that uses an actual connecting rod to determine plain bearing performance in automotive engines, evaluating fundamental bearing properties such as seizure resistance, wear resistance, fatigue resistance and resistance to the impact of foreign material.

This document specifies in accordance with ISO 12301 the checking of the wall-thickness of thin-walled half bearings with or without flange and describes the necessary checking methods and measuring equipment. It applies to a maximum bearing diameter of 150 mm. It can be applied to a bigger diameter, provided that there is an agreement between the supplier and the user.

The aim of this document 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 document 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 document 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 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.

This document specifies guide values for avoiding damage to thrust-pad bearings in service. The explanation of the symbols as well as examples for calculation are given in ISO 12131-1.

This document specifies the general principles, assumptions and preconditions for the calculation of multi-lobed and tilting-pad journal bearings by means of an easy-to-use calculation procedure based on numerous simplifying assumptions. For a reliable evaluation of the results of this calculation method, it is indispensable to consider the physical implications of these assumptions as well as practical experiences for instance from temperature measurements carried out on real machinery under typical operating conditions. Applied in this sense, this document presents a simple way to predict the approximate performance of plain journal bearings for those unable to access more complex and accurate calculation techniques. The calculation method serves for the design and optimisation of plain bearings, for example in turbines, compressors, generators, electric motors, gears and pumps. It is restricted to steady-state operation, i.e. in continuous operating states the load according to size and direction and the angular velocity of the rotor are constant. Unsteady operating states are not recorded. The stiffness and damping coefficients of the plain journal bearings required for the linear vibration and stability investigations are indicated in ISO/TS 31657-2 and ISO/TS 31657-3.

This document specifies the characteristic values for selected tilting-pad journal bearings with four or five centrally or eccentrically supported tilting pads and with angular spans of pad sliding surfaces of Ω = 80°, 60° and 45°. The functions plotted and listed in table form below are required for the operationally safe design of hydrodynamic tilting-pad journal bearings according to ISO/TS 31657-1. They are based on the presumptions and boundary conditions indicated there and only apply to stationary operating states. The symbols used are explained in ISO/TS 31657-1; calculation examples are also included there. The calculation method described in ISO/TS 31657-1 can also be used for other tilting-pad journal bearing designs, if the numerical solutions of the basic equations are available in the same manner for these designs.

This document specifies design characteristics for side flange bearings for the size range 9 to 28, as well as design characteristics for shafts. It is applicable to side flange bearings used mainly in electrical and turbo engineering industries.

This document establishes the permissible operational parameters in terms of guide values for the calculation of selected multi-lobed and tilting-pad journal bearings. In order to attain a sufficient operational safety of multi-lobed and tilting-pad journal bearings by the calculation according to ISO/TS 31657-1, it is necessary for the operational characteristic value hmin to be significantly above the permissible operating parameter hlim,tr and for the permissible operating parameters Tlim and plim not to be exceeded by the calculated operational characteristic values Tmax and pmax. The guide values represent geometrically and technologically founded operational limiting values in the tribological system of plain bearings. They are empirical values that enable sufficient operational safety even in the event of smaller disturbing influences (see ISO/TS 31657-1). The empirical values indicated can be modified for special application areas. NOTE The explanations for the symbols and calculation examples are contained in ISO/TS 31657-1.

This document specifies the characteristic values for selected two-, three- and four-lobe bearings. The functions plotted and listed in table form below are required for the operationally safe design of hydrodynamic multi-lobed journal bearings according to ISO/TS 31657-1. They are based on the presumptions and boundary conditions indicated there and only apply to stationary operating states. The symbols used are explained in ISO/TS 31657-1; calculation examples are also included there.

This document specifies a calculation procedure for oil-lubricated hydrodynamic plain bearings, with complete separation of the shaft and bearing sliding surfaces by a film of lubricant, used for designing plain bearings that are reliable in operation. It deals with circular cylindrical bearings having angular spans, Ω, of 360°, 180°, 150°, 120°, and 90°, the arc segment being loaded centrally. Their clearance geometry is constant except for negligible deformations resulting from lubricant film pressure and temperature. The calculation procedure serves to provide dimensions and optimize plain bearings in turbines, generators, electric motors, gear units, rolling mills, pumps, and other machines. It is limited to steady-state operation, i.e. under continuously driven operating conditions, with the magnitude and direction of loading as well as the angular speeds of all rotating parts constant. It can also be applied if a full plain bearing is subjected to a constant force rotating at any speed. Dynamic loadings (i.e. those whose magnitude and direction vary with time), such as those that can result from vibration effects and instabilities of rapid-running rotors, are not taken into account. NOTE Equivalent calculation procedures exist that enable operating conditions to be estimated and checked against acceptable conditions. The use of them is equally admissible.

This document specifies design characteristics for pillow blocks for size ranges 9 to 28 and 35 to 71, as well as design characteristics for shafts. It is applicable to pillow blocks used mainly in electrical and turbo engineering industries.

This document specifies empirical permissible values for hlim, Tlim and . The empirical values stated can be modified for certain applications, for example if information supplied by the manufacturer is to be taken into account. The descriptions of the symbols and calculation examples are given in ISO 7902-1.

This document specifies the values of the basic functions used in the calculation procedure for oil-lubricated circular cylindrical hydrodynamic bearings under conditions of full lubrication. The values are given for the assumptions and boundary conditions given in ISO 7902-1. The values necessary for the calculation can be determined from the tables of bearing characteristics, the graphs and from the formulae. The descriptions of the symbols used and calculation examples are given in ISO 7902-1.