ISO 12130-2:2020

INTERNATIONAL ISO
STANDARD 12130-2
Third edition
2020-02
Plain bearings — Hydrodynamic plain
tilting pad thrust bearings under
steady-state conditions —
Part 2:
Functions for calculation of tilting pad
thrust bearings
Paliers lisses — Butées hydrodynamiques à patins oscillants
fonctionnant en régime stationnaire —
Partie 2: Fonctions pour le calcul des butées à patins oscillants
Reference number
ISO 12130-2:2020(E)
©
ISO 2020

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ISO 12130-2:2020(E)

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ii © ISO 2020 – All rights reserved

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ISO 12130-2:2020(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Functions for the tilting pad thrust bearing . 1
4.1 General . 1
4.2 Characteristic value of load-carrying capacity . 1
4.3 Characteristic value of friction . 3
4.4 Relative lubricant flow rate . 5
4.5 Relative pressure centre coordinate or tilting pad supporting point . 8
5 Effective dynamic viscosity of the lubricant .10
Bibliography .12
© ISO 2020 – All rights reserved iii

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ISO 12130-2:2020(E)

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
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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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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on the ISO list of patent declarations received (see www .iso .org/ patents).
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iso/ foreword .html.
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 12130-2:2013), of which it constitutes a
minor revision. The changes compared to the previous edition are as follows:
— adjustment to ISO/IEC Directives, Part 2:2018;
— correction of typographical errors.
A list of all parts in the ISO 12130 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.
iv © ISO 2020 – All rights reserved

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ISO 12130-2:2020(E)

Introduction
The functions of the following type are necessary for the calculation of oil-lubricated tilting pad thrust
bearings in accordance with ISO 12130-1, assuming hydrodynamic conditions with full lubrication.
They are based on the premises and boundary conditions specified therein. The values necessary for
the calculation can be determined by means of the given formulae as well as from diagrams and tables.
The formulae are approximations of the numerically determined values traced as curves in accordance
with Reference [2]. The explanation of the symbols and examples for the calculation are included in
ISO 12130-1.
On account of the premises laid down in ISO 12130-1:2001, Clause 3, g) and k), the following definitions
*
are not applicable to the calculation of thrust bearings with centrally supported tilting pads ( a = 0,5),
F
which, under the premises indicated therein, have no hydrodynamic load-carrying capacity. For the
determination of the characteristic values of such bearings, it is necessary to consider at least the
deformations of the tilting pads which occur during operation. For example, References [3] and [4] can
be compared.
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INTERNATIONAL STANDARD ISO 12130-2:2020(E)
Plain bearings — Hydrodynamic plain tilting pad thrust
bearings under steady-state conditions —
Part 2:
Functions for calculation of tilting pad thrust bearings
1 Scope
This document specifies the derivation of mathematical functions to be applied when calculating tilting
pad thrust bearings.
This document is not applicable to heavily loaded tilting pad thrust bearings.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Functions for the tilting pad thrust bearing
4.1 General
An explanation of the symbols is given in ISO 12130-1.
4.2 Characteristic value of load-carrying capacity
The characteristic value of load-carrying capacity, F* is defined as a function of the relative bearing
width, B/L, and the relative minimum lubricant film thickness, h /C .
min wed
By substituting Formulae (2) to (5) into Formula (1), the approximate curves in Figure 1 are obtained
h
min
(range of application: 02,  ≤≤ 2 ).
C
wed
2
   
  1 1
** *
AB +−1  + CC 1 −
2
   
 
 h  1 + hC hC hC
( ) 2
   
min min wed min wed min wed
*  
F =5  × ln  − ×
 
2
 
h
C hC
  min
wed min wed  1 
1 +  2×
 
1 + a
 
C
  BL
wed
 
(1)
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ISO 12130-2:2020(E)

2
   
h h
 
minmin
   
12 −+
2  
2
C C
     
h h wedw ed 
 
10  
 
minmin
 
a =  ×+    + (2)
   
2
C C h 1 + hC
     ( ) 
 
 h   wedwed min min wed 
 
min
12  12 + × ln −2
   
12 +
   
C hC
C   wed  min wed 
 
wed  
 
2 3
B B B
     
*
A =− ,1 168 60 , 329 45×  +×0, 222 67  − 00, 046 51×  (3)
     
L L L
     
2 3
B B B
     
*
B =−0, 100 95+× ,0 197 43  −× ,0 131 36  + 0, 028 703×  (4)
     
 L   L   L 
2 3
B B B
     
...