SIST ISO 4378-5:2015

Plain bearings - Terms, definitions, classification and symbols - Part 5: Application of symbols

ISO 4378-5:2009 specifies practical applications of the general symbols defined in ISO 4378-4, with regard to the calculations, design and testing of plain bearings.

Gleitlager - Begriffe, Definitionen und Einteilung - Teil 5: Formelzeichen

Paliers lisses - Termes, définitions, classification et symboles - Partie 5: Application des symboles

L'ISO 4378-5:2009 précise l'utilisation pratique des symboles généraux définis dans l'ISO 4378‑4 pour le calcul, la conception et l'essai des paliers lisses.

Drsni ležaji - Izrazi, definicije, klasifikacija in simboli - 5. del: Način uporabe simbolov

Ta del standarda ISO 4378 določa praktično uporabo splošnih simbolov iz standarda ISO 4378-4
v zvezi z izračuni, konstrukcijo in preskušanjem drsnih ležajev. Standard ISO 4378-4 ločuje med osnovnimi in dodatnimi znaki. Dodatni znaki so nadpisani ali podpisani. Simboli, potrebni za izračun, konstrukcijo, proizvodnjo in preskušanje drsnih ležajev, so le osnovni znaki ali kombinacije osnovnih in dodatnih znakov.
V tem delu standarda ISO 4378 so navedeni simboli, potrebni za izračune, konstrukcijo in preskušanje drsnih ležajev. Opredeljeni so bili v skladu s priporočili iz standarda ISO 4378-4. Koti in smer rotacije so opredeljeni pozitivno kot vrtenje v levo (v nasprotni smeri urnega kazalca); enako velja za vrtilno frekvenco ter obodno in kotno hitrost.

General Information

• Status: Published
• Public Enquiry End Date: 31-Aug-2008
• Publication Date: 04-Feb-2015
• ICS: 01.040.21 - Mechanical systems and components for general use (Vocabularies)
• ICS: 21.100.10 - Plain bearings
• Technical Committee: ISEL - Mechanical elements
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 02-Feb-2015
• Due Date: 09-Apr-2015
• Completion Date: 05-Feb-2015
• Ref Project: ISO 4378-5:2009 - Plain bearings — Terms, definitions, classification and symbols — Part 5: Application of symbols

Relations

• Replaces: SIST ISO 7904-2:2002 - Plain bearings -- Symbols -- Part 2: Applications
• Effective Date: 01-Mar-2015

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2015
1DGRPHãþD
SIST ISO 7904-2:2002
'UVQLOHåDML,]UD]LGHILQLFLMHNODVLILNDFLMDLQVLPEROLGHO1DþLQXSRUDEH
VLPERORY
Plain bearings - Terms, definitions, classification and symbols - Part 5: Application of
symbols
Gleitlager - Begriffe, Definitionen und Einteilung - Teil 5: Formelzeichen
Paliers lisses - Termes, définitions, classification et symboles - Partie 5: Application des
symboles
Ta slovenski standard je istoveten z: ISO 4378-5:2009
ICS:
01.040.21 Mehanski sistemi in deli za Mechanical systems and
splošno rabo (Slovarji) components for general use
(Vocabularies)
21.100.10 Drsni ležaji Plain bearings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL ISO
STANDARD 4378-5
First edition
2009-09-01
Plain bearings — Terms, definitions,
classification and symbols —
Part 5:
Application of symbols
Paliers lisses — Termes, définitions, classification et symboles —
Partie 5: Application des symboles

Reference number
©
ISO 2009
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2009 – All rights reserved

Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Symbols and terms .1
3.1 Symbols of the Roman alphabet.1
3.2 Symbols of the Greek alphabet.18

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 4378-5 was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 6, Terms
and common items.
This first edition cancels and replaces ISO 4378-4:1997 as well as ISO 7904-2:1995, which have been
technically revised.
ISO 4378 consists of the following parts, under the general title Plain bearings — Terms, definitions,
classification and symbols:
⎯ Part 1: Design, bearing materials and their properties
⎯ Part 2: Friction and wear
⎯ Part 3: Lubrication
⎯ Part 4: Basic symbols
⎯ Part 5: Application of symbols
iv © ISO 2009 – All rights reserved

Introduction
As there is a large number of multiple designations in the domain of plain bearings, there is a considerable
risk of error in the interpretation of standards and technical literature. This uncertainty leads to the continuous
addition of supplementary designations, which only serves to increase the misunderstanding.
This part of ISO 4378 specifies pratical applications of the general symbols used in the field of plain bearings.

INTERNATIONAL STANDARD ISO 4378-5:2009(E)

Plain bearings — Terms, definitions, classification and
symbols —
Part 5:
Application of symbols
1 Scope
This part of ISO 4378 specifies practical applications of the general symbols defined in ISO 4378-4, with
regard to the calculations, design and testing of plain bearings.
ISO 4378-4 distinguishes between basic characters and additional signs. Additional signs are subscripts and
superscripts. The symbols necessary for plain bearing calculations, design, manufacture and testing are just
basic characters or combinations of basic characters and additional signs.
This part of ISO 4378 lists symbols which have been found necessary for the calculations, design and testing
of plain bearings. They have been defined in accordance with the recommendations given in ISO 4378-4.
Angles and directions of rotation are defined positively as rotating in a left-hand (anticlockwise) direction; the
same applies to rotational frequencies, and circumferential and angular velocities.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 4378-4, Plain bearings — Terms, definitions, classification and symbols — Part 4: Basic symbols
3 Symbols and terms
The following listings are not necessarily complete. They may be enlarged, if necessary.
NOTE Some letters of the Roman and Greek alphabet have not yet been used. Therefore, these letters are not listed
below.
3.1 Symbols of the Roman alphabet
A heat-emitting surface area (bearing housing), elongation at fracture
A* heat-emitting surface area parameter [thrust bearing, A* = A/(B × L × Z )]
ax
A area of segment or pad
B
A area of groove cross-section
G
A heat-emitting surface area (bearing housing) inside of the machine (flange bearing)
i
A land area
lan
* *
A relative land area ( A = A /(π × D × B) for hydrostatic journal bearings)
lan lan
lan
A heat-emitting surface area (bearing housing) outside of the machine (flange bearing)
o
A area of lubricant pocket
P
A area of cross-section
S
A specific area of tube
T
A area of tube cross-section flowed through
T,i
a distance, acceleration, thermal diffusivity, inertia factor
a distance between leading edge and pivot position of pad (tilting-pad bearing)

F
*
a relative distance between leading edge and pivot position of pad (tilting-pad bearing)
F
a minimum distance between two circular thrust pads
min
a distance between temperature measuring point and bearing sliding surface
T
B width parallel to the sliding surface, normal to the direction of motion; bearing width, nominal
bearing width, pad width, nominal pad width
B* relative width, relative bearing width, relative pad width, width ratio (B* = B/D)
B width of thrust bearing or thrust pad [B = (D − D )/2]
ax ax o i
B effective bearing width (without grooves, chamfers, etc.), effective pad width
eff
B outer width of bearing housing in axial direction
H
B total bearing width
tot
b width parallel to the sliding surface, normal to the direction of motion or flow
b width of circumferential discharge (hydrostatic bearing, b = B − b )
c c lan
b width of lubricant groove, width of lubricant supply groove, width of bleed groove
G
b land width parallel to the sliding surface, normal to the direction of flow
lan
b width of lubricant pocket, width of lubricant supply pocket

P
*
b relative width of lubricant pocket, relative width of lubricant supply pocket
P
C bearing clearance, nominal bearing clearance, chamfer, concentration
C axial bearing clearance (thrust bearing)
ax
C mean value of C [C = (C + C )/2]
ax,m ax ax,m ax,min ax,max
C maximum value of C
ax,max ax
C minimum value of C
ax,min ax
C bearing clearance, bearing diametral clearance (difference between bearing bore and journal

D
diameter of a journal bearing, C = D − D )
D J
C mean value of C [C = (C + C )/2]
D,m D D,m D,min D,max
2 © ISO 2009 – All rights reserved

C effective bearing diametral clearance

D,eff
C maximum value of C
D,max D
C minimum value of C
D,min D
C circumference of groove cross-section
G
C bearing radial clearance (difference between bearing bore and journal radius of a journal bearing,
R
C = R − R )
R J
∆C elastic change of C
R,el R
C effective bearing radial clearance
R,eff
C mean value of C [C = (C + C )/2]
R,m R R,m R,min R,max
C maximum value of C
R,max R
C minimum value of C
R,min R
∆C thermal change of C
R,th R
∆C total change of C (∆C = ∆C + ∆C )
R,tot R R,tot R,el R,th
c specific heat capacity, lubricant specific heat capacity, stiffness
c axial bearing stiffness
ax
c axial stiffness of the bearing when load is directed into the machine (flange bearing)
ax,i
c axial stiffness of the bearing when load is directed out of the machine (flange bearing)
ax,o
c vertical stiffness of the bearing loaded downwards
dw
c stiffness of pad pivot support in direction of load (tilting-pad bearing)
F
c horizontal bearing stiffness
h
c lubricant film stiffness coefficient of journal bearing (i, k = 1, 2)
ik
*
c non-dimensional lubricant film stiffness coefficient of journal bearing
ik
ψ
*
cc=×i,1k=,2
() ( )
ik ik
2××B ηω×
c inner lubricant film stiffness coefficient of journal bearing (i, k = 1, 2)
ik,i
c outer lubricant film stiffness coefficient of journal bearing (i, k = 1, 2)
ik,o
c flexural stiffness of the Jeffcott Rotor
JR
c specific heat capacity of the lubricant (at constant pressure)

p
c specific heat capacity of the coolant (at constant pressure)

p,cl
c flexural stiffness of shaft
sh
c stiffness of isotropic bearing or bearing shell support
sup
c stiffness coefficient of anisotropic bearing or bearing shell support (i, k = 1, 2)
sup,ik
c vertical stiffness of the bearing loaded upwards
up
c vertical bearing stiffness
v
c angular stiffness of pad pivot support (tilting-pad bearing)
ϑ
D bearing diameter (inside diameter of journal bearing), nominal bearing diameter
D twice the lobe or pad bore radius of a multi-lobed or tilting-pad journal bearing

B
D mean value of D [D = (D + D )/2]

B,m B B,m B,min B,max
D maximum value of D
B,max B
D minimum value of D
B,min B
D outside diameter of bearing shell or pad of a fixed-pad or tilting-pad journal bearing
B,o
D (outside) diameter of lubricating ring fixed to the shaft
fi
D inside diameter of bearing housing

H,i
D outside diameter of bearing housing
H,o
D inside diameter of thrust bearing sliding surface

i
D journal diameter (diameter of the shaft section located inside of a journal bearing)

J
D mean value of D [D = (D + D )/2]

J,m J J,m J,min J,max
D maximum value of D
J,max J
D minimum value of D
J,min J
D (outside) diameter of loose lubricating ring
lo
D mean diameter of thrust bearing sliding surface [D = (D + D )/2]
m m i o
D maximum value of D
max
D minimum value of D
min
D outside diameter of thrust bearing sliding surface

o
D inside diameter of tube
T,i
D outside diameter of tube
T,o
d diameter, distance, depth, damping
d diameter of circular thrust pad
B
d diameter of capillary
cp
d damping of eigenfrequency, system damping
e
d damping of pad pivot support in direction of load (tilting-pad bearing)
F
d diameter of groove
G
d mean diameter of groove
G,m
d lubricant film damping coefficient of journal bearing (i, k = 1, 2)
ik
4 © ISO 2009 – All rights reserved

*
d non-dimensional lubricant film damping coefficient of journal bearing
ik
⎡⎤
ψ
*
dd=×ω×i,1k=,2
⎢⎥()
ik ik
2×
...

INTERNATIONAL ISO
STANDARD 4378-5
First edition
2009-09-01
Plain bearings — Terms, definitions,
classification and symbols —
Part 5:
Application of symbols
Paliers lisses — Termes, définitions, classification et symboles —
Partie 5: Application des symboles

Reference number
©
ISO 2009
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2009
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2009 – All rights reserved

Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Symbols and terms .1
3.1 Symbols of the Roman alphabet.1
3.2 Symbols of the Greek alphabet.18

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 4378-5 was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 6, Terms
and common items.
This first edition cancels and replaces ISO 4378-4:1997 as well as ISO 7904-2:1995, which have been
technically revised.
ISO 4378 consists of the following parts, under the general title Plain bearings — Terms, definitions,
classification and symbols:
⎯ Part 1: Design, bearing materials and their properties
⎯ Part 2: Friction and wear
⎯ Part 3: Lubrication
⎯ Part 4: Basic symbols
⎯ Part 5: Application of symbols
iv © ISO 2009 – All rights reserved

Introduction
As there is a large number of multiple designations in the domain of plain bearings, there is a considerable
risk of error in the interpretation of standards and technical literature. This uncertainty leads to the continuous
addition of supplementary designations, which only serves to increase the misunderstanding.
This part of ISO 4378 specifies pratical applications of the general symbols used in the field of plain bearings.

INTERNATIONAL STANDARD ISO 4378-5:2009(E)

Plain bearings — Terms, definitions, classification and
symbols —
Part 5:
Application of symbols
1 Scope
This part of ISO 4378 specifies practical applications of the general symbols defined in ISO 4378-4, with
regard to the calculations, design and testing of plain bearings.
ISO 4378-4 distinguishes between basic characters and additional signs. Additional signs are subscripts and
superscripts. The symbols necessary for plain bearing calculations, design, manufacture and testing are just
basic characters or combinations of basic characters and additional signs.
This part of ISO 4378 lists symbols which have been found necessary for the calculations, design and testing
of plain bearings. They have been defined in accordance with the recommendations given in ISO 4378-4.
Angles and directions of rotation are defined positively as rotating in a left-hand (anticlockwise) direction; the
same applies to rotational frequencies, and circumferential and angular velocities.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 4378-4, Plain bearings — Terms, definitions, classification and symbols — Part 4: Basic symbols
3 Symbols and terms
The following listings are not necessarily complete. They may be enlarged, if necessary.
NOTE Some letters of the Roman and Greek alphabet have not yet been used. Therefore, these letters are not listed
below.
3.1 Symbols of the Roman alphabet
A heat-emitting surface area (bearing housing), elongation at fracture
A* heat-emitting surface area parameter [thrust bearing, A* = A/(B × L × Z )]
ax
A area of segment or pad
B
A area of groove cross-section
G
A heat-emitting surface area (bearing housing) inside of the machine (flange bearing)
i
A land area
lan
* *
A relative land area ( A = A /(π × D × B) for hydrostatic journal bearings)
lan lan
lan
A heat-emitting surface area (bearing housing) outside of the machine (flange bearing)
o
A area of lubricant pocket
P
A area of cross-section
S
A specific area of tube
T
A area of tube cross-section flowed through
T,i
a distance, acceleration, thermal diffusivity, inertia factor
a distance between leading edge and pivot position of pad (tilting-pad bearing)

F
*
a relative distance between leading edge and pivot position of pad (tilting-pad bearing)
F
a minimum distance between two circular thrust pads
min
a distance between temperature measuring point and bearing sliding surface
T
B width parallel to the sliding surface, normal to the direction of motion; bearing width, nominal
bearing width, pad width, nominal pad width
B* relative width, relative bearing width, relative pad width, width ratio (B* = B/D)
B width of thrust bearing or thrust pad [B = (D − D )/2]
ax ax o i
B effective bearing width (without grooves, chamfers, etc.), effective pad width
eff
B outer width of bearing housing in axial direction
H
B total bearing width
tot
b width parallel to the sliding surface, normal to the direction of motion or flow
b width of circumferential discharge (hydrostatic bearing, b = B − b )
c c lan
b width of lubricant groove, width of lubricant supply groove, width of bleed groove
G
b land width parallel to the sliding surface, normal to the direction of flow
lan
b width of lubricant pocket, width of lubricant supply pocket

P
*
b relative width of lubricant pocket, relative width of lubricant supply pocket
P
C bearing clearance, nominal bearing clearance, chamfer, concentration
C axial bearing clearance (thrust bearing)
ax
C mean value of C [C = (C + C )/2]
ax,m ax ax,m ax,min ax,max
C maximum value of C
ax,max ax
C minimum value of C
ax,min ax
C bearing clearance, bearing diametral clearance (difference between bearing bore and journal

D
diameter of a journal bearing, C = D − D )
D J
C mean value of C [C = (C + C )/2]
D,m D D,m D,min D,max
2 © ISO 2009 – All rights reserved

C effective bearing diametral clearance

D,eff
C maximum value of C
D,max D
C minimum value of C
D,min D
C circumference of groove cross-section
G
C bearing radial clearance (difference between bearing bore and journal radius of a journal bearing,
R
C = R − R )
R J
∆C elastic change of C
R,el R
C effective bearing radial clearance
R,eff
C mean value of C [C = (C + C )/2]
R,m R R,m R,min R,max
C maximum value of C
R,max R
C minimum value of C
R,min R
∆C thermal change of C
R,th R
∆C total change of C (∆C = ∆C + ∆C )
R,tot R R,tot R,el R,th
c specific heat capacity, lubricant specific heat capacity, stiffness
c axial bearing stiffness
ax
c axial stiffness of the bearing when load is directed into the machine (flange bearing)
ax,i
c axial stiffness of the bearing when load is directed out of the machine (flange bearing)
ax,o
c vertical stiffness of the bearing loaded downwards
dw
c stiffness of pad pivot support in direction of load (tilting-pad bearing)
F
c horizontal bearing stiffness
h
c lubricant film stiffness coefficient of journal bearing (i, k = 1, 2)
ik
*
c non-dimensional lubricant film stiffness coefficient of journal bearing
ik
ψ
*
cc=×i,1k=,2
() ( )
ik ik
2××B ηω×
c inner lubricant film stiffness coefficient of journal bearing (i, k = 1, 2)
ik,i
c outer lubricant film stiffness coefficient of journal bearing (i, k = 1, 2)
ik,o
c flexural stiffness of the Jeffcott Rotor
JR
c specific heat capacity of the lubricant (at constant pressure)

p
c specific heat capacity of the coolant (at constant pressure)

p,cl
c flexural stiffness of shaft
sh
c stiffness of isotropic bearing or bearing shell support
sup
c stiffness coefficient of anisotropic bearing or bearing shell support (i, k = 1, 2)
sup,ik
c vertical stiffness of the bearing loaded upwards
up
c vertical bearing stiffness
v
c angular stiffness of pad pivot support (tilting-pad bearing)
ϑ
D bearing diameter (inside diameter of journal bearing), nominal bearing diameter
D twice the lobe or pad bore radius of a multi-lobed or tilting-pad journal bearing

B
D mean value of D [D = (D + D )/2]

B,m B B,m B,min B,max
D maximum value of D
B,max B
D minimum value of D
B,min B
D outside diameter of bearing shell or pad of a fixed-pad or tilting-pad journal bearing
B,o
D (outside) diameter of lubricating ring fixed to the shaft
fi
D inside diameter of bearing housing

H,i
D outside diameter of bearing housing
H,o
D inside diameter of thrust bearing sliding surface

i
D journal diameter (diameter of the shaft section located inside of a journal bearing)

J
D mean value of D [D = (D + D )/2]

J,m J J,m J,min J,max
D maximum value of D
J,max J
D minimum value of D
J,min J
D (outside) diameter of loose lubricating ring
lo
D mean diameter of thrust bearing sliding surface [D = (D + D )/2]
m m i o
D maximum value of D
max
D minimum value of D
min
D outside diameter of thrust bearing sliding surface

o
D inside diameter of tube
T,i
D outside diameter of tube
T,o
d diameter, distance, depth, damping
d diameter of circular thrust pad
B
d diameter of capillary
cp
d damping of eigenfrequency, system damping
e
d damping of pad pivot support in direction of load (tilting-pad bearing)
F
d diameter of groove
G
d mean diameter of groove
G,m
d lubricant film damping coefficient of journal bearing (i, k = 1, 2)
ik
4 © ISO 2009 – All rights reserved

*
d non-dimensional lubricant film damping coefficient of journal bearing
ik
⎡⎤
ψ
*
dd=×ω×i,1k=,2
⎢⎥()
ik ik
2××B ηω×
⎢⎥
⎣⎦
d lubrication hole diameter
L
d inside diameter of orifice
orf,i
d outside diameter of orifice
orf,o
d diameter of lubricating pocket
P
d damping of isotropic bearing or bearing shell support
sup
d damping coefficient of anisotropic bearing or bearing shell support (i, k = 1, 2)
sup,ik
d angular damping of pad pivot support (tilting-pad bearing)
ϑ
E Young's modulus (modulus of elasticity)
E Young's modulus of bearing material

B
E Young's modulus of journal material

J
E resultant Young's modulus
res
E Young's modulus of shaft material
sh
e eccentricity (distance between journal and bearing axis)
e eccentricity of bearing sliding surfaces (segments or pads) of a multi-lobed or tilting-pad journal

B
bearing
e eccentricity of bearing sliding surfaces (segments) of a multi-lobed journal bearing in the

B,h
horizontal direction
e eccentricity of bearing sliding surfaces (segments) of a multi-lobed journal bearing in the vertical
B,v
direction
e eccentricity of centre of gravity (distance between centre of gravity and shaft axis)
CG
e component of eccentricity normal to direction of load
x
e component of eccentricity in direction of load
y
F bearing force, bearing load, nominal bearing load, load-carrying capacit
...

NORME ISO
INTERNATIONALE 4378-5
Première édition
2009-09-01
Paliers lisses — Termes, définitions,
classification et symboles —
Partie 5:
Application des symboles
Plain bearings — Terms, definitions, classification and symbols —
Part 5: Application of symbols

Numéro de référence
©
ISO 2009
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ii © ISO 2009 – Tous droits réservés

Sommaire Page
Avant-propos .iv
Introduction.v
1 Domaine d'application .1
2 Références normatives.1
3 Symboles et termes.1
3.1 Symboles (alphabet romain) .1
3.2 Symboles (alphabet grec).18

Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de
normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiée
aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du
comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI,
Partie 2.
La tâche principale des comités techniques est d'élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur
publication comme Normes internationales requiert l'approbation de 75 % au moins des comités membres
votants.
L'attention est appelée sur le fait que certains des éléments du présent document peuvent faire l'objet de
droits de propriété intellectuelle ou de droits analogues. L'ISO ne saurait être tenue pour responsable de ne
pas avoir identifié de tels droits de propriété et averti de leur existence.
L'ISO 4378-5 a été élaborée par le comité technique ISO/TC 123, Paliers lisses, sous-comité SC 6, Termes et
sujets communs.
Cette première édition annule et remplace l'ISO 4378-4:1997 et l'ISO 7904-2:1995, qui ont fait l'objet d'une
révision technique.
L'ISO 4378 comprend les parties suivantes, présentées sous le titre général Paliers lisses — Termes,
définitions, classification et symboles:
⎯ Partie 1: Conception, matériaux pour paliers et leurs propriétés
⎯ Partie 2: Frottement et usure
⎯ Partie 3: Lubrification
⎯ Partie 4: Symboles de base
⎯ Partie 5: Application des symboles
iv © ISO 2009 – Tous droits réservés

Introduction
Un grand nombre de désignations multiples sont présentes dans le domaine des paliers lisses, ce qui
entraîne un risque considérable d'erreurs lors de l'interprétation des normes et de la littérature technique. Du
fait de cette incertitude, des désignations nouvelles sont constamment ajoutées, ce qui augmente encore la
confusion.
La présente partie de l'ISO 4378 précise l'utilisation pratique des symboles utilisés dans le domaine des
paliers lisses.
NORME INTERNATIONALE ISO 4378-5:2009(F)

Paliers lisses — Termes, définitions, classification et
symboles —
Partie 5:
Application des symboles
1 Domaine d'application
La présente partie de l'ISO 4378 précise l'utilisation pratique des symboles généraux définis dans
l'ISO 4378-4 pour le calcul, la conception et l'essai des paliers lisses.
L'ISO 4378-4 distingue les caractères de base des signes complémentaires. Les signes complémentaires
sont les indices et les exposants. Les symboles requis pour les calculs, la conception, la fabrication et les
essais des paliers lisses peuvent être simplement des caractères de base ou bien des combinaisons de
caractères de base et de signes complémentaires.
La présente partie de l'ISO 4378 énumère les symboles jugés nécessaires pour les calculs, la conception et
les essais des paliers lisses. Ils ont été définis conformément aux recommandations données dans
l'ISO 4378-4.
Les angles et directions de rotation sont définis comme positifs en rotation à gauche (sens inverse des
aiguilles d'une montre); idem pour les fréquences de rotation et les vitesses périphériques et angulaires.
2 Références normatives
Les documents de référence suivants sont indispensables pour l'application du présent document. Pour les
références datées, seule l'édition citée s'applique. Pour les références non datées, la dernière édition du
document de référence s'applique (y compris les éventuels amendements).
ISO 4378-4, Paliers lisses — Termes, définitions, classification et symboles — Partie 4: Symboles de base
3 Symboles et termes
Les listes suivantes ne sont pas exhaustives. Elles peuvent être complétées si nécessaire.
NOTE Certaines lettres des alphabets romain et grec n'ont pas été utilisées jusqu'à présent. Elles ne sont donc pas
répertoriées ci-dessous.
3.1 Symboles (alphabet romain)
A aire de la surface émettant de la chaleur (logement du palier), allongement à la rupture
A* paramètre de l'aire de la surface émettant de la chaleur [butée, A* = A/(B × L × Z )]
ax
A aire du segment ou du patin
B
A aire de la section transversale de la rainure
G
A aire de la surface émettant de la chaleur (logement du palier) à l'intérieur de la machine (palier à
i
collerette)
A aire de la face portante
lan
* *
A aire relative de la face portante [ A = A /(π × D × B) pour les paliers radiaux hydrostatiques]
lan lan
lan
A aire de la surface émettant de la chaleur (logement du palier) à l'extérieur de la machine (palier à
o
collerette)
A aire de la poche de lubrifiant
P
A aire de la section transversale
S
A aire spécifique du tube
T
A aire de la section transversale du tube inondée
T,i
a distance, accélération, diffusivité thermique, facteur d'inertie
a distance entre le bord d'attaque et le point de pivot du patin (palier à patins oscillants)
F
*
a distance relative entre le bord d'attaque et le point de pivot du patin (palier à patins oscillants)
F
a distance minimale entre deux patins de butée circulaires
min
a distance entre le point de mesure de la température et la surface de glissement du palier
T
B largeur parallèle à la surface de glissement, perpendiculaire à la direction du mouvement; largeur
de palier, largeur nominale de palier, largeur de patin, largeur de patin nominale
B* largeur relative, largeur du palier relative, largeur du patin relative, rapport de largeur (B* = B/D)
B largeur de la butée ou du segment axial [B = (D − D )/2]
ax ax o i
B largeur du palier effective (sans rainures, chanfrein, etc.), largeur du patin effective
eff
B largeur extérieure du logement du palier dans la direction axiale
H
B largeur du palier totale
tot
b largeur parallèle à la surface de glissement, perpendiculaire à la direction du mouvement ou flux
b largeur de décharge périphérique (palier hydrostatique, b = B − b )
c c lan
b largeur de rainure de lubrification, largeur de rainure d'alimentation en lubrifiant, largeur de
G
rainure de purge
b largeur de la face portante parallèle à la surface de glissement, perpendiculaire à la direction du
lan
flux
b largeur de la poche de lubrifiant, largeur de la poche d'alimentation en lubrifiant
P
*
b largeur relative de la poche de lubrifiant, largeur relative de la poche d'alimentation en lubrifiant
P
C jeu du palier, jeu nominal du palier, chanfrein, concentration
C jeu axial du palier (butée)
ax
C valeur moyenne de C [C = (C + C )/2]
ax,m ax ax,m ax,min ax,max
C valeur maximale de C
ax,max ax
2 © ISO 2009 – Tous droits réservés

C valeur minimale de C
ax,min ax
C jeu du palier, jeu du diamètre du palier (différence entre l'alésage et le diamètre du tourillon d'un
D
palier radial, C = D − D )
D J
C valeur moyenne de C [C = (C + C )/2]
D,m D D,m D,min D,max
C jeu diamétral effectif du palier
D,eff
C valeur maximale de C
D,max D
C valeur minimale de C
D,min D
C périmètre de la section transversale de la rainure
G
C jeu radial du palier (différence entre l'alésage et le rayon de tourillon d'un palier radial,
R
C = R − R )
R J
∆C changement élastique de C
R,el R
C jeu radial effectif de palier
R,eff
C valeur moyenne de C [C = (C + C )/2]
R,m R R,m R,min R,max
C valeur maximale de C
R,max R
C valeur minimale de C
R,min R
∆C changement thermique de C
R,th R
∆C changement total de C (∆C = ∆C + ∆C )
R,tot R R,tot R,el R,th
c capacité thermique massique, capacité thermique massique de lubrifiant, rigidité
c rigidité axiale du palier
ax
c rigidité axiale du palier lorsque la charge est dirigée dans la machine (paliers à collerette)
ax,i
c rigidité axiale du palier lorsque la charge est dirigée hors de la machine (paliers à collerette)
ax,o
c rigidité verticale du palier chargé vers le bas
dw
c rigidité du support de pivot du patin dans la direction de la charge (palier à patins oscillants)
F
c rigidité horizontale du palier
h
c coefficient de rigidité du film de lubrifiant d'un palier radial (i, k = 1, 2)
ik
*
c coefficient de rigidité du film de lubrifiant non dimensionnel d'un palier radial
ik
ψ
*
cc=×i,1k=,2
()
ik ik
2××B ηω×
c coefficient de rigidité du film de lubrifiant intérieur d'un palier radial (i, k = 1, 2)
ik,i
c coefficient de rigidité du film de lubrifiant extérieur d'un palier radial (i, k = 1, 2)
ik,o
c rigidité à la flexion du rotor de Jeffcott
JR
c capacité de chaleur massique du lubrifiant (à pression constante)
p
c capacité de chaleur massique du refroidisseur (à pression constante)
p,cl
c rigidité à la flexion de l'arbre
sh
c rigidité du support de coquille du coussinet ou palier isotrope
sup
c coefficient de rigidité du support de coquille du coussinet ou palier anisotrope (i, k = 1, 2)
sup,ik
c rigidité verticale du palier chargé vers le haut
up
c rigidité verticale du palier
v
c rigidité angulaire du support de pivot du patin (palier à patins oscillants)
ϑ
D diamètre du palier (diamètre intérieur de palier radial), diamètre nominal du palier
D double du rayon du lobe ou du patin d'un palier radial à lobes multiples ou patins oscillants
B
D valeur moyenne de D [D = (D + D )/2]
B,m B B,m B,min B,max
D valeur maximale de D
B,max B
D valeur minimale de D
B,min B
D diamètre extérieur de la coquille du coussinet ou du patin d'un palier radial à patins fixes ou
B,o
oscillants
D diamètre (extérieur) de la bague de lubrification fixé à l'arbre
fi
D diamètre intérieur du logement du palier
H,i
D diamètre extérieur du logement du palier
H,o
D diamètre intérieur de la surface de glissement d'une butée
i
D diamètre du tourillon (diamètre de la partie d'arbre située à l'intérieur d'un palier radial)
J
D valeur moyenne de D [D = (D + D )/2]
J,m J J,m J,min J,max
D valeur maximale de D
J,max J
D valeur minimale de D
J,min J
D diamètre (extérieur) de la bague de lubrification libre
lo
D diamètre moyen de la surface de glissement de la butée [D = (D + D )/2]
m m i o
D valeur maximale de D
max
D valeur minimale de D
min
D diamètre extérieur de la surface de glissement de la butée
o
D diamètre intérieur du tube
T,i
D diamètre extérieur du tube
T,o
d diamètre, distance, profondeur, amortissement
d diamètre du segment axial circulaire
B
d diamètre de capillaire
cp
d amortissement de la fréquence propre, amortissement du système
e
4 © ISO 2009 – Tous droits réservés

d amortissement du support de pivot du patin dans la direction de la charge (palier à patins
F
oscillants)
d diamètre de la rainure
G
d diamètre moyen de la rainure
G,m
d coefficien
...