SIST EN 13001-3-4:2019

SLOVENSKI STANDARD
01-april-2019
Žerjavi - Konstrukcija, splošno - 3-4. del: Mejna stanja in dokaz varnosti
mehanizma - Ležaji
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Ta slovenski standard je istoveten z: EN 13001-3-4:2018
ICS:
21.100.01 Ležaji na splošno Bearings in general
53.020.20 Dvigala Cranes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13001-3-4
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2018
EUROPÄISCHE NORM
ICS 21.100.01; 53.020.20
English Version
Cranes - General design - Part 3-4: Limit states and proof
of competence of machinery - Bearings
Appareils de levage à charge suspendue - Conception Krane - Konstruktion allgemein - Teil 3-4:
générale - Partie 3-4 : États limites et vérification Grenzzustände und Sicherheitsnachweise für
d'aptitude des éléments de mécanismes - Paliers Maschinenbauteile - Lager
This European Standard was approved by CEN on 22 July 2018.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13001-3-4:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions, symbols and abbreviations . 7
3.1 Terms and definitions . 7
3.2 Symbols and abbreviations . 8
4 General . 15
4.1 Documentation . 15
4.2 Materials . 15
4.2.1 Grades and qualities for slewing rings . 15
4.2.2 Grades and qualities for rolling bearings, except slewing rings . 16
4.2.3 Materials for plain bearings . 16
4.3 Bearings . 17
4.3.1 General . 17
4.3.2 Slewing rings . 17
4.3.3 Rolling bearings . 20
4.3.4 Plain bearings . 21
4.4 Proofs of competence for bearings . 25
5 Proof of static strength . 26
5.1 General . 26
5.2 Limit design stresses and forces . 26
5.2.1 General . 26
5.2.2 Limit design forces and stresses for slewing rings . 26
5.2.3 Execution of the proof for slewing rings . 40
5.2.4 Limit design forces and stresses for rolling bearings . 41
5.2.5 Execution of the proof for rolling bearings . 43
5.2.6 Limit design forces and stresses for plain bearings . 44
5.2.7 Execution of the proof for plain bearings . 49
6 Proof of endurance and fatigue strength . 49
6.1 General . 49
6.2 Slewing rings . 49
6.2.1 Design dynamic loads and load ratings . 49
6.2.2 Fatigue strength of the fixing elements . 56
6.2.3 Execution of the proof for slewing rings . 57
6.3 Rolling bearings . 59
6.3.1 Design dynamic loads and load ratings . 59
6.3.2 Execution of the proof for rolling bearings . 62
6.4 Plain bearings . 65
6.4.1 General . 65
6.4.2 Cylindrical plain bearings . 65
6.4.3 Spherical plain bearings . 69
6.4.4 Execution of the proof of endurance for plain bearings . 73
6.4.5 Plain bearing design life . 75
7 Proof of elastic stability . 75
Annex A (informative) Calculation factors and guide load ratings of slewing rings . 76
A.1 Excess load factor K . 76
rep
A.1.1 General . 76
A.1.2 Analytical method of determining K . 77
rep
A.2 Influence factors . 78
A.2.1 Proof of static strength . 78
A.2.1.1 Factor for shear in sub-hardened layer f . 78
A.2.1.2 Factor for surface hardness f . 79
A.2.2 Proof of fatigue strength: factor f′ for sub-hardened layer . 79
f1
A.2.3 Proof of fatigue strength: Inclusion factor f′ . 80
f2
A.2.4 Proof of fatigue strength: Surface hardness factor f′ . 80
f3
A.3 Guidelines for various load ratings . 81
A.3.1 General . 81
A.3.2 Guide value of limit design static axial load rating C for slewing rings with ball
0aRd
bearings . 81
A.3.3 Guide value of limit design static load ratings C and C for slewing rings
0a,Rd 0r,Rd
with roller bearing . 82
A.3.3.1 Limit design static axial load rating C . 82
0a,Rd
A.3.3.2 Limit design static radial load rating C (three-row roller bearing) . 82
0r,Rd
A.3.4 Basic dynamic axial load rating C of a slewing ring with ball bearings . 83
a
A.3.4.1 Single-row with 4 contact points and double-row with 2 point contacts . 83
A.3.4.2 Double-row with 4 contact points . 84
A.3.5 Basic dynamic load ratings C and C of a slewing ring with roller bearings . 84
a r
A.3.5.1 Basic dynamic axial load rating C . 84
a
A.3.5.2 Basic dynamic radial load rating C (three-row roller bearing) . 85
r
A.4 Fixing elements: alternative calculation of the design stress σ . 85
Sd
A.4.1 Bolt prying moment M . 85
fb
A.4.2 Normal design stress σ . 90
Sd
A.4.3 Calculation of the lever arm s . 90
a
Annex B (informative) Proof of fatigue strength of slewing ring raceway: calculation of load
history parameter s (example) . 92
sr
B.1 General . 92
B.2 Working cycles . 92
B.2.1 Type of crane . 92
B.2.2 Description of the sequence of movements . 93
B.3 Description of the slewing ring . 94
B.3.1 Type of slewing ring . 94
B.3.2 Main data . 95
B.4 Proof of fatigue strength . 95
B.4.1 Load combinations . 95
B.4.2 Dynamic axial equivalent loads P for supporting/retaining raceways . 97
a,i
B.4.3 Dynamic radial equivalent loads P for radial raceway . 99
r,i
B.4.4 Classification of the raceways . 99
B.4.4.1 Supporting raceway . 99
B.4.4.2 Retaining raceway . 100
B.4.4.3 Radial raceway . 101
Annex C (informative) Equivalence of proofs of fatigue strength of slewing rings and rolling
bearings according to EN 13001 method and ISO 281 one . 103
Annex D (informative) Selection of a suitable set of crane standards for a given application . 105
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 2006/42/EC . 107
Bibliography . 108
European foreword
This document (EN 13001-3-4:2018) has been prepared by Technical Committee CEN/TC 147
“Cranes - Safety”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2019, and conflicting national standards shall be
withdrawn at the latest by June 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annexes ZA, which are an integral part of this
document.
This European Standard is one Part of the EN 13001 series. The other parts are as follows:
— Part 1: General principles and requirements;
— Part 2: Load actions;
— Part 3-1: Limit states and proof of competence of steel structures;
— Part 3-2: Limit states and proof of competence of wire ropes in reeving systems;
— Part 3-3: Limit states and proof of competence of wheel/rail contacts;
— Part 3-5: Limit states and proof of competence of forged hooks;
— Part 3-6: Limit states and proof of competence of machinery — Hydraulic cylinders;
— Part 3-7: Limit states and proof of competence of machinery — Gears;
— Part 3-8: Limit states and proof of competence of machinery — Shafts.
Annexes A, B, C and D are informative.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands,
Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
the United Kingdom.
1 Scope
This document is to be used together with EN 13001-1 and EN 13001-2 and as such they specify general
conditions, requirements and methods to prevent mechanical hazards of cranes by design and theoretical
verification.
NOTE 1 Specific requirements for particular types of crane are given in the appropriate European Standard for
the particular crane type.
This document covers bearings in cranes. It is not intended for bearings being part of standard
components, e.g. gearboxes, motors … however those bearings shall be designed using load actions from
EN 13001-2 and classification parameters of EN 13001-1.
NOTE 2 EN 13001-3-7 is under preparation for gears and gearboxes and deals with load actions for bearings in
gear boxes.
The following is a list of significant hazardous situations and hazardous events that could result in risks
to persons during intended use and reasonably foreseeable misuse. Clauses 4 to 7 of this document are
necessary to reduce or eliminate risks associated with the following hazards:
— exceeding the limits of strength (yield, ultimate, fatigue);
— exceeding temperature limits of material or components;
— elastic instability of the crane or its parts (buckling, bulging).
This document is not applicable to cranes which are manufactured before the date of its publication as
an EN and serves as reference base for the European Standards for particular crane types (see Annex D).
NOTE EN 13001-3-4 deals only with limit state method in accordance with EN 13001-1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
EN 10083-1:2006, Steels for quenching and tempering — Part 1: General technical delivery conditions
EN 10247:2017, Micrographic examination of the non-metallic inclusion content of steels using standard
pictures
EN 13001-1, Cranes — General design — Part 1: General principles and requirements
EN 13001-2, Crane safety — General design — Part 2: Load actions
EN 13001-3-1, Cranes — General design — Part 3-1: limit states and proof of competence of steel structure
EN ISO 148-1, Metallic materials, Charpy pendulum impact test — Part 1: Test method (ISO 148-1)
EN ISO 683-17, Heat-treated steels, alloy steels and free-cutting steels — Part 17: Ball and roller bearing
steels (ISO 683-17)
EN ISO 4287:1998, Geometrical product specifications (GPS) — Surface texture: Profile method — Terms,
definitions and surface texture parameters (ISO 4287)
EN ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk
reduction (ISO 12100:2010)
ISO 76:2006, Rolling bearings — Static load ratings
ISO 281:2007, Rolling bearings — Dynamic load ratings and rating life
ISO 4306-1:2007, Cranes — Vocabulary — Part 1: General
3 Terms and definitions, symbols and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 12100:2010 and
ISO 4306-1:2007, Clause 6 for the definitions of loads, and the following applies.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
plain bearing
bearing in which the type of relative movement is sliding but with the exclusion of those operating under
conditions of hydrodynamic lubrication
3.1.2
rolling bearing
bearing operating with rolling motion between the parts supporting load and moving in relation to each
other, which comprises raceway members and rolling elements with or without means for their spacing
and/or guiding
Note 1 to entry: For the purposes of this document, it is designed to support radial, axial, or combined radial and
axial load.
[SOURCE: ISO 5593, modified]
3.1.3
slewing ring
slewing ring bearing
large-size rolling-element bearing providing a connection between two adjacent structures and allowing
rotation and transmission of loads between them (axial and radial loads and a tilting moment)
Note 1 to entry: Slewing ring is usually provided with holes for fixing bolts, with internal or external gear
facilitating the rotation of one structure relative to the other and with lubrication and seals.
3.1.4
nominal contact angle
α
angle between a plane perpendicular to a bearing axis (a radial plane) and the nominal line of action of
the resultant of the forces transmitted by a bearing ring or washer to a rolling element (see
reference 04.02.10 in Figure 1 below)
[see SOURCE: ISO 5593:1997, definition 04.02.10 and Figures 93, 94]
Figure 1 — Rolling bearings dimensions
3.2 Symbols and abbreviations
The symbols and abbreviations used in this document are given in Table 1.
Table 1 — Symbols and abbreviations
Symbols,
Description
abbreviations
a
Life modification factor for reliability (ISO 281:2007)
A Apportionment factor for axial load F (slewing ring)
pF a
A Apportionment factor for tilting moment M (slewing ring)
pM r
A
Bolt stress area (fixing element)
s
b Distance between two adjacent bolts (slewing ring)
C Total number of working cycles (EN 13001-1)
C
Basic dynamic axial load rating (ISO 281:2007)
a
C
Basic dynamic radial load rating (ISO 281:2007)
r
C
Limit design dynamic axial load (slewing ring, rolling bearing)
a,Rd
C
Limit design dynamic radial load (slewing ring, rolling bearing)
r,Rd
Basic static axial load rating (slewing ring, rolling bearing, spherical plain
C
0a
bearing)
Basic static radial load rating (slewing ring, rolling bearing, spherical plain
C
0r
bearing)
C
Limit design static axial load rating (slewing ring)
0a,Rd
C
Limit design static radial load rating (slewing ring)
0r,Rd
Symbols,
Description
abbreviations
C
Tightening torque
D
Internal diameter (thrust washer)
in
D
External diameter (thrust washer, flanged bush)
ex
Pitch Circle Diameter of rolling elements (denoted D in ISO 76 and
pw
D
m
ISO 281)
D
Pitch Circle Diameter of fixing elements
vi
D
Ball diameter (rolling element)
w
D
Roller diameter (rolling element)
we
Nominal diameter of a screw/bolt (slewing ring); shaft diameter (plain
d
bearing)
d
Sphere diameter of a spherical plain bearing
k
E Modulus of elasticity
E
Modulus of elasticity of a bolt
b
E
Modulus of elasticity of a slewing ring supporting flange
p
Distance (lever arm) between external force F and the centre of the
e
e
m
supporting width 2 · u of the slewing ring
*
Lever arm of external load F to bolt axis (slewing ring)
e
e
m
Distance between bolt axis and the centre of the supporting width 2 · u of the
e
n
slewing ring
F
Axial load
a
F
Axial load, range i (fatigue)
a,i
F
Bolt load
b
F
Fatigue bolt load
b,f
F
Equivalent bolt load
b,2
F
Slewing ring contact load
c
F
Limit force
d
F
External load (slewing ring)
e
F
Critical opening force for a slewing ring
e,cr
F
Design maximum external load
e,max
F
Design maximum fatigue external load
e,f,max
Symbols,
Description
abbreviations
F
Minimal preload in bolts
p,min
F
Design plain bearing force
pb,Sd
F
Radial load (slewing ring)
r
F
Radial load, range i (fatigue)
r,i
F
Limit design forces
Rd
F
Design dynamic load (plain bearing)
Sd,f,i
F
Mean equivalent radial load (plain bearing)
Sd,f,eq
F
Bolt yield force
y
f
Calculation factor (ISO 281:2007)
c
f
Reliability factor (fatigue, slewing ring and rolling bearing)
f1
'
f
Inclusion factor (fatigue slewing ring)
f2
f
Factor for additional influences (fatigue)
f2
'
f
Surface hardness factor (fatigue)
f3
f
Limit design stress
Rd
f
Fixing element ultimate strength
ub
f
Yield stress of material
y
f
Fixing element yield stress
yb
f
Factor for calculation of basic static load rating (ISO 76:2006)
f
Factor for shear in slewing ring sub-hardened layer (static)
'
f Factor for shear in slewing ring sub-hardened layer (fatigue)
f1
f
Deformation influence factor for slewing ring (static)
'
f Deformation influence factor for slewing ring (fatigue)
f
Surface hardness factor (static)
H
Height of slewing ring
ring
H
Height of tubular shell (slewing ring)
T
I
Moment of inertia of a bolt (slewing ring)
b
I
Moment of inertia of slewing ring supporting flange
p
'
K
K
Excess load factor for raceway (slewing ring, static and fatigue)
rep;
rep
Symbols,
Description
abbreviations
K
Excess load factor for bolts (slewing ring)
rep,b
k
Dynamic pressure spectrum factor (plain bearing)
pb
k
Dynamic load spectrum factor (slewing ring)
sr
k
Dynamic load spectrum factor (rolling bearing)
rb
L
Axial loading offset (plain bearing)
a
L
Length of plain bearing
b
L ; L
Internal and external chamfers of plain bearing
ci ce
L
Length of equivalent elastic beam (slewing ring)
e
L
Radial loading offset (plain bearing)
r
L
Length between supports of equivalent beam (slewing ring)
sr
l
Effective clamping length
k
M
Tilting moment (slewing ring)
r
M
Tilting moment, range i (fatigue)
r,i
M
Bolt prying moment (slewing ring)
fb
m Slope constant of the log p-log N curve (plain bearing)
N Shaft rotational speed (plain bearing)
N
Total number of cycles (plain bearing)
tot,pb
n
Number of supports (slewing ring)
s
n Number of cycles (plain bearing)
n
Number of slewing rings during a crane design life
sr
P
Design axial dynamic equivalent load, range i
a,i
P
Design axial dynamic load (slewing ring)
a,Sd
P
Design axial dynamic equivalent load, range i (rolling bearing)
a,Sd,i
P
Design dynamic radial equivalent load, range i
r,i
P
Design radial dynamic load (slewing ring)
r,Sd
P
Design radial dynamic equivalent load, range i (rolling bearing)
r,Sd,i
P
Design axial equivalent static load (slewing ring)
0a
P
Static equivalent axial load (rolling bearing)
0a,Sd
P
Design radial equivalent static load (slewing ring)
0r
Symbols,
Description
abbreviations
P
Static equivalent radial load (rolling bearing)
0r,Sd
P
Design equivalent load (spherical plain bearing)
spb,Sd
p Life exponent (slewing ring, rolling bearing)
p
Equivalent design dynamic plain bearing pressure
eq
p
Limit design dynamic plain bearing pressure
L
p
Design dynamic plain bearing pressure, range i
pb,i
p
Maximum design dynamic plain bearing pressure
pb,max
p
Design cylindrical plain bearing pressure (static)
pb,Sd
p
Limit design cylindrical plain bearing pressure (static)
pb,Rd
p
Design surface pressure (spherical plain bearing)
spb
p
Limit design dynamic spherical plain bearing pressure
spb,L
(p · v)
Limit design effective transmitted power density (cylindrical plain bearing)
L
(p · v)
Limit design effective transmitted power density (spherical plain bearing)
spb,L
Q
Highest contact load for a rolling element (slewing ring)
b
R
Average depth of surface profile in accordance with EN ISO 4287:1998
a
R
Design resistance
d
R
Maximum possible hardened depth for an induction hardening
ht
S
Bolt flexibility (slewing ring)
b
S
Flange flexibility (slewing ring)
c
S
Design stress or design force
d
S
Connection flexibility (slewing ring)
sr
s Critical lever arm of the contact force F (slewing ring)
a,cr c
s Lever arm of the contact force F (slewing ring)
a c
s
Bolt stress history parameter
m
s
Rolling bearing load history parameter
rb
s
Slewing ring raceway load history parameter
sr
S
Static safety factor (rolling bearing)
T
Limit operating temperature (plain bearing)
max
t Thickness
Symbols,
Description
abbreviations
t
Projected thickness of plain bearing chamber
ch
t
Thickness of plain bearing low friction layer
af
t
Supporting flange thickness (slewing ring)
p
u Half-supporting with of slewing ring
U
Reference number of revolutions (slewing ring, rolling bearing)
D
U
Number of revolutions of range i
i
U
Total number of revolutions (slewing ring)
tot,sr
U
Total number of revolutions (rolling bearing)
tot,rb
v
Shaft design effective sliding speed (plain bearing)
eff
v
Limit design effective sliding speed (cylindrical plain bearing)
L
v
Spherical plain bearing effective sliding speed
spb,eff
v
Limit design effective sliding speed (spherical plain bearing)
spb,L
X
Average angular displacement (EN 13001-1)
ang
X Rolling bearing dynamic load factor (ISO 281:2007); plain bearing load factor
X
Rolling bearing static load factor (ISO 76:2006)
Y Rolling bearing dynamic load factor (ISO 281:2007) ; plain bearing load factor
Y
Rolling bearing static load factor (ISO 76:2006)
Z
Number of active rolling elements
aF
Z
Number of slewing ring fixing elements
b
Z
Critical depth of the sub-hardened layer shear
d
Nominal contact angle (see 3.1.4) for slewing rings and rolling bearings;
α
Angle of tilt for spherical plain bearings (ISO 12240)
α
Chamfer angle (plain bearing)
c
β Calculation factor for the determination of the excess load factor K
e rep
ΔF
Additional bolt force (slewing ring)
b
ΔM
Additional prying moment (slewing ring)
fb
Δσ
Characteristic fatigue strength
c
Δσ
Design stress range
Sd
Δσ
Limit design stress range
Rd
Symbols,
Description
abbreviations
γ
General resistance factor
m
γ
Risk coefficient (EN 13001-2)
n
γ
Total resistance factor
R
γ γ
Resulting resistance factors for connections loaded in tension
Rb,1; Rb,2
γ
Fatigue strength specific resistance factor of rolling bearing
rbf
γ
Specific resistance factor for slewing ring raceway (axial)
sa
γ
Specific resistance factor for slewing ring raceway (radial)
sr
γ
Specific resistance factor for rolling bearings
srb
γ
Fatigue strength specific resistance factor of slewing ring
srf
ν
Relative total number of revolutions (rolling bearing)
rb
ν
Relative total number of revolutions (slewing ring)
sr
ϕ Stiffness ratio (bolts); total oscillating amplitude angle (plain bearing)
σ
Design (bolt) bending stress
b
σ
Design (bolt) tensile stress
n
σ
Limit design normal stress
Rd
σ
Design normal stress
Sd
τ Design (bolt) shear stress
τ
Sub-hardened layer shear stress (slewing ring)
p
ψ
Slewing sector of range j (slewing ring)
j
4 General
4.1 Documentation
The documentation of the proof of competence shall include:
— design assumptions including calculation models;
— applicable loads and load combinations;
— material grades and qualities;
— used bearing provider instructions and requirements;
— relevant limit states;
— results of the proof of competence calculation and tests when applicable.
4.2 Materials
4.2.1 Grades and qualities for slewing rings
4.2.1.1 Grades
European and International Standards specify materials and specific values. This document gives a
preferred selection of materials with their mechanical properties.
For raceway rings and rolling elements of slewing rings, steel in accordance with the following European
Standards should be used:
— steels for quenching and tempering; Alloy steels: EN 10083-3;
— heat-treated steels, alloy steels and free-cutting steels; Ball and roller bearing steels: EN ISO 683-17.
Grades and qualities other than those mentioned in the above standards may be used if the mechanical
properties and the chemical composition are specified in a manner corresponding to relevant European
standard.
For slewing rings, the steel grades below are recommended:
— rolling elements: through hardening bearing steel in accordance with EN ISO 683-17 (e.g. 100Cr6).
— the minimum elongation based on gauge length of five diameters for the materials for slewing rings
is to be 14 %.
4.2.1.2 Inclusions
As a minimum, the contents of non-metallic inclusions shall comply with the requirements of EN 10083-1.
If an enhanced fatigue performance of the slewing ring is needed, values of the maximum limits of non-
metallic inclusions content from EN ISO 683-17 can be used (see A.2.3).
The methods of measurement shall conform to EN 10247:2017. From the data of measurements obtained
by those methods, evaluation according to EN 10083-1 and EN ISO 683-17 shall be established (see
notably from EN 10247:2017, Annex L).
4.2.1.3 Impact toughness
The slewing ring components shall have sufficient ductility to prevent brittle fracture.
The material shall have a minimum impact toughness of 17 J at −20 °C (operating temperature
T ≥ −30 °C), tested in accordance with EN ISO 148-1, after the heat treatment.
For materials quenched and tempered, the minimum impact toughness shall be 27 J at −20 °C (operating
temperature T ≥ −30 °C).
4.2.2 Grades and qualities for rolling bearings, except slewing rings
4.2.2.1 Grades
European and International Standards specify materials and specific values. This document gives a
preferred selection of materials with their mechanical properties.
For rolling bearings, steel in accordance with following European Standards should be used:
— steels for quenching and tempering; Alloy steels: EN 10083-3;
— heat-treated steels, alloy steels and free-cutting steels; Ball and roller bearing steels: EN ISO 683-17.
Grades and qualities other than those mentioned in the above standards may be used if the mechanical
properties and the chemical composition are specified in a manner corresponding to relevant European
standard.
For rolling elements, through hardening bearing steel (e.g. 100Cr6) is recommended, in accordance with
ISO 683-17.
4.2.2.2 Inclusions
As a minimum, the contents of non-metallic inclusions shall comply with the requirements of EN 10083-1.
If an enhanced fatigue performance of the rolling bearing is needed, values of the maximum limits of non-
metallic inclusions content from EN ISO 683-17 can be used.
The methods of measurement shall conform to EN 10247:2017. From the data of measurements obtained
by those methods, evaluation according to EN 10083-1 and EN ISO 683-17 shall be established (see
notably from EN 10247:2017, Annex L).
4.2.3 Materials for plain bearings
Plain bearings can be made from various steel and low friction materials such as Bronze, Sintered Bronze,
Bronze-lead, Bronze-Graphite, Polymers (Polyamide, Polyacetal, Polyetherethercetone-PEEK),
Fluorinated polymers (TFE, PTFE) and can have low friction fillers as PTFE, MoS or anti-wear fillers as
fibre glass.
For basic properties of the materials below, the following International Standards can be used:
— Fluorinated polymers (PTFE): ISO 6691;
— materials for wrapped bushes: ISO 3547-4;
— Copper alloys (e.g. Bronze): ISO 4382 and EN 1982.
For basic properties of other materials, the designer can refer to specialized data sheets for the plain
bearing materials, as provided by the manufacturers.
For the steel backing, steel in accordance with following European Standards should be used:
— steels for quenching and tempering; Alloy steels: EN 10083-3;
— heat-treated steels, alloy steels and free-cutting steels; Ball and roller bearing steels: EN ISO 683-17.
4.3 Bearings
4.3.1 General
The rotational guiding of rotating parts can be ensured by means of:
— slewing rings;
— rolling bearings;
— plain bearings.
4.3.2 Slewing rings
4.3.2.1 General
Manufacturer’s instructions on installation, maintenance and positioning (lubrication, centring, gear
backlash …), shall be adhered to.
Those instructions are only valid for a not polluted environment, e.g. not containing potentially damaging
elements (dust, water …) which can ingress the raceways of the slewing rings.
This European standard deals with suspended and supported installations of slewing rings. Slewing rings
are generally installed supported on the lower companion structure: the axial load F relieves the bolts.
a
On the contrary, if the installation is suspended, the tension on the bolts are increased by the axial load
F .
a
Load paths due to F are represented in Table 2 for both types of installation of a three-row roller bearing.
a
Table 2 — Supported and suspended slewing rings (principle)

Supported slewing ring
Suspended slewing ring
Key
F is the axial load
a
4.3.2.2 Supporting structure
A slewing ring is a large diameter rolling bearing, connected to a supporting structure by means of
preloaded bolted joint. The preferred construction of supporting structure provides a sufficiently rigid
support for the slewing ring, with the stiffness uniformly distributed around the circumference and
should consist of a machined flange joined to a tubular shell, in a coaxial arrangement with the slewing
ring.
Sufficient stiffness of the supporting structure is usually achieved if the supporting flange thickness t is
p
equal to or greater than half of the slewing ring height (see Figure 2).
H
ring
In order to achieve an optimum distribution of the external forces on the rolling elements, it is
recommended that:
— the thickness of tubular shell t should be equal to or greater than 1/6 of the height of the ring H ;
ring
— the height of tubular shell H should be equal to or greater than 1/4 of the Pitch Circle Diameter of
T
rolling elements D .
m
Table 3 gives recommended flatness tolerances for non-segmented slewing rings, in accordance with
EN ISO 1101. For other slewing rings (e.g. with diameter greater than 8 m), flatness tolerances should be
agreed upon between the crane manufacturer and the slewing ring supplier.
Table 3 — Flatness tolerances (EN ISO 1101)
D
m
Pitch Circle Diameter
Flatness according to EN ISO 1101, per support surface
of rolling elements
[mm]
(see Figure 2)
[mm]
Double-row ball Single-row ball bearing
bearing with 2 point with 4 point contacts per Roller bearings
contacts per ball ball
Double-row ball bearing
with 4 point contacts per
ball
≤ 500 0,15 0,10 0,07
500 < D ≤ 1 000
0,20 0,15 0,10
m
1 000 < D ≤ 1 500
0,25 0,19 0,12
m
1 500 < D ≤ 2 000
0,30 0,22 0,15
m
2 000 < D ≤ 2 500
0,35 0,25 0,17
m
2 500 < D ≤ 4 000
0,40 0,30 0,20
m
4 000 < D ≤ 6 000
0,50 0,40 0,30
m
6 000 < D ≤ 8 000
0,60 0,50 0,40
m
The machining of the slewing ring bearing surfaces should be done after welding in order to achieve the
required flatness tolerances. Grouting compounds can be used as an alternative to machining.

Key
t is the supporting flange thickness
p
H is the height of the ring
ring
H is the height of turbular shell
T
D is the pitch Circle Diameter of rolling elements
m
Figure 2 — Dimensions
4.3.2.3 Hardness
Raceways and rolling elements shall be at least surface hardened in order to support the maximum
contact stress they endure.
The raceways should be induction hardened, in order to achieve a minimal specified surface hardness
and with an effective hardened depth equal to at least twice the depth of the maximum shear stress. A
minimal surface hardness equal to 55 HRC is recommended and if an enhanced fatigue performance of
the slewing ring is needed, at least 58 HRC is recommended.
Hardening junction shall be marked and should be located on the filler plug for the ungeared ring and
placed as close as possible to the neutral axis of the loads: ideally at zero moment axis. For loaded
bearings with intensive duty, soft spot areas shall be ground.
The core crushing effect below the hardened layer shall be taken into account by the slewing ring
manufacturer and technically justified.
A minimal surface hardness equal to 60 H
...