Rolling bearings — Parts library — Reference dictionary for rolling bearings

This document establishes the means to achieve an electronic representation of rolling bearing data by providing a reference dictionary needed to describe various data about rolling bearings together with their descriptive properties and domains of values in various International Standards relevant to rolling bearings. This document is intended to facilitate the use, manipulation and exchange of rolling bearing data, for example, manufacturing, distribution and usage. This document specifies a reference dictionary that contains: — a definition of a general class of bearings intended to be further extended by reference dictionaries specifying bearings in other International Standards; — definitions and identifications of the classes of rolling bearings as they are described in the various International Standards relevant to rolling bearings, with associated classification scheme; — definitions and identifications of data element types that represent properties of rolling bearings; — definitions and identifications of domains of values that prove useful for describing the above-mentioned data element types. Each class, property or domain of values of this application domain constitutes an entry of the reference dictionary defined in this document. It is associated with a computer-sensible and a human-readable definition, and with a computer-sensible identification. Identification of a dictionary entry allows for unambiguous reference from any application. Definitions and identifications of dictionary entries are defined by means of standard data, which consist of instances of the EXPRESS entity data types defined in the common dictionary schema and in their extensions defined in ISO 13584-25. Identification dictionary is given in Annex A. The following are within the scope of this document: — standard data that represent the classes of rolling bearings; — standard data that represent the properties of rolling bearings; — standard data that represent domains of values used for properties of rolling bearings. The following are outside of the scope of this document: — methodology for structuring parts families used for specifying standard data defined in this document; — an implementation method by which the standard data defined in this document can be exchanged. NOTE 1 The structure of the physical file used for exchanging the standard data defined in this document is specified in ISO 10303‑21. NOTE 2 The physical file used for exchanging the standard data is compliant with ISO 13584-42:2010. NOTE 3 It is intended to provide an OntoML-based (XML) representation of the standard data when ISO 13584-32 (OntoML) is published. This document does not establish the reference dictionaries for linear motion rolling bearings and spherical plain bearings.

Roulements — Bibliothèque de composants — Dictionnaire de référence des roulements

General Information

Status
Published
Publication Date
04-Sep-2022
Current Stage
6060 - International Standard published
Due Date
21-Jan-2023
Completion Date
05-Sep-2022
Ref Project

RELATIONS

Buy Standard

Technical specification
ISO/TS 23768:2022 - Rolling bearings — Parts library — Reference dictionary for rolling bearings Released:5. 09. 2022
English language
83 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

TECHNICAL ISO/TS
SPECIFICATION 23768
First edition
2022-09
Rolling bearings — Parts library
— Reference dictionary for rolling
bearings
Roulements — Bibliothèque de composants — Dictionnaire de
référence des roulements
Reference number
ISO/TS 23768:2022(E)
© ISO 2022
---------------------- Page: 1 ----------------------
ISO/TS 23768:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on

the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below

or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
© ISO 2022 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/TS 23768:2022(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction .................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 2

3 Terms, definitions and abbreviated terms .............................................................................................................................. 2

3.1 Terms and definitions ...................................................................................................................................................................... 2

3.2 Abbreviated terms .............................................................................................................................................................................. 8

4 Representation of ontology concepts as dictionary entries .................................................................................. 8

4.1 Identification of data element type ...................................................................................................................................... 8

4.2 Bearing classes ....................................................................................................................................................................................... 8

4.2.1 Modelled classes ................................................................................................................................................................. 8

4.2.2 Referenced class ..............................................................................................................................................................12

4.2.3 Attributes used .................................................................................................................................................................12

4.2.4 Layout ........................................................................................................................................................................................ 13

4.3 Bearing property definitions .................................................................................................................................................. 14

4.3.1 Modelled data types ..................................................................................................................................................... 14

4.3.2 Imported properties .................................................................................................................................................... 14

4.3.3 Attributes used ................................................................................................................................................................. 14

4.3.4 Layout ........................................................................................................................................................................................ 15

4.4 Property data types ........................................................................................................................................................................ 16

4.4.1 Data types used ................................................................................................................................................................ 16

4.4.2 Attributes used ................................................................................................................................................................. 16

5 Classification principles ...........................................................................................................................................................................16

5.1 Connection to pre-existing classifications ................................................................................................................. 16

5.2 Class hierarchy .................................................................................................................................................................................... 16

6 Computer-sensible description .........................................................................................................................................................17

6.1 External file ............................................................................................................................................................................................ 17

6.2 Information model and conformance class ................................................................................................................ 17

Annex A (normative) Information object registration ..................................................................................................................18

Annex B (normative) Classification of rolling bearings ...............................................................................................................19

Annex C (normative) Definition of rolling bearing class.............................................................................................................21

Annex D (normative) Definition of rolling bearing properties ............................................................................................49

Annex E (normative) Computer-interpretable listings.................................................................................................................82

Bibliography .............................................................................................................................................................................................................................83

iii
© ISO 2022 – All rights reserved
---------------------- Page: 3 ----------------------
ISO/TS 23768:2022(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

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

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. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 4, Rolling bearings.

This first edition cancels and replaces ISO/TS 23768-1:2011, which has been technically revised.

The main changes are as follows:

— the part number of this document has been deleted as no further parts will be being developed;

— the scope has been clarified to clearly state that linear motion rolling bearings and spherical plain

bearings are out of the scope;
— this document has been made compatible with ISO 13584-42:2010;

— this document has been aligned with the classes and properties with ISO 21107:2015;

— some figures have been updated.

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.
© ISO 2022 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/TS 23768:2022(E)
Introduction

Rolling bearing data consist of entities of the rolling bearing application domain together with their

descriptive properties and domains of values. Descriptive properties specified by this document

include, but are not limited to, geometrical and dimensional data, identification and designation data,

miscellaneous and spare part data, and material data.

Each entity, property or domain of values defines an entry of the rolling bearing reference dictionary.

The rolling bearing reference dictionary constitutes the formal and computer-sensible representation of

the rolling bearing data. Each rolling bearing datum is associated with a computer-sensible and human-

readable definition, and with a computer-sensible identification. Identification of a dictionary entry

allows for unambiguous reference from any application. Definitions and identifications of dictionary

entries consist of instances of the EXPRESS entity data types defined in the common dictionary schema,

resulting from a joint effort between ISO/TC 184/SC 4/WG 2 and IEC SC 3D, or in its extensions defined

in the logical series of parts of ISO 13584.

This document is intended for use, among others, by manufacturers, rolling bearing vendors or

producers, and developers of manufacturing software. This document is intended to allow or improve

several capabilities, including:

— the provision of a common set of definitions for use in describing rolling bearings,

— the integration and sharing of rolling bearing data between software applications,

— the direct import of vendor rolling bearing data into customer databases or applications, and

— a reduction of the level of effort required for manufacturers to maintain accurate and current rolling

bearing information from multiple sources and for multiple applications.

Some of the definitions of classes and properties of rolling bearings are taken from International

Standards on rolling bearings and from Reference [12].
© ISO 2022 – All rights reserved
---------------------- Page: 5 ----------------------
TECHNICAL SPECIFICATION ISO/TS 23768:2022(E)
Rolling bearings — Parts library — Reference dictionary
for rolling bearings
1 Scope

This document establishes the means to achieve an electronic representation of rolling bearing data

by providing a reference dictionary needed to describe various data about rolling bearings together

with their descriptive properties and domains of values in various International Standards relevant to

rolling bearings.

This document is intended to facilitate the use, manipulation and exchange of rolling bearing data, for

example, manufacturing, distribution and usage.
This document specifies a reference dictionary that contains:

— a definition of a general class of bearings intended to be further extended by reference dictionaries

specifying bearings in other International Standards;

— definitions and identifications of the classes of rolling bearings as they are described in the various

International Standards relevant to rolling bearings, with associated classification scheme;

— definitions and identifications of data element types that represent properties of rolling bearings;

— definitions and identifications of domains of values that prove useful for describing the above-

mentioned data element types.

Each class, property or domain of values of this application domain constitutes an entry of the reference

dictionary defined in this document. It is associated with a computer-sensible and a human-readable

definition, and with a computer-sensible identification. Identification of a dictionary entry allows for

unambiguous reference from any application.

Definitions and identifications of dictionary entries are defined by means of standard data, which

consist of instances of the EXPRESS entity data types defined in the common dictionary schema and in

their extensions defined in ISO 13584-25.
Identification dictionary is given in Annex A.
The following are within the scope of this document:
— standard data that represent the classes of rolling bearings;
— standard data that represent the properties of rolling bearings;

— standard data that represent domains of values used for properties of rolling bearings.

The following are outside of the scope of this document:

— methodology for structuring parts families used for specifying standard data defined in this

document;

— an implementation method by which the standard data defined in this document can be exchanged.

NOTE 1 The structure of the physical file used for exchanging the standard data defined in this document is

specified in ISO 10303-21.

NOTE 2 The physical file used for exchanging the standard data is compliant with ISO 13584-42:2010.

© ISO 2022 – All rights reserved
---------------------- Page: 6 ----------------------
ISO/TS 23768:2022(E)

NOTE 3 It is intended to provide an OntoML-based (XML) representation of the standard data when

ISO 13584-32 (OntoML) is published.

This document does not establish the reference dictionaries for linear motion rolling bearings and

spherical plain bearings.
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.

ISO/IEC Guide 77-2, Guide for specification of product properties and classes — Part 2: Technical principles

and guidance

ISO 286-1, Geometrical product specifications (GPS) — ISO code system for tolerances on linear sizes —

Part 1: Basis of tolerances, deviations and fits

ISO 1998-1, Petroleum industry — Terminology — Part 1: Raw materials and products

ISO 3096, Rolling bearings — Needle rollers — Boundary dimensions, geometrical product specifications

(GPS) and tolerance values
ISO 5593, Rolling bearings — Vocabulary

ISO/IEC 8824-1, Information technology — Abstract Syntax Notation One (ASN.1) — Part 1: Specification

of basic notation

ISO 10303-1, Industrial automation systems and integration — Product data representation and exchange

— Part 1: Overview and fundamental principles

ISO 10303-11, Industrial automation systems and integration — Product data representation and exchange

— Part 11: Description methods: The EXPRESS language reference manual

ISO 13584-1, Industrial automation systems and integration — Parts library — Part 1: Overview and

fundamental principles

ISO 13584-42:2010, Industrial automation systems and integration — Parts library — Part 42: Description

methodology: Methodology for structuring parts families
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO/IEC Guide 77-2, ISO 286-1,

ISO 1998-1, ISO 3096, ISO 5593, ISO 10303-1, ISO 10303-11, ISO 13584-1, ISO 13584-42 and the following

apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
© ISO 2022 – All rights reserved
---------------------- Page: 7 ----------------------
ISO/TS 23768:2022(E)
3.1.1
abstract class
ABS

class (3.1.6) of which all members are also members of one of its subclasses (3.1.37)

[SOURCE: ISO 13584-42:2010, 3.1, modified — the abbreviation has been added and Notes 1, 2 and 3 to

entries have been deleted.]
3.1.2
applicable property of a class

applicable property (3.1.34) necessarily possessed by each part (3.1.28) that is a member of a

characterization class (3.1.32)

EXAMPLE For a roller bearing generic family of parts (3.1.21), the bore diameter is an applicable property:

this characteristic applies to any bearing.

[SOURCE: ISO 13584-42:2010, 3.2, modified — the abbreviation and the example have been added, and

Notes 1, 2, 3, 4 and 5 to entries have been deleted.]
3.1.3
attribute

data (3.1.10) element for the computer-sensible description of a property (3.1.34), a relation or a class

(3.1.6)

[SOURCE: ISO 13584-42:2010, 3.3, modified — the example and Note 1 to entry have been deleted.]

3.1.4
basic semantic unit
BSU

entity (3.1.18) that provides an absolute and universally unique identification of a certain object of the

application domain that is represented as a dictionary element (3.1.16)

[SOURCE: ISO 13584-42:2010, 3.4, modified — the abbreviation has been added, and the examples and

Note 1 to entry have been deleted.]
3.1.6
class
abstraction of a set of similar products (3.1.30)

[SOURCE: ISO 13584-42:2010, 3.6, modified — the example and Notes 1, 2, 3, 4 and 5 to entries have

been deleted.]
3.1.7
class inclusion relationship

relationship between classes (3.1.6) that means inclusion of class members (3.1.8): if A is a superclass

(3.1.38) of A1 this means that, in any context, any member of A1 is also member of A

[SOURCE: ISO 13584-42:2010, 3.7, modified — Examples 1 and 2, and Notes 1, 2, 3 and 4 to entries have

been deleted.]
3.1.8
class member
product (3.1.30) that complies with the abstraction defined by a class (3.1.6)
[SOURCE: ISO 13584-42:2010, 3.8]
© ISO 2022 – All rights reserved
---------------------- Page: 8 ----------------------
ISO/TS 23768:2022(E)
3.1.9
common ISO 13584/IEC 61360 dictionary model

data (3.1.10) model for product ontology (3.1.33), using the information modelling language EXPRESS,

resulting from a joint effort between ISO TC 184/SC 4/WG 2 and IEC SC 3D

Note 1 to entry: The common dictionary (3.1.14) schema is specified in IEC 61360-2 and its content is provided in

ISO 13584-42:2010, Annex D.

[SOURCE: IEC 61360-2,2012 3.10, modified — the reference "ISO 13584-42:1998" has been replaced

with "ISO 13584-42:2010" in Note 1 to entry.]
3.1.10
data

representation of information in a formal manner suitable for communication, interpretation, or

processing by human beings or computers
[SOURCE: ISO 10303-1:2021, 3.1.29]
3.1.11
data element type
DET

unit of data (3.1.10) for which the identification, the description and value representation have been

specified

[SOURCE: ISO 13584-42:2010, 3.13, modified — the abbreviation has been added and Note 1 to entry

has been deleted.]
3.1.13
data type
domain of values
[SOURCE: ISO 10303-11:2004, 3.3.5, modified — the abbreviation has been added.]
3.1.14
dictionary
table consisting of a series of entries

Note 1 to entry: One meaning corresponds to each entry in the dictionary and one dictionary entry identifies one

single meaning.

Note 2 to entry: In the ISO 13584 series, a dictionary is the formal and computer-sensible representation of an

ontology.

Note 3 to entry: In the ISO 13584 series, the kinds of meaning intended to constitute dictionary entries are

— supplier,
— class (3.1.6),
— property (3.1.34),
— program library,
— type,
— table, and
— document.

Note 4 to entry: In the ISO 13584 series, the information that represents a dictionary entry is split into three

entities:
— a basic_semantic_unit (BSU), that provides for reference,
© ISO 2022 – All rights reserved
---------------------- Page: 9 ----------------------
ISO/TS 23768:2022(E)

— a dictionary_element that describes the dictionary entry by means of attributes, and

— possibly, a content_item entity (3.1.18) that describes the dictionary entry by describing its content.

Note 5 to entry: The link available in Annex E shall be used to access the official version of the reference dictionary

for rolling bearings.

[SOURCE: ISO 13584-1:2001, 3.1.2, modified — Notes 2, 3, 4 and 5 to entry have been added.]

3.1.16
dictionary element

set of attributes (3.1.3) that constitutes the dictionary (3.1.14) description of certain objects of the

application domain
EXAMPLE Classes (3.1.6), data (3.1.10) element types.

[SOURCE: ISO 13584-42:2010, 3.15, modified — Example 1 has been replaced and Example 2 has been

deleted.]
3.1.17
dictionary identification
unique character string that identifies the dictionary (3.1.14)

Note 1 to entry: The reference dictionary for rolling bearings given in Annex A shall be referred to.

3.1.18
entity
class (3.1.6) of information defined by common properties
[SOURCE: ISO 10303-11:2004, 3.3.6]
3.1.19
entity data type
representation of an entity (3.1.18)

Note 1 to entry: An entity data type (3.1.13) establishes a domain of values defined by common attributes (3.1.3)

and constraints.
[SOURCE: ISO 10303-11:2004, 3.3.7]
3.1.20
feature

aspect of a product (3.1.30) that can be described by a characterization class (3.1.32) and a set of

property-value pairs

[SOURCE: ISO 13584-42:2010, 3.17, modified — Notes 1, 2 and 3 to entries and Examples 1 and 2 have

been deleted.]
3.1.21
generic family of parts

grouping of simple or generic parts (3.1.28) done for purposes of classification or for factoring common

information
3.1.22
implementation method

technique used by computers to exchange data (3.1.10) that is described using the EXPRESS data

specification language
© ISO 2022 – All rights reserved
---------------------- Page: 10 ----------------------
ISO/TS 23768:2022(E)
3.1.23
is-a relationship

class inclusion relationship (3.1.7) associated with inheritance: if A1 is-a A, then each product (3.1.30)

belonging to A1 belongs to A, and all what is described in the context of A is automatically duplicated in

the context of A1

[SOURCE: ISO 13584-42:2010, 3.23, modified — Notes 1 and 2 to entries have been deleted.]

3.1.24
is-case-of relationship

property (3.1.34) importation mechanism: if A1 is case-of A, then the definition of A products (3.1.30)

also covers A1 products, thus A1 can import any property from A

[SOURCE: ISO 13584-42:2010, 3.24, modified — Notes 1, 2, 3 and 4 to entries have been deleted.]

3.1.25
item

thing that can be characterized by means of a characterization class (3.1.32) to which it belongs and a

set of property (3.1.34) value pairs

Note 1 to entry: This definition supersedes the definition given in ISO 13584-24:2003, that was the following: “a

thing that can be captured by a class structure and a set of properties”.

Note 2 to entry: In ISO 13584 (all parts), both products and features (3.1.20) of products that correspond to

composite properties are items.
[SOURCE: ISO 13584-42:2010, 3.25]
3.1.26
leaf characterization class

characterization class (3.1.32) that is not further subdivided into more precise characterization classes

[SOURCE: ISO 13584-42:2010, 3.26, modified — "specialized" has been replaced with "subdivided" in

the definition and the example has been deleted.]
3.1.27
non-leaf characterization class

characterization class (3.1.32) that is further subdivided into more precise characterization classes

[SOURCE: ISO 13584-42:2010, 3.27, modified — "specialized" has been replaced with "subdivided" in

the definition and the example has been deleted.]
3.1.28
part

material or functional element that is intended to constitute a component of different products (3.1.30)

[SOURCE: ISO 13584-1:2001, 3.1.16]
3.1.29
parts library

computer-sensible product ontology (3.1.33) and computer-sensible description of a set of products

(3.1.30) by means of references to this ontology
[SOURCE: ISO 13584-42:2010, 3.30, modified — Note 1 to entry has been deleted.]
3.1.30
product
thing or substance produced by a natural or artificial process
[SOURCE: ISO 13584-42:2010, 3.31, modified — Note 1 to entry has been deleted.]
© ISO 2022 – All rights reserved
---------------------- Page: 11 ----------------------
ISO/TS 23768:2022(E)
3.1.31
product categorization
part categorization
categorization
recursive partition of a set of products into subsets for a specific purpose

[SOURCE: ISO 13584-42:2010, 3.32, modified — the example and Notes 1, 2, 3, 4 and 5 to entries have

been deleted.]
3.1.32
characterization class
product characterization class
part characterization class

class (3.1.6) of products that fulfil the same function and that share common properties

[SOURCE: ISO 13584-42:2010, 3.35, modified — the example and Note 1 to entry has been deleted.]

3.1.33
product ontology
part ontology
ontology

model of product knowledge, done by a formal and consensual representation of the concepts of a

product domain in terms of identified characterization classes (3.1.32), of class (3.1.6) relations and of

identified properties

[SOURCE: ISO 13584-42:2010, 3.36, modified — the example and Notes 1, 2, 3, 4, 5, 6 and 7 to entries

have been deleted.]
3.1.34
property
defined parameter suitable for the description and differentiation of products

[SOURCE: ISO 13584-42:2010, 3.37, modified — Notes 1, 2, 3, 4 and 5 to entries have been deleted.]

3.1.35
property data type
allowed set of values of a property (3.1.34)
[SOURCE: ISO 13584-42:2010, 3.38]
3.1.36
visible property

property (3.1.34) that has a definition meaningful in the scope of a given characterization class (3.1.32),

but that does not necessarily apply to the various products belonging to this class (3.1.6)

EXAMPLE For a generic family of bearings, contact angle is a visible property: it is clearly defined for any

rolling bearing, but only thrust angular contact ball bearing, angular contact ball bearing or tapered roller

bearing have a value for this property. Contact angle would then be a visible (it has a clear meaning for all the

rolling bearings) and applicable (it may be used to describe any kind of rolling bearing) property.

Note 1 to entry: The code of the class (3.1.6) where a property is defined as visible is part (3.1.28) of the

identification of the data element type (3.1.11) that represents this property.

[SOURCE: ISO 13584-42:2010, 3.46, modified — the example and Note 1 to entry have been modified,

and Notes 2, 3, 4 and 5 to entries have been deleted.]
3.1.37
subclass

class (3.1.6) that is one step below another class in a class inclusion hierarchy

[SOURCE: ISO 13584-42:2010, 3.43]
© ISO 2022 – All rights reserved
---------------------- Page: 12 ----------------------
ISO/TS 23768:2022(E)
3.1.38
superclass
class (3.1.6) that is one step above another class in class inclusion hierarchy

Note 1 to entry: In the common ISO 13584/IEC 61360 dictionary model (3.1.9), a class has at most one superclass

specified by means of an is-a relationship (3.1.23).
[SOURCE: ISO 13584-42:2010, 3.44, modified — Note 1 to entry has been deleted.]
3.2 Abbreviated terms
For the purposes of this document, the following abbreviated terms apply.
AP Applicable property
BSU Basic semantic unit
CD Class definition
CST Constraints
DC Definition class
DCR Date of current revision
DCV Date of current version
DER Derived value
DET Data element type
DOD Date of original definition
DT Data type
PLS Preferred letter symbol
SDD Source document of definition
VF Value format
4 Representation of ontology concepts as dictionary entries
4.1 Identification of data element type

In order to identify a data element type uniquely within the ISO/TS 23768 reference dictionaries and

for electronic information exchange, a language-independent combination of characters as described in

Annex C and Annex D shall be used.
4.2 Bearing classes
4.2.1 Modelled classes

The bearing class is classified in a single subclass in this document (see Figure 1): rolling bearing.

NOTE The role of this classification level allows for the extension of the bearing reference dictionary

...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.