ISO 254:1990

IS0
I N TE R NAT I O NA L
STANDARD
Second edition
1 990- 1 0-0 1
Belt drives - Pulleys - Quality, finish and
ba I a nce
Transmissions par courroies - Poulies - Qualité, état de surface et
équilibrage
Reference number
IS0 254: 1990( E)

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IS0 254:1990(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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, govern-
mental and non-governmental, in liaison with ISO, also take part in the
work. IS0 collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
Drafi International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an Interna-
tional Standard requires approval by at least 75 of the member bodies
casting a vote.
International Standard IS0 254 was prepared by Technical Committee
ISO/TC 41, Pulleys and belts (including veebelts).
This second edition cancels and replaces the first edition
(IS0 254:1981), subclauses 4.1 and 5.8 of which have been technically
revised. Subclause 3.3 has been deleted.
o IS0 1990
All riahts reserved. No Dart of this Dubiication mav be reproduced or utilized in anv form
or bfany means, electronic or mechanical, including phoiocopying and microfilm, without
permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 CH-I211 Genève 20 Switzerland
Prlnted in Switzerland
ii

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INTERNATIONAL STANDARD IS0 254:1990(E)
Belt drives - Pulleys - Quality, finish and balance
abrasion, environment, etc.); moreover it is desira-
1 Scope
ble that the pulley material be capable of dissipating
any significant heat which might be generated by the
This International Standard specifies the character-
belts.
istics of quality which are common to all trans-
mission pulleys; it states specific quality levels for
.-
the finish and balance of transmission pulleys.
3.2 Cast or sintered pulleys shall consist of an ap-
This International Standard applies to transmission
propriate material and be free of porosities or flaws
pulleys for V-belts, flat or synchronous belts: it does and of shrinkage holes or voids.
not apply to those pulleys for variable speed drives
that have one or more moving flanges.
The other characteristics of transmission pulleys
4 Surface roughness
may be found in the relevant International Standard.
4.1 The surface roughness of the working surfaces
shall be measured in a plane parallel to the action
2 Normative references
of the belt and shall in any direction not be coarser
than the value given in table 1.
The following standards contain provisions which,
through reference in this text, constitute provisions
of this International Standard. At the time of publi-
Table 1
cation, the editions indicated were valid. All stan-
dards are subject to revision, and parties to Surface
roughness Ra 1)
agreements based on this International Standard Working surface
to investigate the possibility of ap-
are encouraged
itm
'-- plying the most recent editions of the standards in-
dicated below. Members of IEC and IS0 maintain
V-pulley and V-ribbed pulley
registers of currently valid International Standards.
grooves and all pulley bores
Flat pulley rims and all pulley rim
IS0 468:1982, Surface roughness - Parameters, their
edges
values and general rules for specifying
Synchronous pulley tooth flanks
requirements.
and tips:
- industrial type drives
IS0 1940-1:1986, Mechanical vibration - Balance
- high performance type drives
quality requirements of rigid rotors - Part I: Deter-
(for example for automotive appli-
mination of perm
...