Page 129 - Goodyear2011PTCatalog

P O W E R T R A N S M I S S I O N P R O D U C T S G E N E R A L I N F O R M A T I O N
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G E N E R A L I N F O R M A T I O N
2 0 1 1
O i l & C hemi cal R es i stance
of P ower T ransmi ss ion B elts
In general, the presence of oil or chemicals in contact with
any belt drive system can materially affect the life span and
operational characteristics of the system. The concentration of
the chemical or oil involved, length and type of exposure, choice
of belt type used, and environmental conditions, such as heat
and humidity, all contribute to the rate and degree of effect on
the performance and deterioration.
Two effects may be noted when belts are exposed to oil and/or
chemicals. The most obvious is a swelling or increase in dimen-
sions of the cross section so that they no longer fit the pulley
or sheave groove properly. Less apparent at casual observation,
is the deterioration of the original physical properties, which
includes adhesion between the belt components. If the degree of
swelling and/or loss of physical properties is significant, the life
of the belt will be substantially shortened.
The above effects may be brought about by a large variety of
chemicals, notably oils, acids, and solvents.
No one synthetic rubber is resistant to all of these. Some
compounds may be excellent for one chemical, but poor for
another, and only adequate for still another.
Because of this, all Goodyear Engineered Products stock belts
are constructed to be reasonably oil and chemical resistant.
The nature of the compounds and/or belt construction may
minimize swelling and deterioration. Occasional splattering by
oils and greases does not usually adversely affect standard belts.
The automotive fan belt is a typical example.
In addition, there are a great number of chemicals, such as
gasoline, which swell rubber or extract ingredients from the
belt’s rubber compounds. These may cause embrittlement,
cracking, or swelling of the belt, which results in deterioration of
performance.
If the drive is subjected to the accumulation of a considerable
amount of oil and grease on the belt, it may preclude the use
of a V-belt or a V-ribbed belt. Synchronous belts are not sub-
stantially affected by the loss of friction coefficient and may be
capable of limited operation under these conditions.
As can be seen from the above, there are many variables. However,
the following general guidelines might be of use in selecting a
belt drive system subjected to a chemical environment.
1. Prevent the accumulation of contaminants.
2. If the belts are to be subjected to only an occasional
contamination contact, a standard construction V- or
synchronous belt can be used.
3. If the belts are expected to give long, trouble-free
operation on an industrial drive, and they are in contact
with oil or exposed to an atmosphere laden with chemicals
or solvents, consult the manufacturer for recommendations.
Source: RMA 1P-3-2, 1999