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Maintenance
Installation Guide
Belt drives are a reliable and efficient means of power
transmission. Since they are essentially trouble-free, they are
ignored often and do not receive the minimal attention they
require for the full delivery of benefits over the course of a long
life of use.
Belt drive maintenance is neither complicated nor does it
require a great deal of time or a large variety of special tools.
Primarily, good maintenance requires that you look at and listen
to the drive to discover and correct any problems.
What to look for:
Oil and grease
Police a drive well. Immediately repair leaky bearings as excess
oil on a bearing will splash on the belts. If you cannot correct
these conditions without sacrificing adequate lubrication, use
oil-resistant belts as too little lubrication will cause bearing
failure, which may also cause belt failure when drag
becomes excessive.
Dirt
No equipment operates best when it is dirty. Belts are no
exception. Dirt accelerates belt wear and dirt build-up in a
V-belt sheave groove impairs traction.
Added loads
Check to see that no additional loads have been added since
the original drive was selected.
Belt guards
Belt guards ensure that large debris does not enter the drive.
Cracking
Reduce V-belt bottom cracking by using larger sheaves and
larger reverse bend idler sheaves; however, tooth cracking on
synchronous belts is an early indicator of tooth shear, and
therefore, the belt should be replaced. See Troubleshooting
charts for corrective action.
Belt dressing
Belt dressing is seldom beneficial to belt drives. This tackiness
actually accelerates the time to failure of V-belts. If V-belts slip
or squeak, identify and correct the problem. Never use belt
dressing on synchronous belts.
Vibration
Excessive vibration should be minimized. This is often due to
low tension or damaged tensile member. In extreme cases, a
back side kiss idler may need to be added in the vibrating span.
Tension
Tension is critical in belt drives. For V-belts, the ideal tension is
the lowest tension at which the belts will not slip under peak
load conditions. For synchronous belts, under-tensioning leads
to ratcheting and excessive tooth loading. Adjust tension to
the values shown in the tables provided in this guide. See
section on “Installation” for the type of belt involved for
additional information.
Heat
High temperatures cause heat-aging and shorten belt life.
Check frequently belts operating in temperatures above
180F (82.2C) and consider special heat-resistant
construction if belt life is not satisfactory.
Belt turn over
Turned over V-belts indicate drive misalignment, worn sheaves
or excessive vibration.
Change in ride out
Ride out is the position of the top of the V-belt to the outside
diameter of the sheave. A change in ride out over time indicates
uneven belt wear or worn sheaves.
Lateral vibration
Don’t allow belts to snake.
Belt wear
Wear on V-belt sidewalls indicates consistent slippage,
excessive dust or rough sheaves. Tooth wear on synchronous
belts is an indication of improper tooth meshing. See
Troubleshooting (on pages 46-48) for possible causes
and corrections.
Debris
Broken belts or excessive vibration can result from the
presence of foreign material on the belts or in the sheaves
or sprockets.
Prevent Belt Whipping
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Maintenance
Installation Guide