Page 334 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

314 Major Process Equipment Maintenance and Repair

combination grooves, an A section belt will ride slightly low in the
groove, while a B belt will be in the normal position. In special deep
groove sheaves, belts will ride below the top of the sheave.
However, some V-belts are purposely designed so that the top of the
belt will ride above the OD of the sheave. The tensile cords are located in
the belt so that they ride almost at the OD of the sheave. This simplifies
sheave identification and drive calculations.
No matter which V-belt section the sheave is grooved for, the belts
should never be allowed to bottom in the groove. This will cause the belt
to lose its wedging action, to slip andor burn. Sheaves worn to the point
where they allow a belt to bottom should be replaced immediately.

Keep Belts Clean

Dirt and grease reduce belt life. Belts should be wiped with a dry cloth
occasionally to remove any build-up of foreign material. If the belts have
been splattered with grease and/or oil, clean them with methyl chloro-
form or soap and water. Inflammable cleaners such as gasoline are to be
avoided as a matter of safety.
Although all premium grade V-belts are of oil resistant construction, an
occasional cleaning will help to prolong their life.
Under no circumstance is the use of belt dressing recommended on a V-
belt. The remedial effect is only temporary. It is much better to keep the
belts and grooves of the drive clean.

Use Belt Guards

Belt guards protect personnel and the drive itself. They should be defi-
nitely used in abrasive atmospheres to protect the drive from sand, metal
chips, and other foreign matter. But they should be ventilated to avoid
excessive heat.
Check them periodically for damage and for loose or missing mounting
bolts. These could cause the belts to come in contact with the guard and
cause failure.
Guards alone will generally protect belts from abrasion. But where
abrasive materials are common-in rock processing machinery, grind-
ers, foundries, etc.-drives should be inspected frequently for excessive
belt and groove wear.

Check for Hot Bearings

When the drive has been stopped for inspection, check the bearings to
make sure they are not running hot. If they are, it could be due to im-
proper lubrication or improper drive tension. Hot bearings can be caused