|
SERVICE TIP Sheaves and Belts
SHEAVES
Damaged, worn or dirty sheaves will substantially reduce belt life.
Nicks or gouges can cut the belt, dirt in the grooves can abrade the belt
and oil can attack the belt materials. Worn grooves will allow the belt to
bottom out, slip and become damaged.
Use a stiff brush to clean off rust and dirt. Wipe belts clean of oil
and grease.
Caution:
Do not reinstall damaged or worn sheaves on equipment. Repair
or replace them.
Select the proper sheave groove gauge and template for the sheave
diameter. Insert the gauge in the groove and look for voids which indicate
dishing or other uneven and abnormal wear. Besser Company offers a belt
and groove gauge, part number 112541.
Place a new belt in the sheave groove. The top of the belt should be
flush with the outer diameter of the sheave. If the belt top is below the
outer diameter of the sheave, the groove is worn.
Caution:
Turn off all power and lock out machine panels before
servicing and DO NOT operate machinery without all guards in place.
BELTS
Don’t Mix Belt Brands
Each brand of V-belt has different performance characteristics. Drives
will not deliver the power or service expected when a mix of belt brands
is used.
Don’t Mix New and Used Belts
Always replace complete sets of V-belts with new V-belts, even if only
one or two appear worn or damaged.
Do not attempt to assemble two or more used V-belts for a set. They will
not perform as expected.
Reusing V-belts where matched sets are required will substantially
reduce the life of the drive.
NOTE: Torque team belts (joined belts) provide the benefits of the
joined principal as well as a wider team. A matched set of a two-belt and
a three-belt torque team will provide service equal to five single belts
in a team. Sheave wear is very important to long life for any V-belt, but
critical for torque team belt applications. Worn sheaves will destroy
joined belts very quickly.
Belt Dressings
Do not use belt dressings of any kind. Certain dressings are meant to
build a tacky surface, but only interfere with proper belt and groove fit
as any other foreign material would. Other types attack the belt rubber
and fabric to make it tacky. This actually accelerates the time to
failure. If belts slip or squeak, the problem should be identified and
corrected.
BELT TENSIOMETER
Ideal belt tension is the lowest tension at which the belts will not
slip at peak load conditions. Under tensioning of belts can result in belt
slippage and can shorten belt life. Over tensioning of belts could shorten
both belt and bearing life.
Check belt tension frequently during the first 24 to 48 hours of
"run-in" operation. The average deflection force for Vibrapac
concrete products machines equipped with a Bescodyne Drive is 12 pounds
and for Dynapac concrete products machines it is 10 pounds.
No. 106666 Belt Tensiometer
Posted 31 July 2000
|
