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6.4
Belts
The belt drives are designed for the required drive power. Forcing the drives to grant a higher output by
over tensioning the belts results in belt breaks, bearing damage and thus to lower efficiency. A low belt tension
results in slippage causing an increased belt temperature and thus to premature destruction of the belts.
Temperatures exceeding 70°C for a long period of time reduce the service life and performance of the belts.
The grooves of the belt pulleys have to be free from rust, grease, dirt and damages. The use of belt wax or
similar substances to increase the friction coefficient is unnecessary and damages the belts. Avoid any
contaminations by oil, grease or chemicals.
In order to grant a perfect output transmission, the belt drive must be observed continuously.
Fitting the belts
Release the tension of the belt drive by reducing the distance between both shafts.
Insert the belt in the belt pulley grooves manually without forcing the belt.
Tension the belt by increasing the distance between the shafts of as described below.
Mount the pertaining protective drive equipment.
Tensioning the belts
The correct belt pre-tension is of great importance for the perfect output transmission and for maintaining the
normal service life of the belts. Insufficient or excessive pre-tensioning frequently leads to premature failure of
the belts. Over-tensioning often causes bearing defects in motors and bearing units.
Check the correct pre-tension by pressing down the belt. The distance the belt can be pressed down should be
5-7 mm at approx. 10 kg.
Remove the belt guards only when the driving motors are in
standstill and the main switch of the machine is secured.
