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6.6 The chain drive
A chain drive needs relatively little maintenance when the correct chain is selected, when it is mounted
correctly and, in this case of application, is not lubricated. The drive chain is protected by a chain guard. The
chain guard prevents excessive contamination and prevents accidents.
The chain drive should be cleaned every three months. On these occasions check the aligning of the chain
wheels and the chain tension.
Cleaning
In order to clean thoroughly first remove the dirt adhering to the outside of the chain drive using a hard or
wire brush. Then wash the chain in petroleum ether or similar.
After that clean the dirt from the internal parts of the chain.
Alignment of the chain wheels
Check the mounting precision by means of a ruler to be put to the chain wheels.
Incorrect mounting makes the internal link plates press against the external link
plates and, thus, accelerates the chain wear or even causes the chain wheels to lock
up.
Chain tension
The travel drive motor is mounted on a receiver plate with slotted holes.
When it is necessary to re-tense the chain, this can be carried out by
shifting the motor in the slotted holes (1). The correct chain tension is
achieved when the chain allows to be pressed for about 5 mm between the
chain wheels.
Fitting the chain
Before mounting the chain it must be degreased to prevent any abrasive or abrasive
particles from adhering.
The chain is supplied as a chain string and has to be prepared during mounting. This
is done as follows: Place the chain on the chain wheels so that the links lie in tow
adjacent gaps between the teeth. Now close the chain using the coupling link. With
heavy chains or big distances between the shafts use a pre-stressing tool in order to
bring the two end links so close together that the coupling link can be inserted
without being deformed.
On mounting coupling links with springs, their closed sides should point to the running
direction of the chain (see figure). Put the spring onto the link plate and press it over the
pin into the ring groove by means of a pair of tongs. Demount the spring in the opposite
order.
Re-lubrication of the traction wheel bearings
The bearing units of the traction wheel are equipped with a grease fitting which allows the bearings to be re-
lubricated in service. Re-lubricating the bearings once every 2 years should be more than sufficient.
When lubricating, care must be taken to use greases that are compatible with the original grease. We suggest
a medium temperature, lithium calcium bace, NLGI Grade No. 2 grease having an oil with a viscosity of
200mm
²
/s at 40°C. When a unit is being re-lubricated, avoid excessive pressure which may cause damage to
the bearing seals.
