9
7 Transmission
7.1 Chain drive
The chain drive should be checked before each journey. The
chain drive includes the driving and driven chains of the sprocket.
The main problem during the operation is the chain wear,
respectively, a worn chain “gnaws” for itself a seat in the teeth of
the sprockets.
1 - chain pulley
2 - sprocket
а - rate of wear of the tooth
b - the outlines of the new sprocket.
The wear of the sprocket teeth exceeding the value of 1/4 of the
size of the tooth is considered critical. If one of the components
is criticality worn-out, it is necessary to change the sprocket set
(driven and driving) and the chain. Inspect the condition of the
driven and driving sprocket wear and fractur.
You should ensure that the driven sprocket and shaft are not
damaged. Collision with obstacles leads to bending of and
damage to the sprocket and shaft. The driving sprocket wears
slightly faster than the driven one but it is not subjected to
shocks when driving over obstacles.
Chains with gland packing 1 O-ring can be mounted on
SNOWDOG�
In such chains grease is put for the entire operation period of the
chain but the seals need regular lubrication. The main purpose
of lubrication of seals is to prevent heating and loss of tightness.
Replace the chain, if the seals are damaged and stick out of it.
The chain life depends on its lubrication. It is necessary to clean
and lubricate the chain after each journey. When runs are more
than 20 km, long movement in the puffy snow or water, the chain
should be lubricated during the journey. It is recommended to
use a special lubricant for chains in aerosol containers.
7.1.1 Checking the chain tension
The normally tensioned chain in the middle between the
sprockets has a free wheeling of 10-20 mm. Free wheeling of
less than 5 mm will lead to a rapid stretching of the chain and
sprockets. An overly loose chain can fling on the move. It is
necessary to tighten a free chain. In the operation, the chain
is extended, and the distance between the links changes. If
the chain length adjustment range is no longer enough, it is
necessary to replace the chain. A chain may not be shortened by
removing one or more links. When cleaning the chain, check the
condition of rubber seals between the plates of the chain. If the
seals are damaged and stick out of the chain, the chain requires
urgent replacement.
