Re-Assembly - Siemens 1LA8 Series Operating Instructions Manual

Rolling-contact bearing unit
It is recommended that the components that comprise
the active part of the bearing be marked to ensure
correct assembly.
Removal of Bearings
For removing bearings use proper pullers. Reusable
bearings, which are non-separable (e.g. Deep groove
ball bearing), should be withdrawn by attaching puller
arms to the inner ring of the bearing. If it is a must to
apply puller arms on the outer ring of the bearing, the
bearing should be rotated during withdrawal to avoid
damage to the bearing.
Removal of bearings or inner rings which are not to be-
used is facilitated by heating them with gas or welding
torch.
Outer bearing seal
• V-ring with adjacent protecting ring
Dismantling the V-ring and adjacent protecting ring
Do not remove the press-fitted guard ring when
dismantling!
Pull off the V-ring and bearing cover / bearing shield
from the shaft.
Afterwards press out the adhesively bonded protecting
ring using a suitable tool, taking care not to distort it.

6.3.4 Re-assembly

The motor must be assembled in a dust free, dry and
clean location.
As the motor conforms to the type of protection IP55,
all machined mating surfaces are provided with a thin
even coat of bearing grease. Provide a fresh coat of
this grease at the time of re-assembly.
Unmatched surfaces are provided with rubber gaskets.
At the time of re-assembly, ensure that the gaskets are
in good condition. Place the gaskets carefully to
achieve the correct sealing. Replace the gaskets with
the new ones if the same are damaged.
All fasteners that are used on the exterior of the motor
are provided with a coat of bearing grease to prevent
ingress of water and dust through tapped holes.
Ensure that the same is provided at the time of re-
assembly.
Do not interchange location (DE & NDE) of bearing
covers, as the spigot dimensions may be different.
A bearing must be replaced if it is damaged. Damage
to bearing is often difficult to recognize; in doubtful
cases, replace the bearing. Bearings, which have been
removed, should be reused only if they show no trace
of damage and provided they are thoroughly cleaned
beforehand.
For cleaning bearings use proper cleaning agent e.g.
White spirit. Wear gloves.
Caution
The cleaned bearing must be free of foreign
bodies (fibers from cleaning rags, hair from
brushes, etc.)
Caution
(Environmental Protection)
The bearing to be discarded must be thoroughly
cleaned from grease and should be intentionally
damaged (using weld marks or cutters etc) to
avoid reuse.
The removed grease is a hazardous waste and is
harmful to environment causing soil pollution
and water pollution. It should only be
incinerated at an authorized agency and not
disposed by any other means.
Sealing
Clean and coat the bare joints between the parts and
components (e. g. between frames, end shields and
bearing units) with a non-hardening, permanently
flexible sealing compound, e.g. Hylomar MQ32 (follow
the manufacturer's application and safety
instructions!).
Joint sealing
When reassembling machines with degree of
protection IP56 (see rating plate), the joint between
the motor frame and the end shields are sealed with
rubber 'O' rings. It should be ensured that these are
not damaged.
Installation of the rolling-contact bearings
Before installing the bearings, ensure that the parts
and components, which are located on the shaft inside
the bearing, are put in place first. Take great care and
pay attention to cleanliness when fitting and
assembling the bearings. To fit the rolling-contact
bearings, heat them up to about 80°C in oil or air and
then press them onto the shaft. Avoid any heavy blows
that might damage the bearings. After cooling, grease
is to be filled in the bearing spaces completely, in-
between the gaps of the rolling elements and in one-
third open space, near the bearing, inside the inner
bearing cover.
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