WEG M line Series, Инструкция по установке, эксплуатации и обслуживанию

Страница: 45 / 59

www.weg.net
11371757 Installation, operation and maintenance manual – Squirrel cage motor – M line – Vertical
l 45
7.9.2.6 Bearing assembly
Clean the rolling bearing and the oil tanks thoroughly,
and inspect all the parts before the bearing assembly.
Make sure the rolling bearing contact surfaces are
smooth and free of signs of scratches or corrosion;
Before mounting the rolling bearing on the shaft, heat it
up to a temperature between 50 to 100 ºC;
For the complete assembly of the bearing, follow the
disassembly instructions in the reverse order.
ATTENTION
During the bearing assembly, apply sealant
(e.g. Curil T) in order to seal the surfaces of
the oil tank.
7.9.3 Rolling bearing replacement
The disassembly of rolling bearings must be done with an
appropriate tool (rolling bearing puller).
The arms of the puller must be placed on the lateral
surface of the bearing inner ring to be disassembled or on
an adjacent part.
Figure 7.8: Tool for rolling bearing extraction
7.9.4 Sleeve bearings
7.9.4.1 Bearing data
The characteristic data, such as oil flow, quantity and
type, are indicated on the bearing nameplate and must be
strictly observed; otherwise, overheating and damages to
the bearings may occur.
The hydraulic installation (for bearings with forced
lubrication) and the oil supply for the motor bearings are
responsibilities of the user.
7.9.4.2 Bearing installation and operation
For information on the bill of materials, assembly and
disassembly instructions, and maintenance details, refer to
the specific installation and operation manual of the
bearings.
7.9.4.3 Cooling by water circulation
The sleeve bearings with cooling by water circulation have
a serpentine inside the oil tank through which the water
circulates.
In order to assure an efficient bearing cooling, the
circulating water must have at the bearing inlet a
temperature lower or equal to the ambient, so that the
cooling takes place.
The water pressure must be 0.1 bar and the flow equal to
0.7 l/s. The pH must be neutral.
NOTE
Under no circumstances can water leak into
the oil tank, because this will contaminate
the lubricant.
7.9.4.4 Oil change
Self-lubricated bearings
The bearing oil change must be done according to the
intervals, which depend on the bearing operating
temperatures, shown in Table 7.6:
Table 7.6: Oil change intervals
Bearing operating
temperature
Bearing oil change
intervals
Below 75 ºC 20,000 hours
Between 75 and 80 ºC 16,000 hours
Between 80 and 85 ºC 12,000 hours
Between 85 and 90 ºC 8,000 hours
Between 90 and 95 ºC 6,000 hours
Between 95 and 100 ºC 4,000 hours
Bearings with external oil circulation
The oil of the bearings must be changed every 20,000
hours of operation or whenever the lubricant presents
modifications in its characteristics. The oil viscosity and pH
must be checked periodically.
NOTE
The oil level must be inspected daily, and it
must remain in the middle of the oil sight
glass.
The bearings must be lubricated with the specified oil,
respecting the flow rate informed on their nameplate;
All threaded holes that are not used must be closed with
plugs and no fitting may present leaks.
The oil level is reached when the lubricant can be seen
approximately in the middle of the sight glass. The use of
a larger amount of oil will not damage the bearing, but it
can cause leaks through the shaft seals.
ATTENTION
The care with the lubrication will determine
the useful life of the bearings and the safety
in the motor operation. Therefore, the
following recommendations must be
observed:
The selected lubricant oil must be the
one with proper viscosity for the
operating temperature of the bearings;
That must be observed at every oil
change or during periodical
maintenances;
Never use or mix hydraulic oil with the
lubricant oil of the bearings;
Lack of lubricant, due to incomplete
filling or non-monitoring of the level, can
damage the bearing shells;
The minimum oil level is reached when
the lubricant can be seen in the lower
part of the sight glass with the motor
stopped.