Elmo Rietschle R-WPB - Manual (Page 11)

Rietschle Thomas GmbH + Co. KG page 11 / 23
While the maximum oil level is in the middle of the oil
level gauge, the minimum level is 3 mm lower. The oil
level measured when the machine is turned off must be
maintained within these limits. When the oil level has
reached the minimum, you must immediately top up with
oil. Top up with oil carefully so that its level will not be
above the middle of the oil level gauge. Otherwise, oil
could leak through the release openings or into the blower
when the machine is in operation.
Depending on the operating conditions, the blower oil
temperature could exceed 100 °C. Thus, you must
drain and top it up with oil when it is cool!
Otherwise, you could burn yourself.
Greases (motor):
The bearings of the smaller standard electric motors are
lubricated by a permanent grease charge. The bearings of
the larger electric motors must be greased. The greasing
procedure is described in the directions for motor use.
Increased underpressure in the blower’s suction part
indicates suction filter clogging (indicated by a red strip in
the filter clogging sensor). If a pressure gauge is used
instead of the filter clogging sensor, the working section
and the state of increased underpressure are marked in
green and red respectively. If the filter is clogged, you must
replace its filter insert. You can order filter inserts; their
part numbers are stated on their flanges or in the Certificate
of Completeness and Quality.
After replacing the filter insert, you must release (by
pressing) the mechanical catch of the filter clogging sensor
so that the red strip indicating increased underpressure will
disappear.
Pulleys
The standard blower sets are equipped with V-belt drives.
Taper Lock bushings transfer the torque from the pulleys to
the shafts.
Taper lock clamp bushings –
Disassembly and assembly
Disassembly procedure
Loosen and remove all bolts. Screw bolts onto the releasing
threads. Tighten the bolts evenly (gradually tighten the
bolts opposite one another) until the clamp bushing is
released from the pulley.
Assembly procedure
Degrease the shaft journals, clamp bushing and pulley
hole. Put the clamp bushing in the pulley. Position the half
threaded hole so that the holes of the bushing and the
pulley fit. Oil the bolts slightly and screw them into the
securing holes. Do not tighten them yet! Put the clamp
bushing together with the pulley on the shaft. Now you can
evenly tighten the bolts with a torque wrench. Tighten them
gradually up to the stated torque (M
s
). Check the bolts for
correct tightening (according to the torque) after the clamp
bushings have been in operation for a short time. Put grease
into the empty threaded holes to prevent dirt from
collecting.
Table 5 – Torques according to the clamp bushing types
Type 1008 1108 1210 1215 1310 1610 1615 2012
M
s
[Nm] 5.6 5.6 20 20 20 20 20 31
Type 2517 3020 3030 3535 4040 4545 5050
M
s
[Nm] 48 90 90 112 170 192 271
V-belt Maintenance
Belts are tensioned depending on the transferred output.
During operation, the optimum belt tension is ensured
automatically by tilting of the pendulous motor frame. The
tilt of the pendulous motor frame is limited by the stop bolt
(see Chapter 3.6). After the belts have been lengthened,
you must readjust the bolt so that the pendulous motor
frame will not hit it when the motor is starting.
The belt drive parameters (the sizes and types of pulleys
and the number and sizes of belts) have been designed and
optimized for the required gear ratio and transferred output
so that the V-belts will be maximally employed. If any
functional drive belt is missing, you must always put on
the belt drive a new set of belts of the same type and
size. You must always use belts with a guaranteed
peripheral speed of 50 m.s
-1 ! You can find the type and
length of belts in the Certificate of Completeness and
Quality.
Long operating life of the designed belt drive is assured if
all conditions for regular maintenance are observed and the
replaced belts are the same as those originally designed by
Rietschle Thomas.
The parallelism of the shafts of both the blower and the
motor and the alignment of the pulley grooves are ensured
when the machine is being produced. When reassembling
the pulley, you must put it on the shaft so that the faces of
both pulleys are levelled. The maximum permissible
deviation is 0.4% (the maximum gap between the rule and
the pulley is 4 mm per one metre). When reassembling the
motor, you must ensure that the shafts are parallel and the
pulleys are levelled according to the picture:
Since blowers normally work without operators being
present, they must be protected against overload and/or
sudden failures.
The electrical part supplier is responsible for current
overload protection.
The machine owner must ensure that the machine will not
be overloaded by the safety valve’s being permanently
relieved. This applies mainly to simultaneous operation of
several blower sets (e.g., in wastewater treatment plants)
when one discharge branch is closed but the volume of
supplied air is not reduced to the necessary volume (by
reducing the revolutions or turning off one of the blower
sets). Blower set operation during which the safety valve
releases air for a long time causes pressure fluctuations that
significantly shorten the operating life of both the bearings
and the non-return valve. They might also damage the
blower.
In order to ensure thermal overload protection, it is suitable
to arrange electrical control of the permissible temperatures
of both the discharged air and the surroundings (a thermal
sensor connected to a signalling device or machine
stopping).
1/2 thread 1/2 thread
Securing threads
1/2 thread
Releasing thread
Securing threads
Releasing threads
1/2 thread
5.5.2 R
EPLACING
THE
FILTER INSERTS OF
THE SUCTION FILTER
5.5.3 P
ULLEYS AND
BELT TENSION
5.6 R
UNNING
WITHOUT
OPERATORS