P2.x ATEX
6.6.2 Cleaning the motor
Depending on the operating conditions of the pump, the following routine work is required:
– Check the terminal compartments and terminals are clean.
– Verify the electrical connections are tight.
– Clean ventilation paths.
– Verify the motor runs freely and vibration-free and check for noise. If you notice anything unusual, please contact our Service
Department.
The cooling surface and suction intakes must be protected from clogging and dirt.
6.7 Inspecting and replacing the flexible spider
NOTICE
Restrictions for maintaining the coupling
Only replacement of the flexible spider is allowed.
Loosening, re-tightening and replacing the coupling hub is allowed only by Bühler Tech-
nologies GmbH. The hexagon socket screws are marked with locking varnish which must
not be damaged.
Hub 2
Hub 1
Feeler gauge
Gear ring
B = new condition
X = wear
Guide value/backlash
Fig. 3: Sample gas pump coupling
Please refer to assembly drawing 42/025-Z02-02-2 in the appendix for this maintenance.
The coupling we use (on type P2.4 Atex / P2.74 Atex) is a zero-play coupling!
Check the play between the coupling cam (28a/28b) and the ring gear (28c). As soon as there is play, the ring gear must be re-
placed immediately regardless of the inspection intervals.
To do so, disconnect the pump head and intermediate flange (X/28) assembly by removing the hexagon screws (32) and washers
(31) from the rest. Remove the worn ring gear and clean any dust and other dirt off the coupling- and intermediate flange. Wipe
off stubborn dirt with a damp, clean cloth (do not use solvent-containing cleaning products).
Install a new ring gear on the hub side facing the motor. The required installation force can be reduced by slightly greasing or
lubricating the elastomer. Only use mineral oil based oils and greases without additives for this purpose.
Now reinsert the pump head and intermediate flange assembly in the coupling flange and reattach with the hexagon screws
and washers. A sight hole in the coupling flange allows you to verify proper installation.
Perform a test run and record the maintenance in the „operating log (template)“ of the pump.
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Bühler Technologies GmbH
BE420002 ◦ 07/2022
