Edwards nEXT 730D - Preload Check; Figure 3 Check the Bearing Preload

4. Preload check
WARNING:
Allow the pump r
otor to stop before you remove the pump from your vacuum system
for maintenance procedures.
NOTICE:
If the pump has suer
ed any damage (i.e. the rotor does not spin freely or quietly), it
is recommended that the service is not carried out. Contact local service centre for
advice.
Ensure all tools are clean and free of dirt and grease to avoid contaminaon of the
rotor.
Aer the bearing change the bearing preload must be checked. To become familiar with
how to check bearing preload, we recommend you perform a check at rst.
Preload is the process where a permanent thrust load is applied to the mechanical
bearing. Thrust is applied by the misalignment between the inner stac and the outer
rotang passive magnec bearing located at the inlet of the pump.
Place the pump in the vercal posion.
Figure 3 Check the bearing preload
2
1
A
A
CS/5283/A
1. Adjuster leg 2. Bearing adjuster nut1. Adjuster leg 2. Bearing adjuster nut
Place the preload tool onto the inlet of the turbomolecular pump. The force probe must
be loca
ted in the centre of the pump inlet with the adjuster legs engaged on the
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300872820_002_C2 - Preload check