Alcatel ADP One Series User Manual page 14

Tightness
with environment
Tightness at low
pressure side
Tightness at high
pressure side
2/3
Dry pump
operational principle
The pump bearings on the low pressure side are fitted with
ceramic ball bearings lubricated with fluorinated grease which
resists high temperatures and the possible corrosion due to
the application.
An overpressure zone is created around the bearing by
injecting a neutral gas (Purge LP1). The grease works in a
less severe vacuum and thus lasts longer.
This pressurization also prevents pumped gases from migrating
towards the bearings.
Neutral gas purging for the bearings is imperative for corrosive
processes.
The bearings are lubricated by
oil splashing.
The oil sump is sealed from
stage HP by a trap and a
5
deflector.
This trap is also used :
- as a heat barrier
- as a pumped gas barrier
- to recover fluid
Alcatel - High Vacuum Technology - User's Manual ADP/ADS
A 50
3
6
2
5
1
4
1 - Stage HP
5
2 - Trap
3 - Water cooling
4 - HP
purge
5
5 - Dynamic seal
6 - Lubrication disk
7 - Gear casing
7