2
01
Introduction
Manual 1861 Rev C p/n 001861 0000
CONSTRUCTION
Timing Gear
The timing gear is an important part of the screw
vacuum pump. The tooth surface is heat-cured
and polished with a special high-precision tooth-
polishing machine for reduced noise during pump
operation.
Bearings
The bearings on the fixed side of the SDV pump
(discharge end) are angular-contact ball bearings.
The bearings on the expansion side (inlet end) are
roller bearings with heavy load capacity. These
bearings have been designed to withstand high-
speed, heavy-load service and to preserve the
clearances between gears and between screws.
Oil Level Gauge
An oil level gauge (sight glass type) is located on
the front end cover. Fill the oil to the top of the
red mark, or OL Mark. Oil levels are indicated as
follows for pumps manufactured after October
2005:
OL:
Original Line (Fill oil up to this line
initially)
RH:
Running High (During the Operation) –
In this case, check the pump.
RL:
Running Low (During the Operation) –
In this case, check the pump.
WARNING
!
If the oil level is too low, gears, bearings and
mechanical seals will be damaged as a result
of improper lubrication.
If the pump were operated with low oil level,
the gears and bearings would seize by lack
of lubrications. If the oil is overfilled, the oil
temperature would get elevated and cause high
gear noise and possibly affect the integrity of other
parts in the DE (Drive End) casing. When the pump
is not in use, be sure to check the oil level and
oil contamination, and then add or change the oil
when needed.
During operation, the oil is splashed over the
bearings and mechanical seals by rotation of the
timing gears.