Tuthill KINNEY KC Series, Руководство оператора, Страница: 8 / 48

Manual 1807 Rev B p/n 001807 0000
2
01
Introduction
separator. This combination oil separator and oil
mist eliminator thoroughly filters the pump exhaust
and results in a cleaner pump area, without
expensive and space-consuming exhaust piping
systems.
See Specifications on page 4 for pump
specifications.
PUMP COMPONENTS
Each pump basically consists of two rotary piston
pumping stages connected in series – a high
vacuum stage and a backing stage. The two rotary
pistons are driven by two eccentric cams keyed to
a common shaft. Each rotary piston has a hollow
extension (slide) that moves through a slide pin
and leads to the inlet of the particular pumping
stage. Ports are cast into the inlet side of each
piston and these ports together with the slide pins
form automatic inlet valves.
The two pumping stages are connected in series
by an internal duct and are enclosed in a single
cylinder. The ends of the cylinder are enclosed by
an open head, through which the shaft extends,
and a closed head. The open head contains a shaft
seal to prevent leakage along the shaft.
A spring-loaded discharge valve is located at the
discharge side of the backing stage (on the open
head end of the pump). An oil mist eliminator is
mounted above the backing stage.
A sight gauge is provided for checking the oil level
in the pump. When the pump is operating at low
inlet pressure, the level should be in the center of
the sight gauge. The oil level will change with large
changes in pump inlet pressure.
Operating Cycle
The operating cycle is shown in Figure 1-1 . Gas
from the system enters through the pump inlet.
It passes through the hollow piston slide and out
through the piston slide port into the space being
created between the piston and cylinder wall. As
the piston rotates, this space increases and more
gas is drawn in. At the same time, the gas taken
in and trapped on the previous revolution is on the
compression side of the piston and slide where
it is compressed and discharged into the cored
passageway that leads to the inlet of the backing
stage.
The rotary piston pumping cycle is repeated in the
backing stage. The gas is compressed and forced
out through the discharge valves along with a small
amount of oil and then into the oil mist eliminator
where the oil is separated from the gas. The gas is
discharged to atmosphere and the oil drains back
to the reservoir.