BA-
45.01.0 • US •01/15
2
Principle of operation, machine versions
Operating Principle
Rotary vane compressor/vacuum pumps are multi-cell
compressors that work on the displacement principle.
They provide a constant, low-pulsation supply.
The single-phase machines have a cylindrical bored
casing. The rotor, which is also cylindrical, is mounted
eccentrically in the casing, forming a crescent-shaped
working chamber. Moveable rotor vanes are fitted in
the longitudinal grooves of the rotor; centrifugal force
causes them to glide along the side of the casing when
the rotor turns.
The vanes divide the crescent-shaped working
chamber into cells of varying sizes. When the rotor
turns, the cell volume on the suction side increases,
and the resulting under pressure draws air into the
cell, which is open to the suction nozzle. Upon further
turning, the cell closes and the cell volume decreases.
The enclosed air is thereby compressed and pushed
out on the discharge side through the delivery nozzle.
In accordance with this operating principle, the
machine works with polytropic compression. The
achievable compression ratio P
OUT
/P
IN
is limited by the
final compression temperature.
The operating principle of a rotary vane compressor
or a compressor\ vacuum pump
Machine versions
The various versions differ in their method of
lubrication and of cooling
Oil-lubricated machines are fed by means of an
automatic lube oil pump in the oil well. The rotor
shaft directly drives the lubricating pump.
Dry-running compressors for compressed air that is
absolutely oil free operate with absolutely no oiling
the compression chamber. The rolling bearings in
these
machines
have
permanent
lubrication
(permanent grease unit) or automatic lubricant
input.
In air-cooled machines, two ventilators on the rotor
shaft feed the coolant air axially via the casing
ribbing.
Water-cooled machines have a water sleeve inside
the casing. The coolant water circulates in a forced
circulation system driven by a circulation pump.
Type code
RF
W
260
DVR
Rotary vane compressor
(vacuum pump) with fresh
oil lubrication = RF
Casing cooled by
- Air cooling
= L
- Water cooling = W
Size of the compressor (of
the vacuum pump)
Additional designations
- Compression operation = D
- Suction operation = V
- Clockwise operation = R
The RFW series includes, therefore, water-
cooled and fresh-oil lubricated machines for
operation as compressor/Vacuum pumps.
