Elmo Rietschle S-VSB User Manual

Page 4

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VSB

120 (30)

200 (30)

320 (30)

430 (30)

800 (30)

2700 (20)

m³/h

50 Hz

80

120

220

330

560

1700

60 Hz

100

150

260

400

700

2100

mbar (abs.)

0,3

0,3

0,3

0,3

0,05

0,05

bar (abs.)

max. 1,3

kW

50 Hz

3,0

4,0

5,5

7,5

15

55

60 Hz

3,6

4,8

6,5

9,0

18

65

min

-1

50 Hz

2850

1450

60 Hz

3450

1740

DN

40

50 / 40

50 / 40

80 / 50

100 / 80

150 / 100

l

0,45

1,0

1,6

1,8

2,0

9,0

bar (abs.)

10

l/h

120

240

480

660

1200

2160

bar (abs.)

max. 6

Nm

3

/h

-

-

-

25

30

30

cm³/min

max. 3

kg

120

240

480

660

1200

2160

Note:
(1) The quantity of oil listed is only for reference, and surplus should be available. It should be noted that fluorine and mineral

based oils can be used. For shipping, we supply pure gear oil.

(2) The Cooling Water flow quoted is based on water temperature of 20° C. The amount of water will vary when using an After

Cooler. Please check with Vendor’s approved drawing.

3.3 Technical specifications

3. General Construction
3.1 General
The Rietschle TWISTER pumps gases
and vapours by use of two screw ro-
tors, having a profile comprising a plu-
rality of curves, i.e. Archimedean curve,
Quimby curve and arc, which rotate
smoothly with a certain clearance main-
tained between each other and inside
wall of the casing.
The gases and vapours being pumped
are smoothly pressurised up to the
pressure on the discharge side. The
pump is so constructed as to prevent
oil from entering the pumping chamber.
The power of the motor is transmitted
to the gear by a coupling.

3.2 Construction

• Rotor shaft: The rotor shaft is

made of high grade spheroidal
graphite cast steel, and precision machined through numerical control by a special machine. It is perfectly dynamically
balanced after the rotor is machined.

• Timing Gear: The timing gears are the most important part of the screw vacuum pump, and they are required to maintain

the precision clearance between the rotors. The tooth surface is heat cured, and then polished with a special high precision
tooth polishing machine for noise reduction.

• Bearing: The bearings on the fixed end are angular contact ball bearings and on the floating end are roller bearings of

heavy load capacity. These bearings have been selected for high speed and heavy load service and to assure the accurate
maintenance of clearances between gears and between rotors.

• Shaft sealing suction side: The shaft sealing consists of two double lipped shaft seals.

Shaft sealing pressure side: A mechanical spring plate assures sealing between the chamber and the gear box. An
additional single lipped shaft seal in combination with sealing gas prevents foreign particles from entering the sealing sys-
tem.
Shaft sealing gear box: A single lipped shaft seal seperates the gear box from the atmospheric pressure.

• Oil Level Gauge: The Oil Level Gauge is located in the Front End Cover. Oil should be supplied to the top level of Red mark.

If the oil level is too low, Gear, Bearing and Mechanical Seal will be damaged as a result of improper lubrication. The timing
gears, bearings and mechanical seals are splash lubricated. Check oil level and look for contamination when the pump is
stopped.

Nominal (theoretical) Displacement

Ultimate vacuum

Discharge pressure

Motor rating

Speed

Port size (Suction / Discharge)

Gear oil

Max. internal pressure

Cooling water

Cooling water pressure

Cooling gas

Sealing gas

Front end plate

Bellows type mechanical seal

Seal type

Rear end plate

Lip seals

Front end cover (drive shaft

Oil seal

Weight

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