Pfeiffer Vacuum UniDry 050-P Operating instructions

PP 1007 BE/G (0906)
Service Instructions
Rotary Piston Pump
UniDry™ 050-P/S
UniDryTM 050-P
UniDryTM 050-S

2
Index
Page
Modifications reserved.
1. Important Information.................... 3
1.1. For Your Orientation ......................................... 3
2. Trouble-Shooting ............................ 4
3. Motor, Coupling And Gear ............. 5
3.1. Pump With Claw Coupling ............................... 5
3.2 Pump With Magnetic Coupling......................... 6
3.3. Dismantling And Mounting The Gear ............. 10
3.4. Fitting And Adjusting The Gear Wheels.......... 11
3.5. Changing The Radial Shaft Seal ...................... 13
4. Changing The Loose Bearing....... 15
4.1. Dismantling The Loose Bearing (Greased) ..... 15
4.2. Fitting The Loose Bearing Unit (Greased)....... 16
5. Dismantling And Assembling The
Pump Stages ................................. 17
5.1. Dismantling The Shafts And The Fixed Bearing
Unit ................................................................ 22
6. Tools............................................... 25
7. Spare Parts .................................... 28
7.1. Spare Parts Packs ........................................... 28

3
ACHTUNG
1. Important Information
☞These service instructions are only valid in conjunction
with Operating Instructions UniDryTM 050-P/S,
PP 0938 BN.
☞Read and follow all instructions in this manual.
☞Customers who carry out their own repairs must have
completed the necessary Pfeiffer Vacuum training
courses.
Pfeiffer will not be liable for any damages or operating break-
downs which are caused by improper repair work nor for any
related personal injuries or material damages; neither will
any guarantee claims be accepted.
– Prevent accidental switching on of the motor whenever
carrying out inspection work.
– If necessary, remove the pump from the system when
carrying out inspection work.
– Only dismantle the pump as far as is necessary to effect
repairs.
– Used operating fluid must be disposed of in accordance
with local regulations.
– Where operations involve the use of synthetic operating
fluids and toxic or with corrosive gas enriched
substances, the relevant user instructions must be obser-
ved.
– Pump parts may only be cleaned with petrol, benzine or
similar cleaning agents. Do not use soluble cleaning
agents.
– Do not exceed any torque specification.
– For greasing during assembly only use lubricant F5 or
vacuum grease (PK 055 706-T).
1.1. For Your Orientation
Working instructions in the text:
➡Here you have to do something.
Position numbers
The same position numbers for components and tools are
used throughout in all illustrations in both the service manual
and in the operating instructions.
The use of symbols
The following symbols are used throughout in the
illustrations.
Vacuum flange
Exhaust flange
Pictogram Definitions
Danger of damage to the pump or to the
system.
CAUTION
Danger of an electric shock.
WARNING
Danger of personal injury.
WARNING
Danger of injury from rotating parts.
WARNING
Strong magnetic field!
Danger of personal injury.
WARNING

4
2. Trouble-Shooting
PPrroobblleemmPPoossssiibblleeccaauusseessEElliimmiinnaattiioonn
Pump does not attain final pressure Suction chambers dirty Flush the suction chambers with appropriate solvent.
Lubricant dirty Change the lubricant (see operating instructions)
Unusual operating noises Damage to the pump stages Dismantle casing parts and rotors (see Section 5.0),
re-work damaged parts or replace.
Check the rotor setting and re-adjust as necessary
(see Section 3.3/3.4).
Suction chambers corroded Dismantle casing parts and rotors (see Section 5.0),
or solid body in the chambers replace damaged parts as necessary.
Clean corroded or coated component parts;
sand blast, if necessary,
wash parts thoroughly and phosphatize.
Damage to the coupling Replace damaged parts (see Section 3.1.).
Damage to the bearing Replace defective bearing units in pairs
(see Section 4.1. and 5.1.)
Condensate or fluid in the pump Unscrew locking screws on the gas channels (below) and
drain off condensate and/or fluid.
Too little or no lubricant in
the gear chamber Fill up with lubricant (see operating instructions).
If damage has already occured to the gear or bearing,
exchange the components.
Defective motor bearing Replace motor bearing/motor.
Oil leaking from the shaft feedthrough Defective radial shaft seal Replace radial shaft seal and shaft protection sleeve
(see Section 3.5.).
Pump does not start Dirty pump stages Flush the suction chambers with appropriate solvent.
Dismantle casing parts and rotors (see Section 5.0).
Clean corroded or coated component parts;
sand blast, if necessary,
wash parts thoroughly and phosphatize.
Check the rotor setting and re-adjust as necessary
(see Section 3.3/3.4).
Damaged pump stages Dismantle casing parts and rotors (see Section 5.0),
re-work damaged parts or replace.
Check the rotor setting and re-adjust as necessary
(see Section 3.3/3.4).
Suction chambers corroded Dismantle casing parts and rotors (see Section 5.0),
or solid bodies in the chambers and replace damaged parts as necessary.
Clean corroded or coated component parts;
sand blast, if necessary,
wash parts thoroughly and phosphatize.
Malfunction on the electrical
connection Check mains, mains switch and connections.
Defective motor Replace motor.
Please note
All part numbers with the suffix ∗.4 are only valid for the
UniDryTM 050-S.
All pictures presented in the service instructions, except the
exploded drawing on page 21, shows the three stage pump
UniDryTM 050-P.

5
3.1. Pump With Claw Coupling
The electrical connections in respect of the
motor must be carried out in accordance with
the local regulations.
Please note:
The lubricant does not have to be drained from the pump,
when carrying out motor testing, dismantling and assembly
work.
Dismantling
➡Unscrew screw 205; take care of lock washer 206.
➡Detach motor 98 in an axial direction from lantern 6 (the
weight of the motor is approximately 12 kg).
➡Remove coupling piece 47.2 and coupling guard 22 and
check for wear.
➡Insert an Allen key between the claws and the lantern to
prevent turning.
WARNING
3. Motor, Coupling and Gear
➡Unscrew screw 81; take care of lock washer 92.
➡Remove coupling half 47.3 with an extractor or take out
with two wrenchs, if smooth-running.
➡Dismantle key 42 from the shaft.
Assembly
Assembly is carried out in reverse order of dismantling.
➡Heat up coupling half to approx. 120°C before pushing onto
the drive shaft.
➡Tighten center screw 81 to 15 Nm.
205/206
62298
(81/92)
47.3
42
Extractor
(not included in
the tool set)
Unscrewing the motor cylinder screws
Disassembling the motor from the lantern
Inserting the protection against turning between coupling and
lantern
Extracting the magnetic coupling
Taking out the key from the groove

6
Securing motor from tilting
130
3.2. Pump With Magnetic Coupling
The electrical connections in respect of the
motor must be carried out in accordance with
the local regulations.
Dismantling
TThheeffoolllloowwiinnggssaaffeettyyiinnssttrruuccttiioonnssaarreeoonnllyyrreelleevvaannttwwhheenn
ddiissmmaannttlliinnggtthheeddrriivveessyysstteemmooffppuummppsswwi
itthhmmaaggnneettiicc
ccoouupplliinngg((PPMM//SSMMttyyppeess))..
Persons who have a heart pacemaker must
stay outside the area of influence of magnetic
fields. There is a danger of life.
Label rooms, where parts of the coupling
system be stored or mounted, with the danger
sign:
„No trespassing for persons with heart
pacemaker”!
WARNING
WARNING
WARNING
Note
If the internal rotor of the magnetic coupling should be disas-
sembled, the lubricant must be drained off.
Danger of burning!
Lubricant temperature can be > 80 °C.
➡Secure motor or hang up, so that tilting after unscrewing
screws 141 is prevented (weight of motor approximately
12 kg).
➡Unscrew 2 diagonally arranged screws 141 between the
lantern 124 and the intermediate housing 120.
➡Unscrew 2 screws 141.1 opposite.
➡Screw in guide pins L1.
WARNING
Attention: Magnetic coupling
☞When dismantling the drive system from the pump casing
the powerful magnetic field of the coupling system can
influence the function and operational safety of electrical
and electronic units.
☞Do not place the dismantled magnetic coupling in the vici-
nity of computers, data carriers and other electronic
components.
☞On no account allow the two parts of the magnetic
coupling to come into contact. There is a danger of
crushing.
☞Keep all magnetisable parts away from the magnetic
coupling. There is a danger of personal injury.
Danger of bursting! Separating can is made of
ceramic.
Attach motor and align it horizontally.
CAUTION
➡Loosen the remaining screws 141 between the lantern 124
and the intermediate housing 120.
➡Extract motor with lantern from intermediate housing in
axial direction.

7
➡Remove coupling protection 127 and inspect for damages.
Danger of crushing of fingers!
Take care of the magnetic coupling force, when
extracting.
➡Unscrew the remaining screws 141 between the lantern
124 and the motor 130.
WARNING
Loosening screws and screwing in guide pins,
coupling protection already removed Loosening screws and screwing in guide pins
Extracting magnetic coupling motor side
Dismantling the lantern
L1
141.1
144
121.1
➡Inspect magnetic coupling external rotor 121.1 for
damages.
➡Loosen set screw 144, if necessary.
➡Detach external rotor 121.1 of the magnetic coupling with
extractor from the motor shaft.

8
➡Take out key from the groove of the motor shaft, if
necessary.
Note: The key does not belong to the spare parts of the
pump.
➡Unscrew screw 142 from the collar flange 122.
➡Detach collar flange 122 together with can 125; take care
of O-ring 135.
➡Unscrew screw 143 and take off washer 126.
➡Screw in again screw 143 for protection of countersink
and thread.
➡Extract internal rotor 121.2 from the shaft with extractor.
➡Loosen cylinder head screw 143, if necessary. Take care
of lock washer 92 and washer 126.
Danger of crushing of fingers!
When loosening the cylinder head screw,
insert fan belt piece K between the gear
wheels to prevent turning.
➡Extract magnetic coupling internal rotor 121.2 with extrac-
tor from the pump shaft.
➡Inspect magnetic coupling for damages.
➡Take out key 42 from the groove of the pump shaft, if
necessary.
WARNING
Taking out the key
Dismantling magnetic coupling pump side
Extracting magnetic coupling
Unscrewing screws at the intermediate housing
Assembly
The assembling of the coupling and the motor must be carried
out in reverse order.
➡Heat up the magnetic coupling to 120°C before assembling
the magnetic coupling, use heater.
➡Mount collar flange 122 with flattening to the auxiliary
shaft; tighten screws 142 with a torque of 50 Nm.
➡Tighten screw 143 with a torque of 15 Nm, take care of
lock washer 92 and washer 126.
Danger of crushing of fingers!
When loosening the cylinder head screw,
insert fan belt piece K between the gear
wheels to prevent turning.
WARNING

9
124
141
141.1
143/92 126
127
121.1
121.2 120
42
144
122
142
125 135
Dismantling/assembling magnetic coupling
92 Lock washer
120 Intermediate housing
121.1 Magnetic coupling, external rotor
121.2 Magnetic coupling, internal rotor
122 Collar flange
124 Lantern
125 Can
126 Washer
127 Coupling protection
135 O-ring
141 Cylinder head screw
141.1 Cylinder head screw
142 Cylinder head screw
143 Cylinder head screw
144 Set screw

10
3.3. Dismantling And Mounting The Gear
➡Drain off lubricant, unscrew screw 89; take care of
O-ring 66.
➡To support the pump place a suitable object under bearing
plate 4 so that the rubber feet (rubber buffers) on the
lantern are free.
– As an alternative bring the pump into a vertical position.
➡Unscrew the four securing screws 79 in lantern 6 and
force out the bearing plate 4 (on the fore-vacuum side)
with the forcing screws.
Take care with splash disc 13; depending on
the position of the shaft the splash disc is
seated in a groove in the lantern and this
prevents removal. If this is the case turn the
main shaft 15 somewhat.
CAUTION
➡Dismantle splash disc 13 from gear wheel 14.2.
➡Unscrew the four screws 82 on pressure plate 35 of the
tension element (34,50) while inserting a piece of fan belt
piece K between the gear wheels to prevent turning.
Remove the tension element, complete with gear wheels,
from the shaft.
Dismantling the lantern
79
6
Screwing in the forcing screws
Unscrewing the mounting screws from the lantern
4 13 support
Dismantling the splash disc
14.2 13
Dismantling the tension element
K
35 82
14.1
39
15

11
3.4. Fitting And Adjusting The Gear
Wheels
➡Push spacer 23 onto the shafts.
➡Insert key 33 in main shaft 15.
➡Place gear wheel 14.1 on main shaft 15; the threaded hole
should point to the outside.
➡Position gear wheel 14.1 with the threaded rod J and
mounting sleeve V on the shaft; if necessary heat up gear
wheel to approx. 140°C.
➡Replace the threaded rod with the temporary screw and
tighten the assembly sleeve V with the temporary screw to
15 Nm.
– While further work is being carried out, for example
dismantling/assembling the pump stages, leave the
temporary bolt with sleeve on the main shaft 15 to
prevent axial play of the main shaft.
➡Insert gear wheel 14.2 of the auxiliary shaft 16; take
account of the markings (position of the optimal meshing)
of the front side on the teeth of the two gear wheels.
➡Bring the rotors into the correct position (sectional
view A-B).
➡Fit tension element (34,35,50) onto auxiliary shaft 16; first,
lightly tighten with center screw.
➡Remove gear wheel 14.1 of the main shaft 15 and shaft
protection sleeve 39 using the extractor and extension
bolts Q.
➡Press out the key 33 from the shaft.
➡Remove spacer 23 from the shafts.
Fitting the gear wheel onto the shaft
Removing the gear wheels
Pushing spacer 23 onto the shafts.
Tightening the temporary screw with sleeve to 15 Nm
Dismantling the shaft protection sleeve from the main shaft
14.1
23
15
14.1
X
16 A
T2
T
Q
N
VX
VJ
Check axial run-out at the gear wheels:
desired value: ≤0,02 mm.
CAUTION

12
PP1007/71
Position of optimal meshing
➡Adjust the rotor position in intermediate stage 2 (sectional
view C-D); mark the feeler gauge 0.2mm with a felt tip pen
so that there is a visible reference as to how far to insert
the feeler gauge.
➡Insert the feeler gauge between the gap of the two rotors
and when the two rotors are in their maximum
engagement position (greatest resistance) tighten the
center screw on the tension element; wedge rubber
element A between the gear wheels to prevent turning.
➡Tighten screws 82 of the tension element as follows:
– Tighten center screw to 25 Nm; use locking varnish
(Loctite no. 222) for screw retention.
– Tighten outer screws (4 pieces) step-like and across
with 10; 15; 20 and 25 Nm.
– Now tighten center screw to 30 Nm.
➡Check spacer 23 (behind the gear wheels) for a tight seat;
for this use a thin filament (ømax. = 3 mm).
14.2 14.1
Rotor position, intermediate stage (stage 2, sectional view C-D) at UniDryTM 050-P
Rotor position in 3rd stage at UniDryTM 050-S
Feeler gauge
Rotor clearance, high vacuum stage (sectional view A-B)
34,35,50 82
Z4 14.2 14.1
Adjusting the rotor position in the intermediate
stage to 0.2 mm with the feeler gauge
PP1007/73
Position of the taper bushings 50
of the tension element
35 34
14.2
50

13
3.5. Changing The Radial Shaft Seal
The version with claw coupling, the drive shaft leading to the
outside, is fitted with a radial shaft seal ring.
➡Knock out radial shaft seal ring 57 from the lantern using a
screwdriver.
➡Insert a new radial shaft seal ring in the lantern groove
and position in using an assembly die Y and hammer; use
locking varnish (Loctite 601) for retention.
Dismantling the radial shaft seal ring in the lantern
Mounting the radial shaft seal ring from the lantern
Adjusting the rotor clearance in the high vacuum stage to 0.08 mm
with the feeler gauge
➡Screw splash disc 13 when dismantled onto gear wheel
14.2.; use locking varnish (Loctite no. 222) for screw reten-
tion.
➡Using the feeler gauge check clearance between the
rotors in the high vacuum stage (minimum 0.08 mm); dispo-
se of the gear wheel play by using both hands to move the
gear wheels against each other.
– It should be possible to move the feeler gauge between
the rotors with minimal resistance.
➡Push shaft protection sleeve 39 onto the shaft.
➡Screw in the guide rod L for positioning the lantern in the
housing.
➡Place the taper bush F3 for protecting the radial shaft seal
ring 57 on the shaft.
➡Lightly grease the sealing lip, shaft protection sleeve and
taper bush F3; use vacuum grease PK 055706-T.
➡Knock back the heavy duty dowel pin in the lantern.
➡Fit the lantern; knock in the heavy duty dowel pin and
remove the taper bush F3 from the main shaft.
➡Screw in screws 79 and tighten to 50 Nm.
Screw in the guide rod for positioning the lantern in the housing
13 14.2 14.1
657
Y
L
F3
Z3
A
Mounting the splash disc 13

14
PP1007/75
13 82 35 34 50 14.2 23 20 80
14.1 23 20 17
16
33
15
37 18 41 65
84 4
Fitting and adjusting the gear
4 Bearing plate (fore-vacuum side)
13 Splash disc
14.1 Gear wheel (main rotor)
14.2 Gear wheel (auxiliary rotor)
15 Main shaft
16 Auxiliary shaft
17 Bearing bushing (main shaft)
18 Bearing bushing (auxiliary shaft)
20 Bearing cover
23 Spacer
33 Key
34 Pressure ring (tension element)
35 Pressure plate (tension element)
37 Splash disc
41 Shaft protection sleeve
50 Taper bushes (tension element)
65 O-ring
80 Allen head screw
82 Allen head screw
84 Countersunk socket screw

15
4.1. Dismantling The Loose Bearing
(Greased)
For first time fitting purposes the bearing unit is completely
pre-fitted, including the shaft protection sleeve.
The loose bearing side is quite simply replaced
without any preparation work.
For replacement turn the pump in horizontally or
in vertically position.
➡Screw four aluminium feet onto bearing plate 4 (fore-vacu-
um side) after lantern is dismantled.
– When the motor is dismantled it is also possible to turn
the pump onto the lantern for changing the bearing.
CAUTION
Fitting the aluminium feet to the bearing plate
4. Changing The Loose Bearing
Dismantling the loose bearing cover
Unscrew 83 and loosen the bearing inner ring
➡Unscrew the four screws of each bearing cover 21 and
remove bearing cover.
➡Unscrew the Allen head screw 83 M8x20 (SW 13) seated
on the shaft end; if necessary, lock the shaft on the
coupling (motor side) with an appropriate tool.
➡Screw in screws M6 (mounting screws) for the bearing
cover) into the two threaded holes of bearing housing 19,
press out the bushing evenly until the outer O-ring is free;
remove the bushing by hand.
➡Press the bearing 44 out from the bearing housing by hand;
take care of the bearing compensation washers 45.
➡Remove the shaft protection sleeves 40; if not possible by
hand use an extracting device N.
➡Clean all sliding surfaces (inner and outer bearing housing
and the shaft protection sleeve).
4
83
19
3
21
19
(83)
3
Intersection
A-B
Intersection
C-D
4
Bringing the pump into the vertical position

16
4.2. Fitting The Loose Bearing Unit
(Greased)
Service situation where the loose bearing is completely pre-
assembled, spare parts pack: Maintenance set 2
➡Remove the bearing cover 21 from the pre-mounted loose
bearing unit.
➡Remove the bearing 44 and the bearing compensation
washers 45 from the pre-mounted loose bearing unit.
➡Lightly grease O-ring 66 before mounting.
➡Remove shaft protection sleeves 40 from the bearing unit
and place on the ends of the shafts and then push up to
the stop point either by hand or with an assembly sleeve.
➡Place the taper bushes F1 on the shaft ends to protect the
radial shaft seal rings; lightly grease taper bush.
Evenly pressing out the bearing housing 19
PP1007/70
Changing the loose bearing unit
3 Bearing plate
15 Main shaft
19 Bearing housing
21 Bearing cover
36 Washer
40 Shaft protection sleeve
44 Ball bearing
45 Bearing compensation washers
62 O-ring
80 21/62 83 94/36 44/45 19 40 66
3
15
78
➡Insert bearing housing 19 in bearing plate 3 and evenly
tighten the two Allen head screws 80. Lightly grease the
housing surface and O-rings and sealing lip of the radial
shaft seal ring (use vacuum grease PK 055706-T).
➡Remove the taper bushes F1.
➡Push bearing compensation washers 45 onto the shafts
(shaft protection sleeves 40); position the washers so that
they evenly cover each other.
➡Insert the greased ball bearings with closed side in the
direction of the pump.
➡Place the bearing inner ring of ball bearing 44 with Allen
head screws 83 M 8x20 (SW13) and washers 36/94 on the
shaft end and tighten the screw to 1155NNmm; prevent turn of
shafts.
➡Unscrew both screws from bearing housing 19.
➡Fit bearing cover 21 together with the bearing housing
each with four screws.
Tightening Allen head screws 83 to 15 Nm
66 O-ring
78 Allen head screw
80 Allen head screw
94 Washer

17
Carry out preparation work as in Section 4.0 Changing The
Loose Bearing.
➡Dismantle the bearing plate 3 of the loose bearing unit.
➡Loosen and unscrew the four mounting screws 78.
➡Press out the bearing plate with forcing screws evenly;
check the inner side of the bearing cover for scoring and
take care of the O-ring.
➡Remove shaft protection sleeves 40 with sleeve extractor
T.
➡Dismantle the flange cover or intake flange, if fitted.
➡Release rotors (7: Main rotor, 1st. stage, 8: Auxiliary rotor,
1st. stage) from the shafts. Therefore turn the shafts so
that the set screws are attainable via the vacuum connec-
tion.
➡Remove the rotors from the shafts by hand; use the
extracting device N if this is not possible by hand.
When turning the shafts and rotors there is a
danger of crushing fingers.
WARNING
Removing the rotors from the housing
Removing the rotors from the shafts
5. Dismantling And Assembling The Pump Stages
Unscrew the set screws 91
78
Unscrewing the mounting screws on the bearing plate
87
N
Q
8 7 1.3/5.4
3

18
➡Screw tie bolt R (temporary handle) into the housing.
➡Dismantle each four rotor rings 55 from the shafts.
➡Release rotors (9: main rotor, 2nd stage, 10: auxiliary rotor,
2nd stage) from the shafts. To do this, unscrew the set
screws.
➡Remove the rotors from the shaft by hand; use an extractor
if this is not possible by hand.
➡The dismantling of 3rd stage (fore-vacuum stage) is identi-
cal to dismantling 1st stage (high vacuum stage).
Screwing in tie bolt R and dismantling rotor rings 55
from the shafts
55
R
➡Detach the keys 31 from the shafts. If this cannot be
carried out manually, use forcing screws.
➡Dismantle housing 1.3/5.4 on stage 1 (high vacuum stage).
➡Loosen and unscrew the four mounting screws 76.
➡Press out housing 1.3/5.4 with forcing screws evenly.
➡When the forcing screws are exposed, lift the housing
upwards and out. Ideally, use a crane.
➡Check the sealed surfaces on the housing for scoring and
take care of the O-ring.
The housing weights approximately 35 kg so
there is a danger of crushing.
WARNING
Pressing out the key from the shaft
Unscrewing the mounting screws on the housing of stage1
Lifting out housing 1.3 with a crane
76
R
1.3
10 9
9
77
2.3
10
Fit rotors with the set screws 91 pointed in the
opposite direction (180° shifted); see figures
with the sectional view on page 29.
CAUTION

19
Tightening the mounting screws 76 to 50 Nm
➡Fit rotors 11.4 and 12.4 with an axial clearance of 0.02 mm;
place the feeler gauge 0.02 mm under the rotors and press
on by hand.
➡Fit all other respective parts respective to housing part 2.3
(see above).
➡Detach the keys 31 from the shafts. If this cannot be
carried out manually, use forcing screws.
➡Dismantle housing 2.3 of the 3rd stage (fore-vacuum
stage).
➡Unscrew the four mounting screws 77.
➡Press out housing 2.3 with forcing screws evenly.
➡Remove housing 2.3.
➡Check the sealed surfaces on the housing for scoring and
take care of the O-rings.
➡Dismantle each four rotor rings 55 from the shafts.
➡Release rotors (11: main rotor; 3rd stage, 12: auxiliary rotor;
3rd stage) from the shaft. To do this, unscrew the set
screws 91.
➡Remove the rotors from the shafts by hand; use an extrac-
tor if this is not possible by hand.
Dismantling up to this point is sufficient for checking the
pump system.
Assembling
➡Screw aluminium feet E1 back into the bearing plate ;
place on the feet.
➡Check the O-rings 67 for the water chamber and housing
and replace if necessary.
➡Check the keys 32 and insert, when missing.
➡Fit rotors (11: main rotor; 3rd stage, 12: auxiliary rotor; 3rd
stage) with an axial clearance of 0.02 mm; place the feeler
gauge under the rotors and press on by hand.
➡Tighten set screws 91.
➡Fit four rotor rings 55 to the shafts by hand.
➡Fit housing part 2.3 (fore-vacuum stage); tighten four
housing screws 77 M12 evenly to 50 Nm.
When tightening the mounting screws 77 and
76, screw in tie bolt R into the housing to utilise
counter torque.
➡Place the keys 31 in the shafts and if necessary use the
key presser O to press them in.
➡Fit rotors (9: Main rotor; 2nd stage, 10: Auxiliary rotor, 2nd
stage) with an axial clearance of 0.02 mm; place the feeler
gauge under the rotors and press on by hand.
➡Tighten the set screws.
➡Fit four rotor rings 55 on shaft by hand.
➡Check the O-rings for the water chamber and housing and
replace if necessary.
➡Fit housing part 1.3 (high vacuum stage); tighten four
housing screws 76.3 M12 evenly to 50 Nm.
Please note
For the UniDryTM 050-S (4-stage) there is an additionally
housing part 1.4 existing.
➡Fit housing part 1.4; tighten four housing screws 76.4 M12
evenly to 50 Nm.
WARNING
11
Fitting the rotors to 0.02 mm with the feeler gauge
Z1
E1
32
Pressing the keys into the groove using the key presser O
O

20
➡Place the keys 31 in the shaft and if necessary use the key
presser O to press them in.
➡Fit rotors (7: main rotor; 1st stage, 8: auxiliary rotor; 1st
stage) with an axial clearance of 0.02 mm; place the feeler
gauge under the rotors and press on by hand.
➡Tighten the set screws 91.
➡Fit bearing plate 3 without the bearing unit; tighten the four
screws 78 to 50 Nm.
➡Carry out work as in Section 4.2 Fitting The Loose Bearing
Unit:
After mounting the pump stages carry out work
as described in Section 3.3. Fitting And
Adjusting The Gear Wheels, and as described
in Section 3.1. Dismantling And Fitting The
Motor And Coupling.
CAUTION
Dismantling and fitting the pump stages 1.3 Housing (high-vacuum and intermediate stage); only for UniDryTM 050-P
1.4 Housing (2.- and 3.-stage); only for UniDryTM 050-S
2.3 Housing (fore-vacuum stage)
3 Bearing plate (high-vacuum stage) 4 Bearing plate (fore-vacuum stage)
5.4 Housing (high-vacuum stage); only for UniDryTM 050-
S
6 Lantern 7 Main rotor (high-vacuum stage) 8 Auxiliary rotor (high-vacuum stage) 9 Main rotor (intermediate stage)
10 Auxiliary rotor (intermediate stage) 11 Main rotor (fore-vacuum stage) 12 Auxiliary rotor (fore-vacuum stage) 11.4 Main rotor (2nd stage), only for UniDryTM 050-S
12.4 Auxiliary rotor (2nd stage), only for UniDryTM 050-S
15 Main shaft 22 Coupling guard 31 Key 32 Key
36 Disc 39 Shaft protection sleeve 42 Key 47 Coupling 49 Schauglas 39 Shaft protection sleeve 55 Rotor rings 57 Radial shaft seal ring 60 O-ring 63 O-ring 67 O-ring 78 Allen head screw 81 Allen head screw 91 Set screw 92 Spring washer 98 Motor 205 Allen head screw 206 Spring washer Parts numbered with pos.-no. *.4 are only valid for UniDryTM 050-S.