Propeller Shaft Seal 'ZWB35', 'ZWB40', 'ZWB45', 'ZWB50'
Foreword
This Vetus propeller shaft seal with inner bear-
ing has a double shaft casing.
To ensure a complete seal:
• the propeller shaft must have a maximum
diameter-tolerance of + 0.0 mm / - 16 mm.
• the shaft must be centred within the casing.
Align the propeller shaft with the ship
engine before putting the seal in place!
The propeller shaft speed may not exceed the
D (in mm)
35
RPM
2300
values shown in the Table below.
Installation
N.B. The numbers refer to the numbers in the
drawings.
General
The end of the shaft casing where the rub-
1
ber sleeve is placed must be free of burrs,
grease, and must be clean. The free
length of the tube must be the same as, or
longer than, dimension A shown in the
Table.
The shaft must be free of scratches, burrs,
and must be clean, especially where the
shaft touches the floating bearing and
seal. The end of the shaft or the key way
or holes which may be present must also
be free of burrs. The free length of the
shaft must be the same as, or longer than,
dimension B shown in the Table.
Ensure that the shaft has been placed in the
casing.
Lubrication
The lubrication and cooling of the shaft seal
and any rubber bearings fitted is carried out by
external water.
It is therefore necessary that sufficient
external water is supplied whenever the
shaft is in operation.
The minimum amount of water required is:
- Propeller shaft diameter 35 mm: 35 litres/hour
- Propeller shaft diameter 40 mm: 45 litres/hour
- Propeller shaft diameter 45 mm: 60 litres/hour
- Propeller shaft diameter 50 mm: 70 litres/hour.
The required external water can be sup-
2
plied with a tap from the engine's external
water cooling system.
If an air vent is present (where the water
3
injection point is either under or less than
15cm above the waterline) then tap the
engine's external water cooling system
between the external water pump and
the air vent and not between the air vent
and the water injection point.
The external water requirement can also
4
be supplied via a separate water scoop
with valve:
- Propeller shaft diameter 35 mm: G 3/8
minimum
- Propeller shaft diameter 40 mm, 45 mm
and 50 mm: G 1/2 minimum.
Place the water scoop with its intake
grooves sufficiently in front so that enough
water flows in and it does not interfere with
the propeller water.
The shaft seal may be installed either under or
above the waterline. If it is placed above the
waterline it must, in order to ensure adequate
supply of water, be connected as shown in
drawing 2.
In addition to lubrication by external water,
5
the seal can also be lubricated with grease
between the seal rims.
3
40
45
50
2150
2000
1900
Final Assembly
Fit the rubber sleeve with the 4 hose
6
clamps on the propeller shaft tube. Do not
slide the rubber sleeve further up the shaft
than dimension C in the Table.
Grease the shaft where it will be enclosed
7
by the floating bearing and the shaft seal.
Only use the grease supplied. Any other
lubricants could damage the shaft seal,
the sleeve, or the rubber bearing.
Fit the inner bearing on the propeller shaft
8
and slide it into the sleeve.Tighten the
hose clamps (4 to 5 Nm torque).
Stick a piece of adhesive strip 'A' over the
9
keyway. This will prevent the shaft seal
being damaged when fitted on the shaft.
Damage to the seal edges will lead to
leaks!
Grease the seal lips. Fit the shaft seal on
the propeller shaft. Ensure that the O-ring
is properly in place and secure the shaft
seal with 3 screws.
A
Remove the screw with the washer
10
and fill about 50% of the forward
space with grease (approx. 1 to 2
cm
3
). Use only the grease supplied!
Replace the screw and the washer,
tighten it to about 5Nm.
B
Attach the hose connection tube to
the bearing casing using a liquid
sealant.
N.B. Do not use Teflon tape!
Connect the hose connection tube
11
(water intake) using a piece of hose,
inner diameter 10mm (ø 35 mm) resp. 12
mm (ø 40 , ø 45, ø 50 mm), to the water
supply. Each connection must be
attached by 2 stainless steel hose clips.
After launching
Check the following for leakage immediately:
the shaft seal, the rubber sleeve connections,
and all the hose connections.
It may be necessary to bleed the assembly
first. Disconnect the hose from the inner bear-
ing until water flows out.
Always open the cap (after the water scoop)
before casting off.
Check the shaft seal for leaks and its tempera-
ture while cruising. An excessively high tem-
perature indicates insufficient water for lubrica-
tion and cooling!
Maintenance
The following maintenance must be performed
after every 200 hours of operation or once a
year while the ship is on dry dock:
• Loosen the bolts which attach the shaft seal
to the inner bearing.
• Clean the surface of the deal rims where it
touches the shaft so that it is free of grease,
dirt and residue.
• Check whether the rim of the seal is not vis-
ibly damaged, and replace the shaft seal if
it is.
Article code for replacement:
- 'ZWB35RES' for ø 35mm propeller shaft.
- 'ZWB40RES' for ø 40mm propeller shaft.
- 'ZWB45RES' for ø 45mm propeller shaft.
- 'ZWB50RES' for ø 50mm propeller shaft.
• Lubricate the shaft and the exposed seal
rim .
• Reattach the shaft seal onto the inner bear-
ing, tightening the bolts to about 4 Nm.
• Fill the seal with clean grease, refer to
Installation, point 10 A.
• Check the shaft seal and all connections for
leakage immediately after launching.
ENGLISH
3.0303