Vetus ZWB25 Guia De Inicio Rapido página 3

Propeller Shaft Seal
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 + 0.0mm / - 0.16 mm
• the shaft must be centred within the cas-
ing.
Align the propeller shaft with the ship
engine before putting the seal in place!
The propeller shaft speed may not exceed the
values shown in the table below.
D (in mm) 25
RPM 2700 2500 2300 2150 2000 1900
Installation
N.B. The numbers refer to the numbers in the
drawings.
General

The end of the shaft casing where the
rubber 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 shaft and if applicable, the rubber outer
bearing, gets cooled and lubricated by exter-
nal 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 25 mm: 20 litres/hour
- Propeller shaft diameter 30 mm: 30 litres/hour
- 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
2
The required external water can be sup-
plied with a tap from the engine's external
water cooling system.
3
If an air vent is present (where the water
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.
4
External water may also be supplied by a
separate water scoop with a seal:
- Propeller shaft diameter 25/30/35 mm:
min. G 3/8
- Propeller shaft diameter 40/45/50 mm:
min. G 1/2
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.
5
In addition to lubrication by external water,
the seal must also be lubricated with
grease between the seal lips.
Final Assembly
6
Fit the rubber sleeve with the 4 hose clips
over the prop shaft casing.
- Propeller shaft diameter 25/30 mm: The
inner side of the opening has to touch the
end of the casing.
- Propeller shaft diameter 35/40/45/50 mm:
Do not slide the rubber sleeve further up
the shaft than dimension C in the Table.
3
30 35 40 45
7
Grease the shaft where it will be enclosed
by the floating bearing and the shaft seal.
Grease the rims of the shaft seal.
Only use the grease supplied. Any other
lubricants could damage the shaft seal,
the sleeve, or the rubber bearing.
8
Fit the inner bearing on the propeller shaft
and slide it into the sleeve.Tighten the
hose clamps (4 to 5 Nm torque).
9
Stick a piece of adhesive strip 'A' over the
keyway. This will prevent the shaft seal
being damaged when fitted on the shaft.
Damage to the seal edges will lead to
leaks!
50
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 (10 Nm torque).
0
A Remove the screw with the washer and
fill about 50% of the forward space with
grease (approx. 1 cm
grease supplied! Replace the screw
and the washer, tighten it to about
5-Nm.
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 (water
intake) using a piece of hose, inner dia-
meter 10mm (ø 25, ø 30, 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 tem-
perature while cruising. An excessively high
temperature indicates insufficient water for
lubrication 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
visibly damaged, and replace the shaft
seal if it is.
Article code for replacement:
- 'ZWB25RES' for ø 25 mm propeller
shaft
- 'ZWB30RES' for ø 30 mm propeller
shaft
- 'ZWB35RES' for ø 35 mm propeller
shaft
- 'ZWB40RES' for ø 40 mm propeller
shaft
- 'ZWB45RES' for ø 45 mm propeller
shaft
- 'ZWB50RES' for ø 50 mm propeller
shaft
- Lubricate the shaft and the exposed seal
rim .
- Reattach the shaft seal onto the inner
bearing, tightening the bolts to about
10-Nm.
- Fill the seal with clean grease, refer to
Installation, point 10 B.
- Check the shaft seal and all connections
for leakage immediately after launching.
ENGLISH
3 ). Use only the
030307.04