Vetus ZWB25A Instrucciones De Instalación página 3

Propeller Shaft Seal
Foreword
This Vetus propeller shaft seal with inner bearing
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 casing.
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
1
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 bear-
ing, gets cooled and lubricated by external water.
It is therefore necessary that sufficient external
water is supplied whenever the shaft is in oper-
ation.
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 supplied
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 draw-
ing 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 lubri-
cants 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!
Grease the seal lips. Fit the shaft seal on
50
the propeller shaft. Ensure that the O-ring is
properly in place and secure the shaft seal
with 3 screws (10 Nm torque).
10
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!
11
Connect
(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 bearing until
water flows out.
Always open the cap (after the water scoop)
before casting off.
Check the shaft seal for leaks and its temperature
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 visi-
bly damaged, and replace the shaft seal if it is.
Article code for replacement:
- 'ZWB25RESA' for ø 25 mm propeller shaft
- 'ZWB30RESA' for ø 30 mm propeller shaft
- 'ZWB35RESA' for ø 35 mm propeller shaft
- 'ZWB40RESA' for ø 40 mm propeller shaft
- 'ZWB45RESA' for ø 45 mm propeller shaft
- 'ZWB50RESA' for ø 50 mm propeller shaft
- Lubricate the shaft and the exposed seal rim .
- Reattach the shaft seal onto the inner bear-
ing, 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
the hose connection tube
030307.04