Bertram 540 - Shafts Line, Stuffing Box Seal and Shafts Supports Bushings Maintenance

540
PROPULSION SYSTEMS
Studio ti 03312 540-04usa
140
8
8.6.1 Shafts line, stuffing box seal and shafts supports bushings maintenance
Item Maintenance Notes and precautions
Shaft lines Periodical checks
Assembly/disassembly
It is essential to keep the propellers shafts always clean; the formation of barnacles or the
presence of cloths or plastic bags lead to propulsion power reduction, to propellers
cavitation with consequent surface damage, and to vibrations causing damages to the
staffing box seals and to the bushings of the shaft supports. Checking and eventual
cleaning may be carried out with the yacht in a dry shore or with the help of a diver.
Bushings of shaft
supports
Checks & maintenance
Shaft support bearing
replacement
The Neoprene bushing of the shaft support, when sailing in waters with sandy suspensions,
may wear rapidly. The bushing wear causes a vibration increase. With the yacht in a dry
shore a good technician can evaluate easily, by moving the shaft, if the wear is so bad to
require the bushing replacement.
Propeller shaft seal Checks & maintenance The shaft seals prevent water from leaking around the shaft and into the boat. The seals
installed in your BERTRAM are of the dripless type and do not require adjustment as in a
traditional stuffing box. Special nitrile lip seals endure a watertight fit around the shaft. A
constant supply of water is necessary for cooling and lubricating the shaft and seal. This
water supply is provided by hose connections from the seals to the engine heat exchanger
discharge. Water must be supplied to the seals anytime the shafts are rotating. A lack of
cooling water may cause distortion of the seal resulting in leakage around the shaft.
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NOTICES
Proper alignment of the shaft is very important for the life of the seals.
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WARNING
The seal should never operate without cooling water, so as not to impair
its lifetime.