12 / 60
Medium pressure servo systems
hydraulics reduce noise levels
Cost efficient, easier installation and
maintenance, higher reliability and extended
lifetime. Quieter than a high-pressure system.
Precise Manoeuvring
A variable displacement pump delivers the
exact amount of oil needed for the propeller
pitch movements. The valve mechanism
automatically adjusts the oil flow to enable
smooth and highly precise manoeuvring via
a direct hub linkage mechanism.
One oil type for lube and
servo system
• Gear
• Pitch mechanism
• Multiple propeller shaft sealing system
No forced cooling
for lubrication oil
The HPU uses natural cooling,
as the oil reservoir is located in
the thruster gearbox.
Protection of the
marine environment
– is a growing concern
throughout the shipping
industry. Oil leakage from
thrusters can harm even
the best of reputations.
Brunvoll designs systems
focused on preventing
such pollution.
Easy checking of
oil condition
Valves accessible from the top
of the thruster are connected both
to the seal safety chamber and
gearbox bottom. This makes it easy
to drain oil and detect any traces of water
or particles in the oil – an early warning.
Overhaul without
removal of gearbox
While the gearbox is still in
the tunnel, one can:
• Change individual propeller
blades or blade seals.
• Remove the propeller hub to
change shaft seals.
• Take out the whole propeller
shaft assembly.
Supreme technical solutions
Brunvoll introduced propeller
shaft sealing systems with a
safety chamber and multiple
seals as early as 1965
Compact pitch
feedback mechanism
Ensures the precision needed
for today’s advanced control
systems and optimal DP
operation - without cumber-
some chains. The mechanical
transmission from the propeller
shaft to the feedback unit is
backlash-free.
Outer axial seal
The outer sealing unit is an axial
seal with specially finished
contact surfaces for stationary
and moving parts. This unit has
an inherent capability to absorb
wear, ensuring maximum
lifetime.
Safety chamber
The multiple-seal propeller shaft
sealing system combines an
axial seal and radial lip seals
separated by a drainable safety
chamber. This enables easy oil
sampling for inspection.
Pinion shaft seal
Radial lip seal with
dust cover.
12