Servo Oil System For Vbs Type Cp Propeller - Man B&W S50ME-B9.3-TII Project Manual

MAN B&W

Servo oil system for VBS type CP propeller

The design principle of the servo oil system for
MAN Diesel & Turbo's MAN Alpha VBS type CP
propeller is shown in Fig. 5.18.05.
The VBS system consists of a servo oil tank unit,
the Hydraulic Power Unit, and a coupling flange
with electrical pitch feedback box and oil distribu-
tor ring.
The electrical pitch feedback box continuously
measures the position of the pitch feedback ring
and compares this signal with the pitch order sig-
nal.
Stern
tube oil
tank
Servo
piston
Zinc
anode
Fig. 5.18.05: Servo oil system for MAN Alpha VBS type CP propeller
MAN B&W 70-26 engines
Oil tank
forward
seal
Lip ring seals
Propeller shaft
Monoblock Stern
hub tube
If deviation occurs, a proportional valve is actu-
ated. Hereby high pressure oil is fed to one or the
other side of the servo piston, via the oil distribu-
tor ring, until the desired propeller pitch has been
reached.
The pitch setting is normally remote controlled,
but local emergency control is possible.
Hydraulic Power Unit
TI
TAH
LAL
Hydraulic
pipe
Oil distribution
ring
MAN Diesel
PAL
PI PAH PAL
PSL PSL
M
M
Pitch
feedback
Drain
tank
5.18
Page 4 of 8
Pitch
order
PI
M M
178 22 384.1
198 46 953.6