Steering Gear Actuator And Power Pack - Kongsberg Frydenbo IRV-2 Maintenance Manual

Maintenance Manual
4.

Steering Gear Actuator and Power Pack

The main components of the IRV Steering Gear are illustrated below. The rotor, turning in bearings at
top and bottom, is equipped with vanes upon which the oil pressure is acting and thereby developing
turning torque. The turning movement is limited by stoppers fixed to the housing. The stoppers also
act as mechanical rudder stoppers in hard-over position. In addition to the stoppers, the actuator is
equipped with electrical limit switches stopping the turning movement at a predetermined angle.
The rudder carrier bearing of the actuator has sufficient capacity to carry the full weight of rudder,
rudderstock and rotor, eliminating the need for a separate rudder carrier bearing. The bearing is
lubricated by the system oil. The sealing system consists of synthetic oil resistant material resting in
seal grooves. The sealing system prevents both internal and external leakage.
Hydraulic nut
Actuator
Foundation
Rudderstock
The IRV Steering Gear comprise two identical actuator power systems separated by a double sealing
system. In addition, the IRV Steering Gear consists of a double set of valves:
•
Control valves (Power Pack)
•
Lock valves (Actuator)
•
Isolating valves (Actuator)
•
Safety Relief/By-pass valves (Actuator)
The Control valve is activated according to command and initiate rudder movement. The Lock valve
on the actuator is opened by an increase of external pressure. A loss of external pressure will cause
the lock valve to close, keeping the actuator intact for operation by means of the stand-by pump if
necessary. The Interconnecting/Isolating valves connect the two power actuating systems during
normal operation. If one of the systems are defect, the Interconnecting/Isolating valve will isolate the
systems and enable the intact system to continue with normal operation. The Safety Releif/By-pass
valve protect against excessive external pressure transmitted from the rudder and will by-pass the
defect system if necessary.
KONGSBERG PROPRIETARY. This document and its accompanying elements contain KONGSBERG
information which is proprietary and confidential. Any disclosure, copying, distribution or use is prohibited if not
otherwise explicitly agreed with KONGSBERG in writing. Any authorized reproduction, in whole or in part, must
include this legend. ©2022 KONGSBERG - All rights reserved.
Control valve
IMO valve block
Stuffing Box
Pump unit
Filter
Oil tank
Power Pack
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