STEERING GEAR WITH FEED-BACK
For the MARSILI encoding they are called “systems type G”.
The MARSILI servo assisted steering systems with feedback meet perfectly the needs of motorized vessels of all types from nautical to working ones.
Built with materials which are resistant to the maritime environment.
The system uses three main components:
Electrohydraulic power pack
Hydraulic transmitter, which allows the manoeuvre in the three systems; Hydraulic FU, Electric NFU, Manual Hydraulic/Emergency.
It is made up of a main cylinder and a feedback cylinder which are coaxial and with the same strokes.
During the FU mode, the feedback cylinder is filled by the manual transmitter, its pressure activates the servo valve which consequently manoeuvres the main cylinder.
The control is step by step and direct.
In NFU mode, the main cylinder is manoeuvred directly by a solenoid valve, while the feedback cylinder is set in bypass through the simultaneous command of a second solenoid valve.
In Manual/Emergency mode, the main cylinder is manoeuvred directly by the manual transmitter, while the feedback cylinder is set in bypass by its antishock valve.
ELECTROHYDRAULIC POWER PACK:
It is the core of the system, where both the working elements (motor – gear pump) and the command and control valves are assembled.
When the power pack is switched on the FU and NFU systems are available simultaneously and automatically using the transmitter or the tiller/autopilot.
The Manual/Emergency system takes over automatically if the power pack is switched off or in case of power failure.
In this case, an electric selector connects directly the transmitter to the main cylinder, allowing the manoeuvre automatically.
The power pack is also equipped for the automatic filling of the system and the regulation of the manoeuvre time during the NFU mode.
It is an axial piston pump turned by means of a steering wheel, depending on which mode it is set, it works under servo assisted mode or in manual emergency mode.
The system, as it is designed, allows a total hydraulic separation between the working system and the piloting system, avoiding that the feedback cylinder receives the working pressure during the emergency mode unnecessarily.
It is preferable to the traditional servo assisted systems because it is not only silent (there is no oil under pressure on the bridge), but it allows a safer and better manoeuvre as well.