Hydraulic power packs consist of a brushless electric motor coupled to a 6 or 9 litre/minute submersible pump in function of the cylinder volume to be fed. They also feature a hydraulic distribution block fitted with its coils and delivery solenoid valves and its circuit protection components. The oil tank is equipped with an oil level sight glass, a filler cap and an additional opening to allow draining. These power packs support the logic controller to which the electrical harness is connected.

The cylinders provide the power of the steering system.

They are selected by using the methods described in menu « Selection of the steering system ».

All the cylinders are supplied with their pre-assembled and adjusted linear sensors. The linear sensor is supplied pre-wired with a pre-swaged connector half.

For boats fitted with a rudder with speed not exceeding 25 knots, the torque of the rudder(s) is calculated according to the following formula and correction coefficients.

It should be pointed out that the necessary torque to manoeuver a boat depends on:

• The speed of the water flowing on the surface of the rudder at a certain angle
• The rudder dimensions
• The total sweep of the rudder (and part of the boat), if the rudder stock is not perpendicular
• The compensating surface of the rudder (balanced rudder)
  Torque Calculation Formula for Speed below 25 Knots
  
  

  C = S x [ (0.4 Lg) – Lc ] x V² x K

C = Torque in kpm schema_safran
S = Total surface of rudder (H x Lg) in sq. m
H = Height of rudder in m
Lg = Width of rudder in m
Lc = Compensation width in m
V = Maximum speed of the boat in knots
K = Coefficient according to total angle of rudder

In operating condition, the programmable logic controller continuously analyses the information sent by the cylinder position sensors and relays the orders from the transmitters.

It manages the position and the displacement of each cylinder by means of the hydraulic power pack and the hydraulic distribution system.

Depending on the selected model, a screen display can allow for navigation scrolling through pages and menus, activation or deactivation of an individual receiver or transmitter, thus providing a broad range of applications (safety, maintenance, intervention…). It also allows the fine-tuning of rudder angle settings (Ackerman effect…), reaction speed and rudder alignment. Finally, it triggers alarms (temperature, oil level, filter clogging…) and permits to isolate the components concerned.

The elimination of hydraulic circuits in the boat inhabitable parts and of the mechanical tie bars between the rudders, the lack of interventions on often complex hydraulic circuits such as filling and bleeding are all reasons that make the electro-hydraulic steering system a technically and economically sound solution that meets all of the market requirements.