A variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.

A method and a system for controlling a propulsive power output applied to a propeller shaft of a ship. If a current value of a propulsive power of a propulsive power source equals or falls below a lower power limit value, and/or if a current value of an operational parameter reaches a first/lower parameter limit value, a control unit is configured to: increase a power output of an internal combustion engine of the propulsive power source. Thus, operation of the engine below a lower power limit is avoided.

A method and a system for controlling a propulsive power output applied to a propeller shaft of a ship. If a current value of a propulsive power of a propulsive power source equals or falls below a lower power limit value, and/or if a current value of an operational parameter reaches a first/lower parameter limit value, a control unit is configured to: increase a power output of an internal combustion engine of the propulsive power source. Thus, operation of the engine below a lower power limit is avoided.

A variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.

A power system for a marine vessel comprises an engine and a controllable pitch thruster drivably coupled to the engine. A speed of the controllable pitch thruster various with a speed of the engine. A control unit receives a thrust command value indicating a thrust required from controllable pitch thruster. The control unit determines a current speed of the controllable pitch thruster and calculates a pitch of the controllable pitch thruster that produces thrust in accordance with the thrust command value at the current speed of the controllable pitch thruster. The power system allows for operating the engine at variable speeds to allow for a reduction of the engine speed under partial load conditions.

A power system for a marine vessel comprises an engine and a controllable pitch thruster drivably coupled to the engine. A speed of the controllable pitch thruster various with a speed of the engine. A control unit receives a thrust command value indicating a thrust required from controllable pitch thruster. The control unit determines a current speed of the controllable pitch thruster and calculates a pitch of the controllable pitch thruster that produces thrust in accordance with the thrust command value at the current speed of the controllable pitch thruster. The power system allows for operating the engine at variable speeds to allow for a reduction of the engine speed under partial load conditions.

In an apparatus for controlling an outboard motor mounted on a boat and having an internal combustion engine and a variable pitch propeller, characteristics defining a desired pitch angle of the propeller that makes fuel consumption minimum relative to a navigation speed of the boat are memorized and the pitch angle of the propeller is controlled to the desired pitch angle that is corresponding to the navigation speed detected by a navigation speed detector in accordance with the characteristics.

In an apparatus for controlling an outboard motor mounted on a boat and having an internal combustion engine and a variable pitch propeller, characteristics defining a desired pitch angle of the propeller that makes fuel consumption minimum relative to a navigation speed of the boat are memorized and the pitch angle of the propeller is controlled to the desired pitch angle that is corresponding to the navigation speed detected by a navigation speed detector in accordance with the characteristics.

The object of the invention is a method and an apparatus in an electric propulsion arrangement of a sailing vessel, wherein the sailing vessel has a traction device provided with an electric motor and with a propeller mechanism, the electric motor of traction device is arranged to be used, if necessary, in forward drive and reverse drive as well as during sailing as a generator for charging the accumulators of the sailing vessel. The propeller mechanism comprises a propeller hub with blades, a hollow propeller shaft fixed at its first end to the propeller hub, a shaft controlling the pitch angles of the propeller blades, said control shaft rotating inside the propeller shaft, and a servomotor rotating the control shaft. The servomotor is fixed to the second end of the propeller shaft to be rotatable along with the propeller shaft.

The object of the invention is a method and an apparatus in an electric propulsion arrangement of a sailing vessel, wherein the sailing vessel has a traction device provided with an electric motor and with a propeller mechanism, the electric motor of traction device is arranged to be used, if necessary, in forward drive and reverse drive as well as during sailing as a generator for charging the accumulators of the sailing vessel. The propeller mechanism comprises a propeller hub with blades, a hollow propeller shaft fixed at its first end to the propeller hub, a shaft controlling the pitch angles of the propeller blades, said control shaft rotating inside the propeller shaft, and a servomotor rotating the control shaft. The servomotor is fixed to the second end of the propeller shaft to be rotatable along with the propeller shaft.