An embodiment of a device for marine surface propulsion of a watercraft is provided that facilitates high speed performance in combination with steering and/or trimming control. The propulsion device may include a support member supportably interconnectable to and pivotable about one or both of a reclined axis and upright axis relative to a watercraft transom. A propeller shaft may be supported by the support member for pivotable movement therewith, and may have a first end interconnectable to a watercraft engine output. A hub body and a plurality of propeller blades may be interconnected to a second end of the propeller shaft for co-rotation therewith, wherein the hub body and propeller blades are pivotable with the support member about the reclined and/or upright axes. A variable pitch actuator may be interconnected to the support member for pivotable co-movement therewith about the reclined and/or upright axis, wherein the variable pitch actuator is provided for adjustably controlling a pitch orientation of the propeller blades.

A hydraulically adjustable propeller assembly for an aircraft, a land vehicle or a water craft, includes an engine, a propeller unit having a propeller which comprises at least two propeller blades whose pitch is hydraulically settable, a pressure control unit which predetermines a fluid pressure for setting the pitch of the propeller blades and which is hydraulically connected to a pressure chamber of the propeller via a control line, and a pump unit which supplies a hydraulic fluid which is under a base pressure to the pressure control unit. The pump unit is a unit driven independently of the engine and the pressure control unit and includes at least one electrically operated main pump which supplies the hydraulic fluid which is under the base pressure for the pressure control unit.

A hydraulically adjustable propeller assembly for an aircraft, a land vehicle or a water craft, includes an engine, a propeller unit having a propeller which comprises at least two propeller blades whose pitch is hydraulically settable, a pressure control unit which predetermines a fluid pressure for setting the pitch of the propeller blades and which is hydraulically connected to a pressure chamber of the propeller via a control line, and a pump unit which supplies a hydraulic fluid which is under a base pressure to the pressure control unit. The pump unit is a unit driven independently of the engine and the pressure control unit and includes at least one electrically operated main pump which supplies the hydraulic fluid which is under the base pressure for the pressure control unit.

The invention relates to a control apparatus for a hydraulic variable-pitch propeller (12) of an aircraft, land vehicle or water vehicle, comprising: a hydraulic oil feed line (24); a control line (16) which can be connected to the variable-pitch propeller (12); a pressure generating device (73) which is connected to the hydraulic oil feed line (24) and provides hydraulic oil with a basic pressure; a servo valve (78) which is arranged downstream of the pressure generating device (73), the input pressure to which servo valve is the basic pressure and the output pressure from which servo valve during normal operation defines a control pressure in the control line (16) and which servo valve is connected to a controller (28) which delivers a control signal for changing the control pressure; and pressure reducing means which are arranged downstream of the servo valve (78) and upstream of the control line (16), which are mechanically actuated and which, in the event of a failure of the servo valve (78), change the control pressure in the control line (16).

There is described herein methods and system for correcting steady state errors in propeller speed by calculating a leakage flow rate as a function of engine and propeller parameters.

There is described herein methods and system for correcting steady state errors in propeller speed by calculating a leakage flow rate as a function of engine and propeller parameters.

A method to fill hydraulic oil in hydraulic steering systems for boats. The method uses a closed system to reduce mess and waste, but does not require power and can be performed by a single operator. A bleed lock is secured to a ram's bleeders and hydraulic oil fed to a helm. By rotating a boat's steering wheel and moving the motor, air will flow out of the system into the bottle and hydraulic oil will flow into the system.

A method to fill hydraulic oil in hydraulic steering systems for boats. The method uses a closed system to reduce mess and waste, but does not require power and can be performed by a single operator. A bleed lock is secured to a ram's bleeders and hydraulic oil fed to a helm. By rotating a boat's steering wheel and moving the motor, air will flow out of the system into the bottle and hydraulic oil will flow into the system.

A method to fill hydraulic oil in hydraulic steering systems for boats. The method uses a closed system to reduce mess and waste, but does not require power and can be performed by a single operator. A bleed lock is secured to a ram's bleeders and hydraulic oil fed to a helm. By rotating a boat's steering wheel and moving the motor, air will flow out of the system into the bottle and hydraulic oil will flow into the system.

A method to fill hydraulic oil in hydraulic steering systems for boats. The method uses a closed system to reduce mess and waste, but does not require power and can be performed by a single operator. A bleed lock is secured to a ram's bleeders and hydraulic oil fed to a helm. By rotating a boat's steering wheel and moving the motor, air will flow out of the system into the bottle and hydraulic oil will flow into the system.