Marine propulsion unit

Abstract

A marine propulsion unit for a marine vessel has a power source for rotating a pitchable propeller around an axis. The pitchable propeller is connected with a first shaft and a second shaft, an adjustment device comprising a first part being connected with the first shaft, a second part being connected with the second shaft, and a movable part. The movable part is configured to be moved between a first position and a second position so as to turn the first part and/or the second part thereby providing a phase shift between the first shaft and the second shaft for pitching and/or folding the pitchable propeller.

What is claimed is: 
     
         1 . A marine propulsion unit for a marine vessel, comprising
 a power source for rotating a pitchable propeller around an axis,   the pitchable propeller being connected with a first shaft and a second shaft,   an adjustment device comprising a first part being connected with the first shaft, a second part being connected with the second shaft, and a movable part,   wherein the movable part is configured to be moved between a first position and a second position so as to turn the first part and/or the second part thereby providing a phase shift between the first shaft and the second shaft for pitching and/or folding the pitchable propeller.   
     
     
         2 . The marine propulsion unit of  claim 1 , wherein the first part comprises a first part end being connected with the first shaft and a first projection extending from the first part end in an axial direction, the first projection having a first inner face with a first inner thread and a first outer face. 
     
     
         3 . The marine propulsion unit of  claim 2 , wherein the second part comprises a second part end being connected with the second shaft and a second projection extending from the second part end in the axial direction, the second projection having a second inner face and a second outer face with a second outer thread. 
     
     
         4 . The marine propulsion unit of  claim 3 , wherein the movable part comprises a third part end, a third projection extending from the third part end in the axial direction, the third projection having a third outer face with a third outer thread, and a fourth projection extending from the third part end in the axial direction, the fourth projection being hollow and has a fourth inner face with a fourth inner thread, the fourth projection being arranged around the third projection with a distance between them. 
     
     
         5 . The marine propulsion unit of  claim 1 , wherein the first part, the second part and the movable part are assembled so that the first inner thread interacts with the third outer thread and the second outer thread interacts with the fourth inner thread so that when the movable part is moved in the axial direction the first part and the second part are turned so that a phase shift between the first shaft and the second shaft occur. 
     
     
         6 . The marine propulsion unit of  claim 1 , wherein one or more bearing is/are arranged between the first part and the second part and the movable part, respectively. 
     
     
         7 . The marine propulsion unit of  claim 2 , wherein the treads are formed as helical guides that may interact with each other. 
     
     
         8 . The marine propulsion unit of  claim 7 , wherein the helical guides comprise a helical grooves and helical protrusions or knobs being configured to interact. 
     
     
         9 . The marine propulsion unit of  claim 1 , wherein an actuator is arranged for moving the movable part in the axial direction between the first position and the second position and any intermediate positions there between. 
     
     
         10 . The marine propulsion unit of  claim 1 , further comprising a control unit being operatively connected with the power source, the movable part and/or the actuator. 
     
     
         11 . The marine propulsion unit of  claim 1 , wherein a coupling is arranged between the first shaft, the second shaft and the pitchable propeller for changing a pitch angle of the pitchable propeller when the phase shift between the first shaft and the second shaft occur. 
     
     
         12 . The marine propulsion unit of  claim 11 , wherein the coupling comprises a first gear and a second gear, the first shaft is directly connected to the second gear and the second shaft is directly connected to the first gear. 
     
     
         13 . The marine propulsion unit of  claim 11 , wherein the pitchable propeller has a plurality of propeller blades, each propeller blade being connected to a blade gear. 
     
     
         14 . A marine vessel comprising a marine propulsion unit of  claim 1 . 
     
     
         15 . A method for pitching a pitchable propeller of a marine propulsion unit of  claim 1 , comprising
 arranging a power source for rotating the pitchable propeller around an axis, the pitchable propeller being connected with a first shaft and a second shaft,   arranging an adjustment device comprising a first part being connected with the first shaft, a second part being connected with the second shaft, and a movable part,   moving the movable part between a first position and a second position so as to turn the first part and/or the second part thereby providing a phase shift between the first shaft and the second shaft for pitching and/or folding the pitchable propeller.