Propulsion unit and vessel comprising the propulsion unit

Abstract

Disclosed is a propulsion unit for propelling a vessel. The propulsion unit comprises a main body configured to be arranged at a keel of the vessel and comprising a pivot point, a fin being movably arranged in relation to the main body, and an actuator assembly for generating a heave motion of the fin in relation to the main body. The actuator assembly comprises at least one actuator. The fin is connected to the pivot point, such that the fin is arranged to pivot around the pivot point when the at least one actuator generates the heave motion of the fin, thereby generating a pitch motion of the fin.

What is claimed is: 
     
         1 . A propulsion unit for propelling a vessel, the propulsion unit comprising:
 a main body configured to be arranged at a keel of the vessel and comprising a pivot point,   a fin being movably arranged in relation to the main body, and   an actuator assembly for generating a heave motion of the fin in relation to the main body, the actuator assembly comprising at least one actuator,   wherein the fin is connected to the pivot point such that the fin is arranged to pivot around the pivot point when the at least one actuator generates the heave motion of the fin, thereby generating a pitch motion of the fin.   
     
     
         2 . The propulsion unit according to  claim 1 , wherein the at least one actuator is a linear actuator. 
     
     
         3 . The propulsion unit according to  claim 1 , wherein the propulsion unit comprises at least one actuating rod, the actuator assembly being connected to the fin via the at least one actuating rod. 
     
     
         4 . The propulsion unit according to  claim 1 , wherein the actuator assembly is configured to be operated with an oscillating pattern, thereby generating an oscillating heave and pitch motion of the fin. 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . The propulsion unit according to  claim 1 , wherein the actuator assembly comprises a first actuator and a second actuator, wherein the pivot point is connected to the second actuator such that the pivot point is movably arranged in relation to the main body. 
     
     
         8 . The propulsion unit according to  claim 7 , wherein the first actuator and the second actuator are independently operable in relation to each other, so that a phase difference between the heave motion and the pitch motion of the fin is variable. 
     
     
         9 . The propulsion unit according to  claim 7 , wherein the fin comprises a first fin section, a second fin section, a first connecting rod, and a second connecting rod, wherein the first fin section and the second fin section are connected via the first connecting rod and the second connecting rod, wherein the first connecting rod and the second connecting rod are arranged in parallel and at a respective first distance and second distance from a leading edge of the first and second fin sections. 
     
     
         10 . The propulsion unit according to  claim 9 , wherein the main body comprises a first through-going slot and a second through-going slot for allowing the first connecting rod and the second connecting rods to protrude through the main body and to be slidably arranged within the first through-going slot and the second through-going slot. 
     
     
         11 . The propulsion according to  claim 9 , wherein the first connecting rod is connected to the first actuator and the second connecting rod is connected to the second actuator. 
     
     
         12 . (canceled) 
     
     
         13 . The propulsion unit according to  claim 9 , wherein the first actuating rod and the second actuating rod are arranged inside the main body. 
     
     
         14 . The propulsion unit according to  claim 7 , wherein the actuator assembly comprises a third actuator. 
     
     
         15 . The propulsion unit according to  claim 14 , wherein at least two of the first actuator, the second actuator and the third actuator are correlatively operable, to variably adjust the pitch angle and/or the heave of the fin. 
     
     
         16 . The propulsion unit according to  claim 14 , wherein the fin comprises a third connecting rod, wherein the first fin section and the second fin section are connected via the third connecting rod, wherein the first connecting rod, the second connecting rod and the third connecting rod are arranged in parallel and at a respective first distance, second distance and third distance from the leading edge of the first and second fin sections. 
     
     
         17 . The propulsion unit according to  claim 16 , wherein the main body comprises a third through-going slot for allowing the first connecting rod to protrude through the main body and to be slidably arranged within the three through-going slot. 
     
     
         18 . The propulsion unit according to  claim 16 , wherein the third connecting rod is connected to the third actuator. 
     
     
         19 . The propulsion unit according to  claim 18 , wherein the third connecting rod is connected to the third actuator via a third actuating rod. 
     
     
         20 . The propulsion unit according to  claim 19 , wherein the third actuating rod is arranged inside the main body. 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . (canceled) 
     
     
         25 . (canceled) 
     
     
         26 . (canceled) 
     
     
         27 . The propulsion unit according to  claim 1 , wherein the main body comprises a hollow tube protruding from the main body on a keel-facing side of the main body, wherein the first actuating rod and/or the second actuating rod is/are arranged within the hollow tube, wherein the hollow tube is configured to protrude into the vessel when the main body is arranged to the keel of the vessel. 
     
     
         28 . The propulsion unit according to  claim 27 , wherein the hollow tube comprises a seal arranged at a distal end of the hollow tube for sealing the first actuating rod and/or the second actuating rod to the hollow tube. 
     
     
         29 . (canceled) 
     
     
         30 . (canceled) 
     
     
         31 . (canceled) 
     
     
         32 . A vessel comprising a propulsion unit for propelling the vessel according to  claim 1 , wherein the main body is arranged to the keel of the vessel and wherein the fin is configured to perform a pitch and heave motion in relation to the keel of the vessel. 
     
     
         33 . (canceled) 
     
     
         34 . (canceled)