fin propulsion apparatus

Abstract

A propulsion apparatus is provided for propulsion in a fluid, comprising at least one propulsion fin being fixed to a fin axle, and means for driving the propulsion fin comprising a crankshaft, a pitching mechanism for rotating the propulsion fin around the axis of the fin axle, and a heave mechanism for translating the propulsion fin in a substantially transverse direction with respect to the axis of the fin axle, and where the crankshaft is driving the pitching mechanism and the heave mechanism. A simple, reliable and efficient construction is obtained by having both the heave and the pitch mechanism mounted on a single crank on the crankshaft, or to separate cranks having substantially the same radius and angular position with respect to the axis of rotation of the crankshaft.

1 . A propulsion apparatus provided within a hull of a maritime vessel comprising at least one transverse translating propulsion fin being fixed to a fin axle, and means for driving said fin comprising a crankshaft, a pitching mechanism for rotating said fin around an axis of said fin axle, and a heave mechanism for translating said fin in a substantially transverse direction with respect to said axis of said fin axle and said vessel, and where said crankshaft is driving said pitching mechanism and said heave mechanism, wherein both said heave and said pitch mechanism are connected to a single crank on said crankshaft, or two separate cranks having substantially the same radius and angular position with respect to the axis of rotation of said crankshaft. 
     
     
         2 . A propulsion apparatus according to  claim 1 , wherein said fin axle is mounted to a chariot allowing said fin axle and thereby said fin to rotate around its axis with respect to said chariot, and that said chariot is slidably mounted with respect to said crankshaft, and where said heave mechanism connects said chariot to a crank on said crankshaft and said pitching mechanism connects said fin axle to said crank on said crankshaft. 
     
     
         3 . A propulsion apparatus according to  claim 2 , wherein said heave mechanism and said pitching mechanism are provided by means of a common push/pull rod, connected at one end to said crank of the drive shaft, and at an other end attached to and extending substantially transversally from a fin pitching axle rotatably connected to said chariot, so that said push/pull rod, when said crankshaft rotates, drives said chariot to oscillate or translate to and from said crankshaft, and at the same time drives said fin pitching axle to rotate. 
     
     
         4 . A propulsion apparatus according to  claim 2 , wherein said heave mechanism comprises a slot in said chariot, and a crank on said crankshaft slidably arranged in said slot, and where said pitching mechanism comprises a pitcher rod attached at one end to and extending substantially transversally from a fin pitching axle and attached at an other end to said crank on said crankshaft, and where said pitcher rod is telescopic or connected to either said fin pitching axle or said crank via a slide bushing, so that said pitcher rod compensates for varying distances between said fin axle and said crank, and so that, when said crankshaft rotates, said heave mechanism drives said chariot to oscillate or translate to and from said crankshaft, and at the same time said pitching mechanism drives said fin pitching axle to rotate. 
     
     
         5 . A propulsion apparatus according to  claim 4   wherein said fin pitching axle and the fin axle are the same. 
     
     
         6 . A propulsion apparatus according to  claim 4 , wherein said pitching mechanism comprises a synchronizing link or gearing connecting said fin pitching axle to said fin axle, and where said synchronizing link is arranged for synchronizing rotation of said fin axle with rotation of said fin pitching axle. 
     
     
         7 . (canceled) 
     
     
         8 . A propulsion apparatus according to  claim 6 , wherein said fin axle is parallel to said fin pitching axle. 
     
     
         9 . A propulsion apparatus according to  claim 6 , wherein a gearing is arranged between said fin axle and said fin pitching axle, so that said fin axle is arranged at an angle apart from zero to said fin pitching axle. 
     
     
         10 . A propulsion apparatus according to  claim 6 , wherein said apparatus comprises two or more fins connected to said same fin pitching axle via at least one synchronizing links. 
     
     
         11 . A method of propelling a ship by means of a propulsion apparatus according  claim 1  wherein said heave and said pitch mechanism are connected to a single crank on said crankshaft, or two separate cranks having substantially the same radius and angular position with respect to the axis of rotation of said crankshaft. 
     
     
         12 . A propulsion apparatus according to  claim 3 , wherein said fin pitching axle and the fin axle are the same. 
     
     
         13 . A propulsion apparatus according to  claim 3 , wherein said pitching mechanism comprises a synchronizing link or gearing connecting said fin pitching axle to said fin axle, and where said synchronizing link is arranged for synchronizing rotation of said fin axle with rotation of said fin pitching axle. 
     
     
         14 . A propulsion apparatus according to  claim 13 , wherein said fin axle is parallel to said fin pitching axle. 
     
     
         15 . A propulsion apparatus according to  claim 13 , wherein a gearing is arranged between said fin axle and said fin pitching axle, so that said fin axle is arranged at an angle apart from zero to said fin pitching axle. 
     
     
         16 . A propulsion apparatus according to  claim 13 , wherein said apparatus comprises two or more fins connected to said same fin pitching axle via at least one synchronizing link. 
     
     
         17 . A propulsion apparatus according to  claim 2 , wherein said apparatus comprises means for adjusting the angle between said fin pitching axle and said push/pull rod or said pitcher rod. 
     
     
         18 . A propulsion apparatus according to  claim 4 , wherein said apparatus comprises means for adjusting the angle between said fin pitching axle and said push/pull rod or said pitcher rod.