Propeller pod

Abstract

The invention relates to a propeller pod ( 14 ) having a body ( 16 ) which has a shaft ( 18 ) for attachment to a vehicle ( 10 ), in particular to a watercraft, wherein the shaft ( 18 ) extends along a shaft axis (A S ) and has at least one cross section (Q) with a chord (S), and (b) at least one propeller shaft ( 20, 24 ) for attachment of a propeller ( 22 ), (c) wherein the chord (S) runs at a direction angle (α) with respect to a propeller rotation axis (A P ) of the propeller shaft ( 20, 24 ). The invention provides that the direction angle (α) changes, at least in places, with the distance (r) from the propeller rotation axis (A P ).

1 . A propeller pod ( 14 ) having
 (a) a body ( 16 ) which
 (i) has a shaft ( 18 ) for attachment to a vehicle ( 10 ), in particular to a watercraft, 
 (ii) wherein the shaft ( 18 ) extends along a shaft axis (A S ) and has at least one cross section (Q) with a chord (S), and 
   (b) at least one propeller shaft ( 20 ,  24 ) for attachment of a propeller ( 22 ),   (c) wherein the chord (S) runs at a direction angle (α) with respect to a propeller rotation axis (A P ) of the propeller shaft ( 20 ,  24 ),   wherein   (d) the direction angle (α) changes, at least in places, with a distance (r) from the propeller rotation axis (A P ).   
     
     
         2 . The propeller pod according to  claim 1 , comprising
 a traction propeller shaft ( 20 ) for rotation of a traction propeller ( 22 ) and   a pusher propeller shaft ( 24 ) for rotation of a pusher propeller ( 26 ),   wherein the shaft ( 18 ) is arranged between the traction propeller ( 22 ) and the pusher propeller ( 26 ) with respect to a longitudinal axis of the body ( 16 ).   
     
     
         3 . The propeller pod according to  claim 2 , wherein
 the traction propeller shaft ( 20 ) is designed to rotate the traction propeller ( 22 ) in a traction propeller rotation direction (ω 22 ), and   the pusher propeller shaft ( 24 ) is designed to rotate the pusher propeller ( 26 ) in a pusher propeller rotation direction (ω 26 ), which is opposite the traction propeller rotation direction (ω 22 ).   
     
     
         4 . The propeller pod according to  claim 1 , wherein the direction angle (α) passes through a direction angle maximum as a function of a distance (r) from the traction propeller rotation axis (A P ). 
     
     
         5 . The propeller pod according to  claim 4 , wherein the distance (r) which is associated with the direction angle maximum is at most 0.6 times a propeller radius (R). 
     
     
         6 . The propeller pod according to  claim 1 , wherein
 the traction propeller ( 22 ) has a downstream flow angle ( 8 ), at which water conveyed by the traction propeller ( 22 ) flows away from the traction propeller ( 22 ), on a longitudinal plane (E L ) which runs parallel through the traction propeller rotation axis (A P ) and through the shaft ( 18 ), and   the direction angle (α) differs by at most 10°, in particular by at most 5°, from the downstream flow angle (δ).   
     
     
         7 . The propeller pod according to  claim 1 , wherein, at least in places, the cross sections (Q) of the shaft ( 18 ) are similar in the geometric sense with respect to a cylindrical coordinate system with the origin on the traction propeller rotation axis (A P ). 
     
     
         8 . The propeller pod according to  claim 1 , wherein, at least in places, the cross sections (Q) of the shaft ( 18 ) are essentially minor-image symmetrical with respect to a mirror plane on which the chord runs, with respect to the cylindrical coordinate system with the origin on the traction propeller rotation axis (A P ). 
     
     
         9 . The propeller pod according to  claim 1 , wherein, at least in places, the cross sections (Q) of the shaft ( 18 ) have a thickness setback (D) of more than 40% and in particular of less than 60%. 
     
     
         10 . The propeller pod according to  claim 1 , wherein a projection of an incident-flow edge ( 28 ) of the shaft ( 18 ) onto a lateral plane (E Q ) which is at right angles to the traction propeller rotation axis (A P ) has a curved profile, at least in places. 
     
     
         11 . The propeller pod according to  claim 1 , wherein, at least in places,
 each cross section (Q) has two outermost points (P 1 , P 2 ) of maximum discrepancy from the chord (S) and   a thickness setback point (P D ) at which the chord (S) is cut by a connection straight line through the outermost points (P 1 , P 2 ),   wherein the thickness setback points (P D ) lie on a curve which is curved at least in places.   
     
     
         12 . The propeller pod according to  claim 1 , having
 a drive shaft ( 34 ) for driving the traction propeller ( 22 ) and/or the pusher propeller ( 26 ),   wherein, at least in places, the drive shaft ( 34 ) runs through an interior ( 40 ) of the cross section (Q), wherein the area of the interior ( 40 ) is one quarter of the area of the cross section (Q), and has the same centroid.   
     
     
         13 . The propeller pod according to  claim 1 , wherein a projection of the shaft ( 18 ) onto the lateral plane (E Q ) is concave or bi-concave. 
     
     
         14 . The propeller pod according to  claim 1 , wherein the direction angle (α) has a minimum adjacent to the marine vessel hull ( 12 ). 
     
     
         15 . A marine vessel ( 10 ) having at least one propeller pod ( 14 ) according to  claim 1 . 
     
     
         16 . The marine vessel ( 10 ) according to  claim 15 , having two and only two propeller pods ( 14 ) according to  claim 1 . 
     
     
         17 . The marine vessel ( 10 ) according to  claim 15 , wherein the marine vessel is a yacht.