Rudder arrangement for ships having higher speeds comprising a cavitation-reducing twisted, in particular balanced rudder

A rudder arrangement for ships having higher speeds comprising a cavitation-reducing twisted, in particular balanced rudder, comprising a rudder blade with a propeller (115) arranged on a drivable propeller axis (PA), which is associated with the rudder blade, and a rudder post (140) connected to the rudder blade (100), wherein the rudder arrangement (200)

• a.) comprises of a balanced rudder blade (100) preferably having a slender profile with a small profile thickness, comprising two superposed rudder blade sections (10, 20) having the same or different heights, preferably comprising a lower rudder blade section (20) having a smaller height compared with the height of the upper rudder blade section (10) and comprising nose strips (11, 21) facing the propeller (115), having an approximately semicircular profile, which are positioned in such a manner that one nose strip (11) is offset to port (BB) or starboard (SB) and the other nose strip (21) is laterally offset to starboard (SB) or port (BB) with respect to the longitudinal central line (LML) of the rudder blade (100), wherein the side wall surfaces (12, 13;
• 22, 23) of the two rudder blade sections (10, 20) converge into an end strip (15) facing away from the propeller (115),
• a1.) wherein the two nose strips (11, 21) and the end strip (15) run downwards in a conically tapering manner accompanied by a reduction in the cross-sectional areas (30) from the upper region (OB) to the lower region (UB) of the rudder blade (100),
• a2.) or the end strip (15) runs rectilinearly and parallel to the rudder post (140) and the two nose strips (11, 21) run downwards in a conically tapering manner accompanied by a reduction in the cross-sectional areas (30) from the upper region (OB) to the lower region (UB),
• a3.) wherein the cross-sectional surface sections (31) of the upper rudder blade section (10) and the lower rudder blade section (20) in the region between the end strip (15) and the greatest profile thickness (PD) of the rudder blade (100) have a length (L), which is equal to at least 1½ times the length (L1) of the cross-sectional surface sections (32) of the upper rudder blade section (10) and the lower rudder blade section (20) between the greatest profile thickness (PD) of the rudder blade (100) and the nose strips (11, 21),
• a4.) wherein the upper rudder blade section (10) on the port side (BB) and the lower rudder blade section (20) on the starboard side (SB) each comprise a side wall section (18, 28) running in a flat arcuate manner and extending from the nose strips (11, 21) in the direction of the end strip (15), having a length (L2) which extends over the length (L′2) of the side wall sections (18) from the nose strips (11, 21) as far as the greatest profile thickness (PD) plus a length (L″2) which corresponds to at least ⅓ of the length (L′2), wherein the side wall section (18, 28) running in a flat arcuate manner is adjoined by the rectilinearly running side wall section (16, 26) which runs out in the end strip (15),
• a5.) wherein the upper rudder blade section (10) on the port side (BB) and the lower rudder blade section (20) on the starboard side (SB) each comprise a highly curved side wall section (19, 29) running in an arcuate manner and extending from the nose strips (11, 21) in the direction of the end strip (15), having a length (L3) which extends over the length (L′3) of the side wall sections (19) from the nose strips (11, 21) as far as the greatest profile thickness (PD) plus a length (L″3) which corresponds to at least ⅓ of the length (L′3), wherein the highly curved side wall section (19, 29) running in an arcuate manner is adjoined by the rectilinearly running side wall section (17, 27) which runs out in the end strip (15),
• a6.) wherein the two rectilinearly running side wall sections (16;
• 17;
• 26, 27) have the same lengths in pairs and the cross-sectional surface sections located between the two side wall sections (16, 17;
• 26, 27) are the same size and are configured symmetrically and
• a7.) wherein the distance between the side wall section (18;
• 28) running in a flat arcuate manner from the longitudinal central line (LML) is greater than the distance between the highly arcuately running side wall section (19;
• 29) from the longitudinal central line (LML) and the cross-sectional surface sections located between the two side wall sections (18;
• 28) running in a flat arcuate manner on both sides of the longitudinal central line (LML) are configured asymmetrically and is
• b.) comprised of a rudder post (140) cooperating functionally with the rudder blade (100), having at least one bearing,
• b1.) wherein the rudder post (140), in particular made of forged steel or another suitable material, together with the rudder pipe (120) receiving said post, in particular made of forged steel or another suitable material is arranged in the area of the greatest profile thickness (PD) or between this and the nose strips of the upper rudder blade section (10) therein and extends with its end fastening device (145) over the entire height of the upper rudder blade section (10),
• b2.) wherein the rudder pipe (120) for the rudder post (140) which is drawn deeply into the upper rudder blade section (10) as a cantilever is provided with a central longitudinal hole (125) for receiving the rudder post (140),
• b3.) wherein the rudder pipe cross-section is designed as thin-walled and the rudder pipe (120) preferably has a collar bearing (130) on the inner wall side in the area of its free end for mounting the rudder post (140), and
• b4.) wherein in an end region (140b) thereof rudder post (140) is guided out from the rudder pipe (120) with a section (140a) and the end of this section (140a) is connected to the upper rudder blade section (10).