Marine propulsion and constructional details thereof

Abstract

A hub ( 101 ) for a marine propeller, the hub being formed from first ( 1012 ) and second ( 1011 ) cooperating sections which, when forming the hub, are aligned along the rotational axis of the hub, wherein the two cooperating sections define a plurality of recesses ( 1061 ) into each of which a fin assembly can be inserted, thereby forming a propeller, and wherein of the first and second sections, only the first cooperating section is arranged to be connected, in use, to a drive shaft.

1 . A hub for a marine propeller, the hub being formed from first and second cooperating sections which, when forming the hub, are aligned along the rotational axis of the hub;
 wherein the two cooperating sections define a plurality of recesses into each of which a fin assembly can be inserted, thereby forming a propeller; and   wherein of the first and second sections, only the first cooperating section is arranged to be connected, in use, to a drive shaft.   
   
   
       2 . A hub according to  claim 1 , wherein the first and second cooperating sections define a hollow interior to the hub into which control mechanisms for controlling movement of the fins can be placed. 
   
   
       3 . A hub according to  claim 1 , wherein a plurality of axially extending, circumferentially arrayed holes are provided in the first cooperating section for, in use, connection to a drive shaft. 
   
   
       4 . A hub array according to  claim 3 , wherein the number of holes is twice the number of recesses. 
   
   
       5 . A hub according to  claim 1 , further comprising:
 a plurality of substantially identical fin assemblies, one in each of the recesses.   
   
   
       6 . A hub according to  claim 5 , further comprising one or more control mechanisms within the hub and connected to each of the fins for controlling the pitch, and/or rake and/or dihedral of each fin. 
   
   
       7 . A modular propeller system having:
 a plurality of substantially identical fin assemblies; and   a plurality of hubs according to any one of the preceding claims, each hub being arranged to receive a different number of the substantially identical fin assemblies;   wherein a propeller of the desired number of fins can be created by the selection of the appropriate hub and the required number of the substantially identical fin assemblies.   
   
   
       8 . A system according to  claim 7 , wherein each fin assembly comprises a turret on which the fin is mounted, the turret being arranged to be connected, in use, to an engagement means in one of the hubs. 
   
   
       9 . A system according to  claim 8 , wherein, in use, each fin assembly is connected directly to the hub. 
   
   
       10 . A system according to  claim 7 , wherein each hub is provided with a plurality of engagement means, each engagement means being associated with a respective fin assembly. 
   
   
       11 . A system according to  claim 10 , wherein each engagement means on each hub of the plurality of hubs is identical.