Apparatus and system for propeller blade forward retention

Abstract

An apparatus and system for a marine propeller assembly are provided. A forward retention member that may be used with the marine propeller assembly includes a planar base, a drive shaft engagement end opposite the planar base, and a conic body extending therebetween along a centerline normal to the planar base. The forward retention member also includes at least one protuberance extending radially away from a surface of the conic body, the protuberance extending axially from the planar base arcuately convergent to a predetermined point between the planar base and the drive shaft engagement end.

What is claimed is: 
     
         1 . A forward retention member for a propeller assembly, said forward retention member comprising:
 a planar base, a drive shaft engagement end opposite said planar base, and a conic body extending therebetween along a centerline normal to said planar base; and   at least one protuberance extending radially away from a surface of said conic body, said protuberance extending axially from said planar base arcuately convergent to a predetermined point between said planar base and said drive shaft engagement end.   
     
     
         2 . The forward retention member of  claim 1 , wherein said conic body is truncated at said drive shaft engagement end. 
     
     
         3 . The forward retention member of  claim 1 , wherein said at least one of said conic body and said protuberance are at least partially formed of a composite material. 
     
     
         4 . The forward retention member of  claim 1 , wherein said protuberance is configured to align with a complementary hub protuberance of a propeller assembly hub. 
     
     
         5 . The forward retention member of  claim 1 , wherein said conic body and said at least one protuberance are integrally-formed. 
     
     
         6 . The forward retention member of  claim 1 , further comprising a central bore configured to receive a drive shaft. 
     
     
         7 . The forward retention member of  claim 1 , wherein said planar base is configured to couple to a complementary planar hub surface of a propeller assembly hub. 
     
     
         8 . A marine propeller assembly comprising:
 a hub comprising a forward face, an aft face, and a hub body extending therebetween, said hub configured to couple to a rotatable drive shaft, the hub further configured to receive a plurality of propeller blades spaced circumferentially around said hub;   a forward retention member configured to couple to said forward face, said forward retention member comprising:
 a planar base, a drive shaft engagement end opposite said planar base, and a truncated conic body extending therebetween along a centerline normal to said planar base; 
 a central bore configured to receive a drive shaft and 
 at least one protuberance extending radially away from a surface of said conic body, said protuberance extending axially from said planar base arcuately convergent to a predetermined point between said planar base and said drive shaft engagement end. 
   
     
     
         9 . The marine propeller assembly of  claim 8 , wherein said conic body is at least partially formed of a composite material. 
     
     
         10 . The marine propeller assembly of  claim 8 , wherein said protuberance is at least partially formed of a composite material. 
     
     
         11 . The marine propeller assembly of  claim 8 , wherein said protuberance is configured to hydrodynamically transition a shape of the conic body into a shape of a respective propeller blade of the plurality of propeller blades. 
     
     
         12 . The marine propeller assembly of  claim 8 , wherein said conic body and said at least one protuberance are integrally-formed. 
     
     
         13 . The marine propeller assembly of  claim 8 , wherein said conic body is at least one of centrifugal catenary-shaped and arcuate A-frame shaped in cross-section. 
     
     
         14 . The marine propeller assembly of  claim 8 , wherein said planar base is configured to couple to a complementary planar hub surface of a propeller assembly hub. 
     
     
         15 . A marine propulsion system comprising:
 a rotatable drive shaft extending away from a hull of a water craft;   a hub comprising a forward face, an aft face, and a hub body extending therebetween, said hub body formed of at least one of a metal material and a composite material, said hub body coupled to said drive shaft, said hub comprising a plurality of circumferentially-spaced composite propeller blades; and   a forward retention member configured to couple to said forward face, said forward retention member comprising:
 a planar base, a drive shaft engagement end opposite said planar base, and a conic body extending therebetween along a centerline normal to said planar base; and 
 at least one protuberance extending radially away from a surface of said conic body, said protuberance extending axially from said planar base arcuately convergent to a predetermined point between said planar base and said drive shaft engagement end. 
   
     
     
         16 . The marine propulsion system of  claim 15 , wherein at least some of said plurality of composite propeller blades comprise:
 a cavity formed in an interior space of the composite propeller blades; and   a filler material at least partially filling said cavity.   
     
     
         17 . The marine propulsion system of  claim 15 , wherein at least some of said plurality of composite propeller blades comprise a dovetail formed of at least one of a metal material and a composite material. 
     
     
         18 . The marine propulsion system of  claim 15 , wherein at least some of said plurality of composite propeller blades comprise:
 a plurality of structural members coupled together to form an interior propeller frame;   a filler material positioned between said plurality of structural members; and   a plurality of tows of composite material at least partially surrounding said interior propeller frame and said filler material.   
     
     
         19 . The marine propulsion system of  claim 15 , wherein said protuberances comprise blade extensions configured to hydrodynamically meld a shape of a respective propeller blade of the plurality of propeller blades into a shape of the conic body. 
     
     
         20 . The marine propulsion system of  claim 15 , wherein said conic body is truncated at said drive shaft engagement end.