Wound dovetail wedge for marine propeller retention

Abstract

A marine propeller composite blade an axially extending composite blade root including a dovetail wound in a partial spiral or helix around a centerline. Dovetail tapering down in width between clockwise and counter-clockwise dovetail sides of dovetail from dovetail bottom in a radially outwardly direction away from centerline. Marine propeller may include composite blade roots mounted in axially extending hub slots in a metallic hub, axially extending wedges disposed within the hub slots circumferentially between the blade roots and one of clockwise slot sides and counter-clockwise slot sides, and the wedges abutting the blade roots and the one of clockwise slot sides and counter-clockwise slot sides. Wedges and hub slots wound in a partial spiral or helix around a centerline. Radial retention means for radially retaining wedges in hub slots may include bolts engaging wedges and screwed into threaded holes in hub.

What is claimed: 
     
         1 . A marine propeller blade comprising:
 a composite propeller blade with an axially extending composite blade root, and   the blade root including a dovetail wound in a partial spiral or helix around a centerline.   
     
     
         2 . The marine propeller blade as claimed in  claim 1  further comprising the dovetail tapering down in width between clockwise and counter-clockwise dovetail sides of the dovetail from a dovetail bottom in a radially outwardly direction away from the centerline. 
     
     
         3 . The marine propeller blade as claimed in  claim 2  further comprising the composite propeller blade including a blade suction or forward side and a pressure or aft side extending from the blade root to a blade tip. 
     
     
         4 . The marine propeller blade as claimed in  claim 3  further comprising the blade tip representing a maximum reach of the composite propeller blade from the centerline and separating leading and trailing edges of the blade. 
     
     
         5 . A marine propeller comprising:
 a metallic hub and blade assembly including composite blades with axially extending composite blade roots mounted in axially extending hub slots in a metallic hub,   axially extending wedges disposed within the hub slots circumferentially between the blade roots and one of clockwise slot sides and counter-clockwise slot sides, and   the wedges abutting the blade roots and the one of clockwise slot sides and counter-clockwise slot sides.   
     
     
         6 . The marine propeller as claimed in  claim 5  further comprising a radial retention means for radially retaining and securing the wedges in the hub slots. 
     
     
         7 . The marine propeller as claimed in  claim 6  further comprising the radial retention means including bolts engaging the wedges and screwed into threaded holes in the hub at a slot bottom of the hub slot. 
     
     
         8 . The marine propeller as claimed in  claim 5  further comprising each blade root including a dovetail wound in a partial spiral or helix around the centerline and the dovetail tapering down in width between circumferentially spaced apart clockwise and counter-clockwise dovetail sides of the dovetail in a radially outwardly direction away from the centerline. 
     
     
         9 . The marine propeller as claimed in  claim 8  further comprising a radial retention means for radially retaining and securing the wedges in the hub slots. 
     
     
         10 . The marine propeller as claimed in  claim 9  further comprising the radial retention means including bolts engaging the wedges and screwed into threaded holes in the hub at a slot bottom of the hub slot. 
     
     
         11 . The marine propeller as claimed in  claim 10  further comprising each composite propeller blade including a blade suction or forward side and a pressure or aft side and a blade tip representing a maximum reach of the composite propeller blade from the centerline and separating leading and trailing edges of the blade. 
     
     
         12 . The marine propeller as claimed in  claim 5  further comprising:
 each blade root including a dovetail tapering down in width between circumferentially spaced apart clockwise and counter-clockwise dovetail sides of the dovetail from a dovetail bottom in a radially outwardly direction away from the centerline, 
 each wedge tapering down in width between clockwise and counter-clockwise wedge sides in a radially inwardly direction from a wedge outer surface towards the axis or centerline of the hub, and 
 the dovetails and the wedges wound in partial spirals or helixes around the centerline. 
 
     
     
         13 . The marine propeller as claimed in  claim 12  further comprising:
 a first one of the clockwise and counter-clockwise wedge sides abutting and flush and conformal with a first one of the counter-clockwise dovetail sides respectively, 
 a second one of the clockwise and counter-clockwise wedge sides abutting and flush and conformal with a second one of the counter-clockwise dovetail sides respectively, 
 an obtuse dovetail angle extending between a second one of counter-clockwise slot sides and a slot bottom of the hub slot, and 
 an acute dovetail angle extending between a first one of the counter-clockwise slot sides and the slot bottom of the hub slot. 
 
     
     
         14 . The marine propeller as claimed in  claim 13  further comprising the hub slots wound in partial spirals or helixes around the centerline. 
     
     
         15 . The marine propeller as claimed in  claim 14  further comprising a radial retention means for radially retaining and securing the wedges in the hub slots. 
     
     
         16 . The marine propeller as claimed in  claim 15  further comprising the radial retention means including bolts engaging the wedges and screwed into threaded holes in the hub at a slot bottom of the hub slot. 
     
     
         17 . The marine propeller as claimed in  claim 16  further comprising each composite propeller blade including a blade suction or forward side and a pressure or aft side and a blade tip representing a maximum reach of the composite propeller blade from the centerline and separating leading and trailing edges of the blade. 
     
     
         18 . A marine propeller metallic hub comprising hub slots axially extending through a metallic hub for receiving blade roots of blades and the hub slots wound in partial spirals or helixes around a centerline of the hub. 
     
     
         19 . The marine propeller as claimed in  claim 18  further comprising:
 the hub slots including circumferentially spaced apart counter-clockwise slot sides and a slot bottom therebetween, 
 an obtuse dovetail angle extending between a second one of the counter-clockwise slot sides and the slot bottom, and 
 an acute dovetail angle extending between a first one of the counter-clockwise slot sides and the slot bottom. 
 
     
     
         20 . The marine propeller as claimed in  claim 19  further comprising the metallic hub being conical or cylindrical.