Variable pitch propeller having locking insert

• US 5,520,515 A
• Filed: 05/23/1995
• Issued: 05/28/1996
• Est. Priority Date: 05/23/1995
• Status: Expired due to Term

• Current Assignee: Bailsco Blades & Casting, Inc.
• Original Assignee: Bailsco Blades & Casting, Inc.
• Inventors: Bailey, Fred W., Low, Robert D.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): Lee, Michael S.
• Application Number:
  US08/447,816
• Time in Patent Office: 371 Days
• Field of Search: 416/208, 416/214 R, 416/ 220
• US Class Current: 416/208
• CPC Class Codes: F04D 29/36 adjustable flexible blades F04D29/382

Abstract

A variable pitch propeller has a two part hub assembly, each part of the hub has generally semi-cylindrical half sockets formed therein for receiving the cylindrical blade root shanks of individual fan blades. The sockets have enlarged portions, defining semi-annular shoulders, which receive an enlarged portion of the blade root shank so as to prevent axial movement of the fan blade. The half sockets of at least one part of the hub further have recessed portions for receiving locking insert members having a curved upper surface and a longitudinal keyway formed therein. A radially projecting key extends longitudinally along at least an a portion of the blade root shank and fits into the keyway formed in the locking insert member when the fan blade is placed into the half socket containing the locking insert member. The two parts of the hub assembly are coupled to clamp the fan blades within the aligned half sockets. With the key of the root shank disposed in the keyway of the locking insert member, pitch-wise rotation of the blade is prevented, the orientation of the keyway in the locking insert defining the pitch angle of the blade.

Claims

1. A variable pitch propeller comprising:

a hub assembly comprising;

first and second hub portions, each of said first and second hub portions having a plurality of generally semi-cylindrical half sockets formed therein, each said half socket of at least one of said first and second hub portions having a recessed portion formed therein, said first hub portion being selectively coupled to said second hub portion so that said half sockets of said first hub portion align with said half sockets of said second hub portion to form a plurality of blade sockets;

a fan blade extending from each of said plurality of blade sockets and being clamped therein when said first hub portion is coupled to said second hub portion, said fan blade comprising;

a foil portion; and

a cylindrical blade root shank extending axially from an end of said foil portion, said blade root shank having a key projecting radially from said blade root shank and extending longitudinally along at least a portion of said blade root shank; and

a locking insert member disposed in each said recessed portion, said locking insert member having a longitudinal keyway formed therein for receiving said key projecting from said blade root shank when said blade root shank is placed into said half socket containing said locking insert member, thereby determining pitch of said fan blade and preventing pitch-wise rotation of said fan blade when said fan blade is clamped between said first and second hub portions.

2. The propeller of claim 1 wherein each of said plurality of half sockets further includes an enlarged cylindrical portion defining an inwardly facing semi-annular shoulder and each said blade root shank further includes an enlarged cylindrical head defining an annular shoulder, said inwardly facing shoulders of said half sockets of said first hub portion aligning with said inwardly facing shoulders of said half sockets of said second hub portion when said first and second hub portions are coupled, said annular shoulder of said blade root shank abutting said inwardly facing shoulders of said half sockets of said first and second hub portions to prevent axial movement of said fan blade when said blade root shank is clamped between said first and second hub portions.

3. The propeller of claim 1 further including a tapered bushing for coupling said first hub portion to a drive shaft.

4. The propeller of claim 3 wherein said second hub portion provides a center opening to permit access to said tapered bushing and said second hub portion further includes a closure piece to cover said center opening when said propeller is assembled.

5. The propeller of claim 1 wherein said first and second hub portions are coupled together by means of threaded fasteners.