US20150110630A1 - Retention assembly for a propeller blade - Google Patents
Retention assembly for a propeller blade Download PDFInfo
- Publication number
- US20150110630A1 US20150110630A1 US14/056,322 US201314056322A US2015110630A1 US 20150110630 A1 US20150110630 A1 US 20150110630A1 US 201314056322 A US201314056322 A US 201314056322A US 2015110630 A1 US2015110630 A1 US 2015110630A1
- Authority
- US
- United States
- Prior art keywords
- propeller blade
- inch
- assembly
- outer ring
- retention assembly
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
- F01D5/12—Blades
- F01D5/14—Form or construction
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C11/00—Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft
- B64C11/02—Hub construction
- B64C11/04—Blade mountings
- B64C11/06—Blade mountings for variable-pitch blades
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C11/00—Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft
- B64C11/16—Blades
- B64C11/20—Constructional features
- B64C11/26—Fabricated blades
Abstract
A retention assembly for a propeller blade includes an inner ring that is conformally shaped to a bore of an annular loop, the annular loop being associated with a root portion of the propeller blade; a base that is configured to be immediately adjacent the annular loop; an outer ring that includes an extended tapered portion which decreases in radial thickness from an inboard end to an outboard end; and an adhesive that adhesively connects complementary surfaces of the outer ring and the annular loop. Also, a propeller blade assembly includes a propeller blade having a blade portion and a root portion and the retention assembly configured to be attached to the propeller blade.
Description
- The subject matter disclosed herein relates generally to propeller systems and blades and, more particularly, to a lightweight propeller blade assembly with an improved retention capacity for lower centrifugal loads.
- Modern propeller blades typically incorporate composite materials that reduce weight and enhance performance. The composite blades typically include a blade portion and a root portion which extends into a hub arm of the hub of a propeller system and which is secured to and rotatable relative to the hub arm via a retention assembly. A challenge with lightweight composite blades is that a bending moment (BM) capacity of the retention assembly to the hub arm is often reduced due to a lower centrifugal load (CL) of the blade. A typical lightweight propeller blade using a type of arrangement to address BM includes the system shown in U.S. Pat. No. 6,676,080. As can be seen from the drawings of this patent, the bearing races are sized for bearings that can withstand bending moments, but the interface between the composite blade and outer ring bearing race may become unloaded due to insufficient centrifugal loading. This is an undesirable condition which may reduce the life of the composite blade portion and/or outer ring.
- Thus, there is a need for a lightweight propeller blade with an improved retention capacity that can withstand high bending moments at lower centrifugal loading.
- According to an aspect of the invention, a retention assembly for a propeller blade includes an inner ring that is conformally shaped to a bore of an annular loop, the annular loop being associated with a root portion of the propeller blade; a base that is configured to be immediately adjacent the annular loop; an outer ring that includes an extended tapered portion which decreases in radial thickness from an inboard end to an outboard end; and an adhesive that adhesively connects complementary surfaces of the outer ring and the annular loop.
- According to another aspect of the invention, a propeller blade assembly includes a propeller blade including a blade portion and a root portion; and a retention assembly configured to be attached to the propeller blade. The retention assembly further includes an inner ring that is conformally shaped to a bore of an annular loop, the annular loop being associated with the root portion; a base that is configured to be immediately adjacent the annular loop; an outer ring that includes an extended tapered portion which decreases in radial thickness from an inboard end to an outboard end; and an adhesive that adhesively connects complementary surfaces of the outer ring and the annular loop.
- Other aspects, features, and techniques of the invention will become more apparent from the following description taken in conjunction with the drawings.
- The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which like elements are numbered alike in the several FIGURES:
-
FIG. 1 is a plan view of an aircraft according to an embodiment of the invention; and -
FIG. 2 is a cross-sectional view of a propeller blade assembly ofFIG. 1 according to an embodiment of the invention. - Referring to the drawings,
FIG. 1 is a plan view of anaircraft 10 having a plurality of lightweight propeller blade assemblies 22 with an improved retention capacity according to an embodiment of the invention. Theaircraft 10 includes afuselage 12, acockpit 14, and atail 16. Attached to thefuselage 12 are left andright wings wing respective propeller propeller propeller blade assemblies 22 that are driven for rotation by respectivegas turbine engines specific aircraft 10 is illustrated and described herein, other propeller driven aircrafts are within the scope of the invention. - Referring to
FIG. 2 , a cross-section view of a lightweightpropeller blade assembly 22 that has an improved retention capacity is illustrated according to an embodiment of the invention. Thepropeller blade assembly 22 includes apropeller blade 30 that is received and secured to aretention assembly 32. Thepropeller blade 30 includes ablade portion 34 that terminates into aroot portion 36. Thepropeller blade 30 is generally cylindrical in shape atroot portion 36 and transitions to an airfoil shape that thins and flattens toward a tip (not shown) which is directionallyopposite root portion 36 in a direction of arrow 39 (i.e., from inboard/hub end to an outboard/tip end of the propeller blade 30). In embodiments, the shape ofpropeller blade 30 may also spiral or twist toward the tip (not shown) in a known manner according to the type of propeller blade that is used. In embodiments,propeller blade 30 includingblade portion 34 androot portion 36 may be constructed of one or more layers of unidirectional and/or woven glass fibers, and one or more layers of unidirectional and/or woven graphite fibers that are embedded in a suitable resin material as is well-known to a person of ordinary skill in the art. Theroot portion 36 is configured to attach to aretention assembly 32. It is to be appreciated that theretention assembly 32 is configured to attach to thepropeller blade 30 and provide an improved retention capacity for high blade moments and lower centrifugal loads, as will be described in greater detail below. - The
root portion 36 includes anannular loop 38 that forms a teardrop-shaped bore 41.Retention assembly 32 includes aninner ring 40, an extendedouter ring 42, and a generally cup-shaped base 44. In embodiments,rings base 44 may be machined from aluminum material, but may alternatively be constructed of other materials, such as steel, composites, or the like. Also,inner ring 40 is conformally shaped to the bore 41 (i.e.,inner ring 40 may include a tear-drop shaped cross-section) and is located inside thebore 41. Thebase 44 is positioned immediately adjacentannular loop 38 and includes alower end 46, awall 48, and alateral portion 49. Thewall 48 extends upwardly fromlower end 46 into a hollow root cavity 52 and is in frictional engagement with aninner surface 50 ofroot portion 36. Also,lateral portion 49 resides inside the hollow root cavity 52. Theannular loop 38 andinner ring 40 are sandwiched betweenbase 44 and extendedouter ring 42. Abalance tube 80 extends through a central opening defined bylateral portion 49 inbase 44. Thebalance tube 80 andlateral portion 49 close hollow root cavity ofroot portion 36 to prevent intrusion of oil and/or moisture into the hollow root cavity 52 which may otherwise damagepropeller blade 30. - The extended
outer ring 42 is generally annular in shape and includes, moving inboard to outboard, abearing race interface 54, abearing race groove 56, a lowerannular groove 57, a plurality offlanges race groove 56, and an upperannular groove 58. Thebearing race interface 54 has a radially internal surface that is complementary to radially outercurved surface 78 ofannular loop 38. Thebearing race groove 56 is a bearing race that receives abearing assembly 70 such as, for example, an angular contact ball bearing assembly, tapered roller bearing assembly, deep groove thrust or roller bearing assembly, two-piece bearing race assemblies, or the like. Although a single bearingrace groove 56 is shown and described, in an embodiment, two or more bearing race grooves substantially similar may also be provided for use with apropeller hub 66 that can use multiple row bearing assemblies. - The
flanges annular groove 57 that is adapted to receive an O-ring 68 while an upperannular groove 58 is adapted to receive a locking ring (not shown) for holdingpropeller blade assembly 22 against movement into thepropeller hub 66 when not in use. Theflanges retaining surface 64 of apropeller hub 66 to contain the O-ring 68. Thebearing race groove 56 cooperates with thehub race groove 82 to contain thebearing assembly 70 and prevent separation ofpropeller blade assembly 22 frompropeller hub 66 when high outward centrifugal force applied in a direction ofarrow 69 during rotation ofpropeller hub 66. Also, upperannular groove 58 terminates into atapered portion 72. Thetapered portion 72 has a length L1 that gets progressively thinner radially frominboard end 72 to anoutboard end 76. In an embodiment,tapered portion 72 has an internal taper along an internal surface of portion 72 (to be conformal to the outer surface of blade portion 34) and an external taper along an outer surface ofportion 72, as illustrated in the figure. In embodiments, thickness oftapered portion 72 frominboard end 74 tooutboard end 76 is reduced between about 0.05 inch (0.127 centimeter) to about 0.10 inch (0.254 centimeter) for every inch (2.54 centimeter) of length oftapered portion 72. In an embodiment, thickness atoutboard end 76 is between about 0.005 inch (0.013 centimeter) to about 0.035 inch (0.089 centimeter). In an embodiment, length L1 is about 0.5 inch (1.270 centimeter) to about 2 inch (5.080 centimeter). Also, an adhesive is utilized along complementary mutual interfaces of extendedouter ring 42 androot portion 36 in order to adhesively connect the mutual interfaces (or complementary surfaces). As illustrated inFIG. 2 , mutual interfaces include, onpropeller blade 30, an outercurved surface 78 ofannular loop 38 moving upwards toblade portion 34 which contacts, onretention assembly 32, a radially internal surface ofbearing race interface 54 tooutboard end 76 ofouter ring 42. In embodiments, the adhesive could be a structural adhesive such as an epoxy and/or a compliant adhesive such as polyurethane, polysulfide or RTV silicone. In one example, Hysol® EA 9346.5 epoxy paste adhesive manufactured by the Henkel Corporation may be used as the structural adhesive. - In prior art propeller blades, the retention capacity of an interface between the composite blade and outer ring bearing race may become unloaded due to insufficient centrifugal loading which may reduce the life of the blade portion and/or the outer ring of the propeller blade. However, benefits of the present invention with a use of the
outer ring 42 and an adhesive to coupled mutual interfaces is an improved retention capacity for use with lightweight composite propeller blades. The retention capacity is facilitated with aretention assembly 32 having an added length ofouter ring 42 and an adhesive that couples mutual interfaces of thepropeller blade 30. Using the additional length forouter ring 42 and the adhesive increases a bending moment capacity over prior art propeller blades because it prevents thelightweight propeller blade 30 from separating at abearing race interface 54 ofouter ring 42. Additional benefits of using an adhesive is that an adhesive layer between the contact surface ofouter ring 42 and aroot portion 36 ofpropeller blade 30 provides a shear path to direct the bending loads to thebearings 70 thereby preventing unloading of thepropeller blade 30 at thebearing race interface 54. - The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. While the description of the present invention has been presented for purposes of illustration and description, it is not intended to be exhaustive or limited to the invention in the form disclosed. For instance, aspects of the invention are not limited to propeller blades for aircraft, and can be used in wind turbines and other systems with rotary elements. Many modifications, variations, alterations, substitutions, or equivalent arrangement not hereto described will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. Additionally, while the various embodiment of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
Claims (15)
1. A retention assembly for a propeller blade, comprising:
an inner ring that is conformally shaped to a bore of an annular loop, the annular loop being associated with a root portion of the propeller blade;
a base that is configured to be immediately adjacent the annular loop;
an outer ring that includes an extended tapered portion which decreases in radial thickness from an inboard end to an outboard end; and
an adhesive that adhesively connects complementary surfaces of the outer ring and the annular loop.
2. The retention assembly of claim 1 , wherein the extended tapered portion decreases in radial thickness of between 0.05 inch to 0.10 inch for every one inch of length from the inboard end to the outboard end.
3. The retention assembly of claim 1 , wherein a thickness of the outboard end is about 0.005 inch to about 0.035 inch.
4. The retention assembly of claim 1 , wherein the outer ring further comprises a bearing race interface, a bearing race groove, a lower annular groove, and an upper annular groove.
5. The retention assembly of claim 1 , wherein a radial outer surface of the annular loop is adhesively connected to a radial inner surface of the bearing race interface.
6. The retention assembly of claim 1 , further comprising a bearing assembly coupled to the bearing race groove.
7. The retention assembly of claim 1 , wherein a length of the extended tapered portion is about 0.5 inch to about 2 inch.
8. The retention assembly of claim 1 , wherein the extended tapered portion includes a first taper on an inner surface and a second taper on an external surface.
9. A propeller blade assembly, comprising:
a propeller blade including a blade portion and a root portion; and
a retention assembly configured to be attached to the propeller blade, the retention assembly further comprising:
an inner ring that is conformally shaped to a bore of an annular loop, the annular loop being associated with the root portion;
a base that is configured to be immediately adjacent the annular loop;
an outer ring that includes an extended tapered portion which decreases in radial thickness from an inboard end to an outboard end; and
an adhesive that adhesively connects complementary surfaces of the outer ring and the annular loop.
10. The propeller blade assembly of claim 9 , wherein the extended tapered portion decreases in radial thickness of between 0.05 inch to 0.10 inch for every one inch of length from the inboard end to the outboard end.
11. The propeller blade assembly of claim 9 , wherein a thickness of the outboard end is about 0.005 inch to about 0.035 inch.
12. The propeller blade assembly of claim 9 , wherein a length of the extended tapered portion is about 0.5 inch to about 2 inch.
13. The propeller blade assembly of claim 9 , wherein the outer ring further comprises a bearing race interface, a bearing race groove, a lower annular groove, and an upper annular groove.
14. The propeller blade assembly of claim 9 , further comprising a bearing assembly coupled to the bearing race groove.
15. The propeller blade assembly of claim 9 , wherein the extended tapered portion includes a first taper on an inner surface and a second taper on an external surface.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/056,322 US20150110630A1 (en) | 2013-10-17 | 2013-10-17 | Retention assembly for a propeller blade |
EP14188983.2A EP2862799B1 (en) | 2013-10-17 | 2014-10-15 | Retention assembly for a propeller blade |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/056,322 US20150110630A1 (en) | 2013-10-17 | 2013-10-17 | Retention assembly for a propeller blade |
Publications (1)
Publication Number | Publication Date |
---|---|
US20150110630A1 true US20150110630A1 (en) | 2015-04-23 |
Family
ID=51703047
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/056,322 Abandoned US20150110630A1 (en) | 2013-10-17 | 2013-10-17 | Retention assembly for a propeller blade |
Country Status (2)
Country | Link |
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US (1) | US20150110630A1 (en) |
EP (1) | EP2862799B1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20230044779A1 (en) * | 2020-01-20 | 2023-02-09 | Safran Aircraft Engines | Blade comprising a composite material structure and associated manufacturing method |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR3127472A1 (en) | 2021-09-27 | 2023-03-31 | Airbus Helicopters | rotor blade with a system for retaining and absorbing dissociated forces and rotor equipped with such blades |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6305905B1 (en) * | 1999-05-05 | 2001-10-23 | United Technologies Corporation | Bolted-on propeller blade |
US20130094943A1 (en) * | 2010-04-09 | 2013-04-18 | Snecma | Unducted fan for turbine engine |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3734642A (en) * | 1971-06-29 | 1973-05-22 | United Aircraft Corp | Aerodynamic blade root end attachment |
DE2658876C3 (en) * | 1976-12-24 | 1983-11-10 | Hütter, Ulrich, Prof. Dr.-Ing., 7312 Kirchheim | Shell bodies, for example hydrofoils or rotor blades, in composite construction |
US6676080B2 (en) | 2000-07-19 | 2004-01-13 | Aero Composites, Inc. | Composite airfoil assembly |
US8753088B2 (en) * | 2008-02-28 | 2014-06-17 | Textron Innovations Inc. | Propeller blade retention device |
-
2013
- 2013-10-17 US US14/056,322 patent/US20150110630A1/en not_active Abandoned
-
2014
- 2014-10-15 EP EP14188983.2A patent/EP2862799B1/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6305905B1 (en) * | 1999-05-05 | 2001-10-23 | United Technologies Corporation | Bolted-on propeller blade |
US20130094943A1 (en) * | 2010-04-09 | 2013-04-18 | Snecma | Unducted fan for turbine engine |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20230044779A1 (en) * | 2020-01-20 | 2023-02-09 | Safran Aircraft Engines | Blade comprising a composite material structure and associated manufacturing method |
Also Published As
Publication number | Publication date |
---|---|
EP2862799A1 (en) | 2015-04-22 |
EP2862799B1 (en) | 2019-01-30 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: HAMILTON SUNDSTRAND CORPORATION, CONNECTICUT Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NAGLE, DAVID P.;CARVALHO, PAUL A.;SIGNING DATES FROM 20131014 TO 20131015;REEL/FRAME:031426/0372 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |