Unison ring assembly

Abstract

A unison ring assembly comprises a backing plate, and a plurality of pocket-forming portions. The backing plate is formed as an annular disc, with the annular disc being planar in a radial plane of the unison ring assembly. The plurality of pocket-forming portions are equi-spaced circumferentially around the axis of the unison ring assembly, and each of the plurality of pocket-forming portions is attached to the backing plate to form a corresponding radially extending pocket.

Claims

1. A unison ring assembly comprising: a plurality of lever arms; a plurality of pitch change spindles; a planar backing plate; and a plurality of pocket-forming portions, wherein the backing plate is formed as an annular disc, the annular disc being planar in a radial plane of the unison ring assembly, each of the plurality of pocket-forming portions includes a circumferentially extending portion connecting two axially extending portions, the plurality of pocket-forming portions are equi-spaced circumferentially around the axis of the unison ring assembly, and each of the plurality of pocket-forming portions is attached to the backing plate, the backing plate being spaced from the circumferentially extending portion to form a corresponding radially outwardly opening pocket, with each pocket accommodating a respective one of the lever arms, and each lever arm being operably connected to a respective one of the pitch change spindles.

2. The unison ring assembly as claimed in claim 1, wherein each of the plurality of pocket-forming portions is C-shaped in circumferential cross-section.

3. The unison ring assembly as claimed in claim 1, wherein the plurality of pocket-forming portions is formed integrally.

4. The unison ring assembly as claimed in claim 3, wherein the backing plate comprises a plurality of backing plate portions, each of the plurality of backing plate portions corresponding to a respective one of the pocket-forming portions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) There now follows a description of an embodiment of the invention, by way of non-limiting example, with reference being made to the accompanying drawings in which:

(2) FIG. 1 shows a perspective view of a unison ring according to the prior art;

(3) FIG. 2 shows an exploded perspective view of a unison ring assembly according to a first embodiment of the invention;

(4) FIG. 3 shows an exploded perspective view of a unison ring assembly according to a second embodiment of the invention;

(5) FIG. 4 shows an exploded perspective view of a unison ring assembly according to a third embodiment of the invention; and

(6) FIG. 5 shows an exploded perspective view of a unison ring assembly according to a fourth embodiment of the invention.

(7) It is noted that the drawings may not be to scale. The drawings are intended to depict only typical aspects of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements between the drawings.

DETAILED DESCRIPTION

(8) Referring to FIG. 2, a unison ring assembly according to a first embodiment of the invention is designated generally by the reference numeral 100.

(9) The unison ring assembly 100 comprises a backing plate 110 and plurality of pocket-forming portions 120.

(10) The backing plate 110 is formed as an annular disc that is planar in the radial plane 112 of the unison ring assembly 100. The backing plate 110 corresponds functionally to one of the first and second side members 20,30 of the prior art unison ring illustrated in FIG. 1.

(11) Each of the plurality of pocket-forming portions 120 is equi-spaced circumferentially around the axis 102 of the unison ring assembly 100. Each of the plurality of pocket-forming portions 120 comprises a circumferentially extending portion 124 connecting two axially extending portions 126.

(12) In this embodiment, the plurality of pocket-forming portions 120 is integrally formed with one another. In other words the axially extending portion 126 at one end of one pocket-forming portion 120 is connected to and integral with the axially extending portion 126 at the corresponding opposite end of an adjacent pocket-forming portion 120.

(13) The plurality of pocket-forming portions 120 is attached in co-axial alignment to the backing plate 110 such that each pocket-forming portion 120 forms a corresponding radially extending pocket 130.

(14) Each of the plurality of pocket-forming portions 120 is C-shaped when viewed in the circumferential plane 122.

(15) In the present arrangement the backing plate 110 and the plurality of pocket-forming portions 120 are both formed from a titanium alloy. In other arrangements, the backing plate 110 and the plurality of pocket-forming portions 120 may be formed from another metal or metal alloy, or from a fibre-reinforced composite material.

(16) The backing plate 110 and the plurality of pocket-forming portions 120 are welded to one another to form the unison ring assembly 100. In other arrangements, the backing plate 110 and the plurality of pocket-forming portions 120 may be joined to one another by another fastening method such as, for example, bolting, riveting or adhesively bonding.

(17) In use, each of the pockets 130 accommodates a respective one of the lever arms (not shown) that operate the pitch change spindles (also not shown). In this regard, the pockets correspond functionally to the U-shaped channel 50 of the prior art unison ring 10 shown in FIG. 1.

(18) Referring to FIG. 3, a unison ring assembly according to a second embodiment of the invention is designated generally by the reference numeral 200. Features of the unison ring assembly 200 which correspond to those of unison ring assembly 100 have been given corresponding reference numerals for ease of reference.

(19) The unison ring assembly 200 has a backing plate 110 and plurality of pocket-forming portions 220.

(20) Each of the plurality of pocket-forming portions 220 is equi-spaced circumferentially around the axis 102 of the unison ring assembly 200. Each of the plurality of pocket-forming portions 220 comprises a circumferentially extending portion 224 connecting two axially extending portions 226.

(21) In this embodiment, each of the plurality of pocket-forming portions 220 is separate from each other. In other words the axially extending portion 226 at one end of one pocket-forming portion 220 is separate to and spaced apart from the axially extending portion 226 at the corresponding opposite end of an adjacent pocket-forming portion 220.

(22) The plurality of pocket-forming portions 220 is attached in co-axial alignment to the backing plate 110 such that each pocket-forming portion 220 forms a corresponding radially extending pocket 230.

(23) As for the previous embodiment, each of the plurality of pocket-forming portions 220 is C-shaped when viewed in the circumferential plane 222.

(24) In the present arrangement the backing plate 110 and the plurality of pocket-forming portions 220 are both formed from a titanium alloy with the backing plate 110 and the plurality of pocket-forming portions 220 being welded to one another to form the unison ring assembly 200.

(25) Referring to FIG. 4, a unison ring assembly according to a third embodiment of the invention is designated generally by the reference numeral 300. Features of the unison ring assembly 300 which correspond to those of unison ring assembly 100,200 have been given corresponding reference numerals for ease of reference.

(26) The unison ring assembly 300 comprises a backing plate 310 and plurality of pocket-forming portions 120.

(27) The backing plate 310 comprises a plurality of backing plate portions 312. Each of the backing plate portions 312 is equi-spaced circumferentially around the axis 102 of the unison ring assembly 300.

(28) The plurality of backing plate portions 312 are arranged as a segmented annular disc that is planar in the radial plane 112 of the unison ring assembly 300. As for the earlier described embodiments, the backing plate 310 corresponds functionally to one of the first and second side members 20,30 of the prior art unison ring illustrated in FIG. 1.

(29) Each of the plurality of pocket-forming portions 120 comprises a circumferentially extending portion 124 connecting two axially extending portions 126.

(30) In this embodiment, the plurality of pocket-forming portions 120 is integrally formed with one another. In other words the axially extending portion 126 at one end of one pocket-forming portion 120 is connected to and integral with the axially extending portion 126 at the corresponding opposite end of an adjacent pocket-forming portion 120.

(31) The plurality of pocket-forming portions 120 is attached in co-axial alignment to the backing plate 310 such that each pocket-forming portion 120 forms a corresponding radially extending pocket 130.

(32) In this embodiment the backing plate 310 and the plurality of pocket-forming portions 120 are both formed from a titanium alloy with the backing plate 310 and the plurality of pocket-forming portions 120 being welded to one another to form the unison ring assembly 300.

(33) Referring to FIG. 5, a unison ring assembly according to a fourth embodiment of the invention is designated generally by the reference numeral 400. Features of the unison ring assembly 400 which correspond to those of unison ring assembly 300 have been given corresponding reference numerals for ease of reference.

(34) The unison ring assembly 400 comprises a backing plate 310 and plurality of pocket-forming portions 420.

(35) The backing plate 310 comprises a plurality of backing plate portions 312. Each of the backing plate portions 312 is equi-spaced circumferentially around the axis 102 of the unison ring assembly 300.

(36) Each of the plurality of pocket-forming portions 420 comprises a circumferentially extending portion 424 connecting two axially extending portions 426.

(37) As described above with regard to the third embodiment, the plurality of pocket-forming portions 420 is integrally formed with one another. In other words the axially extending portion 426 at one end of one pocket-forming portion 420 is connected to and integral with the axially extending portion 426 at the corresponding opposite end of an adjacent pocket-forming portion 420.

(38) In addition, the plurality of pocket-forming portions 420, which are integrally formed, also include a plurality of recesses 428. Each of these recesses 428 is positioned between adjoining axially extending portions 426 of adjacent pocket-forming portions 420. Each recess extends axially into the integrally formed pocket-forming portions 420.

(39) The plurality of pocket-forming portions 420 is attached in co-axial alignment to the backing plate 310 such that each pocket-forming portion 420 forms a corresponding radially extending pocket 430.

(40) In this embodiment the backing plate 310 and the plurality of pocket-forming portions 420 are both formed from a titanium alloy with the backing plate 310 and the plurality of pocket-forming portions 420 being welded to one another to form the unison ring assembly 300.

(41) The foregoing description of various aspects of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously, many modifications and variations are possible. Such modifications and variations that may be apparent to a person of skill in the art are included within the scope of the invention as defined by the accompanying claims.