US3376018A

US3376018A - Vane operating mechanism

Info

Publication number: US3376018A
Application number: US603652A
Authority: US
Inventors: Williamson Douglas Herbert
Original assignee: Rolls Royce PLC
Current assignee: Rolls Royce PLC
Priority date: 1966-01-10
Filing date: 1966-12-21
Publication date: 1968-04-02
Anticipated expiration: 1985-04-02
Also published as: DE1601625A1; FR1507701A; GB1063602A

Description

April 1968 D. H. WILLIAMSON 3,376,018

VANE OPERATING MECHANISM Filed Dec. 21, 1966 5 Sheets-Sheet l Inventor oVQ/WZUAL IW v v W, W We),

April 1968 D. H. WILLIAMSO N 3,376,018

VANE OPERATING MECHANISM Filed Dec. 21, 1966 5 Sheets-Sheet 2 Inventor flOm aw 7W Wm, M t

A ttorney;

April 1968 D. H. WILLIAMSON 3,376,018

VANE OPERATING MECHANISM Filed Dec. 21, 1966 5 Sheets-Sheet 5 wL-a" A ttorney 3 Unitid States Patent 3,376,018 VANE OPERATING MECHANISM Douglas Herbert Williamson, Derby, England, assiguor to Rolls-Royce Limited, Derby, England, a British company Filed Dec. 21, 1966, Ser. No. 603,652 Claims priority, application Great Britain, Jan. 10, 1966,

1,123/66 10 Claims. (Cl. 253-78) ABSTRACT OF THE DISCLOSURE A vane operating mechanism having a rotatable ring, connected by arms to a spindle extending from each vane root, rotation of the ring eifecting pivotal movement of the vane. One end of each arm is part-spherical and is received by an aperture in the ring, the aperture being so shaped that the arm may be introduced into theaperture, and then turned to lock it in position. Each arm has a flexible portion to accommodate deformation during operation.

This invention concerns avane operating mechanism and, although the invention is not so restricted, it is more particularly concerned with a mechanism for operating variable stator vanes of a gas turbine engine.

The term vanes as used in this specification is to be understood as including blades.

According to the present invention, there is provided a vane operating mechanism comprising at least one ring, means for rotating the or each ring about its axis and through a predetermined angular range, the or each said ring having associated therewith and being axially spaced from a plurality of angularly spaced apart vanes which are arranged about the said axis and each of which has a radially extending spindle rotation of which effects pivotal movement of the respective vane, and an arm connecting each spindle to its ring so that rotation of the latter eiTects pivotal movement of the vanes associated therewith, each arm having a portion which is located in an aperture in its ring and/ or in its spindle, each said portion and aperture being so formed that the portion may be relatively orientated to introduce it into the aperture and then relatively moved within the aperture to lock it in position therein.

Each arm preferably has a flexible part to accommodate the bending to which it is subjected in operation. Thus each said .fiexible part may be a centrally located and relatively thin part of its arm.

The said portion of each arm is preferably part-spherical and is located in a part-spherical aperture, each said portion having been originally introduced into at least one part of the aperture which is non-spherical. Thus, each part-spherical aperture may have two diametrically oppositely disposed straight sided enlarged parts, the said portion of each arm having parallel fiat sides for reception within the said enlarged parts.

Each said aperture is preferably provided in the or a ring, each arm being provided with the said portion at one end thereof and being detachably connected to its spindle at its other end. Thus, the said other end of each arm maybe provided with a threaded spigot which is located freely in a hole in the respective spindle, the spigot having a nut threaded thereon by means of which the arm is bolted to the spindle.

The means for rotating the or each ring may comprise at least one ram which acts directly upon the respective ring or is connected thereto by an operating linkage.

The invention also comprises a gas turbine engine provided with a vane operating mechanism as set forth above. Thus the said vanes may be variable stator vanes of a compressor of the engine.

The invention is illustrated, merely by way of example, in the accompanying diagrammatic drawings, in which:

FIGURE 1 is a view, partly in section, of part of a gas turbine engine provided with a vane operating mechanism in accordance with the present invention,

FIGURE 2 is a broken-away sectional view showing part of the structure of FIGURE 1 on a larger scale,

FIGURE 3 is a broken-away plan view looking in the direction of the arrow 3 of FIGURE 2,

FIGURE 4 is a broken-away sectional. view showing part of the structure of FIGURE 2 on a yet larger scale,

FIGURE 5 is a broken-away sectional view taken on the line 55 of FIGURE 4, and

FIGURE 6 is a broken-away sectional view taken on the line 6-6 of FIGURE 5.

Referring to the drawings, a gas turbine by-pass engine 10 has an engine casing 11 within which there are mounted in flow series a low pressure compressor 12, a high pressure compressor 13, combustion equipment (not shown) and high pressure and low pressure turbines (not shown).

Part of the air compressed by the low pressure compressor 12 passes to a by-pass passage 14, the by-pass passage 14 being disposed between the engine casing 11 and a casing 15 which forms the outer casing of the high pressure compressor 13. The casing 15 is mounted concentrically within the engine casing 11 and is supported therefrom by way of a plurality of angularly spaced apart struts 16.

The high pressure compressor 13 has angularly spaced apart variable stator vanes which are arranged about the engine axis, the vanes 20 being arranged in three axially spaced apart rows. Each of the vanes 20 has radially extending

spindles

19, 21, rotation of the spindle 21 effecting pivotal movement of the respective vane 20.

Each of the sets of vanes 20 has a ring 22 associated with it and disposed axially upstream of it. Each of the rings 22 is mounted concentrically about the engine axis and is rotatable about this axis through a predetermined angular range.

Although the rings 22 are shown disposed axially upstream of the vanes 20, and this is the preferred construction, in some cases the rings 22 could well be disposed downstream of the respective row of vanes 20.

The rotation of the rings 22 is eifected by means of at least one ram 23 (FIGURE 3) which is arranged to move the outer end of an arm 24 of a pivotally mounted bell crank lever 24, 25. The .arm 25 of the bell crank lever 24, 25 is pivotally connected to the most downstream of the rings 22, while the arm 24 is connected to the remaining rings 22 by way of bell crank levers 26, 27 respectively. Thus operation of the ram 23 will move the arm 24 through a small angle and will therefore move the rings 22 through a small angle.

Each of the spindles 21 is connected to its respective ring 22 by means of a substantially axially extending arm 30. Each of the arms 30 has a centrally located and relatively thin part 31 (best seen in FIGURE 4), which is flexible so as to accommodate the bending to which the arm 30 is subjected in operation.

The downstream portion of each of the arms 30 is provided both with a flange 32, which is located against the respective spindle 21, and with a spigot 33 which is located freely in a hole 34 in the respective spindle 21. The downstream end of the spigot. 33 is threaded and has a nut 35 screwed onto it so as to clamp the spindle 21 between the flange 32 and the nut 35.

Each of the arms 30 has an enlarged part-spherical portion 36 at its upstream end, the part-spherical portion 36 being provided with parallel flat sides 37.

Each of the rings 22 is provided with a plurality of angularly spaced apart apertures 40, in each of which is received the part-spherical portion 36 of the respective arm 30. As will be seen from FlGURE 5, each of the apertures 40 is part-spherical and has two diametrically oppositely disposed straight sided enlarged parts 41. The enlarged parts 41 have spaced sides 42 between which the partspherical portion 36 may be passed when the latter is orientated with fiat sides 37 thereof arranged as indicated in dotted lines in FIGURE 5. The part-spherical portion 36, after having been orientated to introduce it into its aperture 40, may then be moved within the aperture through 90 to the full line position shown in FIGURE 5. In this position, which is illustrated in FIGURE 6, the part-spherical portion 36 is locked in the aperture 40.

The vane operating mechanism shown in the drawings may be assembled by attaching all the arms 30 to their respective rings 22 by entering the part-spherical portions 36 through the enlarged parts 41 of the apertures 40 and then twisting the arms 30 through 90 so as to effect engagement between the spherical surfaces of the partspherical portion 36 and aperture 40. The assembly of each ring 22 with its arms 30 can then be slid into position so that the spigots 33 enter the corresponding holes 34 in the sprindles 21, and the nuts 35 can then be placed on the threaded portions of the spigots 33 and can be tightened.

Alternatively, all the arms 30 of each of the rings 22 can be inserted in the respective spindles 21 and the nuts 35 can be loosely applied so that the arms 30 can be rotated in the holes 34. The respective ring 22 can then be oifered up to the upstream ends of the arms 30 with all the arms 30 in the positions indicated in dotted lines in FIGURE 5. This enables the part-spherical portions 36 to slide through the enlarged parts 41. All the arms 30 can then be twisted through 90 and the nuts 35 tightened to complete the assembly.

As will readily be appreciated, the arrangement shown in the drawings, provides a simple, effective, and compact way of effecting pivotal movement of the vanes 20.

Although the invention has been described above in connection with the variable stator vanes 20 of the high pressure compressor 13, it could also of course be used in any compressor, fan or turbine where one or more rows of vanes (or blades) have to be made variable.

I claim:

1. A vane operating mechanism comprising at least one ring, means for rotating said at least one ring about its axis and through a predetermined angular range, a plurality of angularly spaced-apart vanes, associated with each ring and axially spaced therefrom, said vanes being arranged about the said axis and each having a radially extending spindle rotation of which effects pivotal movement of the respective vane, and an arm connecting each spindle to its respective ring, rotation of the latter effecting pivotal movement of the vanes associated therewith, locking means for connecting and positively retaining each arm to its respective ring, said locking means including providing each arm with an integral portion and providing the respective ring with apertures for receiving the integral portion of the arm, each said integral portion and aperture being formed so that the integral portion may be relatively orientated to introduce it into the aperture by relative movement of the integral portion and the aperture substantially parallel to the axis of the ring and then relatively moved within the aperture to engage sides of the aperture and positively retain the integral portion in the aperture.

2. Vane operating mechanism as claimed in claim 1 in which each arm has a flexible part to accommodate the deformation to which it is subjected in operation.

3. Vane operating mechanism as claimed in claim 2 in which each said flexible part is a centrally located and relatively thin part of its arm.

4. Vane operating mechanism as claimed in claim 1, in

P which each said aperture has a spherical part and a nonspherical part and the said integral portion of each arm is part-spherical and is positively retained in the spherical part of the aperture, each said portion having been originally introduced into the said non-spherical part of the aperture.

5. Vane operating mechanism as claimed in claim 4 in which the non-spherical part of each aperture comprises two, diametrically oppositely disposed, straight sided enlarged parts, the said integral portion of each arm having parallel flat sides for reception within the said enlarged parts.

6. Vane operating mechanism as claimed in claim 1, each arm being provided with the said integral portion at one end thereof and being detachably connected to its spindle at its other end.

7. Vane operating mechanism as claimed in claim 6 in which each spindle has a hole therethrough and the said other end of each arm is provided with a threaded spigot which is located freely in the hole in the respective spindle, the spigot having a nut threaded thereon by means of which the arm is bolted to the spindle.

8. Vane operating mechanism as claimed in claim 1 in which the means for rotating each ring comprises at least one ram operatively connected to the at least ring.

9. A gas turbine engine provided with a vane operating mechanism as claimed in claim 1.

10. A gas turbine engine as claimed in claim 9 in which the said vanes are variable stator vanes of a compressor of the engine.

References Cited UNITED STATES PATENTS 2,933,234 4/1960 Neumann 2301 14 2,955,744 10/1960 Hemsworth 230-114 2,976,015 3/1961 Gilbert 25378 2,999,630 9/1961 Warren et al. 253-78 3,303,992 2/1967 Johnson 230-114 FOREIGN PATENTS 1,096,708 2/ 1955 France. 1,022,348 1/1958 Germany.

EVERETTE A. POWELL, ]R., Primary Examiner.