Variable turbomachine vane

Abstract

A vane assembly for a turbomachine includes a variable vane (10-15), the vane having at least one first, in particular plane or curved, engagement surface (11; 11′) for clamping, in particular without play, an actuator (20) of the vane assembly for adjustment of the vane, this first engagement surface not being inclined toward a longitudinal axis (L) of the vane or being inclined toward it by no more than 15°, and/or the vane assembly including a clamp (30; 31) for clamping the actuator against the first engagement surface by at least partially elastically compressing the clamp transversely to the longitudinal axis of the vane and/or by advancing the clamp in a clamp direction (S) that forms an angle of at least 45° with the longitudinal axis of the vane.

Claims

1. A vane assembly for a turbomachine comprising: a variable vane, the vane having a first engagement, the first engagement surface not being inclined toward a longitudinal axis of the vane or being inclined toward it by no more than 15°; wherein the vane has a second engagement surface, the second engagement surface being inclined toward the first engagement surface, the second engagement surface not being inclined toward the longitudinal axis of the vane or being inclined toward it by no more than 15°; and a clamping means for clamping an actuating means against the first engagement surface and the second engagement surface, wherein (i) the clamping means is a screw that is at least partially elastically compressed transversely to the longitudinal axis of the vane and pressed against the actuating means to secure the actuating means to the first engagement surface and the second engagement surface, or (ii) the clamping means is a wedge that is advanced in a clamp direction forming an angle of less than 45° with the longitudinal axis of the vane to secure the actuating means to the first engagement surface and the second engagement surface.

2. The vane assembly as recited in claim 1 wherein the first engagement surface is planar or curved and the actuating means is secured to the first engagement surface without play.

3. The vane assembly as recited in claim 1 wherein the clamping means is said wedge, and said wedge includes an integrally formed tab that is plastically bent under the actuating means to secure said wedge in place.

4. The vane assembly as recited in claim 3 wherein the actuating means has a cutout for clamping against the first engagement surface or the second engagement surface of the vane, the cutout being open at two ends thereof or closed at one of said two ends.

5. The vane assembly as recited in claim 1 wherein the second engagement surface is planar and the actuating means is secured to the first engagement surface without play.

6. The vane assembly as recited in claim 1 wherein the first and second engagement surfaces are symmetrical to one another.

7. The vane assembly as recited in claim 1 wherein the first and second engagement surfaces are not symmetrical to one another.

8. The vane assembly as recited in claim 1 wherein the clamping means is secured on the actuating means non-destructively and detachably.

9. The vane assembly as recited in claim 1 wherein the clamping means is said wedge and said wedge is secured on the actuating means self-lockingly.

10. The vane assembly as recited in claim 1 wherein the clamping means and a direction of maximum extent of the actuating means away from the vane are located in a same half-circle sector or in opposed half-circle sectors in a circumferential direction about the longitudinal axis of the vane.

11. The vane assembly as recited in claim 1 wherein the clamping means and a direction of maximum extent of the actuating means away from the vane are located in a same quarter-circle sector, in opposed quarter-circle sectors, or in quarter-circle sectors angularly offset from one another by 90° in a circumferential direction about the longitudinal axis of the vane.

12. The vane assembly as recited in claim 1 wherein the clamping means is said screw, and further comprising a sheet metal retainer arranged between the actuating means and the clamping means.

13. The vane assembly as recited in claim 12 further comprising a slotted groove in the vane, one end of the sheet metal retainer being received in the slotted groove.

14. The vane assembly as recited in claim 1 wherein the clamping means is said screw, and the screw is secured into place by a self-locking threaded insert.

15. The vane assembly as recited in claim 1 wherein the actuating means includes an integrally formed projection, wherein said projection is received in a groove in the vane, whereby the actuating means is axially positioned on the vane.

16. The vane assembly of claim 1, wherein the second engagement surface is inclined toward the first engagement surface by no more than 120 degrees.

17. The vane assembly of claim 1, wherein the second engagement surface is inclined toward the first engagement surface by less than 90 degrees.

18. A turbomachine assembly comprising a compressor including a plurality of the vane assembly according claim 1.

19. A turbomachine assembly comprising a turbine stage including a plurality of the vane assembly according to claim 1.

20. A vane assembly for a turbomachine comprising: a variable vane, the vane having a first engagement surface, the first engagement surface not being inclined toward a longitudinal axis of the vane or being inclined toward it by no more than 15°; the vane assembly including a clamping means for clamping the actuating means against the first engagement surface, wherein the clamping means is a screw that is at least partially elastically compressed, transversely to the longitudinal axis of the vane and pressed against the actuating means to secure the actuating means to the first engagement surface.

21. A vane assembly for a turbomachine comprising: a variable vane, the vane having a first engagement surface, the first engagement surface not being inclined toward a longitudinal axis of the vane or being inclined toward it by no more than 15°; the vane assembly including a clamping means for clamping the actuating means against the first engagement surface, wherein the clamping means is a wedge that is advanced in a clamp direction forming an angle of less than 45° with the longitudinal axis of the vane to force the actuating means and the first engagement surface against each other and thereby secure the actuating means to the first engagement surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantageous refinements of the present invention will become apparent from the following description of preferred embodiments. To this end, the drawings show, partly in schematic form, in:

(2) FIG. 1: a side view of a vane assembly including a variable vane and an actuating means according to an embodiment of the present invention;

(3) FIG. 2: a perspective detail view of the vane; and

(4) FIG. 3 a sectional view along A-A of FIG. 1;

(5) FIG. 4 a plan view of the vane assembly of FIG. 1;

(6) FIG. 5 a sectional view along B-B of FIG. 4;

(7) FIG. 6: a plan view, similar to FIG. 4, of a vane assembly including a variable vane and an actuating means according to another embodiment of the present invention;

(8) FIG. 7: a sectional view along C-C of FIG. 6;

(9) FIG. 8: a plan view, similar to FIGS. 4, 6, of a vane assembly including a variable vane and an actuating means according to a further embodiment of the present invention;

(10) FIG. 9: a sectional view along D-D of FIG. 8;

(11) FIG. 10: a plan view, similar to FIGS. 4, 6, 8, of a vane assembly including a variable vane and an actuating means according to yet another embodiment of the present invention; and

(12) FIG. 11: a sectional view along E-E of FIG. 10.

DETAILED DESCRIPTION

(13) FIGS. 1-5 show a vane assembly including a variable vane and an actuating means 20 according to an embodiment of the present invention in a side view (FIG. 1), a plan view (FIG. 4), and sectional views (FIGS. 3, 5), and also the vane in a perspective detail view (FIG. 2).

(14) The vane includes an airfoil 15 and a vane stem 10 which is, or is intended to be, mounted in a casing of a compressor or turbine stage so as to be rotatable about a longitudinal axis L of the vane or vane stem. This is generally known and, therefore, will not be further described herein.

(15) The vane or vane stem have a first engagement surface 11 and a second engagement surface 12 symmetrical thereto, the two engagement surfaces being inclined toward one another, in the exemplary embodiment by about 70°.

(16) In the exemplary embodiment, both engagement surfaces are parallel to longitudinal axis L; i.e., not inclined toward it. In a modification, the two engagement surfaces 11, 12 are not symmetrical to one another and/or slightly inclined toward longitudinal axis L.

(17) On the side opposite the two engagement surfaces 11, 12, the vane or vane stem has a depression having a plane base surface 13 and a slotted groove 14 (see FIG. 5).

(18) Actuating means 20 has a cutout in the form of a through-hole 21, with which it is placed over vane stem 10, so that the vane stem and its engagement surfaces 11, 12 extend through through-hole 21.

(19) A clamping means in the form of a hexagonal screw 30 is threaded into actuating means 20 in a clamping means direction S that is at least substantially perpendicular to longitudinal axis L; i.e., forms an angle of about 90° therewith, (horizontally from left to right in FIGS. 1, 3-5), so that screw 30 engages the depression having the plane base surface 13 and presses against the base surface in clamping means direction S, thereby pulling actuating means 20 against engagement surfaces 11, 12 and clamping or pressing it without play thereagainst, with screw 30 being at least partially elastically compressed transversely to longitudinal axis L of the vane.

(20) Screw 30 is secured in place by a first retaining means in the form of a self-locking threaded insert 41 that is threadedly mounted to or between actuating means 20 and screw 30 and by a second retaining means in the form of a sheet-metal retainer 42, which is partially plastically bent for this purpose.

(21) As can be seen especially in FIG. 5, sheet-metal retainer 42 is resiliently held between the head of screw 30 and actuating means 20, allowing screw 30 to pull actuating means 20 against engagement surfaces 11, 12, thereby clamping them thereagainst. In other words, here, the sheet-metal retainer is flexible to compensate for tolerances.

(22) In addition, sheet-metal retainer 42 engages slotted groove 14, thus axially positioning actuating means 20 on the vane in the direction of its longitudinal axis L. Accordingly, sheet-metal retainer 42 forms an integrally formed retaining and positioning means.

(23) FIG. 6, 7 show, in views similar to FIGS. 4, 5, a vane assembly according to another embodiment of the present invention. Corresponding features are identified by identical reference numerals, so that reference is made to the preceding description and only the differences will be discussed below.

(24) Actuating means 20 has a direction of maximum extent M away from the vane (horizontally from left to right in FIGS. 4-7).

(25) In FIGS. 3, 4, 6, and 8, lines 100 and 200 together divide the vane stem 10 into quarter-circle sectors, and each of lines 100 and 200 alone divide the vane stem into half-circle sectors.

(26) In the embodiment of FIGS. 4, 5, clamping means 30 and this direction of maximum extent M are located in opposed half-circle sectors, as viewed in the circumferential direction about longitudinal axis L, since screw 30 is threaded into actuating means 20, as it were, from the side opposite the actuating means or the direction of maximum extent thereof.

(27) In contrast, in the embodiment of FIGS. 6, 7 clamping means 30 and direction of maximum extent M are located in the same half-circle sector, as viewed in the circumferential direction about longitudinal axis L, since screw 30 is threaded into actuating means 20, as it were, from the side of the direction of maximum extent thereof.

(28) As illustrated by comparison of FIGS. 5, 7, threaded insertion in a direction opposite to the direction of maximum extent M makes it possible to save space on the left in FIG. 7; threaded insertion in the direction of maximum extent M makes it possible to save space at the top in FIG. 5.

(29) FIGS. 8, 9 show, in views similar to FIGS. 4, 5, a vane assembly according to another embodiment of the present invention. Again, corresponding features are identified by identical reference numerals, so that reference is made to the preceding description and only the differences will be discussed below.

(30) In the embodiment of FIGS. 8, 9, the actuating means has an integrally formed projection 22 in the cutout 21, which is open at both ends, the projection engaging wedge-shaped groove 14 in vane stem 10, whereby actuating means 20 is axially positioned on the vane or its vane stem 10 in the direction of its longitudinal axis L. In modifications (not shown), cutout 21 may also be closed at one end (at the top in FIG. 9), or, conversely, the vane or its vane stem 10 may have a projection for axial positioning.

(31) FIGS. 10, 11 show, in views similar to FIGS. 4, 5, a vane assembly according to another embodiment of the present invention. Again, corresponding features are identified by identical reference numerals, so that reference is made to the preceding description and only the differences will be discussed below.

(32) In the embodiment of FIGS. 10, 11, the clamping means does not take the form of a screw 30, but of a wedge 31 that bears self-lockingly on a wedge surface 23 of actuating lever 20, and is thereby at least partially elastically compressed between this wedge surface 23 and the longitudinal side or contact surface 13 of the vane or vane stem 10 which longitudinal side or contact surface is located opposite the wedge surface in a direction transverse to longitudinal axis L, the wedge thereby clamping the actuating lever against first engagement surface 11′, which, in the embodiment of FIGS. 10, 11, is curved.

(33) Formed integrally with wedge 31 is a retaining means in the form of a tab 43 that is plastically bent under the actuating lever to secure the wedge in place.

(34) Although exemplary embodiments have been described hereinabove, it should be understood that many modifications thereof are possible.

(35) For example, the embodiments of FIG. 6-9, in particular, may be combined, or clamping means direction S may, for example, also be perpendicular to the plane of the drawing of FIG. 5, 7 or 9, or be vertical in FIG. 4, 6 or 8.

(36) Similarly, in the embodiment of FIGS. 10, 11, wedge 31 may also be located in the half-circle sector of the direction of maximum extent (see FIG. 6) or a half-circle sector angularly offset by 90° therefrom and/or may additionally or alternatively to integral tab 43 be secured in place by a separate retaining means.

(37) Also, additionally or alternatively to wedge surface 23, the vane stem may also have a wedge surface, so that the actuating lever is clamped against first engagement surface 11′ by inserting wedge 31 or a differently shaped clamping means. In a modification, first engagement surface 11′ may, additionally or alternatively, also be plane.

(38) In the embodiment of FIGS. 10, 11, due to the acute angle of wedge surface 23, the clamping means direction in which wedge 31 is advanced to clamp actuating lever 20 against first engagement surface 11′ forms an angle of less than 45° with longitudinal axis L of the vane.

(39) In a modification (not shown) of the embodiment of FIG. 5 or 7, instead of threading screw 30 in the clamping means direction and at least partially elastically compressing it correspondingly, it is also possible, for example, to use a clamping means that has expanded in the clamping means direction and thereby presses actuating lever 20 against first engagement surface 11′.

(40) It should also be appreciated that the exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing detailed description provides those skilled in the art with a convenient road map for implementing at least one exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described without departing from the scope of protection as is derived from the claims and the combinations of features equivalent thereto.

LIST OF REFERENCE NUMERALS

(41) 10 vane stem 11; 11′ first engagement surface 12 second engagement surface 13 depression/contact surface 14 groove 15 airfoil 20 actuating means 21 cutout 22 projection 23 wedge/supporting surface 30 screw (clamping means) 31 wedge (clamping means) 41 self-locking threaded insert 42 sheet-metal retainer 43 retaining tab L longitudinal axis M direction of maximum extent S clamping means direction