Blade with changeable installation angle and its manufacturing method, stator section unit, stator section, turbomachine module and turbomachine

FIELD: engines and pumps.

SUBSTANCE: blade with changeable installation angle for turbomachine module stator section includes an active part of the blade, on which sides there arranged are radially inner and outer flanges. Active part of the blade divides inner flange to the first part located on the side of the blade convex surface and the second part located on the side of the blade concave surface. The first part of inner flange has external outline overlapping the circle at a distance from which and inside which there located is a part of external outline of the second part of inner flange. The other inventions of the group relate to stator section unit including above blade, to stator sections including such unit, to turbomachine module, including such section, and to turbomachine including this module. During manufacturing of the blade with changeable installation angle, radially performed is an inner flange from round profile machined in a circumferential direction forming the second part of this flange.

EFFECT: group of inventions allows increasing blades service life due to reduction of friction between the blade inner flange and its retaining ring.

12 cl, 7 dwg

This invention relates mainly to those sections of the stator having vanes with a variable angle, where these blades are made with possibility of installation on the modules of the turbomachine of the type of compressor or turbine.

The invention is preferably applicable to the aviation turbomachine such as a turbojet engine or a turboprop engine.

Figure 1 shows a portion of the high pressure compressor of the turbine engine, the construction of which is known in the art and disclosed, for example, in the publications EP 0384706 or EP 1717450. The compressor 1 includes, generally, a few sections 2A, 2b, 2C of the stator and movable impeller (not shown). These elements, the centers of which are located on the axis 4 of the turbomachine, can change its axial direction and are designed to cross the main stream 6 air flowing through the high-pressure compressor.

Each section 2a, 2b, 2c stator includes multiple blades 8, called blades with a variable angle. Each of the blades 8, which are distributed in the circumferential direction around the axis 4, has a top that engages with the outer casing 10 of the compressor, and this peak usually includes a radially outer shelf 11, which continues centering pin 12. Pin 12 is connected to the system 14 that provides a controlled angle from the setting of the vanes 8, moreover, this system is installed on the outer body 10. Thus, the system 14 is able to control the angle of all the blades of the associated section of the stator at the same time.

According to figure 2, the blade 8 has a base which usually also includes a radially inner shelf 13, the ongoing centering pin 16. This pin 16, the axis of which is identical with the axis of the axle 12 and is also the axis 20 of the blade, around which the blade can be rotated to change its angle, is inserted in the ring 22 of the stator blades.

The latter, which is usually made of several angular sectors of the rings, in fact has numerous holes 24, distributed in the circumferential direction, each of which holds the sleeve 26 for receiving the centering pin 16. In addition, these openings 24 are opened, respectively, in the other holes 27 that holds the shelf 13. In addition to retaining the collet 26 and the radially inner shelves 13, the ring 22 of the stator blades in a known manner contributes to the formation of the inner surface, agroniaga the main air flow, cross flow 6 of the air.

Each sleeve 26 has a skirt 28 which is inserted in one of the holes 24 of the ring, and this skirt limits the saddle 30 of the centering pin, which is inserted the axle 16 of the blade. In figure 2 you can see that the pin 16 is covered by item 32, item is edocfile - articulated with the latter, and the function of this element is to facilitate sliding the skirt 28. In addition, the sleeve 26 has a base 34, articulated with the skirt and located radially inside relative to the last. The base 34 of each sleeve is located in the ring groove 36 of the ring 22 of the blades of the stator, which in a known manner provides locking of the rotation of this sleeve.

In fact, each base 34 is limited by the two surfaces, which are facing each other in the circumferential direction 40, and two surfaces that face each other in the axial direction 50, as indicated by the positions 46 and 48. Both surfaces 46, 48, called circumferential surfaces are approximately flat and converted, respectively, to the two edges bounding the groove 36, as shown in figure 2.

The design is such that the surfaces 46, 48 are located as close as possible, respectively, to the two front edges of the grooves and spaced apart in the axial direction 50. Generally speaking, between the elements, which are facing each other in pairs, are only supported the working gap, to ensure the retention of the bases 34 in the ring groove 36 with the holes 24.

In this standard configuration, detected known in the prior art, when the system 14 control angle rotates the blade 8 relative to the axis 20 of rotation, h is usually used to adjust the installation angle to achieve a precise angle, the centering pin 16 of each blade tending to pull a sleeve 26 by the forces of friction applied between the hole 20 and the element 32, surrounding the base 16.

This relative rotation of the sleeve 26 on its axis 20 relative to the ring 22 is terminated by hiding working clearances, initially existing between the circumferential surfaces 46, 48 of the base 34 and the edges of the grooves 36. When the contact between the surfaces 46, 48 of the base 34 and these edges of the grooves is selected, the relative rotation of the Foundation shall be terminated and the relative rotation of the blade 8 with respect to its sleeve 26 and the ring 22 can continue to obtain the desired angle.

Although this node 60 to the section of the stator, which includes a ring 22, the sleeve 26 and the vanes 8, finds wide application in the variants of implementation of the known technical solutions, he still has the disadvantage that cannot be neglected, namely the high degree of wear and tear of its constituent parts. In particular, manifests a degree exclusively coming fast wear and tear the edges of the grooves, which they are constantly exposed under the influence of bases 34; and the result of this wear and tear is the increase in comparable proportion to the amplitude of the rotation of the sleeves every time you change the angle, and therefore is called also the wear and tear to other parts of the ring, such as those facing the skirts 28 due to expansion due to wear and tear holes 24.

During operation, each vane 8 is subjected to the deflection imparted to the resultant of the aerodynamic forces applied to it. The consequence of this model deviations, the magnitude of which is greater, the greater the above-mentioned wear and tear of retaining holes 24, is creating friction between the radially inner shelf 13 and the corresponding hole 27 in the ring 22.

Due to the orientation of the resultant aerodynamic forces applied to the blade, this friction localized in the side of the shelf 13, located on the concave side 62 of the active part 43 of the blade, namely the side of the shelf 13 facing the side of the hole indicated by the position 27 figure 3.

Harmful consequence of friction between the shelf 13 of circular cross section and a wall of the retaining hole 27 is the rapid wear and tear of the ring 22, which must often be replaced.

Another consequence of this friction is increased mechanical stress at the base of the active part of the blade on the concave side, which reduces the service life of the blades, which then may not have the same service life as the engine.

Brief description of the invention

Therefore, the object of the invention is, for men is our least partial elimination of the aforementioned disadvantages compared with the variants of the implementation of the known technical solutions.

To solve this problem, the first object of the invention is a blade with a variable angle to the section of the stator of the turbomachine module, which includes the active part of the blade, on both sides of which are arranged radially inner shelf and radially outer shelf, and includes a first centering pin, which passes radially outward from the radially outer shelf, along with the second centering pin passing radially inward from the radially inner shelf, and the first and second centering pins define a common axis of rotation of the blades, and the active part of the blade, which has a first surface forming a convex surface, and the second surface, forming a concave surface, separates the radially inner shelf at a first part located on the side of the first surface of the blade, and a second part located on the side of the second surface of the scapula. In accordance with the invention, when viewed along the direction of the axis of rotation of the blades, the first part of the radially inner shelf has an external contour that is applied to the circumference, the distance from which and within which is at least part of the external outline of Deuteronomy is the second part of the radially inner shelf.

Therefore, the invention has developed an original way so that it differs from the usual round-shaped cross-section to a radially inner shelf of the scapula. In fact, the second part of the shelf, namely the one that is most exposed to friction in retaining its opening due to wind deflection vanes, is no longer round, and has a peripheral cut the material. This reduction allows it locally separated from the hole, the retaining ring, in which this regiment should be maintained, in order to reduce friction with the hole. Thus, the ring is subjected to less frictional voltage through a radially inner shelves, which it serves to support, and its lifetime is advantageously increased. Similarly, the level of mechanical stress in the blade remains identical degree of mechanical stresses to which the blade should be when it's new, and therefore, the service life of the blades is no longer reduced.

In addition, the fact that this reduction of material is localized, and therefore has no place everywhere around the radially inner shelf allows you to store small gaps between the rest of the plot of circular cross section and a hole, the retaining ring, in which to hold this shelf. This ensures that only the very neznicitelnosti on the aerodynamic flow, crossing the shoulder, due to the low observable phenomena aerodynamic recirculation.

Part of the contour of the radially inner shelf, which is separated from the circumference, preferably occupies an angular sector in the range of from 100° to 140°, and the center of this sector is located in the center of the said circle.

Part of the contour of the radially inner shelf, which is separated from the circumference, preferably is at a maximum radial distance from the circumference whose value is in the range between a value corresponding to 7% of the diameter of a circle, and a value corresponding to 1% of the diameter of this circle.

Another object of the invention is the node section of the stator, which includes a set of blades with variable angle, such as described above, and the said node includes a ring of stator blades associated with each of these blades, hole holding the radially inner shelf of the blade opening in the region of the inner surface bounding the primary air flow is determined by the ring, along with the hole, holding the centering collar of the scapula, in which is inserted the above-mentioned second centering pin so that, when viewed along the direction of the axis of rotation of the blades, the said hole, Ude is living radially inner shelf, has an internal circuit placed on a concentric circle of a diameter greater than the diameter of the above-mentioned circle, which is the outer contour of the first mentioned part of the radially inner shelf.

Each radially inner shelf also preferably forms a part of these internal surfaces bounding the main air stream.

Each of the centering sleeve preferably includes, first, the skirt is inserted in said holding sleeve hole in the ring and limiting the saddle of the second centering pin, and secondly, the base coupled with the said skirt, whereby the said sleeve, each of which passes along the axis of the sleeve, follow each other in the circumferential direction mentioned rings.

The base of each of the centering sleeve is preferably retained in a circumferential groove of a ring bounded by two outer edges spaced from each other in the axial direction of the ring.

Another object of the invention is a stator having vanes with a variable angle for a module of the turbomachine that includes a site described above.

In addition, another object of the invention is a module of the turbomachine, comprising at least one section of the stator described above. In this regard, we note that the module can is t be the compressor, preferably the high-pressure compressor, or turbine.

Another object of this invention is a turbomachine, including a at least one module, described above.

The last object of the invention is also a method of manufacturing a blade with a variable angle to the section of the stator of the turbomachine module, such as described above, the implementation of which get mentioned radially inner shelf of the profile of circular cross section, machined on its periphery to receive the second part of this shelf. Naturally, the blade corresponding to the invention, can be obtained in accordance with any other method, without going beyond the scope of claims of the invention. In this regard, we note that the radially inner shelf can be produced so that its final profile will be obtained directly, for example, by casting, and there would be no transition through some intermediate profile of circular cross section.

Other advantages and features of the invention are clarified in the following detailed description is not restrictive.

Brief description of drawings

This description will be given with reference to the accompanying drawings, on which:

in figure 1, described above, presents casticin is e longitudinal polyacene high-pressure compressor aviation turbomachine in accordance with the embodiment, known in the prior art;

in figure 2, described above, is represented in an enlarged scale a longitudinal polyacene part of the section of the stator of the compressor according to figure 1, illustrating the site of the founding of the stator blades on the ring of stator blades;

figure 3, described above, presents a perspective view of part of the site that is installed on the section of the stator shown in figure 2, and the node includes a ring of stator blades and vanes are mounted on the latter (represented one shoulder);

4 shows a perspective view of the node for the partition stator having vanes with a variable angle, in accordance with the preferred embodiment of the present invention;

figure 5 presents a view on an enlarged scale in perspective of part of the site shown in figure 4;

figure 6 presents a top view along the axis of rotation of the blade shown in figure 5, and

figure 7 presents a cross-section along the line II-VII with 6.

Detailed description of preferred embodiments of the invention

Figure 4 can be considered part of the node 160 in accordance with a preferred embodiment of the present invention, the node 160 is an integral part of the section of stator having vanes with a variable angle, for a module are measured.

This first version of the implementation developed by the La overwrite the previously described node 60 according to the prior art, and so is suitable for location within any of sections 2a, 2b, 2c of the stator of the high-pressure compressor according to figure 1. In this regard, we note that the node has (in cross section along the line II-II of figure 4) is a form identical or similar to the form node 60 according to figure 2. In addition, the items indicated on the drawings identical positions are identical or similar elements.

Thus, the node 160 includes a ring 22 of the stator blades, identical to the ring of stator blades described for node 60 according to the prior art. In particular, the retaining holes 24, 27 are uniformly distributed in the circumferential or tangential direction 40, and the holes 27 are opened in the inner surface bounding the main thread 66 of the air generated by the ring 22 and holes 24 are opened in the region of a circumferential groove (not visible in figure 4), limited by two outer edges spaced from each other in the axial direction 50. Obviously, this ring has a center on the axis of the turbomachine.

Node 160 is also equipped with numerous bushings receiving the base of the blades (not shown) of the same type, as shown in figure 2, the number of which is identical to the number of blades section of the stator, i.e. a few dozen. Therefore, the sleeve 26 is held in the holes 24, follow each other, R is soligas each other throughout the district direction 40, i.e. over 360°.

Finally, the node 160 has many blades 8 with a variable angle, each of which communicates with the holes 24, 27 and body element held in the hole 24.

As mentioned above, each blade 8 includes an active portion 43 of the blade, on both sides of which are arranged radially inner shelf 13 and the radially outer shelf 11, and includes a first centering pin 12 which passes radially outward from the shelf 11, along with the second centering pin passing radially inward from the shelf 13, and these first and second centering pins define a common axis of rotation of the scapula.

In addition, the active portion 43 of the vanes has a first surface forming a convex surface 64, and a second surface opposite to the first and forming the concave surface 62. The basis of this active portion 43 of the scapula is divided radially inner shelf 13 on the first portion 13a located on the side of the convex surface 64, and the second portion 13b located on the side of the concave surface 62, as best seen in figure 5. By the way, we can assume that in the region of the leading edge 68 of the active part of the blades of the first and second parts 13a, 13b is limited by the extension line of the frame 70 of the active part of the blade. In contrast to this area, the border still creates what I concave surface 62 and the convex surface 64, because the back edge of the active part of the blade extends substantially over the shelf 13. In addition, thanks to the continuation of the active part 43 of the scapula over the shelf, the hole 27 has in its part of the small bevel 72, probably cover this active part of the scapula.

The upper surface of the parts 13a and 13b of the inner shelf 13 also forms part of the internal surface bounding the main thread 66 of the air, which is preferably inclined relative to the axial direction and which in the General case is separated from the axis of the engine as it passes down the stream.

One of the features of the invention schematically represented by figure 6, illustrating one of the blades 8 mounted on the ring 22, viewed in the direction of the axis 20 of rotation of the blades. This drawing shows that the first part 13a of the shelf 13, located on the convex side 64 has an outer contour, denoted by Ca, which is superimposed on a circle, denoted by C1, the center of which corresponds to the axis 20. Thanks to the overlay circuit Ca and the circle C1 at each other, these two elements are represented by the same line of the arc of a circle.

In addition, at least one part of Cb1 external circuit Cb of the second part 13b of the shelf 13 is located at a distance from the circle C1 and the inside of it. In the present preferred VA is iante implementation part of the Cb1 circuit, which is located inside the circle C1 corresponds only to the part of the circuit, denoted by Cb, and the other in relation to this part - the part of Cb2 is superimposed on the circle C1. As best seen in figure 6, part b2 may be such, which runs continuously from both ends of the contour part of the Ca, as part of the Cb1 can be carried out, occupying an angular sector 74, for example, about 120°, the center of which is located in the centre 20 of the circle C1. For example, part of the Cb1 circuit Cb may take the form of an arc of a circle with center in the center 76, offset from the center 20 of the circle C1.

Therefore, the shelf 13, which is obtained based on the above geometric definition, is a public profile that is comparable with the cylindrical profile of circular cross section having a peripheral cut the material at the site of its second part 13b to this site was farther from the hole 27 than the other parts of this shelf 13.

In fact, again referring to Fig.6, we note that the retaining hole 27 radially inner shelf 13 has an inner contour C', placed on a concentric circle C2, the diameter of which is larger than the diameter of the above-mentioned circumference C1. Therefore, in the initial state, the first gap separating the contour C' and parts of Ca, Cb2 circuit is approximately constant, for example, is about 0.5 mm,and is smaller than the second, changing the clearance "j"separating circuit C' from part Cb1 circuit. This second gap "j", also shown on Fig.7, in addition, approximately identical to the first gap about two mates with the contour Cb2, and then gradually increases when it reaches the Central section of the parts Cb1 circuit, where the gap reaches its maximum, for example, of the order of 1.75 mm

In this regard, we note that the construction may be such that part of the Cb1 circuit Cb, which is separated from the circumference C1, is at a minimum radial distance from this circle, the value of which is in the range between a value corresponding to 7% of the diameter of the circle C1, and the value corresponding to 1% of the diameter of this circle C1.

It should be noted that the radial distance, of course, must be understood as the distance between the circle C1 and the circuit Cb1 on a straight line passing through the center 20 of the circle C1.

Thus, during operation, the blade 8 is subjected to the deflection imparted to the resultant of the aerodynamic forces acting on it, the consequence of which is a moving path Cb1 closer to the hole 27 does not cause any harmful friction ring 22.

Note that in the preferred embodiment, the side surface of the shelf 13, which determines the contours of Ca, Cb, is cylindrical along the axis 20, as, regardless with the wasp 72, the side surface of the holding hole 27, which determines the contour C, which also is cylindrical along the axis 20.

Of course, specialists in the art can make various modifications in the invention just described solely on non-restrictive examples.

1. Blade (8) with a variable angle to the section of the stator of the turbomachine module that includes an active portion (43) of the blade, on both sides of which are arranged radially inner shelf (13) and radially outer shelf (11), and includes a first centering pin (12), which runs radially outward from the radially outer shelf, along with the second centering pin (16)passing radially inward from the radially inner shelf, and the first and second centering studs (12, 16) define a common axis (20) rotate the scapula while the active portion (43) of the scapula, which has a first surface (64), forming a convex surface and a second surface (62), forming a concave surface, separates the radially inner shelf (13) on the first part (13a)located on the first side surface (64) of the scapula, and the second part (13b)located on the side of the second surface (62) of the blade, characterized in that, when viewed along the direction of the axis (20) of the rotating blades, the first portion (13a) of the radially inner p is the CTL has an external contour (Ca), placed on a circle (C1), at a distance from which and within which is at least part (Cb1) in the external circuit (Cb) of the second portion (13b) of the radially inner shelf.

2. The blade according to claim 1, characterized in that the part (Cb1) of the contour of the radially inner shelf (13), which is separated from the circumference (C1), occupies an angular sector (74) in the range from 100° to 140°, and the center of this sector is located in the center of the said circle (C1).

3. The blade according to claim 1 or 2, characterized in that the part (Cb1) of the contour of the radially inner shelf (13), which is separated from the circumference (C1), is at a maximum radial distance from the circle whose value is in the range between a value corresponding to 7% of the diameter of a circle, and a value corresponding to 1% of the diameter of this circle.

4. Node (160) sections of the stator, characterized in that it contains a number of blades (8) with a variable angle according to claim 1, whereby the said node includes a ring (22) of the stator blades having connection with each of the blades (8), hole (27)holding the radially inner shelf (13) of the blade opening in the region of the inner surface bounding the main stream (66) of air defined by the ring, along with a hole (24)that secure the centering collar (26) of the scapula, in which is inserted the second centering pin (16), so that, if otret along the direction of the axis of rotation of the blades, the said opening (27)holding the radially inner shelf (13)has an inner contour (C), superimposed on the concentric circle (C2), of a diameter greater than the diameter of a circle (C1), which is an external circuit (Ca) the first part (13A) of the radially inner shelf (13).

5. The node according to claim 4, wherein each radially inner shelf (13) also forms part of the internal surface bounding the main stream (66) air.

6. The node according to claim 4 or 5, characterized in that each of the centering sleeve (26) preferably includes, first, the skirt (28)inserted into the retaining sleeve hole (24) in the ring (22) and limiting the saddle of the second centering pin (30), and secondly, the base (34), coupled with a skirt, and the said sleeve, each of which passes along the axis (20) of the sleeve, follow each other in the circumferential direction (40) rings.

7. The node according to claim 6, characterized in that the base (34) of each of the centering sleeve (26) is held in the ring groove (36) of the ring bounded by two outer edges spaced from each other in the axial direction (50) of the ring.

8. Section (2a, 2b, 2c) stator having vanes (8) with a variable angle, measured, characterized in that it contains a node (160) according to claim 4.

9. Module (1) are measured, characterized in that it contains, less than the least one section (2a, 2b, 2c) of the stator of claim 8.

10. The module according to claim 9, characterized in that it is the compressor or turbine.

11. Turbomachine, characterized in that it contains at least one module (1) according to claim 9 or 10.

12. A method of manufacturing a blade with a variable angle to the section of the stator of the turbomachine module according to any one of claims 1 to 3, characterized in that the receive radially inner shelf of the profile of circular cross section, machined on its periphery to receive the second part of this shelf.