阅读说明：本技术 涡轮叶片 (Turbine blade ) 是由 雷诺德·詹姆斯·马泰特 托马斯·兰盖文 西里尔·弗布柳盖 于 2019-07-23 设计创作，主要内容包括：本发明涉及一种用于涡轮机的涡轮叶片(13),其包括径向延伸的涡轮叶片翼型(14),所述涡轮叶片翼型(14)具有上游轴向的前边缘(16)和下游轴向的后边缘,径向外部平台(15)具有上游端(17)和下游端,所述径向外部平台(15)进一步包括朝向外部径向延伸的至少一个唇缘(18、19),所述涡轮叶片翼型(14)的所述前边缘(16)和/或所述涡轮叶片翼型(14)的所述后边缘的径向外端(20)相对于所述平台(15)的所述上游端(17)向上游轴向延伸,和/或相应地相对于所述平台(15)的所述下游端向下游延伸,其特征在于,所述叶片(13)具有至少一个分隔件(21),所述分隔件从所述涡轮叶片翼型(14)的所述径向外端朝向外部径向延伸,且在所述前边缘(16)和所述平台(15)的所述上游端(17)之间和/或相应地在所述后边缘和所述平台(15)的所述下游端之间轴向延伸。(The invention relates to a turbine blade (13) for a turbomachine, comprising a radially extending turbine blade airfoil (14), the turbine blade airfoil (14) having an upstream axial leading edge (16) and a downstream axial trailing edge, a radially outer platform (15) having an upstream end (17) and a downstream end, the radially outer platform (15) further comprising at least one lip (18, 19) extending radially towards the outside, the leading edge (16) of the turbine blade airfoil (14) and/or a radially outer end (20) of the trailing edge of the turbine blade airfoil (14) extending axially upstream with respect to the upstream end (17) of the platform (15) and/or correspondingly downstream with respect to the downstream end of the platform (15), characterized in that the blade (13) has at least one partition (21), the partition extends radially towards the outside from the radially outer end of the turbine blade airfoil (14) and axially between the leading edge (16) and the upstream end (17) of the platform (15) and/or respectively between the trailing edge and the downstream end of the platform (15).)

1. A turbine blade (13) for a turbine intended to extend around an axis of the turbine, the blade (13) having a vane (14) extending radially with respect to the axis between a radially inner platform (4) and a radially outer platform (15), the vane (14) comprising an axially upstream leading edge (16) and an axially downstream trailing edge, the radially outer platform (15) comprising an upstream end (17) and a downstream end, the radially outer platform (15) comprising at least one radially outwardly extending sealing lip (18, 19), characterized in that the leading edge (16) of the vane (14) and/or a radially outer end (20) of the trailing edge of the vane (14) extend axially upstream with respect to the upstream end (17) of the platform (15) and/or respectively downstream with respect to the downstream end of the platform (15), and the blade (13) having at least one partition (21, 27) extending radially outwards from the radially outer end of the vane (14) and axially between the leading edge (16) and the upstream end (17) of the platform (15) and/or respectively between the trailing edge and the downstream end of the platform (15).

2. The turbine blade (13) of claim 1, characterized in that the partition (21, 27) extends axially between the leading edge (16) and an upstream surface (22) of the sealing lip (18) and/or respectively between the trailing edge and a downstream surface of the sealing lip (19).

3. The turbine blade (13) of claim 2, characterized in that the partition (21, 27) extends generally radially outwardly to the radially outer end (24, 26) of the sealing lip (18, 19).

4. The turbine blade (13) of claim 2, characterized in that the partition (21, 27) extends radially outward over only a portion of the radial dimension of the sealing lip (18, 19).

5. The turbine blade (13) of any preceding claim, wherein the divider (21, 27) extends in a direction that is at an angle to a radial direction.

6. Turbine blade (13) according to any one of the preceding claims, characterized in that the partition (21, 27) has an upstream (23) and/or a respective downstream end edge which is rectilinear and forms an angle (a) with the radial direction, the angle (a) lying in a plane perpendicular to the axial direction.

7. The turbine blade (13) of any preceding claim, wherein the sealing lip (18, 19) extends in a plane, at least a portion of the partition (21, 27) extending perpendicular to the plane of the sealing lip (18, 19).

8. The turbine blade (13) of any one of claims 1 to 6, characterized in that the sealing lip (18, 19) extends in a plane, at least a portion of the partition (21, 27) extending in a plane forming an angle (θ) with the axis (X) of the turbine.

9. The turbine blade (13) of any one of claims 1 to 8, characterized in that the partition (21, 27) is curved, e.g. recessed as seen from the lower surface of the vane (14).

10. A turbine for a turbomachine, characterized in that it comprises a vaned wheel having turbine blades (13) according to any one of claims 1 to 9.

Technical Field

The present invention relates to a turbine blade for a turbine, such as an aircraft turbine engine.

Background

Document FR 2970999, representative of the assignee, discloses a turbine vane wheel comprising a turbine disk on which vanes 1 are arranged. Each blade 1 extends radially and has a radially inner foot 2 mounted in a recess in the disc, a profiled vane 3 separated from the foot 2 by a radially inner platform 4. A radially outer platform 5 extends from the radially outer end of the vane 3. The radially outer platform 5 has a radially outwardly extending sealing lip 6 which cooperates with the abradable material to form a labyrinth seal.

The outer platform 5 has an axially upstream end 7 and an axially downstream end 8 located upstream and downstream of the leading edge 9 and trailing edge 10, respectively, of the bucket 3.

In order to lighten the blade 1, it is envisaged to remove a portion of the radially outer platform 5 by making an opening at the level of said outer platform 5. In this case, however, a portion of the air flow may be diverted from the lower deck area 11 to the upper deck area 12 by passing radially through the outer vanes 3 via the openings. This recirculation is detrimental to the efficiency of the turbine and should therefore be limited.

Disclosure of Invention

The object of the present invention is to provide a simple, effective and economical solution to this problem.

To this end, the invention relates to a turbine blade for a turbine, intended to extend around the axis of the turbine, the blade includes a vane extending radially relative to the axis between a radially inner platform and a radially outer platform, the bucket including an axially upstream leading edge and an axially downstream trailing edge, a radially outer platform including an upstream end and a downstream end, the radially outer platform including at least one sealing lip extending radially outward, characterised in that the radially outer end of the leading edge of the vane and/or the trailing edge of the vane extends axially upstream relative to the upstream end of the platform and/or correspondingly downstream relative to the downstream end of the platform, and the blade having at least one divider extending radially outwardly from a radially outer end of the vane, and extends axially between the leading edge and the upstream end of the platform and/or respectively between the trailing edge and the downstream end of the platform.

The retraction of the upstream and/or downstream ends from the leading and/or trailing edges allows limiting the axial dimension of the outer platform and thus the mass of the blade.

Furthermore, the presence of a partition extending radially outwards and axially (i.e. along the turbine axis) between the leading edge of the blade and the upstream end of the platform and/or respectively between the trailing edge and the downstream end of the platform constitutes at least in part an obstacle to air recirculation. These partitions also make it possible to improve the efficiency of the turbine, since these recycles generate aerodynamic losses.

The divider may extend axially between the leading edge and an upstream surface of the seal lip and/or between the trailing edge and a downstream surface of the seal lip, respectively.

This partition prevents any radial air recirculation outside the outer platform.

According to another feature, the partition may extend substantially radially outwards to a radially outer end of the sealing lip.

Thus, the partition avoids air recirculation along the entire length of the sealing lip which, in cooperation with the abradable material, ensures sealing of the air passage.

Further, the partition may extend radially outward for only a portion of the radial dimension of the sealing lip.

Thus, the presence of a partition which opposes the recirculation of air, thus limiting its radial dimension to only a fraction of that of the sealing lip, allows to control the addition of substances and therefore the quality of the blade.

The radial distance between the radially outer end of the partition and the radially outer end of the sealing lip is, for example, between 1 and 10 mm.

The partition may extend in a direction at an angle to the radial direction.

This inclination of the partition improves the positioning of the partition so that it is opposite to the direction of recirculation of air from the lower surface to the upper surface.

Said angle is for example between 30 ° and 60 °.

According to another characteristic, the partition may have upstream and/or downstream end edges that are rectilinear and angled with respect to the radial direction.

This inclination makes it possible to reduce the volume of the partition and thus control the mass of material added to the turbine blade.

Said angle is for example between 0 ° and 60 °.

Furthermore, the sealing lip may extend in one plane, at least a portion of the partition extending perpendicular to said plane of the sealing lip.

Thus, the divider portion extends perpendicular to the sealing lip.

In particular, the sealing lip may extend in one plane, at least a portion of the partition extending in a plane angled to the axis of the turbine.

The axis of the turbine corresponds to the axis of the rotor to which the blades are attached.

Thus, the partition is inclined in the direction of rotation of the blade to form a deflector for the air flow. This position effectively limits air recirculation from the lower surface to the upper surface.

Said angle is for example between 30 ° and 60 °.

According to another feature, the divider may be curved, for example concave when viewed from the lower surface of the vane.

The invention also relates to a turbine having a bladed wheel comprising a turbine blade as described above.

The invention also relates to a turbomachine, such as an aircraft turbojet engine, characterized in that it comprises such a turbine.

The invention will be better understood and its characteristics and advantages will be apparent from the following description, given as a non-limiting example, with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic view of a turbine blade according to the prior art;

FIG. 2 is a schematic view of an example of a turbine blade platform according to an embodiment of the invention;

figures 3A to 4B are perspective views showing a part of a blade in different variants of the invention.

Detailed Description

The terms "upstream" and "downstream" are defined hereinafter with respect to the direction of airflow in the turbine, specifically in the secondary flow path. Also, the terms "radial" and "axial" are defined relative to the axis of the turbine. Each turbine blade extends radially outward from a turbine disk, the axis of rotation of which extends axially.

Reference is made hereinafter to fig. 2, and with respect to fig. 1 of the prior art, which has been described above with respect to the present invention.

Fig. 2 shows a portion of a turbine blade 13 for a turbine according to the present invention. A plurality of turbine blades 13 according to the invention are intended to be mounted on a disk so as to form a turbine.

The blade 13 comprises a radially extending vane 14, and a radially outer platform 15 at a radially outer end of the vane 14. The buckets 14 have an axially upstream leading edge 16 and an axially downstream trailing edge (not shown). The platform 15 has an upstream end 17 and a downstream end (not shown). The platform 15 also has sealing lips, i.e. in the example shown in the figures, an upstream sealing lip 18 and a downstream sealing lip 19.

In the example shown, the platform 15 extends axially between two sealing lips 18, 19 and is permeable with respect to the platform 5 of the prior art presented above. The platform 15 does not include a section that extends axially beyond the sealing lips 18, 19.

A vented platform having a portion extending beyond the sealing lip is also contemplated.

In both cases, the radially outer end 20 of the leading edge 16 of the bucket 14 extends axially upstream relative to the upstream end 17 of the platform 15. Similarly, the radially outer end of the trailing edge (not shown) of the bucket 14 extends axially downstream relative to the downstream end of the platform 15.

The blade 13 according to the invention also has a partition 21. The partition 21 is located radially outward of the radially outer end 20 of the leading edge 16 and/or trailing edge (not shown) of the bucket. In practice, the divider 21 extends circumferentially opposite the radially outer end 20 of the bucket 14.

Furthermore, the partition 21 extends axially between the front edge 16 and the upstream end 17 of the platform 5 and/or respectively between the rear edge and the downstream end of the platform 15.

The illustrated divider 21 extends axially between the leading edge 16 and an upstream surface 22 of the sealing lip 18. Similarly, it is contemplated that the divider 21 may extend axially between the trailing edge and the downstream surface of the sealing lip.

In the embodiment shown in fig. 2, the partition 21 extends only over a part of the height (i.e. radial dimension) of the sealing lips 18, 19 concerned.

The partition 21 has a straight end edge 23 which forms an angle "α" with the radial direction or radial plane. The angle "α" is for example between 30 ° and 90 °. The angle "a" is in a plane perpendicular to the axial direction.

Several embodiment variations are shown in fig. 3A-4B.

The geometry and positioning of the divider 21 may vary depending on the application.

In the embodiment variant shown in fig. 3A and 4A, the partitions 21, 27 extend substantially radially outwards to the radially outer ends 24, 26 of the sealing lips 18, 19. In other words, the partitions 21, 27 have substantially the same height as the sealing lips 18, 19.

Preferably, there is a radial operating clearance between the radially outer end 25 of the partition 21, 27 and the radially outer end 24, 26 of the sealing lip 18, 19. This operating gap is for example between 0.5 and 2 mm.

This gap thus prevents any rubbing of the spacers 21, 27 on the abradable material.

In the embodiment variant illustrated in fig. 3B and 4B, the partitions 21, 27 extend radially outwards only over a portion of the radial dimension of the sealing lips 18, 19.

In other words, the radially outer end 25 of the partition 21, 27 is offset radially inwardly relative to the radially outer end 24, 26 of the sealing lip 18, 19.

The radial distance between the radially outer end 25 of the partition 21, 27 and the radially outer end 24, 26 of the sealing lip 18, 19 is between 0.5mm and 2mm, for example.

As shown in fig. 3A to 4B, the partition 21 at the upstream seal lip 18 and the partition 27 at the downstream seal lip 19 may extend in a direction at an angle (β) to the radial direction.

The angle (β) is for example between 0 ° and 60 °.

The angle (β) is inscribed in a plane comprising the axial direction and the radial direction.

It should be noted that in the embodiment variant of fig. 3A to 4B, the angle "α" is equal to 0.

In each of the alternative configurations of fig. 3A and 3B, the upstream partition 21 is perpendicular to the plane of the upstream sealing lip 18.

Furthermore, in each of the embodiment variants of fig. 4A and 4B, the downstream partition 27 extends at least partially in a plane forming an angle θ with the X-axis of the turbine. Thus, the partition and the sealing lip each extend radially from the blade platform. Specifically, the downstream partition 27 is inclined in the direction of the blade rotation direction R so as to form a deflector for the air flow.

In other words, the downstream partition 27 is inclined toward the lower surface. The inclination towards the lower surface is of particular concern as it makes it more difficult for air to recirculate from the lower surface region to the upper surface region.

Said angle theta is for example between 0 deg. and 60 deg..

In each of the above embodiments, the partitions 21, 27 constitute an obstacle to the recirculation of air from the lower surface area to the upper surface area, and thus reduce the losses associated with this recirculation. This improves turbine performance while limiting the weight of the blades 14 due to the limited size of the outer platforms 15.