CN117027961B

CN117027961B - Turbine blade

Info

Publication number: CN117027961B
Application number: CN202311290604.XA
Authority: CN
Inventors: 李明
Original assignee: China Hangfa Gas Turbine Co ltd
Current assignee: China Hangfa Gas Turbine Co ltd
Priority date: 2023-10-08
Filing date: 2023-10-08
Publication date: 2023-12-01
Anticipated expiration: 2043-10-08
Also published as: CN117027961A

Abstract

The application discloses a turbine blade, and relates to the technical field of turbines. The turbine blade includes: extending roots; the first groove is formed in the first side face of the extending root, and the second groove is formed in the second side face of the adjacent extending root; a root extending gap is formed between the first side surface of the root extending part and the second side surface of the adjacent root extending part; the first groove and the second groove form a sealing cavity; the balancing weight, the first sealing strip and the second sealing strip are arranged in the sealing cavity; the first sealing strip and the second sealing strip are connected with the balancing weight through a connecting component; if the turbine blade rotates around the rotation axis, the balancing weight can apply thrust to the first sealing strip and the second sealing strip by means of centrifugal force and the connecting assembly. The application can push the first sealing strip and the second sealing strip to seal the root extending gap by virtue of the centrifugal force of the balancing weight. The sealing performance is not affected by the roughness of the inside of the sealing cavity.

Description

Turbine blade

Technical Field

The application relates to the technical field of turbines, in particular to a turbine blade.

Background

Turbine blades of a gas turbine or an aeroengine are arranged circumferentially on the turbine disk. In consideration of cold assemblability and thermal expansion and centrifugation, a certain gap is reserved between the extending roots of adjacent turbine blades. It should be appreciated that gas turbines or aeroengines perform work by rotating turbine blades through high temperature gas. If the extending root has a gap, high-temperature fuel gas can overflow from the gap, so that the working efficiency of the gas turbine or the aeroengine is reduced. In order to avoid leakage of high-temperature fuel gas from the gap, sealing blades or end baffles are generally used for sealing the gap. In the prior art, the sealing insert has the defects of complex structure, large assembly difficulty, easy abrasion and the like, the end face baffle plate increases the mass of the turbine, the turbine mass is increased, the working efficiency is reduced, and a fastening structure is required to be designed to fix the end face baffle plate, so that the structure is also relatively complex. In order to solve the above technical problem, chinese patent application No. 202310879847.0 discloses a turbine blade, which constrains a movable column through a first groove under a specific condition, so that the movable column can convert its centrifugal force into pressure between two adjacent extending roots, thereby realizing a sealing function. The sealing mode has higher requirements on the smoothness of the first groove, and if the friction force between the first groove and the movable column is larger, the movable column is difficult to slide, that is, if the movable column cannot slide, the root extending gap cannot be sealed. Secondly, the pressure applied by the movable column between two adjacent extending roots mainly depends on the mass of the movable column and the rotation speed of the turbine, and if the pressure of high-temperature fuel gas is large, under certain application scenes (for example, the mass of the movable column needs to be limited, or the rotation speed of the turbine is low under low working conditions), the extending root clearance is difficult to seal only through the pressure generated by the movable column.

Disclosure of Invention

The application aims to provide a turbine blade, which solves the technical problem that a device for sealing a root extending gap by means of centrifugal force in the prior art has poor sealing effect.

To achieve the above object, the present application provides a turbine blade comprising: extending roots; the first groove is formed in the first side face of the extending root, and the second groove is formed in the second side face of the adjacent extending root; a root extending gap is formed between the first side surface of the root extending part and the second side surface of the adjacent root extending part; the first groove and the second groove form a sealing cavity; the balancing weight, the first sealing strip and the second sealing strip are arranged in the sealing cavity; the first sealing strip and the second sealing strip are connected with the balancing weight through a connecting component; if turbine blade rotates around the rotation axis, then the balancing weight can with help of centrifugal force and coupling assembling to first sealing strip with the thrust is applyed to the second sealing strip, so that first sealing strip with the second sealing strip with the side in sealed chamber is inconsistent.

As a specific solution in the technical solution of the present application, the connection assembly includes: at least one first connector; the first end of each first connecting piece is connected with the balancing weight, and the second end of each first connecting piece is connected with the first sealing strip; the included angle formed by the direction from the first end to the second end of each first connecting piece and the centrifugal force direction is an acute angle; at least one second connector; the first end of each second connecting piece is connected with the balancing weight, and the second end of each second connecting piece is connected with the second sealing strip; the included angle formed by the direction from the first end to the second end of each second connecting piece and the centrifugal force direction is an acute angle.

As a specific scheme in the technical scheme of the application, an included angle formed by the direction from the first end to the second end and the centrifugal force direction of each first connecting piece is more than or equal to 30 degrees and less than or equal to 60 degrees; and an included angle formed by the direction from the first end to the second end and the centrifugal force direction of each second connecting piece is more than or equal to 30 degrees and less than or equal to 60 degrees.

As a specific scheme in the technical scheme of the application, each first connecting piece and each second connecting piece are elastic pieces.

As a specific scheme in the technical scheme of the application, each first connecting piece and each second connecting piece are inelastic pieces, the first end of each first connecting piece is hinged with the balancing weight, and the second end of each first connecting piece is hinged with the first sealing strip; the first end of each second connecting piece is hinged with the balancing weight, and the second end of each second connecting piece is hinged with the second sealing strip.

As a specific scheme in the technical scheme of the application, the sealing device further comprises a limiting structure, wherein the limiting structure is used for limiting the first sealing strip and the second sealing strip to be close to the balancing weight.

As a specific solution in the technical solution of the present application, the limiting structure includes: the clamping groove is arranged in the first groove or the second groove; the clamping block is matched with the clamping groove; the first end of each third connecting piece is connected with the clamping block; the second end of at least one third connecting piece is connected with the first sealing strip, and the second ends of the other third connecting pieces are connected with the second sealing strip.

As a specific solution in the technical solution of the present application, the limiting structure includes: the clamping groove is arranged in the first groove or the second groove; the clamping block is matched with the clamping groove; at least one elastic third connecting piece, wherein the first end of each third connecting piece is connected with the clamping block; the second end of each third connecting piece is connected with the balancing weight.

As a specific scheme in the technical scheme of the application, a concave or convex is formed on the side surface of the sealing cavity, and the first sealing strip is matched with the concave or convex; the second sealing strip is matched with the concave part or the convex part.

As a specific scheme in the technical scheme of the application, the outer surface of the concave or convex is an inclined surface or a curved surface.

Compared with the prior art, the application has the beneficial effects that:

the first sealing strip and the second sealing strip can be pushed to seal the root extending gap by means of the centrifugal force of the balancing weight. The sealing performance of the turbine is not affected by the roughness in the sealing cavity, that is, in the embodiment of the application, the balancing weight can be set into any shape with larger contact area with the surface of the sealing cavity, so that the first sealing strip and the second sealing strip can seal the root extending gap under the lowest working condition of the turbine by adjusting the mass of the configuration block.

Drawings

FIG. 1 is a front view of a turbine blade according to an embodiment of the present application;

FIG. 2 is a schematic illustration of two turbine blades forming a root extending gap in accordance with an embodiment of the present application;

FIG. 3 is a perspective view of a turbine blade according to an embodiment of the present application;

FIG. 4 is a right side view of a turbine blade according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a limiting structure according to an embodiment of the present application;

FIG. 6 is a schematic view of another limiting structure according to an embodiment of the present application;

FIG. 7 is a schematic view of another limiting structure according to an embodiment of the present application;

FIG. 8 is a force analysis chart of a first sealing strip and a second sealing strip according to an embodiment of the present application;

FIG. 9 is a cross-sectional view of a seal chamber according to line A-A of FIG. 2 in accordance with an embodiment of the present application;

fig. 10 is a cross-sectional view of yet another seal chamber according to line A-A of fig. 2 in accordance with an embodiment of the present application.

In the figure: 1. a first turbine blade; 2. a second turbine blade; 3. root extending gap; 41. extending roots; 411. adjacent extending roots; 42. a blade body; 43. a tenon; 44. a first groove; 45. a clamping groove; 46. a second groove; 47. a recess; 48. a protrusion; 49. sealing the cavity; 51. balancing weight; 52. a first connector; 53. a first sealing strip; 54. a second sealing strip; 55. a third connecting member; 56. a clamping block; 57. a second connector; 58. a limit spring; 6. and (3) rotating the shaft.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It should be noted that, in the description of the present application, the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the apparatus or elements to be referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

Furthermore, it should be understood that the dimensions of the various elements shown in the figures are not drawn to actual scale, e.g., the thickness or width of some layers may be exaggerated relative to other layers for ease of description.

It should be noted that like reference numerals and letters refer to like items in the following figures, and thus once an item is defined or illustrated in one figure, no further detailed discussion or description thereof will be necessary in the following description of the figures.

Before understanding the embodiments of the present application, it should be clear that a turbine is an essential component for use in an aircraft engine or gas turbine. The aero-engine or the gas turbine drives the turbine to rotate to do work by utilizing high-temperature gas and outputs power to the outside. Since turbines are well known in the art, they are not described in any great detail.

Specifically, the turbine blade in the prior art, as shown in fig. 1, includes a blade body 42, a root extension 41 and a tenon 43, which are sequentially connected. Among other things, the blade body 42 plays an important role in converting energy during turbine operation. When the high-temperature and high-pressure air flow passes through the blade body 42, the blade body 42 converts the energy of the air flow into mechanical energy to drive the turbine to rotate. The rabbet 43 is mainly used for connection with a turbine disk (not shown in the figures). The root 41 is mainly used for reducing the vibration of the blade body 42 and guiding cooling air so as to optimize the working efficiency of the turbine.

In particular, in the prior art, the turbine is comprised of a plurality of turbine blades and a turbine disk. As shown in fig. 2 (the turbine disc is not shown, and only two turbine blades are shown), two adjacent turbine blades on the turbine disc are a first turbine blade 1 and a second turbine blade 2, respectively, and a root extension gap 3 is formed between the root extensions of the first turbine blade 1 and the second turbine blade 2.

Specifically, as shown in fig. 2, a root extending gap 3 is formed between the root extending portions of the first turbine blade 1 and the second turbine blade 2. It will be readily appreciated that the root extension gap 3 is formed by the opposite sides between the roots of the first turbine blade 1 and the second turbine blade 2. It is easily conceivable that the root extension of each turbine blade and the root extensions of the turbine blades on both sides adjacent thereto can form the root extension gap 3, that is to say that each turbine blade root extension has two sides for forming the root extension gap 3. In the present application, these two sides are respectively named as a first side and a second side, for example: the extension of the first turbine blade 1 has a first side and a second side, and the second turbine blade 2 also has a first side and a second side. It should be clear that a root extension gap 3 is formed between the first side of the root extension on the first turbine blade 1 and the second side of the root extension on the second turbine blade 2, and that the second side of the root extension on the first turbine blade 1 forms a further root extension gap 3 with the first side of the root extension of the further turbine blade (not shown in the figures).

Before understanding the embodiments of the present application, it should be further understood that, in order to reduce friction between the movable column and the first groove, the chinese patent application No. 202310879847.0 sets the movable column to be cylindrical. And in the long-term use process of the cylindrical movable column, the contact area with the first groove is smaller (namely, the pressure intensity is larger), and the larger pressure intensity easily causes the concave pit on the surface of the first groove (namely, the friction force with the movable column is increased) to cause the loose sealing of the root extending gap. Therefore, only the mass of the movable column can be reduced, so that the pressure of the movable column and the first groove is reduced. In other words, if the mass of the movable column is small, in some application scenarios, the movable column is difficult to seal the root extending gap.

In order to seal the root extending gap 3, an embodiment of the present application proposes a turbine blade, specifically, as shown in fig. 3 to 10, the turbine blade includes a root extending portion 41, a first groove 44 formed on a first side surface of the root extending portion 41, a second groove 46 formed on a second side surface of an adjacent root extending portion 411, a balancing weight 51, a first sealing strip 53 and a second sealing strip 54.

Specifically, in the embodiment of the present application, as shown in fig. 9 and 10, a stub clearance 3 is formed between a first side of a stub 41 and a second side of an adjacent stub 411; the first groove 44 and the second groove 46 form a seal cavity 49. The weight 51, the first seal 53 and the second seal 54 are disposed inside the seal cavity 49. The first sealing strip 53 and the second sealing strip 54 are connected with the balancing weight 51 through a connecting assembly. As shown in fig. 8, if the turbine blade rotates around the rotation shaft 6, the weight 51 can apply thrust to the first seal 53 and the second seal 54 by means of the centrifugal force F1 and the connection assembly so that the first seal 53 and the second seal 54 collide with the side surfaces of the seal chamber 49.

It should be clear that in the embodiment of the present application, in order for the first sealing strip 53 and the second sealing strip 54 to seal the root extension gap 3, it is necessary that the thickness of the first sealing strip 53 and the second sealing strip 54 in the first direction is greater than the root extension gap 3 in the design, and the first direction is perpendicular to the first side.

It should be clear that the turbine can generate centrifugal forces on the various parts on its body when rotating. As shown in fig. 8, when the turbine rotates around the rotation shaft 6 as a center axis, a centrifugal force F1 perpendicular to the rotation shaft 6 can be generated to the weight 51. And the centrifugal force F1 can be transmitted to the first sealing strip 53 through the connection assembly to a pushing force F2; transmitting a pushing force F3 to the second sealing strip 54. The thrust F2 is decomposed to obtain a thrust F4 parallel to the rotation axis 6 and a thrust F5 perpendicular to the rotation axis 6. Wherein the thrust force F4 can cause the first sealing strip 53 to collide with the side surface of the sealing cavity 49, thereby realizing the sealing of the root extending gap 3. It will be readily appreciated that in the embodiment of the present application, the thrust force F3 is decomposed to obtain a thrust force F6 parallel to the rotation axis 6 and a thrust force F7 perpendicular to the rotation axis 6. Wherein the thrust force F6 can cause the first sealing strip 53 to collide with the other side surface of the sealing cavity 49, thereby realizing the sealing of the root extending gap 3.

It should be clear that in the embodiment of the present application, the connection assembly needs to have a certain rigidity to transmit the pushing force, and if the connection assembly does not have a rigidity (e.g. a rope or a chain), that is, the connection assembly cannot transmit the pushing force, as shown in fig. 8, the weight 51 can only apply a pulling force to the first sealing strip 53 and the second sealing strip 54 under the action of centrifugal force, so that the first sealing strip 53 and the second sealing strip 54 have a tendency to approach each other. That is, the first seal 53 and the second seal 54 cannot collide with the side face of the seal cavity 49. In other words, the first sealing strip 53 and the second sealing strip 54 cannot seal the root extending gap, which cannot solve the technical problem set forth in the background art.

It should be clear that the seal cavity 49 is formed by the first groove 44 and the second groove 46 being spliced as shown in fig. 9 and 10. That is, the side of the seal cavity 49 is formed by the concatenation of the side of the first groove 44 and the side of the second groove 46. In other words, if the root extending gap 3 is to be sealed, it is necessary that the first sealing strip 53 or the second sealing strip 54 can simultaneously collide with the side face of the first groove 44 and the side face of the second groove 46. The sides of the seal cavity 49 may be perpendicular to the axis of rotation 6 (i.e., the axis of the turbine) in embodiments of the application. That is, the side of the first groove 44 and the side of the second groove 46 lie in the same plane (not shown in the drawing). If the stub 41 is displaced from the adjacent stub 411 in the direction of the rotation axis 6 during production or during long-term use, a step is formed between the side face of the first groove 44 and the side face of the second groove 46 (i.e., the side face of the first groove 44 and the side face of the second groove 46 are parallel but not in the same plane). It should be clear that if a step is formed between the side surface of the first groove 44 and the side surface of the second groove 46, it is difficult for the first seal 53 or the second seal 54 to simultaneously interfere with both the side surfaces of the first groove 44 and the second groove 46. That is, if a step is formed between the side surface of the first groove 44 and the side surface of the second groove 46, it is difficult for the first seal strip 53 or the second seal strip 54 to seal the root extending gap 3.

In one embodiment of the present application, in order to enable the first sealing strip 53 or the second sealing strip 54 to seal the stub clearance 3 even if the stub 41 is offset from the adjacent stub 411 in the direction of the rotation axis 6, as shown in fig. 9, the side surface of the seal cavity 49 is formed with the recess 47, and at this time, the side surface of the first groove 44 and the side surface of the second groove 46 intersect (i.e., are not parallel). In designing, it is necessary to adapt the first sealing strip 53 to the recess 47 and the second sealing strip 54 to the recess 47. That is, in the case where the first seal 53 or the second seal 54 is provided on the protrusion corresponding to the recess 47, the protrusion and the recess 47 can be bonded well even if the projecting root 41 and the adjacent projecting root 411 are displaced in the direction along the rotation axis 6. It will be readily appreciated that in order to solve the above-described technical problem, in another embodiment of the present application, as shown in fig. 10, the side surface of the seal cavity 49 is formed with a protrusion 48, and at this time, the side surface of the first groove 44 and the side surface of the second groove 46 intersect (i.e., are not parallel). In designing, it is necessary to adapt the first sealing strip 53 to the projection 48 and the second sealing strip 54 to the projection 48. That is, in the case where the first seal strip 53 or the second seal strip 54 is provided in the recess corresponding to the protrusion 48, even if the projecting root 41 and the adjacent projecting root 411 are displaced in the direction along the rotation axis 6, the protrusion 48 and the recess can be bonded well.

It should be clear that in the embodiments of the application, the recess 47 or the projection 48 may be such that the sides of the sealing cavity 49 are beveled, as shown in fig. 9 and 10. It will be readily appreciated that in other embodiments of the application, the sides of the seal cavity 49 may also be curved (not shown).

From the foregoing, it will be appreciated that in embodiments of the present application, the connection assembly may be any component capable of transmitting a pushing force. In one embodiment of the present application, as shown in fig. 3-8, the connection assembly includes at least one first connection member 52 and at least one second connection member 57. Wherein, the first end of each first connecting piece 52 is connected with the balancing weight 51, and the second end is connected with the first sealing strip 53. Each second connecting member 57 has a first end connected to the weight 51 and a second end connected to the second sealing strip 54.

As can be seen from fig. 8, the first connecting member 52 forms an angle B with the direction of the centrifugal force F1 from the first end toward the second end. Specifically, in the embodiment of the present application, the direction in which the first connecting member 52 points from the first end to the second end refers to the direction parallel to the first connecting line. The first connection line refers to a connection line between any point on the first end surface of the first connecting piece 52 and any point on the second end surface of the first connecting piece 52. In the embodiment of the present application, the arbitrary point may be a center point, a center point of gravity, or a center point of mass of the face (hereinafter, a direction in which each second connecting piece 57 points from the first end to the second end is also similar, and a description thereof will be omitted). It can be seen that the thrust force F4 may be approximately equal to F5 tan (angle B), and if the angle B is equal to or greater than 90 °, the thrust force F4 approaches 0, that is, the first connecting piece 52 cannot be attached to the side wall of the sealing cavity 49, in other words, the first connecting piece 52 cannot seal the root extending gap 3. Thus, in the embodiment of the present application, the first connection members 52 each form an acute angle with the direction of the centrifugal force F1 from the first end toward the second end.

For the same reasons as described above, in one embodiment of the present application, the angle (not shown) formed by the direction from the first end to the second end and the direction of the centrifugal force F1 of each second connection member 57 is also an acute angle.

It should be clear that in the embodiments of the present application f5+f7=f1, and neither F5 nor F7 may be equal to 0. As can be seen from the foregoing, f4≡f5× (angle B), in order to ensure that the first sealing strip 53 can generate a sufficient interference force with the side surface of the sealing cavity 49, the angle formed by the direction from the first end to the second end of each first connecting piece 52 and the direction of the centrifugal force F1 is greater than or equal to 30 ° and less than or equal to 60 °. Specifically, it may be any one degree of 30 °, 35 °, 40 °, 45 °, 50 °, 55 ° and 60 °, or any degree between the above two adjacent degrees.

For the same reason as described above, in one embodiment of the present application, each of the second connection members 57 forms an angle of 30 ° or more and 60 ° or less with the direction of the centrifugal force F1 from the first end toward the second end. Specifically, it may be any one degree of 30 °, 35 °, 40 °, 45 °, 50 °, 55 ° and 60 °, or any degree between the above two adjacent degrees.

In the embodiment of the present application, as shown in fig. 3 to 5, each of the first connection members 52 and each of the second connection members 57 are elastic members. For example: the elastic piece can be a spring, an elastic straight rod, an elastic curved rod or an elastic sheet, etc. In other embodiments of the present application, as shown in fig. 6 and 7, each of the first and second connection members 52, 57 is a non-elastic member. That is, the first and second connection members 52 and 57 cannot be elastically deformed. At this time, the first end of each first connecting piece 52 is required to be hinged to the balancing weight 51, and the second end is required to be hinged to the first sealing strip 53; each second connecting member 57 has a first end hinged to the weight 51 and a second end hinged to the second sealing strip 54.

From the foregoing, it will be appreciated that in embodiments of the present application the connection assembly needs to have a certain rigidity to avoid that the connection assembly cannot apply a pushing force to the first sealing strip 53 and the second sealing strip 54. Therefore, in the embodiment of the present application, if each of the first connecting member 52 and each of the second connecting members 57 are elastic members, each of the elastic members is required to satisfy the above-mentioned rigidity requirement in the design process.

It is readily associated that in some embodiments of the present application, the particular form of first connector 52 or second connector 57 may be selected as desired. For example: all of the first connection members 52 may be provided as elastic members, and all of the second connection members 57 may be provided as inelastic members; or all the first connection members 52 are provided as non-elastic members and all the second connection members 57 are provided as elastic members.

It should be clear that during rotation of the turbine, centrifugal forces generated on the weight 51, the first seal 53 and the second seal 54 are large. If the movement amplitude of the balancing weight 51, the first sealing strip 53 and the second sealing strip 54 in the sealing cavity 49 is too large, the balancing weight 51, the first sealing strip 53 and the second sealing strip 54 collide and are damaged, and the turbine blade is damaged due to heavy weight. In order to solve the above-mentioned technical problem, in one embodiment of the present application, the turbine blade further includes a limiting structure for limiting the first sealing strip 53 and the second sealing strip 54 to approach the balancing weight 51. That is, the restriction structure is used to prevent the first seal 53, the second seal 54, and the weight 51 from being damaged by collision close to each other.

As shown in fig. 7, in one embodiment of the present application, the limiting structure may be at least one limiting spring 58, and each limiting spring 58 has a first end connected to the first sealing strip 53 and a second end connected to the second sealing strip 54. The limiting spring 58 can avoid the first sealing strip 53 and the second sealing strip 54 from approaching each other, and can avoid the first sealing strip 53 and the second sealing strip 54 from approaching the balancing weight 51.

In one embodiment of the present application, as shown in fig. 3 and 4, the limiting structure includes a clamping groove 45 disposed in the first groove 44, a clamping block 56, and at least two elastic third connecting members 55. The clamping block 56 is matched with the clamping groove 45, that is to say, the clamping block 56 is clamped into the clamping groove 45. A first end of each third connecting member 55 is connected to a clamping block 56; wherein a second end of at least one third connecting member 55 is connected to the first sealing strip 53 and the second ends of the remaining third connecting members 55 are connected to the second sealing strip 54. As shown in fig. 3, 4 and 5, a diamond-like elastic structure is formed between the first, second and third connection members 52, 57 and 55, preventing the first, second and balancing weights 53, 54 from approaching each other.

In one embodiment of the present application, as shown in fig. 6, the limiting structure includes a clamping groove 45 provided in the first groove 44, a clamping block 56, and at least one third connecting member 55 having elasticity. Specifically, the clamping block 56 is matched with the clamping groove 45. A first end of each third connecting member 55 is connected to a clamping block 56; a second end of each third link 55 is connected to the weight 51. The first sealing strip 53, the second sealing strip 54 and the weight 51 are prevented from approaching each other under the support between the first connecting member 52, the second connecting member 57 and the third connecting member 55.

It is easily conceivable that in other embodiments of the application, the snap-in groove 45 may also be provided inside the second recess 46. Or half of the clamping groove 45 is positioned in the first groove 44 and the other half is positioned in the second groove 46, and the position, shape and construction of the clamping groove 45 are not limited.

Specifically, the embodiment of the turbine blade provided by the application can push the first sealing strip and the second sealing strip to seal the root extending gap by virtue of the centrifugal force of the balancing weights. The sealing performance of the turbine is not affected by the roughness in the sealing cavity, that is, in the embodiment of the application, the balancing weight can be set into any shape with larger contact area with the surface of the sealing cavity, so that the first sealing strip and the second sealing strip can seal the root extending gap under the lowest working condition of the turbine by adjusting the mass of the configuration block. The turbine blade provided by the application can ensure that the root extending gap is strictly sealed, and the service life of the turbine blade can be prolonged.

Although embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the application, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A turbine blade, comprising:

a root extension (41);

a first groove (44) arranged on the first side surface of the extending root (41) and a second groove (46) arranged on the second side surface of the adjacent extending root (411); a root extending gap (3) is formed between the first side surface of the root extending part (41) and the second side surface of the adjacent root extending part (411); -said first recess (44) and said second recess (46) form a sealed cavity (49);

the balancing weight (51), the first sealing strip (53) and the second sealing strip (54) are arranged in the sealing cavity (49); the first sealing strip (53) and the second sealing strip (54) are connected with the balancing weight (51) through a connecting component; if the turbine blade rotates around the rotating shaft (6), the balancing weight (51) can apply thrust to the first sealing strip (53) and the second sealing strip (54) by means of centrifugal force (F1) and the connecting assembly, so that the first sealing strip (53) and the second sealing strip (54) are in contact with the side face of the sealing cavity (49).

2. The turbine blade of claim 1, wherein the connection assembly comprises:

at least one first connector (52); the first end of each first connecting piece (52) is connected with the balancing weight (51), and the second end of each first connecting piece is connected with the first sealing strip (53); the included angle formed by the direction from the first end to the second end of each first connecting piece (52) and the centrifugal force (F1) is an acute angle;

at least one second connection (57); the first end of each second connecting piece (57) is connected with the balancing weight (51), and the second end is connected with the second sealing strip (54); each second connecting piece (57) forms an acute angle with the centrifugal force (F1) direction from the first end to the second end.

3. The turbine blade according to claim 2, wherein each first connection piece (52) forms an angle of 30 ° or more, 60 ° or less with the centrifugal force (F1) direction from the first end towards the second end; each second connecting piece (57) forms an included angle which is more than or equal to 30 degrees and less than or equal to 60 degrees with the direction of the centrifugal force (F1) from the first end to the second end.

4. Turbine blade according to claim 2, wherein each first connection element (52) and each second connection element (57) are elastic elements.

5. Turbine blade according to claim 2, wherein each first connection element (52) and each second connection element (57) are non-elastic elements, a first end of each first connection element (52) being hinged to the balancing weight (51) and a second end being hinged to the first sealing strip (53); the first end of each second connecting piece (57) is hinged with the balancing weight (51), and the second end of each second connecting piece is hinged with the second sealing strip (54).

6. The turbine blade of any one of claims 1 to 5, further comprising a limiting structure for limiting the proximity of the first sealing strip (53) and the second sealing strip (54) to the balancing weight (51).

7. The turbine blade of claim 6, wherein the limiting structure comprises:

a clamping groove (45) arranged in the first groove (44) or the second groove (46);

the clamping block (56) is matched with the clamping groove (45);

at least two elastic third connecting pieces (55), wherein the first end of each third connecting piece (55) is connected with the clamping block (56); wherein a second end of at least one third connecting piece (55) is connected with the first sealing strip (53), and second ends of the rest of the third connecting pieces (55) are connected with the second sealing strip (54).

8. The turbine blade of claim 6, wherein the limiting structure comprises:

the clamping block (56) is matched with the clamping groove (45);

at least one elastic third connecting piece (55), wherein the first end of each third connecting piece (55) is connected with the clamping block (56); a second end of each third connecting piece (55) is connected with the balancing weight (51).

9. Turbine blade according to any of claims 1 to 5, wherein the side of the sealing cavity (49) is formed with a recess (47) or a bulge (48), the first sealing strip (53) being adapted to the recess (47) or the bulge (48); the second sealing strip (54) is matched with the concave (47) or the convex (48).

10. Turbine blade according to claim 9, wherein the outer surface of the recess (47) or the projection (48) is beveled or curved.