Axial locking assembly for blade root of moving blade

Abstract

The present invention provides an axial locking assembly for a moving blade root. The blade root is mounted within a tenon groove, and the locking assembly axially locks the blade root and the tenon groove. The locking assembly includes a locking body, a first mounting portion, and a second mounting portion. The first mounting portion is disposed on the blade root, and the second mounting portion is disposed within the tenon groove. The locking body is radially disposed between the first mounting portion and the second mounting portion and is at least partially accommodated within the first mounting portion and / or the second mounting portion. The locking body is rotatable to a locking position in which it is axially locked with the first mounting portion and / or the second mounting portion. This moving blade root axial locking assembly effectively limits axial movement of the blade root within the tenon groove, thereby axially securing the moving blade and the impeller. Installation and removal can be achieved by rotating the locking body, making operation convenient.

Description

Technical Field

[0001] The present invention relates to a moving blade installation structure, in particular to a moving blade root axial locking assembly. Background Art

[0002] When a heavy-duty gas turbine is operating, the compressor rotor blades are connected to the tongue and groove on the outer edge of the disc via the blade root, thereby transferring the load acting on the rotor blade body to the disc. The blade root-tongue and groove connection structure should not only have sufficient strength and appropriate rigidity to avoid excessive stress concentration, but also be simple in structure to facilitate processing, assembly, disassembly, and replacement. The axial dovetail blade root is a blade root form widely used in heavy-duty gas turbine compressor rotor blades, steam turbine rotor blades, and aircraft engine fans. The axial blade root is drawn out with an axial groove using a broach, and one axial blade is assembled into each axial groove.

[0003] There are three main existing solutions for limiting axial movement of dovetail blade roots within their mortises. First, to accommodate the need for blade assembly and disassembly, lugs are machined in front and behind the mortises on the disc. These lugs are then installed with front and rear baffles to limit axial displacement. Second, keyways are cut perpendicular to the mortises in the disc and blade root, with locking blocks inserted into the keyways to limit axial displacement. Third, a spring is used to push up a stop pin at the bottom of the mortises to limit axial displacement and facilitate blade installation.

[0004] However, all three solutions have obvious defects. For the first structural solution of processing ears on the tenon, using ears and baffles to limit the axial movement of the axial dovetail blade root, the ears need to be processed in one circle, the structure is complex, and the processing is difficult; and this solution requires processing ears on the wheel disc, which increases the risk of wheel disc processing errors. For the second solution of opening a keyway perpendicular to the tenon on the wheel disc and the blade root, inserting a locking block in the keyway to limit the axial displacement of the tenon, the keyway and the locking block are difficult to process, and the last two locking blocks need to be bent using specific tools, which makes disassembly and assembly inconvenient. For the third solution of using a spring to lift the stop pin at the bottom of the tenon to prevent the axial movement of the blade root, the structure is simple and easy to install, but it is very difficult to remove. There is a need for a locking structure for the axial dovetail blade root of a moving blade that is easy to process, easy to assemble and disassemble, and safe.

[0005] Patent RU2302532C2 discloses a compressor blade locking device. The blades are axially secured to the gas turbine rotor disk using a locking structure on each blade that inserts into a matching end slot. The locking structure is shaped like an inverted isosceles triangle, with two sides intersecting at the base and grooves on each side forming a series of teeth. However, this patented solution is difficult to manufacture and inconvenient to assemble and disassemble. Summary of the Invention

[0006] The main purpose of the present invention is to provide an axial dovetail blade root locking structure for a moving blade, so as to solve the problem in the prior art of limiting the axial movement of the axial dovetail blade root in the tenon groove.

[0007] To achieve the above objectives, according to one aspect of the present invention, a rotor blade root axial locking assembly is provided. The blade root is mounted within a tenon groove, and the locking assembly axially locks the blade root and the tenon groove. The locking assembly includes a locking body, a first mounting portion, and a second mounting portion. The first mounting portion is disposed on the blade root, and the second mounting portion is disposed within the tenon groove. The locking body is radially disposed between the first mounting portion and the second mounting portion and is at least partially accommodated within the first mounting portion and / or the second mounting portion. The locking body is rotatable to a locking position in which it is axially locked with the first mounting portion and / or the second mounting portion. This rotor blade root axial locking assembly can effectively limit axial movement of the axial dovetail-shaped blade root within the tenon groove, thereby axially securing the rotor blade and the impeller.

[0008] Furthermore, the first mounting portion and the second mounting portion jointly define an accommodating cavity, in which the locking body is accommodated.

[0009] Furthermore, the first mounting portion is a first groove opened at the bottom of the blade root, the locking body is partially arranged in the first groove, and in the locking position, part of the end surface of the locking body is pressed against the groove surface of the first groove, and / or the second mounting portion is a second groove arranged in the tenon groove, the locking body is partially arranged in the second groove, and in the locking position, part of the end surface of the locking body is pressed against the groove surface of the second groove.

[0010] Furthermore, an extension direction of the first groove and / or the second groove is perpendicular to the blade root end surface.

[0011] Furthermore, the extension direction of the first and / or second grooves forms a predetermined angle with the extension direction of the blade root, thereby increasing the load-bearing surface of the locking body. The angle between the locking body's installation direction and the mortise-slotting direction allows the locking body's cross-section to bear the axial force of the blade root. This results in a large load-bearing area, relatively uniform stress distribution, a large stress safety margin, and a low risk of fracture, ensuring a high degree of safety.

[0012] Furthermore, the predetermined angle is 10°-40°.

[0013] Furthermore, the locking body includes a first locking block and a second locking block, and the first locking block and the second locking block are jointly accommodated in the accommodating cavity.

[0014] Furthermore, the first locking block includes a clamping groove, and the second locking block includes a clamping protrusion; the clamping protrusion cooperates with the clamping groove so that the first locking block and the second locking block become one.

[0015] Furthermore, the locking body composed of the first locking block and the second locking block is a columnar body with a long side and a short side in its cross section.

[0016] Furthermore, the end surfaces of the first and / or second locking blocks include a process hole, through which the locking body can be rotated to gradually deflect the long side toward the vertical direction, thereby securing the locking body within the accommodating cavity. The locking body cross-section, engaging groove, engaging protrusion, process hole, and other components of this assembly can be configured into various other shapes as needed, providing a flexible structural design.

[0017] Furthermore, the cross section of the locking body is elliptical.

[0018] Furthermore, the cross section of the accommodating cavity is elliptical, and the major axis of the ellipse extends in the horizontal direction.

[0019] Furthermore, the first groove also includes an adjustment hole, through which the process hole can be rotated to drive the first locking block and the second locking block to rotate together. The rotor blade root axial locking assembly can be installed and removed by rotating the locking body, which is easy to operate.

[0020] Furthermore, the locking body can be fixedly connected to the first groove or the second groove at a position close to the blade root end surface.

[0021] Furthermore, the fixed connection is riveting or electric welding, which can prevent the locking body from rotating automatically in the accommodating cavity.

[0022] By applying the technical solution of the present invention, the following technical effects are achieved:

[0023] 1. The rotor blade root axial locking assembly can effectively limit the axial movement of the axial dovetail blade root in the mortise and tenon, thereby axially fixing the rotor blade and the impeller;

[0024] 2. The blade root axial locking assembly can be installed and removed by rotating the locking body, which is easy to operate;

[0025] 3. The rotor blade root axial locking assembly has a simple structure, is easy to process, can be mass-produced, and has economic value;

[0026] 4. There is an angle between the installation direction of the locking body and the mortise and tenon slotting direction. The cross section of the locking body is used to bear the axial force of the blade root. The bearing area is large, the stress distribution is relatively uniform, the stress safety margin is large, and it is not easy to break. The component has a certain degree of safety.

[0027] 5. The locking body cross section, snap-in groove, snap-in protrusion, process hole and other parts of the component can be set into various other shapes as required, and the structural design is relatively flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 shows an assembly diagram of an axial dovetail blade root locking assembly according to the present invention; and

[0030] Figure 2 An exploded view of an axial dovetail blade root locking structure according to the present invention is shown;

[0031] Figure 3 A cross-sectional view of an axial dovetail blade root locking assembly according to the present invention is shown;

[0032] Figure 4 It shows a schematic structural diagram of the upper half locking block according to the present invention;

[0033] Figure 5 It shows a schematic structural diagram of the lower half locking block according to the present invention;

[0034] Figure 6 A schematic diagram of the assembly structure of the upper half locking block and the lower half locking block according to the present invention is shown;

[0035] Figure 7 It shows a schematic structural diagram of the blade root locking assembly in unlocked state according to the present invention;

[0036] Figure 8 A schematic structural diagram of the blade root locking assembly in an unlocked state according to the present invention is shown.

[0037] The above drawings include the following reference numerals:

[0038] 1. Moving blade; 2. First locking block; 3. Second locking block; 4. Wheel; 5. Process hole; 6. Snap-fit ​​groove; 7. Snap-fit ​​protrusion; 8. First groove; 9. Second groove; 10. Adjustment hole;

[0039] X, horizontal direction; Y, vertical direction; α, predetermined angle. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] The present invention is described in further detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed by the present invention. The term "including" when used indicates the existence of a feature, but does not exclude the existence or addition of one or more other features; the terms "lateral", "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be construed as limiting the present invention; in addition, the terms "first", "second", etc. are used to distinguish different objects, rather than to describe a specific order.

[0042] In this description, it should be noted that, unless otherwise specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention. Furthermore, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0043] The compressor rotor blades are connected to the outer edge of the disc via a blade root. This connection restricts the blade's circumferential movement within the disc, but the blade root retains axial freedom. However, the prior art lacks a technology for safely limiting the axial movement of axial dovetail blade roots within the disc's mortise and tenon grooves that is easy to manufacture, convenient to assemble and disassemble, and safe.

[0044] According to the present invention, a rotor blade root axial locking assembly is proposed, such as Figure 1 As shown, the moving blade 1 is installed on the wheel disc 4 through a blade root-tenon structure, the blade root is installed inside the tenon, and the locking assembly limits the relative displacement of the blade root and the wheel disc in the axial direction by limiting the axial freedom of the blade root and the tenon.

[0045] Specifically, the locking assembly includes a locking body, a first mounting portion, and a second mounting portion. The first mounting portion is opened on the blade root, and the second mounting portion is opened in the tenon. The locking body is arranged between the first mounting portion and the second mounting portion in the radial direction and is at least partially accommodated in the first mounting portion and / or the second mounting portion. The locking body can be rotated to a locking position axially locked with the first mounting portion and / or the second mounting portion. Preferably, the locking body is placed in a space jointly formed by the first mounting portion at the bottom of the blade root and the second mounting portion in the tenon. The locking body can be rotated to a locking position in this space to limit the axial movement of the axial dovetail blade root in the tenon.

[0046] like Figure 2As shown, the first mounting portion is a first groove 8 provided at the bottom of the blade root, with the locking body partially disposed within the first groove 8. In the locked position, a portion of the end face of the locking body presses against the groove surface of the first groove 8. Alternatively, the second mounting portion is a second groove 9 disposed within the tenon groove, with the locking body partially disposed within the second groove 9. In the locked position, a portion of the end face of the locking body presses against the groove surface of the second groove 9. The locking body is disposed within the space formed by the first and second grooves 8, 9. That is, the first and second grooves 8, 9 jointly define a receiving cavity within which the locking body is accommodated. This impeller blade root axial locking assembly can effectively limit the axial movement of the axial dovetail blade root within the tenon groove, thereby axially securing the impeller and the impeller.

[0047] In addition, the extension direction of the first groove 8 and / or the second groove 9 is perpendicular to the end face of the blade root, that is, the extension direction of the first groove 8 and / or the second groove 9 is consistent with the axial direction of the wheel disc. The extension direction of the first groove 8 and / or the second groove 9 forms a predetermined angle α with the extension direction of the blade root. The range of the predetermined angle α is generally 10°-40°. The present invention does not limit the specific value of the predetermined angle α, which is determined by the tenon design. The extension direction of the first groove 8 and / or the second groove 9 forms a predetermined angle with the extension direction of the blade root, so that the bearing surface of the locking body is not only the end face, but the cylindrical surface will also bear the force, which increases the bearing surface of the locking body, makes the stress distribution more uniform, and has a large safety margin for stress. It is not easy to break, so that the component has a certain degree of safety.

[0048] like Figure 3 As shown, the locking body includes a first locking block 2 and a second locking block 3, which are accommodated together in the accommodating cavity. The locking body has a simple structure, is easy to process, can be mass-produced, and has economic value.

[0049] Specifically, if Figure 4 and Figure 5 As shown, the first locking block 2 includes a snap-in groove 6, and the second locking block 3 includes a snap-in protrusion 7; the snap-in protrusion 7 cooperates with the snap-in groove 6 to make the first locking block 2 and the second locking block 3 become one. The snap-in protrusion 7 and the snap-in groove 6 fit tightly together, so that the first locking block 2 and the second locking block 3 are connected to form a locking body, as shown in FIG. Figure 6 shown.

[0050] In addition, the locking body composed of the first locking block 2 and the second locking block 3 is a cylindrical body with a long side and a short side in cross section. Preferably, the cross section of the locking body in this embodiment is elliptical. The cross section of the accommodating cavity composed of the first groove 8 and the second groove 9 also has a long axis and a short axis and can be designed to be elliptical. The long axis of the elliptical cross section of the accommodating cavity extends along the horizontal direction X. The length of the long axis of the cross section of the accommodating cavity should not be less than the long side of the cross section of the locking body, so that the locking body can be placed in the accommodating cavity during installation. The short axis of the cross section of the accommodating cavity extends along the vertical direction Y, and its length should be slightly less than the long side of the cross section of the locking body.

[0051] During the process of rotating the locking body, the long side of the cross section of the locking body gradually deflects from the horizontal direction X to the vertical direction Y. During the rotation process, the long side of the locking body gradually approaches the short axis of the accommodating cavity. The length of the short axis of the cross section of the accommodating cavity is slightly smaller than the long side of the cross section of the locking body, so that the locking body and the accommodating cavity form a transition fit or interference fit, so that the locking body fits reliably in the accommodating cavity and is not easy to rotate.

[0052] The first locking block 2 and / or the second locking block 3 also have a process hole 5 on their end faces. A tool inserted into the process hole 5 allows the locking body to be rotated. An adjustment hole 10 is provided in the first groove 8 at the base of the blade root. A tool inserted into the adjustment hole 10 allows the process hole to be rotated, thereby driving the first and second locking blocks 2 and 3 to rotate together. The locking body's cross-section, engaging grooves, engaging protrusions, process holes, and other components of this assembly can be configured in various other shapes as needed, providing a flexible structural design.

[0053] like Figure 2 As shown, during the installation process, first place the second locking block 3 into the second groove 9 at the bottom of the axial groove, and insert the blade root of the dovetail-shaped moving blade 1 into the axial groove; then insert the first locking block 2 along the snap-on protrusion 7 of the second locking block 3, so that the first locking block 2 and the second locking block 3 are connected to form a locking body. Afterwards, a tool such as an iron bar or a screwdriver can be inserted through the adjustment hole 10 into the process hole 5 to rotate the locking body, so that the long side of the cross section of the locking body gradually deflects toward the vertical direction Y, so that the locking body is tightened in the accommodating cavity, as shown in FIG. Figure 8 shown.

[0054] Preferably, the locking body can be rotated 90° so that the dividing surface of the first locking block 2 and the second locking block 3 is perpendicular to the dividing surface of the blade root and the mortise and tenon, thereby preventing the first locking block 2 from falling out, limiting the axial movement of the locking body to the maximum extent, and thus achieving axial locking of the dovetail blade 1.

[0055] To remove a dovetail blade 1, first insert a tool through adjustment hole 10 into process hole 5 and rotate the locking body until the dividing surface between the first locking block 2 and the second locking block 3 is parallel to the dividing surface between the blade root and the mortise. Afterwards, remove the first locking block 2, and the dovetail blade 1's root can be pulled out of the mortise. This blade root axial locking assembly can be easily installed and removed simply by rotating the locking body, making it easy to operate.

[0056] In addition, the locking body can be fixedly connected to the first groove 8 or the second groove 9 near the blade root end face to prevent the locking body from rotating in the accommodating cavity. The fixing method can be riveting or electric welding.

[0057] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: 1. The axial locking assembly of the blade root of the moving blade can effectively limit the axial movement of the axial dovetail blade root in the mortise and tenon, thereby axially fixing the moving blade and the wheel disc; 2. The axial locking assembly of the blade root of the moving blade can be installed and removed by rotating the locking body, which is easy to operate; 3. The axial locking assembly of the blade root of the moving blade has a simple structure, is easy to process, can be mass-produced, and has economic value; 4. There is an angle between the installation direction of the locking body and the mortise and tenon opening direction, and the cross-section of the locking body is used to bear the axial force of the blade root. The bearing area is large, the stress distribution is relatively uniform, the stress safety margin is large, and it is not easy to break. The assembly has a certain degree of safety; 5. The locking body cross-section, snap-in groove, snap-in protrusion, process hole and other parts of the assembly can be set to various other shapes as required, and the structural design is relatively flexible.

[0058] It should be noted that the present invention can also be applied to the installation of the axis of moving blades of compressors or steam turbines with other integrally forged rotors or welded rotors.

[0059] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An axial locking assembly for a blade root of a moving blade, wherein the blade root is installed in a tenon groove, and the locking assembly axially locks the blade root and the tenon groove, characterized in that: The locking assembly includes a locking body, a first mounting portion, and a second mounting portion, wherein the first mounting portion is provided on the blade root, and the second mounting portion is provided in the mortise and tenon groove. The locking body is radially disposed between the first mounting portion and the second mounting portion and is at least partially accommodated in the first mounting portion and / or the second mounting portion. The locking body is rotatable to a locking position axially locked with the first mounting portion and / or the second mounting portion. The first mounting portion and the second mounting portion jointly define an accommodating cavity, in which the locking body is accommodated; The first mounting portion is a first groove (8) provided at the bottom of the blade root, the locking body is partially arranged in the first groove (8), and in the locking position, a part of the end surface of the locking body is pressed against the groove surface of the first groove (8), and / or the second mounting portion is a second groove (9) provided in the mortise, the locking body is partially arranged in the second groove (9), and in the locking position, a part of the end surface of the locking body is pressed against the groove surface of the second groove (9); The locking body comprises a first locking block (2) and a second locking block (3), and the first locking block (2) and the second locking block (3) are accommodated together in the accommodating cavity; the first locking block (2) comprises a snap-fit ​​groove (6), and the second locking block (3) comprises a snap-fit ​​protrusion (7); the snap-fit ​​protrusion (7) cooperates with the snap-fit ​​groove (6) so that the first locking block (2) and the second locking block (3) become one body.

2. The axial locking assembly according to claim 1, characterized in that: The extension direction of the first groove (8) and / or the second groove (9) is perpendicular to the blade root end surface.

3. The axial locking assembly according to claim 1, wherein: The extension direction of the first groove (8) and / or the second groove (9) forms a predetermined angle with the extension direction of the blade root, so as to increase the bearing surface of the locking body.

4. The axial locking assembly according to claim 3, wherein: The predetermined angle is 10°-40°.

5. The axial locking assembly according to claim 4, characterized in that: The locking body formed by the first locking block (2) and the second locking block (3) is a columnar body with a cross section having a long side and a short side.

6. The axial locking assembly according to claim 5, characterized in that: The end faces of the first locking block (2) and / or the second locking block (3) include a process hole (5), through which the locking body is rotated so that the long side is gradually deflected in a vertical direction, so that the locking body is fastened in the accommodating cavity.

7. The axial locking assembly according to claim 6, wherein: The cross section of the locking body is elliptical.

8. The axial locking assembly according to claim 1, wherein: The cross section of the accommodating cavity is elliptical, and the major axis of the ellipse extends in the horizontal direction.

9. The axial locking assembly according to claim 6, wherein: The first groove (8) further comprises an adjustment hole (10), through which the process hole can be rotated to drive the first locking block (2) and the second locking block (3) to rotate together.

10. The axial locking assembly according to claim 9, wherein: The locking body is fixedly connected to the first groove (8) or the second groove (9) at a position close to the blade root end surface.

11. The axial locking assembly according to claim 10, wherein: The fixed connection is punch riveting or electric welding.

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