A compressor blade vibration damping and locking structure and assembly method

Abstract

This invention discloses a compressor blade vibration damping and locking structure and assembly method. The vibration damping and locking structure includes a compressor disc and compressor blades connected to the compressor disc. The compressor disc has a groove for mounting the compressor blades, and the compressor blades have at least one damping block mounting groove. At least two damping blocks stacked together form a damping element in the damping block mounting groove. The damping element has a damping hole in the middle, and the groove surface has a positioning pin hole. A positioning pin is installed in the positioning pin hole. The vibration damping and locking structure has a first state. In the first state, under the action of centrifugal force, the damping element is displaced in the damping block mounting groove, and the positioning pin extends at least partially from the positioning pin hole and enters the damping hole. In use, the positioning pin achieves axial locking between the blades and the disc. The vibration damping effect is achieved by damping generated between the damping blocks and the damping block mounting grooves, between adjacent damping blocks, and between the damping blocks and the positioning pin.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, specifically to a compressor blade vibration damping and locking structure and assembly method. Background Technology

[0002] When the compressor blades of a gas turbine are operating, they are constantly subjected to the excitation force of the airflow, causing the blades to vibrate. In particular, the excitation force generated by the deceleration of the airflow during startup can easily cause blade resonance and even damage the blades. It is difficult to avoid all resonance points in blade design, and stall is even more difficult to predict. Therefore, considering vibration reduction measures in blade design can effectively reduce blade vibration and improve blade life.

[0003] Compressor blades are typically mounted axially into the grooves of the compressor impeller. To prevent axial movement and rubbing against the stator structure during operation, the blades need to be locked in the grooves to prevent relative axial movement between the blades and the impeller. Therefore, various locking structures have been designed. Common methods include riveting and locking plates. However, riveting damages the blade structure, and the removed blades cannot be reused. While locking plates do not damage the blade structure, they require specialized equipment to bend the plates, and the plates cannot be reused. Patents regarding compressor blade locking primarily focus on the locking function, neglecting vibration damping. Therefore, designing a structure that combines locking and vibration damping is crucial.

[0004] Patent CN115727000A discloses an axial locking assembly and a compressor including the axial locking assembly. In this patent, the blade root is installed within a rotor. The locking assembly includes a first mounting part, a second mounting part, and a locking body. The first mounting part is disposed on the blade root, and the second mounting part is disposed on the rotor. The locking body can be at least partially accommodated within a cavity formed by the first and second mounting parts to limit the relative displacement of the blade root and rotor in the axial direction. The locking body is an integral elastic structure. This integral elastic structure allows for axial locking of the blade and rotor through a single component. Disassembly and assembly do not require damage to the locking structure, which can be reused. The existing compressor blade locking structures lack vibration damping effects or have poor vibration damping effects, failing to dampen the blades when subjected to airflow force.

[0005] Patent CN210509729U discloses a blade locking structure with vibration reduction effect. This patent involves setting mounting holes between the blade root groove and the blade root, with a vibration damping rod inserted through the mounting holes. The two ends of the vibration damping rod are connected to the first and second locking blocks, respectively. When the blade is in operation, due to centrifugal force, the vibration damping rod will contact the blade root, and friction will occur between the root and the vibration damping rod under airflow excitation. Because the blade root is tightly fitted to the blade groove, the vibration stress on the blade root itself is very small; more vibration stress occurs at the blade root. Therefore, this method has limited vibration reduction effect and is unlikely to achieve the desired effect.

[0006] To address the problem mentioned in the background art that existing compressor blades cannot simultaneously achieve locking and vibration reduction during installation, this invention provides a compressor blade and impeller vibration reduction and axial locking structure and its installation method. Based on a thorough study of the compressor blade vibration reduction and damping structure, the vibration-damping locking mechanism at the blade-impeller connection effectively reduces blade vibration by establishing dry friction damping, while ensuring the blade is firmly installed and easy to install, significantly improving the working stability of the compressor blade. Summary of the Invention

[0007] To solve the above technical problems, the present invention provides a compressor blade vibration damping and locking structure. This structure achieves axial locking between the blade and the impeller through a positioning pin, and achieves vibration reduction by generating damping between the damping block and the damping block mounting groove, between adjacent damping blocks, and between the damping block and the positioning pin. Furthermore, the damping block, positioning pin, and other structures are reasonably installed between the blade and the impeller through an assembly method.

[0008] The present invention adopts the following technical solution:

[0009] A compressor blade vibration damping and locking structure includes a compressor disk and compressor blades connected to the compressor disk. The compressor disk has a groove for mounting the compressor blades, and the compressor blades have at least one damping block mounting groove. At least two damping blocks stacked together form a damping element within the damping block mounting groove. The damping element has a damping hole in its center, and a locating pin hole is provided on the surface of the groove. A locating pin is provided within the locating pin hole. The vibration damping and locking structure has a first state in which, under the action of centrifugal force, the damping element is displaced within the damping block mounting groove, and at least part of the locating pin extends out of the locating pin hole and enters the damping hole. This structure achieves axial locking between the blades and the compressor disk through the locating pin, and effectively reduces blade vibration and improves blade vibration performance by establishing dry friction damping between the damping blocks and the damping block mounting grooves, between adjacent damping blocks, and between the damping blocks and the locating pin.

[0010] Preferably, in the first state, damping occurs between the damping block and the damping block mounting groove, between adjacent damping blocks, and between the damping block and the locating pin. Under the action of centrifugal force, the damping block moves up and down within the damping block mounting groove, generating dry friction. Simultaneously, collisions occur between the damping block and the bottom of the damping block mounting groove. The first damping effect is achieved through these two methods. A second damping effect is achieved through horizontal friction and vertical collisions between adjacent damping blocks. Dry friction occurs between each damping block and the locating pin. Additionally, since the damping hole is slightly larger than the locating pin, collisions also occur between the locating pin and the inner wall of the damping hole. The third damping effect is achieved through these two methods. A triple damping effect is achieved through the movement of the damping block, the damping block mounting groove, and the locating pin. The structure is simple and easy to use.

[0011] Preferably, the width of the damping block mounting groove is d, and the lateral gap between the damping component and the damping block mounting groove is less than 0.01d. This avoids excessive gap between the damping component and the damping block mounting groove, which could cause the compressor blades to wobble after installation, resulting in unstable installation.

[0012] Preferably, the depth of the damping block mounting groove is H, the longitudinal gap between the damping element and the damping block mounting groove is less than 0.1H, and the distance between the damping element and the bottom surface of the damping block mounting groove is small. When the compressor blades are excited by the airflow force, it is convenient for the damping element to collide with the bottom surface of the damping block mounting groove multiple times, resulting in a better damping effect.

[0013] Preferably, a locking hole is provided below the wheel groove, and a locking pin is slidably fitted in the locking hole.

[0014] Preferably, the locking pin head is tapered, and the bottom of the positioning pin is an inclined surface that matches the locking pin head. The positioning pin enables axial locking between the compressor blade and the compressor disc, and also facilitates the positioning pin to cooperate with the damping hole to achieve a damping effect.

[0015] Preferably, the positioning pin is formed by two cylindrical sections with different radii, with the root of the smaller-radius section being inclined at an angle of a1, where 10°≤a1≤30°.

[0016] A method for assembling compressor blades, using the aforementioned compressor blade vibration damping and locking structure, includes:

[0017] S1: Place the locating pin in the locating pin hole at the bottom of the wheel groove and ensure that the top does not extend beyond the locating pin hole, with the locating pin indicator groove facing the air intake side.

[0018] S2: The damping element is placed into the damping block mounting slot of the compressor blade;

[0019] S3: The compressor blade root is inserted into the impeller groove to complete the blade installation. Damping blocks, locating pins, and other components are rationally installed between the blade and the impeller, allowing for very convenient assembly and disassembly without damaging the blades or impeller. Furthermore, the locating pins and locking cone pins can be reused after disassembly.

[0020] Preferably, the following steps are also included:

[0021] S4: Insert the locking pin into the locking hole and lift the positioning pin with the tapered head;

[0022] S5: Rivet the end of the locking pin to the compressor wheel.

[0023] Preferably, the small-radius section of the locating pin extends into the locking hole, and the length of the protruding part of the small-radius section is less than the radius of the locking hole.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. This invention provides a compressor blade vibration reduction and locking structure. The structure achieves axial locking between the blade and the impeller through a positioning pin. Dry friction damping is established between the damping block and the damping block mounting groove, between adjacent damping blocks, and between the damping block and the positioning pin to effectively reduce blade vibration and improve blade vibration performance.

[0026] 2. The vibration damping locking structure in this invention has various variations, which can effectively reduce blade vibration. During gas turbine operation, the vibration damping locking structure contacts the damping block mounting groove at the blade root under the action of centrifugal force. When the blade is excited by airflow force, dry friction damping is formed between the damping block and the blade, between adjacent damping blocks, and between the damping block and the positioning pin, achieving the purpose of vibration reduction. At the same time, the vibration reduction capacity can be adjusted by increasing or decreasing the number of damping blocks or replacing damping blocks of different masses.

[0027] 3. The present invention uses an assembly method to reasonably install damping blocks, positioning pins and other structures between the blades and the wheel, and achieves very convenient disassembly and assembly without damaging the blades and wheel. Furthermore, the positioning pins and locking cone pins can be reused after disassembly. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the vibration damping and locking structure.

[0029] Figure 2 This is a bottom view of the compressor blades.

[0030] Figure 3 This is a schematic diagram of the locating pin hole.

[0031] Figure 4 for Figure 3 AA sectional view.

[0032] Figure 5 This is a schematic diagram of the damping component.

[0033] Figure 6 This is a structural diagram of a locating pin.

[0034] Figure 7 This is a schematic diagram of the locking pin.

[0035] Figure 8 This is a schematic diagram of the installation structure for the locating pin.

[0036] Figure 9 This is a schematic diagram of the structure in the second state.

[0037] Figure 10 This is a schematic diagram of the structure in the first state.

[0038] In the figure, compressor wheel 1, wheel groove 1-1, locating pin hole 1-2, locking hole 1-3, compressor blade 2, damping block mounting groove 2-1, blade root 2-2, damping component 3, damping block 3-1, damping hole 3-2, locating pin 4, locating pin indicator groove 4-1, small radius section 4-2, large radius section 4-3, and locking pin 5. Detailed Implementation

[0039] To facilitate understanding of the technical solution of the present invention, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0040] Example 1

[0041] like Figure 1-2 As shown, a compressor blade vibration damping and locking structure includes a compressor disc 1 and compressor blades 2 connected to the compressor disc 1.

[0042] The compressor disc 1 is provided with a groove 1-1, and the blade root 2-2 of the compressor blade 2 is detachably installed in the groove 1-1. The compressor blade 2 is provided with at least one damping block mounting groove 2-1. Figure 5 As shown, at least two damping blocks 3-1 are stacked together to form a damping element 3 in the damping block mounting groove 2-1. The damping element 3 has a damping hole 3-2 in the middle. After the damping block 3-1 is installed in the damping block mounting groove 2-1, the surface of the damping block 3-1 does not exceed the end face of the damping block mounting groove 2-1, that is, the depth of the damping block mounting groove 2-1 is greater than the height of the damping element 3.

[0043] like Figure 3As shown, the surface of the wheel groove 1-1 is provided with a positioning pin hole 1-2, and a positioning pin 4 is provided in the positioning pin hole 1-2. The positioning pin 4 is movably fitted in the positioning pin hole 1-2 and can move up and down relative to the positioning pin hole 1-2. The vibration damping locking structure has a first state. In the first state, under the action of centrifugal force, the damping member 3 is displaced in the damping block mounting groove 2-1, and the positioning pin 4 extends at least partially from the positioning pin hole 1-2 and enters the damping hole 3-2.

[0044] Specifically, such as Figure 10 As shown, in the first state, damping occurs between the damping block 3-1 and the damping block mounting groove 2-1, between adjacent damping blocks 3-1, and between the damping block 3-1 and the positioning pin 4. Under centrifugal force, the damping block 3-1 moves up and down within the damping block mounting groove 2-1, generating dry friction. Simultaneously, a collision occurs between the damping block 3-1 and the bottom of the damping block mounting groove 2-1, achieving the first damping effect through these two methods. Horizontal friction and vertical collision occur between adjacent damping blocks 3-1, achieving the second damping effect. Dry friction occurs between each damping block 3-1 and the positioning pin 4. Furthermore, since the damping hole 3-2 is slightly larger than the size of the positioning pin 4, the positioning pin 4 collides with the inner wall of the damping hole 3-2, achieving the third damping effect through these two methods. In other words, a triple damping effect is achieved through the movement between the damping block 3-1, the damping block mounting groove 2-1, and the positioning pin 4, resulting in a simple structure and convenient use.

[0045] As a preferred embodiment, the lifting stroke of the positioning pin 4 is greater than the thickness of the damping element 3, ensuring that the positioning pin 4 can generate dry friction with all damping blocks 3-1, thereby improving the damping effect.

[0046] Specifically, if the width of the damping block mounting groove 2-1 is d, then the lateral gap between the damping component 3 and the damping block mounting groove 2-1 is less than 0.01d. This avoids excessive gap between the damping component 3 and the damping block mounting groove 2-1, which could cause the compressor blade 2 to shake after installation, resulting in unstable installation.

[0047] The depth of the damping block mounting groove 2-1 is H. The longitudinal gap between the damping element 3 and the damping block mounting groove 2-1 is less than 0.1H. The distance between the damping element 3 and the bottom surface of the damping block mounting groove 2-1 is small. When the compressor blade 2 is excited by the airflow force, it is convenient for the damping element 3 to collide with the bottom surface of the damping block mounting groove 2-1 multiple times, so as to produce a better damping effect.

[0048] like Figure 8-9As shown, a locking hole 1-3 is provided below the wheel groove 1-1. A locking pin 5 is slidably fitted in the locking hole 1-3. The locking pin 5 moves into the locking hole 1-3 and pushes the positioning pin 4 upward until it exceeds the surface of the positioning pin hole 1-2 and part of the positioning pin 4 enters the damping hole 3-2. The positioning pin 4 realizes the axial locking of the compressor blade 2 and the compressor wheel 1. At the same time, it also facilitates the positioning pin 4 to cooperate with the damping hole 3-2 to achieve the damping effect.

[0049] The first state is the compressor operating state. Under the action of centrifugal force, the damping element 3 is displaced within the damping block mounting groove 2-1, and the positioning pin 4 extends at least partially from the positioning pin hole 1-2 and enters the damping hole 3-2. The vibration damping locking structure also has a second state. In the second state, the compressor is not working, and the locking pin 5 is installed in the locking hole 1-3, pushing the positioning pin 4 upward to achieve axial locking of the compressor blade 2 and the compressor disc 1.

[0050] like Figure 6-7 As shown, to facilitate the upward movement of the locking pin 5 and the positioning pin 4, the head of the locking pin 5 is tapered, and the bottom of the positioning pin 4 is an inclined surface that matches the head of the locking pin 5. The positioning pin hole 1-2 includes a first positioning pin hole and a second positioning pin hole. The first positioning pin hole is located above the second positioning pin hole and has a larger diameter than the second positioning pin hole. The positioning pin 4 includes a small radius segment 4-2 located below and a large radius segment 4-3 located above. The lower end of the small radius segment 4-2 is an inclined surface that matches the head of the locking pin 5. The large radius segment 4-3 is provided with a positioning pin indicator groove 4-1, the orientation of which is consistent with the inclined surface at the lower end of the small radius segment 4-2.

[0051] The positioning pin 4 is formed by two cylindrical sections with different radii. The root of the smaller radius cylindrical section is inclined with an angle of a1, where 10°≤a1≤30°. The cone angle of the head of the locking pin 5 is a2, and a2=a1. That is, the angle of the head of the locking pin 5 is consistent with the inclination angle of the inclined surface at the lower end of the smaller radius section 4-2, which facilitates the locking pin 5 to push the positioning pin 4 upward.

[0052] like Figure 8-10 As shown, a method for assembling compressor blades, used in the aforementioned compressor blade vibration damping and locking structure, includes:

[0053] S1: Place the positioning pin 4 in the positioning pin hole 1-2 at the bottom of the wheel groove 1-1. The small radius section 4-2 is located in the second positioning pin hole, and the large radius section 4-3 is located in the first positioning pin hole. The top of the large radius section 4-3 does not extend beyond the positioning pin hole 1-2, and its positioning pin indicator groove 4-1 faces the air intake side. The small radius section 4-2 of the positioning pin 4 extends into the locking hole 1-3, and the length of the extended part of the small radius section 4-2 is less than the radius of the locking hole 1-3.

[0054] S2: The damping component 3 is placed into the damping block mounting groove 2-1 of the compressor blade 2, and an appropriate amount of damping block 3-1 is selected according to the depth of the damping block mounting groove 2-1.

[0055] S3: The blade root 2-2 of compressor blade 2 is inserted into the wheel groove 1-1 to complete the blade installation;

[0056] S4: Insert the locking pin 5 into the locking hole 1-3. The conical head cooperates with the small radius section 4-2 of the positioning pin 4 to lift the positioning pin 4, so that the large radius section 4-3 extends out of the first positioning pin hole and enters the damping hole 3-2. The compressor blade 2 and the compressor wheel 1 are axially locked through the positioning pin 4.

[0057] S5: Rivet the tail of the locking pin 5 to the compressor disc 1 to complete the assembly of the compressor blades.

[0058] When in use, when the compressor blade 2 is excited by the airflow force, damping is generated between the damping block 3-1 and the damping block mounting groove 2-1, between adjacent damping blocks 3-1, and between the damping block 3-1 and the positioning pin 4, thereby achieving the vibration reduction effect.

[0059] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention shall be determined by the scope defined in the claims. Any improvements and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall also be considered as within the scope of protection of the present invention.

Claims

1. A compressor blade vibration damping and locking structure, characterized in that, The compressor includes a compressor wheel (1) and compressor blades (2) connected to the compressor wheel (1). The compressor wheel (1) is provided with a wheel groove (1-1) for mounting the compressor blades (2). The compressor blades (2) are provided with at least one damping block mounting groove (2-1). The damping block mounting groove (2-1) is provided with a damping element (3) formed by stacking at least two damping blocks (3-1). The damping element (3) has a damping hole (3-2) in the middle. The surface of the wheel groove (1-1) is provided with a positioning pin hole (1-2). The positioning pin hole (1-2) is provided with a positioning pin (4). The vibration damping locking structure has a first state. In the first state, under the action of centrifugal force, the damping element (3) is displaced in the damping block mounting groove (2-1), and the positioning pin (4) extends out from the positioning pin hole (1-2) and enters the damping hole (3-2) at least partially.

2. The compressor blade vibration damping and locking structure according to claim 1, characterized in that, In the first state, damping is generated between the damping block (3-1) and the damping block mounting groove (2-1), between adjacent damping blocks (3-1), and between the damping block (3-1) and the positioning pin (4).

3. The compressor blade vibration damping and locking structure according to claim 1, characterized in that, The width of the damping block mounting groove (2-1) is d, and the lateral gap between the damping component (3) and the damping block mounting groove (2-1) is less than 0.01d.

4. The compressor blade vibration damping and locking structure according to claim 1, characterized in that, The depth of the damping block mounting groove (2-1) is H, and the longitudinal gap between the damping component (3) and the damping block mounting groove (2-1) is less than 0.1H.

5. The compressor blade vibration damping and locking structure according to claim 1, characterized in that, A locking hole (1-3) is provided below the wheel groove (1-1), and a locking pin (5) is slidably fitted in the locking hole (1-3).

6. The compressor blade vibration damping and locking structure according to claim 5, characterized in that, The head of the locking pin (5) is tapered, and the bottom of the positioning pin (4) is an inclined surface that matches the head of the locking pin (5).

7. The compressor blade vibration damping and locking structure according to claim 1, characterized in that, The positioning pin (4) is formed by two cylindrical sections with different radii. The root of the smaller radius cylindrical section is inclined with an angle of a1, where 10°≤a1≤30°.

8. A method for assembling compressor blades, characterized in that, The compressor blade vibration damping and locking structure according to any one of claims 1-7 includes: S1: Place the positioning pin (4) in the positioning pin hole (1-2) at the bottom of the wheel groove (1-1) and the top does not exceed the positioning pin hole (1-2), with its positioning pin indicator groove (4-1) facing the air intake side; S2: The damping element (3) is placed in the damping block mounting slot (2-1) of the compressor blade (2); S3: The blade root (2-2) of the compressor blade (2) is inserted into the wheel groove (1-1) to complete the installation of the blade.

9. The method for assembling compressor blades according to claim 8, characterized in that, It also includes the following steps: S4: Insert the locking pin (5) into the locking hole (1-3) and lift the positioning pin (4) with the conical head; S5: Rivet the tail of the locking pin (5) to the compressor wheel (1).

10. The method for assembling compressor blades according to claim 8, characterized in that, In S1, the small radius segment (4-2) of the positioning pin (4) extends into the locking hole (1-3), and the length of the extended part of the small radius segment (4-2) is less than the radius of the locking hole (1-3).

Images