Turbine guide structure and assembly method

Abstract

The invention discloses a turbine guider structure and an assembling method, and belongs to the technical field of turbofan engines, a turbine guider comprises a turbine guider unit, a turbine casing and a guider inner casing assembly, a guider outer cover of a whole ring structure is arranged between the turbine guider unit and the turbine casing, and the turbine casing is arranged in the guider outer cover. The outer side of the guider outer cover is connected with a turbine case, the turbine guider unit comprises guider blades, a guider upper margin plate and a guider lower margin plate, the guider upper margin plate and the guider lower margin plate are located on the different sides of the guider blades, the guider lower margin plate is connected with the guider inner case assembly in a matched mode, and the guider upper margin plate is embedded in the guider outer cover to be connected in a matched mode. The turbine guider units are distributed in the circumferential direction of the guider outer cover so that centering of the turbine guider units can be achieved. The technical problem that when the turbine guider unit is assembled, the centering effect is poor due to the fact that a clamping groove gap is large can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of turbofan engines, and particularly to a turbine guide vane structure and an assembly method thereof. Background Art

[0002] The turbine guide vane unit is a key structural component in an aeroengine. Its main function is to guide the gas flow towards the turbine blades and improve the working efficiency of the engine. In the design of modern aeroengines, the turbine guide vane unit usually adopts a single-row or multi-row blade structure to adapt to the high-temperature and high-load working environment.

[0003] Refer to Figure 2 , the existing turbine guide vane unit structure includes a turbine guide vane unit, a turbine casing, and a guide vane inner casing assembly. Below the lower edge plate of the turbine guide vane unit are two convex edge structures that cooperate with two U-shaped grooves on the guide vane inner casing assembly. Each turbine guide vane unit has a U-shaped groove. The guide vane inner casing assembly is provided with pin holes equal in number to the guide vane blades. One anti-rotation pin is assembled on each guide vane for circumferential anti-rotation. There is a certain radial clearance between the two convex edges of the turbine guide vane unit and the guide vane inner casing assembly and the anti-rotation pin, ensuring that the turbine guide vane unit can expand freely. After the turbine guide vane unit and the guide vane inner casing assembly are assembled, they are assembled with the high-pressure turbine casing. The upper edge plate of the turbine guide vane unit is a hook structure. The front hook structure is centered with the front card slot of the high-pressure turbine casing, and the rear hook structure, the high-pressure turbine casing, and the high-pressure turbine outer ring card slot are centered.

[0004] In this design, the turbine guide vane unit is centered with the turbine casing and the high-pressure turbine outer ring through card slots. Since the turbine guide vane unit is of a single-row or multi-row structure and the number is large, in order to facilitate assembly and disassembly, a relatively large gap is selected between the card slots, resulting in poor centering effect. Summary of the Invention

[0005] The present invention provides a turbine guide vane and an assembly method thereof to solve the technical problem of poor centering effect due to a large gap between card slots during the assembly of the turbine guide vane unit.

[0006] According to one aspect of the present invention, a turbine guide vane is provided, which includes a turbine guide vane unit, a turbine casing, and a guide vane inner casing assembly. An integral ring-shaped guide vane outer cover is provided between the turbine guide vane unit and the turbine casing. The outer side of the guide vane outer cover is connected to the turbine casing. The turbine guide vane unit includes guide vanes, and a guide vane upper edge plate and a guide vane lower edge plate on different sides of the guide vanes. The guide vane lower edge plate is connected to the guide vane inner casing assembly in a matching manner, and the guide vane upper edge plate is nested and connected to the guide vane outer cover. The turbine guide vane units are distributed along the circumferential direction of the guide vane outer cover to achieve the centering of the turbine guide vane units.

[0007] Optionally, a first card slot is formed on the guide outer casing, and a first anti-rotation pin adapted to the first card slot is provided on the turbine casing.

[0008] Optionally, the first card slots are evenly spaced along the circumferential direction of the guide outer casing, and the number thereof is not less than three.

[0009] Optionally, a retaining ring is provided on the turbine casing, and the retaining ring abuts against the end face of the guide outer casing to axially limit the guide outer casing.

[0010] Optionally, two clamping edges are formed on the lower edge plate of the guide. The guide inner casing assembly includes a front guide inner casing and a rear guide inner casing. Blocking edges are respectively provided on the front guide inner casing and the rear guide inner casing. The front guide inner casing and the rear guide inner casing are closely attached together and locked by a locking member, so that a clamping space is formed between the two blocking edges to clamp the two clamping edges of the turbine guide unit.

[0011] Optionally, the locking member includes a bolt and a nut. The bolt passes through the front guide inner casing and the rear guide inner casing and is in threaded cooperation with the nut.

[0012] Optionally, a limiting groove is formed on the clamping edge of the lower edge plate of the guide, and a boss adapted to the limiting groove is provided on the front guide inner casing for circumferential anti-rotation.

[0013] Optionally, a second card slot is formed on the upper edge plate of the guide, and a second anti-rotation pin adapted to the second card slot is provided on the guide outer casing.

[0014] Optionally, a dismounting groove is provided at the rear end of the guide outer casing.

[0015] According to another aspect of the present invention, a method for assembling a turbine guide is further provided, which includes the following steps: S100: Assemble the turbine guide unit and the guide outer casing. Embed the turbine guide unit into the guide outer casing to ensure precise fit with the outer casing structure and achieve reliable centering. S300: Assemble the front guide inner casing and the rear guide inner casing. Assemble the front guide inner casing and the rear guide inner casing with the turbine guide unit to ensure that the turbine guide unit is completely clamped. S400: Fasten the front guide inner casing and the rear guide inner casing. Insert the bolt and tighten the nut to ensure that the front guide inner casing and the rear guide inner casing are firmly connected to form an integral assembly. S500: Assemble the assembled component with the turbine casing. Install the assembled guide component into the turbine casing. S600: Install anti-rotation pins. Insert the first anti-rotation pin into the first card slot of the guide housing to fix the circumferential position of the guide housing, and insert the second anti-rotation pin into the second card slot of the upper edge plate of the guide to fix the circumferential position of the turbine guide unit. S700: Install a retaining ring. Install a retaining ring between the guide housing and the turbine casing to provide axial limit.

[0016] In summary, the present application includes at least one of the following beneficial technical effects: In this solution, by arranging a guide housing with an integral ring structure between the turbine guide unit and the turbine casing, the problem of poor centering effect caused by large gaps in the card slots during the assembly of the traditional turbine guide unit is effectively solved. In the traditional solution, the turbine guide mainly relies on the card slot structures of the turbine casing and the outer ring for centering. However, since the turbine guide unit usually adopts a single-row or multi-row non-integral ring structure, in order to facilitate assembly and disassembly, the gaps between the card slots are large, resulting in low centering accuracy. It is easy to have a slight offset during operation, affecting the stability of the air flow guidance and even causing a decrease in turbine efficiency. This solution adopts a guide housing with an integral ring structure, whose outer side is fixedly connected to the turbine casing, providing an overall rigid support structure. The upper edge plate of the turbine guide unit is nested in the guide housing and cooperates with it. When the guide is installed, it relies on the outer housing for precise alignment instead of relying solely on the card slot positioning, thus significantly improving the centering accuracy during the assembly process. In addition, the lower edge plate of the turbine guide unit cooperates with the inner casing assembly of the guide to ensure double constraints in the axial and radial directions, enabling the guide to maintain a stable position in a high-temperature operating environment and avoiding positioning errors caused by thermal expansion or external forces. At the same time, since the guide housing is an integral ring structure, multiple turbine guide units can be evenly distributed along its circumferential direction, further improving the centering effect of the overall guide in terms of structure and avoiding affecting the stability of the entire system due to the assembly clearance error of a single guide. Through this optimized assembly method, this solution effectively overcomes the problem of inaccurate positioning caused by large gaps in the traditional card slot centering method, enabling the turbine guide unit to always maintain precise centering during assembly and operation, and improving the working stability and efficiency of the turbine system.

[0017] In addition to the purposes, features, and advantages described above, the present invention has other purposes, features, and advantages. The present invention will be further described in detail below with reference to the drawings. Description of the Drawings

[0018] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1It is a schematic structural diagram of the turbine guide device of the present invention; Figure 2 It is a structural schematic diagram of an existing turbine guide vane structure; Figure 3 It is a schematic structural diagram of the turbine guide vane unit of the present invention.

[0019] Legend: 1. Turbine casing; 2. Turbine guide unit; 3. First anti-rotation pin; 4. Second anti-rotation pin; 5. Retaining ring; 6. Guide cover; 7. Front inner casing of guide; 8. Rear inner casing of guide; 9. Bolt; 10. Nut; 11. Limiting groove. DETAILED DESCRIPTION

[0020] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0021] The following is combined with Figures 1-3 This application is described in further detail.

[0022] Reference Figure 1 The turbine guide structure includes a turbine guide unit 2, a turbine casing 1, and a guide inner casing assembly. The main function of the turbine guide unit 2 is to guide the high-temperature gas flow, optimize the gas flow direction, and improve the turbine efficiency. At the same time, its structure needs to withstand high temperature and high pressure environment and maintain good aerodynamic performance. It is composed of guide blades, guide upper edge plates, and guide lower edge plates. The turbine casing 1 serves as the main support and fixing frame of the entire turbine system. It is used to provide shell constraints and mechanical support to ensure that all components can still work stably under high temperature and high-speed rotation environments. It also plays a sealing role to prevent gas leakage and improve system efficiency. The guide inner casing assembly mainly plays a supporting, fixing and restraining role. It is connected with the lower edge plate of the turbine guide unit 2 to ensure that the guide maintains the correct position during operation.

[0023] The high-pressure turbine section of a modern turbofan engine includes 1 to 2 stages of high-pressure turbines. A circle of turbine guide vane units 2 is provided in front of each stage of high-pressure turbine, and each circle of turbine guide vane units 2 contains several turbine guide vane units 2. The turbine guide vane unit 2 can be a single blade or a multi-blade. A single blade means that each guide vane is manufactured and installed independently. Due to the simple structure of a single blade, it can be installed one by one during assembly, which is convenient for replacement and maintenance. However, its rigidity is low and may produce large vibrations or deviations under the impact of high-speed airflow. A multi-blade refers to a structure in which multiple blades are combined together through integral molding or mechanical connection, such as a double, triple or more blade structure, which has higher rigidity and vibration resistance, reduces deformation caused by aerodynamic or centrifugal forces, and improves the stability of airflow guidance.

[0024] Referring to Figure 3 , in this embodiment, taking a single-stage vane as an example, the turbine guide vane unit 2 includes guide vanes, a guide vane upper flange and a guide vane lower flange located on different sides of the guide vanes. The guide vane is the core part, and its main function is to guide the gas flow to the high-pressure turbine blades, optimize the air flow distribution, improve the energy conversion efficiency of the turbine, while withstanding the high-temperature and high-pressure environment and reducing the flow loss. The guide vane upper flange is located at the top of the guide vane, and its main function is to cooperate and connect with the guide vane outer casing 6 to achieve stable centering and sealing, prevent high-temperature gas leakage, improve the engine efficiency, and at the same time provide certain structural support to enhance the overall rigidity. The guide vane lower flange is located at the bottom of the blade, and its main function is to cooperate and connect with the guide vane inner casing assembly to form a fixed support structure, ensure the stable positioning of the guide vane unit, and at the same time allow a certain amount of thermal expansion to avoid structural stress concentration caused by temperature changes.

[0025] Referring to Figure 2 , in the traditional solution, the turbine guide vane unit 2 mainly relies on the slot structure of the turbine casing 1 and the outer ring for centering. However, since the turbine guide vane unit 2 usually adopts a single-stage or multi-stage non-integral ring structure, in order to facilitate assembly and disassembly, the gap between the slots is relatively large, resulting in low centering accuracy. It can be understood that low centering accuracy means that the turbine guide vane cannot accurately and stably maintain its position at the predetermined center during assembly and operation, resulting in a position offset relative to the turbine casing 1 or other components.

[0026] In order to improve the stability of the centering of the turbine guide vane unit 2, a guide vane outer casing 6 with an integral ring structure is provided between the turbine guide vane unit 2 and the turbine casing 1. The outer side of the guide vane outer casing 6 is connected to the turbine casing 1, and the turbine guide vane units 2 are distributed along the circumferential direction of the guide vane outer casing 6 to achieve the centering of the turbine guide vane units 2. The integral guide vane outer casing 6 in this solution is a whole annular structure, which can provide a unified centering reference during the assembly process, enabling each turbine guide vane unit 2 to be evenly arranged and fixed relying on the integral ring structure during assembly, avoiding the decrease in the overall centering accuracy caused by the accumulation of individual blade clearance errors.

[0027] The guide vane outer casing 6 is provided with a first slot, and the turbine casing 1 is provided with a first anti-rotation pin 3 that cooperates with the first slot. In the high-pressure turbine working environment, due to the high-speed impact of the gas flow on the turbine guide vane unit 2, a large aerodynamic moment and centrifugal force may be applied to the guide vane outer casing 6. If there is no effective anti-rotation mechanism on the outer casing itself, a small rotational displacement may occur during long-term operation, affecting the precise positioning of the turbine guide vane unit 2 and thus reducing the engine efficiency. Therefore, the cooperation between the first anti-rotation pin 3 and the first slot can form a stable anti-rotation constraint in the structure, ensuring that the guide vane outer casing 6 always maintains the correct angle and does not undergo circumferential offset.

[0028] Specifically, the shape of the first card slot can be designed as a U-shaped, rectangular slot or wedge-shaped slot. Its length and depth need to be matched with the thickness of the outer cover and the diameter of the anti-rotation pin to ensure a tight fit, while allowing a certain tolerance compensation to accommodate thermal expansion. The first anti-rotation pin 3 is usually a cylindrical pin or a tapered pin, and its diameter should match the width of the card slot to ensure sufficient positioning effect, while avoiding looseness caused by excessive tolerance or assembly difficulties caused by interference fit. The first card slots should be evenly distributed in the circumferential direction of the guide vane outer cover 6, usually not less than 3, which can form a multi-point constraint, enabling the guide vane outer cover 6 to maintain its original position more firmly during assembly and operation, enhancing the overall anti-rotation ability. The first anti-rotation pin 3 should be arranged on the inner wall of the turbine casing 1 and be precisely aligned with the card slots on the guide vane outer cover 6 to be smoothly inserted during assembly, ensuring the normal operation of the anti-rotation mechanism.

[0029] A retaining ring 5 is provided on the turbine casing 1, and the retaining ring 5 abuts against the end face of the guide vane outer cover 6 to axially limit the guide vane outer cover 6. During turbine operation, the gas flow exerts high temperature and high pressure on the guide vane outer cover 6, which may cause the outer cover to displace axially. The retaining ring 5 forms a fixed axial support by abutting against the end face of the guide vane outer cover 6, keeping the outer cover stable. Specifically, a mounting groove for the retaining ring 5 is designed on the turbine casing 1, and the retaining ring 5 is fixed to the casing by embedded clamping. This method facilitates assembly and disassembly, while ensuring that the retaining ring 5 does not loosen during operation.

[0030] To achieve the stable connection between the turbine guide vane unit 2 and the guide vane inner casing assembly, two clamping edges are formed on the lower edge plate of the guide vane. The guide vane inner casing assembly includes a front guide vane inner casing 7 and a rear guide vane inner casing 8. Blocking edges are respectively provided on the front guide vane inner casing 7 and the rear guide vane inner casing 8. The front guide vane inner casing 7 and the rear guide vane inner casing 8 are closely attached together and locked by a locking member, so as to form a clamping space between the two blocking edges to clamp the two clamping edges of the turbine guide vane unit 2.

[0031] A core function of this clamping method is to provide stable mechanical constraints, ensuring that the guide vane unit does not experience axial or radial displacement inside the high-speed rotating turbine casing 1, thereby enhancing the overall stability and precision of the system. Compared with the traditional slot-fitting method, this solution uses a bilateral clamping structure to make the fixation of the guide vane unit more uniform, thus avoiding problems such as deformation or increased clearance caused by excessive unilateral force. In addition, considering the high-temperature characteristics of the turbine operating environment, this clamping structure allows a certain degree of thermal expansion freedom, avoiding thermal stress concentration or structural damage caused by restricted expansion of the guide vane unit. Specifically, the clamping edge of the lower guide vane plate is tightly fixed within the clamping space but still retains a certain small gap, enabling it to undergo controlled thermal expansion along the axial or radial direction in a high-temperature environment without being deformed or cracked due to restriction. Another advantage of this structural design is to enhance the anti-vibration ability. Since the turbine system will withstand the impact of high-speed gas flow and the vibration of the engine itself during operation, simply relying on the traditional single-point fixation method is often difficult to suppress vibration. However, this solution uses multi-point clamping fixation, which not only improves the assembly accuracy of the guide vane unit but also significantly reduces the risk of loosening caused by vibration, improving the long-term operation reliability of the engine. From the perspective of assembly, this structure also improves the convenience of maintenance and replacement. When the guide vane unit needs to be disassembled, only the locking parts need to be loosened, and then the front and rear inner casings of the guide vane can be separated, releasing the clamping space, facilitating the quick removal or replacement of the guide vane unit, thereby reducing the engine maintenance time and improving the maintenance efficiency.

[0032] Specifically, the locking parts include bolts 9 and nuts 10. The bolts 9 pass through the front inner casing 7 of the guide vane and the rear inner casing 8 of the guide vane and are threadedly engaged with the nuts 10. The connection of the bolts 9 and nuts 10 provides a strong clamping force, ensuring that the casings fit tightly together, preventing the guide vane unit from loosening or shifting in a high-temperature and high-speed gas flow environment, and at the same time evenly distributing the force to improve the anti-vibration ability. Compared with riveting or welding, this method is convenient for disassembly, assembly, and adjustment. During maintenance, the guide vane unit can be quickly replaced, reducing the maintenance cost. In addition, the bolts 9 and nuts 10 made of high-temperature alloy materials can maintain reliable locking in an extreme thermal load environment, ensuring safe and stable long-term operation.

[0033] To achieve circumferential anti-rotation, limiting grooves are provided on the clamping edge of the lower guide vane plate, and protrusions that cooperate with the limiting grooves are provided on the front inner casing 7 of the guide vane. The matching design of the limiting grooves and the protrusions can provide a reliable circumferential limiting effect, ensuring that the guide vane is accurately positioned during assembly and remains stable during long-term operation. The limiting grooves can be U-shaped, rectangular, or semi-circular grooves to facilitate cooperation with the protrusions. The height of the protrusions should be slightly less than the depth of the limiting grooves to ensure that the cooperation can still be maintained during thermal expansion, while avoiding assembly difficulties or jamming caused by interference fit.

[0034] To further improve stability, a second card slot is provided on the upper edge plate of the guide vane, and a second anti-rotation pin 4 cooperating with the second card slot is provided on the guide vane housing 6. The circumferential anti-rotation of the turbine guide vane unit 2 is achieved through the cooperation of the second card slot and the second anti-rotation pin 4, preventing it from generating rotational displacement due to the impact of high-speed gas flow, centrifugal force or vibration during the operation of the engine, thereby maintaining the precise positioning of the guide vane and ensuring the stability of air flow guidance and the reliability of engine performance.

[0035] A disassembly groove is provided at the rear end of the guide vane housing 6. The main purpose of setting the disassembly groove is to improve the disassembly convenience of the turbine guide vane unit 2, optimize the maintenance efficiency, and reduce the problems of structural damage or excessive maintenance time caused by traditional disassembly methods. During the operation of the turbine engine, the guide vane housing 6 and other components cooperate in a high-temperature and high-speed environment for a long time, and large frictional forces or adhesion forces will be formed between the assembled components due to thermal expansion, oxidation, and sediment accumulation, making disassembly difficult. Even additional tools or violent knocking are required, which is likely to damage the components. The design of the disassembly groove can provide a dedicated force application point or operating space, enabling maintenance personnel to easily apply force using a crowbar, disassembly tool, etc. to separate the guide vane housing 6 from the turbine casing 1, thereby reducing damage caused by improper disassembly and improving the engine maintenance efficiency.

[0036] According to another aspect of the present invention, a method for assembling a turbine guide vane is also provided, which includes the following steps: S100: Assemble the turbine guide vane unit 2 and the guide vane housing 6, embed the turbine guide vane unit 2 into the guide vane housing 6, and ensure precise cooperation with the outer housing structure to achieve reliable centering.

[0037] There are multiple turbine guide vane units 2, which form a complete circle along the guide vane housing 6 to ensure uniform distribution of air flow and achieve an overall stable centering effect. During assembly, first check the dimensional accuracy of all turbine guide vane units 2 and the guide vane housing 6 to ensure that no machining defects or impurities affect the assembly. Then, according to the installation reference of the guide vane housing 6, embed each turbine guide vane unit 2 into the outer housing in turn, so that its upper edge plate and lower edge plate can be accurately aligned, and ensure that the second card slot on the upper edge plate is aligned with the installation position of the second anti-rotation pin 4 on the guide vane housing 6. At the same time, the card edge of the lower edge plate can also cooperate with the subsequent front inner casing 7 and rear inner casing of the guide vane. During the assembly process, individual adjustment is required to ensure that all guide vane units are evenly distributed and there is no obvious gap or looseness after embedding. After the assembly is completed, the cooperation between all guide vane units and the guide vane housing 6 should be checked to ensure that the gaps in the overall circumferential direction are uniform, and avoid affecting the subsequent assembly and operation stability due to local looseness or interference fit.

[0038] S200: Assemble the front inner casing 7 and the rear inner casing 8 of the guide vane; assemble the front inner casing 7 and the rear inner casing 8 of the guide vane with the turbine guide vane unit 2 to ensure that it completely clamps the turbine guide vane unit 2.

[0039] After completing the assembly of the guide vane unit and the guide vane outer casing 6, align the front inner casing 7 and the rear inner casing of the guide vane with the lower edge plate of the turbine guide vane unit 2 for assembly to ensure that they can completely clamp the clamping edges of all guide vane units, thereby forming a stable structural support. First, check the machining accuracy and assembly reference of the front and rear inner casings of the guide vane to ensure that its clamping surface matches the clamping edge of the lower edge plate of the guide vane unit. Then, bring the front inner casing 7 and the rear inner casing of the guide vane close to the guide vane outer casing 6 respectively, align the blocking edges of the two with the clamping edges of the lower edge plate of the guide vane, and gradually push forward to ensure that the clamping edges can smoothly enter the clamping space. During this process, temporary positioning pins or jigs can be used for fixation to prevent relative misalignment or uneven clamping of the front and rear inner casings during the assembly process. Ensure that the lower edge plates of all guide vane units are evenly stressed and can be stably inserted into the clamping space before proceeding to the next locking operation.

[0040] S300: Fasten the front inner casing 7 and the rear inner casing 8 of the guide vane, insert the bolt 9 and tighten the nut 10 to ensure that the front inner casing 7 and the rear inner casing 8 of the guide vane are firmly connected to form an integral assembly.

[0041] After completing the assembly of the front and rear inner casings of the guide vane, it is necessary to fasten them with bolts 9 and nuts 10 to form an integral assembly, ensure clamping stability and enhance structural rigidity. First, select bolts 9 that meet the design requirements and pass them through the bolt holes of the front inner casing 7 and the rear inner casing of the guide vane to ensure that the bolts 9 can pass through smoothly and there will be no assembly difficulties due to hole pitch errors. Then, install the nut 10 at the end of the bolt 9 and initially tighten it by hand to ensure uniform fitting of the front and rear inner casings, and then use a torque wrench to gradually tighten it according to the specified tightening torque. The tightening sequence should be diagonal to avoid gaps or uneven clamping between the front and rear inner casings due to local stress unevenness. After tightening, check whether the lower edge plate of the turbine guide vane unit 2 in the clamping space is firm, ensure that all guide vane units are evenly stressed, and there will be no loosening or axial movement during operation.

[0042] S400: Assemble the assembled component with the turbine casing 1; install the assembled guide vane component into the turbine casing 1.

[0043] After completing the assembly of the guide vane assembly, install it into the turbine casing 1 to ensure its stable positioning in the turbine system. First, check the installation reference of the turbine casing 1 to ensure that its inner surface is clean, and confirm that the first card slot of the guide vane outer cover 6 can correctly match the first anti-rotation pin 3 on the turbine casing 1. Then, slowly place the assembled guide vane assembly into the turbine casing 1, maintaining axial and radial alignment, and ensure that the first card slot and the first anti-rotation pin 3 can be smoothly docked to avoid assembly difficulties caused by misalignment. During the installation process, gradually adjust the position of the guide vane assembly to ensure that it fully fits the internal structure of the turbine casing 1, while avoiding component damage caused by assembly interference. After installation, check the joint condition between the guide vane outer cover 6 and the turbine casing 1 to ensure no gaps and no looseness, and ensure that the overall assembly is in a stable stress state inside the casing.

[0044] S500: Install the anti-rotation pins. Insert the first anti-rotation pin 3 into the first card slot of the guide vane outer cover 6 to fix the circumferential position of the guide vane outer cover, and insert the second anti-rotation pin 4 into the second card slot of the upper edge plate of the guide vane to fix the circumferential position of the turbine guide vane unit 2.

[0045] To ensure that the guide vane outer cover 6 and the turbine guide vane unit 2 do not rotate circumferentially during engine operation, anti-rotation pins need to be installed to provide reliable anti-rotation constraints. First, insert the first anti-rotation pin 3 into the first card slot of the guide vane outer cover 6 to fix the circumferential position of the guide vane outer cover 6 and ensure that it does not rotate or shift during the high-temperature gas flow and turbine operation. When inserting, check the fit between the anti-rotation pin and the first card slot to ensure that the pin can enter smoothly and there is no obvious gap or interference jamming after assembly. Then, install the second anti-rotation pin 4 and insert it into the second card slot of the upper edge plate of the guide vane to fix the circumferential position of all turbine guide vane units 2 and prevent individual guide vane units from rotating due to vibration or airflow impact during operation. After installation, check whether the two groups of anti-rotation pins are fully inserted and ensure that they can effectively limit the circumferential movement of the guide vane outer cover 6 and the guide vane unit, improving the overall stability of the system.

[0046] S600: Install the retaining ring 5. Install the retaining ring 5 between the guide vane outer cover 6 and the turbine casing 1 to provide axial limit.

[0047] A retaining ring 5 is installed between the guide vane outer casing 6 and the turbine casing 1 to provide axial limitation and prevent axial movement of the guide vane outer casing 6 during engine operation. First, check the matching of the size of the retaining ring 5 and the limiting groove to ensure that the retaining ring 5 can be smoothly inserted into the limiting groove on the turbine casing 1 and be in close contact with the end face of the guide vane outer casing 6. Then, slowly insert the retaining ring 5 and ensure that it can completely cover the end face of the guide vane outer casing 6, thereby forming a reliable axial constraint. During the installation process, attention should be paid to avoiding uneven force on the retaining ring 5 or improper installation to prevent loosening or displacement during operation. After the installation of the retaining ring 5 is completed, its fixing effect should be checked to ensure that it can provide sufficient axial limitation and will not affect the thermal expansion compensation ability of the guide vane outer casing 6 due to over-tight assembly, so as to ensure the stability and reliability of the entire guide vane assembly during long-term high-temperature operation.

[0048] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A turbine guide vane structure, comprising a turbine guide vane unit (2), a turbine casing (1) and a guide vane inner casing assembly, characterized in that: A guide cover (6) with a full-ring structure is arranged between the turbine guide guide unit (2) and the turbine casing (1); the outer side of the guide cover (6) is connected to the turbine casing (1); the turbine guide guide unit (2) comprises a guide blade and a guide upper edge plate and a guide lower edge plate located on different sides of the guide blade; the guide lower edge plate is cooperatively connected to the guide inner casing assembly; the guide upper edge plate is nested in the guide cover (6) and cooperatively connected; the turbine guide guide unit (2) is distributed along the circumferential direction of the guide cover (6) to achieve centering of the turbine guide guide unit (2).

2. The turbine guide vane structure according to claim 1, characterized in that: The guide cover (6) is provided with a first slot, and the turbine casing (1) is provided with a first anti-rotation pin (3) that matches the first slot.

3. The turbine guide vane structure according to claim 2, characterized in that: The first card slots are evenly spaced and distributed along the circumferential direction of the guide cover (6), and the number of the first card slots is not less than three.

4. The turbine guide vane structure according to claim 2, characterized in that: The turbine casing (1) is provided with a retaining ring (5), and the retaining ring (5) abuts against the end surface of the guide outer cover (6) to axially limit the guide outer cover (6).

5. The turbine guide vane structure according to claim 1, characterized in that: Two clamping edges are formed on the lower edge plate of the guide, and the guide inner casing assembly includes a guide front inner casing (7) and a guide rear inner casing (8). The guide front inner casing (7) and the guide rear inner casing (8) are respectively provided with blocking edges. The guide front inner casing (7) and the guide rear inner casing (8) are tightly attached together and locked by a locking member, so that a clamping space is formed between the two blocking edges to clamp the two clamping edges of the turbine guide unit (2).

6. The turbine guide vane structure according to claim 5, characterized in that: The locking member comprises a bolt (9) and a nut (10). The bolt (9) passes through the guide front inner casing (7) and the guide rear inner casing (8) and is threadedly matched with the nut (10).

7. The turbine guide vane structure according to claim 5, characterized in that: A limiting groove is provided on the clamping edge of the lower edge plate of the guide, and a boss cooperating with the limiting groove is provided on the front inner casing (7) of the guide to prevent circumferential rotation.

8. The turbine guide vane structure according to claim 5, characterized in that: A second slot is provided on the upper edge plate of the guide, and a second anti-rotation pin (4) cooperating with the second slot is provided on the outer cover (6) of the guide.

9. The turbine guide vane structure according to claim 7, characterized in that: The rear end of the guide cover (6) is provided with a removal groove.

10. A method for assembling a turbine guide vane, used for the turbine guide vane structure according to any one of claims 1 to 9, characterized in that: The steps include: S100: Assembling the turbine guide unit (2) and the guide cover (6), embedding the turbine guide unit (2) into the guide cover (6), ensuring accurate matching with the cover structure, and achieving reliable centering; S300: Assemble the guide front inner casing (7) and the guide rear inner casing (8); assemble the guide front inner casing (7) and the guide rear inner casing (8) with the turbine guide unit (2) to ensure that they completely enclose the turbine guide unit (2); S400: Tighten the guide front inner casing (7) and the guide rear inner casing (8), insert the bolt (9) and tighten the nut (10), and ensure that the guide front inner casing (7) and the guide rear inner casing (8) are firmly connected to form an integral assembly; S500: Assembling the assembled components with the turbine casing (1); installing the assembled guide assembly into the turbine casing (1); S600: installing anti-rotation pins, inserting a first anti-rotation pin (3) into a first slot of a guide cover (6) to fix the circumferential position of the guide cover, and inserting a second anti-rotation pin (4) into a second slot of a guide upper edge plate to fix the circumferential position of the turbine guide cover unit (2); S700: Install the retaining ring (5) between the guide cover (6) and the turbine casing (1) to provide axial limit.

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