An adjustable nozzle blade assembly for a turbine

Abstract

This application relates to the field of turbomachinery, and more particularly to an adjustable nozzle blade assembly for a turbine. The turbine includes a turbine, a nozzle ring, and a linkage mechanism. The assembly includes a nozzle shaft, a stationary blade, a drive arm, and a countersunk screw. One end of the nozzle shaft forms a rotating seat, and the other end forms an extension column along the axial direction. The rotating seat is positioned on the nozzle ring. The extension column has a square or regular hexagonal cross-section and a central screw hole. The stationary blade is integrally connected to the rotating seat to rotate with the rotating seat. The drive arm has a first and second arc-shaped convex end and a second convex end. The second convex end is connected to the linkage mechanism. The first convex end has a limiting hole that mates with the extension column, and one end of the limiting hole has a countersunk groove. The countersunk screw is screwed into the central screw hole, and the head of the countersunk screw is embedded in the countersunk groove. This adjustable nozzle blade assembly has the advantages of having fewer parts, convenient installation, and reliability.

Description

Technical Field

[0001] This utility model relates to the field of turbomachinery technology, and in particular to an adjustable nozzle blade assembly for a turbine. Background Technology

[0002] A radial turbine relies on the input of gas at a certain pressure and temperature to drive the rotation of its internal impeller, achieving energy conversion and outputting mechanical work. As the fluid flows through the nozzle ring, it is accelerated and its flow direction is adjusted, impacting the impeller blades and driving the rotor to rotate. This, in turn, drives the turbine shaft to rotate. The turbine shaft, directly or via a transmission mechanism, drives other machinery, outputting mechanical work. It is commonly used in engine turbochargers, waste heat power generation expanders, and other fields. The structure of a radial turbine includes three important components: the volute, the nozzle ring, and the impeller. The volute collects and guides the gas to a uniform circumferential distribution into the nozzle ring, minimizing airflow energy loss within the volute to improve overall efficiency. The nozzle ring consists of multiple uniformly circumferentially distributed nozzle blades. The blades form a converging channel for airflow, accelerating the airflow and directing it in a specific direction, ensuring that the airflow speed and direction meet design requirements. The impeller is a radial impeller with blades arranged radially. Gas ejected from the nozzle ring enters from the outer edge of the impeller and flows toward the center. During this process, the gas expands and does work, driving the impeller to rotate.

[0003] Based on design conditions, the ability to efficiently cover a wide range of operating conditions is one of the key points in the performance design of centripetal turbines. However, for a given structure, the coverage range is limited. To ensure that the impeller operates with high efficiency under different conditions, the angle and flow rate of the airflow can be adjusted by regulating the angle of the nozzle blades and the throat area. Therefore, many turbines that need to operate under varying conditions adopt adjustable nozzle structures. Existing adjustable nozzle designs mainly fall into two categories: one, which is more commonly used, involves the adjustable nozzle blades rotating around an axis, changing the blade angle and the spacing between the blades, thereby altering the throat area and flow rate; the other, less commonly used design, involves each adjustable nozzle blade having two fulcrums, changing the blade angle and throat area by adjusting the position and sliding of these two fulcrums. In the first type of adjustable nozzle blade design, which uses a single rotating axis, the rotational motion of each adjustable nozzle blade needs to be converted into the oscillating motion of the transmission arm via a transmission arm, and the transmission arms are connected through a linkage structure to unify the actions.

[0004] Currently, taking the turbine assembly scheme disclosed in US Patent No. US10302011B2, published on May 25, 2017, as an example, its nozzle blades and nozzle shaft are separately connected, and are matched with limiting holes by limiting pins with square or star-shaped cross-sections. The nozzle shaft and drive arm are separately connected, with a connecting hole at one end of the nozzle shaft. The nozzle shaft and drive arm are fastened together by a connector passing through the connecting hole. The outer end of the connector protrudes from the surface of the drive arm. The protruding part of the connector and the drive arm are circumferentially limited by a spline-type limiting groove and a limiting part. The drive arm abuts axially between the bushing on the outside of the nozzle shaft and the connector. The current adjustable nozzle blades and linkage structure have many parts, making installation complex and cumbersome. Furthermore, the connector protrudes from the surface of the drive arm and is placed in a complex flow field with turbulence and strong pulses, making the connection point prone to airflow friction and vibration, causing connection failure, or even instability of the drive arm. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide an adjustable nozzle blade assembly for turbines, which has the advantages of fewer parts, convenient installation and reliability.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: An adjustable nozzle blade assembly for a turbine, the turbine including a turbine, a nozzle ring, and a linkage mechanism for driving the blade assembly, the assembly including: a nozzle shaft, one end forming a rotating seat and the other end forming an extension column along the axial direction, the rotating seat being positioned on the nozzle ring, the extension column having a square or regular hexagonal cross-section, and a central threaded hole on the extension column; a stationary blade integrally connected to the rotating seat to rotate with the rotating seat; a drive arm having a first and second arc-shaped convex end, the second convex end being connected to the linkage mechanism, the first convex end having a limiting hole that mates with the extension column, and one end of the limiting hole having a countersunk groove; and a countersunk screw screwed into the central threaded hole, the head of the countersunk screw being embedded in the countersunk groove to lock the relative position of the drive arm and the extension column.

[0007] To optimize the above solution, the following technical measures will be further adopted: In one embodiment, the other end of the nozzle shaft has a shoulder portion, the extension post is formed on the shoulder portion, the transmission arm has a lower end face and an upper end face, the upper end face abuts against the shoulder portion, the lower end face abuts against the head of the countersunk screw, the countersunk groove is formed on the lower end face, and the head end face of the countersunk screw is flush with the lower end face of the transmission arm.

[0008] In one embodiment, the limiting hole and the extension post are configured to limit the stationary blade and the transmission arm to be offset from each other by a set angle in the circumferential direction.

[0009] In one embodiment, the first protrusion is coaxially arranged with the countersunk groove, the nozzle shaft, and the central screw hole, and the axis of the nozzle shaft is arranged near the aerodynamic torque center of the stationary blade.

[0010] In one embodiment, the rotating seat is disc-shaped, the diameter of the rotating seat is larger than that of the nozzle shaft, and the rotating seat and the nozzle ring are fitted with a clearance.

[0011] In one embodiment, the diameter of the extension post is smaller than that of the nozzle shaft, the diameter of the second protrusion is larger than that of the nozzle shaft, and the extension post is sleeved with the limiting hole.

[0012] In one embodiment, the countersunk screw is a standard part.

[0013] In one embodiment, the head of the countersunk screw is arranged to fit closely with the countersunk groove.

[0014] In one embodiment, the transmission arm includes a main body, with the first convex end and the second convex end respectively located at both ends of the main body and transitioning to the main body with an arc. The cross-section of the main body is square, and the diameters of the first convex end and the second convex end are both greater than the width of the main body.

[0015] In one embodiment, the transmission arm is a one-piece molded part.

[0016] Because of the above-described solutions, one or more technical solutions provided in this application embodiment have at least the following technical effects or advantages: On the one hand, in this application, the nozzle shaft, the rotating seat for rotating and supporting the stationary blade, the extension column for cooperating with the transmission arm and the stationary blade are integrally connected, reducing the number of assembly parts. The extension column and the transmission arm are circumferentially limited by the shaft hole of the square hole / square column or the hexagonal hole / hexagonal prism, and their axial positions are locked by directly tightening the countersunk screw that passes through the central screw hole. The installation process is quick and convenient.

[0017] On the other hand, in this application, the threaded connector does not protrude from the lower end face of the transmission arm, but is embedded in the countersunk groove, thereby avoiding the protruding part of the connector from being placed in the complex flow field of turbulence and / or strong pulses, reducing airflow friction and vibration, thereby preventing connection failure, and making the blade assembly operate more smoothly.

[0018] On the other hand, multiple adjustable nozzle blade assemblies are installed on the nozzle ring inside the turbine. The transmission arm and the nozzle shaft in each nozzle blade assembly need to be connected by a connector. In this application, the countersunk screws used as connectors can be standard parts, which reduces costs and makes replacement and maintenance more convenient. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only involve some embodiments of this application and should not be construed as limiting this application.

[0020] Figure 1 This is a schematic diagram of the assembly of components and parts in this embodiment from one perspective; Figure 2 This is a schematic diagram of the assembly of components and parts in this embodiment from another perspective; Figure 3 This is a schematic diagram of the transmission arm in this embodiment from one perspective; Figure 4 This is a schematic diagram of the transmission arm from another perspective in this embodiment; Figure 5 This is a schematic diagram of the overall structure of the adjustable nozzle blade assembly in this embodiment; Figure 6 This is a cross-sectional schematic diagram of the adjustable nozzle blade assembly in this embodiment.

[0021] Figure label: 1. Nozzle shaft; 11. Rotary seat; 12. Extension column; 121. Center screw hole; 2. Stationary blade; 21. Trailing edge; 22. Leading edge; 3. Drive arm; 31. Main body; 32. First protrusion; 321. Limiting hole; 322. Countersunk groove; 33. Second protrusion; 4. Countersunk screw; 41. Head. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings, so as to more clearly understand the purpose, features and advantages of this utility model. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of this utility model, but are only for illustrating the essential spirit of the technical solutions of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0023] Unless the context requires otherwise, throughout the specification and claims, the word “comprising” and its variations, such as “including” and “having”, shall be understood to have an open, inclusive meaning, that is, to be interpreted as “including, but not limited to”.

[0024] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the appearance of "in an embodiment" or "an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any manner in one or more embodiments.

[0025] The singular forms “a” and “the” used in this specification and the appended claims include plural references unless otherwise expressly stated herein. It should be noted that the term “or” is generally used to mean “and / or” unless otherwise expressly stated herein.

[0026] In the following description, in order to clearly demonstrate the structure and working method of this utility model, a number of directional terms will be used. However, terms such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and not as limiting terms.

[0027] The implementation details of the embodiments of this utility model will be described in detail below with reference to the accompanying drawings. The following implementation details are provided only for ease of understanding and are not necessary for implementing this solution.

[0028] This embodiment proposes an adjustable nozzle blade assembly for turbines, aiming to solve the problems of numerous components, complex and cumbersome installation, and airflow friction and vibration caused by the protruding part of the connection between the transmission arm and the nozzle shaft in the prior art. Compared with the prior art, the solution provided in this embodiment can not only reduce the number of components in the nozzle blade assembly and simplify the installation operation, but also make the connection between the nozzle shaft and the transmission arm more reliable, and make the working process of the nozzle blade assembly more stable and smooth.

[0029] In this embodiment, the turbine may be, for example, a turbocharger, a turbine engine, a turbo pump, an expander, or other machinery, without any limitation. The turbine includes a turbine, a nozzle ring, and a linkage mechanism. Here, the nozzle ring is configured around the outer periphery of the turbine (impeller) and is used to position a plurality of adjustable nozzle blade assemblies that are distributed in a circumferential direction. The linkage mechanism is used to drive the blade assembly to move. The above structure has been described in the prior art and will not be repeated here.

[0030] Specifically, such as Figures 1 to 6As shown, the blade assembly includes a nozzle shaft 1, a stationary blade 2, a drive arm 3, and a countersunk screw 4. One end of the nozzle shaft 1 forms a rotating seat 11, and the other end forms an extension column 12 along the axial direction. In one case, the nozzle shaft 1 is cylindrical, and the rotating seat 11 is disc-shaped. The diameter tolerance of the rotating seat 11 is controlled. The rotating seat 11 is rotatably positioned on other stationary parts of the turbine, such as the nozzle ring, and has a clearance fit with the nozzle ring, allowing the stationary blade 2 to be positioned and rotate flexibly. The nozzle shaft 1 guides the entire nozzle blade to rotate. The stationary blade 2 has a shape formed by a special curved surface, and its profile can be obtained through aerodynamic calculations. The stationary blade 2 is integrally connected to the rotating seat 11 to rotate with the rotating seat 11. The shape of the stationary blade 2 guides the airflow direction and accelerates it to a certain extent. Specifically, the stationary blade 2 has a trailing edge 21 and a leading edge 22. When viewed from a cross-section parallel to the front-rear direction, the trailing edge 21 of the blade is thicker, and the leading edge 22 is thinner, forming an airfoil blade with a bulging rear and a sharp front. Airflow enters from the trailing edge and is deflected by the side of the blade, then flows into the turbine from the leading edge. The cross-section of the extension column 12 is square or regular hexagonal. A central screw hole 121 is provided on the extension column 12. The transmission arm 3 is a cantilever arm with a first convex end 32 and a second convex end 33 in an arc shape. The second convex end 33 is connected to the linkage mechanism. The first convex end 32 has a limiting hole 321. The limiting hole 321 cooperates with the extension column 12. The shaft hole cooperation between the two is used to limit the angle of the transmission arm 3 relative to the stationary blade 2 on the one hand, and to realize the direct power transmission between the transmission arm 3 and the stationary blade 2 on the other hand, so as to dynamically adjust the angle position of the stationary blade 2. One end of the limiting hole 321 has a countersunk groove 322. The countersunk screw 4 is screwed into the central screw hole 121, and the head 41 of the countersunk screw 4 is embedded in the countersunk groove 322 to lock the relative position of the transmission arm 3 and the extension column 12.

[0031] In this embodiment, the nozzle shaft 1, the rotating seat 11 for rotating and supporting the stationary blade 2, the extension column 12 for cooperating with the transmission arm 3 for transmission, and the stationary blade 2 are integrally connected to reduce the number of assembly parts. The extension column 12 and the transmission arm 3 are circumferentially limited by the shaft hole of the square hole / square column or the hexagonal hole / hexagonal prism, and their axial positions are locked by directly tightening the countersunk screw 4 that passes through the central screw hole. The installation process is quick and convenient.

[0032] On the other hand, in the prior art, the connector between the nozzle shaft and the drive arm protrudes from the surface of the drive arm. The protruding part has a limiting part that engages with the connecting part on the nozzle shaft to achieve circumferential positioning between the drive arm and the nozzle shaft. While this also achieves the coordinated transmission between the nozzle shaft and the drive arm, the protruding part is located inside the turbine casing. During operation, complex flow fields such as turbulence or strong pulses are formed inside the casing, which easily causes friction and vibration between the airflow and the blades, thus affecting the connection and transmission between the nozzle shaft and the drive arm. In this embodiment, as... Figure 5 As shown, after the countersunk screw 4 is screwed into place, it does not protrude from the lower end face of the transmission arm 3, that is, the surface away from the nozzle shaft 1 along the axial direction, but is embedded in the countersunk groove 322. This avoids the protruding part of the connector being placed in the complex flow field of turbulence and / or strong pulse, reduces airflow friction and vibration, thereby preventing connection failure and hindering the swing of the transmission arm 3, making the blade assembly move more smoothly.

[0033] On the other hand, multiple adjustable nozzle blade assemblies are installed on the nozzle ring inside the turbine. The transmission arm 3 and the nozzle shaft 1 in each nozzle blade assembly need to be connected by a connector. In this application, the countersunk screw 4, which serves as the connector, can be a standard part, which reduces costs and makes replacement and maintenance more convenient.

[0034] Here, the head 41 of the countersunk screw 4 should be fully embedded in the countersunk groove 322. That is to say, the head 41 of the countersunk screw 4 can be built into the countersunk groove 322, or the end face can be flush with the lower end face of the transmission arm 3.

[0035] Specifically, the other end of the nozzle shaft 1 has a shoulder portion, the extension post 12 is formed on the shoulder portion, the transmission arm 3 has a lower end face, an upper end face, and an outer peripheral surface formed between the lower end face and the upper end face, the upper end face abuts against the shoulder portion, the lower end face abuts against the head 41 of the countersunk screw 4, the countersunk groove 322 is formed on the lower end face, and the end face of the head 41 of the countersunk screw 4 is flush with the lower end face of the transmission arm 3.

[0036] On one hand, the countersunk groove 322 on the transmission arm 3 makes it easy for the countersunk screw 4 to be fully screwed into the component, thereby saving space and preventing jamming of the movement.

[0037] On another front, after the adjustable nozzle blade assembly is installed on the turbine's nozzle ring, a gap is left between the lower end face of the transmission arm 3 and other stationary parts of the turbine for convenient transmission. This gap is in an open flow field environment, and the protruding connecting parts continuously rub and vibrate with the airflow within this gap, affecting the transmission of the transmission arm 3. Here, the head 41 end face of the countersunk screw 4 is flush with the lower end face of the transmission arm 3, so that the lower end face of the transmission arm 3 can still maintain a relatively intact surface, reducing the impact of airflow vibration on the transmission arm 3 within this gap.

[0038] In this embodiment, in one scenario, the transmission arm 3 drives the nozzle shaft 1 to rotate by swinging around the central axis of the second protrusion 33, thereby adjusting the angular position of the stationary blade 2. For this purpose, as follows... Figure 4 As shown, the limiting hole 321 and the extension post 12 are configured to limit the stationary blade 2 and the transmission arm 3 to be offset from each other by a set angle in the circumferential direction. Taking the limiting hole 321 as a square hole as an example, that is, the limiting hole 321 is obliquely placed and has a certain angle with the axis of the transmission arm 3 along the arm length direction. This angle is designed and processed according to the installation position and swing angle of the transmission arm 3.

[0039] In this embodiment, as Figure 1 , Figure 2 , Figure 5 and Figure 6 As shown, the first protrusion 32, countersunk groove 322, nozzle shaft 1, and central screw hole 121 are all arranged coaxially. The axis of the nozzle shaft 1 is arranged near the aerodynamic torque center of the stationary blade 2, so that when the stationary blade 2 is impacted by the airflow, the torque generated on the adjustable nozzle blade is minimized, thus saving effort.

[0040] In this embodiment, the rotating seat 11 is disc-shaped, and its diameter is larger than that of the nozzle shaft 1. The rotating seat 11 and the nozzle ring are fitted with a clearance to ensure the installation accuracy of the adjustable nozzle blades and allow for flexible rotation. Furthermore, the diameter of the extension post 12 is smaller than that of the nozzle shaft 1, while the diameter of the second protrusion 33 is larger than that of the nozzle shaft 1. The extension post 12 is fitted with the limiting hole 321 to constrain their relative angular positions, ensuring the consistency of movement of each adjustable nozzle blade and the correct orientation of the transmission arm 3.

[0041] In this embodiment, the head 41 of the countersunk screw 4 is arranged in close contact with the countersunk groove 322, which can prevent airflow from entering the component through the gap between the head 41 of the countersunk screw 4 and the countersunk groove 322, causing movement.

[0042] In this embodiment, as Figure 3 and Figure 4As shown, the transmission arm 3 includes a main body 31, with the first protruding end 32 and the second protruding end 33 respectively placed at both ends of the main body 31 and transitioned to the main body 31 by an arc. The cross-section of the main body 31 is square, and the diameters of the first protruding end 32 and the second protruding end 33 are both greater than the width of the main body 31.

[0043] In this embodiment, the transmission arm 3 is a one-piece molded part.

[0044] In this embodiment, the transmission arm 3 is a short, swingable arm that is larger at both ends and smaller in the middle. The two ends are rounded protrusions of the same size, while the middle section is square, with a width smaller than the diameter of the rounded protrusions at both ends. The ends and the middle section are connected by an arc. This structure facilitates the swinging of the transmission arm 3, making it more stable and preventing it from being jammed by other components. It also allows for smoother movement and a wider adjustment angle.

[0045] In summary, in the above embodiments, the adjustable nozzle blade assembly simplifies the existing structure and optimizes the installation and fastening structure, making the adjustment of the blade angle more reliable and precise.

[0046] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this utility model, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0047] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An adjustable nozzle vane assembly for a turbine, the turbine comprising a turbine, a nozzle ring and a linkage mechanism for driving the vane assembly into action, characterised in that, The components include: The nozzle shaft has a rotating seat at one end and an extension column at the other end along the axial direction. The rotating seat is positioned on the nozzle ring. The cross-section of the extension column is square or regular hexagonal, and a central screw hole is provided on the extension column. The stationary blade is integrally connected to the rotating base to rotate with the rotating base; The transmission arm has a first and second arc-shaped convex end and a second convex end, the second convex end being connected to a linkage mechanism. The first convex end has a limiting hole that mates with an extension post, and one end of the limiting hole has a countersunk groove. A countersunk screw is screwed into the central screw hole, and the head of the countersunk screw is embedded in the countersunk groove to lock the relative position of the drive arm and the extension column.

2. The adjustable nozzle vane assembly for a turbomachine of claim 1, wherein, The other end of the nozzle shaft has a shoulder portion, the extension post is formed on the shoulder portion, the transmission arm has a lower end face and an upper end face, the upper end face abuts against the shoulder portion, the lower end face abuts against the head of the countersunk screw, the countersunk groove is formed on the lower end face, and the head end face of the countersunk screw is flush with the lower end face of the transmission arm.

3. The adjustable nozzle vane assembly for a turbomachine of claim 1, wherein, The limiting hole and the extension post are configured to limit the stationary blade and the transmission arm to be offset from each other by a set angle in the circumferential direction.

4. The adjustable nozzle vane assembly for a turbomachine of claim 1, wherein, The first protrusion is coaxially arranged with the countersunk groove, the nozzle shaft, and the central screw hole. The axis of the nozzle shaft is arranged near the aerodynamic torque center of the stationary blade.

5. The adjustable nozzle blade assembly for a turbine according to any one of claims 1 to 4, characterized in that, The rotating seat is disc-shaped, and its diameter is larger than that of the nozzle shaft. The rotating seat and the nozzle ring are fitted with a clearance.

6. The adjustable nozzle blade assembly for a turbine according to any one of claims 1 to 4, characterized in that, The diameter of the extension post is smaller than that of the nozzle shaft, and the diameter of the second protrusion is larger than that of the nozzle shaft. The extension post is sleeved with the limiting hole.

7. The adjustable nozzle blade assembly for a turbine according to claim 1, characterized in that, The countersunk screws are standard parts.

8. The adjustable nozzle blade assembly for a turbine according to claim 1, characterized in that, The head of the countersunk screw is arranged to fit closely into the countersunk groove.

9. The adjustable nozzle blade assembly for a turbine according to claim 1, characterized in that, The transmission arm includes a main body, with the first convex end and the second convex end respectively located at both ends of the main body and transitioned to the main body by an arc. The cross-section of the main body is square, and the diameters of the first convex end and the second convex end are both greater than the width of the main body.

10. The adjustable nozzle blade assembly for a turbine according to claim 1, characterized in that, The transmission arm is a one-piece molded part.

Images