High-pressure turbine outer ring connecting and positioning structure capable of being used for adjusting blade tip clearance

Abstract

The invention provides a high-pressure turbine outer ring connecting and positioning structure capable of being used for adjusting blade tip gaps, and belongs to the field of aero-engines. The outer ring fixing ring is fixed on the turbine case; the high-pressure turbine outer ring is mounted on the outer ring fixing ring through a connecting pin; the connecting pins are provided with pin heads with circumferential positioning surfaces, large-diameter matching sections and small-diameter matching sections, the circumferential positioning surfaces are matched with planes or arc surfaces on the outer ring fixing ring to realize circumferential positioning, the large-diameter matching sections are matched with mounting holes in the outer ring fixing ring, and the small-diameter matching sections are matched with pin holes in the outer ring of the high-pressure turbine; the connecting pin comprises a non-eccentric structure and an eccentric structure with a small-diameter matching section facing downwards or upwards at different degrees; when the outer ring of the high-pressure turbine is assembled on the outer ring fixing ring, the radial height of the outer ring of the high-pressure turbine is adjusted by selecting and matching the connecting pins with different eccentricity as required, so that the blade tip clearance between the blade and the outer ring of the high-pressure turbine is adjusted.

Description

Technical Field

[0001] The present application relates to the field of aero-engines, and in particular to a high-pressure turbine outer ring connection and positioning structure that can be used to adjust blade tip clearance. Background Art

[0002] The high-pressure turbine tip clearance (i.e., the radial clearance between the turbine rotor blade tip and the stator flow passage) in aircraft engines and gas turbines is a key factor affecting turbine aerodynamic performance. To achieve optimal high-pressure turbine performance while avoiding severe friction between the blade tip and the stator flow passage, the blade tip assembly clearance is typically adjusted multiple times during the high-pressure turbine development process to find the optimal clearance value.

[0003] To adjust the HPT tip clearance, the blade tip height or the radial height of the stator flow path (often referred to as the "HPT outer ring") must be adjusted. Currently, each clearance adjustment requires returning the pre-assembled parts to the factory for re-processing or replacing them with new parts. Reducing the clearance can only be achieved by replacing new parts. Consequently, each newly developed engine requires the ordering of one or more expensive spare rotor blades or HPT outer rings, increasing development costs. Summary of the Invention

[0004] The purpose of the present application is to provide a high-pressure turbine outer ring connection and positioning structure that can be used to adjust the blade tip clearance, so as to solve or alleviate at least one problem in the background technology.

[0005] The technical solution of the present application is: a high-pressure turbine outer ring connection and positioning structure that can be used to adjust the blade tip clearance, comprising:

[0006] turbine casing;

[0007] an outer fixing ring, the outer fixing ring being fixed to the turbine casing;

[0008] a high-pressure turbine outer ring, the high-pressure turbine outer ring being mounted to the outer ring fixing ring via connecting pins; and

[0009] Connecting pins of various specifications, each having a pin head with a circumferential positioning surface, a large-diameter mating section, and a small-diameter mating section. The circumferential positioning surface cooperates with a flat surface or arc surface on an outer ring fixing ring to achieve circumferential positioning. The large-diameter mating section cooperates with a mounting hole on an outer ring fixing ring, and the small-diameter mating section cooperates with a pin hole on an outer ring of a high-pressure turbine. The connecting pin includes a non-eccentric structure in which the small-diameter mating section and the large-diameter mating section are coaxial, and a structure in which the small-diameter mating section is eccentric to varying degrees downward or upward relative to the large-diameter mating section along the circumferential positioning surface.

[0010] When assembling the high-pressure turbine outer ring onto the outer ring fixing ring, connecting pins with different eccentricities are selected as needed to adjust the radial height of the high-pressure turbine outer ring, thereby adjusting the tip clearance between the blades and the high-pressure turbine outer ring.

[0011] In at least one embodiment of the present application, the outer ring fixing ring is a fan-shaped segment structure, and the outer ring fixing ring has two mounting edges arranged forward and backward along the airflow. Multiple outer ring fixing rings are spliced to form a full ring structure and fixed to the turbine casing.

[0012] In at least one embodiment of the present application, the outer ring fixing ring is limited by a front baffle, and the front baffle is fixed to the turbine casing by locking pins.

[0013] In at least one embodiment of the present application, the outer ring of the high-pressure turbine is a fan-shaped segment structure, and the outer ring of the high-pressure turbine has a mounting edge adapted to the outer ring fixing ring, and a first pin hole and a second pin hole are provided at both circumferential ends of the mounting edge. The outer ring of the high-pressure turbine is installed on the outer ring fixing ring by a connecting pin passing through the first pin hole and the second pin hole.

[0014] In at least one embodiment of the present application, the first pin hole is a circular hole, and the second pin hole is a long hole with a longer circumferential distance.

[0015] In at least one embodiment of the present application, the circumferential length of the outer ring fixing ring is N times the circumferential length of the high-pressure turbine outer ring, so that a single outer ring fixing ring can install N high-pressure turbine outer rings, and N is a natural number.

[0016] In at least one embodiment of the present application, a sealing groove is provided on the circumferential side surface of the outer ring fixing ring and / or the high-pressure turbine ring, and a sealing sheet is installed in the sealing groove.

[0017] In at least one embodiment of the present application, a orifice plate is further included, wherein the orifice plate is arranged between the outer ring of the high-pressure turbine and the outer ring fixing ring, and the cooling gas flowing from the cooling channel arranged inside the outer ring fixing ring into the inner side of the outer ring fixing ring impact-cools the outer ring of the high-pressure turbine through the cooling holes arranged on the orifice plate.

[0018] In at least one embodiment of the present application, the degree or amount of eccentricity of the small-diameter fitting segment does not exceed the projection range of the large-diameter fitting segment in the direction of the center line of the small-diameter fitting segment.

[0019] The high-pressure turbine outer ring connection and positioning structure provided in the present application can realize the adjustment of the radial height of the high-pressure turbine outer ring and the adjustment of the tip clearance of the high-pressure turbine blades. Compared with the prior art method in which each tip clearance adjustment requires re-processing or assembly, the present application can be achieved by replacing the connecting pins with appropriate eccentricity to install the high-pressure turbine outer ring. There is no need to customize spare parts for clearance adjustment, and the process of returning to the factory for reprocessing is eliminated, with low development cost, high efficiency and short cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0021] Figure 1 This is an overall schematic diagram of the high-pressure turbine outer ring connection and positioning structure of this application.

[0022] Figure 2 This is a schematic diagram of the high-pressure turbine outer ring structure of this application.

[0023] Figure 3 Schematic diagram of different types of connecting pins in this application.

[0024] Reference numerals:

[0025] 1-turbine casing, 11-front baffle ring, 12-locking pin;

[0026] 2- Outer ring fixing ring,

[0027] 3-high-pressure turbine ring, 31-mounting edge, 32-first pin hole, 33-second pin hole, 34-sealing groove;

[0028] 4-leaf;

[0029] 5-connecting pin, 51-large diameter matching section, 52-small diameter matching section, 53-circumferential positioning surface, 54-pin head;

[0030] 61-clamp ring, 62-locking plate;

[0031] 7-well plate;

[0032] 8- Bellows sealing ring. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0034] In order to overcome the problems that the traditional high-pressure turbine outer ring connection structure does not have the tip clearance adjustment function and cannot achieve multiple tip clearance verifications during the development stage, resulting in high cost, low efficiency, long cycle, etc., the present application provides a high-pressure turbine outer ring connection positioning structure that can be used to adjust the tip clearance.

[0035] like Figures 1 to 3 As shown, the high-pressure turbine outer ring connection and positioning structure provided in the present application and which can be used to adjust the blade tip clearance includes: a turbine casing 1, an outer ring fixing ring 2, a high-pressure turbine outer ring 3 and a connecting pin 5.

[0036] The outer ring fixing ring 2 is installed on the turbine casing 1 by plugging. After the plugged outer ring fixing ring 2 is axially limited by the front retaining ring 11, the front retaining ring 11 is fixed to the turbine casing 11 by the locking pin 12, thereby achieving the fixation of the outer ring fixing ring 2.

[0037] Combine Figure 2 As shown, the main body of the high-pressure turbine outer ring 3 is a sector structure, and multiple sector structures can be spliced circumferentially to form a complete ring structure. The sector structure is provided with two radially extending front and rear (airflow direction) mounting edges 31, and a first pin hole 32 and a second pin hole 33 are respectively provided at the circumferential ends of the front and rear mounting edges 31 of the high-pressure turbine outer ring 3. Among them, the first pin hole 32 is a circular hole, and the second pin hole 33 is a long hole with a slightly longer circumferential distance. The first pin hole 32 and the second pin hole 33 are located on the front and rear mounting edges 31 on the same side. By configuring the first pin hole 32 and the second pin hole 33 as a circular hole and a long hole, when the high-pressure turbine outer ring 3 is installed on the outer ring fixing ring 2, the coordination ability of circumferential thermal deformation can be achieved while ensuring the radial positioning of the high-pressure turbine outer ring 2.

[0038] Similar in structure to the high-pressure turbine outer ring 3, the outer retaining ring 2 also has a sector-shaped structure. The circumferential length of the outer retaining ring 2 is typically greater than that of the high-pressure turbine outer ring 3, being several times longer. For example, the circumferential length of the outer retaining ring 2 can be 2 to 4 times that of the high-pressure turbine outer ring 3, allowing approximately 2 to 4 high-pressure turbine outer rings 3 to be mounted on each outer retaining ring 2.

[0039] The outer ring retaining ring 2 is also provided with front and rear mounting edges, each of which has mounting holes corresponding to the first pin hole 32 and second pin hole 33 of the high-pressure turbine outer ring 3. The outer ring retaining ring 2, which has a plurality of fan-shaped segments, is assembled to form a complete ring structure and then installed on the turbine casing 1. The front and rear mounting edges 31 of each high-pressure turbine outer ring 3 are respectively mounted and positioned on the front and rear mounting edges of the outer ring retaining ring 2 via two connecting pins 5. The front and rear connecting pins 5 are respectively limited to the outer ring retaining ring 2 by a retaining ring 61 or a locking plate 62, thereby achieving the connection between the high-pressure turbine outer ring 3 and the turbine casing 1. A corrugated sealing ring 8 can be provided between the mounting edge 31 on the front side of the high-pressure turbine outer ring 3 and the outer ring retaining ring 2 to achieve sealing.

[0040] In some embodiments of the present application, in order to enhance the impact cooling effect on the high-pressure turbine outer ring 3, a cooling channel for connecting to a lower temperature gas is provided inside the outer ring fixing ring 2. At the same time, a perforated plate 7 is provided between the outer ring fixing ring 2 and the high-pressure turbine outer ring 3. The perforated plate 7 is provided with multiple cooling holes facing the high-pressure turbine outer ring 7. The cooling gas flowing into the cooling channel of the outer ring fixing ring 2 can flow through the cooling holes of the perforated plate 7 and impact the surface of the high-pressure turbine outer ring 3. In some embodiments of the present application, the perforated plate 7 can be installed on the inner side or lower side of the outer ring fixing ring 2 by welding.

[0041] In order to ensure the axial sealing and deformation coordination between the high-pressure turbine outer ring 3 and the outer ring fixing ring 2, a full-ring sealing ring is provided between the high-pressure turbine outer ring 3 and the outer ring fixing ring 2.

[0042] In some embodiments of the present application, sealing grooves 34 may be provided on both circumferential side surfaces of the high-pressure turbine outer ring 3 and the outer ring fixing ring 2 for installing sealing sheets.

[0043] like Figure 3 Shown is a schematic diagram of the structure of different types of connecting pins in this application. The connecting pin 5 includes a pin head 54, a large diameter fitting section 51 and a small diameter fitting section 52. The pin head 54 is provided with a circumferential positioning surface 53. The circumferential positioning surface 53 cooperates with the plane or arc surface on the outer ring fixing ring 2 to achieve circumferential positioning. The large diameter fitting section 51 cooperates with the mounting hole on the outer ring fixing ring 2, and the small diameter fitting section 52 cooperates with the pin hole on the high-pressure turbine outer ring 3.

[0044] The connecting pins 5 come in a variety of sizes and types, including a non-eccentric configuration (i.e., the large-diameter mating section 51 and the small-diameter mating section 52 are coaxial) and a configuration where the small-diameter mating section 52 is eccentric to varying degrees, either downward or upward, relative to the large-diameter mating section 51, along the normal direction of the circumferential positioning surface 53. When assembling the high-pressure turbine outer ring 3 to the outer retaining ring 2, selecting connecting pins 5 with varying eccentricities as needed allows adjustment of the radial height of the high-pressure turbine outer ring 3, thereby achieving the desired tip clearance adjustment between the blades 4 and the high-pressure turbine outer ring 3.

[0045] like Figure 3 Shown are schematic diagrams of different types of connecting pins in this application, where Figure a is a connecting pin with a non-eccentric structure, Figure b is a structure in which the small-diameter fitting section 52 is eccentric downward relative to the large-diameter fitting section 51, and Figure b is a structure in which the small-diameter fitting section 52 is eccentric upward relative to the large-diameter fitting section 51.

[0046] To ensure the assembly of the connecting pin 5, the degree or amount of eccentricity of the small-diameter mating section 52 does not exceed the projection of the large-diameter mating section 51 along its centerline. For example, if the diameter of the large-diameter mating section 51 is 5 mm and the diameter of the small-diameter mating section 52 is 4 mm, the small-diameter mating section 52 is allowed to be eccentric within a range of 0.5 mm downward or upward relative to the large-diameter mating section 51 to ensure a complete outer circular mating surface of the small-diameter mating section 52.

[0047] The assembly process of the high-pressure turbine outer ring connection and positioning structure of this application is as follows:

[0048] S1. Before installing the high-pressure turbine outer ring 3, first assemble the outer ring retaining ring 2 of the sector structure piece by piece onto the turbine casing 1 of the full-ring structure. During the installation process, seals are installed between adjacent outer ring retaining rings 2 by installing sealing sheets. The full-ring sealing ring is embedded in the annular cavity of the outer ring retaining ring 2. After all outer ring retaining rings 2 are installed, install the axial limit front stop ring 11 and locking pin 12 at the front end of the outer ring retaining ring 2;

[0049] S2. After completing the installation of the outer ring fixing ring 2, push the high-pressure turbine outer ring 3 into the outer ring fixing ring 2 piece by piece from the radial direction. At the same time, install sealing plates between the high-pressure turbine outer rings 3, and select and install connecting pins 5 with appropriate eccentricity as needed to install the front and rear mounting edges 31 of the high-pressure turbine outer ring 3, and limit the connecting pins 5 to the outer ring fixing ring 2 through the retaining ring 61 or the locking plate 62.

[0050] The high-pressure turbine outer ring connection and positioning structure provided in the present application can adjust the radial height of the high-pressure turbine outer ring 3 to the outer ring fixing ring 2 by selecting connecting pins with different offset amounts, thereby realizing the adjustment of the tip clearance of the high-pressure turbine blades. Compared with the prior art method in which each tip clearance adjustment requires reprocessing or assembly, the present application can be achieved by installing the high-pressure turbine outer ring by replacing the connecting pins with appropriate eccentricity. There is no need to customize spare parts for clearance adjustment, and the process of returning to the factory for reprocessing is eliminated, with low development cost, high efficiency and short cycle.

[0051] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A high-pressure turbine outer ring connection and positioning structure for adjusting blade tip clearance, characterized in that: include: turbine casing; an outer fixing ring, the outer fixing ring being fixed to the turbine casing; a high-pressure turbine outer ring, the high-pressure turbine outer ring being mounted on the outer ring fixing ring via connecting pins; as well as Connecting pins of various specifications, each having a pin head with a circumferential positioning surface, a large-diameter mating section, and a small-diameter mating section. The circumferential positioning surface cooperates with a flat surface or arc surface on an outer ring fixing ring to achieve circumferential positioning. The large-diameter mating section cooperates with a mounting hole on an outer ring fixing ring, and the small-diameter mating section cooperates with a pin hole on an outer ring of a high-pressure turbine. The connecting pin includes a non-eccentric structure in which the small-diameter mating section and the large-diameter mating section are coaxial, and a structure in which the small-diameter mating section is eccentric to varying degrees downward or upward relative to the large-diameter mating section along the circumferential positioning surface. When assembling the high-pressure turbine outer ring onto the outer ring fixing ring, connecting pins with different eccentricities are selected as needed to adjust the radial height of the high-pressure turbine outer ring, thereby adjusting the tip clearance between the blades and the high-pressure turbine outer ring.

2. The high-pressure turbine outer ring connection and positioning structure for adjusting blade tip clearance according to claim 1, characterized in that: The outer ring fixing ring is a fan-shaped segment structure, and the outer ring fixing ring has two mounting edges arranged forward and backward along the airflow. A plurality of the outer ring fixing rings are spliced together to form a complete ring structure and fixed to the turbine casing.

3. The high-pressure turbine outer ring connection and positioning structure for adjusting blade tip clearance according to claim 2, characterized in that: The outer ring fixing ring is limited by a front baffle, and the front baffle is fixed to the turbine casing by locking pins.

4. The high-pressure turbine outer ring connection and positioning structure for adjusting blade tip clearance according to claim 2, characterized in that: The outer ring of the high-pressure turbine is a fan-shaped segment structure, and the outer ring of the high-pressure turbine has a mounting edge adapted to the outer ring fixing ring. A first pin hole and a second pin hole are provided at both circumferential ends of the mounting edge. The outer ring of the high-pressure turbine is installed on the outer ring fixing ring by a connecting pin passing through the first pin hole and the second pin hole.

5. The high-pressure turbine outer ring connection and positioning structure for adjusting blade tip clearance according to claim 4, characterized in that: The first pin hole is a circular hole, and the second pin hole is a long hole with a longer circumferential distance.

6. The high-pressure turbine outer ring connection and positioning structure for adjusting blade tip clearance according to claim 5, characterized in that: The circumferential length of the outer ring fixing ring is N times the circumferential length of the high-pressure turbine outer ring, so that a single outer ring fixing ring can install N high-pressure turbine outer rings, and N is a natural number.

7. The high-pressure turbine outer ring connection and positioning structure for adjusting blade tip clearance according to claim 6, characterized in that: The circumferential side surfaces of the outer ring fixing ring and / or the high-pressure turbine ring are provided with sealing grooves, and the sealing grooves are used for installing sealing sheets.

8. The high-pressure turbine outer ring connection and positioning structure for adjusting blade tip clearance according to any one of claims 1 to 7, characterized in that: It also includes a orifice plate, which is arranged between the outer ring of the high-pressure turbine and the outer ring fixing ring. The cooling gas flowing from the cooling channel arranged inside the outer ring fixing ring into the inner side of the outer ring fixing ring impact-cools the outer ring of the high-pressure turbine through the cooling holes arranged on the orifice plate.

9. The high-pressure turbine outer ring connection and positioning structure for adjusting blade tip clearance according to claim 1, characterized in that: The degree or amount of eccentricity of the small-diameter fitting section does not exceed the projection range of the large-diameter fitting section in the direction of the center line of the small-diameter fitting section.

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