Novel turbine sectioning outer ring structure

Abstract

The invention belongs to the technical field of mechanical structures, and relates to a gas turbine engine structure, in particular to a novel turbine split outer ring structure which is used for enabling circumferential, radial and circumferential positioning of a turbine split outer ring to be more stable, reducing the space occupancy of the turbine split outer ring occupying a turbine stator part and reducing thermal expansion deformation along with a turbine case. According to the technical scheme, the device comprises at least 20 sectioned outer rings (1); each sectioning outer ring (1) is of a Z-shaped structure, the left end of each sectioning outer ring (1) is a lap joint part, the right end of each sectioning outer ring (1) is a lap joint part, and threaded holes are formed in the lap joint parts and the lap joint parts. All the sectioned outer rings (1) are lapped together end to end to form a complete outer ring structure; and the lapped part of the previous sectioning outer ring (1) and the lapped part of the next sectioning outer ring (1) are screwed together through a fixing screw (4) and are fixed with a turbine case. The invention is applicable to gas turbine engines.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical structures, relates to a gas turbine engine structure, and in particular to a novel turbine petal outer ring structure. Background Art

[0002] The basic function of the turbine split outer ring is to form a part of the engine gas flow path. Its special function is to cooperate well with the turbine blade tip to reduce the engine gas leakage. In addition to the necessary consideration of the gap with the turbine blade tip, the turbine split outer ring must also consider the radial thermal expansion with the turbine casing and the outer ring. In order to prevent the impact of the thermal expansion of the turbine casing, the turbine split outer ring is generally processed into 3-6 sections along the circumference, leaving a certain gap between the sections and splicing them together. Conventional turbine outer rings are all castings, and are all positioned circumferentially, radially and axially with pins, hooks and retaining rings. Because the working environment of the turbine outer ring is in a high-temperature gas environment, the material of the turbine split outer ring is selected from high-temperature alloys. At the same time, in order to ensure the cooperation with the turbine blades, especially in the acceleration and deceleration state, the turbine has a large rotational inertia, and there may be scraping between the turbine blades and the split outer ring. In order to further protect the turbine blade tip, it is necessary to select a coating with a softer material and higher temperature resistance to be applied to the split outer ring body. Summary of the invention

[0003] The technical problem to be solved by the present invention is: a new type of turbine split-petal outer ring structure, which makes the circumferential, radial and circumferential positioning of the turbine split-petal outer ring more stable, reduces its space occupancy of the turbine stator, and reduces deformation due to thermal expansion of the turbine casing; selects materials with reasonable processing and appropriate prices to further solve the problem of difficulty and high cost in processing the split-petal outer ring.

[0004] The technical solution of the present invention is:

[0005] A novel turbine petal outer ring structure comprises: at least 20 petal outer rings 1;

[0006] Each petal outer ring 1 is a "Z"-shaped structure, with the left end being an overlapping portion and the right end being an overlapped portion, and threaded holes are provided in the overlapped portion and the overlapping portion; all petal outer rings 1 are overlapped together end to end to form a complete outer ring structure; the overlapped portion of the previous petal outer ring 1 and the overlapping portion of the next petal outer ring 1 are screwed together by fixing screws 4 and fixed to the turbine casing.

[0007] A plugging piece 2 is provided below the threaded hole of the overlapped portion of the split outer ring 1 .

[0008] A locking washer 5 is provided between the fixing screw 4 and the petal outer ring 1 .

[0009] The inner surface of the petal outer ring 1 is sprayed with a silicon dioxide coating.

[0010] The outer surface of the petal outer ring 1 is provided with weight-reducing grooves.

[0011] The outer surface of the petal outer ring 1 is provided with reinforcing ribs.

[0012] The plug 2 is welded by energy storage electric welding.

[0013] The plug 2 is welded by energy storage electric welding.

[0014] The petal outer ring 1 is made of cast high-temperature alloy.

[0015] The beneficial effects of the present application are: it can effectively reduce the space occupancy rate of the turbine outer ring in the entire turbine casing, can effectively reduce the processing difficulty, and reduce the assembly process; it can reduce the failure rate of common engine failures such as blade tip scraping, and has low processing costs, so as to better meet the needs of large quantities of short-life unmanned engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the turbine outer ring in the present invention;

[0017] Figure 2 It is a structural schematic diagram of an embodiment of the present invention;

[0018] Figure 3 It is an engineering application diagram of an embodiment of the present invention;

[0019] 1—split outer ring, 2—blocking piece, 3—coating, 4—fixing screw, 5—locking washer. DETAILED DESCRIPTION

[0020] The present application is further described in detail below in conjunction with the accompanying drawings of the embodiments.

[0021] like Figure 1 , 2 As shown in Figures 3 and 4, the present invention provides a novel turbine split-petal outer ring structure: comprising a split-petal outer ring 1, a plugging piece 2, a coating 3, a fixing screw 4, and a locking washer 5, a total of five parts. The main parts are the split-petal outer ring 1, the plugging piece 2, and the coating 3, and the auxiliary structures are the fixing screw 4 and the locking washer 5.

[0022] The petal outer ring 1 is designed as an integral overlap structure and has a fan-shaped shape. Through its special step-type overlap structure, 20 petal outer rings can be combined into a complete ring to achieve axial positioning in the turbine casing. At the same time, the step structure can prevent the combustion gas from leaking through the gap.

[0023] Specifically, each petal outer ring 1 is a "Z"-shaped structure, with the left end being an overlapping portion and the right end being an overlapped portion, and threaded holes are provided in the overlapped portion and the overlapping portion; all petal outer rings 1 are overlapped together end to end to form a complete outer ring structure; the overlapped portion of the previous petal outer ring 1 and the overlapping portion of the next petal outer ring 1 are screwed together by fixing screws 4 and fixed to the turbine casing.

[0024] In order to fix each split outer ring 1 after the ring is completed, it is necessary to process threaded holes on its surface to facilitate installation with the turbine casing. In order to realize the special characteristics of the turbine outer ring and cooperate with the tip of the turbine blade to prevent gas leakage, it is necessary to spray a silicon dioxide coating 3 on the inner surface of the split outer ring. Due to the influence of the threaded through hole and the inner surface silicon dioxide coating 3, it is necessary to weld the bottom of the inner surface threaded through hole with a plug 2. The raised structure and threaded step on the left side of the split outer ring 1 can fit with the inside of the turbine casing to achieve radial positioning. After the split outer ring is fixed by the fixing screw 4, the outer ring rib and the stop of the turbine casing are axially positioned. Three-way positioning ensures the structural stability of the turbine outer ring. Finally, to prevent the fixing screw 4 from slipping, it is locked with a locking washer 5 to complete the installation of the entire turbine outer ring.

[0025] As an optimization and improvement, there are two reinforcing ribs on the petal outer ring to increase the rigidity of the outer ring. The plug is welded by energy storage electric welding to reduce welding deformation. The petal outer ring is cast as a whole, which reduces the difficulty of processing and has high processing efficiency. The threaded through-hole structure is easy to process, provides space for screw assembly, and can be repeatedly mass-produced. The coating adopts silicon dioxide coating, which has a low manufacturing cost while ensuring wear resistance and high temperature resistance. The mounting edge of the threaded hole is thickened to increase the tensioning stiffness and is not easy to damage. The screws are hidden in the turbine casing, which does not affect the installation and use of the turbine casing components and does not bring unnecessary complex design. The bottom of the threaded hole is blocked with a plug for spraying. The asymmetrically designed threaded boss and reinforcing ribs are used to prevent assembly errors and facilitate combined installation with the turbine casing.

[0026] The entire turbine split-petal outer ring has a simple structure, abandoning the traditional complex structures such as pins, hooks, and retaining rings. There is only the split-petal outer ring body included in the turbine casing mounting components, which can reduce the space occupancy rate more than the traditional turbine outer ring. There are threaded holes on its surface for subsequent assembly of fixing screws and circumferential positioning. Its protruding steps and side retaining edges are used to cooperate with the turbine casing for radial and axial positioning. The split-petal outer ring structure is an integral overlap structure. Through step overlap, it can meet the characteristics of sealing the gas and preventing gas from overflowing. At the same time, the entire ring is overlapped, which can ensure the integrity of the turbine outer ring to the greatest extent. While completing the assembly of the entire turbine split-petal outer ring, it can achieve overall thermal expansion during use to reduce the possibility of blade tip scratching.

Claims

1. A novel turbine split-petal outer ring structure, characterized in that: include: At least 20 petal outer rings (1); Each petal outer ring (1) is a "Z"-shaped structure, with the left end being an overlapping portion and the right end being an overlapped portion, wherein the overlapped portion and the overlapping portion are provided with threaded holes; all petal outer rings (1) are overlapped together end to end to form a complete outer ring structure; the overlapped portion of the preceding petal outer ring (1) is screwed together with the overlapping portion of the following petal outer ring (1) by means of fixing screws (4), and are fixed to the turbine casing.

2. A novel turbine split-petal outer ring structure as claimed in claim 1, characterized in that: A blocking piece (2) is provided below the threaded hole of the overlapped portion of the petal outer ring (1).

3. A novel turbine split-petal outer ring structure as claimed in claim 2, characterized in that: A locking washer (5) is provided between the fixing screw (4) and the petal outer ring (1).

4. A novel turbine split-petal outer ring structure as claimed in claim 3, characterized in that: The inner surface of the petal outer ring (1) is sprayed with a silicon dioxide coating.

5. A novel turbine split-petal outer ring structure as claimed in claim 4, characterized in that: The outer surface of the petal outer ring (1) is provided with a weight-reducing groove.

6. A novel turbine split-petal outer ring structure as claimed in claim 5, characterized in that: The outer surface of the petal outer ring (1) is provided with reinforcing ribs.

7. A novel turbine split-petal outer ring structure as claimed in claim 2, characterized in that: The plugging piece (2) is welded by energy storage electric welding.

8. A novel turbine split-petal outer ring structure as claimed in claim 2, characterized in that: The plugging piece (2) is welded by energy storage electric welding.

9. A novel turbine split-petal outer ring structure as claimed in claim 1, characterized in that: The split outer ring (1) is made of cast high-temperature alloy.

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