A turbine after casing duct assembly structure connected by different cross-section joints

Abstract

The application provides a turbine rear casing pipeline assembly structure connected by different cross-section joints, comprising: a circular joint on a bearing seat of a turbine rear casing, an outer surface of the circular joint being provided with a threaded structure, a lower end surface of the circular joint being provided with a groove, and a flat channel being arranged in the groove; and a pipeline assembly connected with the circular joint by penetrating an inner cavity of a support plate of a load-bearing frame, the pipeline assembly comprising a flat pipe, an upper end of the flat pipe being fixed with a flat joint, and a lower end of the flat pipe being fixed with an external pipe joint; wherein the flat joint has a flat pipe part fixed integrally with the flat pipe and a base part integrated with the flat pipe part, the base part being an axisymmetric structure with two ends in a circular arc shape and the other two ends in a flat shape, the base part being installed in the groove on the circular joint and being fixed by a sleeve nut and an elastic snap ring. The pipeline assembly structure of the application does not need to be welded with the load-bearing frame, is convenient to assemble and disassemble, and has good workability and maintainability.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of pipeline connection of an aero-engine, and particularly relates to a turbine rear casing pipeline assembly structure connected by different cross sections. BACKGROUND

[0002] The turbine rear casing of an aero-engine is an important load-bearing component. The turbine rear casing is composed of an inner casing and an outer casing connected to the two ends of a plurality of circumferentially distributed support plates, and a gas flow channel is formed between adjacent support plates (or between adjacent heat shields). In order to ensure that the turbine rear casing has sufficient gas flow area in the circumferential direction and small flow loss in the axial direction, the cross sections of the support plates in the load-bearing frame of the turbine rear casing are characterized by a long axial length and a small circumferential width.

[0003] The turbine rear casing pipeline includes an oil inlet pipe, an oil return pipe, an air induction pipe and the like. Each of the pipes passes through the inner cavity of the support plate in the load-bearing frame of the turbine rear casing, connects the oil chamber or the air induction chamber interface on the bearing seat of the turbine rear casing to the external pipeline of the aero-engine, and forms an oil flow or air flow channel. In order to reduce the thermal influence of high-temperature gas on the pipeline, a heat insulation layer is sometimes arranged on the outer wall of the pipeline.

[0004] In order to better adapt to the shape of the inner cavity of the support plate of the load-bearing frame, obtain a larger cross-sectional area and better flow capacity, the pipeline section passing through the inner cavity of the support plate of the load-bearing frame sometimes needs to be designed as a flat tube (with an axial length and a short circumferential length). Figures 1 to 3 As shown in the embodiment of the oil return pipe and the air induction pipe passing through the inner cavity of the support plate of the load-bearing frame, in order to realize the connection with the bearing cavity 110 at the inner side of the bearing seat 109 and the external pipeline, the two ends of the oil return pipe are provided with a joint structure 105 (or a connecting nut), and the flat tube section 103 of the oil return pipe is connected to the joint structure through a variable cross-section pipeline section 104, thereby forming an oil return pipe assembly. Similarly, in order to realize the connection with the air induction cavity 11 at the inner side of the bearing seat 109 and the external pipeline, the two ends of the air induction pipe are provided with a joint structure 108 (or a connecting nut), and the flat tube section 106 of the air induction pipe is connected to the joint structure through a variable cross-section pipeline section 107, thereby forming an air induction pipe assembly. The joint structure at the two ends of the oil return pipe assembly or the air induction pipe assembly cannot directly pass through the support plate 102 of the load-bearing frame 101. In order to realize the assembly of the pipeline assembly on the turbine rear casing, the inner end of the flat tube is usually welded and combined with the variable cross-section pipe joint (or the variable cross-section pipe), and then the outer end is passed out of the support plate 102 and is welded and combined with the variable cross-section pipe joint (or the variable cross-section pipe), so that the pipeline assembly is integrally welded with the load-bearing frame.

[0005] However, the pipeline assembly with the load-bearing frame currently mainly has the following disadvantages:

[0006] 1) The outer dimension of the force frame of the rear casing is large, the pipe assembly with the force frame is difficult to clamp during welding, and is often limited by heat treatment and weld inspection equipment capacity, resulting in poor weldability of the pipe assembly, difficulty in post-weld heat treatment and weld quality inspection;

[0007] 2) The pipe assembly has poor maintainability. The pipe assembly cannot be directly removed after welding with the force frame, and it is difficult to inspect and maintain the pipe. When replacing, the original part needs to be cut off and removed, and a new part needs to be welded with the force frame again, which has poor maintainability. SUMMARY

[0008] The purpose of the present application is to provide a turbine rear casing pipe assembly structure connected by different cross-section joints to solve or alleviate at least one problem in the background art.

[0009] The technical solution of the present application is: a turbine rear casing pipe assembly structure connected by different cross-section joints, comprising:

[0010] A circular joint located on the bearing seat of the turbine rear casing, the outer surface of the circular joint is provided with a threaded structure, the lower end surface of the circular joint is provided with a groove, and a flat channel is arranged in the groove;

[0011] A pipe assembly connected with the circular joint through the inner cavity of the support plate of the force frame, the pipe assembly comprising a flat tube, the upper end of the flat tube being fixed with a flat joint, and the lower end of the flat tube being fixed with an external pipe joint;

[0012] Wherein, the flat joint has a flat tube part fixed integrally with the flat tube and a base part integrated with the flat tube part, the base part is an axisymmetric structure with two ends in circular arc shape and the other two ends in flat shape, the base part is installed in the groove on the circular joint and fixed by a sleeve nut and an elastic ring.

[0013] Further, the pipe assembly comprises an air induction pipe and an oil return pipe.

[0014] Further, the flat tube, the flat joint and the external pipe joint are fixed by welding.

[0015] Further, the outer circular surface radius of the two circular arc ends of the flat joint is smaller than the inner diameter of the sleeve nut, so that the sleeve nut can be sleeved from one side of the flat joint.

[0016] Further, the base part is provided with an outer conical surface on the two circular arc end faces, and the base part is provided with a circumferential positioning groove on the two flat ends.

[0017] Further, the elastic snap ring is a circumferential belt opening and locally radially thinned annular structure, the inner side of the elastic snap ring is provided with an inner conical surface which is radially matched with the outer side of the flat joint, and each of the two ends of the opening of the elastic snap ring is provided with a hook, and the hook is used for matching with the positioning groove on the flat joint.

[0018] Further, the elastic snap ring is a circumferential belt opening and locally radially thinned annular structure, the inner side of the elastic snap ring is provided with an inner conical surface which is radially matched with the outer side of the flat joint, and each of the two ends of the opening of the elastic snap ring is provided with a hook, and the hook is used for matching with the positioning groove on the flat joint.

[0019] The turbine rear casing pipeline assembly structure provided by the application does not need to be welded with the force-bearing frame, is convenient to assemble and disassemble, has good processability and maintainability, and has high engineering application value. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions provided by the application, the following will briefly introduce the drawings. Obviously, the drawings described below are only some embodiments of the application.

[0021] Figure 1 It is a schematic diagram of the pipeline structure in the force-bearing casing support plate of the prior art.

[0022] Figure 2 It is a schematic diagram of the oil return pipe structure based on the B-B view. Figure 1

[0023] It is a schematic diagram of the air induction pipe structure based on the B-B view. Figure 3 Figure 1 It is a schematic diagram of the air induction pipe structure based on the A-A view.

[0024] Figure 4 It is a schematic diagram of the turbine rear casing pipeline assembly structure in the application.

[0025] Figure 5 Figure 4 It is a schematic diagram of the air induction pipe structure based on the C-C view.

[0026] Figure 6 It is a schematic diagram of the oil return pipe structure based on the D-D view. Figure 4

[0027] It is an enlarged schematic diagram of the end of the air induction pipe in an embodiment of the application. Figure 7

[0028] It is a schematic diagram of the round joint structure in the application. Figure 8

[0029] It is a schematic diagram of the flat joint structure in the application. Figure 9

[0030] It is a schematic diagram of the elastic snap ring structure in the application. Figure 10

[0031] Figure 11 ​​​Figure 2 is a schematic diagram of the pipeline assembly installed in the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described in more detail below with reference to the drawings of the embodiments of the present application.

[0033] The present application provides a turbine rear casing pipeline assembly structure which can realize the direct connection between the flat joint and the round joint through the compression nut, wherein the flat joint is welded with one end of the flat tube to form an integral body, can directly pass through the inner cavity of the support plate, the flat joint is connected with the round joint through the elastic clasp and the compression nut, and the pipeline assembly is connected with the round joint of the joint seat from the outside to the inside of the force bearing frame support plate during assembly, without welding with the force bearing frame, and has the advantages of convenient assembly, disassembly and maintenance, good process and maintenance.

[0034] As shown in Figures 4 to 7 , the turbine rear casing force bearing frame 201 includes a plurality of support plates 202, and the outer side of the force bearing frame 201 and the support plates 202 is provided with a heat shield 203, and the pipeline assembly 204 passes through the inner cavity of the support plate 202 to connect the joints at the upper and lower ends. In the present application, the pipeline assembly 204 includes air guide pipes and oil return pipes and the like. As shown in Figure 5 , it is a schematic diagram of the air guide pipe structure in the present application, and as shown in Figure 6 , it is a schematic diagram of the oil return pipe structure in the present application.

[0035] The present application takes the schematic diagram of the air guide pipe structure as shown in Figure 5 for example, the main part of the pipeline assembly 204 is a flat tube 2041, the upper end of the flat tube 2041 is provided with a flat joint 2042, the lower end of the flat tube 2041 is provided with an external pipe joint 2043, and the flat tube 2041, the flat joint 2042 and the external pipe joint 2043 form a pipeline welded assembly by welding. The bearing seat 205 of the turbine rear casing part is provided with a round joint 2051, and the two can be welded or bolted. After the flat joint 2042 on the pipeline assembly 204 is butted with the round joint 2051 on the bearing seat 205, the outer sleeve nut 206 and the elastic clasp 207 are locked and fixed.

[0036] In combination with Figures 8 to 10 , the root of the round joint 2051 is a supporting plate structure, the main body outer surface is provided with a threaded structure 2052, the lower end surface of the main body is provided with a groove 2053, and the groove 2053 is provided with a flat channel 2054 matched with the flat joint 2042.

[0037] The flat joint 2042 comprises a flat tube part 2044 and a base part 2045, the flat tube part 2044 can be welded and fixed integrally with the flat tube 2041, the base part 2045 is an axisymmetric structure with two arc-shaped ends and two straight ends, the shape is adapted to the groove 2053 on the round joint 2051. The outer circular surface radius of the two arc-shaped ends of the flat joint 2042 is slightly smaller than the inner diameter of the sleeve nut 206, so that the sleeve nut 206 can be sleeved from one side of the flat joint 2042. The two arc-shaped end faces of the base part 2045 are provided with outer conical surfaces 2047, and the two straight ends are provided with circumferential positioning grooves 2046 for cooperating with the related structure of the elastic clamping ring 207.

[0038] The elastic clamping ring 207 is a ring structure with a circumferential opening and a local radial thinning, the elastic clamping ring 207 can be sleeved into the pipeline welding assembly through the flat tube 2041, and then the opening of the elastic clamping ring 207 is compressed by the clamp to reduce the outer diameter of the elastic clamping ring 207 and make it shrink into the sleeve nut 206. After the clamp is loosened, the opening of the elastic clamping ring 207 is expanded and enters the annular groove in the sleeve nut 206, thereby constituting the pipeline assembly.

[0039] In order to avoid that the rigidity of the elastic clamping ring 207 is too large and increase the assembly difficulty, a thin-walled section 2071 is arranged at the middle position of the elastic clamping ring 207, so that it is convenient to compress. When compressed and deformed, the thin-walled section 2071 is radially shrunk to a smaller extent compared with the rest, so that the outer circular surface radius of the thin-walled section 2071 is reduced to a corresponding extent compared with the rest, and then the appropriate wall thickness and elasticity are obtained by adjusting the inner circular surface radius of the thin-walled section 2071.

[0040] The inner side of the elastic clamping ring 207 is provided with an inner conical surface 2073 which is radially matched with the outer side of the flat joint 2042, and each end of the opening of the elastic clamping ring 207 is provided with a hook 2072, the two hooks 2072 are close to the two sides of the positioning groove 2053 of the flat joint 2042 during assembly, and after the clamp is loosened, the hook 2072 is hooked on the positioning groove 2053 to play a circumferential positioning role, thereby ensuring the cooperation between the elastic clamping ring 207 and the conical surface of the flat joint 2042.

[0041] The structure assembly process of the turbine rear casing pipeline assembly of the present application is as follows:

[0042] During assembly, the pipeline assembly of the bleed air pipe or the oil return pipe is in a welded assembly state (i.e. without the elastic clamping ring 207 and the sleeve nut 206), and is first inserted into the inner cavity through the outer part of the support plate 202 of the force bearing frame 201, at this time, the outer shape characteristics of the flat joint 2042 ensure that the welded assembly has good passability;

[0043] After the flat connector 2042 passes through the inner cavity of the support plate 202, the elastic retaining ring 207 is inserted into the pipeline welding assembly through the opening of the flat pipe section. The elastic retaining ring 207 is radially contracted by applying force to the small holes on the two hooks at the opening of the caliper, and then inserted into the outer nut 206 through the flat connector 2042, so that the annular groove of the outer nut 206 is aligned with the elastic retaining ring 207. When the caliper is released, the opening of the elastic retaining ring 207 springs open and enters the annular groove of the outer nut 207.

[0044] When the pipeline assembly is assembled with the circular connector 2051, the outer nut 206 on the pipeline assembly is connected to the circular connector 2051 by threads. The bottom surface of the groove 2053 on the circular connector 2051 is pressed and fitted with the end face of the flat connector 2042 to achieve a sealing function. The two sides of the groove 2053 on the circular connector 2051 are fitted with the two side planes of the flat connector 2042 to achieve circumferential positioning and anti-rotation function.

[0045] like Figure 11 The diagram shown illustrates the installation process. With the above installation, the vent pipe connects the external connector 2043 to the vent chamber 208 inside the bearing housing 205, and the return oil pipe connects the external connector 2043 to the bearing cavity 209 outside the bearing housing 205. In a preferred embodiment of this application, for the return oil pipe, a rubber ring can be provided in the groove 2053 of the circular connector 2051, and pressed against the end face of the flat connector 2042 to achieve a better lubricating oil sealing effect.

[0046] The turbine rear casing piping assembly structure provided in this application does not require welding to the load-bearing frame, and is easy to install and disassemble, with good manufacturability and maintainability, and has high engineering application value.

[0047] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A turbine aft casing plumbing assembly structure connected by different section joints, characterized by, The application relates to a bearing seat (205) of a turbine rear casing, wherein a circular joint (2051) is arranged on the bearing seat (205), the outer surface of the circular joint (2051) is provided with a threaded structure (2052), the lower end surface of the circular joint (2051) is provided with a groove (2053), and a flat channel (2054) is arranged in the groove (2053). A pipeline assembly (204) is connected with the circular joint (2051) through the inner cavity of a support plate (202) of a bearing frame (201), the pipeline assembly (204) comprises a flat pipe (2041), the upper end of the flat pipe (2041) is fixed with a flat joint (2042), and the lower end of the flat pipe (2041) is fixed with an external pipe joint (2043). The flat joint (2042) has a flat pipe part (2044) fixedly connected with the flat pipe (2041) and a base part (2045) integrated with the flat pipe part (2044), the base part (2045) is an axisymmetric structure with two arc-shaped ends and two flat ends, the base part (2045) is arranged in the groove (2053) on the circular joint (2051), and the base part (2045) is fixed by means of an outer sleeve nut (206) and an elastic clamping ring (207). The pipeline assembly (204) comprises an air guide pipe and an oil return pipe.

2. The turbine aft casing plumbing assembly structure of claim 1, wherein, The flat pipe (2041), the flat joint (2042) and the external pipe joint (2043) are fixed by welding.

3. The turbine aft casing plumbing assembly structure of claim 1 or 2, wherein, The outer circle surface radius of the two arc-shaped ends of the flat joint (2042) is smaller than the inner diameter of the outer sleeve nut (206), so that the outer sleeve nut (206) can be sleeved on one side of the flat joint (2042).

4. The turbine aft casing plumbing assembly structure of claim 3, wherein, The two arc-shaped end surfaces of the base part (2045) are provided with outer conical surfaces (2047), and the two flat ends of the base part (2045) are provided with circumferential positioning grooves (2046).

5. The turbine aft casing plumbing assembly structure of claim 3, wherein, The elastic clamping ring (207) is a ring-shaped structure with an opening in the circumferential direction and a local radial thinning part, the inner side of the elastic clamping ring (207) is provided with an inner conical surface (2073) which is radially matched with the outer side of the flat joint (2042), one bending hook (2072) is arranged at each of the two ends of the opening of the elastic clamping ring (207), and the bending hook (2072) is matched with the positioning groove (2046) on the flat joint (2042).

6. The turbine aft casing plumbing assembly structure of claim 5, wherein, A thin wall section (2071) is arranged at the middle position of the elastic clamping ring (207).

7. The turbine aft casing plumbing assembly structure of claim 6, wherein, ​

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