Turbine aft load bearing casing and method of forming same

Abstract

The turbine rear load-bearing casing with improved vacuum electron beam welding process forming quality comprises a plurality of assembly units, and the plurality of assembly units comprise a plurality of fan-shaped segments; each fan-shaped segment comprises an outer ring segment, an inner ring segment and a support plate connecting the outer ring segment and the inner ring segment; the plurality of fan-shaped segments are spliced into a turbine rear load-bearing casing body, the outer ring segments and the inner ring segments of adjacent fan-shaped segments are connected by welds respectively, forming an outer ring and an inner ring of the turbine rear load-bearing casing body; the plurality of assembly units further comprise an end member, the end member comprises an inner flow channel end member, the inner flow channel end member is connected with an end portion of the inner ring, and for at least part of the weld connection of the inner ring segments of adjacent fan-shaped segments, a T-shaped structure part causing a wall thickness mutation is partially or entirely located in the inner flow channel end member; the welds are formed by vacuum electron beam welding. The turbine rear load-bearing casing forming method adopts a forging and then welding process, and reduces the forming difficulty of the turbine rear load-bearing casing.

Description

TECHNICAL FIELD

[0001] The present application relates to a turbine rear load-bearing casing and a forming method thereof. BACKGROUND

[0002] The turbine rear load-bearing casing (hereinafter referred to as "rear casing") of a turbine fan engine, also known as an exhaust section load-bearing casing, is part of the engine load-bearing frame. On the one hand, it guides the gas from the low-pressure turbine to the tail jet to the outside of the engine, and on the other hand, it fixes the engine fulcrum bearing to transmit the rotor load to the engine mounting joint. The rear casing generally includes an outer ring, an inner ring, a plurality of support plates and the like. High-temperature gas enters the tail jet section in the flow channel formed by the outer ring and the inner ring, and the inner ring and the outer ring are connected by a plurality of support plates. The inner ring is connected to the rear fulcrum bearing seat, which transmits the load from the bearing seat to the support plate, the outer ring and the entire load-bearing system of the engine. The support plate between the inner and outer rings is generally a hollow thin-walled blade structure with oil pipes and air pipes inside. The support plate not only bears the load but also isolates the high temperature for the oil pipes and air pipes.

[0003] The manufacturing method of the rear casing generally has two process routes, namely, integral casting forming and split casting plus welding. The integral casting forming method refers to the forming of the outer ring, the inner ring, the support plate and the like by one-time casting. The split casting plus welding method divides the integral casing into multiple castings. The individual castings have low production cost and high qualification rate, and after machining, they are welded into an integral body. For small and medium-sized load-bearing casings, the integral casting process is relatively easy to implement and has high structural reliability. For large-sized rear casings with a diameter exceeding 1.5 m, the weight of the integral casting and the casting system is large, requiring high capacity of the melting and casting equipment. Moreover, due to the minimum wall thickness of the casing being 2 mm, the strength of the integral wax mold is insufficient, and the process stability is poor. Split casting divides the casing into structures that are easy to cast and are welded into an integral body, which is a relatively feasible process route for large-sized rear casings.

[0004] The applicant has proposed a solution to meet the above process route in the Chinese patent application with the application number "202322353380.4" and the name "Exhaust section load-bearing casing". However, further research is needed to improve the quality and reliability of the manufacturing process. SUMMARY

[0005] An object of the present application is to provide a turbine rear load-bearing casing with improved forming quality.

[0006] Another object of the present application is to provide a turbine rear load-bearing casing forming method that adopts a forging plus welding process to reduce the forming difficulty of the turbine rear load-bearing casing.

[0007] According to an aspect of the present application, a turbine rear load carrying casing comprises a plurality of assembly units, the plurality of assembly units comprising a plurality of sector segments; each of the sector segments comprises an outer ring segment, an inner ring segment, and a web connecting the outer ring segment and the inner ring segment; the plurality of sector segments are spliced into a turbine rear load carrying casing body, the outer ring segments of adjacent sector segments are connected by a weld, and the inner ring segments of adjacent sector segments are connected by a weld, forming an outer ring and an inner ring of the turbine rear load carrying casing body; the plurality of assembly units further comprise an end member, the end member comprises an inner flow passage end member, the inner flow passage end member is connected to an end of the inner ring, and for at least part of the weld connecting the inner ring segments of the adjacent sector segments, a T-shaped structure part where the wall thickness changes abruptly is located in the inner flow passage end member; the weld is formed by vacuum electron beam welding.

[0008] In one embodiment, the inner ring segment of the sector segment comprises an inner ring wall and an inner cone wall, the inner ring wall is connected to the inner cone wall at a front end inner peripheral side of the inner ring wall, and at a weld connecting position of the inner ring segments of the two sector segments, a front end of the inner ring wall ends at a connection transition position of the inner ring wall and the inner cone wall; the end member comprises an inner flow passage front segment; the inner flow passage front segment comprises an inner ring wall front segment and a front connecting portion extending from an inner peripheral side of the inner ring wall front segment; a rear end of the inner ring wall front segment and a front end of the inner ring wall are butted to provide a front segment of an inner flow passage surface of the turbine rear load carrying casing; the front connecting portion and the inner cone wall are connected by a fastener.

[0009] In one embodiment, at the weld connecting position of the inner ring segments of the two sector segments, the front end of the inner ring wall is a concave structure.

[0010] In one embodiment, the inner flow passage end member comprises an inner flow passage rear segment; the inner flow passage rear segment comprises an inner ring wall rear segment and a rear connecting portion extending from an inner peripheral side of the inner ring wall rear segment; the inner ring segment of the sector segment further comprises an inner flow passage rear mounting edge, the inner ring wall is connected to the inner flow passage rear mounting edge at a rear end inner peripheral side of the inner ring wall, and at a weld connecting position of the inner ring segments of the two sector segments, a rear end of the inner ring wall ends at a connection transition position of the inner ring wall and the inner flow passage rear mounting edge; a front end of the inner ring wall rear segment and a rear end of the inner ring wall are butted to provide a rear segment of an inner flow passage surface of the turbine rear load carrying casing; the rear connecting portion and the inner flow passage rear mounting edge are connected by a fastener.

[0011] In one embodiment, at the weld connecting position of the inner ring segments of the two sector segments, the rear end of the inner ring wall is a concave structure.

[0012] In one embodiment, the end member comprises an outer flow channel front mounting edge comprising a flange edge on the outer circumferential side, the outer ring segment comprises an outer ring wall, and the rear end of the outer flow channel front mounting edge and the front end of the outer ring wall are connected by a weld seam.

[0013] In one embodiment, the end member further comprises an outer flow channel rear mounting edge comprising a flange edge on the outer circumferential side, and the front end of the outer flow channel rear mounting edge and the rear end of the outer ring wall are connected by a weld seam.

[0014] In one embodiment, the end member is a whole ring structure or a ring structure formed by connecting a plurality of segments end to end.

[0015] In one embodiment, the fan-shaped segments are cast formings.

[0016] The forming method of a turbine rear load casing according to another aspect of the present application comprises:

[0017] A plurality of the fan-shaped segments and the end member are provided, and the fan-shaped segments are each formed by casting;

[0018] The fan-shaped segments are spliced to form a complete annular flow channel, and are clamped by a tool;

[0019] A vacuum electron beam welding process is adopted to first weld the weld seam of the inner flow channel and then weld the weld seam of the outer flow channel. After the inner flow channel is welded, the outer flow channel is deformed to a certain extent. The outer flow channel is one-step corrected by a tool to ensure that the gap and the misalignment of the butt joint position are within the allowable range of the welding process.

[0020] The end member and the end of the outer ring or the inner ring are connected to form a complete turbine rear load casing.

[0021] According to the embodiments of the present application, the whole framework is formed by vacuum electron beam welding, and the T-shaped structure part with sudden wall thickness change is partially or entirely located in the end member, so that the weld seam between adjacent fan-shaped segments is suitable for the electron beam welding process, thereby improving the forming quality. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and other features, properties, and advantages of the present application will become more apparent by describing in detail the embodiments thereof with reference to the accompanying drawings as follows:

[0023] Figure 1 is a perspective view of a turbine rear load casing;

[0024] Figure 2 is a front view of a turbine rear load casing;

[0025] Figure 3 is a sectional view of a turbine rear load casing;

[0026] Figure 4 is a perspective view of a sector segment;

[0027] Figure 5 is a schematic view of the incidence angle of the electron beam welding of adjacent sector segments at the forward end of the inner flowpath;

[0028] Figure 6 is a schematic view of the incidence angle of the electron beam welding of adjacent sector segments at the aft end of the inner flowpath;

[0029] Figure 7 is a schematic view of the incidence angle of the electron beam welding of adjacent sector segments at the outer flowpath;

[0030] Figure 8 is a partial view of the inner ring segment of a sector segment;

[0031] Figure 9 is a schematic view of the interfacing of the forward inner flowpath segment with the inner ring segment;

[0032] Figure 10 is a schematic view of the interfacing of the aft inner flowpath segment with the inner ring segment;

[0033] Figure 11 is a cross-sectional view of the forward mounting edge of the outer flowpath;

[0034] Figure 12 is a cross-sectional view of the aft mounting edge of the outer flowpath;

[0035] Figure 13 is a cross-sectional view of a sector segment as a pair of scales. DETAILED DESCRIPTION

[0036] Reference will now be made in detail to embodiments of the application, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the application, not limitation of the application. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the scope or spirit of the application. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present application cover modifications and variations of this application provided they come within the scope of the appended claims and their equivalents.

[0037] As used herein, the terms "forward" and "aft" refer to the relative direction of fluid flow in the fluid path in the flowpath of a turbine aft support casing. For example, "forward" refers to the direction from which fluid flows and "aft" refers to the direction to which fluid flows.

[0038] A "turbine aft support casing" is a component in a turbofan engine or gas turbine located aft of the low pressure turbine that directs low pressure turbine exit gases to the tailpipe and secures the aft support bearing.

[0039] “Electron-beam Weld” or “Vacuum Electron-beam Weld” is a process of welding workpieces by high-energy electron beam bombarding metal surface in vacuum to melt and weld the workpieces.

[0040] Figure 1 and Figure 2 An embodiment of the turbine aft load-bearing case according to the present application is shown, which comprises a plurality of assembly units, the plurality of assembly units comprising a plurality of sector segments 1, 2, 4. Figure 4 A sector segment is shown, which generally corresponds to Figure 2 the sector segment 2 in FIG. 2, and other sector segments can be understood by reference. Each sector segment 1, 2, or 4 comprises an outer ring segment 31, an inner ring segment 32, and a web plate 33 connecting the outer ring segment 31 and the inner ring segment 32. The sector segment 1 comprises three web plates 33, and the outer ring segment 31 is provided with three lifting devices, one example of which is an eye. The sector segment 2 is divided into two parts symmetrically left and right, and comprises four web plates 33. The sector segment 4 comprises three web plates 33, and the sector segment 1 and the sector segment 4 are symmetrical structures to each other if the eyes are not considered. The load-bearing case with 14 web plates is taken as an example for illustration in the figures, but the implementation of the present application is not limited thereto, for example, the sector segments of a load-bearing case with 15 web plates can comprise one sector segment with 3 web plates, and three sector segments with 4 web plates. In another embodiment, the division of the sector segments can be that at least one sector segment comprises at least two web plates. As shown in Figure 2 FIG. 2, the adjacent sector segments 1, 2, or 4 are connected by weld seams 11, 12, 13, 14, 15, 16, 17, 18 to form the outer ring and the inner ring of the turbine aft load-bearing case body, and the weld seams are vacuum electron-beam weld seams. Compared with other weld seams, the vacuum electron-beam weld seam has a narrow width, a deep fusion depth, a large depth-width ratio, and small welding deformation. Compared with a conventional segmented exhaust section load-bearing case, the number of weld seams is reduced, and the manufacturing process quality and reliability are improved. Too many weld seams bring higher risks, and even if welding quality problems are found in the process, the subsequent repair welding process requires a large amount of manual operation and repeated inspection, which will reduce the production efficiency to a certain extent. Therefore, the selection of the vacuum electron-beam weld seam connection can provide a reasonable load-bearing case segmented structure form, control the number and position of the weld seams as much as possible, improve the process method reliability and efficiency, and improve the reliability of the service of the parts.

[0041] As shown in Figure 1 and Figure 2 The plurality of assembly units further comprise end members connected to the ends of the outer ring or the inner ring. The “ends of the outer ring or the inner ring” refer to the ends in terms of the axial direction of the turbine aft load-bearing case. The “inner flow channel” is a flow channel surface provided by the inner ring of the turbine aft load-bearing case. The “outer flow channel” is a flow channel surface provided by the outer ring of the turbine aft load-bearing case. Figure 3Four types of end members are shown, including the inner flow channel front section 7, the inner flow channel rear section 8, the outer flow channel front mounting edge 5, and the outer flow channel rear mounting edge 6. The inner flow channel front section 7 and the inner flow channel rear section 8 are inner flow channel end members. For at least a portion of the weld connection between the adjacent sector segments, the T-shaped structure causing the abrupt change in wall thickness is partially or entirely located in the end members. Figure 3 For example, the front mounting edge 5 of the outer flow channel and the outer ring are on both sides of weld 19 and connected by weld 19. The T-shaped structure is located on one side of the front mounting edge 5 of the outer flow channel, and there is no T-shaped structure at the front end of the outer ring. Similarly, the rear mounting edge 6 of the outer flow channel and the outer ring are on both sides of weld 20 and connected by weld 20. The T-shaped structure is located on one side of the rear mounting edge 6 of the outer flow channel, and there is no T-shaped structure at the rear end of the outer ring. Figure 9 It shows more clearly Figure 3 Assembly method between the front section 7 of the inner flow channel and the inner ring. Figure 10 It shows more clearly Figure 3 The assembly method between the rear section 8 of the inner flow channel and the inner ring. For example... Figure 9 As shown, the rear end of the inner flow channel front section 7 is joined to the front end of the outer ring to form a T-shape. The T-shape is divided into an angular portion t1 and a wing portion t2. The angular portion t1 is located at the front end of the outer ring, and the wing portion t2 is located at the rear end of the inner flow channel front section 7. Similarly, in Figure 10 In the middle section, the front end of the inner flow channel rear section 8 is spliced ​​with the rear end of the outer ring to form an approximately T-shaped structure. This approximately T-shaped structure is divided into an angular part t3 and a wing t4. The angular part t3 is located at the rear end of the outer ring, and the wing t4 is located at the front end of the inner flow channel rear end 8. The term "T-shaped structure part" means that this part is no longer a T-shaped structure. Figure 5 , Figure 6 and Figure 7 The incident angles of adjacent sector segments in electron beam welding are shown. Because the T-shaped structure, which causes abrupt changes in wall thickness, is partially or entirely located in the end members, large variations in wall thickness along the electron beam welding incident direction are avoided. The relatively uniform wall thickness is beneficial for improving the welding quality of electron beam welding and reducing welding defects. As a comparative example, Figure 13 When the T-shaped structure at point A is used for electron beam welding of two adjacent sector segments, regardless of the electron beam direction, there will be a significant variation in wall thickness, which easily leads to welding defects. It can be understood that any of the aforementioned four types of end members, and the segmentation method between the end member and the sector segment, is beneficial to improving the welding quality of electron beam welding. Accordingly, any implementation of one or more combinations of the aforementioned four types of end members is an embodiment of the present invention.

[0042] like Figure 3 , Figure 8 , Figure 9As shown, the inner ring segment 32 of the sector includes an inner ring wall 321 and an inner cone wall 322, the inner ring wall 321 is connected to the inner cone wall 322 at the front end inner circumferential side of the inner ring wall 321, and the front end of the inner ring wall 321 at the weld joint of the inner ring segments 32 of two adjacent sectors terminates at the connection transition position of the inner ring wall 321 and the inner cone wall 322. For example, the front end of the inner ring wall 321 does not extend to the left beyond the connection transition position of the inner ring wall 321 and the inner cone wall 322, which ensures that the T-shaped structure is substantially separated, reducing the large change in wall thickness. One implementation of the front end of the inner ring wall 321 terminating at the connection transition position of the inner ring wall 321 and the inner cone wall 322 at the weld joint is as shown in Figure 9 As shown, the front end of the inner ring wall 321 has a Figure 8 The recess structure 323 is shown, so that the front end of the inner ring wall 321 does not need to be recessed to the right as a whole, the wing portion t2 is similar to a tab shape, embedded in the recess structure 323. The function of the wing portion t2 is to prevent the opening caused by the recess structure 323 from being too large to allow the flow passage gas to enter the outer cavity. In addition, by controlling the pressure of each cavity of the engine rear casing, the inner cavity pressure should be greater than the pressure in the flow passage, which can also avoid the problem of gas entering the inner cavity.

[0043] The inner flow passage front segment 7 includes an inner ring wall front segment 71 and a front connecting portion 72 extending from the inner circumferential side of the inner ring wall front segment 71, the inner ring wall front segment 71 is Figure 9 a horizontally extending portion, and the front connecting portion 72 is Figure 9 a vertically extending portion, and the aforementioned wing portion t2 belongs to a part of the inner ring wall front segment.

[0044] The rear end of the inner ring wall front segment 71 and the front end of the inner ring wall 321 are butt-jointed to provide the front segment of the inner flow passage surface of the turbine rear load-bearing casing. The rear end of the inner ring wall front segment 7 is Figure 3 and Figure 9 the right end thereof.

[0045] The front connecting portion and the inner cone wall 322 are connected by fasteners 91. In the embodiment as shown, except for the recess structure 323, at the right end of the inner ring wall front segment 7, the inner ring wall front segment and the front connecting portion are in a right angle shape, and correspondingly, the connection transition position of the inner ring wall 321 and the inner cone wall 322 is also in a right angle shape, so that the two right angle shapes can be in contact and fit, and only maintain a gap at the recess structure 323. The aforementioned fasteners can be selected to be bolts and nuts.

[0046] The inner flow passage front segment 7 can be selected to be a whole ring structure, or a ring structure formed by connecting segments end to end. One example of the front connecting portion 72 is a lug extending from the inner circumferential side of the inner ring wall front segment 71.

[0047] Continuing to refer to Figure 3 , Figure 8 , Figure 9The inner ring wall 321 is connected with the inner flow passage mounting edge 325 at the rear end inner circumferential side of the inner ring wall 321, and the rear end of the inner ring wall 321 at the weld joint between two adjacent inner ring segments 32 ends at the connection transition position of the inner ring wall 321 and the inner flow passage mounting edge 325. For example, the rear end of the inner ring wall 321 does not extend to the right beyond the connection transition position of the inner ring wall 321 and the inner conical wall 322, which can ensure that the T-shaped structure is substantially separated, and reduce the large change in wall thickness. One implementation of the rear end of the inner ring wall 321 at the weld joint ending at the connection transition position of the inner ring wall 321 and the inner flow passage mounting edge 325 is shown in Figure 9 As shown in Figure 8 The rear end of the inner ring wall 321 at the weld joint has a recessed structure 326, so that the rear end of the inner ring wall 321 does not need to be recessed to the right as a whole, and the wing portion t4 is similar to a tab shape, embedded in the recessed structure 326.

[0048] Figure 9 The inner flow passage rear segment 8 includes an inner ring wall rear segment 81 and a rear connecting portion 82 extending from the inner circumferential side of the inner ring wall rear segment 81, the inner ring wall rear segment 81 is a Figure 9 portion extending horizontally, and the rear connecting portion 82 is a portion extending vertically, and the aforementioned wing portion t4 belongs to a part of the inner ring wall rear segment.

[0049] Figure 3 The front end of the inner ring wall rear segment 81 and the rear end of the inner ring wall 321 are butted to provide the rear segment of the inner flow passage surface of the turbine rear thrust casing. The front end of the inner ring wall rear segment 81 is the left end thereof in Figure 9 and

[0050] The rear connecting portion 82 and the inner flow passage mounting edge 325 are connected by fasteners 92. In the embodiment as shown, in addition to the recessed structure 326, at the left end of the inner ring wall rear segment 7, the inner ring wall rear segment and the rear connecting portion are in a right angle shape, and correspondingly, the connection transition position of the inner ring wall 321 and the inner flow passage mounting edge 325 is also approximately in a right angle shape, so that the two right angle shapes can be in contact and fit, and only maintain a gap at the recessed structure 326. The aforementioned fasteners can be selected to be bolts and nuts.

[0051] The inner flow passage rear segment 8 can be optionally an integral ring shape structure, or a ring shape structure formed by connecting segments end to end. One example of the rear connecting portion 82 is a lug extending from the inner circumferential side of the inner ring wall rear segment 81.

[0052] As shown in Figure 3 and Figure 11As shown, the outer flow passage front mounting edge 5 includes a flange edge 51 on the outer circumferential side, and the outer ring segment 31 is mainly composed of the outer ring wall. The rear end of the outer flow passage front mounting edge 5 and the front end of the outer ring wall or the outer ring segment 31 are connected by a weld. The outer circumferential wall of the outer ring segment 31 has no substantial wall thickness mutation, so the welding quality is easy to control.

[0053] As shown in Figure 3 and Figure 12 , the outer flow passage rear mounting edge 6 includes a flange edge 61 on the outer circumferential side, and the front end of the outer flow passage rear mounting edge 61 and the rear end of the outer ring wall are connected by a weld. This also makes the outer circumferential wall of the outer ring segment 31 have no substantial wall thickness mutation, so the welding quality is easy to control.

[0054] Examples of the forming method for the exhaust segment force-bearing casing are described as follows.

[0055] Each of the four fan-shaped segments is formed by casting. The fan-shaped segments including 3-plate and 4-plate segments, and the 3-plate fan-shaped segments with lugs on the outer ring surface are each completed by casting parts separately.

[0056] Six sides (e.g., the six sides a, b, c, d, e, f in Figure 4 ) of a single part are machined before welding. After the sides a, b, c, d are machined, the sides a and b and the sides c and d between two fan-shaped segments can be spliced. Four pieces are spliced to form a complete ring flow passage. The sides e and f are left with a margin, which is removed after the whole ring is welded.

[0057] The welds of the inner flow passage are welded first, and then the welds of the outer flow passage are welded using the vacuum electron beam welding process. After the inner flow passage is welded, the outer flow passage is deformed to a certain extent, and the outer flow passage is one-step corrected by a tooling to ensure that the gap and the misalignment of the butt joint position are within the allowable range of the welding process. For example, the four fan-shaped segments are clamped into a whole ring before welding, and the front mounting edge 5 and the rear mounting edge 6 can be used to clamp tightly. The two adjacent pieces are connected into a whole circle by vacuum electron beam welding. The welds between the fan-shaped segments are shown in Figure 2 , in which the welds 11, 12, 13, 14, 15, 16, 17, and 18 are shown.

[0058] The margin on the front and rear transition edges (e.g., the sides e and f in Figure 4 ) of the whole ring frame is removed. The roundness of the front and rear transition edges e and f of the whole ring frame after welding is measured, and the places with larger deviations are adjusted by a fixed tooling to meet the shape requirements when the front and rear mounting edges are welded.

[0059] The excess material at e and f is removed to make the whole ring frame have the welding conditions with the mounting edges. The front and rear mounting edges are welded to the whole ring frame by vacuum electron beam welding. The side e on the frame is welded to the side h of the front mounting edge, and the side f is welded to the side i of the rear mounting edge.

[0060] The frame after welding is subjected to stress relief heat treatment to release welding stress. Then the manufacturing process of the segmented welding of the load-bearing casing of the exhaust section is completed.

[0061] Although the present application is disclosed with reference to the preferred embodiments above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the technical solutions of the present application, fall within the protection scope defined by the claims of the present application.

Claims

1. A turbine rear load-bearing casing, characterized in that, It includes multiple assembly units, and the multiple assembly units include multiple sector segments; Each of the sector segments includes an outer ring segment, an inner ring segment, and a support plate connecting the outer ring segment and the inner ring segment; The multiple sector segments are spliced ​​together to form the turbine rear bearing casing body. The outer ring segments and inner ring segments of adjacent sector segments are connected by welds to form the outer ring and inner ring of the turbine rear bearing casing body. The plurality of assembly units further include end members, the end members including inner flow channel end members, the inner flow channel end members being connected to the end of the inner ring. For at least a portion of the welded joint of the inner ring segment of the adjacent sector segment, the T-shaped structure that causes the abrupt change in wall thickness is partially or entirely located in the end member of the inner flow channel; The weld was formed by vacuum electron beam welding.

2. The turbine rear load-bearing casing as described in claim 1, characterized in that, The inner ring segment of the sector segment includes an inner ring wall and an inner conical wall. The inner ring wall is connected to the inner conical wall on the inner circumferential side of the front end of the inner ring wall. At the weld connection of the inner ring segments of the two sector segments, the front end of the inner ring wall terminates at the connection transition position between the inner ring wall and the inner conical wall. The inner flow channel end component includes the front section of the inner flow channel; The front section of the inner flow channel includes a front section of the inner ring wall and a front connecting portion extending from the inner circumferential side of the front section of the inner ring wall; The rear end of the front section of the inner ring wall and the front end of the inner ring wall are joined to provide the front section of the inner flow channel surface of the turbine rear bearing casing. The front connecting part and the inner conical wall are connected by fasteners.

3. The turbine rear load-bearing casing as described in claim 2, characterized in that, At the weld joint of the inner ring segment of the two fan-shaped segments, the front end of the inner ring wall has a recessed structure.

4. The turbine rear load-bearing casing as described in claim 1, characterized in that, The end component of the inner flow channel includes the rear section of the inner flow channel; The rear section of the inner flow channel includes a rear section of the inner ring wall and a rear connecting portion extending from the inner circumferential side of the rear section of the inner ring wall; The inner ring section of the fan-shaped segment further includes an inner flow channel rear mounting edge, the inner ring wall is connected to the inner circumferential side of the rear end of the inner ring wall, and at the weld connection of the inner ring sections of the two fan-shaped segments, the rear end of the inner ring wall terminates at the connection transition position between the inner ring wall and the inner flow channel rear mounting edge. The front end of the rear section of the inner ring wall and the rear end of the inner ring wall are connected to provide the rear section of the inner flow channel surface of the turbine rear bearing casing. The rear connecting part and the rear mounting edge of the inner flow channel are connected by fasteners.

5. The turbine rear load-bearing casing as described in claim 4, characterized in that, At the weld joint of the inner ring segment of the two fan-shaped segments, the rear end of the inner ring wall has a recessed structure.

6. The turbine rear load-bearing casing as described in claim 1, characterized in that, The end component also includes a front mounting edge for the outer flow channel. The front mounting edge of the external flow channel includes a flange edge located on the outer periphery. The outer ring segment includes an outer ring wall. The rear end of the front mounting edge of the outer flow channel and the front end of the outer ring wall are connected by a weld.

7. The turbine rear load-bearing casing as described in claim 6, characterized in that, The end component also includes a rear mounting edge for the outer flow channel. The rear mounting edge of the outer flow channel includes a flange edge located on the outer periphery. The front end of the outer flow channel rear mounting edge and the rear end of the outer ring wall are connected by a weld.

8. The turbine rear load-bearing casing as described in any one of claims 1 to 7, characterized in that, The end component is a complete ring structure or a ring structure formed by connecting multiple segments end to end.

9. The turbine rear load-bearing casing as described in any one of claims 1 to 7, characterized in that, The sector segment is a cast part.

10. The method for forming the turbine rear load-bearing casing as described in any one of claims 1 to 9, characterized in that, A plurality of the aforementioned sector segments and the aforementioned end members are provided, wherein the sector segments are all formed by casting; The fan-shaped segments are spliced ​​together to form a complete annular flow channel, and then clamped together using tooling. The vacuum electron beam welding process is adopted. First, the weld seam of the inner flow channel is welded, and then the weld seam of the outer flow channel is welded. After the inner flow channel is welded, the outer flow channel will undergo a certain deformation. The outer flow channel is then corrected by tooling to ensure that the gap and misalignment at the docking position are within the allowable range of the welding process. The end member and the end of the outer or inner ring are connected to form a complete turbine rear bearing casing.

Images