A two-stage low-pressure turbine disc shaft connecting structure

Abstract

The application provides a two-stage low-pressure turbine disc shaft connecting structure, and belongs to the technical field of gas turbines. The connecting structure comprises a low-pressure turbine shaft, a high-pressure turbine rear shaft, a labyrinth ring, an adapter shaft installed on the low-pressure turbine shaft, a first axial part and a second axial part connected with the low-pressure turbine shaft sleeve tooth structure, a radial part connecting the first axial part and the second axial part, and a web plate arranged on the second axial part. The two-stage low-pressure turbine disc comprises a first-stage low-pressure turbine disc and a second-stage low-pressure turbine disc, and the first-stage low-pressure turbine disc and the second-stage low-pressure turbine disc are connected at the web plate of the adapter shaft through a self-limiting double-head connecting piece. The rear end of the first axial part is provided with a rear bearing inner ring assembly surface, the rear bearing is installed on the assembly surface, the inner side of the second axial part is provided with a front bearing outer ring, the front bearing supports the high-pressure turbine rear shaft after being matched with the front bearing outer ring, the front end of the second axial part is provided with a sealing honeycomb matched with the labyrinth ring and an oil sealing coating, so as to form a front bearing oil cavity oil sealing structure together with the labyrinth ring.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aero-engines and gas turbines, and particularly relates to a two-stage low-pressure turbine disc shaft connecting structure. BACKGROUND

[0002] As Figure 1 shown in the drawings is a typical two-stage low-pressure turbine disc shaft connecting structure in a modern aero-engine and gas turbine, in which a low-pressure turbine shaft 110 with a web 111 is used to connect with a first-stage low-pressure turbine disc 121 and a second-stage low-pressure turbine disc 121 in a two-stage turbine disc. However, in this structure layout, a front bearing 130 and its oil seal system and a high-pressure turbine rear shaft neck 140 need a large structural space, which leads to a large axial space between the high-pressure turbine and the low-pressure turbine, increases the length of the engine, and greatly increases the weight of the engine. In addition, due to the limitation of the structural space, the web 111 of the low-pressure turbine shaft 110 is located high from the low-pressure turbine disc connection position, the stress at the web 111 position is high, the bolt assembly is difficult, and there are four rotor parts connected by the same bolt on the web 111, and the safety is poor. SUMMARY

[0003] The purpose of the present application is to provide a two-stage low-pressure turbine disc shaft connecting structure to solve or alleviate at least one problem in the background art.

[0004] The technical solution of the present application is: a two-stage low-pressure turbine disc shaft connecting structure, comprising:

[0005] a low-pressure turbine shaft;

[0006] a high-pressure turbine rear shaft;

[0007] a labyrinth ring;

[0008] an adapter shaft mounted on the low-pressure turbine shaft, the adapter shaft comprising a first axial part connected with a low-pressure turbine shaft sleeve tooth structure and a second axial part parallel to the first axial part, the first axial part and the second axial part being connected through a radial part, and a web being arranged on the second axial part;

[0009] a two-stage low-pressure turbine disc, the two-stage low-pressure turbine disc comprising a first-stage low-pressure turbine disc and a second-stage low-pressure turbine disc, the first-stage low-pressure turbine disc and the second-stage low-pressure turbine disc being connected at the web of the adapter shaft through a self-limiting double-head connecting piece;

[0010] wherein an outer side of a rear end of the first axial part is provided with a rear bearing inner ring assembly surface, a front bearing outer ring is arranged on an inner side of the second axial part, and the front bearing supports the high-pressure turbine rear shaft after being matched with the front bearing outer ring;

[0011] The outer surface of the second axial part forms a graphite oil sealing surface, and the front end of the second axial part is provided with a sealing honeycomb matched with the labyrinth ring and an oil sealing coating, so as to form an oil sealing structure of the front bearing oil cavity together with the labyrinth ring.

[0012] In the preferred embodiment of the present application, the front side and the rear side of the first axial part of the adapter shaft are respectively provided with a front positioning surface and a rear positioning surface, and the front and rear positioning surfaces form a front and rear double-stop positioning structure, so as to ensure the connection and positioning of the adapter shaft and the low-pressure turbine shaft.

[0013] In the preferred embodiment of the present application, an adjusting pad is arranged between the adapter shaft and the low-pressure turbine shaft, and the axial position of the adapter shaft and the two-stage low-pressure turbine disc is adjusted and controlled through the adjusting pad.

[0014] In the preferred embodiment of the present application, the middle part of the self-limiting double-head connector is provided with a profiled section with a rectangular cross section, and the two sides of the profiled section are provided with threaded sections, and the connection of the first low-pressure turbine disc, the second low-pressure turbine disc and the web plate of the adapter shaft is realized through the locking nuts installed on the threaded sections.

[0015] In the preferred embodiment of the present application, the first low-pressure turbine disc and the second low-pressure turbine disc respectively have a forwardly extending first mounting edge and a rearwardly extending second mounting edge, the first mounting edge and the rearwardly extending second mounting edge are provided with bolt holes, and any one of the mounting edges is provided with a special hole matched with the self-limiting double-head connector.

[0016] In the preferred embodiment of the present application, the outer side of the sealing honeycomb on the second axial part is provided with a boss, and the boss is overlapped with the disc core of the first low-pressure turbine disc.

[0017] In the preferred embodiment of the present application, the front end of the second axial part is provided with a first air hole, and the web plate is provided with a second air hole, so that the front bearing oil cavity sealing structure is connected with the rear bearing oil cavity through the first air hole and the second air hole.

[0018] In the preferred embodiment of the present application, the radial part is provided with an oil return hole for connecting the front bearing oil cavity and the rear bearing oil cavity.

[0019] In the preferred embodiment of the present application, the web plate is matched with the front bearing outer ring in the axial direction.

[0020] In the preferred embodiment of the present application, the web plate is provided with a sealing labyrinth, and the sealing labyrinth forms a sealing structure with the honeycomb ring installed on the load-bearing casing, so as to separate the cavity between the first low-pressure turbine disc and the second low-pressure turbine disc.

[0021] The two-stage low-pressure turbine disc shaft connection structure provided by the present application has the following advantages:

[0022] 1) can shorten the axial distance between the low-pressure turbine disc and the high-pressure turbine disc, effectively shorten the engine axial length, reduce the engine weight, and solve the problem of long assembly space of the front bearing and its oil seal system and the high-pressure turbine disc rear shaft neck,

[0023] 2) the integrated adapter shaft integrates sealing, lubrication, force transmission and other functions, cancels the bolt fastening structure of multiple rotor parts (4 or more), improves the rotor reliability and safety, reduces the assembly difficulty, can reduce a row of bolt structure, reduces the radial height of the turbine disc connecting web plate and connecting bolt, reduces the stress at this position, simplifies the bearing outer ring support structure and the outer structure of the oil cavity, makes the bearing oil cavity structure more compact, reduces the turbine disc core radial height limit, effectively improves the turbine disc strength reserve, and provides a selection scheme for high-load turbine disc design;

[0024] 3) cancels the low-pressure turbine shaft web plate, improves the machining process of the low-pressure turbine shaft. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions provided in the present application, the following will briefly introduce the drawings. Obviously, the drawings described below are only some embodiments of the present application.

[0026] Figure 1 It is a typical two-stage low-pressure turbine disc shaft connection structure schematic diagram.

[0027] Figure 2 It is a two-stage low-pressure turbine disc shaft connection structure schematic diagram of the present application.

[0028] Figure 3 It is a one-stage low-pressure turbine disc structure schematic diagram in the present application.

[0029] Figure 4 It is a two-stage low-pressure turbine disc structure schematic diagram in the present application.

[0030] Figure 5 It is an adapter shaft schematic diagram in the present application.

[0031] Figure 6 It is a self-limiting double-head connecting piece schematic diagram in the present application.

[0032] Figure 7 It is an adjustment pad schematic diagram in the present application.

[0033] LIST OF REFERENCE NUMERALS:

[0034] 200-two-stage low-pressure turbine disc connection structure

[0035] 210-low-pressure turbine shaft

[0036] 220 - two-stage low-pressure turbine disk, 221 - first-stage low-pressure turbine disk, 222 - second-stage low-pressure turbine disk 230 - adapter shaft

[0037] 231 - first axial part,

[0038] 2311 - torque transmission sleeve tooth

[0039] 2312 - front locating surface

[0040] 2313 - rear locating surface

[0041] 2314 - rear bearing inner ring assembly surface

[0042] 232 - second axial part

[0043] 2321 - graphite oil seal surface

[0044] 2322 - front bearing outer ring

[0045] 2323 - oil seal coating

[0046] 2324 - sealing honeycomb

[0047] 2325 - first air hole

[0048] 233 - radial part

[0049] 2331 - oil return hole

[0050] 234 - web

[0051] 2341 - special-shaped through hole

[0052] 2342 - sealing grate

[0053] 2343 - second air hole

[0054] 240 - high-pressure turbine rear shaft

[0055] 251 - front bearing, 252 - rear bearing

[0056] 260 - bearing seat,

[0057] 261 - first pressing nut, 262 - second pressing nut, 263 - third pressing nut

[0058] 270 - self-limiting double-headed connecting piece

[0059] 271 - special-shaped section

[0060] 272 - threaded section

[0061] 273 - locking nut

[0062] 280 - grate ring

[0063] 290-adjusting pad DETAILED DESCRIPTION

[0064] For the purpose, technical solutions and advantages of the present application, the technical solutions in the embodiments of the present application will be described in more detail below in combination with the drawings in the embodiments of the present application.

[0065] In order to overcome the problems in the prior art, the present application provides a novel two-stage low-pressure turbine disc shaft connection structure.

[0066] As Figures 2 to 7 shown, the two-stage low-pressure turbine disc connection structure 200 of the present application comprises a low-pressure turbine shaft 210, a two-stage low-pressure turbine disc 220, an adapter shaft 230, a high-pressure turbine rear shaft 240, front and rear bearings 251 and 252, a bearing seat 260, a plurality of compression nuts (including a first compression nut 261, a second compression nut 262 and a third compression nut 263), a self-limiting double-headed connecting piece 270 and a grid ring 280.

[0067] The two-stage low-pressure turbine disc 220 comprises a first-stage low-pressure turbine disc 221 and a second-stage low-pressure turbine disc 222, as Figure 3 and Figure 4 shown, the first-stage low-pressure turbine disc 221 is provided with a rear-facing first-stage mounting edge 2111, and the second-stage low-pressure turbine disc 222 is provided with a front-facing second-stage mounting edge 2121. Both the first-stage mounting edge 2111 and the second-stage mounting edge are provided with bolt holes, and a special-shaped hole 2112 is provided at the rear section of the bolt holes of the first-stage mounting edge 2111, for forming a self-limiting connection with the special-shaped section 271 in the middle of the self-limiting double-headed connecting piece 270, to realize axial limiting and circumferential anti-rotation of the self-limiting double-headed connecting piece 270. It can be understood that the special-shaped hole 2112 can also be provided on the second-stage mounting edge 2121.

[0068] The adapter shaft 230 is mounted on the low-pressure turbine shaft 210 and can rotate together with the low-pressure turbine shaft 210. As Figure 5 shown, the adapter shaft 230 has a first axial portion 231 and a second axial portion 232 substantially parallel to the first axial portion 231, and the first axial portion 231 and the second axial portion 232 are connected by a radial portion 233, and the second axial portion 232 is provided with a radially outwardly extending web plate 234.

[0069] The inner side of the first axial part 231 is provided with a torque transmission sleeve tooth 2311, the adapter shaft 230 is connected with the low-pressure turbine shaft 210 through the torque transmission sleeve tooth 2311 and locked by a third compression nut 263, so as to realize the torque transmission between the adapter shaft 230 and the low-pressure turbine shaft 210. The front side and the rear side of the torque transmission sleeve tooth 2311 of the first axial part 231 are respectively provided with a front positioning surface 2312 and a rear positioning surface 2313, a front-rear double-stop positioning structure is formed by the front positioning surface 2312 and the rear positioning surface 2313, the positioning reliability of the adapter shaft 230 and the low-pressure turbine shaft 210 is ensured, and the harmful deformation of the adapter shaft 230 under the engine dynamic load is limited. The outer side of the rear end of the first axial part 231 is provided with a rear bearing inner ring assembly surface 2314, the rear bearing 252 is installed on the rear bearing inner ring assembly surface 2314, the bearing seat 260 is supported on the rear bearing 252 and locked by a second compression nut 262, and is used to transmit the rotor load to the engine rear bearing structure.

[0070] The outer side surface of the second axial part 232 forms a graphite oil sealing surface 2321, which cooperates with a graphite ring to jointly constitute a rear bearing oil cavity oil sealing structure, so as to ensure that the working oil is not leaked. The inner side of the second axial part 232 is provided with a front bearing outer ring 2322 in the middle, the front bearing 251 is installed at the front bearing outer ring 2322 and locked by a first compression nut 261, and is used to support the high-pressure turbine rear shaft 240. The front end of the second axial part 232 is provided with a sealing honeycomb 2324, an oil sealing coating 2323 and a first air hole 2325, which jointly constitute a front bearing oil cavity oil sealing structure with a labyrinth ring 280, so as to ensure that the working oil is not leaked. In the present application, the outer side of the sealing honeycomb 2324 is provided with a boss, which overlaps with the disc core of the first-stage low-pressure turbine disc 221, so as to ensure that the sealing honeycomb 2324 and the oil sealing coating 2323 do not have harmful deformation in working.

[0071] The radial part 233 of the inner side of the graphite oil sealing ring 2321 is provided with an oil return hole 2331, so as to communicate the front bearing oil cavity and the rear bearing oil cavity.

[0072] The web plate 234 is located outside the front bearing outer ring 2322 of the second axial part 232, the web plate 234 forms a mounting edge for connecting the first-stage low-pressure turbine disc 221 and the second-stage low-pressure turbine disc 222, is provided with a special-shaped through hole 2341, is used to assemble a self-limiting double-head connecting piece 270, and is fastened by a nut to the double-stage low-pressure turbine disc 220. The outer side of the web plate 234 is provided with a sealing labyrinth 2342, which can form a sealing structure with a honeycomb ring installed on a bearing casing (not shown), so as to separate the cavities between the first-stage and second-stage low-pressure turbine discs. Further, the web plate 234 is also provided with a second air hole 2343, which communicates the front bearing oil cavity and the rear bearing oil cavity.

[0073] As Figure 6The self-limiting double-head connector is shown in the schematic view. The middle section of the self-limiting double-head connector 270 is provided as a special-shaped section 271, which is rectangular with rounded corners in cross section, and can form a self-limiting structure with the special-shaped through hole 2341 on the web plate of the adapter shaft 230, so as to ensure the fastening of the self-limiting double-head connector 270 before and after. The two sides of the special-shaped section 271 are threaded sections 272, and the threaded sections 272 are installed with lock nuts 273, so as to fix and connect the first low-pressure turbine disc 221, the web plate 234 of the adapter shaft 230 and the second low-pressure turbine disc 222 together.

[0074] As shown in the schematic view, the application also includes an adjusting pad 290, which is arranged between the low-pressure turbine shaft 210 and the rear positioning structure of the adapter shaft 230, and is provided with a repairable and grindable surface 291 on the side facing the adapter shaft 230, which is used to adjust and control the axial position of the adapter shaft 230 and the double-stage low-pressure turbine disc 220. Figure 7

[0075] The double-stage low-pressure turbine disc shaft connecting structure provided by the application has the following advantages:

[0076] 1) The axial distance between the low-pressure turbine disc and the high-pressure turbine disc can be shortened, the axial length of the engine can be effectively shortened, the weight of the engine can be reduced, and the problem of excessive assembly space of the front bearing and its oil seal system and the high-pressure turbine disc rear shaft neck is solved,

[0077] 2) The integrated adapter shaft integrates multiple functions such as sealing, lubrication and force transmission, cancels the structure of multiple rotor parts (4 or more) using bolt fastening, improves the reliability and safety of the rotor, reduces the assembly difficulty, can reduce a row of bolt structure, reduces the radial height of the turbine disc connecting web plate and connecting bolt, reduces the stress at this position, simplifies the bearing outer ring support structure and the outer structure of the oil cavity, makes the bearing oil cavity structure more compact, reduces the radial height limit of the turbine disc hub, effectively improves the strength reserve of the turbine disc, and provides a selection scheme for high-load turbine disc design;

[0078] 3) The low-pressure turbine shaft web plate is cancelled, and the processability of the low-pressure turbine shaft is improved.

[0079] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto. Any changes or replacements within the technical scope disclosed in the application can be easily thought of by those skilled in the art, and should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.​

Claims

1. A two-stage low-pressure turbine disc shaft connection structure, characterized by comprising: The application relates to a low-pressure turbine shaft, a high-pressure turbine rear shaft, a labyrinth ring, an adapter shaft installed on the low-pressure turbine shaft, a double-stage low-pressure turbine disc, a front bearing, a rear bearing, a first axial part of the adapter shaft, a second axial part of the adapter shaft, a radial part of the adapter shaft, a radially extending plate on the second axial part of the adapter shaft, a first axial part of the low-pressure turbine shaft, a second axial part of the low-pressure turbine shaft, a double-stage low-pressure turbine disc, a self-limiting double-head connecting piece, a first mounting edge of the first-stage low-pressure turbine disc, a second mounting edge of the second-stage low-pressure turbine disc, a first air hole on the second axial part of the adapter shaft, a second air hole on the radially extending plate, an oil return hole on the radial part of the adapter shaft, a sealing labyrinth on the radially extending plate, and a honeycomb ring installed on a force-bearing casing. The application relates to a low-pressure turbine shaft, a high-pressure turbine rear shaft, a labyrinth ring, an adapter shaft installed on the low-pressure turbine shaft, a double-stage low-pressure turbine disc, a front bearing, a rear bearing, a first axial part of the adapter shaft, a second axial part of the adapter shaft, a radial part of the adapter shaft, a radially extending plate on the second axial part of the adapter shaft, a first axial part of the low-pressure turbine shaft, a second axial part of the low-pressure turbine shaft, a double-stage low-pressure turbine disc, a self-limiting double-head connecting piece, a first mounting edge of the first-stage low-pressure turbine disc, a second mounting edge of the second-stage low-pressure turbine disc, a first air hole on the second axial part of the adapter shaft, a second air hole on the radially extending plate, an oil return hole on the radial part of the adapter shaft, a sealing labyrinth on the radially extending plate, and a honeycomb ring installed on a force-bearing casing. The first axial part of the adapter shaft is provided with a rear bearing inner ring assembly surface on the outer side of the rear end, the rear bearing is installed on the rear bearing inner ring assembly surface, the inner side of the second axial part is provided with a front bearing outer ring, the radially extending plate is adapted to the front bearing outer ring in the axial direction, and the front bearing supports the high-pressure turbine rear shaft after being matched with the front bearing outer ring. The outer surface of the second axial part forms a graphite oil sealing surface, the front end of the second axial part is provided with a sealing honeycomb and an oil sealing coating matched with the labyrinth ring, so that the labyrinth ring and the second axial part jointly form a front bearing oil cavity oil sealing structure. The front side and the rear side of the first axial part of the adapter shaft are respectively provided with a front positioning surface and a rear positioning surface, the front positioning surface and the rear positioning surface form a front-rear double-joint positioning structure, and the connection and positioning of the adapter shaft and the low-pressure turbine shaft are guaranteed. An adjusting pad is arranged between the adapter shaft and the low-pressure turbine shaft, the axial position of the adapter shaft and the double-stage low-pressure turbine disc is adjusted and controlled through the adjusting pad. The middle part of the self-limiting double-head connecting piece is provided with a profiled section with a rectangular cross section, the two sides of the profiled section are provided with threaded sections, the connection of the first-stage low-pressure turbine disc, the second-stage low-pressure turbine disc and the radially extending plate of the adapter shaft is realized through lock nuts installed on the threaded sections. The first-stage low-pressure turbine disc and the second-stage low-pressure turbine disc are respectively provided with a rearwardly extending first-stage mounting edge and a forwardly extending second-stage mounting edge, bolt holes are arranged on the first-stage mounting edge and the second-stage mounting edge, and a profiled hole matched with the self-limiting double-head connecting piece is arranged on any mounting edge.

2. The two-stage low-pressure turbine disc shaft connection structure as recited in claim 1, characterized by, The outer side of the sealing honeycomb on the second axial part is provided with a boss, and the boss is overlapped with the disc core of the first-stage low-pressure turbine disc.

3. The two-stage low-pressure turbine disc shaft connection structure according to claim 2, characterized by The front end of the second axial part is provided with a first air hole, the radially extending plate is provided with a second air hole, and the front bearing oil cavity sealing structure is communicated with the rear bearing oil cavity through the first air hole and the second air hole.

4. The two-stage low-pressure turbine disc shaft connection structure according to Claim 1, characterized by The radial part is provided with an oil return hole for communicating the front bearing oil cavity and the rear bearing oil cavity.

5. The two-stage low-pressure turbine disc shaft connection structure as recited in claim 4, characterized by The radially extending plate is provided with a sealing labyrinth, and the sealing labyrinth and the honeycomb ring installed on the force-bearing casing form a sealing structure to separate the cavity between the first-stage low-pressure turbine disc and the second-stage low-pressure turbine disc.

6. The two-stage low-pressure turbine disc shaft connection structure according to Claim 1, characterized by ​ 7. The two-stage low-pressure turbine disc shaft connection structure according to Claim 1, characterized by ​ 8. The two-stage low-pressure turbine disc shaft connection structure according to Claim 1, characterized by ​ 9. The two-stage low-pressure turbine disc shaft connection structure according to Claim 1, characterized by ​

Images