A disc rim cone shell jamming structure for preventing turbine overspeed of an aero-engine

Abstract

This invention provides a disc-rim conical shell jamming structure for preventing turbine overspeed in aero-engines, comprising a disc-rim baffle and a conical shell baffle. The disc-rim baffle is installed on the rear side of the turbine disk, and its head has a petal-shaped outer ring surface. The conical shell baffle is installed on the oil chamber bushing, and its shoulder has a petal-shaped inner ring surface. In the installed state and the engine's normal left-hand position, the outer ring surface of the disc-rim baffle head and the inner ring surface of the conical shell baffle shoulder face each other, with a certain distance between them in the axial direction. Once the rotor shaft breaks, the turbine rotor moves backward, and the petal-shaped outer ring surface of the disc-rim baffle head and the petal-shaped inner ring surface of the conical shell baffle shoulder come into contact and jam, generating friction and severe deformation, absorbing rotor kinetic energy, limiting the turbine rotor speed, achieving rapid braking, and ensuring the integrity and safety of the turbine rotor.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine design, specifically designing a disk rim cone shell jamming structure for preventing turbine over-spinning in aero-engines. Background Technology

[0002] Due to manufacturing and assembly errors, extreme loads, material defects, or other events, aero engines may experience shaft fracture during operation. This can cause the turbine rotor to over-spin under the drive of high-energy combustion gases, or even the turbine disk to rupture. The resulting high-energy debris could penetrate the engine nacelle or even the aircraft fuselage, causing catastrophic consequences. Therefore, turbine over-spin protection design is necessary to reduce turbine rotor speed in the event of shaft fracture.

[0003] Current research on turbine overspeed prevention in aero-engines mostly focuses on cutting off the fuel supply to the combustion chamber after shaft fracture, thus decelerating the turbine rotor due to the lack of high-energy combustion gas. However, the engine control system still requires a certain amount of time to detect and cut off the fuel supply after shaft fracture, during which the turbine rotor speed can rapidly increase. Therefore, relying solely on actively cutting off the fuel supply to prevent turbine rotor speed is still a very demanding requirement. It is necessary to design and install a turbine rotor overspeed protection structure to rapidly reduce the turbine rotor speed after shaft fracture. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention aims to provide a disc-edge conical shell jamming structure for preventing turbine overspeed in aero-engines, comprising a disc-edge baffle and a conical shell baffle. The disc-edge baffle is installed on the rear side of the turbine disk, and its head has a petal-shaped outer ring surface. The conical shell baffle is installed on the oil chamber bushing, and its shoulder has a petal-shaped inner ring surface. In the installed state and the engine's normal left-hand position, the outer ring surface of the disc-edge baffle head and the inner ring surface of the conical shell baffle shoulder face each other, with a certain axial distance between them. Once the turbine shaft breaks, the turbine rotor moves backward, and the petal-shaped outer ring surface of the disc-edge baffle head and the petal-shaped inner ring surface of the conical shell baffle shoulder come into contact and jam, generating friction and severe deformation, absorbing rotor kinetic energy, limiting the turbine rotor speed, achieving rapid braking, and ensuring the integrity and safety of the turbine rotor. This invention can limit the turbine speed after the engine shaft breaks, avoiding a catastrophic accident of turbine disk rupture; at the same time, this disc-edge conical shell jamming structure has the advantages of simple configuration, easy disassembly and assembly, and the ability to achieve rapid braking.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A disc rim cone shell jamming structure for preventing over-rotation of an aero-engine turbine includes a disc rim baffle and a cone shell baffle; the disc rim cone shell jamming structure is installed at the low-pressure turbine component location, and after the low-pressure turbine shaft breaks, it limits the rotational speed of the low-pressure turbine rotor component, thereby preventing over-rotation of the low-pressure turbine rotor component and breakage of the low-pressure turbine disc.

[0007] The disc edge baffle has a bottom mounting edge, a head axial end face and a top outer ring surface, wherein the outer ring surface has a certain taper and is wavy, and has a first pit and a first protrusion evenly distributed in the circumferential direction.

[0008] The conical shell baffle has a bottom mounting edge, a head overlapping edge, and a shoulder inner ring surface. The inner ring surface has a certain taper, but it is smaller than the taper of the outer ring surface. The inner ring surface is wavy and has a second pit and a second protrusion evenly distributed around it in the circumferential direction.

[0009] The disk edge baffle is connected to the turbine disk mounting edge at the bottom mounting edge by a second bolt to achieve its fixed installation; the disk edge baffle is axially pressed against the rear end face of the turbine disk tenon joint structure at the head axial end face to restrict the axial displacement of the low-pressure turbine blades.

[0010] The conical shell baffle is fixedly installed by connecting the bottom mounting edge of the conical shell baffle to the head mounting edge of the bearing oil cavity via a third bolt; the head overlapping edge of the conical shell baffle overlaps with the load-bearing inner ring of the rear frame, enhancing the conical shell baffle's resistance to deformation.

[0011] The outer ring surface of the top of the disc edge baffle and the inner ring surface of the shoulder of the conical shell baffle are opposite each other in the installation state, and there is a certain distance between them in the axial direction.

[0012] Furthermore, during normal operation of the aero-engine, a certain axial distance is maintained between the top outer ring surface of the disc edge baffle and the inner ring surface of the cone shell baffle shoulder, so that no contact friction occurs;

[0013] When the low-pressure shaft breaks, the low-pressure turbine rotor component moves backward, and the disk edge baffle moves backward with the low-pressure turbine disk. The outer ring surface at the top of the baffle will press against the inner ring surface of the shoulder of the conical shell baffle. The first boss is embedded in the second pit, forming a jam, and causing the conical shell baffle to deform violently. This consumes the kinetic energy of the low-pressure turbine rotor component, restricts its rotor from rising, and achieves rapid braking, thereby ensuring the integrity of the low-pressure turbine component.

[0014] Furthermore, both the wavy outer ring surface at the top of the disk edge baffle and the wavy inner ring surface at the shoulder of the conical shell baffle are conical surfaces, and the cone angle of the outer ring surface is greater than that of the inner ring surface. The greater the backward movement of the low-pressure turbine rotor component, the tighter the jamming between the outer ring surface and the inner ring surface, and the stronger the speed restriction on the low-pressure turbine rotor component.

[0015] Furthermore, it is applied to dual-rotor aircraft engines.

[0016] The advantages of this invention compared to the prior art are as follows:

[0017] The disc rim cone shell jamming structure of the present invention for preventing turbine over-spinning in aero-engines can quickly brake the turbine after the turbine shaft breaks, thus preventing further catastrophic accidents such as turbine over-spinning and turbine rupture, and ensuring the integrity of the turbine.

[0018] The aforementioned disk rim cone shell jamming structure for preventing turbine over-spinning in aero-engines has the advantages of simple structural configuration, minimal impact on existing engine structures, ease of processing, and low cost.

[0019] The aforementioned disk rim cone shell jamming structure for preventing turbine over-spinning in aero engines can be used not only for low-pressure turbines but also for high-pressure turbines. It can be applied not only to dual-rotor engines but also to aero engines with other structural layouts such as single-rotor or dual-rotor engines. Attached Figure Description

[0020] The above-described and other features, properties, and advantages of the present invention will be more vividly described below in conjunction with the accompanying drawings and examples, wherein:

[0021] Figure 1 This is a schematic diagram of a typical twin-rotor aero-engine.

[0022] Figure 2 This is a partial schematic diagram of a low-pressure turbine component using an example of the present invention.

[0023] Figure 3 This is a partial schematic diagram of a disc-edge conical shell locking structure using an example of the present invention.

[0024] Figure 4 This is a partial schematic diagram of a disc rim baffle using an example of the present invention.

[0025] Figure 5 This is a partial schematic diagram of a conical shell baffle using an example of the present invention. Detailed Implementation

[0026] The present invention will now be described in detail with reference to the accompanying drawings and examples.

[0027] Figure 1 A schematic diagram of a typical twin-rotor aircraft engine 100 is shown. The twin-rotor aircraft engine 100 includes a low-pressure compressor component 11, a high-pressure compressor component 12, a combustion chamber 13, a high-pressure turbine component 14, and a low-pressure turbine component 15, etc.

[0028] The low-pressure compressor component 11 includes a low-pressure compressor rotor component 11A and a low-pressure compressor stator component 11B; the high-pressure compressor component 12 includes a high-pressure compressor rotor component 12A and a high-pressure compressor stator component 12B; the high-pressure turbine component 14 includes a high-pressure turbine rotor component 14A and a high-pressure turbine stator component 14B; and the low-pressure turbine component 15 includes a low-pressure turbine rotor component 15A and a low-pressure turbine stator component 15B.

[0029] The high-pressure compressor rotor assembly 12A is driven by the high-pressure turbine rotor assembly 14A, and the two are connected by a high-pressure shaft 16; the low-pressure compressor rotor assembly 11A is driven by the low-pressure turbine rotor assembly 15A, and the two are connected by a low-pressure shaft 17.

[0030] The low-pressure compressor rotor assembly 11A is supported by the first roller bearing 1 and the first ball bearing 2, and the high-pressure compressor rotor assembly 12A is supported by the second ball bearing 3. The axial and radial forces on these three bearings are transmitted outward through the front load-bearing frame 18. The high-pressure turbine rotor assembly 14A is supported by the second roller bearing 4, and the radial force on the bearing is transmitted outward through the high-pressure turbine rear frame 19. The low-pressure turbine rotor assembly 15A is supported by the third roller bearing 5, and the radial force on the bearing is transmitted outward through the low-pressure turbine rear frame 32.

[0031] During the operation of the dual-rotor aero-engine 100, high-temperature, high-energy gas is discharged from the combustion chamber 13 and impacts the high-pressure turbine component 14 and the low-pressure turbine component 15 backward (in the direction of arrow A), driving the low-pressure turbine rotor component 15A and the high-pressure turbine rotor component 14A to rotate. Furthermore, the high-pressure turbine rotor component 14A drives the high-pressure compressor rotor component 12A to rotate, and the low-pressure turbine rotor component 15A drives the low-pressure compressor rotor component 11A to rotate.

[0032] When the low-pressure shaft 17 breaks, for example at the fracture location 171, on the one hand, the low-pressure turbine rotor component 15A suddenly sheds the load of the low-pressure compressor rotor component 11A, and under the continuous drive of the high-energy gas in the flow channel, the speed increases rapidly; on the other hand, since the fracture location 171 is located behind the first ball bearing 2, the low-pressure shaft 17 loses its axial constraint, and the low-pressure shaft 17 and the low-pressure turbine rotor component 15A will move axially backward (in the direction of arrow A) under the push of the high-energy gas.

[0033] Figure 2 In the low-pressure turbine component 15 of the aircraft engine 101, the disc rim cone shell jamming structure 102 of the present invention for preventing turbine over-rotation of the aircraft engine is used. The aircraft engine 101 is structurally similar to the dual-rotor aircraft engine 100, and the component designations of the dual-rotor aircraft engine 100 are used here.

[0034] The low-pressure turbine component 15 includes a low-pressure turbine rotor component 15A and a low-pressure turbine stator component 15B. The low-pressure turbine rotor component 15A mainly includes a low-pressure turbine disk 21 and low-pressure turbine blades 22. The low-pressure turbine blades 22 are mounted on the low-pressure turbine disk 21 via a tenon joint structure 23. A clamping disc 24 is mounted on the front side of the tenon joint structure 23, and a disc rim baffle 25 is mounted on the rear side. The clamping disc 24 is mounted on the low-pressure turbine disk 21 via a first bolt 26, and the disc rim baffle 25 is mounted on the low-pressure turbine disk 21 via a second bolt 27.

[0035] The low-pressure turbine stator component 15B mainly includes a bearing housing 31 for the third roller bearing 5, a low-pressure turbine rear frame 32, and a bearing oil cavity 33.

[0036] Figures 3-5 The specific structure of an example of the present invention and its installation method in the low-pressure turbine component 15 are shown.

[0037] The disc edge baffle 25 has a bottom mounting edge 251, a head axial end face 252 and a top outer ring face 253. The top outer ring face 253 has a certain taper and is wavy. It has a first pit 254 and a first protrusion 255 evenly distributed around its circumference.

[0038] The conical shell baffle 35 has a bottom mounting edge 351, a head overlapping edge 352 and a shoulder inner ring surface 353. The shoulder inner ring surface 353 has a certain taper, but it is smaller than the taper of the top outer ring surface 253. The shoulder inner ring surface 353 is wavy and has a second recess 354 and a second protrusion 355 evenly distributed around it in the circumferential direction.

[0039] The disk edge baffle 25 is connected to the turbine disk mounting edge 211 at the bottom mounting edge 251 by the second bolt 27 to achieve its fixed installation; the disk edge baffle 25 is pressed against the rear end face 231 of the tenon structure 23 at the head axial end face 252 to restrict the axial movement of the low-pressure turbine blade 22.

[0040] The conical shell baffle 35 is connected to the head mounting edge 331 of the bearing oil cavity 33 by a third bolt 34 at the bottom mounting edge 351 to achieve its fixed installation; the head overlapping edge 352 of the conical shell baffle 35 also overlaps with the load-bearing inner ring 321 of the low-pressure turbine rear frame 32 to enhance the deformation resistance of the conical shell baffle 35.

[0041] After installation, the top outer ring surface 253 of the disc edge baffle 25 and the inner ring surface 353 of the shoulder of the cone shell baffle 35 are opposite each other, and there is a certain distance between them in the axial direction.

[0042] The working principle of this invention is as follows:

[0043] When the aircraft engine 101 is operating normally, there is a certain distance in the axial direction between the top outer ring surface 253 of the disc edge baffle 25 and the inner ring surface 353 of the shoulder of the cone shell baffle 35, so no contact friction will occur.

[0044] After the low-pressure shaft 17 breaks, the low-pressure turbine rotor component 15A moves backward, and the disk edge baffle 25 moves backward with the low-pressure turbine disk 21. Its top outer ring surface 253 will press against the inner ring surface 353 of the shoulder of the conical shell baffle 35. At this time, the first boss 255 is embedded in the second recess 354, forming a jam, and causing the conical shell baffle 35 to undergo severe deformation, thereby consuming the kinetic energy of the low-pressure turbine rotor component 15A, limiting its speed increase, achieving rapid braking, and ensuring the integrity of the low-pressure turbine component 15.

[0045] The top outer ring surface 253 of the disc rim baffle 25 and the shoulder inner ring surface 353 of the conical shell baffle 35 are both conical surfaces, and the cone angle of the top outer ring surface 253 is greater than that of the shoulder inner ring surface 353. Therefore, the greater the rearward movement of the low-pressure turbine rotor component 15A, the tighter the jamming between the top outer ring surface 253 and the shoulder inner ring surface 353, and the stronger the speed restriction on the low-pressure turbine rotor component 15A.

[0046] The aforementioned disk rim cone shell jamming structure 102 for preventing turbine over-spinning in aero-engines has the advantages of simple structural configuration, easy processing and manufacturing, low cost, and minimal impact on the existing engine structure. It can be used not only for low-pressure turbines but also for high-pressure turbines, and can be applied not only to dual-rotor engines but also to aero-engines with other structural layouts such as single-rotor or triple-rotor engines.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A disc-rim cone shell jamming structure for preventing turbine over-spinning in aero-engines, characterized in that: It includes a disk rim baffle and a conical shell baffle; the disk rim conical shell locking structure is installed at the low-pressure turbine component to limit the speed of the low-pressure turbine rotor component after the low-pressure shaft breaks, so as to prevent the low-pressure turbine rotor component from over-rotating and the low-pressure turbine disk from over-rotating. The disc edge baffle has a bottom mounting edge, a head axial end face and a top outer ring surface, wherein the top outer ring surface has a certain taper and is wavy, and has a first pit and a first protrusion evenly distributed in the circumferential direction. The conical shell baffle has a bottom mounting edge, a head overlapping edge, and a shoulder inner ring surface. The shoulder inner ring surface has a taper, but the taper is smaller than that of the top outer ring surface. The shoulder inner ring surface is wavy and has a second pit and a second protrusion evenly distributed around it in a circumferential direction. The disk edge baffle is connected to the turbine disk mounting edge at the bottom mounting edge by a second bolt to achieve its fixed installation; the disk edge baffle is axially pressed against the rear end face of the turbine disk tenon joint structure at the head axial end face to restrict the axial displacement of the low-pressure turbine blades. The conical shell baffle is fixedly installed by connecting the bottom mounting edge of the conical shell baffle to the head mounting edge of the bearing oil cavity via a third bolt; the head overlapping edge of the conical shell baffle overlaps with the load-bearing inner ring of the rear frame, enhancing the conical shell baffle's resistance to deformation. The top outer ring surface of the disc rim baffle and the inner ring surface of the shoulder of the conical shell baffle are opposite each other in the installed state, and there is a certain distance between them in the axial direction.

2. The disc rim cone shell jamming structure for preventing turbine over-spinning in an aero-engine according to claim 1, characterized in that: When the aero engine is operating normally, a certain axial distance is maintained between the top outer ring surface of the disc edge baffle and the inner ring surface of the shoulder of the cone shell baffle, and no contact friction occurs. When the low-pressure shaft breaks, the low-pressure turbine rotor component moves backward, and the disk edge baffle moves backward with the low-pressure turbine disk. Its top outer ring surface will press against the inner ring surface of the shoulder of the conical shell baffle. The first boss is embedded in the second pit, forming a jam, and causing the conical shell baffle to deform violently, consuming the kinetic energy of the low-pressure turbine rotor component, restricting its rotor from rising, achieving rapid braking, and thus ensuring the integrity of the low-pressure turbine component.

3. A disc-rim cone shell jamming structure for preventing turbine over-spinning in an aero-engine according to claim 1 or 2, characterized in that: The top outer ring surface of the disc rim baffle and the shoulder inner ring surface of the conical shell baffle are both conical surfaces, and the cone angle of the top outer ring surface is greater than that of the shoulder inner ring surface. The greater the backward movement of the low-pressure turbine rotor component, the tighter the jamming between the top outer ring surface and the shoulder inner ring surface, and the stronger the speed restriction on the low-pressure turbine rotor component.

4. A disc-rim cone shell jamming structure for preventing turbine over-spinning in an aero-engine according to claim 1 or 2, characterized in that: It is used in aircraft engines with a load-bearing frame after the last stage turbine rotor.

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