Grate tooth heat insulation structure and aero-engine

Abstract

Provided is a labyrinth heat insulation structure, the heat insulation structure is used for a labyrinth structure, the labyrinth structure comprises a rotor side labyrinth and a stator side labyrinth, the stator side labyrinth further comprises a connecting arm, and the structure comprises a heat insulation cover arranged on the surface of the connecting arm. According to the labyrinth heat insulation structure, the heat insulation cover is installed on the stator side of the labyrinth, the heat insulation cover is attached to the elongated thin-wall face of the stator, heat convection on the surface of the labyrinth on the stator side is weakened, the thermal response of the labyrinth on the stator side can be effectively slowed down, and therefore the labyrinth on the rotor side and the labyrinth on the stator side are matched and coordinated, and the thermal response is consistent. The invention further provides an aero-engine.

Description

Technical Field

[0001] The invention relates to the field of aviation engines, and in particular to the field of comb tooth thermal insulation. Background Art

[0002] The comb structure is generally used for sealing, such as the comb set at the connection between the engine interstage casing and the low-pressure turbine rotor. The comb connected to one side of the stator generally includes an elongated thin-walled part, and the comb rotor side connected to one side of the rotor is generally connected to the rotating shaft of the low-pressure turbine and is relatively short. At the same time, the rotor shaft is generally relatively thick, so the thermal response of the comb rotor side is relatively slow, and the elongated thin-walled part on the comb stator side has a faster thermal response, which makes the comb stator side expand or contract rapidly under the action of thermal stress, thereby making the thermal response on both sides inconsistent.

[0003] Between the engine rotor and stator, the comb teeth generally need to set an initial steady-state clearance value due to the need for sealing. Therefore, under steady-state conditions, the clearance between the rotor and stator is coordinated. However, when the engine is in a transient change process of increasing or decreasing speed, the deformation of the comb teeth on both sides of the rotor and stator is not coordinated due to the inconsistent thermal response between the rotor and stator, which will cause the comb teeth to collide or the clearance to be too large.

[0004] The specific manifestation of inconsistent thermal response is that during the acceleration of the engine, the stator side of the comb teeth quickly heats up and expands, the gap between the comb teeth quickly increases, the cooling air of the rim seal leaks downward, the rim seal of the low-pressure turbine fails, and the mainstream gas flows back, causing damage to the low-pressure turbine rotor disk; while during the deceleration process, the stator side of the comb teeth quickly cools down and shrinks, and the gap between the comb teeth quickly decreases, so there is a risk of collision and wear. This situation is very dangerous for the engine. Summary of the invention

[0005] An object of the present invention is to provide a comb tooth heat insulation structure which can significantly improve the thermal response consistency of the comb tooth rotor and stator parts.

[0006] The comb tooth heat insulation structure for achieving the above purpose is used for the comb tooth structure, the comb tooth structure includes rotor side comb teeth and stator side comb teeth, the stator side comb teeth also include a connecting arm, and the structure includes a heat insulation cover arranged on the surface of the connecting arm.

[0007] In one or more embodiments, the heat shield comprises a fixing portion, and the fixing portion is used to be fixedly connected to the connecting arm.

[0008] In one or more embodiments, the fixing portion is welded or fixed on the connecting arm via a fixing member.

[0009] In one or more embodiments, the heat shield further includes a protrusion abutting against a surface of the connecting arm, so that a cavity insulation layer is formed between the surface of the connecting arm and the heat shield.

[0010] In one or more embodiments, the protrusion is hemispherical.

[0011] In one or more embodiments, the protrusion is disposed on an opposite side of the fixing portion.

[0012] In one or more embodiments, the heat shield is disposed on both sides of the connecting arm.

[0013] In one or more embodiments, the thickness of the heat shield is in the range of 0.3 to 0.5 mm.

[0014] In one or more embodiments, the connecting arm is provided with a convex portion or a concave portion, and the heat insulation cover is provided with a heat insulation convex portion or a heat insulation concave portion correspondingly covering the convex portion and the concave portion.

[0015] Another object of the present invention is to provide an aircraft engine provided with the above-mentioned comb tooth heat insulation structure.

[0016] The above-mentioned comb tooth insulation structure installs a heat insulation cover on the stator side of the comb teeth. The heat insulation cover fits the extended thin wall surface of the stator, weakening the convective heat transfer on the surface of the comb teeth on the stator side. It can effectively slow down the thermal response of the comb teeth on the stator side, so that the rotor and stator comb teeth cooperate and coordinate, and the thermal response is consistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0018] Figure 1 is a schematic diagram of an embodiment of a comb tooth structure;

[0019] Figure 2 It is a schematic diagram of an embodiment of a comb teeth thermal insulation structure.

[0020] Symbols and Markings

[0021] 11 Rotor side grate teeth

[0022] 12 Stator side comb teeth

[0023] 13 Heat shield

[0024] 15 Cavity compartment

[0025] 120 Connecting arm

[0026] 124 Raised parts

[0027] 131 Fixed part

[0028] 132 Bump DETAILED DESCRIPTION

[0029] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0030] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0031] The comb tooth heat insulation structure disclosed in the present invention is used for a comb tooth structure. Figure 1 As shown, it includes a rotor side grate 11 and a stator side grate 12 , the rotor side grate 11 is connected to the low-pressure turbine shaft 22 , and the stator side grate 12 is connected to the casing 20 via a connecting arm 120 .

[0032] The connecting arm 120 is preferably an elongated thin-walled member, generally connected to the stator member such as the casing 20, and has a thin wall surface, so the thermal response is fast. Therefore, during the engine lifting and turning process, the connecting arm 120 and the stator side grate 12 will have the problem of deformation incompatibility with the rotor side grate 11.

[0033] Due to the inconsistent thermal response, the two are not coordinated in a transient environment. Therefore, the comb tooth heat insulation structure includes a heat insulation cover 13 arranged on the surface of the connecting arm 120, such as Figure 2 By setting a heat shield 13 on the stator side comb teeth 12, the thermal response of the stator side comb teeth 12 is significantly improved, thereby changing the deformation rate of the comb teeth stator end, so that the comb teeth and the stator are better matched, and effectively preventing the problems caused by the uncoordinated matching of the comb teeth and the stator during the rapid rise and fall of the aircraft engine.

[0034] The heat shield 13 can be an integral structure or a split structure. Figure 1 The heat shield 13 shown on the outside of the stator-side comb teeth 12 is installed in several sections.

[0035] The heat shield can also be arranged on both sides of the connecting arm 120, such as Figure 1 The upper and lower sides shown are used to weaken the heat convection effect on the inner and outer surfaces of the connecting arm, thereby delaying the thermal response of the stator side of the comb teeth.

[0036] The heat shield 13 includes a fixing portion 131, which is used to be fixedly connected to the connecting arm 120, for example, by welding or fixing on the connecting arm 120 by fixing members such as bolts. Figure 1 As shown, there is a protrusion 124 at the right end of the upper side of the connecting arm 120, and the fixing portion 131 is welded to the protrusion 124 on the stator side comb teeth 12. The left end of the lower side of the connecting arm 120 is the casing mounting edge, and bolt holes are set at the corresponding positions of the casing mounting edge on the heat insulation cover, and the casing is fixedly connected with the casing by bolts.

[0037] Preferably, only one end of the heat shield is fixedly connected to the stator-side comb teeth 12, and the other end can be suspended so that it can expand freely after being heated.

[0038] In some embodiments, the heat insulation cover 13 also includes a protrusion 132 that abuts against the surface of the connecting arm 120 to form a cavity partition 15 between the surface of the connecting arm 120 and the heat insulation cover. The cavity partition 15 generally contains air as a convection heat transfer layer to avoid direct contact between the heat insulation cover and the comb tooth stator component, thereby preventing the heat insulation cover from being affected by the airflow and transferring excessive temperature to the comb tooth stator component.

[0039] The protrusion 132 is preferably hemispherical to avoid damage to the surface of the connecting arm 120. The protrusion may also be in other shapes such as a rectangle.

[0040] There may be a plurality of protrusions 132. For example, three to five hemispherical protrusions may be distributed on each section of the heat shield, so that the extended surface where the heat shield and the stator side comb teeth 12 cooperate forms a cavity layer.

[0041] The protrusion 132 is preferably disposed on the opposite side of the fixing portion 131 so as to expand and slightly move after being heated.

[0042] In some embodiments, the heat shield has a low thickness, which can achieve the effect of slowing down the thermal response of the stator. Preferably, the thickness ranges from 0.3 to 0.5 mm. Compared with increasing the thickness of the stator to slow down the thermal response, it is more efficient and more beneficial to engine weight reduction.

[0043] The surfaces of the connecting arms shown in the drawings are mostly planes. Those skilled in the art will appreciate that, if the surface is uneven, such as the surface of the connecting arm 120 includes uneven convexities or concave portions, the heat insulation cover is provided with heat insulation convexities or heat insulation concave portions correspondingly covering the convexities and concave portions to achieve a heat insulation effect.

[0044] The above structure installs a heat shield on the stator side of the comb teeth. The heat shield fits the extended thin wall surface of the stator, weakening the convective heat exchange on the stator side comb tooth surface, which can effectively slow down the thermal response of the stator components, thereby making the rotor and stator cooperate and coordinate, and then taking effect on the comb tooth gap.

[0045] Combined with the above introduction to the comb tooth thermal insulation structure, it can also be understood that an aircraft engine includes the above-mentioned comb tooth thermal insulation structure, which can delay the thermal response of the comb tooth stator side under transient and steady-state conditions such as accelerated takeoff and rapid rotation, optimize the comb tooth clearance in the operating state, and provide protection for the safe operation of the engine.

[0046] The present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0047] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. Comb tooth heat insulation structure, used for the comb tooth structure, characterized in that: The grate structure includes rotor-side grate and stator-side grate, and the stator-side grate also includes a connecting arm. The structure includes: A heat shield is arranged on the surface of the connecting arm.

2. The comb teeth heat insulation structure according to claim 1, characterized in that: The heat insulation cover comprises a fixing portion, and the fixing portion is used for fixedly connecting with the connecting arm.

3. The comb teeth heat insulation structure according to claim 2, characterized in that: The fixing portion is welded or fixed on the connecting arm via a fixing piece.

4. The comb teeth heat insulation structure according to claim 2, characterized in that: The heat insulation cover also includes a protrusion that abuts against the surface of the connecting arm, so that a cavity insulation layer is formed between the surface of the connecting arm and the heat insulation cover.

5. The comb teeth heat insulation structure according to claim 4, characterized in that: The protrusion is hemispherical.

6. The comb teeth heat insulation structure according to claim 4, characterized in that: The protrusion is disposed on the opposite side of the fixing portion.

7. The comb teeth heat insulation structure according to claim 1, characterized in that: The heat insulation cover is arranged on both sides of the connecting arm.

8. The comb teeth heat insulation structure according to claim 1, characterized in that: The thickness of the heat insulation cover ranges from 0.3 to 0.5 mm.

9. The comb teeth heat insulation structure according to claim 1, characterized in that: The connecting arm is provided with a convex portion or a concave portion, and the heat insulation cover is provided with a heat insulation convex portion or a heat insulation concave portion correspondingly covering the convex portion and the concave portion.

10. An aircraft engine, characterized in that: It comprises the comb tooth heat insulation structure as described in any one of claims 1 to 9.

Images