Composite thermal protection device and bearing cavity

Abstract

The invention belongs to the technical field of thermal protection, and discloses a composite thermal protection device and a bearing cavity. The composite thermal protection device comprises a thermal protection shell, a thermal insulation assembly and a spraying assembly. One side of the thermal protection shell is provided with a thermal insulation surface, and the other side of the thermal protection shell is provided with a cooling surface opposite to the rotating wall surface of the rotating shaft; the heat insulation assembly is arranged in the protection cavity to reduce the transfer efficiency of heat from the heat insulation surface to the cooling surface; the spraying assembly is used for spraying lubricating oil to the cooling face to form an oil film on the cooling face. When the composite thermal protection device is used, the heat transfer efficiency is reduced by the thermal protection shell and the heat insulation assembly, and meanwhile, an oil film is formed on the cooling surface to absorb heat of the cooling surface in time, so that the composite thermal protection device can keep a good thermal protection effect in the continuous operation process, and the service life of the composite thermal protection device is prolonged. And the possibility of continuous temperature rise in the rotating wall surface of the rotating shaft is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of thermal protection, and in particular to a composite thermal protection device and a bearing cavity. Background Art

[0002] The greater the flight Mach of the aircraft, the higher the inlet airflow temperature of the engine will be due to the aerodynamic heating effect. In particular, the gas temperature outside the bearing cavity in the hot zone of the engine will increase significantly. The heat will be transferred to the bearing cavity through the cavity structure, causing the temperature of the rotating wall of the bearing cavity to continue to rise. When the temperature reaches the upper limit, it will affect the normal operation of the engine.

[0003] In the prior art, the thermal protection of the engine bearing cavity is mainly divided into active, passive and composite types. The active type is to continuously cool by means of cold air surround, so as to achieve the effect of thermal protection, while the passive type is to set up thermal insulation materials such as thermal insulation interlayer to reduce the heat transfer efficiency. The composite type is to use the active and passive types together, which has the best thermal protection effect.

[0004] However, in traditional turbine engines, high Mach number flight will cause the temperature of the gas used for cooling around the bearing cavity to continue to rise, and the continuous cooling effect of the gas will become poor, causing the effect of thermal protection through gas cooling and high-temperature insulation to gradually decrease, making it unable to meet the temperature control requirements of the rotating wall of the bearing cavity, which can easily affect the normal operation of the engine. Summary of the invention

[0005] The purpose of the present invention is to provide a composite thermal protection device and a bearing cavity, which solves the problem in the prior art that when the engine is continuously running at a high Mach number, the continuous thermal protection of the thermal protection device is difficult to meet the demand, resulting in the temperature of the rotating wall of the bearing cavity being easily and continuously increased, thereby affecting the normal operation of the engine.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a composite thermal protection device for thermally protecting a rotating wall surface of a rotating shaft, comprising:

[0008] A heat protection shell, wherein the heat protection shell has a protection cavity therein, and one side of the heat protection shell has a heat insulation surface, and the other side of the heat protection shell has a cooling surface for being opposite to the rotating wall surface of the rotating shaft;

[0009] A heat insulation component is disposed in the protective cavity to reduce the efficiency of heat transfer from the heat insulation surface to the cooling surface;

[0010] The spray assembly is used for spraying lubricating oil toward the cooling surface to form an oil film on the cooling surface.

[0011] Optionally, the heat protection shell comprises:

[0012] An upper base plate, one side of which serves as the heat insulation surface;

[0013] The lower bottom plate is opposite to the other side of the upper bottom plate and is spaced apart from each other. The protection cavity is formed between the upper bottom plate and the lower bottom plate. The side of the lower bottom plate away from the upper bottom plate serves as the cooling surface.

[0014] Optionally, at least two spaced-apart washers are provided in the protection cavity, one end of the washers abuts against the upper bottom plate, and the other end of the washers abuts against the lower bottom plate.

[0015] Optionally, the heat protection shell further comprises:

[0016] A plurality of fasteners are arranged at intervals, wherein the fasteners are passed through the upper base plate and fixedly connected to the lower base plate.

[0017] Optionally, the fastener and the washer are both made of ceramic material.

[0018] Optionally, each of the fasteners is sleeved with a washer.

[0019] Optionally, the thermal insulation assembly comprises:

[0020] A buffer layer, attached to the upper base plate to reduce the efficiency of heat transfer from the upper base plate to the protective cavity;

[0021] A heat-insulating layer, attached to the lower base plate to reduce the efficiency of heat transfer to the lower base plate;

[0022] The reflective layer is arranged between the buffer layer and the heat insulating layer to reduce the radiation heat transfer from the buffer layer to the heat insulating layer.

[0023] Optionally, the buffer layer is made of aerogel thermal insulation material;

[0024] And / or, the reflective layer is made of metal material;

[0025] And / or, the heat insulation layer is made of nanocomposite material.

[0026] Optionally, the injection assembly comprises:

[0027] a first nozzle, wherein a nozzle of the first nozzle is located at the rotation axis of the heat shield to spray lubricating oil onto the cooling surface;

[0028] A plurality of second nozzles are arranged at intervals from the first nozzles to spray lubricating oil onto the cooling surface.

[0029] In a second aspect, the present invention further provides a bearing cavity, which comprises:

[0030] A rotating shaft having a rotating wall surface;

[0031] The composite thermal protection device as described in any one of the first aspects is arranged opposite to the rotating wall surface.

[0032] Beneficial effects of the present invention:

[0033] On the one hand, the efficiency of heat transfer to the rotating wall surface is reduced by the heat protection shell and the heat insulation component arranged in the protection cavity to achieve passive heat protection, and at the same time, the injection component is used to form an oil film on the cooling surface to absorb the heat of the cooling surface in time to achieve active heat protection, thereby achieving efficient and stable heat protection for the rotating wall surface under the combined action of passive and active methods. In this way, when the composite heat protection device is in use, the heat transfer efficiency is reduced by the heat protection shell and the heat insulation component, and at the same time, the oil film formed on the cooling surface can absorb the heat of the cooling surface in time, thereby ensuring that the composite heat protection device can maintain a good heat protection effect during continuous operation, and effectively reduce the possibility of continuous increase in the temperature of the rotating wall surface.

[0034] Secondly, when the bearing cavity is in use, the rotating wall of the rotating shaft is in the process of continuous high-speed rotation. The composite thermal protection device can use active and passive composite methods to provide thermal protection for the rotating wall, effectively blocking the transfer of heat into the rotating wall, and ensuring that the temperature of the rotating wall remains within a safe range. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is an overall schematic diagram of a composite thermal protection device in an embodiment of the present invention;

[0036] Figure 2 Schematic diagram of the structure of the heat insulation component of the composite heat protection device in the embodiment of the present invention.

[0037] In the figure:

[0038] 1. Injection assembly; 2. Upper base plate; 3. Protective cavity; 4. Lower base plate; 5. Gasket; 6. Fasteners; 7. Buffer layer; 8. Reflective layer; 9. Thermal insulation layer. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0040] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0042] In the description of this embodiment, the terms "upper", "lower", "left", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0043] The embodiment of the invention discloses a thermal protection device and a bearing cavity.

[0044] Please see attached Figure 1 and attached Figure 2 The composite heat protection device is used for heat protection of the rotating wall surface of the rotating shaft, and comprises a heat protection shell, a heat insulation component and a spray component 1. The heat protection shell has a protection cavity 3, one side of the heat protection shell has a heat insulation surface, and the other side has a cooling surface for facing the rotating wall surface of the rotating shaft; the heat insulation component is arranged in the protection cavity 3 to reduce the efficiency of heat transfer from the heat insulation surface to the cooling surface; the spray component 1 is used to spray lubricating oil toward the cooling surface to form an oil film on the cooling surface.

[0045] Specifically, the heat protection shell is a frame structure, and its internal hollow space serves as a protection cavity 3, and its two opposite sides serve as a heat insulation surface and a cooling surface respectively, and the cooling surface corresponds to the rotating wall surface. A heat insulation component is arranged in the protection cavity 3, and the heat insulation component is pressed against the cavity wall of the protection cavity 3. The heat insulation component can be composed of multiple layers of different materials to effectively reduce the efficiency of heat transfer from the heat insulation surface to the cooling surface. The injection component 1 can spray lubricating oil to the cooling surface. The heat protection shell can rotate at high speed following the rotating wall surface of the rotating shaft, so that when the lubricating oil is sprayed onto the cooling surface, the impact of the lubricating oil on the cooling surface combined with the rotation of the cooling surface can form an oil film, without the need for an additional film-forming structure, which effectively simplifies the complexity of the structure. The thickness of the oil film is small, and it can absorb the heat of the heat protection shell in time, and the oil film can be continuously formed during the continuous injection of the lubricating oil, and the lubricating oil separated from the cooling surface can flow back and be recycled after heat dissipation and cooling through the radiator.

[0046] The efficiency of heat transfer to the rotating wall surface is reduced by the heat protection shell and the heat insulation component arranged in the protection cavity 3 to achieve passive heat protection. At the same time, the injection component 1 is used to form an oil film on the cooling surface to absorb the heat of the cooling surface in time to achieve active heat protection, thereby achieving efficient and stable heat protection for the rotating wall surface under the combined action of passive and active methods. In this way, when the composite heat protection device is in use, the heat transfer efficiency is reduced by the heat protection shell and the heat insulation component, and at the same time, the oil film formed on the cooling surface can absorb the heat of the cooling surface in time, thereby ensuring that the composite heat protection device can maintain a good heat protection effect during continuous operation, and effectively reducing the possibility of continuous increase in the temperature of the rotating wall surface.

[0047] Optionally, the heat protection shell includes an upper base plate 2 and a lower base plate 4. One side of the upper base plate 2 is used as a heat insulation surface; the lower base plate 4 is opposite to the other side of the upper base plate 2 and is spaced apart, a protection cavity 3 is formed between the upper base plate 2 and the lower base plate 4, and the side of the lower base plate 4 away from the upper base plate 2 is used as a cooling surface.

[0048] Specifically, the upper base plate 2 is in the shape of an elongated strip and can rotate along its central axis. The lower base plate 4 is the same as the upper base plate 2. The two are arranged opposite to each other, and the above-mentioned protective cavity 3 is formed between the two. The upper base plate 2 and the lower base plate 4 are both made of materials with good thermal insulation, such as ceramics, etc., and the present invention does not limit this material. The upper base plate 2 and the lower base plate 4 can be fixedly connected together, and the fixing method can be a detachable connection method such as a bolt connection or a snap-on connection, or a non-detachable method such as welding or bonding, and the present invention does not limit this.

[0049] An upper base plate 2 and a lower base plate 4 are provided to enclose a protective cavity 3, so that a protective cavity 3 that meets the requirements can be formed through a simple structural combination, so as to facilitate the installation of structures such as heat insulation components, so that the overall composite thermal protection device can be installed in a corresponding space, thereby improving the adaptability of the composite thermal protection device.

[0050] Optionally, at least two spaced-apart washers 5 are provided in the protection cavity 3 , one end of the washers 5 abuts against the upper bottom plate 2 , and the other end of the washers 5 abuts against the lower bottom plate 4 .

[0051] Specifically, the upper base plate 2 and the lower base plate 4 are both disc-shaped, and a plurality of gaskets 5 can be circumferentially spaced at the edge of the protective cavity 3. The gaskets 5 can be long strips, and their two ends are respectively abutted against the upper base plate 2 and the lower base plate 4. The gaskets 5 and the upper base plate 2 and the lower base plate 4 can be formed into a non-detachable fixed connection by bonding or welding, or by passing bolts or other structures through the gaskets 5 so that the gaskets 5 are only tightly abutted against the upper base plate 2 and the lower base plate 4, so that different lengths of gaskets 5 can be selected to support the upper base plate 2 and the lower base plate 4 according to different space requirements.

[0052] The upper bottom plate 2 and the lower bottom plate 4 are supported and separated by the gasket 5 to ensure that the above-mentioned protective cavity 3 is formed between the upper bottom plate 2 and the lower bottom plate 4. Moreover, the length of the gasket 5 can be adjusted according to actual needs, so that the spacing between the upper bottom plate 2 and the lower bottom plate 4 can be flexibly changed, and the space size of the protective cavity 3 can also be changed. The length of the gasket 5 can be changed by replacing the gasket 5 of different sizes, or by setting the gasket 5 as a telescopic rod structure, which is not limited by the present invention.

[0053] Optionally, the heat protection shell further comprises a plurality of spaced apart fasteners 6. The fasteners 6 are passed through the upper base plate 2 and fixedly connected to the lower base plate 4.

[0054] Specifically, corresponding holes are provided on the upper base plate 2 and the lower base plate 4, and a fastener 6 is inserted into each group of corresponding holes. The fastener 6 may include a locking bolt and a locking nut. The locking bolt is inserted into the upper base plate 2 and passes through the lower base plate 4. One end of the locking bolt passing through the lower base plate 4 is threadedly connected with the locking nut to lock the lower base plate 4. In order to save space, a through hole may be provided in the washer 5, and each fastener 6 is sleeved with one of the above-mentioned washers 5.

[0055] By setting the fastener 6, the upper base plate 2, the lower base plate 4 and the gasket 5 can be locked and fixed to ensure the overall stability of the composite thermal protection device. The gasket 5 can also be adjusted by tightening and loosening the fastener 6, so as to quickly adjust the size of the composite thermal protection device.

[0056] Optionally, the fastener 6 and the washer 5 are both made of ceramic material.

[0057] The ceramic material may be of a high temperature resistant type so that the thermal conductivity of the fastener 6 and the gasket 5 as a whole is kept within a relatively low range, thereby facilitating the reduction of the heat transfer efficiency between the upper base plate 2 and the lower base plate 4 .

[0058] Optionally, the heat insulation assembly includes a buffer layer 7, a heat insulation layer 9 and a reflective layer 8. The buffer layer 7 is attached to the upper base plate 2 to reduce the efficiency of heat transfer from the upper base plate 2 to the protective cavity 3; the heat insulation layer 9 is attached to the lower base plate 4 to reduce the efficiency of heat transfer to the lower base plate 4; the reflective layer 8 is arranged between the buffer layer 7 and the heat insulation layer 9 to reduce the radiant heat transfer from the buffer layer 7 to the heat insulation layer 9.

[0059] Specifically, the buffer layer 7, the heat insulating layer 9 and the reflective layer 8 can all be made of different materials, wherein the buffer layer 7 is attached to the upper base plate 2, and the two can be fixed together by heat insulating adhesive, or by embedding or clamping. The buffer layer 7 is mainly made of high temperature resistant material to block the heat transfer from the heat insulating surface to the protective cavity 3, and the thickness of the buffer layer 7 is less than or equal to 10 mm.

[0060] The reflective layer 8 is arranged closely to the buffer layer 7. The reflective layer 8 is made of a material with reflective properties and is used to block the radiation heat transfer from the buffer layer 7 to the heat insulation layer 9. The thickness of the reflective layer 8 is less than or equal to 1 mm.

[0061] The heat insulating layer 9 is attached to the inner side of the lower bottom plate 4, and the two can also be bonded together by heat insulating glue, or fixed together by embedding or clamping. The heat insulating layer 9 is mainly used to reduce the efficiency of heat transfer to the lower bottom plate 4, so it is made of a material with good heat insulating performance. The buffer layer 7, the heat insulating layer 9 and the reflective layer 8 can be directly pressed together by pressing to ensure that the three can form sufficient contact.

[0062] In this embodiment, the buffer layer 7 is made of aerogel heat-insulating material; the reflective layer 8 is made of metal material; and the heat-insulating layer 9 is made of nano-composite material.

[0063] Aerogel insulation material has good high temperature resistance and can effectively block heat transfer from the insulation surface. Metal materials such as platinum, gold and silver have high reflective properties and can effectively block the radiation heat transfer of the buffer layer 7. The insulation layer 9 is made of nanocomposite materials, which has excellent insulation performance and can effectively reduce the efficiency of heat transfer to the lower bottom plate 4, thereby minimizing the temperature of the surface of the lower bottom plate 4.

[0064] Optionally, the spray assembly 1 comprises a first nozzle and a plurality of second nozzles. The nozzle of the first nozzle is located at the rotation axis of the heat shield to spray lubricating oil onto the cooling surface; and the plurality of second nozzles are spaced apart from the first nozzle to spray lubricating oil onto the cooling surface.

[0065] Specifically, the cooling surface is disc-shaped, and the nozzle of the first nozzle is located on the rotation axis of the cooling surface. Then, the nozzle of the first nozzle can spray lubricating oil toward the central area of ​​the cooling surface, and the second nozzle and the first nozzle can extend radially and spaced apart from each other along the cooling surface, so that the second nozzle can spray lubricating oil in other areas of the cooling surface. In this embodiment, only one second nozzle is provided, and in other embodiments, the number of second nozzles can be designed according to the actual size of the cooling surface, which is not limited by the present invention.

[0066] By providing the first nozzle and the plurality of second nozzles, the lubricating oil can be uniformly sprayed to various parts of the cooling surface to ensure that an oil film is formed on the entire cooling surface.

[0067] The bearing cavity comprises a rotating shaft and a composite heat protection device as in the above-mentioned embodiment. The rotating shaft has a rotating wall surface; the heat protection device is arranged opposite to the rotating wall surface.

[0068] When the bearing cavity is in use, the rotating wall of the rotating shaft is in the process of continuous high-speed rotation. The composite thermal protection device can use active and passive composite methods to provide thermal protection for the rotating wall, effectively blocking the transfer of heat into the rotating wall, and ensuring that the temperature of the rotating wall is maintained within a safe range.

[0069] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A composite thermal protection device, characterized in that: Used for thermal protection of the rotating wall of the rotating shaft, including: A heat protection shell, wherein a protection cavity (3) is provided in the heat protection shell, one side of the heat protection shell has a heat insulation surface, and the other side of the heat protection shell has a cooling surface for being opposite to a rotating wall surface of a rotating shaft; A heat insulation component is arranged in the protective cavity (3) to reduce the efficiency of heat transfer from the heat insulation surface to the cooling surface; The spray assembly (1) is used for spraying lubricating oil toward the cooling surface to form an oil film on the cooling surface.

2. The composite thermal protection device according to claim 1, characterized in that: The thermal protection shell comprises: An upper base plate (2), one side of the upper base plate (2) serving as the heat insulation surface; The lower base plate (4) is opposite to the other side of the upper base plate (2) and is spaced apart from each other. The protective cavity (3) is formed between the upper base plate (2) and the lower base plate (4). The side of the lower base plate (4) away from the upper base plate (2) serves as the cooling surface.

3. The composite thermal protection device according to claim 2, characterized in that: At least two spaced-apart washers (5) are arranged in the protection cavity (3); one end of the washers (5) abuts against the upper base plate (2), and the other end abuts against the lower base plate (4).

4. The composite thermal protection device according to claim 3, characterized in that: The thermal protection shell also includes: A plurality of fasteners (6) are arranged at intervals, wherein the fasteners (6) are passed through the upper base plate (2) and are fixedly connected to the lower base plate (4).

5. The composite thermal protection device according to claim 4, characterized in that: The fastener (6) and the washer (5) are both made of ceramic material.

6. The composite thermal protection device according to claim 4, characterized in that: Each of the fasteners (6) is sleeved with a washer (5).

7. The composite thermal protection device according to claim 2, characterized in that: The thermal insulation assembly comprises: A buffer layer (7) is attached to the upper base plate (2) to reduce the efficiency of heat transfer from the upper base plate (2) to the protective cavity (3); A heat insulating layer (9) is attached to the lower base plate (4) to reduce the efficiency of heat transfer to the lower base plate (4); A reflective layer (8) is arranged between the buffer layer (7) and the heat insulation layer (9) to reduce radiation heat transfer from the buffer layer (7) to the heat insulation layer (9).

8. The composite thermal protection device according to claim 7, characterized in that: The buffer layer (7) is made of aerogel thermal insulation material; And / or, the reflective layer (8) is made of metal material; And / or, the heat insulation layer (9) is made of nanocomposite material.

9. The composite thermal protection device according to claim 1, characterized in that: The injection assembly (1) comprises: a first nozzle, wherein a nozzle of the first nozzle is located at the rotation axis of the heat shield to spray lubricating oil onto the cooling surface; A plurality of second nozzles are arranged at intervals from the first nozzles to spray lubricating oil onto the cooling surface.

10. The bearing cavity is characterized in that: include: A rotating shaft having a rotating wall surface; The composite thermal protection device according to any one of claims 1 to 9 is arranged opposite to the rotating wall surface.

Images