Fuel nozzle and aero-engine

Abstract

The invention provides a fuel nozzle and an aero-engine, and relates to the technical field of aero-engines. The fuel nozzle comprises an oil collecting ring shell, an oil injection rod core and an oil collecting ring, and the oil injection rod core is communicated with the oil collecting ring, so that oil is supplied to the oil collecting ring through the oil injection rod core; a main oil injection opening is formed in the oil collecting ring, and fuel oil entering the oil collecting ring from the oil injection rod core is injected out of the oil collecting ring shell through the main oil injection opening. The main spraying opening is formed in the peripheral face of the oil collecting ring, and meanwhile a spraying opening hole corresponding to the main spraying opening is formed in the oil collecting ring shell. A check ring is further arranged on the peripheral surface of the oil collecting ring, is located in the downstream direction of the main nozzle and is in contact with the oil collecting ring shell, so that the kinetic energy of the rod core can be dissipated through heat generated by dry friction generated between the check ring and the oil collecting ring shell, and the amplitude and vibration stress of the rod core in the nozzle are reduced; the vibration resistance magnitude of the fuel nozzle is improved, and the high-cycle fatigue failure risk of the fuel nozzle is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and in particular to a fuel nozzle and an aeroengine. Background Art

[0002] An aircraft engine is a device that provides power for aircraft, and generates driving force through the combustion of fuel in the combustion chamber. The fuel nozzle is a device that supplies fuel to the combustion chamber. It is installed on the combustion chamber casing and atomizes the fuel through the fuel nozzle to accelerate the formation of the oil-gas mixture. The oil-gas mixture enters the combustion chamber for combustion, which can ensure stable combustion and improve combustion efficiency.

[0003] In order to meet the design requirements of low fuel consumption and low emissions, civil aviation engines usually adopt a center-staged lean premixed prevaporized combustion method (Lean Premixed Prevaporized, referred to as LPP). The fuel nozzle contains multiple fuel flow paths such as the pre-combustion stage and the main combustion stage. The fuel nozzle is subjected to extremely high temperature and pressure loads when working. The pressure load comes from the high-pressure compressor outlet airflow, which can reach 4MPa. The temperature load comes from the heat convection generated by the high-pressure compressor outlet airflow and the heat radiation generated by the combustion flame in the flame tube, which can reach 900-1000K. Therefore, the fuel nozzle is made of high-temperature alloy to cope with the harsh working environment and ensure certain mechanical properties. In order to meet the design requirements of aerodynamics and thermal protection, the fuel nozzle has a complex design structure, and the injection rod core inside its shell is integrally formed using a 3D printing process. In addition to the high temperature and high pressure static loads, the nozzle also has to withstand vibration loads such as the combustion pulsation pressure in the flame tube, the vibration excitation of the rotor transmitted by the casing, and the vibration excitation of the fuel pipeline, making thermal vibration fatigue one of the severe challenges facing the fuel nozzle.

[0004] The structure of the fuel nozzle assembly is complex. The low-order vibration mode is the cantilever vibration of the nozzle as a whole, and the high-order vibration mode is the local vibration of the injection rod core inside the nozzle housing. The high-order vibration has many natural frequencies and a high risk of coupling with the excitation load. In addition, the amplitude of the nozzle core vibration is high, and the vibration stress is large. It is very easy to cause high-cycle fatigue fracture failure, causing fuel leakage and threatening engine safety. Therefore, it is particularly important to carry out the damping and vibration reduction design of the fuel nozzle, reduce the vibration stress of the injection rod core inside the nozzle, and improve the high-cycle fatigue vibration resistance of the fuel nozzle. Summary of the invention

[0005] The object of the present invention is to provide a fuel nozzle which can effectively reduce the internal vibration of the fuel nozzle and the risk of high cycle fatigue failure caused by the vibration.

[0006] Another object of the present invention is to provide an aircraft engine that can effectively reduce the internal vibration of the fuel nozzle and the risk of high cycle fatigue failure caused by the vibration.

[0007] The embodiments of the present invention can be implemented in the following ways:

[0008] A fuel nozzle, comprising an oil collecting ring shell, an oil injection rod core and an oil collecting ring, wherein the oil injection rod core is connected to the oil collecting ring so as to supply oil to the oil collecting ring through the oil injection rod core; a main nozzle is provided on the oil collecting ring, and the main nozzle is used to spray fuel outside the oil collecting ring shell;

[0009] The main nozzle is arranged on the outer circumferential surface of the oil collecting ring, and the outer shell of the oil collecting ring is provided with a nozzle opening corresponding to the main nozzle, and the main nozzle is used to spray fuel outward through the nozzle opening along the radial direction of the oil collecting ring to the outside of the outer shell of the oil collecting ring; the outer circumferential surface of the oil collecting ring is also provided with a stop ring, which is located in the downstream direction of the main nozzle, and the stop ring is in contact with the outer shell of the oil collecting ring.

[0010] Optionally, the retaining ring includes a plurality of friction protrusions distributed at intervals along the circumference of the oil collecting ring, and the plurality of friction protrusions are all used to contact the outer shell of the oil collecting ring.

[0011] Optionally, the fuel nozzle further comprises a rod core sleeve arranged on the oil collecting ring housing, and the rod core sleeve and the oil collecting ring housing form an annular mounting cavity for mounting the oil collecting ring;

[0012] A flexible support is also provided on the rod core sleeve, one end of the flexible support is fixedly connected to the rod core sleeve, and the other end of the flexible support is fixedly connected to the upstream end of the oil collecting ring, so that gaps are formed between the inner circumference of the oil collecting ring and the rod core sleeve, and between the outer circumference of the oil collecting ring and the outer shell of the oil collecting ring.

[0013] Optionally, a gap formed between the inner circumferential surface of the oil collecting ring and the rod core sleeve serves as an air intake passage; a first airflow gap is formed between two adjacent friction protrusions, and the first airflow gap is communicated with the air intake passage.

[0014] Optionally, the first airflow gap corresponds to the position of the main nozzle in a one-to-one manner in the circumferential direction of the oil collecting ring, so as to provide a purge airflow to the main nozzle through the first airflow gap.

[0015] Optionally, a cooling hole communicating with the air intake passage is provided at the downstream end of the oil collecting ring housing, and part of the gas in the air intake passage is used to be discharged from the oil collecting ring housing through the cooling hole.

[0016] Optionally, the oil injection rod core, the rod core sleeve, the flexible support and the oil collecting ring are integrally formed by 3D printing.

[0017] Optionally, a boss is provided inside the oil collecting ring housing, and an upstream end surface of the boss contacts with a downstream end surface of the stop ring; and an outer peripheral surface of the stop ring contacts with an inner peripheral surface of the oil collecting ring housing.

[0018] Optionally, the retaining ring includes a plurality of friction protrusions spaced apart along the circumference of the oil collecting ring, the boss includes a plurality of boss portions spaced apart along the circumference of the oil collecting ring housing, and the plurality of friction protrusions are arranged in one-to-one correspondence with the plurality of boss portions.

[0019] An aircraft engine comprises a combustion chamber casing and the above-mentioned fuel nozzle, wherein the fuel nozzle is installed in the combustion chamber casing.

[0020] The beneficial effects of the fuel nozzle and the aircraft engine provided by the embodiments of the present invention include:

[0021] An embodiment of the present invention provides a fuel nozzle, which includes an oil collecting ring shell, an injection rod core and an oil collecting ring. The injection rod core is connected to the oil collecting ring, so that oil is supplied to the oil collecting ring through the injection rod core; a main injection port is arranged on the oil collecting ring, and the fuel entering the oil collecting ring from the injection rod core is sprayed to the outside of the oil collecting ring shell through the main injection port. The main injection port is arranged on the outer peripheral surface of the oil collecting ring, and a nozzle opening corresponding to the main nozzle is arranged on the oil collecting ring shell. The fuel sprayed outward from the main nozzle along the radial direction of the oil collecting ring is sprayed to the outside of the nozzle shell through the nozzle opening. A stop ring is also arranged on the outer peripheral surface of the oil collecting ring, and the stop ring is located in the downstream direction of the main nozzle, and the stop ring is in contact with the oil collecting ring shell. In this way, when the oil collecting ring and the oil collecting ring shell are relatively displaced, dry friction is generated between the stop ring and the oil collecting ring shell, so that the kinetic energy of the rod core is dissipated through the dry friction heat generation, the amplitude and vibration stress of the rod core inside the nozzle are reduced, the vibration resistance level of the fuel nozzle is improved, and the high cycle fatigue failure risk of the fuel nozzle is greatly reduced.

[0022] An embodiment of the present invention also provides an aircraft engine, which includes the above-mentioned fuel nozzle. Therefore, the aircraft engine also has the beneficial effects of being able to dissipate the kinetic energy of the rod core in the fuel nozzle through dry friction heat generation, reducing the amplitude and vibration stress of the rod core inside the nozzle, improving the vibration resistance of the fuel nozzle, and significantly reducing the risk of high-cycle fatigue failure of the fuel nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above features and advantages of the present invention can be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, the components are not necessarily drawn to scale, and components with similar related properties or features may have the same or similar reference numerals.

[0024] Figure 1 A schematic diagram of the structure of a combustion chamber in an aero-engine according to one aspect of the present invention is shown;

[0025] Figure 2 A schematic diagram of the internal structure of a fuel nozzle provided according to one aspect of the present invention is shown;

[0026] Figure 3 Shows Figure 2 A schematic diagram of the enlarged local structure at point A in the middle;

[0027] Figure 4 A schematic cross-sectional view of the matching structure between an oil collecting ring and an oil collecting ring housing in a fuel nozzle provided according to one aspect of the present invention is shown;

[0028] Figure 5 It shows a schematic structural diagram of an oil collecting ring in a fuel nozzle provided according to one aspect of the present invention;

[0029] Figure 6 A schematic structural diagram of an oil collecting ring housing in a fuel nozzle provided according to one aspect of the present invention is shown.

[0030] Reference numerals:

[0031] 10-aircraft engine; 111-combustion chamber outer casing; 112-diffuser; 113-flame tube outer ring; 114-flame tube inner ring; 115-combustion chamber casing; 200-fuel nozzle; 211-nozzle cover plate; 212-valve mounting seat; 213-nozzle housing; 214-nozzle rod core; 215-rod core sleeve; 216-flexible support; 220-oil collecting ring; 221-main nozzle; 222-stop ring; 223-friction protrusion; 224-first airflow gap; 225-main combustion stage oil circuit; 230-oil collecting ring housing; 231-nozzle opening; 232-boss; 233-boss portion; 234-second airflow gap; 235-cooling hole; 236-diverter structure; 241-intake channel. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Note that the aspects described below in conjunction with the accompanying drawings and specific embodiments are only exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0033] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", "vertical" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship in which the product of the invention is usually placed when used, rather than indicating or implying that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] At the same time, it should be noted that the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified or limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, an integral connection, or a detachable 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, or the internal communication of two components, etc. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Relevant terms mentioned in the description of the present invention:

[0037] Lean Premixed Prevaporized (LPP): A combustion method in which lean fuel and air are premixed evenly and the liquid fuel is pre-vaporized completely in the air.

[0038] Goodman Diagram: A curve showing the relationship between the average stress and the amplitude of alternating stress for a component subjected to the combined action of alternating stress and static stress under the condition of equivalent number of failure cycles, also known as the "equal life curve".

[0039] Figure 1 FIG. 1 shows a schematic diagram of the structure of the combustion chamber of the aircraft engine 10 provided in this embodiment. Figure 1 This embodiment provides a fuel nozzle 200 and also provides an aircraft engine 10.

[0040] The aircraft engine 10 includes a burner casing, and a fuel nozzle 200 is installed on the combustion chamber casing. The fuel is atomized through the fuel nozzle 200 to form an oil-air mixture that enters the combustion chamber for combustion. Figure 1 The structure shown is used to introduce the operation of the aircraft engine 10. The high pressure compressor outlet airflow is pressurized after passing through the diffuser 112 and is divided into three paths after entering the combustion chamber ( Figure 1 The arrow in the middle is used to indicate the air flow path): one path is the fuel nozzle head air intake, which forms a swirl with the fuel, and the other two paths are the flame tube outer ring cavity air intake and the inner ring cavity air intake, which are used to cool the flame tube outer ring 113 and the flame tube inner ring 114. It should be noted that in the description of this embodiment, the "fuel nozzle head" refers to the flame tube outer ring 113 and the flame tube inner ring 114. Figure 1 The cylindrical barrel portion at the lower end of the fuel nozzle 200 is shown in FIG.

[0041] The fuel nozzle 200 is connected to the combustion chamber casing by bolts. Specifically, the combustion chamber casing is the combustion chamber outer casing 111. Correspondingly, the combustion chamber casing also includes the combustion chamber casing 115. The head of the fuel nozzle is located at the air inlet end of the flame tube, directly contacts the combustion flame and will withstand the combustion pulsation pressure P4 in the flame tube. The fuel nozzle 200 also has a nozzle cover plate 211 and a valve mounting seat 212. The nozzle cover plate 211 is used to connect with the combustion chamber casing, so that the nozzle cover plate 211 withstands the rotor vibration excitation transmitted by the combustion chamber casing. The valve mounting seat 212 is used to connect with the fuel pipeline, thereby withstanding the fuel pipeline vibration excitation. Therefore, the source of the excitation load in the working state of the fuel nozzle is complex and the load magnitude is high. In addition, the fuel nozzle works in a high temperature environment. The mechanical properties of the material decrease in the high temperature environment, and high-cycle fatigue failure is very likely to occur. Therefore, the fuel nozzle faces severe challenges of thermal vibration fatigue.

[0042] At present, in order to reduce the risk of high-cycle fatigue damage to fuel nozzles, the following two methods are usually used: 1. Design frequency modulation for fuel nozzles to avoid specific combustion oscillation excitation frequencies, rotor excitation frequencies, etc.; 2. Carry out damping and vibration reduction design to reduce dynamic stress at key positions of the nozzles, so that the superposition of dynamic and static stresses at fatigue risk positions is within the Goodman Diagram envelope to avoid the risk of high-cycle fatigue damage. However, when designing fuel nozzles, it is necessary to meet design requirements such as aerodynamics, thermal protection, and strength. The internal structure of the fuel nozzle is complex and some orders of frequency modulation are difficult, so it is particularly important to design damping and vibration reduction for the fuel nozzle.

[0043] Figure 2 This is a schematic diagram of the internal structure of the fuel nozzle 200 provided in this embodiment. Figure 3 for Figure 2 The enlarged schematic diagram of the local structure at A in the middle. Please refer to Figure 1-Figure 3The fuel nozzle 200 provided in this embodiment includes an oil collecting ring housing 230, an injection rod core and an oil collecting ring 220. The injection rod core is connected to the oil collecting ring 220, so that the oil is supplied to the oil collecting ring 220 through the injection rod core. The oil collecting ring 220 is provided with a main injection port, and the fuel entering the oil collecting ring 220 from the injection rod core is sprayed to the outside of the oil collecting ring housing 230 through the main injection port. The main injection port is arranged on the outer peripheral surface of the oil collecting ring 220, and the oil collecting ring housing 230 is provided with a nozzle opening 231 corresponding to the main nozzle 221. The fuel sprayed outwardly from the main nozzle 221 along the radial direction of the oil collecting ring 220 is sprayed to the outside of the nozzle housing 213 through the nozzle opening 231, that is, the fuel nozzle 200 is a radial injection type fuel nozzle 200. A stop ring 222 is also provided on the outer peripheral surface of the oil collecting ring 220. The stop ring 222 is located in the downstream direction of the main nozzle 221, and the stop ring 222 is in contact with the oil collecting ring shell 230. In this way, when the oil collecting ring 220 and the oil collecting ring shell 230 are relatively displaced, dry friction is generated between the stop ring 222 and the oil collecting ring shell 230, thereby dissipating the kinetic energy of the rod core through heat generated by dry friction, reducing the amplitude and vibration stress of the rod core inside the nozzle, improving the vibration resistance of the fuel nozzle 200, and greatly reducing the risk of high-cycle fatigue failure of the fuel nozzle 200.

[0044] Specifically, the stop ring 222 is disposed at the downstream end of the oil collecting ring 220 and protrudes outwardly in the radial direction of the oil collecting ring 220. This position is where the amplitude of the oil collecting ring 220 is high, and can effectively achieve a vibration reduction effect.

[0045] It should be noted that, in the description of this embodiment, "upstream" and "downstream" are used to illustrate the relative position relationship. For example, the upstream of a component is a portion closer to the diffuser 112 than the downstream of the component. Correspondingly, the downstream of a component is a portion farther away from the diffuser 112 than the upstream of the component.

[0046] Furthermore, the fuel nozzle 200 further includes a nozzle housing 213, which is a tubular member, with a valve mounting seat 212 mounted on its upper end, and a fixed connection with an oil collecting ring housing 230 at its lower end, and a nozzle rod core 214 is disposed in the nozzle housing 213. The nozzle rod core 214 is connected to the oil collecting ring 220, and the oil collecting ring 220 is provided with mutually independent pre-combustion stage oil circuits and main combustion stage oil circuits 225 ( Figure 4 As shown in the figure, the fuel in the nozzle rod core 214 is ejected outwardly from the main nozzle 221 along the radial direction of the oil collecting ring 220 through the main combustion stage oil path 225; the fuel entering the pre-combustion stage oil path is ejected axially from the center of the fuel nozzle 200 after the circumferential rotation of the oil collecting ring 220.

[0047] Figure 4 The cross-sectional view of the matching structure of the oil collecting ring 220 and the oil collecting ring housing 230 in the fuel nozzle 200 provided in this embodiment is as follows: Figure 5The schematic diagram of the structure of the oil collecting ring 220 in the fuel nozzle 200 provided in this embodiment is as follows: Figure 6 This is a schematic diagram of the structure of the oil collecting ring housing 230 in the fuel nozzle 200 provided in this embodiment. Figure 1-Figure 6 In this embodiment, the oil collecting ring 220 and the oil collecting ring shell 230 are both annular structures. The oil collecting ring 220 is arranged on the radial inner side of the oil collecting ring shell 230, and the oil collecting ring 220 and the oil collecting ring shell 230 are arranged coaxially. A plurality of main nozzles 221 are arranged circumferentially on the outer peripheral surface of the oil collecting ring 220. The plurality of main nozzles 221 are all connected with the main fuel level oil path 225. Correspondingly, a plurality of nozzle openings 231 are arranged on the oil collecting ring shell 230. The plurality of nozzle openings 231 are respectively opened along the radial direction of the oil collecting ring shell 230 and penetrate the oil collecting ring shell 230. At the same time, they are arranged one by one with the main nozzles 221, that is, the number of the main nozzles 221 is consistent with the number of the nozzle openings 231. At the same time, the nozzle openings 231 and the corresponding main nozzles 221 are located at the same circumferential position, so that the fuel sprayed from the main nozzles 221 can be sprayed to the outside of the oil collecting ring shell 230 through the nozzle openings 231. A protrusion is provided on the outer peripheral surface of the oil collecting ring 220, which forms a stop ring 222. Through the contact between the stop ring 222 and the oil collecting ring shell 230, when the oil collecting ring 220 and the oil collecting ring shell 230 move relative to each other, dry friction is generated between the stop ring 222 and the oil collecting ring shell 230 to dissipate the kinetic energy of the rod core.

[0048] Furthermore, the fuel nozzle 200 further includes a rod core sleeve 215 and a flexible support 216. The rod core sleeve 215 and the oil collecting ring housing 230 form an annular installation cavity for installing the oil collecting ring 220. One end of the flexible support 216 is fixedly connected to the rod core sleeve 215, and the other end of the flexible support 216 is fixedly connected to the upstream end of the oil collecting ring 220, so that gaps are formed between the inner circumference of the oil collecting ring 220 and the rod core sleeve 215, and between the outer circumference of the oil collecting ring 220 and the oil collecting ring housing 230, thereby forming an air insulation layer to prevent the fuel in the oil collecting ring 220 from coking due to excessive temperature. Specifically, the structure composed of the oil collecting ring housing 230, the oil collecting ring 220, the rod core sleeve 215 and the flexible support 216 constitutes the fuel nozzle head.

[0049] Furthermore, the nozzle rod core 214, the rod core sleeve 215, the flexible support 216 and the oil collecting ring 220 are integrally formed by 3D printing. Optionally, other components of the fuel nozzle 200 such as the nozzle housing 213, the oil collecting ring housing 230 and the valve mounting seat 212 can be manufactured by casting or forging machining, and finally connected by brazing. Figure 3 The area B in the middle is the brazing area between the rod core sleeve 215 and the oil collecting ring housing 230 .

[0050] The stop ring 222 is a raised structure arranged on the outer circumference of the oil collecting ring 220. The outer circumference of the oil collecting ring 220 is spaced from the inner circumference of the oil collecting ring outer shell 230. The outer circumference of the stop ring 222 contacts the inner circumference of the oil collecting ring outer shell 230, so that the outer circumference of the stop ring 222 forms a first friction surface for dry friction with the inner circumference of the oil collecting ring outer shell 230.

[0051] Furthermore, the inner circumferential surface of the oil collecting ring housing 230 is also provided with a boss 232, which is located downstream of the stop ring 222, and the upstream end surface of the boss 232 contacts the downstream end surface of the stop ring 222, so that the downstream end surface of the stop ring 222 forms a second friction surface for dry friction with the boss 232 of the oil collecting ring housing 230. At the same time, through the abutment between the boss 232 and the stop ring 222, the positioning of the oil collecting ring 220 in the oil collecting ring housing 230 can also be achieved.

[0052] In this embodiment, the stop ring 222 includes a plurality of friction protrusions 223 distributed at intervals along the circumference of the oil collecting ring 220, and the plurality of friction protrusions 223 are all used to contact the oil collecting ring housing 230. In this way, when the oil collecting ring 220 and the oil collecting ring housing 230 slide relative to each other, the dry friction between the stop ring 222 and the inner circumferential surface of the oil collecting ring housing 230 and the boss 232 has a larger discontinuous contact surface, and can form multi-point contact, providing greater contact stiffness and dry friction damping in a wider frequency range, thereby absorbing more vibration energy of the oil collecting ring 220.

[0053] Furthermore, the gap formed between the inner circumference of the oil collecting ring 220 and the rod core sleeve 215 serves as an air intake channel 241, and part of the gas entering the fuel nozzle 200 flows from upstream to downstream along the air intake channel 241. A first airflow gap 224 is formed between two adjacent friction protrusions 223, and the first airflow gap 224 is connected to the air intake channel 241, so that the airflow in the air intake channel 241 flows to the first airflow gap 224 (such as Figure 5 As shown by the middle arrow, the airflow flowing through the first airflow gap 224 can take away part of the dry friction heat energy, thereby reducing friction loss.

[0054] Furthermore, the positions of the first airflow gap 224 and the main nozzle 221 are arranged in a one-to-one correspondence in the circumferential direction of the oil collecting ring 220, that is, each first airflow gap 224 and a main nozzle 221 are located at the same circumferential position of the oil collecting ring 220. In other words, the friction protrusion 223 and the main nozzle 221 are staggered in the circumferential direction of the oil collecting ring 220, so that the airflow flowing along the first airflow gap 224 to the upstream end of the oil collecting ring 220 can purge the fuel at the main nozzle 221 to avoid fuel coking.

[0055] Furthermore, the boss 232 includes a plurality of boss portions 233 spaced apart along the circumference of the oil collecting ring housing 230, and the plurality of friction protrusions 223 are arranged one by one in correspondence with the plurality of boss portions 233. Since the plurality of boss portions 233 are spaced apart, the gap between two adjacent boss portions 233 forms a second airflow gap 234, and the first airflow gap 224 is connected to the airflow channel through the second airflow gap 234, so that while ensuring that planar dry friction can be generated between the boss 232 and the stop ring 222, the boss 232 is prevented from blocking the airflow.

[0056] Specifically, a diverter structure 236 is provided at the downstream end of the rod core sleeve 215. The airflow flowing along the airflow channel to the downstream end of the rod core sleeve is divided into two flows under the action of the diverter structure 236. One flow flows along the radial direction of the oil collecting ring housing 230 to the second airflow gap 234, passes through the second airflow gap 234 and the first airflow gap 224 in sequence, and then purges the fuel at the main nozzle 221; the other flows downstream of the oil collecting ring housing 230. A cooling hole 235 connected to the air inlet channel 241 is provided downstream of the oil collecting ring housing 230. The airflow is discharged from the oil collecting ring housing 230 from the cooling hole 235, thereby cooling the nozzle interstage splash plate (not shown in the figure). There is a thermal protection coating on the downstream side of the nozzle interstage splash plate that directly contacts the combustion flame.

[0057] The fuel nozzle 200 and the aircraft engine 10 provided by the embodiment of the present invention, when the oil collecting ring 220 and the oil collecting ring housing 230 slide relative to each other during operation, the outer peripheral surface of the stop ring 222 and the inner peripheral surface of the oil collecting ring housing 230 perform arc surface dry friction, and the downstream end surface of the stop ring 222 and the upstream end surface of the boss 232 perform plane dry friction, that is, both friction surfaces can provide dry friction damping, thereby further dissipating the kinetic energy of the nozzle rod core 214, and the dry friction is multi-point contact dry friction, which provides greater contact stiffness and dry friction damping in a wider frequency range, absorbs more vibration energy of the oil collecting ring 220, and can effectively improve the vibration resistance level of the fuel nozzle 200, and greatly reduce the risk of high-cycle fatigue failure of the fuel nozzle 200. At the same time, by setting the air flow path, on the one hand, the dry friction heat can be taken away, and on the other hand, the fuel of the main nozzle 221 can be purged, thereby ensuring the thermal protection effect of the fuel nozzle 200 and improving the working reliability of the fuel nozzle 200.

[0058] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technology in the field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A fuel nozzle, comprising an oil collecting ring housing, an oil injection rod core and an oil collecting ring, wherein the oil injection rod core is connected to the oil collecting ring so as to supply oil to the oil collecting ring through the oil injection rod core; a main nozzle is provided on the oil collecting ring, and the main nozzle is used to spray fuel outside the oil collecting ring housing; characterized in that: The main nozzle is arranged on the outer circumferential surface of the oil collecting ring, and the outer shell of the oil collecting ring is provided with a nozzle opening corresponding to the main nozzle, and the main nozzle is used to spray fuel outward through the nozzle opening along the radial direction of the oil collecting ring to the outside of the outer shell of the oil collecting ring; the outer circumferential surface of the oil collecting ring is also provided with a stop ring, which is located in the downstream direction of the main nozzle, and the stop ring is in contact with the outer shell of the oil collecting ring.

2. The fuel nozzle according to claim 1, characterized in that: The stop ring includes a plurality of friction protrusions distributed at intervals along the circumference of the oil collecting ring, and the plurality of friction protrusions are all used for contacting the outer shell of the oil collecting ring.

3. The fuel nozzle according to claim 2, characterized in that: The fuel nozzle further comprises a rod core sleeve arranged on the oil collecting ring housing, wherein the rod core sleeve and the oil collecting ring housing form an annular mounting cavity for mounting the oil collecting ring; A flexible support is also provided on the rod core sleeve, one end of the flexible support is fixedly connected to the rod core sleeve, and the other end of the flexible support is fixedly connected to the upstream end of the oil collecting ring, so that gaps are formed between the inner circumference of the oil collecting ring and the rod core sleeve, and between the outer circumference of the oil collecting ring and the outer shell of the oil collecting ring.

4. The fuel nozzle according to claim 3, characterized in that: The gap formed between the inner circumferential surface of the oil collecting ring and the rod core sleeve serves as an air intake passage; a first airflow gap is formed between two adjacent friction protrusions, and the first airflow gap is communicated with the air intake passage.

5. The fuel injection nozzle according to claim 4, characterized in that: The first airflow gap corresponds to the position of the main nozzle in a one-to-one manner in the circumferential direction of the oil collecting ring, so that a purge airflow is provided to the main nozzle through the first airflow gap.

6. The fuel injection nozzle according to claim 4, characterized in that: A cooling hole communicating with the air intake passage is disposed at the downstream end of the oil collecting ring housing, and part of the gas in the air intake passage is used to be discharged from the oil collecting ring housing through the cooling hole.

7. The fuel nozzle according to claim 4, characterized in that: The oil injection rod core, the rod core sleeve, the flexible support and the oil collecting ring are integrally formed by 3D printing.

8. The fuel nozzle according to claim 1, characterized in that: A boss is arranged inside the oil collecting ring housing, and an upstream end surface of the boss contacts with a downstream end surface of the stop ring; an outer peripheral surface of the stop ring contacts with an inner peripheral surface of the oil collecting ring housing.

9. The fuel nozzle according to claim 8, characterized in that: The retaining ring includes a plurality of friction protrusions spaced apart along the circumference of the oil collecting ring, and the boss includes a plurality of boss portions spaced apart along the circumference of the oil collecting ring housing, and the plurality of friction protrusions are arranged in one-to-one correspondence with the plurality of boss portions.

10. An aircraft engine, characterized in that: The aircraft engine comprises a combustion chamber casing and a fuel nozzle as described in any one of claims 1 to 9, wherein the fuel nozzle is installed in the combustion chamber casing.

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