Load reduction device and open type rotor engine

Abstract

The invention provides a load reduction device and an open type rotor engine, and relates to the field of open type rotor engines. The load reducing device comprises a peripheral frame and rollers. An energy absorption structure or an energy dissipation material is filled in the peripheral frame and used for absorbing kinetic energy and achieving cushioning. The rollers are rotationally arranged on the peripheral frame in series and make contact with the energy absorption structures or the energy dissipation materials in the peripheral frame, the swing radius of the fan rotor can be effectively reduced, and stress concentration of the fan shaft is weakened.

Description

Technical Field

[0001] The present invention relates to the field of open rotor engines, and in particular to a load reduction device and an open rotor engine. Background Art

[0002] The open rotor engine is a new type of engine between turboprops and turbofans. It can achieve an extremely high bypass ratio (30-90), boasts higher propulsion efficiency than turbofans at high subsonic cruise speeds, and offers 25% lower fuel consumption than currently in-service engines. The application of open rotor engines is one of the key approaches to achieving green aviation.

[0003] To improve the efficiency of open rotor engines, the fan blades are adjusted to a matching angle using a variable pitch system based on flight conditions. The fan blades of an open rotor rotate around the engine axis, causing the airflow exiting the fan blades to have both axial velocity and circumferential rotational velocity. The fan blades are typically mounted to the mounting holes of the blade hub using a retaining structure (such as a blade shank mated with a bearing). The blade hub is mounted on the fan shaft and further attached to the load-bearing case via fan bearings. The position of the fan bearings gives the open rotor a cantilever structure. During engine operation, the fan blades rotate under the torque of the variable pitch system applied to the end of the blade shank, adjusting the fan blade pitch angle. The open rotor must withstand the loads of the blades themselves, the aerodynamic loads, and the drive loads of the variable pitch system. These loads are transmitted through the hub to the fan shaft, and then through the fan bearings to the load-bearing case and even the mounting system.

[0004] Airworthiness regulations require that open rotor engines maintain sufficient structural integrity after being hit by an accident such as a bird strike, ensuring flight safety during the continuous rotation phase until safe return. After the fan blades are hit by an accident such as a bird strike, the impact load will be transmitted to the hub and fan shaft through the retaining structure, and further transmitted to the load-bearing casing. Damage to the fan blades not only easily causes flow field turbulence, but the fan rotor may also generate a huge unbalanced load, causing the fan rotor to vibrate more and swing more. Since the open rotor part does not have an external casing, it is impossible to limit the swing radius of the fan rotor. The increase in the swing amplitude of the fan rotor will lead to a series of risks such as stress concentration on the fan shaft and uncoordinated deformation of the variable pitch system, which may endanger the safety of the engine during the continuous rotation phase and even the risk of broken shaft. Therefore, there is a need for a load reduction device that can effectively reduce the swing radius of the fan rotor and reduce the stress concentration on the fan shaft after the open rotor is damaged. Summary of the Invention

[0005] The purpose of the present invention is at least to provide a load reduction device and an open rotor engine, which can effectively reduce the swing radius of the fan rotor and reduce the stress concentration of the fan shaft.

[0006] The following is a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all conceivable aspects and is neither intended to identify key or critical elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that will be provided later.

[0007] One embodiment of the present invention provides a load reduction device comprising a peripheral frame and rollers. The peripheral frame is filled with an energy-absorbing structure or energy-dissipating material to absorb kinetic energy and achieve vibration damping. The rollers are rotatably mounted on the peripheral frame and in contact with the energy-absorbing structure or energy-dissipating material within the peripheral frame.

[0008] In some embodiments, the peripheral frame is a parallelogram structure.

[0009] In some embodiments, the number of rollers is plural.

[0010] In some embodiments, the material of the peripheral frame includes a metal material with high strength and high toughness, so as to be able to undergo plastic deformation under the action of an impact load to absorb kinetic energy.

[0011] In some embodiments, the metal material with high strength and high toughness includes titanium alloy or nickel-based alloy.

[0012] In some embodiments, the energy dissipation material includes aluminum foam, nickel foam, or an elastomeric material.

[0013] In some embodiments, the energy absorbing structure includes a mesh structure, a honeycomb structure, a porous structure, or a spring structure.

[0014] The embodiments of this specification provide an open rotor engine, including the load reduction device of the above embodiment.

[0015] In some embodiments, the open rotor engine includes fan blades mounted on a blade hub, and the blade hub is mounted to a load-bearing casing through a fan shaft, a fan bearing, and a corresponding supporting cone wall.

[0016] The load reduction device is located between the fan blades and the fan shaft. The outer frame of the load reduction device extends out of a fixed end, and the load reduction device is connected and fixed to the supporting cone wall through the fixed end.

[0017] In some embodiments, the load reduction device includes a first side and a second side, the first side is parallel to the impeller hub, the second side is parallel to the fan shaft, and there is a preset gap between the first side and the impeller hub and the second side and the fan shaft.

[0018] Rollers are arranged in series on both the first side and the second side.

[0019] In some embodiments, the rollers on the first side are rotatable about the axial direction of the impeller hub.

[0020] The rollers on the second side are rotatable about the axial direction of the fan shaft.

[0021] The load-reducing device disclosed herein utilizes an energy-absorbing structure or dissipative material within its outer frame and rollers mounted on the outer frame. When subjected to an external load, the outer frame deforms and the rollers rotate under the impact load. Both the deformation of the outer frame and the rotation of the rollers absorb a portion of the impact load. Simultaneously, the deformed outer frame and the rotating rollers compress and rub against the internally filled energy-absorbing structure or dissipative material, which also absorbs a portion of the impact load. By utilizing the outer frame, the energy-absorbing structure or dissipative material, and the rollers, the load-reducing device can absorb significant impact loads, achieving a shock-absorbing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above features and advantages of the present invention will be better understood after reading the detailed description of the embodiments of the present disclosure in conjunction with the following drawings. In the drawings, components are not necessarily drawn to scale, and components with similar related properties or characteristics may have the same or similar reference numerals. Among them:

[0023] Figure 1 is a schematic structural diagram of a load shedding device according to some embodiments;

[0024] Figure 2 is a schematic diagram of a fan portion of an open rotor engine according to some embodiments.

[0025] Description of reference numerals:

[0026] 1-intake cone;

[0027] 2- fan blades;

[0028] 3-petiole;

[0029] 4- impeller hub;

[0030] 5-Fan shaft;

[0031] 6- supporting cone wall;

[0032] 7-Load-bearing receiver;

[0033] 8- fan stator blades;

[0034] 9-Fan bearing;

[0035] 10- load reduction device;

[0036] 11- peripheral frame;

[0037] 12-roller;

[0038] 13-Energy absorbing structure. DETAILED DESCRIPTION

[0039] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Note that the various aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention.

[0040] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, other terms may be used to replace a term if they achieve the same purpose.

[0041] It is understood that the technical terms that may be involved in the description of this specification, such as "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., which indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the implementation methods, and do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it cannot be understood as limiting the scope of protection of the invention.

[0042] It should be noted that the use of words such as "first" and "second" to define features is only for the convenience of distinguishing the corresponding features. Unless otherwise stated, the above words have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention. As shown in this specification and claims, words such as "one", "a", "a kind" and / or "the" do not specifically refer to the singular, but may also include the plural, unless the context clearly indicates an exception. Generally speaking, the terms "comprises" and "includes" only indicate the inclusion of clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0043] It should also be noted that, in the description of this specification, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connection, integral connection, or detachable connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this specification based on the specific circumstances.

[0044] Figure 1 is a schematic structural diagram of a load reduction device according to some embodiments.

[0045] The embodiments of this specification provide a load reduction device that can be used in scenarios requiring shock absorption and kinetic energy absorption.

[0046] like Figure 1 As shown, the load reduction device 10 includes a peripheral frame 11. The peripheral frame 11 defines a cavity therein, and the cavity is filled with an energy absorbing structure 13 or energy dissipating material for absorbing kinetic energy and achieving shock absorption.

[0047] The peripheral frame 11 is the supporting structure of the load-reducing device 10, providing a fixed space for the energy-absorbing structure 13 or energy-dissipating material inside it. In some embodiments, the peripheral frame 11 is a parallelogram structure, and the overall structure is formed as a prism with a parallelogram cross-section. The parallelogram structure has good stability and space utilization, and can effectively withstand impacts from different directions. In other embodiments, the peripheral frame 11 is a structure of other shapes that adapt to its installation space. For example, the peripheral frame 11 is formed into a cylindrical structure that can be mounted on an axis. For another example, the peripheral frame 11 is formed into a triangular structure. In some embodiments, the peripheral frame 11 is made of a metal material with high strength and high toughness, which can undergo large plastic deformation under the action of impact loads to absorb kinetic energy. In some embodiments, the metal material with high strength and high toughness includes but is not limited to titanium alloy or nickel-based alloy. It should be noted that the load-reducing device 10 may include one peripheral frame 11 or multiple peripheral frames 11.

[0048] Energy-absorbing structures 13 or energy-dissipating materials are placed within the outer frame 11. These materials deform or convert energy when impacted, effectively absorbing the impact energy. When the outer frame 11 is subjected to an external impact load, it deforms. After being squeezed and deformed by the outer frame 11, the energy-absorbing structures 13 or materials efficiently absorb the energy, reducing the load.

[0049] In some embodiments, the energy dissipation material includes aluminum foam, nickel foam, or an elastomeric material, and also includes, for example, rubber foam, carbon fiber composites, and glass fiber composites. Energy dissipation materials are lightweight, have high energy absorption capacity, and provide excellent cushioning properties. For example, aluminum foam and nickel foam undergo plastic deformation when impacted, absorbing significant amounts of kinetic energy. Elastomers, on the other hand, cushion impact forces through elastic deformation.

[0050] In some embodiments, the energy-absorbing structure 13 comprises a mesh structure, a honeycomb structure (e.g., an aluminum honeycomb structure), a porous structure (e.g., porous titanium), or a spring structure. The energy-absorbing structure 13, through its unique geometry and mechanical properties, effectively disperses and absorbs energy during impact. For example, the honeycomb structure, due to its regular hexagonal arrangement, offers high strength and excellent energy absorption. The spring structure absorbs impact energy through elastic deformation.

[0051] The roller 12 is rotatably mounted on the peripheral frame 11, and the roller 12 contacts the energy-absorbing structure 13 or energy-absorbing material in the peripheral frame. In some embodiments, the roller 12 is rotatably mounted on an existing rod on the peripheral frame 11. In some embodiments, a through groove is provided on the peripheral frame 11, and the roller 12 is provided in the through groove. The roller 12 is rotatably connected to the body of the peripheral frame 11 through a rod or an axis. The roller 12 is provided protruding from the peripheral frame 11. The provision of the roller 12 enables the peripheral frame 11 to further absorb kinetic energy through the rotation of the roller 12 when it is impacted, thereby enhancing the buffering effect, and further squeezes and rubs the energy-absorbing structure 13 or energy-absorbing material during the rotation of the roller 12 to absorb more kinetic energy. In some embodiments, there are multiple rollers 12. This helps to disperse the impact force and improve the buffering effect.

[0052] The embodiments of this specification propose an open rotor engine, including the load reduction device 10 of the above-mentioned embodiment. In an open rotor engine, the fan blades may be damaged during operation due to external impact or fatigue, thereby causing problems such as increased vibration and swing amplitude of the fan rotor. This will not only lead to stress concentration on the fan shaft, and even cause safety accidents such as broken shaft or serious deformation of the pitch control system, but may also affect the normal operation of the engine. Therefore, a load reduction device 10 is provided in the open rotor engine to achieve a buffering effect on the fan rotor by absorbing the vibration and swing kinetic energy of the fan rotor.

[0053] It should be noted that this specification uses the load shedding device 10 in a traction-configured open rotor engine as an example to illustrate the application of the load shedding device 10. However, this is not limited to the use of the load shedding device 10 in traction-configured open rotor engines. Those skilled in the art may adapt the application of the load shedding device 10 in other types of open rotor engines based on the disclosure of this specification.

[0054] Figure 2 is a schematic diagram of a fan portion of an open rotor engine according to some embodiments. Figure 1 The part shown is Figure 2 Schematic diagram of part A in .

[0055] like Figure 2 As shown, the open rotor engine includes a fan blade 2. The blade shank 3 of the fan blade 2 is mounted on the blade hub 4 through a retaining structure. The blade hub 4 is connected to the fan shaft 5 and is further mounted on the load-bearing casing 7 through a fan bearing 9 and a corresponding supporting cone wall 6. Figure 2In the illustrated traction-configuration open-rotor engine, the intake cone 1 is located at the very front end of the engine, with the fan blades 2 immediately adjacent to it. A small portion of the gas flowing out of the front fan blades 2 passes through the diverter ring assembly and enters the engine interior, while the majority of the gas flows out after being rectified by the fan stators 8, providing thrust for the engine. In some embodiments, the fan blades 2 are typically wide-chord, swept-back blades and are made of composite materials.

[0056] The load reduction device 10 is located between the fan blades 2 and the fan shaft 5 . The load reduction device 10 has certain flexibility and shock-absorbing capabilities, and is used to absorb the vibration and swing kinetic energy of the fan blades 2 and the fan shaft 5 .

[0057] In some embodiments, the load reduction device 10 is located between the support cone wall 6 and the impeller hub 4. The outer frame 11 of the load reduction device 10 extends out of a fixed end, and the load reduction device 10 is connected and fixed to the support cone wall 6 through the fixed end.

[0058] In some embodiments, see Figure 1 and Figure 2 The load shedding device 10 is a prism with a parallelogram cross-section. It includes a first side and a second side. The first side is parallel to (the axial direction of) the impeller hub 4, and the second side is parallel to (the axial direction of) the fan shaft 5. A predetermined gap exists between the first side and the impeller hub 4, and a predetermined gap exists between the second side and the fan shaft 5.

[0059] In some embodiments, rollers 12 are mounted in series on both the first and second sides of the load-reducing device 10. In some embodiments, the rollers 12 on the first side rotate about the axial direction of the impeller hub 4. The rollers 12 on the second side rotate about the axial direction of the fan shaft 5. The rollers 12 rotate under the rotational force of the impeller hub 4 or fan shaft 5, rubbing against and compressing the energy-absorbing material or energy-absorbing structure 13 within the outer frame 11, further reducing the kinetic energy of the impeller hub 4 or fan shaft 5.

[0060] During normal operation of an open rotor engine, a preset clearance exists between the load shedding device 10 and both the fan impeller hub 4 and the fan shaft 5, which does not affect the normal operation of the open rotor. However, if the fan impeller 2 is damaged by external impact or fatigue, the fan rotor vibrates more vigorously, increasing its swing amplitude and causing the impeller hub 4 or fan shaft 5 to swing even more. When the swing radius of the impeller hub 4 or fan shaft 5 exceeds the preset clearance, it will impact the load shedding device 10, triggering the buffer mechanism.

[0061] At this point, the impeller hub 4 or fan shaft 5 will impact the corresponding roller 12 of the load-reducing device 10, causing it to rotate. This rotation of the roller 12 absorbs some of the open rotor's kinetic energy. Furthermore, the impact causes the outer frame 11 of the load-reducing device 10 to undergo significant plastic deformation. Simultaneously, the rotating roller 12 and deformed outer frame 11 compress the energy-absorbing material or energy-absorbing structure 13 within the outer frame 11, further absorbing the open rotor's kinetic energy. This reduces the load transferred from the fan impeller 2 to the load-bearing casing 7, ensuring its safety.

[0062] Moreover, the shape and size of the load reduction device 10 itself can limit the maximum swing radius of the open rotor, so that the maximum stress of the fan shaft 5 is within a safe range, preventing the occurrence of shaft breakage events or inharmonious events such as severe deformation of the variable pitch system, and ensuring engine safety.

[0063] Although in some embodiments, the load reducing device 10 is installed between the fan rotor blades 2 and the fan shaft 5, in other embodiments, the load reducing device 10 may be installed in other locations, such as between the fan bearing 9 and the load-bearing casing, between the fan shaft 5 and the supporting cone wall, etc. The selection of these installation locations can be optimized based on the specific engine structure and cushioning requirements to achieve the best cushioning effect and structural stability.

[0064] The basic concepts have been described above. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of this specification. In addition, unless expressly stated in the claims, the order of elements and sequences, the use of alphanumeric characters, or the use of other names in this specification are not intended to limit the order of the processes and methods in this specification. Although some embodiments of the invention currently considered useful are discussed through various examples in the above disclosure, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this specification.

Claims

1. A load reduction device, characterized in that: The load reduction device comprises: A peripheral frame filled with an energy-absorbing structure or energy-dissipating material for absorbing kinetic energy and achieving shock absorption; The roller is rotatably mounted on the peripheral frame and contacts the energy absorbing structure or the energy dissipating material in the peripheral frame.

2. The load reduction device according to claim 1, characterized in that: The peripheral frame is a parallelogram structure; and the number of the rollers is multiple.

3. The load reduction device according to claim 1, characterized in that: The material of the peripheral frame includes a metal material with high strength and high toughness, so as to be able to undergo plastic deformation under the action of an impact load to absorb kinetic energy.

4. The load reduction device according to claim 3, characterized in that: The metal material with high strength and high toughness includes titanium alloy or nickel-based alloy.

5. The load reduction device according to claim 1, characterized in that: The energy dissipation material includes foamed aluminum, foamed nickel or an elastomer material.

6. The load reduction device according to claim 1, characterized in that: The energy absorbing structure includes a mesh structure, a honeycomb structure, a porous structure or a spring structure.

7. An open rotor engine, characterized in that: The device comprises a load reduction device as claimed in any one of claims 1 to 6.

8. The open rotor engine according to claim 7, characterized in that The open rotor engine includes fan blades, which are mounted on a blade hub, and the blade hub is mounted on a load-bearing casing via a fan shaft, a fan bearing and a corresponding supporting cone wall; The load-reducing device is located between the fan blades and the fan shaft. The outer frame of the load-reducing device extends out a fixed end, and the load-reducing device is connected and fixed to the supporting cone wall through the fixed end.

9. The open rotor engine according to claim 8, characterized in that The load reduction device includes a first side and a second side, the first side is parallel to the impeller hub, the second side is parallel to the fan shaft, and a preset gap is formed between the first side and the impeller hub, and between the second side and the fan shaft; The rollers are arranged in series on both the first side and the second side.

10. The open rotor engine according to claim 9, characterized in that The roller on the first side is capable of generating rotation around the axial direction of the impeller hub; The roller on the second side is capable of generating an axial rotation around the fan shaft.

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