Ram air turbine release shock mitigating device and aircraft

Abstract

This invention relates to a ram air turbine release shock mitigation device and an aircraft. The ram air turbine release shock mitigation device includes a frame installed between the aircraft fuselage and the actuator of the ram air turbine. The longitudinal direction of the frame is aligned with the aircraft's heading. The frame has five mounting portions for mounting to the aircraft fuselage. The first and second mounting portions are located at the front of the frame, while the third, fourth, and fifth mounting portions are located at the rear. The longitudinal centerline of the frame and the longitudinal centerline of the actuator are located in the same vertical plane. The first and second mounting portions are symmetrically arranged with respect to the longitudinal centerline of the frame, as are the third and fourth mounting portions. The fifth mounting portion is located on the longitudinal centerline of the frame.

Description

Technical Field

[0001] This invention relates to a ram air turbine release shock mitigation device and an aircraft including the ram air turbine release shock mitigation device. Background Technology

[0002] The ram air turbine (RAT) system is an emergency power generation system for aircraft, providing emergency AC power to the aircraft in the event of a dual-engine failure. Currently, the RAT system is recovered into the RAT compartment during normal flight. In the event of a dual-engine failure, it is released into the airflow via actuators, utilizing the aircraft's kinetic energy to provide emergency electrical power. The design of the RAT compartment, in addition to ensuring uninterrupted recovery and release, must also consider the impact of the release impact load on the compartment's structural strength. To accommodate excessively large release impact loads, the compartment needs to be reinforced. Large impact loads make the compartment extremely heavy, significantly impacting the aircraft's fuel economy. Summary of the Invention

[0003] One object of the present invention is to provide a ram air turbine release impact mitigation device that can overcome at least some of the defects of the prior art, effectively reduce the impact load on the body baffle during the release impact, and thus reduce the weight of the ram air turbine compartment baffle.

[0004] The above-mentioned objective of the present invention is achieved by a ram air turbine release impact mitigation device, which includes a frame installed between the aircraft fuselage and the actuator of the ram air turbine. The longitudinal direction of the frame is consistent with the flight direction of the aircraft. The frame is provided with five mounting parts for mounting to the aircraft fuselage. The first and second mounting parts are located on the front side of the frame, and the third, fourth, and fifth mounting parts are located on the rear side of the frame. The longitudinal centerline of the frame and the longitudinal centerline of the actuator are located in the same vertical plane. The first and second mounting parts are symmetrically arranged with respect to the longitudinal centerline of the frame, and the third and fourth mounting parts are also symmetrically arranged with respect to the longitudinal centerline of the frame. The fifth mounting part is located on the longitudinal centerline of the frame.

[0005] According to the above technical solution, the ram air turbine release impact mitigation device of the present invention can achieve the following beneficial technical effects: it can effectively reduce the impact load on the body baffle during the release impact, thereby reducing the weight of the ram air turbine compartment baffle.

[0006] Preferably, the frame is rectangular, with the first mounting part, the second mounting part, the third mounting part and the fourth mounting part located at the four vertices of the rectangle, and the fifth mounting part located at the midpoint of the short side of the rectangle.

[0007] Preferably, the ram air turbine release impact mitigation device further includes a bracket, which is fixedly connected within the frame, and the bracket is X-shaped.

[0008] Preferably, when the frame is rectangular, the support is composed of two struts that coincide with the two diagonals of the rectangle.

[0009] Preferably, the ram air turbine release impact mitigation device further includes a booster spring, one end of which is connected to the center point of the bracket, and the other end is connected to the actuator.

[0010] Preferably, the center point of the support coincides with the center point of the frame.

[0011] Preferably, the aspect ratio of the rectangle is 2.0 to 3.0:1.

[0012] Preferably, the frame is made of an impact-resistant metal material.

[0013] Preferably, the support is made of metal.

[0014] The above-mentioned objectives of the present invention are also achieved by an aircraft comprising a ram air turbine release shock mitigation device as described in any of the above aspects.

[0015] According to the above technical solution, the aircraft of the present invention can achieve the following beneficial technical effects: it can effectively reduce the impact of the impact load on the fuselage baffle during the release impact, thereby reducing the weight of the ram air turbine nacelle baffle. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the ram air turbine release impact mitigation device before release, according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the ram air turbine release impact mitigation device according to an embodiment of the present invention after release.

[0018] List of reference numerals

[0019] 1: Framework;

[0020] 2: Bracket;

[0021] 3: Power assist spring;

[0022] 10: Actuator;

[0023] 11: First Installation Section;

[0024] 12: Second Installation Section;

[0025] 13: Third Installation Department;

[0026] 14: Fourth Installation Department;

[0027] 15: Fifth Installation Department;

[0028] A: Course. Detailed Implementation

[0029] The following describes specific embodiments of the present invention. It should be noted that, in order to provide a concise description, this specification cannot exhaustively describe all features of the actual embodiments. It should be understood that, in the actual implementation of any embodiment, just as in any engineering or design project, various specific decisions are often made to achieve the developer's specific goals and to meet system-related or business-related constraints, and this can change from one embodiment to another. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, some design, manufacturing, or production modifications based on the technical content disclosed herein are merely conventional technical means and should not be construed as insufficient content of this disclosure.

[0030] Unless otherwise defined, the technical or scientific terms used in the claims and description shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in the patent application description and claims of this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the element or object preceding "comprising" or "including" encompasses the element or object listed following "comprising" or "including" and its equivalents, and do not exclude other elements or objects. The terms "connected" or "linked" and similar terms are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections.

[0031] In the following description, in order to clearly demonstrate the structure and operation of the present invention, a number of directional terms will be used. However, terms such as "front," "rear," "left," "right," "outer," "inner," "outward," "inward," "up," and "down" should be understood as convenient terms and not as limiting terms. In particular, it should be noted that "front" and "rear" are determined according to the heading of the aircraft.

[0032] Figure 1This is a schematic diagram of the ram air turbine release impact mitigation device before release, according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the ram air turbine release impact mitigation device according to an embodiment of the present invention after release.

[0033] This invention relates to a ram air turbine release impact mitigation device. In existing technology, ram air turbines are normally retracted into the ram air turbine housing and released into the airflow automatically or manually in emergency situations. During the release process, the ram air turbine generates a very large impact load. Based on experience with civil aircraft products, it is estimated that the maximum release impact force of a ram air turbine and actuator, with a total weight of approximately 75 kg, is between 35,000 and 45,000 N.

[0034] Because the existing technology only has one mounting point at the interface between the actuator and the body, the stress (impact load / contact area) of the installation structure under dynamic release impact conditions is extremely high. At the same time, according to the design requirements, considering a safety factor of 1.5, the baffle of the ram air turbine compartment is designed to withstand 1.5 times the maximum impact force on the contact surface. The extremely high impact load means that the ram air turbine compartment needs to be reinforced with baffles to offset the impact load on the compartment.

[0035] like Figures 1 to 2 As shown, an embodiment of the ram air turbine release impact mitigation device of the present invention includes a frame 1, which is installed between the aircraft fuselage and the actuator 10 of the ram air turbine. The longitudinal direction of the frame 1 is consistent with the heading A of the aircraft. The frame 1 is provided with five mounting parts (also called mounting points) for mounting to the aircraft fuselage. The first mounting part 11 and the second mounting part 12 are located on the front side of the frame 1, and the third mounting part 13, the fourth mounting part 14 and the fifth mounting part 15 are located on the rear side of the frame 1. The longitudinal centerline of the frame 1 and the longitudinal centerline of the actuator 10 are located in the same vertical plane. The first mounting part 11 and the second mounting part 12 are symmetrically arranged with respect to the longitudinal centerline of the frame 1, the third mounting part 13 and the fourth mounting part 14 are also symmetrically arranged with respect to the longitudinal centerline of the frame 1, and the fifth mounting part 15 is located on the longitudinal centerline of the frame 1.

[0036] According to the above technical solution, the ram air turbine release impact mitigation device of the present invention can achieve the following beneficial technical effects: it can effectively reduce the impact load on the body baffle during the release impact, thereby reducing the weight of the ram air turbine compartment baffle.

[0037] Specifically, this invention uses a frame to distribute the force originally borne by one mounting section into five mounting sections. This further reduces the load on each mounting section, thereby reducing the weight of the ram air turbine nacelle baffle. This invention reduces the impact load to 55% of its original value and the baffle thickness to 50-55%, thus achieving a baffle weight reduction of 8-10 kg. Considering the equipment itself weighs 2.5 kg, the overall weight reduction is 6-8 kg.

[0038] In some embodiments, such as Figures 1 to 2 As shown, the frame 1 is rectangular, with the first mounting part 11, the second mounting part 12, the third mounting part 13 and the fourth mounting part 14 located at the four vertices of the rectangle, and the fifth mounting part 15 located at the midpoint of the short side of the rectangle.

[0039] Of course, the above-mentioned frame shape (rectangular) is only a preferred form of the frame used in the ram air turbine release impact mitigation device of this application. Those skilled in the art can understand, based on the disclosure of this application, that other suitable frame shapes (e.g., runway shape, ellipse, etc.) can also be used without departing from the protection scope of the claims of this application.

[0040] In some embodiments, such as Figures 1 to 2 As shown, the ram air turbine release impact mitigation device also includes a bracket 2, which is fixedly connected within the frame 1. The bracket 2 is X-shaped. That is, the four vertices of the X-shaped bracket 2 are located at the first mounting part 11, the second mounting part 12, the third mounting part 13, and the fourth mounting part 14, respectively. Due to the bracket's placement within the frame, the impact load can be better transferred from the actuator to the frame via the bracket. Furthermore, the five-point mounting frame can further effectively reduce the impact load on the fuselage baffle during release impact, thereby reducing the weight of the ram air turbine compartment baffle.

[0041] In some embodiments, such as Figures 1 to 2 As shown, when frame 1 is rectangular, support 2 consists of two struts coinciding with the two diagonals of the rectangle. By using appropriate frame and support designs, the impact load on the fuselage baffles during the release impact can be further and effectively reduced, thereby reducing the weight of the ram air turbine nacelle baffles.

[0042] In some embodiments, such as Figures 1 to 2As shown, the ram air turbine release impact mitigation device also includes a booster spring 3. One end of the booster spring 3 is connected to the center point of the bracket 2, and the other end is connected to the actuator 10. When the booster spring is in the retracted state, it is in a compressed state. At the moment of release, the actuator experiences a greater downward force than without the booster spring (estimated to increase by 1500N). This increased force further shortens the direct release time of the ram air turbine (estimated to shorten by 0.2s). The ram air turbine power supply time consists of the direct release time, turbine start-up time, and grid switching time. Shortening the direct release time of the ram air turbine can shorten the power restoration time under dual-engine failure conditions, improving system safety. Simultaneously, the upward reaction force of the booster spring in the compressed state is borne by the five mounting parts of the frame, thus further reducing the load.

[0043] According to strength simulation tests, the maximum interface load after the invention is 20,000 N. Considering the assist spring, the maximum load under the most stringent calculation is approximately 23,000 N, which is significantly reduced compared to the maximum load of 35,000-45,000 N in the prior art. In the released state of the ram air turbine of this invention, the assist spring is in its normal state (non-extended). According to the locking mechanism of the ram air turbine system, the ram air turbine system starts rotating within a range of 6-8° from the fully released position. At the fully released position, the lower lock of the actuator engages, and the assist spring does not apply force to the ram air turbine body. Therefore, the assist spring in this invention has no effect on the locking of the ram air turbine in the fully released position.

[0044] The ram air turbine system recovery process in this invention is consistent with the ram air turbine system recovery process of most aircraft models. It usually uses aircraft hydraulic pressure recovery. During the recovery process, the assist spring is gradually adjusted from the normal state to the compressed state. The upper position lock is locked at the fully recovered position. This invention does not affect the current ram air turbine system recovery.

[0045] The failure mode of the booster spring, fracture, does not affect the original release time of the ram air turbine, and therefore does not affect safety.

[0046] This invention is expected to reduce the release time by 0.2s. The current release time and hydraulic pressure recovery time are the design time of the hydraulic accumulator. The current pressurization time of the accumulator of a certain aircraft model is less than 10s, and the dry weight is less than 6kg. If the weight of the hydraulic oil itself is taken into account, the current reduction of the release time by more than 0.2s can further reduce the weight of the accumulator (including hydraulic oil) by 0.5kg, thereby achieving equipment weight reduction.

[0047] In some embodiments, such as Figures 1 to 2As shown, the center point of bracket 2 coincides with the center point of frame 1. That is, the center of mass of bracket 2 coincides with the center of mass of frame 1. Through the above technical solution, the impact load on the fuselage baffle during the release impact can be further effectively reduced, thereby reducing the weight of the ram air turbine compartment baffle.

[0048] In some embodiments, such as Figures 1 to 2 As shown, the aspect ratio of the rectangle (rectangular frame) is 2.0 to 3.0:1. By using a suitable aspect ratio of the rectangular frame, the impact of the impact load on the fuselage baffle during the release impact can be further and effectively reduced, thereby reducing the weight of the ram air turbine nacelle baffle.

[0049] In some embodiments, such as Figures 1 to 2 As shown, frame 1 is made of impact-resistant metal material, such as alloy steel or high-density carbon steel, for impact resistance.

[0050] In some embodiments, such as Figures 1 to 2 As shown, bracket 2 is made of metal material, such as ordinary stainless steel, and is used to fix the shape of the frame.

[0051] The innovations and beneficial technical effects of the ram air turbine release impact mitigation device of the present invention are mainly as follows:

[0052] (1) The present invention designed a release impact mitigation device and verified through strength simulation calculation that it can reduce the maximum impact load on the body to 55% of the original maximum impact load, with a significant effect.

[0053] The device itself weighs approximately 2.5 kg, but the increased number of mounting points reduces the impact load at each mounting point, thus lowering the impact risk to the baffle. Preliminary estimates based on strength data suggest that the ram air turbine compartment baffle can reduce weight by approximately 6-8 kg (taking a typical ram air turbine and actuator with a total weight of approximately 75 kg as an example), achieving weight reduction across the entire machine.

[0054] (2) The addition of the booster spring further shortens the release time, thereby reducing the time to restore power in emergency situations and improving aircraft safety.

[0055] The release time is further reduced. Based on the current release time of less than 1.6 seconds (taking a typical ram air turbine and actuator with a total weight of about 75 kg as an example), the release time can be reduced by about 12.5%.

[0056] According to one embodiment of the present invention, an aircraft includes a ram air turbine release impact mitigation device as described in any of the above aspects. Based on the above technical solution, the aircraft of the present invention can achieve the following beneficial technical effects: it can effectively reduce the impact load on the fuselage baffle during the release impact, thereby reducing the weight of the ram air turbine nacelle baffle.

[0057] The specific embodiments of the present invention have been described above. However, those skilled in the art will understand that the above specific embodiments do not constitute a limitation on the present invention. Those skilled in the art can make various modifications based on the above disclosure without exceeding the scope of the present invention.

Claims

1. A ram air turbine release impact mitigation device, the ram air turbine release impact mitigation device comprising a frame, the frame being installed between an aircraft fuselage and an actuator of a ram air turbine, the longitudinal direction of the frame being aligned with the aircraft's heading, and the frame being provided with five mounting portions for mounting to the aircraft fuselage, wherein, The first and second mounting parts are located on the front side of the frame, and the third, fourth and fifth mounting parts are located on the rear side of the frame. The longitudinal centerline of the frame and the longitudinal centerline of the actuator are located in the same vertical plane. The first and second mounting parts are arranged symmetrically with respect to the longitudinal centerline of the frame, and the third and fourth mounting parts are also arranged symmetrically with respect to the longitudinal centerline of the frame. The fifth mounting part is located on the longitudinal centerline of the frame. The ram air turbine release impact mitigation device also includes a bracket, which is fixedly connected within the frame. The bracket is X-shaped, and the center point of the bracket coincides with the center point of the frame. The ram air turbine release impact mitigation device also includes a booster spring, one end of which is connected to the center point of the bracket, and the other end is connected to the actuator.

2. The ram air turbine shock release mitigation device of claim 1, wherein, The frame is rectangular, with the first mounting part, the second mounting part, the third mounting part, and the fourth mounting part located at the four vertices of the rectangle, and the fifth mounting part located at the midpoint of the short side of the rectangle.

3. The ram air turbine shock release mitigation device of claim 1, wherein, The frame is rectangular, and the support is composed of two struts that coincide with the two diagonals of the rectangle.

4. The ram air turbine release impact mitigation device as described in claim 2, characterized in that, The aspect ratio of the rectangle is 2.0 to 3.0:

1.

5. The ram air turbine shock reduction release apparatus of claim 1, wherein, The frame is made of impact-resistant metal material.

6. The ram air turbine shock reduction release apparatus of claim 1, wherein, The support is made of metal.

7. An aircraft comprising a ram air turbine release shock mitigation device as claimed in any one of claims 1-6.

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