APU air intake damper system

Abstract

An APU air intake damper system, which can increase the length of an air intake damper without changing the opening of an aircraft skin. The APU air intake damper system comprises: an air passage (1); an air intake damper (10) for opening or closing the air passage (1); and an actuator (2) for opening or closing the air intake damper (10), wherein the air intake damper (10) comprises a fixed damper section (5) and a movable damper section (4) capable of extending and retracting relative to the fixed damper section (5); when the air intake damper (10) is closed, the actuator (2) retracts the movable damper section (4) relative to the fixed damper section (5) to shorten the overall length of the air intake damper (10); and when the air intake damper (10) is opened, the actuator (2) extends the movable damper section (4) relative to the fixed damper section (5) to increase the overall length of the air intake damper (10).

Description

APU Intake Damper System Technical Field

[0001] This invention relates to an air intake damper system for an aircraft auxiliary power unit (APU), also known as an APU air intake damper system. Background Technology

[0002] The function of the APU's intake system is to provide the airflow required by the APU under various operating conditions and to reduce pressure loss and intake distortion at the APU inlet, thereby ensuring the normal operation of the APU system. The APU intake damper system is an important component of the APU intake system. Intake dampers are generally located at openings in the aircraft skin. When the auxiliary power unit is operating, the intake dampers are opened by an actuation system. The size of the intake dampers is generally consistent with the opening size of the aircraft skin to reduce aerodynamic drag. Since the size of the aircraft skin opening is usually determined by the air intake duct, the size of the APU intake dampers is limited by the cross-sectional dimensions of the air intake duct.

[0003] The damper actuator is the actuating component that opens and closes the APU intake damper. Typically, the actuator and damper form a swing guide rod mechanism, as shown in Figure 1(a). During damper opening, in addition to the extension of the pull rod, the actuator itself also needs to rotate. The actuator usually needs to pass through the intake duct to act on the damper. However, since the intake system is part of the circumferential firewall of the APU compartment, the actuator often requires fireproof sealing at the passage point. In Figure 1(a), A represents the damper, B represents the actuator pull rod, and C represents the actuator.

[0004] Since the actuator itself needs to rotate, a fireproof cover needs to be added to the outside of the actuator, and flexible seals and other parts need to be added at the point where the lever passes through the cabin to meet the fire protection requirements of the APU cabin, as shown in Figure 1(b). In Figure 1(b), D represents the APU air intake damper, E represents the aircraft skin, F represents the air intake duct, G represents the actuator, and H represents the actuator fireproof cover.

[0005] The existing APU damper actuation system mainly has the following two problems:

[0006] (1) During the flight of the aircraft, due to the existence of the boundary layer, the airflow velocity near the aircraft fuselage is low. At the same time, the length of the APU intake flap is limited by the size of the intake duct. The APU intake flap cannot effectively capture the main incoming flow, which leads to a decrease in the actual intake total pressure recovery coefficient of the APU, thereby affecting the APU's high-altitude start-up and other performance.

[0007] (2) Because the actuator itself needs to rotate, in order to meet the fire protection requirements, it is necessary to add flexible fire protection components such as metal fireproof cover and rubber sealing sleeve to achieve the fire protection function. The fireproof sealing structure at the actuator through the cabin is relatively complex, costly and difficult to install. Summary of the Invention

[0008] In view of the above problems, the purpose of this invention is to provide an APU intake damper system that can increase the length of the intake damper without changing the openings in the aircraft skin.

[0009] Another object of the present invention is to provide an APU intake damper system that can meet the fire protection requirements of actuators through compartment penetration in a simple manner.

[0010] To achieve the above-mentioned objective of the present invention, the present invention provides an APU intake damper system, comprising: an air passage; an intake damper for opening or closing the air passage; and an actuator for opening or closing the intake damper, wherein the intake damper includes a fixed damper section and a movable damper section capable of extending and retracting relative to the fixed damper section; when the intake damper is closed, the actuator retracts the movable damper section relative to the fixed damper section to shorten the overall length of the intake damper; when the intake damper is open, the actuator extends the movable damper section relative to the fixed damper section to increase the overall length of the intake damper.

[0011] According to the APU intake damper system of the present invention, since the intake damper includes a fixed section and a movable section that can extend and retract relative to the fixed section, the length of the intake damper can be increased without changing the opening of the aircraft skin. This is beneficial for the intake damper to capture the incoming airflow, improve the APU intake / ventilation total pressure recovery coefficient, and improve the APU in-flight start-up performance.

[0012] Preferably, the movable section of the damper achieves its extension and retraction relative to the fixed section of the damper by sliding relative to the fixed section of the damper.

[0013] According to the APU intake damper system of the present invention, the extension and retraction of the damper moving section relative to the damper fixed section can be achieved through a simple sliding structure.

[0014] Preferably, a slide rail is provided on the fixed section of the damper, and a slider that can slide on the slide rail is provided on the moving section of the damper.

[0015] According to the APU intake damper system of the present invention, the extension and retraction of the damper moving section relative to the damper fixed section can be achieved through a simple sliding rail and slider cooperation structure.

[0016] Preferably, limiting members are provided at both ends of the slide rail, and the limiting members are used to limit the extension and retraction range of the damper moving section.

[0017] The APU intake damper system according to the present invention can limit the extension and retraction range of the damper moving section relative to the damper fixed section, and prevent the damper moving section from detaching from the damper fixed section.

[0018] Preferably, the actuator has an actuating rod, which is connected to the damper moving section via a ball joint, and the damper moving section extends and retracts as the actuating rod extends and retracts.

[0019] According to the APU intake damper system of the present invention, the movement between the damper fixed section and the damper moving section replaces the rotation of the actuator itself. Therefore, the actuator only needs to perform linear movement during the operation and does not need to rotate. The fire protection requirements of the actuator through the compartment can be met in a simple form without the need to install flexible components such as fireproof covers or rubber seals.

[0020] Preferably, an actuator fixing boss for fixing the actuator is provided in the air intake duct, and the flange on the actuator housing is connected to the actuator fixing boss by fasteners.

[0021] The APU intake damper system according to the present invention can meet the fire protection requirements of the actuator through the compartment by means of a simple metal connection structure. Attached Figure Description

[0022] Figure 1(a) is a schematic diagram illustrating the operating principle of the existing APU intake damper system.

[0023] Figure 1(b) is a schematic diagram showing the structure of an existing APU intake damper system.

[0024] Figure 2 is a front view schematically showing the structure of the APU intake damper system according to an embodiment of the present invention.

[0025] Figure 3 is a side view schematically showing the structure of the APU intake damper system according to an embodiment of the present invention.

[0026] Figure 4 is a schematic diagram showing the connection structure of the damper moving section, the damper fixed section, and the actuator in the APU intake damper system according to an embodiment of the present invention.

[0027] Figure 5 is a cross-sectional view along line AA of Figure 4.

[0028] (Symbol Explanation)

[0029] 100 APU Intake Damper System

[0030] 10. Intake damper

[0031] 11 Opening

[0032] 1. Airway

[0033] 2. Actuator

[0034] 3 Actuator fixing boss

[0035] 4. Air damper moving section

[0036] 5. Fixed section of damper

[0037] 6. Aircraft skin

[0038] 7 Slider

[0039] 8 slide rails

[0040] 9. Actuating lever Detailed Implementation

[0041] Various embodiments of the invention will now be described in detail, examples of which are shown in the accompanying drawings and described below. Although the invention will be described in conjunction with exemplary embodiments, it should be understood that this specification is not intended to limit the invention to those exemplary embodiments. Rather, the invention is intended to cover not only these exemplary embodiments, but also various alternatives, modifications, equivalents, and other embodiments that may be included within the spirit and scope of the invention as defined by the appended claims.

[0042] The APU intake damper system 100 of the present invention will now be described with reference to Figures 2 to 5.

[0043] Figure 2 is a front view schematically showing the structure of the APU intake damper system 100 according to an embodiment of the present invention. Figure 3 is a side view schematically showing the structure of the APU intake damper system 100 according to an embodiment of the present invention. Figure 4 is a schematic diagram schematically showing the connection structure of the damper moving section 4, the damper fixing section 5, and the actuator 2 in the APU intake damper system 100 according to an embodiment of the present invention. Figure 5 is a cross-sectional view along line AA of Figure 4.

[0044] The APU intake damper system 100 of the present invention is used in the auxiliary power unit intake system of an aircraft, as shown in Figures 2-3, and includes: an air passage 1; an intake damper 10 for opening or closing the air passage 1; and an actuator 2 for opening or closing the intake damper 10.

[0045] The air intake duct 1 is located inside the aircraft skin 6 and is used to introduce external air into the APU. An actuator mounting boss 3 is provided in the air intake duct 1 for fixing the actuator 2.

[0046] An opening 11 is provided on the aircraft skin 6 at a position corresponding to the air duct 1. The air intake damper 10 is used to open or close the opening 11, thereby opening or closing the air duct 1. Normally, the air intake damper 10 is open when the APU (Auxiliary Power Unit) is working; otherwise, the air intake damper 10 is closed.

[0047] The intake damper 10 includes, for example, a damper fixed section 5 connected to the aircraft via a pin and a damper movable section 4 that can extend and retract relative to the damper fixed section 5. When the intake damper 10 is closed, the actuator 2 causes the damper movable section 4 to retract relative to the damper fixed section 5, thereby shortening the overall length of the intake damper 10. When the intake damper 10 is open, the actuator 2 causes the damper movable section 4 to extend relative to the damper fixed section 5, thereby increasing the overall length of the intake damper 10.

[0048] In this embodiment, the damper moving section 4 extends and retracts relative to the damper fixed section 5 by sliding relative to the damper fixed section 5. Of course, the present invention is not limited to this, as long as the damper moving section 4 can extend and retract relative to the damper fixed section 5.

[0049] Specifically, in this embodiment, as shown in Figures 4 and 5, slide rails 8 are respectively provided on both sides of the damper fixed section 5, and sliders 7 that can slide on the slide rails 8 are respectively provided on both sides of the damper moving section 4. By sliding the sliders 7 on the slide rails 8, the damper moving section 4 can extend and retract relative to the damper fixed section 5.

[0050] In this embodiment, the slide rail 8 is fixed to the damper fixed section 5, and the damper moving section 4 is connected to the actuator 2 via a ball joint, as described later. This invention allows the movement between the damper fixed section 5 and the damper moving section 4 to replace the rotation of the actuator 2 itself, so that the actuator 2 only needs to perform linear motion without rotation.

[0051] In addition, protrusions or other limiting components can be set at both ends of the slide rail 8 to play a mechanical limiting role, which is used to limit the maximum position of the extension or shortening of the damper moving section 4, that is, to limit the extension and contraction range of the damper moving section 4.

[0052] Of course, the structure in which the moving section 4 of the damper slides relative to the fixed section 5 is not limited to this, and there are many different structural forms of the slide rail and slider. Figure 5 is just one typical combination, as long as it allows the moving section 4 of the damper to slide relative to the fixed section 5. For example, a slider can be provided on the fixed section 5 of the damper, while a slide rail can be provided on the moving section 4 of the damper. That is, a slide rail can be provided on one of the fixed section 5 and the moving section 4 of the damper, and a slider that can slide on the slide rail can be provided on the other.

[0053] As shown in Figures 2 and 3, the actuator 2 passes through the intake duct 1 and acts on the intake damper 10, causing the intake damper 10 to open or close. In this embodiment, the actuator 2 has an actuating rod 9, which is connected to the damper moving section 4 via a ball joint. The damper moving section 4 extends and retracts with the extension and retraction of the actuating rod 9. When the intake damper 10 is open, the actuating rod 9 of the actuator 2 extends, and the sliders 7 on both sides of the damper moving section 4 extend along the slide rails 8 on both sides of the damper fixed section 5. Conversely, when the intake damper 10 is closed, the actuating rod 9 of the actuator 2 shortens, and the sliders 7 on both sides of the damper moving section 4 shorten along the slide rails 8 on both sides of the damper fixed section 5.

[0054] That is, during the opening or closing of the intake damper 10, the actuator rod 9 of the actuator 2 extends or shortens, and the damper moving section 4 extends / shortens relative to the damper fixed section 5. During this process, the actuator 2 does not need to rotate.

[0055] The flange on the housing of actuator 2 is connected to the actuator mounting boss 3 of the air intake duct 1 by fasteners such as screws. At this time, the material and thickness of actuator mounting boss 3, as well as the type and spacing of fasteners, meet the fire resistance test requirements specified in AC20-135 (Federal Aviation Administration Regulations), and detailed descriptions are omitted here.

[0056] Actuator 2 passes through air intake 1, and fireproof sealing is required at this penetration point. In this embodiment, since actuator 2 does not need to rotate, fireproof sealing can be achieved by a fixed method (connected with fasteners). Therefore, the fireproof requirements for actuator 2 through the compartment can be met by a simple metal connection structure, without the need for flexible components such as fireproof covers or rubber seals.

[0057] (Technical effects of the embodiments of the present invention)

[0058] (1) The present invention provides a retractable air intake damper 10, that is, the air intake damper 10 includes a damper fixed section 5 and a damper movable section 4 that can extend and retract relative to the damper fixed section 5. Therefore, the length of the air intake damper 10 can be increased without changing the opening 11 of the aircraft skin 6, which is beneficial for the air intake damper 10 to capture the incoming flow, improve the APU intake / ventilation total pressure recovery coefficient, and improve the APU in-flight start-up performance.

[0059] (2) The actuation method of the air intake damper 10 in this invention makes it possible for the actuator 2 to operate without rotating. Therefore, the fire protection requirements of the cabin can be met through a simple metal connection structure, saving parts such as metal covers.

[0060] (3) The air intake door 10 proposed in this invention is an optimization of the common air intake door. It does not require changing the structure of the aircraft body. It is only necessary to replace the existing air intake door with the retractable air intake door 10. It is easy to implement on existing aircraft and has strong practicality.

[0061] (Modified Example)

[0062] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above embodiments.

[0063] (1) In the above embodiment, the damper moving section 4 overlaps with the damper fixed section 5 inside, and the length of the damper moving section 4 is shorter than the length of the damper fixed section 5. When the intake damper 10 is closed, the opening 11 is closed by the damper fixed section 5. However, it is not limited to this. As long as the intake damper 10 includes the damper fixed section 5 and the damper moving section 4, the length of the intake damper 10 when the opening 11 is open is longer than the length of the intake damper 10 when the opening 11 is closed.

[0064] (2) The damper moving section 4 can extend and retract relative to the damper fixed section 5. Its extension and retraction method is not limited to sliding, but can also be other methods.

[0065] While the structure and working principle of the present invention have been described above with reference to preferred embodiments, those skilled in the art should recognize that the above examples are merely illustrative and should not be construed as limiting the invention. Therefore, modifications and variations can be made to the invention within the spirit and scope of the claims, and all such modifications and variations will fall within the scope claimed by the claims.

Claims

1. An APU intake damper system, comprising: airway; An intake damper that opens or closes the air passage; as well as An actuator that opens or closes the air intake damper. Its features are, The air intake damper includes a fixed damper section and a movable damper section that can extend and retract relative to the fixed damper section. When the intake damper is closed, the actuator retracts the moving section of the damper relative to the fixed section, thereby shortening the overall length of the intake damper. When the air intake damper is opened, the actuator causes the damper moving section to extend relative to the damper fixed section, thereby increasing the overall length of the air intake damper.

2. The APU intake damper system as described in claim 1, characterized in that, The movable section of the damper extends or retracts relative to the fixed section of the damper by sliding relative to the fixed section of the damper.

3. The APU intake damper system as described in claim 2, characterized in that, A slide rail is provided on the fixed section of the damper, and a slider that can slide on the slide rail is provided on the moving section of the damper.

4. The APU intake damper system as described in claim 3, characterized in that, Limiting elements are provided at both ends of the slide rail, which are used to limit the extension and retraction range of the damper moving section.

5. The APU intake damper system as described in claim 1, characterized in that, The actuator has an actuating lever. The actuating rod is connected to the damper moving section via a ball joint, and the damper moving section extends and retracts as the actuating rod extends and retracts.

6. The APU intake damper system as described in claim 1, characterized in that, An actuator mounting boss for fixing the actuator is provided in the air intake duct. The flange on the actuator housing is connected to the actuator mounting boss by fasteners.

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