Turbofan engine thrust reverser blocker door and its actuating mechanism

Abstract

The present invention provides a turbofan engine reverse thrust damper and an actuating mechanism thereof. The actuating mechanism adopts a gear-rack motion transmission structure to transmit the fixed-axis rotation of the gear into the planar curved motion of the rack, thereby realizing the folding and unfolding of the damper with edge strips arranged on the panel. The damper panel is provided with edge strips. From a structural perspective, the panel rigidity can be increased to resist the large deflection deformation caused by the strong airflow during the lowering of the damper; from an aerodynamic perspective, the premature separation of the airflow can be suppressed to enhance the aerodynamic drag reduction characteristics during the lowering of the damper. The damper actuating mechanism greatly reduces the complexity of the mechanism and the driving load of the mechanism movement. All related parts of the mechanism are not connected to the core hood part of the nacelle, which not only facilitates the disassembly and maintenance of the nacelle, but also optimizes the air intake characteristics of the nacelle outer duct and improves the accuracy of the damper movement.

Description

Technical Field

[0001] The present invention relates to the technical field of reverse thrust of aviation engines, in particular to a reverse thrust choke of a turbofan engine and an actuating mechanism for the reverse thrust choke of the turbofan engine. Background Art

[0002] As high-bypass turbofan engine technology matures, the thrust reverser, a crucial component of large aircraft nacelles, reduces the aircraft's rolling distance during normal landings by redirecting the airflow flowing into the outer duct. This positive effect is particularly pronounced on wet or semi-dry runways. Furthermore, the thrust reverser can also assist in aborting takeoff in an emergency.

[0003] Currently, the mainstream cascade thrust reverser system is widely used in high-bypass ratio engines. The thrust reverser choke and its motion mechanism are the primary unit for switching between the engine's forward and reverse thrust modes. The choke is lowered from its stowed state to its deployed state by driving the motion mechanism, thereby blocking the outer duct over a large area and causing the outer duct airflow to be diverted, thereby generating reverse thrust. The prior art offers numerous solutions for thrust reverser choke mechanisms. First, the mainstream pull-rod choke utilizes a rod mechanism between the core cowling and the outer moving cowling. This affects engine intake performance during forward thrust and increases the difficulty of separating the cowling during maintenance operations. Second, the pull-rod motion mechanism connecting the inner and outer cowlings also reduces the acoustic treatment area. A choke motion mechanism has also been proposed, in which the choke's retraction and extension are controlled by an actuating cylinder mounted on the door. While this solution eliminates the technical difficulties associated with the pull-rod mechanism, it undoubtedly increases the drive burden on the powertrain.

[0004] Therefore, it is desired to have a new technical solution to solve or alleviate at least one technical problem existing in the above prior art. Summary of the Invention

[0005] In order to solve at least some of the defects of the reverse thrust damper and its motion mechanism in the prior art, the present invention proposes a reverse thrust damper for a turbofan engine and its actuating mechanism. The actuating mechanism adopts a gear-rack motion transmission structure to transmit the fixed-axis rotation of the gear into the planar curved motion of the rack, thereby realizing the folding and unfolding of the damper with edge strips arranged on the panel.

[0006] The technical solution of the present invention is:

[0007] A turbofan engine thrust reverser choke comprises a panel facing the airflow in the duct of the turbofan engine and a back plate facing away from the airflow. The choke is special in that:

[0008] The panel is provided with two or more edge strips protruding from the panel. The edge strips extend along the airflow direction and are symmetrically arranged about the central axis of the baffle in a direction perpendicular to the airflow direction. The two ends of the edge strips in the airflow direction are streamlined structures.

[0009] Furthermore, a cross section of the edge strip in a direction perpendicular to the airflow direction is in a parabolic shape.

[0010] Furthermore, in a direction perpendicular to the airflow direction, the ribs closer to the outside have a longer length and a larger cross-section than the ribs closer to the inside.

[0011] Furthermore, a cross section of the edge strip in a direction perpendicular to the airflow direction is gradually tapered along the airflow direction.

[0012] Furthermore, the number of the edge strips is four or six.

[0013] An actuating mechanism for a reverse thrust choke of a turbofan engine according to the above-mentioned embodiment, wherein the actuating mechanism is characterized in that it comprises: a driving unit, a frame unit and a motion unit;

[0014] The driving unit includes a driving member, a rotating shaft and a connecting rod, wherein the driving member is used to drive the rotating shaft to rotate, and the connecting rod is used to connect the rotating shaft;

[0015] The frame unit includes a nacelle frame, a frame support and a rotating shaft support. The frame support and the rotating shaft support are fixed to the nacelle frame. The rotating shaft support is used to support the rotating shaft.

[0016] The motion unit includes a gear, an arc-shaped seat with an arc-shaped rack, a hinge and a door support, the gear is sleeved on the rotating shaft to rotate with the rotating shaft, the gear is engaged with the arc-shaped rack, and the hinge and the door support are fixed to the back plate of the blocking door;

[0017] The arc seat is connected to the hinge, and the door support is connected to the frame support via a pin shaft, so that when the arc rack moves, the blocker door can rotate relative to the nacelle frame, thereby moving between the stowed position and the deployed position.

[0018] Furthermore, the hinged member is a first U-shaped spring leaf, and the motion unit also includes a second U-shaped spring leaf and a third U-shaped spring leaf; the second U-shaped spring leaf and the third U-shaped spring leaf are installed to the back plate of the blocker door, so that when the blocker door is in the expanded position, the arc seat contacts both the second U-shaped spring leaf and the third U-shaped spring leaf.

[0019] Furthermore, the connecting rod is a universal joint transmission connecting rod.

[0020] Furthermore, the actuating mechanism further includes a limiting unit, which includes:

[0021] The bracket is U-shaped and has a crossbar and two legs, the two legs of the bracket are fixed to the shaft support, and the arc seat is located between the two legs;

[0022] The sleeve bearing is sleeved on the crossbar of the bracket, and a gap is left between the sleeve bearing and the arc seat.

[0023] Furthermore, a plurality of baffle doors and actuating mechanisms are arranged in a one-to-one correspondence along the circumference of the nacelle frame to form an annular structure.

[0024] The beneficial effects of the present invention are:

[0025] 1. The spoiler panel is equipped with edge strips. From a structural perspective, the edge strips can increase the panel rigidity to resist the large deflection deformation caused by the strong airflow during the lowering of the spoiler. From an aerodynamic perspective, the edge strips can inhibit the premature separation of the airflow to enhance the aerodynamic drag reduction characteristics during the lowering of the spoiler.

[0026] 2. The choke door actuation mechanism adopts a gear-rack motion transmission structure, which transmits the fixed-axis rotation of the gear into the planar curved motion of the rack, greatly reducing the complexity of the mechanism and the driving load of the mechanism movement. All related parts of the mechanism are not connected to the core hood of the nacelle, which not only facilitates the disassembly and maintenance of the nacelle, but also optimizes the air intake characteristics of the nacelle outer duct and improves the accuracy of the choke door movement.

[0027] 3. U-shaped spring pieces are arranged at three points on the back panel of the choke door. They not only provide elastic movement margin for the retraction and extension of the choke door, but also under reverse thrust conditions, when strong airflow acts on the choke door, on the one hand, the U-shaped spring pieces can weaken the additional bending moment borne by the arc seat. On the other hand, the U-shaped spring pieces further compensate for the inaccurate movement caused by design and manufacturing errors, and avoid the occurrence of failure behaviors such as jamming and twisting of the actuating mechanism.

[0028] 4. The universal joint transmission link set between the two actuating mechanisms ensures the synchronization of the choke door's rotation. At the same time, the easy-to-disassemble transmission link also reduces the difficulty of maintaining the actuating mechanism.

[0029] 5. The limit unit of the actuating mechanism prevents the gear and rack from disengaging when the mechanism moves, ensuring smooth and reliable motion transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The features and advantages of the present invention will become more readily understood through the following description with reference to the accompanying drawings, which are not drawn to scale and in which some features are exaggerated or minimized to show details of particular components.

[0031] Figure 1is a perspective schematic diagram of a reverse thrust choke of a turbofan engine and its actuating mechanism according to an exemplary embodiment of the present invention;

[0032] Figure 2A is a front view of a thrust reverser choke of a turbofan engine according to an exemplary embodiment of the present invention;

[0033] Figure 2B is a perspective schematic diagram of a reverse thrust choke of a turbofan engine according to an exemplary embodiment of the present invention;

[0034] Figure 2C is a perspective schematic diagram of a reverse thrust blocker of a turbofan engine according to an exemplary embodiment of the present invention viewed from another angle;

[0035] Figure 3 is a perspective schematic diagram of a portion of an actuating mechanism for a reverse thrust choke of a turbofan engine according to an exemplary embodiment of the present invention, illustrating the actuating principle of the actuating mechanism;

[0036] Figure 4A is a front view of a turbofan engine thrust reverser blocker door and its actuating mechanism according to an exemplary embodiment of the present invention, showing the blocker door in a deployed position, when viewed from a panel of the blocker door;

[0037] Figure 4B is a perspective schematic diagram showing a turbofan engine thrust reverser blocker door and its actuating mechanism according to an exemplary embodiment of the present invention, with the blocker door in a deployed position, when viewed from a back panel of the blocker door;

[0038] Figure 5A is an enlarged perspective schematic diagram of a portion of an actuating mechanism for a reverse thrust choke of a turbofan engine according to an exemplary embodiment of the present invention, showing a first U-shaped spring leaf in the actuating mechanism;

[0039] Figure 5B is an enlarged perspective schematic diagram of a portion of an actuating mechanism for a reverse thrust choke door of a turbofan engine according to an exemplary embodiment of the present invention, showing a second U-shaped spring leaf and a third U-shaped spring leaf in the actuating mechanism;

[0040] Figure 6 It is a perspective schematic diagram of a limiting unit in an actuating mechanism for a reverse thrust choke of a turbofan engine according to an exemplary embodiment of the present invention.

[0041] Reference numerals:

[0042] 1-turbofan engine reverse thrust choke, 101-face plate, 102-back plate, 103-first edge strip, 104-second edge strip, CC-center axis;

[0043] 2- driving unit, 201- rotating shaft, 202- connecting rod;

[0044] 3-frame unit, 301-nacelle frame, 302-frame support, 303-rotating shaft support;

[0045] 4 - Motion unit, 401 - Gear, 402 - Arc-shaped rack; 403 - Arc-shaped seat, Cover plate - 4031, Bump - 4032, 404 - Hinge, 4041 - Hinge hole, 405 - Door support, 4051 - Cylindrical portion, 407 - Second U-shaped spring piece, 4071 - Hole for second U-shaped spring piece, 408 - Third U-shaped spring piece, 4081 - Hole for third U-shaped spring piece;

[0046] 5-limiting unit, 501-bracket, 5011-cross bar, 5012-support leg, 502-sleeve bearing. DETAILED DESCRIPTION

[0047] The present invention will be described in detail below with reference to the accompanying drawings by way of exemplary embodiments of the present invention. It should be noted that the following detailed description of the present invention is for illustrative purposes only and is not intended to limit the present invention. In addition, the same reference numerals are used throughout the accompanying drawings to represent the same components.

[0048] First refer to Figure 1 The turbofan engine reverse thrust choke and its actuating mechanism provided by the present invention are generally described. Figure 1 It is a three-dimensional schematic diagram of a reverse thrust choke of a turbofan engine and its actuating mechanism according to an exemplary embodiment of the present invention.

[0049] like Figure 1 As shown, a turbofan engine thrust reverser blocker 1, as an exemplary embodiment of the present invention, and an actuating mechanism for a turbofan engine thrust reverser blocker, as an exemplary embodiment of the present invention, can be assembled together in a one-to-one correspondence and arranged in plurality along the circumference of the nacelle frame to form an annular structure. Preferably, ten blockers 1 are arranged, but this is not intended to limit the present invention. For example, eight, nine, etc., blockers 1 may be arranged. However, preferably, the number of blockers 1 is an even number so that the internal spatial structure of the nacelle in which the blockers 1 are installed is vertically symmetrical.

[0050] Now refer to Figures 2A to 2C The reverse thrust choke of the turbofan engine provided by the present invention is described in detail. Figure 2A FIG. 1 is a front view of a thrust reverser choke of a turbofan engine according to an exemplary embodiment of the present invention. Figure 2B 2 is a perspective schematic diagram of a reverse thrust choke of a turbofan engine according to an exemplary embodiment of the present invention. Figure 2CIt is a perspective schematic diagram of a reverse thrust choke of a turbofan engine according to an exemplary embodiment of the present invention, viewed from another angle.

[0051] Figure 2A The arrows in FIG show the flow direction of the airflow in the outer duct of the turbofan engine, which is referred to as the airflow direction hereinafter. Figures 2A to 2C As an exemplary embodiment of the present invention, the reverse thrust blocker 1 of the turbofan engine can be roughly in the shape of a trapezoid, with the upper base of the trapezoid located upstream in the airflow direction and the lower base of the trapezoid located upstream in the airflow direction. Figure 2A As shown in FIG, the choke door 1 may have a central axis CC in a direction perpendicular to the air flow direction.

[0052] like Figures 2A to 2C As shown, the spoiler 1 may include a panel 101 facing the airflow in the outer duct of the turbofan engine and a back plate 102 facing away from the airflow, and the panel 101 is an aerodynamic surface that meets aerodynamic requirements.

[0053] See also Figure 2A Panel 101 is equipped with two or more flanges 103 and 104 protruding from it. These flanges 103 and 104 extend along the airflow direction and are symmetrically arranged about central axis CC. The ends of flanges 103 and 104 facing the airflow direction are streamlined. From a structural perspective, these flanges serve as reinforcement ribs to increase the rigidity of the spoiler panel, thereby resisting the large deflection caused by the strong airflow during the lowering of the spoiler 1. From an aerodynamic perspective, these flanges, with their unique shape, act like "vortex generators," inhibiting premature airflow separation and thereby enhancing the aerodynamic drag reduction characteristics of the spoiler 1 during its lowering.

[0054] In the illustrated embodiment of the present invention, the edge strips provided on the air blocking door 1 include an edge strip 103 located relatively inner in a direction perpendicular to the airflow direction and an edge strip 104 located relatively outer in a direction perpendicular to the airflow direction. In some exemplary embodiments, the cross-sections of the edge strips 103 and 104 in a direction perpendicular to the airflow direction may be substantially parabolic.

[0055] In some embodiments, the shape and size of ribs 103 and 104 may be identical, but the present invention is not limited thereto. Preferably, ribs 103 and 104 have different lengths, with rib 104 being longer than rib 103. Also preferably, ribs 103 and 104 have different cross-sectional dimensions perpendicular to the airflow direction, with rib 104 having a larger cross-sectional dimension perpendicular to the airflow direction than rib 103. Particularly preferably, ribs 104 positioned more toward the outside, perpendicular to the airflow direction, are longer and have a larger cross-sectional dimension than ribs 103 positioned more toward the inside.

[0056] In addition, in an exemplary embodiment of the present invention, the cross-sections of the edge strips 103 and 104 in a direction perpendicular to the airflow direction may be tapered along the airflow direction.

[0057] In addition, the number of edge strips provided on the blocker door 1 is preferably four or six, but this does not limit the present invention. For example, the number of edge strips may be eight, nine or more.

[0058] Next refer to Figures 3 to 4B The actuating mechanism of the reverse thrust choke of a turbofan engine provided by the present invention is described in detail. Figure 3 It is a perspective schematic diagram of a portion of an actuating mechanism for a reverse thrust choke door of a turbofan engine according to an exemplary embodiment of the present invention, illustrating the actuating principle of the actuating mechanism. Figure 4A 1 is a front view of a turbofan engine thrust reverser blocker door and an actuating mechanism thereof according to an exemplary embodiment of the present invention, showing the blocker door in a deployed position, when viewed from a panel of the blocker door. Figure 4B 1 is a perspective schematic diagram showing a turbofan engine thrust reverser blocker and its actuating mechanism according to an exemplary embodiment of the present invention, with the blocker in a deployed position, when viewed from a back plate of the blocker.

[0059] Return to reference Figure 1 As an exemplary embodiment of the present invention, an actuating mechanism for a turbofan engine thrust reverser choke 1 may include a driving unit 2 , a frame unit 3 and a motion unit 4 .

[0060] like Figure 1As shown, the drive unit 2 may include a drive member, a rotating shaft 201 and a connecting rod 202. The drive member not shown in the figure is used to drive the rotating shaft 201 to rotate, and the connecting rod 202 is used to connect the rotating shaft 201. The drive member may be electrically driven, such as a motor, or hydraulically driven, and the present invention is not limited to this. In some embodiments of the present invention, the connecting rod 202 arranged between the two actuating mechanisms is a universal joint transmission connecting rod, which ensures the synchronization of the rotation of the damper 1. At the same time, the transmission connecting rod that is easy to disassemble also reduces the difficulty of maintaining the actuating mechanism. However, the connecting rod 202 can be redesigned according to actual needs. For example, a flexible and decomposable universal joint can be used at the end of the rod to meet actual work needs.

[0061] like Figure 1 and Figure 3 As shown, the frame unit 3 may include a nacelle frame 301, a frame support 302, and a shaft support 303. The frame support 302 and the shaft support 303 are fixed to the nacelle frame 301, and the shaft support 303 is used to support the shaft 201. As shown, the frame support 302 and the shaft support 303 are located on both sides of the nacelle frame 301 in the airflow direction.

[0062] Now refer to Figure 4A In the embodiment shown in the present invention, each actuating mechanism is provided with two rotating shaft supports 303 arranged symmetrically about the central axis CC. The two rotating shaft supports 303 are offset by a certain distance in the circumferential direction, so that the span of the rotating shaft 201 can be reduced, which greatly reduces the deformation of the rotating shaft 201. Figure 3 It can be seen that in some embodiments, the shaft support 303 may include a cylindrical portion, a plate portion, and a rod portion connecting the cylindrical portion and the plate portion. The cylindrical portion is used to allow the shaft 201 to pass through to support the shaft 201. For example, a bearing can be sleeved on the shaft 201 and then accommodated in the cylindrical portion. The plate portion contacts the nacelle frame 301 and has holes for screws to pass through to secure the shaft support 303 to the nacelle frame 301. However, the shape, number, and connection method of the shaft support 303 to the nacelle frame 301 are not limited thereto.

[0063] Now refer to Figure 4B In the illustrated embodiment of the present invention, each secondary actuating mechanism is equipped with two frame supports 302, but the number of frame supports 302 is not specifically limited. As shown, the frame supports 302 may be generally U-shaped, having a disc-shaped portion and two legs. The disc-shaped portion contacts the nacelle frame 301 and has holes for screws to pass through, securing the frame support 302 to the nacelle frame 301. The legs are used to sandwich the pins described below. However, the shape of the frame supports 302 and the method of connection to the nacelle frame 301 are not limited to this.

[0064] Combined with reference Figure 1 、 Figure 3 and Figure 4A and Figure 4B The motion unit 4 may include a gear 401, an arcuate seat 403 with an arcuate rack 402, a hinge 404, and a door support 405. The gear 401 may be sleeved on the rotating shaft 201 to rotate together with the rotating shaft 201, and the gear 401 meshes with the arcuate rack 402. The hinge 404 and the door support 405 are fixed to the back plate 102 of the blocking door 1.

[0065] like Figure 4B As shown, the arcuate seat 403 may include a cover plate 4031 for covering the axial end of the arcuate rack 402 with respect to the gear 401. The arcuate seat 403 may also be provided with a streamlined convex hump 4032 at the end opposite the end connected to the choke door 1. The convex hump 4032 may be fixed to the cover plate 4031. The streamlined convex hump structure at the windward end of the arcuate seat 403 significantly reduces airflow resistance at the windward end of the arcuate seat when the choke door is stowed under forward thrust conditions.

[0066] like Figure 1 and Figure 4B It can be seen that the hinge 404 is used to connect the arc seat 403 to the blocker door 1. In the illustrated embodiment of the present invention, the hinge 404 is located in the lower middle portion of the blocker door 1 in the direction of the central axis CC, and is approximately located in the middle portion of the blocker door 1 in the direction perpendicular to the central axis CC, but this is merely an example and is not intended to limit the present invention.

[0067] As from Figure 4B As can be seen, in the illustrated embodiment of the present invention, two door supports 405 are provided corresponding to the frame supports 302. As shown, the door support 405 may have a disc-shaped portion and a cylindrical portion 4051. The disc-shaped portion contacts the blocker door 1 and has a hole for a screw to pass through to fix the door support 405 to the blocker door 1. The cylindrical portion 4051 allows the aforementioned pin to pass through to connect the frame support 302 and the door support 405 so that the door support 405 can rotate relative to the frame support 302.

[0068] The arc seat 403 is connected to the hinge 404, and the door support 405 is connected to the frame support 302 via a pin shaft, so that when the arc rack 402 moves, the blocker door 1 can rotate relative to the nacelle frame 301, thereby moving between the stowed position and the deployed position.

[0069] Next refer to Figures 5A to 5B The U-shaped spring piece in the actuating mechanism of the reverse thrust choke of a turbofan engine provided by the present invention is described in detail. Figure 5AIt is an enlarged perspective schematic diagram of a portion of an actuating mechanism for a reverse thrust choke door of a turbofan engine according to an exemplary embodiment of the present invention, showing a first U-shaped spring leaf in the actuating mechanism. Figure 5B It is an enlarged perspective schematic diagram of a portion of an actuating mechanism for a reverse thrust choke door of a turbofan engine according to an exemplary embodiment of the present invention, showing a second U-shaped spring leaf and a third U-shaped spring leaf in the actuating mechanism.

[0070] like Figure 5A As shown, the hinge 404 can be a U-shaped spring leaf, hereinafter referred to as a first U-shaped spring leaf. One leg of the first U-shaped spring leaf is used to connect with the arc seat 403, and the other leg is provided with a hole 4041 for fixing the first U-shaped spring leaf to the blocking door 1.

[0071] As in Figure 4B and Figure 5B As shown in FIG, the motion unit 4 may further include a second U-shaped spring piece 407 and a third U-shaped spring piece 408 .

[0072] See also Figure 5B The second U-shaped spring piece 407 and the third U-shaped spring piece 408 can be mounted to the back plate 102 of the blocker door 1, specifically by screws passing through the holes 4071 and 4081 provided on the second U-shaped spring piece 407 and the third U-shaped spring piece 408, respectively, to fix them to the blocker door 1, so that when the blocker door 1 is in the deployed position, the arc seat 403 contacts both the second U-shaped spring piece 407 and the third U-shaped spring piece 408, and in particular, the middle position of the length portion of the arc seat 403 in the direction of the central axis CC is respectively at Figure 5B The position indicated by the one-way arrow in FIG. 1 is in contact with both the second U-shaped spring piece 407 and the third U-shaped spring piece 408. The second U-shaped spring piece 407 and the third U-shaped spring piece 408 are in contact with each other. Figure 5B In this way, three U-shaped spring pieces are arranged on the back plate 102 of the choke door 1, namely, a first U-shaped spring piece, a second U-shaped spring piece, and a third U-shaped spring piece. This not only provides elastic movement margin for the retraction and extension of the choke door, but also, under reverse thrust conditions, when strong airflow acts on the choke door, on the one hand, reduces the additional bending moment borne by the arc seat, and on the other hand, further compensates for the inaccurate movement caused by design and manufacturing errors, thereby avoiding failure behaviors such as sticking and twisting of the actuating mechanism.

[0073] The actuating mechanism for the reverse thrust blocker of a turbofan engine according to the present invention may further include a limiting unit 5. Figure 6 A limiting unit in an actuating mechanism for a reverse thrust choke of a turbofan engine according to an exemplary embodiment of the present invention is described in detail. Figure 6 It is a perspective schematic diagram of a limiting unit in an actuating mechanism for a reverse thrust choke of a turbofan engine according to an exemplary embodiment of the present invention.

[0074] like Figure 6 As shown, the limiting unit 5 may include a bracket 501 and a sleeve bearing 502 .

[0075] The bracket 501 may be U-shaped and have a crossbar 5011 and two legs 5012. The two legs 5012 of the bracket 501 may be fixed to the two shaft supports 303, in particular, to the cylindrical portions of the shaft supports 303. The arc seat 403 may be located between the two legs 5012.

[0076] The sleeve bearing 502 can be sleeved on the crossbar 5011 of the bracket 501 , and a small movement gap can be left between the sleeve bearing 502 and the arc seat 403 .

[0077] The configuration of the limiting unit 5 in the actuating mechanism for the reverse thrust choke of a turbofan engine according to the present invention is not limited to this, as long as it prevents the gear from disengaging from the arcuate rack during mechanism movement. The limiting unit in the actuating mechanism prevents disengagement between the gear and rack during mechanism movement, ensuring smooth and reliable motion transmission. Furthermore, if a failure of one of the motion mechanisms causes the gear and rack to disengage, the easily disassembled transmission link prevents direct impact on the movement of other chokes.

[0078] Now return to reference Figure 3 The operating principle of the reverse thrust choke door and its actuating mechanism of the turbofan engine provided by the present invention is described. When the choke door 1 is in the retracted position, the entire actuating mechanism is located behind the lip of the duct, and the duct of the turbofan engine is open. In the reverse thrust starting state, when the driving member is started and drives the rotating shaft 201 along the duct, the duct 201 is opened. Figure 3 When the blocker 1 rotates in the clockwise direction, that is, in the direction of the solid arrow, the gear 401 rotates clockwise together with the rotating shaft 201, and the arc-shaped rack 402 meshing with the gear 401 performs a planar curved motion in the clockwise direction. The hinge 404 connected to the arc-shaped seat 403 with the arc-shaped rack 402 transmits the planar motion to the blocker 1, thereby lowering the blocker 1 to the deployed position. When the blocker 1 is in the deployed position, the blocker 1 blocks and closes the outer duct of the turbofan engine. When the reverse thrust condition is changed to the forward thrust condition, the movement process of the blocker 1 in the deployed position to the stowed position is opposite to the above-mentioned deployment process. For example, Figure 3 The direction of the dotted arrow is shown in FIG, and will not be repeated here.

[0079] As described above, the actuating mechanism for the reverse thrust choke of a turbofan engine provided by the present invention adopts a gear-rack motion transmission structure, which transmits the fixed-axis rotation of the gear into the planar curved motion of the rack, greatly reducing the complexity of the mechanism and the driving load of the mechanism movement. All related components of the mechanism have no connection with the core hood part of the nacelle, which not only facilitates the disassembly and maintenance of the nacelle, but also optimizes the air intake characteristics of the nacelle outer duct and improves the accuracy of the choke movement.

[0080] The features mentioned and / or illustrated in the above description of the exemplary embodiments of the present invention may be incorporated into one or more other embodiments in the same or similar manner, combined with the features in other embodiments, or substituted for the corresponding features in other embodiments. The technical solutions obtained by such combination or substitution shall also be deemed to be included in the scope of protection of the present invention.

Claims

1. A thrust reverser choke for a turbofan engine, the choke comprising a panel facing an airflow in a duct of the turbofan engine and a back panel facing away from the airflow, the choke being characterized by: The panel is provided with two or more edge strips protruding from the panel, the edge strips extending along the airflow direction and symmetrically arranged about the central axis of the baffle in a direction perpendicular to the airflow direction, and the two ends of the edge strips in the airflow direction are streamlined structures.

2. The turbofan engine thrust reverser according to claim 1, characterized in that: The cross section of the edge strip in a direction perpendicular to the airflow direction is in a parabolic shape.

3. The turbofan engine thrust reverser according to claim 2, characterized in that: In a direction perpendicular to the air flow direction, the edge strips farther from the central axis have a longer length and a larger cross-section than the edge strips closer to the central axis.

4. The turbofan engine reverse thrust blocker according to claim 1 or 2, characterized in that: A cross section of the edge strip in a direction perpendicular to the airflow direction tapers along the airflow direction.

5. The reverse thrust blocker for a turbofan engine according to claim 1 or 2, characterized in that: The number of the edge strips is four or six.

6. An actuating mechanism for a reverse thrust block valve of a turbofan engine according to any one of claims 1 to 5, wherein the actuating mechanism comprises: Drive unit, frame unit and motion unit; The driving unit includes a driving member, a rotating shaft and a connecting rod, wherein the driving member is used to drive the rotating shaft to rotate, and the connecting rod is used to connect the rotating shaft; The frame unit includes a nacelle frame, a frame support, and a rotating shaft support, wherein the frame support and the rotating shaft support are fixed to the nacelle frame, and the rotating shaft support is used to support the rotating shaft; The motion unit includes a gear, an arc-shaped seat with an arc-shaped rack, a hinge and a door support, the gear is sleeved on the rotating shaft to rotate together with the rotating shaft, the gear is engaged with the arc-shaped rack, and the hinge and the door support are fixed to the back plate of the blocking door; The arc seat is connected to the hinge, and the door support is connected to the frame support via a pin shaft, so that when the arc rack moves, the blocker door can rotate relative to the nacelle frame, thereby moving between a stowed position and a deployed position.

7. The actuating mechanism according to claim 6, characterized in that: The hinge is a first U-shaped spring leaf, and the motion unit further comprises a second U-shaped spring leaf and a third U-shaped spring leaf; The second U-shaped spring piece and the third U-shaped spring piece are mounted to the back plate of the blocker door so that when the blocker door is in the deployed position, the arcuate seat contacts both the second U-shaped spring piece and the third U-shaped spring piece.

8. The actuating mechanism according to claim 6 or 7, characterized in that: The connecting rod is a universal joint transmission connecting rod.

9. The actuating mechanism according to claim 6 or 7, characterized in that It also includes a limiting unit, which includes: a bracket, the bracket being U-shaped and having a crossbar and two legs, the two legs of the bracket being fixed to the shaft support, and the arc-shaped seat being located between the two legs; A sleeve bearing is sleeved on the crossbar of the bracket, and a gap is left between the sleeve bearing and the arc seat.

10. The actuating mechanism according to claim 6 or 7, characterized in that: A plurality of the blocker doors and the actuating mechanisms are arranged along the circumference of the nacelle frame in a one-to-one correspondence to form an annular structure.

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