Helicopter double-motion-track fairing

Abstract

The invention provides a helicopter double-motion-track fairing, and belongs to the technical field of helicopter structural design, in the helicopter double-motion-track fairing, a fairing body is connected with a rear supporting column and a front supporting column through a movable control mechanism; the rear strut and the front strut are connected with the fuselage through a hinge mechanism; a pulley in the pulley slide rail mechanism is fixed on the fairing body, and a slide rail in the pulley slide rail mechanism is fixed on the fuselage; a bolt in the bolt mechanism is fixed on the fairing body, and a bolt seat in the bolt mechanism is fixed on a fuselage; one end of the steel cable is connected with the fairing body; the locking mechanism is fixed on the fairing body; the first section of motion trail in the motion trail of the fairing is the motion trail of the fairing along the pulley and sliding rail mechanism, the motion trail of the upper portion of the fairing is limited, and collision between the fairing and blades and a propeller hub is avoided; and the second section of movement track is the rotating track of the rotating shaft of the hinge mechanism, enough space is provided for the opening angle of the fairing, and disassembly and assembly of internal equipment are completed.

Description

Technical Field

[0001] The present invention belongs to the technical field of helicopter structural design, and particularly relates to a helicopter fairing with a double motion trajectory. Background Art

[0002] Equipment such as a main speed reducer and an engine are installed in the power cabin of a helicopter. Due to the maintenance, disassembly, and assembly requirements of the equipment, the fairing of the power cabin must be designed as an openable fairing.

[0003] In the prior art, there are two ways to open the fairing: one is to rotate and open around the hinge or hinge at the bottom of the fairing, and the other is to slide and open along the slide rail; the fairing that rotates and opens around the rotating shaft has a big defect that if the rotation radius is too large, it will collide with the upper blades and blade hubs during the opening process; while the fairing that slides and opens along the slide rail cannot provide enough space to complete the disassembly and assembly of the internal equipment. Summary of the Invention

[0004] In order to solve the technical problems that the fairing is prone to collide with the blades and blade hubs during opening and cannot provide enough space to complete the disassembly and assembly of the internal equipment in the prior art, the present invention provides a fairing with a double motion trajectory. The first motion trajectory is the trajectory of the fairing moving along a straight slide rail, which restricts the motion trajectory of the upper part of the fairing and avoids collision with the blades and blade hubs; the second motion trajectory is the trajectory of the fairing rotating along the rotating shaft, which ensures that the opening angle of the fairing provides enough space to complete the disassembly and assembly of the internal equipment; and when the movable cover is closed, by arranging the bolt and the locking mechanism, the trampling requirements of maintenance personnel are met. The technical solution is as follows:

[0005] In a first aspect, a helicopter fairing with a double motion trajectory is provided, including: a fairing body 1, two movable control mechanisms 2, a rear support 3, a front support 4, two hinge mechanisms 5, a pulley slide rail mechanism 6, a bolt mechanism 7, a locking mechanism 8, and a steel cable 9.

[0006] The fairing body 1 is respectively connected to the rear support 3 and the front support 4 through two movable control mechanisms 2; the rear support 3 and the front support 4 are respectively connected to the fuselage through two hinge mechanisms 5; the pulley in the pulley slide rail mechanism 6 is fixed on the fairing body 1, and the slide rail in the pulley slide rail mechanism 6 is fixed on the fuselage; the bolt in the bolt mechanism 7 is fixed on the fairing body 1, and the bolt seat in the bolt mechanism 7 is fixed on the fuselage; one end of the steel cable 9 is connected to the fairing body 1, and the other end is connected to the fuselage; the locking mechanism 8 is fixed on the fairing body 1 for locking the fairing; the motion trajectory of the fairing includes a first motion trajectory and a second motion trajectory. The first motion trajectory is the trajectory of the fairing moving based on the pulley slide rail mechanism 6, and the second motion trajectory is the trajectory of the fairing rotating based on the rotating shaft of the hinge mechanism 5.

[0007] The first-stage movement trajectory is the trajectory of the fairing moving along the pulley slide rail mechanism 6, which restricts the movement trajectory of the upper part of the fairing and avoids collisions with the blades and the hub; the second-stage movement trajectory is the trajectory of the rotation of the rotating shaft of the hinge mechanism 5, ensuring that the opening angle of the fairing provides sufficient space to complete the disassembly and assembly of the internal equipment; and when the movable cover is closed, by arranging bolts and locking mechanisms, the trampling requirements of maintenance personnel are met.

[0008] Among them, each movable control mechanism 2 is composed of an upper joint 21, an intermediate connecting member 23, a lower joint 22, and a long sleeve 24;

[0009] The long sleeve 24 and the upper joint 21 are in interference fit to ensure that the long sleeve 24 and the upper joint 21 are fixedly connected; the intermediate connecting member 23 is installed on the long sleeve 24, and there is a clearance fit between them, so that the intermediate connecting member 23 can rotate flexibly around the long sleeve 24;

[0010] The upper joint 21 is connected to the lower joint 22; the two mounting holes of the lower joint 22 are designed as concentric holes so that the upper joint 21 can rotate flexibly;

[0011] After the lower joints 22 of the two movable control mechanisms 2 are assembled, concentricity is ensured to ensure that the fairing body can rotate flexibly around the axis of the lower joint mounting hole.

[0012] Among them, the rear strut 3 and the front strut 4 have the same structure, both of which are integrally formed composite material structures with a square tube cross-section. Selecting composite material molding compared with the metal riveting structure, the process method is simple, the weight is reduced, and the surface quality is greatly improved.

[0013] Among them, each hinge mechanism 5 is composed of an upper hinge joint 51, a lower hinge joint 52, and an intermediate rotating shaft 53. The upper hinge joint 51 is fixedly connected to the rear strut 4 and the lower hinge joint 52 is fixedly connected to the fuselage by rivets; the upper hinge joint 51 and the lower hinge joint 52 are connected by the rotating shaft 53 and can rotate around the rotating shaft 53; and the rotating shafts of the two hinge mechanisms are coaxial.

[0014] Among them, the pulley slide rail mechanism 6 is composed of a slide rail 61 and a pulley assembly 62; the slide rail 61 is a C-shaped cross-section structure, which is connected to the fuselage by countersunk screws 63. The slide rail is provided with a lower groove 64 and an upper opening 65; the pulley assembly is composed of a pulley 69, a variable cross-section rotating shaft 66, and a self-lubricating bushing 67. The pulley 69 is fixed on the fairing body 1 by the variable cross-section rotating shaft 66 and a self-locking nut 68;

[0015] The slide rail 61 restricts the movement trajectory of the fairing body 1 by restricting the freedom degree of the pulley assembly 62 in the Z direction. The Z direction is perpendicular to the course; the pulley assembly 62 rolls in the slide rail 61 to ensure that the movement of the fairing at the pulley in the initial stage is a linear movement;

[0016] When the pulley assembly 62 rolls to the lower groove 64 at the rear of the slide rail 61, the pulley stops here, and the two movable control mechanisms 2 are operated; when the fairing rotates and opens, the pulley mechanism 62 smoothly disengages from the slide rail 61 through the upper opening 65 at the rear of the slide rail.

[0017] The bolt mechanism 7 consists of a bolt 71, a bolt seat 73, a peelable gasket 74, and a bolt seat pressing plate 75; the rear part of the bolt 71 is designed with a thread and is fixed to the fairing body 1 through a slotted nut 72; the bolt seat 73 is fixed to the fuselage through the bolt seat pressing plate 75 and a bolt 76. The inner diameter of the bolt seat pressing plate 75 is slightly larger than the outer diameter of the bolt seat 73, which can ensure that the bolt seat 73 can be finely adjusted in the plane, making it easier for the bolt 71 to be inserted into the bolt seat, and can ensure that the bolt seat 73 is convenient to replace after wear;

[0018] The bolt mechanism 7 restricts the degrees of freedom of the fairing in a plane perpendicular to the axis of the bolt 71; the axis of the locking mechanism 8 is parallel to the axis of the bolt 71 and is used to restrict the degrees of freedom of the fairing in the direction of the bolt axis; the movement of the fairing is completely restricted by the bolt mechanism 7 and the locking mechanism 8.

[0019] The fairing body 1 is a composite material sandwich structure, with the sandwich being honeycomb and foam. The foam is filled in the rounded corner area of the fairing body 1, and the honeycomb fills the remaining areas. The honeycomb and the foam are bonded together with foaming glue, ensuring the strength and stiffness of the fairing body 1 and meeting the requirements for maintenance personnel to step on.

[0020] The upper joint 21 and the lower joint 22 are connected by long bolts 25 and self-locking nuts 26 in the area close to the aircraft contour;

[0021] The upper joint 21 and the lower joint 22 are connected by two groups of hexagon head bolts 27 and slotted nuts 28 in the area far from the aircraft contour, where the length of the plain shank part of the hexagon head bolt is greater than the thickness of the middle sandwich.

[0022] The beneficial effects of the present invention are at least as follows:

[0023] 1. By reasonably designing and arranging the positions of the pulley and the slide rail, the radius of the fairing rotating and opening is restricted, avoiding the collision between the edge of the fairing and the hub and the blades when opening;

[0024] 2. By adding a bolt mechanism, the requirement for stepping on the fairing when it is closed is met;

[0025] 3. By operating the movable control mechanism, the movable cover can be transformed between two motion trajectories, and each motion trajectory is uniquely determined;

[0026] 4. When the movable cover is closed, even if the locking mechanism fails, the bolt mechanism can ensure that the movable cover remains closed, providing a safety protection measure and enhancing the safety of the helicopter during flight. Brief Description of the Drawings

[0027] Figure 1 It is a side view of the double-movement trajectory movable fairing structure;

[0028] Figure 2 It is a top view of the double-movement trajectory movable fairing structure;

[0029] Figure 3 It is a schematic structural diagram of the movable control mechanism;

[0030] Figure 4 It is a schematic cross-sectional view of the outside of the movable control mechanism;

[0031] Figure 5 It is a schematic cross-sectional view of the inside of the movable control mechanism;

[0032] Figure 6 It is a schematic structural diagram of the pulley and slide rail mechanism;

[0033] Figure 7 It is a schematic cross-sectional view of the pulley mechanism;

[0034] Figure 8 It is a schematic cross-sectional view of the bolt mechanism;

[0035] Figure 9 It is a schematic diagram of the rear hinge mechanism;

[0036] Figure 10 It is a schematic diagram of the end position of the first section of the fairing trajectory;

[0037] Figure 11 It is a schematic diagram of the pulley and slide rail mechanism at the end position of the first section of the fairing trajectory;

[0038] Figure 12 It is a schematic diagram of the movable control mechanism at the end position of the first section of the fairing trajectory;

[0039] Figure 13 It is a schematic diagram of the fully opened fairing body. Detailed Embodiments

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0041] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0042] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other, and the various embodiments may refer to and quote each other.

[0043] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] The embodiment of the present invention provides a double motion track fairing, the first motion track is the track of the fairing moving along the straight slide rail, which limits the motion track of the upper part of the fairing to avoid collision with the blades and the propeller hub; the second motion track is the track of the fairing rotating along the shaft, which ensures that the opening angle of the fairing provides enough space to complete the disassembly and assembly of the internal equipment; and when the movable cover is closed, the latch and locking mechanism are arranged to meet the stepping requirements of the maintenance personnel. The details are as follows:

[0045] See also Figure 1 , Figure 2 , Figure 13 A helicopter double motion track fairing includes: a fairing body 1, two movable control mechanisms 2, a rear support 3, a front support 4, two hinge mechanisms 5, a pulley and slide rail mechanism 6, a latch mechanism 7, a locking mechanism 8, and a steel cable 9.

[0046] The fairing body 1 is connected to the rear strut 3 and the front strut 4 respectively through two active control mechanisms 2; the rear strut 3 and the front strut 4 are connected to the fuselage through two hinge mechanisms 5 respectively; the pulley in the pulley-rail mechanism 6 is fixed on the fairing body 1, and the rail in the pulley-rail mechanism 6 is fixed on the fuselage; the bolt in the bolt mechanism 7 is fixed on the fairing body 1, and the socket in the bolt mechanism 7 is fixed on the fuselage; one end of the steel cable 9 is connected to the fairing body 1, and the other end is connected to the fuselage; the locking mechanism 8 is fixed on the fairing body 1 for locking the fairing; the movement trajectory of the fairing includes a first movement trajectory and a second movement trajectory. The first movement trajectory is the trajectory of the fairing moving based on the pulley-rail mechanism 6, and the second movement trajectory is the trajectory of the fairing rotating around the rotating shaft of the hinge mechanism 5.

[0047] The first movement trajectory is the trajectory of the fairing moving along the pulley-rail mechanism 6, which restricts the movement trajectory of the upper part of the fairing and avoids collision with the blades and the hub; the second movement trajectory is the trajectory of the rotating shaft of the hinge mechanism 5 rotating, which ensures that there is enough space for the opening angle of the fairing to complete the disassembly and assembly of the internal equipment; and when the movable cover is closed, by arranging bolts and locking mechanisms, the trampling requirements of maintenance personnel are met.

[0048] Please refer to Figure 3 、 Figure 4 、 Figure 5 Each active control mechanism 2 is composed of an upper joint 21, an intermediate connector 23, a lower joint 22, and a long sleeve 24;

[0049] The long sleeve 24 and the upper joint 21 are in interference fit to ensure that the long sleeve 24 and the upper joint 21 are fixedly connected; the intermediate connector 23 is installed on the long sleeve 24, and there is a clearance fit between them, so that the intermediate connector 23 can rotate flexibly around the long sleeve 24;

[0050] The upper joint 21 is connected to the lower joint 22; the two mounting holes of the lower joint 22 are designed as concentric holes so that the upper joint 21 can rotate flexibly;

[0051] The upper joint 21 and the lower joint 22 are connected by a long bolt 25 and a self-locking nut 26 in the area close to the aircraft contour;

[0052] The upper joint 21 and the lower joint 22 are connected by two groups of hexagon head bolts 27 and grooved nuts 28 in the area far from the aircraft contour, where the length of the shank part of the hexagon head bolt is greater than the thickness of the intermediate sandwich. After the lower joints 22 of the two active control mechanisms 2 are assembled, they are ensured to be concentric, ensuring that the fairing body can rotate flexibly around the axis of the lower joint mounting hole.

[0053] The rear strut 3 and the front strut 4 have the same structure, both are integrally formed composite structures with a square tube cross-section. Selecting composite material forming instead of metal riveting structure has a simple process method, reduced weight and greatly improved surface quality; Selecting composite material forming instead of metal riveting structure has a simple process method, reduced weight and a large improvement in surface quality.

[0054] Please refer to Figure 9 , each hinge mechanism 5 consists of an upper hinge joint 51, a lower hinge joint 52, and an intermediate rotating shaft 53. The upper hinge joint 51 is fixedly connected to the rear strut 4 and the lower hinge joint 52 is fixedly connected to the fuselage by rivets; The upper hinge joint 51 and the lower hinge joint 52 are connected by the rotating shaft 53 and can rotate around the rotating shaft 53; Moreover, the rotating shafts of the two hinge mechanisms are coaxial.

[0055] Please refer to Figure 6 , Figure 7 , Figure 11 , the pulley-rail mechanism 6 consists of a rail 61 and a pulley assembly 62; The rail 61 has a C-shaped cross-section structure and is connected to the fuselage by countersunk screws 63. The rail is provided with a lower groove 64 and an upper opening 65; The pulley assembly consists of a pulley 69, a variable cross-section rotating shaft 66, and a self-lubricating bushing 67. The pulley 69 is fixed to the fairing body 1 by the variable cross-section rotating shaft 66 and a lock nut 68;

[0056] The rail 61 restricts the movement trajectory of the fairing body 1 by restricting the freedom of the pulley assembly 62 in the Z direction, and the Z direction is perpendicular to the course; The pulley assembly 62 rolls in the rail 61 to ensure that the movement of the fairing at the pulley in the initial stage is a linear movement;

[0057] When the pulley assembly 62 rolls to the lower groove 64 at the rear of the rail 61, the pulley stops here and operate the two movable control mechanisms 2; When the fairing rotates and opens, the pulley mechanism 62 smoothly disengages from the rail 61 through the upper opening 65 at the rear of the rail.

[0058] Please refer to Figure 8 , the pin mechanism 7 consists of a pin 71, a pin seat 73, a peelable gasket 74, and a pin seat pressing plate 75; The rear part of the pin 71 is designed with a thread and is fixed to the fairing body 1 by a slotted nut 72; The pin seat 73 is fixed to the fuselage by the pin seat pressing plate 75 and a bolt 76. The inner diameter of the pin seat pressing plate 75 is slightly larger than the outer diameter of the pin seat 73, which can ensure the in-plane fine adjustment of the pin seat 73, facilitate the easier insertion of the pin 71 into the pin seat, and can ensure the convenient replacement after the wear of the pin seat 73;

[0059] The latch mechanism 7 restricts the degrees of freedom of the fairing in a plane perpendicular to the axis of the latch pin 71; the axis of the locking mechanism 8 is parallel to the axis of the latch pin 71 and is used to restrict the degrees of freedom of the fairing in the direction of the latch pin axis; the movement of the fairing is completely restricted by the latch mechanism 7 and the locking mechanism 8.

[0060] The fairing body 1 is a composite sandwich structure, with the sandwich being honeycomb and foam. The foam is filled in the rounded corner area of the fairing body 1, and the honeycomb is filled in the remaining area. The honeycomb and the foam are bonded together with foaming adhesive, ensuring the strength and stiffness of the fairing body 1 and meeting the requirements for maintenance personnel to step on.

[0061] The working principle of the fairing in the embodiment of the present invention is as follows:

[0062] State 1: The fairing is in the closed state, see Figure 1 、 Figure 2 。

[0063] The locking mechanism 8 is in the locked state, the latch pin 71 is inserted into the latch socket 73, and the pulley mechanism 62 is disengaged from the slide rail 61; the long bolt 25 connects the upper joint 21 and the lower joint 22 together;

[0064] State 2: The fairing opens according to the first movement trajectory, see Figure 10 。

[0065] Preparation work: Open the locking mechanism 8 and at the same time remove the long bolt 25 of the two active control mechanisms 2.

[0066] Pull the fairing body 1, and the pulley mechanism 62 on the fairing body 1 makes a linear motion in the slide rail 61 along the plane of the slide rail. The rear strut 3 and the front strut 4 rotate along the rotating shaft 53. The upper joint 21 on the fairing body 1 and the lower joint 22 on the strut can rotate along the axis of the bolt 27. At this time, the movement of the fairing is uniquely determined;

[0067] State 3: The fairing opens according to the second movement trajectory.

[0068] Preparation work: When the pulley mechanism 62 slides into the lower groove 64 of the slide rail, the fairing is in a temporary static state, see shown in 11; through the removed long bolt 25 on the two active control mechanisms 2, connect the lower joint 22 and the intermediate connecting member 23. At this time, the fairing body 1 is fixedly connected to the rear strut 3 and the front strut 4, see Figure 12 。

[0069] Pull the fairing body 1, and the fairing body 1 rotates along the rotating shaft 53 of the hinge mechanism 5. The pulley mechanism 62 disengages from the upper opening 65 of the slide rail 61. At this time, the movement of the fairing is uniquely determined;

[0070] Status 4: The fairing body 1 is fully opened and is pulled by a steel cable 9. See Figure 13 .

[0071] Status 5: The fairing closes along the motion trajectory 2. See Figure 10 .

[0072] Push the fairing body 1, and the fairing body 1 rotates along the rotating shaft 53 of the hinge mechanism 5. When the pulley mechanism 62 enters from the upper opening 65 of the slide rail 61 and contacts the lower groove 64 of the slide rail, the fairing body 1 stops moving;

[0073] Status 6: The fairing closes along the motion trajectory 1. See Figure 1 .

[0074] Preparation work: Remove the long bolts 25 of the two movable control mechanisms 2.

[0075] Push the fairing body 1, and the pulley mechanism 62 on the fairing body 1 makes a linear motion along the plane of the slide rail 61 in the slide rail. The rear strut 3 and the front strut 4 rotate along the rotating shaft 53. The upper joint 21 on the fairing 1 and the lower joint 22 on the strut can rotate along the axis of the bolt 27. At this time, the motion of the fairing is uniquely determined;

[0076] Status 7: The fairing is closed. See Figure 1 , Figure 2 .

[0077] Lock the locking mechanism 8, and at the same time connect the upper joint 21 and the lower joint 22 together with the long bolt 25.

[0078] The above only expresses the implementation manners of the present invention. The description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. In addition, the parts not detailed in the present invention are all conventional techniques.

Claims

1. A helicopter double-motion trajectory fairing, characterized in that Comprising: Fairing body (1), two active control mechanisms (2), rear struts (3), front struts (4), two hinge mechanisms (5), pulley-rail mechanism (6), latch mechanism (7), locking mechanism (8), steel cable (9). The fairing body (1) is connected to the rear strut (3) and the front strut (4) respectively through two active control mechanisms (2); the rear strut (3) and the front strut (4) are connected to the fuselage through two hinge mechanisms (5) respectively; the pulley in the pulley-rail mechanism (6) is fixed on the fairing body (1), and the rail in the pulley-rail mechanism (6) is fixed on the fuselage; the latch in the latch mechanism (7) is fixed on the fairing body (1), and the socket of the latch in the latch mechanism (7) is fixed on the fuselage; one end of the steel cable (9) is connected to the fairing body (1), and the other end is connected to the fuselage; the locking mechanism (8) is fixed on the fairing body (1) for locking the fairing; the movement trajectory of the fairing includes a first movement trajectory and a second movement trajectory. The first movement trajectory is the trajectory of the fairing moving based on the pulley-rail mechanism (6), and the second movement trajectory is the trajectory of the fairing rotating around the rotating shaft of the hinge mechanism (5).

2. The helicopter double-motion trajectory fairing according to claim 1, characterized in that, Each active control mechanism (2) is composed of an upper joint (21), an intermediate connecting member (23), a lower joint (22), and a long sleeve (24). The long sleeve (24) is in interference fit with the upper joint (21) to ensure that the long sleeve (24) and the upper joint (21) are fixedly connected; the intermediate connecting member (23) is installed on the long sleeve (24), and there is a clearance fit between them, so that the intermediate connecting member (23) can rotate flexibly around the long sleeve (24). The upper joint (21) is connected to the lower joint (22); the two mounting holes of the lower joint (22) are designed as concentric holes to enable the upper joint (21) to rotate flexibly. After the lower joints (22) of the two active control mechanisms (2) are assembled, they are guaranteed to be concentric to ensure that the fairing body can rotate flexibly around the axis of the lower joint mounting hole.

3. The helicopter double-motion trajectory fairing according to claim 1, characterized in that, The rear strut (3) and the front strut (4) have the same structure, both are integrally formed composite structures with a square tube cross-section.

4. The helicopter double-motion trajectory fairing according to claim 1, wherein, Each hinge mechanism (5) is composed of an upper hinge joint (51), a lower hinge joint (52), and an intermediate rotating shaft (53). The upper hinge joint (51) is fixedly connected to the rear strut (4) and the lower hinge joint (52) is fixedly connected to the fuselage by rivets; the upper hinge joint (51) and the lower hinge joint (52) are connected by a rotating shaft (53) and can rotate around the rotating shaft (53); moreover, the rotating shafts of the two hinge mechanisms are coaxial.

5. The helicopter double-motion trajectory fairing according to claim 1, characterized in that, The pulley-rail mechanism (6) is composed of a rail (61) and a pulley assembly (62). The rail (61) has a C-shaped cross-section structure and is connected to the fuselage by countersunk screws (63). The rail (61) is provided with a lower groove (64) and an upper opening (65); the pulley assembly (62) is composed of a pulley (69), a variable cross-section rotating shaft (66), and a self-lubricating bushing (67). The pulley (69) is fixed on the fairing body (1) through the variable cross-section rotating shaft (66) and a self-locking nut (68). The slide rail (61) restricts the movement trajectory of the fairing body (1) by restricting the freedom of movement of the pulley assembly (62) in the Z direction, where the Z direction is perpendicular to the heading; the pulley assembly (62) rolls in the slide rail (61) to ensure that the movement of the fairing at the pulley during the initial stage is a linear movement. When the pulley assembly (62) rolls to the lower groove (64) at the rear of the slide rail (61), the pulley stops here, and two movable control mechanisms (2) can be operated; when the fairing rotates and opens, the pulley mechanism (62) smoothly disengages from the slide rail (61) through the upper opening (65) at the rear of the slide rail.

6. The helicopter double-motion trajectory fairing according to claim 1, wherein, The latch mechanism (7) consists of a latch (71), a latch seat (73), a peelable gasket (74), and a latch seat pressing plate (75). The rear part of the latch (71) is designed with a thread and is fixed to the fairing body (1) through a slotted nut (72); the latch seat (73) is fixed to the fuselage through the latch seat pressing plate (75) and bolts (76), and the inner diameter of the latch seat pressing plate (75) is slightly larger than the outer diameter of the latch seat (73). The latch mechanism (7) restricts the freedom of movement of the fairing in a plane that is perpendicular to the axis of the latch (71); the axis of the locking mechanism (8) is parallel to the axis of the latch (71) and is used to restrict the freedom of movement of the fairing in the direction of the latch axis; the movement of the fairing is completely restricted by the latch mechanism (7) and the locking mechanism (8).

7. The helicopter double-motion trajectory fairing according to claim 1, wherein, The fairing body (1) is a composite sandwich structure, with the sandwich being honeycomb and foam. The foam is filled in the rounded corner area of the fairing body (1), and the honeycomb is filled in the remaining areas. The honeycomb and the foam are bonded together with foaming adhesive.

8. The helicopter double-motion trajectory fairing according to claim 2, characterized in that, The upper joint (21) and the lower joint (22) are connected by long bolts (25) and self-locking nuts (26) in the area close to the aircraft contour; the upper joint (21) and the lower joint (22) are connected by two sets of hexagon head bolts (27) and slotted nuts (28) in the area far from the aircraft contour. Among them, the length of the shank part of the hexagon head bolt is greater than the thickness of the intermediate sandwich.

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