Anti-torsion arm structure of automatic inclinator

Abstract

The invention relates to the technical field of helicopter rotor systems, in particular to an anti-torsion arm structure of an automatic inclinator. The structure is arranged in the tangential direction of a non-rotating ring instead of the radial direction of a traditional automatic inclinator, and comprises an anti-torque arm upper arm, an anti-torque arm middle arm and an anti-torque arm lower arm; one end of the upper arm of the anti-torsion arm is connected with the non-rotating ring assembly through a joint bearing; two connecting points are arranged at the other end of the anti-torque arm upper arm in the length direction, the inner connecting point is connected with one end of the anti-torque arm middle arm through a rotating shaft, and the outer connecting point is connected with a knuckle bearing at one end of the anti-torque arm lower arm; the other end of the anti-torque arm middle arm is connected with the main reducer fixed end through a knuckle bearing, and the other end of the anti-torque arm lower arm is connected with the main reducer casing through a rotating shaft.

Description

Technical Field

[0001] The present invention relates to the technical field of helicopter rotor systems, and relates to an anti-torsion arm structure of a swashplate. Background Art

[0002] The swashplate is an important component of a helicopter rotor system, mainly transmitting the control instructions from the servo to the rotor blades, realizing the change of the angle of attack of the blades, thereby controlling the magnitude and direction of the rotor lift, and realizing the attitude control of the helicopter.

[0003] A typical swashplate consists of a rotating ring assembly, a non-rotating assembly, a torsion arm assembly, an anti-torsion arm assembly and a pitch link assembly. One end of the anti-torsion arm assembly is connected to the fixed end of the main reducer, and the other end is connected to the non-rotating ring assembly. Its main function is to ensure that the non-rotating ring assembly does not rotate with the rotating ring assembly.

[0004] A typical anti-torsion arm assembly mainly consists of an upper anti-torsion arm and a lower anti-torsion arm. The upper anti-torsion arm is connected to the non-rotating ring assembly through a spherical bearing, the lower anti-torsion arm is connected to the fixed end of the main reducer through a rotating shaft, and the upper anti-torsion arm and the lower anti-torsion arm are connected through a rotating shaft. During the total pitch and cyclic pitch control process of the swashplate, there are relative swings between the upper anti-torsion arm and the non-rotating ring assembly, the lower anti-torsion arm and the fixed end of the main reducer, and between the upper anti-torsion arm and the lower anti-torsion arm. Moreover, the larger the pitch range of the swashplate, the larger the swing angle range between the upper anti-torsion arm and the lower anti-torsion arm.

[0005] According to the swashplate design specification, the change range of the angle between the upper anti-torsion arm and the lower anti-torsion arm during the swing process needs to meet the requirement of 45° to 135°. Otherwise, a friction self-locking phenomenon will occur, and there is a risk of swashplate pitch jamming. When the pitch range of the helicopter rotor system is large, the structural dimensions of the upper anti-torsion arm and the lower anti-torsion arm need to be designed larger. If the swashplate is installed above the main reducer where the space is limited, it will cause difficulties in the connection design between the anti-torsion arm structure of the typical configuration and the main reducer, and the limited space cannot meet the design requirements. Summary of the Invention

[0006] Object of the Invention: To solve the above problems, the present invention provides an anti-torsion arm structure of a swashplate, which is more suitable for the anti-torsion arm structure of a swashplate with a large pitch range requirement, and can greatly reduce the overall structural dimensions and swing movement space of the anti-torsion arm assembly.

[0007] Technical Solution:

[0008] The present invention provides an anti-torsion arm structure of a swashplate, which is arranged along the tangential direction of the non-rotating ring instead of the radial direction of the traditional swashplate. The structure includes: an upper anti-torsion arm, a middle anti-torsion arm, and a lower anti-torsion arm;

[0009] One end of the upper arm of the anti-twist arm is connected to the non-rotating ring assembly through a spherical bearing; two connection points are arranged along the length direction at the other end of the upper arm of the anti-twist arm. The inner connection point is connected to one end of the middle arm of the anti-twist arm through a rotating shaft, and the outer connection point is connected to the spherical bearing at one end of the lower arm of the anti-twist arm; the other end of the middle arm of the anti-twist arm is connected to the fixed end of the main reduction gear through a spherical bearing, and the other end of the lower arm of the anti-twist arm is connected to the main reduction gear housing through a rotating shaft.

[0010] Further, the positions of the connection points between the middle arm of the anti-twist arm and the lower arm of the anti-twist arm and the fixed end of the main reduction gear are adjusted according to space requirements.

[0011] Further, the rotating shaft includes a bolt, a wear-resistant shoulder bushing, a wear-resistant washer, a wear-resistant straight bushing and a nut; the bolt connects all the components of the rotating shaft. The wear-resistant washer is installed below the bolt head and the nut. The wear-resistant shoulder bushing is installed at the outermost side of the rotating shaft hole at the inner connection point. The wear-resistant straight bushing is installed between the bolt and the wear-resistant shoulder bushing, and the outer end of the wear-resistant straight bushing is pressed against the wear-resistant washer, and the inner end is pressed against the middle arm of the anti-twist arm or the main reduction gear housing.

[0012] Further, during the swinging process of the angles between the upper arm of the anti-twist arm and the middle arm of the anti-twist arm, and between the upper arm of the anti-twist arm and the lower arm of the anti-twist arm, as long as one of the angles satisfies the range of 45° to 135°, it can ensure that the anti-twist arm assembly moves flexibly without jamming.

[0013] Further, self-lubricating spherical bearings are respectively designed at the connection points on the upper arm of the anti-twist arm, the middle arm of the anti-twist arm and the lower arm of the anti-twist arm except for the connection points where the rotating shafts are provided. PTFE self-lubricating liners are pasted on the surfaces of the self-lubricating spherical bearings.

[0014] Further, when the swashplate performs a pitch change movement, relative swinging exists between the non-rotating assembly and the upper arm of the anti-twist arm, between the upper arm of the anti-twist arm and the middle arm of the anti-twist arm, between the upper arm of the anti-twist arm and the lower arm of the anti-twist arm, between the middle arm of the anti-twist arm and the fixed end of the main reduction gear, and between the lower arm of the anti-twist arm and the fixed end of the main reduction gear.

[0015] Further, during swinging, the bolt, the wear-resistant washer, the wear-resistant straight bushing and the nut at the rotating shaft part rotate together around the axis of the rotating shaft.

[0016] Further, the surface roughness requirements of the wear-resistant washer, the wear-resistant shoulder bushing and the wear-resistant straight bushing are relatively high, and a certain gap is usually designed between the wear-resistant shoulder bushing and the wear-resistant washer.

[0017] Beneficial effects:

[0018] The present invention provides a swashplate anti-twist arm structure, which is designed and installed in the tangential direction of the non-rotating ring, rather than the radial direction of the traditional swashplate, and can greatly reduce the overall contour size and moving space of the swashplate.

[0019] When any one of the angles between the upper anti-twist arm 1 and the middle anti-twist arm 2, and between the upper anti-twist arm 1 and the lower anti-twist arm 3 satisfies 45° to 135°, it can not only ensure the anti-twist function of the anti-twist arm, but also ensure the flexible operation of the anti-twist arm, reduce the structural design size and weight of the anti-twist arm assembly, and is applicable to the structural design of the anti-twist arm of the swashplate with a large pitch change range. Brief Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of a swashplate anti-twist method and device.

[0021] Figure 2 It is a schematic diagram of the sliding bearing connection.

[0022] Figure 3 It is a schematic diagram of the spherical plain bearing connection. Detailed Description of the Invention

[0023] The present invention provides a swashplate anti-twist device structure, as Figures 1-3 shown, including the upper arm 1, the middle arm 2, the lower arm 3, etc.

[0024] One ends of the upper arm 1, the middle arm 2 and the lower arm 3 are installed with spherical plain bearings. The upper arm 1 and the middle arm 2 are connected by a sliding bearing, the upper arm 1 and the lower arm 3 are connected by a spherical plain bearing, the upper arm 1 is connected to the non-rotating ring through a spherical plain bearing, the middle arm 2 is connected to the main reduction gearbox through a spherical plain bearing, and the lower arm 3 is connected to the main reduction gearbox through a sliding bearing.

[0025] The sliding bearing connection part mainly includes a wear-resistant shoulder bushing 4, a wear-resistant washer 5 and a wear-resistant straight bushing 6.

[0026] The spherical plain bearing connection part mainly includes a spherical plain bearing 7.

[0027] One end of the upper anti-twist arm 1 is connected to the non-rotating ring assembly through a spherical plain bearing 7, and is arranged along the tangential direction of the non-rotating ring, rather than the radial direction of the traditional swashplate, which can greatly reduce the overall profile size and moving space of the swashplate.

[0028] The other end of the upper anti-twist arm 1 has two connection points. Among them, the inner connection point is connected to the middle anti-twist arm 2 through a rotating shaft, and the outer connection point is connected to the spherical plain bearing of the lower anti-twist arm 3. The other end of the middle anti-twist arm 2 is connected to the main reduction fixed end through a spherical plain bearing, and the other end of the lower anti-twist arm 3 is connected to the main reduction gearbox through a rotating shaft. The connection point positions of the middle anti-twist arm 2 and the lower anti-twist arm 3 to the main reduction fixed end can be adjusted according to space requirements.

[0029] The rotating shaft mainly includes a bolt, a wear-resistant shoulder bushing 4, a wear-resistant washer 5, a wear-resistant straight bushing 6, and a nut. The bolt connects all the components at the rotating shaft part. The wear-resistant washer 5 is installed below the bolt head and the nut. The wear-resistant shoulder bushing 4 is installed at the outermost side of the rotating shaft hole. The wear-resistant straight bushing 6 is installed between the bolt and the wear-resistant shoulder bushing 4, with one end pressed against the wear-resistant washer and the other end pressed against the middle section of the rotating shaft.

[0030] When the swashplate performs a pitch change movement, there are relative swings between the non-rotating assembly and the upper arm 1 of the anti-torsion arm, between the upper arm 1 and the middle arm 2 of the anti-torsion arm, between the upper arm 1 and the lower arm 3 of the anti-torsion arm, between the middle arm 2 and the fixed end of the main reducer, and between the lower arm 3 and the fixed end of the main reducer.

[0031] During the swing, the bolt, the wear-resistant washer 5, the wear-resistant straight bushing 6, and the nut at the rotating shaft part rotate together around the axis of the rotating shaft. To ensure the flexible swing movement of the anti-torsion arm assembly, the surface roughness design requirements of the wear-resistant washer 5, the wear-resistant shoulder bushing 4, and the wear-resistant straight bushing 6 are relatively high, and a certain clearance is usually designed between the wear-resistant shoulder bushing 4 and the wear-resistant washer 5.

[0032] According to the design specifications of the swashplate, during the swing process, as long as any one of the angles between the upper arm 1 and the middle arm 2 of the anti-torsion arm and between the upper arm 1 and the lower arm 3 of the anti-torsion arm can meet the range of 45° to 135°, it can ensure the flexible movement of the anti-torsion arm assembly without jamming. Compared with the traditional anti-torsion arm structure, the size and weight of the anti-torsion arm structure of the present invention can be further reduced.

[0033] A self-lubricating spherical plain bearing 7 is respectively designed on the upper arm 1, the middle arm 2, and the lower arm 3 of the anti-torsion arm. A PTFE self-lubricating liner is pasted on the surface of the self-lubricating spherical plain bearing 7 to reduce the friction force at the joint and improve the wear resistance reliability. Each self-lubricating spherical plain bearing 7 acts as a hinge function, allowing the entire anti-torsion arm assembly to perform small-angle degree-of-freedom adjustment along with the non-rotating ring assembly.

[0034] The key points of the present invention:

[0035] 1. A swashplate anti-torsion method and device, characterized in that: it includes an upper arm 1 of the anti-torsion arm, a middle arm 2 of the anti-torsion arm, a lower arm 3 of the anti-torsion arm, and a bolt connection assembly. One end of the upper arm 1 of the anti-torsion arm is connected to the non-rotating ring assembly through a spherical plain bearing 7 and is arranged along the tangential direction of the non-rotating ring, rather than the radial direction of the traditional swashplate, which can greatly reduce the overall contour size and moving space of the swashplate.

[0036] 2. Another key point of the present invention: During the pitch change of the swashplate, the upper anti-twist arm 1, the middle anti-twist arm 2, and the lower anti-twist arm 3 of the anti-twist arm will swing relative to the non-rotating ring assembly and the fixed end of the main reducer. During the swinging process, as long as the angle between any one of the upper anti-twist arm 1 and the middle anti-twist arm 2 or the upper anti-twist arm 1 and the lower anti-twist arm 3 is 45° to 135°, the structural design dimensions and weight of the upper anti-twist arm 1, the middle anti-twist arm 2, and the lower anti-twist arm 3 can be greatly reduced, meeting the requirements of lightweight design;

[0037] 3. Another key point of the present invention: Wear-resistant shoulder bushings 4, wear-resistant washers 5, and wear-resistant straight bushings 6 are adopted at the rotating shaft part, and the surface roughness design requirements of the wear-resistant shoulder bushings 4, the wear-resistant washers 5, and the wear-resistant straight bushings 6 are relatively high. A certain gap is designed between the wear-resistant washer 5 and the wear-resistant shoulder bushing 4 to ensure the flexible operation of the rotating shaft part;

[0038] 4. Another key point of the present invention: A self-lubricating spherical plain bearing 7 is designed on the upper anti-twist arm 1, the middle anti-twist arm 2, and the lower anti-twist arm 3 of the anti-twist arm respectively, which allows the anti-twist arm assembly to make small-angle degree-of-freedom adjustments with the non-rotating assembly to ensure the normal function of the anti-twist arm.

[0039] To make the purpose, technical solutions, and advantages of the implementation of this application clearer, the technical solutions in the implementation manners of this application will be described in more detail below in conjunction with the accompanying drawings in the implementation manners of this application. In the drawings, the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The described implementation manners are part of the implementation manners of this application, rather than all of the implementation manners. The implementation manners described below by referring to the drawings are exemplary and are intended to explain this application, and should not be construed as a limitation of this application. Based on the implementation manners in this application, all other implementation manners obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application. The implementation manners of this application will be described in detail below in conjunction with the accompanying drawings.

[0040] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "axial direction", "vertical", "upper", "lower", "upper end", "bottom end", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the protection scope of the present invention.

[0041] Other embodiments of the present disclosure will be readily apparent to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include known common general knowledge or conventional technical means in the technical field not disclosed herein. The specification and examples are only to be considered as exemplary, and the true scope and spirit of the present disclosure are pointed out by the following claims.

[0042] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. An anti-torsion arm structure of a swashplate, characterized in that, This structure is arranged along the tangential direction of the non-rotating ring, rather than the radial direction of the traditional swashplate. This structure includes: the upper anti-torsion arm (1), the middle anti-torsion arm (2), and the lower anti-torsion arm (3). One end of the upper anti-torsion arm (1) is connected to the non-rotating ring assembly through a spherical bearing (7); two connection points are arranged along the length direction at the other end of the upper anti-torsion arm (1). The inner connection point is connected to one end of the middle anti-torsion arm (2) through a rotating shaft, and the outer connection point is connected to the spherical bearing at one end of the lower anti-torsion arm (3); the other end of the middle anti-torsion arm (2) is connected to the fixed end of the main reduction gear through a spherical bearing, and the other end of the lower anti-torsion arm (3) is connected to the main reduction gear housing through a rotating shaft.

2. The structure according to claim 1, characterized in that The connection point positions of the middle anti-torsion arm (2) and the lower anti-torsion arm (3) with the fixed end of the main reduction gear are adjusted according to space requirements.

3. The structure according to claim 1, wherein The rotating shaft includes a bolt, a wear-resistant shoulder bushing (4), a wear-resistant washer (5), a wear-resistant straight bushing (6), and a nut; the bolt connects all components of the rotating shaft. The wear-resistant washer (5) is installed below the bolt head and the nut. The wear-resistant shoulder bushing (4) is installed at the outermost side of the rotating shaft hole at the inner connection point. The wear-resistant straight bushing (6) is installed between the bolt and the wear-resistant shoulder bushing (4), and the outer end of the wear-resistant straight bushing (6) is pressed against the wear-resistant washer, and the inner end is pressed against the middle anti-torsion arm (2) or the main reduction gear housing.

4. The structure according to claim 1, characterized in that During the swinging process of the upper anti-torsion arm (1) and the middle anti-torsion arm (2), and the upper anti-torsion arm (1) and the lower anti-torsion arm (3), as long as one of the included angles satisfies the range of 45° to 135°, it can ensure that the anti-torsion arm assembly moves flexibly without jamming.

5. The structure according to claim 4, wherein Self-lubricating spherical bearings (7) are respectively designed at the connection points of the upper anti-torsion arm (1), the middle anti-torsion arm (2), and the lower anti-torsion arm (3) except for the connection points where the rotating shafts are set. A PTFE self-lubricating liner is pasted on the surface of the self-lubricating spherical bearing (7).

6. The structure according to claim 5, wherein, When the swashplate performs the pitch change movement, there are relative swings between the non-rotating assembly and the upper anti-torsion arm (1), the upper anti-torsion arm (1) and the middle anti-torsion arm (2), the upper anti-torsion arm (1) and the lower anti-torsion arm (3), the middle anti-torsion arm (2) and the fixed end of the main reduction gear, and the lower anti-torsion arm (3) and the fixed end of the main reduction gear.

7. The structure according to claim 6, wherein During swinging, the bolt, the wear-resistant washer (5), the wear-resistant straight bushing (6), and the nut at the rotating shaft part rotate together around the axis of the rotating shaft.

8. The structure according to claim 7, characterized in that, The surface roughness requirements of the wear-resistant washer (5), the wear-resistant shoulder bushing (4), and the wear-resistant straight bushing (6) are relatively high, and a certain gap is usually designed between the wear-resistant shoulder bushing (4) and the wear-resistant washer (5).

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