An arm structure and an aircraft hub system

Abstract

The present invention relates to a boom structure and an aircraft hub system, belonging to the technical field of flight equipment, and solves the problems of many parts, high design difficulty, and complex manufacturing process in the existing aircraft hub system. The boom structure provided by the present invention includes a flapping unit and a centrifugal unit; the flapping unit includes a multi-directional joint and a flapping elastic member; the multi-directional joint is arranged at the end of the flapping unit, and the multi-directional joint is hinged to the central part of the hub system; one end of the flapping elastic member is fixed to the central part of the hub system, and the other end is fixed to the multi-directional joint; the flapping elastic member is used to limit the flapping amplitude of the flapping unit; the centrifugal unit includes a centrifugal elastic member; the inside of the centrifugal elastic member is connected to the end of the flapping unit. The present invention reduces the number of structural parts of the aircraft hub system and reduces the design and manufacturing difficulty.

Description

Technical Field

[0001] The present invention relates to the technical field of flight devices, and in particular, to an arm structure and an aircraft hub system. Background Art

[0002] For a rotorcraft, the hub system is a connecting structure of a transmission shaft, rotor blades and a control system. The fourth generation is a central elastic gimbal hub, which realizes the flapping and lead-lag motions through a central gimbal, and combines a centrifugal bearing and a pitch-changing bearing through a relatively large star-shaped part to realize the transmission of pitch change and centrifugal force. The typical representative is V280. However, the design and verification of the central elastic part and the star-shaped part are both difficult, and it is very difficult for small enterprises and even most countries to complete the whole process. Summary of the Invention

[0003] In view of the above analysis, embodiments of the present invention aim to provide an arm structure and an aircraft hub system to solve the problems of many hub parts, large design difficulty and complex manufacturing process of rotorcrafts in the prior art.

[0004] The object of the present invention is mainly achieved through the following technical solutions:

[0005] The present invention provides an arm structure, including a flapping unit and a centrifugal unit;

[0006] The flapping unit includes a multi-directional joint and a flapping elastic member; the multi-directional joint is arranged at the end of the flapping unit, and the multi-directional joint is hinged to the central part of the hub system; one end of the flapping elastic member is fixed to the central part of the hub system, and the other end is fixed to the multi-directional joint; the flapping elastic member is used to limit the flapping amplitude of the flapping unit;

[0007] The centrifugal unit includes a centrifugal elastic member; the centrifugal elastic member is connected to the end of the flapping unit.

[0008] Further, the flapping elastic member has a bent portion;

[0009] The bent portion has a plurality of first sections and at least one second section, and the first sections and the second section are arranged alternately.

[0010] Further, the first section has an included angle with the axis of the central part of the hub system.

[0011] Further, the axis of the second section is perpendicular to that of the first section.

[0012] Further, at least one of the second sections is a cylindrical structure; at least one of the cylindrical structures is an elastic body.

[0013] Further, the flapping elastic member is symmetrically arranged with respect to the plane where the multi-directional joint is located.

[0014] Further, the centrifugal unit further includes an anti-twist member; the flapping unit further includes a connecting member;

[0015] The anti-twist member includes an insertion portion having an external thread, the connecting member has an internal thread blind hole, and the insertion portion is screwed to the internal thread blind hole through a first thread;

[0016] The connecting member has an external thread, the centrifugal elastic member has an internal thread, and the internal thread is screwed to the external thread through a second thread.

[0017] Further, the flapping unit further includes a support arm;

[0018] The support arm is disposed between the multi-directional joint and the connecting member.

[0019] Further, the multi-directional joint has a first connecting portion, a second connecting portion, and a third connecting portion;

[0020] The first connecting portion is connected to the central portion of the hub system; the second connecting portion is connected to the flapping assembly of the hub system, and the third connecting portion is connected to the support arm.

[0021] Another aspect of the present invention provides an aircraft hub system including the support arm structure described above.

[0022] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0023] (1) Compared with the prior art, the support arm structure of the present invention is provided with a flapping elastic member and a centrifugal elastic member for realizing the flapping and pitch change of the support arm structure. Compared with the existing hub system, the support arm structure provided by the present invention is connected to the transmission shaft of the rotor by a hinged manner to realize flapping, and does not require a central universal joint; and in the support arm structure provided by the present invention, the pitch change is realized through a centrifugal assembly, and no centrifugal bearing and pitch change bearing are required, and even less a star member is required to combine the centrifugal bearing and the pitch change bearing; therefore, the number of structural parts of the hub system including the support arm structure provided by the present invention is reduced, and the design and manufacturing difficulty is lower.

[0024] (2) The bending structure of the flapping elastic member can, on the one hand, improve the overall stiffness and stability of the flapping elastic member, on the other hand, is beneficial to deformation coordination, and at the same time disperses the stress during rotation, enhancing the stability and operation reliability of the component and the entire system.

[0025] (3) When the flapping elastic member performs a flapping motion, the elastomer is arranged such that the flapping elastic member has both the stiffness of a metal and elastic properties. During the flapping motion, compared with the prior art, due to the arrangement of the flapping elastic member, the compressive stiffness of the elastomer is stronger than the tensile stiffness. Therefore, the elastic member will not be damaged due to stretching, improving the safety of the system.

[0026] (4) The centrifugal elastic member and the connecting member are connected by a second thread, and the anti-torsion member and the connecting member are connected by a first thread. The helix directions of the first thread and the second thread are opposite to avoid the loosening of the threads due to long-term high-frequency motion, improving the safety of the system.

[0027] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the following content. Moreover, some advantages can be made obvious from the description or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained from the content specifically pointed out in the text and the drawings. Description of the Drawings

[0028] The drawings are only for the purpose of showing specific embodiments and are not considered as a limitation to the present invention. Throughout the drawings, the same reference signs denote the same components.

[0029] Figure 1 It is a schematic structural diagram of the boom structure;

[0030] Figure 2 It is a schematic structural diagram of the aircraft hub system;

[0031] Figure 3 It is a schematic structural diagram of the flapping unit;

[0032] Figure 4 It is a schematic structural diagram of the multi-directional joint;

[0033] Figure 5 It is a schematic structural diagram of the flapping elastic member;

[0034] Figure 6 It is a schematic structural diagram of the centrifugal unit;

[0035] Figure 7 It is a schematic structural diagram of the centrifugal elastic member.

[0036] Reference Signs:

[0037] 1 - Flapping unit, 11 - Multi - directional joint, 111 - First connecting part, 112 - Second connecting part, 113 - Third connecting part, 12 - Flapping elastic member, 121 - First mounting part, 122 - Second mounting part, 123 - First section, 124 - Second section, 13 - Arm, 14 - Connecting member, 141 - Fourth connecting part, 142 - Fifth connecting part, 1421 - Internal - thread blind hole, 2 - Centrifugal unit, 21 - Centrifugal elastic member, 211 - Rotating part, 212 - Fixed part, 22 - Fixing member, 23 - Anti - torsion member, 231 - Cover - shaped part, 232 - Insertion part, 3 - Central part of the hub system, 4 - Flapping - lag assembly, 5 - Sleeve, 51 - Pitch - change rocker arm. Detailed implementation mode

[0038] The preferred embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings, where the accompanying drawings form a part of the present invention and are used together with the embodiments of the present invention to explain the principle of the present invention, rather than to limit the scope of the present invention.

[0039] A specific embodiment of the present invention, as Figure 1 shown, discloses an arm structure.

[0040] As Figure 2 shown, one end of the arm structure is connected to the central part 3 of the hub system, and the other end is connected to the sleeve 5 of the hub system, for driving the blade to flap up and down and controlling the blade pitch. It should be noted that the central part 3 of the hub system includes a constant - velocity joint, and the constant - velocity joint has a spline keyway, and the constant - velocity joint is connected to the rotor shaft through splines. In one implementation, the axis of the central part of the hub system coincides with the axis of the rotor shaft.

[0041] The arm structure includes a flapping unit 1 and a centrifugal unit 2. The flapping unit 1 is used to achieve the flapping motion, and the centrifugal unit 2 is used to jointly achieve the pitch - change motion with the sleeve 5.

[0042] As Figure 3 shown, the flapping unit 1 includes a multi - directional joint 11 and a flapping elastic member 12.

[0043] As Figure 4 shown, the multi - directional joint 11 includes a first connecting part 111 and a second connecting part 112. Specifically, the first connecting part 111 is connected to the central part 3 of the hub system. The first connecting part 111 and the central part 3 of the hub system form a hinged structure, enabling the flapping unit 1 to flap up and down along the axis of the central part 3 of the hub system. The second connecting part 112 is connected to the flapping - lag assembly 4, and the second connecting part 112 and the flapping - lag assembly 4 form a hinged structure, enabling the flapping - lag assembly 4 to perform a flapping - lag motion in a plane perpendicular to the axis of the central part 3 of the hub system.

[0044] Furthermore, the multi-directional joint 11 further includes a third connection portion 113 for connecting the support arm 13. Exemplarily, the third connection portion 113 is a U-shaped groove, and the opening of the U-shaped groove accommodates the support arm 13.

[0045] Compared to the prior art, this embodiment employs a multi-directional joint 11 with multiple connecting portions. Multi-directional joint 11 connects the hub system's central portion 3, the hub system's oscillating assembly 4, and the arm 13, respectively. The upper and lower portions are connected to the flapping elastic member 12. The provision of multi-directional joint 11 effectively reduces the number of parts in the arm structure, lowering the difficulty of processing and manufacturing.

[0046] The flapping spring 12 is used to limit the flapping amplitude of the flapping unit 1. One end of the flapping spring 12 is connected to the hub system's central portion 3, and the other end is connected to the multi-directional joint 11. Two flapping springs 12 are provided: an upper flapping spring and a lower flapping spring. These two flapping springs 12 are symmetrically arranged with respect to a plane perpendicular to the axis of the hub system's central portion 3.

[0047] Specifically, if Figure 5 As shown, the flapping elastic member 12 includes a first mounting portion 121 and a second mounting portion 122 provided at both ends. The first mounting portion 121 is connected to the central portion 3 of the hub system, and the second mounting portion 122 is connected to the third connecting portion 113 of the multi-directional joint 11 .

[0048] Furthermore, the swinging elastic member 12 has a bent portion in the middle.

[0049] The bending portion has a plurality of first segments 123 and at least one second segment 124 , and the first segments 123 and the second segments 124 are alternately arranged.

[0050] It should be noted that the plurality of first sections 123 are arranged in parallel, and the first section 123 forms an angle with the axis of the hub system's central portion 3. The first section 123 is a flat plate structure, a columnar structure, or a special-shaped structure.

[0051] The axis of the second section 124 is perpendicular to the first section 123. At least one second section 124 is a cylindrical structure.

[0052] Compared with the prior art, the swinging elastic member 12 in this embodiment is provided with a bending structure, which can, on the one hand, improve the overall stiffness and stability of the swinging elastic member 12, and on the other hand, is conducive to deformation coordination, so that the stress during rotation is dispersed, and the stability and operational reliability of the components and the entire system are enhanced.

[0053] It should be noted that, in the flapping elastic member 12, at least one second section 124 of the cylindrical structure is an elastomer. The elastomer has an elastic stiffness along its own axis. Exemplarily, the elastomer is formed by alternately laminating metal layers and rubber layers. The setting of the elastomer makes the flapping elastic member 12 have both the stiffness of metal and elastic properties. Compared with the prior art, in this embodiment, the flapping elastic member 12 is provided with an elastomer. During the flapping motion, due to the presence of the elastomer in the flapping elastic member 12, the compression stiffness of the elastomer is stronger than the tensile stiffness, and the flapping elastic member 12 will not be damaged due to stretching, improving the safety of the system.

[0054] Further, the flapping unit 1 further includes a connecting member 14. The connecting member 14 is used to connect the centrifugal unit 2 to the flapping unit 1. The connecting member 14 has a fourth connecting portion 141 connected to the support arm 13 and a fifth connecting portion 142 connected to the centrifugal unit 2. Exemplarily, the fourth connecting portion 141 has a U-shaped groove structure opposite to the opening of the third connecting portion 113, and the support arm 13 is accommodated in the middle of the opening.

[0055] The fifth connecting portion 142 is a rod-shaped structure with an external thread, and an internal thread blind hole 1421 is provided at its end. The external thread of the fifth connecting portion 142 and the internal thread blind hole 1421 are used for screwing connection with the centrifugal unit 2.

[0056] Further, the flapping unit 1 further includes a support arm 13. Exemplarily, the support arm 13 is a regular hexahedron structure, extending radially along the central portion 3 of the hub system, and is used to form a swing arm of the support arm structure. One end of the support arm 13 is installed on the multi-directional joint 11, and the other end is installed on the connecting member 14, and is used to drive the connecting member 14 and the centrifugal unit 2 thereon to perform flapping motion along with the multi-directional joint 11.

[0057] The centrifugal unit 2 is sleeved on the fifth connecting portion 142 and is used to jointly realize the pitch change of the blade with the sleeve 5. As Figure 6 shown, the centrifugal unit 2 includes a centrifugal elastic member 21.

[0058] As Figure 7 shown, the centrifugal elastic member 21 is a hollow cylindrical shape, including a rotating portion 211 and a fixing portion 212. The rotating portion 211 is connected to the sleeve 5, and when the pitch change rocker arm 51 drives the sleeve 5 to rotate, the rotating portion 211 rotates along with the sleeve 5. The fixing portion 212 is provided with an internal thread and is screwed and fixed to the external thread of the fifth connecting portion 142.

[0059] The outside of the rotating portion 211 is connected to the sleeve 5. Exemplarily, the outside of the rotating portion 211 is screwed and fixed to the sleeve 5.

[0060] It should be noted that the fixing part 212 of the centrifugal elastic member 21 is provided with an elastomer. The elastomer has an elastic stiffness along its own axis. Exemplarily, the elastomer is formed by alternately laminating metal layers and rubber layers. The setting of the elastomer enables the centrifugal elastic member 21 to have both the stiffness of metal and elastic properties.

[0061] When the cuff 5 and the blade pitch change and rotate, the rotating part 211 of the centrifugal elastic member 21 is driven to rotate; while the fixing part 212 is fixed to the fifth connecting part 142 of the connecting member 14 and is relatively fixed to the flapping unit 1. Thus, the end face of the fixing part 212 near the rotating part 211 rotates, the inner wall surface and the end face near the fixing member 22 are fixed, and the fixing part 212 is subjected to shear force and torsional moment. Compared with the prior art, in this embodiment, the setting of the elastomer in the centrifugal elastic member 21 enables the centrifugal elastic member 21 to have a smaller shear stiffness and a smaller torsional stiffness, and will not be damaged due to excessive force, improving the safety and reliability of the system.

[0062] Furthermore, the centrifugal unit 2 further includes a fixing member 22 and an anti-torsion member 23.

[0063] The fixing member 22 is adjacent to the centrifugal elastic member 21. The fixing member 22 is circular ring-shaped, and its end face is fixed to the outer end face of the fixing part 212.

[0064] The anti-torsion member 23 includes a cover-shaped part 231 and an insertion part 232. The cover-shaped part 231 is fixed to the end face of the fixing member 22, and the insertion part 232 can be inserted into the threaded groove 1421 of the fifth connecting part 142 and is screwed and fixed to the fifth connecting part 142.

[0065] Specifically, to avoid the loosening of the thread due to long-term high-frequency movement, the anti-torsion member 23 is screwed to the fifth connecting part 142 through a first thread, and the centrifugal elastic member 21 is screwed to the fifth connecting part 142 through a second thread to improve the safety of the system. It should be noted that the first thread and the second thread have opposite helix directions.

[0066] Compared with the prior art, the arm structure of this embodiment is provided with a flapping elastic member 12 and a centrifugal elastic member 21 for realizing the flapping and pitch change movements of the hub system. Compared with the existing hub systems, the arm structure provided by the present invention is connected to the rotor shaft in a hinged manner to realize flapping, and does not require a central universal joint; and in the arm structure provided by the present application, the pitch change is realized through a centrifugal component, and no centrifugal bearing and pitch change bearing are required, and even less a star part is needed to combine the centrifugal bearing and the pitch change bearing; therefore, the number of structural parts of the hub system including the arm assembly provided by the present application is reduced, and the design and manufacturing difficulty is lower.

[0067] The embodiment of the present invention also provides an aircraft hub system, including the arm structure in the above-mentioned embodiment.

[0068] Compared with the prior art, the advantages of the aircraft hub system according to the embodiments of the present invention are the same as those of the above-mentioned support arm structure, and will not be elaborated herein.

[0069] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A boom structure, characterized in that, It includes a flapping unit (1) and a centrifugal unit (2); The flapping unit (1) includes a multi-direction joint (11) and a flapping elastic member (12); the multi-direction joint (11) is arranged at the end of the flapping unit (1), and the multi-direction joint (11) is hinged to the central part (3) of the hub system; one end of the flapping elastic member (12) is fixed to the central part (3) of the hub system, and the other end of the flapping elastic member (12) is fixed to the multi-direction joint (11); the flapping elastic member (12) is used to limit the flapping amplitude of the flapping unit (1); The centrifugal unit (2) includes a centrifugal elastic member (21); the centrifugal elastic member (21) is connected to the end of the flapping unit (1); The flapping elastic member (12) has a bent portion; The bent portion has a plurality of first sections (123) and at least one second section (124), and the first sections (123) and the second sections (124) are arranged alternately; The centrifugal unit (2) further includes an anti-twist member (23); the flapping unit (1) further includes a connecting member (14); The anti-twist member (23) includes an insertion portion (232) with an external thread, the connecting member (14) has an internal thread blind hole (1421), and the insertion portion (232) is screwed to the internal thread blind hole (1421) through a first thread; The connecting member (14) has an external thread, the centrifugal elastic member (21) has an internal thread, and the internal thread is screwed to the external thread through a second thread.

2. The boom structure according to claim 1, characterized in that, The first section (123) has an included angle with the axis of the central part (3) of the hub system.

3. The arm structure according to claim 2, wherein The axis of the second section (124) is perpendicular to the first section (123).

4. The arm structure according to claim 3, characterized in that At least one of the second sections (124) is a cylindrical structure; at least one of the cylindrical structures is an elastomer.

5. The arm structure according to claim 1, characterized in that, The flapping elastic member (12) is symmetrically arranged with respect to the plane where the multi-direction joint (11) is located.

6. The arm structure according to claim 1, wherein The flapping unit (1) further includes an arm (13); The arm (13) is arranged between the multi-direction joint (11) and the connecting member (14).

7. The boom structure according to claim 6, wherein The multi-direction joint (11) has a first connection portion (111), a second connection portion (112) and a third connection portion (113); The first connection portion (111) is connected to the central part (3) of the hub system; the second connection portion (112) is connected to the flapping component (4) of the hub system, and the third connection portion (113) is connected to the arm (13).

8. An aircraft hub system, characterized in that, It includes the arm structure according to any one of claims 1-7.

Images