Support arm structure and aircraft propeller hub system

Abstract

The invention relates to a support arm structure and an aircraft propeller hub system, belongs to the technical field of flight equipment, and solves the problems that in the prior art, an aircraft propeller hub system has many parts, the related difficulty is high, and the manufacturing process is complex. The support arm structure provided by the invention comprises a waving unit and a centrifugal unit, the waving unit comprises a multidirectional joint and a waving elastic piece; the multidirectional joint is arranged at the end part of the waving unit and is hinged with the central part of the propeller hub system; one end of the waving elastic piece is fixed to the center of the propeller hub system, and the other end is fixed to the multidirectional connector. The waving elastic piece is used for limiting the waving amplitude of the waving unit; the centrifugal unit comprises a centrifugal elastic part; the interior of the centrifugal elastic piece is connected with the end of the waving unit. The number of structural parts of the aircraft propeller hub system is reduced, and the design and manufacturing difficulty is lowered.

Description

Technical Field

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

[0002] For rotorcraft, the hub system is the connection structure of the drive shaft, blades and control system. The fourth generation is a central elastic universal hinge hub, which uses a central universal hinge to achieve flapping and swinging movements, and combines the centrifugal bearing and variable pitch bearing through a larger star-shaped piece, thereby achieving variable pitch and transmission of centrifugal force. The typical representative is V280, but the design and verification of the central elastic part and star-shaped part are difficult, and it is difficult for small companies and even most countries to complete the entire process. Summary of the invention

[0003] In view of the above analysis, an embodiment of the present invention aims to provide an arm structure and an aircraft hub system to solve the problems in the prior art that the rotorcraft hub has many parts, is difficult to design, and has a complex manufacturing process.

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

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

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

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

[0008] Further, the swinging elastic member has a bending portion;

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

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

[0011] Furthermore, the axis of the second section is arranged perpendicular to the first section.

[0012] Furthermore, at least one of the second sections is a cylindrical structure; and at least one of the cylindrical structures is an elastomer.

[0013] Furthermore, the swinging elastic member is arranged symmetrically relative to the plane where the multi-directional joint is located.

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

[0015] The anti-twist member comprises an inserting portion with an external thread, the connecting member comprises an internal thread blind hole, and the inserting portion and the internal thread blind hole are screwed together via a first thread;

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

[0017] Furthermore, the waving unit further includes a support arm;

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

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

[0020] The first connection part is connected to the central part of the hub system; the second connection part is connected to the swing assembly of the hub system; and the third connection part is connected to the support arm.

[0021] Another aspect of the present invention provides an aircraft hub system, comprising the above-mentioned support arm structure.

[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 in an articulated manner to realize flapping, and does not require a central universal joint; and the support arm structure provided by the present invention realizes pitch change through a centrifugal assembly, does not require a centrifugal bearing and a pitch change bearing, and does not require a star-shaped member 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 relatively low.

[0024] (2) The bending structure of the swinging elastic member can improve the overall stiffness and stability of the swinging elastic member on the one hand, and is conducive to deformation coordination on the other hand, while dispersing the stress during rotation, thereby enhancing the stability and operational reliability of the component and the entire system.

[0025] (3) When the swinging elastic member is in swinging motion, the setting of the elastic body enables the swinging elastic member to have both the rigidity of metal and elasticity. Compared with the prior art, during the swinging motion, due to the setting of the swinging elastic member, the compression rigidity of the elastic body is stronger than the tension rigidity. Therefore, the elastic member will not be damaged due to tension, thereby improving the safety of the system.

[0026] (4) The centrifugal elastic member is connected to the connecting member through a second thread, and the anti-twist member is connected to the connecting member through a first thread. The first thread and the second thread have opposite rotation directions to prevent the thread from becoming loose due to long-term high-frequency movement, thereby improving the safety of the system.

[0027] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the following content, and some advantages can be obvious from the description or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the text and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0029] Figure 1 is a structural schematic diagram of the support arm structure;

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

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

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

[0033] Figure 5 It is a schematic diagram of the structure of the swinging elastic member;

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

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

[0036] Reference numerals:

[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-support arm, 14-connecting member, 141-fourth connecting part, 142-fifth connecting part, 1421-inner threaded blind hole, 2-centrifugal unit, 21-centrifugal elastic member, 211-rotating part, 212-fixing part, 22-fixing member, 23-anti-twist member, 231-cover-shaped part, 232-insertion part, 3-central part of the hub system, 4-oscillation assembly, 5-sleeve, 51-pitch rocker arm. DETAILED DESCRIPTION

[0038] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0039] A specific embodiment of the present invention, as Figure 1 As shown, a support arm structure is disclosed.

[0040] like Figure 2 As shown, one end of the arm structure is connected to the center part 3 of the hub system, and the other end is connected to the sleeve 5 of the hub system, which is used to drive the blades to swing up and down and control the pitch of the blades. It should be noted that the center part 3 of the hub system includes a constant velocity joint, which has a spline keyway, and the constant velocity joint is connected to the rotor shaft through a spline. In one embodiment, the axis of the center part of the hub system coincides with the axis of the rotor shaft.

[0041] The arm structure includes a swinging unit 1 and a centrifugal unit 2. The swinging unit 1 is used to realize the swinging motion, and the centrifugal unit 2 is used to realize the variable pitch motion together with the sleeve 5.

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

[0043] like Figure 4 As shown, the multi-directional joint 11 includes a first connection portion 111 and a second connection portion 112. Specifically, the first connection portion 111 is connected to the center portion 3 of the hub system. The first connection portion 111 and the center portion 3 of the hub system form a hinged structure, so that the flapping unit 1 flaps up and down along the axis of the center portion 3 of the hub system. The second connection portion 112 is connected to the swing assembly 4, and the second connection portion 112 and the swing assembly 4 form a hinged structure, so that the swing assembly 4 performs a swinging motion in a plane perpendicular to the axis of the center portion 3 of the hub system.

[0044] Furthermore, the multi-directional joint 11 further comprises 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 with the prior art, the present embodiment is provided with a multi-directional joint 11 having a plurality of connecting parts, the multi-directional joint 11 is respectively connected to the central part 3 of the hub system, the swing assembly 4 of the hub system and the support arm 13, and the upper and lower parts are connected to the swinging elastic member 12. The provision of the multi-directional joint 11 effectively reduces the number of parts of the support arm structure and reduces the difficulty of processing and manufacturing.

[0046] The flapping elastic member 12 is used to limit the flapping amplitude of the flapping unit 1. One end of the flapping elastic member 12 is connected to the central part 3 of the hub system, and the other end is connected to the multi-directional joint 11. There are two flapping elastic members 12, namely an upper flapping elastic member and a lower flapping elastic member. The two flapping elastic members 12 are symmetrically arranged relative to a plane perpendicular to the axis direction of the central part 3 of the hub system.

[0047] Specifically, Figure 5 As shown, the flapping elastic member 12 includes a first mounting portion 121 and a second mounting portion 122 arranged 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 sections 123 and at least one second section 124 , and the first sections 123 and the second sections 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 has an angle with the axis of the central portion 3 of the hub system. 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 disposed perpendicularly 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 improve the overall stiffness and stability of the swinging elastic member 12 on the one hand, and is conducive to deformation coordination on the other hand, 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 swinging elastic member 12, at least one second section 124 of the cylindrical structure is an elastomer. The elastomer has elastic stiffness along its own axis. Exemplarily, the elastomer is formed by alternating metal layers and rubber layers. The provision of the elastomer enables the swinging elastic member 12 to have both the stiffness of metal and elastic properties. Compared with the prior art, the swinging elastic member 12 in this embodiment is provided with an elastomer. During the swinging motion, due to the presence of the elastomer in the swinging elastic member 12, the compression stiffness of the elastomer is stronger than the tensile stiffness, and the swinging elastic member 12 will not be damaged due to stretching, thereby improving the safety of the system.

[0054] Further, the waving unit 1 also includes a connecting member 14. The connecting member 14 is used to connect the centrifugal unit 2 to the waving 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 middle of the opening is used to accommodate the support arm 13.

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

[0056] Furthermore, the swing unit 1 further includes a support arm 13. Exemplarily, the support arm 13 is a regular hexahedron structure, which is arranged to extend 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 mounted on the multi-directional joint 11, and the other end is mounted on the connecting member 14, which is used to drive the connecting member 14 and the centrifugal unit 2 thereon to perform a swinging 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 realize the pitch change of the blade together with the sleeve 5. Figure 6 As shown, the centrifugal unit 2 includes a centrifugal elastic member 21 .

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

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

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

[0061] When the sleeve 5 and the blade change pitch and rotate, the rotating part 211 of the centrifugal elastic member 21 is driven to rotate; and the fixed part 212 is fixed to the fifth connecting part 142 of the connecting member 14, and is relatively fixed to the swing unit 1. As a result, the end surface of the fixed part 212 near the rotating part 211 rotates, the inner wall surface and the end surface near the fixed member 22 are fixed, and the fixed part 212 is subjected to shear force and torsional moment. Compared with the prior art, the setting of the elastic body in the centrifugal elastic member 21 in this embodiment 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, thereby improving the safety and reliability of the system.

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

[0063] The fixing member 22 is adjacent to the centrifugal elastic member 21. The fixing member 22 is annular, and its end surface is fixed to the outer end surface of the fixing portion 212.

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

[0065] Specifically, to prevent the threads from becoming loose due to long-term high-frequency movement, the anti-twist member 23 and the fifth connection portion 142 are screwed together by a first thread, and the centrifugal elastic member 21 and the fifth connection portion 142 are screwed together by a second thread to improve the safety of the system. It should be noted that the first thread and the second thread have opposite rotation directions.

[0066] Compared with the prior art, the arm structure of the present embodiment is provided with a flapping elastic member 12 and a centrifugal elastic member 21, which are used to realize the flapping and pitch changing movement of the hub system. Compared with the existing hub system, the arm structure provided by the present invention is connected to the rotor shaft in an articulated manner to realize flapping, and does not require a central universal joint; and the arm structure provided by the present application realizes pitch changing through a centrifugal assembly, does not require a centrifugal bearing and a pitch changing bearing, and does not require a star-shaped member to combine the centrifugal bearing and the pitch changing 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 relatively low.

[0067] An embodiment of the present invention further provides an aircraft hub system, comprising the support arm structure in the above-mentioned embodiment.

[0068] Compared with the prior art, the advantages of the aircraft hub system of the embodiment of the present invention are the same as the advantages of the above-mentioned support arm structure, which will not be repeated here.

[0069] The above description is only a preferred specific implementation manner 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 any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A support arm structure, characterized in that: It comprises a waving unit (1) and a centrifugal unit (2); The swinging unit (1) comprises a multi-directional joint (11) and a swinging elastic member (12); the multi-directional joint (11) is arranged at the end of the swinging unit (1), and the multi-directional joint (11) is hinged to the central part (3) of the hub system; one end of the swinging elastic member (12) is fixed to the central part (3) of the hub system, and the other end of the swinging elastic member (12) is fixed to the multi-directional joint (11); the swinging elastic member (12) is used to limit the swinging amplitude of the swinging unit (1); The centrifugal unit (2) comprises a centrifugal elastic member (21); the centrifugal elastic member (21) is connected to the end of the waving unit (1).

2. The support arm structure according to claim 1, characterized in that: The swinging elastic member (12) has a bending portion; The bending 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 alternately arranged.

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

4. The support arm structure according to claim 3, characterized in that: The axis of the second section (124) is arranged perpendicular to the first section (123).

5. The support arm structure according to claim 4, 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.

6. The support arm structure according to claim 1, characterized in that: The swinging elastic member (12) is arranged symmetrically relative to the plane where the multi-directional joint (11) is located.

7. The support arm structure according to claim 1, characterized in that: The centrifugal unit (2) further comprises an anti-twist component (23); and the waving unit (1) further comprises a connecting component (14). The anti-twist component (23) comprises an inserting portion (232) having an external thread, the connecting component (14) has an internal thread blind hole (1421), and the inserting portion (232) and the internal thread blind hole (1421) are screwed together via a first thread; The connecting member (14) has an external thread, and the centrifugal elastic member (21) has an internal thread, and the internal thread is threadedly connected to the external thread via a second thread.

8. The support arm structure according to claim 1, characterized in that: The waving unit (1) further comprises a supporting arm (13); The support arm (13) is arranged between the multi-directional joint (11) and the connecting member (14).

9. The support arm structure according to claim 9, characterized in that: The multi-directional joint (11) comprises a first connecting portion (111), a second connecting portion (112) and a third connecting portion (113); The first connection part (111) is connected to the central part (3) of the hub system; the second connection part (112) is connected to the swing assembly (4) of the hub system; and the third connection part (113) is connected to the support arm (13).

10. An aircraft hub system, characterized in that: It comprises the support arm structure described in any one of claims 1-9.

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