A main rotor system

Abstract

The present invention relates to the field of aviation technology, and specifically discloses a main rotor system; the torsion strip includes a torsion strip housing, an installation cavity arranged inside the torsion strip housing and in an annular structure, two groups of steel sleeves installed on the torsion strip housing, and a torsion piece sleeved on the installation cavity; the installation cavity is a waist-shaped annular structure; it includes two groups of arc segments with the same structure and symmetrically arranged, and a straight segment for connecting the two groups of arc segments; the two groups of steel sleeves are arranged along the long direction of the straight segment, and the axis connecting line and the center of the arc segment are on the same straight line. And a main rotor system based on the torsion strip is disclosed; the torsion strip in the present invention has good tensile bearing capacity, improves reliability, and improves torsional stiffness, can have adaptive reset, and has good recovery ability; the hub and the hub support arm are integrally formed, which effectively improves the installation accuracy and prevents the reduction of rotor fatigue life due to installation errors.

Description

Technical Field

[0001] The present invention relates to the field of aviation technology, and more particularly to a main rotor system. Background Art

[0002] Most existing unmanned helicopter main rotor systems use large-diameter steel bearings to withstand centrifugal force, which increases the weight of the rotor system. At the same time, the variable pitch hinge housing, internal bearings, and fixed distance rings will also withstand the centrifugal force of the blades, which increases the design weight, poor maintenance, increased costs, shorter service life, complex structure, and low reliability.

[0003] The torsion bar type main rotor hub is the main structural load-bearing component of unmanned helicopters. Its main function is to withstand the centrifugal force generated by the rotation of the main rotor blades and produce torsional deformation to achieve the pitch change movement of the main rotor blades, making the main rotor system simple, compact, light in weight, safe to use, easy to maintain, and with a longer service life. It is an inevitable trend in the development of the main rotor system. The torsion bar is required to be able to withstand a large axial load and have a very small torsional stiffness. The axial load is the centrifugal force of the blades under different working conditions. The torsional angle and stiffness are necessary conditions for the main rotor pitch change, that is, to overcome the control force transmitted from the tilting gear servo. At the same time, under working conditions, it must have elastic recovery ability;

[0004] In the prior art, the structural forms of tension and twist strips generally include rubber steel wire tension and twist strips, steel wire tension and twist strips, laminated tension and twist strips, etc. Among them, rubber steel wire tension and twist strips are usually formed by winding a whole steel wire, which has problems such as low reliability and low safety. Single-layer steel wire winding products have poor stability, very small torsional stiffness, and are prone to plastic deformation, which affects the normal work of the tension and twist strips; laminated tension and twist strips are heavy, inefficient, and have high torsional stiffness, which is not conducive to the variable pitch movement of the variable pitch hinge. Adjusting the torsional stiffness requires adjusting the axial length of the variable pitch hinge. In addition, laminated tension and twist strips have high requirements on material properties, low laminate thickness, and great manufacturing difficulty.

[0005] In the prior art, the propeller hub support arm is generally connected to the propeller hub via a clamping plate, which greatly increases the processing accuracy and assembly requirements. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a main rotor system;

[0007] The solution adopted by the present invention to solve the technical problem is:

[0008] on the one hand:

[0009] The invention discloses a torsion bar, comprising a torsion bar housing, an annular mounting cavity arranged inside the torsion bar housing, two sets of steel sleeves mounted on the torsion bar housing, and a torsion piece sleeved on the mounting cavity;

[0010] The installation cavity is a waist-shaped ring structure; it includes two groups of arc segments with the same structure and symmetrical arrangement, and a straight segment for connecting the two groups of arc segments;

[0011] The two groups of steel sleeves are arranged along the long direction of the straight section, and the axis connecting line and the center of the arc section are on the same straight line.

[0012] In some possible implementations,

[0013] The pulling and twisting member comprises a laminate layer which is in an annular structure and is sleeved in the installation cavity, and two groups of winding members which are located on both sides of the laminate layer and are symmetrically arranged.

[0014] In some possible implementations,

[0015] The winding member comprises two groups of steel wire layers sleeved in the installation cavity and a flexible material layer located between the two groups of steel wire layers;

[0016] Fiber cloth is wrapped on the outer sides of the laminate layer, the steel wire layer and the flexible material layer.

[0017] In some possible implementations, in order to effectively improve torsional stiffness;

[0018] The laminate layer comprises a plurality of groups of metal sheets which are arranged in parallel and sleeved in the installation cavity, and sealant is arranged between two adjacent groups of metal sheets.

[0019] on the other hand:

[0020] The present invention discloses a main rotor system, comprising a rotor shaft, a propeller hub sleeved on the outside of the rotor shaft, a propeller hub support arm integrally formed with the propeller hub, a variable pitch hinge assembly sleeved on the outside of the propeller hub support arm, a tension-torsion assembly sleeved in the propeller hub support arm, and a flapping hinge assembly installed above the propeller hub and sleeved on the outside of the rotor shaft; the propeller hub support arms are two groups with the same structure and are symmetrically arranged; the axes of the two groups of propeller hub support arms are on the same plane; the variable pitch hinge assembly, the tension-torsion assembly and the propeller hub support arms are arranged one by one;

[0021] One end of the tension-torsion assembly is connected to the propeller hub support arm, and the other end passes through the propeller hub support arm and is connected to the pitch hinge assembly via a fixing bolt;

[0022] The pull-twist assembly includes a sleeve sleeved in the propeller hub support arm, and a pull-twist strip as described above, one end of which is connected to the sleeve; the other end of the pull-twist strip passes through the propeller hub support arm and is connected to the pitch hinge assembly by a fixing bolt.

[0023] In some possible implementations,

[0024] The included angles formed by the axes of the two sets of hub arms and the axis of the hub are A, where A>90°; 94°≥A≥92°. This makes it possible to offset the hub root bending moment caused by aerodynamic loads.

[0025] In some possible implementations,

[0026] The propeller hub is provided with a mounting hole for being sleeved on the outside of the rotor shaft, and the propeller hub support arm is provided with a through hole connected with the mounting hole and used for installing the tension and torsion assembly;

[0027] The through hole includes a sleeve hole arranged near one side of the mounting hole and connected to the mounting hole, and a torsion hole arranged coaxially with the sleeve hole and used for installing the torsion strip;

[0028] The shaft sleeve comprises a sealing section installed in the shaft sleeve hole, and a matching section coaxially connected to the sealing section and arranged on the side of the sealing end close to the twisting hole; the matching section is in a frustum shape, and its large end is connected to the sealing section; wherein the outer diameter of the sealing section is larger than the outer diameter of the large end of the matching section.

[0029] In some possible implementations,

[0030] Two groups of anti-rotation parts are arranged at the bottom of the hub, and the anti-rotation parts are located at the bottom of the hub support arm; the anti-rotation parts are L-shaped structures, including part one located between the rotor shaft and the hub and abutting against the outer side surface of the sleeve, and part two connected to the bottom of part one and installed at the bottom of the hub.

[0031] In some possible implementations,

[0032] The flap hinge assembly is a prior art, which includes a flap hinge housing mounted on a hub, two sets of symmetrically arranged articulated seats mounted on the flap hinge housing, and a flap hanging point assembly mounted on a rotor shaft and connected to the articulated seats.

[0033] In some possible implementations,

[0034] The pitch hinge assembly is the same as the pitch hinge assembly in the prior art; it includes a pitch hinge housing that is sleeved on the outside of the hub support and is provided with a blind hole, a bearing assembly installed in the blind hole and cooperating with the hub support arm, an axial seal installed in the blind hole, and a pitch rocker arm installed on the pitch hinge housing.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The torsion strip provided in the present invention has good tensile bearing capacity, improves reliability, and improves torsional rigidity, and can have adaptive reset, thus having good recovery ability;

[0037] The present invention effectively avoids wear between two adjacent layers by providing the fiber cloth and the flexible material layer; at the same time, the flexible material layer can also effectively improve the torsional deformation capacity of the steel wire layer;

[0038] In the present invention, the hub and the hub support arm are integrally formed, which effectively improves the installation accuracy and prevents the reduction of the rotor fatigue life due to installation errors;

[0039] The shaft sleeve of the present invention is provided with a frustum-shaped matching section to offset the bending moment of the hub root caused by the aerodynamic load; and the hub support arm is abutted and fixedly connected with the shaft sleeve through the anti-rotation part, thereby avoiding the rotation of the torsion bar and realizing the swing limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the three-dimensional structure of the pull-twist strip of the present invention;

[0041] Figure 2 for Figure 1 A side view of;

[0042] Figure 3 for Figure 2 Sectional view at AA in the middle;

[0043] Figure 4 for Figure 2 Sectional view at the middle BB;

[0044] Figure 5 It is a structural schematic diagram of the main rotor system in the present invention;

[0045] Figure 6 It is a schematic diagram of the connection relationship between the rotor shaft, the propeller hub, the propeller hub support arm, the variable pitch hinge assembly, and the flapping hinge assembly in the present invention;

[0046] Figure 7 It is a schematic diagram of the connection relationship between the propeller hub support arm, the propeller hub, and the torsion bar in the present invention;

[0047] Figure 8 It is a schematic diagram of the cross-sectional connection relationship of a group of propeller hub arms, a propeller hub, a rotor shaft, and a torsion bar in the present invention;

[0048] Among them: 1. rotor shaft; 2. hub; 3. hub support arm; 4. pitch hinge assembly; 41. pitch hinge shell; 42. pitch rocker arm; 43. end cover 1; 44. bearing assembly; 5. swing hinge assembly; 51. hinge seat; 52. swing hanging point assembly; 6. tension and twist assembly; 61. bushing; 611. sealing section; 612. matching section; 62. tension and twist strip; 621. tension and twist strip shell; 622. installation cavity; 623. steel sleeve; 624. tension and twist part; 6241. laminated layer; 6242. steel wire layer; 6243. flexible material layer; 10. fixing bolt; 20. pin; 30. sealing ring; 40. anti-rotation part; 401. part 1; 402. part 2. DETAILED DESCRIPTION

[0049] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. The "first", "second" and similar words mentioned in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "one" or "one" and other similar words do not indicate a quantity restriction, but indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "multiple" refers to two or more. For example, multiple positioning columns refer to two or more positioning columns. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] The present invention is described in detail below.

[0051] Embodiment 1:

[0052] like Figure 1-Figure 4 As shown:

[0053] The present invention discloses a torsion bar 62, comprising a torsion bar housing 621, an annular mounting cavity 622 disposed inside the torsion bar housing 621, two sets of steel sleeves 623 mounted on the torsion bar housing 621, and a torsion piece 624 sleeved on the mounting cavity 622;

[0054] The torsion bar housing 621 includes two groups of arc segments with the same structure and symmetrically arranged, and a straight line segment located between the two groups of arc segments and connected to the arc segments; the three segments form a mounting cavity 622 with an annular structure.

[0055] The installation cavity 622 is a waist-shaped ring structure; it includes two groups of arc segments with the same structure and symmetrically arranged, and a straight segment for connecting the two groups of arc segments; preferably, the arc segments of the torsion strip shell 621 and the arc segments of the installation cavity 622 are both semicircular arc segments, and their centers are concentric.

[0056] The two groups of steel sleeves 623 are arranged along the long direction of the straight section, and the axis connecting the axis and the center of the arc section are on the same straight line.

[0057] The tension and torsion member is wrapped in the installation cavity 622; the two sets of steel sleeves 623 cooperate with the pin 20 to connect with the hub support arm 3 and the pitch hinge assembly 4 respectively, and the steel sleeves 623 are used to transmit centrifugal force and torsional load;

[0058] The steel sleeve 623 is mainly used to connect the hub 2 and the pitch hinge assembly 4, and mainly bears the centrifugal force of the blade and the manipulation force of the pitch torsion deformation. The torsion piece 624 is made of a material with high tensile strength and low torsion stiffness. When the tensile strength is met, a layered design can be used to reduce the torsion stiffness of the torsion strip 62.

[0059] Preferably, in order to reduce the weight of the torsion bar housing 321, a waist-shaped hole is provided on the torsion bar housing 321; the waist-shaped hole and the long axis and the axis line of the two sets of steel sleeves are on the same plane.

[0060] In some possible implementations,

[0061] The pulling and twisting member 624 includes a laminate layer 6241 in an annular structure and sleeved in the installation cavity 622 , and two groups of winding members located on both sides of the laminate layer 6241 and symmetrically arranged.

[0062] In some possible implementations,

[0063] The winding member includes two groups of steel wire layers 6242 sleeved in the installation cavity and a flexible material layer 6243 located between the two groups of steel wire layers;

[0064] The outer sides of the laminate layer 6241 , the steel wire layer 6242 , and the flexible material layer 6243 are wrapped with fiber cloth.

[0065] The laminate layer 6241 includes a plurality of groups of metal sheets arranged in parallel and sleeved in the installation cavity, and sealant is arranged between two adjacent groups of metal sheets.

[0066] like Figure 1-4As shown, the laminate layer 6241 is arranged on the center line of the installation cavity along its width direction, dividing the installation cavity into two small chambers, and the two groups of winding parts will be symmetrically arranged and located in the two small chambers; the laminate layer 6241 is made of multiple groups of metal sheets arranged in parallel and sleeved in the installation cavity; the two adjacent groups of metal sheets are separated by sealant. The purpose of doing this is, on the one hand, to strengthen the tensile bearing capacity of the pull-twist strip 62 and improve the reliability of the pull-twist strip 62 when the size is small, and on the other hand, to appropriately increase the torsional stiffness of the pull-twist strip 62, so that it can have adaptive reset and have good recovery ability.

[0067] The present invention sets four groups of steel sheet layers, which are arranged along the axial direction of the steel sleeve 623 and sleeved in the installation cavity 622. This is mainly for safety considerations, so that when two groups are damaged, the other two groups can still be used normally.

[0068] When assembling the pull-twist strip 62: first, a layer of steel wire 6242 is wound in the installation cavity 622, then fixed by a dipping process, and then wrapped with fiber cloth;

[0069] Secondly, the flexible material layer 6243 is installed, and after the flexible material layer 6243 is installed, it is wrapped with fiber cloth;

[0070] Subsequently, the second steel wire layer 6242 is wound in the same manner as the first steel wire layer 6242;

[0071] Next, the laminate layer 6241 is installed. Multiple groups of metal sheets are sequentially mounted in the installation cavity 622, and the gap between two adjacent layers of metal sheets is filled with sealant. The laminate layer 6241 is formed by using multiple groups of metal sheets to further improve the torsional rigidity.

[0072] Finally, install the wrapping piece on the other side in the same way as above;

[0073] The steel wire layer 6242 adopts the resin dipping process and uniform winding technology; each layer of steel wire layer 6242 is wound with a steel wire, and the uniform load of each strand of steel wire in the same layer is achieved through deformation coordination, while ensuring that the preload of the steel wire winding is within the design range;

[0074] In the transverse section of the tension and twist strip 62, a laminate layer 6241, a steel wire layer 6242, and a flexible material layer 6243 are arranged in sequence, and each layer is separated by fiber cloth to prevent wear between different material layers.

[0075] The flexible material layer 6243 and the fiber cloth reduce the wear between the adjacent two side materials, and the flexible material layer can also improve the torsional deformation capacity of the steel wire layer.

[0076] Preferably, the metal sheet is in a thin sheet structure.

[0077] Preferably, the flexible material layer can be made of a material with good flexibility, such as rubber or silicone.

[0078] After receiving the command of the main propeller pitch change from the flight tube computer, the servo drives the pull rod to move, and the servo control force is transmitted to the pitch rocker arm 42. The pitch rocker arm 42 drives the pitch hinge assembly 4 to rotate around the hub support arm 3, thereby realizing the change of the main rotor blade pitch. Specifically, the pitch movement of the pitch hinge assembly 4 is achieved by the elastic torsional deformation of the torsion bar 62 along its long center line; when the blade rotates at high speed, all centrifugal forces are transmitted by the torsion bar 62. Compared with the traditional structure, the torsion bar 62 of the present invention greatly optimizes the force condition of the pitch hinge assembly 4, so that the pitch hinge assembly 4 only transmits the lift of the unmanned helicopter.

[0079] on the other hand:

[0080] like Figure 1-Figure 8 As shown:

[0081] The present invention discloses a main rotor system, comprising a rotor shaft 1, a propeller hub 2 sleeved on the outside of the rotor shaft 1, a propeller hub support arm 3 integrally formed with the propeller hub 2, a variable pitch hinge assembly 4 sleeved on the outside of the propeller hub support arm 3, a tension-torsion assembly 6 sleeved in the propeller hub support arm 3, and a flapping hinge assembly 5 located above the propeller hub 2 and sleeved on the outside of the rotor shaft 1; the propeller hub support arms 3 are two groups with the same structure and are symmetrically arranged; the axes of the two groups of the propeller hub support arms 3 are on the same plane; the variable pitch hinge assembly 4, the tension-torsion assembly 6 and the propeller hub support arms 3 are arranged one by one;

[0082] One end of the tension-torsion assembly 6 is connected to the hub support arm 3 and the other end passes through the hub support arm 3 and is connected to the pitch hinge assembly 4 through the cooperation of the fixing bolt 10 and the steel sleeve; the cooperation between the fixing bolt 10 and the pitch hinge assembly 4 can effectively prevent the tension-torsion bar 62 from rotating away from one end of the rotor shaft 1.

[0083] The torsion assembly 6 comprises a sleeve 61 sleeved in the propeller hub support arm 3, a torsion bar 62 as described above, one end of which is connected to the sleeve 61; the other end of the torsion bar 62 passes through the propeller hub support arm 3 and is connected to the pitch hinge assembly 4 via a fixing bolt 10. The fixing bolt 10 will also effectively prevent the torsion bar 62 from rotating. Preferably, a protrusion can be provided on the pitch hinge housing 41, and a notch can be provided on the fixing bolt 10 to prevent rotation.

[0084] The pitch hinge assembly 4 is sleeved on the outer side of the propeller hub support arm 3, and can rotate around the axial direction of the propeller hub support arm 3 when in use;

[0085] A sealing ring 30 is provided on the outer side of the shaft sleeve 61, and the sealing ring 30 is used to seal the shaft sleeve 61 and the propeller hub support arm 3, thereby effectively preventing external dust and impurities from entering the pitch hinge housing 41;

[0086] In some possible implementations,

[0087] The hub 2 is provided with a mounting hole for being sleeved on the outside of the rotor shaft 1, and the hub support arm 3 is provided with a through hole connected with the mounting hole and used for installing the tension-torsion assembly 6;

[0088] The through hole includes a shaft sleeve 61 hole arranged near one side of the mounting hole and connected to the mounting hole, and a torsion hole arranged coaxially with the shaft sleeve 61 hole and used to install the torsion strip 62;

[0089] The shaft sleeve 61 includes a sealing section 611 installed in the hole of the shaft sleeve 61, and a matching section 612 coaxially connected to the sealing section 611 and arranged on the side of the sealing end close to the twisting hole; the matching section 612 is in a frustum shape, and its large end is connected to the sealing section 611; wherein the outer diameter of the sealing section 611 is larger than the outer diameter of the large end of the matching section 612.

[0090] Through the setting of the above-mentioned sleeve 61, the sleeve 61 will set a step that cooperates with the hub support arm 3, and realize the connection with the torsion bar 62 through the cooperation of the pin 20 and the steel sleeve, so as to prevent the torsion bar 62 from being pulled out of the hub support arm 3 after being stressed; the cone-shaped structure setting makes it easy to position and install the sleeve 61, making the installation of the sleeve 61 more convenient.

[0091] An end cover 2 is provided at one end of the hub support arm 3 away from the rotor shaft 1 , and one end of the torsion bar 62 away from the rotor shaft 1 passes through the end cover 2 and is connected to the variable pitch hinge assembly 4 by bolts.

[0092] In some possible implementations,

[0093] Two groups of anti-rotation parts 40 are provided at the bottom of the hub 2, and the anti-rotation parts 40 are located at the bottom of the hub support arm 3; the anti-rotation parts 40 are L-shaped structures, including a part 1 401 located between the rotor shaft 1 and the hub 2 and abutting against the outer side of the sleeve 61, and a part 2 402 connected to the bottom of the part 1 401 and installed at the bottom of the hub 2.

[0094] The second component 402 is connected to the bottom of the hub 2 by bolts to realize the connection between the hub 2 and the anti-rotation component 40.

[0095] When in use, the hub 2, driven by the flapping hinge assembly 5 and the pitch hinge assembly 4, will rotate around the hinge point between the hub and the flapping hinge assembly 5. During the rotation, the inner side of the hub 2 will come into contact with the rotor shaft 1. Component 401 is arranged between the hub 2 and the outer side of the rotor shaft 1, which will effectively avoid hard contact between the hub 2 and the rotor shaft 1 and achieve the effect of flapping limit. At the same time, component 401 will fix the sleeve 61 in the hub support arm 3, so that its anti-torsion strip will not rotate with the rotation of the pitch hinge assembly 4 around the axis of the hub support arm 3.

[0096] In some possible implementations,

[0097] The flap hinge assembly 5 is a prior art, which includes a flap hinge housing installed on the hub 2, two sets of hinge seats 51 installed on the flap hinge housing in a symmetrical manner and hinged to the flap hinge housing, and a flap hanging point assembly 52 mounted on the rotor shaft 1 and connected to the hinge seats 51.

[0098] Two sets of hinged seats 51 are fixedly connected to the rotor shaft 1 through the flapping hanging point assembly 52, and the flapping hinge housing is installed on the hub 2 and connected to the hinged seat, so that the hub 2 can rotate around the hinge point between the flapping hinge housing and the hinged seat after being subjected to force;

[0099] In some possible implementations,

[0100] The pitch hinge assembly 4 is the same as the pitch hinge assembly 4 in the prior art; it includes a pitch hinge housing 41 which is sleeved on the outer side of the hub 2 support and is provided with a blind hole, a bearing assembly 44 installed in the blind hole and cooperating with the hub support arm 3, an axial seal installed in the blind hole, a pitch rocker arm 42 installed on the pitch hinge housing 41, and an end cover 43 which is arranged on the side of the pitch hinge housing 41 close to the rotor shaft 1 and sleeved on the outer side of the hub support arm 3; the end cover 43 is connected to the pitch hinge housing 41 by bolts.

[0101] Furthermore, the bearing assembly 44 includes two groups of needle bearings and a bearing spacer sleeve located between the two groups of needle bearings, and the needle bearing sleeve is installed on the outer side of the hub support arm 3; an oil inlet channel is formed between the bearing spacer sleeve and the outer side of the hub support arm 3, and an oil filling hole and an oil drain hole connected to the oil inlet channel are provided on the pitch hinge housing 41; oil filling holes and oil drain holes are provided on the upper and lower parts of the pitch hinge housing 41 for lubrication of the needle bearings, an oil inlet channel is arranged inside, and a magnetic bolt is arranged at the oil drain hole for detecting the wear condition inside the pitch hinge housing 41.

[0102] The axial seal includes an oil seal arranged at the opening end of the blind hole and an end cover 43 oil seal arranged at the bottom of the blind hole; ensuring that the needle roller bearing has a good lubrication environment;

[0103] The flapping attachment point assembly 52 is mounted on the rotor shaft 1 by bolts, the flapping hinge assembly 5 is hingedly connected to the hub 2 by an articulated seat, and the variable pitch rocker arm 42 is connected to other components, thereby realizing the flapping motion of the seesaw rotor.

[0104] When in use, the main rotor blades (not shown in the figure) are connected to the pitch hinge housing 41 by installing bolts. The cooperation of the above two needle bearings and the bearing spacing sleeve can realize the rotation of the pitch hinge housing 41 around the axis of the hub support arm 3. One end of the pitch rocker arm 42 is installed on the pitch hinge housing 41 by bolt connection and the other end is connected to the articulated seat 51, ensuring that the pitch hinge housing 41 can realize pitch change movement.

[0105] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A main rotor system, It is characterized in that It comprises a rotor shaft, a propeller hub sleeved on the outside of the rotor shaft, a propeller hub support arm integrally formed with the propeller hub, a variable pitch hinge assembly sleeved on the outside of the propeller hub support arm, a tension-torsion assembly sleeved in the propeller hub support arm, and a flapping hinge assembly installed above the propeller hub and sleeved on the outside of the rotor shaft; the propeller hub support arms are two groups with the same structure and are symmetrically arranged; the axes of the two groups of propeller hub support arms are on the same plane; the variable pitch hinge assembly, the tension-torsion assembly and the propeller hub support arms are arranged one by one; One end of the tension-torsion assembly is connected to the propeller hub support arm, and the other end passes through the propeller hub support arm and is connected to the pitch hinge assembly via a fixing bolt; The tension-twist assembly comprises a shaft sleeve sleeved in the propeller hub support arm, and a tension-twist strip connected to the shaft sleeve at one end; the other end of the tension-twist strip passes through the propeller hub support arm and is connected to the pitch hinge assembly by a fixing bolt; The twist bar comprises a twist bar housing, a mounting cavity in an annular structure arranged inside the twist bar housing, two sets of steel sleeves mounted on the twist bar housing, and a twist piece sleeved on the mounting cavity; The installation cavity is a waist-shaped annular structure; it includes two groups of arc segments with the same structure and symmetrically arranged, and a straight segment for connecting the two groups of arc segments; the two groups of steel sleeves are arranged along the long direction of the straight segment, and the axis connecting line and the center of the arc segment are on the same straight line; The hub is provided with a mounting hole for being sleeved on the outside of the rotor shaft, and the hub support arm is provided with a through hole connected with the mounting hole and used for installing the torsion assembly; the through hole includes a sleeve hole arranged near one side of the mounting hole and connected with the mounting hole, and a torsion hole coaxially arranged with the sleeve hole and used for installing the torsion strip; The shaft sleeve comprises a sealing section installed in the shaft sleeve hole, and a matching section coaxially connected to the sealing section and arranged on the side of the sealing end close to the twisting hole; the matching section is in a frustum shape, and its large end is connected to the sealing section; wherein the outer diameter of the sealing section is larger than the outer diameter of the large end of the matching section; Two groups of anti-rotation parts are arranged at the bottom of the hub, and the anti-rotation parts are located at the bottom of the hub support arm; the anti-rotation parts are L-shaped structures, including part one located between the rotor shaft and the hub and abutting against the outer side surface of the sleeve, and part two connected to the bottom of part one and installed at the bottom of the hub.

2. A main rotor system according to claim 1, It is characterized in that The included angles formed by the axes of the two sets of propeller hub arms and the axis of the propeller hub are A, wherein A>90°.

3. A main rotor system according to claim 2, It is characterized in that 94°≥A≥92°。 4. A main rotor system according to claim 1, It is characterized in that The flap hinge assembly comprises a flap hinge housing mounted on a propeller hub, two sets of hinge seats symmetrically arranged on the flap hinge housing, and a flap hanging point assembly sleeved on a rotor shaft and connected to the hinge seats.

5. A main rotor system according to claim 4, It is characterized in that The pitch-changing hinge assembly comprises a pitch-changing hinge housing which is sleeved on the outside of a hub support and provided with a blind hole, a bearing assembly which is installed in the blind hole and cooperates with the hub support arm, an axial seal which is installed in the blind hole, and a pitch-changing rocker arm which is installed on the pitch-changing hinge housing.

6. A main rotor system according to claim 1, It is characterized in that The pulling and twisting member comprises a laminate layer which is in an annular structure and is sleeved in the installation cavity, and two groups of winding members which are located on both sides of the laminate layer and are symmetrically arranged.

7. A main rotor system according to claim 6, It is characterized in that The winding member comprises two groups of steel wire layers sleeved in the installation cavity and a flexible material layer located between the two groups of steel wire layers; Fiber cloth is wrapped on the outer sides of the laminate layer, the steel wire layer and the flexible material layer.

8. A main rotor system according to claim 6, It is characterized in that The laminate layer comprises a plurality of groups of metal sheets which are arranged in parallel and sleeved in the installation cavity, and sealant is arranged between two adjacent groups of metal sheets.

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