Hingeless variable pitch propeller hub, helicopter rotor and helicopter

Abstract

The present invention relates to a hingeless variable pitch hub, a helicopter rotor and a helicopter, belonging to the technical field of helicopters, and solves the problem that the rotor oscillation cannot be efficiently absorbed during helicopter flight, the blades stall, and thus restrict the helicopter's flight speed. The hingeless variable pitch hub of the present invention includes a hub central shell and a hub pitch-changing component; the hub pitch-changing component is connected to the outer peripheral side of the hub central shell; the hub pitch-changing component includes a blade clamp shell, a torque transmission assembly, a pitch-changing hinge support and a pitch-changing pull rod assembly; the torque transmission assembly is limited between the blade clamp shell and the pitch-changing hinge support; the proximal end of the blade unit is connected to the inside of the pitch-changing hinge support; the pitch-changing pull rod assembly is arranged inside the hub central shell and drives the pitch-changing hinge support to rotate, and the blade unit performs pitch-changing motion accordingly. The helicopter rotor and helicopter of the present invention can efficiently absorb the centrifugal force and oscillation of the blade unit, reduce the hub stiffness, and avoid the risk of resonance of the helicopter rotor and helicopter.

Description

Technical Field

[0001] The present invention relates to the technical field of helicopters, and in particular to a hingeless variable-pitch propeller hub, a helicopter rotor and a helicopter. Background Art

[0002] The rotor system is the heart of a helicopter, providing lift. The development of helicopter rotor systems has gone through three stages: the first generation featured articulated hubs and metal blades; the second generation employed radial flexible hubs, titanium alloy spherical flexible hubs, and all-composite blades; and the third generation employed large composite blades, spherical flexible hubs, and bearingless tail rotors. Most third-generation rotor systems have been widely installed.

[0003] Hingeless or bearingless rotors have been widely studied and applied because of their high control efficiency, ability to improve the maneuverability and followability of helicopters to a certain extent, and good driving quality.

[0004] At present, many domestic and foreign manufacturers will choose hingeless rotors (such as BO105 or Lynx) or bearingless rotors (such as EC135) at the beginning of aircraft design.

[0005] However, existing hingeless rotors and hingeless variable pitch propeller hubs lack flapping or shimmying hinges, only variable pitch hinges. The flapping and shimmying motions of the rotor blades are achieved through elastic deformation of the structure. This leads to the following technical problems:

[0006] 1. The coaxial rigid rotor in the existing technology adopts a rigid hingeless rotor configuration, eliminating the flapping and shimmying hinges, retaining only the variable pitch hinge, and the blade root is rigidly connected to the hub; because the blade stiffness must satisfy the requirements of the forward side bearing most of the lift and maintaining the spacing between the upper and lower rotor tips, the blade is stiffer than the conventional blade in the flapping, shimmying and torsion directions, and its dynamic characteristics are different from those of the conventional configuration rotor, resulting in the existing hingeless variable pitch hub stiffness being large, there is a risk of rotor resonance, affecting the flight safety and service life of the helicopter.

[0007] 2. The hingeless hub and blade connection method of the existing technology generally adopts a double-pin method. The blade airfoil starts at the blade root, and the blade root and the hub are connected by a blade pin. As a result, the blade airfoil that actually generates lift is not as close to the hub as possible, causing the starting position of the rotor airfoil to deviate from the rotor rotation center, which is not conducive to improving the aerodynamic efficiency of the helicopter and reducing aerodynamic drag.

[0008] 3. Existing hingeless hubs typically use large nuts to axially lock bearings. On one hand, these larger nuts are bulky and require specialized tooling for tightening, making conventional tools impossible, increasing installation costs. On the other hand, the large nuts exert significant torque, requiring the metal parts to be secured axially (typically no less than 6-8mm per side) to achieve this. This significantly increases hub stiffness, causing rotor resonance and impacting the helicopter's flight safety and service life.

[0009] Therefore, how to optimize the variable pitch hinge structure to reduce stiffness and solve the problem of helicopter resonance that may be caused during the transmission of hub power to blades is one of the technical difficulties. Summary of the Invention

[0010] In view of the above analysis, the present invention aims to provide a hingeless variable pitch propeller hub, a helicopter rotor and a helicopter to solve the technical problems that the existing rotor hub structure is unreasonable, easily generates rotor resonance, and affects the aerodynamic efficiency and flight safety of the helicopter.

[0011] The specific technical solutions are as follows:

[0012] A hingeless variable pitch hub comprises a hub central shell and a plurality of hub pitch change components; the plurality of hub pitch change components are distributed on the outer peripheral side of the hub central shell; each hub pitch change component is provided with a pitch change hinge support which can pass through a blade unit; the hub pitch change component also comprises a blade clamp shell, a torque transmission assembly and a pitch change pull rod assembly; the pitch change hinge support is rotatably arranged inside the blade clamp shell, and the torque transmission assembly is limitedly arranged between the blade clamp shell and the pitch change hinge support; the proximal end of the blade unit is connected to the inside of the pitch change hinge support; the pitch change pull rod assembly is arranged inside the hub central shell; one end of the pitch change pull rod assembly is connected to the proximal end of the pitch change hinge support and is located inside the hub central shell.

[0013] Furthermore, the proximal end of the blade unit is connected to the interior of the variable pitch hinge support; the interior of the variable pitch hinge support is provided with a support inner cavity positioning portion, a support inner cavity transition portion and a support inner cavity cone portion in axial sequence; the support inner cavity cone portion is a conical cavity with a distal end diameter larger than a proximal end diameter.

[0014] Furthermore, the propeller clamp housing includes a propeller clamp housing cylinder; a cylindrical roller bearing outer mounting portion, a thrust cylindrical bearing outer mounting portion, a propeller clamp housing limit platform and an angular bearing outer mounting portion are sequentially arranged inside the propeller clamp housing cylinder along the axial direction.

[0015] Furthermore, the outside of the variable pitch hinge support is provided with a cylindrical roller bearing inner mounting part, a thrust cylindrical bearing inner mounting part, an angular bearing inner mounting part, a support axial positioning groove, an axial positioning block positioning ring and a support barrel tail in sequence along the axial direction; an axial positioning block positioning ring is radially provided with an axial positioning block ring locking part.

[0016] Furthermore, the torque transmission assembly includes a torque transmission unit; the torque transmission unit includes a cylindrical roller bearing, a thrust cylindrical bearing unit and an angular bearing arranged in sequence along the axial direction; the thrust cylindrical bearing unit includes two thrust cylindrical bearings arranged continuously in the axial direction.

[0017] Furthermore, a second retaining ring is provided between the cylindrical roller bearing and the thrust cylindrical bearing unit, and a first retaining ring is provided at the distal end surface of the angular bearing;

[0018] An axial positioning unit is provided at the distal end surface of the first retaining ring; the axial positioning unit includes at least two axial positioning blocks.

[0019] Furthermore, the axial positioning block is provided with an axial positioning platform, a positioning locking portion, an anti-rotation limiting groove and an axial adjustment mounting portion; the axial adjustment mounting portion is connected to an axial position adjustment component.

[0020] Furthermore, the axial positioning platform is arranged at the proximal end of the axial positioning block; the anti-rotation limit groove is axially penetrating and arranged in the middle of the inner ring of the axial positioning block; a positioning locking portion is provided on the axial positioning block, and a radial clamping bolt is connected to the positioning locking portion.

[0021] A helicopter rotor comprises at least one hingeless variable pitch hub as described above, and also includes a blade unit and a rotor hub connecting unit; the rotor hub connecting unit includes an anti-rotation pin and a blade locking nut; the blade unit includes a blade mounting portion and a blade airfoil portion; the blade mounting portion is arranged through the interior of the variable pitch hinge support and is connected to the proximal end of the variable pitch hinge support through the blade locking nut; the anti-rotation pin is arranged at the connection between the blade mounting portion and the blade airfoil portion, and is used to radially limit the blade unit on the variable pitch hinge support.

[0022] A helicopter comprises the helicopter rotor and a helicopter fuselage; a control system is provided on the helicopter fuselage; the control system is located inside the central shell of the hub and is connected to the pitch-changing rod assembly; the control system can drive the blade unit to perform pitch-changing movement through the pitch-changing rod assembly and the pitch-changing hinge support.

[0023] Compared with the prior art, the present invention can achieve at least the following beneficial effects:

[0024] 1. The hingeless variable-pitch hub of the present invention connects the proximal end of the blade unit to the inside of the variable-pitch hinge support and the variable-pitch pull rod assembly is arranged inside the central shell of the hub. This connection method not only makes the overall structure of the hingeless variable-pitch hub compact, but also makes the starting position of the blade unit as close as possible to the rotation center of the hingeless variable-pitch hub; this connection method can effectively reduce the aerodynamic drag of the helicopter's control system, improve the helicopter's aerodynamic efficiency, and reduce the helicopter's aerodynamic resistance.

[0025] 2. The blade unit of the hingeless variable pitch hub of the present invention is compressed during the installation process by the blade locking nut, and the support position of the blade unit is set between the blade mounting portion and the conical surface of the variable pitch hinge support, avoiding the need for special tooling for rotor installation and effectively improving installation efficiency.

[0026] 3. The variable pitch hinge support of the present invention has a larger proximal end thickness and a thinner distal end design, which effectively reduces the overall stiffness of the hingeless variable pitch hub, not only improving the service life of the hingeless variable pitch hub, but also avoiding the occurrence of rotor resonance, effectively ensuring the improvement of the helicopter's aerodynamic efficiency and flight safety.

[0027] Other features and advantages of the present invention will be described in the following description, and some advantages may become apparent from the description or may be understood by practicing the present invention. The purpose and other advantages of the present invention may be realized and obtained through the contents particularly pointed out in the description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0029] Figure 1 This is a schematic structural diagram of the hingeless variable pitch propeller hub after the blade unit is installed in Example 1 of the present invention;

[0030] Figure 2 for Figure 1 Middle AA section view;

[0031] Figure 3 Schematic diagram of the structure of the variable pitch hinge support member according to Example 1 of the present invention;

[0032] Figure 4 for Figure 3 Middle BB section view;

[0033] Figure 5 This is a schematic diagram of the hub flange structure of Example 1 of the present invention;

[0034] Figure 6 for Figure 5 Middle CC section view;

[0035] Figure 7 This is a schematic structural diagram of the axial positioning block according to Example 1 of the present invention;

[0036] Figure 8 Schematic diagram of the rotor rocker arm structure of Example 1 of the present invention;

[0037] Figure 9 This is a schematic structural diagram of the hub central housing according to Example 1 of the present invention;

[0038] Figure 10 for Figure 9 Middle DD section view;

[0039] Figure 11 This is a schematic diagram of the helicopter rotor structure according to embodiment 2 of the present invention;

[0040] Figure 12 It is a schematic diagram of the blade unit structure of the present invention.

[0041] Reference numerals:

[0042] 1. Hub central housing; 11. Housing upper mounting platform; 111. Housing upper mounting portion; 12. Housing lower mounting platform; 121. Housing lower mounting portion; 13. Housing side mounting portion; 131. Housing pitch change mounting surface; 1311. Housing hub mounting position; 132. Housing hub clearance; 2. Hub components; 21. Propeller clamp housing; 211. Propeller clamp housing cylinder; 2111. Angular bearing outer mounting portion; 2112. Propeller clamp housing limit platform; 21121. Limit platform oil hole; 2113. Thrust cylindrical bearing outer mounting portion; 2114. Cylindrical roller bearing outer mounting portion; 212. Propeller clamp housing flange; 2121. Propeller clamp housing flange mounting position; 213. First oil filling hole; 214. Second oil filling hole; 2151. First slot; 2152. Second slot; 22. Torque transmission assembly; 2211. Axial positioning block; 22111. Axial positioning platform; 22112. Positioning and locking portion; 22113. Anti-rotation limit groove; 22114. Reserved mounting portion; 22115. Axial adjustment mounting portion; 2212. First retaining ring; 2213. Second retaining ring; 2221. First retaining ring; 2222. Second retaining ring; 2231. First oil seal; 2232. Second oil seal; 224. Angular bearing; 225. Thrust cylindrical bearing; 226. Cylindrical roller bearing; 23. Pitch hinge support; 231. Inner cavity of support; 2311. Inner cavity of support Cavity cone; 2312. Support member inner cavity transition portion; 2313. Support member inner cavity positioning portion; 232. Support member axial positioning groove; 233. Angular bearing inner mounting portion; 234. Thrust cylindrical bearing inner mounting portion; 235. Cylindrical roller bearing inner mounting portion; 236. Axial positioning block positioning ring; 2361. Axial positioning block ring locking portion; 2362. Axial positioning block ring circumferential limiting portion; 237. Anti-slip pin passing portion; 238. Support member flange; 2381. Support member flange connection position; 2382. Support member flange mounting position; 239. Support member barrel tail; 24. Oil filling unit; 241. First oil filling plug; 242. Second oil filling plug; 25. Pitch rod assembly ;251. Rotor rocker arm; 2511. Rotor rocker arm mounting platform; 25111. Rotor rocker arm mounting part; 2512. Rotor rocker arm connecting arm; 25121. Rotor rocker arm connecting part; 252. Pitch rod unit; 2521. Pitch rod power input part; 26. Radial compression bolt; 27. Counterweight; 3. Blade unit; 31. Blade mounting part; 311. Blade locking part; 312. Blade locking support part; 313. Blade transition part; 314. Blade anti-slip pin connecting part; 315. Blade damping chamber; 32. Blade airfoil part; 4. Rotor hub connecting unit; 41. Anti-rotation pin; 42. Blade locking nut; 100. Upper rotor part; 200. Lower rotor part. DETAILED DESCRIPTION

[0043] The following is combined with Figures 1-12The 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.

[0044] This embodiment sets:

[0045] (1) For all components, units, and parts, the end closest to the center of the hub central housing 1 is the proximal end, and the end away from the center of the hub central housing 1 is the distal end.

[0046] (2) The up and down direction settings are marked with the position of the helicopter when it is grounded.

[0047] Example 1

[0048] Embodiment 1 of the present invention shows a hingeless variable pitch propeller hub.

[0049] Combine Figures 1-10 , the hingeless variable pitch hub technical solution of this embodiment 1 is introduced.

[0050] like Figure 1 As shown, the hingeless variable-pitch hub of this embodiment 1 includes a hub central housing 1 and a hub pitch-changing component 2. The hub central housing 1 is used to connect the hub pitch-changing component 2 to the helicopter fuselage. Multiple hub pitch-changing components 2 are evenly distributed around the circumference of the hub central housing 1. The helicopter's blade units 3 are connected through the hub pitch-changing component 2. The hub central housing 1 is axially connected to the helicopter fuselage, and the central axis of the hub central housing 1 serves as the rotation center of the helicopter's rotor.

[0051] Specifically, this embodiment 1 includes four hub pitch change components 2; the four hub pitch change components 2 are evenly distributed around the middle of the outer circumference of the hub central housing 1. The four hub pitch change components 2 are used to connect to the blade units 3 of four helicopters.

[0052] The hub central housing 1 is open at both ends and includes a housing upper mounting platform 11, a housing lower mounting platform 12 and a housing side mounting portion 13. The housing side mounting portion 13 is arranged on the outer circumference of the hub central housing 1.

[0053] like Figure 9 and Figure 10 As shown, in this embodiment 1, the hub central shell 1 preferably has an overall structure of a rotary shell with an arc-shaped busbar and open ends, and a through hole formed in the middle is used to connect to the helicopter fuselage.

[0054] The upper shell mounting platform 11 and the lower shell mounting platform 12 are distributed at the upper and lower ends of the hub central shell 1; the upper shell mounting platform 11 and the lower shell mounting platform 12 are provided with an upper shell mounting portion 111 on the periphery of the upper end surface through hole of the upper shell mounting platform 11, and a lower shell mounting portion 121 on the periphery of the lower end surface through hole of the lower shell mounting platform 12.

[0055] The upper housing mounting portion 111 and the lower housing mounting portion 121 are screw holes for mounting the helicopter fuselage. The control system within the helicopter fuselage is housed within the rotary housing cavity of the hub central housing 1. The control system has a power output portion, which outputs power through the hub pitch control component 2 to drive the blade unit 3 to perform pitch movement.

[0056] Specifically, four housing-side mounting portions 13 are evenly distributed on the middle circumference of the outer circumference of the hub central housing 1 of this embodiment 1; each housing-side mounting portion 13 is connected to one hub pitch-changing component 2 .

[0057] like Figure 9 and Figure 10 As shown, each of the housing side mounting portions 13 includes a housing pitch change portion mounting surface 131 and a housing hub clearance portion 132. The housing hub clearance portion 132 is provided at the end surface of the housing pitch change portion mounting surface 131 and passes through the housing of the hub central housing 1.

[0058] Specifically, the shell hub yield portion 132 of this embodiment 1 is located in the middle of the shell pitch change portion mounting surface 131 and passes through the rotary shell side wall of the hub central shell 1; the helicopter's control system can connect the hub pitch change component 2 through the space of the shell hub yield portion 132.

[0059] The housing pitch-changing portion mounting surface 131 is provided with a plurality of housing hub mounting positions 1311. The hub pitch-changing component 2 is fitted onto the housing pitch-changing portion mounting surface 131 and connected to the hub central housing 1 at the housing pitch-changing portion mounting surface 131. Preferably, the housing hub mounting positions 1311 are screw holes.

[0060] The hub pitch-changing component 2 and the helicopter blade unit 3 connected thereto are connected to the hub central housing 1 along the normal direction of the housing pitch-changing portion mounting surface 131 .

[0061] like Figure 2 and Figure 10 As shown, preferably, the casing pitch changing portion mounting surface 131 of this embodiment 1 is tilted relative to the central axis of the hub central casing 1 .

[0062] Specifically in this embodiment 1, a pre-taper angle a is formed between the normal line of the housing pitch-changing portion mounting surface 131 and the end surface of the hub central housing 1. This pre-taper angle a enables the distal end of the hub pitch-changing component 2 and the blade unit 3 connected thereto to be higher than the proximal end thereof (in the grounded position), thereby increasing the centrifugal force unloading effect of the blade unit 3, reducing the static bending moment at the proximal end of the blade unit 3, and improving the service life of the overall structure of the blade unit 3.

[0063] The pre-cone angle a is related to parameters such as the take-off weight of the helicopter, overload design parameters, the centrifugal force of the blade unit 3 , and the number of blades of the blade unit 3 .

[0064] Preferably, in this embodiment 1, a≤5°.

[0065] like Figure 1 and Figure 2 As shown, the hub pitch change component 2 includes a blade clamp housing 21, a torque transmission assembly 22, a pitch change hinge support 23 and a pitch change rod assembly 25.

[0066] The paddle clamp housing 21 is connected to the housing pitch change portion mounting surface 131 of the housing side mounting portion 13 at the proximal end by fasteners; the pitch change hinge support 23 is arranged inside the paddle clamp housing 21, and the torque change transmission assembly 22 is limitedly arranged between the paddle clamp housing 21 and the torque change transmission assembly 22; the pitch change hinge support 23 can rotate relative to the paddle clamp housing 21 through the torque change transmission assembly 22.

[0067] like Figure 1 As shown, in this embodiment 1, the pitch-changing rod assembly 25 is located in the inner cavity of the hub central housing 1. The first end of the pitch-changing rod assembly 25 is connected to the proximal end of the pitch-changing hinge support 23, and the second end of the pitch-changing rod assembly 25 can be connected to the helicopter control system. The helicopter control system is located on the helicopter fuselage in the inner cavity of the hub central housing 1.

[0068] The blade unit 3 is connected through the pitch hinge support 23 and is fixedly connected to the pitch hinge support 23 through the rotor hub connection unit 4, and rotates with the rotation of the pitch hinge support 23.

[0069] The control system drives the pitch-changing hinge support 23 to rotate with the central axis of the blade clamp housing 21 as the center line through the pitch-changing pull rod assembly 25, thereby realizing the pitch-changing movement of the blade unit 3 under the control of the control system, thereby adjusting the size and direction of the lift and controlling the helicopter to achieve various flight postures.

[0070] like Figure 5 and Figure 6As shown, the blade clamp housing 21 of this embodiment 1 is a cylindrical structure with two ends open, including an integrally formed blade clamp housing cylinder 211 and a blade clamp housing flange 212. Inside the blade clamp housing cylinder 211, a cylindrical roller bearing outer mounting portion 2114 for connecting to the torque converter assembly 22, a thrust cylindrical bearing outer mounting portion 2113, a blade clamp housing stop 2112, and the blade clamp housing cylinder 211 are sequentially arranged along the axial direction.

[0071] The blade clamp housing flange 212 is an outer flange located proximal to the blade clamp housing cylindrical body 211. It is provided with a blade clamp housing flange mounting position 2121 that matches the position and size of the housing propeller hub mounting position 1311. The outer end surface of the blade clamp housing flange 212 abuts the housing pitch change portion mounting surface 131. In this embodiment, the blade clamp housing flange mounting position 2121 is a through hole that matches the position and size of the housing propeller hub mounting position 1311.

[0072] The fastener passes through the flange mounting position 2121 of the propeller clamp housing and is screwed onto the housing hub mounting position 1311 to fasten the hub pitch change component 2 to the hub central housing 1 .

[0073] The blade clamp housing cylinder 211 has a stepped shaft exterior, with an arcuate transition at its proximal end to the blade clamp housing flange 212. The blade clamp housing cylinder 211 has a stepped hole interior for axially limiting connection with the external structure of the variable pitch hinge support 213 to the torque transmission assembly 22.

[0074] The special-shaped cylindrical structure of the blade clamp housing flange 212 can increase the structural rigidity of the blade clamp housing 21 while achieving lightweight.

[0075] like Figure 6 Specifically, in this embodiment 1, a paddle clamp housing stop 2112 is provided near the distal end of the paddle clamp housing cylinder 211. The paddle clamp housing stop 2112 is provided distally with the paddle clamp housing cylinder 211. A thrust cylindrical bearing outer mounting portion 2113 and a cylindrical roller bearing outer mounting portion 2114 are sequentially provided proximally with the paddle clamp housing stop 2112. An axially extending stop oil hole 21121 is provided on the paddle clamp housing stop 2112.

[0076] The paddle clamp housing 21 of this embodiment 1 is further provided with a first slot 2151 and a second slot 2152 at both ends thereof. The first slot 2151 and the second slot 2152 are annular slot structures.

[0077] The variable pitch hinge support 23 of this embodiment 1 is a cylindrical structure, which is rotatably arranged inside the propeller clamp housing 21 and can be rotated relative to the propeller clamp housing 21 through the torque transmission assembly 22; the proximal end of the blade unit 3 is connected to the inside of the variable pitch hinge support 23; the variable pitch pull rod assembly 25 is connected to the proximal end of the variable pitch hinge support 23.

[0078] like Figure 3 and Figure 4 As shown, specifically, a support flange 238 is provided at the proximal end of the variable pitch hinge support 23. A plurality of support flange connection positions 2381 are evenly distributed around the outer circumference of the support flange 238; the support flange connection positions 2381 are used to connect the variable pitch tie rod assembly 25.

[0079] Preferably, the support flange connection position 2381 is a screw hole.

[0080] A support flange mounting position 2382 is provided at the center of the proximal end surface of the support flange 238; the support flange mounting position 2382 is used to connect the blade unit 3. Preferably, the support flange mounting position 2382 is a sunken platform structure.

[0081] The exterior of the variable pitch hinge support 23 is a stepped shaft structure, and a cylindrical roller bearing inner mounting portion 235, a thrust cylindrical bearing inner mounting portion 234, an angular bearing inner mounting portion 233, a support axial positioning groove 232, and an axial positioning block positioning ring 236 are sequentially arranged along the axial direction from the proximal end to the distal end, for connecting the torque transmission assembly 22; the farthest end of the variable pitch hinge support 23 is the support barrel tail 239.

[0082] A plurality of radially arranged axial positioning block ring stage locking portions 2361 are evenly distributed on the circumference of the axial positioning block positioning ring stage 236. Preferably, the axial positioning block ring stage locking portions 2361 of this embodiment 1 are screw holes.

[0083] The axial positioning block positioning ring 236 is further provided with a plurality of raised axial positioning block ring circumferential limiting portions 2362. The axial positioning block ring circumferential limiting portions 2362 are arranged along the busbar direction.

[0084] The support member barrel tail 239 is provided with an anti-slip pin passage 237 in the radial direction. The anti-slip pin passage 237 is used to install an anti-rotation pin 41 that limits the blade unit 3 from rotating.

[0085] In the first embodiment, the anti-slip pin passage portion 237 is preferably connected to a counterweight 27 ; the counterweight 27 is preferably mounted on the outer periphery of the oar clamp housing 21 through the anti-rotation pin 41 .

[0086] When the dynamic balance of the helicopter rotor needs to be adjusted, the counterweight 27 can be added or removed to perform balancing.

[0087] like Figure 4 As shown, inside the variable pitch hinge support 23, there are arranged a support inner cavity positioning portion 2313, a support inner cavity transition portion 2312 and a support inner cavity tapered portion 2311 in sequence from the proximal end to the distal end along the axis. The support inner cavity tapered portion 2311 is a tapered cavity with a distal diameter larger than a proximal diameter.

[0088] The support member inner cavity positioning portion 2313 is used to position the proximal end of the blade unit 3.

[0089] like Figure 4 As shown, the variable pitch hinge support 23 is a special-shaped cylindrical body with a thicker proximal end. The distal end of the support's inner conical portion 2311 is a conical cavity with a tapered angle that opens toward the distal end, and the distal wall thickness gradually becomes thinner. This structure can achieve the following technical effects:

[0090] (1) The variable pitch hinge support 23 has a wall thickness that gradually becomes thinner and an inner cavity diameter that gradually increases toward the distal end at the support tube tail 239, which can adapt to the gradual increase in the shape of the blade unit 3 toward the distal end, making it easier to design a strength-enhancing structure for the blade unit 3.

[0091] (2) During the flight of the helicopter, the stiffness of the blade unit 3 is required to satisfy the requirement that the forward side bears most of the lift and maintains the spacing between the upper and lower rotor tips. Therefore, the blade unit 3 is stiffer than conventional blades in the flapping, swinging and torsion directions. Therefore, the hub stiffness must be reduced to avoid the risk of rotor resonance. The variable pitch hinge support 23 of the present invention has a larger proximal end thickness and a thinner distal end design, which can effectively reduce the overall stiffness of the hingeless variable pitch hub and meet the requirements for the stiffness of the hingeless variable pitch hub during the flight of the helicopter.

[0092] like Figure 2 As shown, the torque transmission assembly 22 of this embodiment 1 is installed between the inner wall surface of the blade clamp housing 21 and the outer wall surface of the pitch hinge support 23.

[0093] The torque transmission assembly 22 includes a torque transmission unit, a torque transmission axial limiting unit, an oil seal unit and a retaining ring unit.

[0094] Specifically, the torque transmission unit includes a cylindrical roller bearing 226, a thrust cylindrical bearing unit, and an angular bearing 224, which are sequentially arranged axially from the proximal end to the distal end. The thrust cylindrical bearing unit includes two thrust cylindrical bearings 225 that are sequentially arranged axially.

[0095] like Figure 2 、 Figure 4 and Figure 6 As shown, the cylindrical roller bearing 226 is disposed between the cylindrical roller bearing inner mounting portion 235 and the cylindrical roller bearing outer mounting portion 2114; the angular bearing 224 is disposed between the angular bearing inner mounting portion 233 and the angular bearing outer mounting portion 2111. The cylindrical roller bearing 226 and the angular bearing 224 withstand the swinging bending moment of the blade unit 3, providing radial damping.

[0096] Specifically, the thrust cylindrical bearing unit is arranged between the thrust cylindrical bearing inner mounting portion 234 and the thrust cylindrical bearing outer mounting portion 2113; the two thrust cylindrical bearings 225 of the thrust cylindrical bearing unit bear the axial centrifugal load of the blade unit 3 to form tangential damping.

[0097] The torque transmission axial limiting unit includes an axial positioning unit, a first retaining ring 2212 and a second retaining ring 2213. The axial positioning unit includes at least two axial positioning blocks 2211.

[0098] like Figure 2 As shown, the axial positioning unit of this embodiment 1 includes two axial positioning blocks 2211 of semicircular arc plates, and the two axial positioning blocks 2211 are connected together on the outer periphery of the variable pitch hinge support 23, specifically located at the axial positioning groove 232 of the support and the axial positioning block positioning ring 236.

[0099] like Figure 7 As shown, preferably, the axial positioning block 2211 is a semicircular arc plate, which facilitates connecting the two axial positioning blocks 2211 to the variable pitch hinge support 23 without interference.

[0100] Specifically, the proximal end of the axial positioning block 2211 is provided with an axial positioning platform 22111 of the inner ring platform, and the middle part of the inner ring of the axial positioning block 2211 is provided with a through anti-rotation limit groove 22113 along the busbar. The axial positioning platform 22111 is installed in the axial positioning groove 232 of the support member. The anti-rotation limit groove 22113 is used to accommodate the circumferential limit portion 2362 of the axial positioning block ring platform to limit the circumferential rotation of the axial positioning block positioning ring platform 236. The anti-rotation limit groove 22113 and the axial positioning platform 22111 can prevent the axial positioning unit from circumferentially rotating and axially displacing on the variable pitch hinge support member 23, ensuring that the positions of the two are relatively fixed and can maintain consistency in movement.

[0101] Specifically, the axial positioning block 2211 is provided with a plurality of positioning locking portions 22112 along the circumference; preferably, the positioning locking portions 22112 are radial through holes symmetrically arranged on both sides of the anti-rotation limit groove 22113, and the positioning locking portions 22112 are connected with radial clamping bolts 26, and the radial clamping bolts 26 can further fasten the axial positioning unit to the outer periphery of the variable pitch hinge support 23.

[0102] Specifically, the axial positioning block 2211 is further provided with an axial adjustment mounting portion 22115 for mounting an axial position adjustment component to adjust the axial position of the internal structure of the torque transmission assembly 22 .

[0103] Preferably, the axial adjustment mounting portion 22115 of this embodiment 1 is a structure of multiple through screw holes arranged circumferentially, and the axial position adjustment component is an axial position adjustment screw.

[0104] Specifically, the axial positioning block 2211 is further provided with an axial positioning block connecting ear, and the axial positioning block connecting ear is provided with a reserved mounting portion 22114. Preferably, the reserved mounting portion 22114 is a screw hole structure for screwing an external device.

[0105] The first retaining ring 2212 is disposed between the proximal end of the axial positioning unit and the distal end of the angular bearing 224. Tightening the axial position adjustment screw of the axial position adjustment member pushes the first retaining ring 2212 proximally, thereby adjusting the axial position of the angular bearing 224 and axially securing the angular bearing 224 to the distal end surface of the blade clamp housing limit platform 2112, ensuring that the angular bearing 224 does not move axially, that it bears minimal radial load, and that it does not slip during operation.

[0106] The second retaining ring 2213 is disposed between the distal end of the cylindrical roller bearing 226 and the proximal end of the thrust cylindrical bearing unit. By selecting a suitable axial height dimension, on the one hand, the second retaining ring 2213 can cooperate with the proximal end face of the paddle clamp housing limit platform 2112 to clamp the thrust cylindrical bearing unit, ensuring that the thrust cylindrical bearing unit does not move axially; on the other hand, the second retaining ring 2213 is disposed between the cylindrical roller bearing 226 and the thrust cylindrical bearing unit, which can effectively ensure the direction of force transmission (because: the inner ring of the cylindrical roller bearing 226 is relatively narrow, and when transmitting centrifugal force, it is similar to a point load, which affects the load and life of the thrust cylindrical bearing 225; the second retaining ring 2213 can convert the point load into a surface load and then apply pressure to the thrust cylindrical bearing 225, preventing the thrust cylindrical bearing unit from bearing an unbalanced load).

[0107] Specifically, the oil seal unit includes a first oil seal 2231 and a second oil seal 2232 .

[0108] Specifically, the retaining ring unit includes a first retaining ring 2221 and a second retaining ring 2222 .

[0109] In the overall structural layout of the torque converter assembly 22, the first oil seal 2231 is disposed at the proximal end of the first retaining ring 2221, and the second oil seal 2232 is disposed at the distal end of the second retaining ring 2222. The retaining ring unit axially positions the oil seal unit, which is used to lock the grease in the torque converter assembly 22 to prevent the grease from being ejected due to centrifugal force.

[0110] Specifically, the first retaining ring 2221 is arranged in the first groove 2151 at the distal end of the paddle clamp housing 21, and the first oil seal 2231 is axially installed at the proximal end of the first groove 2151 and radially installed between the outer periphery of the first retaining ring 2212 and the outer mounting portion 2111 of the angular bearing.

[0111] Specifically, the second retaining ring 2222 is arranged in the second groove 2152 at the proximal end of the paddle clamp housing 21; the second oil seal 2232 is axially installed at the distal end of the second groove 2152 and radially installed between the outer periphery of the cylindrical roller bearing inner mounting portion 235 and the cylindrical roller bearing outer mounting portion 2114.

[0112] like Figure 5 As shown, an oil injection structure is provided on the wall of the cylinder body 211 of the paddle clamp housing, and the oil injection structure includes a first oil injection hole 213 and a second oil injection hole 214 .

[0113] The oil injection structure is used to connect to the oil injection unit 24, and the oil injection unit 24 is used to inject the grease into the torque transmission assembly 22 inside the blade clamp housing 21 to enable the torque transmission assembly 22 to rotate flexibly. Preferably, the grease is aviation grease.

[0114] The oil filling unit 24 includes a first oil filling plug 241 and a second oil filling plug 242. The first oil filling plug 241 is connected to the first oil filling hole 213, and the second oil filling plug 242 is connected to the second oil filling hole 214.

[0115] like Figure 2 and Figure 6 As shown, preferably, the axis of the first oil filling hole 213 is radially arranged on the proximal wall of the limit platform 2112 of the propeller clamp housing, and is connected with the oil hole 21121 of the limit platform; so that the grease injected by the first oil filling plug 241 can lubricate the thrust cylindrical bearing unit and the angular bearing 224 at the same time.

[0116] like Figure 2 and Figure 6 As shown, preferably, the axis of the second oil plug 242 is radially arranged at the junction of the cylindrical roller bearing outer mounting portion 2114 and the thrust cylindrical bearing outer mounting portion 2113 and is located on one side of the thrust cylindrical bearing outer mounting portion 2113; so that the grease injected by the second oil plug 242 can lubricate the thrust cylindrical bearing unit and the cylindrical roller bearing 226 at the same time.

[0117] like Figure 1 and Figure 2 As shown, the proximal end surface of the support flange 238 of the variable pitch hinge support 23 is connected to the variable pitch pull rod assembly 25 through the support flange connection position 2381.

[0118] The control system drives the pitch-variable lever assembly 25 and the pitch-variable hinge support 23 to rotate together about the central axis of the blade clamp housing 21, thereby achieving pitch-variable motion of the blade unit 3 under the control of the control system, thereby adjusting the magnitude and direction of the lift generated by the blade unit 3 and thereby controlling the helicopter to achieve various flight attitudes. Specifically, the pitch-variable lever assembly 25 includes a rotor rocker arm 251 and a pitch-variable lever unit 252; the rotor rocker arm 251 is hinged to the pitch-variable lever unit 252.

[0119] Preferably, the rotor rocker arm 251 of this embodiment 1 is connected to the proximal end of the pitch-changing hinge support 23, and the pitch-changing pull rod unit 252 is connected to the control system.

[0120] like Figure 8 As shown, the rotor rocker arm 251 includes a rotor rocker arm mounting platform 2511 and a rotor rocker arm connecting arm 2512 , and the rotor rocker arm mounting platform 2511 is hinged to the rotor rocker arm connecting arm 2512 .

[0121] The rotor rocker arm mounting platform 2511 is a ring-shaped structure with multiple rotor rocker arm mounting portions 25111 evenly distributed around its circumference. The structure of the rotor rocker arm mounting portions 25111 corresponds to the structure of the support flange connection position 2381, and is preferably a through-hole structure. A fastener passes through the rotor rocker arm mounting portion 25111 and is screwed into the screw hole of the support flange connection position 2381, thereby fixing the pitch-changing rod assembly 25 to the proximal end face of the pitch-changing hinge support 23. This allows the control system to drive the pitch-changing hinge support 23 to rotate about the central axis of the blade clamp housing 21 through the pitch-changing rod assembly 25, thereby achieving pitch-changing motion of the blade unit 3.

[0122] like Figure 8As shown, the rotor rocker arm connecting arm 2512 is a support arm structure relative to the rotor rocker arm mounting platform 2511, and a rotor rocker arm connecting part 25121 is provided at the far end of the support arm of the rotor rocker arm connecting arm 2512; the center of the rotor rocker arm connecting part 25121 is away from the central axis of the rotor rocker arm mounting platform 2511; the pitch rod assembly 25 is connected to the power output part of the control system through the rotor rocker arm connecting part 25121.

[0123] The variable pitch pull rod assembly 25 of this embodiment 1 is connected to the inner cavity of the blade clamp housing 21, which can not only reduce the peripherals of the drone, but also effectively reduce the aerodynamic drag of the control system.

[0124] Example 2

[0125] This embodiment 2 discloses a helicopter rotor.

[0126] Combine Figure 1 、 Figure 2 、 Figure 11 and Figure 12 , the technical solution of this embodiment 2 is introduced.

[0127] like Figure 1 and Figure 2 As shown, the helicopter rotor of this embodiment 2 includes two propeller hubs; wherein, at least one propeller hub is the hingeless variable pitch propeller hub of embodiment 1 of the present invention.

[0128] like Figure 11 As shown, the helicopter rotor of this embodiment 2 further includes a blade unit 3 and a rotor hub connection unit 4.

[0129] Specifically, each hingeless variable pitch hub is evenly connected to four blade units 3 around its outer circumference; each blade unit 3 is fixedly connected to the hingeless variable pitch hub via a rotor hub connection unit 4. The blade unit 3 rotates with the rotation of the variable pitch hinge support 23.

[0130] Preferably, the helicopter rotor of this embodiment 2 includes two coaxially arranged hingeless variable pitch propeller hubs, specifically an upper rotor unit 100 and a lower rotor unit 200. The helicopter fuselage is coaxially connected to the upper rotor unit 100 and the lower rotor unit 200. The upper rotor unit 100 and the lower rotor unit 200 are the same and both include the hingeless variable pitch propeller hub of embodiment 1.

[0131] The rotor hub connection unit 4 of this embodiment 2 includes an anti-rotation pin 41 and a blade locking nut 42 .

[0132] like Figure 12As shown, the blade unit 3 of this embodiment includes a blade mounting portion 31 and a blade airfoil portion 32. The blade mounting portion 31 is provided at the proximal end of the blade unit 3, and the blade airfoil portion 32 is provided at the distal end of the blade unit 3.

[0133] like Figure 12 As shown, the blade mounting portion 31 is provided with a blade locking portion 311 , a blade locking support portion 312 , a blade transition portion 313 and a blade anti-slip pin connecting portion 314 in sequence from the proximal end to the distal end.

[0134] In the installed state, the blade locking portion 311 is located outside the end face of the proximal end of the pitch hinge support 23, specifically outside the end face of the support flange mounting position 2382 and in the inner cavity of the hub central shell 1; the blade locking support portion 312 and the blade transition portion 313 are located inside the pitch hinge support 23; the blade anti-slip pin connection portion 314 is arranged on the blade transition portion 313.

[0135] like Figure 2 As shown, the blade mounting portion 31 is further provided with a blade damping cavity 315 having a cavity structure in the blade locking support portion 312 and the blade transition portion 313; the function of the blade damping cavity 315 is:

[0136] (1) Reducing the weight of the blade unit 3 and the effective weight of the helicopter is beneficial to improving the aerodynamic efficiency of the helicopter.

[0137] (2) Optimizing the structure of the helicopter rotor so that the overall structural wall thickness of the blade mounting portion 31 tends to be consistent, which not only reduces the structural stress during the manufacturing process of the blade unit 3, but also overcomes the sudden change in torque transmission stress and improves the service life of the helicopter rotor.

[0138] In this embodiment 2, preferably, the blade locking portion 311 and the blade locking support portion 312 are stepped pillow blocks; the blade locking support portion 312 is positioned on the inner wall surface of the support member inner cavity positioning portion 2313; a bolt structure is provided on the blade locking portion 311, and the blade locking portion 311 extends out of the support member flange mounting position 2382, and the blade locking nut 42 is screwed to the blade locking portion 311, so as to axially position the blade unit 3 and connect it to the proximal end of the pitch hinge support 23, specifically to the end face of the support member flange mounting position 2382.

[0139] Preferably, the outer wall surface of the blade locking support portion 311 and the inner wall surface of the support member inner cavity positioning portion 2313 are transitionally connected.

[0140] The blade transition portion 312 is a cone structure, and the taper of the blade transition portion 312 is consistent with the taper of the inner cavity cone portion 2311 of the support member.

[0141] Preferably, the outer wall surface of the blade transition portion 312 and the inner wall surface of the support member inner cavity cone portion 2311 are transitionally connected.

[0142] This transition connection between the blade mounting portion 31 and the variable pitch hinge support 23 further structurally ensures the radial position stability of the blade unit 3 relative to the variable pitch hinge support 23 after the blade unit 3 is axially positioned by the blade locking nut 42, ensuring that the blade unit 3 can rotate synchronously with the variable pitch hinge support 23.

[0143] The blade unit 3 of the present invention is tightened during the installation process by the blade locking nut 42 at the proximal end, and the support position of the blade unit 3 is set between the blade mounting portion 31 and the conical surface of the pitch hinge support 23, which avoids the need for special tooling for rotor installation and is conducive to effectively improving installation efficiency. At the connection between the blade mounting portion 31 and the blade airfoil portion 32, which is also the starting position of the blade airfoil portion 32, there is provided a blade anti-slip pin connection portion 314 that is relatively perpendicular to the main structure of the blade airfoil portion 32. The blade anti-slip pin connection portion 314 corresponds to the position of the anti-slip pin passing portion 237 radially arranged at the distal end of the pitch hinge support 23, for the passage of the anti-rotation pin 41.

[0144] During the installation of the blade unit 3, the blade mounting portion 31 passes through the interior of the variable pitch hinge support 23, and the blade unit 3 is rotated. The blade transition portion 312 gradually matches and combines with the conical surface of the support inner cavity cone portion 2311 in a progressive manner until the support inner cavity cone portion 2311 of the variable pitch hinge support 23 and the blade anti-slip pin connecting portion 314 on the blade unit 3 are aligned, and the anti-rotation pin 41 is installed.

[0145] During the installation of the anti-rotation pin 41 , the counterweight 27 is simultaneously deployed and installed.

[0146] The anti-rotation pin 41 passes through the anti-slip pin passing portion 237 on the support member barrel tail 239 and the blade anti-slip pin connecting portion 314 on the blade unit 3 at the same time, which can limit the circumferential position of the blade unit 3 and effectively limit the circumferential swinging of the blade airfoil portion 32 at the distal end.

[0147] like Figure 2 and Figure 1As shown, compared with the double-pin method used in the existing hingeless hub and blade connection, the blade mounting portion 31 of this embodiment 2 can achieve the following technical effects:

[0148] (1) The blade mounting portion 31 of the second embodiment passes through the interior of the hingeless variable pitch propeller hub, making the helicopter propeller hub structure of the second embodiment compact.

[0149] (2) Compared with the prior art, the blade mounting portion 31 of this embodiment 2 is fixed at a position close to the rotation center of the hingeless variable pitch propeller hub, so that the starting position of the blade airfoil portion 32 is as close as possible to the rotation center of the rotor, thereby improving aerodynamic efficiency and reducing aerodynamic drag.

[0150] After installing the blade unit 3, the blade locking nut 42 must be tightened again. The torque applied by the blade locking nut 42 can further compress the blade unit 3 against the conical surface of the pitch hinge support 23, further strengthening the structural consistency and overall linkage between the blade unit 3 and the pitch hinge support 23.

[0151] Preferably, in this embodiment 2, after the blade locking nut 42 finally re-locks the blade unit 3 at the proximal end of the pitch hinge support 23, axial positioning reinforcement is performed on the blade locking nut 42. That is, axial positioning bolts are driven into the outer periphery of the end surface of the blade locking nut 42 to additionally axially fix the blade locking nut 42 to the pitch hinge support 23. This additional axial connection can prevent the blade unit 3 from loosening during the pitch change process.

[0152] The technical solution of this embodiment 2 can significantly improve the aerodynamic efficiency of the helicopter and reduce the aerodynamic resistance of the helicopter.

[0153] Example 3

[0154] This embodiment 3 discloses a helicopter.

[0155] The helicopter comprises a helicopter fuselage and a rotor. A control system is arranged on the helicopter fuselage.

[0156] This embodiment 3 assumes that: the control system is located in the inner cavity of the hub central shell 1, and the rotor is the helicopter rotor of embodiment 2 of the present invention.

[0157] The control system is located in the inner cavity of the hub central shell 1 and is connected to the pitch rod assembly 25.

[0158] Specifically, the control system is connected to the pitch variable rod unit 252 of the pitch variable rod assembly 25, and the control system can drive one end of the pitch variable rod unit 252 to perform up and down displacement movement; the other end of the pitch variable rod unit 252 is hinged to one end of the rotor rocker arm 251 of the pitch variable rod assembly 25; the pitch variable rod unit 252 drives the rotor rocker arm 251 and the pitch variable hinge support 23 fixed to the other end of the rotor rocker arm 251 to rotate around the axis of the pitch variable hinge support 23, thereby driving the blade unit 3 connected to the pitch variable hinge support 23 to perform pitch movement.

[0159] The above are only preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A hingeless variable pitch propeller hub, characterized in that: It comprises a hub central housing (1) and a plurality of hub pitch-changing components (2); The hub central housing (1) includes a housing side mounting portion (13); each housing side mounting portion (13) includes a housing pitch-changing portion mounting surface (131) and a housing hub paving portion (132); the housing hub paving portion (132) is arranged at the end surface of the housing pitch-changing portion mounting surface (131) and passes through the housing of the hub central housing (1); The plurality of hub pitch-changing components (2) are distributed on the outer peripheral side of the hub central housing (1); each hub pitch-changing component (2) is provided with a pitch-changing hinge support (23) capable of penetrating and connecting a blade unit; The hub pitch-changing component (2) further includes a blade clamp housing (21), a torque transmission assembly (22), and a pitch-changing pull rod assembly (25); The pitch-variable hinge support (23) is rotatably arranged inside the propeller clamp housing (21), and the torque transmission assembly (22) is limitedly arranged between the propeller clamp housing (21) and the pitch-variable hinge support (23); One end of the pitch-changing rod assembly (25) is connected to the proximal end of the pitch-changing hinge support (23) and is located inside the hub central housing (1); The proximal end of the blade unit (3) is connected to the interior of the pitch-variable hinge support member (23); the interior of the pitch-variable hinge support member (23) is provided with a support member inner cavity positioning portion (2313), a support member inner cavity transition portion (2312), and a support member inner cavity cone portion (2311) in axial order; the support member inner cavity cone portion (2311) is a conical cavity with a distal end diameter greater than a proximal end diameter; the support member inner cavity positioning portion (2313) is used to position the proximal end of the blade unit (3).

2. The hingeless variable pitch propeller hub according to claim 1, characterized in that: The paddle clamp housing (21) comprises a paddle clamp housing cylinder (211); a cylindrical roller bearing outer mounting portion (2114), a thrust cylindrical bearing outer mounting portion (2113), a paddle clamp housing limit platform (2112), and an angular bearing outer mounting portion (2111) are sequentially arranged inside the paddle clamp housing cylinder (211) along the axial direction.

3. The hingeless variable pitch propeller hub according to claim 2, characterized in that: The variable pitch hinge support member (23) is provided with a cylindrical roller bearing inner mounting portion (235), a thrust cylindrical bearing inner mounting portion (234), an angular bearing inner mounting portion (233), a support member axial positioning groove (232), an axial positioning block positioning ring platform (236), and a support member barrel tail (239) in sequence along the axial direction on the outside; an axial positioning block positioning ring platform (236) is radially provided with an axial positioning block ring platform locking portion (2361).

4. The hingeless variable pitch propeller hub according to claim 1, characterized in that: The torque transmission assembly (22) includes a torque transmission unit; the torque transmission unit includes a cylindrical roller bearing (226), a thrust cylindrical bearing unit, and an angular bearing (224) sequentially arranged in the axial direction; the thrust cylindrical bearing unit includes two thrust cylindrical bearings (225) sequentially arranged in the axial direction.

5. The hingeless variable pitch propeller hub according to claim 4, characterized in that: A second retaining ring (2213) is provided between the cylindrical roller bearing (226) and the thrust cylindrical bearing unit, and a first retaining ring (2212) is provided at the distal end surface of the angular bearing (224); an axial positioning unit is provided at the distal end surface of the first retaining ring (2212); and the axial positioning unit includes at least two axial positioning blocks (2211).

6. The hingeless variable pitch propeller hub according to claim 5, characterized in that: The axial positioning block (2211) is provided with an axial positioning platform (22111), a positioning locking portion (22112), an anti-rotation limiting groove (22113) and an axial adjustment mounting portion (22115); the axial adjustment mounting portion (22115) is connected to an axial position adjustment component.

7. The hingeless variable pitch propeller hub according to claim 6, characterized in that: The axial positioning platform (22111) is arranged at the proximal end of the axial positioning block (2211); the anti-rotation limiting groove (22113) is axially penetrating and arranged in the middle of the inner ring of the axial positioning block (2211); and a positioning locking portion (22112) is provided on the axial positioning block (2211).

8. A helicopter rotor, characterized in that: Comprising at least one hingeless variable pitch propeller hub according to any one of claims 1 to 7, and further comprising a blade unit (3) and a rotor hub connection unit (4); The rotor hub connection unit (4) includes an anti-rotation pin (41) and a blade locking nut (42); The blade unit (3) comprises a blade mounting portion (31) and a blade airfoil portion (32); the blade mounting portion (31) is arranged to penetrate the interior of the pitch hinge support (23) and is connected to the proximal end of the pitch hinge support (23) through the blade locking nut (42); the anti-rotation pin (41) is arranged at the connection between the blade mounting portion (31) and the blade airfoil portion (32) and is used to radially limit the blade unit (3) on the pitch hinge support (23).

9. A helicopter, characterized in that: The helicopter rotor according to claim 8 further comprises a helicopter fuselage; a control system is provided on the helicopter fuselage; The control system is connected to the pitch-changing rod assembly (25); the control system can drive the blade unit (3) to perform pitch-changing movement through the pitch-changing rod assembly (25) and the pitch-changing hinge support (23).

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