A twist-strip helicopter blade support arm and rotor hub system

Abstract

The present invention belongs to the technical field of helicopter accessories. It is a twist bar type helicopter blade support arm and a rotor hub system, which aims to solve the problems in the prior art that the helicopter hub is heavy, has a relatively short life, is difficult to maintain, and has a high manufacturing and use cost. A twist bar type helicopter blade support arm, comprising a variable pitch hinge assembly and a clamping plate assembly; the clamping plate assembly comprises an upper clamping plate and a lower clamping plate, and a support column is arranged between the upper clamping plate and the lower clamping plate; the variable pitch hinge assembly is fixed to the inner end of the clamping plate assembly and is located between the upper clamping plate and the lower clamping plate; a twist bar assembly is arranged between the upper clamping plate and the lower clamping plate, and the twist bar assembly comprises a forked end and a closed end opposite to the forked end; the closed end of the twist bar assembly is fixed to the outer end of the clamping plate assembly by a blade clip, the forked end of the twist bar assembly extends out of the inner end of the clamping plate assembly, and the forked end of the twist bar assembly is provided with a rotor hub connecting portion.

Description

Technical Field

[0001] The invention belongs to the technical field of helicopter accessories, and in particular relates to a twist-strip type helicopter blade support arm and a rotor hub system. Background Art

[0002] The rotor hubs of existing light helicopters mainly consist of two structural forms: the most commonly used structural form is the seesaw type, which mainly realizes the pitch change of the rotor blades through angular contact bearings or elastic bearings, and realizes the flapping of the rotor through a flapping hinge shared by two rotor blades. However, this structure uses too many bearings, is generally larger in overall size, has a heavier hub mass, a relatively short lifespan, is difficult to maintain, and increases manufacturing and use costs.

[0003] The other is a fully articulated structure. This type of rotor hub realizes the flapping, oscillating and pitch-changing motion of the blades by setting a flapping hinge, a swing hinge and a pitch-changing hinge on the hub. Generally, a thrust bearing is used to bear the centrifugal force of the rotor blade movement. This structure also has the above-mentioned seesaw structure problem. That is, the overall size of the rotor hub is large, the mass is heavy, the life is relatively short, and the rotor hub is difficult to maintain. Summary of the invention

[0004] The present invention provides a twist-strip type helicopter blade support arm and a rotor hub system, aiming to solve the problems in the prior art that the helicopter hub is heavy, has a relatively short life, is difficult to maintain, and has a high manufacturing and use cost.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] In a first aspect, a pull-twist bar type helicopter blade support arm comprises a variable pitch hinge assembly and a clamping plate assembly;

[0007] The clamping plate assembly comprises an upper clamping plate and a lower clamping plate, and a support column is arranged between the upper clamping plate and the lower clamping plate;

[0008] The variable pitch hinge assembly is fixed to the inner end of the clamping plate assembly and is located between the upper clamping plate and the lower clamping plate; a twist bar assembly is arranged between the upper clamping plate and the lower clamping plate, and the twist bar assembly includes a forked end and a closed end opposite to the forked end; the closed end of the twist bar assembly is fixed to the outer end of the clamping plate assembly through a blade clip, the forked end of the twist bar assembly extends out of the inner end of the clamping plate assembly, and the forked end of the twist bar assembly is provided with a rotor hub connecting portion.

[0009] The torsion bar assembly is used to bear the centrifugal force generated when the blade rotates. Compared with the seesaw hub structure and the fully hinged hub structure, the torsion bar assembly can produce a certain elastic deformation, thus improving the reliability and service life of the hub. In addition, the torsion bar assembly can produce elastic deformation, making it easy for the torsion bar assembly to withstand the torsion force generated by the blade's waving, shimmying and pitch-changing motion.

[0010] Due to the use of a deformable torsion bar assembly, the blade support arm does not need to use a traditional ball bearing, which greatly increases the life of the rotor blade support arm. In actual design, the number of torsion bar blade support arms can be increased or decreased according to the performance requirements of the helicopter design.

[0011] The clamping plate assembly includes an upper clamping plate and a lower clamping plate, and a support column is arranged between the upper clamping plate and the lower clamping plate. The support column allows a certain distance between the upper clamping plate and the clamping plate. A part of the tension and twist bar assembly is located between the upper clamping plate and the lower clamping plate. The tension and twist bar assembly can be maintenance-free, or, when maintaining the tension and twist bar assembly, direct visual maintenance and inspection can be performed, which greatly reduces the maintenance and inspection intensity of ground staff.

[0012] The torsion bar assembly is installed in the form of an upper and lower clamping plate structure, which makes the torsion bar assembly easy to install and process, and greatly reduces the manufacturing cost of the overall rotor hub.

[0013] A further improved solution: the blade clip is provided with a first U-shaped groove for fixing the blade and a second U-shaped groove for accommodating and fixing the closed end of the torsion bar assembly, and the blade clip is fixed to the outer end of the clamping plate assembly;

[0014] The outer end of the upper clamp plate and the outer end of the lower clamp plate are respectively arranged on the upper and lower sides of the second U-shaped groove, and the closed end of the pull-twist strip assembly is inserted into the inner side of the second U-shaped groove; the outer end of the upper clamp plate, the outer end of the lower clamp plate, the second U-shaped groove and the pull-twist strip assembly are fixed together by bolts.

[0015] A further improved solution: an upper pressure plate is provided between the twist bar assembly and the upper side wall of the second U-shaped groove, and a lower pressure plate is provided between the twist bar assembly and the lower side wall of the second U-shaped groove. The bolts pass through the upper pressure plate, the twist bar assembly and the lower pressure plate in sequence, and fix the upper pressure plate, the twist bar assembly and the lower pressure plate together.

[0016] The upper pressing plate and the lower pressing plate cooperate with the upper and lower side walls of the second U-shaped groove to effectively fasten the tension and twist strip assembly through bolts.

[0017] Further improved solution: an upper clamping bushing is provided between the upper side wall of the second U-shaped groove and the upper pressure plate, and a lower clamping bushing is provided between the lower side wall of the second U-shaped groove and the lower pressure plate, and the upper clamping bushing and the lower clamping bushing are both sleeved on the bolt.

[0018] A further improved solution: there are two bolts, two upper clamping bushings and two lower clamping bushings are provided, and each of the bolts is sleeved with one upper clamping bushing and one lower clamping bushing.

[0019] The upper compression bushing and the lower compression bushing are in contact with the upper side and the lower side of the pull-twist strip assembly respectively, which can effectively tighten the pull-twist strip assembly and prevent the pull-twist strip assembly from being delaminated or generating unnecessary elastic deformation when being stressed.

[0020] Further improved solution: the torsion bar assembly is V-shaped, which can better withstand the torsion force generated by the blades when they are waving, shimmying and changing pitch, thereby increasing the service life of the torsion bar assembly and reducing the cost of use.

[0021] A further improved solution: the pull-twist strip assembly is Y-shaped.

[0022] A further improved solution: the twist bar assembly is provided with a transition arc that allows a smooth transition from the closed end to the side wall of the forked end, and the transition arc is arranged on the twist bar assembly near the closed end. The twist bar assembly includes stacked twist bar sheets, and the twist bar sheets have at least two sheets.

[0023] Based on the above solution, the transition arc can prevent stress concentration at the closed end of the pull-twist bar assembly when subjected to force, thereby preventing the pull-twist bar assembly from breaking, and at the same time can limit the movement range of the closed end of the pull-twist bar assembly.

[0024] The torsion bar assembly includes stacked torsion bar sheets, which are easy to deform after being subjected to force, and can well withstand the torsional force generated by the blade arms and rotor blades during flapping, oscillating, and pitch changing movements, as well as the centrifugal force generated during high-speed rotation.

[0025] A further improved solution: both the upper clamping plate and the lower clamping plate are provided with perspective holes for observing the pull-twist strip assembly.

[0026] Based on the above solution, the splint assembly adopts an open design with a simple structure, which is convenient for observing the status of the pull-twist strip assembly during use and easy for maintenance. It can improve safety and reduce use and manufacturing costs.

[0027] A further improved solution: a downward pressure limit plate is provided at the inner end of the clamping plate assembly, the downward pressure limit plate is located between the lower clamping plate and the rotor hub connecting portion, and the downward pressure limit plate is fixed to the lower clamping plate.

[0028] Based on the above scheme, when the blade support arm is subjected to force so that the downward pressure limit plate interferes with the rotor hub, the downward pressure limit plate can limit the swinging of the blade support arm to prevent the blade support arm from swinging too much.

[0029] A further improved solution: a variable pitch rocker arm is provided at the inner end of the clamping plate assembly, and the variable pitch rocker arm is fixed on the lower clamping plate.

[0030] Based on the above scheme, the pitch-changing push-pull rod can operate the blade support arm through the pitch-changing rocker arm to change the pitch of the rotor blade.

[0031] A further improved solution: the variable pitch hinge assembly includes a variable pitch hinge and a radial spherical bearing, the upper end of the variable pitch hinge is fixed to the upper clamping plate, and the lower end of the variable pitch hinge assembly is fixed to the lower clamping plate, the variable pitch hinge is provided with a mounting hole for installing the radial spherical bearing, the radial spherical bearing is installed in the mounting hole, a rubber pad is provided between the radial spherical bearing and the rotor hub, and the inner end of the radial spherical bearing is arranged toward the rotor hub.

[0032] Based on the above scheme, the rubber pad is used to play a buffering role during the flapping, oscillation and pitch change of the blade support arm and the rotor blade.

[0033] In a second aspect, a rotor hub system includes a rotor hub, wherein the rotor hub is provided with three arm connection portions;

[0034] Each arm connection portion is connected to one of the above-mentioned twist bar type helicopter blade arms;

[0035] The torsion bar assembly is fixed to the outer end of the support arm connecting part; the variable pitch hinge assembly is rotatably arranged on the rotor hub through a connecting shaft.

[0036] Compared with the seesaw hub structure and the fully hinged hub structure, since the torsion strip can produce a certain elastic deformation, the reliability and service life of the hub are improved, thereby improving the service life of the rotor hub system.

[0037] The beneficial effects of the present invention are:

[0038] The torsion bar assembly is used to bear the centrifugal force generated when the blade rotates. Compared with the seesaw hub structure and the fully hinged hub structure, the torsion bar assembly can produce a certain elastic deformation, thus improving the reliability and service life of the hub. In addition, the torsion bar assembly can produce elastic deformation, making it easy for the torsion bar assembly to withstand the torsion force generated by the blade's waving, shimmying and pitch-changing motion.

[0039] Due to the use of a deformable torsion bar assembly, the blade support arm does not need to use a traditional ball bearing, which greatly increases the life of the rotor blade support arm. In actual design, the number of torsion bar blade support arms can be increased or decreased according to the performance requirements of the helicopter design.

[0040] The clamping plate assembly includes an upper clamping plate and a lower clamping plate, and a support column is arranged between the upper clamping plate and the lower clamping plate. The support column allows a certain distance between the upper clamping plate and the clamping plate. A part of the tension and twist bar assembly is located between the upper clamping plate and the lower clamping plate. The tension and twist bar assembly can be maintenance-free, or, when maintaining the tension and twist bar assembly, direct visual maintenance and inspection can be performed, which greatly reduces the maintenance and inspection intensity of ground staff.

[0041] The torsion bar assembly is installed in the form of an upper and lower clamping plate structure, which makes the torsion bar assembly easy to install and process, and greatly reduces the manufacturing cost of the overall rotor hub.

[0042] The technical solution provided by the present invention is particularly suitable for unmanned helicopters. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For users of ordinary technology in the field, other related drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 It is a schematic diagram of a pull-twist strip type helicopter blade support arm in the present invention.

[0045] Figure 2 It is a structural schematic diagram of the variable pitch hinge assembly in the present invention.

[0046] Figure 3 It is a structural schematic diagram of the pull-twist strip assembly in the present invention.

[0047] Figure 4 It is a structural schematic diagram of the splint assembly in the present invention.

[0048] Figure 5 It is a schematic diagram of a rotor hub system in the present invention.

[0049] Description of the numbers in the figure:

[0050] 1-variable pitch hinge assembly; 2-twist bar assembly; 3-blade clip; 4-clamp plate assembly; 5-variable pitch rocker arm; 6-bolt; 11-variable pitch hinge; 12-radial spherical bearing; 13-rubber pad; 21-twist bar; 22-upper pressure plate; 221-lower pressure plate; 23-upper clamping bushing; 231-lower clamping bushing; 41-upper clamping plate; 42-lower clamping plate; 43-support column; 44-lower limit pressure plate; 7-rotor hub. DETAILED DESCRIPTION

[0051] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by users of the present invention without creative work belong to the protection scope of the present invention.

[0052] Embodiment 1:

[0053] See also Figures 1 to 4 , this embodiment provides a pull-twist strip type helicopter blade support arm, including a variable pitch hinge assembly 1 and a clamping plate assembly 4;

[0054] The clamping plate assembly 4 includes an upper clamping plate 41 and a lower clamping plate 42, and a support column 43 is provided between the upper clamping plate 41 and the lower clamping plate 42;

[0055] The variable pitch hinge assembly 1 is fixed to the inner end of the clamping plate assembly 4 and is located between the upper clamping plate 41 and the lower clamping plate 42; a twist bar assembly 2 is arranged between the upper clamping plate 41 and the lower clamping plate 42, and the twist bar assembly 2 includes a forked end and a closed end opposite to the forked end; the closed end of the twist bar assembly 2 is fixed to the outer end of the clamping plate assembly 4 through the blade clip 3, the forked end of the twist bar assembly 2 extends out of the inner end of the clamping plate assembly 4, and the forked end of the twist bar assembly 2 is provided with a rotor hub 7 connecting part.

[0056] The inner end in this embodiment refers to the end of the clamping plate assembly 4 close to the rotor hub 7. The outer end refers to the end of the clamping plate assembly 4 away from the rotor hub 7.

[0057] Generally, the support columns 43 are arranged in pairs, and two support columns in a pair of support columns are respectively arranged on both sides of the upper clamping plate 41 and the lower clamping plate 42 .

[0058] Embodiment 2:

[0059] In order to improve the connection strength between the blade clip 3 and the twist bar assembly 2, based on the above embodiment: the blade clip 3 is provided with a first U-shaped groove for fixing the blade and a second U-shaped groove for accommodating and fixing the closed end of the twist bar assembly 2, and the blade clip 3 is fixed to the outer end of the clamping plate assembly 4.

[0060] The outer end of the upper clamp plate 41 and the outer end of the lower clamp plate 42 are respectively arranged on the upper and lower sides of the second U-shaped groove, and the closed end of the pull-twist strip assembly 2 is inserted into the inner side of the second U-shaped groove; the outer end of the upper clamp plate 41, the outer end of the lower clamp plate 42, the second U-shaped groove and the pull-twist strip assembly 2 are fixed together by bolts 6.

[0061] An upper pressure plate 22 is provided between the pull-twist bar assembly 2 and the upper side wall of the second U-shaped groove, and a lower pressure plate 221 is provided between the pull-twist bar assembly 2 and the lower side wall of the second U-shaped groove. The bolt 6 passes through the upper pressure plate 22, the pull-twist bar assembly 2 and the lower pressure plate 221 in sequence, and fixes the upper pressure plate 22, the pull-twist bar assembly 2 and the lower pressure plate 221 together.

[0062] An upper clamping bushing 23 is provided between the upper side wall of the second U-shaped groove and the upper pressing plate 22 , and a lower clamping bushing 231 is provided between the lower side wall of the second U-shaped groove and the lower pressing plate 221 . Both the upper clamping bushing 23 and the lower clamping bushing 231 are sleeved on the bolt 6 .

[0063] There are two bolts 6 , two upper pressing bushings 23 and two lower pressing bushings 231 , and each bolt 6 is sleeved with one upper pressing bushing 23 and one lower pressing bushing 231 .

[0064] Specifically, the bolt 6 passes through the upper clamping plate 41, the upper side wall of the second U-shaped groove, the upper clamping bushing 23, the upper pressure plate 22, the tension and twisting strip assembly 2, the lower pressure plate 221, the lower clamping bushing 231, the lower side wall of the second U-shaped groove and the lower clamping plate 42 in sequence, and fixes the upper clamping plate 41, the lower clamping plate 42, the upper pressure plate 22, the lower pressure plate 221, the upper clamping bushing 23, the lower clamping bushing 231, and the tension and twisting strip assembly 2 together.

[0065] Embodiment three:

[0066] In order to optimize the performance of the pull-twist bar assembly 2, based on the above embodiment: the pull-twist bar assembly 2 is V-shaped.

[0067] Alternatively, the twist bar assembly 2 is in a Y shape.

[0068] The twist bar assembly 2 is provided with a transition arc that enables a smooth transition from the closed end to the side wall of the forked end. The transition arc is arranged on the twist bar assembly 2 near the closed end. The twist bar assembly 2 includes twist strip pieces 21 that are stacked, and the twist strip pieces 21 have at least two pieces.

[0069] Embodiment 4:

[0070] In order to optimize the performance of the clamping plate assembly 4 , based on the above embodiment: both the upper clamping plate 41 and the lower clamping plate 42 are provided with perspective holes for observing the tension and twisting strip assembly 2 .

[0071] The inner end of the clamping plate assembly 4 is provided with a downward pressure limiting piece, and the downward pressure limiting piece is located between the connecting portion of the lower clamping plate 42 and the rotor hub 7 , and the downward pressure limiting piece is fixed on the lower clamping plate 42 .

[0072] The inner end of the clamping plate assembly 4 is provided with a variable pitch rocker arm 5, and the variable pitch rocker arm 5 is fixed on the lower clamping plate 42. The variable pitch rocker arm 5 can be an integrated structure with the lower pressure plate 221.

[0073] The variable pitch hinge assembly 1 includes a variable pitch hinge 11 and a radial spherical bearing 12. The upper end of the variable pitch hinge 11 is fixed to the upper clamping plate 41, and the lower end of the variable pitch hinge assembly 1 is fixed to the lower clamping plate 42. The variable pitch hinge 11 is provided with a mounting hole for installing the radial spherical bearing 12. The radial spherical bearing 12 is installed in the mounting hole. A rubber pad 13 is provided between the radial spherical bearing 12 and the rotor hub 7. The inner end of the radial spherical bearing 12 is arranged toward the rotor hub 7.

[0074] Embodiment five:

[0075] See also Figures 1 to 5 , this embodiment provides a rotor hub system, including a rotor hub 7, wherein the rotor hub 7 is provided with three arm connecting parts;

[0076] Each arm connection portion is connected to one of the above-mentioned twist bar type helicopter blade arms;

[0077] The torsion bar assembly 2 is fixed to the outer end of the support arm connecting part; the variable pitch hinge assembly 1 is rotatably arranged on the rotor hub 7 through the connecting shaft.

[0078] The following further describes a twist-strip helicopter blade support arm and a rotor hub system provided by the present invention in combination with the working principle:

[0079] During the rotation of the blades: the torsion bar assembly 2 can produce elastic deformation, thereby making it easy for the torsion bar assembly 2 to withstand the torsion force generated by the flapping, swinging and pitch changing movements of the blades. The torsion force generated by the blades is partially absorbed by the torsion bar assembly 2, so that the rotor hub 7 does not need to withstand excessive torsion force, thereby extending the service life of the rotor hub 7.

[0080] During the maintenance of the blade arm: the support column 43 allows a certain distance between the upper clamps 41 and the clamps, and a portion of the twist bar assembly 2 is located between the upper clamp 41 and the lower clamp 42. The twist bar assembly 2 can be maintenance-free, or, when maintaining the twist bar assembly 2, direct visual maintenance inspection can be performed, which greatly reduces the maintenance inspection intensity of ground crew members.

[0081] The present invention is not limited to the above optional implementation modes. Under the premise of not conflicting with each other, the various schemes can be combined arbitrarily. Anyone can derive other forms of products under the inspiration of the present invention. However, no matter what changes are made in their shapes or structures, all technical solutions that fall within the scope defined by the claims of the present invention fall within the protection scope of the present invention.

Claims

1. A twist bar type helicopter blade support arm, characterized in that: It includes a variable pitch hinge assembly and a clamping plate assembly; The clamping plate assembly comprises an upper clamping plate and a lower clamping plate, and a support column is arranged between the upper clamping plate and the lower clamping plate; The variable pitch hinge assembly is fixed to the inner end of the clamping plate assembly and is located between the upper clamping plate and the lower clamping plate; a torsion bar assembly is provided between the upper clamping plate and the lower clamping plate, and the torsion bar assembly includes a forked end and a closed end opposite to the forked end; the closed end of the torsion bar assembly is fixed to the outer end of the clamping plate assembly through a blade clip, the forked end of the torsion bar assembly extends out of the inner end of the clamping plate assembly, and the forked end of the torsion bar assembly is provided with a rotor hub connecting portion; The blade clip is provided with a first U-shaped groove for fixing the blade and a second U-shaped groove for accommodating and fixing the closed end of the torsion bar assembly, and the blade clip is fixed to the outer end of the clamping plate assembly; The outer ends of the upper clamping plate and the lower clamping plate are respectively arranged on the upper and lower sides of the second U-shaped groove, and the closed end of the pull-twist strip assembly is inserted into the inner side of the second U-shaped groove; the outer end of the upper clamping plate, the outer end of the lower clamping plate, the second U-shaped groove and the pull-twist strip assembly are fixed together by bolts; An upper pressing plate is provided between the pull-twist bar assembly and the upper side wall of the second U-shaped groove, and a lower pressing plate is provided between the pull-twist bar assembly and the lower side wall of the second U-shaped groove, and the bolts pass through the upper pressing plate, the pull-twist bar assembly and the lower pressing plate in sequence, and fix the upper pressing plate, the pull-twist bar assembly and the lower pressing plate together; An upper pressing bushing is provided between the upper side wall of the second U-shaped groove and the upper pressing plate, and a lower pressing bushing is provided between the lower side wall of the second U-shaped groove and the lower pressing plate, and both the upper pressing bushing and the lower pressing bushing are sleeved on the bolt; There are two bolts, two upper compression bushings and two lower compression bushings, and each bolt is sleeved with one upper compression bushing and one lower compression bushing; The twist bar assembly is V-shaped, or Y-shaped; the twist bar assembly is provided with a transition arc that allows the closed end to smoothly transition to the side wall of the bifurcated end, and the transition arc is provided on the twist bar assembly at a position close to the closed end, and the twist bar assembly includes twist bar sheets that are stacked, and the twist bar sheets have at least two sheets; The upper clamping plate and the lower clamping plate are both provided with perspective holes for observing the pull-twist strip assembly; The inner end of the clamping plate assembly is provided with a downward pressure limiting piece, the downward pressure limiting piece is located between the lower clamping plate and the rotor hub connecting portion, and the downward pressure limiting piece is fixed to the lower clamping plate; The inner end of the clamping plate assembly is provided with a variable pitch rocker arm, and the variable pitch rocker arm is fixed to the lower clamping plate; The variable pitch hinge assembly includes a variable pitch hinge and a radial spherical bearing. The upper end of the variable pitch hinge is fixed to the upper clamping plate, and the lower end of the variable pitch hinge assembly is fixed to the lower clamping plate. The variable pitch hinge is provided with a mounting hole for installing the radial spherical bearing. The radial spherical bearing is installed in the mounting hole. A rubber pad is provided between the radial spherical bearing and the rotor hub, and the inner end of the radial spherical bearing is arranged toward the rotor hub.

2. A rotor hub system, characterized in that: It includes a rotor hub, and the rotor hub is provided with three arm connecting parts; Each arm connection portion is connected to a twist-strip type helicopter blade arm as claimed in claim 1; The torsion bar assembly is fixed to the outer end of the support arm connecting part; the variable pitch hinge assembly is rotatably arranged on the rotor hub through a connecting shaft.

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