A blade root connection assembly

Abstract

The embodiment of the present invention provides a blade root connection assembly, which includes two dampers, a connecting rocker, a bearing, a bearing cover plate, a first connecting member and a second connecting member; the bearing is installed in the through hole of the connecting rocker, and is placed in the through hole A after passing through the through hole of the blade root, and the two ends of the connecting rocker pass through the two dampers fixed to the blade root respectively, one end of the second connecting member passes through the through hole B, the bearing and the bearing cover plate in sequence and is fixedly connected to the bearing cover plate, and the other end is limited to the port side of the through hole B, one end of the first connecting member is connected to the hub, and the other end is fixedly connected to the plate surface of the flexible beam. The blade root connection assembly provided by the embodiment of the present invention has a simple structure, convenient maintenance and high reliability.

Description

Technical Field

[0001] The invention relates to the technical field of helicopter rotors, and in particular to a blade root connection assembly. Background Art

[0002] During flight, because the blades deflect in multiple directions and are subject to high loads in each direction, the blades must be designed to withstand these high loads while still providing the required flexibility or articulation to enable the blades to perform flapping, shimmying, and pitch changing motions.

[0003] At present, most drone rotors use articulated (also known as fully articulated) rotors, which are connected to the hub by setting a flapping hinge, a swing hinge and a pitch hinge on the rotor hub to achieve flapping, swinging and pitching movements. Although the bending load at the root of the articulated blade is small, the structure is complex and maintenance is inconvenient. Summary of the invention

[0004] The purpose of the embodiment of the present invention is to provide a blade root connection assembly, which is simple in structure and easy to maintain while ensuring that the blade can withstand movement in the flapping direction, the swing direction and the pitch change direction.

[0005] The specific technical solutions are as follows:

[0006] A blade root connection assembly, a connector for connecting a hub and a blade, the root of the blade being a hollow structure, a through hole M being provided through the outer wall of the blade root, and a flexible plate-like structure extending along the length direction of the blade toward the end of the blade, the plate-like structure being recorded as a flexible beam, a through hole A being provided on the plate surface of the flexible beam, a through hole B being provided at a second preset position on the end surface of the flexible beam, the through hole B being mutually connected with the through hole A, and the center point of the through hole A and the center point of the through hole M being on the same axis;

[0007] The connecting assembly comprises: two dampers, a connecting rocker, a bearing, a bearing cover plate, a first connecting member and a second connecting member;

[0008] The connecting rocker is a rod-shaped structure with a through hole in the middle, and both ends of the rod-shaped structure are respectively provided with limit plates at second preset positions, and the limit plates are used to limit the length of the connecting rocker passing through the damper through hole;

[0009] The bearing is placed in the through hole of the connecting rocker;

[0010] The damper is used to be fixedly mounted on the outer side of the blade root, and the inner hole of the damper is communicated with the through hole M;

[0011] The connecting rocker is used to pass through the through hole M so that the bearing is placed in the through hole A, and the two ends of the connecting rocker are respectively used to pass through the through holes of the two dampers;

[0012] One end of the second connecting member is used to pass through the through hole B, the bearing and the bearing cover plate in sequence and then be fixedly connected to the bearing cover plate, and the other end is limited to the port side of the through hole B;

[0013] One end of the first connecting member is connected to the hub, and the other end is used to be fixedly connected to the plate surface of the flexible beam.

[0014] Furthermore, at least two through holes C are provided on the plate surface at the end of the flexible beam, and a through hole for matching and installing with the through hole C is provided on the assembly surface of the first connecting member fixedly connected to the flexible beam.

[0015] Furthermore, the flexible beam is made of composite material.

[0016] Furthermore, the flexible beam is made of a glass fiber reinforced epoxy resin system material.

[0017] Furthermore, the blade root connection assembly further includes an inner support tube matched with the through hole C;

[0018] The inner support tubes are used to pass through the through holes C respectively and be fitted and fastened to the inner walls of the through holes C. Furthermore, the blade root connection assembly further includes a first support tube;

[0019] The first support tube is used to be fixedly connected to the inner wall of the through hole B;

[0020] One end of one end of the second connecting rod is used to pass through the first supporting tube, the bearing and the bearing cover plate in sequence and then be fixedly connected to the bearing cover plate, and the other end is limited to be located outside the supporting tube.

[0021] Furthermore, the blade root connection assembly further includes a second support tube and a gasket.

[0022] A plate-like structure is extended radially outward from one end edge of the second support tube, and a side wall opposite to the second support tube is provided along the edge of the plate-like structure, the side wall is provided with a notch, and a convex edge is provided at the end of the through hole B to be mounted in cooperation with the notch;

[0023] The second support tube is used to pass through the through hole B to fit the notch and the convex edge;

[0024] One end of the second connecting rod is used to pass through the gasket, the second support tube, the bearing and the bearing cover plate in sequence and then be fixedly connected to the bearing cover plate, and the other end is limited to be located outside the gasket.

[0025] Furthermore, the second connecting rod is a capped screw.

[0026] Furthermore, the second connecting rod is a screw rod with a hole at one end.

[0027] Furthermore, the damper is a viscoelastic damper.

[0028] A blade root connection assembly is provided in an embodiment of the present invention, and the blade root connection assembly includes two dampers, a connecting rocker, a bearing, a bearing cover plate, a first connecting member and a second connecting member; the connecting rocker is a rod-shaped structure with a through hole in the middle, and the two ends of the rod-shaped structure are respectively provided with limit plates at second preset positions, and the limit plates are used to limit the length of the connecting rocker passing through the damper through hole; the bearing is placed in the through hole of the connecting rocker; the damper is used to be fixedly installed on the outside of the blade root, and the inner hole of the damper is connected to the through hole M; the connecting rocker is used to pass through the through hole M, so that the bearing is placed in the through hole A, and the two ends of the connecting rocker are respectively used to pass through the through holes of the two dampers; one end of the second connecting member is used to pass through the through hole B, the bearing and the bearing cover plate in sequence and then be fixedly connected to the bearing cover plate, and the other end is limited to the port side of the through hole B; one end of the first connecting member is connected to the hub, and the other end is used to be fixedly connected to the plate surface of the flexible beam. Compared with the connection method between the hub and the blade in the articulated rotor in the prior art, the blade root connection assembly eliminates the horizontal hinge, vertical hinge and axial hinge, and relies on the deformation of the flexible beam at the root of the blade to achieve the blade flapping, shimmying and pitch change movement, and has the characteristics of simple structure, convenient maintenance and high reliability. Of course, any product or method implementing the present invention does not necessarily need to achieve all the advantages mentioned above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0030] Figure 1 A schematic diagram of the internal structure of a blade root connection assembly provided in an embodiment of the present invention;

[0031] Figure 2 A schematic diagram of the overall structure of a blade root connection assembly provided by an embodiment of the present invention;

[0032] Figure 3 An exploded view of a blade root connection assembly provided in an embodiment of the present invention.

[0033] Among them, 1-damper, 2-connecting rocker, 3-bearing, 4-bearing cover plate, 5-first connecting piece, 6-second connecting piece, 7-flexible beam, 8-gasket, 9-second supporting tube, 10-nut. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In order to solve the problems of the prior art, an embodiment of the present invention provides a blade root connection assembly. A connector for connecting a hub and a blade, the root of the blade is a hollow structure, a through hole M is provided through the outer wall of the root of the blade, and a flexible plate-like structure extends along the length direction of the blade toward the end of the blade, the plate-like structure is recorded as a flexible beam, a through hole A is provided on the plate surface of the flexible beam, a through hole B is provided at a second preset position on the end surface of the flexible beam, the through hole B is mutually connected with the through hole A, and the center point of the through hole A and the center point of the through hole M are on the same axis.

[0036] The blade root connection assembly comprises: two dampers 1, a connecting rocker 2, a bearing 3, a bearing cover plate 4, a first connecting member 5 and a second connecting member 6;

[0037] The connecting rocker 2 is a rod-shaped structure with a through hole in the middle, and both ends of the rod-shaped structure are provided with limit plates at second preset positions, and the limit plates are used to limit the length of the connecting rocker 2 passing through the through hole of the damper 1;

[0038] The bearing 3 is placed in the through hole of the connecting rocker 2;

[0039] The damper 1 is used to be fixedly mounted on the outer side of the blade root, and the inner hole of the damper 1 is communicated with the through hole M;

[0040] The connecting rocker 2 is used to pass through the through hole M, so that the bearing 3 is placed in the through hole A, and the two ends of the connecting rocker 2 are respectively used to pass through the through holes of the two dampers 1;

[0041] One end of the second connecting member 6 is used to pass through the through hole B, the bearing 3 and the bearing cover plate 4 in sequence and then be fixedly connected to the bearing cover plate 4, and the other end is limited to the port side of the through hole B;

[0042] One end of the first connecting member 5 is connected to the propeller hub, and the other end is used to be fixedly connected to the plate surface of the flexible beam 7 .

[0043] The flexible beam 7 and the blade may be an integrated structure.

[0044] It should be noted that the first preset position may be at the center of the end surface of the flexible beam, and the second preset position may be at a position that is greater than the thickness of the damper from the end surface of the connecting rocker 2 .

[0045] It is worth mentioning that the deformation of the blade root and the flexible beam 7 at the outer end of the blade root forms a displacement difference at the installation of the damper 1, and the displacement difference is the deformation of the damper, thereby providing stiffness and damping. If the stiffness of the damper 1 is high, the displacement of the blade root at the installation of the damper 1 is limited, so that the deformation of the damper 1 is small or not deformed, resulting in the damper 1 not providing damping. Therefore, it is necessary to correctly and reasonably select the damper stiffness and damping parameters, and configure the stiffness of the flexible beam 7 and the stiffness of the blade root.

[0046] In addition, the stiffness of the flexible beam 7 for improving the damping of the damper is matched with the stiffness of the blade root. The middle part of the flexible beam 7 is designed to be the section with the lowest stiffness in the swing direction, which is exactly the part where the flexible beam 7 deforms more greatly. Increasing the stiffness of the blade root can effectively increase the displacement of the blade root at the damper 1, thereby improving the damping efficiency of the damper.

[0047] It should be noted that one end of the second connecting rod 6 is used to pass through the through hole B, the bearing and the bearing cover plate in sequence and then be fixedly connected to the bearing cover plate, and the other end is limited to the port side of the through hole B, and is connected to the damper 1 installed on the outside of the blade root through the connecting rocker 2 to provide swing damping for the rotor.

[0048] As can be seen from the above, the present invention provides a blade root connection assembly, which, relative to the connection method between the hub and the blade in the articulated rotor in the prior art, eliminates the horizontal hinge, vertical hinge and axial hinge, and relies on the deformation of the flexible beam 7 at the root of the blade to achieve the blade flapping, swinging and pitch change movement, and has the characteristics of simple structure, easy maintenance and high reliability.

[0049] In one implementation, Figure 1 As shown, in order to realize the connection between the hub and the blade, at least two through holes C are provided on the plate surface at the end of the flexible beam 7, and a through hole for matching with the through hole C is provided on the assembly surface of the first connecting member 5 fixedly connected to the flexible beam 7. After two screws pass through the through hole C and the through hole on the flexible beam 7 respectively, nuts are used to match and tighten the screws respectively, so that the hub and the blade are fixedly connected.

[0050] In one implementation, Figure 2 As shown, the flexible beam 7 is made of composite material. Therefore, the flexible beam 17 has good elasticity.

[0051] It should be noted that, since the outer end of the flexible beam 7 is fixed to the hub, its swing stiffness is very large, but the stiffness of the middle part of the flexible beam 7 for swinging and flapping needs to be lower.

[0052] In one implementation, the flexible beam 7 is made of a glass fiber reinforced epoxy resin system. This implementation makes the blade root connection assembly structure simple and reliable, can reliably transmit centrifugal force and other loads of the blade, and reasonably match the stiffness of the flexible beam and the blade root as needed to increase the vibration damping efficiency.

[0053] Among them, the above-mentioned glass fiber reinforced epoxy resin refers to a fiber reinforced plastic with long fiber, cloth, tape, felt and other glass fibers as reinforcing materials and epoxy resin as the matrix. It belongs to FRP, a kind of glass fiber reinforced thermosetting plastic, and a polymer composite material with good performance. Its main advantages are: small specific gravity, high specific strength, specific gravity of 1.6 to 2.0, lighter than the lightest metal aluminum, and corrosion resistance.

[0054] In one implementation, since the flexible beam is made of composite material, the blade root connection assembly further includes an inner support tube matched with the through hole C; the inner support tube is used to pass through the through hole C and fit and fasten to the inner wall of the through hole C. The inner support tube is placed in the through hole C to prevent the flexible beam 7 from deformation or breakage.

[0055] In one implementation, the blade root connection assembly further includes a first support tube;

[0056] The first support tube is used to be fixedly connected to the inner wall of the through hole B;

[0057] One end of one end of the second connecting rod 6 is used to pass through the first supporting tube, the bearing 3 and the bearing cover plate 4 in sequence and then be fixedly connected to the bearing cover plate 4, and the other end is limited to be located outside the first supporting tube.

[0058] Since the flexible beam 7 is made of composite material and the second connecting member 6 is made of rigid material, the first support tube is fixedly connected to the through hole B of the flexible beam 7 so that the first support tube and the second connecting member 6 interact with each other, thereby extending the service life of the flexible beam 7. Even if the first support tube is damaged, it is easy to replace, thereby reducing maintenance costs.

[0059] It should be noted that the above-mentioned blade root connection assembly may also include a gasket 8. The above-mentioned first support tube is fixedly connected to the above-mentioned through hole B. One end of the above-mentioned second connecting rod 6 passes through the gasket 8, the first support tube, the bearing 3 and the bearing cover plate 4 in sequence and is fixedly connected to the above-mentioned bearing cover plate 4. The other end is limited to the outside of the above-mentioned gasket 8. The function of the gasket 8 is to prevent shaking, swaying and instability between the second connecting member 6 and the support tube due to interaction.

[0060] In one implementation, Figure 3 As shown, the blade root connection assembly further includes a second support tube 9 and a gasket 8.

[0061] A plate-like structure is extended radially outward from one end edge of the second support tube 9, and a side wall opposite to the second support tube 9 is provided along the edge of the plate-like structure, the side wall is provided with a notch, and the end of the through hole B is provided with a convex edge that is mounted in cooperation with the notch;

[0062] The second support tube 9 is used to pass through the through hole B to fit the notch and the convex edge;

[0063] One end of the second connecting rod 6 is used to pass through the gasket 8, the second support tube 9, the bearing 3 and the bearing cover plate 4 in sequence and then be fixedly connected to the bearing cover plate 4, and the other end is limited to the outside of the gasket 8.

[0064] It should be noted that the configuration of the notch and the convex edge enables the support tube 9 to be fixedly connected to the through hole B and to be easily disassembled. Once the support tube 9 is damaged, it can be directly disassembled and a new support tube 9 can be installed.

[0065] In one implementation, the second connecting rod 6 is a screw with a cap.

[0066] It should be noted that, after the second connecting rod 6 passes through the through hole B, the bearing 3 and the bearing cover plate 4 in sequence, a nut is used to cooperate with the thread of the cap screw so that the nut just abuts against the bearing cover plate 4.

[0067] In one implementation, the second connecting rod 6 is a screw rod with a hole at one end.

[0068] It should be noted that the threaded end of the second connecting rod passes through the through hole B, the bearing 3 and the bearing cover plate 4 in sequence, and then a nut is used to cooperate with the threaded part of the cap screw so that the nut is cut to rest against the bearing cover plate 4. The other end is fixed after passing through the through hole with a flexible steel wire, which saves costs and facilitates installation.

[0069] In addition, a blade root connection assembly provided by an embodiment of the present invention can be applicable to unmanned helicopters with a rotor radius within 5m and a hub radius within 0.12m.

[0070] As can be seen from the above, the blade root connection assembly provided by the present invention can not only realize the blade flapping, shimmying and pitch changing motion, but also has a simple structure, convenient maintenance, low cost and high reliability.

[0071] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0072] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A blade root connection assembly, a connector for connecting a hub and a blade, characterized in that: The root of the blade is a hollow structure, a through hole M is provided through the outer wall of the root of the blade, and a flexible plate-like structure extends along the length direction of the blade toward the end of the blade, the plate-like structure is recorded as a flexible beam (7), a through hole A is provided on the plate surface of the flexible beam, a through hole B is provided at a first preset position on the end surface of the flexible beam, the through hole B and the through hole A are mutually connected, and the center point of the through hole A and the center point of the through hole M are on the same axis; The connection assembly comprises: two dampers (1), a connecting rocker (2), a bearing (3), a bearing cover plate (4), a first connecting member (5), a second connecting member (6), an inner support tube and a first support tube; The connecting rocker (2) is a rod-shaped structure with a through hole in the middle, and both ends of the rod-shaped structure are provided with limit plates at second preset positions, the limit plates being used to limit the length of the connecting rocker (2) passing through the through hole of the damper (1); The bearing (3) is placed in the through hole of the connecting rocker (2); The damper (1) is used for being fixedly mounted on the outer side of the root of the blade, and the inner hole of the damper (1) is communicated with the through hole M; The connecting rocker (2) is used to pass through the through hole M so that the bearing (3) is placed in the through hole A, and the two ends of the connecting rocker (2) are respectively used to pass through the through holes of the two dampers (1); One end of the second connecting member (6) is used to sequentially pass through the through hole B, the bearing (3) and the bearing cover plate (4) and then be fixedly connected to the bearing cover plate (4), and the other end is limited to the end side of the through hole B; One end of the first connecting member (5) is connected to the propeller hub, and the other end is used to be fixedly connected to the plate surface of the flexible beam (7); At least two through holes C are provided on the plate surface at the end of the flexible beam (7); and a through hole for cooperating with the through hole C is provided on the assembly surface of the first connecting member (5) fixedly connected to the flexible beam (7); The inner support tube cooperates with the through hole C, passes through the through hole C respectively and is fitted and fastened to the inner wall of the through hole C; the first support tube is used to be fixedly connected to the middle and upper inner wall of the through hole B; One end of the second connecting member (6) is used to pass through the first supporting tube, the bearing (3) and the bearing cover plate (4) in sequence and then be fixedly connected to the bearing cover plate (4), and the other end is limited to be located outside the first supporting tube.

2. The blade root connection assembly according to claim 1, characterized in that: The flexible beam (7) is made of composite material.

3. The blade root connection assembly according to claim 2, characterized in that: The flexible beam (7) is made of a glass fiber reinforced epoxy resin system material.

4. The blade root connection assembly according to claim 2, characterized in that: The blade root connection assembly further comprises a second support tube (9) and a gasket (8). A plate-like structure is extended radially outward from the edge of one end of the second support tube (9), and a side wall opposite to the second support tube (9) is provided along the edge of the plate-like structure, the side wall is provided with a notch, and the end of the through hole B is provided with a convex edge that is mounted in cooperation with the notch; The second support tube (9) is used to pass through the through hole B to fit the notch and the convex edge; One end of the second connecting member (6) is used to sequentially pass through the gasket (8), the second support tube (9), the bearing (3) and the bearing cover plate (4) and then be fixedly connected to the bearing cover plate (4), and the other end is limited to be located outside the gasket (8).

5. The blade root connection assembly according to claim 4, characterized in that: The second connecting member (6) is a screw with a cap.

6. The blade root connection assembly according to claim 4, characterized in that: The second connecting member (6) is a screw with a hole at one end.

7. The blade root connection assembly according to any one of claims 1 to 6, characterized in that: The damper (1) is a viscoelastic damper.

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