Flutter counterweight device and anti-flutter propeller or rotor wing
By designing a flutter counterweight device on the propeller or rotor, the streamlined head and tail structures enhance the bending stiffness and torsional resistance of the propeller, the high-frequency flutter problem is solved, the production accuracy and safety are improved, and the cost is reduced.
Patent Information
- Application Number
- CN202422342759.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2034-09-25
AI Technical Summary
Propellers or rotors are prone to high-frequency flutter when they are insufficient stiffness, insufficient torsion resistance or insufficient power, resulting in increased motor load and safety hazards. The position of traditional built-in weight strips is strictly required and production is difficult.
A flutter counterweight device is designed, including a flow line head and a flow line tail, a blade mating groove and a fixing hole are installed, and a counterweight device is installed at the leading edge of the blade, which improves the bending stiffness and torsional resistance of the propeller through external concentrated mass, and ensures installation accuracy through positioning planes and limiting slots.
In the high-speed rotation state, increase the centrifugal force of the propeller, suppress high-frequency flutter, improve production yield, reduce production costs, and achieve better vibration control through external installation.
Smart Images
Figure CN223161973U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of aircraft, in particular to a flutter counterweight device and an anti-flutter propeller or rotor. Background Art
[0002] In the case of insufficient stiffness / torsion resistance of the propeller or rotor, when the propeller works, the tip of the blade warps up to a certain position. If the stiffness is insufficient or the blade has insufficient torsion resistance, high-frequency flutter will occur, the torque will increase sharply, the load on the motor will increase sharply, and there are potential safety hazards. It is necessary to increase the counterweight to increase the centrifugal force of the propeller in the high-speed rotation state and assist in improving the bending stiffness of the propeller tip.
[0003] In the case of insufficient power tolerance of the propeller or rotor, the propeller or rotor is designed according to a certain power. When used on a higher-power device to increase the lift / thrust of the propeller, due to insufficient power tolerance, the torsion resistance performance of the blade is insufficient, and high-frequency flutter occurs in a certain rotational speed range. The external counterweight device has a large force arm from the X-axis of the propeller, and it is necessary to increase the counterweight to improve the torsion resistance and solve the high-frequency flutter.
[0004] When traditional propellers or rotors are produced, the counterweight strips are usually placed inside the blades. The placement position of the counterweight strips has very strict requirements. The counterweight is in the shape of a long strip, and the distances from the X-axis and Y-axis need to be accurately controlled to avoid difficult propeller trimming, which puts very high requirements on the production quality. Summary of the Utility Model
[0005] Aiming at the above-mentioned defects existing in the prior art, the purpose of the utility model is to provide a flutter counterweight device and an anti-flutter propeller or rotor.
[0006] To achieve the above purpose, the utility model adopts the following technical solutions:
[0007] On the one hand, the utility model provides a flutter counterweight device, including a streamlined head and a streamlined tail connected to each other, with a smooth transition between the streamlined head and the streamlined tail, and a blade fitting groove is arranged at the rear end of the streamlined tail; a fixing hole is arranged through the streamlined tail, and the fixing hole penetrates the blade fitting groove.
[0008] Further, a positioning plane is arranged at the deepest part of the blade fitting groove.
[0009] Further, the positioning plane is a vertical plane, and the fixing hole is a vertical hole.
[0010] Further, the outer shape of the streamlined head is hemispherical, the outer shape of the streamlined tail is conical, and an arc-shaped cut surface is arranged for transition between the streamlined head and the streamlined tail.
[0011] Further, the outer shapes of the streamlined head and the streamlined tail are in the shape of wing knives.
[0012] Furthermore, the head and tail of the streamline are integrally formed.
[0013] On the other hand, the present invention provides a propeller or rotor for anti-flutter, including a blade. A connecting part is arranged at one end of the blade, and at least one flutter counterweight device as described above is arranged on the leading edge of the blade; the shape of the blade fitting groove corresponds to the leading edge of the blade.
[0014] Furthermore, a counterweight device limiting groove is arranged on the leading edge of the blade, and the counterweight device limiting groove cooperates with the positioning plane to position the flutter counterweight device.
[0015] The present invention has the following beneficial effects compared with the prior art:
[0016] 1. The flutter counterweight device of this patent can increase the centrifugal force of the propeller in the high-speed rotation state, assist in improving the bending stiffness of the propeller tip; can generate greater anti-torsion performance, solve high-frequency flutter; can change the vibration frequency of the blade and reduce the occurrence of flutter phenomenon.
[0017] 2. This patent can suppress the occurrence of flutter with the smallest mass. The principle is that the flutter counterweight device is arranged outside the blade, with concentrated mass, relatively large concentrated mass and large gravity, and the vibration suppression effect is good; when the blade tends to vibrate or is about to reach the vibration critical point, the installation centroid distance of the flutter counterweight device from the X-axis is far, the force arm is large, and the vibration suppression effect is good.
[0018] 3. When the flutter counterweight device of this patent is installed, the installation accuracy control is strong and the flutter control accuracy is strong, which improves the production yield rate of good products and thus reduces the production cost. Description of the Drawings
[0019] Figure 1 is a schematic structural diagram of a traditional blade with an internal counterweight bar;
[0020] Figure 2 is a schematic diagram of the centroid of a traditional blade with an internal counterweight bar;
[0021] Figure 3 is a schematic structural diagram of the anti-flutter propeller or rotor of the present invention;
[0022] Figure 4 is Figure 3 the cross-sectional schematic diagram at A-A in
[0023] Figure 5 is a schematic structural diagram of the flutter counterweight device of the present invention;
[0024] Figure 6 is a schematic structural diagram of the counterweight device limiting groove on the leading edge of the blade in the present invention;
[0025] In the figure: 1. Connecting part; 2. Blade; 3. Counterweight bar;
[0026] 4. Flutter counterweight device; 4.1 Streamlined head; 4.2 Streamlined tail; 4.3 Blade fitting groove; 4.4 Fixing hole; 4.5 Positioning plane;
[0027] A1. Centroid position of the built-in counterweight bar; B1. Centroid position after the counterweight bar is combined with the blade; C1. Centroid position of the current cross-section of the blade;
[0028] A2. Centroid position of the flutter counterweight device; B2. Centroid position after the flutter counterweight device is combined with the blade. Specific embodiments
[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0030] Embodiment 1: Please refer to Figures 3 to 5 , the flutter counterweight device provided by the present invention includes a streamlined head 4.1 and a streamlined tail 4.2 that are connected to each other. The streamlined head 4.1 and the streamlined tail 4.2 are integrally formed, and there is a smooth transition between the streamlined head 4.1 and the streamlined tail 4.2. A blade fitting groove 4.3 is provided at the rear end of the streamlined tail 4.2, and the shape of the blade fitting groove 4.3 corresponds to the leading edge of the blade 2; a fixing hole 4.4 is provided through the streamlined tail 4.2, and the fixing hole 4.4 penetrates the blade fitting groove 4.3 to strengthen the connection between the flutter counterweight device and the blade 2.
[0031] Furthermore, a positioning plane 4.5 is provided at the deepest part of the blade fitting groove 4.3 for positioning with the blade 2.
[0032] Specifically, the positioning plane 4.5 is a vertical plane, and the fixing hole 4.4 is a vertical hole.
[0033] Specifically, the outer shape of the flutter counterweight device is obtained by aerodynamic calculation and simulation to obtain an airfoil with the least resistance to high-speed airflow. The flutter counterweight device is formed by metal processing technology, and the weight of the flutter counterweight device can be changed by the material density, such as stainless steel, die steel, titanium alloy, etc.
[0034] Preferably, the outer shape of the streamline head 4.1 is hemispherical, the outer shape of the streamline tail 4.2 is conical, and an arc-shaped cut surface is provided between the streamline head 4.1 and the streamline tail 4.2 for transition, so that the overall outer shape of the flutter counterweight device is in the shape of a water droplet, which will not affect the rotation of the blade 2.
[0035] Another preferably, the outer shapes of the streamline head 4.1 and the streamline tail 4.2 are in the shape of wing knives, which will generate turbulent flow. Through simulation calculation, the turbulent flow generated by the wing knives can increase the lift force.
[0036] More preferably, the overall outer shapes of the streamline head 4.1 and the streamline tail 4.2 are not limited to the shape of a water droplet or the shape of wing knives, and other shapes that do not affect the aerodynamic shape of the blade or can enhance the lift force of the blade can be obtained through aerodynamic calculation and simulation.
[0037] Embodiment 2: On the basis of Embodiment 1, combined with Figure 6 , this embodiment provides a propeller or rotor equipped with a flutter counterweight device, including a blade 2, a connecting portion 1 is provided at one end of the blade 2, and at least one flutter counterweight device 4 described in Embodiment 1 is provided at the leading edge of the blade 2.
[0038] Specifically, a counterweight device limiting groove is provided at the leading edge of the blade 2. As Figure 6 shown, the counterweight device limiting groove cooperates with the positioning plane 4.5 to position the flutter counterweight device 4.
[0039] Specifically, the number of flutter counterweight devices 4 is not limited to one, and can be increased to 2 or more according to the flutter frequency and power tolerance requirements, or can be increased to 2 or more according to the weight and size of the flutter counterweight device 4.
[0040] Steps for installing the flutter counterweight device 4: Before installing the counterweight device, it is necessary to grind a counterweight device limiting groove at the corresponding position of the leading edge of the blade 2 for limiting the flutter counterweight device 4. Apply aviation glue in the blade fitting groove 4.3, press the flutter counterweight device 4 on the counterweight device limiting groove, and cure it at room temperature for 24 hours. Drill holes in the carbon fiber blade body of the blade 2 through the fixing holes 4.4 with a diameter of 2 mm on the flutter counterweight device 4, and rivet with a 2 mm steel wire. Hammer all the exposed parts of the steel wire flat to complete the fastening and complete the installation of the flutter counterweight device 4.
[0041] Comparative Example 1: As Figure 1 , Figure 2As shown in the figure, when the blade 2 is produced, the additional counterweight bar 3 is usually placed inside the blade 2, and the position requirements are very strict. The counterweight bar 3 is in a long strip shape, and the distances from the X-axis and Y-axis need to be accurately controlled to avoid difficult propeller trimming, which poses high requirements for production quality. From the centroid position A1 of the built-in counterweight bar, the centroid position B1 after the combination of the counterweight bar and the blade, and the centroid position C1 of the current cross-section of the blade, it can be seen that the counterweight bar 3 mainly affects the centroid position of the blade 2 on the Y-axis. Through Figure 1 it can be seen that the counterweight bar 3 has no obvious influence on the centroid position of the blade 2 on the X-axis.
[0042] As Figure 3 , Figure 4 shown, for the blade 2 of Embodiment 2, from the centroid position A2 of the flutter counterweight device, the centroid position B2 after the combination of the flutter counterweight device and the blade, and the centroid position C1 of the current cross-section of the blade, it can be seen that the flutter counterweight device 4 has a greater influence on the centroid position of the blade 2 on the Y-axis than the counterweight bar 3. Through Figure 3 it can be seen that the flutter counterweight device 4 has a greater influence on the centroid position of the blade 2 on the X-axis than the counterweight bar 3.
[0043] The weight of the counterweight device needs to be customized according to the flutter frequency or flutter rotational speed. If the concentrated weight is too light, the flutter cannot be suppressed. If the concentrated mass is too heavy, the centrifugal force is large when the propeller rotates, and there is a risk of out-of-control.
[0044] Performance comparison between the flutter counterweight device 4 and the counterweight bar 3:
[0045] Comparison item Flutter counterweight device 4 Counterweight bar 3 Weight 1 / 4 of the counterweight bar weight Heavier Mass distribution Concentrated Dispersed Flutter control accuracy Strong General Production accuracy control Strong Poor Distance of the counterweight center of gravity from the X-axis Far Near Flutter suppression Very good General
[0046] In this application, all components themselves that are not elaborated and the connection methods of the various components in this application belong to the well-known technologies in the technical field. They can be directly applied and will not be elaborated further.
[0047] In the present utility model, the term "plurality" refers to two or more, unless otherwise clearly defined. Terms such as "installation", "connection", "linkage", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linkage" can be a direct linkage or an indirect linkage through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0048] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, should not be construed as a limitation of the present utility model.
[0049] In the description of this specification, the descriptions of the terms "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.
[0050] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, the present utility model may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A flutter counterweight device, characterized in that, It includes a streamlined head and a streamlined tail that are connected to each other, with a smooth transition between the streamlined head and the streamlined tail, and a blade fitting groove is provided at the rear end of the streamlined tail; a fixing hole is provided through the streamlined tail, and the fixing hole penetrates the blade fitting groove.
2. The flutter counterweight device according to claim 1, wherein A positioning plane is provided at the deepest part of the blade fitting groove.
3. The flutter weight device according to claim 2, wherein The positioning plane is a vertical plane, and the fixing hole is a vertical hole.
4. The flutter counterweight device according to claim 1, wherein The outer shape of the streamlined head is hemispherical, the outer shape of the streamlined tail is conical, and an arc-shaped cutting surface is provided for transition between the streamlined head and the streamlined tail.
5. The flutter counterweight device according to claim 1, characterized in that, The outer shapes of the streamlined head and the streamlined tail are wing-knife-shaped.
6. The flutter counterweight device according to any one of claims 1-5, characterized in that, The streamlined head and the streamlined tail are integrally formed.
7. A propeller or rotor for anti-flutter, comprising a blade, wherein a connecting portion is arranged at one end of the blade, and is characterized in that At least one flutter weight device as described in claim 2 is provided at the leading edge of the blade; The shape of the blade fitting groove corresponds to the leading edge of the blade.
8. A propeller or rotor for anti-flutter according to claim 7, characterized in that, A weight device limiting groove is provided at the leading edge of the blade, and the weight device limiting groove cooperates with the positioning plane to position the flutter weight device.