Manual rotor blade variable pitch structure

Abstract

The utility model belongs to the technical field of structural design of helicopters, and particularly relates to a manual rotor blade variable pitch structure. Comprising a propeller hub, an adapter and blades, the center of the hub is a circular hole for connecting a motor shaft; propeller hub supporting arms are arranged in the circumferential direction of the propeller hub; t-shaped grooves are formed in the outer sides of the propeller hub supporting arms, and upper and lower connecting plates are arranged on the two sides of the outer end faces of the T-shaped grooves; the adapter pieces are L-shaped, and the number of the adapter pieces is two; an arc-shaped recess is formed in the middle of the end plate, and bolt holes are formed in the two ends of the arc-shaped recess; the two adapter pieces are symmetrically arranged, and the two adapter piece end plates are fixed through bolts; the paddle penetrates through a fixing hole formed by the two arc-shaped recesses and then is inserted into the propeller hub; the variable torque of the paddle is adjusted by opening or loosening the two adapters, and the paddle is tightened and fixed after the variable torque is adjusted in place.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of helicopter structure design, especially relates to a manual rotor blade variable pitch structure. BACKGROUND

[0002] Traditional rotorcraft mainly includes propeller aircraft and helicopter. Among them, large propeller aircraft blade variable pitch generally adopts internal control form, is formed by 1 variable pitch sleeve, 2 blade eccentric pin and 3 blade root bearing section, as shown in Figure 1 Small or unmanned propeller aircraft generally directly adopts fixed pitch blade or manual split type hub variable pitch form, is formed by 4 blade root section and 5 hub cover plate, as shown in Figure 2 Helicopter blade variable pitch generally adopts pull rod external control form, is formed by 6 variable pitch pull rod, 7 variable pitch rocker arm, 8 blade root, 9 hub support arm and 10 hub main body, as shown in Figure 3 .

[0003] Test model is obtained by full-size aircraft scale reduction, and variable pitch rotor test model often has the following difficulties or shortcomings:

[0004] 1 small space, difficult to arrange control components;

[0005] 2 automatic variable pitch model high cost and prone to failure;

[0006] 3 manual split type variable pitch hub needs to disassemble hub, and variable pitch is difficult and time-consuming. INVENTION CONTENTS

[0007] The utility model relates to a manual rotor blade variable pitch structure for rotor test model and unmanned aerial vehicle rotor blade variable pitch.

[0008] TECHNICAL SCHEME

[0009] A manual rotor blade variable pitch structure, comprising: hub, adapter and blade;

[0010] The hub center is a circular hole for connecting the motor shaft;The hub is provided with hub support arms in the circumferential direction;

[0011] The outer side of the hub support arm is provided with a T-shaped groove, and the outer end surface of the T-shaped groove is provided with upper and lower connecting plates on both sides;

[0012] The adapter is L-shaped, and there are two pieces;The long plate is bolted to the upper and lower connecting plates, the middle part of the end plate is provided with an arc-shaped recess, and the both ends of the arc-shaped recess are provided with bolt holes;

[0013] Two adapters are symmetrically arranged, and the end plates of the two adapters are fixed by bolts;The blade is inserted into the hub after passing through the fixing hole formed by the two arc-shaped recesses;

[0014] The pitch of the blade is adjusted by opening or loosening the two adapters, and the blade is fixed after the adjustment is completed.

[0015] Further, the hub is provided with weight-reducing holes around the circular hole.

[0016] Further, the hub is cylindrical.

[0017] Further, the hub is an N-sided cylindrical body, and N is the number of blade pieces.

[0018] Further, the blade is divided into four sections: an end face cylindrical section, a middle cylindrical section, a transition section, and an airfoil section.

[0019] The end face cylindrical section is installed in the arm of the hub, the middle cylindrical section is connected with the adapter, the transition section refers to the part between the middle cylindrical section and the airfoil section, and the airfoil section is the actual shape section of the blade.

[0020] Further, a grinding piece is arranged between the middle transition section and the adapter to generate friction to prevent the pitch of the blade from changing.

[0021] In summary, the beneficial effects of the utility model are as follows:

[0022] The utility model provides a manual rotor blade pitch structure, which adopts an integrated hub, and the pitch is adjusted by only disassembling the blade adapter without disassembling the hub, so that the structure is simple and the pitch is quickly adjusted. DRAWINGS

[0023] Figure 1 It is an inside control schematic diagram of the blade pitch of a large propeller airplane;

[0024] Figure 2 It is a fixed-pitch blade or a manual split hub pitch schematic diagram of a small or unmanned propeller airplane;

[0025] Figure 3 It is an outside control schematic diagram of the blade pitch of a helicopter;

[0026] Figure 4 It is a rotor system composition diagram;

[0027] Figure 5 It is an assembly axial view;

[0028] Figure 6 It is an assembly plan view;

[0029] Figure 7 It is an assembly front view;

[0030] Figure 8 It is a hub view;

[0031] Figure 9 It is a connecting piece view;

[0032] Figure 10 For the blade view. DETAILED DESCRIPTION

[0033] For a better understanding of the present application, the following will describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0034] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0035] In addition, the terms "mount", "set", "provided with", "connected", "connected", "sleeved" should be broadly understood. For example, it can be fixedly connected, detachably connected, or integrally constructed; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, or it can be internal communication between two devices, elements or components. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] A manual rotor blade pitch structure, comprising a hub, an adapter and a blade.

[0037] The hub is a cylindrical or polygonal column, such as a quadrangular column for two blades, a triangular column for three blades, a quadrangular column for four blades, a pentagonal column for five blades, and so on. The center of the hub is a circular hole for connecting the motor shaft. In order to reduce weight or counterweight, corresponding holes are punched around the hub. The hub arm adopts a T-shaped groove form, and the blade is put in from the side or up and down direction, which can overcome the centrifugal force to prevent the blade from flying out when rotating.

[0038] The adapter is L-shaped, one side is connected with the hub arm, and the other side is connected with the root of the blade, and the friction force is generated by compression to prevent the blade from changing pitch.

[0039] The paddle is mainly divided into four sections: end face cylinder section, middle cylinder section, transition section, and airfoil section. The end face cylinder section is installed in the paddle hub support arm; the middle cylinder section is connected with the adapter, and there is a grinding piece between the two, which is used to generate friction to prevent the paddle from changing pitch; the transition section refers to the part between the middle cylinder section and the airfoil section, which is smooth except for specific requirements; and the airfoil section is the actual shape section of the paddle, which has no other specific requirements.

[0040] Embodiment

[0041] A specific example effect is given for a 1.5m diameter two-paddle rotor. The rotor system is composed of Figure 4 as shown in Table 1. Figure 5 is an assembly view, composed of 11 paddles, 12 upper connecting pieces, 13 lower connecting pieces, 14 paddle hub support arms, 15 paddle hub bodies, 16 motor shaft holes, and 17 paddle hub mounting holes, Figure 6 is a top view, Figure 7 is a side view, and for simplicity, only one paddle is shown in the figure. Figure 8 , 9 , 10 are respectively a paddle hub view, a connecting piece view, and a paddle view.

[0042] Table 1

[0043] Serial number Parameter Value 1 Rotor diameter 1.5m 2 Blade number 2 3 Blade airfoil NACA0012 4 Blade maximum chord length 0.08m 5 Blade minimum chord length 0.04m 6 Hub cylinder diameter 0.15m 7 Hub cylinder height 0.14m 8 Hub arm diameter 0.26m

[0044] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A manually operated variable pitch rotor blade structure, characterized in that: include: Hub, adapter and blades; The center of the propeller hub has a circular hole for connecting the motor shaft; the propeller hub is equipped with a propeller hub support arm around its circumference. The outer side of the propeller hub support arm is provided with a T-shaped groove, and the outer end face of the T-shaped groove is provided with upper and lower connecting plates on both sides. The adapter is L-shaped and consists of two pieces. The long plate is bolted to the upper and lower connecting plates, and the end plate has an arc-shaped recess in the middle, with bolt holes at both ends of the arc-shaped recess. Two adapters are symmetrically arranged and their end plates are fixed by bolts; the blades are inserted into the rotor hub after passing through the fixing holes formed by two arc-shaped recesses. Adjust the blade torque by opening or loosening the two adapters, and tighten the blades to fix them after adjustment.

2. The structure according to claim 1, characterized in that: Weight reduction holes are provided around the circular hole of the propeller hub.

3. The structure according to claim 2, characterized in that: The propeller hub is cylindrical.

4. The structure according to claim 3, characterized in that: The propeller hub is an N-sided prism, where N is the number of propeller blades.

5. The structure according to claim 4, characterized in that: The blade is divided into four sections: end cylindrical section, middle cylindrical section, transition section, and airfoil section; The end cylindrical section is installed in the rotor hub support arm; the middle cylindrical section is connected to the adapter; the transition section refers to the part between the middle cylindrical section and the airfoil section; the airfoil section is the actual shape of the rotor blade.

6. The structure according to claim 5, characterized in that: A grinding disc is provided between the intermediate transition section and the adapter to generate friction and prevent the blade pitch from changing.

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