KR20130078482A - Bearingless main rotor hub system - Google Patents

Abstract

The present invention relates to a bearingless hub hub system applied to a small and medium-sized helicopter, wherein the rotor blades are coupled to each other, and the flexible beams, which serve as hinges with respect to the flap, lead-lag and feathering directions of the rotor blades, surround the flexible beams. Torque tube for adjusting the pitch angle of the rotor blades, coupled to the torque tube and the flexible beam penetrated through the lead-lag damper to prevent ground and flight resonance generated when the rotor blade rotates, and the flexible beam from the engine It includes a hub plate that is secured to the rotor mast is rotated by receiving power. According to the present invention, by removing the bearing, having a flap and lead-lag hinge, and a flexbeam formed of a composite material that performs a pitch bearing function, the structure can be simplified to reduce weight and thereby maintain operating costs. By reducing the hub drag as well as reducing the overall power of the helicopter can be improved.

Description

Bearingless main rotor hub system

The present invention relates to a bearingless hub hub system applied to small to medium sized helicopters.

Helicopter rotor system handles rotor blades that generate lift, thrust and maneuverability for the helicopter, thrust and moment generated from the rotor blades, and a rotor hub that transmits the force required for flight to the fuselage It consists of a rotor hub system and a rotor control system that controls the thrust and maneuverability of the helicopter.

Here, the helicopter rotor hub system enables various movements of the rotor blades and handles deformations and loads resulting from such movements. Representative motions generated by the aerodynamic force as the rotor blades rotate here include flapping motions moving up and down the rotating plane, lead-lag motions moving forward and backward, and pitching motions moving in the blade pitch angle direction. (pitching motion or feathering motion)

However, the conventional helicopter rotor hub system has a problem that it is difficult to advance the horizontal flight of the helicopter due to the excessive load because the forced hub structure directly responsible for the movement, load and deformation of the blade.

The concept introduced to solve this problem is a hub system to which a hinge is applied.

The hub system, with the concept of the original hinge, is an articulated hub system with all three hinges for flap, lead-lag and feathering motion. However, this is a complicated structure, a large number of parts, a heavy weight consumes a lot of operating maintenance costs, the flight safety and performance is deteriorated, and the problems such as reduction of payload due to excessive weight. To solve this problem, a hingeless hub system has been developed in which the hinges are replaced with structural elastic materials. The hingeless hub system replaces two hinges for flap and lead-lag movement with blade structural flexure and has only one feathering (pitch) hinge. Accordingly, it is formed in a relatively simple structure, the weight is low, and the operation maintenance cost is consumed less.

However, all helicopters currently in use use mechanical or elastomer bearings to implement blade movement. These bearings increase the weight of the helicopter and incur large operating costs such as maintenance and parts replacement for regular lubrication.

The present invention has been made to solve the problems as described above, the problem to be solved by the present invention is to remove the bearing to reduce the weight of the rotor system and simplify the structure to reduce the operating cost and reduce the hub drag It is to provide a bearingless rotor hub system.

Bearingless rotor hub system according to an embodiment of the present invention for achieving the above object is a flexible beam, the rotor blade is coupled and acts as a hinge to the flap, lead-lag and feathering direction of the rotor blade, the flexible Torque tube that surrounds the beam and adjusts the pitch angle of the rotor blade, coupled to penetrate through the torque tube and the flexible beam lead-lag damper to prevent ground and flight resonance generated when the rotor blade rotates, and the flexible beam It includes a hub plate that receives power from the engine and is fixed to the rotating rotor mast.

The flexible beam may include a flap direction motion section performing a flap hinge function, a lead-lag direction motion section performing a lead-lag hinge function, and a torsion direction motion section performing a pitch bearing function.

The shape of the cross section of the torsion direction movement section may be a double H shape.

The flexible beam may be formed of glass fiber and carbon fiber.

There may be a plurality of flexible beams.

The torque tube may be formed in an elliptical structure to minimize aerodynamic drag and improve flight capability.

The torque tube may be formed of carbon fiber.

The torque tube may be a plurality.

The double H-shape is a shape in which two H-shape are formed side by side with a connecting portion connecting each other at the center of the two H-shape.

According to the present invention, by removing the bearing, and having a flexible beam formed of a composite material that performs a flap and lead-lag hinge, and a pitch bearing function, it is possible to simplify the structure to reduce the weight, thereby reducing the operating cost By reducing the hub drag, the overall performance of the helicopter can be improved.

1 is a perspective view in which a bearingless hub hub system according to an embodiment of the present invention is applied to a helicopter.
FIG. 2 is an enlarged view of a portion “A” of FIG. 1 enlarged.
Figure 3 is an exploded perspective view schematically showing a bearingless hub hub system according to an embodiment of the present invention.
4 is a perspective view of a flexible beam of a bearingless hub hub system according to an embodiment of the present invention.
5 is a cross-sectional view taken along the line VV of FIG. 4.
6 is a perspective view of a torque tube of a bearingless hub hub system according to one embodiment of the invention.
FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 6.
8 is a schematic view showing a torque tube and a flexible beam of a bearingless hub hub system according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view in which a bearingless hub hub system according to an embodiment of the present invention is applied to a helicopter, and FIG. 2 is an enlarged view of an enlarged portion "A" of FIG. 1. Figure 3 is an exploded perspective view schematically showing a bearingless hub hub system according to an embodiment of the present invention, Figure 4 is a perspective view of a flexible beam of the bearingless hub hub system according to an embodiment of the present invention. 5 is a cross-sectional view taken along the line V-V of FIG. 4, and FIG. 6 is a perspective view of a torque tube of a bearingless hub hub system according to an embodiment of the present invention. FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 6, and FIG. 8 is a schematic view showing a torque tube and a flexible beam of a bearingless hub hub system according to an embodiment of the present invention.

Bearingless hub hub system 1 according to an embodiment of the present invention (hereinafter referred to as the 'boneless bearing hub hub system 1') is a bearingless hub hub system 1 applied to a helicopter 20 having a small and medium-sized presence. ) The configuration will now be described in relation to the present bearingless hub hub system 1.

The bearingless hub hub system 1 includes a flexbeam 30.

1 to 3, there are a plurality of flexible beams 30, the rotor blades 10 are coupled to each other, and the hinge blades serve as hinges with respect to the flap, lead-lag, and feathering directions of the rotor blades 10. do.

Here, the flap, the lead-lag and the feathering direction refer to a representative direction of movement caused by the air force while the rotor blade 10 rotates.

For example, the flap direction of movement refers to the direction of movement that moves up and down as the bird flaps while the rotor blades 10 rotate. Next, the lead-lag movement direction refers to a movement direction in which the rotor blade 10 rotates back and forth in the rotational direction as the rotor blade 10 rotates. Finally, the feathering direction (or pitch direction) refers to the direction of motion generated by changing the rotor blade 10 pitch angle as the rotor blade 10 rotates to increase thrust or change direction.

Referring to FIG. 4, the flexible beam 30 performs a flap direction movement section 31 which performs a flap hinge function, a lead-lag direction movement section 33 which performs a lead-lag hinge function, and a pitch bearing function. It may include a torsion direction movement section 35 to. This is a section in which flapping motion, lead-lag motion, and feathering motion are implemented in the flexible beam 30.

By way of example, the flap direction of motion 31 is present at about 3% radial position from the hub center, where deformation in the flap direction is most significant. The section in which this deformation occurs serves as a flap hinge instead of the existing articulated hub system. Next, the lead-lag direction movement section 33 is located at a radial position of about 11% to 12% from the hub center as the center portion. In this section, the deformation of the lag direction occurs the most and serves as a lag hinge of the existing articulated hub system. Finally, the torsion direction movement section 35 occurs in the entire length section having a cross-sectional shape of the flexible beam 30.

Referring to FIG. 5, the cross-sectional shape of the torsion direction movement section 35 of the flexible beam 30 may be a double H shape. Here, the double H shape may be a shape in which two H shapes are integrally formed side by side with a connecting part connecting each other at a central portion of two H shapes arranged side by side when looking at a cross section. Such a double H shape is a shape that allows deformation to occur in the torsion direction (rotational movement in the X-axis direction) and lowers the stiffness in the lag direction.

This cross-sectional shape serves as the pitch bearing of the existing rotor hub system. As a result, in the flexible beam 30 structure, the motion in the flap direction, the motion in the lag direction, and the motion in the torsion direction according to the pitch motion are generated.

In addition, the flexible beam 30 may be formed of glass fibers and carbon fibers.

For example, the flexible beam 30 mostly uses unidirectional glass fibers to secure flap and lag stiffness and high fatigue life, and partially uses unidirectional carbon fibers as a partial optimization material. Here, the difference in the stiffness characteristics is optimized according to the cross-sectional shape, the torsional stiffness is lowered when the unidirectional glass fibers are laminated at 0 degrees, and the torsional rigidity may be increased when laminated to ± 45 degrees.

The bearingless rotor hub system 1 also includes a torque tube 40.

6 and 7, the torque tube 40 is a plurality, wrap the flexible beam 30 and adjusts the pitch angle of the rotor blade (10). More specifically, the torque tube 40, which is flexible to bending loads and includes a flexible beam 30, is connected to the pitch rank to adjust the pitch angle of the rotor blade 10.

In this case, the torque tube 40 may be formed of carbon fibers so as to increase rigidity in the torsion direction and to be relatively flexible in the bending direction.

For example, the carbon fibers may be stacked in a direction of ± 45 degrees to maximize rigidity in the torsion direction. In addition, by strengthening the stiffness in the lag direction so that the deformation in the lag direction occurs in the flexible beam 30, for this purpose, carbon fibers stacked on the leading edge and trailing edge of the torque tube 40 to 0 degrees By strengthening the lag stiffness can be enhanced.

In addition, referring to Figure 8, the torque tube 40 may be formed in an elliptical structure to minimize the aerodynamic drag to improve the flight capability. That is, the air flows smoothly along the outer surface of the torque tube 40 of the elliptical structure to minimize drag. Here, minimizing aerodynamic drag may refer to the fact that the air flows smoothly along the outer surface of the torque tube of the elliptical structure to reduce the occurrence of drag. In addition, such an elliptical structure is advantageous in terms of the force and the shear stress to transfer torque.

In addition, the torque tube 40 may be formed in a size that does not cause interference with the flexible beam (30). More specifically, the torque tube 40 may be formed so that the aspect ratio is 2: 1 or more. For example, when viewed from the cross-sectional direction, the flexible beam 30 and the torque tube 40 may not be in contact with each other even when the pitch angle reaches a maximum of 25 degrees.

The bearingless rotor hub system 1 also includes a lead-lag damper 50.

2 and 3, the lead-lag damper 50 is coupled to penetrate the torque tube 40 and the flexible beam 30 to prevent ground and flight resonances generated when the rotor blade 10 rotates. .

For example, the resonance phenomenon is an aerodynamic instability phenomenon in which the flap of the rotor of the helicopter 20, the lag mode and the roll of the fuselage, and the pitch mode are linked to each other, and are mainly generated in the non-hinge rotor or the bearingless rotor. When the resonance occurs, the body is pendulum movement during flight, the helicopter 20 is inclined by such a periodic vibration.

The present bearingless rotor hub system 1 also includes a hub plate 80.

2 and 3, the hub plate 80 fixes the flexible beam 30 to a rotor mast 70 that is rotated by receiving power from the engine.

For example, the hub plate 80 may fix the flexible beam 30 to the rotor mast 70 with eight hub connecting pins 81.

Hereinafter, each configuration of salping will be briefly described with reference to FIGS. 1 to 3.

1 to 3, the bearingless hub hub system 1 is a flexible beam 30 formed of a composite material that enables flap, lead-lag movement, and feathering movement of the rotor blades 10 and the rotor. Torque tube 40 formed of a composite material that changes the pitch angle of the blade 10 and supports and maintains the pitching moment force by air force, and the front and rear of the rotor rotating surface by drag force caused by the rotation of the rotor blade 10. Shear restrainer that supports relative movement between the torque tube 40 and the flexible beam 30 by the lead-lag damper 50 and the lead-lag damper 50 to prevent the movement of the direction from increasing. (51), a pitch horn (60), which is connected to the pitch link 100 of the rotor control system to allow the rotor blade (10) pitch angle to be changed, the flexible beam ( 30) Do not cross the rotor cross Hub plate 80 for fastening to hub 70 with hub connecting pin 81, blade connecting pin 11 for connecting flexible beam 30 and torque tube 40 and rotor blade 10, rotor It may be composed of a swash plate (90) that implements while rotating the pitch angle of the hub system.

At this time, the flexible beam 30 is connected to the rotor blade 10 by the torque tube 40 and the blade connecting pin 11, the rotor mast 70 is the hub plate 80 by the hub connecting pin 81. ) And the flexible beam 30 is crosswise fastened together. The lead-lag damper 50 is connected to the torque tube 40 by share retainer 51.

In addition, in order for the pitch angle of the rotor blade 10 to be varied, the swash plate 90 rotates by the torque tube 40 connected to the pitch horn 60 through a vertically or horizontally tilted movement of the flexible beam 30. The pitch angle of the rotor blades 10 is changed by the state of the torsional motion.

In this way, by removing the bearing, and having a flexible beam 30 formed of a composite material that performs a flap and lead-lag hinge, and a pitch bearing function, the system structure can be simplified to reduce the weight and thereby maintain operating costs. By reducing hub drag as well as reducing, the overall performance of the helicopter 20 can be improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, And all changes and modifications to the scope of the invention.

1. Bearingless rotor hub system
10. Rotor blade 11. Blade connecting pin
20. Helicopter 30. Flexbeam
31.Flap motion section 33. Lead-lag direction motion section
35. Torsion direction movement section 40. Torque tube
50. Lead-lag dampers 51. Shear restrainers
60. Pitch horn 70. Rotor mast
80. Hub plate 81. Hub connecting pin
90. Swash plate 100. Pitch link

Claims (9)

Flexible beams coupled to the rotor blades and hinged with respect to the flap, lead-lag and feathering direction of the rotor blades,
Torque tube surrounding the flexible beam and adjusting the pitch angle of the rotor blade,
A lead-lag damper coupled to penetrate the torque tube and the flexible beam to prevent ground and flight resonance generated when the rotor blade is rotated, and
Bearing-free rotor hub system including a hub plate for fixing the flexible beam to the rotor mast is rotated by receiving power from the engine. In claim 1,
The flexible beam flap direction movement section performing a flap hinge function,
A lead-lag direction movement section performing a lead-lag hinge function, and
Bearingless rotor hub system with torsional directional motion zones that perform pitch bearing functions. 3. The method of claim 2,
The shape of the cross section of the torsional direction of motion is a double bearing H-shaped bearing hub system. In claim 1,
The flexible beam bearingless hub hub system is formed of glass fiber and carbon fiber. In claim 1,
The flexible beam has a plurality of bearingless hub hub system. In claim 1,
The torque tube is a bearingless hub hub system is formed in an elliptical structure to minimize the aerodynamic drag to improve the flight capacity. In claim 1,
And said torque tube is formed of carbon fiber. In claim 1,
And said torque tube has a plurality of bearingless hub hub systems. 4. The method of claim 3,
The dual H-shape is a bearing-free hub hub system having a connection portion for connecting each other at the center of the two H-shape is a shape in which two H-shape formed side by side.

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