JP2006160167A - Rotor hub structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor hub system assuring favorableness in terms of structural strength and the weight, capable of simplifying the shape of its flex beam, suppressing the cost, and enhancing the reliability when it is applied to rotary wing aircraft. <P>SOLUTION: A rotor hub structure of rotary wing aircraft has rod-shaped members 6 and 7 borne by a shaft 1 and sustaining the centrifugal force and torsion load and a supporting member 8 borne by the shaft and supporting approximately the two ends of the rod-shaped members. According to this constitution, the load is dispersed to the rod-shaped members and the supporting member, which assures favorableness in terms of strength, allows simplifying the structure, reducing the weight, suppressing the cost, and heightening the reliability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a rotor hub structure that transmits torque from a shaft to a blade in a rotary wing aircraft.

In a rotor hub structure of a rotary wing aircraft, there are an all-joint rotor, an unjoint rotor (bearingless rotor or hingeless rotor), and the like.

The all-joint rotor is a flapping motion, feathering motion, lead-lag hinge, blade flapping hinge, feathering hinge, lead-lag hinge. Lug motion refers to a type of rotor that can perform each motion, and an articulated rotor refers to a rotor that does not have a flapping hinge and a lead lug hinge. The articulated rotor allows flapping motion and lead lug motion by providing a flexible portion with low bending rigidity at the base of the hub or blade.

There are various ways of calling the hinge, and the lead lug hinge is also called a drag hinge, and the feathering hinge is also called a torsion hinge.

In an articulated rotor hub system, a flex plate is formed with a hub plate. By fixing the hub plate and the rotary shaft of the rotorcraft, torque can be transmitted from the rotary shaft to the hub plate to obtain lift. it can. Examples of means for fixing the flex beam and the hub plate include those described in Patent Document 1 and Patent Document 2. According to the above document, a plurality of holes are drilled in the hub plate, a plurality of holes are similarly drilled in the mounting bracket provided at the upper end of the rotating shaft, and the hub plate and the mounting bracket are connected via bolts. It is joined. Thereby, the centrifugal force, lift, torque, and bending moment from the blade are supported by the hub plate, the mounting bracket, and the bolt.
JP 61-21894 JP-A-6-270893

However, the articulated rotor is characterized by the absence of a flapping hinge and a lead lug hinge, and the loads in the flapping direction and the lead lug direction are supported by a hub plate, mounting brackets, and bolts. Therefore, a large stress is generated on the hub plate, the mounting bracket, and the bolt that are the base of the blade. In particular, if a flapping hinge offset is provided at a position away from the rotation axis of the flex beam in order to improve mobility, the bending load applied to the hub plate increases. Furthermore, the hub plate had to be responsible for centrifugal force. Therefore, the hub plate needs to be thick enough to withstand the load, which increases the weight of the rotorcraft. This results in a decrease in operational efficiency.

Further, if the strength of the flex beam is increased in order to allow loads in the flapping direction and the lead / lag direction, a thick flex beam is obtained. This leads to an increase in the weight of the flex beam and an increase in torsional rigidity, resulting in a decrease in operational efficiency. Therefore, in order to allow this load, it has been considered to make the shape of the flex beam complicated and to make the flex beam more flexible and as if it had a hinge. Such a configuration is disclosed in Patent Document 3, for example. However, adopting such a configuration results in an increase in manufacturing cost.

In addition, it is conceivable to use a composite material to increase the strength of the hub plate. However, many composite materials are difficult to cut, and it is difficult to make accurate holes. Even if the hub plate and the mounting bracket are drilled and joined with bolts, the accuracy is poor. Therefore, it is actually disadvantageous in terms of strength because it is in the same state as being joined with several bolts.
Japanese Patent Laid-Open No. 10-287297

In view of the above, the present invention provides a rotary wing aircraft that has a sufficient strength during operation of a rotary wing aircraft, a structure that is advantageous in terms of weight, while maintaining manufacturing costs. The purpose is to provide a rotor hub system.

A rotor hub structure according to the present invention is a rod-shaped member that is pivotally supported by a shaft, is connected to a rotor blade of a rotorcraft at both ends, and receives a centrifugal force and a torsional load acting by rotation of the rotor,
And a support member that is supported by a shaft and supports substantially both ends of the rod-shaped member via a bearing.

With this configuration, the bending load in the flapping direction and the lead / lag direction generated by the blade during operation of the rotorcraft is transmitted from the rod-shaped member to the support member via the support portion.

Further, since the bearing does not restrain the twisting load and centrifugal force in the feathering direction of the rod-shaped member, the torsional load and centrifugal force in the feathering direction generated by the blade during operation is transmitted to the rod-shaped member without being transmitted to the support member. .

Thus, the support member only needs to allow the load in the flapping direction and the lead / lag direction during operation of the rotary wing aircraft, and the rod-like member only needs to allow the load in the feathering direction and the centrifugal force. .

Thus, by distributing the load generated by the blade during operation to the support member and the rod-like member, the support member can be made thinner and lighter, leading to improved operational efficiency of the rotary wing aircraft. Moreover, since the shape of the rod-shaped member can be simplified, the manufacturing cost can be greatly reduced.

The rotor hub structure according to the present invention is further characterized in that a portion closer to the rotation center than substantially both ends of the rod-like member is supported.

Accordingly, the support member supports at least four points of the both ends of the rod-shaped member and at least four points on the rotation center side of the rod-shaped member from the both ends. As a result, the rod-shaped member can be stably supported from the time of operation of the conventional rotary wing aircraft, and since the shear load is not applied to the central axis side from substantially both ends, the support member and the rod-shaped member are advantageous in strength. become.

In the rotor hub structure according to the present invention,
A rod-shaped member provided to support and support the rotor blades of a rotorcraft at both ends thereof. A rod-shaped member comprising a torque tube that handles the load;
A support member that is pivotally supported by the shaft and supports both ends of the rod-like member via bearings;
A part or all of the flex beam is arranged inside the torque tube.

  During operation of a rotary wing aircraft, the shear load due to bending from the blade is transmitted to the support member by the torque tube via the bearing, so that the flex beam only needs to bear the centrifugal force. Thereby, the shape of the flex beam can be simplified, the manufacturing cost can be greatly reduced, and high reliability can be obtained because of the simple structure.

Since the support member supports substantially both ends of the rod-shaped member via bearings, only the shear load due to bending from the blade is handled. As a result, the thickness of the support member can be reduced, which is advantageous in terms of weight and strength.

In the rotor hub structure according to the present invention, the pitch angle control means for changing the pitch angle of the rod-shaped member is provided on a torque tube that bears a torsional load between substantially both ends of the rod-shaped member and a portion adjacent to the shaft. It is characterized by being.

The rod-shaped member includes a flex beam that handles centrifugal force and a torque tube that handles torsional load. Since the torque tube is designed to handle torsional loads, pitch angle control means can be provided on the torque tube. Thereby, since the pitch angle control means can be disposed inside substantially the both ends of the rod-like member supported by the support member, the air resistance can be reduced.

According to the rotor hub structure according to the present invention,
By distributing the load generated from the blade during operation to the support member and the rod-like member, the support member can be made thinner and lighter, leading to improved operational efficiency of the rotorcraft. Further, since the shape of the rod-shaped member can be simplified, the manufacturing cost can be greatly reduced.

Moreover, since the pitch angle control means is provided in the torque tube between the substantially both ends of the rod-shaped member supported by the support member and the shaft adjacent portion, the air resistance can be reduced.

Further, since the support member supports the substantially both ends of the rod-shaped member and the substantially adjacent portion of the shaft, the rod-shaped member can be stably supported during the operation of the conventional rotary wing aircraft. Further, with such a configuration, the load is dispersed, and the support member and the rod-shaped member are advantageous in strength.

  Next, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a rotor hub structure according to an embodiment of the present invention.

First, a sectional view will be described.

The shaft 1 is coupled to a pressure plate 4, and the pressure plate 4 is coupled to a hub 5 (support member) via bolts 13 and the like.

The rod-shaped member including the flex beam 6 is attached to the shaft by a flex beam attachment portion 11, and a feathering motion called a feathering element 6a is provided between a portion substantially adjacent to the shaft 1 of the flex beam 6 and substantially both ends. The element for accepting is formed. The flex beam 6 is preferably a composite material that can realize a low torsional rigidity with a tensile strength. A part or all of the flex beam 6 is arranged inside a hollow rod-like torque tube 7 that transmits a torsional load. The hub 5 supports the torque tube 7 via an inner bearing 8a and an outer bearing 8b.

The swash plate 2 is coupled to a pitch control rod 3 (part of pitch angle control means), and the pitch control rod 3 is coupled to a torque tube 7. A joint between the pitch control rod 3 and the torque tube 7 is provided between the inner bearing 8a and the outer bearing 8b.

A blade 9 is coupled to an outer position adjacent to a portion of the torque tube 7 supported by the outer bearing 8b. In addition, a flapping element 9a that allows the lift generated during operation of the rotary wing aircraft to be allowed by elastic deformation of the blade material, and a lead lug necessary for the blade movement, in the vicinity of the joint of the blade 9 with the torque tube 7 A lead lug element 9b is formed which acts as a directional hinge and allows inertial force generated when the rotor is started and stopped.

Further, a structural member called a fairing 10 having substantially the same diameter as the hub 5 is coupled to the shaft 1 by a fairing support member 12.

Next, the function of each part will be described.

Torque is transmitted from the rotor shaft 1 to the hub 5 via the pressure plate 4. The torque transmitted to the hub 5 is transmitted to the torque tube 7 via the inner bearing 8a and the outer bearing 8b, and the torque is transmitted from the torque tube 7 to the blade 9.

Also, the pitch control rod 3 transmits the movement of the swash plate 2 to the torque tube 7 to change the blade 9 to a necessary pitch angle.
Here, the torsional load in the pitch angle direction of the blade 9 is transmitted from the pitch control rod 3 to the torque tube 7 by transmitting a shear load in the longitudinal direction of the pitch control rod.

The shear load from the blade is transmitted to the hub 5 through the inner bearing 8a and the outer bearing 8b supporting the torque tube 7, and is allowed by the hub.
Further, the torsional load is not restricted by the inner bearing 8 a and the outer bearing 8 b that support the torque tube 7, and is allowed by the flex beam 6 that is coupled to the torque tube 7.

Centrifugal force generated in the blade 9 is transmitted from the blade 9 to the flex beam 6 through a part of the torque tube 7, and the centrifugal force is canceled by the flex beam mounting portion 11. For this reason, the inner bearing 8a and the outer bearing 8b have a bearing structure that does not restrain displacement of the flex beam 6 in the centrifugal force direction.

Further, since the torque tube 7 can be arranged inside the hub 5, the pitch control rod 3 can be provided inside the hub 5, and a part of the pitch angle control mechanism and other control mechanisms can be provided inside the hub 5. Or since all can be arrange | positioned, the air resistance at the time of operation | movement can be reduced.

Further, a structural member 10 called a fairing 10 having a diameter substantially the same as that of the hub 5 is coupled to the upper portion of the hub 5 by a fairing support member 12. The air resistance can be reduced by accommodating a part or all of the rotor control mechanism of the rotorcraft in the space surrounded by the fairing 10 and the hub 5.

Further, the fairing and the hub also have an effect of preventing the rotor control mechanism, the torque tube 7, the flex beam 6, and the like from being damaged due to collision of flying objects from the outside.

FIG. 2 is an enlarged view of the vicinity of the bearing 8 that supports the torque tube 6. The bearing 8 does not restrict displacement in the centrifugal force direction and the torsional direction, and has a structure that supports the flapping direction and the lead / lag direction with rigidity. For this reason, the bearing 8 is formed of a bearing or a Teflon (registered trademark) bearing capable of withstanding a bending load.

Needless to say, the type of bearing is not limited to the bearings listed above.

In addition, this embodiment is only one embodiment, and the present invention is not limited to this embodiment.

As described above, according to the present invention, the rod-like member and the support member can be thinned, and the weight can be significantly reduced. Further, it is possible to reduce the manufacturing cost of the rotor hub structure, reduce the air resistance during operation, and improve the reliability during operation by protecting the control mechanism inside the hub 5.

It is sectional drawing of the rotor hub structure of this invention.

It is detail drawing of the bearing 8 which supports the torque tube of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotor shaft 2 Swash plate 3 Pitch control rod 4 Pressure plate 5 Hub 6 Flex beam 6a Feathering element 7 Torque tube 8 Bearing 8a Inner bearing 8b Outer bearing 9 Blade 9a Flapping element 9b Lead lug element 10 Fairing 11 Flex Beam mounting part 12 Fairing support member 13 Bolt

Claims (4)

In a rotor hub structure of a rotary wing aircraft, a rod-shaped member that is pivotally supported by a shaft and coupled to both ends of the rotor wing of the rotary wing aircraft and is responsible for centrifugal force and torsional load acting on the rotation of the rotary wing, and a shaft on the shaft A rotor hub structure comprising a support member supported and supporting substantially both ends of the rod-like member via bearings. 2. The rotor hub structure according to claim 1, wherein the support member further supports a portion closer to a rotation center than the substantially both ends of the rod-shaped member. In a rotor hub structure of a rotorcraft, a rotor blade of a rotorcraft is coupled to both ends of the rotor hub, and is a rod-like member provided to support the rotor. A rod-shaped member that includes a flex beam that handles centrifugal force and a torque tube that handles torsional load, and a support member that is supported by the shaft and supports both ends of the rod-shaped member via bearings. And a part or all of the flex beam is disposed inside the torque tube. The pitch angle control means for changing the pitch angle of the rod-shaped member is provided in a torque tube between the substantially both ends of the rod-shaped member and a portion adjacent to the shaft. The described rotor hub structure.

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