JP2009045977A - Tail rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tail rotor capable of generating a propulsive force in a forward flight, and increasing a forward speed. <P>SOLUTION: The trail rotor comprises: a rotating shaft 12 extending along the horizontal axis of a helicopter; a plurality of blades 11 extending orthogonally to the rotating shaft 12, rotating with the rotating shaft 12, and formed so that at least a wing tip 11a may be bent outward; and an pitch angle changing mechanism including a collective pitch mode for simultaneously changing the same amount of pitch angles of the blades 11, and a cyclic pitch mode for periodically changing the pitch angles during one rotation. The pitch angle changing mechanism causes the blades 11 to generate the force f1 going outward in a semicircle at the front side of one rotation in the cyclic pitch mode, causes the blades 11 to generate the force f2 going inward in the semicircle at the rear side of one rotation, and adjusts these forces f1, f2 to be a thrust F2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tail rotor that is disposed at a rear end portion of a tail boom of a helicopter and generates thrust.

As a tail rotor that is arranged at the rear end of the tail boom of a helicopter and generates thrust, for example, the one disclosed in Patent Document 1 is known.
Japanese Patent Laid-Open No. 2002-145196 (FIG. 2)

  However, the tail rotor as disclosed in Patent Document 1 only generates anti-torque of the main rotor, and does not generate thrust that contributes to forward force.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tail rotor capable of generating a forward force during forward flight and increasing a forward speed.

The present invention employs the following means in order to solve the above problems.
A tail rotor according to the present invention is a tail rotor that is disposed at a rear end portion of a tail boom of a helicopter and generates a thrust that contributes as a forward force during forward flight, and is a rotating shaft that extends along a horizontal axis of the helicopter A plurality of blades that extend along a direction orthogonal to the rotation axis, rotate with the rotation axis, and at least the blade tip is bent outward, and the pitch angle of the blades at the same time A pitch angle changing mechanism having a collective pitch mode for changing the same amount and a cyclic pitch mode for periodically changing the pitch angle during one rotation, the pitch angle changing mechanism in the cyclic pitch mode, Forces the blade to generate outward force in the front half circle during one revolution and inward direction in the rear half circle during one revolution. Starts selling force is generated on the blade, and the resultant of these forces is operated such that the thrust.

According to the tail rotor of the present invention, the force for canceling the torque effect of the main rotor toward the outside by operating the pitch angle changing mechanism in the collective pitch mode, that is, on the side opposite to the tail boom. When the pitch angle changing mechanism is operated in the cyclic pitch mode, thrust (combined force) is generated rearward.
That is, according to the tail rotor according to the present invention, for example, a force (anti-torque) for canceling the torque effect can be generated during hovering, and a force (auxiliary thrust) that contributes as a forward force during forward flight. Can be generated.

  The helicopter according to the present invention includes, for example, a tail boom that can generate a force for canceling the torque effect during hovering and can generate (auxiliary) thrust that contributes as a forward force during forward flight. Yes.

According to the helicopter according to the present invention, the force generated by the tail rotor is mainly used to cancel the torque action of the main rotor during hovering, and is mainly used to obtain the forward force during forward flight. .
Since the thrust generated by the tail rotor can contribute to (use) the forward force during forward flight, the forward speed of the helicopter can be increased and the speed of the helicopter can be increased.

  According to the tail rotor of the present invention, it is possible to generate a forward force during forward flight and to increase the forward speed.

Hereinafter, an embodiment of a tail rotor according to the present invention will be described with reference to FIGS. 1 to 3.
FIG. 1 is a schematic overall plan view of a helicopter (also referred to as “rotary wing aircraft”) 1 including a tail rotor 10 according to the present embodiment.

  As shown in FIG. 1, the helicopter 1 includes a fuselage 2, a main rotor 3 disposed above the fuselage 2, an landing gear 4 disposed below the fuselage 2, and a tail disposed behind the fuselage 2. The boom 5 and a tail rotor 10 arranged at the rear end of the tail boom 5 are configured as main elements.

Next, the configuration and operation of the tail rotor 10 will be described with reference to FIGS. 2 and 3 in which the tail rotor 10 shown in FIG. 1 is enlarged.
The tail rotor 10 includes a plurality of (two in the present embodiment) blades 11, a rotating shaft 12 extending along the Y axis (pitch axis: horizontal axis) of the helicopter 1, and a pitch angle changing mechanism (not shown). ing.

  As shown in FIGS. 2 and 3, each blade 11 is a plate-like member having a substantially rectangular shape in a plan view and a blade shape in a sectional view along the chord (blade chord length) direction. The end portion 11a is bent so that the blade tip 11b is located outward (outside) from the tip (attachment end) of the rotating shaft 12, that is, is projected (projected) to the side opposite to the tail boom 5. It has been. Each blade 11 is attached (fixed) to a tail rotor hub (not shown) only through a feathering hinge (not shown).

  The rotary shaft 12 is rotated by the rotational force of a prime mover (not shown) (for example, a gas turbine engine) provided through a main gear box, a drive shaft (drive shaft), and a tail gear box (not shown). It rotates around an axis, and a tail rotor hub is attached (fixed) to its tip (attachment end). When the rotating shaft 12 rotates, the tail rotor hub, the feathering hinge, and the blade 11 also rotate integrally (with each other).

  The pitch angle changing mechanism changes the pitch angle of the blades 11 by rotating the feathering hinge around the axis extending along the span direction of the blades 11 and simultaneously changes the pitch angles of all the blades 11 by the same amount. It has a collective pitch mode and a cyclic pitch mode that periodically changes the pitch angle during one rotation.

As shown in FIG. 2, the collective pitch mode is a mode for generating a force (anti-torque) F1 for canceling the torque effect of the main rotor 3 during hovering, for example, the magnitude of the force F1, that is, the blade 11 Is adjusted (changed: controlled) in accordance with a change in the output (engine power) of the prime mover.
Further, as shown in FIG. 3, the cyclic pitch mode is a mode for generating a forward force (auxiliary thrust) F2 during forward flight, that is, outward (outside) within a semicircle on the front side during one rotation. A force f1 is generated toward (on the side opposite to the tail boom 5), and a force f2 is generated toward the inside (inside) (on the tail boom 5 side) within a semicircle on the rear side during one rotation. The magnitude of the force F2, that is, the pitch angle of the blade 11, is adjusted (changed: controlled) according to the forward speed of the helicopter 1 and the output of the prime mover.
F2 is the resultant force of f1 and f2.

According to the tail rotor 10 according to the present embodiment, the pitch angle changing mechanism is operated in the collective pitch mode to move outward (outside), that is, on the side opposite to the tail boom 5, A force F1 for canceling the torque effect is generated, and a forward force (auxiliary thrust) F2 is generated backward (rear side) by operating the pitch angle changing mechanism in the cyclic pitch mode.
That is, according to the tail rotor 10 according to the present embodiment, for example, a force F1 for canceling the torque effect can be generated during hovering, and a force (auxiliary thrust) F2 that contributes as a forward force during forward flight. Can be generated.

  The tail rotor 10 is attached to the rear end portion of the tail boom 5 and, like the conventional tail rotor, the rotational force of a prime mover (not shown) (for example, a gas turbine engine or the like) Since it is configured (designed) to be provided via a drive shaft and a tail gearbox, the tail rotor mounted on an existing helicopter can be removed and applied instead Is possible.

  According to the helicopter 1 including the tail rotor 10 according to the present embodiment, the force (auxiliary thrust) F2 generated by the tail rotor 10 can be contributed (utilized) to the forward force during forward flight. 1 can be increased, and the speed of the helicopter 1 can be increased.

In the above-described embodiment, it is more preferable that a vertical tail is provided at the rear end portion of the tail boom 5.
As a result, the anti-torque during forward flight is offset by the force generated by the vertical tail, and all the force F2 generated by the tail rotor 10 can contribute to the forward force, further increasing the forward speed of the helicopter 1. Further speeding up of the helicopter 1 can be achieved.

  Further, the present invention is not limited to the above-described embodiment, and can be appropriately modified as necessary. For example, the cross-sectional view shape along the span direction of the blade 11 is not limited to the shape shown in FIGS. 1 to 3, and any shape (as long as it can generate the force F <b> 2 described above) ( The shape may be bent several times along the span direction (for example, W-shaped or corrugated).

1 is a schematic overall plan view of a helicopter including a tail rotor according to an embodiment of the present invention. FIG. 2 is an enlarged view of the tail rotor shown in FIG. 1 and shows a state during hovering. FIG. 2 is an enlarged view of the tail rotor shown in FIG. 1 and shows a state during forward flight.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Helicopter 5 Tail boom 10 Tail rotor 11 Blade 11a Blade end part 12 Rotating shaft F2 Thrust f1 Force f2 Force

Claims (2)

A tail rotor that is disposed at the rear end of a helicopter tail boom and generates thrust that contributes as forward force during forward flight;
A rotation axis extending along a horizontal axis of the helicopter;
A plurality of blades extending along a direction orthogonal to the rotation axis, rotating with the rotation axis, and formed so that at least the blade tip portion is bent outward;
A pitch angle changing mechanism having a collective pitch mode for simultaneously changing the pitch angle of the blade by the same amount and a cyclic pitch mode for periodically changing the pitch angle during one rotation;
In the cyclic pitch mode, the pitch angle changing mechanism causes the blade to generate an outward force in a semicircle on the front side during one rotation, and generates an inner force in the semicircle on the rear side in one rotation. The tail rotor is characterized in that a force directed in the direction is generated in the blade and the resultant force of these forces becomes the thrust.   A helicopter comprising the tail rotor according to claim 1.

Images