JP2005186881A - Helicopter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a helicopter capable of efficiently generating the anti-torque thrust in the hovering flight and the advancing thrust in the high-speed advancing flight, and adjusting the center of gravity. <P>SOLUTION: The helicopter has a tail rotor 5 which is rotatably supported above a vertical tail 4 of a fuselage, a driving mechanism 6 to rotate the tail rotor 5, and a direction variable mechanism 7 which turns the tail rotor 5 above the vertical tail 4 and changes the direction of the tail rotor 5 to at least the side and forward directions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a helicopter having a tail rotor function suitable for high-speed flight.

Some helicopters are equipped with a tail rotor for canceling the torque generated by the main rotor in addition to the main rotor for obtaining lift. The tail rotor is driven to rotate toward the side of the fuselage and generates an anti-torque thrust particularly during hovering.
When performing high-speed forward flight with such a helicopter, a certain amount of anti-torque is obtained with the vertical tail itself, so generation of anti-torque by the tail rotor is unnecessary, but the tail rotor facing sideways becomes a resistor, This will hinder speeding up. For this reason, conventionally, as shown in Patent Document 1, for example, a helicopter having a tail rotor as a duct fan structure and provided with a thrust deflection mechanism for changing the direction of thrust of the tail rotor has been proposed. That is, by appropriately changing the direction of air flow from the tail rotor during hovering or high-speed forward flight, the thrust of the tail rotor can be used for forward thrust during high-speed forward flight.
Further, for example, “Lockheed AH-56 Cheyenne” includes two tail rotors, an anti-torque tail rotor and a forward thrust tail rotor, which can be switched and driven.

US Pat. No. 5,123,613 (see FIGS. 3, 4, 8)

However, the following problems remain in the conventional helicopter. That is, in the case of a helicopter having a duct fan structure in the tail rotor, the thrust deflecting mechanism changes only the direction of the flow from the tail rotor in order to change the thrust direction of the tail rotor. There was an inconvenience that could not be obtained. In addition, it is necessary to provide a large thrust deflection mechanism with a duct fan structure, and the center of gravity of the fuselage moves rearward.
In addition, since the helicopter that switches between the two tail rotors has two tail rotors, the center of gravity of the fuselage also moves backward, and the anti-torque tail rotor also becomes a resistor during high-speed forward flight. There was an inconvenience.

  The present invention has been made in view of the above-described problems, and has a tail rotor function that can efficiently generate anti-torque thrust during hovering and forward thrust during high-speed forward flight, and can also adjust the center of gravity. It aims at providing the helicopter which has.

The present invention employs the following configuration in order to solve the above problems. That is, the helicopter of the present invention includes a tail rotor that is rotatably supported on the tail wing of the fuselage, a drive mechanism that rotationally drives the tail rotor, and the tail rotor is rotated on the tail wing so that the direction of the tail rotor is at least on the aircraft side. And a direction variable mechanism that can be changed in two directions, i.e., the front side and the front side.
In this helicopter, the direction of the tail rotor can be changed to at least two directions, the side and the front, by the direction variable mechanism. Therefore, the tail rotor itself can be set to the side direction that generates the anti-torque of the main rotor when hovering. In addition, it can be set forward so that forward thrust can be obtained during high-speed forward flight.

In the helicopter of the present invention, it is preferable that the direction variable mechanism can tilt the direction of the tail rotor upward.
That is, in this helicopter, by tilting the tail rotor further upward by the direction variable mechanism, it is possible to obtain thrust as lift and adjust the center of gravity.

In the helicopter of the present invention, the drive mechanism includes a rotation drive source provided in the airframe, a first bevel gear connected to the rotation shaft of the rotation drive source and having a vertical rotation shaft, and a horizontal rotation shaft. A second bevel gear that meshes with the first bevel gear, and a third bevel gear that meshes with the second bevel gear and is fixed to the rotation shaft of the tail rotor. The bevel gear is supported so as to be able to turn around the rotation axis of the first bevel gear, and the third bevel gear is supported so as to be able to turn around the rotation axis of the second bevel gear.
In this helicopter, the direction variable mechanism supports the second bevel gear so as to be able to turn around the rotation axis of the first bevel gear, and can turn the third bevel gear around the rotation axis of the second bevel gear. Therefore, the direction of the tail rotor can be rotated around the two axes of the vertical axis and the horizontal axis while rotating the tail rotor.

In the helicopter according to the present invention, the direction variable mechanism is rotatably supported by the tail wing and rotatably supported by the first and second bevel gears and accommodated therein, and the first housing is rotatable. , A second housing for rotatably supporting and storing the third bevel gear, a horizontal tilt mechanism for rotating the first housing around the rotation axis of the first bevel gear, and the second housing And a vertical tilt mechanism for rotating the second bevel gear around the rotation axis of the second bevel gear.
In this helicopter, the tail rotor can be rotated in the horizontal direction together with the first and second housings by rotating the first housing around the rotation axis of the first bevel gear by the horizontal tilt mechanism. By rotating the second housing around the rotation axis of the second bevel gear by the vertical tilt mechanism, the tail rotor can be rotated up and down together with the second housing to be tilted.

The helicopter according to the present invention is characterized in that the first, second, and third bevel gears are speed reduction mechanisms each set to a gear ratio that lowers the rotational speed of the tail rotor below the rotational speed of the rotational drive source. To do.
In this helicopter, the first, second and third bevel gears are used as a speed reduction mechanism for reducing the rotational speed of the tail rotor, so there is no need to provide a separate speed reduction mechanism, and the number of parts can be reduced by sharing parts. Can do.

The present invention has the following effects.
That is, according to the helicopter according to the present invention, the direction variable mechanism that can change the direction of the tail rotor in at least two directions, ie, the side and the front, is provided. Torque thrust and forward thrust during high-speed forward flight can be generated efficiently.

  Hereinafter, an embodiment of a helicopter according to the present invention will be described with reference to FIGS. 1 to 6.

As shown in FIGS. 1 and 2, the helicopter of the present embodiment includes a body 1, a main rotor 3 that is rotationally driven by an engine (rotation drive source) 2 in the body 1 and generates lift and horizontal thrust, and the body And a tail rotor 5 rotatably supported on one vertical tail 4. The main rotor 3 has a plurality of rotor blades 3b fixed to the rotation shaft 3a. The tail rotor 5 has a plurality of rotor blades 5b fixed to the rotary shaft 5a.
As shown in FIGS. 3 and 4, the helicopter has a drive mechanism 6 for rotationally driving the tail rotor 5, and the tail rotor 5 is rotated on the vertical tail 4 so that the direction of the tail rotor 5 is changed to the side and the front. And a direction changing mechanism 7 that can be tilted upward.

The vertical tail 4 is fixed to the tail cone 8 of the airframe 1 for directional stability and the like, and the anti-torque of the main rotor 3 can be obtained during high-speed forward flight.
The drive mechanism 6 includes a first bevel gear 9 having a vertical rotation shaft 9a connected to a drive shaft (rotation shaft) of the engine 2 via a connection member (not shown), and a horizontal rotation shaft 10a. A second bevel gear 10 that meshes with the first toothed bevel wheel 9, and a third bevel gear 11 that meshes with the second bevel gear 10 and is fixed to the rotating shaft 5 a of the tail rotor 5. As a result, the rotation of the drive shaft of the engine 2 is transmitted to the tail rotor 5 via the first bevel gear 9, the second bevel gear 10, and the third bevel gear 11.

The direction variable mechanism 7 includes an intermediate housing (first housing) 12, a tail rotor housing (second housing) 13, a horizontal tilt mechanism 14, and a vertical tilt mechanism 15.
The intermediate housing 12 is supported in the upper hole 4 a of the vertical tail 4 so as to be rotatable about an axis line x that coincides with the rotation shaft 9 a of the first bevel gear 9. Inside the intermediate housing 12, a first bevel gear 9 and a second bevel gear 10 are rotatably supported by a first through hole 12 a and a second through hole 12 b formed in the intermediate housing 12. Are stored.
The tail rotor housing 13 has a shape that sandwiches the intermediate housing 12 from both sides. The tail rotor housing 13 is orthogonal to the axis x around which the intermediate housing 12 rotates, and the rotation shaft 10a of the second bevel gear 10 is inserted into the intermediate housing 12. Is supported so as to be rotatable about an axis y that coincides with. In the tail rotor housing 13, a third bevel gear 11 connected to the tail rotor 5 is rotatably supported and accommodated in a third through hole (not shown).

The horizontal tilt mechanism 14 rotates the intermediate housing 12 around the axis x. As a result, the tail rotor housing 13 supported by the intermediate housing 12 is also rotated integrally, and the tail rotor 5 held by the tail rotor housing 13 is turned around the axis x.
The vertical tilt mechanism 15 rotates the tail rotor housing 13 around the axis y. As a result, the tail rotor 5 held in the tail rotor housing 13 is turned around the axis y.
The horizontal tilt mechanism 14 and the vertical tilt mechanism 15 are, for example, provided with a drive source such as a motor on the vertical tail 4 and the tail rotor housing 13, respectively. A ring ultrasonic motor, an electric motor, and a worm gear are used as a drive system. The intermediate housing 12 and the tail rotor housing 13 are pivoted about the axis x and the axis y and have a mechanism that can be fixed at an arbitrary position (angle). . Note that the rotation shaft 10 a of the second bevel gear 10 is not connected to the drive source of the tail rotor housing 13.
Thus, the direction variable mechanism 7 makes the direction of the tail rotor 5 variable about the axis x and the axis y.

The first, second, and third bevel gears 9, 10, and 11 are reduction mechanisms that are set to gear ratios that lower the rotational speed of the tail rotor 5 than the rotational speed of the engine 2. In the present embodiment, the reduction gear mechanism is formed by increasing the gear diameter in the order of the first bevel gear 9, the second bevel gear 10, and the third bevel gear 11.
Such a technique of the drive mechanism 6 and the direction variable mechanism 7 can also be adopted as a technique for changing the orientation of the main rotor 3 as necessary.

  Next, the flight method in the helicopter of the present embodiment will be described below with reference to FIGS. 1, 2, 5, and 6 for two cases of hovering and high-speed forward flight.

[When hovering]
First, at the time of hovering, both the main rotor 3 and the tail rotor 5 are driven to rotate, and the direction of the tail rotor 5 is changed by the direction variable mechanism 7 as shown in FIGS. 1, 5A and 6A. The main rotor 3 is disposed on the side of the body 1 where the anti-torque is generated (perpendicular to the side surface of the vertical tail 4). That is, the intermediate housing 12 is rotated by the horizontal tilt mechanism 14 so that the tail rotor 5 is directed to the side together with the tail rotor housing 13. At this time, the vertical tilt mechanism 15 is not operated, and the tail rotor 5 is kept in the horizontal direction. In this state, the anti-torque of the main rotor 3 can be effectively generated by the tail rotor 5.
Note that the anti-torque of the main rotor 3 is generated by setting the tail rotor 5 in the same direction not only during hovering but also during forward flight at low speed.

[High speed forward flight]
Next, during high-speed forward flight, the main rotor 3 and the tail rotor 5 are both rotationally driven, and the tail rotor is rotated by the direction variable mechanism 7 as shown in FIGS. 2, 5 (b) and 6 (b). The direction of 5 is arranged forward (front of the fuselage 1). That is, the intermediate housing 12 is rotated together with the tail rotor housing 13 by the horizontal tilt mechanism 14 so that the tail rotor 5 is directed forward. Thereby, the thrust of the tail rotor 5 can be contributed to a forward thrust. Further, it is possible to prevent the tail rotor 5 from becoming a resistor during high-speed forward flight with the tail rotor 5 facing sideways.

  At this time, the vertical tilt mechanism 15 may not be operated and the tail rotor 5 may be horizontally oriented. However, the tail rotor 5 may be tilted upward by the vertical tilt mechanism 15 in order to adjust the center of gravity. Good. That is, the tail rotor housing 13 is rotated with respect to the intermediate housing 12 by the vertical tilt mechanism 15, and the tail rotor 5 is tilted upward at an appropriate tilt angle corresponding to the flight state. Thereby, a part of the thrust of the tail rotor 5 becomes the lift of the rear part of the airframe 1, and the center of gravity in the pitching direction of the airframe 1 can be adjusted. That is, it becomes possible to appropriately change the pitch posture of the aircraft according to the flight state. As shown in FIG. 6 (c), it is also possible to make all the thrusts lift by turning the tail rotor 5 completely vertically upward.

Thus, in the helicopter of the present embodiment, the direction of the tail rotor 5 can be changed to the side and the front by the direction variable mechanism 7, so that the side direction in which the anti-torque of the main rotor 3 is generated when the tail rotor 5 itself is hovered. And can be set forward so that forward thrust can be obtained during high-speed forward flight. As a result, the tail rotor 5 does not become a resistor during high-speed forward flight, but contributes to forward thrust, enabling efficient use of engine power.
Further, by tilting the tail rotor 5 further upward by the direction variable mechanism 7, it is possible to obtain thrust as lift and to adjust the center of gravity.

Further, the direction variable mechanism 7 supports the second bevel gear 10 so as to be rotatable around the rotation axis 9 a of the first bevel gear 9 and also supports the third bevel gear 11 as the rotation axis of the second bevel gear 10. Since the tail rotor 5 is supported so as to be able to turn, the direction of the tail rotor 5 can be rotated around the two axes of the vertical axis and the horizontal axis while being driven to rotate.
Further, by rotating the intermediate housing 12 around the axis x by the horizontal tilt mechanism 14, the tail rotor 5 can be rotated in the horizontal direction together with the intermediate housing 12 and the tail rotor housing 13. By rotating the tail rotor housing 13 around the rotation axis of the second bevel gear 10, the tail rotor 5 together with the tail rotor housing 13 can be rotated up and down to be tilted.

In this way, by combining the three gears, the direction of the tail rotor 5 can be deflected left and right and up and down while rotating the tail rotor 5, and the forward speed is increased by directing the tail rotor 5 in an appropriate direction for the flight state. And balance adjustment according to the movement of the center of gravity.
In addition, the first, second and third bevel gears 9, 10 and 11 can be used in combination with a speed reduction mechanism for reducing the rotational speed of the tail rotor 5 by appropriately selecting the gear ratio. There is no need to provide it, and the number of parts can be reduced.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

It is a perspective view at the time of hovering which shows the helicopter of one embodiment concerning the present invention. It is a perspective view at the time of high-speed forward flight showing a helicopter of one embodiment concerning the present invention. In the helicopter of one embodiment concerning the present invention, it is a mimetic diagram showing the meshing state of the 1st-3rd gears. In the helicopter of one embodiment concerning the present invention, it is a sectional view showing the inside of the middle housing on the tail and the inside of the tail rotor housing. In the helicopter of one embodiment concerning the present invention, it is a principal part perspective view at the time of hovering and high-speed advance flight which shows the direction of a tail rotor. In the helicopter of one embodiment concerning the present invention, it is a principal part front view showing a tail rotor which turned to the side, the front, and the upper part on a tail.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Airframe, 2 ... Engine (rotation drive source), 4 ... Vertical tail, 5 ... Tail rotor, 6 ... Drive mechanism, 7 ... Direction variable mechanism, 9 ... 1st bevel gear, 10 ... 2nd bevel gear, DESCRIPTION OF SYMBOLS 11 ... 3rd bevel gear, 12 ... Intermediate housing (1st housing), 13 ... Tail rotor housing (2nd housing), 14 ... Horizontal tilt mechanism, 15 ... Vertical tilt mechanism

Claims (5)

A tail rotor rotatably supported on the tail of the aircraft,
A drive mechanism for rotationally driving the tail rotor;
A helicopter comprising: a direction variable mechanism capable of rotating the tail rotor on the tail wing and changing the direction of the tail rotor in at least two directions, ie, the side of the fuselage and the front.   The helicopter according to claim 1, wherein the direction variable mechanism is capable of tilting the direction of the tail rotor upward. The drive mechanism is a rotational drive source provided in the airframe;
A first bevel gear coupled to the rotational shaft of the rotational drive source and having a vertical rotational shaft;
A second bevel gear having a horizontal axis of rotation and meshing with the first bevel gear;
A third bevel gear meshing with the second bevel gear and fixed to the rotating shaft of the tail rotor;
The variable direction mechanism supports the second bevel gear so as to be pivotable about the rotation axis of the first bevel gear, and pivots the third bevel gear about the rotation axis of the second bevel gear. The helicopter according to claim 2, wherein the helicopter is supported. A first housing in which the direction variable mechanism is rotatably supported by the tail wing and rotatably supports the first and second bevel gears;
A second housing rotatably supported by the first housing and rotatably supporting the third bevel gear;
A horizontal tilt mechanism for rotating the first housing around a rotation axis of the first bevel gear;
The helicopter according to claim 3, further comprising a vertical tilt mechanism for rotating the second housing around a rotation axis of the second bevel gear.   The first, second, and third bevel gears are reduction mechanisms that are respectively set to gear ratios that lower the rotational speed of the tail rotor below the rotational speed of the rotational drive source. The helicopter according to 3 or 4.

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