JPH09240594A - Rotor control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor control system capable if reducing noise and vibration of a helicopter by realizing a flap driving mechanism capable of effectively drawing out flap performance. SOLUTION: A rotor control system is provided with a blade 10 attached to a main rotor shaft 1 so that the pitch angle may be changed, a flap 20 attached on the reargue side if the blade 10 so that the pitch angle mat be changed, a first link mechanism for controlling the pitch angle of the blade 10, and a second link mechanism for controlling the pitch angle of the flap 20. The first link mechanism includes a swath plate 14 composed of a rotational part 12 connected to the blade 10 by the link mechanism, and a control part 13 to be displaced according to the steering amount. The second link mechanism includes a swath plate 31 composed of a rotational part 29 connected to the flap 20 by the link mechanism, and a control part 31 to be displaced by actuators 36a, 36b, and a higher harmonic wave controller 37.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a control system for a helicopter rotor comprising a blade with a flap.

[0002]

2. Description of the Related Art Since a helicopter generates various noises and body vibrations, reduction of the noises and body vibrations is a major problem, especially when used as a regular sea route in an urban area.
Noises include main rotor noise, tail rotor noise, BVI (b
lade vortex interaction) noise. Above all, BV
I-noise is caused by the next blade crossing the air vortex created by the preceding blade during rotor rotation, and is greatest when the helicopter descends forward. In addition, the interaction between the rotor and the air causes a large body vibration in the helicopter itself, which causes factors such as deterioration of riding comfort, misidentification of instruments, and metal fatigue.

As a countermeasure, a technique called harmonic control (HHC), which controls the local lift distribution on the rotor rotating surface at an integral multiple of the rotor rotating frequency, is effective. Generally, the pitch of the blade itself is increased. This is achieved by vibrating the corners at a fine cycle.

On the other hand, normal helicopter operation is realized by controlling a pitch angle at a blade root of a main rotor via an actuator, a swash plate, a link mechanism and the like.

Since a helicopter rotor is a high-speed rotating object and has a considerably high vibration level, a high-precision mechanism for controlling the pitch angle of the blade is required. In addition, the aerodynamic moment and inertia moment generated around the feathering axis over the entire blade are large, and high-power actuators and hydraulic mechanisms are needed to overcome the mass of the rotor drive mechanism and change the blade pitch angle. Become. This is one reason that it is difficult to reduce the weight of the aircraft.

As a countermeasure, a method has been proposed in which a relatively small flap is attached near the blade tip where the dynamic pressure is sufficiently high, and the blade pitch angle is controlled by utilizing a large aerodynamic force generated in this portion (particularly). Kaihei 6-107293
No. 3,077,934, U.S. Pat.
No. 69, U.S. Pat. No. 3,589,831 and U.S. Pat.
No. 61611). By providing the flap near the blade tip, control is possible with a small steering force, and the overall control mechanism is light and compact.

[0007]

However, there has been no effective flap driving mechanism, and a helicopter having a blade with a flap has not yet been put to practical use.

An object of the present invention is to provide a flap drive mechanism capable of effectively extracting flap performance, and to provide a rotor control system capable of reducing helicopter noise and vibration.

[0009]

According to the present invention, a blade mounted on a rotor shaft in a variable pitch angle, a flap mounted on the trailing edge of the blade in a variable pitch angle, and a pitch angle of the blade are controlled. And a second control means for controlling the pitch angle of the flap, and a rotor control system. According to the invention, a second flap pitch angle control
Since the control means is provided independently of the first control means for controlling the pitch angle of the blade, the pitch angle of the flap can be controlled arbitrarily. Therefore, by such flap control, harmonic control for reducing noise and vibration can be efficiently performed.

According to the present invention, the first control means includes a first swash plate including a rotating portion connected to the blade by a link mechanism and a non-rotating portion that is displaced according to a steering amount,
The second control means includes a second swash plate including a rotating portion connected to the flap by a link mechanism and a non-rotating portion displaced by the actuator, and a harmonic control device for driving the actuator at an integral multiple of the rotation frequency of the rotor. It is characterized by including and. According to the present invention, by providing a swash plate different from the blade for controlling the pitch angle of the flap, the flap can be driven independently of the blade, and the pitch angle can be controlled with a high degree of freedom. become. In addition, since the actuator for driving the flap can be installed on the non-rotating portion, the actuator only needs to have a simple mechanism, which contributes to reducing the size and weight of the body.
Further, in the case of performing harmonic control by flap driving, the more the flap is provided on the blade tip side, the more efficiently the lift distribution on the rotor rotation surface can be controlled, so that the effect of reducing noise and vibration is high. Furthermore, driving a flap having a small mass at a high speed is more advantageous than driving a blade having a large mass at a high speed, which is advantageous for reducing the weight of the fuselage.
Further, as the swash plate and the link mechanism for driving the flap, those which have been conventionally used in many cases for driving the blade can be used, and a highly reliable flap mechanism can be realized.

According to the present invention, the first control means includes a swash plate including a rotating portion connected to the blade by a link mechanism and a non-rotating portion that is displaced according to a manipulated variable.
The control means is characterized by including an actuator which is connected to the flap by a link mechanism and rotates together with the rotor shaft, and a flap control device for individually driving the actuator. According to the present invention, an actuator that rotates together with the rotor shaft is provided for controlling the pitch angle of the flaps, and by individually driving each actuator, the flap drive can be performed independently of the blades. It becomes possible to control the pitch angle arbitrarily. Further, in the case of performing harmonic control by flap driving, the more the flap is provided on the blade tip side, the more efficiently the lift distribution on the rotor rotation surface can be controlled, so that the effect of reducing noise and vibration is high. Furthermore, driving a flap having a small mass at a high speed is more advantageous than driving a blade having a large mass at a high speed, which is advantageous for reducing the weight of the fuselage. Further, as the actuator and the link mechanism for driving the flap, those which have been conventionally used in many cases for driving the blade can be used, and a highly reliable flap mechanism can be realized.

[0012]

FIG. 1 is a partial perspective view showing an embodiment of the present invention. In FIG. 1, the connection mechanism between the blade 10 and the main rotor shaft 1 is not shown for easy understanding.

The helicopter rotor has two blades 10 (only one blade is shown in FIG. 1), and the blades 10 are mounted on a main rotor shaft 1 (partially omitted in FIG. 1 with a hollow shape in FIG. 1). And rotate at high speed counterclockwise when viewed from above. The blade 10 is supported so as to be angularly displaceable around its axis in the span direction, and the pitch angle of the blade 10 is controlled. Near the root of the blade 10, the upper end of the rod 11 and the leading edge of the blade are pin-connected, and the lower end of the rod 11 is pin-connected to the rotating part 12 of the swash plate 14.

The swash plate 14 includes a rotating unit 12 that rotates together with the rotor, and a control unit 13 that does not rotate. The control unit 13 controls the vertical position and the tilt angle of the rotating unit 12. Further, a link mechanism such as a rod 15, a lever 16, and a rod 17 is connected to the controller 13.
It is linked to a control system such as a control stick. In this way, the pitch angle of the blade 10 is controlled by linearly or angularly displacing the swash plate 14 according to the amount of operation such as the collective pitch or the cyclic pitch.

On the other hand, near the blade tip of the blade 10, a flap 20 having a blade cross-sectional shape is supported by a hinge (not shown) so as to be notched at a part of the trailing edge thereof, and a pitch angle of the flap 20 is supported. Is controlled. A link mechanism for driving the flap 20 is housed inside the blade 10, and includes a flap shaft 21, a lever 22, rods 23 and 24, and a lever 2.
5. The rod 26 is connected in this order. Furthermore, rod 2
6 is connected via a lever 27 to a rod 28 housed in the main rotor shaft 1.
, The pitch angle of the flap 20 changes.

The lower end of the rod 28 is connected to the rotating part 29 of the swash plate 31. The swash plate 31 includes a rotating unit 29 that rotates together with the rotor, and a control unit 30 that does not rotate. The control unit 30 controls the vertical position and the tilt angle of the rotating unit 29. Further, the control unit 30
Has two rods 32a, 32b extending in two orthogonal directions.
Are connected, and the rod 32a is connected via a link mechanism including a rod 33a, a lever 34a, a rod 35a, and the like.
It is driven by the actuator 36a. Similarly, the rod 32b includes a rod 33b, a lever 34b, a rod 35
actuator 36 via a link mechanism consisting of
b. Thus, the two actuators 36a and 36b control the inclination angle of the rotating portion 29 of the swash plate 31, and further control the pitch angle of the flap 20.

The actuators 36a and 36b are driven by a harmonic control (HHC) device 37. For example, by driving the actuator at an integral multiple of the rotation frequency of the rotor, it is possible to realize harmonic control of the rotor by flap driving. As a result, helicopter noise and vibration can be reduced.

FIG. 2 is a partial cross-sectional view of the transmission mechanism 2 near the swash plate 31 taken along the line AA of FIG. Here, the link mechanisms 32b to 36b will be described, but the same applies to the link mechanisms 32a to 36a. A collector gear 1a connected to the engine output shaft is formed on the hollow main rotor shaft 1, and is supported by a housing 3 of the transmission mechanism 2 via a bearing 1b. A housing 4 for supporting the swash plate 31 is attached to the bottom of the housing 3.

A ring-shaped spherical bearing 41 is mounted at the center of the housing 4 and is angularly displaced together with a control shaft 42 around an angular displacement center RC. These spherical bearings 4
The control shaft 1 and the control shaft 42 constitute the control unit 30 of the swash plate 31, and the ring-shaped rotating unit 29 is attached to the upper portion of the control shaft 42 via a bearing. A rod 28 for flap control is connected to the upper surface of the rotating part 29 via a rod end bearing 28a. Note that a seal 40 for preventing oil leakage is mounted between the rotating part and the non-rotating part of each member.

On the other hand, the lower end of the control shaft 42 has a rod 32b
Is fixed, the tip of the rod 32b is connected to the rod 33b by a rod end bearing 43, and the rod 33b is connected to the actuator 36b via a link mechanism including a lever 34b and a rod 35b.

FIG. 3A is a partial sectional view taken along the line BB of FIG. 2, and FIG. 3C is a view taken along the line CC of FIG. The tip of the rod 32b is bifurcated, and a ball-shaped rod end bearing 43 is pin-connected between the two ends to facilitate conversion between the angular displacement of the rod 32b and the linear displacement of the rod 33b.

Next, the operation will be described. Actuator 36
When the rod 35b, which is the movable part of the rod b, is displaced upward, for example, the rod 33b is displaced downward by the lever 34b, and the tip of the rod 32b is angularly displaced downward around the angular displacement center RC, so that the control shaft 42 Similarly, angular displacement occurs.
Then, the rotating portion 29 of the swash plate 31 is also angularly displaced around the angular displacement center RC, and the rod 28 is displaced downward,
Returning to FIG. 1, the rod 26 is displaced toward the blade root side, the rod 23 is displaced toward the blade leading edge side, and the trailing edge of the flap 20 is angularly displaced upward. Similarly, the rotary unit 29 of the swash plate 31 is angularly displaced about the orthogonal axis also in the actuator 36a of FIG. In this manner, the pitch angle of the flap 20 can be arbitrarily controlled around the axis in the two orthogonal directions on the rotor rotation surface.

FIG. 4 is a partial perspective view showing another embodiment of the present invention. In FIG. 4, a connection mechanism between the blade 10 and the main rotor shaft 1 is not shown for easy understanding. The driving mechanism of the blade 10 is the same as that of FIG.

In the vicinity of the blade tip of the blade 10, a flap 20 having a blade cross-sectional shape is supported by a hinge (not shown) so as to be angularly displaceable so that a part of the trailing edge is notched.
A pitch angle of 0 is controlled. The link mechanism that drives the flap 20 is housed inside the blade 10 and includes a flap shaft 21, a lever 22, rods 23 and 24, a lever 25,
The rods 26 are connected in this order. Further, the root of the rod 26 is connected to a rod 28 housed inside the main rotor shaft 1 via a lever 27, and the pitch angle of the flap 20 is changed according to the vertical displacement of the rod 28. Change.

The lower end of the rod 28 is connected to a movable part of an actuator 38 mounted inside the main rotor shaft 1.
8, two actuators 38 are provided since the rotor is a two-blade type rotor in FIG. Since the actuator 38 rotates together with the main rotor shaft, the actuator 38 is connected to a flap control device 50 via a slip ring mechanism 39, and the pitch angle of each flap 20 is individually controlled.

For example, by driving the actuator 38 at an integral multiple of the rotation frequency of the rotor, harmonic control of the rotor by flap driving can be realized, and noise and vibration of the helicopter can be reduced.

[0027]

As described above, according to the present invention, since the pitch angle of the flap can be arbitrarily controlled, harmonic control for reducing noise and vibration can be efficiently performed.

Further, by providing a swash plate different from that for the blade for controlling the pitch angle of the flap, the flap can be driven independently of the blade, and a high degree of freedom can be achieved without depending on the rotation angle of the rotor. Pitch angle control in degrees becomes possible. In addition, since the actuator for driving the flap can be installed on the non-rotating portion, the actuator only needs to have a simple mechanism, which contributes to reducing the size and weight of the body.

Further, by providing an actuator that rotates together with the rotor shaft for controlling the pitch angle of the flap, and by driving each actuator individually, the flap drive can be performed independently of the blade. The pitch angle can be controlled with a high degree of freedom without dependence.

Further, in the case of harmonic control by flap driving, the more the flap is provided on the blade tip side, the more efficiently the lift distribution on the rotor rotating surface can be controlled, so that the effect of reducing noise and vibration is high. Furthermore, it is advantageous to drive a flap having a small mass at a high speed rather than driving a blade having a large mass at a high speed because a small drive mechanism is required, which is advantageous for reducing the weight of the machine body.

In this way, a flap drive mechanism that can effectively bring out the flap performance can be realized, and the noise and vibration of the helicopter can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view taken along line AA of FIG. 1 showing a transmission mechanism 2 near a swash plate 31;

FIG. 3A is a partial cross-sectional view along the line BB in FIG. 2, and FIG. 3C is a view as seen from the line CC in FIG.

FIG. 4 is a partial perspective view showing another embodiment of the present invention.

[Explanation of symbols]

1 main rotor shaft 10 blades 11, 15, 17, 23, 24, 26, 28, 32a,
32b, 33a, 33b, 35a, 35b Rod 12, 29 Rotating part 13, 30 Control part 14, 31 Swash plate 16, 22, 25, 27, 34a, 34b Lever 20 Flap 36a, 36b, 38 Actuator 50 Flap control device

Claims (3)

[Claims] 1. A blade attached to the rotor shaft in a variable pitch angle, a flap attached to the blade on the trailing edge side in a variable pitch angle, and a first control means for controlling the pitch angle of the blade. A second control means for controlling the pitch angle of the flap, the rotor control system. 2. The first control means includes a first swash plate including a rotating portion connected to the blade by a link mechanism and a non-rotating portion that is displaced according to a steering amount, and the second control means includes a flap and a link. A second swash plate comprising a rotating part connected by a mechanism and a non-rotating part displaced by an actuator, and a harmonic control device for driving the actuator at an integral multiple of the rotation frequency of the rotor. The rotor control system according to item 1. 3. The first control means includes a swash plate composed of a rotating portion connected to the blade by a link mechanism and a non-rotating portion that is displaced according to a manipulated variable, and the second control means includes a flap and a link mechanism. The rotor control system according to claim 1, further comprising: an actuator that is coupled to rotate with the rotor shaft; and a flap control device that individually drives the actuators.