RU2335432C2 - Rescue helicopter (versions) - Google Patents

Abstract

FIELD: transportation.

SUBSTANCE: rescue helicopter includes fuselage (1) and coaxial propellers (4), at that there can be two or more propellers and they can have different diameter. At least one of the propellers is controlled with variable increment, and the rest - with fixed diameter. In the second variant the propeller has tail boom (5) with elastic expander tube (5) at the end, at that, when tail boom is raised derating is blocked. In the third variant, engine and reducing gear are located in separate engine nacelle (2) positioned over fuselage on suspension towers and/or elastic inserts.

EFFECT: increase operation efficiency of lifting propeller.

5 cl, 4 dwg

Description

There are various types of helicopters known, but they are characterized by: a small static ceiling, fairly high requirements for the landing site, strong noise and vibration in the cabin (see AS 244895).

The invention relates to coaxial helicopters with primary purposes: medical, rescue, landing, helicopter crane.

Helicopters with such specifications should be characterized by:

a) good work in hover mode and a large static ceiling; b) the ability to land on an unequipped site in cramped conditions; c) low noise and vibration in the cabin for the medical.

To solve this triune problem, the following three technical solutions are proposed:

Solution "A". When operating helicopters with one or two coaxial rotors of the same diameter, the thrust is created mainly by the ends of the blades (radical 50% of the blades create only 6% of the thrust). Therefore, a decent zone or even a reverse turbulence zone is created closer to the rotor hub, which impairs the operation of the end parts of the blade and, possibly, impairs the accuracy of helicopter control.

To increase the efficiency of the propeller, the proposed helicopter has two or more (actually no more than three) coaxial rotors of different diameters, rotating with different angular speeds, but with approximately the same linear speed at the end of the blade (figure 1).

In this case, the largest screw rotates in one direction, and the middle and small screw - in the other (in order to balance the reactive moments). It is also desirable that all the screws or at least the middle of the three have a different number of blades, for example, large - 5, medium - 4, small - 3 or 2-3-2, or 3-2-3. This will reduce the vibration of the blades from their mutual influence.

To control the flight, it is enough that only one of the screws can be controlled, for example, the lower one (unless it is small), and the rest can be variable pitch screws or even simple constant pitch screws. Or one of them is a variable step, and a small one is a constant step. Large, medium and small screws can be arranged in different order in height, for example, the upper - large, in the middle - small, lower - medium.

The rotation of the helicopter is controlled by changing the ratio of the steps of the large and medium propellers or by simultaneously changing the “gas” and the pitch of a single controlled propeller (for example, decreasing the pitch while increasing the gas).

Solution B Sometimes a helicopter cannot land in cramped conditions because of the danger of hitting a slope or rock with a screw in case of an accidental gust of wind.

To protect the helicopter propeller when approaching the slope, the rock of the proposed helicopter has a tail beam of sufficient strength and length, rising under the flight position of the blades (figure 1). At the end of the beam there is an inflatable elastic pneumatic chamber to soften possible touches. The approximate force of the required hydraulic cylinder is 900 kg / 9000 N /.

In order to prevent the blades from sagging and hitting the beam during a short landing, the traction control when the beam is raised is blocked at the minimum value (for example, not less than 50% dry weight).

So that when lifting the beam there is no noticeable violation of the weight distribution, the hinge of the beam should be located above the axis of the beam, possibly even outside its contour - it is moved up. In this case, the displacement of the center of gravity of the beam will be almost vertical.

To reduce weight, the beam can be trussed without sheathing or have fabric or film sheathing from modern high-strength and high-modulus materials. For example, Vectran 2000.

Since, to protect the propeller, the helicopter must fly up to the slope behind, then the helicopter must have two or more cameras, pairwise directed to one side with a transverse distance (base) between them (stereo camera). And the pilot must have at his disposal stereo monitors in the form of glasses or a helmet-mounted lowered device.

To make it easier for the pilot to control in the stereo-observation mode back, the helicopter has “forward-backward” and “right-left” switches in the control system, reversing the directions of the indicated influences. If the system is remote, then the switches are electrical, interchanging the positive and negative mismatch signals between the positions of the controls and the swashplate (figure 2). If the system is mechanical, then in the control circuit for the longitudinal movement of the helicopter and in the control circuit for the lateral sliding of the helicopter (in each) there should be a link with rotational transmission of movement, in which there should be a reverse gear, switched by two friction clutches (Fig. 3).

To remove the injured person from a vertical rock on the side surface of the fuselage and the beam, there can be two electrically isolated rails from the casing, along which a trolley with a pulley moves on a spring-loaded or equipped with a destructible fastening (pin) rotary axis from the door to the end of the beam (Fig. 4). Using this trolley, you can bring the rope with the rescue equipment close to the rock.

The cart is controlled by changing the polarity of the voltage on the rails. It is possible to insulate only one rail, but this will require a separate power source, such as a transformer.

The rails and the trolley are not designed for the perception of the weight of a person, therefore they have a very low weight and a simple structure.

The modification of the helicopter for flat terrain may have a conventional tail fairing of shorter length.

Solution "B". In the proposed helicopter, the engine with the gearbox and screws is located in a separate nacelle above the fuselage and is attached to it on one or more pylons (Fig. 1). This is done, firstly, in order to raise the rotors to facilitate landing on a bush or on a slope (the chassis for landing on a slope is described in the separate invention "Chassis"). And secondly, to reduce noise and vibration in the cabin. To better suppress noise and vibrations, the pylons can be made of composite material and attached to the fuselage and the engine nacelle through elastic inserts.

To control the engine and the swashplate, it is advisable to use an electrical control system.

The proposed helicopter is about 10% more expensive than usual and will not have high speed, but it will have an increased take-off mass, a large static and dynamic ceiling and will be able (if there is the mentioned "Chassis") to take injured or wounded in places not accessible to other helicopters. Or deliver cargo to this place.

Figure 1, shows the proposed helicopter, where: 1 - the fuselage, 2 - the nacelle on the pylons 3, 4 - rotors of different diameters, 5 - tail boom (dotted line in the raised position) with a pneumatic chamber 6 at the end.

Figure 2 and 3 depict options for electrical and mechanical switches "forward-backward" and "right-left", where: AP - the sensor position of the transfer machine, OS - the sensor position of the controls, BS - comparison unit, ± - the error signal, P - switch, IM - actuator, RRFU - reverse gear with friction control.

Figure 4 shows the rails 7 on the casing of the helicopter 1, mounted on dielectric spacers 8, and a trolley 9 with a pulley 10 on the axis 11, spring-loaded 12. The trolley moves on wheels 13.

The helicopter in FIG. 1 operates as follows: the large propeller rotates in one direction, the middle and small rotate in the other. The diameters, peripheral speed and the number of blades are selected so that the total reactive moment is zero. Recommended diameter ratios are 1-0.618-0.382. If the driven screw is medium, the ratio can be changed in the direction of its increase.

The scheme in figure 2 works as follows: the signals from the sensors AP and op-amp are compared in the comparison unit BS and amplified are transmitted through the switch P to the actuator MI. Switching the switch will cause a change in control response, for example, when the handle moves forward, the helicopter will begin to move backward.

The mechanical control in figure 3 works like this: during normal operation, turning the input shaft in one direction leads to the rotation of the output shaft in the same direction (direct transmission of rotation). When two friction clutches are switched, the transmission of rotation goes through gears and is reversed, and the control reaction becomes inverse.

The truck in figure 4 operates as follows: a constant voltage of one or another polarity is supplied to the insulated rails 7 and, through electrically insulated wheels 13, is supplied to an electric motor (located inside, not shown), which rotates the wheels in one direction or another.

The trolley deflects the rescue rope to the end of the tail boom and then returns it. When the allowable force is exceeded, the axis 11 deviates down or down and forward, the rope jumps off the pulley 10 and the weight of the load is perceived by the winch.

Expected results: obtaining a helicopter with previously unattainable landing capabilities, especially in combination with a chassis made according to the separate invention “CHASSIS (options).”

Claims (6)

1. A rescue helicopter comprising a fuselage and coaxial rotors, characterized in that it has two or more coaxial rotors of different diameters, at least one of them being controlled with a variable pitch, and the rest with a fixed pitch. 2. Rescue helicopter according to claim 1, characterized in that the screws have a different number of blades. 3. A rescue helicopter including a fuselage and coaxial rotors, characterized in that it has a rising tail boom with an elastic air chamber at the end, and when the beam is raised, thrust reduction is blocked. 4. Rescue helicopter according to claim 3, characterized in that on the lateral surface of the fuselage and beam there are rails electrically isolated from the body, on which an electric trolley and with a roller or pulley are mounted on a rotary axis with a spring-loaded or equipped with a destructible safety mount. 5. The rescue helicopter according to claim 3, characterized in that it has two or more television cameras or stereo television cameras directed backward, has stereo-monitors in the form of glasses, has a forward-backward and right-to-left remote control switch interlocked with the inclusion of stereo monitors, or in a mechanical control system for longitudinal motion and lateral motion, a link with rotational motion transmission, in which there is a reverse gear controlled by two friction clutches. 6. Rescue helicopter, including the fuselage and coaxial rotors, characterized in that the engine and gearbox are located in the engine nacelle located above the fuselage on the pylons and / or elastic inserts.

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