RU2499737C2 - Helicopter - Google Patents

Abstract

FIELD: aircraft engineering.

SUBSTANCE: helicopter comprises fuselage to accommodate passengers, four sets of rotors, engine, undercarriage and manual control system. Extra vertical wings are attached to blade outer end parts so that revolution of rotors, positive angle of attack of said extra wings is created to force air inside the area swept by rotors. Every blade features angle of attack varying along blade length, from maximum at tip and minimum at root, and width varying in likewise way. Helicopter power plant is configured to engine-generator while every rotor is driven by its independent motor. All screws are arranged in one plane in symmetry about fuselage and attached thereto by supports.

EFFECT: higher efficiency of rotors and their thrust.

3 cl, 4 dwg

Description

The invention relates to helicopter engineering, in particular to a device for supporting helicopter systems of twin-screw transverse and longitudinal circuits.

Known designs of the supporting systems of helicopters of twin-screw transverse and longitudinal schemes, see, for example, E. RUZHITSKY Modern aviation. Helicopters - M .: Victoria, ACT, 1997, p. 161. JP 3292295 A, 12.24.1991. RU 2267657 C2, 10.01.2006. RU 2160689 C2, 20.12.2000. RU 99114461 A, 05.20.2001. RU 2089456 C1, 09/10/1997. RU 2278800 C2, 06/27/2006. GB 626 690 A, 07.20.1949. RU 2389651 C2, 03/07/2008.

As a prototype we take the proposal set forth in patent RU 2389651 C2, 03/07/2008, where the task is to increase and balance the stability of helicopters of a twin-screw transverse circuit. The problem itself arises due to the fact that the author places the rotors on the sides of the fuselage at about the level of the center of mass of the helicopter, which creates the problem of instability. However, the proposed solution, which involves the creation of an appropriate automatic control system, does not fundamentally solve the instability problem. In addition, low-lying screws pose a threat to human life.

The aim of the invention is to increase the operating efficiency of the bearing blades of the helicopter, which allows to reduce their length, and as a result to increase the angular velocity of their rotation, thereby increasing the traction of the supporting system and reduce its dimensions. Upon reaching this goal, the goal is to reduce inductive losses, as well as to increase the reliability of the bearing system by simplifying the design of the rotor. Next, the goal is to increase the safety of passengers, as well as to increase the balancing stability of the helicopter, and the goal is to provide the ability to control the angular speed of each of the sets of bearing blades, and the goal is to develop a method of controlling the movement of the helicopter that does not allow the occurrence of jet moment.

These goals are achieved by the fact that additional vertically arranged planes are attached to the outer end part of the bearing blades so that during the circular movement of the bearing blades there is a positive angle of attack of the additional planes forcing air into the area swept away by the bearing blades, each of the blades having variable along its length, the angle of attack is greater at the beginning and smallest at the end, as well as a variable width - large at the beginning and smallest at the end.

These goals are also achieved by the fact that two, highly located (above the fuselage) sets of bearing blades (screws) are attached to the fuselage of the helicopter, in addition to the existing ones, so that the center of mass of the helicopter is located in the center and below the quadrangle formed by the supporting screws, while all the screws are located in the same plane, symmetrically with respect to the helicopter fuselage and are removed from it in the specified plane so that the air (inductive flux) rejected by the bearing planes is minimally salsya said fuselage.

These goals are also achieved by the fact that each of the rotors is equipped with its own engine, while the front right and rear right, relative to the longitudinal axis of the helicopter, the engines rotate their sets of blades, rigidly connected with the engine shaft, counterclockwise, and the front left and rear left, relative to the longitudinal axis of the helicopter, the engines rotate their sets of blades, rigidly connected with the engine shaft, in a clockwise direction, and the opposite direction of rotation is possible for all engines simultaneously.

These goals are also achieved by the fact that the helicopter controls the movement as follows: the pilot performs vertical movement by setting the control to a position in which all engines rotate at the same angular speed, the pilot moves forward by setting the control to in which both front engines reduce their angular speed by the same amount, and both rear engines increase it by the same amount, the pilot moves backward by setting the control to a position in which both rear engines reduce their angular speed by the same amount, and both front engines increase it by the same amount, the pilot moves the left movement mode by setting the control to both left-hand engines lower their the angular speed is the same amount, and both right-hand sides increase it by the same amount, the pilot exercises the right movement mode by setting the control to a position in which both right-hand engines reduce their angular speed is the same amount, and both left ones increase it by the same amount, while the pilot moves the helicopter in intermediate directions, guided by the principle of superposition, while changing the height and speed of horizontal movement, the pilot controls the total thrust of all engines simultaneously .

Figure 1 schematically shows the proposed device of the helicopter (top view). In this drawing: xx - the longitudinal axis of the helicopter; 1, 2, 3, 4 - rotors of the helicopter; 5 - helicopter fuselage; 10, 11, 12, 13 - rotor engines; 6, 7, 8, 9 — consoles with which rotor engines are attached to the fuselage, arrows indicate the direction of rotation of the screws.

Figure 2 schematically shows a control system for the movement of a helicopter. In this diagram 14 is a direction control knob; 17 - control knob for the general thrust of all engines simultaneously; 15 - angle sensor β roll of the helicopter, set by the pilot; 16 - pitch angle sensor α specified by the pilot; 18 - angle sensor γ, which is a control signal of the total thrust specified by the pilot; 19 is a control unit, where the signals from the sensors 15, 16, 18 are converted into control actions, for example, currents in the excitation windings of the motors 10, 11, 12, 13, changing their angular speed of rotation, and therefore the traction force of each of engines. In this diagram also: xx - longitudinal, yy - transverse to the axis of the helicopter.

Figure 3, a) schematically shows the proposed device of the helicopter (right view). In this drawing: xx - the longitudinal axis of the helicopter; 5 - its fuselage; TsM - the center of mass of the helicopter; P is the strength of its weight; 11 - front, 13 - rear helicopter engines; T _p - the total thrust of the front engines; T _s - the total thrust of the rear engines; 20 - point of application T _p - resultant thrust from all engines. Note that the line of action of the resultant thrust does not pass through the center of mass of the helicopter. As a result, it is acted upon by a moment rotating the helicopter clockwise. The drawing corresponds to a situation where the pilot pulls the control handle 14 away from him.

Figure 3, b) schematically shows the proposed device of the helicopter (right side view). In this drawing: xx - the longitudinal axis of the helicopter under the action of the moment formed by the forces T _p and P, tilted clockwise; Also inclined is the resultant force T _{p of the} thrust of all screws, which can be decomposed into the vertical - T _in and horizontal - T _g components. When the line of action of the forces T _in and P coincides, the moment acting on the helicopter disappears. By simultaneously changing the thrust of all propellers, the forces T _in and P can be made equal and the helicopter will make horizontal movement under the action of the horizontal force T _g .

Figure 4, a) schematically shows a top view of one of the rotors of the helicopter, consisting of four blades, rigidly mounted on the shaft of its engine. In this drawing: 11 - the engine, 22 - its output shaft, 23 - additional, vertically located planes attached to the outer ends of the blades, α _VP - angle of attack of additional vertical planes, the arrow indicates the direction of rotation of the blades.

Figure 4, b) schematically shows a front view of the rotor blade. In this drawing: 21 is the lower edge of the blade, 23 is an additional vertically located plane, 24 is the upper edge of the blade.

Figure 4, c) schematically shows a top view and at an angle from the center of rotation of the rotor blade. In this drawing: 21 is the lower edge of the blade, 24 is the upper edge of the blade, α _int is the angle of attack at the beginning of the blade, α _VK is the angle of attack at the end of the blade. The angle of attack at the beginning of the blade is greater than the angle of attack at the end of the blade. This is done to increase the efficiency of the entire surface of the blade, because peripheral linear speed of the blade at its beginning is significantly lower than at the end.

The proposed helicopter (let's call it “longitudinal-transverse helicopter (WPS) helicopter”) consists of a fuselage, a power plant, a carrier system and a control system. The supporting system of the helicopter is at the same time the executive body of its control system and operates as follows. Let us assume that the helicopter’s power plant is carried out according to the “engine-generator” scheme, and each of the rotors is driven by its own electric motor, which is part of a controlled drive. By means of a drive, according to signals set by the pilot, for example, when moving forward, both front engines change their rotational speed by the same amount equal to -Δω, at the same time both rear engines change their rotational speed by the same amount, but with the opposite sign, equal to + Δω. In this case, the total reactive moment remains equal to zero. In this case, the point of application of the resultant thrust force changes its position relative to the fuselage, creating, together with the force of the weight, a moment deploying the helicopter and the thrust force in the direction of flight. When the line of action of the vertical component of the resultant thrust force and the weight force coincide, the moment acting on the helicopter disappears. By simultaneously changing the thrust of all the screws, the vertical component of the thrust force and the weight force can be made equal. In this case, the helicopter will make a horizontal movement under the action of the horizontal component of the thrust force.

The considered example applies to all directions of the helicopter motion due to the superposition principle, which in turn is valid due to the linearity of the control system (SU) and the identity of the control channels of the electric drive.

We find the conditions imposed on the control system, necessary to ensure that the reactive moment always remains equal to zero. The equations of motion of the rotors have the form:

$$J\Delta {\dot{\omega }}_i=M_i,i=\mathrm{one},2,3,\mathrm{four}\text{(one)}$$

- угловые ускорения i-го винта, M_i - момент, приложенный к i-му винту. Условие отсутствия реактивного момента в любой момент времени имеет вид:Here: J is the moment of inertia of the rotors, $$\Delta {\dot{\omega }}_i$$

- angular acceleration of the i-th screw, M _i - the moment applied to the i-th screw. The condition for the absence of a reactive moment at any moment in time has the form:

$${\displaystyle \sum _{\mathrm{one}}^{\mathrm{four}}{M}_i\left(t\right)=0}\text{(2)}$$

Taking into account equations (1), and also taking into account the equality of the moments of inertia of all the rotors, this condition takes the form:

$$\Delta {\dot{\omega }}_{\mathrm{one}}+\Delta {\dot{\omega }}_2+\Delta {\dot{\omega }}_3+\Delta {\dot{\omega }}_{\mathrm{four}}=0\text{(3)}$$

Integrating the obtained expression under zero initial conditions, we obtain the desired condition for the absence of a reactive moment at any current moment of time:

$$\Delta {\omega }_{\mathrm{one}}+\Delta {\omega }_2+\Delta {\omega }_3+\Delta {\omega }_{\mathrm{four}}=0\text{(four)}$$

With that said, the algorithm of the SU, i.e. the connection of the signals specified by the pilot with increment of the angular velocities of the rotors has the form:

Pitch Control: $$\Delta {\omega }_{\mathrm{one}}=k\alpha \text{A.},\Delta {\omega }_2=k\alpha \text{A.},\Delta {\omega }_3=-k\alpha ,\Delta {\omega }_{\mathrm{four}}=-k\alpha \text{A.}(5)$$

Roll Control: $$\Delta {\omega }_{\mathrm{one}}=k\beta \text{A.},\Delta {\omega }_2=-k\beta \text{A.},\Delta {\omega }_3=k\beta ,\Delta {\omega }_{\mathrm{four}}=-k\beta \text{A.}(6)$$

Note that in all the given equalities there is the same transmission coefficient k. This establishes the identity of all control channels and thus establishes the fulfillment of the condition for the absence of a reactive moment at any current time. Let us verify what has been said on a concrete example. For this, we add all the equalities in expressions (5) and (6). As a result, we will have:

$$\Delta {\omega }_{\mathrm{one}}+\Delta {\omega }_2+\Delta {\omega }_3+\Delta {\omega }_{\mathrm{four}}=2k\alpha -2k\alpha \text{A.}(7)$$

$$\Delta {\omega }_{\mathrm{one}}+\Delta {\omega }_2+\Delta {\omega }_3+\Delta {\omega }_{\mathrm{four}}=2k\beta -2k\beta \text{A.}(8)$$

This implies that for any position of the electric control knob, i.e. for any control signals α and β, equality (4), which is a condition for the absence of a reactive moment at any current time, is satisfied. The task of controlling an electric drive is well known in the art (see, for example, the monograph: A. Sirotin, “Automatic Control of Electric Drives”, M., “Energy”, 1969, 560 pp.) And was solved, for example, in such vehicles means like tram, trolleybus, electric train, etc. Therefore, specific circuit solutions are not given here and are not protected.

The technical result, which consists in increasing the thrust of the supporting system and reducing its size, is achieved by narrowing the density distribution diagram of the inductive flux and increasing its speed by increasing the efficiency of the helicopter's bearing blades. Increasing the efficiency is carried out by attaching additional vertically arranged planes to the outer end part of the bearing blades, and also due to the fact that each of the blades has a variable, along its length, angle of attack - greater at the beginning and smallest at the end, as well as a variable width - large at the beginning and the smallest at the end. These measures can reduce the length of the blades, and as a result, increase the angular velocity of their rotation and, consequently, the thrust of the rotors. In addition, reducing the length of the blades and increasing their angular velocity (while maintaining the dimensions of the helicopter) allows you to increase the number of rotors. The technical result is also to reduce inductive losses, as well as to increase the reliability of the helicopter support system by simplifying the design of the rotors in which the blades are rigidly connected to the motor shaft and there is no such complex mechanism as a swash plate. In this case, the introduction of another, highly located (above the fuselage), transverse set of rotors and the location of all the screws in one plane increases the safety of passengers, and also due to the fact that the center of mass of the helicopter is located in the middle between the rotors and below the point of application of the resultant thrust , the problem of its balancing stability is radically solved. The technical result also consists in developing a method for controlling the movement of a helicopter that does not allow the occurrence of a reactive moment by properly controlling the angular velocity of rotation of each of the rotors.

Claims (3)

1. A helicopter containing a fuselage for accommodating passengers, four sets of bearing blades, an engine, a landing gear and a manual control system, characterized in that additional vertically arranged planes are attached to the outer end part of these blades so that during circular motion of the bearing blades there is positive angle of attack of additional planes forcing air into the area swept by the bearing blades, each of the blades having a variable angle of attack along its length - higher at the beginning and at the end of the smallest, as well as a variable width - great at the beginning and at the lowest end. 2. The helicopter according to claim 1, characterized in that four highly located (above the fuselage) sets of bearing blades (screws) are attached to its fuselage through the consoles so that the center of mass of the helicopter is located in the center and below the quadrangle formed by the centers of the rotors, all the screws are located in the same plane symmetrically with respect to the helicopter fuselage and are removed from it in the indicated plane so that the air (inductive flux) discharged by the bearing planes minimally touches the fuselage. 3. The helicopter according to claim 1 or 2, characterized in that the helicopter power plant is performed according to the “engine-generator” scheme, with each of the rotors being rotated by its own electric motor, which is part of the controlled drive, while the sets of blades of each screw are rigidly connected to the shaft of their engine.

Images