RU2277498C1 - Helicopter main rotor - Google Patents

Abstract

FIELD: propellers, helicopter main rotors.

SUBSTANCE: proposed main rotor is made from blades of two-dimensional profile; these blades are provided with tip fences at rotor diameter. Tip fences of all blades are movable for smooth change of angle from 180° to 60° between working surfaces of blades and their tip fences, thus ensuring fixation of preset angle. Minimum height of end edge of each fence relative to working surface of each blade is equal to 0.1% of rotor diameter. Mobility of tip fences is obtained due to articulated joints. These articulated joints are driven by means of chain rods or flexible shafts located in cavities of blades.

EFFECT: possibility of forming augmented thrust with no increase of rotational speed of main rotor.

4 cl, 2 dwg

Description

The invention relates to the technique of air, namely rotors for a helicopter, and can be used in passenger, airborne transport and military helicopters.

Known rotors for helicopters are made in the form of a multi-blade axisymmetric device. Each rotor blade is made in the form of a plane-parallel or plane-profile strip installed at a certain angle to the plane of rotation, which allows the working surface to move a mass of air from the leading edge to the rear, while providing a reactive force directed totally from all the blades along the axis of rotation of the screw up from the ground, and thus create a lifting force that provides vertical lift, for example, of the two-bladed helicopter AN-1, "Hugh Cobra" [1] or the domestic helicopter MI-24 [2].

A disadvantage of the known rotors of helicopters [1] and [2] is that when the rotor rotates, energy from centrifugal force is not used, since when the rotor operates, the air is not only displaced by the inclined working surfaces of the blades along the rotational axis of the rotor, providing its bearing capacity, but and due to centrifugal force, a significant part of the air mass from under the rotor blades rushes in the radial direction along the blades and breaks from their end ridges into the surrounding air space, transferring the entire kinetic nergiyu obtained by radially moving large air mass along the blades, thereby reducing the efficiency and operation of the screw.

The closest technical solution, selected as a prototype, is the rotor of a helicopter [3]. All the rotor blades of the prototype are made with end ridges bent at an angle of 90 to 135 °. In this case, the end edge of the bent ridges protrudes relative to the working surfaces of the blades by an amount from 0.5 to 3.5% of the screw diameter. This technical solution allows you to summarize the air flow moved by centrifugal force with the air flow moved by the inclined working surfaces of the blades and direct them in one direction, thereby increasing the traction properties of the rotor.

The disadvantage of the prototype is that the bend angle of the end ridge of each screw blade is made statically, that is, it is bent strictly at a certain angle when manufacturing the screw. However, this technical solution reduces the possibility of maneuver by changing the angle of the end ridge and thereby makes it impossible for the main rotor to obtain forced additional traction, for example, in an emergency.

The problem to which the invention is directed, is to create conditions for accelerated traction without increasing the rotor speed.

This is achieved by the fact that in the rotor of the helicopter, made in the form of balanced and aligned on one axis of one of its two ends several plane-profile plate blades having end diameters in diameter of the screw bent towards the working surfaces of the blades, with a working surface and an end edge, according to the invention, the end ridges of all blades are movable with the possibility of a smooth change of angle from 180 to 60 ° between the working surfaces of the blades and the working surfaces of the end ridges and fix a given angle, while the minimum height of the end edge of each ridge relative to the working surface of each blade is 0.1% of the screw diameter. In this case, the mobility of the end ridges is provided with the help of loop hinged joints. The drive of the end ridges is made using chain rods or flexible shafts located in the cavities of the blades. In addition, when performing the drive end ridges in the form of flexible shafts, it is implemented from one control shaft placed coaxially in the drive shaft of the screw.

The hinge-loop connection characterizes a specific mechanical connection between the elements, namely between the blade and the end ridge, which can be made according to the known structural type of hinge sashes [4], when one sash is rigidly connected to the end ridge, and the second sash is rigidly connected to the screw blade . The flap connected to the end ridge has a rod passing through the hinges and is rigidly fixed to them, on which a bevel gear is rigidly mounted in the middle of the loop, connected by a gear connection to a second gear wheel, rigidly fixed on a flexible shaft located in the cavity of the blade. At the second ends of the flexible shafts located in each blade, bevel gears are also rigidly mounted, connected by a gear connection to a drive bevel gear placed on the control shaft coaxially with the drive shaft of the screw.

The invention is illustrated by drawings, where figure 1 shows a top view of a four-bladed screw, with outcrops of the blades. Figure 2 shows a view of a section of one rotor blade with an end ridge in the direction of arrow A.

The rotor device is made of four plane-profile blades 1, having screw diameters end ridges 2, bent towards the working surfaces 3 of the blades 1. Each end ridge 2 has an end edge 4 and a working surface 5. The end edge 4 of each ridge 2 is relative to the working surface blades 1 at a distance h, the minimum value of which is 0.1% of the diameter of the screw D. Each blade 1 is connected to its end ridge 4 movably using a loop hinge 6. Deviation of the working surface 5 ka dogo terminal comb 2 with respect to the working surface 3 by an angle α in each blade by means of shafts 7 placed in the cavities of the blades 1.

The device operates as follows.

A rotor with a diameter D when rotating in air provides the movement of a large mass of air to the ground, creating a reactive force that holds or raises the helicopter. The movement of air to the ground is carried out using the working surfaces of the 3 blades 1. In this case, with the fast rotation of the screw, the air washing the blades receives a large amount of centrifugal force, which is radially directed along the working surfaces of the 3 blades 1. A significant mass of air moved by centrifugal force along the working surfaces 3 blades 1, reaches the ridges 2, changes its direction of motion by an angle α and mixes with the main stream of air moved by inclined working surfaces 3. At the same time, Adding air flow quantity transported by the centrifugal force and be mixed with the main flow by means of deviations of end combs 2 in a certain angle α with subsequent mechanical fixation selected angle values. And drastically changing the angle α, it is possible to provide a forced traction mode without increasing the rotational speed of the screw and, therefore, ensuring maneuver with minimal energy consumption.

The rationale for the range (from 180 to 60 °) of the possible deviation of the end ridges of 2 blades 1 is explained as follows. When the end ridge 2, and hence its working surface 5 is deflected 180 ° relative to the working surface 3 of its blade, the latter becomes similar to the analogue blades [1] or [2], that is, the device of the blade in which the bent end ridge is towards the working the surface of the blade is generally absent. And this allows the centrifugal force to dump part of the energy-intensive air flow outside the screw diameter, without doing any useful work. When the end ridge 2 is deflected by 60 ° relative to the working surface 3 of its blade, it is necessary because the ends of the rapidly rotating helicopter blades bend, and the greater the greater the mass of the helicopter. And since at the same time the working surface of the 3 blades 1 becomes convex, in order to ensure the effective use of centrifugal force to change the direction of the air flow down along the vertical axis and summing it to the main stream received from the working surfaces of the 3 blades 1, this angle is not taken 90 °, as in the prototype, and 33% less. The minimum height h of the end edge 4, equal to 0.1% of the diameter D of the screw, allows to minimize the aerodynamic drag of the screw.

Information sources

1. Magazine "Modeller-constructor" No. 7, 2001, p.24.

2. The same.

3. Patent of Russia No. 2229422, M. cl. B 64 C 27/32, 27/46, 11/16, publ. 05/27/2004

4. D.D. Churabo. Parts and components of devices. Design and calculation. Reference manual. Ed. 4th, rev. and add. M., "Mechanical Engineering", 1975 (pp. 459-463).

Claims (4)

1. The rotor of the helicopter, made in the form of balanced and aligned on one axis with one of its two ends of several plane-profile plate blades, with screw diameters end ridges bent towards the working surfaces of the blades, with a working surface and an end edge, characterized in that end ridges of all blades are movable with the possibility of a smooth change of angle from 180 to 60 ° between the working surfaces of the blades and the working surfaces of the end ridges and fixing a given angle, at ohm, the minimum height of the end edge of each ridge relative to the working surface of each blade is 0.1% of the screw diameter. 2. The rotor according to claim 1, characterized in that the mobility of the end ridges is provided using loop hinges. 3. The main rotor according to claim 2, characterized in that the drive end ridges are made using chain rods or flexible shafts located in the cavities of the blades. 4. The main rotor according to claim 3, characterized in that when performing the drive end ridges in the form of flexible shafts, it is carried out from one control shaft placed coaxially in the drive shaft of the screw.

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