RU2281885C1 - Main rotor - Google Patents

Abstract

FIELD: aviation; main rotors.

SUBSTANCE: proposed main rotor includes revolving outer body with gear wheel of preliminary overspeeding and gimbal frame. Non-revolving inner shaft is connected with outer shaft by means of bearings. Leverage control mechanism arranged inside non-revolving shaft is used for tilting of axis and motion if revolving unit in vertical direction; this unit is mounted on control mechanism and is connected with blade turning levers which are connected with hub through axles and attachment members with feathering hinges. Attachment members are made in form of clamps to which blades are connected. Hub is provided with gimbal frame and two beams with elastic cantilever parts interconnected by means of pins. Clamps secured on spherical bearings at angle of conicity relative to plane of plates are turnable in bearings. Beams are articulated with revolving outer body of hub by means of gimbal frame located above bell crank body. Axes of gimbal frame are mutually perpendicular and point of intersection of axes lie on hub rotational axis; axis of frame lying in plane of flapping is common axis of feathering hinge.

EFFECT: reduced level of hub loading; increased service life; enhanced reliability of control and enhanced safety of flight.

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Description

The invention relates to aviation and can be used in any form of technology where the aerodynamic principle of movement and spatial control of the apparatus using a rotor is used.

The following basic rotor circuits are known, which are close in design and conceptual solutions to the described invention.

Main rotor with Jung’s sleeve [IP Bratukhin Design and construction of helicopters. - M .: State Publishing House of the defense industry, 1955, - 357 pp.] Consists of a shaft with a cardan attached to it. One of the axles of the cardan is a common horizontal hinge of two blades, which are connected to the sleeve by means of a rocker and axial joints. This axis allows the blades to carry out a joint swing movement. The second axis of the cardan is a common axial hinge of the blades, in which, by changing the angle of inclination of the cardan with the rocking chair and the blades relative to the body of the aircraft, the rotor is controlled. Axial hinges of the blades are designed to change the angle of the overall pitch of the blades. Leads to control the angles of installation of the blades connected to an external swash plate are connected to the axial hinges. The sleeve does not have individual horizontal and vertical hinges of the blades.

The disadvantages of the rotor with a Young's sleeve include:

- large overall dimensions caused by the external location of the swashplate, leading to a large harmful resistance of the sleeve;

- the insecurity of the parts of the swashplate from abrasive wear in view of the external location;

- the presence of movable loaded joints of the swashplate having a reduced resource;

- increased requirements for the accuracy of the manufacture of bearings of the plates of the swash plate;

- a large weight of the swashplate;

- high level of rocking load.

Main rotor with Hafner bushing (spider type) [Zhabrov A. Autogyro and helicopter. - M .: Publishing house OSOAAVAHIMA USSR, 1939, - 240 p.] Consists of a rotating shaft mounted on bearings attached to a non-rotating shaft, inside of which there is a lever control mechanism consisting of driven and driving levers. The driven axis of the linkage mechanism through the bearing is connected by a “spider” to the leads of the blades attached to the axial joints. The suspension of each blade to the sleeve has a horizontal hinge for the implementation of the flywheel movement and a vertical hinge for the swinging movement in the plane of rotation. The control of the cyclic step is carried out by changing the angle of installation of the blades in the axial joints at the corresponding azimuthal positions, which is carried out by tilting the driven axis of the lever mechanism, spider and leashes of the blades. Thus, when the slope of the driven axis changes, the plane of constant rotor mounting angles changes its angular position relative to the aircraft body, while the blades make periodic movement in axial joints. The angle of the common pitch of the blades is controlled by moving the lever mechanism along the vertical axis of the sleeve, while the blades associated with the mechanism change the installation angles by the same amount. The disadvantages of the rotor with a Hafner sleeve include:

- design complexity due to the large number of hinges of the blades;

- the complex nature of the loading of the sleeve due to the presence of periodic movements of each blade in the axial, horizontal and vertical joints, adversely affecting the resource of the sleeve;

- the need to develop additional means of dealing with terrestrial resonance due to the periodic movement of the blades in vertical hinges.

The main rotor with the sleeve of the helicopter R-22 [Chizhov N.T. Light helicopters and gyroplanes. Technical Information TsAGI, No. 18 (1664), 09.1991. S.9-24], designed for a two-bladed main rotor, includes a rotating shaft on which a rocking chair is suspended through a common horizontal hinge, having two individual horizontal blades hinges. Axial hinges are attached to the rocker, which are connected by means of rods to a rotating inclined plate of the swash plate, which allows changing the angles of the cyclic and common pitch of the blades. Swing movements are performed both in general and in individual horizontal joints.

The disadvantages of the rotor hub of the helicopter R-22 include:

- high load axial joints in which the cyclical movement of the blades;

- the presence of an external swashplate, leading to an increase in the size of the sleeve and harmful aerodynamic drag of the aircraft;

- the insecurity of the parts of the swashplate from abrasive wear in view of the external location;

- the presence of movable loaded joints of the swashplate having a reduced resource;

- increased requirements for the accuracy of the manufacture of bearings of the plates of the swash plate;

- a large weight of the swashplate.

The closest technical solution selected for the prototype is the main rotor with the sleeve of the gyroplane A-002 [RF Patent No. 2235662, priority 12.08.2002, IPC 7 V 64 C 27/48]. The rotor hub contains a rotating outer casing with a pre-spinning gear, a non-rotating inner shaft, inside which there is a lever control mechanism for tilting the axis and moving in the vertical direction of the rotating device connected thereto, mounted on the control mechanism and connected with the blade rotation levers connected to a sleeve through a fastener with an axial joint. Moreover, the rotating device is made in the form of a rocker arm, the fastening element is made in the form of a bracket. The sleeve is equipped with a cardan frame and a rocker housing connected to each of the two blades through a bracket. The axial hinge is made in the form of a finger mounted in the rocking housing at a constructive angle of conicity to the plane of rotation, on the cantilever parts of which there is a bracket with a thrust bearing support that can be rotated about the axis of the finger and connected to the rocking housing through a support with a thrust bearing. In this case, the rocking housing is pivotally connected to the rotating outer sleeve housing of the cardan frame located above the rocking body, the axes of the cardan frame are mutually perpendicular, and the point of intersection of the axes is located on the axis of rotation of the sleeve, and the axis of the frame parallel to the axis of the blades is the axis of the common axial hinge, and the axis of the frame perpendicular to the axis of the blades is aligned with the axis connecting the beam with the levers of rotation of the blades at one of the angles of installation of the blades and is the axis of a common horizontal hinge. The control mechanism is made with three separate rods.

The disadvantage of the rotor with the hub of the gyroplane A-002 is the high level of loading of the rocking chair with brackets, as a result of which the possibility of its use in autorotating rotors with a variable pitch angle, characterized by a wide range of values of the angular velocity of rotation and, accordingly, the values of the bending moment in the plane of the swing .

The technical problem solved by the proposed rotor is to reduce the level of loading of the sleeve, which allows to increase the multi-mode of its operation as an integral part of the autorotating rotor and increase its resource.

To achieve the technical task, a rotor is proposed comprising a rotating outer casing with a pre-unwound gear and a cardan frame, a non-rotating internal shaft connected to the external shaft through bearings; inside the non-rotating shaft there is a lever control mechanism designed to tilt the axis and move in the vertical direction of the rotating device connected to it, mounted on the control mechanism and connected with the rotation levers of the blades; levers of rotation of the blades are connected to the sleeve through the axes and fastening elements with axial joints; fasteners are made in the form of brackets to which the blades are attached; the rotating device is made in the form of a rocker; the sleeve is provided with a cardan frame and two beams with elastic cantilever parts connected by fingers; the rigid central parts of the beams are connected to each other by means of plates; each axial joint is made in the form of two spherical bearings, one of which is mounted on a finger connecting the beams, and the second is fixed between the plates; brackets are mounted on spherical bearings at an angle of taper to the plane of the plates, which can be rotated in the bearings, with their inner part relative to the sleeve, the brackets are mounted on the spherical bearings of the plates by means of rods that allow the brackets to move along the axes of the rods; the beams are pivotally connected to the rotating outer case of the sleeve by a cardan frame located above the rocking case; the axes of the gimbal frame are mutually perpendicular, and the point of intersection of the axes is located on the axis of rotation of the sleeve, the axis of the frame lying in the plane of the swing is the axis of the common axial hinge, and the axis of the frame perpendicular to the plane of the swing is the axis of the common horizontal hinge; the control mechanism is made with three separate rods.

Distinctive features of the proposed rotor from the rotor selected as a prototype is that the sleeve is equipped with two beams with elastic cantilever parts connected by fingers; the rigid central parts of the beams are connected to each other by means of plates; each axial joint is made in the form of two spherical bearings, one of which is mounted on a finger connecting the beams, and the second is fixed between the plates; brackets are mounted on spherical bearings at an angle of taper to the plane of the plates, which can be rotated in the bearings, with their inner part relative to the sleeve, the brackets are mounted on the spherical bearings of the plates by means of rods that allow the brackets to move along the axes of the rods; the axis of the gimbal frame lying in the plane of the swing is the axis of the common axial hinge, and the axis of the frame perpendicular to the plane of the swing is the axis of the common horizontal hinge.

Due to the presence of these signs in conjunction with the known, the proposed design of the sleeve allows you to reduce the level of loading and increase the resource of the sleeve due to the unloading of its elements from loads from the blades, providing the perception of large values of bending moments in the plane of the swing compared with the known bushings.

The drawing shows a view of the proposed rotor in isometric projection with a slit.

The main rotor includes a non-rotating shaft 1. Shaft 1 through the upper 15 and lower 16 bearings is connected to a rotating shaft 2, which has seats for mounting the bearings of the universal joint frame 3. The upper parts of these seats on the shaft after installing the universal joint frame 3 along the ZZ axis closed by covers 22 attached to the shaft 2. On the second axis of the universal joint frame XX, perpendicular to the ZZ axis, two beams 13 are hung through the eyes 23, interconnected in the middle by means of plates 21, and by the rigid ends of the cantilever parts by Vuh fingers 20. The resilient cantilever beams deflected portion taper at an angle relative to the plane of plates 21. To the fingers 20 are attached spherical bearing 24, which sets stringent bracket lugs 12. Bolted clamps are attached rotor blades (not shown). These eyes have the same angle of inclination relative to the axes of the finger 20, which is the angle of the common pitch of the blades. The rods 26 are fixed to the internal parts of the brackets 12 relative to the rotor hub, by means of which the brackets are connected to spherical hinge assemblies 7 mounted on the plates 21. The axles 25 to the brackets 12 are attached to the rotation levers of the blades 6, which are connected through the bearing assemblies to the beam 8. The beam 8 is installed through the bearing 14 on the driven lever 4 of the lever control mechanism. The lever mechanism includes a follower 4 and a leading 5 levers mounted in a slider 9 on spherical bearings. A cup 11 is attached to the lower part of the slider 9, having windows for the exit of the control rods along the pitch channel 17 and the roll 18, which are attached to the lower part of the drive lever 5. The cup 11 is connected to the rocker of the common step 19. A gear wheel is attached to the bottom of the rotating shaft 2 10.

The main rotor operates as follows. As a result of interaction with the oncoming air stream, the blades in autorotation mode create the lifting force necessary for the flight of the aircraft, and also transmit rotation to the rotating elements of the sleeve - brackets 12, beams 13 with plates 21, levers of rotation of the blades 6 with axes 25, rocker 8 with bearings, eyelets 23, cardan frame 3 with bearings, shaft 2 with gear 10 and outer rings of bearings 15 and 16. In the modes of preliminary rotor rotation of the rotor, gear from engine 10 is supplied with Performan in an increase in the angular velocity of the rotating sleeve parts and the blades.

Joint flywheel movement of the rotor blades occurs in a common horizontal hinge (axis X-X of the universal joint frame 3). In addition, each blade carries out its own flywheel movement in the spherical hinged nodes 7, which occurs due to the elasticity of the cantilever parts of the beams 13, and is limited by the magnitude of their deformation under load.

To control the spatial position of the aircraft, a lever control mechanism is used. When the angular position of the driving lever 5 in its spherical bearing fixed in the slider 9 changes, by means of rods 17 or 18, a corresponding change occurs in the pitch channel or roll channel — the slope of the driven lever 4 relative to the Y-Y axis. As a result, the angle of inclination relative to the vertical axis of the sleeve YY of the following rotating elements changes: rocker arm 8, levers of rotation of the blades 6, brackets 12, beams 13, plates 13, eyes 23, cardan frame 3. Thus, the axis of rotation of the blades and the corresponding parts of the sleeve deviate relative to the vertical axis of the sleeve, i.e. changing the angular position of the plane of constant angles of installation of the rotor relative to the aircraft. This entails a change in the direction of action of the rotor aerodynamic force vector required for control. In this case, in the process of rotation of the sleeve, there is a cyclic movement around the Z-Z axis of the cardan frame 3. Thus, during cyclic control of the sleeve, movements in individual axial joints do not occur, which allows to increase their resource and reduce weight.

The angle control of the common pitch of the rotor is as follows. The rocking chair 19 defines the movement of the glass 11, the slider 9 and, respectively, the levers 4 and 5 along the axis Y-Y. As a result of this, the rocker arm 8 and the blades rotation levers 6 are moved in the vertical direction. The brackets connected with the blades rotation levers rotate in the bearing units 24 and 7 with respect to their own longitudinal axes by the same angle.

The main power elements of the proposed rotor are beams 13 with fingers 20, as well as brackets 12. Due to the hinged suspension of brackets 12, the beams work together with brackets 12. Due to the fact that the brackets with blades on one side abut against the bearing units 24, and on the other the sides can freely move along the axes of the rods 26 relative to the bearing assemblies 7, the cantilever parts of the beams 13 perform the function of an elastic unloading section, using the effect of unloading by centrifugal forces arising from the rotation of the carrier nta. When the load on the blade increases due to the deformation of the elastic cantilever parts of the beams, the angle of deviation of the blade with the bracket 12 from the plane of rotation increases, and this leads to a decrease in the load on the central parts of the beams due to an increase in the bending moment from centrifugal forces, which counteracts the bending moment from aerodynamic forces. The bending moment in the plane of rotation is perceived by the fingers 20 and beams 13. Thanks to this design, the level of loads perceived by the elements of the swinging part of the sleeve is less than that of the prototype sleeve, which allows to reduce the weight of the sleeve when designing it for multi-mode operation.

The proposed rotor has a simple design, small overall dimensions, low load on the sleeve elements and the wiring of the control system, increased resource; provides the multi-mode operation of the rotor with different angles of the common pitch of the blades, necessary, in particular, for the jump take-off of the gyroplane, landing with undermining of the common pitch, preliminary unwinding and braking of the rotor, maneuvering in flight, and can be recommended, first of all, on autogyros.

Claims (1)

A rotor comprising a rotating outer casing with a pre-unwind gear, a non-rotating inner shaft connected to the outer shaft through bearings, and inside which there is a lever control mechanism for tilting the axis and moving in the vertical direction of the rotary device connected to it, made in the form of a rocker arm, mounted on the control mechanism and connected with the levers of rotation of the blades, the levers of rotation of the blades are connected to the sleeve through brackets with axial joints, to which the blades are insulated, the control mechanism is made with three separate rods, characterized in that the sleeve is provided with a cardan frame and two beams with elastic cantilever parts connected by fingers, the rigid central parts of the beams are connected to each other by means of plates, each axial hinge is made in the form two spherical bearings, one of which is mounted on a finger connecting the beams, and the second is fixed between the plates, on spherical bearings at an angle of taper to the plane of the plates are fixed the possibility of rotation in the bearings, with their inner part relative to the sleeve, the brackets are mounted on the spherical bearings of the plates by means of rods that enable the brackets to move along the axes of the rods, the axis of the cardan frame lying in the plane of the swing is the axis of the common axial hinge, and the axis of the frame is perpendicular plane swing, is the axis of a common horizontal hinge.