RU2578706C1 - Summing mechanism for control systems of common and cyclic pitch of helicopters of three-point control system with inclined arrangement of hydraulic actuators - Google Patents

Abstract

FIELD: aviation.

SUBSTANCE: invention relates to aviation, in particular to control systems of helicopters. Summing mechanism for control systems of common and cyclic pitch helicopters three-point control circuit with inclined arrangement of hydraulic drive comprises a system of input rockers, slider, movable and fixed brackets, fixed frame. Input pumping units are connected with handles cyclic pitch over “roll” and “pitch”. Slide is connected with common pitch control handle. Movable bracket secured on slide, can turn in plane perpendicular to input rockers, and move along guide fixed frame. Movable bracket is connected through a system of links with system output rockers to control hydraulic drives swash plate.

EFFECT: achieving implementation of advance angle control and compensation of inclined installation of hydraulic drives.

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Description

The invention relates to the field of helicopter engineering, in particular to the equipment of helicopters with controls for the general and cyclic pitch of the rotor of a helicopter, and in particular to a control system for the general and cyclic pitch of helicopters with a hydromechanical control system (GMSU) and a three-point arrangement of hydraulic drives.

To create the forces and moments necessary for a given movement of the helicopter, a control system is used.

To date, only an electronic control system has been installed on ANSAT helicopters.

Known electronic control system "HELICOPTER CONTROL SYSTEM" (RF patent №2282562 from 01.12.2004).

The system contains in each control channel a control element kinematically connected to a sensor of its position, electrically connected to an electronic computer, to which an on-board information control system is connected, which is connected via analog output to electric steering gear drives. The outputs of the flight parameters sensors are connected to an electronic computer. The position sensor of the control element in each control channel and the electronic computer on the digital and analog parts are made at least twice redundant with the function of generating and processing signals simultaneously in all redundant channels.

The disadvantage of the electronic control system installed on the ANSAT-U and ANSAT-K helicopters is the lack of reliability.

At this stage in the development of technology, mechanical control systems are still superior in reliability to electronic systems.

Most existing helicopters use a mechanical control system. Such systems have high reliability, a significant number of parts, complex adjustment.

The system of hydromechanical control of the rotor of a helicopter with a three-point layout of hydraulic drives

The helicopter control system consists of four main channels. They are divided into general step control (lifting force control along the vertical axis), rotor rotational step (longitudinal and lateral control) and directional control (rotation about the vertical axis).

In the ANSAT helicopter control system, a three-point layout of hydraulic actuators was selected, which has proven itself in the ANSAT-U and ANSAT-K helicopters.

The pilot controls the general step with the help of a lever located to his left. The control of the rotor pitch of the rotor is performed using the control knob installed in the cab. Directly, the rotor blades change their installation angles using the kinematic mechanism of the swashplate.

The cyclic and vertical control is connected with a swashplate.

Swashplate is a device that allows you to change the installation angles of the rotor blades and, accordingly, the magnitude and direction of the resultant aerodynamic forces of the rotor. Using the swashplate, a general and cyclic change in the angles of installation of the blades is made on each revolution of the rotor. A cyclical change in the angles of installation of the blades allows you to control the helicopter in the longitudinal and transverse directions using the corresponding tilt of the swashplate.

Ring-type swash plates are the most common. The swash plate is located under the rotor hub and consists of two rings: non-rotating and rotating, interconnected by a bearing. A non-rotating ring with a cardan or ball joint is attached to the sleeve located on the shaft of the main gearbox. The rings can be tilted simultaneously in any axis lying in a plane perpendicular to the axis of the rotor shaft. The shoulders of the rotating ring are articulated with traction that goes directly to the blades. Levers of rotation of the blade are connected through leashes to the bodies of the axial joints.

Known automatic swash rotor of the rotor of the helicopter mounted guide glass on the stationary housing of the gearbox symmetrically to the drive shaft of the rotor. (US patent No. 6,325,326 publ. 12/04/2001. A device for controlling the total and cyclic pitch of the rotor of the helicopter.)

A slider with a spherical outer surface is installed on the guide cup, which can be moved axially with respect to the housing. The slider with the lower control ring is prevented from rotating on the fixed cup by a slot-joint.

There are also two ring elements interconnected by ball bearings, the first of which is mounted on a slider using antifriction liners and occupies a fixed azimuthal position, and the second rotates around the first one together with the drive shaft of the main rotor by means of a two-piece splined hinge attached to it swinging levers having the ability to deviate in all directions relative to the slide and connected to the rods of rotation of the blades.

The fastening and driving means of the rotor common and cyclic pitch control system interact with the first annular element to move the levers and the slider along the axis of symmetry relative to the body and for tilting the levers relative to the slider (US Patent No. 6,325,326. A device for controlling the general and cyclic pitch of the rotor of a helicopter, published on December 4, 2001).

Known automatic swash rotor of the rotor of the helicopter, made a prototype (RU 2261822, publ. 10.10.2005).

The helicopter rotor swash plate comprises a guiding cup rigidly mounted on a fixed housing symmetrically to the rotor rotor drive shaft, a slider with a spherical outer surface mounted on the guiding cup by means of an antifriction liner with the possibility of linear movement along the rotor axis of the rotor shaft, a control ring with an antifriction liner movably mounted on the spherical surface of the slider and provided with a device for preventing angular movement I am around the guide cup in the form of a two-link slot-joint. The control ring is prefabricated, the lower part of which is made in the form of a cantilever system with ears on the ends of the consoles for kinematic connection of the ring with the control system for the common and cyclic pitch of the rotor and is equipped with upper and lower flanges, respectively, of larger and smaller diameters, with which it is rigidly connected to the upper part of the control ring, forming between themselves a rigid annular box structure. An outer ring is mounted on the control ring with ball bearings, which is driven by a two-link splined joint connected to the rotor hub. The outer ring is made prefabricated, the outer part being made in the form of a frame with the shape of an equilateral polygon, the angles of which are pivotally connected to the rotation rods of the blade, and inside the frame is rigidly fixed sleeve for installation of ball bearings in it. The inner elements of the outer ring frame are made with a ∩-shaped cross section, and the sides with a U-shaped cross section. In cylindrical joints and spherical bearings, antifriction liners made of a material with self-lubricating properties are installed. The consoles are located at an angle of 90 ° to each other and are pivotally connected to boosters (hydraulic boosters) of the control system for the common and cyclic pitch of the rotor of the helicopter.

The control of the swashplate is carried out by three hydraulic boosters (boosters), pivotally connected directly to the lower control ring of the swashplate (directly with a non-rotating plate).

The swashplate is installed on the main gearbox. A spherical support is attached to the slider, which serves to ensure the inclination of the swash plate. The change in the thrust of the rotor simultaneously along all azimuths is carried out by moving the slider along the guide (change in the total step).

The lower control ring is mounted on the slider of the swashplate through a spherical support, which allows it to tilt in the longitudinal and transverse directions, as well as move vertically with the slider. The change in the thrust of the rotor simultaneously along all azimuths is carried out by moving the slider vertically along the axis of the rotor shaft (change in the total pitch).

When controlling the “roll” and “pitch” channels, the lower control ring of the swashplate is tilted using the same hydraulic drives, while the slider can remain motionless. Each of these hydraulic actuators is the final link of the longitudinal or lateral control wiring.

Backlash in control adversely affect the handling of the helicopter. The appearance of excessive total backlash can lead to spontaneous movement of the spools and the inclusion of hydraulic booster. The control system should have practically no backlash

The objective of the invention is the creation of a summing mechanism introduced into the rotor control system in the design of the helicopter control system, made according to a three-point scheme with an inclined arrangement of hydraulic amplifiers, which allows for complete mutual independence of the rotor control channels.

The development of the summing mechanism and its introduction into the control system of the rotor of the helicopter is carried out for the case when the control system is designed according to a three-point scheme (when three hydraulic drives are in operation) and the angle of installation of the hydraulic actuator rods with respect to the levers of the swash plate differs from 90 ° (i.e. hydraulic drives are installed obliquely).

The inventive summing mechanism for the control system for the common and cyclic pitch of helicopters can be used both independently and in conjunction with the KSU (integrated, electronic, control system used on ANSAT-U helicopters) as a backup channel.

EFFECT: summing mechanism realizes an angle of advance of control and compensates for the inclined installation of hydraulic drives available on ANSAT helicopters.

The problem is solved by the fact that in the kinematic control scheme of the rotor of the helicopters, made according to the three-point scheme (when three hydraulic boosters are in operation), an element (summing mechanism) is introduced that implements the lead angle and simulates the angle of the hydraulic actuators.

The technical result is achieved by the fact that the summing mechanism for the control system for the common and cyclic pitch of helicopters of a three-point control circuit with an inclined arrangement of hydraulic actuators includes a system of input rockers connected to the cyclic pitch handles along the “roll” and “pitch” channels, the slider associated with the common control handle step, with a movable bracket fixed on it, with the ability to rotate in a plane perpendicular to the plane of the input rockers, and move along the guide of the fixed frame, and with connected through a traction system with a system of output rockers, to control the hydraulic drives of the swashplate.

The summing mechanism for helicopters (ANSAT) with a hydromechanical control system (GMSU) is part of the mechanical control wiring that performs the addition and transformation of the control movements created by the pilot to the final movements of the hydraulic drives that control the swash plate.

The hydromechanical control summing mechanism is designed to convert the movements of the roll, pitch and total pitch channels into the movements of each of the three hydraulic drives controlling the swashplate located on the cover of the helicopter’s main gearbox, i.e. converting the movements created by the pilot on the control sticks to the movements of hydraulic drives.

As a result of introducing it into the hydromechanical control system of the rotor of the helicopter, the angle of control is obtained (displacement of the direction of control action of the pilot relative to the rotational axis of the rotor of the rotor by a predetermined angle), and they also compensate for the error in the travel of the hydraulic actuator rods due to their inclined location

Description of the summing mechanism

The summing mechanism is shown in the drawings.

FIG. 1 is a left view.

FIG. 2 - bottom view.

FIG. 3 is a longitudinal section along the axis of the slider.

FIG. 4 is a front view.

The summing mechanism consists of:

- fixed frame 14 (the base of the summing mechanism) (Fig. 3),

- guide 4 (Fig. 1, Fig. 3),

- a slider 3 located in the center of the frame and having the ability to move in the axial direction (Fig. 3),

- bracket 2, fixedly mounted on the slider 3 (Fig. 3),

- a movable bracket 1, mounted on the end of the slide, with the ability to rotate around the axes A, B (Fig. 1, Fig. 4),

- sphere 5 (Fig. 3), on which the movable bracket 1 is installed,

- output rocking pos. 10, 11 and 16, mounted on the frame 14 and connected by rods 12, 13 and 15 with the bracket 1 (Fig. 2, Fig. 3),

- input rocking. 6 and 7, pivotally mounted on the bracket 2 and connected by rods 8 and 9 with the bracket 1 (Fig. 2).

The summing mechanism is a geometric similarity to inclined hydraulic drives RP-14 and the lower control ring of the swash plate controlled by them. So we can note the similarity of the following nodes:

The movements of the output rockers 10, 11, 16 reproduce the displacements of the hydraulic actuator rods, scale the displacements to their actual values (all displacements to the summing mechanism are made in a 1: 2 scale from the displacements of the hydraulic actuators) and set the direction of the subsequent control wiring in the helicopter layout (the routes of all channels are set in one line).

The displacement of the axes A and B by an angle α ° relative to the axes B and D sets the angle of advance of control by moving the input rockers 6 and 7 in the plane AB (see Fig. 4).

The implementation of the invention

The operation of the summing mechanism in the control system for the common and cyclic pitch of helicopters of a three-point control circuit with an inclined arrangement of hydraulic drives.

The summing mechanism is located under the right hand block of the common pitch handle and occupies the entire entire height of the bottom panel of the helicopter.

The pilot, controlling the summing mechanism, directly controls the movable bracket 1, i.e. reproduces what he needs to get on the lower control ring of the swashplate, and the real swashplate installed on the main gearbox repeats these movements.

Addition and transformation of displacements in the summing mechanism occurs on the bracket 1. The control of the movable bracket 1 is carried out through a system of rods and rockers from the handles of the common and cyclic steps.

When controlling from the cyclic step knob: the input control rockers 6 and 7 are set in motion by the pilot from the cyclic step knob (the input rocker 6 works on the pitch channel, the input rocker 7 on the roll channel) and transmit movement through rods 8 and 9 on bracket 1.

The bracket 1 transfers the received movements to the output rocking pos. 10, 11 and 16 through rods 12, 13 and 15.

At the output arm of the rockers 10, 11 and 16, displacements equal to the necessary displacements at the input link of the hydraulic drive are obtained.

When controlling from the handle a cyclic step along the pitch channel, rotation of the bracket 1 occurs around axis A.

When controlling from the handle, a cyclic step along the “roll” channel rotates the bracket 1 around axis B.

When operating from the handle of the common step: the slider 3 is set in motion from the handle of the common step and moves along its axis. Together with the slider, the brackets 1 and 2 fixed on it move

The movement of the bracket 1 drives the output rockers 10, 11 and 16 through the rods 12, 13 and 15.

In the absence of rotational movement at the input rockers 6 and 7, the movement of the bracket 1 from the handle of the common pitch will be plane-parallel, and the movements of the output links of the rockers 10, 11 and 16 will be equal.

Addition and transformation of displacements in the summing mechanism occurs on the movable bracket 1.

Through the roll channel, control through the rod 9 and the input rocker 7 is brought to the point K, along the pitch channel the control through the rod 8 and the input rocker 6 is brought to the point по and through the channel of the common step through the slider to the point W. (Fig. 4).

(point K is the connection point of the bracket 1 with the rod 9,

point T - the place of connection of the bracket 1 with rod 8,

point W - the connection point of the bracket 1 with a sphere 5 moving along the guide 4)

The input rockers 6 and 7 are installed through the bracket 1 directly on the slider 3. This is necessary to separate the movement of the common step and the movements in the channels of the cyclic step. When moving the handle of the general step, the slider 3 moves, but the input rockers 6 and 7, moving in parallel with the slider, do not rotate and there are no movements along the roll and pitch. When moving in the “roll” and “pitch” channels, the input rockers 6 and 7 will rotate when the slider is stationary.

As seen in FIG. 4, the bracket 1 is made in such a way that the displacements of the point T at fixed points K and W (the displacements occur in a plane perpendicular to the plane of the bracket) will cause it to rotate around axis B, which will correspond to the deviation of the swash plate in pitch (longitudinal channel).

The offset of the axis B by the angle α ° relative to the axis G sets the lead angle of control.

The roll control (transverse channel) is similar. Movement of the point K leads to rotation of the bracket on axis A, which corresponds to the deviation of the swash plate roll. The perpendicularity of the axes A and B eliminates the influence of control channels on the bracket 1.

The movements of the hydraulic actuators are modeled by turning the output rockers 10, 11, 16, connected to the bracket through rods 12, 13, 15.

During the operation of the summing mechanism, the mutual subtraction of errors created by the inclined arrangement of hydraulic actuators and the same arrangement of rods 12, 13, 15 occurs.

When the handle of the common pitch moves, the shaft moves the slider 3 through the rod (not shown in the drawing). Slider 3 sets the plane-parallel movement of the bracket 1, which leads to plane-parallel movement of the lower ring of the swash plate and, consequently, an equal change in the angle of installation of the blades. (Unlike other ANSAT helicopters on an ANSAT machine with a GMSU, this shaft is also used to control the summing mechanism).

The claimed invention meets the criterion of "novelty", because from available sources of information, technical solutions with the same essential features were not identified.

The claimed invention meets the criterion of "inventive step" as it is not obvious to a specialist.

The claimed invention meets the criterion of "industrial applicability", as it can be obtained from known means and known methods.

Claims (1)

The summing mechanism for the control system for the common and cyclic pitch of helicopters of a three-point control circuit with an inclined arrangement of hydraulic actuators, including a system of input rockers connected to the cyclic pitch handles along the roll and pitch channels, a slider connected to the common pitch control handle, fixed to it with a movable bracket, which has the ability to rotate in a plane perpendicular to the plane of the input rockers, and move along the guide of the fixed frame, connected through the linkage system to the system rocking chairs for controlling the hydraulic drives of the swashplate.

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