RU2256823C2 - Hydromechanical drive for flying vehicle control systems - Google Patents

Abstract

FIELD: flying vehicle control systems.

SUBSTANCE: proposed drive has housing with power member and passages connected with hydraulic pressure and return lines, hydraulic motor with differential piston forming rod and rodless cavities, distributor kinematically linked with control crank and three spring-loaded check valves; one check valve is used for admitting working fluid from pressure hydraulic line to distributor and rod cavity of hydraulic motor and excluding its return. Two other spring-loaded check valves are used for admitting working fluid from return line to rod cavity and rodless cavity and excluding its return.

EFFECT: possibility of manual control.

1 dwg

Description

The present invention relates to a device that can be used in control systems of aircraft.

Known hydromechanical actuators containing a housing with discharge and discharge channels, a hydraulic distributor, an input link with rocking wheels, a hydraulic motor with a differential piston forming a rod and rodless cavity, a power eye (see the book by E. Lewis, H. Stern, “Hydraulic control systems”, Mir, Moscow, 1966, p. 358, Fig. 9.39, p. 359, Fig. 9.41, p. 360, Fig. 9.33, p. 362, Fig. 9.46, see book V.I. .Goniodsky et al. “Aircraft steering surfaces drive” Moscow “Mashinostroenie” 1974 p. 202, Fig. 4.40, see T. P. Basht’s book “Calculations and cons ruktsiya aircraft hydraulic devices "State scientific and technical publishing house" Defense Industry ", Moscow, 1961 p. 315, fig.218, p. 316, fig.214's Certificate USSR SU 1349999 A1).

The closest in technical essence is a hydromechanical drive containing a housing with discharge and drain channels, a hydraulic distributor, an input link with rocking wheels, a hydraulic motor with a differential piston forming a rodless and rod cavity in communication with the discharge hydraulic line, a power eye (see book T.P. .Bashta “Calculations and design of aircraft hydraulic devices” State scientific and technical publishing house “Oborongiz”, Moscow, 1961, p. 317, Fig. 211 a).

The main advantages of drives of such a scheme are to reduce the harmful effects of undissolved air in the liquid and backlash in control, reduced cylinder dimensions and the friction force of the expansion joints by eliminating the use of a through rod.

A disadvantage of the known drives is the complete loss of their performance in the event of a failure of the hydraulic pump of the aircraft and, as a result, the impossibility of providing a muscular control mode.

This drawback significantly reduces the reliability of the drives and can lead to a catastrophic situation during flight. The specified disadvantage is due to the following:

- in the event of a pump failure, the pilot needs to switch to a muscular mode of operation, in which, by applying forces to the input rocker, it is necessary to move the power link of the drive associated with the controls of the aircraft;

- during the indicated movement, the working fluid must be forced out of the rod cavity of the hydraulic motor into the discharge line with which it is connected, but in the latter, due to a pump failure, a hydraulic lock is formed;

- due to the formation of a hydraulic lock, the displacement of fluid from the rod cavity is not possible, which leads to the inability to move the power link, and therefore the control in this mode.

Reasons for this:

- the absence in the known drives of a number of structural devices and elements of their execution and location relative to each other, which does not allow to eliminate these disadvantages, significantly reducing the reliability of the control system.

The technical task of the invention is to eliminate this drawback, namely increasing the reliability of the drive by ensuring the movement of its power link in the muscular mode.

The problem is solved in that in the proposed actuator two spring-loaded check valves are installed in such a way that they ensure the passage of the working fluid from the drain line, respectively, into the rod and rodless cavities of the hydraulic motor and prevent the passage of the working fluid in the opposite direction.

The essence of the invention is illustrated in the drawing, which presents its General scheme.

The hydromechanical drive comprises a housing 1 with a power link 2, a hydraulic motor with a differential piston 3, forming a rod 4 and rodless cavity 5, a spool valve 6, kinematically connected to the input control rocker 7, a travel limiter 8 of the spool valve.

Three spring-loaded check valves are installed in the actuator, one of which is 9, which ensures the passage of the working fluid from the discharge line to the spool valve and the stem cavity and prevents its passage in the opposite direction, the other two 10, 11 allow the passage of the working fluid from the discharge line, respectively, into the rod and rodless cavities of the hydraulic motor and prevent its passage in the opposite direction. A filter 12 is also installed in the drive.

In the standard hydromechanical mode, if there is a discharge pressure in the hydraulic line, the operation of the drive is similar to the work of known drives.

In case of failure of the hydraulic pump, a transition to the muscular control mode is carried out. The pilot, applying force to the input rocker 7, for example to the right according to the drawing, against the stop in the travel stop 8, moves the housing with the power link relative to the differential piston also to the right (the spool valve in this case is shifted to the left). In this case, the working fluid from the rod cavity through the channel 13, through the slot 14, formed as a result of the displacement of the spool of the spool distributor, channel 15, enters the rodless cavity 5 of the hydraulic motor. The check valve 9 divides the cavity of the hydraulic motor from the discharge line. At the same time, the volume of fluid, due to the piston differential, additionally enters the rodless cavity through channel 16 through the check valve 10 (pressing it to the right in the figure) from the drain line of the hydraulic system (suction effect).

In the case of applying the pilot's effort to the left according to the drawing (the spool moves to the right), the working fluid from the rodless cavity will be forced out through channel 15 and a slot in the spool into the drain line of the hydraulic system and simultaneously through channel 16, through the check valve 11 (squeezing it) into the rod cavity of the hydraulic motor . Thus, it is possible to move the power link of the drive.

This ultimately leads to improved muscular handling of the aircraft.

Numerous tests, including flight tests, of hydromechanical drives, performed in accordance with the attached scheme, fully confirmed their advantage compared to the known drives in improving the reliability of the aircraft control system.

Claims (1)

A hydromechanical drive comprising a housing with a power link and channels connected to discharge and discharge hydraulic lines, a hydraulic motor with a differential piston forming a rod and rodless cavity, a spool valve kinematically connected to the control input rocker, three spring-loaded check valves, one of which provides passage working fluid from the discharge line to the spool valve and the stem cavity of the hydraulic motor and prevents its passage in the opposite direction, from characterized in that the other two spring-loaded check valves are installed in such a way that they allow the passage of the working fluid from the drain line to the rod and rodless cavities of the hydraulic motor, respectively, and prevent the passage of the working fluid in the opposite direction.