RU2154594C2 - Shock-absorber - hydraulically operated hoist - Google Patents

Abstract

FIELD: aeronautical engineering. SUBSTANCE: shock-absorber - hydraulically operated hoist includes liquid-spring gas shock-absorber with low- and high-pressure chambers. Hydraulically operated hoist is located between low- and high-pressure chambers; cylinder of this hoist is rigidly connected with cylinder of low-pressure chamber and rod is connected with piston provided with locking device for keeping the rod from motion when in inoperative position; it is rigidly connected with high-pressure chamber and may reciprocate over cylinder of hydraulically operated hoist; cavity of hydraulically operated hoist is separated from cavities of low- and high-pressure chambers by bottom of low-pressure chamber and crown of rod of high-pressure chamber. Shock-absorber - hydraulically operated hoist is additionally provided with device for excluding turn of rod of hydraulically operated hoist relative to its cylinder. EFFECT: enhanced efficiency of hoisting and dampening of main undercarriage leg of helicopter. 2 cl, 3 dwg

Description

 Hydraulic shock absorber refers to aircraft, in particular, to landing devices of aircraft, for example, helicopters. The purpose of the shock absorber-hydraulic lift is to reduce the loads and absorb the work of impact energy during landing, take-off and run of the helicopter on the ground, as well as changing the clearance and position of the building horizontal of the fuselage relative to the ground in the parking lot at the request of the crew.

 Often when rolling wheeled vehicles or cargo with large dimensions, lifting the tail boom of the helicopter is required. This is achieved through the use of hydraulic lifts.

 Known shock absorbers, hydraulic lifts, for example, according to the application of France N 2686902 from 01/07/92, B 64 C 25/58, ME EP-B CATT. The shock absorber includes a housing and a sliding rod with a movable bottom, forming an inner chamber with a working fluid, which communicates through a diaphragm with an upper hydraulic chamber located in the upper part of the housing next to the chamber containing gas under pressure. An independent linear leash is installed in the sliding rod, located between the movable bottom and the lower stop rigidly connected with the sliding rod. To control the leash, autonomous elements are provided, the fixation of which allows the landing gear to be lifted when the aircraft is stationary.

 Known shock absorber-hydraulic lift of the main chassis by MI-14 helicopters (Operation and Maintenance Manual, Book II, design, part I ed. N 11 / 95893r-P81). It is a single-chamber liquid-gas shock absorber with a hydraulic cavity with a floating bottom built into the rod. If it is necessary to increase the clearance of the helicopter in the parking lot, a pressure is applied to the hydraulic cavity, which moves the floating bottom up, and since a constant parking load is applied to the shock absorber rod, the rod extends to the stroke corresponding to the movement of the floating bottom, and increases the helicopter clearance.

 The shock absorber-hydraulic lift of the MI-14 helicopter is intended for use on a particular helicopter and its use on another type of helicopter (for example, MI-8) will entail significant structural changes both in the shock absorber-hydraulic lift and in the fuselage of the helicopter.

 Known two-chamber shock absorber according to the technical description of the MI-8 helicopter (Book II, design, publishing house "Engineering" - Moscow 1970, p. 43) is a prototype of the invention. This shock absorber is designed to mitigate shock during landing to damp lateral vibrations of the “earth resonance” type. The presence of low and high pressure chambers ensures the elimination of lateral vibrations that may occur during the run or take-off of the helicopter, when the rotor removes a significant part of the load from the chassis. These two chambers are structurally connected by a hollow pipe, which in the lower part is the rod of the high pressure shock absorber, and the upper part is the cylinder of the low pressure shock absorber.

 To perform the functions of raising and lowering the helicopter in the parking lot, it is necessary to additionally apply hydraulic hoists from the ground support facilities to the helicopter (MI-8 helicopter, technical description, book VI, M. Mechanical Engineering, 1980, pages 4-5). This will lead to a decrease in the net mass of the aircraft, and the placement of hydraulic lifts in the cargo compartment takes a certain useful volume. These limitations are disadvantages of such shock absorbers.

 The invention solves the problem of creating a shock absorber-hydraulic lift in a fixed gear rack of the main chassis.

 The task is achieved in the shock absorber-hydraulic lift, consisting of a liquid-gas shock absorber with low and high pressure chambers and a hydraulic lift. The hydraulic lift is located between the low and high pressure chambers, the hydraulic lift cylinder is rigidly connected to the cylinder of the low pressure chamber, and the piston rod having a locking device to keep the rod from moving in the off position is rigidly connected to the high pressure chamber rod. The rod is made with the possibility of reciprocating movement along the cylinder of the hydraulic lift. The cavity of the hydraulic cylinder is separated from the cavities of the low and high pressure chambers, respectively, by the bottom of the cylinder of the low pressure chamber and the bottom of the rod of the high pressure chamber. The hydraulic shock absorber comprises a device for preventing the hydraulic lift rod from turning relative to the cylinder. The device consists of a guide rigidly mounted on the cylinder of the hydraulic lift, and a rocker, pivotally fixed at one end to the hydraulic lift rod, and the other, using a slider connected to the guide, with the possibility of reciprocating movement along it according to the stroke of the hydraulic lift piston.

 The invention is illustrated in FIG. 1, 2, 3. Here, in FIG. 1 shows a General view of the shock absorber-hydraulic lift in section. In FIG. 2 shows a place A - a hydraulic elevator in a section in an enlarged view. In FIG. 3 shows a view B - a device for preventing the rotation of the hydraulic lift rod in an enlarged view.

The shock absorber-hydraulic lift (Fig. 1, 2, 3) contains:
1 - The cylinder of the high-pressure chamber;
2 - The sealing axle box of the high-pressure chamber;
3 - Charging nipple of the high-pressure chamber;
4 - Rod hydraulic lift; 4a - Stock of the high-pressure chamber;
5 - The bottom of the rod of the high-pressure chamber;
6 - Charging nipple of a hydraulic lift;
7 - The sealing axle box of a hydraulic lift;
8 - cylinder hydraulic lift; 8a - cylinder of the low pressure chamber;
9 - Piston with hydraulic lift seal;
10 - Spring;
11 - Spring;
12 - Piston sleeve;
13 - locking sleeve;
14 - Castle ring;
15 - Thrust liner;
16 - Sleeve;
17 - bottom;
18 - Guide;
19 - Rocking chair;
20 - Slider;
21 - Pusher;
22 - Installation of the limit switch;
23 - Lever;
24 - drain fitting hydraulic lift;
25 - Stem with a piston;
26 - Sealing axle box;
27 - Charging nipple of the low-pressure chamber.

 The shock absorber-hydraulic lift includes a high-pressure chamber having a cylinder 1, a stem 4a, a sealing box 2, a charging nipple 3. The high-pressure chamber is separated from the hydraulic lift chamber by the bottom 5. The hydraulic lift includes a cylinder 8, a rod 4, which is rigidly connected to the chamber rod high pressure, with a piston 9 and a sealing box 7. An annular locking device is placed on the piston, consisting of a locking sleeve 13, a locking ring 14, a thrust bearing 15, a sleeve 16, a piston sleeve 12 and springs 10, 11.

 On the base of the rod 4, a rocker 19 is pivotally fixed with a slider 20 at the end. The guide 18 with the slider 20, rigidly mounted on the cylinder 8, prevents the rod from turning relative to the longitudinal axis of the cylinder 8. The slider 20 slides along the guide 18 when moving. A pusher 21 is installed in the upper part of the rocker 19, which actuates the lever 23 for installing the microswitch 22.

 In the cylinder 8a of the low-pressure chamber, rigidly connected to the cylinder of the hydraulic lift, there is a rod with a piston 25 and a sealing box 26. A charging connector 27 is installed on the rod.

Device operation
When jacking the helicopter, the fluid pressure in the cavity 1 presses the locking sleeve 13, releasing the locking ring 14. The locking ring under the pressure of the sleeve 16 slides off the thrust bearing 15, releasing the rod, and enters the piston sleeve 12, which, under the action of the spring 11, abuts the sleeve 16, preventing the lock ring from falling out. At the end of the stroke, the piston 9 of the rod 4 abuts against the axle box 7, which means the end of the rise of the helicopter.

 When you return the cylinder of the hydraulic lift 8 to its original position, the liquid cavity of the cylinder is connected to the drain and the rod 4 is moved inward by the weight of the helicopter. When the rod approaches the extreme retracted position, the piston sleeve 12 abuts against the thrust bearing 15, and compressing the spring 10, releases the locking ring 14, which with further movement of the rod is pressed onto the seating surface of the thrust bearing 15. The locking sleeve 13 under the influence of the spring 10 and nitrogen pressure in the gas cavity (chamber) II is pushed all the way into the sleeve 16, locking the locking ring. The hydraulic lift has returned to its original position.

 Thus, the proposed shock absorber-hydraulic lift is a single unit, made in the dimensions of a serial shock absorber, which is able to perform the functions of a shock absorber, absorbing the impact energy during take-off, run and landing of a helicopter - vibration damper of the “earth resonance” type and to change the position of the helicopter fuselage relative to the ground at the request of the crew - to raise or lower the helicopter.

Claims (2)

 1. A shock absorber-hydraulic lift, consisting of a liquid-gas shock absorber with low and high pressure chambers, characterized in that a hydraulic lift is located between the low and high pressure chambers, the hydraulic lift cylinder is rigidly connected to the low pressure chamber cylinder, and the rod connected to the piston having locking device for holding the rod from displacement in the idle position, is rigidly connected to the rod of the high-pressure chamber and is made with the possibility of reciprocating movement along the cylinder receiver, while the cavity of the hydraulic lift is separated from the cavities of the low and high pressure chambers, respectively, the bottom of the cylinder of the low pressure chamber and the bottom of the rod of the high pressure chamber.  2. The shock absorber-hydraulic lift according to claim 1, characterized in that it further comprises a device for preventing rotation of the hydraulic lift rod relative to the cylinder of the latter, consisting of a guide rigidly mounted on the hydraulic lift cylinder and a rocker articulated at one end to the hydraulic lift rod and the other connected by means of a slider with a guide with the possibility of reciprocating movement along it according to the stroke of the hydraulic lift piston.

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