Main landing gear of aircraft chassis

FIELD: mechanics.

SUBSTANCE: invention relates to aviation, namely to aircraft chassis gear. Walking-type chassis contains lifter and consists of shock-absorber hinge-connected to the aircraft framework. The shock-absorber is hinge-connected with brace coupled with carrier that actuates upper brace bearing hooking on a wing when the main landing gear is released. The carrier is provided with a tail, which is hinge-connected with a traction having hinged connection with framework. The brace is controlled by the lifter through the lever, which is hinge connected to the framework. Lifter and carrier are also in hinged connection with the lever. The lifter contains inner mechanical lock and is in hinge connection with the lever. One arm of the lever is hinge-fixed on lever framework, while the other arm is hinge connected with locking cylinder of emergency release of gear. The lock is represented with two jaws having grooves and latch, which are perpendicular to the released brace axis. Bushings of square external circuit are mounted on operating pins of the upper brace unit. Flat surfaces of bushings interact with hook grooves when main landing gear is released.

EFFECT: improved reliability and simplified design of main landing gear of aircraft chassis.

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The proposal relates to aircraft and can be used for the design supports a swinging type for aircraft of different types.

There are various schemes of the main landing gear swing type and hydraulic systems of the aircraft (see, for example, System equipment aircraft operational (edited A.m.matveenko and Viekimova). - M., engineering, 2005, or the book Kondrashev N.A. Design retractable gear aircraft. M., engineering, 1991). In the book Nagendra on RISD, d, d, d, d lists all known scheme of the main supports, and the circuit shown in RISD and d actually correspond to the structures used on the TU-134 and TU 154.

Swinging supports the axis of the strut and shock absorber overlap around the axis of the hinge mounting of the support element (wheels, trucks, skis and the like), so that the force acting on the support, is decomposed into components directed along the axis of the strut and shock absorber. As a result, the shock absorber is practically not subject to bending in the longitudinal plane.

Strut in these bearings is both a lift, and its diameter is determined by the loads acting on it when the ground motion, which exceed the load required for cleaning bearings. Therefore, it is complicated by the additional is sustained fashion pistons, reducing its effective area of the hydraulic cavity filled with liquid when cleaning support. This increases the weight and decreases the reliability. In addition, when the depressurization of the release bearing is impossible, that is unacceptable and contrary to existing regulations.

It should also be noted that in the retracted position are considered pillars of the strut is located under the lower surface of the wing, and therefore, the supporting elements are also below the surface of the wing. To reduce the negative impact of the protruding support elements on the wing aerodynamics them close fairing, which, however, still affects the quality of the wing and at the same time increases its weight.

All known schemes assume the existence of a separate lock that holds the support in the retracted position.

In addition, a support, a schematic of which is shown in RISD and d contain only one lift, and the rod moves when the compression of the shock absorber, which creates great difficulties in the work connected with it the hydraulic system, because when boarding the strike is injected very high fluid flow, creating considerable surges.

You want to ensure the connection of the brace to lock in a released position and retaining strut support in the retracted position, the fixation of the support in the retracted position on the kinematic castle, ware the emergency release bearing, improving the reliability and the relief of the castle of the top node of the strut.

To address this problem, the leash of the strut provided with a shank pivotally connected to the thrust, also hinged to the frame, which is controlled by the lift through a hinge mounted on the frame, a lever, with which the hinge is connected and the lift and leash, and the lift has an internal mechanical lock and hinged to the lever, one arm of which is pivotally attached to the frame arm, and the other shoulder of which is pivotally connected with the lock cylinder emergency release bearing, and the castle is made of two cheeks and perpendicular to the axis of the released lock grooves and latch and pivots the upper node of the strut mounted sleeve square outer contour with flat faces, interacting with the slots of a hook in the extended position the support.

Features of the proposed design is illustrated by illustrations.

Figure 1 shows a General diagram of the device. Figure 2 gives the schematic circuit released position. Figure 3 shows the design of the combination of basic elements. Figure 4 shows a control circuit of the castle.

The proposed design consists of a shock absorber 1 with the supporting element 2 (wheel), hinged to the frame can be rotated in the longitudinal plane and pivotally connected to PADCO the Ohm 3 thus, so that their axes are in a released position intersected near the axis of fastening the support element to minimize bending of the absorber.

When cleaning support latch 5 is released the connected cylinder, after which the lift rotates the lever 8, by rotating the lead 4, which displays the top ear of the strut from the grooves of the castle. Then turn lasts as long as the leash and the knee will not take the position kinematic castle, in which the lift is locked with an internal mechanical lock, locking the support in the retracted position on the kinematic castle.

When the release bearing opens the lock lift and he turns the lever 8 with a collar 4, which brings the upper ear of the strut to the castle on the wing, press the latch 5 and gets a square sleeve on the axle journal and the bearing ear lock into the slots on the cheeks of the castle. After that, the latch secures the top node of the lock in the lock.

Lift hinged to one arm hinged to the frame of the lever 9, the other shoulder of which is pivotally connected with the lock cylinder 10. accidental release bearing, the retaining lever 9 when the lift. In case of failure of the main system or auxiliary lift the release bearing is made by the cylinder 10, managed from the backup hydraulic system.

The top node of the brace ends the ear with a spherical bearing, the axis to which the first hinge is connected to the lead 4, providing at release supports the connection of brace with lock on the lower surface of the wing that is facilitated by the presence of axial play in the design of the leash. Castle top node of the knee consists of two cheeks and perpendicular to the axis of the released lock grooves and latch, so that the load from the brace perceived cheeks, fixed to the frame of the wing. Latch 5, hinged to the cheeks of hooks, only protects the top node of the knee against accidental displacement. The latch is connected with a spring cylinder, holding it in the closed position and utaplivaem when cleaning support. Inside the cylinder containing the valve, the gate of which is shifted to the retraction of the latch and opens the passage of fluid to the lift.

On the axle journal and the top node of the strut mounted sleeve 11 square outer contour of the flat faces of the limiting axial movement of the bearing with the ear of the knee and interacting in a released position of support with the grooves in his cheeks castle. Sleeves are made from a material with a low coefficient of friction, such as bronze or grafiana. Square planar faces of the bushings provide a valid voltage collapse in the perception of stress on the knee in order in the slots of the cheeks was not created dents, deteriorating the reliability of the lock.

The leash is equipped with a shank, swivel soedinenii draft 6, also pivoted on the frame, and is controlled by the lift 7 via a hinge mounted on the frame arm 8, which is pivotally connected at the same time and lift and leash.

The main support chassis of the plane of swinging of the type with lift and consists of a hinge mounted on the frame of the plane of the shock absorber pivotally connected to the strut connected to the leash of the knee, resulting in release supports the upper hinge knee to the castle on the wing, wherein the leash is equipped with a shank pivotally connected to the thrust, also hinged to the frame, and is controlled by the lift through a hinge mounted on the frame, a lever, with which the hinge is connected and the lift and leash, and the lift has an internal mechanical lock and hinged to the lever, one arm of which is pivoted on the frame arm and the other shoulder pivotally connected with the lock cylinder emergency release bearing, and the castle is made of two cheeks and perpendicular to the axis of the released lock grooves and latch, and on the pins of the top node of the strut mounted sleeve square outer contour of the flat faces, interacting with the slots of a hook in the extended position the support.