RU2289033C2 - Thrust reverser of double-flow turbojet engine - Google Patents

Abstract

FIELD: aircraft engineering; double-flow turbojet engines.

SUBSTANCE: invention relates to devices for changing direction of thrust vector, namely, to thrust reversers of double-flow turbojet engines. Proposed device contains fixed housing with deflecting grids arranged around synchronizing ring around which fairing is installed for movement. Fairing is intercoupled with synchronizing ring by means of additional front load-carrying rings and rotary front and rear flaps hinge-connected to form pairs, V-shaped in position of reversing. Front flaps of each pair are hinge-connected by front ends with synchronizing ring. Said synchronizing ring is provided with shaped ports arranged over circumference and pointed to said grids with streamlined leading and trailing edges. In position of reversing, synchronizing ring is arranged after front ends of front flaps and before rear ends of rear flaps.

EFFECT: provision of minimum longitudinal dimensions of thrust reverser at maximum accuracy of synchronization of its units, reduced energy losses of gas flow at reversing.

3 cl, 7 dwg

Description

The claimed technical solution relates to devices for changing the direction of the thrust vector, and in particular to devices for reversing thrust, for example, bypass turbojet engines, especially engines with a high degree of bypass.

Close enough to the claimed technical solution is the design of a reversing device for a gas turbine engine (UK patent 1209098, applicant Rolls-Royce, IPC ² B 64 from 15/06, filing date September 11, 1968, patent publication date October 14, 1970) .

Known reversing device contains a stationary housing and movable elements. In turn, the stationary housing of the reversing device is formed by the input device and the nozzle of the external circuit of the engine. The input device and the nozzle are interconnected using deflecting gratings. Inside the input device is a hydraulic cylinder, the rod of which is connected to the bracket of the sliding hood.

Movable elements include a hydraulic cylinder rod, an arm, a movable hood, front and rear rotary flaps, and inserts.

A movable hood with an arm, which is pivotally connected to the front rotary leaf, has the ability to move under the influence of the hydraulic cylinder rod.

The front and rear pivoting flaps are trapezoidal in shape and are located symmetrically on the same radius. Together with each other, they form pairs of pivoting wings, which are placed around the circumference. The narrow base of the rotary flaps are pivotally connected to each other, and the wide - the front flap is connected to the bracket of the movable hood, and the rear - pivotally connected to the nozzle.

The device operates as follows.

In the “Direct thrust” position, the deflecting grilles are covered externally by a sliding hood, and from the inside (from the outer channel of the engine) by inserts and pairs of pivoting flaps. Diamond-shaped slots formed by adjacent pairs of pivoting flaps cover the inserts. They lie on the pivoting flaps on the side of the deflecting grids and are pressed against the flaps by the action of a wire-ramrod hinge.

The inserts also have a trapezoidal shape, but smaller in size. They are shorter than the swing shutters, so there is a gap between the inserts. A pair of inserts is pivotally connected to the pivoting flaps, and along the front edge it is connected to the front pivoting flap, and on the back - to the rear. The inserts, with their narrow base, face the wide base of the pivoting wings, and the wide ones, on the contrary.

The transition in the "Reverse" position is effected by the action of the hydraulic cylinder rod on the bracket to move the sliding hood along the gas flow to the extreme position (to the stop). The inserts rotate with the rotary wings. The pivoting flaps move into the channel of the outer motor circuit, forming the letter V. In this case, inserts are located between the front and rear flaps. Rotary flaps completely block the channel and direct the gas flow to the deflecting grilles. In deflecting gratings, the flow is turned to the required angle with respect to the longitudinal axis of the engine, and then flows into the environment, creating a reverse traction.

However, this design of a turbojet engine thrust reverser device has some disadvantages:

1. The presence of inserts that rotate in the "Reverse" position causes difficulties with their placement inside the folded rotary wings due to the very limited space between.

2. The rotation of pairs of leaves together with the inserts requires the development of special hinges.

3. The efficiency of the thrust reversing device is insufficient due to the non-use of part of the reversed gas flow past the deflecting gratings through the slots at the junctions of the front rotary shutters with a sliding hood.

From the description of the patent of Russia No. 1563310, class. F 02 K 1/12 according to the application No. 4413834/06 JSC Aviadvigatel dated 04/19/98, a technical solution is known relating to the device for reversing the thrust of the outer loop of an aircraft turbojet dual-circuit engine.

The known thrust reversal device comprises an axially movable housing with a cowl outer shell mounted on longitudinal rods which are guides.

Fixed power housings, front and rear, are connected by a deflecting grate composed of separate sector gratings located between the rails.

There are also rotary flaps, which in the forward thrust position are placed concentrically inside the deflecting grids and flush with the outer surface of the tract.

These flaps, each kinematically interconnected with hinges with a two-link lever mechanism, initially forming a common three-link lever mechanism.

On direct traction, a movable housing (fairing) closes the grilles from the inside and outside. And these flaps together with levers are laid flush with the surface of the flowing part of the path behind the engine fan.

In reverse mode, the cowl moves backward along with the wings. The ends of the valves from the influence of two levers deviate inward, blocking the flow part. In the reversing position, two levers of the linkage mechanism extend in a common longitudinal axis into one link and form at least partially V-shaped pairs with a part of each of the flaps overlapping the path.

By moving backward along the guide rods, the fairing exposes the grilles through which air flows in the calculated direction to decelerate the aircraft.

The described device is complicated and, due to its design features, requires large longitudinal dimensions, which entails additional weight.

If necessary, reduce the longitudinal dimensions, without changing the design, there is a problem of energy losses during landing or interrupted take-off.

Nevertheless, the known thrust reversal device according to the patent of the Russian Federation No. 1563310 is close to the claimed solution in terms of technical essence, the functions and technical results, and therefore the authors have chosen as a prototype.

The authors were faced with the task of creating such a technical solution that would achieve an aggregate technical result containing several logically interconnected and causally connected progressive technical results, namely:

1. Placement of the reversing device in minimum longitudinal dimensions, limited by the design features of the engine while ensuring the most accurate synchronization of the interaction of all nodes of the device in any of its operating positions.

2. Achievement of minimal energy losses of the gas flow of the outer contour of the engine while providing reverse thrust for braking the aircraft during landing or interrupted take-off.

3. Simplification of the design of the device while increasing its reliability.

This problem is solved in that in the known device for reversing the thrust of a turbojet bypass engine, comprising a stationary casing with deflecting gratings arranged around the synchronizing ring, around which a cowl is movably mounted, interconnected with the synchronizing ring and pivoting front and rear wings, articulated in pairs, V- figurative in the reverse position, improvements are made.

Improvements are as follows.

The fairing is interconnected with the synchronization ring by means of an additional front power ring, and the front flaps of each pair are pivotally interconnected by their front ends with the mentioned synchronization ring.

The specified synchronization ring in the reverse position is located behind the front ends of the front wings and in front of the rear ends of the rear wings.

At the same time, the synchronizing ring contains profiled windows with streamlined inlet and outlet edges located around the circumference directed to said gratings.

This allows you to both reduce the long dimensions of the device, and reduce energy losses in reverse modes.

Inside the said fixed body in the circumferential gaps between the pairs of pivoting flaps there are fixed inserts that ensure the rigidity of the structure and its reliability and ensure smooth flow around the direct thrust.

At the junction of the front rotary shutters with a synchronizing ring, a spring compensator is additionally introduced.

This prevents sagging of the rotary flaps on direct thrust and compensates for shock loads, and therefore, increases reliability and also reduces energy losses, but already on direct thrust.

The inventive device for reversing the thrust of a turbojet bypass engine is illustrated by figures, where on:

- figure 1 shows a turbojet bypass engine in forward and reverse thrust;

- figure 2 is an enlarged view of the element I of figure 1 (thrust reverser in the "Reverse" position);

- figure 3 is an enlarged view of the element II of figure 1 (the relative position of the hydraulic cylinder, one of the longitudinal guides, the carriage and the movable power ring with each other and relative to the movable fairing of the thrust reverser in the "Direct thrust" position);

- figure 4 is a cross section aa of figure 1 (mutual arrangement around the circumference of a set of sections of deflecting thrust reversing grids, longitudinal guides and a synchronizing ring between themselves and relative to the pylon of the aircraft);

- figure 5 is a longitudinal section bB of figure 4 (thrust reverser in the "Direct thrust" position);

- Fig.6 is an enlarged view of the element III of Fig.5 (front pivoting sash with a spring compensator pivotally mounted on it);

- Fig.7 is a synchronization diagram of the operation of the thrust reverser in the "Reverse" position.

The device for reversing the thrust 1 of a turbojet bypass engine 2 is trellised, ring type, on-off (in Fig. 1 both positions are shown — “Direct thrust” and “Reverse”). The device is located between the intermediate housing 3 and the mixing chamber 4 of the internal and external gas flows of the engine 2. In this case, the thrust reverser 1 is structurally integrated into the channel of the outer circuit 5 of the engine 2.

The thrust reverser 1 comprises a front power ring 6 (see FIG. 2). Around the axis of the engine 2, forming a cylinder, a set of sections of the deflecting grids 7 of thrust reversal is placed. Each of the sections of the deflecting gratings 7 with its front end is rigidly connected to the specified front power ring 6, and its rear end is also rigidly connected to the rear power stationary ring 8.

In the “Direct thrust” position (see FIG. 5), the sections of the deflecting gratings 7 are surrounded by a movable fairing 9, forming part of the overall aerodynamically streamlined surface of the engine 2

The front power ring 6 is rigidly connected to the rear power ring 8 (see FIGS. 4 and 5) by longitudinal guides 10 (see FIG. 3). Together with the sections of the deflecting grids 7, this design forms a fixed housing of the device 1 reverse thrust.

Inside this stationary case, there are inserts 11 around the circumference (see FIG. 4), and in the circumferential spaces between them are two rows of pivoting flaps — the front 12 and rear 13. The pivoting flaps 12 and 13 are hinged 14 (see FIG. 5) between themselves and form pairs.

At the same time, the front edges of the sash 12 are attached using the hinge 15 (see Fig.6) to the synchronization ring 16, and the rotary sash 13 (see Fig.5) with its rear edge is attached using the hinge 17 to the rear power ring 8 of the device 1 reverse thrust. Around the circumference of the synchronizing ring 16 (see figure 2) are profiled windows having streamlined input and output edges.

The pairs of rotary flaps 12 and 13 together with the synchronizing ring 16 form a lever mechanism (see Fig. 3, 5 and 6), which, moving along the guides 10 (see Fig. 3), using hydraulic cylinders 19, occupies two fixed positions - "Direct thrust" (see figure 5) and "Reverse" (see figure 2).

The synchronizing ring 16 is connected by means of brackets 20 and carriages 21 with a movable power ring 22 (see Fig.6). Moreover, the power ring 22 is made in conjunction with the shell of the movable fairing 9, which is part of the engine nacelle 2.

The carriages 21 (see FIG. 3) are mounted on guides 10 through compliant slide bushings 23. In this case, the slide bushings 23 have a certain degree of freedom to prevent jamming when moving the fairing 9 of the thrust reversing device 1 in the “Reverse” position.

At the junction of the front rotary flaps 12 with the synchronizing ring 16 there is a spring compensator 24 (see Fig. 5 and 6). This design not only eliminates the sag of the pivoting flaps 12 and 13 into the outer loop 5 of the engine 2 in the “Direct thrust” position, but also compensates for the shock load perceived by the front pivoting flap 12 from the gas flow when switching to the “Reverse” position.

To prevent overflow (leakage) of air from the outer circuit 5 of the engine 2 in the “Direct thrust” position through the parts of the thrust reversing device 1 on the power ring 22 (see FIG. 5) of the fairing 9 and on the rear power ring 8 of the thrust reversing device 1 front 25 and rear 26 seals, for example, from profiled rubber.

The sections of the deflecting grids 7 are located around the perimeter of the fixed body (see figure 4). In addition, in places where the docking of engine 2 with the aircraft, i.e. where the pylon 27 of the aircraft is located (see Fig. 6), instead of the deflecting grating section 7, a plug 28 is installed that prevents the gas flow of the external circuit 5 from entering the structure of the pylon 27 of the aircraft.

The section of the deflecting grids 7 and the plug 28 are interchangeable, which allows the interchanging of the plugs 28 and the section of the deflecting grids 7 to ensure the configuration of the thrust reversing device 1 for the left, right, lower and upper power units of the aircraft from the same elements.

The device operates as follows.

The thrust reversal device 1 is part of the channel of the outer circuit 5 of the turbojet bypass engine 2 and does not interfere with the passage of the gas flow (the direction of flow is indicated by arrows).

In the “Direct thrust” position, the air flow enters the air intake, where the energy of movement is partially converted into energy of pressure. Then the air flow enters the fan blades, which compress it. After the fan stage, the flow is divided into internal and external. Moving along the outer contour 5 of the engine 2 (see figure 1), the air enters the channel formed by the outer casing of the gas generator and the reversing device 1.

At the same time, pairs of rotary flaps 12 and 13 (see Figs. 4 and 5) are arranged in such a way that together with the inserts 11 form part of the channel of the outer contour 5 of the engine 2.

The transition to the "Reverse" position is carried out after giving a command to the control hydraulic cylinders 19 (see figure 3). Then, the rod of the hydraulic cylinder 19 starts to move, transmitting the force through the slide bushings 23 to the carriages 21 installed on the guides 10, and through them to the synchronization ring 16 and the power ring 22 of the fairing 9 (see Fig. 7).

Since the synchronization ring 16 (see Fig. 4) is connected by means of brackets 20 and carriages 21 to the movable power ring 22 of the fairing 9, simultaneous synchronous movement of these moving parts of the thrust reversing device 1 in the longitudinal axis of the engine 2 towards the nozzle is provided.

The force from the synchronization ring 16 (see Fig.6, 7) when it is transferred is transmitted through the spring compensator 24 to the front rotary leaf 12, which forces it together with the rear rotary leaf 13 (since they are connected by a hinge 14) to accept V- figurative position in the channel of the outer circuit 5 of the engine 2 (see figure 2).

In this case, the front rotary leaf 12 with the configuration calculated in a known manner only partially overlaps the channel of the outer circuit 5 of the engine 2, while the rear rotary leaf 13 is designed so that it blocks the channel of the outer circuit 5 completely and blocks the movement in the forward direction of the gas flow, directing it on the section of the deflecting grids 7.

However, the synchronizing ring 16, located between the front 12 and rear 13 pivoting wings, due to its design (it has profiled windows 18) does not prevent the passage of part of the gas stream, but directs it to the sections of the deflecting gratings 7 (see Fig. 2).

Located between the pairs of pivoting flaps 12 and 13 of the insert 11 (see Fig. 4) they prevent gas from entering the actuators of the thrust reversing device 1 (guides 10, hydraulic cylinders 19, brackets 20, carriages 21).

When the movable fairing 9 is displaced (see FIG. 1), the gas flow opens through the sections of the deflecting gratings 7. The flow directed at an angle α to the longitudinal axis of the engine 2 creates reverse thrust.

The synchronous operation of the moving parts of the thrust reverser 1 is provided by the synchronizing ring 16 together with the movable power ring 22 through the brackets 20 and the carriage 21 (see Fig. 7).

Prototypes of the proposed technical solution have confirmed the reduction of energy losses in the stream and high throughput in the modes of its reversal. The proposed design of the technical solution allowed to reduce the weight and size characteristics of the reversing device and place it in a limited space between the outlines of the channel of the external circuit and the cowl of the engine. At the same time, the most accurate synchronization of the interaction of all nodes of the device in any of its operating positions was confirmed.

Claims (3)

1. A device for reversing the thrust of a turbojet bypass engine, comprising a stationary casing with deflecting gratings arranged around the synchronizing ring, around which a cowl is movably mounted, interconnected with the synchronizing ring and pivoting front and rear wings, articulated in pairs, V-shaped in the reversing position, characterized in that the fairing is interconnected with the synchronization ring by means of an additional front power ring, and the front wings Each pair is pivotally interconnected by its front ends with said synchronizing ring, wherein said synchronizing ring in the reversing position is located behind the front ends of the front wings and in front of the rear ends of the rear wings, the synchronizing ring comprising profiled windows arranged around the circumference and directed to said gratings with streamlined input and exit edges. 2. The thrust reversal device according to claim 1, characterized in that the fixed inserts are located inside the said fixed body in circumferential gaps between the pairs of pivoting wings. 3. The thrust reverser according to claim 1 or 2, characterized in that a spring compensator is additionally introduced at the junction of the front rotary wings with a synchronizing ring.

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