RU2529283C1 - Turbojet adjustable nozzle - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed nozzle comprises fixed casing with spherical end and moving casing with seal fitted to turn relative to crosswise axis of the nozzle. Said seal is composed of segments fitted in place to displace radially spring loaded to fixed casing spherical end. Ledges are made at ends of adjacent segments for contact between them over inner mating surfaces.

EFFECT: modular design, optimum arrangement relative to spherical end, positive and negative angles of nozzle turns, simplified assembly, reliable tightness and reparability.

2 cl, 4 dwg

Description

The invention relates to aircraft engine manufacturing, and in particular to the design of axisymmetric nozzles of turbojet engines (turbojet engines).

An axisymmetric nozzle for a turbojet engine is known, comprising a stationary body with a spherical tip and a movable body with a sealing element mounted for rotation about the transverse axis of the nozzle (see Utility Model Certificate RU 33175 of class F02K 1/78, published on 10/10/2003).

The disadvantages of this model include the lack of tightness on the mating surfaces of the sealing element of the movable housing and the spherical tip of the stationary housing due to the necessary clearance between them to compensate for the thermal expansion of the warmer spherical tip and less heated sealing ring, as well as compensation for possible deviations of the shapes of their surfaces. Depressurization also occurs during deformations of the movable and stationary bodies when the nozzle rotates in operation. The specified leakage leads to leaks of cooling air and, as a consequence, burnout of the nozzle.

The objective of the invention is to provide the necessary tightness of the cooling path of the nozzle.

This problem is solved in that in the known axisymmetric nozzle of the turbojet engine containing a stationary housing with a spherical tip and a movable housing with a sealing element mounted rotatably relative to the transverse axis of the nozzle, according to the invention, the sealing element is made in the form of segments mounted for radial movement and spring-loaded to the spherical tip of the fixed body, and on the ends of adjacent elements made protrusions in contact with each other on the inner answer th surfaces.

This embodiment of the device allows to prevent leakage of cooling air into the gap between the mating surfaces of the sealing element of the movable body and the spherical tip of the stationary nozzle body, and thus increase the reliability of the nozzle in afterburner engine operation modes.

Figure 1 shows a longitudinal section of an axisymmetric nozzle;

figure 2 is a section along the transverse axes of the mounting of the housings (section bb);

figure 3 is a cross section of the seal (BB);

figure 4 is a top view of the seal (case not shown).

The axisymmetric nozzle contains a stationary housing 1 with a spherical tip 2 and a movable housing 3. A sealing element 5 is installed on the front flange 4 of the movable housing 3, inside of which in the circumferential direction segments 6 with graphite inserts 7 are placed. Springs 8 are installed on each segment 6. Ends 9 springs 8 are introduced under the axis 10, which are located in the grooves of 11 segments 6 and are fixed on the side walls of 12 segments. At the ends 13 of adjacent segments 6, protrusions 14 are made, which contact each other on the internal mating surfaces 15. Inside the spherical tip 2 and the bracket 16 of the fixed housing 1, as well as inside the movable housing 3, pins 17, 18, 19 are arranged for installing the transverse axes 20, around which the deviation of the movable housing 3 at a given angle of rotation of the nozzle.

To ensure the specified rotation angles, the sealing element 5 should be placed at a distance L from the rotation axes, not less than the outer radius of the trunnions R of the movable and fixed bodies 3 and 1.

When the signal to turn the thrust vector, the power elements rotate the movable housing 3 around two transverse axes 20 of the stationary housing 1 at a certain angle. In this case, segments 6 with graphite inserts slide along the spherical tip 2, pressing against it by springs abutting against the movable housing 3. Even with a slight deviation of the tip shape, the graphite inserts 7 together with segments 6 move radially without forming a gap with both the mating surface and each other around the circumference. Thus, the cooling air passes from cavity to cavity without flowing out into the atmosphere due to the snug fit of segments 6 with graphite inserts 7 to the fixed body 1, and air in the required quantity for this mode of operation of the nozzle is losslessly supplied to the nozzle flaps. When flowing with hot gases, the fixed body 1 increases in diameter relative to the outer movable body 3. Also, when the thrust vector is rotated, deformations of the movable and stationary bodies relative to each other occur. But in all these cases, the joint of the sealing elements along the spherical tip remains airtight. Thus, when the nozzle operates with a thrust vector, there is no leakage of cooling air into the atmosphere, which increases the reliability of the nozzle and increases its service life.

The proposed design allows to ensure the modularity of the sealing element and its optimal location relative to the spherical tip of the stationary body, which allows for positive and negative angles of rotation of the nozzle relative to the stationary body in the required range of angles. The design of the fastening of the sealing element to the movable nozzle body facilitates assembly, provides the specified tightness and maintainability.

Claims (2)

1. An axisymmetric nozzle of a turbojet engine containing a stationary body with a spherical tip and a movable body with a sealing element mounted rotatably relative to the transverse axis of the nozzle, characterized in that the sealing element is made in the form of segments mounted for radial movement and spring-loaded to a spherical tip the stationary body, and at the ends of adjacent segments made protrusions in contact with each other on the internal mating surfaces. 2. The axisymmetric nozzle of a turbojet engine according to claim 1, characterized in that the sealing element is placed at a distance from the axis of rotation, not less than the outer radius of the pins of the movable and stationary bodies.

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