RU2189483C2 - Solid-propellant rocket engine - Google Patents

Abstract

FIELD: rocket manufacturing. SUBSTANCE: solid-propellant rocket engine has combustion chamber, powder charge, ignition, nozzle unit with seat for holder with nozzle insert and diaphragm. Holder is made in form of thin- walled housing with two cylindrical skirts. Inner skirt mates with nozzle insert. Outer skirt is provided with sealing rings and end face bead and is fixed in seat of nozzle unit by means of split spring ring. Supercritical insert made of heat-resistant plastic in form of hollow cylinder with inner cone and stiffening ribs is glued in seat of nozzle unit. Stiffening ribs in front part are provided with projections which contact with spring ring. Thin-walled housing and front end face of nozzle insert from side of combustion chamber are protected by thermal protection insert glued along equidistant surfaces. EFFECT: improved reliability of engine in operation by provision of hermetic sealing of nozzle unit under intensive heating and high-pressure conditions in engine combustion chamber made of composite material. 3 dwg

Description

 The invention relates to rocket science and takes into account the increasing requirements to improve the perfection of the design of rocket engines and the reliability of their work.

 A known design of a rocket engine of solid fuel [1], containing a combustion chamber, a powder charge, an ignitor, a nozzle block, in the socket of which a graphite insert with a membrane is installed. The graphite insert is placed in a steel thin-walled cylindrical cage with annular flanging along the generatrix, the membrane being installed in the supercritical zone between the end face of the nozzle insert and the annular flanging of the casing, the membrane being made in the form of a unit consisting of a thin-walled aluminum disk with an annular groove and equidistant a groove of a steel high-strength ring, and the steel ring on the disk side is made with concentric annular protrusions and a blockage on the outer diameter It is made of the peripheral part of the disk, and on the disk from the nozzle insert side, a calibrated annular groove of triangular section is made.

 This design of a rocket engine in relation to engines made of composite materials is not reliable due to the installation of the nozzle insert and the membrane in the protrusion of the bearing housing, because the composite material negatively works for shear, an increase in the area of the protrusion support is not advisable due to an increase in the passive weight of the engine, in addition, the nozzle insert with the cage is pasted over the entire length of the engine, which is not technologically advanced and does not provide reliable control of the insert, which leads to burnout of the nozzle block .

 Known rocket engine of solid fuel [2], containing a combustion chamber, a powder charge, an igniter, a nozzle block, in the socket of which a graphite insert with a membrane is installed, placed in a steel thin-walled cylindrical cage.

 The cage is made with a stepped cylindrical-conical shank reinforced with a heat-erosion skirt along the conical part, the profile of the inner surface of which forms part of the supersonic outlet of the bell, and the outer surface contacts the nozzle block seat and forms an annular rectangular groove with the cage, through diametrical in the nozzle block holes in which the steel pins are placed, abutting in the annular groove of the holder, and the holder and pins in the nozzle block installation enes on the heat-resistant adhesive, and from the holder is formed an annular groove in which an O-ring.

 However, this design of a solid fuel rocket engine with respect to engines made of composite material with a jellied charge becomes unreliable, since the presence of a jellied charge implies an increase in the pole hole for installing a press tool that forms the inner surface of the charge. When increasing the diameter of the pole hole, it is necessary to increase the number of pins to compensate for the increasing load on the nozzle block holder and to tighten control over the quality of their gluing. On the other hand, the combustion temperature of the filler charge is much higher than the ballistic charge, and the use of a thin-walled cage, in which a graphite insert is inserted, can lead to engine burnout due to heating of the cage and combustion of rubber o-rings.

 The objective of the invention is to increase the reliability of the engine by reliably ensuring the tightness of the sealing assembly of the nozzle block under conditions of intense heating and high pressure in the combustion chamber of the engine made of composite material.

 This task is achieved by the fact that in a rocket engine of solid fuel containing a combustion chamber, a powder charge, an igniter, a nozzle block with a seat for a holder with a nozzle insert and a membrane, the holder is made in the form of a thin-walled body with two cylindrical skirts, while the inner skirt is mated with a nozzle insert, and the outer skirt is equipped with o-rings and an end collar and is fixed in the seat of the nozzle block using a split spring ring, while in the seat the nozzle block is glued with a supercritical liner made of heat-resistant plastic in the form of a hollow cylinder with an inner cone and stiffeners, and the stiffeners in the front part have protrusions in contact with the spring ring, and the thin-walled body and the front end of the nozzle insert on the side of the combustion chamber are protected by an equidistant surface heat shield insert.

 The essence of the invention lies in the fact that the implementation of the sealing assembly on the outer surface of the skirt equidistant from the main casing through a thin-walled body and the air gap between them reliably ensures the safety of the sealing assembly of the nozzle block until the powder charge burns out in the engine.

In the accompanying drawings, figure 1, figure 2 and 3 shows the design of a rocket engine of solid fuel, where
1 - combustion chamber;
2 - powder charge;
3 - igniter;
4 - nozzle block;
5 - seat under the clip;
6 - clip;
7 - membrane;
8 - nozzle insert;
9 - inner skirt of the cage;
10 - outer skirt of the cage;
11 - a sealing ring;
12 - end shoulder;
13 - split spring ring;
14 - thin-walled housing;
15 - front end of the nozzle liner;
16 - supercritical liner made of heat-resistant plastic in the form of a hollow cylinder with an inner cone (figure 3);
17 - stiffening ribs supercritical liner with protrusions;
18 - heat-insulating insert.

 The device and operation of the rocket engine of solid fuel is as follows.

 In the nozzle block 4 of the cylinder-conical engine equipped with the mixed powder charge 2, a clip 6 is installed, the assembly of which is carried out previously, i.e. a membrane 7 is mounted on the glue 6 on the glue and, matching the inner skirt 9 of the cage, the nozzle insert 8, then the thin-walled body 14, is closed (protected) by a heat-shielding insert glued over equidistant surfaces 18. After the glue has dried, the assembly is checked for leaks. O-rings 11 are installed in the annular grooves of the outer skirt 10. The collar 6 is installed in the cylindrical conical rocket engine of solid fuel from the nozzle side until it stops with the end collar 12 of the skirt in the groove of the seat 5 under the collar 6. The end collar 12 on the outer skirt 10 of the collar 6 is intended to fix the clip 6 in a predetermined position and limits axial movement inward of the engine. To prevent axial movement of the holder 6 of the nozzle insert 8 towards the nozzle, the holder 6 is fixed in the seat 5 with a split spring ring 13 and is closed by a heat-resistant plastic with an internal hollow supercritical insert 16 with internal stiffening ribs 17. After assembling the nozzle block 4, an igniter 3 is installed in the engine. To prevent the split spring ring 13 from leaching out during vibration testing and transportation, spontaneous compression of the spring ring is limited by the protrusions of the stiffeners 17 on which it relies. The supercritical insert 16 is hollow to facilitate weight, and stiffeners provide the necessary rigidity and strength. To prevent gas-dynamic losses, the supersonic part of the supercritical insert 16 is a continuation of the supersonic part of the nozzle thermo-screen. The nozzle block is the most stressed section of the engine subjected to intense heating by the outgoing powder gases, therefore, the heat-shielding insert 18 and the supercritical insert 16 are made of heat-erosion-resistant material, and the skirts 9, 10 of the cage are spaced apart relative to each other and interconnected by a thin-walled case 14 to reduce heat transfer and ensure reliable preservation of the sealing rings 11 until the high-energy powder charge 2 is completely burned out.

 The operation of a solid fuel rocket engine is carried out as follows: when the igniter is activated, the ignited powders are poured into the combustion chamber of the engine and ignite the powder charge, when the design pressure is reached, which ensures reliable heating and ignition of the powder charge, the membrane is cut off, the outgoing powder gases create traction, and when the engine is installed they accelerate it to a rocket to hypersonic speed, after which the engine is separated.

Sources of information
1. Patent of Russia 2124138 dated 12/27/98, IPC 7 F 02 K 9/24 - analogue.

 2. Patent of Russia 2156374 dated September 20, 2000. IPC 7 F 02 K 9/08 - prototype.

Claims (1)

 A rocket engine of solid fuel containing a combustion chamber, a powder charge, an igniter, a nozzle block with a seat for a holder with a nozzle insert and a membrane, characterized in that the holder is made in the form of a thin-walled body with two cylindrical skirts, while the inner skirt is mated with nozzle insert, and the outer skirt is equipped with o-rings and an end collar and is fixed in the seat of the nozzle block using a split spring ring, while in the seat of the nozzle A supercritical liner made of heat-resistant plastic in the form of a hollow cylinder with an inner cone and stiffeners is glued in, the stiffeners in the front part have protrusions in contact with the spring ring, and the thin-walled body and the front end of the nozzle liner on the side of the combustion chamber are protected by heat-shielding glued over the equidistant surfaces insertion.

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