Solid rocket engine nozzle throat area continuous variable structure and nozzle

Abstract

The invention relates to a solid rocket engine nozzle throat area continuous variable structure and a nozzle. The variable structure comprises a front end cover, a shell, a rear end cover, a rotary telescopic component and a driving assembly. The rotary telescopic part comprises a plurality of fan-shaped assemblies which can synchronously rotate and do telescopic motion inwards / outwards, the fan-shaped assemblies are annularly distributed in the shell, a gas channel is formed in the center of the fan-shaped assemblies, and a control rod is arranged on one side of each fan-shaped assembly; the front end cover and the rear end cover are respectively arranged at the two opening ends of the shell, gas through holes are formed in the middle parts of the front end cover and the rear end cover, crank connecting rod assemblies in one-to-one correspondence with the fan-shaped assemblies are arranged on the front end cover, and a limiting groove I for limiting the trend of a control rod of each fan-shaped assembly is formed in the rear end cover; one end of the crank connecting rod assembly is connected with the driving assembly, and the other end of the crank connecting rod assembly is connected with the front end of the control rod. Continuous and large-range adjustment of the throat area of the jet pipe of the solid rocket engine can be achieved, and then real-time adjustment and control of the thrust of the solid rocket engine are achieved.

Description

Technical Field

[0001] The present invention specifically relates to a solid rocket engine nozzle throat area continuously variable structure, belonging to the field of variable thrust solid rocket engines. Background Art

[0002] Solid rocket motors have advantages such as simple structure, reliable operation, easy maintenance, convenient use, long-term standby and immediate launch, rapid startup and operational advantages, and compact structure and easy loading. They are widely used in various missile weapon systems and spacecraft propulsion systems. Given the fixed profile of the solid propellant and its grain, the combustion process is generally fixed, and therefore the thrust of the solid rocket motor is also fixed, making it difficult to adjust in real time. If the thrust of a solid rocket motor can be adjusted in real time at a low cost, it would significantly improve the energy utilization and operational flexibility of the solid rocket motor.

[0003] Adjusting the nozzle throat area of a solid rocket motor is one of the primary methods for achieving variable thrust in solid rocket motors. According to the formulas for calculating the equilibrium pressure and thrust of a solid rocket motor's combustion chamber, once the propellant and its grain profile are determined, along with the propellant density, characteristic velocity, burning rate coefficient, pressure exponent, and charge burning surface, the nozzle throat area becomes the primary factor influencing the equilibrium pressure. Among the factors influencing solid rocket motor thrust, the thrust coefficient has a narrow range of variation, so the primary influencing factors are the equilibrium pressure and the nozzle throat area. Since the equilibrium pressure is primarily affected by the nozzle throat area, the nozzle throat area is the primary factor influencing the thrust of a solid rocket motor when the propellant and its grain profile are determined.

[0004] Currently, the main method for achieving variable thrust in solid rocket motors by changing the nozzle throat area is throat plug technology. This technology has been applied in engineering projects abroad, such as in the Hawk missile, the Precision Attack Missile (PAM), and the Standard Missile-3 IB, as well as the attitude and orbit control engine system of the Orion spacecraft escape system. However, traditional coaxial throat plug solid rocket motors have the problem that the throat plug rod directly passes through the combustion chamber, which greatly restricts the propellant and introduces a large amount of negative mass. In contrast, non-coaxial throat plug solid rocket motors cause the gas channel axis to be out of line, which adversely affects gas flow. Other methods for adjusting the throat area of solid rocket motors have problems such as a small adjustment range or the inability to achieve continuous adjustment. Therefore, it is necessary to find a new solid rocket motor nozzle structure with continuously variable throat area. Summary of the Invention

[0005] The purpose of the present invention is to solve the above-mentioned problems in the prior art, and further provide a structure for continuously variable throat area of the nozzle of a solid rocket engine, so as to solve the problems in the prior art of achieving variable thrust of a solid rocket engine by changing the throat area, such as large negative mass, adverse effect on gas flow, small throat area adjustment range and inability to achieve continuous thrust adjustment.

[0006] To solve the above technical problems, the specific technical solutions of the present invention are as follows: A solid rocket engine nozzle throat area continuously variable structure includes a front end cover, a shell, a rear end cover, a rotating telescopic component, and a driving assembly for driving the rotating telescopic component to rotate;

[0007] The shell is a cylindrical structure with openings at both ends;

[0008] The rotating telescopic component includes a plurality of sector-shaped components that can rotate synchronously and telescopically move inwards / outwards. The plurality of sector-shaped components are arranged in a circle in the shell, and a gas channel is formed in the center. A control rod is provided on one side of each sector-shaped component.

[0009] The front cover and the rear cover are separately installed on the two open ends of the shell, and there are gas through holes in the middle of the front cover and the rear cover. The front cover is equipped with a crank connecting rod assembly corresponding to the fan-shaped components one by one, and the rear cover is provided with a limiting groove for limiting the direction of the control rod of each fan-shaped component;

[0010] One end of the crank-connecting rod assembly is connected to the driving assembly, and the other end is connected to the front end of the control rod. The rear end of the control rod extends into a limiting groove 1 of the rear end cover. When the driving assembly drives the fan-shaped assemblies to rotate clockwise, the shielding area of the rotating telescopic component increases and the cross-sectional area of the gas channel decreases; when the driving assembly drives the fan-shaped assemblies to rotate counterclockwise, the shielding area of the rotating telescopic component decreases and the cross-sectional area of the gas channel increases.

[0011] The fan-shaped component is a fan-shaped block, and the front end surface of the fan-shaped component is gradually tilted backward from the outside to the inside to form an inclined surface.

[0012] There are six fan-shaped components in total.

[0013] The front and rear end surfaces of each fan-shaped component protrude to form a front control rod and a rear control rod. The front control rod is longer than the rear control rod, and the front control rod passes through the connecting rod end hole of the crank connecting rod assembly and extends into the limiting groove 2 on the front end cover, and the rear control rod extends into the limiting groove 1 of the rear end cover.

[0014] Each crank-connecting rod assembly includes a crank, one end of the crank is hinged to the connecting rod, and the other end is provided with a driving rod, which is connected to the driving assembly.

[0015] The inner side of the front end cover is provided with holes for the crank driving rods to pass through, a second limiting groove for the movement direction of the control rods on each sector assembly, and a third limiting groove for limiting the movement of the crank connecting rod assembly.

[0016] The driving assembly includes an internal gear and external gears corresponding to the sector assemblies one by one. Each external gear is connected to the driving rod of the crank-connecting rod assembly respectively, and the external gears are meshed with the internal gear at the same time.

[0017] A solid rocket engine nozzle structure with a continuously variable throat area includes the continuously variable throat area structure described in the above technical solution, wherein the front end cover of the continuously variable throat area structure is connected to the nozzle convergent section, and the rear end cover is connected to the nozzle divergent section.

[0018] The shell is connected to the front end cover and the rear end cover, and surrounds the six sector components and the six groups of crank-connecting rod structures.

[0019] The present invention has the following beneficial effects:

[0020] The present invention can achieve continuous and large-scale adjustment of the throat area of the solid rocket engine nozzle, thereby achieving real-time regulation of the thrust of the solid rocket engine.

[0021] In the present invention, one internal gear simultaneously drives six external gears to rotate, driving six groups of crank-connecting rod structures to move in coordination, ultimately achieving coordinated movement of six sector-shaped components. The overall structure has good coordination and high synchronization.

[0022] The present invention adopts a crank-connecting rod structure to convert the complex planar motion of the fan-shaped assembly (planar linear motion combined with fixed-axis rotation) into fixed-axis rotation of the crank, which facilitates dynamic sealing of the overall structure. In the design of solid rocket engine nozzles, dynamic sealing is very important. If the fan-shaped assembly is directly driven to move, the control rod on the fan-shaped assembly will perform linear translation and simultaneously perform fixed-axis rotation along the axis of the control rod, which will sweep a certain area. Then, a hole of a specific shape needs to be opened on the front end cover, which basically cannot achieve dynamic sealing. Therefore, the present invention adopts a crank-connecting rod structure for motion conversion, and ultimately only needs to perform dynamic sealing of the hole set in the front end cover through which the crank extends out. Such dynamic sealing is relatively simple and reliable.

[0023] The present invention designs the inner surface of the fan-shaped component, such as an inclined plane or a conical surface, so that the airflow in the nozzle flows along the designed surface, avoiding the phenomenon of flow blockage caused by the fan-shaped component directly extending into the nozzle, and reducing flow loss to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the three-dimensional structure of the present invention Figure 1 ; Figure 2 Schematic diagram of the three-dimensional structure Figure 2 ; Figure 3 It is a front view of the present invention; Figure 4is a side view of the present invention; Figure 5 It is a back view of the present invention; Figure 6 This is a structural diagram of the front end cover of the present invention; Figure 7 It is a structural diagram of the crank-connecting rod assembly of the present invention; Figure 8 It is an assembly diagram of the front end cover and the crank connecting rod assembly of the present invention; Figure 9 This is an assembly diagram of the rear end cover and all fan-shaped components of the present invention; Figure 10 An assembly diagram of the rear end cover and part of the fan-shaped assembly of the present invention; Figure 11 Schematic diagram of the fan-shaped block structure Figure 1 ; Figure 12 Schematic diagram of the fan-shaped block structure Figure 2 ; Figure 13 This is the assembly drawing of the internal gear and the external gear; Figure 14 Rotation simulation diagram of the fan component. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] In the description of the present invention, it should be understood that the terms "front," "rear," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. The specific dimensions used in this embodiment are merely illustrative of the technical solution and do not limit the scope of protection of the present invention.

[0027] like Figure 1-5As shown, the present invention provides a solid rocket engine nozzle throat area continuously variable structure, including an internal gear 1, an external gear 2, a front end cover 3, a crank 4, a connecting rod 5, a fan-shaped assembly 6, a shell 7 and a rear end cover 8. The housing 7 is a cylindrical structure with two open ends. The front and rear covers are coaxially located at the two open ends of the housing 7. Six sector-shaped assemblies 6, which can rotate synchronously and telescopically inward and outward, are arranged in a circle within the housing 7, forming a rotating and telescopic component. A gas passage 9 is formed in the center. Each sector-shaped assembly 6 is equipped with a control rod on one side. The ends of the control rods protrude from the front and rear end surfaces of the sector-shaped assembly 6 to form a front control rod 62 and a rear control rod 63. The rear control rod 63 extends into a stopper groove 1 81 on the rear cover 8. The front control rod 62 passes through a hole at one end of the connecting rod 5 and then extends into a stopper groove 2 31 on the front cover 3. The stopper groove 2 31 on the front cover and the stopper groove 1 81 on the rear cover match one another. The stopper groove 1 81 and the stopper groove 2 31 have the same structure as the stopper groove 2 31, which is a waist-shaped slot. The control rod can slide within the stopper groove as the sector-shaped assembly 6 moves. The other end of the connecting rod 5 is connected to the drive assembly consisting of an internal gear 1 and an external gear 2 after passing through the crank 4. Gas through holes are formed in the middle of the front cover 3 and the rear cover 8. When the driving assembly drives each fan-shaped assembly 6 to rotate clockwise, the shielding area of the rotating telescopic component increases and the cross-sectional area of the gas channel 9 decreases; when the driving assembly drives each fan-shaped assembly 6 to rotate counterclockwise, the shielding area of the rotating telescopic component decreases and the cross-sectional area of the gas channel 9 increases.

[0028] like Figure 13 As shown, an internal gear 1 is meshed with six external gears 2. When the internal gear 1 is driven to rotate by an external force, it can simultaneously drive the six external gears 2 to rotate in coordination. The internal gear 1 can be connected to the output shaft of the motor. In this embodiment, to meet the dimensional requirements, gear meshing conditions and prevent undercutting during gear processing, the number of teeth of the internal gear 1 is selected as 156, the number of teeth of the external gear 2 is selected as 18, and the module is selected as 0.5.

[0029] like Figure 6-8As shown, one end of the crank 4 is hinged to the connecting rod 5, and the other end is provided with a driving rod 41. The driving rod 41 is connected to the external gear 2 corresponding to the driving assembly. The front end cover 3 is provided with a limiting groove three 32 for the movement of the crank 4 and the connecting rod 5, a hole 33 for the driving rod 41 at one end of the crank 4 to pass through, and a limiting groove two 31 for the movement and positioning of the front control rod of the fan-shaped assembly 6. The crank 4 and one end of the connecting rod 5 are hinged by a hinge shaft 42 and can move in the limiting groove three 32. When the external gear 2 fixedly connected to the driving rod of the crank 4 is driven to rotate by the internal gear 1, the crank 4 rotates along the driving rod 41 on a fixed axis, driving the connecting rod to perform a planar motion of a fixed-axis rotation and a compound translation along the hinge shaft 42. The other end of the connecting rod 5 is hinged to the front control rod of the fan-shaped assembly 6, driving the fan-shaped assembly 6 to perform a planar motion of a fixed-axis rotation and a compound linear translation along the axis 64. The combination of six sector-shaped components 6 can form a gas channel in the middle of the structure. The minimum cross-section of the gas channel is a regular hexagon. When the six sector-shaped components 6 are driven to move in coordination, the cross-sectional area of the gas channel can be changed, and the minimum cross-sectional area also changes, thereby realizing the thrust adjustment of the solid engine.

[0030] like Figure 9-12 As shown, the rear end cover 8 is provided with a limiting groove 81 for the movement and positioning of the rear control rod 63 of the fan-shaped component 6. The fan-shaped component 6 is a fan-shaped block. The profile of the front end face of the fan-shaped component 6 is designed to be an inclined surface 61 that gradually tilts backward from the outside to the inside. The inclined surface 61 can be an inclined plane or a smooth curved surface. The two ends of the control rod of each fan-shaped component 6 protrude from the front and rear end faces of the fan-shaped component 6 to form a front control rod 62 and a rear control rod 63. The front control rod is longer than the rear control rod 63. After the front control rod passes through the end hole of the connecting rod 5 of the crank connecting rod assembly, it extends into the limiting groove 2 31 on the front end cover 3, and the rear control rod 63 extends into the corresponding limiting groove 1 81 on the rear end cover 8. The limiting groove 1 81 on the rear end cover 8 matches the limiting groove 2 31 on the front end cover to jointly control and position the movement of the fan-shaped component 6. To ensure the integrity of the structure, there are a total of six fan-shaped components 6, each of which has a central angle of 60 degrees. Each fan-shaped component 6 is provided with a control rod at the front and rear, and respectively cooperates with the limit grooves provided on the front cover 3 and the rear cover 8. The sides of every two fan-shaped components 6 fit together, and the six fan-shaped components work together to form a gas channel 9 in the middle.

[0031] The front end cover 3, the rear end cover 8 and the shell 7 are fixedly connected. The front end cover 3 is connected to the convergent section of the nozzle, and the rear end cover 8 is connected to the divergent section of the nozzle.

[0032] All parts described in the present invention are made of tungsten-infiltrated copper material.

[0033] The present invention uses O-rings for static sealing at the connection between the front cover 3 and the housing 7 and the rear cover 8 and the housing 7, and also uses O-rings for dynamic sealing at the hole where the front cover 3 matches the crank 4 drive rod.

[0034] like Figure 14 , A is the center of the control rod on the fan-shaped component, O is the vertex of the fan-shaped component, assuming that AO is the position before the fan-shaped component moves, BC is the position after the fan-shaped component moves, A moves to point B, and O moves to point C, where the distance of line segment AB, that is, the straight-line distance of the fan-shaped component moving along the second limiting groove 31, is recorded as m, the distance traveled by the vertex of the fan-shaped component when OC rotates is recorded as l, and the angle of rotation of the fan-shaped component control rod is recorded as a; the six fan-shaped components cooperate with each other to form a regular hexagonal cross-section in the middle position, and the adjustment of the middle regular hexagonal cross-section can be achieved by only controlling the movement of the six fan-shaped components. The front control rod of the fan-shaped component moves in the second limiting groove 31 set on the front end cover, and its movement is divided into fixed-axis rotation along the axis of the control rod and linear translation along the center line of the limiting groove. By controlling the movement of the fan-shaped component, the side length of the middle regular hexagon can be adjusted. The rotation of the fan-shaped component satisfies the following relationship:

[0035]

[0036]

[0037] Among them: a is the angle of fixed-axis rotation of the sector assembly, m is the distance the control rod moves along the center line of the second limit groove, and l is the distance the vertex of the sector assembly travels during rotation. According to the above two formulas, the sector assembly only needs to be driven to move along the center line of the limit groove to rotate along the control rod to a corresponding angle and form a corresponding gas channel 9.

[0038] The working process of the present invention is as follows:

[0039] When an external force drives the internal gear 1 to rotate, it simultaneously drives the six meshing external gears 2 to rotate synchronously, which in turn drives the crank-connecting rod assembly connected to the external gears, and further drives the sector assembly 6 to move. Ultimately, the six sector assemblies 6 move in coordination, achieving the function of adjusting the throat area of the solid motor nozzle and the thrust of the solid rocket motor. In this embodiment, when the six sector assemblies move to form a minimum cross-section, the side length of the minimum cross-section regular hexagon is 5mm. When the six sector assemblies move to form a maximum cross-section, the side length of the maximum cross-section regular hexagon is 15mm. Therefore, the structure described in this embodiment can achieve a maximum area adjustment ratio of 1:9, and it is continuously adjustable.

[0040] The above describes the present application in detail in combination with specific embodiments and working processes. However, these descriptions are not intended to limit the scope of protection of the present application. As long as they do not deviate from the spirit and principles of the present application, any equivalent replacement, modification or improvement of the technical solution and implementation method of the present application shall fall within the scope of protection of the present application.

Claims

1. A solid rocket motor nozzle throat area continuously variable structure, characterized in that: It comprises a front end cover (3), a housing (7), a rear end cover (8), a rotating telescopic component, and a driving assembly for driving the rotating telescopic component to rotate; The housing (7) is a cylindrical structure with openings at both ends; The rotating telescopic component comprises a plurality of fan-shaped components (6) that can rotate synchronously and telescopically move inwards / outwards, the plurality of fan-shaped components (6) are arranged in a ring in the housing (7), and a gas channel (9) is formed in the center, and a control rod is provided on one side of each fan-shaped component (6); The front end cover (3) and the rear end cover (8) are separately mounted on the two open ends of the housing (7). Gas through holes are provided in the middle of the front end cover (3) and the rear end cover (8). The front end cover (3) is provided with crank-connecting rod assemblies corresponding to the fan-shaped assemblies (6) one by one. The rear end cover (8) is provided with a limiting groove (81) for limiting the direction of the control rod of each fan-shaped assembly (6). One end of the crank-connecting rod assembly is connected to the driving assembly, and the other end is connected to the front end of the control rod. The rear end of the control rod extends into a limiting groove (81) of the rear end cover (8). When the driving assembly drives the fan-shaped assemblies (6) to rotate clockwise, the shielding area of the rotating telescopic component increases, and the cross-sectional area of the gas channel (9) decreases; when the driving assembly drives the fan-shaped assemblies (6) to rotate counterclockwise, the shielding area of the rotating telescopic component decreases, and the cross-sectional area of the gas channel (9) increases.

2. A solid rocket motor nozzle throat area continuously variable structure according to claim 1, characterized in that: The fan-shaped component (6) is a fan-shaped block, and the front end surface of the fan-shaped component (6) gradually tilts backward from the outside to the inside to form an inclined surface (61).

3. A solid rocket motor nozzle throat area continuously variable structure according to claim 1 or 2, characterized in that: There are six fan-shaped components (6) in total.

4. A solid rocket motor nozzle throat area continuously variable structure according to claim 3, characterized in that: The front and rear end surfaces of each fan-shaped assembly (6) protrude to form a front control rod (62) and a rear control rod (63), the front control rod (62) is longer than the rear control rod (63), and the front control rod (62) passes through the hole at one end of the connecting rod (5) of the crank connecting rod assembly and extends into the second limiting groove (31) on the front end cover (3), and the rear control rod (63) extends into the first limiting groove (81) of the rear end cover (8).

5. The solid rocket motor nozzle throat area continuously variable structure according to claim 1, characterized in that: Each crank-connecting rod assembly comprises a crank (4), one end of the crank (4) is hinged to the connecting rod (5), and the other end is provided with a driving rod (41), and the driving rod (41) is connected to the driving assembly.

6. A solid rocket motor nozzle throat area continuously variable structure according to claim 5, characterized in that: The front end cover (3) is provided with a hole (33) for the driving rod of each crank (4) to pass through, a second limiting groove (31) for the movement direction of the control rod (62) on each fan-shaped component (6), and a third limiting groove (32) for limiting the movement of the crank connecting rod component.

7. A solid rocket motor nozzle throat area continuously variable structure according to claim 1 or 5, characterized in that: The driving assembly comprises an internal gear (1) and external gears (2) corresponding one to one with the sector assembly (6), each external gear (2) being connected to a driving rod (41) of the crank-connecting rod assembly, and the external gears (2) are simultaneously meshed with the internal gear (1).

8. A solid rocket motor nozzle structure with continuously variable throat area, characterized by: The invention comprises a throat area continuously variable structure as described in any one of claims 1 to 7, wherein the front end cover (3) of the throat area continuously variable structure is connected to the nozzle convergence section, and the rear end cover (8) is connected to the nozzle expansion section.

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