A stable socket connection structure for a liquid rocket engine cavitation tube

Abstract

The invention relates to a stable sleeve connection structure of a cavitation tube of a liquid rocket engine, which belongs to the field of design of cavitation tubes of liquid rocket engines; the structure comprises a reducing pipeline, a cavitation tube, bolts, a fixed shell, a cavitation tube fixing structure and a sealing gasket; the fixed shell is provided with a reducing channel arranged axially and horizontally; the reducing pipeline is coaxially connected with the reducing channel; the reducing pipeline and the fixed shell are fixedly connected by bolts; the cavitation tube is coaxially arranged in the inner cavity of the reducing pipeline, and the cavitation tube extends into the reducing channel of the fixed shell; the cavitation tube is axially limited by a step of the reducing channel; the sealing gasket is sleeved on the outer wall of one end of the cavitation tube axially extending into the fixed shell; the cavitation tube fixing structure is arranged on the outer wall of the sealing gasket to realize the fixing of the cavitation tube and the fixed shell; the stable sleeve connection structure of the cavitation tube of the invention does not need to change the cavitation tube structure, and the processing and assembly operations are simple and feasible. In addition, the sleeve connection structure and structural optimization solve the problems of assembly layout and frequency coupling.

Description

Technical Field

[0001] The invention belongs to the field of liquid rocket engine cavitation tube design and relates to a stable sleeve connection structure of a liquid rocket engine cavitation tube. Background Art

[0002] Cavitation Venturi is widely used as a flow adjustment element in liquid rocket engines. The connection between the cavitation Venturi and the pipeline is generally welded or threaded. The cavitation Venturi is generally long, resulting in a long overall length after connection with the pipeline, which limits the engine structure layout. In addition, the cavitation Venturi outlet is directly connected to the pipeline, which causes the problem of coupling between the pipeline frequency and the Venturi frequency, which may lead to unstable combustion. In the study of the existing layout, there is an idea to solve the problem by changing the cavitation Venturi structure, but its processing and assembly become complicated, which is not conducive to reducing costs. Summary of the invention

[0003] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and propose a stable socket connection structure for a cavitation tube of a liquid rocket engine. The stable socket connection structure of the cavitation tube does not require changing the cavitation tube structure, and the processing and assembly operations are simple and feasible. In addition, the socket structure and structural optimization are used to solve the problems of assembly layout and frequency coupling.

[0004] The solution of the present invention is:

[0005] A stable sleeve connection structure for a cavitation tube of a liquid rocket engine comprises a reducing pipeline, a cavitation tube, bolts, a fixed shell, a cavitation tube fixing structure and a sealing gasket; the fixed shell is provided with a reducing channel arranged axially and horizontally; the reducing pipeline is installed on the side wall of the fixed shell, and the reducing pipeline and the reducing channel are coaxially connected; the reducing pipeline and the fixed shell are fixedly connected by bolts; the cavitation tube is coaxially arranged in the inner cavity of the reducing pipeline, and the cavitation tube extends into the reducing channel of the fixed shell; the cavitation tube is axially limited by the step of the reducing channel; the sealing gasket is sleeved on the outer wall of the cavitation tube axially extending into one end of the fixed shell; the cavitation tube fixing structure is arranged on the outer wall of the sealing gasket to realize the fixing of the cavitation tube and the fixed shell.

[0006] In the above-mentioned stable sleeve connection structure of the cavitation tube of a liquid rocket engine, the large diameter section of the reducer pipe is axially facing the fixed shell, and the small diameter section of the reducer pipe is opposite to the fixed shell; the cavitation tube is located in the inner cavity of the large diameter section of the reducer pipe.

[0007] In the above-mentioned stable sleeve connection structure of the cavitation tube of a liquid rocket engine, the large diameter section of the variable diameter channel points to the variable diameter pipeline; the diameter of the large diameter section of the variable diameter channel is 6 mm larger than the diameter of the small diameter section.

[0008] In the above-mentioned stable sleeve connection structure of the cavitation tube of a liquid rocket engine, an annular groove is provided on the inner wall of the large diameter section of the variable diameter channel for installing the cavitation tube fixing structure; the diameter of the annular groove is 4-8 mm larger than the diameter of the large diameter section.

[0009] In the above-mentioned stable sleeve connection structure of the cavitation tube of a liquid rocket engine, an annular protrusion is provided on the outer wall of one end of the cavitation tube extending into the fixed shell, and the annular protrusion cooperates with the step of the variable diameter channel of the fixed shell to achieve limiting; the diameter of the annular protrusion is 4 mm larger than the diameter of the small diameter section of the variable diameter channel.

[0010] In the above-mentioned stable sleeve connection structure of the cavitation tube of a liquid rocket engine, a bevel transition is adopted between the small diameter section and the large diameter section of the variable diameter pipeline, and the bevel angle is 60°.

[0011] In the above-mentioned stable sleeve connection structure of the cavitation tube of a liquid rocket engine, a gap is left between the inner wall of the reducer pipe and the outer wall of the cavitation tube, and the gap is 2-3 mm.

[0012] In the above-mentioned stable socket connection structure of the cavitation tube of a liquid rocket engine, the outer wall of the joint between the reducer pipe and the fixed shell is thickened, the bolts are installed in the thickened position of the reducer pipe, and the axial direction of the bolts is parallel to the axial direction of the reducer pipe.

[0013] In the above-mentioned stable sleeve connection structure of the cavitation tube of a liquid rocket engine, the thickened part of the variable diameter pipeline includes a thickened cone and a thickened column; the thickened cone and the thickened column are both mounted on the outer wall of the large diameter section of the variable diameter pipeline; the thickened column is connected to the side wall of the fixed shell; the large diameter end of the thickened cone is connected to the end face of the thickened column; the thickened cone realizes the transition connection between the large diameter section of the variable diameter pipeline and the thickened column.

[0014] In the above-mentioned stable sleeve connection structure of the cavitation tube of a liquid rocket engine, the angle between the beveled side of the generatrix of the thickened cone and the outer wall of the large diameter section of the reducer pipe is 105°-110°; the diameter of the large diameter end of the thickened cone is 6mm larger than the diameter of the large diameter section of the reducer pipe; the butt joint of the thickened cone and the thickened cylinder adopts a chamfered transition with a chamfer radius of 3mm; the butt joint of the small diameter end of the thickened cone and the large diameter section of the reducer pipe adopts a chamfered transition with a chamfer radius of 5mm.

[0015] The beneficial effects of the present invention compared with the prior art are:

[0016] (1) The cavitation venturi tube of the present invention is sleeved in the pipeline, which reduces the length of the system pipeline without changing the structure of the cavitation venturi tube, facilitates assembly, and solves the problem of overall assembly structure layout;

[0017] (2) In the sleeve structure of the present invention, a gap is left between the outer wall of the cavitation venturi tube and the inside of the pipeline, and the cavitation venturi tube is in a free state in the pipeline and has no contact with the pipeline, which effectively solves the problem of coupling between the pipeline frequency and the cavitation venturi tube frequency and avoids the influence of pipeline disturbance on cavitation tube disturbance;

[0018] (3) The minimum inner diameter of the sealing groove of the present invention is 4 mm to 8 mm larger than the inner diameter of the concave step, which ensures both sealing and compact structure, thus saving assembly space;

[0019] (4) In the present invention, a chamfered transition is adopted at the joint between the thickened cone and the thickened cylinder, and a chamfered transition is adopted at the joint between the small diameter end of the thickened cone and the large diameter section of the variable diameter pipeline, so as to avoid stress concentration at sharp corners. In addition, by setting the thickened cone and the thickened cylinder, the thickening treatment can enhance the anti-interference and impact capabilities of the pipeline cantilever. After the variable diameter pipeline is fixed to the fixed shell, it is sealed by the sealing gasket in the sealing groove, and the sealing structure is simple and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the stable sleeve connection structure of the cavitation tube of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the embodiments.

[0022] The present invention provides a stable sleeve connection structure for a cavitation tube of a liquid rocket engine, which does not require changing the structure of the cavitation tube, and is simple and feasible to process and assemble. In addition, the sleeve structure and structural optimization are used to solve the problems of assembly layout and frequency coupling.

[0023] Cavitation tube stable socket connection structure, such as Figure 1 The specifically comprises a reducing pipe 1, a cavitation tube 2, bolts 3, a fixed shell 4, a cavitation tube fixing structure 5, and a sealing gasket 6; the fixed shell 4 is provided with an axially horizontally arranged reducing channel; the reducing pipe 1 is installed on the side wall of the fixed shell 4, and the reducing pipe 1 is coaxially connected with the reducing channel; the reducing pipe 1 and the fixed shell 4 are fixedly connected by bolts 3; the cavitation tube 2 is coaxially arranged in the inner cavity of the reducing pipe 1, and the cavitation tube 2 extends into the reducing channel of the fixed shell 4; the cavitation tube 2 is axially limited by the step of the reducing channel; the sealing gasket 6 is sleeved on the outer wall of the cavitation tube 2 axially extending into one end of the fixed shell 4; the cavitation tube fixing structure 5 is arranged on the outer wall of the sealing gasket 6 to realize the fixing of the cavitation tube 2 and the fixed shell 4.

[0024] The large diameter section of the variable diameter pipeline 1 is axially oriented toward the fixed housing 4, and the small diameter section of the variable diameter pipeline 1 is opposite to the fixed housing 4; the cavitation tube 2 is located in the inner cavity of the large diameter section of the variable diameter pipeline 1. The large diameter section of the variable diameter channel points to the variable diameter pipeline 1; the diameter of the large diameter section of the variable diameter channel is 6mm larger than the diameter of the small diameter section. The inner wall of the large diameter section of the variable diameter channel is provided with an annular groove for installing the cavitation tube fixing structure 5; the diameter of the annular groove is 4-8mm larger than the diameter of the large diameter section. It ensures both sealing and compact structure, which can save assembly space.

[0025] The cavitation tube 2 is placed in the variable diameter pipeline, so that the length of the cavitation tube is reduced in the assembly structure, which is beneficial to the layout of the assembly structure. The inner surface size of the cavitation tube is designed according to the design standard of the Venturi tube. The minimum wall thickness of the cavitation tube is determined by the pressure of the fluid flowing through the cavitation tube. The present invention takes 3.55mm. The outer wall of one end of the cavitation tube 2 extending into the fixed shell 4 is provided with an annular protrusion, and the annular protrusion cooperates with the step of the variable diameter channel of the fixed shell 4 to achieve position limiting; the diameter of the annular protrusion is 4mm larger than the diameter of the small diameter section of the variable diameter channel. The cavitation tube is fixed in the fixed shell by a fixed structure, and the fixing structure includes fixing methods such as threaded matching or welding.

[0026] A bevel transition is adopted between the small diameter section and the large diameter section of the reducer pipe 1, and the bevel angle is 60°. A gap of 2-3mm is left between the inner wall of the reducer pipe 1 and the outer wall of the cavitation tube 2. The existence of the gap ensures that the cavitation tube is in a free state in the pipeline, effectively solving the problem of frequency coupling between the pipeline and the cavitation tube.

[0027] In addition, the inner diameter of the small diameter section of the variable diameter pipeline 1 is consistent with the inner diameter of the outlet of the cavitation tube 2. This inner diameter is generally determined according to the flow rate. The inner diameter of the smaller end of the pipeline is consistent with the inner diameter of the cavitation tube outlet to ensure a uniform and smooth transition of the flow field between the cavitation venturi outlet and the pipeline.

[0028] The outer wall of the joint between the variable diameter pipeline 1 and the fixed shell 4 is thickened, and the bolt 3 is installed at the thickened position of the variable diameter pipeline 1, and the axial direction of the bolt 3 is parallel to the axial direction of the variable diameter pipeline 1. The thickened part of the variable diameter pipeline 1 includes a thickened cone 11 and a thickened column 12; the thickened cone 11 and the thickened column 12 are both mounted on the outer wall of the large diameter section of the variable diameter pipeline 1; the thickened column 12 is docked with the side wall of the fixed shell 4; the large diameter end of the thickened cone 11 is docked with the end face of the thickened column 12; the thickened cone 11 realizes the transition connection between the large diameter section of the variable diameter pipeline 1 and the thickened column 12. The thickening treatment adopted by the present invention can enhance the anti-interference and impact capabilities of the pipeline cantilever. After the variable diameter pipeline is fixed to the fixed shell, it is sealed by the sealing gasket in the sealing groove, and the sealing structure is simple and reliable.

[0029] The included angle between the bevel of the generatrix of the thickened cone 11 and the outer wall of the large diameter section of the reducer pipe 1 is 105°-110°; the diameter of the large diameter end of the thickened cone 11 is 6mm larger than the diameter of the large diameter section of the reducer pipe 1; the butt joint of the thickened cone 11 and the thickened cylinder 12 adopts a chamfered transition with a chamfer radius of 3mm; the butt joint of the small diameter end of the thickened cone 11 and the large diameter section of the reducer pipe 1 adopts a chamfered transition with a chamfer radius of 5mm, so as to achieve the effect of avoiding stress concentration at sharp corners.

[0030] The wall thickness of the variable diameter pipeline is determined by the pressure of the fluid flowing through the variable diameter pipeline. In the present invention, the wall thickness is 1.5 mm.

[0031] The cavitation venturi tube of the present invention is sleeved and assembled in the pipeline, and the length of the regulating valve or the system pipeline is reduced without changing the structure of the cavitation venturi tube. In the sleeve structure, a gap is left between the outer wall surface of the cavitation venturi tube and the inside of the pipeline, and the free state is maintained in the pipeline, which effectively solves the problem of coupling between the pipeline frequency and the cavitation venturi tube frequency. The gap value between the outer wall surface of the cavitation venturi tube and the inside of the pipeline is within a certain range and should not be too large. In the sleeve structure, the maximum inner diameter of the cavitation venturi tube outlet is kept within the same range as the inner diameter of the pipeline cross section. The pipe is consistent with the cavitation venturi tube outlet, which can ensure a uniform and smooth transition of the flow field between the cavitation venturi tube outlet and the pipeline; there is a variable diameter structure in the pipeline inlet area, which is convenient for the assembly of the cavitation venturi tube and ensures the minimum cross-sectional inner diameter of the pipeline and the maximum inner diameter of the cavitation venturi tube outlet; the wall of the pipeline inlet root is thickened and strengthened to enhance the anti-interference and impact capabilities of the pipeline cantilever; the sealing structure between the pipeline inlet and the wall of the front-end valve housing is simple, and a single-channel sealing groove structure or a double-channel sealing groove structure can be adopted. In the present invention, a single-channel sealing groove structure is adopted for sealing.

[0032] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A stable sleeve connection structure for a liquid rocket engine cavitation tube, characterized in that: The invention comprises a variable diameter pipeline (1), a cavitation tube (2), bolts (3), a fixed shell (4), a cavitation tube fixing structure (5), and a sealing gasket (6); the fixed shell (4) is provided with a variable diameter channel arranged axially and horizontally; the variable diameter pipeline (1) is installed on the side wall of the fixed shell (4), and the variable diameter pipeline (1) and the variable diameter channel are coaxially connected; the variable diameter pipeline (1) and the fixed shell (4) are fixedly connected by bolts (3); the cavitation tube (2) is coaxially arranged in the inner cavity of the variable diameter pipeline (1), and the cavitation tube (2) extends into the variable diameter channel of the fixed shell (4); the cavitation tube (2) is axially limited by the step of the variable diameter channel; the sealing gasket (6) is sleeved on the outer wall of the cavitation tube (2) at one end axially extending into the fixed shell (4); the cavitation tube fixing structure (5) is arranged on the outer wall of the sealing gasket (6) to realize the fixed connection between the cavitation tube (2) and the fixed shell (4); An annular protrusion is provided on the outer wall of one end of the cavitation tube (2) extending into the fixed housing (4), and the annular protrusion cooperates with the step of the variable diameter channel of the fixed housing (4) to achieve position limiting; the diameter of the annular protrusion is 4 mm larger than the diameter of the small diameter section of the variable diameter channel; A gap is left between the inner wall of the variable diameter pipeline (1) and the outer wall of the cavitation tube (2), and the gap is 2-3 mm.

2. A liquid rocket engine cavitation tube stable sleeve connection structure according to claim 1, characterized in that: The large diameter section of the variable diameter pipeline (1) is axially oriented toward the fixed housing (4), and the small diameter section of the variable diameter pipeline (1) is opposite to the fixed housing (4); the cavitation tube (2) is located in the inner cavity of the large diameter section of the variable diameter pipeline (1).

3. A liquid rocket engine cavitation tube stable sleeve connection structure according to claim 1, characterized in that: The large diameter section of the variable diameter channel points to the variable diameter pipeline (1); the diameter of the large diameter section of the variable diameter channel is 6 mm larger than the diameter of the small diameter section.

4. A liquid rocket engine cavitation tube stable sleeve connection structure according to claim 3, characterized in that: The inner wall of the large diameter section of the variable diameter channel is provided with an annular groove for installing the cavitation tube fixing structure (5); the diameter of the annular groove is 4-8 mm larger than the diameter of the large diameter section.

5. A liquid rocket engine cavitation tube stable sleeve connection structure according to claim 2, characterized in that: A bevel transition is adopted between the small diameter section and the large diameter section of the reducer pipeline (1), and the bevel angle is 60°.

6. A liquid rocket engine cavitation tube stable sleeve connection structure according to claim 1, characterized in that: The outer wall of the joint between the reducer pipe (1) and the fixed housing (4) is thickened, the bolt (3) is installed at the thickened position of the reducer pipe (1), and the axial direction of the bolt (3) is parallel to the axial direction of the reducer pipe (1).

7. A liquid rocket engine cavitation tube stable sleeve connection structure according to claim 6, characterized in that: The thickened portion of the variable diameter pipeline (1) comprises a thickened cone (11) and a thickened column (12); the thickened cone (11) and the thickened column (12) are both mounted on the outer wall of the large diameter section of the variable diameter pipeline (1); the thickened column (12) is butted against the side wall of the fixed shell (4); the large diameter end of the thickened cone (11) is butted against the end face of the thickened column (12); the thickened cone (11) realizes the transition connection between the large diameter section of the variable diameter pipeline (1) and the thickened column (12).

8. A liquid rocket engine cavitation tube stable sleeve connection structure according to claim 7, characterized in that: The included angle between the generatrix bevel of the thickened cone (11) and the outer wall of the large diameter section of the reducer pipe (1) is 105°-110°; the diameter of the large diameter end of the thickened cone (11) is 6 mm larger than the diameter of the large diameter section of the reducer pipe (1); a chamfered transition is adopted at the joint between the thickened cone (11) and the thickened cylinder (12), and the chamfered transition radius is 3 mm; a chamfered transition is adopted at the joint between the small diameter end of the thickened cone (11) and the large diameter section of the reducer pipe (1), and the chamfered transition radius is 5 mm.

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