An Expanding Snap Ring Structure for a Solid Rocket Motor

Abstract

The present invention relates to an expanding snap ring structure for a solid rocket motor, belonging to the field of solid rocket motors; it includes a head, an engine housing, an O-ring, a snap ring and a screw; wherein, the engine housing is a hollow cylindrical structure horizontally placed axially; the head coaxially extends into the inner cavity of the engine housing; the O-ring is arranged at the docking position of the inner wall of the engine housing and the outer wall of the head; the snap ring is embedded in the inner wall of the engine housing; the snap ring and the head are fixedly connected by a screw; the snap ring is an open snap ring, and the radial compression and expansion of the snap ring are realized through the opening; the structure of the present invention is simple, light in weight and good in processability, the connection is simple, and the disassembly and assembly are more convenient.

Description

Technical Field

[0001] The present invention belongs to the field of solid rocket engines and relates to an expandable snap ring structure for a solid rocket engine. Background Art

[0002] There are connection requirements between components such as the cylinder body of the combustion chamber shell of a solid rocket engine and the head, the rear head and the nozzle, and the front head and the igniter. The main requirements for the connection structure are: reliable connection, good coaxiality and sealing. When designing the connection structure, it is necessary to take into account the convenience of propellant loading or casting, light weight, and easy processing and assembly. For the need of loading propellant or casting propellant, at least one of the connection parts at both ends of the shell should be a detachable structure. Snap ring connection is a common detachable connection structure, which is widely used in the connection of medium and small engines. Its advantages are simple structure, light weight and good processability. The expandable snap ring connection structure has the advantages of the simplest connection and more convenient disassembly and assembly.

[0003] The existing expandable snap ring connection structure mainly has the following disadvantages:

[0004] 1) The expandable snap ring structure installed circumferentially has a small application range. It is usually applicable to the connection structure of engines with a smaller diameter, and it needs to be used in conjunction with tooling. The installation and disassembly processability is poor and it cannot be reused.

[0005] 2) The expandable snap ring structure installed circumferentially is mostly of a split design, including a snap ring and a snap ring fastener. The snap ring itself cannot achieve axial limit; in addition, the split snap ring connection structure has more mating surfaces and poor disassembly and assembly processability. Summary of the Invention

[0006] The technical problem solved by the present invention is: overcoming the deficiencies of the prior art, and proposing an expandable snap ring structure for a solid rocket engine, which has a simple structure, light weight, good processability, simple connection, and more convenient disassembly and assembly.

[0007] The technical solution adopted by the present invention to solve the problem is:

[0008] An expandable snap ring structure for a solid rocket engine includes a head, an engine shell, an O-ring, a snap ring and a screw; wherein, the engine shell is a hollow cylindrical structure horizontally placed axially; the head coaxially extends into the inner cavity of the engine shell; the O-ring is arranged at the butt joint of the inner wall of the engine shell and the outer wall of the head; the snap ring is embedded in the inner wall of the engine shell; and the snap ring and the head are fixedly connected by screws.

[0009] In the above-mentioned expandable snap ring structure for a solid rocket engine, the axial head end of the head is an ellipsoidal structure; the circumferential direction of the head end of the head is a thickened area, and screw holes are uniformly arranged along the circumferential direction in the thickened area.

[0010] In the above-mentioned expanding snap ring structure of a solid rocket motor, a snap ring groove is provided on the inner wall of the motor housing; the snap ring is embedded in the snap ring groove and is located at the corresponding position of the head end thickening area of the head.

[0011] In the above-mentioned expanding snap ring structure of a solid rocket motor, the snap ring is evenly provided with counterbores in the circumferential direction, and the positions of the counterbores correspond one by one to the screw holes of the head.

[0012] In the above-mentioned expanding snap ring structure of a solid rocket motor, the screws respectively pass through the corresponding counterbores of the snap ring and are fixed in the corresponding screw holes of the head.

[0013] In the above-mentioned expanding snap ring structure of a solid rocket motor, the snap ring is an open snap ring, and the radial compression and expansion of the snap ring are realized through the opening.

[0014] In the above-mentioned expanding snap ring structure of a solid rocket motor, the maximum outer diameter of the snap ring is greater than the bottom diameter of the snap ring groove on the motor housing. The snap ring is axially placed in the snap ring groove of the motor housing in the compressed state, and after the snap ring expands, it is tightly and closely attached to the surface of the snap ring groove of the motor housing.

[0015] In the above-mentioned expanding snap ring structure of a solid rocket motor, the snap ring is fixed on the outer wall surface of the head through screws, realizing the connection and axial positioning between the head and the motor housing.

[0016] In the above-mentioned expanding snap ring structure of a solid rocket motor, the installation process of the expanding snap ring structure is as follows:

[0017] Move the head axially along the motor housing until the outer wall surface of the head is flush with the end face of the snap ring groove of the motor housing; manually compress the snap ring radially to deform it, and axially embed the snap ring into the snap ring groove of the motor housing; after the snap ring is embedded in the snap ring groove of the housing, the snap ring uses its own elastic deformation to closely fit with the snap ring groove of the motor housing in the compressed state; the bottom surface of the counterbore of the snap ring contacts the end face of the head; rotate the snap ring circumferentially to align the counterbore of the snap ring with the screw hole of the head, and screw the screw through the counterbore of the snap ring into the screw hole of the head to fasten it to the head.

[0018] In the above-mentioned expanding snap ring structure of a solid rocket motor, the disassembly process of the expanding snap ring structure is as follows:

[0019] Unscrew the screws in sequence, and then compress the snap ring radially from the opening of the snap ring, and the snap ring can be disassembled from the snap ring groove of the motor housing; then use the reserved tooling interface on the head to remove the head, realizing the separation of the motor housing and the head.

[0020] The beneficial effects of the present invention compared with the prior art are:

[0021] (1) The expandable snap ring structure of the present invention is particularly applicable to the connection between the engine housing and the head of an engine with a free-loading charge structure;

[0022] (2) The snap ring of the present invention is made of high-strength steel material and is integrally processed. The structure is simple and there is no complex processing technology;

[0023] (3) Compared with the circumferentially installed snap ring, the installation process of the present invention is simple. The snap ring is axially placed in the snap ring groove reserved on the housing in a compressed state and is closely attached to the bottom of the groove through its own expansion;

[0024] (4) The snap ring of the present invention fastens the housing and the head through screws and realizes axial positioning;

[0025] (5) The disassembly and assembly process of the present invention is simple. After compressing the snap ring and removing it axially, the housing and the head are separated; and the snap ring can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic diagram of the overall expandable snap ring structure of the present invention;

[0027] Figure 2 is a schematic diagram of the snap ring of the present invention;

[0028] Figure 3 is a schematic diagram of the counterbore of the snap ring of the present invention;

[0029] Figure 4 is a partially enlarged schematic diagram of the connection of the expandable snap ring structure of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention will be further described below in conjunction with embodiments.

[0031] The present invention provides an expandable snap ring structure for a solid rocket engine, which is integrally processed from high-strength steel and is used for the detachable connection of a solid rocket engine, including the connection between the head and the housing, the connection between the housing stages, and the connection between the housing and the nozzle, and realizes axial installation and positioning.

[0032] The expandable snap ring structure of the solid rocket engine, as Figure 1 、 Figure 4 shown, specifically includes a head 1, an engine housing 2, an O-ring 3, a snap ring 4, and screws 5; wherein, the engine housing 2 is a hollow cylindrical structure horizontally placed axially; the head 1 coaxially extends into the inner cavity of the engine housing 2; the O-ring 3 is arranged at the butt joint of the inner wall of the engine housing 2 and the outer wall of the head 1; the snap ring 4 is embedded in the inner wall of the engine housing 2; and the snap ring 4 and the head 1 are fixedly connected by screws 5.

[0033] Among them, the axial head end of the head 1 is an ellipsoidal structure; the circumferential head end of the head 1 is a thickened area, and screw holes are uniformly arranged along the circumference in the thickened area.

[0034] The inner wall of the engine housing 2 is provided with a snap ring groove; the snap ring 4 is embedded in the snap ring groove and is located at the corresponding position of the head end thickening area of the head 1.

[0035] As Figure 3 shown, the snap ring 4 is evenly provided with counterbores in the circumferential direction, and the positions of the counterbores correspond one by one to the screw holes of the head 1. The screws 5 respectively pass through the counterbores of the corresponding snap ring 4 and are fixed in the corresponding screw holes of the head 1.

[0036] As Figure 2 shown, the snap ring 4 is an open snap ring, and the radial compression and expansion of the snap ring 4 are realized through the opening. The maximum outer diameter of the snap ring 4 is greater than the bottom diameter of the snap ring groove on the engine housing 2. The snap ring 4 is axially placed in the snap ring groove of the engine housing 2 in the compressed state, and after the snap ring 4 expands, it is in close fit with the snap ring groove surface of the engine housing 2.

[0037] The snap ring 4 is fixed on the outer wall surface of the head 1 through the screw 5, realizing the connection between the head 1 and the engine housing 2 and the axial and circumferential positioning.

[0038] The installation process of the expansion type snap ring structure is as follows:

[0039] Move the head 1 axially along the engine housing 2 until the outer wall surface of the head 1 is flush with the end face of the snap ring groove of the engine housing 2; manually compress and deform the snap ring 4 and axially place it into the snap ring groove of the engine housing 2; the snap ring 4 makes close contact with the snap ring groove of the engine housing 2 by using its own elastic deformation in the compressed state; the bottom surface of the counterbore of the snap ring 4 contacts the end face of the head 1; rotate the snap ring 4 circumferentially to align the counterbore of the snap ring 4 with the screw hole of the head 1, and screw the screw 5 through the counterbore of the snap ring 4 into the screw hole of the head 1 and fasten it to the head 1.

[0040] The disassembly process of the expansion type snap ring structure is as follows:

[0041] Unscrew the screws 5 in sequence, and then compress the snap ring 4 from the opening of the snap ring 4, and the snap ring 4 can be disassembled from the snap ring groove of the engine housing 2; then use the reserved tooling interface on the head 1 to remove the head 1, realizing the separation of the engine housing 2 and the head 1.

[0042] The design content of the present invention includes the snap ring design method, the installation process and the disassembly process.

[0043] The present invention adopts this structure and realizes the following technical effects:

[0044] 1) The expansion type snap ring structure is particularly suitable for the connection between the engine housing and the head adopting the free loading charge structure;

[0045] 2) The snap ring is integrally designed with high-strength steel material, with higher structural reliability. It is integrally processed and formed, with a simple structure and no complex processing technology;

[0046] 3) Compared with the circumferentially installed snap ring, the installation process is simple. The snap ring is axially placed in the groove reserved on the shell in a compressed state and is in close fit with the bottom of the shell groove through its own expansion;

[0047] 4) The snap ring can fasten the shell and the head through screws and achieve axial positioning;

[0048] 5) The disassembly and assembly process is simple. After compressing the snap ring and moving it out axially, the head and the shell are separated;

[0049] 6) The snap ring can be reused.

[0050] A detachable expansion snap ring connection structure for a solid rocket motor according to the present invention. Among them, screw holes are circumferentially and evenly distributed on the outer wall of the ellipsoidal head of the head along the thickened area on the outer edge; a snap ring groove is provided on the inner wall of the engine shell; the snap ring is placed in the snap ring groove, and the snap ring faces the head; the screw passes through the counterbore on the snap ring and is connected and fastened to the screw hole on the head, fastening the head and the shell and achieving circumferential and axial positioning.

[0051] The installation and disassembly sequence is as follows: ① Move the head axially along the shell until the outer wall surface of the head is flush with the end face of the snap ring groove of the shell; ② Manually compress and deform the snap ring and axially place it into the snap ring groove of the shell. In the compressed state, the snap ring is in close fit with the snap ring groove of the shell by using its own elastic deformation, and the bottom surface of the step hole of the snap ring contacts the outer wall surface of the head; ③ Rotate the snap ring circumferentially to align the counterbore of the snap ring with the screw hole, and pass the screw through the counterbore of the snap ring and screw it into the screw hole of the head to fasten it to the head; ④ During disassembly, unscrew the screw in sequence, and then compress the snap ring from the opening of the snap ring, and the snap ring can be disassembled from the snap ring groove of the shell; ⑤ Then use the tooling interface reserved on the head to remove the head to separate the shell and the head.

[0052] The structure of the present invention has been applied in a certain model product, and the processability and producibility of the product have been verified, and it has passed multiple ground tests and flight test assessments. The structure is reliable, the function is stable, and it meets the use requirements.

[0053] Although the present invention has been disclosed above with preferred embodiments, it is not used to limit the present invention. Any person skilled in the art can 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 modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the technical solution of the present invention all belong to the protection scope of the technical solution of the present invention.

Claims

1. An expansion snap ring structure for a solid rocket motor, characterized in that: It includes a head (1), an engine housing (2), an O-ring (3), a snap ring (4) and screws (5); among them, the engine housing (2) is a hollow cylindrical structure horizontally placed axially; the head (1) extends coaxially into the inner cavity of the engine housing (2); the O-ring (3) is arranged at the butt joint of the inner wall of the engine housing (2) and the outer wall of the head (1); the snap ring (4) is embedded in the inner wall of the engine housing (2); the snap ring (4) and the head (1) are fixedly connected by screws (5). The installation process of the expansion snap ring structure is as follows: Move the head (1) axially along the engine housing (2) until the outer wall surface of the head (1) is flush with the end face of the snap ring groove of the engine housing (2); manually compress the snap ring (4) along the radial direction of the snap ring and axially place it into the snap ring groove of the engine housing (2); in the compressed state, the snap ring (4) makes tight contact with the snap ring groove of the engine housing (2) by its own elastic deformation; the bottom surface of the counterbore of the snap ring (4) contacts the end face of the head (1); rotate the snap ring (4) circumferentially to align the counterbore of the snap ring (4) with the screw hole of the head (1), and screw the screw (5) through the counterbore of the snap ring (4) into the screw hole of the head (1) to fasten it to the head (1). The disassembly process of the expansion snap ring structure is as follows: Unscrew the screws (5) in sequence, and then compress the snap ring (4) radially from the opening of the snap ring (4). When the outer diameter of the snap ring is compressed to be smaller than the bottom diameter of the snap ring groove, the snap ring (4) is removed from the snap ring groove of the engine housing (2); then use the reserved tooling interface on the head (1) to remove the head (1) to separate the engine housing (2) from the head (1).

2. The expansion snap ring structure for a solid rocket motor according to claim 1, characterized in that: The axial head end of the head (1) is an ellipsoidal structure; the circumferential direction of the head end of the head (1) is a thickened area, and screw holes are evenly arranged along the circumference in the thickened area.

3. The expansion snap ring structure for a solid rocket motor according to claim 2, characterized in that: The inner wall of the engine housing (2) is provided with a snap ring groove; the snap ring (4) is embedded in the snap ring groove and is located at the corresponding position of the thickened area at the head end of the head (1).

4. The expansion snap ring structure for a solid rocket motor according to claim 3, characterized in that: The snap ring (4) is evenly provided with counterbores along the circumferential direction, and the positions of the counterbores correspond one by one to the screw holes of the head (1).

5. The expansion snap ring structure for a solid rocket motor according to claim 4, characterized in that: The screws (5) respectively pass through the corresponding counterbores of the snap ring (4) and are fixed in the corresponding screw holes of the head (1).

6. The expansion snap ring structure for a solid rocket motor according to claim 5, characterized in that: The snap ring (4) is an open snap ring, and the radial compression and expansion of the snap ring (4) are realized through the opening.

7. The expansion snap ring structure for a solid rocket motor according to claim 6, characterized in that: The maximum outer diameter of the snap ring (4) is larger than the bottom diameter of the snap ring groove on the engine housing (2). The snap ring (4) in the radially compressed state is axially embedded in the snap ring groove of the engine housing (2), and after the snap ring (4) expands, it makes tight contact with the snap ring groove surface of the engine housing (2).

8. The expansion snap ring structure for a solid rocket motor according to claim 7, characterized in that: The snap ring (4) is fixed on the outer wall surface of the head (1) by screws (5), realizing the connection and axial positioning between the head (1) and the engine housing (2).

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