An aeronautical graphite seal auxiliary seal rubber ring air tightness test tool and its working method

Abstract

The application relates to an auxiliary sealing rubber ring air tightness inspection tool for aviation graphite sealing, which comprises a simulation static ring, a simulation inner ring, a simulation outer ring, an inner ring clamp and an outer ring clamp. The simulation static ring comprises an inner ring sleeve and an outer ring boss which are coaxial and integrally arranged, and the outer ring boss is fixedly arranged at the front end of the inner ring sleeve. The outer diameter and the inner diameter of the simulation inner ring are the same as the outer diameter and the inner diameter of the inner ring sleeve, and the outer diameter of the simulation outer ring is the same as the outer diameter of the outer ring boss. The annular outer wall of the simulation inner ring is in clearance fit with the annular inner wall of the simulation outer ring, and the simulation outer ring and the simulation inner ring are sleeved to form a combined body which is the same in shape as the simulation static ring. The simulation static ring can be used for inspecting the air tightness of the tool itself, and the simulation inner ring and the simulation outer ring can be used for air tightness detection of the auxiliary sealing rubber ring arranged between the two.

Description

Technical Field

[0001] This invention relates to the field of engine mechanical seal testing equipment technology, and in particular to a tooling for testing the air tightness of auxiliary sealing rings in aviation graphite seals and its working method. Background Technology

[0002] In recent years, the aviation industry has developed rapidly, and the requirements for aircraft maneuverability and reliability have been increasing. Therefore, it is urgent to improve the quality of various parts of aero engines in order to ensure their high performance requirements.

[0003] Graphite sealing devices, also known as end-face seals, are a type of mechanical seal. They are axial end-face sealing devices that achieve a seal by pre-tightening the static and dynamic ring end-face sealing pairs with elastic elements and by compressing the medium pressure against the elastic elements. Under the premise of a pressure difference between the sealed fluid and the external environment, maintaining a certain end-face contact pressure minimizes the axial clearance between the sealing friction pair end faces, thereby reducing leakage of the sealed fluid.

[0004] The sealing friction pair end face is the main sealing surface, which is the key to determining the friction, wear and sealing performance of the mechanical seal, and also determines the service life of the mechanical seal. As long as the surface roughness and straightness of the main sealing surface can meet the requirements, and as long as the material has good wear resistance, the mechanical seal can achieve very little leakage.

[0005] like Figure 1 As shown, the graphite sealing device consists of a graphite stationary ring assembly and a moving ring 64 (friction ring). The stationary ring assembly includes an outer ring 61, an inner ring 62, and a graphite ring 63. An auxiliary sealing ring 6 is provided between the inner wall of the outer ring 61 and the outer wall of the inner ring 62. The auxiliary sealing ring 6 provides a portion of the elastic force to realize the follow-up movement of sealing compensation. At the same time, a wave spring 65 acting axially is also provided between the outer ring 61 and the inner ring 62 for automatic compensation to prevent liquid or gas from leaking from the relatively moving parts of the sealing assembly.

[0006] Typical auxiliary sealing materials include synthetic rubber, with O-rings being the most commonly used auxiliary seals for end face sealing. Rubber compounds are selected based on operating temperature and media compatibility, primarily including nitrile rubber and fluororubber.

[0007] Research shows that the size selection and compression amount control of the auxiliary sealing rubber ring affect the elasticity and sealing performance of its components. There are three types of auxiliary sealing rubber rings: ① inner expansion and outer pressure type d1 < D1, d2 > D2; ② outer pressure type d1 > D1, d2 > D2; ③ inner expansion type d1 < D1, d2 < D2 (where D1 is the outer diameter of the inner ring, D2 is the inner diameter of the outer ring, d1 is the inner diameter of the rubber ring, and d2 is the outer diameter of the rubber ring). The elasticity and sealing performance of the three types of rubber rings are different, so when selecting different rubber rings, their sealing performance must be qualified. How to simply and quickly detect the airtightness of the auxiliary sealing rubber ring before it enters the graphite sealing device is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a tooling and its working method for airtightness inspection of the auxiliary sealing rubber ring in aviation graphite sealing, which has a simple structure and is easy to operate.

[0009] To solve the above-mentioned technical problems, the present invention provides a tooling for testing the airtightness of auxiliary sealing rings in aerospace graphite seals, comprising: a simulated stationary ring, a simulated inner ring, a simulated outer ring, an inner ring clamp, and an outer ring clamp. The simulated stationary ring includes a coaxial and integrally formed inner ring sleeve and an outer ring boss, the outer ring boss being fixedly disposed at the front end of the inner ring sleeve. The outer diameter and inner diameter of the simulated inner ring are the same as the outer diameter and inner diameter of the inner ring sleeve, and the outer diameter of the simulated outer ring is the same as the outer diameter of the outer ring boss. The annular outer wall of the simulated inner ring and the annular inner wall of the simulated outer ring are in clearance fit. The outer ring and the simulated inner ring are fitted together to form an assembly with the same shape as the simulated stationary ring. The outer ring clamp includes an integrally formed annular cylindrical body and a cylindrical bottom. An annular step is provided along the circumferential direction inside the cylindrical body. The annular inner wall of the annular step is clearance-fitted with the outer wall of the simulated outer ring and the outer ring boss. An outer ring clamp air tube is provided at the cylindrical bottom. The inner ring clamp is disc-shaped and includes a columnar boss located at the center of its end face and an annular sleeve located at the edge of its end face, so that a cavity is formed between the columnar boss and the annular sleeve. The inner ring clamp is provided with an inner ring clamp air tube communicating with the cavity. The annular outer wall of the boss fits with the inner wall of the simulated inner ring and inner ring sleeve with a clearance fit, and the outer wall of the annular sleeve fits with the inner wall of the outer ring clamp with a clearance fit. In use, the airtightness of the tooling is first checked, including fitting the outer ring boss of the simulated stationary ring into the annular step of the outer ring clamp, the inner wall of which is provided with a third sealing ring for sealing; the columnar boss of the inner ring clamp fits into the tail end of the inner ring sleeve, the outer wall of which is provided with a fourth sealing ring for sealing; the annular sleeve of the inner ring clamp fits into the cylinder of the outer ring clamp, the annular... A second sealing ring is provided between the sleeve and the cylinder body for sealing, so that a cylindrical cavity is formed between the bottom of the outer ring clamp, the inner ring sleeve of the simulated stationary ring, and the columnar boss of the inner ring clamp, and an annular cavity is formed between the annular cylinder body of the outer ring clamp, the outer ring sleeve of the simulated stationary ring, and the inner ring clamp; after the tooling airtightness test is qualified, the auxiliary sealing ring to be tested is placed between the outer wall of the simulated inner ring and the inner wall of the simulated outer ring, and the simulated stationary ring is replaced by the assembly formed by the simulated outer ring and the simulated inner ring, and the airtightness test is performed on the auxiliary sealing ring placed between the simulated inner ring and the simulated outer ring.

[0010] Furthermore, the annular inner wall of the simulated outer ring is provided with an annular groove along the circumference for placing the auxiliary sealing ring to be inspected.

[0011] Furthermore, the annular outer wall of the columnar boss is provided with a first annular groove along the circumference. During assembly, the fourth sealing ring is placed in the first annular groove to enhance the sealing effect between the columnar boss and the simulated inner ring.

[0012] Furthermore, a second annular groove is provided on the outer wall of the annular sleeve, and the second sealing ring is placed in the second annular groove during assembly to enhance the sealing effect between the inner ring clamp and the outer ring clamp.

[0013] Furthermore, a third annular groove is provided circumferentially inside the annular step, and a third sealing ring is placed inside the third annular groove during assembly to enhance the sealing effect between the annular step and the simulated outer ring.

[0014] Furthermore, the inner ring clamp is provided with a stepped portion on its edge, so that when the outer ring clamp's cylinder body is fitted with the annular sleeve, the stepped portion provides a limiting position.

[0015] Furthermore, the inner ring clamp is provided with a through first hole, through which the inner ring clamp air tube passes, such that the front end of the inner ring clamp air tube is placed inside the annular cavity and the tail end is placed outside the inner ring clamp. A first sealing ring is provided between the inner ring clamp air tube and the inner ring clamp for sealing. The bottom of the cylinder is provided with a through second hole, through which the outer ring clamp air tube passes, such that the tail end of the outer ring clamp air tube is placed inside the cylindrical cavity and the front end is placed outside the outer ring clamp. A fifth sealing ring is provided between the outer ring clamp air tube and the bottom of the cylinder for sealing.

[0016] Furthermore, the outer wall of the annular sleeve is provided with a positioning blind hole, and the annular body is provided with a through positioning insertion hole along its radial direction, so that when the annular sleeve is fitted into the annular body, a positioning pin can be inserted into the positioning insertion hole and the positioning blind hole to position the inner ring clamp and the outer ring clamp.

[0017] Furthermore, multiple unconnected bosses are provided on the inner side of the annular step on the bottom of the cylinder, so that when the simulated inner ring and simulated outer ring are fitted into the outer ring clamp, the ends of the simulated inner ring and simulated outer ring are supported by the bosses, avoiding direct contact between the ends of the simulated inner ring and simulated outer ring and the bottom of the cylinder, increasing the gap between the simulated inner ring and simulated outer ring and the bottom of the cylinder, so that when the auxiliary sealing ring leaks air, the leaked air can flow quickly between the annular cavity and the cylindrical cavity to reach the corresponding air pipe.

[0018] The working method of the above-mentioned auxiliary sealing ring airtightness testing fixture includes the following steps:

[0019] A. First, use a simulated stationary ring to test the airtightness of the inner and outer ring clamps. Fit the outer ring boss of the simulated stationary ring into the annular step of the outer ring clamp, and seal it with a third sealing ring. Fit the columnar boss of the inner ring clamp into the tail end of the inner ring sleeve, and seal it with a fourth sealing ring. Fit the annular sleeve of the inner ring clamp into the cylinder of the outer ring clamp, and seal it with a second sealing ring. Insert the positioning pin into the positioning hole and the positioning blind hole to limit and fix the inner and outer ring clamps. A cylindrical cavity is formed between the bottom of the outer ring clamp, the inner ring sleeve of the simulated stationary ring, and the columnar boss of the inner ring clamp. An annular cavity is formed between the annular cylinder of the outer ring clamp, the outer side of the inner ring sleeve of the simulated stationary ring, and the inner ring clamp.

[0020] B. Introduce gas at a certain pressure into the annular cavity through the inner ring clamp air tube, and place the outer ring clamp air tube below the water surface. Observe whether bubbles emerge. If no bubbles emerge, it proves that the gas in the annular cavity cannot enter the cylindrical cavity. Then, remove the gas pressure in the inner ring clamp air tube so that the gas pressure in the annular cavity is equal to the pressure outside the water surface. Place the inner ring clamp air tube below the water surface, and remove the outer ring clamp air tube from the water surface. Introduce gas at a certain pressure and observe whether bubbles emerge from the inner ring clamp air tube below the water surface. If no bubbles emerge, it proves that the gas in the cylindrical cavity cannot enter the annular cavity. If no bubbles emerge in both cases, it indicates that the airtightness of the third and fourth sealing rings is good.

[0021] C. Remove the simulated stationary ring, place the auxiliary sealing ring to be tested into the annular groove of the simulated outer ring, and replace the simulated stationary ring with the assembly formed by fitting the simulated outer ring and the simulated inner ring together. Repeat step B. If no bubbles emerge in either test, it indicates that the auxiliary sealing ring to be tested has good airtightness.

[0022] Furthermore, in step B, when gas is introduced into the annular cavity through the inner ring clamp air pipe, the fixed tool is placed below the water surface, and the surface of the tool is observed for air bubbles; when gas is introduced into the cylindrical cavity through the outer ring clamp air pipe, the surface of the tool is observed for air bubbles to check the airtightness of the first sealing ring, the second sealing ring, and the fifth sealing ring; if no air bubbles emerge in both instances, it indicates that the airtightness of the first sealing ring, the second sealing ring, and the fifth sealing ring is good.

[0023] Technical effects of the invention: (1) The air tightness test fixture for auxiliary sealing rings in aviation graphite seals of the present invention, compared with the prior art, can test the air tightness of the fixture itself by setting up a simulated stationary ring; (2) The simulated inner ring and simulated outer ring can be used to test the air tightness of the auxiliary sealing ring placed between the two. The simulated inner ring and simulated outer ring have simple structures and are easy to assemble and operate; (3) The fixture has a simple structure, low cost, and quick assembly. It is applicable to the air tightness test of sealing rings of internal expansion and external pressure type, internal expansion type, and external pressure type, and has a wide range of applications. Attached Figure Description

[0024] The present invention will now be described in further detail with reference to the accompanying drawings:

[0025] Figure 1 This is a cross-sectional structural diagram of a graphite sealing device in the prior art;

[0026] Figure 2 This is a schematic cross-sectional view of the simulated inner ring, simulated outer ring, inner ring fixture, and outer ring fixture after assembly according to the present invention.

[0027] Figure 3 This is a cross-sectional structural diagram of the inner ring clamp of the present invention;

[0028] Figure 4 This is a cross-sectional structural diagram of the outer ring clamp of the present invention;

[0029] Figure 5 This is a schematic cross-sectional view of the simulated stationary ring of the present invention.

[0030] In the figure: Inner ring clamp 1, columnar boss 11, annular sleeve 12, cavity 13, first annular groove 14, second annular groove 15, positioning blind hole 16, step 17, annular cavity 18, cylindrical cavity 19, inner ring clamp air tube 2, outer ring clamp air tube 3, first sealing ring 31, second sealing ring 32, third sealing ring 33, fourth sealing ring 34, fifth sealing ring 35, positioning pin 4, simulated inner ring 5, auxiliary sealing rubber ring 6, outer ring 61, inner ring 62, graphite ring 63, moving ring 64, wave spring 65, simulated stationary ring 7, outer ring boss 71, inner ring sleeve 72, outer ring clamp 8, annular step 81, third annular groove 82, positioning insertion hole 83, cylinder body 84, cylinder bottom 85, boss 86, simulated outer ring 9. Detailed Implementation

[0031] Example 1 like Figure 2As shown, the airtightness testing fixture for the auxiliary sealing ring in the aviation graphite seal of this embodiment includes a simulated stationary ring 7, a simulated inner ring 5, a simulated outer ring 9, an inner ring clamp 1, and an outer ring clamp 8. When the inner ring clamp 1 and the outer ring clamp 8 are used in conjunction with the simulated stationary ring 7, the airtightness of the fixture itself is tested. When the inner ring clamp 1 and the outer ring clamp 8 are used in conjunction with the simulated inner ring 5 and the simulated outer ring 9, the airtightness of the auxiliary sealing ring 6 placed between the simulated inner ring 5 and the simulated outer ring 9 is tested.

[0032] like Figure 5 As shown, the simulated stationary ring 7 includes an inner ring sleeve 72 and an outer ring boss 71 that are coaxially and integrally formed. The outer ring boss 71 is fixedly disposed at the front end of the inner ring sleeve 72; as Figure 2 As shown, the outer and inner diameters of the simulated inner ring 5 are the same as those of the inner ring sleeve 72. The outer diameter of the simulated outer ring 9 is the same as that of the outer ring boss 71. The annular outer wall of the simulated inner ring 5 and the annular inner wall of the simulated outer ring 9 are fitted with a clearance fit. The annular inner wall of the simulated outer ring 9 is provided with an annular groove along the circumference. The auxiliary sealing ring 6 to be inspected is placed in the annular groove. After the simulated outer ring 9 and the simulated inner ring 5 are fitted together, they form an assembly with the same shape as the simulated stationary ring 7.

[0033] like Figure 4 As shown, the outer ring clamp 8 includes an integrally formed annular cylindrical body 84 and a cylindrical bottom 85. An annular step 81 is provided circumferentially inside the cylindrical body 84. The annular inner wall of the annular step 81 is in clearance fit with the outer wall of the simulated outer ring 9 / outer ring boss 71. A third annular groove 82 is provided circumferentially inside the annular step 81, and a third sealing ring 33 for sealing is provided within the third annular groove 82. Two non-connected bosses 86 are provided on the inner side of the annular step 81 on the cylindrical bottom 85, so that when the simulated inner ring 5 and simulated outer ring 9 are fitted into the outer ring clamp 8, the ends of the simulated inner ring 5 and simulated outer ring 9 are supported by the bosses 86, preventing the ends of the simulated inner ring 5 and simulated outer ring 9 from directly contacting the cylindrical bottom 85.

[0034] like Figure 3 As shown, the inner ring clamp 1 is disc-shaped, including a columnar boss 11 located at the center of its end face and an annular sleeve 12 located at the edge of its end face, so that a cavity 13 is formed between the columnar boss 11 and the annular sleeve 12. The annular outer wall of the columnar boss 11 is in clearance fit with the inner wall of the simulated inner ring 5 / inner ring sleeve 72. The annular outer wall of the columnar boss 11 is provided with a first annular groove 14 in the circumferential direction, and a fourth sealing ring 34 for sealing is provided in the first annular groove 14. The outer wall of the annular sleeve 12 is in clearance fit with the inner wall of the cylinder 84 of the outer ring clamp 8. The outer wall of the annular sleeve 12 is provided with a second annular groove 15, and a second sealing ring 32 for sealing is provided in the second annular groove 15.

[0035] The inner ring clamp 1 is also provided with a stepped portion 17 on its edge, so that when the outer ring clamp 8's cylindrical body 84 is fitted with the annular sleeve 12, the stepped portion 17 is used to limit the movement. The outer wall of the annular sleeve 12 is provided with a positioning blind hole 16, and the annular cylindrical body 84 is provided with a through positioning insertion hole 83 along its radial direction, so that when the annular sleeve 12 is fitted inside the annular cylindrical body 84, a positioning pin 4 can be inserted into the positioning insertion hole 83 and the positioning blind hole 16 to limit and fix the inner ring clamp 1 and the outer ring clamp 8. The positioning pin 4 is fitted with the positioning blind hole 16 and the positioning insertion hole 83 with a clearance of 0.1 to 0.2 mm, which is easy to install and disassemble.

[0036] The inner ring clamp 1 is provided with a through hole, and the inner ring clamp air pipe 2 is provided through the first through hole. A first sealing ring 31 is provided between the inner ring clamp air pipe 2 and the inner ring clamp 1 for sealing. The bottom of the cylinder 85 is provided with a through hole at the center, and the outer ring clamp air pipe 3 is provided through the second through hole. A fifth sealing ring 35 is provided between the outer ring clamp air pipe 3 and the bottom of the cylinder 85 for sealing.

[0037] The inner ring clamp 1 and the simulated inner ring 5, the simulated inner ring 5 and the simulated outer ring 9, and the simulated outer ring 9 and the outer ring clamp 8 are radially fitted with a clearance of 0.05 to 0.1 mm; the simulated inner ring 5 and the inner ring clamp 1 and the outer ring clamp 8 are axially fitted with a clearance of 0.1 to 0.2 mm to facilitate installation.

[0038] When the inner ring clamp 1 and the outer ring clamp 8 are used in conjunction with the simulated stationary ring 7, the outer ring boss 71 of the simulated stationary ring 7 is fitted into the annular step 81 of the outer ring clamp 8, the columnar boss 11 of the inner ring clamp 1 is fitted into the tail end of the inner ring sleeve 72, and the annular sleeve 12 of the inner ring clamp 1 is fitted into the cylindrical body 84 of the outer ring clamp 8. A cylindrical cavity 19 is formed between the bottom 85 of the outer ring clamp 8, the inner ring sleeve 72 of the simulated stationary ring 7, and the columnar boss 11 of the inner ring clamp 1. An annular cavity 18 is formed between the annular cylindrical body 84 of the outer ring clamp 8, the outer side of the inner ring sleeve 72 of the simulated stationary ring 7, and the inner ring clamp 1. The front end of the inner ring clamp air tube 2 is placed in the annular cavity 18, and the tail end is placed outside the inner ring clamp 1. The tail end of the outer ring clamp air tube 3 is placed in the cylindrical cavity 19, and the front end is placed outside the outer ring clamp 8.

[0039] When the inner ring clamp 1 and outer ring clamp 8 are used in conjunction with the simulated inner ring 5 and simulated outer ring 9, the simulated outer ring 9 is fitted into the annular step 81 of the outer ring clamp 8, the front end of the simulated inner ring 5 is fitted into the simulated outer ring 9, the annular groove of the simulated outer ring 9 places the auxiliary sealing ring 6 to be tested between the simulated outer ring 9 and the simulated inner ring 5, the columnar boss 11 of the inner ring clamp 1 is fitted into the tail end of the simulated inner ring 5, and the annular sleeve 1 of the inner ring clamp 1... 2 is fitted inside the cylinder body 84 of the outer ring clamp 8. The cylindrical cavity 19 is formed between the columnar protrusion 11 of the inner ring clamp 1, the inner wall of the simulated inner ring 5, and the cylinder bottom 85 of the outer ring clamp 8. The cylindrical cavity 19 is also connected to the outside of the cylinder bottom 85 through the outer ring clamp air tube 3. The annular cavity 18 is formed between the outer wall of the simulated inner ring 5, the inner wall of the cylinder body 84, and the inner ring clamp 1. The annular cavity 18 is also connected to the outside of the inner ring clamp 1 through the inner ring clamp air tube 2. Example 2

[0040] The working method of the auxiliary sealing ring airtightness testing fixture in the aviation graphite seal, as described in Example 1, includes the following steps:

[0041] A. First, the airtightness of the inner ring clamp 1 and the outer ring clamp 8 is tested using a simulated stationary ring. The outer ring boss 71 of the simulated stationary ring 7 is fitted into the annular step 81 of the outer ring clamp and sealed by the third sealing ring 33. The columnar boss 11 of the inner ring clamp 1 is fitted into the tail end of the inner ring sleeve 72 and sealed by the fourth sealing ring 34. The annular sleeve 12 of the inner ring clamp 1 is fitted into the cylinder body 84 of the outer ring clamp 8 and sealed by the second sealing ring 34. The sealing ring 32 is used for sealing; the positioning pin 4 is inserted into the positioning hole 83 and the positioning blind hole 16 to limit and fix the inner ring clamp 1 and the outer ring clamp 8; a cylindrical cavity 19 is formed between the bottom 85 of the outer ring clamp 8, the inner ring sleeve 72 of the simulated stationary ring 7 and the columnar boss 11 of the inner ring clamp 1; an annular cavity 18 is formed between the annular body 84 of the outer ring clamp 8, the outer side of the inner ring sleeve 72 of the simulated stationary ring 7 and the inner ring clamp 1.

[0042] B. Introduce an airflow at a pressure of 0.5 MPa into the annular cavity 18 through the inner ring clamp air pipe 2, and place the outer ring clamp air pipe 3 below the water surface. Observe for 1 minute to see if any bubbles emerge. If no bubbles emerge, it proves that the gas in the annular cavity 18 cannot enter the cylindrical cavity 19 through the third sealing ring 33 and the fourth sealing ring 34. Then, remove the airflow introduced through the inner ring clamp air pipe 2, so that the air pressure in the annular cavity 18 is equal to the pressure outside the water surface. Place the inner ring clamp air pipe 2 below the water surface, and remove the outer ring clamp air pipe 3 from the water surface. Introduce an airflow at a pressure of 0.5 MPa and observe for 1 minute to see if any bubbles emerge from the inner ring clamp air pipe 2 below the water surface. If no bubbles emerge, it proves that the gas in the cylindrical cavity 19 cannot enter the annular cavity 18 through the third sealing ring 33 and the fourth sealing ring 34. The fact that no bubbles emerge in both instances indicates that the third sealing ring 33 and the fourth sealing ring 34 have good airtightness.

[0043] C. Remove the simulated stationary ring 7, place the auxiliary sealing ring 6 to be tested into the annular groove of the simulated outer ring 9, and then fit the simulated outer ring 9 and the simulated inner ring 5 together to form a combination to replace the simulated stationary ring 7. Repeat step B. If no bubbles emerge in either test, it means that the gas in the annular cavity 18 cannot enter the cylindrical cavity 19 through the third sealing ring 33, the fourth sealing ring 34, and the auxiliary sealing ring 6, and the gas in the cylindrical cavity 19 cannot enter the annular cavity 18 through the third sealing ring 33, the fourth sealing ring 34, and the auxiliary sealing ring 6. Therefore, the airtightness of the auxiliary sealing ring 6 to be tested is good. If bubbles emerge, since the airtightness of the third sealing ring 33 and the fourth sealing ring 34 has been tested in step B, it can be determined that the airtightness of the auxiliary sealing ring 6 does not meet the requirements.

[0044] To verify the airtightness of the first, second, and fifth sealing rings and avoid the airtightness of these rings affecting the testing efficiency, in step B, after introducing 0.5 MPa of airflow into the annular cavity through the inner ring clamp air pipe, the fixed device is placed below the water surface, with only the tail end of the inner ring clamp air pipe above the water surface. Observe for 1 minute, checking for bubbles emerging at the connection points of the inner ring clamp air pipe 2 and the inner ring clamp 1, the outer ring clamp air pipe 3 and the outer ring clamp 8, and the outer ring clamp 8 and the inner ring clamp 1. If no bubbles emerge, the airflow introduced through the inner ring clamp air pipe 2 is removed, leaving the annular cavity... The air pressure inside the cavity is equal to the pressure outside the water surface. The outer ring clamp air tube 3 is removed from the water surface, and the workpiece is placed below the water surface, with only the front end of the outer ring clamp air tube 3 above the water surface. A 0.5 MPa airflow is introduced into the cylindrical cavity through the front end of the outer ring clamp air tube 3. Observe for 1 minute, checking for air bubbles at the connections between the inner ring clamp air tube 2 and the inner ring clamp 1, the outer ring clamp air tube 3 and the outer ring clamp 8, and the outer ring clamp 8 and the inner ring clamp 1. If no air bubbles emerge in either connection, it indicates that the first sealing ring 31, the second sealing ring 32, and the fifth sealing ring 35 are airtight. Then proceed to step C. This effectively prevents air leakage from the first sealing ring 31, the second sealing ring 32, and the fifth sealing ring 35 from causing deviations in the test results.

[0045] The above-described tooling method is suitable for inspecting the airtightness of internal expansion and external pressure type, internal expansion type, and external pressure type sealing rings.

[0046] Obviously, the above embodiments are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, these obvious variations or modifications derived from the spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A tooling for testing the airtightness of auxiliary sealing rings in aerospace graphite seals, characterized in that, include: The system comprises a simulated stationary ring, a simulated inner ring, a simulated outer ring, an inner ring clamp, and an outer ring clamp. The simulated stationary ring includes a coaxial and integrally formed inner ring sleeve and an outer ring boss, with the outer ring boss fixedly disposed at the front end of the inner ring sleeve. The outer and inner diameters of the simulated inner ring are the same as those of the inner ring sleeve, and the outer diameter of the simulated outer ring is the same as that of the outer ring boss. The annular outer wall of the simulated inner ring and the annular inner wall of the simulated outer ring are clearance-fitted. After the simulated outer ring and the simulated inner ring are fitted together, they form an assembly with the same shape as the simulated stationary ring. The outer ring clamp includes an integrally formed annular cylindrical body and an outer ring clamp. At the bottom of the cylinder, an annular step is provided along the circumferential direction inside the cylinder body. The inner wall of the annular step is in clearance fit with the outer wall of the simulated outer ring and the outer ring boss. An outer ring clamp air tube is provided at the bottom of the cylinder. The inner ring clamp is disc-shaped, including a columnar boss located at the center of its end face and an annular sleeve located at the edge of its end face, so that a cavity is formed between the columnar boss and the annular sleeve. An inner ring clamp air tube communicating with the cavity is provided in the inner ring clamp. The annular outer wall of the columnar boss is in clearance fit with the inner wall of the simulated inner ring and the inner ring sleeve. The outer wall of the annular sleeve is in clearance fit with the inner wall of the cylinder body of the outer ring clamp. The simulated outer ring has an annular groove along its circumferential direction on its annular inner wall; a cylindrical cavity is formed between the bottom of the outer ring clamp, the inner ring sleeve of the simulated stationary ring, and the columnar boss of the inner ring clamp; an annular cavity is formed between the annular body of the outer ring clamp, the outer ring sleeve of the simulated stationary ring, and the inner ring clamp. The inner ring clamp has a through first hole, through which the inner ring clamp air tube passes, such that the front end of the air tube is placed inside the annular cavity and the tail end is placed outside the inner ring clamp. A first sealing ring is provided between the inner ring clamp air tube and the inner ring clamp for sealing. The bottom of the cylinder has a through second hole, through which the outer ring clamp air tube passes, such that the tail end of the outer ring clamp air tube is placed inside the cylindrical cavity and the front end is placed outside the outer ring clamp. A fifth sealing ring is provided between the outer ring clamp air tube and the bottom of the cylinder for sealing. The outer wall of the annular sleeve is provided with a positioning blind hole, and the annular cylinder body is provided with a through positioning insertion hole along its radial direction.

2. The fixture for testing the air tightness of auxiliary sealing rings in aerospace graphite seals according to claim 1, characterized in that, The inner ring clamp also has a stepped portion on its edge.

3. The fixture for testing the airtightness of auxiliary sealing rings in aerospace graphite seals according to claim 2, characterized in that, Multiple non-connected bosses are provided on the bottom of the cylinder along the inner side of the annular step, so that when the simulated inner ring and simulated outer ring are fitted into the outer ring clamp, the ends of the simulated inner ring and simulated outer ring are supported by the bosses.

4. The working method of the tooling for testing the air tightness of auxiliary sealing rings in aerospace graphite seals as described in any one of claims 1 to 3, characterized in that, Includes the following steps: A. First, use a simulated stationary ring to test the airtightness of the inner and outer ring clamps. Fit the outer ring boss of the simulated stationary ring into the annular step of the outer ring clamp, and seal it with a third sealing ring. Fit the columnar boss of the inner ring clamp into the tail end of the inner ring sleeve, and seal it with a fourth sealing ring. Fit the annular sleeve of the inner ring clamp into the cylinder of the outer ring clamp, and seal it with a second sealing ring. Insert the positioning pin into the positioning hole and the positioning blind hole to limit and fix the inner and outer ring clamps. A cylindrical cavity is formed between the bottom of the outer ring clamp, the inner ring sleeve of the simulated stationary ring, and the columnar boss of the inner ring clamp. An annular cavity is formed between the annular cylinder of the outer ring clamp, the outer side of the inner ring sleeve of the simulated stationary ring, and the inner ring clamp. B. Introduce gas at a certain pressure into the annular cavity through the inner ring clamp air tube, and place the outer ring clamp air tube below the water surface. Observe whether bubbles emerge. If no bubbles emerge, it proves that the gas in the annular cavity cannot enter the cylindrical cavity. Then, remove the gas pressure introduced into the inner ring clamp air tube, so that the gas pressure in the annular cavity is equal to the pressure outside the water surface. Place the inner ring clamp air tube below the water surface, and take the outer ring clamp air tube out of the water surface and introduce gas at a certain pressure. Observe whether bubbles emerge from the inner ring clamp air tube placed below the water surface. If no bubbles emerge, it proves that the gas in the cylindrical cavity cannot enter the annular cavity. If no bubbles emerge in both cases, it indicates that the airtightness of the third and fourth sealing rings is good. C. Remove the simulated stationary ring, place the auxiliary sealing ring to be tested into the annular groove of the simulated outer ring, and replace the simulated stationary ring with the assembly formed by fitting the simulated outer ring and the simulated inner ring together. Repeat step B. If no bubbles emerge in either test, it indicates that the auxiliary sealing ring to be tested has good airtightness.

5. The working method according to claim 4, characterized in that, In step B, when gas is introduced into the annular cavity through the inner ring clamp air pipe, the fixed tool is placed below the water surface, and the surface of the tool is observed to see if there are air bubbles; when gas is introduced into the cylindrical cavity through the outer ring clamp air pipe, the surface of the tool is observed to see if there are air bubbles, in order to check the airtightness of the first sealing ring, the second sealing ring, and the fifth sealing ring.

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