Airtightness pressure maintaining inspection tool for mechanical seal of centrifugal pump

Abstract

The application relates to the technical field of centrifugal pump mechanical seal detection, in particular to an air tightness pressure maintaining and detecting tool for a centrifugal pump mechanical seal, which comprises a base, a tool frame, a simulation mandrel and a gas path system. Through the cooperation of the sliding mandrel and the conical sliding block, the conical sliding block is axially moved along the sliding mandrel under the push of air pressure, so that dynamic loading between the dynamic ring and the static ring of the mechanical seal is realized. The design simulates the stress condition of the mechanical seal in the actual assembly state, and can effectively detect whether there are small defects on the grinding surface of the dynamic ring and the static ring. Meanwhile, through the design of the multi-stage sealing area, it is ensured that the gas in the test cavity cannot leak, so that the accuracy of the test result is improved. In addition, the tool is simple to operate, and the air tightness test of the mechanical seal can be quickly completed without professional training, the efficiency of finished product inspection is significantly improved, and reliable guarantee is provided for the overall quality of the centrifugal pump.

Description

Technical Field

[0001] This invention belongs to the field of mechanical seal testing technology, specifically a tooling for testing the air tightness and pressure holding of a centrifugal pump mechanical seal. Background Technology

[0002] Mechanical seals are a critical component of centrifugal pumps, and their performance directly affects the pump's reliability and service life. Currently, the inspection of unbalanced mechanical seals mainly relies on measuring instruments and spectrometers to inspect key dimensions and the light bands on the polished surfaces of the dynamic and static rings, combined with visual inspection to complete quality control. However, this inspection method lacks an evaluation step for the overall sealing performance of the assembled mechanical seal.

[0003] In practical applications, the grinding surfaces of the dynamic and static rings of mechanical seals may contain minute defects invisible to the naked eye, which are difficult to detect using conventional testing methods. When the mechanical seal is installed in the pump body, these potential problems can cause leakage, leading to pump failure during the testing phase. This not only increases the rework rate during assembly but also negatively impacts production efficiency and product quality.

[0004] To address the aforementioned issues, there is an urgent need to design a specialized measuring fixture capable of simulating the assembly state of a mechanical seal in a pump, for conducting more rigorous airtightness tests on finished mechanical seals. This fixture, by filling the pump with gas at a specific pressure and monitoring pressure changes, can effectively evaluate the sealing performance of the mechanical seal. Furthermore, it is easy to operate, provides accurate measurements, and can be quickly mastered without specialized training, thereby improving the accuracy and efficiency of finished mechanical seal inspection and providing technical support for enhancing the overall quality of pumps. Summary of the Invention

[0005] The purpose of this invention is to provide a pressure-holding test fixture for the air tightness of a centrifugal pump mechanical seal, so as to solve the problem that the sealing performance test is missing in the inspection process of finished mechanical seals in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A pressure-holding test fixture for the airtightness of a centrifugal pump mechanical seal includes a base, a fixture frame, a simulated mandrel, and an air circuit system.

[0008] A tooling frame is arranged on the base, and a pressure cap is fixedly connected to the top of the tooling frame. The base, tooling frame, and pressure cap form a cavity for airtightness pressure testing. The mechanical seal to be tested is provided at the top of the cavity.

[0009] The simulation mandrel is arranged in the cavity, penetrates the tool frame and extends to the base; the upper end of the simulation mandrel is provided with a tapered slider which moves axially along the simulation mandrel under the push of air pressure;

[0010] The air path system comprises an air inlet pipe and a differential pressure detection device; one end of the air inlet pipe penetrates the side wall of the tool frame and communicates with the inside of the cavity; the other end of the air inlet pipe is connected with an external air source; and the differential pressure detection device is connected with the air inlet pipe through a signal line.

[0011] As a preferred scheme of the present application, the mechanical seal comprises a sealing rubber ring and a mechanical seal static ring; the outer side of the sealing rubber ring is in contact with the inner side wall of the gland; the lower part of the sealing rubber ring is connected with the mechanical seal static ring; the mechanical seal static ring and the sealing rubber ring are pressed into the gland; and the outer side of the sealing rubber ring and the inner side wall of the gland form a first sealing area.

[0012] As a preferred scheme of the present application, the mechanical seal further comprises a mechanical seal dynamic ring and a bellows; the mechanical seal dynamic ring is located at the lower part of the mechanical seal static ring; the bellows is located at the lower part of the mechanical seal dynamic ring; the outer side wall of the tapered slider gradually expands towards the axis direction of the simulation mandrel from top to bottom; the wedge-shaped gap is formed between the outer side wall of the tapered slider and the inner side wall of the bellows; and the wedge-shaped gap is used for guiding the outward expansion of the bellows when the tapered slider moves upward.

[0013] As a preferred scheme of the present application, the mechanical seal further comprises a spring and a spring seat; the lower part of the spring seat is mounted on the base; the upper part of the spring seat is mounted with the spring; the spring is a compression spring; one end of the spring abuts against the spring seat; and the other end of the spring abuts against the mechanical seal dynamic ring.

[0014] As a preferred scheme of the present application, under the air pressure push of the air path system, when the tapered slider pushes the mechanical seal dynamic ring and the bellows to form an interference fit, the inner side wall of the mechanical seal dynamic ring and the bellows and the outer side wall of the tapered slider form a second sealing area.

[0015] As a preferred scheme of the present application, under the air pressure push of the air path system and the pressure of the spring, when the tapered slider moves upward to a predetermined position along the simulation mandrel under the air pressure, the upper end surface of the mechanical seal dynamic ring and the lower end surface of the mechanical seal static ring form a third sealing area.

[0016] As a preferred scheme of the present application, the lower part of the simulation mandrel is provided with a mandrel annular groove; and the piston type sealing structure is formed between the mandrel annular groove and the base through a sealing ring.

[0017] As a preferred scheme of the present application, the lower part of the tooling frame is provided with a first frame annular groove, the upper part of the tooling frame is provided with a second frame annular groove, the first frame annular groove forms a fourth sealing area with the base through a sealing ring, and the second frame annular groove forms a fifth sealing area with the gland through a sealing ring.

[0018] As a preferred scheme of the present application, the bottom of the base is provided with a plurality of base mounting through holes, the lower part of the tooling frame is provided with first frame threaded holes matched with the base mounting through holes, and the base and the tooling frame are fixedly installed together through threaded connecting pieces in the base mounting through holes and the first frame threaded holes.

[0019] The upper part of the tooling frame is provided with second frame threaded holes matched with the gland mounting through holes, and the gland and the tooling frame are fixedly installed together through threaded connecting pieces in the gland mounting through holes and the second frame threaded holes.

[0020] As a preferred scheme of the present application, the middle part of the base is provided with a base through hole matched with the outer diameter of the simulation mandrel, the base through hole is provided with a limiting groove, and the simulation mandrel is provided with a limiting protrusion matched with the limiting groove.

[0021] Compared with the prior art, the present application has the following beneficial effects:

[0022] In the present application, the cooperation structure of the sliding mandrel and the conical slider is introduced, and the conical slider moves axially along the sliding mandrel under the action of air pressure, so that the dynamic loading between the dynamic ring and the static ring of the mechanical seal is realized. This design simulates the stress condition of the mechanical seal in the actual assembly state, and can effectively detect whether there is a small defect in the grinding surface of the dynamic ring and the static ring. At the same time, through the design of multiple sealing areas, it is ensured that the gas in the test cavity will not leak, so as to improve the accuracy of the test result. In addition, the tooling operation is simple, and the air tightness test of the mechanical seal can be quickly completed without professional training, which significantly improves the efficiency of finished product inspection and provides reliable guarantee for the overall quality of the centrifugal pump.

[0023] In the present application, the base, the tooling frame and the gland are set, and multiple sealing rings are used to realize reliable sealing between the components to form a closed cavity. This design can ensure that the gas will not leak from the connection, and improve the accuracy of the detection result.

[0024] In the present application, the gas path system is set, and the differential pressure detection device is used to monitor the change of the gas pressure in the chamber in real time, so as to judge the sealing performance of the mechanical seal. This design is simple to operate and has high detection efficiency, and can be quickly used without professional training.

[0025] In the present application, the structure design of the simulation mandrel, the base, the tool frame and the gland is optimized to ensure the stable connection and reliable sealing between the components. This design not only improves the overall performance of the detection tool, but also enhances its durability and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0026] The present application will be further described below with reference to the accompanying drawings:

[0027] Figure 1 It is a perspective view of the air-tight pressure maintaining inspection tool of the embodiment of the present application.

[0028] Figure 2 It is a top view of the air-tight pressure maintaining inspection tool of the embodiment of the present application.

[0029] Figure 3 It is a sectional view of the embodiment of the present application Figure 2 towards A.

[0030] Figure 4 It is a structural view of the connection between the mechanical seal and the simulation mandrel of the embodiment of the present application.

[0031] Figure 5 It is a perspective view of the connection between the base, the tool frame and the gland of the embodiment of the present application.

[0032] Figure 6 It is an exploded view of the air-tight pressure maintaining inspection tool of the embodiment of the present application.

[0033] The reference signs are as follows:

[0034] 1. Base; 2. Tool frame; 3. Simulation mandrel; 4. Gas path system; 5. Gland; 6. Cavity; 7. Mechanical seal; 8. Conical sliding block; 9. Inlet pipe; 10. First sealing area; 11. Second sealing area; 12. Third sealing area; 13. Wedge-shaped gap; 14. Sealing ring; 15. Piston type sealing structure; 16. Fourth sealing area; 17. Fifth sealing area; 18. Base mounting through hole; 19. Threaded connecting piece; 20. Base through hole; 21. First frame annular groove; 22. Second frame annular groove; 23. First frame threaded hole; 24. Second frame threaded hole; 25. Limiting groove.

[0035] 31. Mandrel annular groove; 32. Limiting protrusion.

[0036] 51. Gland mounting through hole.

[0037] 71. Sealing rubber ring; 72. Mechanical seal static ring; 73. Mechanical seal dynamic ring; 74. Bellows; 75. Spring; 76. Spring seat. DETAILED DESCRIPTION

[0038] In order to make the objects, technical solutions and advantages of the present application clearer, the following will be further described in detail with the help of the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the scope of the present application. In addition, in the following description, the description of the known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0039] The present application provides a kind of air-tightness pressure maintaining inspection tool for centrifugal pump mechanical seal, as shown in the figure, the overall structure of the inspection tool is assembled by base 1, tool frame 2, gland 5, simulation mandrel 3 and gas path system 4, form a complete closed cavity 6 by mechanical connection and sealing design. Figures 1-6

[0040] The base 1 is arranged with tool frame 2, the top of the tool frame 2 is fixedly connected with gland 5, the base 1, tool frame 2 and gland 5 form the cavity 6 of air-tightness pressure maintaining inspection, the top of the cavity 6 is provided with the mechanical seal 7 to be detected.

[0041] The simulation mandrel 3 is arranged in the cavity 6, the simulation mandrel 3 penetrates the tool frame 2 and extends to the base 1;The upper end of the simulation mandrel 3 is provided with a tapered slide 8, which moves axially along the simulation mandrel 3 under the action of gas pressure.

[0042] The gas path system 4 includes air inlet pipe 9 and differential pressure detection device (not shown in the figure), one end of the air inlet pipe 9 penetrates the side wall of the tool frame 2 and communicates with the inside of the cavity 6, the other end of the air inlet pipe 9 is connected with external gas source, the differential pressure detection device is connected with the air inlet pipe 9 through signal line, for real-time monitoring of gas pressure in test cavity 6. When the external gas source injects gas into the test cavity 6 through the air inlet pipe 9, the gas pressure pushes the tapered slide 8 to move upward along the simulation mandrel 3, and the inner side wall of the mechanical seal rotating ring 73 and the bellows 74 contacts with the outer side wall of the tapered slide 8 to form the second sealing area 11. When the gas pressure reaches the preset value, the tapered slide 8 moves upward along the simulation mandrel 3 to the predetermined position, and the upper end surface of the mechanical seal rotating ring 73 and the lower end surface of the mechanical seal rotating ring 73 static ring form the third sealing area.

[0043] Specifically, the side wall of the tool frame 2 is provided with a through hole for the one end of the air inlet pipe 9 to communicate with the test cavity 6. The inside of the tool frame 2 is provided with a space for accommodating the simulation mandrel 3, and the simulation mandrel 3 penetrates the tool frame 2 and extends into the base through hole 20.

[0044] ​As a further illustration of the present embodiment, the mechanical seal 7 comprises a sealing rubber ring 71 and a mechanical seal static ring 72, the outer side of the sealing rubber ring 71 is in contact with the inner side wall of the gland 5, the lower part of the sealing rubber ring 71 is connected with the mechanical seal static ring 72, the mechanical seal static ring 72 is pressed into the gland 5 with the sealing rubber ring 71, and the contact between the outer side of the sealing rubber ring 71 and the inner side wall of the gland 5 forms a first sealing area 10.

[0045] As a further illustration of the present embodiment, the mechanical seal 7 further comprises a mechanical seal dynamic ring 73 and a bellows 74, the mechanical seal dynamic ring 73 is located at the lower part of the mechanical seal static ring 72, the bellows 74 is located at the lower part of the mechanical seal dynamic ring 73, the outer side wall of the tapered slide block 8 gradually expands towards the axis direction of the simulation mandrel 3 from top to bottom, and the wedge-shaped gap 13 is formed between the outer side wall of the tapered slide block 8 and the inner side wall of the bellows 74, which is used to guide the outward expansion of the bellows 74 when the tapered slide block 8 moves upward.

[0046] Specifically, the upper end of the simulation mandrel 3 is provided with a tapered slide block 8, the outer side wall of the tapered slide block 8 gradually expands towards the axis direction of the simulation mandrel 3 from top to bottom, forming a trapezoidal cross section which is small at the top and large at the bottom, and further forming a wedge-shaped gap 13 between the tapered slide block 8 and the mechanical seal 7. That is, the wedge-shaped gap 13 is formed between the outer side wall of the tapered slide block 8 and the inner side wall of the mechanical seal dynamic ring 73 and the bellows 74, and when the tapered slide block 8 moves upward along the simulation mandrel 3, the wedge-shaped gap 13 guides the outward expansion of the bellows 74, thereby realizing the dynamic loading of the mechanical seal dynamic ring 73. The bellows 74 is a rubber elastic bellows 74.

[0047] As a further illustration of the present embodiment, the mechanical seal 7 further comprises a spring 75 and a spring seat 76, the lower part of the spring seat 76 is mounted on the base 1, the upper part of the spring seat 76 is mounted with the spring 75, the spring 75 is a compression spring, one end of the spring 75 abuts against the spring seat 76, and the other end of the spring 75 abuts against the mechanical seal dynamic ring 73, thereby providing an elastic force upward for the mechanical seal dynamic ring 73. Specifically, the spring seat 76 is fixed on the base 1 by threaded connection or welding.

[0048] As a further illustration of the present embodiment, when the tapered sliding block 8 is pushed upward by the gas pressure of the gas path system 4, the inner side wall of the mechanical seal dynamic ring 73 and the bellows 74 and the outer side wall of the tapered sliding block 8 form a second sealing area 11. Specifically, the tapered sliding block 8 moves along the axial direction of the simulation mandrel 3 under the action of the gas pressure, and when it moves upward to a predetermined position, the tapered sliding block 8 pushes the bellows 74 to expand outward and form a tight contact with the mechanical seal dynamic ring 73, simulating the force condition of the actual working state of the mechanical seal.

[0049] As a further illustration of the present embodiment, when the tapered sliding block 8 is pushed upward by the gas pressure of the gas path system 4 and the pressure of the spring 75, the upper end surface of the mechanical seal dynamic ring 73 and the lower end surface of the mechanical seal static ring 72 form a third sealing area 12 when the tapered sliding block 8 moves upward to a predetermined position along the simulation mandrel 3 under the action of the gas pressure.

[0050] As a further illustration of the present embodiment, the lower part of the simulation mandrel 3 is provided with a mandrel annular groove 31, and the mandrel annular groove 31 forms a piston type sealing structure 15 with the base 1 through a sealing ring 14. Specifically, the simulation mandrel 3 penetrates the base 1 and forms a piston type sealing structure 15 with it, and the piston type sealing structure 15 is composed of two O-shaped sealing rings 14.

[0051] As a further illustration of the present embodiment, the lower part of the tooling frame 2 is provided with a first frame annular groove 21, and the upper part of the tooling frame 2 is provided with a second frame annular groove 22, the first frame annular groove 21 forms a fourth sealing area 16 with the base 1 through a sealing ring 14, and the second frame annular groove 22 forms a fifth sealing area 17 with the gland 5 through a sealing ring 14.

[0052] As a further illustration of the present embodiment, the bottom of the base 1 is provided with a plurality of base mounting through holes 18, the lower part of the tooling frame 2 is provided with a first frame threaded hole 23 matched with the base mounting through hole 18, and the base mounting through hole 18 and the first frame threaded hole 23 are fixedly installed together through a threaded connecting piece 19. The threaded connecting piece 19 is a connecting piece such as a screw or a bolt.

[0053] The upper part of the tooling frame 2 is provided with a second frame threaded hole 24 matched with the gland mounting through hole 51, and the gland mounting through hole 51 and the second frame threaded hole 24 are fixedly installed together through a threaded connecting piece 19.

[0054] As a further illustration of the present embodiment, the middle part of the base 1 is provided with a base through hole 20 which matches the outer diameter of the simulation mandrel 3, and the base through hole 20 is provided with a limiting groove 25, and the simulation mandrel 3 is provided with a limiting protrusion 32 which matches the limiting groove 25, so as to ensure that the moving range of the simulation mandrel 3 in the axial direction is limited.

[0055] In the actual operation process, first, the sealing rubber ring 71, the mechanical seal static ring 72, the mechanical seal dynamic ring 73, the bellows 74, the spring 75 and the spring seat 76 of the mechanical seal are sequentially installed between the base 1 and the tooling frame 2. Then the simulation mandrel 3 is penetrated through the tooling frame 2 and extends into the base through hole 20, and the limiting protrusion 32 of the simulation mandrel 3 is matched with the limiting groove 25 on the inner wall of the base through hole 20. Then the gland 5 is fixed on the top of the tooling frame 2 through the threaded connecting piece 19, and the fifth sealing area 17 is formed between the gland 5 and the tooling frame 2 through the sealing ring 14. Subsequently, one end of the gas inlet pipe 9 is penetrated through the side wall of the tooling frame 2 and communicates with the test cavity 6, and the other end is connected with the external gas source, and at the same time, the differential pressure detection device is connected with the gas inlet pipe 9 through the signal line.

[0056] After the above installation is completed, the external gas source is started, and the gas is injected into the test cavity 6 through the gas inlet pipe 9. With the increase of the gas pressure, the conical sliding block 8 moves upward along the simulation mandrel 3 under the action of the gas pressure, and the wedge-shaped gap 13 is formed between the outer side wall of the conical sliding block 8 and the inner side wall of the mechanical seal dynamic ring 73 and the bellows 74, which guides the bellows 74 to expand outward, thereby realizing the dynamic loading of the mechanical seal dynamic ring 73, and the outer side of the sealing rubber ring 71 contacts with the inner side wall of the gland 5 to form the first sealing area 10. When the gas pressure reaches the preset value, the conical sliding block 8 moves upward along the simulation mandrel 3 to the predetermined position, and the second sealing area 11 is formed between the upper end surface of the mechanical seal dynamic ring 73 and the lower end surface of the mechanical seal static ring 72. At this time, the differential pressure detection device monitors the gas pressure in the test cavity 6 in real time, and if the gas pressure in the test cavity 6 can be stabilized at the preset value, it indicates that the gas tightness of the mechanical seal is good; if the gas pressure in the test cavity 6 cannot be stabilized at the preset value, it indicates that there is a leakage problem in the mechanical seal.

[0057] Through the above structure design and operation process, the dynamic loading between the mechanical seal dynamic ring and the static ring is realized, the stress condition of the mechanical seal in the actual assembly state is simulated, and whether there is a small defect in the mechanical seal dynamic ring and the static ring can be effectively detected. At the same time, through the design of the multi-stage sealing area, it is ensured that the gas in the test cavity 6 will not leak, thereby improving the accuracy of the test result. In addition, the tooling operation is simple, and professional training is not required to quickly complete the gas tightness test of the mechanical seal, which significantly improves the efficiency of finished product inspection and provides reliable guarantee for the overall quality of the centrifugal pump.

[0058] In order to better enable those skilled in the art to fully understand and implement the present application, the specific implementation principles of the present application are further described below in conjunction with a specific application scenario.

[0059] Firstly, the mechanical seal 7 to be detected is installed into the tooling. The tooling frame 2 serves as the base component of the overall structure, and the first frame annular groove 21 at the lower part of the tooling frame 2 is used to install the seal ring 14, forming the fourth sealing area 16 and ensuring the initial sealing of the test cavity 6. Subsequently, the sealing rubber ring 71, the mechanical seal static ring 72, the mechanical seal dynamic ring 73, the bellows 74, the spring 75, and the spring seat 76 are sequentially assembled between the base 1 and the tooling frame 2. The simulation mandrel 3 penetrates through the tooling frame 2 and extends into the base through-hole 20, and the outer wall thereof forms a piston type sealing structure 15 with the inner wall of the base through-hole 20 through the seal ring 14. The gland 5 is fixed to the top of the tooling frame 2 through the threaded connection 19 and forms the fifth sealing area 17 through the seal ring 14, ensuring the closure of the entire tooling.

[0060] Subsequently, one end of the air inlet pipe 9 penetrates through the side wall of the tooling frame 2 and communicates with the test cavity 6, and the other end is connected to an external gas source. The differential pressure detection device is connected to the air inlet pipe 9 through a signal line for real-time monitoring of the gas pressure change in the test cavity 6. At this time, the multi-stage sealing area design of the tooling has been completed, including the first sealing area 10, the second sealing area 11, the third sealing area 12, the fourth sealing area 16, the fifth sealing area 17, and the piston type sealing structure 15. These sealing areas work together to ensure that the gas in the test cavity 6 does not leak, thereby providing reliable protection for subsequent air tightness testing.

[0061] After starting the external gas source, the gas enters the test cavity 6 through the air inlet pipe 9, and as the gas pressure gradually increases, the conical slider 8 moves upward along the simulation mandrel 3 under the action of the gas pressure. The wedge-shaped gap 13 is formed between the outer side wall of the conical slider 8 and the inner side wall of the mechanical seal dynamic ring 73 and the bellows 74, and the design of the wedge-shaped gap 13 enables the conical slider 8 to guide the bellows 74 to expand outward when moving upward, thereby achieving dynamic loading of the mechanical seal dynamic ring 73. This dynamic loading process simulates the stress condition of the mechanical seal in the actual assembly state, especially the contact pressure distribution between the mechanical seal dynamic ring 73 and the mechanical seal static ring 72, thereby effectively detecting whether there are micro defects on the dynamic and static ring running surfaces.

[0062] When the gas pressure reaches the preset value, the conical slider 8 moves upward along the simulation mandrel 3 to a predetermined position, at which time the upper end face of the mechanical seal rotating ring 73 is in close contact with the lower end face of the mechanical seal stationary ring 72, forming a third sealing area 12. At the same time, the differential pressure detection device monitors the gas pressure changes in the test cavity 6 in real time. If the gas pressure in the test cavity 6 can be stabilized at the preset value, it indicates that the mechanical seal has good air tightness; otherwise, if the gas pressure cannot be stabilized at the preset value, it indicates that the mechanical seal has a leakage problem. This detection method based on gas pressure changes can intuitively and accurately reflect the overall sealing performance of the mechanical seal.

[0063] In addition, the limiting protrusion 32 of the simulation mandrel 3 cooperates with the limiting groove 25 on the inner wall of the base through hole 20 to ensure that the movement range of the simulation mandrel 3 in the axial direction is limited, avoiding structural damage or test errors caused by excessive movement. The spring 75 provides an upward tendency force for the mechanical seal rotating ring 73 through compression spring force, further enhancing the contact stability between the mechanical seal rotating ring 73 and the mechanical seal stationary ring 72, thereby improving the reliability of the test results.

[0064] Through the above steps, the tool realizes dynamic loading between the mechanical seal rotating ring and the stationary ring, and ensures the sealing performance of the test cavity 6 through the design of multiple sealing areas. This design not only can effectively detect possible minor defects of the mechanical seal in the assembled state, but also significantly improves the efficiency of finished product inspection, providing reliable protection for the overall quality of the centrifugal pump. At the same time, the tool is easy to operate and can quickly complete the air tightness test of the mechanical seal without professional training, which is suitable for quality control links in large-scale production environment.

[0065] The contents not described in detail in the specification are all prior art known to those skilled in the art, and the model parameters of each electric appliance are not specifically limited, and conventional equipment can be used. In the technical solution, the electric appliance control elements not mentioned belong to prior art, so they are not shown in the figure, and will not be described here.

[0066] The above is only a specific embodiment of the present application, but the technical features of the present application are not limited to this. Any simple change, equivalent replacement or modification made on the basis of the present application to solve the same technical problem and achieve the same technical effect is covered by the protection scope of the present application.

Claims

1. A gas-tight pressure retaining inspection tool for a mechanical seal of a centrifugal pump, characterized by, The base, tooling frame, simulation mandrel and gas path system are included, The tooling frame is arranged on the base, and the top of the tooling frame is fixedly connected with a gland, and the base, tooling frame and gland form a cavity for airtight pressure maintaining inspection, and the top of the cavity is provided with a mechanical seal to be detected, The simulation mandrel is arranged in the cavity, penetrates through the tooling frame and extends to the base, and the upper end of the simulation mandrel is provided with a tapered slide block which moves axially along the simulation mandrel under the push of air pressure, The gas path system includes an air inlet pipe and a differential pressure detection device, one end of the air inlet pipe penetrates through the side wall of the tooling frame and communicates with the inside of the cavity, the other end of the air inlet pipe is connected with an external air source, and the differential pressure detection device is connected with the air inlet pipe through a signal line, The mechanical seal includes a sealing rubber ring and a mechanical seal static ring, the outer side of the sealing rubber ring is in contact with the inner side wall of the gland, the lower part of the sealing rubber ring is connected with the mechanical seal static ring, the mechanical seal static ring and the sealing rubber ring are pressed into the gland, and the outer side of the sealing rubber ring and the inner side wall of the gland form a first sealing area in contact with each other, The mechanical seal further includes a mechanical seal dynamic ring and a bellows, the mechanical seal dynamic ring is located at the lower part of the mechanical seal static ring, and the bellows is located at the lower part of the mechanical seal dynamic ring, the outer side wall of the tapered slide block gradually expands towards the axis direction of the simulation mandrel from top to bottom, a wedge-shaped gap is formed between the outer side wall of the tapered slide block and the inner side wall of the bellows, and the wedge-shaped gap is used for guiding the bellows to expand outward when the tapered slide block moves upward, Under the push of air pressure of the gas path system, the tapered slide block pushes the mechanical seal dynamic ring and the bellows to form an interference fit, and the inner side wall of the mechanical seal dynamic ring and the bellows is in contact with the outer side wall of the tapered slide block to form a second sealing area, Under the push of air pressure of the gas path system and the pressure of the spring, when the tapered slide block moves upward to a predetermined position along the simulation mandrel under the action of air pressure, the upper end surface of the mechanical seal dynamic ring and the lower end surface of the mechanical seal static ring are in contact to form a third sealing area.

2. The air-tightness pressure maintaining inspection tool for the mechanical seal of the centrifugal pump according to claim 1, characterized in that, The mechanical seal further includes a spring and a spring seat, the lower part of the spring seat is mounted on the base, the upper part of the spring seat is mounted with the spring, the spring is a compression spring, one end of the spring abuts against the spring seat, and the other end of the spring abuts against the mechanical seal dynamic ring.

3. The air-tightness pressure maintaining inspection tool of a centrifugal pump mechanical seal according to any one of claims 1-2, characterized in that, The lower part of the simulation mandrel is provided with a mandrel annular groove, and a piston type sealing structure is formed between the mandrel annular groove and the base through a sealing ring.

4. The air-tightness pressure maintaining inspection tool of mechanical seal of a centrifugal pump according to any one of claims 1-2, characterized in that, The lower part of the tooling frame is provided with a first frame annular groove, and the upper part of the tooling frame is provided with a second frame annular groove, the first frame annular groove forms a fourth sealing area with the base through a sealing ring, and the second frame annular groove forms a fifth sealing area with the gland through a sealing ring.

5. The air-tightness pressure maintaining inspection tool of a centrifugal pump mechanical seal according to any one of claims 1-2, characterized in that, The bottom of the base is provided with a plurality of base mounting through holes, the lower part of the tool frame is provided with first frame threaded holes matched with the base mounting through holes, and the base and the tool frame are fixedly installed together through threaded connecting pieces in the base mounting through holes and the first frame threaded holes. The upper part of the tool frame is provided with second frame threaded holes matched with the gland mounting through holes, and the gland and the tool frame are fixedly installed together through threaded connecting pieces in the gland mounting through holes and the second frame threaded holes.

6. The air-tightness pressure maintaining inspection tool of a centrifugal pump mechanical seal according to any one of claims 1-2, characterized in that, The middle part of the base is provided with a base through hole matched with the outer diameter of the simulation mandrel, the base through hole is provided with a limiting groove, and the simulation mandrel is provided with a limiting protrusion matched with the limiting groove.

Images