High-precision embedded gas film thickness measurement experiment device and method

Abstract

The invention relates to a high-precision embedded gas film thickness measurement experiment device and method, and belongs to the technical field of dry gas sealing, and the high-precision embedded gas film thickness measurement experiment device comprises a driving shaft, a shaft sleeve, a tool, an experiment sealing mechanism, an electromagnetic wave receiving and transmitting module and a target body. The experimental sealing mechanism comprises an experimental moving ring assembly and an experimental static ring assembly, the electromagnetic wave receiving and transmitting module is arranged on the experimental static ring assembly and used for transmitting high-frequency electromagnetic waves to the experimental moving ring assembly, the electromagnetic wave receiving and transmitting module is electrically connected with an external control system, and the target body is arranged on the experimental moving ring assembly and used for transmitting the high-frequency electromagnetic waves to the experimental moving ring assembly. The target body is used for reflecting electromagnetic waves after being irradiated by high-frequency electromagnetic waves, and the electromagnetic wave receiving and transmitting module is further used for receiving the electromagnetic waves reflected by the target body. The method has the effect of improving the measurement precision of the thickness of the dry gas sealing gas film.

Description

Technical Field

[0001] This application relates to the field of dry gas sealing technology, and in particular to a high-precision embedded gas film thickness measurement experimental device and method. Background Technology

[0002] Dry gas seals are a type of non-contact mechanical seal widely used in high-speed rotating equipment such as centrifugal compressors and expanders. During operation, a stable gas film forms between the rotating and stationary rings of a dry gas seal. The thickness of this gas film is crucial for assessing the health of the dry gas seal and predicting its service life.

[0003] Currently, there is no standard experimental method for measuring the thickness of the gas film during dry gas seal operation. Therefore, there is a need to provide a high-precision experimental device and method for measuring the thickness of the gas film. Summary of the Invention

[0004] To improve the accuracy of dry gas sealing film thickness measurement, this application provides a high-precision embedded gas film thickness measurement experimental device and method.

[0005] Firstly, this application provides a high-precision embedded air film thickness measurement experimental device, which adopts the following technical solution: A high-precision embedded air film thickness measurement experimental device includes: A drive shaft for connecting to an external drive mechanism; A bushing, which is mounted on the drive shaft to rotate synchronously with the drive shaft; The tooling is located outside the bushing and is used to connect to the housing of the drive mechanism. The tooling is provided with a sealing air port. An experimental sealing mechanism includes an experimental dynamic ring assembly and an experimental stationary ring assembly. The experimental dynamic ring assembly is mounted on a bushing, and the experimental stationary ring assembly is mounted on a tooling. A dry gas seal is formed between the experimental stationary ring assembly and the experimental dynamic ring assembly. A sealing cavity is formed between the bushing, the tooling, and the experimental sealing mechanism. The sealing gas interface communicates with the sealing cavity. An electromagnetic wave transceiver module is installed on the experimental static ring assembly and is used to transmit high-frequency electromagnetic waves to the experimental dynamic ring assembly. The electromagnetic wave transceiver module is electrically connected to an external control system. The target body is mounted on the experimental dynamic environment assembly. The target body is used to reflect electromagnetic waves after being irradiated by high-frequency electromagnetic waves. The electromagnetic wave transceiver module is also used to receive the electromagnetic waves reflected by the target body.

[0006] Preferably, multiple electromagnetic wave transceiver modules are evenly spaced along the circumference of the experimental static ring assembly, and the number of target objects is the same as the number of electromagnetic wave transceiver modules, with the multiple target objects evenly spaced along the circumference of the experimental dynamic ring assembly.

[0007] Preferably, the target body includes multiple sheet bodies, which are stacked sequentially along the axial direction of the drive shaft.

[0008] Preferably, the target body is made of an electromagnetic alloy material, which includes niobium, zinc, copper, iron and titanium.

[0009] Preferably, the outer rings of the experimental moving ring assembly and the experimental stationary ring assembly are connected to the sealing cavity. The experimental moving ring assembly includes a first moving ring, and the experimental stationary ring assembly includes a first spring, a first push ring, and a first stationary ring. An installation ring is provided on the inner side of the first stationary ring. The electromagnetic wave transceiver module is mounted on the installation ring. The distance from the target body to the drive shaft axis is equal to the distance from the electromagnetic wave transceiver module to the drive shaft axis.

[0010] Preferably, the distance from the sealing end face of the first stationary ring to the sealing end face of the first rotating ring is less than the distance from the side of the mounting ring near the first rotating ring to the sealing end face of the first rotating ring. The side of the electromagnetic wave transceiver module near the target body is flush with the side of the mounting ring near the first rotating ring, and the side of the target body near the electromagnetic wave transceiver module is flush with the side of the first rotating ring near the first stationary ring.

[0011] Preferably, the measurement experimental apparatus further includes a balancing sealing mechanism located on the side of the experimental sealing mechanism closer to the drive mechanism. The balancing sealing mechanism includes a balancing moving ring assembly and a balancing stationary ring assembly. The balancing moving ring assembly is mounted on a bushing, and the balancing stationary ring assembly is mounted on a fixture. A dry gas seal is formed between the balancing stationary ring assembly and the balancing moving ring assembly. The sealing cavity is enclosed by the balancing sealing mechanism, the bushing, the fixture, and the experimental sealing mechanism. The experimental stationary ring assembly is located on the side of the experimental moving ring assembly away from the balancing sealing mechanism. The connecting cable of the electromagnetic wave transceiver module extends out through the side of the fixture away from the drive mechanism. A leakage cavity is formed between the experimental sealing mechanism, the bushing, and the side of the fixture away from the balancing sealing mechanism. A leakage gas interface is provided on the fixture, and the leakage gas interface communicates with the leakage cavity.

[0012] Preferably, the bushing includes a tapered sleeve and a transition sleeve. The tapered sleeve is used to connect with the drive shaft, and the transition sleeve is fitted outside the tapered sleeve. The experimental moving ring assembly and the balance moving ring assembly are respectively disposed at both ends of the transition sleeve. Both ends of the transition sleeve are provided with clamping sleeves, which are used to press and fix the experimental moving ring assembly or balance moving ring assembly at the corresponding end onto the transition sleeve.

[0013] Preferably, the tooling has a cooling cavity, which is arranged circumferentially along the tooling. The tooling has a coolant inlet and a coolant outlet, which are connected to the cooling cavity. The cooling cavity is aligned with the sealing cavity.

[0014] Secondly, this application provides a high-precision embedded air film thickness measurement experimental method, which adopts the following technical solution: A high-precision embedded air film thickness measurement experimental method, using the aforementioned measurement experimental device, includes the following steps: Before the dry gas seal is put into operation, the experimental stationary ring assembly and the experimental moving ring assembly are in close contact. Let x be the number of electromagnetic wave transceiver modules on the experimental stationary ring assembly, and let the axial distance between each electromagnetic wave transceiver module and the corresponding target body be . ; During dry gas sealing operation, a gas film forms between the experimental stationary ring assembly and the experimental moving ring assembly. The experimental stationary ring assembly drives x electromagnetic wave transceiver modules to synchronously generate axial displacement, transmitting high-frequency electromagnetic waves to the experimental moving ring assembly through these modules. After being irradiated by the high-frequency electromagnetic waves, the target object rebounds with electromagnetic waves. The electromagnetic wave transceiver modules receive the rebounding electromagnetic waves from the aligned target object. The external control system calculates the round-trip propagation time difference of the electromagnetic waves at each transceiver module along the ranging path. i takes the values ​​1, 2, ..., x in sequence; During dry gas sealing operation, the electromagnetic wave transmission speed at each electromagnetic wave transceiver module for, Where c is the speed of light in a vacuum. Let be the refractive index of the electromagnetic wave at the i-th electromagnetic transceiver module in the sealed gas; During dry gas seal operation, the average axial distance L1 between all electromagnetic transceiver modules and the aligned target is, ; The gas film thickness b is obtained during dry gas seal operation. .

[0015] In summary, this application includes the following beneficial technical effects: Before the dry gas seal operates, the experimental stationary ring assembly and the experimental moving ring assembly are in close contact. The initial axial distance between the electromagnetic wave transceiver module and the target object is known at this point. When the dry gas seal operates, the drive mechanism drives the drive shaft to rotate, filling the sealing gas interface with compressed air. The drive shaft drives the bushing and the experimental moving ring assembly to rotate synchronously, forming an air film between the experimental stationary ring assembly and the experimental moving ring assembly. The experimental stationary ring assembly drives the electromagnetic wave transceiver module to synchronously generate axial displacement, transmitting high-frequency electromagnetic waves to the experimental moving ring assembly. After being irradiated by the high-frequency electromagnetic waves, the target object rebounds with electromagnetic waves. The electromagnetic wave transceiver module receives the rebounding electromagnetic waves from the target object, and the electromagnetic wave at each transceiver module is measured through an external control system. The external control system calculates the transmission speed of electromagnetic waves at each electromagnetic transceiver module based on the refractive index of the electromagnetic waves in the sealing gas, taking into account the round-trip propagation time difference along the path. Then, it calculates the axial distance between each electromagnetic transceiver module and the target body using the electromagnetic wave transmission speed and the round-trip propagation time difference. The difference between the average distance between all electromagnetic transceiver modules and the target body during sealing operation and the initial distance is the gas film thickness. This allows for the measurement of gas film thickness during operation at the sealed end face. Designing the electromagnetic transceiver modules and the target body close to the sealed end face helps to reflect the deformation of the sealed end face, effectively improving the accuracy of gas film thickness measurement during dry gas sealing operation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the measurement experimental device according to an embodiment of this application.

[0017] Figure 2 This is a schematic diagram of the experimental sealing mechanism in the measurement experimental apparatus of this application embodiment.

[0018] Figure 3 This is a schematic diagram of the structure of the balancing sealing mechanism in the measurement experimental device of this application embodiment.

[0019] Explanation of reference numerals in the attached drawings: 1. Drive shaft; 2. Bushing; 21. Tapered sleeve; 22. Transition sleeve; 221. Sleeve body; 3. Tooling; 31. First assembly; 32. Second assembly; 33. End cap; 4. Sealing gas interface; 5. Experimental sealing mechanism; 51. Experimental moving ring assembly; 52. Experimental stationary ring assembly; 521. First spring; 522. First push ring; 523. First stationary ring; 6. Sealing cavity; 7. Electromagnetic wave transceiver module; 8. Target body; 9. Mounting ring; 10. Balance sealing mechanism; 101. Balance moving ring assembly; 102. Balance stationary ring assembly; 1021. Second spring; 1022. Second push ring; 1023. Second stationary ring; 11. Leakage cavity; 12. Leakage gas interface; 13. Cooling cavity; 14. Coolant inlet; 15. Coolant outlet; 16. Compression sleeve; 17. Spare interface; 18. Experimental interface. Detailed Implementation

[0020] The following combination Figure 1-3 This application will be described in further detail.

[0021] This application discloses a high-precision embedded air film thickness measurement experimental device. (Refer to...) Figure 1 and Figure 2 The high-precision embedded air film thickness measurement experimental device includes a drive shaft 1, a bushing 2, a fixture 3, an experimental sealing mechanism 5, an electromagnetic wave transceiver module 7, and a target body 8. One end of the drive shaft 1 is connected to the drive mechanism, which drives the drive shaft 1 to rotate for measurement testing. The bushing 2 is fixedly sleeved on the end of the drive shaft 1 away from the drive mechanism to rotate synchronously with the drive shaft 1. The fixture 3 is located outside the bushing 2. Specifically, the fixture 3 is detachably connected to the spindle box of the drive mechanism by bolts, so that the fixture 3 remains relatively fixed when the drive shaft 1 rotates. The fixture 3 is provided with a sealing gas interface 4, which is used to introduce test sealing gas. In this embodiment, the test sealing gas is compressed air.

[0022] Reference Figure 1 and Figure 2 The experimental sealing mechanism 5 includes an experimental dynamic ring assembly 51 and an experimental stationary ring assembly 52. ​​The experimental dynamic ring assembly 51 is mounted on the bushing 2, and the experimental stationary ring assembly 52 is mounted on the tooling 3. A dry gas seal is formed between the experimental stationary ring assembly 52 and the experimental dynamic ring assembly 51. A sealing cavity 6 is formed between the bushing 2, the tooling 3, and the experimental sealing mechanism 5. The sealing gas interface 4 is connected to the sealing cavity 6. By introducing sealing gas into the sealing gas interface 4, a gas film is formed between the experimental dynamic ring assembly 51 and the experimental stationary ring assembly 52.

[0023] Reference Figure 1 and Figure 2The electromagnetic wave transceiver module 7 is installed on the experimental static environment assembly 52 and is electrically connected to the external control system. Specifically, the electromagnetic wave transceiver module 7 includes an electromagnetic wave transmitter and an electromagnetic wave receiver, both of which are electrically connected to the external control system via connecting cables. The electromagnetic wave transceiver module 7 is used to transmit high-frequency electromagnetic waves to the experimental dynamic environment assembly 51. The target body 8 is installed on the experimental dynamic environment assembly 51. The target body 8 is used to rebound electromagnetic waves after being irradiated by high-frequency electromagnetic waves. The electromagnetic wave transceiver module 7 is also used to receive the electromagnetic waves rebounded by the target body 8.

[0024] Before the dry gas seal is put into operation, the experimental stationary ring assembly 52 and the experimental moving ring assembly 51 are in close contact. The initial axial distance between the electromagnetic wave transceiver module 7 and the target body 8 is known at this time.

[0025] When the dry gas seal is running, the drive mechanism drives the drive shaft 1 to rotate, filling the sealing gas interface 4 with compressed air. The drive shaft 1 drives the bushing 2 and the experimental dynamic ring assembly 51 to rotate synchronously. An air film is formed between the experimental stationary ring assembly 52 and the experimental dynamic ring assembly 51. The experimental stationary ring assembly 52 drives the electromagnetic wave transceiver module 7 to generate axial displacement synchronously. The electromagnetic wave transceiver module 7 transmits high-frequency electromagnetic waves to the experimental dynamic ring assembly 51. After being irradiated by the high-frequency electromagnetic waves, the target body 8 rebounds electromagnetic waves. The electromagnetic wave transceiver module 7 receives the rebound electromagnetic waves from the target body 8, so that the electromagnetic waves at each electromagnetic wave transceiver module 7 can be measured at the external control system. The round-trip propagation time difference along the path is used to calculate the transmission speed of electromagnetic waves based on the refractive index of electromagnetic waves in the sealing gas at each electromagnetic transceiver module 7. The axial distance between each electromagnetic transceiver module 7 and the aligned target body 8 is calculated using the electromagnetic wave transmission speed at each electromagnetic transceiver module 7 and the round-trip propagation time difference. The difference between the average distance between all electromagnetic transceiver modules 7 and the target body 8 and the initial distance is the gas film thickness. Designing the electromagnetic transceiver modules and the target body close to the sealing end face helps to reflect the deformation of the sealing end face and effectively improves the accuracy of gas film thickness measurement during dry gas sealing operation.

[0026] Reference Figure 1 and Figure 2The outer rings of the experimental moving ring assembly 51 and the experimental stationary ring assembly 52 are connected to the sealing cavity 6. The experimental moving ring assembly 51 includes a first moving ring, which is fixedly mounted on the bushing 2. The experimental stationary ring assembly 52 includes a first spring 521, a first push ring 522, and a first stationary ring 523. The first push ring 522 is axially slidably mounted on the fixture 3 by multiple first springs 521. The first stationary ring 523 is fixedly connected to the side of the first push ring 522 closest to the first moving ring. Under the elastic force of the multiple first springs 521, the first stationary ring 523 is tightly abutted against the first moving ring before the dry gas seal is in operation. To prevent the first stationary ring 523 from rotating, multiple anti-rotation guide pins (not shown in the figure) are spaced apart along the circumference of the first push ring 522. The anti-rotation guide pins slide axially through the fixture 3.

[0027] Reference Figure 1 and Figure 2 Multiple electromagnetic transceiver modules 7 are evenly spaced along the circumference of the first stationary ring 523 in the experimental stationary ring assembly 52. ​​The number of target bodies 8 is the same as that of electromagnetic transceiver modules 7, and the multiple target bodies 8 are evenly spaced along the circumference of the first moving ring in the experimental moving ring assembly 51. Specifically, four electromagnetic transceiver modules 7 are arranged along the circumference of the first stationary ring 523, and the four electromagnetic transceiver modules 7 and the four target bodies 8 are all distributed at 90° intervals. In other embodiments, the number of electromagnetic transceiver modules 7 can be set as needed. By using the average axial distance between the multiple electromagnetic transceiver modules 7 and the aligned target body 8, the accuracy of gas film thickness measurement is further improved. Moreover, multi-point distributed measurement can realize three-dimensional spatial measurement data of dry gas sealing gas film thickness. The distance measured at each electromagnetic transceiver module 7 is different. Through the three-dimensional grid processing of multi-point measurement data, a three-dimensional display model of gas film thickness is formed, which can fit the thickness of one ring of the gas film and more intuitively and accurately reflect the characteristics of the gas film thickness.

[0028] Reference Figure 1 and Figure 2To facilitate the installation of the electromagnetic wave transceiver module 7 and the target 8, an installation ring 9 is fixed to the inner ring of the first stationary ring 523. The installation ring 9 is made of a high-temperature resistant material, specifically a copper ring. The soft installation ring 9 can avoid affecting the hardness of the first stationary ring 523. The electromagnetic wave transceiver module 7 is embedded on the surface of the installation ring 9 near the first moving ring, and the target 8 is embedded on the side of the first moving ring near the installation ring 9. The distance from the target 8 to the axis of the drive shaft 1 is equal to the distance from the electromagnetic wave transceiver module 7 to the axis of the drive shaft 1. This allows the target 8 on the first moving ring to intermittently align with the electromagnetic wave transceiver module 7 on the installation ring 9 while the drive shaft 1 is rotating continuously. Because the gap between the electromagnetic wave transceiver module 7 and the target 8 is small and the electromagnetic wave transmission speed is fast, the electromagnetic wave can be completed in a short time during the alignment of the electromagnetic wave transceiver module 7 and the target 8 even while the drive shaft 1 is rotating continuously, without affecting the measurement accuracy.

[0029] By adopting the design of mounting ring 9, a miniature electromagnetic wave transceiver module 7 can be embedded without damaging the sealing ring structure, which helps to accurately measure the gas film thickness of the sealing end face in operation. Since the target body 8 is embedded on the end face of the first moving ring close to the first stationary ring 523, the target body 8 can reflect the deformation of the sealing end face of the first moving ring. The mounting ring 9 is set in the inner ring of the first stationary ring 523, which also reflects the deformation of the sealing end face of the first stationary ring 523 to a certain extent, further improving the measurement accuracy.

[0030] Reference Figure 1 and Figure 2 To reduce eddy current effects and ensure measurement accuracy, each target body 8 includes multiple plates, which are stacked sequentially along the axial direction of the drive shaft 1. To improve the stability of electromagnetic wave rebound, each plate of the target body 8 is made of electromagnetic alloy material, including niobium, zinc, copper, iron and titanium. The alloy formed by niobium, zinc, copper, iron and titanium materials can stably rebound electromagnetic waves after irradiation with high-frequency electromagnetic waves, thus ensuring measurement accuracy.

[0031] Reference Figure 1 and Figure 2To prevent wear on the electromagnetic transceiver module 7 and the target body 8, the distance from the sealing end face of the first stationary ring 523 to the sealing end face of the first rotating ring is less than the distance from the side of the mounting ring 9 near the first rotating ring to the sealing end face of the first rotating ring. That is, when the dry gas seal is not in operation, there is a preset gap between the side of the mounting ring 9 near the sealing end face of the first rotating ring and the first rotating ring. The side of the electromagnetic transceiver module 7 near the target body 8 is flush with the side of the mounting ring 9 near the first rotating ring, and the side of the target body 8 near the electromagnetic transceiver module 7 is flush with the side of the first rotating ring near the first stationary ring 523. This ensures that the target body 8 and the electromagnetic transceiver module 7 will not come into contact or rub against each other as the first rotating ring rotates continuously with the drive shaft 1, improving the service life of both the target body 8 and the electromagnetic transceiver module 7. Furthermore, the target body 8, being close to the sealing end face, can provide feedback on waveform changes at the sealing end face of the first rotating ring.

[0032] Reference Figure 1 , Figure 2 and Figure 3 To facilitate the collection of leaked gas at the experimental sealing mechanism 5 for verifying the gas film thickness between the first stationary ring 523 and the first rotating ring, the measuring experimental device also includes a balancing sealing mechanism 10. The balancing sealing mechanism 10 is located on the side of the experimental sealing mechanism 5 closer to the drive mechanism. Further, the balancing sealing mechanism 10 includes a balancing rotating ring assembly 101 and a balancing stationary ring assembly 102. The balancing rotating ring assembly 101 is fixedly mounted on the bushing 2 and includes a second rotating ring, which is fixedly connected to the bushing 2 by screws. The balancing stationary ring assembly 102 is mounted on the tooling 3 and is located on the balancing rotating ring assembly. On the side away from the experimental sealing mechanism 5, a dry gas seal is formed between the balancing stationary ring assembly 102 and the balancing rotating ring assembly 101. Specifically, the balancing stationary ring assembly 102 includes a second spring 1021, a second push ring 1022, and a second stationary ring 1023. The second push ring 1022 is axially slidably mounted on the fixture 3 via multiple second springs 1021. The second stationary ring 1023 is fixedly connected to the side of the second push ring 1022 closest to the second rotating ring. Under the elastic force of the multiple second springs 1021, the second stationary ring 1023 is tightly abutted against the second rotating ring before the dry gas seal operates. To prevent the second stationary ring 1023 from rotating, multiple anti-rotation pins (not shown in the figure) are spaced apart along the circumference of the second push ring 1022. The anti-rotation pins slide axially through the fixture 3.

[0033] Reference Figure 1 and Figure 2The sealing cavity 6 is formed by the balancing sealing mechanism 10, the bushing 2, the tooling 3, and the experimental sealing mechanism 5. The experimental stationary ring assembly 52 is located on the side of the experimental moving ring assembly 51 away from the balancing sealing mechanism 10. The connecting cable of the electromagnetic wave transceiver module 7 on the first stationary ring 523 extends through the tooling 3 on the side away from the drive mechanism, and is sealed at the point where the cable passes through the tooling 3. A leakage cavity 11 is formed between the experimental sealing mechanism 5, the bushing 2, and the side of the tooling 3 away from the balancing sealing mechanism 10. A leakage gas interface 12 is provided on the tooling 3, which is connected to the leakage cavity 11. To facilitate the monitoring of leakage gas, a spare interface 17 is provided on the tooling 3, which is connected to the leakage cavity 11. The spare interface 17 is normally closed during the dry gas seal operation.

[0034] When the dry gas seal is in operation, the sealing gas leaking from the first moving ring and the first stationary ring 523 enters the leakage chamber 11. By detecting the amount of gas discharged from the leakage gas port 12, it helps to verify the gas film thickness between the first moving ring and the first stationary ring 523. The sealing gas leaking from the second moving ring and the second stationary ring 1023 is directly discharged into the air. Since the sealing gas is compressed air, it will not have an impact on the environment.

[0035] Reference Figure 1 To maintain a relatively constant internal temperature for the sealing cavity 6 and ensure measurement accuracy, a cooling cavity 13 is provided on the fixture 3. The cooling cavity 13 is arranged circumferentially on the fixture 3. A coolant inlet 14 and a coolant outlet 15 are provided on the fixture 3, both connected to the cooling cavity 13, which is aligned with the sealing cavity 6. Since the first and second rotating rings generate heat during their continuous high-speed rotation, the coolant is introduced into the coolant inlet 14 and discharged through the cooling cavity 13 and coolant outlet 15, thus helping to cool the sealing cavity 6 and reduce the temperature at the dry gas seal. A temperature sensor (not shown in the figure) is installed on the fixture 3 to measure the internal temperature of the sealing cavity 6. The temperature sensor is electrically connected to an external control system, allowing for real-time monitoring of the internal temperature of the sealing cavity 6 and facilitating the adjustment of parameters such as coolant temperature and flow rate.

[0036] Reference Figure 1 To improve the versatility of the fixture 3, the fixture 3 also has multiple experimental interfaces 18. The experimental interfaces 18 are closed when the gas film thickness test is performed, while the experimental interfaces 18 can be opened and closed as needed when the fixture 3 is used for the two-stage dry gas seal test.

[0037] Reference Figure 1To improve the versatility of the bushing 2, the bushing 2 includes a tapered sleeve 21 and a transition sleeve 22. The inner wall of the tapered sleeve 21 is a tapered surface, and the diameter of the tapered surface decreases in the direction away from the drive mechanism. The tapered sleeve 21 is fixedly connected to the drive shaft 1 by an interference fit or a shaft clamp. The transition sleeve 22 is fixedly fitted outside the tapered sleeve 21. Specifically, the transition sleeve 22 includes multiple sleeve bodies 221 that are sequentially fitted together. The multiple sleeve bodies 221 are fixed together by connecting screws. Specifically, the structural shape of the sleeve bodies 221 can be set as needed and is not limited here. The bushing 2 formed by combining the tapered sleeve 21 with multiple sleeve bodies 221 can adjust the diameter of the bushing 2 as needed, making it suitable for dry gas sealing mechanisms of different diameters and providing greater flexibility.

[0038] Reference Figure 1 , Figure 2 and Figure 3 The first and second moving rings are respectively disposed at both ends of the transition sleeve 22. Specifically, the outermost rings at both ends of the transition sleeve 22 are fixedly provided with assembly rings (not shown in the figure). The first and second moving rings are respectively fixed to the assembly rings at their corresponding ends by fixing screws. Moving ring sealing rings are provided between the first and second moving rings and their corresponding assembly rings. Compression sleeves 16 are fixedly provided on the assembly rings at both ends by screws. Compression sleeves 16 are used to compress and fix the first or second moving ring at its corresponding end to the corresponding assembly ring, thereby improving the connection stability and reliability of the first and second moving rings. There is a gap between the compression sleeve 16 and the mounting ring 9 or tooling 3 at its corresponding end to avoid unnecessary wear. To ensure that the transition sleeve 22, the first moving ring, and the second moving ring can all remain concentric with the drive shaft 1, elastic tolerance zones are provided between the transition sleeve 22 and the tapered sleeve 21, between the first moving ring and its corresponding assembly ring, and between the second moving ring and its corresponding assembly ring, to adjust the center of the transition sleeve 22, the first moving ring, and the second moving ring.

[0039] Reference Figure 1To facilitate the assembly and maintenance of the experimental apparatus, tooling 3 includes a first assembly 31, a second assembly 32, and an end cap 33. Both the first assembly 31 and the second assembly 32 are annular. The first assembly 31, the second assembly 32, and the end cap 33 are sequentially fixed together by fastening screws in the direction away from the drive mechanism. The first assembly 31 is fixedly connected to the spindle box of the drive mechanism by screws. The end cap 33 seals the end of the second assembly 32 away from the first assembly 31. The experimental stationary ring assembly 52 and the balance stationary ring assembly 102 are both installed on the second assembly 32. The sealing gas interface 4, the leakage gas interface 12, the spare interface 17, the experimental interface 18, the cooling chamber 13, the coolant inlet interface 14, and the coolant outlet interface 15 are all located on the second assembly 32. The temperature sensor is installed on the second assembly 32. The leakage chamber 11 is formed by the second assembly 32, the bushing 2, the experimental sealing mechanism 5, and the end cap 33. The connection cable of the electromagnetic wave transceiver module 7 passes through the end cap 33.

[0040] The implementation principle of the measurement experimental device in this application embodiment is as follows: before the dry gas seal is in operation, the first stationary ring 523 and the first moving ring are in close contact, and the initial axial distance between each electromagnetic wave transceiver module 7 and the target body 8 is known at this time.

[0041] When the dry gas seal is running, the drive mechanism drives the drive shaft 1 to rotate, while simultaneously filling the sealing gas interface 4 with compressed air. The drive shaft 1 drives the bushing 2 and the first moving ring to rotate synchronously. Gas films are formed between the first stationary ring 523 and the first moving ring, and between the second stationary ring 1023 and the second moving ring. The first stationary ring 523 drives multiple electromagnetic wave transceiver modules 7 to generate axial displacement synchronously. High-frequency electromagnetic waves are emitted to the experimental moving ring assembly 51 through the electromagnetic wave transceiver modules 7. After being irradiated by the high-frequency electromagnetic waves, the target body 8 rebounds electromagnetic waves. The electromagnetic wave transceiver modules 7 receive the rebound electromagnetic waves from the target body 8, thereby calculating the round-trip propagation time difference of the electromagnetic waves on the ranging path at each electromagnetic wave transceiver module 7 at the external control system. The external control system calculates the round-trip propagation time difference of the electromagnetic waves at each electromagnetic wave transceiver module 7 based on each The electromagnetic wave transmission speed is calculated by the refractive index of the electromagnetic wave in the sealing gas at the electromagnetic transceiver module 7. The axial distance between the electromagnetic transceiver module 7 and the aligned target body 8 is calculated by the electromagnetic wave transmission speed and the round-trip propagation time difference. The difference between the average distance between all electromagnetic transceiver modules 7 and the target body 8 and the initial distance is the gas film thickness. Designing the electromagnetic transceiver module and the target body close to the sealing end face helps to reflect the deformation of the sealing end face, effectively improving the accuracy of gas film thickness measurement during dry gas sealing operation, and facilitating the measurement of minute gaps of 0-20um. Furthermore, the electromagnetic transceiver modules 7 at different positions on the first stationary ring 523 can emit electromagnetic waves of the same or different frequencies as needed, thereby reducing the requirements for the working environment.

[0042] Meanwhile, by adopting multi-point distributed measurement, three-dimensional spatial measurement data of dry gas sealing film thickness can be obtained. Through the three-dimensional grid processing of multi-point measurement data, a three-dimensional display model of film thickness is formed, which can fit the thickness of one ring of the film and reflect the characteristics of film thickness more intuitively and accurately.

[0043] This application also discloses a high-precision embedded air film thickness measurement experimental method. The air film thickness measurement experimental method uses the aforementioned measurement experimental apparatus and includes the following steps: Step 1: Before the dry gas seal is put into operation, the first stationary ring 523 is in close contact with the first moving ring. Let x be the number of electromagnetic wave transceiver modules 7 on the mounting ring 9. At this time, the axial distance between each electromagnetic wave transceiver module 7 and the target body 8 is _____. ; Step 2: During dry gas sealing operation, an air film is formed between the first stationary ring 523 and the first moving ring. The first stationary ring 523 will drive the mounting ring 9 and x electromagnetic wave transceiver modules 7 to synchronously generate axial displacement. High-frequency electromagnetic waves are emitted to the first moving ring through the x electromagnetic wave transceiver modules 7. After being irradiated by the high-frequency electromagnetic waves, the target body 8 rebounds with electromagnetic waves. The electromagnetic wave transceiver modules 7 receive the electromagnetic waves rebounding from the aligned target body 8. The external control system calculates the round-trip propagation time difference of the electromagnetic waves at each electromagnetic wave transceiver module 7 based on the electromagnetic wave transmission and reception time. i takes the values ​​1, 2, ..., x in sequence; Step 3: During dry gas sealing operation, the electromagnetic wave transmission speed at point 7 of each electromagnetic wave transceiver module. for Where c is the speed of light in a vacuum. Let be the refractive index of the electromagnetic wave at point 7 of the i-th electromagnetic transceiver module in the sealed gas; Step 4: During dry gas sealing operation, the average axial distance L1 between all electromagnetic wave transceiver modules 7 and the aligned target body 8 is, ; Step 5: Obtain the gas film thickness b during dry gas seal operation. .

[0044] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-precision embedded air film thickness measurement experimental device, characterized in that, include: A drive shaft (1) is used to connect to an external drive mechanism; A bushing (2) is mounted on a drive shaft (1) to rotate synchronously with the drive shaft (1); Tooling (3), the tooling (3) is located outside the bushing (2) and is used to connect with the housing of the drive mechanism. The tooling (3) is provided with a sealing air port (4). The experimental sealing mechanism (5) includes an experimental dynamic ring assembly (51) and an experimental stationary ring assembly (52). The experimental dynamic ring assembly (51) is mounted on the bushing (2), and the experimental stationary ring assembly (52) is mounted on the tooling (3). A dry gas seal is formed between the experimental stationary ring assembly (52) and the experimental dynamic ring assembly (51). A sealing cavity (6) is formed between the bushing (2), the tooling (3), and the experimental sealing mechanism (5). The sealing gas interface (4) is connected to the sealing cavity (6). Electromagnetic wave transceiver module (7) is installed on the experimental static ring assembly (52) and is used to transmit high-frequency electromagnetic waves to the experimental dynamic ring assembly (51). The electromagnetic wave transceiver module (7) is electrically connected to the external control system. The target body (8) is set on the experimental dynamic ring assembly (51). The target body (8) is used to reflect electromagnetic waves after being irradiated by high-frequency electromagnetic waves. The electromagnetic wave transceiver module (7) is also used to receive the electromagnetic waves reflected by the target body (8).

2. The high-precision embedded air film thickness measurement experimental device according to claim 1, characterized in that: The electromagnetic wave transceiver module (7) is evenly spaced along the circumference of the experimental static ring component (52). The target body (8) corresponds one-to-one with the electromagnetic wave transceiver module (7). The multiple target bodies (8) are evenly spaced along the circumference of the experimental dynamic ring component (51).

3. The high-precision embedded air film thickness measurement experimental device according to claim 2, characterized in that: The target body (8) includes multiple sheet bodies, which are stacked sequentially along the axial direction of the drive shaft (1).

4. The high-precision embedded air film thickness measurement experimental device according to claim 2, characterized in that: The target body (8) is made of an electromagnetic alloy material, which includes niobium, zinc, copper, iron and titanium.

5. The high-precision embedded air film thickness measurement experimental device according to claim 2, characterized in that: The outer rings of the experimental moving ring assembly (51) and the experimental stationary ring assembly (52) are connected to the sealed cavity (6). The experimental moving ring assembly (51) includes a first moving ring. The experimental stationary ring assembly (52) includes a first spring (521), a first push ring (522), and a first stationary ring (523). An installation ring (9) is provided on the inner side of the first stationary ring (523). The electromagnetic wave transceiver module (7) is installed on the installation ring (9). The distance from the target body (8) to the axis of the drive shaft (1) is equal to the distance from the electromagnetic wave transceiver module (7) to the axis of the drive shaft (1).

6. The high-precision embedded air film thickness measurement experimental device according to claim 5, characterized in that: The distance from the sealing end face of the first stationary ring (523) to the sealing end face of the first moving ring is less than the distance from the side of the mounting ring (9) near the first moving ring to the sealing end face of the first moving ring. The side of the electromagnetic wave transceiver module (7) near the target body (8) is flush with the side of the mounting ring (9) near the first moving ring. The side of the target body (8) near the electromagnetic wave transceiver module (7) is flush with the side of the first moving ring near the first stationary ring (523).

7. The high-precision embedded air film thickness measurement experimental device according to claim 2, characterized in that: The measuring experimental apparatus also includes a balancing sealing mechanism (10), which is located on the side of the experimental sealing mechanism (5) near the drive mechanism. The balancing sealing mechanism (10) includes a balancing moving ring assembly (101) and a balancing stationary ring assembly (102). The balancing moving ring assembly (101) is mounted on the bushing (2), and the balancing stationary ring assembly (102) is mounted on the tooling (3). A dry gas seal is formed between the balancing stationary ring assembly (102) and the balancing moving ring assembly (101). The sealing cavity (6) is connected to the balancing sealing mechanism (10) and the shaft. The experimental static ring assembly (52) is located on the side of the experimental dynamic ring assembly (51) away from the balance sealing mechanism (10). The connecting cable of the electromagnetic wave transceiver module (7) extends through the side of the tooling (3) away from the drive mechanism. A leakage cavity (11) is formed between the experimental sealing mechanism (5), the bushing (2), and the side of the tooling (3) away from the balance sealing mechanism (10). A leakage gas interface (12) is provided on the tooling (3), and the leakage gas interface (12) is connected to the leakage cavity (11).

8. The high-precision embedded air film thickness measurement experimental device according to claim 7, characterized in that: The bushing (2) includes a tapered sleeve (21) and a transition sleeve (22). The tapered sleeve (21) is used to connect with the drive shaft (1). The transition sleeve (22) is sleeved on the outside of the tapered sleeve (21). The experimental dynamic ring assembly (51) and the balance dynamic ring assembly (101) are respectively arranged at both ends of the transition sleeve (22). Both ends of the transition sleeve (22) are provided with clamping sleeves (16). The clamping sleeves (16) are used to press and fix the experimental dynamic ring assembly (51) or the balance dynamic ring assembly (101) at the corresponding end onto the transition sleeve (22).

9. The high-precision embedded air film thickness measurement experimental device according to claim 2, characterized in that: The tooling (3) is provided with a cooling chamber (13), which is arranged along the circumference of the tooling (3). The tooling (3) is provided with a coolant inlet (14) and a coolant outlet (15) opposite to each other. Both the coolant inlet (14) and the coolant outlet (15) are connected to the cooling chamber (13). The position of the cooling chamber (13) is aligned with the position of the sealing chamber (6).

10. A high-precision embedded air film thickness measurement experimental method, using the measurement experimental device as described in any one of claims 2-9, characterized in that, Includes the following steps: Before the dry gas seal is put into operation, the experimental stationary ring assembly (52) and the experimental moving ring assembly (51) are in close contact. Let x be the number of electromagnetic wave transceiver modules (7) on the experimental stationary ring assembly (52). At this time, the axial distance between each electromagnetic wave transceiver module (7) and the corresponding target body (8) is x. ; During dry gas sealing operation, an air film is formed between the experimental stationary ring assembly (52) and the experimental moving ring assembly (51). The experimental stationary ring assembly (52) drives x electromagnetic wave transceiver modules (7) to synchronously generate axial displacement. High-frequency electromagnetic waves are emitted to the experimental moving ring assembly (51) through the x electromagnetic wave transceiver modules (7). After being irradiated by the high-frequency electromagnetic waves, the target body (8) rebounds electromagnetic waves. The electromagnetic wave transceiver modules (7) receive the electromagnetic waves rebounded by the aligned target body (8). The external control system calculates the round-trip propagation time difference of the electromagnetic waves at each electromagnetic wave transceiver module (7) on the ranging path. i takes the values ​​1, 2, ..., x in sequence; During dry gas sealing operation, the electromagnetic wave transmission speed at each electromagnetic wave transceiver module (7) is... for, Where c is the speed of light in a vacuum. Let be the refractive index of the electromagnetic wave at the i-th electromagnetic transceiver module (7) in the sealed gas; During dry gas sealing operation, the average axial distance L1 between all electromagnetic transceiver modules (7) and the aligned target (8) is, ; The gas film thickness b is obtained during dry gas seal operation. .

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