An experimental device and experimental method for testing dynamic sealing performance of a sealing ring

Abstract

This invention discloses an experimental apparatus and method for testing the dynamic sealing performance of a sealing ring, belonging to the field of dynamic sealing performance testing of structural components. The apparatus includes: a cavity for containing a medium, with a shaft hole in its wall; a simulated shaft axially movable within the shaft hole; and a sealing ring disposed between the shaft hole and the simulated shaft to achieve a dynamic seal between them. The dynamic sealing performance of the sealing ring is tested through the reciprocating motion of the simulated shaft. The axial reciprocating motion of the simulated shaft accurately replicates the high-frequency axial micro-motion condition of the sealing ring in a mechanical seal compensation ring assembly. Simultaneously, the cavity can contain the working medium, simulating both the media environment and the reciprocating motion conditions, thus more closely resembling actual field usage conditions. It can directly and accurately measure key indicators such as leakage and friction of the sealing ring under dynamic sealing conditions, providing reliable data for evaluating failure issues such as wear, deformation, and hysteresis.

Description

Technical Field

[0001] This invention belongs to the field of mechanical seal technology, specifically relating to an experimental device and method for testing the dynamic sealing performance of sealing rings. Background Technology

[0002] Mechanical seals, as the core component of rotary shaft dynamic seals, are widely used in fluid machinery such as pumps and mixing equipment. Their sealing performance and operational reliability directly affect the overall stability of the machine. The compensating ring assembly typically uses an O-ring to achieve axial micro-seismic sealing. During equipment operation, this O-ring undergoes high-frequency axial reciprocating motion along with the compensating ring assembly, and is in direct contact with the medium for extended periods.

[0003] In actual working conditions, micro-motion O-rings are prone to excessive wear, permanent deformation, aging and failure due to frequent reciprocating friction. Furthermore, under the influence of the media environment, phenomena such as jamming of the compensation ring assembly and delayed action may occur, leading to imbalance of the mechanical seal end face pressure, seal failure, and media leakage, which seriously affects the safe and stable operation of the equipment.

[0004] To ensure the stability and reliability of mechanical seals in field use, it is necessary to conduct thorough testing and evaluation of the sealing performance and friction characteristics of the micro-motion O-rings during the early research and development phase. However, existing conventional sealing testing equipment is mostly used for comprehensive performance testing of the overall mechanical seal assembly, lacking dedicated testing equipment for micro-motion O-rings under media conditions. This makes it difficult to accurately simulate their high-frequency axial reciprocating motion, effectively measure key performance indicators such as leakage and frictional forces affecting jamming, and systematically study the influence of different O-ring materials, installation structures, and mating surface quality on the performance of micro-motion O-rings. Consequently, the optimization of micro-motion seal structures lacks reliable experimental data support.

[0005] Therefore, it is necessary to develop a test device that can simulate actual working conditions and is specifically used for micro-motion O-ring performance testing, in order to solve the problems of insufficient test targeting and lack of data support in existing technologies.

[0006] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art.

[0007] This invention provides a testing device that can test key performance indicators of micro-motion sealing rings under working conditions, such as leakage and frictional force affecting jamming, providing data support for later field use. At the same time, it can test and measure the influence of different rubber ring materials, installation methods, and surface quality on the sealing ring performance. Summary of the Invention

[0008] To address the aforementioned problems in the prior art, this invention proposes an experimental apparatus for testing the dynamic sealing performance of sealing rings, used to detect the sealing performance of micro-movement sealing rings under working conditions of the medium.

[0009] To achieve the above-mentioned objectives, the present invention employs the following technical solution: An experimental apparatus for testing the dynamic sealing performance of a sealing ring, comprising: A cavity for containing a medium, and the cavity wall has a shaft hole; A simulated shaft, which is axially movable and passes through the shaft hole; A sealing ring is disposed between the shaft hole and the simulated shaft to achieve a dynamic seal between the shaft hole and the simulated shaft. The dynamic sealing performance of the sealing ring is tested by the axial reciprocating motion of the simulated shaft.

[0010] In some embodiments of this application, a base and a motion frame are also included. The cavity is fixed on the base, and the shaft hole is provided at the lower end of the cavity. The lower end of the simulated shaft is fixed on the motion frame, which is movable up and down and is located below the cavity.

[0011] In some embodiments of this application, a first support spring is provided between the motion frame and the cavity, and a second support spring is provided between the motion frame and the base; the vertical movement of the motion frame is achieved by adjusting the pressure of the medium inside the cavity.

[0012] In some embodiments of this application, a cam is also included for pushing the motion frame upward.

[0013] In some embodiments of this application, a leakage structure for detecting medium leakage at the sealing ring is also included, the leakage structure having a collection groove formed on the motion frame, the collection groove being located below the shaft hole, and the simulated shaft being located within the collection groove.

[0014] In some embodiments of this application, the leakage structure further includes a lower leakage hole communicating with the collection tank and a measuring instrument located below the lower leakage hole.

[0015] In some embodiments of this application, a motion frame is also included, on which multiple simulated shafts are provided, and multiple matching shaft holes are formed in the cavity, with sealing grooves for accommodating the sealing rings formed on the hole walls of the shaft holes.

[0016] In some embodiments of this application, sealing grooves are formed in multiple shaft holes. By setting differences in the width and depth of the multiple sealing grooves, the sealing performance test values ​​of the sealing ring under different compression rates are obtained.

[0017] In some embodiments of this application, the coating material or surface hardening method of the surfaces of multiple simulated shafts is changed to obtain the sealing performance test values ​​of the sealing ring under different surface grinding qualities.

[0018] In some embodiments of this application, a flow driving structure for driving the flow of medium within the cavity is further included. The flow driving structure includes a first rotating frame rotatably disposed within the cavity. A plurality of lower circulation grooves are formed on the first rotating frame. The lower circulation grooves have a first guide surface that is inclined downward and toward the axis of the first rotating frame. The lower circulation grooves are located on the side of the simulation shaft away from the axis of the first rotating frame. The lower circulation grooves are used to guide the medium to flow downward and inward.

[0019] In some embodiments of this application, the simulation axis is provided with a first rotating seat, and the first rotating bracket is mounted on the first rotating seat.

[0020] In some embodiments of this application, the flow drive structure further includes a second rotating frame rotatably disposed within the cavity, on which a plurality of upper circulation grooves are formed. Each upper circulation groove has a second guide surface that is inclined upward and toward the axis of the second rotating frame. The upper circulation groove is located on the side of the simulation shaft close to the axis of the second rotating frame. The upper circulation groove is used to guide the medium to flow inward and upward.

[0021] In some embodiments of this application, the axis of the first rotating frame is coaxial or parallel to the axis of the second rotating frame.

[0022] In some embodiments of this application, the first rotating seat is provided with a first passage located in the middle, and the first rotating frame is provided with a second passage located in the middle. The first passage and the second passage are connected and disposed together, and the second rotating frame guides the medium to flow upward through the first passage and the second passage.

[0023] In some embodiments of this application, the flow driving structure further includes an electromagnet disposed outside the cavity, a first permanent magnet disposed on the first rotating frame, and a second permanent magnet disposed on the second rotating frame. By controlling the change of the magnetic poles of the electromagnet, the first rotating frame is driven to rotate, thereby driving the rotation of the second rotating frame and driving the circulation flow of the medium inside the cavity.

[0024] In some embodiments of this application, the first permanent magnet is given a magnetic force to drive the first rotating frame to rotate, so that the medium in the cavity flows downward and inward; then the rotating first permanent magnet gives the second permanent magnet a magnetic force to drive the second rotating frame to rotate, so that the medium flows upward and inward.

[0025] In some embodiments of this application, a temperature control chamber is provided on the outside of the cavity, and the temperature of the medium inside the cavity is controlled by adjusting the temperature and flow rate of the liquid input into the temperature control chamber; the experimental device also includes a pressure sensor for detecting the pressure inside the cavity and a temperature sensor for detecting the temperature of the sealing ring.

[0026] Based on the above-described experimental apparatus for testing the dynamic sealing performance of a sealing ring, the present invention also provides a test method for the above-described experimental apparatus for detecting the sealing performance of a micro-motion sealing ring.

[0027] A test method for an experimental apparatus for detecting the frictional force on a sealing ring, and further comprising a distance measuring sensor for detecting the moving distance of the moving frame; the test method includes the following steps: S110. Adjust the working pressure of the medium inside the cavity to 0.9*p0. After the entire system stabilizes, record the distance measured by the ranging sensor as t1 and the working pressure of the medium as p0. S120. Increase the working pressure of the medium to 1.1*p0, and record the distance t2 measured by the ranging sensor when the working pressure reaches p0; record the distance t3 measured by the ranging sensor when the working pressure reaches 1.1*p0. S130. Reduce the working pressure of the medium to 0.9*p0, and record the continuous data measured by the ranging sensor to find the working pressure p1 corresponding to the moment when the distance t3 first recovers to the distance t2; S140. Calculate the frictional force f according to the formula: f = π * n1 * d2 * 0.5 * p / (p0 - p1).

[0028] Compared with existing technologies, the advantages and positive effects of this invention are as follows: By using a micro-motion sealing ring in an axial reciprocating dynamic sealing configuration, the sealing performance and friction characteristics of the sealing ring under high-frequency reciprocating motion are tested. By simulating the axial reciprocating motion of the shaft, the high-frequency axial micro-motion working condition of the sealing ring in the mechanical seal compensation ring assembly is accurately reproduced. Simultaneously, the cavity can accommodate the working medium, achieving simulation of both the media environment and reciprocating motion working conditions, more closely resembling field usage conditions. It can directly and accurately measure core indicators such as leakage and friction of the sealing ring under dynamic sealing conditions, providing reliable data for evaluating failure issues such as wear, deformation, and hysteresis. It allows for easy replacement of sealing rings of different materials and structures, as well as replacement of simulated shafts with different surface qualities, enabling systematic research on the influence of parameters such as materials, structure, fitting precision, and media on the sealing ring performance, providing data support for structural optimization. It eliminates the need for assembling a complete mechanical seal assembly, simplifying the device structure and enabling rapid replacement and repeated testing, significantly improving the testing efficiency during the R&D phase.

[0029] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of an embodiment of an experimental apparatus for testing the dynamic sealing performance of a sealing ring, as proposed in this invention. Figure 2 for Figure 1 Enlarged structural diagram of region A in the middle; Figure 3 for Figure 1 A magnified structural diagram of region B in the middle; Figure 4 This is a schematic diagram of the structure at the interface between the cam and the moving part; Figure 5 This is a schematic diagram of a motor-driven cam. Figure 6 for Figure 1 Schematic diagram of the middle cavity; Figure 7 for Figure 6 A schematic diagram of the structure viewed from below; Figure 8 This is a structural schematic diagram of the movable assembly; Figure 9 This is a schematic diagram of the motion frame structure; Figure 10 for Figure 9 A schematic diagram of the structure viewed from below; Figure 11 This is a schematic diagram of the structure of the first rotating frame; Figure 12 for Figure 11 Schematic diagram of the cross-sectional structure along the CC direction; Figure 13 This is a schematic diagram of the second rotating frame; Figure 14 for Figure 13 Schematic diagram of the cross-sectional structure along the DD direction; Among them, experimental apparatus 100; Cavity 10; Shaft hole 11; Sealing groove 12; Temperature control cavity 13; Temperature sensor 15; Gas inlet 161; Gas outlet 162; Liquid inlet 163; Liquid outlet 164; Pressure sensor interface 165; 20; motion frame; 21; first rotating seat; 22; first through-hole; 221; spring cylinder; 23; collection groove; 25; lower drain hole; 26; measuring device; 27; distance sensor; Base 30; First rotating frame 41; lower circulation groove 411; first guide surface 4111; second passage 412; first permanent magnet 413; second rotating frame 42; upper circulation groove 421; second permanent magnet 422; second guide surface 4211; electromagnet 43; 50 sealing ring; First support spring 61; Second support spring 62; Cam 71; Motor 72. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0033] In the description of this invention, it should be noted that the terms "upper," "lower," "left," and "right," etc., indicate the orientation or positional relationship based on the positional relationship shown in the accompanying drawings, with the direction closer to the component axis being "inner" and the opposite being "outer." These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit the present invention.

[0037] See Figures 1-14 This is an embodiment of an experimental apparatus 100 for testing the dynamic sealing performance of a sealing ring, as proposed in this invention. The apparatus includes a cavity 10, a simulated shaft 21, and a sealing ring 50. The cavity 10 is used to contain a medium and is fixed to a base 30. A shaft hole 11 is formed in the cavity wall of the cavity 10. The simulated shaft 21 is axially movable and passes through the shaft hole 11. The sealing ring 50 is disposed between the shaft hole 11 and the simulated shaft 21 to achieve a dynamic seal between them. The dynamic sealing performance of the sealing ring 50 is tested through the axial reciprocating motion of the simulated shaft 21.

[0038] In this embodiment, the high-frequency axial micro-motion of the sealing ring in the mechanical seal compensation ring assembly is accurately reproduced by simulating the axial reciprocating motion of the shaft 21. Simultaneously, the cavity 10 can accommodate the working medium, achieving simulation of both the media environment and the reciprocating motion, thus more closely resembling actual field conditions. It can directly and accurately measure key indicators such as leakage and friction of the sealing ring 50 under dynamic sealing conditions, providing reliable data for evaluating failures such as wear, deformation, and hysteresis. Different materials and structures of sealing rings, as well as simulation shafts 21 with different surface qualities, can be easily replaced, allowing for systematic research on the influence of parameters such as materials, structure, fit precision, and media on the sealing ring performance, providing data support for structural optimization. The device simplifies the structure by eliminating the need for assembling a complete mechanical seal assembly, enabling rapid replacement and repeated testing, significantly improving testing efficiency during the R&D phase.

[0039] In some embodiments of this application, the experimental apparatus 100 further includes a base 30 and a motion frame 20. The cavity 10 is fixed on the base 30, and a shaft hole 11 is provided at the lower end of the cavity 10. The lower end of the simulated shaft 21 is fixed on the motion frame 20, which is movable up and down and is located below the cavity 10. The cavity 10 is fixed on the base 30, and the motion frame 20 is located below the cavity 10. The simulated shaft 21 extends from bottom to top into the shaft hole 11. The overall center of gravity is low and the rigidity is good, making it less prone to shaking during high-frequency reciprocating motion and ensuring test accuracy. The lower end of the simulated shaft 21 is directly fixed on the motion frame 20 and is driven up and down by the motion frame 20. The transmission path is short and the rigidity is high, which can effectively reduce lateral sway and more realistically simulate the pure axial micro-motion condition of the sealing ring 50, improving the test accuracy of friction and jamming characteristics. With cavity 10 fixed in place, only the simulated shaft 21 moves axially. The dynamic-static coupling interface is simple and controllable, which helps to maintain stable pressure inside the cavity, facilitates accurate measurement of minute leaks, and makes the test results more reliable.

[0040] In some embodiments of this application, a second support spring 62 is provided between the motion frame 20 and the base 30, and a first support spring 61 is provided between the motion frame 20 and the cavity 10. The motion frame 20 is not rigidly fixed, allowing it to float elastically. This enables the simulated shaft 21 to move axially while generating radial offset and radial runout, highly replicating the actual working conditions of the shaft in real equipment, such as eccentricity, wobbling, and assembly errors. The test environment is closer to the actual usage conditions. It can simulate the effects of shaft eccentricity and radial runout on the sealing ring 50, causing compression, wear, and jamming. It accurately tests the sealing performance, wear characteristics, and jamming risk of the sealing ring 50 under non-ideal alignment conditions, providing more comprehensive test results. The second support spring 62 is elastic in the vertical direction.

[0041] In some embodiments of this application, the vertical movement of the motion frame 20 can be achieved by adjusting the pressure of the medium inside the cavity 10, thereby obtaining the frictional force on the sealing ring 50. Without the need for a driving component, adjusting the pressure of the medium inside the cavity 10 causes the motion frame 20 to move the simulated shaft 10 in the vertical direction; based on the distance the motion frame 20 moves after the medium pressure adjustment, the magnitude of the frictional force on the sealing ring 50 under the working pressure p0 of the medium is calculated.

[0042] In some embodiments of this application, the experimental apparatus 100 further includes a cam 71 for pushing the motion frame 20 upward, and a motor 72 for driving the cam 71 to rotate. The cam 71 and the motor 72 constitute a driving component for driving the motion frame 20 to move. The cam 71 provides both upward driving force and radial force, causing the motion frame 20 to drive the simulated shaft 21 to produce radial runout, more realistically simulating actual working conditions. The motor 72 drives the cam 71 to rotate continuously, which can drive the motion frame 20 and the simulated shaft 21 to perform stable, continuous, and high-frequency axial reciprocating motion, accurately simulating the high-frequency reciprocating working conditions of the micro-seal ring 50 in actual equipment. The motion frequency and amplitude are controllable, and the test repeatability is good. When the cam 72 rotates and pushes the motion frame 20, in addition to the axial driving force, it naturally generates a radial component, which can cause the motion frame 20 and the simulated shaft 21 to produce reasonable radial offset and radial runout, highly replicating the eccentricity and wobbling working conditions of the actual shaft system, making the sealing test closer to the real use state. By replacing cams 71 with different lift and profile curves, the reciprocating stroke, movement speed, and radial runout amplitude of the simulated shaft can be flexibly adjusted; the movement frequency can be changed by adjusting the speed of motor 72. The device is highly adaptable and can meet the dynamic sealing test requirements of the sealing ring under different working conditions. The axial and radial forces generated by cam 71, combined with the elastic floating effect of the first support spring 61 and the second support spring 62, can realize a composite motion of axial reciprocating and radial runout, more realistically reflecting the friction, jamming, and sealing performance of the sealing ring under complex working conditions.

[0043] In some embodiments of this application, the experimental apparatus 100 includes a motion frame 20, on which multiple simulated shafts 21 are provided. Multiple matching shaft holes 11 are formed in the cavity 10, and sealing grooves for accommodating sealing rings 50 are formed on the wall of each shaft hole 11. By setting multiple simulated shafts 21 and multiple shaft holes 11, multiple sealing rings 50 need to be set. Multiple sealing rings 50 can be installed and tested simultaneously, obtaining multiple sets of test data in a single test, significantly shortening the R&D testing cycle and improving the efficiency of performance screening and comparison of sealing rings 50. Multiple sealing rings are tested synchronously under the same medium pressure, the same motion conditions, and the same temperature environment, eliminating the interference from differences in working conditions caused by separate tests, making the performance comparison of sealing rings with different materials and structures more accurate and convincing. The sealing performance test values ​​of the sealing rings 50 under different surface grinding qualities can be obtained by using different coating materials or surface hardening methods on the surfaces of the multiple simulated shafts 21. The simulation axis 21 can be set with different coating materials, such as WC coating, ceramic coating, DLC coating, etc., and different surface hardening methods, such as cold work hardening, surface grinding, polishing, etc., to obtain multiple different simulation axes 21. The simulation axis 21 is installed and fixed on the motion frame 20. Multiple different simulation axes 21 can be set on the motion frame 20, and the simulation axis 21 can also be replaced to obtain test values ​​for different grinding surface quality.

[0044] In some embodiments of this application, sealing grooves 12 are formed in multiple shaft holes 11. By setting differences in the width and depth of the multiple sealing grooves 12, the sealing performance test values ​​of the sealing ring 50 under different compression rates can be obtained. By setting sealing grooves 12 with different widths and depths in different shaft holes 11, multiple sealing rings 20 can obtain different compression rates under the same medium and the same motion conditions. The sealing performance, friction characteristics, and leakage data of the sealing ring 50 under multiple compression rates can be obtained simultaneously in a single test, greatly improving the test efficiency. Multiple sealing rings 50 are tested simultaneously under the same pressure, the same reciprocating motion, the same radial runout, and the same medium environment, avoiding the fluctuation of working conditions caused by separate tests, making the comparative data of the influence of different compression rates on the sealing ring performance more realistic and comparable. The influence law between the size of the sealing groove 12, the compression rate of the sealing ring 50, and the sealing performance, friction, wear life, and jamming risk can be systematically studied, providing a reliable test basis for the selection of the sealing ring 50, the structural design of the sealing groove 12, and the setting of the assembly compression amount.

[0045] In some embodiments of this application, the experimental apparatus 100 further includes a leakage structure for detecting media leakage at the sealing ring 50. The leakage structure has a collection groove 25 formed on the motion frame 20, located below the shaft hole 11. The simulated shaft 21 is located inside the collection groove 25 and extends upward. Because the collection groove 25 is directly below the shaft hole 11, the leaking medium can fall directly into the collection groove 25 under gravity, leaving no residue or splashing. This accurately reflects the actual leakage of the sealing ring 50 under micro-motion conditions, improving the accuracy of leakage measurement. The simulated shaft 21 extends upward from inside the collection groove 25 into the shaft hole. The overall structure is compact and has high space utilization. It does not affect the axial movement and radial runout of the simulated shaft 21, and can achieve full-circumferential leakage collection, resulting in a cleaner sealing test area.

[0046] In some embodiments of this application, the leakage structure also includes a lower leakage hole 26 connected to the collection tank 25 and a measuring instrument 27 located below the lower leakage hole 26. After the leakage medium is collected by the collection tank 25, it flows naturally downwards through the lower leakage hole 26. The measuring instrument 27, located below the lower leakage hole 26, can directly, accurately, and visually measure the leakage of the sealing ring 50, solving the problem of inaccurate measurement of minute leaks in micro-seals, resulting in more objective and quantifiable test data. Each simulated shaft 21 corresponds to a set of collection tank 25, lower leakage hole 26, and measuring instrument 27, ensuring no crosstalk and facilitating comparison of sealing performance differences under different structures and compression ratios. Multiple sealing rings can be measured independently and simultaneously. The entire process of collection, guidance, and measurement can be completed by gravity flow, eliminating the need for auxiliary devices such as pumps or negative pressure. The structure is simple, easy to assemble, and suitable for long-term durability testing.

[0047] In some embodiments of this application, the experimental apparatus 100 further includes a flow driving structure for driving the flow of medium within the cavity 10. The flow driving structure includes a first rotating frame 41 rotatably disposed within the cavity 10. Multiple lower circulation grooves 411 are formed on the first rotating frame 41, located on the outer side of the first rotating frame 41. Each lower circulation groove 411 has a first guiding surface 4111, which is the bottom surface of the lower circulation groove 411. The first guiding surface 4111 is inclined downwards towards the axis of the first rotating frame 41. The lower circulation groove 41 is located on the side of the simulation shaft 21 away from the axis of the first rotating frame 41, and is used to guide the medium downwards and inwards. By rotating the first rotating frame 411 to drive the medium flow, the traditional static testing mode is changed, simulating the real environment of medium flow, scouring, and disturbance during equipment operation, making the sealing performance test of the sealing ring 50 more consistent with field usage conditions. The bottom surface of the lower circulation groove 411 is a downward-facing and inclined first guide surface 4111. Under the action of rotation and centrifugal force, it can guide the medium to the shaft hole 11, effectively testing the anti-leakage and anti-wear capabilities of the sealing ring 50 under flowing medium. The structure of the rotating frame 41 and the inclined groove 411 can stir and disturb the medium in the cavity. Under the combined action of rotational centrifugal force and the inclined first guide surface 4111, the medium is pressed towards the shaft hole 11, which can increase the local pressure and medium renewal speed at the sealing ring 50, and more realistically reflect the stress and lubrication state of the dynamic seal under fluid conditions.

[0048] In some embodiments of this application, a first rotating seat 22 is provided on the simulation shaft 21, and a first rotating frame 41 is rotatably mounted on the first rotating seat 22. Multiple simulation shafts 21 are circumferentially arranged on the motion frame 20. The first rotating seat 22 is fixed to the top of the multiple simulation shafts 21. The upper end of the simulation shaft 21 is provided with the first rotating seat 22, and the lower end is provided with the motion frame 20. When the motion frame 20 moves up and down, it drives the simulation shafts 21, the first rotating seat 22, and the first rotating frame 41 to move up and down together. The first rotating frame 41 can also be rotatably mounted. The upper ends of the multiple simulation shafts 21 are fixed by the first rotating seat 22, and the lower ends are fixed by the motion frame 20, forming a rigid frame structure with rigid connections at both ends. During axial reciprocating and radial runout, the movement height of each simulation shaft is synchronized, preventing individual simulation shafts 21 from swaying or tilting, and ensuring consistent testing conditions across multiple workstations. Multiple simulated shafts 21, constrained vertically, achieve high radial positioning accuracy. Driven by cam 71 and floating with springs, they allow for permissible radial runout without excessive offset, ensuring the sealing ring 50 experiences forces closer to real-world conditions and making friction and leakage tests more reliable. The first rotating frame 41 is mounted on the first rotating seat 22, with its rotation center coinciding with the axis of the entire device. Rotation is free of eccentricity and wobbling, resulting in a more uniform medium flow field and improved test data accuracy.

[0049] In some embodiments of this application, the flow drive structure further includes a rotatable second rotating frame 42 disposed within the cavity 10. Multiple upper circulation grooves 421 are formed on the second rotating frame 42, each upper circulation groove 421 having a second guiding surface 4211. The second guiding surface 4211 is inclined upwards towards the axis of the second rotating frame 42. The upper circulation grooves 421 are located on the side of the simulation shaft 21 near the axis of the second rotating frame 42, and are used to guide the medium flow upwards and inwards. The upper circulation grooves 421 guide the medium upwards and inwards, while the lower circulation grooves 411 guide the medium downwards and inwards, forming a complete and continuous vertical circulation within the cavity 10, thus fully agitating the medium. The second guiding surface 4211 is upwards and inclined towards the axis, achieving efficient directional flow guidance under the action of rotational centrifugal force, with low flow resistance and low energy loss. The medium flow rate can be precisely controlled by adjusting the rotational speed.

[0050] In some embodiments of this application, the axis of the first rotating frame 41 is coaxial or parallel to the axis of the second rotating frame 42. The flow drive structure has a first rotating frame 41 and a second rotating frame 42 located within the cavity 10 and capable of rotation. The rotation of the first rotating frame 41 and the second rotating frame 42 drives the circulation of the medium within the cavity 10. The upper circulation groove 421 on the first rotating frame 41 is located outside the plurality of simulated shafts 21, and the upper circulation groove 421 on the second rotating frame 42 is located inside the plurality of simulated shafts 21; the direction closest to the rotation axis is considered inward. Multiple upper circulation grooves 421 can be provided circumferentially on the first rotating frame 41, and multiple upper circulation grooves 421 can be provided circumferentially on the second rotating frame 42. Rotation of the first rotating frame 41 can convey the medium inward and downward, while rotation of the second rotating frame 42 can convey the medium inward and upward, forming a continuous circulation flow within the cavity 10 with the inner side upward and the outer side downward. Multiple circulation grooves are evenly distributed circumferentially along the inner and outer sets of rotating frames, ensuring uniform flow velocity and pressure distribution within the cavity 10. This guarantees that multiple sealing rings 50 are tested synchronously under the same medium flow velocity and scouring intensity, resulting in more accurate and reliable test data comparison. Driven by the rotating frames, the medium flows directionally through the shaft hole, continuously carrying away frictional heat, wear debris, and air bubbles. This effectively prevents localized overheating and impurity deposition, making the sealing performance and frictional characteristics tests of the sealing rings 50 more closely reflect actual usage conditions.

[0051] In some embodiments of this application, the first rotating seat 22 is provided with a first passage 221 located in the middle, and the first rotating frame 41 is provided with a second passage 412 for the medium to flow upward through the middle. The first passage 221 and the second passage 412 are connected and arranged in communication. The second rotating frame 42 guides the medium to flow upward through the first passage 221 and the second passage 412.

[0052] In some embodiments of this application, the flow drive structure further includes an electromagnet 43 disposed outside the cavity 10, a first permanent magnet 413 disposed on the first rotating frame 41, and a second permanent magnet 422 disposed on the second rotating frame 43. By controlling the change of the magnetic poles of the electromagnet 43, the rotation of the first rotating frame 41 and the second rotating frame 42 is driven; controlling the change of the magnetic poles of the electromagnet 43 drives the rotation of the first rotating frame 41, and then drives the rotation of the second rotating frame 42, thereby driving the circulation flow of the medium inside the cavity 10. By controlling the current magnitude and commutation frequency of the electromagnet 43, the rotation speed and rotation direction of the rotating frame can be steplessly adjusted, and the medium circulation flow rate and flow field state can be precisely controlled. It can simulate working conditions with different flow rates and different disturbance intensities, which is convenient for systematically studying the influence of fluid state on the dynamic sealing performance of the sealing ring. The magnetic coupling between the electromagnet 43 and the permanent magnet drives the rotating frame, ensuring the stability of the internal pressure and medium environment of the cavity 10, making the sealing ring leakage test more accurate.

[0053] In some embodiments of this application, electromagnet 43 applies magnetic force to the first permanent magnet 413, causing the first rotating frame 41 to rotate, thus enabling the medium within the cavity 10 to flow downwards and inwards. Subsequently, the rotating first permanent magnet 413 applies magnetic force to the second permanent magnet 422, causing the second rotating frame 42 to rotate, thus enabling the medium to flow upwards and inwards. By first driving the first rotating frame 41 with electromagnet 43, and then magnetically coupling the second rotating frame 42 with the first permanent magnet 413 on the first rotating frame 41, synchronous linkage of the two rotating frames can be achieved with only one set of electromagnets, significantly simplifying the structure and making control easier. Magnetic linkage causes the first rotating frame 41 and the second rotating frame 42 to rotate in a preset direction, naturally forming a stable medium circulation with the outer side flowing downwards and inwards, and the inner side flowing upwards and inwards. An ideal flow field can be achieved without complex control, resulting in more stable operating condition simulation.

[0054] In some embodiments of this application, a temperature control chamber 13 is fitted around the outside of the cavity 10. The temperature of the medium inside the cavity 10 is controlled by adjusting the temperature and flow rate of the liquid input into the temperature control chamber 13. The experimental apparatus 100 also includes a pressure sensor for detecting the pressure inside the cavity 10, a temperature sensor 15 for detecting the temperature of the sealing ring 50, and a distance sensor 28 for detecting the moving distance of the motion frame 20. By controlling the temperature of the medium in the cavity 10 through the temperature control chamber 13, different temperature environments can be simulated to test the sealing performance, friction characteristics, and aging behavior of the sealing ring 50 under high temperature, low temperature, and variable temperature conditions, providing a more comprehensive testing scenario.

[0055] In some embodiments of this application, the cavity 10 is provided with a gas inlet 161, a gas outlet 162, a liquid inlet 163, a liquid outlet 164, and a pressure sensor interface 165. According to testing requirements, simulated liquid media such as oil or water can be injected through the liquid inlet 163, and excess liquid can flow out through the liquid outlet 164, with a reserved gas space at the top. Simulated gas media such as nitrogen, air, carbon dioxide, hydrogen, or ammonia can be injected through the gas inlet 161. When replacing the gas, excess gas can flow out through the gas outlet 162, and the gas outlet 162 can be closed. The entire simulated medium cavity 10 can be pressurized through the gas inlet 163, simulating the actual working environment of gas dissolved in liquid. An external pressure sensor 14 connected to the pressure interface can monitor the pressure of the simulated medium cavity.

[0056] In some embodiments of this application, the diameter of the simulated shaft 21 is d (unit: mm, the same unit for length below); all components that move together with the simulated shaft 21 are moving assemblies, and the weight of the moving assembly is W (unit: kg). The free length of the first support spring 61 is L1, the working length is H1, and the stiffness coefficient is K1 (unit: N / mm, the same unit for stiffness coefficient below); the free length of the second support spring 62 is L2, the working length is H2, and the stiffness coefficient is K2; then the relationship between the initial working length H10 of the first support spring 61 and the initial working length H20 of the second support spring 62 is: H10 = 9.8*W / K1 + L1 - K2 / K1*n2*L2 + n2*K2 / K1*H20. Based on the weight W of the moving assembly, suitable design parameters and the number of the two springs can be selected. When the working pressure of the medium inside cavity 10 is p (unit: MPa, the same unit for pressure below), the moving assembly will move downwards by dH under the pressure. This distance change can be measured by the distance sensor 28. After the moving assembly stabilizes, the moving distance dH = π*n1*d2*p / (4*K1+4*n2*K2). After balancing, cam 71 is placed in position. When cam 71 is running, the moving assembly, such as the simulated shaft 21, will move up and down with the change of the outer surface of cam 71. The maximum moving distance is the value of the long shaft r1 minus the short shaft r2, which is the maximum shaft runout amplitude of the simulated shaft 21 at the micro-seal in the mechanical seal. The vibration frequency is controlled by the rotational speed ω (unit: r / min) of motor 72. The vibration frequency is (ω / 30) Hz. The maximum vertical force F borne by the main shaft of motor 72 is K1*(r1-r2)+n2*K2*(r1-r2). This data should be checked before the test to avoid overload. One first support spring 61 is provided, and n2 second support springs 62 are provided. Multiple spring cylinders 23 extending downward are provided on the motion frame 20, and the multiple spring cylinders 23 are evenly distributed circumferentially.

[0057] In some embodiments of this application, the cavity 10 has a cavity cylinder 16 and a bottom pressure cover 17, which are sealed and fixed together. A plurality of circumferentially arranged shaft holes 11 are formed on the bottom pressure cover 17, and a sealing groove 12 is formed in each shaft hole 11. A plurality of temperature sensors 15 are disposed on the bottom pressure cover 17. A second rotating frame 42 is disposed on the bottom pressure cover 17 and located inside the cavity 10.

[0058] In some embodiments of this application, the experimental apparatus 100 includes a conventional experiment with the cam 71 mounted, and a friction experiment with the cam 71 dismounted, the friction experiment being used to measure the friction force experienced by the sealing ring 50.

[0059] A test method for an experimental apparatus 100, used to detect the frictional force on a sealing ring 50, in a state where the cam 71 is disassembled, or in a state where the cam 71 is not installed; a distance sensor 28 is mounted on a motion frame 20 to detect the distance between the distance sensor 28 and the cavity 10; the test method includes the following steps: S110. Adjust the working pressure of the medium in the cavity 10 to 0.9*p0. After the entire system stabilizes, record the distance measured by the ranging sensor 28 as t1 and the working pressure of the medium as p0. S120. Increase the working pressure of the medium to 1.1*p0, and record the distance t2 measured by the distance sensor 28 when the working pressure reaches p0; record the distance t3 measured by the distance sensor 28 when the working pressure reaches 1.1*p0. S130. Reduce the working pressure of the medium to 0.9*p0 and record the continuous data measured by the distance sensor 28 to find the working pressure p1 corresponding to the moment when the distance t3 is first recovered to the distance t2; S140. Calculate the frictional force f according to the formula: f = π * n1 * d2 * 0.5 * p / (p0 - p1), where n1 is the number of sealing rings. The number of sealing rings 50 is equal to the number of simulated shafts 21.

[0060] In conventional experiments, the testing method for an experimental apparatus 100 includes the following steps: S210. Under set conditions, start motor 72 to drive cam 71 to rotate, thereby driving motion frame 20 to move up and down; set conditions may be a certain medium filling cavity 10, a certain medium pressure, a certain motor speed 72, a certain medium temperature, etc. S220. Monitor data during the experimental process; S230. Turn off the motor 72 and remove the lower sealing ring 50; measure the sealing performance data of the sealing ring 50, which may include measuring the wear condition of the sealing ring 50 and leakage conditions.

[0061] By adjusting the settings and continuing with steps S210 to S230, the sealing performance of the sealing ring 50 under different conditions can be obtained. Adjusting the settings can involve changing the medium, adjusting the medium pressure, changing the cam 71, adjusting the medium temperature, or adjusting the rotation speed of the rotating frame, etc.

[0062] Before S210, there is a motor overload calculation step. Based on the stiffness coefficients of the first support spring 61 and the second support spring 62, the number of the second support spring 62, and the lengths of the major and minor axes of the cam 72, the maximum vertical force F that the main shaft of the motor 72 needs to withstand is calculated. If F is less than the rated pressure of the main shaft of the motor 72, there is no overload and the experiment can be carried out.

[0063] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. An experimental device for testing the dynamic sealing performance of a sealing ring, characterized in that, include: A cavity for containing a medium, and the cavity wall has a shaft hole; A simulated shaft, which is axially movable and passes through the shaft hole; A sealing ring is disposed between the shaft hole and the simulated shaft to achieve a dynamic seal between the shaft hole and the simulated shaft. The dynamic sealing performance of the sealing ring is tested by the reciprocating motion of the simulated shaft. It also includes a flow drive structure for driving the flow of the medium within the cavity. The flow drive structure includes a first rotating frame rotatably disposed within the cavity. Multiple lower circulation grooves are formed on the first rotating frame to guide the medium to flow downward and inward. The lower circulation grooves have a first guide surface that is inclined downward and toward the axial direction of the first rotating frame. It also includes a base and a motion frame. The cavity is fixed on the base, and the shaft hole is opened at the lower end of the cavity. The lower end of the simulated shaft is fixed on the motion frame, and the motion frame can be moved up and down. A first support spring is provided between the motion frame and the cavity, and a second support spring is provided between the motion frame and the base.

2. The experimental setup of claim 1, wherein, The vertical movement of the motion frame is achieved by adjusting the pressure of the medium inside the cavity.

3. The experimental setup of claim 1, wherein, It also includes a leakage structure for detecting medium leakage at the sealing ring, the leakage structure having a collection groove formed on the motion frame, the collection groove being located below the shaft hole, and the simulated shaft being located within the collection groove.

4. The experimental setup of claim 1, wherein, It also includes a motion frame, on which multiple simulated shafts are provided, and multiple matching shaft holes are opened in the cavity. Sealing grooves for accommodating the sealing rings are opened on the hole walls of the shaft holes.

5. The experimental setup of claim 4, wherein, Sealing grooves are formed in multiple shaft holes. By setting differences in the width and depth of the multiple sealing grooves, the sealing performance test values ​​of the sealing ring under different compression rates are obtained.

6. The experimental setup according to any one of claims 1 to 5, characterized in that The flow drive structure also includes a second rotating frame that is rotatable within the cavity. Multiple upper circulation grooves are provided on the second rotating frame to guide the medium to flow inward and upward. The upper circulation grooves have a second guide surface that is inclined upward and toward the axis of the second rotating frame.

7. The experimental setup according to any one of claims 1 to 5, characterized in that A temperature control chamber is provided on the outside of the cavity. The temperature of the medium inside the cavity is controlled by adjusting the temperature and flow rate of the liquid input into the temperature control chamber. The experimental device also includes a pressure sensor for detecting the pressure inside the cavity and a temperature sensor for detecting the temperature of the sealing ring.

8. A test method of the test device according to any one of claims 1 to 7, characterized by, The test method includes a distance sensor for detecting the frictional force on the sealing ring and a distance sensor for detecting the movement distance of the moving frame; the test method includes the following steps: S110. Adjust the working pressure of the medium inside the cavity to 0.9*p0. After the entire system stabilizes, record the distance measured by the ranging sensor as t1 and the working pressure of the medium as p0. S120. Increase the working pressure of the medium to 1.1*p0, and record the distance t2 measured by the ranging sensor when the working pressure reaches p0; record the distance t3 measured by the ranging sensor when the working pressure reaches 1.1*p0. S130. Reduce the working pressure of the medium to 0.9*p0, and record the continuous data measured by the distance sensor, find the working pressure p1 corresponding to the moment when the distance t3 first recovers to the distance t2; S140. Calculate the friction force f according to the formula f=π*n1*d2*0.5*p / (p0-p1).

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