Hydraulic seal microscopic leakage observation device and method

Abstract

The invention provides a microscopic leakage observation device for a hydraulic seal. The microscopic leakage observation device comprises a shell (1), a base (2), a plug (3), an oil nozzle (4), an oil path (5), a sealing element (6), an oil path (9), a transparent sheet (10) and an optical amplifier, a sealing groove is formed in the bottom of the shell (1), the sealing piece (6) is located in the sealing groove in the bottom of the shell (1), and the depth of the sealing groove is smaller than the thickness of the sealing piece (6). The transparent sheet (10) is arranged in the base (2), is positioned right below the sealing groove in the bottom of the shell (1) and completely covers the sealing groove in the bottom of the shell (1); a through hole is formed in the bottom of the base (2) and serves as a microscopic leakage observation hole of a contact area of the sealing piece (6) and the transparent piece (10), and the area of the through hole is smaller than that of the transparent piece (10) and larger than that of a sealing groove in the bottom of the shell (1). And the optical amplifier is used for amplifying and displaying the microstructure of the contact area of the sealing element (6) in the microscopic leakage observation hole and the transparent sheet (10). The device can be used for directly observing a small gap at the edge of a sealing contact area, so that trace leakage of a sealing structure can be detected, and the method can be used as a rapid judgment method for sealing leakage.

Description

Technical Field

[0001] The invention belongs to hydraulic sealing technology, and in particular relates to a hydraulic sealing micro leakage observation device and method. Background Art

[0002] Hydraulic sealing technology is to block the leakage loss of hydraulic working medium in the internal space and external leakage loss through the contact and close fit between the sealing ring and the plane or cylindrical surface, prevent the invasion of external medium or pollutants, and ensure the integrity of the hydraulic system boundary. The hydraulic mechanism with high-pressure hydraulic oil as the working medium has the characteristics of high power density, large output force, and simple control. It is used in the drive and control of engineering machinery, aerospace and other equipment, but at the same time, it is inevitable that there is a need for hydraulic medium sealing and leakage problems.

[0003] Nowadays, sealing design usually selects an appropriate sealing compression amount to achieve mutual squeezing and close contact between the seal and the sealing surface to block the channel for oil leakage. It is generally believed that as long as the maximum contact pressure on the sealing surface is always greater than the oil pressure, the fluid leakage channel can be blocked and the sealing function can be achieved.

[0004] However, even if the sealing surface of a real part looks smooth, there are actually microscopic rough peaks. Therefore, even if two surfaces are in good contact, there will still be leakage channels under higher precision observation. In order to fundamentally understand the sealing mechanism and the cause of leakage, it is necessary to study the sealing mechanism from the perspective of microscopic contact. However, the current research on the hydraulic sealing mechanism is mainly based on theoretical and simulation research, and there is a lack of effective direct observation methods to observe and record the sealing contact state between the seal and the sealing surface, and to characterize the formation mechanism and law of the sealing leakage channel. Therefore, there is a need for a device that can observe the microscopic leakage of a hydraulic seal, characterize the formation mechanism of the sealing leakage, and can be used to detect trace leakage in the sealing structure. Summary of the invention

[0005] The present invention provides a hydraulic seal micro leakage observation device and method, which has the function of directly observing the seal interface contact state and the micro leakage process, can characterize the seal leakage mechanism, and can realize the detection of the micro leakage of the seal structure.

[0006] The first aspect of the present invention provides a hydraulic seal micro leakage observation device, comprising: a housing 1, a base 2, a screw plug 3, an oil nozzle 4, an oil circuit 5, a seal 6, an oil circuit 9, a transparent sheet 10 and an optical amplifier; wherein:

[0007] The housing 1 is located above the base 2, and the housing 1 and the base 2 are fastened together by bolts;

[0008] The top of the housing 1 is provided with a first oil hole, a screw plug 3 is installed at the first oil hole, and the screw plug 3 is connected to the housing 1 through threaded matching;

[0009] The housing 1 has a second oil hole on its side, and the oil nozzle 4 is installed at the second oil hole on the housing 1 and is fastened by bolts;

[0010] The bottom of the housing 1 is provided with a sealing groove, and the sealing member 6 is located in the sealing groove at the bottom of the housing 1, and the depth of the sealing groove is less than the thickness of the sealing member 6;

[0011] The oil passage 5 is located inside the housing 1, and is connected to the first oil hole at the top of the housing 1 and the sealing groove at the bottom of the housing 1;

[0012] The oil circuit 9 is located inside the housing 1, connecting the second oil hole on the side of the housing 1 with the oil circuit 5;.

[0013] The oil nozzle 4 is connected to an external oil source;

[0014] The transparent sheet 10 is arranged in the base 2, located just below the sealing groove at the bottom of the shell 1, and completely covers the sealing groove at the bottom of the shell 1;

[0015] A through hole is provided at the bottom of the base 2, which serves as a microscopic leakage observation hole for the contact area between the seal 6 and the transparent sheet 10. The area of ​​the through hole is smaller than the transparent sheet 10 and larger than the sealing groove at the bottom of the housing 1.

[0016] The optical amplifier is used to amplify and display the microstructure of the contact area between the sealing member 6 and the transparent sheet 10 in the microscopic leakage observation hole.

[0017] Optionally, the transparent sheet 10 is made of organic glass.

[0018] Optionally, the diameter of the oil passage 5 is smaller than the inner diameter of the sealing member 6 .

[0019] Optionally, the through hole is an expanded hole structure.

[0020] Optionally, a sealing groove is provided on the oil nozzle 4 , an auxiliary seal is provided in the sealing groove, and the auxiliary seal is interference fit with the housing 1 .

[0021] Optionally, an auxiliary seal is provided between the screw plug 3 and the housing 1 , and the auxiliary seal is interference fit with the housing 1 .

[0022] Optionally, the optical magnifier is a microscope.

[0023] A second aspect of the present invention provides a method for observing microscopic leakage of a hydraulic seal, using the device described in any one of the first aspects, the method comprising:

[0024] During the test, a lower medium pressure is selected, and the observation optical path and related external instruments are adjusted so that the seal 6 and the sealing contact area 12 can be clearly observed through the observation optical path 11, and the initial form of the seal 6 is checked to confirm that there is no initial abnormality;

[0025] The medium pressure is gradually increased, and the changes of the sealing member 6 and the sealing contact area 12 are observed by observing the optical path 11 , and pressure points can be selected for observation and recording as needed.

[0026] The present invention provides a hydraulic seal microscopic leakage observation device and method. The device is used to observe the microscopic structure of the hydraulic seal. Through direct observation images, the structural forms such as compression deformation, extrusion and damage of the seal under different medium pressure conditions and the distribution state of the seal contact area can be intuitively characterized. Further, through processing and analysis of the observation images, the contact width value of the seal contact area can be obtained, and the form and dynamic process of the seal contact microscopic leakage channel can be obtained. In addition, through the direct observation of the tiny gap at the edge of the seal contact area by the device, the micro leakage of the seal structure can be detected, which can be used as a quick judgment method for seal leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a hydraulic seal micro leakage observation device of the present invention;

[0028] Figure 2 It is a cross-sectional view of the hydraulic seal micro leakage observation device of the present invention;

[0029] Figure 3 It is a schematic diagram of the implementation effect of the hydraulic seal micro leakage observation device of the present invention;

[0030] Description of reference numerals:

[0031] Shell-1, base-2, screw plug-3, oil nozzle-4, oil passage hole-5, seal-6, auxiliary seal-7, auxiliary seal-8, oil passage hole-9, transparent sheet-10, observation light path-11, sealing contact area-12. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] The features and illustrative embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. The present invention is by no means limited to any specific settings and methods proposed below, but covers any improvements, replacements and modifications of structures, methods, devices without departing from the spirit of the present invention. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid unnecessary ambiguity in the present invention.

[0034] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other, and the embodiments can refer to and quote each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figure 1-3 As shown, the present invention provides a hydraulic seal micro leakage observation device, including a housing 1, a base 2, a screw plug 3, an oil nozzle 4, an oil circuit 5, a seal 6, an auxiliary seal 7, an auxiliary seal 8, an oil circuit 9, a transparent sheet 10, an observation optical path 11, and a sealing contact area 12, wherein:

[0037] The housing 1 is located above the base 2, and the housing 1 and the base 2 are fastened together by bolts;

[0038] The top of the housing 1 is provided with an oil hole;

[0039] The screw plug 3 is installed in the oil hole at the top of the housing 1, and the screw plug 3 is connected to the housing 1 through threaded matching;

[0040] The auxiliary seal 7 is located between the screw plug 3 and the housing 1 and has an interference fit with the housing 1;

[0041] The side of the housing 1 is provided with an oil hole;

[0042] The oil nozzle 4 is installed on the oil hole on the side of the housing 1 and is fastened by bolts;

[0043] The auxiliary seal 8 is located in the sealing groove of the oil nozzle 4 and has an interference fit with the housing 1;

[0044] The bottom of the housing 1 is provided with a sealing groove;

[0045] The transparent sheet 10 is located directly below the sealing groove at the bottom of the housing 1 and completely covers the sealing groove at the bottom of the housing 1;

[0046] The sealing member 6 is located in the sealing groove at the bottom of the housing 1;

[0047] The sealing member 6 and the transparent sheet 10 are interference fit;

[0048] The sealing contact area 12 is a sealing contact area formed by the sealing member 6 and the transparent sheet 10;

[0049] The transparent sheet 10 is located between the housing 1 and the base 2;

[0050] A through hole is provided in the middle of the base 2 , and the range of the through hole is smaller than the transparent sheet 10 , and larger than the sealing groove at the bottom of the shell 1 .

[0051] The observation light path 11 is located directly below the transparent sheet 10 , and the transparent sheet 10 , the sealing member 6 , and the sealing contact area 12 can be observed through the observation light path 11 .

[0052] The oil passage 5 is located inside the housing 1, and is connected to the oil hole at the top of the housing 1 and the sealing groove at the bottom of the housing 1;

[0053] The oil circuit 9 is located inside the housing 1, connecting the oil hole on the side of the housing 1 with the oil circuit 5;.

[0054] The oil nozzle 4 is connected to an external oil source;

[0055] The transparent sheet 10 is made of PMMA, but is not limited to PMMA. It can also be made of other materials with high strength and good optical transparency to ensure that it will not be damaged under the action of pre-pressure and medium pressure and has good light transmittance.

[0056] The specific form of the observation light path 11 is an optical microscope located directly below the device, and other light path structures can also be connected to change the observation mode or enhance the microstructure resolution capability.

[0057] In the hydraulic seal micro leakage observation device, a screw plug 3 is installed at the top of a shell 1, the screw plug 3 has an external thread, the oil hole at the top of the shell 1 has an internal thread, an auxiliary seal 7 is installed at the root of the thread of the screw plug 3, the screw plug 3 is connected to the shell 1 through threaded matching, and tightening the screw plug 3 can cause the auxiliary seal 7 to be squeezed by interference, thereby achieving the sealing of the oil hole at the top of the shell 1.

[0058] The oil nozzle 4 is installed on the side of the housing 1 and fastened by bolts. The oil nozzle 4 has a sealing groove and is installed with an auxiliary seal 8. The auxiliary seal 8 is interference fit with the housing 1 to achieve a sealed connection between the oil hole on the side of the housing 1 and the oil nozzle 4.

[0059] The bottom of the housing 1 has a sealing groove, the sealing member 6 is installed in the sealing groove at the bottom of the housing 1, and the transparent sheet 10 is pressed on the surface of the sealing member 6. The transparent sheet 10 is located between the housing 1 and the base 2, and the housing 1 and the base 2 are fastened by bolts, so that the transparent sheet 10 is closely attached to the bottom of the housing 1 and presses the sealing member 6. The sealing member 6 and the transparent sheet 10 are interference fit to form a sealing contact area 12.

[0060] The base 2 has a through hole in the middle, and the range of the through hole is smaller than the transparent sheet 10, which can ensure that the bottom plate 2 presses the transparent sheet 10 tightly. The range of the through hole in the middle of the base 2 is larger than the sealing groove at the bottom of the shell 1. The transparent sheet 10 is optically transparent, and the observation light path 11 located below the base 2 can observe the transparent sheet 10, the sealing member 6, and the sealing contact area 12.

[0061] The oil circuit 5 and the oil circuit 9 are located inside the housing 1. The oil circuit 5 intersects with the oil circuit 9, and is connected to the oil hole at the top of the housing 1, the sealing groove at the bottom of the housing 1, the oil hole on the side of the housing 1, and the oil nozzle 4 installed on the side of the housing 1. The oil nozzle 4 is connected to an external oil source, and the external hydraulic medium flows into the housing 1 through the oil nozzle 4 and flows into the sealing groove at the bottom of the housing 1 through the connecting oil circuit.

[0062] After the external hydraulic medium enters, due to the difference in sealing, the air in the oil passage inside the housing 1 will gather in the oil hole at the top of the housing. The oil hole at the top of the housing 1 is sealed by a screw plug 3. Tightening or loosening the screw plug 3 can change the sealing state of the oil hole at the top of the housing 1. By slightly rotating the screw plug 3, the sealing performance can be reduced to discharge the air gathered in the oil passage at the top of the housing. After the air is discharged, the screw plug 3 can be tightened to restore the sealing state.

[0063] In the implementation of the device, oil filling and exhaust should be carried out before the test begins. The oil nozzle 4 is connected to the external oil source, and the pressure of the external oil source is adjusted to about 0.02MPa. The external oil is filled into the device, and the screw plug 3 is slightly loosened. Air and oil will flow out from the top of the shell 1. After the internal air is discharged, the screw plug 3 is tightened to restore the sealing state to achieve exhaust of the oil circuit.

[0064] During the test, select a lower medium pressure, adjust the observation optical path and related external instruments, so that the seal 6 and the sealing contact area 12 can be clearly observed through the observation optical path 11, check the initial shape of the seal 6, and confirm that there is no initial abnormality. Gradually increase the medium pressure, observe the changes of the seal 6 and the sealing contact area 12 through the observation optical path 11, and select pressure points for observation and recording as needed.

[0065] The device is used to observe the microstructure of hydraulic seals. Through direct observation images, the structural morphology of seals under different medium pressure conditions, such as compression deformation, extrusion and damage, and the distribution state of the seal contact area can be intuitively characterized. Further, through processing and analysis of the observation images, the contact width value of the seal contact area can be obtained, and the morphology and dynamic process of the seal contact micro leakage channel can be obtained. In addition, through direct observation of the tiny gap at the edge of the seal contact area by the device, the trace leakage of the seal structure can be detected, which can be used as a quick judgment method for seal leakage.

[0066] By using this device in an environmental test chamber, it is also possible to observe the environmental response behavior of the sealing structure under different temperature and air pressure conditions and evaluate the environmental adaptability of the sealing performance.

[0067] The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that the above-mentioned embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the art can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A hydraulic seal micro leakage observation device, characterized in that: include: A housing (1), a base (2), a screw plug (3), an oil nozzle (4), an oil passage (5), a sealing element (6), an oil passage (9), a transparent sheet (10) and an optical amplifier; wherein: The housing (1) is located above the base (2), and the housing (1) and the base (2) are fastened together by bolts; The top end of the housing (1) is provided with a first oil hole, a screw plug (3) is installed at the first oil hole, and the screw plug (3) is connected to the housing (1) through threaded matching; The side of the housing (1) is provided with a second oil hole, and the oil nozzle (4) is installed at the second oil hole on the side of the housing (1) and is fastened by bolts; The bottom of the shell (1) is provided with a sealing groove, the sealing member (6) is located in the sealing groove at the bottom of the shell (1), and the depth of the sealing groove is less than the thickness of the sealing member (6); The oil circuit (5) is located inside the housing (1) and is connected to the first oil hole at the top of the housing (1) and the sealing groove at the bottom of the housing (1); The oil circuit (9) is located inside the housing (1) and is connected to the second oil hole on the side of the housing (1) and the oil circuit (5); The oil nozzle (4) is connected to an external oil source; The transparent sheet (10) is arranged inside the base (2), is located directly below the sealing groove at the bottom of the shell (1), and completely covers the sealing groove at the bottom of the shell (1); A through hole is provided at the bottom of the base (2) as a microscopic leakage observation hole in the contact area between the sealing member (6) and the transparent sheet (10), and the area of ​​the through hole is smaller than that of the transparent sheet (10) and larger than that of the sealing groove at the bottom of the housing (1); The optical amplifier is used to magnify and display the microstructure of the contact area between the sealing member (6) and the transparent sheet (10) in the microscopic leakage observation hole.

2. The hydraulic seal micro leakage observation device according to claim (1), characterized in that: The material of the transparent sheet (10) is organic glass.

3. The hydraulic seal micro leakage observation device according to claim (1), characterized in that: The diameter of the oil passage (5) is smaller than the inner diameter of the sealing element (6).

4. The hydraulic seal micro leakage observation device according to claim (1), characterized in that: The through hole is an expanded hole structure.

5. The hydraulic seal micro leakage observation device according to claim (1), characterized in that: A sealing groove is provided on the oil nozzle (4), an auxiliary seal is provided in the sealing groove, and the auxiliary seal is interference-fitted with the housing (1).

6. The hydraulic seal micro leakage observation device according to claim (1), characterized in that: An auxiliary seal is provided between the screw plug (3) and the housing (1), and the auxiliary seal is interference-fitted with the housing (1).

7. The hydraulic seal micro leakage observation device according to claim (1), characterized in that: Optical magnifier for microscope.

8. A method for observing microscopic leakage of hydraulic seals, characterized in that: Using the device according to any one of claims 1 to 2, the method comprises: During the test, a relatively low medium pressure is selected, and the observation optical path and related external instruments are adjusted so that the seal (6) and the sealing contact area (1) (2) can be clearly observed through the observation optical path, and the initial shape of the seal (6) is checked to confirm that there is no initial abnormality; The medium pressure is gradually increased, and the changes of the sealing element (6) and the sealing contact area (12) are observed by observing the optical path. Pressure points can be selected as needed for observation and recording.

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