CN115899286A - Method for reducing leakage of valve element structure of fuel control device - Google Patents
Method for reducing leakage of valve element structure of fuel control device Download PDFInfo
- Publication number
- CN115899286A CN115899286A CN202211566045.6A CN202211566045A CN115899286A CN 115899286 A CN115899286 A CN 115899286A CN 202211566045 A CN202211566045 A CN 202211566045A CN 115899286 A CN115899286 A CN 115899286A
- Authority
- CN
- China
- Prior art keywords
- valve
- annular
- valve core
- control device
- bush
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Lift Valve (AREA)
Abstract
The invention relates to the technical field of valve elements, in particular to a method for reducing the leakage of a valve element structure of a fuel control device. However, metal parts such as the valve core and the valve bush of the valve can expand under the heating of high-temperature fuel, and as the gap between the valve core and the valve bush of the valve becomes smaller, the metal expansion is more likely to cause the clamping stagnation of the valve and the like to cause destructive consequences on the feedback regulation control function of the fuel control device. And under the condition of a small gap, the abrasion between the valve core and the bush is more serious, so that the service life of the valve element is prolonged.
Description
Technical Field
The invention relates to the technical field of valve elements, in particular to a method for reducing the leakage amount of a valve element structure of a fuel control device.
Background
According to different working states, the fuel control device provides fuel for the aircraft engine at different flow rates through a hydraulic control system formed by valve elements such as an isobaric difference execution valve and a metering valve, so that the fuel requirements of the aircraft engine under different working states are ensured. The stability and dynamic performance of the flap member will therefore directly affect the actual operating performance of the fuel control device. Because the two sides of the valve core of the valve generally have larger pressure difference, and an annular slit is formed between the valve core and the valve bushing in actual work due to the requirements of machining errors and actual movement, fuel oil can flow through the annular slit under the action of the pressure difference to cause the leakage of the valve, the stability of the pressure difference between the two sides of the valve element is directly influenced, and the actual control performance of the fuel oil control device is further influenced. Therefore, a technical solution that can suppress the leakage flow is required to improve the stability of the operation performance of the shutter. The existing technical means for improving the sealing performance of the valve element mainly comprise 3 technical means and defects:
1. the width of a gap between the valve core of the valve and the valve bushing is continuously reduced through a high-precision machining process, so that the sectional area of a leakage flow passage is reduced, and the sealing performance of the valve is improved. However, metal parts such as the valve core and the valve bush of the valve can expand under the heating of high-temperature fuel, and as the gap between the valve core and the valve bush of the valve becomes smaller, the metal expansion is more likely to cause the clamping stagnation of the valve and the like to cause destructive consequences on the feedback regulation control function of the fuel control device. And under the condition of a small gap, the abrasion between the valve core and the bush is more serious, so that the service life of the valve element is prolonged.
2. A flexible rubber ring is arranged in a groove on the valve core of the valve, and the sealing performance of the valve is improved by utilizing the O-shaped rubber ring. However, the flexible sealing ring is broken and fails quickly under the actions of high-temperature fuel infiltration and strong friction in the movement process of the valve core of the valve, so that the service life of the whole valve element is shortened, and the flexible sealing ring is only suitable for the conditions of non-high temperature and small axial stroke interval of the valve core of the valve. In addition, the friction resistance between the valve core additionally provided with the O-shaped rubber ring and the valve bushing is obviously increased in the movement process of the valve core, the damping of a control system of the fuel control device can be increased, and the dynamic response performance of the control system is reduced.
3. The end face of the valve core of the valve is provided with an annular groove, and the pressure of fuel at the high-pressure end of the valve core of the valve is utilized to deform the outer part of the annular groove towards the direction of the valve bush, so that the actual gap width between the valve core of the valve and the valve bush is reduced, and the sealing performance of the valve element is improved. However, because the deformation degree of the outer part of the annular groove of the end face is different under different pressures, the valve end face is only suitable for a working environment with a pressure within a certain range after a certain annular groove is processed on the end face of the valve.
Disclosure of Invention
In view of the existing shortcomings, the invention provides a method for reducing the leakage amount of a valve element structure of a fuel control device.
In order to achieve the purpose, the invention adopts the technical scheme that:
a method for reducing the leakage of a valve element structure of a fuel control device comprises a valve shell, wherein a valve core and a valve bush which plays a role of a gasket are arranged in the valve shell, the valve bush and the valve shell are in interference fit, the valve bush and the valve shell are in clearance fit, fuel oil on two sides of the valve core can flow through an annular slit on the circumference of the valve core under the driving of pressure difference, so that the fuel oil in the annular slit between the valve core and the valve bush plays a role of lubricating the movement of the valve core, and lubricating oil is filled in the valve core;
and the valve core of the valve is positioned on a part soaked in the oil way in the valve shell, and the axial position of the part is adjusted according to the actual pressure difference of two sides of the part.
Preferably, a cross section of a gap between the valve core and the valve bushing, which is perpendicular to the axial direction of the valve core, is annular.
Preferably, when fluid in the valve housing flows through the flow channel, the kinetic energy loss of the fluid is caused by resistance generated by viscosity of the fluid and additional resistance generated by the position of the constant section change of the valve core and the valve port of the valve;
according to different working states, the fuel control device provides fuel for the aircraft engine at different flow rates through a hydraulic control system formed by valve elements such as an isobaric difference execution valve and a metering valve.
Preferably, an annular groove is formed in the valve bushing, a flat annular slit flow channel is changed, sudden expansion and sudden contraction of the width of the flow channel occur in the middle of the valve bushing, flowing pressure loss is caused, and sealing for reducing flow under a certain pressure difference condition is achieved;
the valve bush, which is only subjected to radially outward pressure and does not serve as a strength support, is provided with an annular groove.
Preferably, the valve shell directly receives the action of the pressure in the oil way and the action of the pressure difference of the oil ways at two sides of the valve on the valve core of the valve, and additional machining and structural change are carried out;
the annular groove formed in the valve bush is filled with fuel oil, and the fuel oil flows from the oil way on the high pressure side to the oil way on the low pressure side through the annular slit between the valve core and the valve bush under the driving of pressure difference.
Preferably, when a certain pressure difference and the width of the annular gap exist, the flow resistance inside the valve housing is increased, so that an annular groove is formed on the valve core or the valve bushing in the valve housing to form an additional flow passage cross-sectional area.
Preferably, the inside of the valve bush is provided with an annular groove, when the flow in the annular slit meets the annular groove, the sectional area of the flow passage is suddenly enlarged, the flow speed is reduced, and the annular grooves are distributed at equal intervals.
Preferably, the inner hole of the valve bushing is processed by a boring mill to form an annular groove, the section of the annular groove can be rectangular, semicircular, V-shaped and the like, and the radial depth and the axial width of the annular groove are both required to be greater than 5d by taking the width d of the annular slit as a reference.
Preferably, the valve core moves the valve slit axially during actual operation, and the annular grooves distributed at equal intervals can ensure that the annular slit formed between the valve core and the valve bushing can be always broken by a certain number of annular grooves.
Compared with the prior art, the invention has the following beneficial effects:
1. the ring-shaped groove is arranged on the valve bush to change the smooth annular slit flow passage, so that the sudden expansion and the sudden contraction of the width of the flow passage occur in the middle of the valve bush to cause the pressure loss of the flow, thereby achieving the sealing purpose of reducing the flow under the condition of certain pressure difference. Firstly, compared with the existing valve sealing technology, the purpose of improving the sealing performance of the valve can be achieved without reducing the clearance between the valve core of the valve and the valve bush, namely increasing the risk of valve clamping stagnation.
2. The annular groove is formed in the valve bushing which is only acted by radial outward pressure and does not act as strength support, deformation of the valve element after being pressed cannot be changed, and the problem that the pressure range of a specific structure is limited like the method of opening the annular groove on the end face is solved.
3. Then, the method does not need to carry out additional machining and structural change on parts needing strength consideration in the valve element, namely the valve shell is directly acted by the pressure in an oil way and the valve core is acted by the pressure difference of the oil ways at two sides of the valve, so that the strength of the valve element does not need to be checked again in the process of using the method. Finally, compared with the situation that additional friction resistance is brought by adding the O-shaped rubber ring, the annular groove formed in the valve bushing in a machining mode is filled with fuel oil, so that the lubricating effect of the annular oil film on the valve core of the valve in the moving process is more facilitated, the friction force is reduced, and the dynamic response performance of the control system is improved. In addition, the annular oil film has better lubricating property, so that the abrasion between the valve core and the valve bushing of the valve in the working process can be reduced, and the overall service life of the valve element is prolonged.
Drawings
FIG. 1 is a schematic view of a valve housing for a method of reducing leakage in a valve member structure of a fuel control device in accordance with the present invention;
FIG. 2 is a schematic perspective view of a valve housing for a method of reducing leakage from a valve member structure of a fuel control device in accordance with the present invention;
FIG. 3 isbase:Sub>A schematic cross-sectional view taken along line A-A of FIG. 2 illustratingbase:Sub>A method of reducing leakage inbase:Sub>A valve member structure ofbase:Sub>A fuel control device in accordance with the present invention;
fig. 4 is an enlarged view at B in fig. 3 illustrating a method of reducing leakage in a valve member structure of a fuel control device according to the present invention.
In the figure: 1. a shutter housing; 2. a valve core of the valve; 3. a shutter bushing.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Examples
As shown in fig. 1 to 4, a method for reducing the leakage of a valve element structure of a fuel control device comprises a valve shell 1, a valve core 2 is arranged inside the valve shell 1, a valve bush 3 which is arranged between the valve core 2 and the valve shell 1 and plays a role of a gasket is adopted, the valve bush 3 is in interference fit with the valve shell 1 and is in clearance fit with the valve core 2, fuel oil on two sides of the valve core 2 can flow through an annular slit on the circumference of the valve core 2 under the driving of pressure difference, so that the fuel oil in the annular slit between the valve core 2 and the valve bush 3 plays a role of lubricating for the movement of the valve core 2, and the valve core 2 is filled with lubricating oil;
and the valve core 2 of the valve is positioned in the valve shell 1 and is a part soaked in an oil way, and the axial position of the valve core 2 is adjusted according to the actual pressure difference at the two sides of the valve core.
In the present embodiment, the slit between the valve core 2 and the valve bush 3 has a circular cross-sectional shape perpendicular to the axial direction of the valve core 2.
In this embodiment, the kinetic energy loss of the fluid is caused by the resistance generated by the viscosity of the fluid when the fluid flows through the flow channel inside the valve housing 1 and the extra resistance generated by the position of the valve port of the valve core 2 with the uniform cross section change;
according to different working states, the fuel control device provides fuel for the aircraft engine at different flow rates through a hydraulic control system formed by valve elements such as an isobaric difference execution valve and a metering valve.
In the embodiment, the valve bush 3 is provided with an annular groove, a flat annular slit flow channel is changed, the middle part of the valve bush is subjected to sudden expansion and sudden contraction of the width of the flow channel, the pressure loss of the flow is caused, and the sealing for reducing the flow under the condition of a certain pressure difference is achieved;
the ring-shaped groove is opened on the shutter bushing 2 which is only acted on by the radially outward pressure and not as a strength support.
In the embodiment, the valve shell 1 is directly acted by the pressure in the oil way, and the valve core 2 is acted by the pressure difference of the oil ways at two sides of the valve, so that additional machining and structural change are carried out;
the annular groove formed on the valve bush 3 is filled with fuel oil, and the fuel oil flows from the oil path on the high pressure side to the oil path on the low pressure side through the annular slit between the valve core 2 and the valve bush 3 under the drive of pressure difference.
In the present embodiment, at a certain pressure difference and a certain width of the annular gap, the flow resistance inside the valve housing 1 is increased, so that an annular groove is formed on the valve core or the valve bushing of the valve housing 1 to form an additional flow passage cross-sectional area.
In this embodiment, the inner side of the valve liner 2 is divided into annular grooves, and when the flow in the annular slit meets the annular grooves, the sectional area of the flow passage is suddenly enlarged, the flow rate is slowed, and the annular grooves are distributed in a plurality of equal intervals.
In this embodiment, the inner hole of the valve bushing 2 is processed by a boring machine to form an annular groove, the cross-sectional shape of the annular groove may be rectangular, semicircular, V-shaped, etc., and both the radial depth and the axial width of the annular groove need to be greater than 5d based on the width d of the annular slit.
In this embodiment, the valve core 2 will move axially during the actual operation, and the annular slots formed between the valve core 2 and the valve bush 3 can be always cut off by a certain number of annular slots.
The leakage problem of the valve element occurs because pressure difference occurs due to different pressures of oil paths on two sides of the valve core of the valve, and fuel oil flows from the oil path on the high pressure side to the oil path on the low pressure side through the annular slit between the valve core of the valve and the valve bushing under the driving of the pressure difference, so that the actual working performance of the fuel oil control device is influenced. When certain pressure difference and annular gap's width, increase the flow resistance, improve the pressure loss who flows promptly, can reduce flow velocity, reduce the valve volume of revealing, promote the sealing performance of valve. The section of the annular oil film in the annular slit flow passage in the valve element of the original structure is not changed along the axial direction, and the pressure loss of the flow is mainly caused by the resistance generated by the viscosity of the fluid. Therefore, the condition that the cross section of the flow channel is increased and changed suddenly can be achieved, and the extra pressure loss of the annular oil film flow can be improved. Therefore, it is conceivable to open an annular groove in the valve element on the valve core or the valve bush to form an additional abrupt change in the flow path cross-sectional area. The valve sleeve is optionally provided with an open ring groove on its inner side, considering that the valve core is directly loaded by a pressure difference in the axial direction, the open ring groove on the valve core affects its own strength and even deformation, which easily leads to failure of the valve element, while the valve sleeve is only stressed radially outwards and does not act as a strength support (the valve shell is present on its outer side to ensure the strength of the valve element under internal pressure conditions). When the flow in the annular slit meets the annular groove, the sectional area of the flow passage is suddenly enlarged, the flow speed is reduced, and the fuel with higher speed at the back collides with the fuel with lower speed at the front to generate collision loss. Secondly, when entering the annular groove from the annular slit, the fuel oil does not flow along the geometric shape of the original annular slit, but enters the annular groove like jet flow, and adheres to the wall after a certain distance, so that the flow separation is formed, the rotation angle of the pipe wall at the enlarged part is vortex, the main flow transfers energy to the vortex to rotate the vortex, and the part of energy is dissipated in the form of heat under the influence of viscosity. When the flow enters the annular slit of the next section after passing through the annular groove, the flow is equivalent to the sudden contraction of the flow entering the small-section flow passage from the large-section flow passage, and the flow needs extra pressure to be extruded into the slit, so that the pressure loss is caused.
And an inner hole of the valve bush is processed by a boring mill to form an annular groove, and the section of the annular groove can be rectangular, semicircular, V-shaped and the like. By taking the width d of the annular slit as a reference, the radial depth and the axial width of the annular groove are both required to be more than 5d so as to reflect sudden expansion and sudden contraction of the annular groove relative to the flow passage sectional area of the annular slit in the actual working process. The small radial depth and axial width of the annular slit lead to small disturbance of the annular groove to the flow in the annular slit, and the established sealing effect cannot be achieved.
A plurality of axial annular grooves distributed at equal intervals are processed in the inner hole of the valve bush, the promotion of the sealing performance of the valve by extra pressure loss caused by a single annular groove is limited, and the sealing performance of the valve is promoted as much as possible by the plurality of annular grooves distributed at equal intervals. In addition, the valve core of the valve moves along the axial direction in the actual working process (the actual valve slit also moves in the axial direction), and the annular slits formed between the valve core of the valve and the valve bushing can be guaranteed to be always broken by a certain number of annular grooves by the aid of the annular grooves distributed at equal intervals, so that high sealing performance of the valve under all working conditions is guaranteed.
The working principle of the method for reducing the leakage amount of the valve element structure of the fuel control device is as follows: the method adopts the ring-opening groove on the valve bush to change the flat annular slit flow passage, so that the sudden expansion and the sudden contraction of the width of the flow passage occur in the middle part of the flow passage, and the flowing pressure loss is caused, thereby achieving the sealing purpose of reducing the flow under the condition of certain pressure difference. Firstly, compared with the existing valve sealing technology, the purpose of improving the sealing performance of the valve can be achieved without reducing the clearance between the valve core of the valve and the valve bushing of the valve, namely increasing the risk of valve clamping stagnation. Secondly, the annular groove is formed in the valve bushing which is only acted by the radial outward pressure and does not act as a strength support, the deformation condition of the valve element after being pressed cannot be changed, and the problem that the applicable pressure range of a specific structure is limited like the method of opening the annular groove on the end face does not exist. Then, the method does not carry out additional machining and structural change on parts needing strength consideration in the valve element, namely the valve shell (directly acted by pressure in an oil way) and the valve core (acted by pressure difference of the oil way on two sides of the valve), so that the strength of the valve element does not need to be checked again in the process of using the method. Finally, compared with the fact that the O-shaped rubber ring is added to bring extra frictional resistance, the annular groove formed in the valve bush in a machining mode is filled with fuel oil, the lubricating effect of an annular oil film on the valve core of the valve in the moving process is better facilitated, the frictional force is reduced, and the dynamic response performance of a control system is improved. In addition, the annular oil film has better lubricating property, so that the abrasion between the valve core and the valve bush of the valve in the working process can be reduced, and the overall service life of the valve element is prolonged.
It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations and modifications can be made on the basis of the above description, and all embodiments cannot be exhaustive, and obvious variations and modifications may be made within the scope of the present invention.
Claims (9)
1. A method of reducing leakage in a valve member arrangement of a fuel control device, comprising a valve housing (1), characterized by: the valve comprises a valve shell (1), a valve core (2) and a valve bush (3) which is arranged in the valve shell (1) and plays a role of a gasket, wherein the valve bush (3) is in interference fit with the valve shell (1) and is in clearance fit with the valve core (2), oil paths on two sides of the valve core (2) can flow through an annular slit on the circumference of the valve core (2) under the driving of pressure difference, so that the oil in the annular slit between the valve core (2) and the valve bush (3) plays a role of lubricating the movement of the valve core (2), and the valve core (2) is filled with lubricating oil;
the valve core (2) is positioned on a part soaked in an oil way in the valve shell (1), and the axial position of the part is adjusted according to the actual pressure difference on the two sides of the part.
2. A method of reducing leakage from a fuel control device valve member arrangement according to claim 1, wherein: the gap between the valve core (2) and the valve bushing (3) is annular in cross section perpendicular to the axial direction of the valve core (2).
3. A method of reducing leakage from a fuel control device valve member arrangement according to claim 1, wherein: when fluid in the valve shell (1) flows through the flow channel, the kinetic energy loss of the fluid is caused by resistance generated by the viscosity of the liquid and additional resistance generated by the position of the constant section change of the valve port of the valve core (2) of the fluid flowing through;
according to different working states, the fuel control device provides fuel for the aircraft engine at different flow rates through a hydraulic control system formed by valve elements such as an isobaric difference execution valve and a metering valve.
4. A method of reducing leakage from a fuel control device valve member arrangement according to claim 1, wherein: the valve bush (3) is provided with an annular groove, a flat annular slit flow channel is changed, the middle part of the valve bush is subjected to sudden expansion and sudden contraction of the flow channel width, flowing pressure loss is caused, and the purpose of sealing the valve bush under the condition of certain pressure difference is achieved;
the valve bush (2) is provided with an annular groove which is only acted by radial outward pressure and not used as a strength support.
5. A method of reducing leakage from a fuel control device valve member arrangement according to claim 1, wherein: the valve shell (1) is directly acted by the pressure in the oil way, and the valve core (2) is acted by the pressure difference of the oil ways at two sides of the valve, so that additional machining and structural change are carried out;
the annular groove formed in the valve bushing (3) in a machining mode is filled with fuel oil, and the fuel oil flows from an oil way on a high-pressure side to an oil way on a low-pressure side through an annular slit between the valve core (2) of the valve and the valve bushing (3) under the driving of pressure difference.
6. A method of reducing leakage from a fuel control device valve member arrangement according to claim 1, wherein: and when a certain pressure difference and the width of the annular gap exist, the flow resistance in the valve shell (1) is increased, so that an annular groove is formed in the valve core or the valve bush of the valve in the valve shell (1) to form an additional flow passage sectional area.
7. A method of reducing leakage from a fuel control device valve member arrangement according to claim 1, wherein: the inner side of the valve bushing (2) is provided with an annular groove, the flow in the annular slit meets the annular groove, the sectional area of a flow channel is suddenly enlarged, the flow speed is slowed down, and the annular grooves are distributed at a plurality of equal intervals.
8. A method of reducing leakage from a fuel control device valve member arrangement according to claim 1, wherein: the inner hole of the valve bushing (2) is processed by a boring machine to form an annular groove, the section of the annular groove can be rectangular, semicircular, V-shaped and the like, and the radial depth and the axial width of the annular groove are both required to be greater than 5d by taking the width d of the annular slit as a reference.
9. A method of reducing leakage from a fuel control device valve member arrangement according to claim 8, wherein: the valve core (2) moves axially in the actual working process, and the annular slits formed between the valve core (2) and the valve bushing (3) can be always broken by a certain number of annular grooves due to the plurality of annular grooves which are distributed at equal intervals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211566045.6A CN115899286A (en) | 2022-12-07 | 2022-12-07 | Method for reducing leakage of valve element structure of fuel control device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211566045.6A CN115899286A (en) | 2022-12-07 | 2022-12-07 | Method for reducing leakage of valve element structure of fuel control device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115899286A true CN115899286A (en) | 2023-04-04 |
Family
ID=86486702
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211566045.6A Pending CN115899286A (en) | 2022-12-07 | 2022-12-07 | Method for reducing leakage of valve element structure of fuel control device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115899286A (en) |
-
2022
- 2022-12-07 CN CN202211566045.6A patent/CN115899286A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5639095A (en) | Low-leakage and low-instability labyrinth seal | |
| EP0745794B1 (en) | Radial flow seals for rotating shafts which deliberately induce turbulent flow along the seal gap | |
| US5496047A (en) | Mechanical seal containing a sealing face with grooved regions which generate hydrodynamic lift between the sealing faces | |
| EP2376822B1 (en) | Segmented seal with hydrodynamic feature and assembly | |
| KR20210113364A (en) | sliding parts | |
| WO1996015397A1 (en) | A shaft seal | |
| US11680645B2 (en) | Aspirating face seal assembly for a rotary machine | |
| WO2012117292A1 (en) | Segmented seal with axial load control feature | |
| SE432645B (en) | Sealing device for sealing in a direction between the interacting surface of a cylindrical cavity and the mantle surface of a moving spindle | |
| CN111335968B (en) | Sealing device for high-speed rotating impeller machine | |
| CN109702501B (en) | Intracavity feedback throttling static pressure rotary table | |
| CN104235380A (en) | Mechanical seal with two-stage staggered hydrodynamic grooves | |
| CN115899286A (en) | Method for reducing leakage of valve element structure of fuel control device | |
| CN104019024B (en) | Anti-leak dynamic pressure type valve plate | |
| CN112963543A (en) | Diffusion type self-pumping fluid dynamic and static pressure type mechanical seal | |
| US10895324B2 (en) | Aspirating face seal assembly for a rotary machine | |
| CN102865369B (en) | A kind of fluctuate hermetical ring with static pressure and dynamic pressure double effect | |
| US8882445B2 (en) | Hydraulic machine, an energy conversion installation including such a machine, and a method of adjusting such a machine | |
| JPH0739805B2 (en) | Turbine seal clearance adjustment device | |
| JP3068432B2 (en) | mechanical seal | |
| CN221145310U (en) | Liquid film mechanical sealing device for aero-engine rotating machinery | |
| EP1531295B1 (en) | Gas film hydraulic shaft seal | |
| CN110594218A (en) | Expansion valve core, hydraulic lock structure with expansion valve core and sealing method of hydraulic lock structure | |
| CN111089000A (en) | Self-adaptive high-durability floating sealing structure suitable for extreme conditions | |
| CN218440636U (en) | End face seal assembly |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |