Energy storage sealing structure and dynamic sealing device for high-pressure easily-vaporized medium
Technical Field
The invention relates to the technical field of sealing, in particular to an energy storage sealing structure and a dynamic sealing device for a high-pressure easily-vaporized medium.
Background
The liquid oxygen pump is used as an important component of the liquid oxygen methane engine and is used for conveying low-temperature liquid oxygen required by the operation of the engine. The liquid oxygen pump is closely adjacent to the methane pump, and a set of sealing device is usually arranged between the liquid oxygen pump and the methane pump in the turbopump of the liquid rocket engine to prevent working medium from leaking. At present, sealing devices used in low temperature environments at home and abroad are mainly divided into two forms:
one is non-contact seal, which adopts labyrinth local gap to realize gradual decompression and sealing, such as floating ring, labyrinth seal, etc. The sealing structure is simple, but the sealing performance is not ideal, namely, the leakage amount of a medium is large during working, and a high-pressure blowing system is required to be added for improving the sealing reliability. As for non-contact mechanical seal, its cost is higher, and it is higher to environmental condition's requirement: the vibration is small, the working condition is stable, and the like, and the requirements are difficult to meet on a rocket engine.
The other is common contact type mechanical seal, and the principle is that an elastic element is utilized to enable a friction pair to be tightly attached to realize sealing. The sealing elastic element in a low-temperature environment generally adopts a welding corrugated pipe, the sealing assembly works ideally in a low-pressure medium, the welding corrugated pipe deforms seriously after the medium pressure exceeds 3MPa, and the sealing abrasion loss is large, the sealing performance is reduced, and even the sealing corrugated pipe fails, so that the sealing can not meet the requirements of long service life and repeated use of a turbo pump under severe working conditions of high rotating speed, high pressure and the like.
However, in the existing high-pressure dynamic sealing device, other auxiliary means are adopted to reduce the pressure before sealing, so that the system is complicated, and the risk that the auxiliary device fails to work to cause sealing failure may occur.
Disclosure of Invention
Therefore, the technical problem to be solved by the invention is to overcome the defects that the high-pressure dynamic sealing device in the prior art is complex in structure and causes medium leakage due to volatile effect, so that an energy storage sealing structure with simple structure and good sealing effect and a dynamic sealing device for high-pressure medium easy to vaporize are provided.
The invention also aims to solve the problem that the static ring in the prior art is easy to collide with the dynamic ring after being worn, so that the sealing effect is influenced.
The invention also aims to solve the technical problem of overcoming the defect of poor sealing effect caused by unstable specific pressure before and after working due to friction of the sealing end surfaces of the movable ring and the static ring.
In order to solve the above technical problem, the present invention provides an energy storage sealing structure, including:
the elastic shell is provided with a pair of elastic arms which are oppositely arranged, one ends of the elastic arms are connected, the other ends of the elastic arms are provided with openings allowing a medium to enter spaces between the elastic arms, each elastic arm comprises a first support arm and a second support arm which are arranged in an included angle, and a first included angle between the first support arm and the axis of the elastic shell is larger than a second included angle between the second support arm and the axis of the elastic shell;
and the energy storage elastic piece is arranged in the space of the elastic shell, is used for supporting the elastic shell and generates deformation energy storage under the action of pressure.
The energy storage elastic part is in a U shape consistent with the space shape of the elastic shell.
The energy storage sealing structure is characterized in that the elastic shells are a pair of oppositely arranged, the openings of the elastic shells are arranged towards the direction away from each other, and each elastic shell is internally provided with one energy storage elastic part.
The dynamic sealing device for the high-pressure easily-vaporized medium is further provided, and comprises the energy storage sealing structure, and the energy storage sealing structure is arranged between the spring shell and the static ring assembly.
The dynamic sealing device for the high-pressure easily-vaporized medium is characterized in that the spring shell is connected with the static ring assembly through a plurality of fasteners.
The dynamic sealing device for the high-pressure easily vaporized medium is characterized in that the static ring assembly comprises a static ring body and a graphite ring partially embedded in the static ring body, the graphite ring is arranged in contact with the dynamic ring, the fastener is installed on the static ring body, and the distance between the fastener and the dynamic ring is smaller than the distance between the graphite ring and the static ring body.
The distance between the fastener and the movable ring is 0.2 mm.
The diameter of the graphite ring is gradually increased from a first end close to the moving ring to a second end far away from the moving ring.
The dynamic sealing device for the high-pressure easily-vaporized medium further comprises an elastic piece arranged between the spring shell and the static ring assembly, and the elastic piece is used for applying pretightening force towards the dynamic ring to the static ring assembly.
The dynamic sealing device for the high-pressure easily vaporized medium further comprises a split floating ring arranged on the periphery of the shaft sleeve.
The technical scheme of the invention has the following advantages:
1. according to the energy storage sealing structure provided by the invention, as the first included angle between the first support arm of the elastic shell and the axis of the elastic shell is larger than the second included angle between the second support arm and the axis of the elastic shell, after a medium enters the space between the pair of elastic arms, the second support arm is closer to the sealing surface contacted with the first support arm relative to the first support arm under the action of pressure, namely the contact areas of the first support arm and the second support arm with the sealing surface are different, so that the energy storage sealing structure is prevented from being locked with the sealing surface after being pressed, the sealing is prevented from failing, and the medium is prevented from leaking.
2. The energy storage sealing structure provided by the invention is a pair of energy storage sealing structures arranged in a back direction, and the problem of bidirectional sealing is effectively solved.
3. According to the dynamic sealing device for the high-pressure easily-vaporized medium, the arrangement of the fastening piece between the spring shell and the static ring assembly can play a role in preventing rotation, and the distance between the fastening piece and the dynamic ring is smaller than the distance between the graphite ring and the static ring body, so that when the graphite ring is abraded to a certain degree, the dynamic ring and the static ring body are prevented from colliding under the blocking effect of the fastening piece, and the sealing effect is ensured.
4. According to the dynamic sealing device for the high-pressure easily-vaporized medium, the diameter of the graphite ring is gradually increased from the first end close to the dynamic ring to the second end far away from the dynamic ring. Therefore, after the graphite ring is worn, the elastic force of the elastic part on the sealing end face is correspondingly compensated by increasing the cross section area of the graphite ring, so that the stability of the specific pressure before and after the working of the sealing end face is kept, and the sealing performance is ensured; meanwhile, the inclined surface of the graphite ring can guide a medium to smoothly enter the friction surface to cool the friction surface, so that the medium is prevented from being vaporized.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a schematic view of an energy storage sealing structure provided by the invention before charging;
FIG. 2 is a schematic view of the stored energy sealing structure provided by the present invention after being pressurized;
FIG. 3 is a schematic view of a dynamic sealing device for high-pressure easily vaporized media provided by the invention;
FIG. 4 is an enlarged view of portion A of FIG. 3;
fig. 5 is an enlarged schematic view of a portion B in fig. 3.
Description of reference numerals:
1. an elastic housing; 2. an energy storage elastic member; 3. a first support arm; 4. a second support arm; 5. a first included angle; 6. a second included angle; 7. a housing; 8. a shaft; 9. a bearing; 10. a moving ring; 11. a shaft sleeve; 12. a first gasket; 13. a split floating ring; 14. a spring housing; 15. a second gasket; 16. a third gasket; 17. a fourth gasket; 18. a stationary ring body; 19. a graphite ring; 20. a fastener; 21. an elastic member.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. 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.
In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
One embodiment of the stored energy seal configuration shown in figures 1 and 2 comprises an elastomeric housing 1 and a stored energy elastomeric member 2 disposed within the elastomeric housing 1. The elastic shell 1 is made of reinforced polytetrafluoroethylene and is provided with a pair of elastic arms which are oppositely arranged, one ends of the pair of elastic arms are connected, an opening allowing a medium to enter a space between the pair of elastic arms is formed at the other end of the pair of elastic arms, the medium enters the elastic shell 1 from the opening and applies pressure to the pair of elastic arms to enable the pair of elastic arms to deform towards a sealing surface, and sealing is achieved. The elastic arm includes first support arm 3 and the second support arm 4 that becomes the contained angle setting, and the length of first support arm 3 is less than the length of second support arm 4, first support arm 3 with first contained angle 5 between the axis of elastic housing 1 is greater than second support arm 4 with second contained angle 6 between the axis of elastic housing 1. Before pressurizing, the elastic shell 1 is in line contact with the sealing surface through a connecting line between the first support arm 3 and the second support arm 4; after pressurizing, first support arm 3 and second support arm 4 all take place deformation towards sealed face, because second support arm 4 is close to sealed face more, therefore the area of contact of second support arm 4 and sealed face is greater than the area of contact of first support arm 3 and sealed face, and the line contact between elastic housing 1 and the sealed face changes into face contact. The energy storage elastic part 2 is a U-shaped spring which is consistent with the space shape of the elastic shell 1 and is used for supporting the elastic shell 1 and generating deformation energy storage when being under the action of pressure. The two ends of the U-shaped spring are respectively clamped at the bending part of the first supporting arm 3 of the elastic shell 1, so that the connection stability is ensured.
In order to realize bidirectional sealing, as shown in fig. 4, the elastic housings 1 are a pair arranged oppositely, and the openings are arranged in a direction away from each other, and each elastic housing 1 is provided with one energy storage elastic member 2.
A specific embodiment of the dynamic sealing device for high-pressure easy-vaporization medium shown in fig. 3-5 includes a housing 7, which is sequentially sleeved on a bearing 9, a dynamic ring 10 and a shaft sleeve 11 on a shaft 8, a first sealing gasket 12 is arranged between the dynamic ring 10 and the shaft sleeve 11, a static ring component and a split floating ring 13 are sleeved on the shaft sleeve 11, the dynamic ring 10 is in contact with the static ring component, a spring housing 14 is further sleeved on the periphery of the static ring component, and an energy storage sealing structure is arranged between the spring housing 14 and the static ring component, which not only ensures the sealing performance between the spring housing 14 and the static ring component, but also ensures that the deformation of the energy storage sealing structure is small in a high-pressure environment. A second sealing gasket 15 is arranged between the spring shell 14 and the shell 7, a third sealing gasket 16 and a fourth sealing gasket 17 are arranged between the split floating ring 13 and the shell 7, and inert gas is blown off between the split floating rings 13 to prevent left-side media from leaking to the right.
The static ring assembly comprises a static ring body 18 and a graphite ring 19 partially embedded in the static ring body 18, wherein the graphite ring 19 is arranged in contact with the moving ring 10. The spring housing 14 is connected with the stationary ring assembly through a screw serving as a fastening member 20, the stationary ring body 18 is stepped, the fastening member 20 is mounted on the highest step of the stationary ring body 18, which is far away from the shaft sleeve 11, and the distance between the fastening member 20 and the moving ring 10 is smaller than the distance that the graphite ring 19 extends out of the stationary ring body 18, in this embodiment, the distance between the fastening member 20 and the moving ring 10 is 0.2 mm; the graphite ring 19 is mounted on the lowest step of the stationary ring body 18 close to the sleeve 11.
In order to ensure the stability of the specific pressure of the contact sealing end face of the moving ring 10 and the graphite ring 19 before and after operation, as shown in fig. 5, the diameter of the graphite ring 19 is gradually increased from the first end close to the moving ring 10 to the second end far away from the moving ring 10, and the reducing part extends out of the stationary ring body 18. In this embodiment, the outer wall of the graphite ring 19 far away from the shaft sleeve 11 side is an inclined plane, and the outer side of the graphite ring 19 near the shaft sleeve 11 side is a horizontal plane, which can meet the requirement, because the medium can not enter the space between the graphite ring 19 and the shaft sleeve 11, and only can flow outside the graphite ring 19, the inclined plane graphite ring 19 plays a role in guiding the medium to flow into the friction surfaces of the moving ring 10 and the graphite ring 19, so as to reduce the friction heat at the position, ensure that the medium at the position of the friction surfaces can not be vaporized, avoid the dry friction from occurring on the friction surfaces, prolong the service life of the graphite ring, and ensure the sealing performance.
In order to ensure that the movable ring 10 and the stationary ring assembly are always in effective contact, a spring serving as an elastic element 21 is arranged between the spring shell 14 and the stationary ring assembly, the deformation direction of the spring is parallel to the axial direction of the shaft sleeve 11, and two ends of the spring are respectively abutted against the movable ring 10 and the stationary ring assembly so as to apply pre-tightening force towards the movable ring 10 to the stationary ring assembly.
The dynamic sealing device for the high-pressure easily-vaporized medium provided by the invention meets the following technical conditions: the medium pressure is less than or equal to 5 MPa; the sealing medium is liquid oxygen, methane, liquid hydrogen, etc.; the medium temperature is less than or equal to-196 ℃: the rotating speed is less than or equal to 50000r/min, is mainly applied between a liquid oxygen pump and a methane pump of a liquid rocket engine, is used for isolating two media of liquid oxygen and methane, belongs to a sealing device for a turbo pump of the liquid rocket engine, and can also be used in rotating devices in the fields of aviation, weapons and the like. The invention can meet the requirements of repeated use, long service life, easy vaporization of medium, high parameter and the like, and meets the functions of long service life and repeated use of developed machines.
As an alternative embodiment, the part of the graphite ring 19 extending out of the stationary ring body 18 may also be frustum-shaped, i.e. the outer wall is a bevel.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.