CN107387766B

CN107387766B - Carbon ring sealing structure of desert beetle-imitated back shell surface texture

Info

Publication number: CN107387766B
Application number: CN201710748374.5A
Authority: CN
Inventors: 彭旭东; 沈伟; 江锦波; 陈源; 孟祥铠
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2017-08-28
Filing date: 2017-08-28
Publication date: 2019-12-24
Anticipated expiration: 2037-08-28
Also published as: CN107387766A

Abstract

A carbocycle sealing structure of a desert beetle imitating dorsal shell surface texture is characterized in that one axial side of a carbocycle seal is a sealing liquid side, the other axial side of the carbocycle seal is an isolating gas side, and the pressure of the isolating gas is 0.05-0.15 MPa lower than that of the sealing liquid; the sealed internal diameter side surface of carbocycle constitutes a pair of sealed vice with the pivot surface by sealed machine, the internal diameter side surface comprises smooth hydrophilic surface 1, imitative fin water conservancy diversion arch 2 and the hydrophobic surface helicla flute 3 of upper reaches pump sending of circumference equipartition, imitative fin water conservancy diversion arch 2 is seted up between smooth hydrophilic surface 1 and the hydrophobic surface helicla flute 3 of upper reaches pump sending, the bottom surface coating of the hydrophobic surface helicla flute 3 of upper reaches pump sending has hydrophobic coating and is processed and has the hydrophilic microprotrusions of segment shape.

Description

Carbon ring sealing structure of desert beetle-imitated back shell surface texture

Technical Field

The invention belongs to the field of non-contact sealing, and relates to a carbon ring sealing structure which utilizes the hydrophilic or hydrophobic characteristics of a back surface texture and a surface material of sand-like desert beetles to achieve the purposes of collecting liquid components in wet gas or an atomized sealing medium and pumping the collected liquid back to the side of the sealing medium through a directional texture.

Background

The main seal commonly used in the oil-free screw compressor in the prior art has three forms, wherein the carbon ring seal realizes the sealing function by means of small-gap throttling and pressure reduction, and is widely used in the oil-free screw compressor in the prior art due to simple structure, convenience in installation and maintenance and good economical efficiency; in addition, carbon ring seals are also widely used in gas compressor shaft end seals and their bearing seals. However, the carbon ring sealing has self defects, and some problems to be solved exist in practical field operation and use. The existing carbon ring structure can be integral or split. The multilobe formula carbocycle structure that designs in chinese patent CN2011201380, by the sealing washer that is cut into the multistage encloses into a ring, the incision of every section sealing ring that is cut is the scarf, and every section incision is along same direction average cutting, and the tangent line of scarf is the circumference tangent line of sealing ring inner circumference, guarantees that the carbocycle slides along the scarf inwards and closes to the axle sleeve after the sealing ring is worn and torn, makes the seal clearance keep unchangeable. However, the carbon ring seal has large gaps, so that the leakage is large at high rotating speed, and the excessive gaps can reduce the flowing dynamic pressure, so that the self-centering capability is poor. When the carbon ring seal is applied to bearing seal, the lubricating oil is often led to flow into the compressor to cause gas entrainment due to poor sealing capability of the bearing lubricating oil, and the operation safety and stability of a unit are directly damaged.

Disclosure of Invention

The invention provides a carbon ring structure with hydrophilic and hydrophobic diversion upstream pumping, which has better annular surface sealing effect and better dynamic pressure effect and has hydrophilic and hydrophobic diversion upstream pumping, aiming at overcoming the defects of large leakage amount, poor dynamic pressure effect and the like caused by larger gaps in carbon ring sealing in the prior art and based on the action principle of the back surface texture of the bionic desert beetle.

The technical scheme of the invention is as follows:

a carbocycle sealing structure of a desert beetle imitating dorsal shell surface texture is characterized in that one axial side of a carbocycle seal is a sealing liquid side, the other axial side of the carbocycle seal is an isolating gas side, and the pressure of the isolating gas is 0.05-0.15 MPa lower than that of the sealing liquid; the inner diameter side surface of the carbon ring seal and the surface of a rotating shaft of a sealed machine form a pair of seal pairs, the inner diameter side surface consists of a smooth hydrophilic surface 1, fin-like guide bulges 2 and an upstream pumping hydrophobic surface spiral groove 3 which are uniformly distributed in the circumferential direction, a plurality of fin-like guide bulges 2 are arranged between the smooth hydrophilic surface 1 and the upstream pumping hydrophobic surface spiral groove 3, the base surface of each fin-like guide bulge 2 and the smooth hydrophilic surface 1 are positioned on the same surface, the curved surface of the fin-like guide bulge 2 facing the gas has hydrophilic characteristics, and the surface of each fin-like guide bulge 2 forms a guide groove; the bottom surface of the upstream pumping hydrophobic surface spiral groove 3 is coated with hydrophobic coating and is processed with a segment-shaped hydrophilic microprotrusion body; the diversion trench and the upstream pumping drainage surface spiral groove are communicated from the sealing liquid side to the isolation gas side.

Further, an included angle alpha between the tangent of the fin-like flow guide protrusion 2 and the smooth hydrophilic surface 1 is 35-55 degrees; the curved surface of the gas facing side of the fin flow guide protrusion 2 inclines slightly to the spiral groove, and the inclination angle is 1-5 degrees.

Further, the groove depth of the spiral groove of the upstream pumping drainage surface is 5-20 microns, the diameter of a segment-shaped hydrophilic microprotrusion processed at the groove bottom is 5-20 microns, the protrusion height of the segment-shaped hydrophilic microprotrusion is 1-10 microns, and the included angle beta between the central line of the segment-shaped hydrophilic microprotrusion and the groove bottom surface is 1-10 degrees.

Furthermore, the length ratio of the smooth hydrophilic surface 1, the fin-like flow guide protrusion 2 and the spiral groove 3 of the upstream pumping hydrophobic surface, which are distributed along the circumferential direction, is 1.5:3.5: 5.0.

The working principle of the invention is as follows:

based on the hydrophilic and hydrophobic characteristics of the back smooth surface or the surface texture of the sand-like desert beetle, the bionic carbocycle sealing surface unit consisting of the hydrophilic smooth surface, the fin-like flow guide protrusion and the groove bottom spiral groove containing the hydrophobic microprotrusion body is provided, and the unit is periodically distributed along the surface of the inner side of the carbocycle seal to form a novel bionic carbocycle sealing structure. The working principle of the coating is that water drops are collected on the hydrophilic smooth surface of the back shell of the desert beetle, so that liquid in a gas-liquid mixed phase medium (moisture-containing gas or atomized sealing medium) is partially condensed on the smooth hydrophilic surface to the maximum extent, and the leakage amount of the liquid medium to the gas side or the isolation gas side of the compressor is reduced. In addition, the working principle of the fin flow guide protrusion and the segment-shaped micro-protrusion on the bottom surface of the spiral groove is also based on the mechanism of collecting water drops on the hydrophilic smooth surface of the back shell of the desert-imitating beetle, so that liquid accumulated on the smooth hydrophilic surface and the fin flow guide protrusion enters the spiral groove by virtue of the rotating inertia force, and condensed liquid is pumped back to the sealed liquid medium side under the pumping action of the spiral groove; the gas-facing surface of the fin-like flow guide bulge 2 slightly inclines towards the spiral groove, and the inclination angle is 1-5 degrees, so that the condensate can be well guided into the spiral groove. Meanwhile, the hydrophilic segment-shaped micro-protrusions on the bottom surface of the spiral groove also play a role in assisting in condensing mist, further strengthening the liquid removal effect of gas and ensuring that the humidity of the isolated gas is the lowest. The bottom surface of the spiral groove is coated with a hydrophobic surface, so that the condensate is prevented from staying at the bottom surface of the groove, and the staying time of the condensate in the groove is shortened to the maximum extent.

The advantages and the beneficial effects of the invention are mainly shown in that: (1) the smooth hydrophilic coating surface adopted by the side ring surface of the inner diameter of the carbon ring can lead the gas-liquid mixed phase medium to be condensed, and the condensed liquid is accumulated on the smooth surface, thus preventing the liquid from leaking to the gas; (2) compared with the common carbon ring without the flow guide protrusion, the flow guide protrusion provided on the fish fin-like structure can effectively condense moisture-containing gas, and the slightly inclined flow guide condensation surface can more timely and effectively guide accumulated liquid into the spiral groove area, so that excessive friction torque and friction heat caused by excessive liquid content in the fluid film thickness of the whole sealing area are prevented, and the rigidity of the fluid film is prevented from being reduced or insufficient. (3) The hydrophobic characteristic of the upper reaches pump sending tank bottom surface of seting up plays timely flowing back effect, and tank bottom surface hydrophilicity segment shape microprotrusions further produces the condensation effect to moisture-containing gas, has increased the circulation of pump sending back liquid side, has reduced the liquid and has leaked the volume, reduces the delay of liquid in the district of groove, and the most important can effectively avoid in the compressor gas band liquid and bearing lubricating oil scurrying into the unit, has improved the operation security and the stability of whole unit.

Drawings

FIG. 1 is a three-dimensional schematic diagram of a desert beetle-like carbon ring for pumping hydrophobic liquid discharge upstream of the present invention;

FIG. 2 is a three-dimensional schematic view of the fin-like flow guide protrusion of FIG. 1;

fig. 3a is a schematic diagram of the arrangement of the bottom texture of the upstream pumping hydrophobic tank in fig. 1, and fig. 3b is a schematic diagram of the segmental hydrophilic microprotrusions of fig. 3 a.

Detailed Description

The invention will be further described with reference to the accompanying drawings

Referring to fig. 1 to 3: a carbocycle sealing structure of a desert beetle imitating dorsal shell surface texture is characterized in that one axial side of a carbocycle seal is a sealing liquid side, the other axial side of the carbocycle seal is an isolating gas side, and the pressure of the isolating gas is 0.05-0.15 MPa lower than that of the sealing liquid; the inner diameter side surface of the carbon ring seal and the surface of a rotating shaft of a sealed machine form a pair of seal pairs, the inner diameter side surface consists of a smooth hydrophilic surface 1, fin-like flow guide bulges 2 and an upstream pumping hydrophobic surface spiral groove 3 which are uniformly distributed in the circumferential direction, a plurality of fin-like flow guide bulges 2 are arranged between the smooth hydrophilic surface 1 and the upstream pumping hydrophobic surface spiral groove 3 in parallel, the base surface of each fin-like flow guide bulge 2 and the smooth hydrophilic surface 1 are positioned on the same surface, the curved surface of the fin-like flow guide bulge 2 facing the gas has the hydrophilic characteristic, and the surface of each fin-like flow guide bulge 2 forms a flow guide groove; the bottom surface of the upstream pumping hydrophobic surface spiral groove 3 is coated with hydrophobic coating and is processed with a segment-shaped hydrophilic microprotrusion body; the diversion trench and the upstream pumping drainage surface spiral groove are communicated from the sealing liquid side to the isolation gas side.

An included angle alpha between the tangent of the curved surface of the fish fin-like flow guide bulge 2 facing the gas side and the smooth hydrophilic surface 1 is 35-55 degrees; the curved surface of the gas facing side of the fin flow guide protrusion 2 inclines slightly to the spiral groove, and the inclination angle is 1-5 degrees.

The length ratio of the smooth hydrophilic surface 1, the fin-like flow guide bulge 2 and the spiral groove 3 of the upstream pumping hydrophobic surface distributed along the circumferential direction is 1.5:3.5: 5.0.

The embodiments described in this specification are merely illustrative of implementations of the inventive concept and the scope of the present invention should not be considered limited to the specific forms set forth in the embodiments but includes equivalent technical means as would be recognized by those skilled in the art based on the inventive concept.

Claims

1. A carbocycle sealing structure of a desert beetle imitating surface texture of a back shell is characterized in that one axial side is a sealing liquid side, the other axial side is an isolating gas side, and the pressure of the isolating gas is 0.05-0.15 MPa lower than that of the sealing liquid; the method is characterized in that: the inner diameter side surface of the carbon ring seal and the surface of a rotating shaft of a sealed machine form a pair of seal pairs, the inner diameter side surface consists of a smooth hydrophilic surface (1), fin-like flow guide bulges (2) and an upstream pumping hydrophobic surface spiral groove (3) which are uniformly distributed in the circumferential direction, a plurality of fin-like flow guide bulges (2) are arranged between the smooth hydrophilic surface (1) and the upstream pumping hydrophobic surface spiral groove (3), the base surface of each fin-like flow guide bulge (2) and the smooth hydrophilic surface (1) are positioned on the same surface, the curved surface of the fin-like flow guide bulges (2) on the side facing gas has hydrophilic characteristics, and the surface of each fin-like flow guide bulge (2) forms a flow guide groove; the bottom surface of the upstream pumping hydrophobic surface spiral groove (3) is coated with hydrophobic coating and is processed with a segment-shaped hydrophilic microprotrusion body; the diversion trench and the upstream pumping drainage surface spiral groove are communicated from the sealing liquid side to the isolation gas side.

2. The carbocycle seal structure of the desert beetle amoeba surface texture of claim 1, wherein: the length ratio of the smooth hydrophilic surface (1), the fin-like flow guide bulges (2) and the spiral grooves (3) of the upstream pumping hydrophobic surface distributed along the circumferential direction is 1.5:3.5: 5.0.