CN106090223B - Foil end face air film sealing structure of high-pressure deformation cross-scale hole texture - Google Patents

Abstract

A foil end face air film sealing structure with a high-pressure deformation cross-scale pore texture comprises a dynamic ring and a static ring for air film sealing; the sealing end face of at least one sealing ring in the dynamic ring or the static ring is a foil end face, the sealing ring with the foil end face comprises an annular ring body, an annular foil and a fastening screw, the outer side of the ring body is slightly recessed to form an annular concave surface, and the inner side of the ring body is slightly raised to form an annular step; a sealing dam is formed on the upper surface of the annular step, a plurality of pores symmetrically distributed according to the rotation center are opened on the annular concave surface, the pore depth is micron level, and they are evenly distributed along the circumferential direction to form pore ring bands, and are distributed radially to form pore rows, the outer common tangent of the pore row passes through the center of the annular concave surface, and sealing weir areas are formed between the pore ring bands or between the pore rows; the lower surface of the annular foil is in close contact with the annular concave surface of the ring body, and the upper surface is flush with the sealing dam, and the annular foil is fixed to the ring body by screws.

Description

A High Pressure Deformation Span-Scale Pore Texture Air Film Sealing Structure on Foil End Face

(1) Technical field

The invention relates to the technical field of mechanical end face sealing structure design, in particular to a foil end face gas film sealing structure based on a cross-scale waviness deformation mechanism, which is especially suitable for shaft end sealing devices of high-pressure rotating machines.

(2) Background technology

As a form of gas-lubricated non-contact mechanical seal, the gas film end face seal is widely used in the shaft end seal of rotating machinery, such as compressors, pumps, reaction Shaft end seals of rotating machinery such as kettles and fans. As we all know, the waviness seal artificially processes the micron-level circumferential waviness on the end face of the sealing ring, with the help of the circumferential waviness to form a gas dynamic pressure effect, and finally opens the sealing end face to achieve non-contact, but the micron-level circumferential waviness is difficult to process and the processing cost is high. , at the same time, once the waviness is processed and formed, its waviness shape will not be able to be adaptively adjusted as the external working conditions change. In recent years, with the rapid development of the petrochemical industry and aerospace, it is required that the gas film end face seal can adapt to high parameters, variable working conditions and harsh sealing environments. With the rapid development of "controllable" and "adaptive" technologies, It provides a new idea for the design of the "dynamic" waviness of the end face of the mechanical seal.

As a product of the development of "adaptive" technology, foil bearings have the advantages of high dynamic stability, shock resistance and low requirements for rotor concentricity by means of adaptive adjustment between foil deformation and film pressure. Based on the relevant principles of the disc bearing and the excellent characteristics of the foil, it is possible to design the "dynamic" waviness of the foil end face seal as the pressure of the sealing medium changes.

(3) Contents of the invention

The present invention aims to solve the defect that the circumferential waviness of the sealing end face is difficult to process in the prior art and cannot be changed with the working conditions and the membrane pressure after one-time processing, and provides a kind of end face with the circumferential waviness that is easy to form, can be changed with the membrane pressure, and can be adjusted to change the membrane pressure so that Air film sealing structure on the end face of the foil to achieve dynamic balance.

The present invention is achieved through the following technical solutions:

A foil end face gas film seal structure with high pressure deformation and cross-scale hole texture, including a gas film sealed moving ring and a static ring; the sealing end face of at least one sealing ring in the moving ring or the static ring is a foil end face , the sealing ring with a foil end face includes an annular ring body 1, an annular foil 5 and a fastening screw 6, the outer side of the ring body is slightly depressed to form a circular concave surface, and the inner side of the ring body is slightly raised Form a ring-shaped step; the upper surface of the ring-shaped step forms a sealing dam 4, and the concave surface of the ring has a number of holes 2 symmetrically distributed according to the center of rotation, and the depth of the holes is on the order of microns. Uniformly distributed along the circumferential direction to form a ring of type holes, distributed along the radial direction to form a row of holes, the external tangent of the row of holes passes through the center of the circular concave surface, the area between the rings of holes and the row of holes The area of the sealed weir 3 is formed; the lower surface of the annular foil 5 is in close contact with the annular concave surface of the ring body, and the upper surface is flush with the sealing dam. The annular foil 5 is connected to the ring body 1 by fastening screws 6 fixed.

Further, the depth of the molded holes ranges from 2 to 10 μm, and the diameter of the molded holes ranges from 1 to 5 mm.

Further, the ratio θ _g /θ _l of the angle θ _g between the two outer common tangents of the same hole row and the adjacent outer common tangent angle θ _l of the two adjacent hole rows ranges from 0.25 to 1.5.

Furthermore, the shape of the type hole may be circular, oval, olive or other regular shapes.

The working principle of the present invention:

The present invention provides a foil end face gas film sealing structure based on the deformation of the foil under high pressure and with the help of the constraints of the micron-level depth and millimeter-level diameter holes, so that the foil sealing surface forms a cross-scale waviness scale feature, specifically described It is: on the circular concave surface of the ring body, there are several molded holes distributed symmetrically according to the center of rotation. The depth of the molded holes is on the order of microns. row, the outer public tangent line of the hole row passes through the center of the circular concave surface, and a sealing weir area is formed between the ring belts of the hole or between the hole rows; after the foil is assembled with the ring body by screws, the foil above the hole The area of the sheet is prone to depression due to the force action. When there is a certain medium pressure in the sealed cavity, under the action of gas static pressure, the foil area above the hole will be deformed, and the foil will be sunken into the hole at micron level, and the foil above the weir area between the hole rows will be deformed. The micron-scale bulge occurs on the sheet, so that the axial and circumferential deformation of the foil becomes a cross-scale circumferential waviness, and the number of waves depends on the number of circumferential holes. After sealing operation, the circumferential waviness deformation formed on the end face of the foil will cause a certain gas dynamic pressure effect on the end face of the seal and make the end face open. The change of the foil end surface will cause the change of the circumferential waviness shape and scale, which will further affect the gas dynamic pressure effect, and finally make the film pressure and waviness shape and scale self-adaptive coordination, so the film pressure and film thickness can be effectively guaranteed. The change is in a state of dynamic balance; in addition, each waveform as a separate adaptive unit can be locally fine-tuned, and at the same time the synergistic effect of deformation between waves can strengthen the dynamic stability of the sealing operation; when the sealing speed increases , the reduction of the pressure on the leeward side of the waveform reduces the divergent deformation of the foil at this location, and suppresses the formation of the negative pressure effect.

The present invention has the following beneficial effects:

The interaction between the film pressure change and the cross-scale circumferential waviness profile of the foil end surface can form an automatic regulation mechanism for the hydrodynamic pressure effect, improve the dynamic stability of the sealing operation, and at the same time effectively avoid the generation of the negative pressure effect, with anti-disturbance Strong capacity, good dynamic stability, small leakage, high reliability, adaptable to high pressure and variable working conditions, etc.

(4) Description of drawings

Fig. 1 is a schematic explosion diagram of the present invention.

Fig. 2 is a schematic diagram of assembly of the present invention.

Fig. 3 is a schematic diagram of the structure of the ring body of the present invention.

Fig. 4 is a schematic diagram of the layout of the hole positions of the present invention.

Fig. 5 is a schematic diagram of the foil structure of the present invention.

in:

1-ring body; 2-type hole; 3-weir area; 4-sealing dam; 5-foil; 6-screw;

(5) Specific implementation methods

The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to Fig. 1 to Fig. 5, the air film sealing structure of foil end face with high pressure deformation cross-scale pore texture includes a moving ring and a static ring of air film sealing; the sealing ring of at least one of the moving ring or static ring The sealing end face is a foil end face, and the sealing ring with a foil end face includes an annular ring body 1, an annular foil 5 and a fastening screw 6, and the outer side of the ring body is slightly depressed to form an annular concave surface, The inner side of the ring body slightly protrudes to form a ring-shaped step; the upper surface of the ring-shaped step forms a sealing dam 4, and the concave surface of the ring is opened with a number of holes 2 symmetrically distributed according to the center of rotation. The depth of the type holes is in the order of microns, and the type hole rings are evenly distributed along the circumferential direction, and the type hole rows are formed along the radial distribution. The area between the area and the type hole row forms a sealing dam area 3; the lower surface of the annular foil 5 is in close contact with the annular concave surface of the ring body, and the upper surface is flush with the sealing dam. The annular foil 5 passes through the tight The fastening screw 6 is fixed with the ring body 1. The foil area above the hole 2 is easily sunken under force, and the depression of the foil area above the hole 2 causes the foil above the weir area 3 to bulge, so the annular foil 5 will form circumferential waviness under the action of the air film pressure .

The groove depth of the type hole ranges from 2 to 10 μm, and the diameter ranges from 1 to 5 mm. The waviness formed by the foil 5 under the action of membrane pressure is micron-scale in the axial direction and millimeter in the circumferential direction. level scale. The ratio (θ _g /θ _l ) of the angle θ _g between the two outer common tangents 7 of the same type of hole row to the angle θ _l of the adjacent outer common tangent 7 of the two adjacent hole rows is in the range of 0.25～ 1.5. The shape of the hole can be circular, elliptical, olive-shaped or other regular shape whose circumference is a smooth curve.

The content described in the embodiments of this specification is only an enumeration of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments. The protection scope of the present invention also includes those skilled in the art. Equivalent technical means conceivable by the concept of the present invention.

Claims (4)

1. A foil end face gas film sealing structure with high pressure deformation cross-scale hole texture, including a moving ring and a static ring of gas film sealing; the sealing end face of at least one sealing ring in the moving ring or static ring is a foil The sealing ring with a foil end face includes an annular ring body, an annular foil and fastening screws. The outer side of the ring body is slightly concave to form a circular concave surface, and the inner side of the ring body is slightly convex Circular step; the upper surface of the circular step forms a sealing dam, and the circular concave surface is provided with a number of holes symmetrically distributed according to the center of rotation. Evenly distributed to form the ring belt of the type hole, distributed along the radial direction to form the row of the type hole, the outer common tangent of the row of the type hole passes through the center of the circular concave surface, and the area between the ring belt of the type hole and the area between the row of type holes are formed Sealing weir area: the lower surface of the annular foil is in close contact with the circular concave surface of the ring body, and the upper surface is flush with the sealing dam, and the annular foil is fixed to the ring body by screws. 2. The air film sealing structure of the foil end face with high-pressure deformation cross-scale hole texture as claimed in claim 1, characterized in that: the depth of the hole is in the range of 2-10 μm, and the diameter of the hole is in the range of 1~5mm. 3. The air film sealing structure of the foil end surface with high-pressure deformation cross-scale hole texture as claimed in claim 2, characterized in that: the angle θ _g between the two outer common tangent lines of the same hole row and the two adjacent holes The value range of the ratio θ _g /θ _l of the included angle θ _l of the adjacent outer common tangent lines of the column is 0.25 to 1.5. 4. The air film sealing structure of the foil end surface with high-pressure deformation cross-scale hole texture as claimed in claim 3, characterized in that: the shape of the hole is round, oval, olive-shaped or other peripheral lines are smooth The regular shape of the curve.