CN103615539A

CN103615539A - Arc groove type dry gas seal friction pair structure

Info

Publication number: CN103615539A
Application number: CN201310617827.2A
Authority: CN
Inventors: 崔正军
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-11-29
Filing date: 2013-11-29
Publication date: 2014-03-05

Abstract

The invention provides an arc groove type dry gas seal friction pair structure which is technically characterized in that arc grooves are evenly formed in the sealing end face of a moving ring or a static ring, the outer portions of the long edges and the short edges of all arc grooves are connected end-to-end without breaking points, the long edges and the short edges of every two adjacent arc grooves and the outer circle are connected end-to-end, so that all parts of the outer circle are used as gas inlets of the arc grooves, and dry gas seal gas inflow is increased as much as possible. The number of the arc grooves is increased along with increase of the axis diameter. The arc groove type dry gas seal friction pair structure has the advantages that the outer portions of the long edges and the short edges of all arc grooves are connected end-to-end without breaking points, and dry gas seal gas inflow is increased; each long edge and the corresponding short edge intersect at one point III, gas is compressed to one point, so that gas is more compact, gas film rigidity is improved, and sealing operation is more stable and reliable; compressed gas flows into a dam through the points III, gas expands immediately, and more heat is taken away compared with the traditional method that gas enters a dam through short edges of arcs.

Description

Circular arc slot type dry-gas sealed friction pair structure

Technical field

The present invention relates to a kind of novel non-contacting mechanical seal friction pair structure.Particularly on a kind of rotating ring at friction pair or stationary ring seal face, be carved with the dry-gas sealed friction pair of novel arc groove.

Background technique

As non-contact mechanical seal, dry gas seals is with its long service life, without the large unit shaft end seal pattern of a series of advantages the become current state-of-the-art high rate turbine compressor axle head seal style ，Shi designing institute such as leakage, energy-conserving and environment-protective, operation and maintenance cost be low, main engine factory and terminal use's first-selection.The fundamental difference of dry gas seals and conventional machinery sealing is, on a seal ring end face of dry gas seals, is processed with equally distributed shallow slot.During running, in gas cut-in groove, form hydrodynamic effect, sealing surface is separated, realize non-contact sealing.Dry gas seals is for keeping contactless state, in design, particular importance data is gas film stiffness, the ratio of buoyancy (being recuperability) variable quantity and gap variable quantity namely, gas film stiffness is larger, dry gas seals antijamming capability is stronger, sealing operation is more reliable and more stable, and the design of dry gas seals be take and obtained maximum gas film stiffness and carry out as object.Gas film stiffness is larger theoretically, and gap is more difficult for changing, and sealability is more stable.And dry gas seals dynamic pressure groove shape is the key factor that affects gas film stiffness.Between when running sealing dynamic and static ring end face because air film sticky shearing produces heat, the heat of the larger generation of the equipment diameter of axle is more, in real work, too high end face temperature can cause the problems such as sealing ring deformation, end face point contact, leakage rate increases, end face air film is unstable, end face minimum thickness reduces, hot tearing with excessive temperature gradient, the performance, security of operation and the working life that are having a strong impact on sealing, dynamic pressure groove shape also has considerable influence to distributing of heat.Surface groove shape technology has become the core technology of dry gas seals.At present there is oneself patent shape groove technology in famous sealing manufacturer in the world, and end face shape groove has become the key character of each company's product marking.

Summary of the invention

The object of the invention is the deficiency existing in above-mentioned technology, a kind of novel dry-gas sealed friction pair that is carved with arc groove on rotating ring or stationary ring surface is provided, the rigidity of end face air film when strengthening equipment operation, dissipation of heat during sealing operation is faster.

The object of the present invention is achieved like this, comprises rotating ring, stationary ring.It is characterized in that: at the uniform arc groove of seal face of rotating ring or stationary ring, the outside all end-to-ends in arc groove length limit are without breakpoint, the equal end-to-end of intersection point of long limit, minor face and the cylindrical of two groups of adjacent arc grooves, make cylindrical all as arc groove suction port, large as far as possible increase dry gas seals air inflow.The quantity of arc groove increases with the diameter of axle.

Beneficial effect of the present invention: 1, the outside all end-to-ends in arc groove length limit, without breakpoint, have increased dry gas seals air inflow; 2, growing that limit 3 and minor face 5 receive is 1 III, and gas is compressed to a bit, makes gas become finer and close, and gas film stiffness is larger, and sealing operation is more steadily reliable; 3, the gas after compression flows into dam 8 from an III, and gas instantaneous expansion, enters Ba Qu than traditional gas from circular arc minor face and take away more heat.

accompanying drawing explanation:

Fig. 1 is structural representation of the present invention;

Fig. 2 is arc groove trench structure schematic diagram of the present invention

Fig. 3 arc groove rotation direction Dry Gas Seal schematic diagram that is axle of the present invention when being rotated counterclockwise

Fig. 4 arc groove rotation direction Dry Gas Seal schematic diagram that is axle of the present invention when turning clockwise

embodiment:

Below in conjunction with accompanying drawing, concrete enforcement of the present invention is described further:

From Fig. 1-Fig. 3, at the uniform arc groove 4 of seal face of rotating ring 2 or stationary ring 1, the outside all end-to-ends in arc groove length limit are without breakpoint.Arc groove 4 is regions that long limit 3, minor face 5 and cylindrical 6 surround, and between two groups of arc grooves 4, region is weir 7, closes up with an III with minor face 5 in long limit 3, and institute has an III to form groove root circle, and the position between groove root circle and graphite annulus internal diameter 9 is dam 8.The equal end-to-end of intersection I, II of the long limit 3 of two groups of adjacent arc grooves, minor face 5 and cylindrical 6, makes cylindrical 6 all as arc groove suction port, large as far as possible increase dry gas seals air inflow.The quantity of arc groove 4 increases with the diameter of axle.Long limit 3 is with minor face 5 circular arc that radius equals R, and the area on arc groove and weir equates.Long limit 3 equals 360 ° divided by arc groove number with minor face 5 suction port angle a.The quantity of arc groove 4 increases with the diameter of axle.Long limit 3 envelope angle b=a * 2+e, e is constant, this constant is chosen between 10 to 20 with diameter of axle size, guarantees that the area on arc groove and weir equates.Balance coefficient K=0.5.After equipment operation, sealing gas enters arc groove from cylindrical, cylindrical is to center flow, gas flow center is controlled on sealing dam, gas is along with the variation of arc groove sectional shape is compressed to an III, cause that pressure raises, force dynamic and static seal ring open and form air film, when the closing force that the opening force being produced by air film and dry gas seals spring and medium form reaches balance, sealing system forms non-contact running.Because gas enters dam 8 after being compressed to a bit, the compactness ratio of compressed gas is compressed to that to enter dam 8 after an arc-shaped edges better, has increased the stability of gas film stiffness and dry gas seals operation.Gas instantaneous expansion when the gas that is compressed to an III flows into dam 8, thus take away more heat.The rotation direction of arc groove changes with the rotation direction of axle, guarantees that gas flows to dam 8 by cylindrical 6.

From Fig. 3-Fig. 4, Fig. 3 arc groove rotation direction schematic diagram that is axle when being rotated counterclockwise, Fig. 4 arc groove rotation direction schematic diagram that is axle when turning clockwise.When axle rotates, arc groove rotation direction is identical with the rotation direction of axle, and when the rotation direction of arc groove rotation direction and axle is consistent, during axle rotation, arc groove entrance is the direction of meeting air flow direction, and gas is entered in arc groove.

Claims

1. a circular arc slot type dry-gas sealed friction pair structure, comprise rotating ring, stationary ring, it is characterized in that: at the uniform arc groove of seal face of rotating ring or stationary ring, the outside all end-to-ends in arc groove length limit are without breakpoint, the equal end-to-end of intersection point of long limit, minor face and the cylindrical of two groups of adjacent arc grooves, make cylindrical all as arc groove suction port, large as far as possible increase dry gas seals air inflow; The quantity of arc groove increases with the diameter of axle.

2. circular arc slot type dry-gas sealed friction pair structure according to claim 1, is characterized in that, long limit and minor face suction port angle a equal 360 ° divided by arc groove number.

3. circular arc slot type dry-gas sealed friction pair structure according to claim 1, is characterized in that, long limit envelope angle b=a * 2+e, and e is constant, this constant is chosen between 10 to 20 with diameter of axle size, guarantees that the area on arc groove and weir equates, balance coefficient K=0.5.

4. circular arc slot type dry-gas sealed friction pair structure according to claim 1, it is characterized in that, axle when rotation arc groove rotation direction is identical with the rotation direction of axle, when the rotation direction of arc groove rotation direction and axle is consistent, during axle rotation, arc groove entrance is the direction of meeting air flow direction, and gas is entered in arc groove.