DE3404705A1 - Self-adjusting axial face seal - Google Patents

Abstract

Self-adjusting axial face seal arranged in a seal housing, in particular a seal for a shaft (1) which is to be sealed against high operating pressures, having at least one slip ring (3) and a counter-ring (4), the slip ring (3) revolving with the shaft (1) and sliding by its sealing face on the sliding face of the axially displaceable counter-ring (4), which is secured against rotation, feed conduits (10) leading to the sliding face (12) being provided for a liquid lubricant, and the support (7) of at least one of the rings (3, 4) being of displaceable and/or swivelling design to compensate for wobble errors or the like between the shaft (1) and the seal housing. <IMAGE>

Description

Designation: Self-adjusting axial mechanical seal

The invention relates in particular to a self-adjusting axial slide ring seal arranged in a seal housing for a shaft / which is to be sealed against high operating pressures, with at least one sliding ring and one Counter ring, whereby the sliding ring rotates with the shaft and with its sliding surface on the sliding surface of the axially displaceable, The counter ring secured against rotation slides, with feed lines to the sliding surface for a liquid Lubricants are provided.

Such seals are

e.g. for essentially horizontally lying ship shafts and pump shafts and for usually vertical upright agitator shafts are used. In contrast to arrangements also referred to as mechanical seals, at where a counter ring is held in contact with a shaft collar, seals of the type mentioned are of the continuous type Shaft can be removed for repair and regeneration purposes and the shaft expansion is not done for the Seal used shaft collars obstructed.

«2"

"Σ. It is known,

Mechanical seals of both types for the separation of different To use gas compartments and, especially when it comes to cooling turbo generators with hydrogen gas is to feed a gaseous release agent under pressure into a separation gap. In these cases, "contactless" working seals spoken.

It is also known to lubricate the sealing gap between the sliding ring and the counter ring with liquid lubricants, it is possible to work with boundary friction, mixed friction or pure fluid friction. Although in the latter The surfaces moving against each other fall through the lubricant film maintained under the appropriate pressure remain separate, one speaks here generally not of "contactless" seals, but at most from the "swimming" of the parts bearing the surfaces moving against each other. The invention relates to seals working with pure fluid friction in the seal gap.

It is also known that oscillations of the shaft, vibrations leading to deflections, are very disadvantageous on the operation and service life of mechanical seals

act, which is why m $ n for the storage of sliding and counter rings merged into rubber-elastic rings, see e.g. Mayer, Axiale Mechanical Seal, VDI-Verlag, 6th edition. 1977, p. 122/123, section 5.3.9 "Influence of vibrations". From DE-OS 31 20 185 it was also known to design the counter-rings like a piston, to guide them in an axially movable manner and to seal their guides with O-rings, these O-rings and equivalent arrangements being elastic elements other than the sealing effect also had a vibration-damping effect, but this was not emphasized.

The invention is based on the object of further reducing wear in a seal of this type compared to known types and to reduce the number of parts subject to wear, and also to reduce the overall height compared to comparable known types, for high pressures by means of a single-acting seal get along without excluding the possibility of a modification to a double-acting design, to use the control of the lubricant pressure for the purpose of maintaining a fluid friction as the only control of a medium and to save expensive special material for sliding surfaces in the course of maintaining the pure fluid friction. The aim is to keep the detrimental effects of shaft deflections, in particular vibrations, on sliding under pure fluid friction from the sliding surfaces to a greater extent than was previously possible by using elastic elements alone or by embedding the rings in elastic elements.
20th

The solution to this problem is, according to the invention, that the support of at least one of the rings to compensate for wobble errors or the like. Between the shaft and the seal housing is designed to be displaceable and / or pivotable. 25th

This means that the transmission of oscillatory movements of the shaft is either with respect to the counter ring of a ring pair or with respect to the sliding ring of a pair of rings geared interrupted, so that the participation of this ring to the Tumbling movements are prevented to a far greater extent than is the case with the vibration-damping mounting of the sliding rings was possible alone. Therefore, the pressure lubricant film, which is in the sliding surfaces for the achievement pure fluid friction is to be maintained by oscillating movements emanating from the shaft no longer interrupted. Because this way that

If the pure fluid friction is maintained, special materials are used for the Sliding surfaces largely dispensable with a simultaneous reduction the risks associated with the destruction of the sliding surfaces »This applies to both the use of the new Mechanical seals for sealing agitator or pump shafts, but also when used on ship shafts.

Advantageous refinements and developments of the invention are specified in the features of the subclaims.

The invention is based on schematic drawings of Embodiments described in more detail. Show it:

Fig. 1 is a partial section through an embodiment with adapting movements of the counter ring in a double-L-shaped arrangement,

Fig. 2 is a partial section through another double-L-shaped Design and arrangement of a counter ring,

3 shows a partial section through an exemplary embodiment

a spherical bearing for the sliding ring,

Fig. 4 shows an embodiment in partial section with a

sliding ring working between two mating rings with two sliding surfaces,

5 shows a preferred configuration of the embodiment according to Fig. 3,

6 shows an embodiment with additional pressurization of the counter ring.

In the example of Fig. 1, a protective sleeve 2 is arranged on a rotating shaft 1, which is firmly connected to the shaft in a manner not shown. The protective sleeve 2 carries a sliding ring 3 which is connected to it in a rotationally fixed and axially immovable manner, for example by means of clamping rings or pressure screws, that is to say rotates with the shaft. The upper surface of the sliding ring 3 in FIG. 1 forms the sealing sliding surface 12. The opposing surface of a non-rotating, but axially movable, opposing ring 4 interacts with it. The counter ring 4 is ^{held in a floating manner between metal bellows rings 7, 7 1} within a space enclosed by a seal housing 5 with a housing cover 6. The bellows ring 7 is firmly connected to one side of the counter ring 4 near the inside diameter and the bellows ring 7 'is connected to the counter ring 4 on the other side near the outside diameter, so that an overall arrangement with a double L-shaped cross section arises. The edges of the bellows rings 7, 7 ¹ facing away from the counter ring 4 are firmly and tightly connected to the bottom of the housing 5 or to its cover 6. The connection is effected by means of connecting rings 77 with which the resilient bellows sections of the bellows rings 7 and 7 'are equipped on both sides. A pressure chamber 11 is formed between the double L arrangement of the counter ring and the bellows rings 7, 7 ¹ on the one hand and the housing 5 with its cover 6 on the other hand. In the wall of the housing 5, a supply connection 8 and a discharge connection 9 for a pressure medium used to build up pressure in the pressure chamber 11 are attached. In the example shown, a lubricant is used as the pressure medium, which is fed through lubrication bores 10 from the pressure chamber 11 to the sliding surface 12. The space 13 on the side of the counter ring 4 facing away from the housing cover 6 serves as a leakage space for escaping lubricant; he is

otherwise exposed to the operating pressure that prevails, for example, in a stirred tank into which the shaft 1 leads and on which the housing 5 is tightly fitted.

The bellows' rings 7, 7 ¹ are elastically expandable in the axial direction, thus enable axial movements of the counter ring 4, which rests on the lubricant film formed on the sliding surface 12 under the differential pressure, which is on the one hand from the lubricant pressure supplied to the pressure chamber 11 and on the other hand to the in

Fig. 1 shows the lower side of the counter ring 4 acting operating pressure. The bellows rings 7, 7 ^{1 also} allow a resilient deflection in the radial direction and thus movements composed of axial and radial components, so that bearing changes between the sliding surface 12 of the rotating sliding ring 3 and the counter ring 4 during deflection movements of the shaft 1, as they arise in particular when the shaft vibrates, can be avoided. The effect of vibrations is thus kept out of ^u sliding surface, so that the support zone formed by the pressurized lubricating film on the sliding surface is not interrupted. The lubricant is evenly distributed over the circumference via an annular channel 40 in the counter ring 4.

The housing cover 6 is sealed off from the protective sleeve 2 by a rib ring 32. Between the protective sleeve 2 and the sliding ring arrangement, a cooling space 44 is formed, to which coolant is supplied through a connection 14 will. The continuous drainage of the coolant

takes place through a drain line, not shown.

Modifications arise when the bellows rings 7, 7 ^{1 are} replaced by inflatable bodies or by elastomeric and metallic membranes or by annular pistons, as shown in FIG

the applicant's DE-OS 31 20 185 mentioned at the beginning. The counter ring 4 is useful opposite the housing secured against rotation.

While in the example according to FIG. 1 the double-L arrangement of the counter ring 4 was formed in that bellows rings 7, 7 ¹ directed towards opposite sides were placed on the essentially flat counter ring, these rings are in the example according to FIG ^{replaced by ring legs 4 1} and 4 ¹¹ protruding on opposite sides and consisting of one piece with the flat part of the counter ring 4, which are guided in a piston-like manner in the housing 5 or between the housing 5 and an annular shoulder 6 'of the housing cover 6.

A protective sleeve is again attached to the rotating shaft 1 and is fastened here by means of a clamping screw 41 and is sealed along the shaft 1 by seals 42, 43. On the protective sleeve 2 is the circumferential Fastened sliding ring 3, the surface of which, in contrast to Fig.l below, represents the sliding surface 12, against which is a counter surface formed by the counter ring 4 with the interposition of a lubricant film is present.

The annular piston-like ring leg 4 'is opposite the Wall of the housing 5 sealed by two seals 16 and opposite the annular shoulder 6 'of the cover 6 through another seal 16; it is guided so that it can move axially through these seals in the annular space surrounding it. The pressure chamber 11 is formed over its end face, to which a pressure medium is provided over the housing connection 8

is fed. The pressure medium is again lubrication
^ou means used, which is arranged in the sliding ring 4

Boreholes IO is forwarded to the sliding surface 12, on which a film of lubricant is maintained. The constantly supplied lubricant flows from the sliding surface 12 via the "" See holes 17 in one in Fig. 2 below the

-AL

Counter ring 4 located pressure chamber 15 and from there via a connection 9 back to a storage container.

The annular space between the ring leg 4 'and the shaft is a pressure chamber 19 under operating pressure, in which the majority of the on the sliding surface 12 escaping leakage oil arrives. Oil escaping on the outer circumference of the sliding surface 12 reaches an above of the sliding ring 4 and formed below the cover 6, the protective sleeve 2 surrounding cooling chamber 18, the has a coolant connection 14. In Fig. 2 from below acts against the counter ring 4 of the end face of the ring leg 4 'onerous operating pressure in the pressure chamber 19 and the lubricant return pressure in chamber 15; in addition, the counter ring 4 in FIG. 2 is from loaded from below by compression springs 26 clamped between the bottom of the housing and the inside of the counter ring 4, while on the top of the mating ring 4 in addition to the lubricant supplied into the pressure chamber 11 ^ O pressure is still the coolant pressure in chamber 18 works.

The chambers 11 and 15 in the lubricant supply and return make it easier to use the annular channels 40 in the counter ring 4 on the Sliding surface 12 to maintain a supporting lubricant film.

The elasticity of the seals 16 again allows a possibility of movement, composed of axial and radial components, of the double-L-shaped cross-section.

^ Formation of the counter ring 4, which enables the flat support to be maintained without destroying the lubricant support layer on the sliding surface 12 with respect to deflections of the shaft 1, which arise, for example, as a result of vibrations of this shaft.

The modifications discussed in connection with the example of FIG. 1 can also be in the embodiment of FIG. 2 with respect to the manner of a piston ring used herein legs 4 'and 4 of ¹¹ do not realize with rotating mating ring 4.

The modified forms have in common compared to the types according to DE-OS 31 20 185 that the elastic Elements no longer in essentially one plane next to one another, but via intermediate links that are lever-like in cross-section are arranged on their opposite sides. In the examples described so far, these double-L-arrangements for the stationary, i.e. not rotating with the shaft, but axially movable permanent mating ring hit.

In contrast, the examples according to FIGS. 3 and 4 relate to arrangements in which the shaft rotating with the shaft, rotating slip ring is held by means of geared intermediate links that the sliding surface system also in the case of deflections caused by vibrations, for example the shaft is preserved and thus also interruptions of the upright on the sliding surface Lubricant film can be avoided.

In the example according to FIG. 3, the shaft 1 is firmly connected to, for example, a screw 20, geqen the Shaft sealed and with her circumferential protective sleeve 2 with a spherical bearing surface 21 as a bearing body for the correspondingly spherically shaped sliding ring 3 placed on it is formed. The slip ring 3 has a cutout 25 in which a driving pin 24 inserted into the protective sleeve 2 with play on all sides intervenes. This clearance enables shaft deflections Movements of the protective sleeve in relation to the sliding ring 3.

In an annular groove of the sliding ring 3, a seal 33 is a

. ΑΤΙ set, which represents an elastic member connected between the spherical surface 21 and the sliding ring. In the operating position, it is elastically compressed and seals the bearing gap between the protective sleeve and sliding ring. The operating position is given by the bearing of the sliding ring 3 on the sliding surface 12 of the stationary but axially flexible annular piston-shaped counter ring 4 with the interposition of a lubricant film on the sliding surface. This counter-ring 4 is sealed against the seal housing 5 by piston-ring-like sealing rings 23 in a manner permitting its axial movement. The counter ring 4 contains bores for the supply of a lubricant to the sliding surface 12, which are connected to a supply line IO and a discharge line 17 in the housing 5. The lubricant film is maintained under a pressure that is opposite to the seal in the sliding surface 12 an operating pressure 19, such as that prevails in an agitator tank, for example. This operating pressure also acts on the lower end face of the annular piston-like counter ring 4 in FIG facing away from the outside of the mating ring 4 is the coolant-filled space 18 to which a coolant is supplied via a housing connection 14 and which is sealed against the rotating slide ring 3 by a lip ring 29 in the housing 5 axial direction is through an adjusting disk 28 attached to the housing 5 limited. To prevent rotation, a locking plate 30 is provided for the annular piston-like counter ring 4 which protrudes into a vertical groove 31 on the outer circumference of the counter ring 4 without impairing its axial mobility. The locking plate 30 can by an in

the vertical groove 31 engaging bolts be replaced.

Instead of the adjusting disk 28, an axial thrust bearing can be arranged with the allowance of the necessary play.

When driving without significant operating pressure, the axial contact of the stationary counter ring 4 on the circumferential Sliding ring 3 on the sliding surface 12 with the interposition of a lubricant film also by means of concentrically distributed compression springs 26 are effected, which on one against a shoulder of the counter ring 4 applied pressure ring 27 act. The compression springs 26 can be replaced by a concentric disc spring will.

¹ ^ The formation of a special pressure chamber for the sealing sliding ring pressure remains unnecessary in any case; the sealing lubricant film is maintained by metering the lubricant feed and return.

In deflection movements of the ^T "? Elle 1 3 pivotal movements / but not lead because of kugeliegen storage between protection sleeve 2 and seal ring 3 to wobbling movements of the slide ring 3 caused to the slip ring. This ensures that it rests on the sliding surface 12. The lubricating film between the sliding surfaces of both rings, which contributes to the seal, is not interrupted, which is particularly important in the case of an excess operating pressure in area 19

is.
30th

The embodiment according to FIG. 4 represents a modification of the design according to FIG. 3 in that it has two sliding surfaces 12 ", 38 are provided, so the seal is designed to be double-acting is, but this while maintaining the principle implemented in the seal according to FIG. 3, deflection movements keep the shaft away from the sliding ring rotating with it and thus also from the sliding surfaces.

In the design according to FIG. 4, the sliding ring 3 rotating with the shaft 1 forms, in addition to its lower one in FIG. 4 Slide surface 12 has a second slide surface 38 on its upper side in FIG. 4 as described with reference to FIG. 3 with the top of the ring piston-like counter ring 4 below Interposition of a load-bearing lubricant film cooperates, the mating surface for the second, upper sliding surface 38 is formed by a second mating ring 34, which corresponds to the first, axially displaceable, with the interposition of springs 26 ', possibly with simultaneous Application of the operating pressure is supported. A film of lubricant is also maintained on the sliding surface 38. The axial pressure exerted by the operating pressure 19 and / or the compression springs 26, 26 'is exerted by the two counter-rings 4, 34 transferred to the rotating seal ring 3, via holes 35 arranged in the seal ring 3, the Lubricant supply from the annular channel 40 of the sliding surface 12 via a mounted in the second counter ring 34 Annular grooves 37 continuously to form and maintain a pressure lubricant film also on the second sliding surface 34 transmitted and flows via the external annular groove 37 through the bore 35 in the sliding ring 3 and the external Annular channel 40 in the counter ring 4 and the discharge line 17 again. The leakage oil from the maintained under controllable pressure In all the examples described, lubricant films flow to the coolant space 18, could but can also be deducted separately.

In contrast to the design according to Fig. 3, a fitting ring 39 is here with the rotating sliding ring 3, e.g. by screws firmly connected. The fitting ring 39 forms together with the rotating slide ring 3 the spherical bearing surface for the spherical surface 21 formed by the protective sleeve 2.

The one that engages in a recess with play Drive pin enabled entrainment of the slip ring on rotation is realized here in such a way that the Driving pin 24 is inserted into the fitting ring 39 and with play from a cutout made in the protective sleeve 2 25 is included. The rest of the training corresponds to that described with reference to FIG. 3.

In this embodiment, too, deflections of the lead Shaft 1 does not cause wobbling movements of the sliding ring 3.

The center M of the spherical surface 21 is expediently located on a plane running parallel to the two sliding surfaces 12 and 38, which are expediently the same Keeps the distance between the two surfaces / because there are deflections of the shaft 1 do not lead to a slight axial displacement at the same time. Considered here However, coming small dimensions in the axial direction also lead in the illustrated embodiment

^ O slight deviation of the plane of the center of the sphere M in the direction of one of the two sliding surfaces to harmless axial displacements. Because the two counter rings 4 and 34 are in turn held axially displaceable, changes in length of the shaft, as shown for example in

^ ° Agitators occur when handling hot substances can be recorded without the sealing effect being canceled here.

While in the embodiment according to FIG. 3 the center 1 point M is arranged on a plane above the sliding surface at a distance from the sliding surface 12 and causes deflections of corresponding axial displacements, an embodiment is shown in FIG. 5 in which the sliding ring 3 'on the one hand and the protective sleeve 2 ¹ with their spherical surfaces 21 'are designed so that the plane of the center point M coincides with the sliding surface 12 and, accordingly, axial displacements of the overall arrangement are avoided even in the event of shaft deflections.

6 shows a form which is modified compared to the embodiment according to FIG. For this purpose, the counter ring 4 is provided with a collar-shaped extension 44 which has a seal 45 on its circumferential surface. This divides a cylinder space 22 in the housing 5, which is connected to a pressure generator via a pressure medium channel 46. The application of pressure medium can be regulated, for example as a function of the lubricant pressure, so that it is practical for the lubricant film on the sliding surface
constant pressure conditions can be maintained,
even if the operating pressure in the container to be sealed changes.

With a double-acting seal according to FIG

apply this principle as well. For this it is only necessary to the lower counter ring 4 and the
to form upper counter ring 34 accordingly and to lead accordingly in parts of the housing designed as pressure chambers.

lg-ks
25th

/ 4.

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Claims (13)

Maxton · Maxton · Langmaack Patent Attorneys Patent Attorneys Maxton & Langrnaack · Pferdmengesstr. 50 - 5000 KOIn 51 Robert Brede (1895-1943) _. . Tr, Alfred Maxton «r. «943-1978! Applicant: Dieter Kupka Aifr.d M.xton Binger Landstr. 37a Jürgen L. nBme.ck 6570 Kirn / Nahe Dlplom-InBenleure approved by the European Patent Office 5000 Cologne si Our reference 623 pg 841 02/08/84 Description: Self-adjusting axial mechanical seal Claims: 1. Self-adjusting / arranged in a seal housing axial mechanical seal, in particular for a
Shaft, which is to be sealed against high operating pressures, with at least one sliding ring and one counter ring, wherein
the sliding ring rotates with the shaft and slides with its sliding surface on the sliding surface of the axially displaceable counter-ring secured against rotation, supply lines to the sliding surface for a liquid lubricant being provided, characterized in that the support (7; 2, 21) at least one of the Rings (3, 4) to compensate for wobble or the like. Slidable and / or pivotable between the shaft and the seal housing
is trained. f ,,,,. tc \ 101 \ ^ R (VJ-JR · Tolonramm · Inuontatnr kftln. Tolov RRRI «Wl m = v H 2. Mechanical seal according to claim 1, characterized in that the counter ring (4) in a cross-sectionally double-L-shaped arrangement by in the axial direction flexible / in the circumferential direction practically torsion-resistant elements (7/7 ¹ ; 16) in the seal housing (5, 6) floating, namely kept axially movable and tiltable by small amounts. 3. Mechanical seal according to claim 1 _# characterized in that one of the rings (3, 4) is connected via a support provided with a spherical surface (21). 4. Mechanical seal according to claim 1 or 2, characterized in that the counter ring (4) has on its inner and outer circumference directed towards opposite sides bellows rings (7, 7 ¹ ) which are tightly connected to it and which are connected to the seal housing ( 5) are in turn tightly connected. 5. Mechanical seal according to claim 1, 2 and 4, characterized in that the counter ring (4) with the bellows rings (7, 7 ') in the housing (5) divides a pressure chamber (11) used for the supply of lubricant, from which the lubricant is fed to the sliding surface (12) by means of lubrication bores (10) penetrating the counter ring (4) will. 6. Mechanical seal according to claim 1 and 2, characterized in that the counter ring (4) is double-L-shaped in cross section and ^{carries on its circumference directed towards opposite sides ring legs (4 1} , 4 "), which with the interposition of radially flexible seals are guided on the walls of the seal housing (5). 7. Mechanical seal according to claim 1, 2 and 6, characterized characterized in that one of the lubricants is located above the outer ring leg (4 ") of the counter ring (4) Supply pressure chamber (11) is formed, from which the lubricant through the counter ring (4) penetrating lubrication bores (10) of the sliding surface (12) is fed. 8. Mechanical seal according to claim 1 and 2, and 6 and 7, characterized in that on the Sliding surface (12) opposite side of the counter ring (4) compression springs (26) are arranged. 9. Mechanical seal according to claim 1, 3 and 8, characterized in that one attached to the shaft (1) and a spherical bearing surface (21) is provided, which is sealed against the protective sleeve (2) The diameter increases in the direction of pressing the counter ring (4) on which the sliding ring (3) is located a mating surface that matches this bearing surface (21) is supported by a seal in the region of the bearing gap (33) is arranged that furthermore the counter ring (4) is axially movably guided in the housing and the effect an operating pressure (19) and exposed to the supply lines is provided for the lubricant to the sliding surface (12). (Fig. 3) 10. Mechanical seal according to claim 1, 3 and 8, characterized characterized in that the sliding ring (3) has two opposing sliding surfaces (12 *, 38) that a sliding surface (12 ') with a first counter ring (4) and the other sliding surface (38) cooperates with a second counter ring (34) that with the sliding ring (3) a fitting ring (39) is firmly connected, with sliding ring (3) and fitting ring (39) together the mating surface for a on the protective sleeve (2) formed spherical surface (21) and that the spherical mating surface of the sliding ring (3) and the fitting ring (39) each have a seal (33). (Fig. 4) 11. Mechanical seal according to claim 10, characterized in that both counter rings (A, 34) are axially displaceable in the seal housing (5) and are provided with feed lines for the lubricant which open into sliding surfaces (12, 38), and that both counter rings (4, 34) are acted upon by the operating pressure on the side facing away from the sliding surfaces (12, 38). 12. Mechanical seal according to one of claims 1, 3, 8, 9, 10 or 11, characterized in that the center point (M) of the spherical bearing surface (21) on the The axis of rotation of the shaft (1) in the plane of the sliding surface (12) or in the case of two sliding surfaces (12 ', 38) in one Level lies that is approximately the same distance between the two sliding surfaces. 13. Mechanical seal according to one of claims 1, 3, 8 and 9 to 12, characterized in that the counter ring (4; 34) is designed as a piston and in one as a pressure chamber (22) formed part of the seal housing (5) is guided, which via a pressure medium channel (46) with can be acted upon by a pressure medium.