DE1600589A1 - Sealing device for a shaft passage - Google Patents

Description

Dioht device for a shaft passage

You invention relates to a sealing device which is provided around the shaft of a machine or any apparatus in the baw. in which a housing sits, which contains a pluid, such as gas, vapors
or contains liquid, the pressure of which shows a difference compared to the AuBendruok.

Ea numerous devices are known, dl · it see sus? Have set task _t in such a case a leak of Wellendurohlai see below ensure "

They can be divided into two main kat-ugoriea One since «it concerns slsfe et al medium contact awieoiita awti on the! parts sltat, wäbrsai

wslsfea ii ©

efe Äot3 _c aiese

BATH

if they can cause a minor leak has the disadvantage of being subject to high wear and tear On the other hand, there are devices whose rotating and immovable surfaces do not come into contact and consequently are not subject to wear and tear during their use. These devices however, generally have the disadvantage that they have a greater play due to the play required to avoid fretting ^ Show leakage

The invention is to be classified in the second category, but avoids the disadvantages set out above, insofar as a slight leak can be achieved with it and without fear of corrosive friction Trooke friction between the shaft and the immovable part is even permitted *

They are substantially Merkaale this apparatus, in which the shaft is seated in a ψ liner, to be seen in * that this sleeve is mounted freely in radial direction relative to the rotating shaft, jedooh "eans suitable means is prevented from rotation and at least one of two opposite cylindrical surfaces _f ie the liner · v && the surface dec part of the rotating shaft g- from »la ©» material with low »friction coefficient f ££ zi * aten feeetehi * .11 · It & ii £ bu3 & st is part of a connection * «» A d & s Stfetas · »ag» ®efel0gs «si ₉ w # lenee fte the biohhtness

öi © uafi®hindered disability

BAP

Shifting of the liner in the radial direction to the shaft in none Way impaired, so that due to the slight play between the liner and shaft caused by an initial retraction or a suitable machining is to be achieved, this bushing takes on the role of an aerodynamic or hydrodynamic bearing

The sealing device according to the invention can be the subject of various Citation options are taken where the made of a material with a low coefficient of friction part once the ma the rotatable shaft arranged liner can or a coat attached to the shaft itself "

Another aspect of the gate direction consists in the fact that the part consisting of a material with a low coefficient of friction is deformable and an annular chamber is provided between it and the holder, the annular chamber with a system of pipes for the fluid under bridge is in communication, whereby the annular clearance "between the sleeve and the rotatable shaft can be changed by changing the pressure of the fluid.

The last-mentioned embodiment can be modified to this effect be that the deformable friction material is applied to the rotatable if / elle, so that the dumbbell is under the action of Centrifugal force deforms, the radial play being automatically compensated for by the centrifugal, aerodynamic or hydrodynamic indefinitely and is determined by the elasticity of the jacket.

009817/1040

The idea of the invention allows the most diverse implementation possibilities to. % of these are shown in the accompanying drawings, namely show:

1 shows an axial section through the sealing device according to the invention,

FIG. 2 shows a cross section along the line II-II according to FIG. 1,

Fig. 3 is a partial view of an axial section of a variant of Device according to FIG. 1,

4 ^and 5 each show axial sections of two further possible embodiments according to the invention,

FIGS. 6 to 8 each show partial views of other possible embodiments in axial section

The embodiment according to FIGS. 1 and 2 is to a sealing device which is used according to the invention in a machine in the housing 1 of which there is a pressure P1 which is above the atmospheric pressure Pa. In the housing of the machine there is a harmless gas, which consequently due to the device internal leakage can be released into the atmosphere undamaged

The device consists of a bushing 2, whose Material has a low coefficient of friction, such as given by tetrafluoroethylene or graphite, and around the rotatable 'Shaft 35 of the machine is provided around. On the assigned part

009817 / 104Q

the shaft an attached metal jacket 4 can be provided, the Surface is sanded.

The cylinder liner 2 is inserted into a metal holder 5 forcibly or with liquid nitrogen. She socket 5 by means of a ring "shaped steered 6 in the housing 1 is held and is located partly in an annular groove which is presented on the outer surface of the socket m view and partly in an associated groove formed in in the housing 1 provided bead 1a is formed. This joint or coupling ensures both tightness between the tree having the Sruok ^ 1 and the space filled with atmospheric pressure and an elastic connection between the socket 2 and the socket 5 on the one hand and the housing 1 on the other. As a result, slight displacements of the socket 5 and the socket 2 in

radial sighting to shaft 3 possible. The joint also serves to that the socket 2 and the associated socket 5 in the axial direction remain, provided that they are filled from the pressure difference between the lines with the pressure P1 and the atmospheric pressure resulting force are exposed.

They inner wall of the socket 5, a ring-shaped joint 7 which serves a vollkoaaene tightness sswissliea d © r B% @ hs @ and the corresponding version zn gawütalsieteB © AuS d '§ 6 · θ1®ε verziehtet werdea _s provided 4i © te® ii®a feil® aw @ © feäl @ ali © h are wedged

Furthermore, the socket 5 has a longitudinally extending one ^{on the outer surface.} Comb θ which engages with a certain clearance in a groove 9 which is recessed in the bead 1 a of the housing 1. This means that the socket 5 and consequently also the socket 2 cannot move when rotated.

The locking means provided enable the bushing 2 and the associated socket 5, the slight movements of the rotatable shaft fc to follow. The processing of the contact points between the comb 8 and the bead 1a must be carried out carefully, because these movements, despite their insignificance, have the frequency of rotation of the shaft, so that the contact points are endangered in the long run,

to be disturbed, which adversely affects the freedom of movement of the

Buohse would affect

An important feature of Torrichtung is that "wipe the Buohse 2 and fitted onto the rotary shaft Metallman- _B tel 4 * is present in slight play. This game, which has a limited amount of leakage, _t enables the entire structure to »function like an air cushion? as soon as the shaft is in working speed, e.g. 3ooo n / m. turns. When there is contact between the socket and the rotatable shaft there can be no galling friction, since the socket is made of a material with a low coefficient of friction, such as, for example, su * XetXftfluorthylen eä * r graphite.

The insignificant® game ₅ that zwiseiaesa der Biiehs © Taad der dr®hbar @ & Welle required is ₉ ksna dadmreh. ersielt cheap ;, that the Buehse is retracted to the corrugated © g pressed mounted i7 ± rd _s Dana TBEI ßasehwin slower "velocity ,, b © © sick äs the game diarafe JTIuS or Down ~ use of the iäaterials Mldet ₉ from which the Baefes © Tbsstekt or dadtirelij that the ImaeHwandimg the Buefese "ad the arranged surface of the rotary shaft before asi genausa locations such gssehliff © a, are known to have a gap bulk © Bad consequently siae TJndichtheit certain G-ize obtained

The G-ize this Undiohtheit iiäagt of dea koasteßlitioasaäßig g © gefoenen ParaHetern sM, in particular won d © a Biff © © r ASÜ @ rt between the atmospheric pressure and dea iateraen Maschiaendnickj, from Tsa <=> temperature, vo3i erkiaalen the ^ of in the -undishtea position © circulating fluiduiESj the eotation activity of the 17 © lle _s of, d © a Durehaesses? and the length of the bush "ad from the radial clearance E-t7iseh © a book © WeIIe and _9, it is possible to change the geometric Sferknale the socket within certain limits ^ namely as function of the permissible Tlndi chthe i twer th _e"

For example, _c in the case of an air compressor, where the air permeability at the shaft passage Eic & t should be more than 10 liters per hour p the following values are to be observed a.2

«Sotation speed 3 © Clipart o vtjm.

»» Air temperature is a housing: is 80 G

«Air pressure in Sehäases 1 _g 5 Τϋ &

«Wel] endurchE3essers 60 sau

W _HO lift _! I ₉ O - gpg ^

ORIGINAL INSPECTED

- radial play between bushing and corrugation 0.02 now.

The door direction according to Fig..3 represents a variant of the device according to FIGS. 1 and 2, inasmuch as two seal couplings 6a between the socket 5b of the socket (not shown) and the Bead 1b of the housing are τοr seen. The bead has a passage 10, which is provided between the two couplings and serves to enable a fluid, such as a neutral gas or air, by means of supply openings (which are not in this figure are shown) can be inserted across the socket 2

In another possible embodiment of the device, or the annular coupling 6 or couplings 6a can be replaced by a completely different device that both the tightness and ensures the possibility of radial displacement of the bushing, such as a bellows or a metal membrane made of rubber or plastic material ' In this case, the bushing must be in the axial direction, e.g. by means of fibers or mechanical stops or also more hydrodynamic or aerodynamic Abutments, as will be described below, are made immobile. However, it is also possible to make this immovable the bushing in the axial direction serving means to be omitted if the acting through the on both sides of the device Axialdruok caused by pressure difference is low. If this locking means omitted, the bushing of the device slides insignificantly, until the axial pressure is compensated for by the elasticity of the connecting means provided between the bushing and the mechanical housing «,

009817 / 1CUG

In the embodiment according to FIGS. 1 and 2 "there is the socket the device made of a material with a low coefficient of friction «This could also be done on the dumbbell attached to the rotating shaft hold true. In this case the socket could be made of metal, it could but also consist of a material with a low coefficient of friction

If the bushing is made of a material with a low coefficient of friction is created, the version 5 assigned to it could be omitted if the the material used is sufficiently resistant and sealing

The one made of a material with a low coefficient of friction Surface could be from a support layer of generally as much

she Bead can be created as / on the inner surface of socket 5 of the socket

and is made on the outer surface of the rotatable shaft

This manufacturing technique is interesting insofar as in this way the size of the clearance during operation and in particular the dependence on the temperature reached can be seen. * The fact that the support of the material bit with low frictional resistance is low, the play arises during operation only as a function of the Aus & elin-aags & ifferenzeii of Faeöuag waA rotendes Fell · Bs can «nn ■ therefore be selected outside and laebsaoadere it can be constant, "if the to Fasauag uad Dreheaiaa rope rerweadetea materials« in the · «coefficient & tea ait lower or aäfeedautea & a? Auedehnuag».

BAD OBKälNAL

- ίο -

The embodiment according to FIG. 4 represents an advantageous possibility of the device, the device being designed so that a control of the radial play between the bushing of the device and the rotatable shaft is possible «

The device has a bush 2c made of a material with a low friction coefficient which is deformable. The ^B ligands t ■ the bushing are Hontageteilen means 11 and annular couplings 12 impermeable on the ends of the inner wall of a cylindrical barrel » Solution 5c attached and between the socket and the socket is a annular chamber 15 provided

The socket 5o is mounted in a holder 1c, which is attached to the Housing 1 of the machine sitxt and the annular chamber 13 protrudes Channels 14 and 15 in communication with a fluid source, the pressure of which is P3 is regulated · The tightness of the connection between the ^ anal 14 and 15 as well as between the inside of the machine (fluid with the pressure Pi) and the outer space (fluid with the pressure P2) is ensured by means of ring-shaped couplings 16, which also take on the task of holding the socket 5e inside the holder 1o.

Duroh i ± m change in pressure P? a deformation of the bushing 2o can be brought about, whereby the possibility is given of being able to change the wiping of the bushing 2e and the radial play that precedes the dumbbell 4c placed on the shaft 5o ·

009817/1040

In the execution option according to ^ ig. 5 pursues the same goal. In this case, the aterial "consisting of ^M with low coefficient of friction member is a shell 4 'is attached to the rotatable shaft 3d and the ends of which are sealingly attached to the exterior surface of the shaft, by means of mounting members 11d and annular couplings 12d"

Between the deformable jacket 4 & un & the associated part of the ™ An annular chamber 13d is provided on the outer surface of the shaft Jd

Dog around the dumbbell 4 & sits the socket 2d of the device, its attachment is made on a fixed bracket 1d, which is attached to the Housing 1 of the machine aagebrasht isto

The jacket 4d is attached in such a way that it can deform under the action of the centrifugal force. As a result, the radial play required between the jacket and the bush 2d is automatically increased by balancing the centrifugal force _s by aerodynamic or hydrodynamic forces and by the deformation of the jacket determined by the elasticity inherent in the jacket. Movable organs inside the chamber can either 13d, ie under the jacket 4d ₉ , or it can be inside the rotatable

009817/1040

Shaft 5d a channel 14d are provided, which in the annular Chamber 13d opens and is connected to a pressurized fluid is"

As a result, the play between the deformable jacket 4Ί and the socket 2d can then be changed by changing the pressure _e

^ Another possible embodiment of the device according to the invention, Fig. 6, shows one made of material with a low coefficient of friction " Liner 2e, created by applying a tiny layer of said material to the inner wall of a metal mount 5e will. The socket can be attached to the housing by means of a bellows 6e 1 connected to the machine · The support made of material with a low coefficient of friction, which is placed on the inner wall the fit 5 © is provided, could of course by a similar support on the outer surface of the shaft 3e or the on the shaft attached casing 4 © by a support on both the jacket as well as on the inner wall of the socket 5e can be replaced «

In this version it sits on one of the ends of the frame 5e of the bushing has a flange 17 »which is opposite to a flange 18 is arranged, which is provided on the jacket 4e. At least one of the opposing surfaces of the two flanges has a covering made of material with a low coefficient of friction • 19 on.

009817/1040

The two planes thus represent a hydradynamic or aerodynamic stop system, which serves to hold off the impact »which results from the compressive force that acts against the moving part, ie the bushing 2e and the fit 5e as well as the sleeve 6e ·

The device of the illustrated embodiment is then · » going designed that an internal pressure P1 is weaker than the external pressure P2 is * If a pressure reversal is to be feared, a counter-soling based on the same principle can be provided »

The embodiment according to FIG. 1 represents a variant of the embodiment according to FIG. 5, the difference being that an aerodynamic or hydrodynamic stop arrangement similar to that in the embodiment according to FIG. 6 is provided. The liner 2d of the device has a flange 17 &, which is arranged opposite a flange 18d seated on the rotatable shaft 3d

They inventive device the Aueführungsaögliohkeit geaaft Fig. 8 is particularly gedaoht for the case where a significant difference between the inner · pressure Pt ₁ weloher ia de »housing 1 of the ^M asohine prevails ud de» Augeadruok P2 occurs ·

Yes, the terrioctation shows this execution possibility ! »Aufbuohsen 2f and 2g, which aageerdaet around the assigned wave Jf

009817/1040

-H-

are and of two versions 5f. and 5g are held. 2> The sockets sit in a common, hollow holder 1f, which is attached to the housing 1 of the machine. ^T he tightness between the housing and the sockets in each case ensured by means of an annular coupling 6f or 6g "

^{At the} point that remains free between the two liners 2f and 2g, a connecting tube 20 is provided in the holder, through which a barrier fluid can be introduced at a pressure PJ low pressure difference between ^ and? 3 works · This means that there is a considerable pressure difference between Pj and P2. However, it is possible to introduce a barrier fluid of low commercial value into the connecting pipe 20, so that the consumption of this fluid is not a disadvantage. Furthermore, this fluid is selected so that it is compatible with the fluid present inside the machine.

Ss aei »once pointed out that the inventive Oil device can be changed depending on the case and area

kaaa · ...

111 "AusftüirumgsMÖglichkei-fcen the erfindungsgemtien vision device weiae» amf a beatimate Amiakl of distribution, of which werdemt listed in .folgernden some

009817/1040

- 15 -

a) simplicity of the device structure,

b) Presence of a leak of small size and constant Y / ert, the leakage from the characteristics of the to be isolated Fluidum, the geometry of the liner and the rotational speed of the shaft as well as that between the liner and the rotating one Wave depends on existing game.

c) lack of eating friction,

d) Ability to use the device to ensure the tightness of each incompressible or compressible fluid, be it gaseous or liquid or in vapor form.

e) Possibility of a relatively high pressure difference on both sides of the device, thus the device can be used in machines that work under positive or negative pressure

f) Possibility of introducing a neutral gas (e.g. nitrogen) if the gas inside the machine is dangerous and not allowed to escape to the outside, even in small quantities.

g) The lack of regulation if no neutral gas is introduced will and otherwise ^ possibility of regulation by means of a simple Device, such as an anchoring device}

h) Use of materials with good resistance to corrosion and in particular an absence of fat bodies j

i) Limitation of the possible temperature solely by the 'Characteristics of the materials used are determined if at start-up and use caution when operating f

009817/1040

j) Increased service life of the device due to the simplicity of the Construction and due to the lack of friction in normal operation;

k) Possibility to regulate the size of the leakage of the device in the design options according to Fig. 4> 5 and 7 «

009817/1040

Claims (1)

- 17 claims t 1. A sealing device with limited permeability to the passage of a rotating Walle by a housing whose inner ¹ Fluidumsdruok differs from the external pressure, wherein um dia shaft a bushing is arranged, characterized in that the running "bushing in radial direction relative to the rotating shaft is freely movable is mounted, but the rotation is prevented by means of suitable means and at least one of the two opposing cylindrical surfaces, ie the liner and the surface of the associated part of the rotating shaft _{9 is} made of a material with a low coefficient of friction, the Liner by means of a coupling element to the housing eye ·· closed and the coupling element ensures tightness between the bush and the housing and the unimpeded® Yoraohisbimg of the cylinder in the radial direction? to the WqIla is kaiaer way "feeeia ·· pregnant, so that due to the goring-addigea game sviseh ©» liner and shaft, which is to essieles by © ia anfäßglisho® Sirnfstees, respectively, a suitable bee? teeituag, the Buohs® - 41 © of an aerodynamic or hydpodsTaamiEohen bearing 2. DichtTO ^ r Richtmag n & uh l & styxnah 1, äädmOh fek «iassäd> 3fei © t _s d * S 44 · ' m, s ^M e, t®ri * l alt gesim ^ m 009317/10 / ^ and is fixed in a holder made of resistant material, cooperate with the means to which the task is assigned, the "" "to ensure locking of the socket in radial sighting and also Means, which the shifting of the! Socket at the ho tat ion ensure, with the coupling or connecting element sitting in the socket, which the coupling and connection to the housing or another / existing component of the machine. 3. Viewing device according to claim 2, characterized in that the a bush made of a material with a low coefficient of friction a support made of this material on the inside area of the socket intended for the socket. 4 «sealing device according to claim 1, characterized in that the made of material with a low coefficient of friction is provided on the rotating shaft and the surface consists of a layer of this material on the shaft. 5. Viewing device according to claim 2 _f, characterized in that the Buoftse Aeformiersar consisting of material with a low coefficient of friction is mat fine ring-shaped chamber between the Buofese mat of the socket serving for ^ nsrinfung the lynx is provided1 vesei the annular chamber with a line of a material bridge stchen & en Tluitams eats the binding, what why that 009817/1040 between the rotating shaft and the deformable sleeve existing ring-shaped play can be changed »by changing the pressure of the fluid. 6 · Sealing device according to claim 1, characterized in that the shaft part located opposite the bushing is a deformable one Jacket made of material with a low coefficient of friction carries and between the jacket and the surface of the rotating Shaft an annular chamber is provided " 7 · Sealing device according to claim 6, characterized in that between the deformable shell and the surface of the The annular chamber provided with a rotating shaft communicates with a pressurized pluidum leading ear system, thereby changing the annular clearance present between the outer surface of the shell and the bushing arranged around the shaft can be changed by changing the pressure. 8. Sealing device according to claim 1-7 »characterized in that that an aerodynamic or hydrodynamic abutment is provided which is suitable for axially viewing the bushing withhold, and the abutment consists of the combination of two opposing flanges, each on the rotatable shaft or are formed on the socket, at least one of the opposing flange surfaces vorbeslieh is covered with a material with a low coefficient of friction 009817/1040 9 «Sealing device according to claims 1-8 for cases where an increased Pressure difference between the inside of the housing and the outside space in front of is handled, characterized in that in the same way as the first and at a certain distance from the first a second bushing is provided around the rotating shaft and the two bushings are attached by means of sealing connecting means in a common hollow holder, the space remaining free between the connecting means in the interior of the holder to a lower Pressurized barrier fluid bypass system is connected, its Pressure is determined to the effect that one of the two device sockets has only a small pressure difference (small or no Permeability), while the other is exposed to most of the total difference in pressures (relatively greater permeability) endures 001817/1040