CN1875211B

CN1875211B - Device and method for conducting at least two floating medium

Info

Publication number: CN1875211B
Application number: CN2004800322974A
Authority: CN
Inventors: 斯蒂芬·沃纳
Original assignee: Allweiler AG
Current assignee: Allweiler GmbH
Priority date: 2003-10-29
Filing date: 2004-10-06
Publication date: 2010-06-02
Anticipated expiration: 2024-10-06
Also published as: CN1875211A; DE102004013735B4; DE102004013735A1; DE102004013735B9

Abstract

The invention relates to a device which is used to guide at least two flow media having different pressures with a shaft or similar force-transmitting element (10), and a pressure insulating element such as a housing surrounding the shaft or similar. Areas (90a; 96; 98) arranged next to each other in the direction of the axis are determined between the force-transmitting element (10) and the pressure-insulating element by means of sealing elements (70); at least one of the preferably magnetofluidic sealing elements (70) is leakage-free, and two areas (90a; 98) for fluids (A, B) having different pressures flank an area (96) for an auxiliary liquid (H), whereby said area is subdivided by a device (100) into two partial areas (96a, 96b) for two different pressure areas. A conveying medium is allocated to the area (90a) at high pressure and ambient air is allocated to the area (98) at low pressure. The auxiliary liquid (H) is a carrier oil of the magnetofluid, optionally a silicon oil, allocated to the sealing element (70).

Description

The apparatus and method of at least two kinds of flowing mediums of guiding

Technical field

The present invention relates to the apparatus and method that at least two kinds of a kind of guiding have the flowing medium of different pressures.

Background technique

The transmission routine that keeps the motion of boundary wall and power by the pressure between two fluid systems with different pressures such as gas and liquid realizes by shaft sealing and rod seal such as packing, seal ring and bearing ring seal basically.Ambient air under external pressure is present in low voltage side usually.In vacuum system, ambient air is in the high pressure side.For with the effect of fault-free mode, the sealing of the above-mentioned type needs certain leakage current from higher-pressure side to low voltage side, and this is because these are to need oiling agent so that the contact seal that is not damaged during operation.

Yet, in many application, this leakage be undesirable or or even forbid, having harmful smell or volatile because this fluid for example is poisonous, perhaps because must keep high vacuum.The doublet system of utilize blocking medium, the bearing ring seal of double action for example makes to reduce and leaks or become possibility with the leakage of the alternative pressure fluid of leakage of the less obstruction fluid of harmfulness.

No leakage system is realized according to three know-whies at present basically: hermetically-sealed motor, magnetic coupling and magnet fluid sealing.

Under the situation of hermetically-sealed motor, motor is the part of machine, equipment or device, for example is generally used in the pump.Stator is positioned on the low voltage side of pump and by not magnetisable shell and high pressure side isolation.Rotor is positioned in the high pressure side of pump.Torque is sent to rotor via the electromagnetic force by shell from stator in the non-contact mode.

Also be that the magnetic coupling of using always is operated according to the principle of similitude in the pump technology, but replace the stator coil on the low voltage side of pump, there is external rotor with permanent magnet configuration, relative with it, on rotor-side, there are corresponding permanent magnet configuration or induction housing or ring.External rotor is connected to the conventional motor that produces torque, and described torque is sent to rotor in the non-contact mode via magnetic field line once more.Two coupling elements under stress are separated from each other by cup-shaped receiving element, container shield.

In design based on magnetic fluid, usually the magnetisable liquid that utilizes auxiliary material that very fine ferromagnetic microparticles is dispersed in the carrier oil forms fluid-tight seal element very soft and that be suitable for, for example, with the form of " liquid O shape ring " between axle and the shell, this ring is fixed on the interstitial site place by the magnetic field sealing of appropriate structuring.Such sealing utilizes sufacing for example to be used in the hard disk driver motivation and vacuum system commercial.

The sealing of described no leak type particularly has many shortcomings at the pump technical elements; Hermetically-sealed motor and magnetic coupling all need to be used for the bearing element of rotor bearing, and this bearing element must be lubricated also and then be subject to fault effects by the transmission medium of pump itself.Magnetic-coupled advantage promptly uses the ability of standard motor can not obtain under the situation of hermetically-sealed motor.On the contrary, magnetic coupling has following shortcoming: if must transmit different power, not only must use different motor, but also must use the Coupler of different model, so that its any price adverse condition needn't consider small-power the time.When high power owing to cross the cost that vast scale increases, make torque transfer and bearing arrangement according to the ability of its delivering power by its type-restriction two kinds of principles.The high-eddy loss by being produced in made container of nonmagnetic metal alloy and the container shield of general type is extremely disadvantageous.

The usability of magnet fluid sealing is limited to little pressure difference.According to example,, need each other along 6 Sealings that connect in order to seal 1 crust with respect to vacuum., the conventional pressure range of single stage centrifugal pump extends to 25 crust, and surpasses this scope according to special applications and other pumping system.In addition, must consider the fluid and chemical compatibility between the magnetic fluid and the mixed process that are comprised.

Summary of the invention

These situations have been understood, the inventor has set the purpose of oneself, a kind of no leakage system that is used for the above-mentioned type device promptly is provided, it has been eliminated above-mentioned defective and has allowed has High Pressure Difference, is being preferably between at least 25 zones of clinging to and carries out very high-power transmission, and does not need contained arbitrary fluid that any of bearing lubricated.In addition, the present invention is than one type of prior art syringe, usefulness cost efficient and easier use more.

The invention provides the device that at least two kinds of a kind of guiding have the flowing medium of different pressures, comprise as the axle of power transmission part with as the shell around described axle of pressure isolation element, be limited to by means of seal element between described axle and the pressure isolation element along the zone that axial direction is adjacent to each other, wherein at least one described seal designs is become not have and leak, two zones of fluid that are used to have different pressures are in the side in the zone that is used for auxiliary fluid, wherein, the described zone that is used for the auxiliary fluid that formed by auxiliary liquid is divided into two regional areas that are used for two different pressures zones by a device, and parts are set to produce pressure difference between described regional area, the device of wherein dividing the zone that is used for auxiliary fluid is a feedway.Instruction according to independent claims realizes above-mentioned purpose; Independent claims provide the advantage of further research and development.In addition, all combinations of at least two features disclosed in specification, accompanying drawing and/or the claim all fall within the scope of the present invention.At the digital scope place of explanation, the numerical value that is in the explanation restricted portion also tends to be disclosed as limit value and use according to wish.

According to the present invention, seal arrangement or seal element are arranged between the power transmission part and the pressure isolation element such as shell of axle for example, axially specifically form three zones that are adjacent to each other in this mode, described three zones are: a zone with first fluid (for example transmission medium under 25 crust) of certain pressure, have a zone of second fluid (for example at the ambient air of 1 crust under the absolute pressure) of the pressure that is different from first fluid, and be arranged on the 3rd zone between the described zone of assist medium or auxiliary liquid.Two regional areas (partial area) that the 3rd zone are divided into the different pressures district by a device.

Auxiliary liquid for example can be a silicone oil, and it also is used as the carrier oil of magnetic fluid; This is because silicone oil for using device for sealing magnetic fluid, particularly delimited the auxiliary liquid zone and is proved to be favourable.This magnet fluid sealing carries out hermetic seal to above-mentioned zone.

The zone that comprises auxiliary liquid or auxiliary fluid is built-in with the device that produces pressure difference in above-mentioned zone, and wherein in that fluid one side of high pressure produces higher pressure towards having more, vice versa.The pressure difference that can produce at least must be corresponding to the maximum pressure differential that produces between first and second fluids.

Advantageously, transmission medium should be assigned to higher pressure span, and ambient air should be assigned to the area of low pressure.Auxiliary liquid should be the carrier oil that is assigned to the magnetic fluid of seal element, optional silicone oil.

According to the present invention, the zone of auxiliary liquid has two bindiny mechanisms, and one is set to and produces vacuum and another is set to the path of auxiliary liquid.In addition, the regional area of the auxiliary liquid of elevated pressures is assigned to the zone of the fluid with elevated pressures.

The feature of theme of the present invention also is relative to each other to move and to be assigned to how much parts (geometric parts) of pressure isolation element and power transmission part, and described parts form the transmitting set of auxiliary liquid so that produce pressure difference.The device of separating the auxiliary liquid zone is preferably transmitting set.

Pressure difference in the auxiliary liquid is advantageously produced to relatively moving of how much parts of power transmission part and pressure isolation element (shell) by static allocation, and the transmitting set of formation auxiliary liquid, for example pump.Adequate measures for example provide and do not return valve, and guaranteeing in the case when system is idle does not have pressure compensation to produce between the high-pressure area of auxiliary liquid and area of low pressure.

According to another characteristic of the invention, the pressure difference that can produce is at least corresponding to the maximum pressure differential that produces between the fluid.

According to the present invention, parts also are provided, it acts on mutually with pressure difference between the auxiliary liquid of fluid with high pressure and pressure maximum.According to the present invention, above-mentioned effect is used for by suitable parts described pressure difference being transferred near zero numerical value.This can be for example by the power of the parts of regulating described generation pressure difference, or the backflow of regulating from the high-pressure area of auxiliary liquid to the area of low pressure realizes.The parts that have the power of some parts that are used to regulate described generation pressure difference, or regulate parts from the high pressure regional area of auxiliary liquid to the backflow of low pressure regional area.

Advantageously, the pipeline with valve formula overflow means is arranged between the regional area of auxiliary liquid.

According to the present invention, if the regional volume of auxiliary liquid is designed to variablely at least, then particularly the regional area of the low pressure area of auxiliary liquid can be configured and has variable-volume.Change auxiliary liquid zone volume ability compensation variable density and because temperature or even the Volume Changes of the auxiliary fluid that causes of variation in pressure.

The zone of distributing to auxiliary liquid by structure makes it have variable-volume, then can guarantee the pressure minimum of auxiliary liquid according to the present invention and the pressure difference that has between the hydrodynamic pressure of lower pressure also almost nil.For example, this can be by means of in the zone of auxiliary liquid one side with have flexible membrane between the fluid of relevant pressure, or in particularly advantageous mode, makes its mode that can move realize above-mentioned purpose by means of at least one magnet fluid sealing is set.Have in the configuration of ambient air of normal pressure (1 crust) in low pressure one side, sharpest edges are zones that structure has variable-volume on this side.

Described device is guaranteed magnet fluid sealing even also only bear low differential pressure under the situation of High Pressure Difference between first and second fluids, and then guaranteed its hermetic seal effect.Via for example transmission of shaft mechanical ground generation power of power transfer element, so that the highland through-put power is possible.

On high-tension side magnet fluid sealing preferably is made of three seal elements, described element is by shown along magnetized three permanent magnets with relevant ferromagnetic pole shoe of axle direction, described each pole shoe produces concentric magnetic field, and it is fixed as sealing medium with ferrofluid.These seal elements are arranged in the non-magnetic packing ring.According to the present invention, packing ring is fixed on the shell via the bellows of preferable alloy.Described bellows tend to against packing ring or lock ring and at opposite side against the pressure load-carrying unit.The simple and easy assembling of device realizes that by bellows is fixed on the lining this assembling is fixed on the shell lining by the sealing of O ring and by threaded collar about shell.

In text of the present invention, lock ring or packing ring also comprise a seal disc (advantageously forming by silicon carbide is molded), and described seal disc forms the mechanical sealing system that is made of two similar SiC dishes.A dish has depression in surface of contact, described depression have a few μ m the degree of depth and with the mode corresponding with the axial screw groove bearing from the outside to the dish the center form in a spiral manner, described axial screw groove bearing from the outside to internal action; These depressions advantageously begin and finish in a distance away from ring packing disk center opening from the edge of dish.An effect of described bellows is with the mode that is assigned to shell lining fitting tight dish movably, thus and its transmitting effect of causing by pressure difference of restriction.

During operation, if seal disc produces the pressure higher than the pressure that seals in pump, the packing ring that then has the related seals dish also moves along pressure-tight direction; Distance between the seal disc becomes big and has reduced transmitting effect thus.On the other hand, the low-pressure of crossing that is produced by seal disc causes the gap between the seal disc to reduce and the transmitting effect increase.

Within the scope of the invention, promptly mean under situation about being assigned on axle sleeve and the shell lining and realize seal action.The contacted parts of transmitting fluid of axle sleeve and shell lining and all and pump are by enough strong and have the nonmagnetic substance of chemoresistance to make to transmitting fluid.O ring provide axle sleeve with respect to axle static sealing and the shell lining with respect to the static sealing of shell.The shell lining can be by screw on shell.Seal can be used as the mode that assembly is mounted and removes with it in the case and forms.

According to another characteristic of the invention, keep axle sleeve and shell lining and make it pass through roller bearing, for example relative to each other rotation with one heart by two angle contact ball bearings with the axial spacing that limits.If necessary, bearing also is suitable for the axial force of absorption on axle.For this reason, for example axle sleeve must be fixed on the axle by retaining ring or spindle nut.

It is verified that to be fixed on roller bearing in the annular space of being delimited by axle sleeve and shell lining be favourable.This roller bearing should be fixed in the described annular space by the retaining ring of shell lining or axle bush and/or by flange shape radially outer shroud.

According to another characteristic of the invention, roller bearing is against the outer shroud of axle sleeve, and a seal disc of being made by silicon carbide is assigned to its opposite side.Advantageously, in the part that the edge that seal disc is configured in annular space is widened gradually away from the radial direction of outer shroud, the lock ring that wherein comprises another seal disc is arranged on the place ahead of this part.

According to the present invention, radial clearance is formed between the outer surface and adjacent lock ring of seal disc, the described radial clearance axial annular space between a side and axle and seal element alternatively is adjacent, and adjacent with another axial annular space of passing through below the adjacent seals dish at opposite side.

In order to fix better, seal disc should link to each other with the center wall of lock ring by at least one parallel to an axis drive pin.

It is also important that the partially filled for example chamber of air or inert gas of gas that has for the present invention, can be arranged on the front of device side, wherein be used as the liquid effects of fluid in described device, the front of the magnet fluid sealing element on packing ring or the lock ring for example, described chamber also the seal clearance by about 0.1mm from towards sealed away from the axle on the side of device; The diameter of selected described seal clearance is greater than the diameter of the seal clearance of magnet fluid sealing element on the packing ring, but less than the diameter of outside locular wall.

According to the present invention, construct the volume of described chamber and the width of seal clearance, make in configuration level and system when idle, and indoor be under the situation of ambient pressure, always have certain residual gas volume in the upper area of the chamber above the seal clearance of chamber.In operating process, this gas volume in this case for concentrating on one heart around the axle, and is compressed to littler volume by working pressure in the zone of the seal clearance of magnet fluid sealing in the zone of the minimum diameter of axle.Even two volumes have identical size,, there is not gas to overflow from the seal clearance of chamber by suitably selecting the latter's width.What on the other hand, second volume should be enough is big so that can cover the seal clearance of magnet fluid sealing fully in operating process even under the situation of pressure maximum.According to another characteristic of the invention, the ratio of favourable width between the seal clearance of the seal clearance of magnet fluid sealing, chamber and the latter's inner and outer diameter or diameter is 1: 1.2: 1.5.

Above-mentioned setting guarantees that in operating process magnet fluid sealing always only contacts with gas.And then prevented effectively magnetic fluid and mixing sealed liquid.

About with sealed liquid, do not expect and air generation chemical reaction that any in other words reaction is harmful, in the gas replenishment process of pump, can use the air of indoor residual volume.Otherwise, need the auxiliary connection of described chamber, so that before pump is started working, fill inert gas.

Therefore, the present invention comprises the functional complex of many connection that are relative to each other, and promptly at first for having the zone of seal and auxiliary fluid, also is useful on the device that produces pressure difference, carries out pressure difference by high pressure subsequently and regulates.The pressure compensation that the present invention also comprises auxiliary fluid and is used for introducing the described additional device of gas is promptly with respect to the pressure difference of low pressure.

Equally, a kind of method is provided within the scope of the invention, wherein particularly between power transmission part and pressure isolation element, used said apparatus, fluid with different pressures remains in the zone in every kind of situation that seal element delimit, and between described zone, auxiliary liquid or auxiliary fluid remain in the zone; In the latter, set up the zone of two different pressures, and the regional area of the auxiliary liquid of described elevated pressures tends to be assigned to the zone of the fluid with elevated pressures.The zone of auxiliary liquid tend to by with respect to the magnet fluid sealing element of the either side of fluid mass by hermetic seal.

Vacuum action was in the zone of auxiliary liquid before other method step was provided at and introduces described liquid; And then auxiliary liquid can the interior all spaces of filling device.

In addition, regulate backflow from the high pressure regional area of auxiliary liquid to the low pressure regional area.

The method according to this invention also comprises the pressure difference in the generation auxiliary liquid that relatively moves that is assigned to the geometric element on the pressure isolation element by being assigned to axle on the one hand on the other hand, and described geometric element forms transmitting set.

According to another feature of this method, the transmitting effect of auxiliary liquid produces by seal disc, and described seal disc is determined spiral chute or depression between them.The transmitting effect of seal disc should increase with pressure that increases seal disc and distance each other.

Another feature of the method according to this invention provides, before being arranged on seal element and air inclusion indoor, in operating process, concentrate on one heart around the axle in the zone of the seal clearance of gas volume between seal element and described axle, and be compressed by working pressure.

Especially, following details can be considered to the advantage according to system of the present invention:

Can be with low-cost production;

No eddy current loss;

Can install as ammunition;

Can simply replace;

Take a little space;

In pump, do not need sliding bearing;

Integrated roller bearing can absorb radial force;

Ferrite lattice that can the effective utilization cost efficient;

Even applicable to high power pumps;

Can be integrated at an easy rate in the existing pump model.

Description of drawings

Further advantage of the present invention, feature and detailed description will be from the following explanations of embodiment's preferred example and apparent with reference to the accompanying drawings, in the accompanying drawings:

It is preceding according to the sealing area of the pump shaft of part longitudinally with Sealing of the present invention that Fig. 1 shows assembling;

Fig. 2 shows the sealing area of the Fig. 1 under the assembling condition;

Fig. 3 shows not to be had pump shaft and compares the sealing area that ratio enlarges a little with Fig. 2;

Fig. 4 shows Fig. 2,3 expansion details;

Fig. 5 shows the expansion details of the Fig. 4 in different embodiments;

Fig. 6 shows the shell lining of the sealing area of part longitudinally;

Fig. 7 shows the axle sleeve of the sealing area of part longitudinally;

Fig. 8 to 10 shows the radial component by the different parts of the sealing area that centers on axle bush;

Figure 11 shows the expansion details of Figure 10;

Figure 12 shows the planimetric map of the ring packing dish that is intended for use sealing area;

Figure 13 and 14 shows the radial component that passes through a pair of seal disc along the line D of Figure 12;

Figure 15 shows the schematic cross-sectional by a part of device;

Figure 16 shows the schematic representation of magnet fluid sealing;

Figure 17 shows the cross section that has the signal distribution of additional device in the diverse ways stage;

Figure 18 to 20 shows three kinds of different sealing situations on the pump shaft, and this pump shaft illustrates with side view.

Embodiment

The sealing area Q of the pump shaft 10 of centrifugal pump (not being shown specifically) comprises that length is that 60mm and inner diameter d are the axle sleeve 12 of 30mm in this case, with respect to the longitudinal axis M of pump shaft 10, and described axle sleeve and its longitudinal axis M ₁Coaxial; The wall thickness b of axle sleeve 12 is 5mm.At centre distance a from leading edge 14 about 25mm of axle sleeve 12 ₁Integrally formed outer shroud 16 stretches out from axle sleeve 12 in the place, and as shown in Figure 7, described outer shroud has identical wall thickness b and the ring length e of about 7mm.External slot 18 for O ring 20 approaches outer shroud 16 as can be seen; Another O ring 20 is installed in the interior groove 19 that approaches leading edge 14.With second external slot 22 location approach axle sleeve 12 shown in trailing edge 15, as the recess of the retaining ring that is used to will be described below.

Axle sleeve 12 is centered on shaft housing lining 26, and this lining 26 has described length a, its inner diameter d ₁Be 68mm in this case, and have the wall thickness b of 5mm ₁O ring 20 provide axle sleeve 12 with respect to pump shaft 10 static sealing and shell lining 26 with respect to the static sealing of pump casing.In addition, shell lining 26 can be by screw to shell.

From certain of the leading edge 28 of shell lining 26 apart from a ₂The place, be about 20mm in this case, stretch out integrally formed flanged ring 32 from its wall 30, it has the diameter f of 100mm and the width g of 10mm, and comprises (for example two) for the radial screw bore 34 of plug screw 35 and also comprise four parallel to an axis perforates 36 for attachment screw 38.

Locating from the axial distance i of described leading edge 28 (approximately 10mm), the wall 30 of shell lining 26 has along two steps of inside and axial direction.These two steps 40,40 _aBe necessary, wherein each has little radial height, because the inner diameter d of the 73mm of leading edge 28 ₂Diameter d greater than the 68mm of opposite side ₁Leading edge 28 is by the wall section 30 in abutting connection with described flanged ring 32 _aProvide.In the zone of this flanged ring 32, has path to height and 10mm width i ₁Inner molded ring 42 mould by wall 30 and make (see figure 6).

Interior groove 23 is near the trailing edge 44 of shell lining 26, and the said external groove of described interior groove and axle sleeve 12 22 is relative and keep a pair of retaining rings 46,46 jointly _i, it is formed in the cylinder annular space 50 of axle sleeve 12 and 26 formation of shell lining; As shown in Figure 1, described cylinder annular space is integrated with in the stepped part 51 of the intermediate space between shaft housing 12 and the shell lining 26 at molded ring 42 places.

At retaining ring 46,46 _iAnd between the external rings 16 of shaft housing 12, roller bearing 52 is arranged in cylinder annular space 50, for example two angle contact ball bearings, its with axle sleeve 12 and shell lining 26 remain on qualification axially and the radial space place so that they can rotate with one heart.For this reason, axle sleeve 12 must be for example by internal fixation ring 46 _iOr spindle nut is fixed on the axle 10.

Fig. 1,4,5 shows above-mentioned step 40,40 especially _aAs cross section is the stops of L shaped retaining ring 56, and O ring 20 is kept by described retaining ring; These rings are axially pushed in the stepped part 51, as shown in Figure 1.Another step 40, it has the external rings 57 that integrally formed height n3 is approximately 5mm, be positioned at certain distance relative with retaining ring 56, described retaining ring applies pressure to step 40a and have the internal diameter n of 64mm, the external diameter n of 74mm by the preceding ring 54 that is centered on by leading edge 28 ₁Width k with 7mm.

Have the axial width k1 of 15mm and radially have the packing ring of two steps or lock ring 60 be assembled in before in ring 54 and the retaining ring 56, described packing ring or lock ring have parallel to an axis exterior wall 61, its internal diameter z is 65mm, can know from Fig. 8 and find out.The big center between the radial ringed antetheca 65 of the outer rim 62 of this exterior wall 61 and lock ring 60, described lock ring forms stepped by (same annular) radial center wall 63; Be integrally formed on the described center wall is to have 51mm external diameter z ₁Parallel to an axis wall ring 64, and described antetheca 65 is integrally formed on the described parallel to an axis wall ring.The diameter z of the central opening 66 of antetheca 65 ₂Be 35mm.Thereby the cross section of retaining ring 56 is by two angled portion, and the exterior section and the center wall 63 that comprise outer wall 61 constitute; This center wall is adjacent to the wall ring 64 of inner angled portion, and it also comprises antetheca 65 and in the end at central opening 66 places.

The center wall 63 of non magnetic packing ring or lock ring 60 and above-mentioned before between the ring 54, can see the bellows (bellow) 68 of annular, preferable alloy, it is connected to external rings 57 and on the inboard of the center wall 63 of packing ring 60.The latter is fixed in the shell lining 26.Be arranged in wall ring 64 or the packing ring 60 be three separately the annular magnetic seals 70, its structure can be found out from Figure 10,11 especially.Their width q is approximately 3mm, and the internal diameter y of ring opening 72 is that about 35mm and external diameter y1 are 50mm in this case.Reference character 74 expressions are for the permanent magnet of ferrofluid, it comprises two pole shoe N, S, as shown in figure 16, for example cross section is the ring of U-shaped, in Figure 11, illustrate with 76, and constitute by at least two parts, as the iron limiter with gap 78 (iron limiter), this gap has the width q of about 0.1mm ₁And it is unlimited to ring opening 72.

Three seal elements 70 form with respect on high-tension side magnet fluid sealing, and are axially magnetized three permanent magnets with relevant ferromagnetic pole shoe N, S, and each pole shoe produces the centered magnetic field that ferrofluid is fixed as sealing medium.In order to make device be easier to assembling, bellows 68 is against preceding ring 54, and by retaining ring 56 by O ring 20 with respect to 26 sealings of shell lining, described O ring is fixed to shell lining 26 by the preceding ring 54 that is provided with external screw-thread.

Two other magnetic seal 70 of the above-mentioned type is arranged in the rear side place of retaining ring 46.These magnetic seal spares 70 are centered on by two respective magnetic Sealing 70a of different-diameter, and isolating ring 79 is arranged in therebetween.

Described lock ring or packing ring 60 also comprise the dish of being made by silicon carbide 80, and it schematically shows in Figure 12,13, and described dish forms by two

similar SiC dishes

80,80 _aThe part of the mechanical sealing system that constitutes, described dish has the width g of about 7mm ₁, and the central opening 82 with diameter t of about

39mm.Dish

80,80 _aExternal diameter t ₁Be assumed to about 65mm.Here, 16 spiral chutes 86 with one section shape bending of circle, are etched or grind to form at the right hand dish 80 shown in Fig. 1 to 5 and 13 when it is seen from plate edge 81 beginning and with planimetric map _aFront or surface of contact 84, according to the effect of axial screw groove bearing outside-in, described groove 86 has the degree of depth c of 10 μ m to 20 μ m.These spiral chutes 86 finish in the radial distance of decentre opening 66, and separate by the barrier ribs 88 of respective curved.Pump direction and the center of spiral chute 86 from the Figure 12 of lateral are limited to dish 80 _aOn.

Spiral chute 86 can be at

dish

80,80 fixing and that moving _aMiddle formation.Importantly another coils 80,80 _aThe front that has processed 84 directly relatively, to such an extent as to transmitting effect produces during operation.

Dish 80 in seal element 70 and the packing ring 60 is with respect to latter sealing, for example by hot jacket closely.Second dish 80 _aWith the dish of first on the axle sleeve 12 positioned opposite.Fig. 5 clearly show that the annular space 13 between dish 80 and the axle sleeve 12.In embodiment's selected example, SiC dish 80 _aBy fixing as the external rings 16 of side stops with by O ring 20, this O ring forms with respect to the Sealing of axle sleeve 12 simultaneously and makes its rotary driving.If necessary, rotation can be for example by stops 16 and SiC dish 80 _aBetween drive pin assist.Dish 80,80 _aThe opposing side surface roughness that is machined into the plane in micrometer range and has the suitable meticulous degree of depth.The bellows 68 of packing ring 60 guarantees to coil 80,80 _aSurface of contact relative to each other axial direction with from zero mobility to a few tenths of distance of millimeter.When system is idle, dish 80,80 _aPressure difference by sealing is pressed together, thereby the high pressure side of this device is by dish 80,80 _aSealed from low voltage side.As mentioned above, the seal disc 80 on seal element 70 and the packing ring 60 remains on the concentric distance of qualification from about 0.1mm of axle sleeve 12 by annular space 13 (Fig. 5).

Figure 14 explanation is because two

dishes

80,80 _aBetween the foundation (three sectional views relatively) of the pressure that causes of transmitting effect.The highest curve K that illustrates, expression is subjected to power P and the foundation of pressure during with pressure level identical (the super helix fluted shaft is to the effect of bearing) on the inboard in the outside of dish when the dish 80 of left hand only.Following two illustrate curve K _mAnd K _e, represent pressure gradient possible when power produces by the corresponding higher pressure level on the inboard of the intermediate pressure on the left hand dish 80 and this dish, as situation according to the present invention.Depend on pressure gradient, as shown in Figure 5 can be necessary for pressure controlled addition thereto, as hereinafter explaining.

Towards the magnet fluid sealing of ambient side by four above-mentioned

seal elements

70,70 _aConstitute, these elements are arranged in retaining ring 46 places with two elements 70 to the mode of axle sleeve 12 guiding and 26 guiding of two outside hub plate covers of element 70a as mentioned above.In this case, magnetic fluid not only has seal action but also has the centering effect, therefore the dish 80 that has seal element can in axial direction move freely between axle sleeve 12 and shell lining 26, the relative to each other concentric and cylinder location of seal element in this zone.As a result, the volume in the zone between magnet fluid sealing is variable in low voltage side as required like that, thus guarantee pressure difference between the low voltage side of auxiliary fluid and environment towards zero.

How the space that Figure 15 shows between magnet fluid sealing element 70 advantageously is full of auxiliary fluid by two bindiny mechanisms 33 or two tapped holes 34.When a bindiny mechanism 33 was used to be full of the operation of auxiliary liquid, another was used to make this device to reach vacuum in advance, so auxiliary liquid is full of the space of being had time among the device Q.By suitable layout bindiny mechanism 33 opposite side of the annular space 27 in the hub plate cover 26 outside, this annular space is around the seal disc 80 of distributing to axle sleeve 12 _a, might between bindiny mechanism 33, produce pressure difference, this can be used to make this device that the auxiliary liquid from external container is flow through, and for example is used to cool off purpose.This can realize that for example, because annular space 27 has two different sides, one of side of annular space 27 is the 0.1mm place in this case at the very little radial distance of separation disc 80, and opposite side is in the big distance of about 1mm of separation disc 80.

During operation, the

SiC seal disc

80,80 that has spiral chute 86 _aTransmitting effect relative to each other is provided on auxiliary liquid, and this produces the pressure difference corresponding to transmitting effect between low voltage side of installing Q and high pressure side.Auxiliary liquid is selected in the following manner: on the one hand, the good lubrication of roller bearing 52 is guaranteed that the highest possible pressure difference can be via

seal disc

80,80 _aProduce (advantageously: high viscosity), on the other hand, the heating of auxiliary liquid remain in the controlled range (maximum about 80 ℃, advantageously: low viscosity).Auxiliary liquid is selected in addition in the following manner: it and

Sealing

70,70 _aMagnetic fluid can be compatible; It is favourable using the carrier oil (for example silicone oil) of magnetic fluid.

In order to prevent since superpressure and on the high pressure side magnet fluid sealing " spilling (breakthrough) " (three rings sustain the pressure difference of the most about 0.5 crust),

seal disc

80,80 _aTransmitting effect must limit by the pressure difference of Sealing on the high pressure side.This realizes by the above-mentioned mobility of distributing to the seal disc 80 of shell lining 26 by means of bellows 68.If during operation,

seal disc

80,80 _aThe pressure that produces is greater than pressure sealed in pump, and the carrier 60 with related seals dish 80 is along sealed pressure direction being moved

seal disc

80,80 _aBetween distance become big, therefore reduce transmitting effect.On the other hand, by

seal disc

80,80 _aThe too

low seal disc

80,80 that causes of pressure that produces _aBetween the gap reduce, thereby cause transmitting effect to increase.

At above-mentioned

seal disc

80,80 _aBetween the situation of self-regulation effect deficiency under, adjusting can obtain the high pressure of auxiliary liquid and the help of the overcurrent function between the area of low pressure (overcurrent function).In this case, can in packing ring 60, axially move, and arrange to have the radial clearance 17 of the 0.1mm between packing ring 60 and seal disc 80 in radial air-Fig. 5 of outside at the seal disc on the high pressure side 80.In order to be fixed and to drive, use at least two drive pins 67, as shown in Figure 5 with packing ring 60 rotations.At the place, outer end of seal disc 80, radially stops surface (stop face) 69 determines seal clearance.The layout on stops surface 69 is selected in the following manner: when the pressure between seal disc 80 and the packing ring 60 was higher than in the high pressure side pressure with sealed fluid, seal disc 80 rose away from packing ring 60, thereby opens seal clearance.Annular space 21 forms in the parallel to an axis mode from stops surface 69, and described annular space is determined by the outer wall 61 of packing ring 60 in a side, determined by the circumference of the seal disc 80 of distributing to shell lining 26 at opposite side.

Especially do not have the chemical corrosivity medium with sealed application in, have the multiple possibility that is used to reduce design cost.For example, the function of the function of axle sleeve 12 and shell lining 26 can be undertaken by axle 10 and shell.If axle 10 is made by ferromagnetic substance, magnet fluid sealing can be made in the mode of usefulness cost efficient, so magnetic field line is by axle 10 guiding.As a result, wherein the magnetic field of single permanent magnet is possible across the layout that many seal clearances guide.Yet the centering effect that needs on low voltage side no longer provides then.On the contrary, unstability exists, and therefore the adaptive of regional volume for auxiliary liquid must realize to be different from more described modes.For simple application, the described seal disc of making by

SiC

80,80 _aCan and be integrated in other element by the made of usefulness cost efficient more.

By

seal disc

80,80 with spiral chute 86 _aThe described principle that produces pressure difference only is a possible embodiment.It is conceivable and possible that other principle is for example transmitted screw thread.

The basic structure of magnet fluid sealing can be found out in Figure 16.Magnetic field with ring shape permanent magnet 74 of axial magnetized concentrates on the annular space 77 around axle 10 by two pole shoes 73.The field of concentrating keeps magnetic fluid 75 to be fixed in the described annular space 77, thereby this causes the seal action between the both sides of this structure.The width q of the seal clearance 77 of Sealing 70 ₂Expression.

In order to prevent, said apparatus is done following replenishing, as shown in figure 17 with any mixing between the magnetic fluid of sealed liquid and Sealing 70.

Scope, zone or chamber 90 are arranged in before the magnet fluid sealing 70 on the packing ring 60, described chamber part gassy G, for example air or inert gas.On the side away from device, chamber 90 is sealed with respect to axle 10 by annular space or seal clearance 92, and this gap has the width q of about 0.1mm ₃, and diameter f ₁, it is greater than the diameter of the seal clearance 78 of the magnet fluid sealing on packing ring 60 70 but less than the diameter f of outside locular wall 94 ₂

The volume of chamber 90 and the diameter of seal clearance be configured so that, when configuration level and system's free time, and chamber 90 is inner when being external pressure, and certain residual gas volume V0 always is present in the upper area of the chamber 90 on its seal clearance 92.During operation, this gas volume concentrates in the zone of the minimum diameter of rotor near the axle 10 with one heart, and this zone is the seal clearance 77 of magnet fluid sealing 70 under present case, and is compressed to volume V1 by working pressure.Even V1 equals V0, by the diameter f of the described seal clearance 92 of suitable selection ₁, should not have gas from the seal clearance 92 of chamber 90, to overflow.On the other hand, V1 should be enough greatly with during operation even cover the seal clearance 77 of magnet fluid sealing 70 when the pressure maximum fully.At the seal clearance 77 of magnet fluid sealing 70, the favourable diameter ratio of the seal clearance 92 of chamber 90 and the inner and outer diameter of chamber is 1: 1.2: 1.5.In Figure 17, V1* represents the gas volume under the pressure maximum.

As has been described, said structure guarantees that the magnet fluid sealing of operation period always only contacts with gas.Therefore, magnetic fluid with mixing of sealed liquid prevented effectively.

Figure 18 to 20 shows a principle of the present invention about two magnet fluid sealings 70 in the mode of summarizing, the axial distance s operation away from each other of sealing part, described seal arrangement is on the axle 10 and be parallel on the casing wall 24 (as the pressure isolation element) of axle operation, so that three scopes or regional formation: have a regional 90a with the fluid A (for example transmission medium under 25 crust) of certain sealed pressure, between Sealing 70, have the zone 96 of auxiliary liquid H, and the zone 98 with the fluid B (for example ambient air under 1 crust absolute pressure) that is different from fluid A pressure.Zone line 96 is divided into two halves or two-part 96 by transmitting set 100 _a, 96 _b, this device 100 schematically shows and is the pump symbol with the form of circle with inside triangle, thereby is suitable for producing the parts that transmitting effect produces pressure difference.Circle is connected 71 with shell side _aWith triangle and axle side be connected 71 elements of having represented transmitting set moving and the distribution of fixed component to this device.

By point shown regional 90 _a, 96 _aThe high pressure zone has been described; Pressure difference between the described zone by proper device detect (with " slotted line " 95 and symbol " Δ P=0! " representative), and signal is (with arrow line 95 _aRepresentative) function as pressure difference produces, and is used to regulate transmitting set 100.Low-pressure is present in the non-hatched area 96 that does not have a little _b, in 98.

In Figure 18, pressure is regulated separately and is undertaken by regulating transmitting set via pressure difference (preferred solution).In addition, can be with reference to figure 4.Figure 19 shows by overcurrent device 97 (by arrow line 95 _bBe connected to described slotted line 95 and represent by the excess current valve) pressure regulate, this device is by the pressure difference activation and be positioned at join domain 96 _bIn 98 pipeline (line) 99.Figure 20 has illustrated two combinations of adjusting distortion according to the specific embodiment of Fig. 5.

What be arranged in the zone 96 that comprises auxiliary liquid H is the device that produces pressure differences in this zone 96, and wherein elevated pressures produces in the side of the fluid A with elevated pressures, and vice versa.The pressure difference that can produce must be at least corresponding to the maximum pressure differential that produces between fluid A and fluid B.Also there is the device that the pressure difference between the pressure maximum of fluid A with elevated pressures and auxiliary liquid H is reacted.Utilize proper device, this reaction is used for described pressure difference is adjusted to and approaches zero value.This can for example produce the power of the device of pressure difference by adjusting, or by the high-pressure area 90 from auxiliary liquid H _aTo the area of low pressure 96 _bBackflow realize.

Distribute to auxiliary liquid H so that have the zone of variable-volume by structure, might guarantee the pressure minimum of auxiliary liquid H and the pressure difference that has between the pressure of fluid B of lower pressure also almost nil.This can be for example by in the side in the zone of auxiliary liquid H with have flexible membrane between the fluid of relevant pressure, or by arranging that one of magnet fluid sealing 70 realizes so that it can move.Have in low voltage side in the configuration of the ambient air under normal pressure (1bar), the zone 96 that has variable-volume at this side structure is best.

Described device is guaranteed magnet fluid sealing 70 even at fluid A, also only is subjected to low pressure difference between the B under the situation of high pressure difference, thereby guarantees their hermetic seal function.Power transmits via for example axle 10 machinery generations of power transfer element, makes that high delivering power is possible.

For example by the generation that relatively moves of geometric element, this element is given axle 10 and shell and the formation transmitting set for auxiliary liquid H by static allocation to pressure difference in auxiliary liquid H.Adequate measures for example provide the described valve that do not return, and guarantee when system is idle high-pressure area and area of low pressure 96 at auxiliary liquid H in this case _aWith 96 _bBetween do not have pressure compensation to produce.

Claims

1. at least two kinds of devices with flowing medium of different pressures of a guiding comprise as the axle of power transmission part with as the shell around described axle of pressure isolation element, along the zone (90,90 that axial direction is adjacent to each other _a96; 98) by means of seal element (70,70 _a) and be limited between described axle (10) and the pressure isolation element, wherein with at least one described seal element (70,70 _a) be designed to not have and leak, be used to have fluid (A, two zones (90,90 B) of different pressures _a98) in the side of the zone that is used for auxiliary liquid (H) (96), it is characterized in that the described zone (96) that is used for the auxiliary liquid (H) that formed by auxiliary liquid is divided into two regional areas (96 that are used for two different pressures zones by a device (100) _a, 96 _b), and parts are set with at described regional area (96 _a, 96 _b) between produce pressure difference, the device of wherein dividing the zone (96) be used for auxiliary liquid (H) is a feedway (100).

2. device according to claim 1 is characterized in that transmission medium is distributed to described high-pressure area (90 _a), and ambient air distributed to described area of low pressure (98).

3. device according to claim 1 and 2 is characterized in that each seal element (70,70 _a) be the magnet fluid sealing element.

4. device according to claim 3 is characterized in that described auxiliary liquid (H) is to be assigned to described seal element (70,70 _a) the carrier oil of magnetic fluid.

5. device according to claim 1 and 2, the zone (96) that it is characterized in that being used for described auxiliary liquid (H) has two bindiny mechanisms (33), and one of them is set to and produces vacuum and another is set the path as described auxiliary liquid (H).

6. device according to claim 1 and 2 is characterized in that the regional area (96 of the described auxiliary liquid (H) of elevated pressures _a) be assigned to the zone (90 of described fluid (A) with elevated pressures _a).

7. according to each described device in the claim 1 to 2, it is characterized in that described at described regional area (96 _a, 96 _b) between produce pressure difference parts be set in the described regional area.

8. according to each described device in the claim 1 to 2, it is characterized in that relative to each other moving and being assigned to how much parts of pressure isolation element and transmission part (10), described how much parts form the transmitting set of described auxiliary liquid (H) so that produce pressure difference.

9. according to each described device in the claim 1 to 2, it is characterized in that design is at described regional area (96 _a, 96 _b) between produce the parts of pressure difference, make the pressure difference that can produce at least corresponding to described fluid (A, the maximum pressure differential that produces between B).

10. device according to claim 9 is characterized in that, parts are provided, and can be adjusted to zero via the pressure difference between the pressure of the pressure maximum of the described auxiliary liquid of these parts and described fluid with elevated pressures.

11. device according to claim 10 is characterized in that regulating the high pressure regional area (96 from described auxiliary liquid (H) _a) to low pressure regional area (96 _b) the parts (97,99) of backflow.

12. according to claim 10 or 11 described devices, the pipeline (99) that it is characterized in that having valve formula overflow means (97) is arranged on the regional area (96 of described auxiliary liquid (H) _a, 96 _b) between.

13., it is characterized in that the volume in the zone (96) of described at least auxiliary liquid (H) is designed to variable according to each described device in the claim 1 to 2.

14. device according to claim 6 is characterized in that the regional area (96 of the low pressure area of described at least auxiliary liquid (H) _b) be configured and have variable-volume.

15. device according to claim 1 and 2 is characterized in that being used for determining the membrane type sealed element in the zone (96) of described auxiliary liquid (H).

16. device according to claim 3 is characterized in that described magnet fluid sealing element (70,70 _a) on the either side in the zone (96) of the auxiliary liquid (H) between described power transmission part (12) and the described pressure isolation element (24), extend.

17., it is characterized in that described seal element (70,70 according to each described device in the claim 1 to 2 _a) be included at least one permanent magnet (74) in the ring (76), and the magnetic fluid (75) that also is included in annular space (77) the punishment described axle of dispensing (10).

18. device according to claim 17 is characterized in that described ring (76) around described axle (10), the magnetic field of wherein said permanent magnet (74) concentrates on the described annular space (77) by relevant pole shoe (73).

19. device according to claim 17 is characterized in that in the lock ring of being made by nonmagnetic substance (60) the axially magnetized permanent magnet (74) in the high pressure side, or is at least two concentric seal elements (70,70 _a), described seal element (70,70 _a) cross section separate by at least one parallel to an axis spacer ring (79).

20. device according to claim 19 is characterized in that a bellows (68) against described lock ring (60), described bellows at opposite side against the pressure load-carrying unit.

21. device according to claim 20 is characterized in that described bellows (68) made by metallic material and centered on by retaining ring (56) at its radial outside, and/or against the preceding ring (54) that is fixed to shell lining (26).

22. device according to claim 19 is characterized in that described lock ring (60) comprises at least one seal disc (80) as the part of mechanical sealing system, this mechanical sealing system comprises at least two seal discs (80,80 with central opening (82) _a), wherein said seal disc (80,80 _a) form by silicon carbide is molded.

23. device according to claim 22 is characterized in that described seal disc (80,80 _a) abut against each other at least one seal disc (80 wherein at surface of contact (84) _a) have the spiral chute or a depression (86) of the little degree of depth (c), it forms with bend mode to disk center from plate edge (81) in described surface of contact (84), described groove or be recessed in away from a distance of described central opening (82) finishing and covered by the surface of contact of another seal disc (80).

24. according to each described device in the claim 1 to 2, it is characterized in that axle sleeve (12) that at least one centers on described axle (10) and the shell lining (26) coaxial with it made by nonmagnetic substance under each situation, and at least two magnet fluid sealing elements (70,70 around described axle _a) be arranged between described axle sleeve and the described shell lining.

25. device according to claim 24, it is characterized in that O ring (20) provide described axle sleeve (12) with respect to described axle (10) static sealing and shell lining (26) with respect to the static sealing of described shell.

26. device according to claim 24 is characterized in that keeping described axle (10) or described axle sleeve (12) and described shell or described shell lining (26) with the axial spacing that limits, and makes that they can be by the longitudinal axis (M with respect to described axle sleeve ₁) roller bearing (52) of radial arrangement, and rotation with one heart.

27. device according to claim 22 is characterized in that the outer shroud (16) of described roller bearing (52) against described axle sleeve (12), the described seal disc of being made by silicon carbide (80 _a) one of distribute to its opposite side.

28. device according to claim 22 is characterized in that a seal disc (80 _a) in the part (51) of widening gradually away from the axial direction of outer shroud (16) of the edge that is installed in described annular space (50), described part is distributed to the described lock ring (60) that comprises another seal disc (80).

29. device according to claim 3 is characterized in that the axle of being made by ferromagnetic substance (10).

30. device according to claim 22 is characterized in that, radial clearance (17) is formed between the outer surface and adjacent lock ring (60) of described seal disc (80).

31. device according to claim 30, it is characterized in that described radial clearance (17) is in a side and axial annular space (77) adjacency between described axle (10) and described seal element (70), and in opposite side and axial annular space (13) adjacency of passing through in adjacent seal disc (80) below, and/or stops surface (69) are arranged on the radial outer end portion place of described radial clearance (17), described stops surface and outer ring gap (21) adjacency that forms in the parallel to an axis mode.

32. device according to claim 28 is characterized in that described another seal disc (80) links to each other with the center wall (63) of described lock ring (60) by at least one parallel to an axis drive pin (67).

33., it is characterized in that the partially filled chamber (90) that gas (G) is arranged and be provided with seal clearance (92) is set at before the side that fluid is applied to it according to each described device in the claim 1 to 2.

34. device according to claim 33, it is characterized in that the described partially filled chamber (90) that gas (G) is arranged and be provided with seal clearance (92) be set on the lock ring (60) described magnet fluid sealing element (70) before.

35. device according to claim 33 is characterized in that the width (q of described seal clearance (92) ₃) greater than the width (q that goes up the seal clearance (77) of seal element (70) about the lock ring (60) of described axle (10) ₂), the width (q of wherein said seal clearance (77) ₂), the width (q of the seal clearance (92) of described chamber (90) ₃) and the inner and outer diameter (f of described chamber (90) or outer chamber walls (94) ₂) between ratio be 1: 1.2: 1.5.

36. device according to claim 33 is characterized in that the cross section of described chamber (90) is widened to the outside.

37. device according to claim 33 is characterized in that the auxiliary bindiny mechanism that is used for inert gas distributes to described chamber (90).

38. according to claim 9 or 10 described devices, it is characterized in that, comprise the device of the power of regulating the parts that produce pressure difference.

39. device according to claim 19 is characterized in that, comprises seal disc (80,80 _a), wherein said seal disc (80,80 _a) form by silicon carbide is molded.

40. at least two kinds of methods of a guiding with flowing medium of different pressures, comprise power transmission part and pressure isolation element, between described power transmission part (10) and described pressure isolation element, have the fluid (A of different pressures, B) remain on by seal element (70,70 under every kind of situation _a) determined zone (90,90 _a98) in; And between described zone, a kind of auxiliary liquid (H) remains in the zone (96), utilization is the described device of any claim in claim before, it is characterized in that in by the formed described auxiliary liquid of auxiliary liquid (H), setting up the zone of two different pressures, and the regional area of the elevated pressures of auxiliary liquid (H) is assigned to the zone of the fluid (A) with elevated pressures.

41. according to the described method of claim 40, the zone (96) that it is characterized in that described auxiliary liquid (H) is by means of with respect to described fluid (A, zone (90,90 B) _aThe magnet fluid sealing element (70,70 of either side 98) _a) and by hermetic seal.

42., it is characterized in that vacuum action is in the zone (96) of described auxiliary liquid (H) before described liquid according to claim 40 or 41 described methods.

43., it is characterized in that transmission medium is assigned to described high-pressure area (90,90 according to each described method in the claim 40 to 41 _a), ambient air is assigned to described area of low pressure (98).

44., it is characterized in that the pressure difference that can produce is at least corresponding in described fluid (A, the maximum pressure differential that produces between B), or regulate the power of the parts that produce pressure difference according to each described method in the claim 40 to 41.

45., it is characterized in that regulating high pressure regional area (90 from described auxiliary liquid (H) according to each described method in the claim 40 to 41 _a) to low pressure regional area (96 _b) backflow.

46. according to each described method in the claim 40 to 41, the relatively moving of geometric element that it is characterized in that being assigned to described pressure isolation element on the other hand by being assigned on the one hand described axle (10) and form transmitting set (100) produces pressure difference in the described auxiliary liquid (H).

47. according to each described method in the claim 40 to 41, the transmitting effect that it is characterized in that described auxiliary liquid (H) is by means of seal disc (80,80 _a) and produce, at described seal disc (80,80 _a) between determine spiral chute or depression (86), wherein seal disc (80,80 _a) transmitting effect by increasing described seal disc pressure and distance each other increase.

48. according to each described method in the claim 40 to 41, it is characterized in that, in the chamber (90) that is arranged at the preceding and air inclusion of described seal element (70), in operating process, concentrate on described axle (10) with one heart on every side in the zone of the seal clearance (77) of gas volume between described seal element and described axle, and be compressed by working pressure.