DE3040409A1 - DEVICE FOR HYDRODYNAMIC SEALING OF CIRCULAR MACHINE PARTS - Google Patents

Description

The invention relates to a device for hydrodynamic Sealing a stationary or rotatable first machine part under fluid pressure from a rotatable one second machine part, for example a hydraulic machine, with at least one under static pressure one elastic element standing sealing member.

For sealing hydraulic parts that are under high oil pressure Machines are usually of different types

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pen of sealing rings, so-called O-rings, which consist of elastic material, mostly plastic, and rest against the machine part to be sealed under prestress.

The problem with using such sealing rings is that they are not subjected to uniform pressure are, the entire hydraulic pressure acts rather only on parts of the sealing surface, which a high friction and a results in a correspondingly large amount of heat. This in turn has a detrimental effect on the macromolecular plastic material which deforms in the process. In order to avoid such deformations as far as possible, the seal to be sealed must be applied rotating part must be provided very narrow gaps. The O-ring must always be on the sealing ring Apply sufficient contact pressure to ensure its sealing function.

Another disadvantage of such combined sealing devices is that they only have very small installation tolerances may have a value that does not exceed a value, which corresponds to the reduction in cross-section of the O-ring caused by preloading. The sealing ring is here over its cross-sectional area is unevenly loaded and is therefore subject to premature wear. Another post

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part is that a rotary movement can take place between the sealing ring and the O-ring, which also leads to premature damage to the O-ring and thus failure of the sealing function. Also through Heat influences that cause the O-ring to set the sealing function can be endangered or impaired.

The invention is based on the object of providing a sealing device while avoiding the aforementioned disadvantages create at which the pressure acting on the surface of the sealing element and on the opposing surface to be sealed, at least as far as this comes from the hydraulic pressure, thereby largely reduced or completely eliminated, that the sealing member is evenly subjected to pressure and the device is insensitive to axial displacements and is also carried out with relatively wide tolerances.

This object is achieved according to the invention in that the device in the characterizing part of claim 1 features listed and advantageously also has the features listed in the subclaims.

The inventive design of the sealing device In particular, the following advantages are achieved:

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There is extensive pressure equalization on the sealing element, so that only a relatively large amount of pressure is applied to the surface of the sealing element low pressure acts, whereby frictional forces and thus also wear are reduced. The special one Design of the sealing member results in only a very low edge load. The fact that the sealing member and thus also the plastic ring, which is under the action of a spring element, opposite the first machine part cannot rotate, heat generation and wear caused by friction is avoided * The sealing function is thus retained. The sealing member can be made of metal and allows the arrangement of relatively wide gaps between the surfaces to be sealed. As a result of the axial mobility of the sealing element, the peripheral sealing gap is retained even if the hydraulic Machine should occur due to an external load. The sealing member is thus adaptable and does not require tight installation tolerances.

In the drawing are exemplary embodiments of the invention Device shown in a schematic manner. Show it

Fig. 1 is a section through an axial sealing device According to the state of the art,

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FIG. 2 shows the detail FF2 from FIG. 1 on an enlarged scale with drawing of the occurring compressive forces,

2a shows a diagram of the resulting pressure distribution on the sealing ring according to FIG. 2,

3 shows a section through part of a hydraulic machine with an axial sealing device according to the invention ,

4 shows the detail FF4 of FIG. 3 showing an inner axial sealing collar on an enlarged scale,

5 shows the relationship between oil film pressure, distribution and pressure differences for different widths Diagram showing sealing gaps,

6, 6a, 7, 7a, 8, 8a, 9, 9a, and 10 pressure distribution diagrams for different widths Sealing gaps for inner axial sealing collars according to Fig. 4,

11 and 11a show, contrary to the teaching of the invention, an inner sealing collar with a pressure distribution diagram ,

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Fig. 12 shows an inner axial sealing collar in one of Fig. 4 different configuration,

FIG. 13 shows a section along the section line XIII - XIII in FIG. 12,

14 and 14a show the compressive forces occurring on the sealing collar according to FIGS. 12 and 13 and that resulting pressure distribution diagram,

15 shows the detail FF15 from FIG. 3 with an outer axial sealing collar designed according to the invention.

In the known axial sealing device shown in FIGS is an inner and an outer sealing ring 1 and 2 in an annular groove 3 and 4 of a housing body 5 installed in a hydraulic machine, which has the cylinder block 6. The two under static pressure one O-rings 7 and 8 standing sealing rings 1 and 2 are intended to reduce the leakage flow, which on the one hand between the flat vertical surfaces 9 and 10 of the housing body 5 and on the other hand the flat vertical sealing surfaces 11 and 12 of a distributor 14 rotating about the axis of rotation 13 can occur. The cylinders, not shown, of the

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hydraulic machine are also not shown Pressure source fed via the inlet channel 15 with oil under high pressure. To the inlet channel 15 a first annular channel part 16 adjoins in the housing body 5, which with a second annular channel 17 and is connected via this to a distribution channel 18 arranged in the distributor 14. With a circulating distributor 14, oil passes from the distributor duct 18 to the cylinder inlet ducts 19 provided in the cylinder block 6, of which only one is shown. The oil return from the cylinders takes place from channel 19 via outlet channels 20 and 21 in the Distributor 14 or the housing body 5. If the hydraulic machine rotates in the opposite direction, the channel 21 is fed with pressurized oil, which reaches the cylinders via channel 20, while the pressurized oil flows back via the Channels 19,18,17 / 16 and 15 takes place.

The diagrams T, T _A2 , T _A3? T _A4 and T _A5 of FIGS. 2 and 2a show the pressure distribution on the inner sealing ring 1. The purpose of this known construction is, with suitable optimization of leakage and surface pressure, to reduce oil leakage as far as possible and to reduce the oil pressure from a value Ρ _Λ on the high pressure side to a value P ~

ι 2.

on the low-pressure side of the sealing gap 22.

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The diagrams T and T, _o show that the pressure conditions in the radial direction are by and large balanced against each other. The diagram T ₀ - shows that the pressure in the axial direction on the rear side of the sealing ring 1 in the sealing gap 22 is constant over the entire width of the inner sealing ring 1. In contrast, the pressure between the inner sealing ring 1 and the sealing surface 11 decreases from the high pressure side to the low pressure side, as shown in diagram T. shows in a schematic linearly drawn manner. This means, as shown in Fig. 2a, that the pressure forces acting on the inner sealing ring 1 in the axial direction increase from the high pressure side to the low pressure side, which leads to high friction, corresponding heat generation and rapid wear due to the different loading of the inner sealing ring 1 over its cross-section . Another disadvantage is that an undesirable rotary movement takes place between the inner sealing ring 1 and the O-ring 7, which quickly damages the O-ring and jeopardizes the sealing function.

With regard to the outer sealing ring 2, which in principle is shown in FIG the same way as the inner sealing ring 1 is constructed, there are the same disadvantages.

in Fig. 3 shown in a partial section hydraulic

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see machine has a first machine part 23, namely a stationary connection flange with flow channels 24 and 25, which with channels 26 and 27 in a second machine part, a rotating manifold 28, are in communication. This distributor 28 rotating about the axis 29 is in a stationary cylinder block 30 with piston 31 and cylinder inlet or outlet channels 32, of which only one is shown. The pistons 31 work in a known manner against a cam curve, not shown, which is connected to the rear end face 33 of the machine is, thus rotates and is usually connected to the unit to be driven. The manifold 28 is in the cylinder block 30 supported axially by means of the roller bearing 34 and via a driver 35 with the rear end face 33 connected to the machine and thus has the same rotational speed as this.

To create a seal between the connecting flange 23 and the To achieve manifold 28 are two axial sealing members in the form of an inner and outer axial sealing collar 36 and 37 - hereinafter referred to as "sealing collars 36 and 37" for short - both of which extend longitudinally in the axial direction and secured against rotational movement with respect to the connecting flange 23 with the aid of dowel pins 38 and 39, respectively are.

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The cylindrical outer surface 40 of the outer sealing collar 37 as well as an axially limited one in the area of the outer Sealing collar 37 located part of the cylindrical outer surface 41 of the distributor 28 have opposite the cylinder block 30 a clearance 42 or 43 to facilitate the drainage of leakage oil. This leak oil passes through the drain opening 44 and the channel 45 leading to the oil reservoir. A first annular channel part cut out in the distributor 28 46 stands with an annular second, between the inner and outer sealing collars 36 and 37 in the connecting flange 23 arranged channel part 47 in connection, so that these channel parts a connection between the channels 25 and 27 form. In one direction of rotation of the machine, pressurized oil is supplied through channel 25, through channels 46-47 and 27 are fed to the cylinder inlet channel 32 of the piston 31. The oil is returned via channels 26 and 24. If the machine rotates in the opposite direction, the flow is in the opposite direction, i.e. the pressure oil is Piston supplied through channels 24 and 26, while the oil return is via channels 32, 27, 46-47 and 25.

Fig. 4 shows the installation of the inner sealing collar 36 more clearly, between its end face 48 and that of this opposite surface 49 of the manifold 28 the seal is to take place. The sealing gap 50 is the better

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Exaggerated because of the clarity. The inner sealing collar 36 has on its cylindrical surface by annular shoulders 51 and 52 limited cylindrical surfaces 53 and 54, which with corresponding surfaces of the Connection flange 23, the end face 55, the annular shoulder 56 and the cylindrical inner surfaces 57 and 58, cooperate. Between the outer surface 54 of the inner sealing collar 36 and the inner surface 58 of the connecting flange 23 an annular space 59 is recessed, which allows axial mobility of the inner sealing collar 36 in the connecting flange 23 permitted. In this recess 59 is a plastic ring 60 with a rectangular shape for static sealing Cross-section used. In addition, the device has a spring element in the form of an annular spring 61, which is in a Gap 62 between the annular shoulder surface 51 of the sealing collar 36 and the end face 55 of the connecting flange 23 is inserted to the inner sealing collar 36 to impart a bias against the surface 49 to be sealed. The dowel pin 38 is inserted in the connecting flange 23 and extends into the installation groove 63 of the inner sealing collar 36. On the cylindrical inner surface 64 an annular groove 65 is recessed in the inner sealing collar 36.

The equation for the flow of liquid in a gap

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results for the oil film pressure as a function of the structural design of the sealing member or the sealing collar 36 given depth b of the gap depending on the width h of the gap different values. In the diagram of Fig. 5 Curve I shows the oil film pressure in a narrow gap h

well a

and curve II. the oil film pressure in a wide gap h. In the following it is described how a completely or partially pressure-balanced sealing element at a fluid pressure P ₁ from the outside and a lower fluid pressure P ₂ from the inside ", ie on the outflow side, an inner one Sealing collar obtained using a static seal in the form of a plastic ring 60. The inner axial sealing collar 36 is designed so that it has a sealing function in both directions The mode of operation is exactly the same in both cases. The mode of operation is also not influenced by whether the rear face 33 of the machine (FIG. 3) is stationary and only the connecting flange 23 rotates or whether both parts rotate .

FIG. 6 shows a pressure distribution diagram of the device according to FIG. 4 with a constant width of the sealing gap 50, which was drawn exaggeratedly wide for the sake of clarity.

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When the fluid pressures P ₁ and P ″ are the same on both sides of the inner sealing collar 36, the arcuate annular spring 61 presses the inner sealing collar 36 against the sealing surface 49.

When pressurized oil is applied to the device, it flows into the gap 62 and from there into the annular space 59 between the inner axial sealing collar 36 and the connecting flange 23 and acts against the radial surfaces 51 and 52 so that the inner sealing collar 36 against the sealing surface 49 of the distributor 28 is pressed. As shown in FIG. 6, the tongue of the two surfaces acted upon by the pressure is A ₁₁ and h. = A ₁ and the corresponding force fields T _ß1 and T _ß "assume a rectangular shape.

The oil, which is pressed into the sealing gap 50 and acts on the boundary surfaces of this gap, the surface 49 of the inner sealing collar 36 and the surface 49 of the distributor 28, has an opposite effect. The counterpressure thus formed, the so-called burst pressure, strives to widen the sealing gap 50. The printed image T ₃ assumes the shape of a triangle with a slightly curved hypotenuse (FIG. 6). This resulted in an expedient measure to design the sealing device in such a way that the inner sealing collar 36 is deformed under the application of pressure in such a way that the sealing gap 50 is

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expands. The resulting print image T _R. assumes the shape shown in FIG. 6a, ie one obtains an inner sealing collar 36 which is essentially in complete pressure equilibrium. With the correct geometrical dimensioning of the surfaces 48 and 49, this is ensured, the inner annular groove 65 of the inner sealing collar 36 taking on the important task To give this a somewhat limp web I, which is in a certain ratio to the other cross-sectional areas and thus also to the flexibility of the part of the inner sealing collar 36, the wall thickness of which has been designated by I ". _{The forces which are produced by the oil pressure P 1} acting on the outer surface 66 and the surfaces 53 and 54 of the inner sealing collar are designated in FIGS. 6 and 7 by F., F.sub.1 and F.sub.1.

7 shows the printed images for a sealing gap 67 which narrows inwardly due to the inward _{deflection of the web I 1 caused by the forces F 1 and F 1.} The sum of the force fields T, T and T " ₅ is = T,., So that the resulting print image shown in FIG. 7a results. The result is that a force directed to the right acts on the inner sealing collar.

Fig. 8 shows a broader one, for the aforementioned reasons

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gap 68 narrowing towards the inside (h ₅ > hg), the force fields T, T _ and T "" adding up to T "and the result is the print image shown in FIG. 8a. A force directed to the left thus acts on the inner sealing collar 36.

FIG. 9 shows the printed images for a gap, the width of which has a mean value between that of FIGS. 7 and 8. If the force fields acting on the radial surfaces are selected so that Y ₁ , the sum of the two force fields Y ₁₁ and Y ₁ -, is equal to the area of the force field Y ₁ , there is pressure equilibrium with an only slightly narrowing gap 69, the width of which on the side of the higher pressure Υΐη and on the side of the lower pressure h „is. That from the sum of the three force fields T _n -, T _DO and T ₀₀

ts ι OiL tsy

The resulting force field ^T _Qin consists, as the diagram in FIG. 9a shows, of two triangular surfaces of equal size, so that the seal at the given gap width h _{? ;} h “is completely balanced. In this case, the annular spring 61 is of no particular importance with regard to the pressure distribution.

Should the area Y "become larger than the area Y-, so the sealing gap 69 widens and a force field is obtained which is smaller than the area Y- in FIG. 9 T, as can be seen from FIG. The you-

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Processing gap 69 is so large that the resulting force acting on the inner sealing collar 36 is the same. As already mentioned, the annular groove 65 has an important function in that it enables the inner sealing collar 36 to adjust itself to a certain extent. If the area Y _{2 should be} somewhat smaller than the area Y., this means that the width of the sealing gap 69 decreases and a diagram as shown in FIG. 7a is obtained. Here, the area Y_ increases until it reaches the size of the area Y.

Fig. 10 shows a case in which the pressure prevailing in the sealing gap 70 fluid pressure on the input side to the value P., has risen and is on the output side P., which may correspond to the value _P2. The corresponding force fields are _labeled T ßll, T _ßl2 and T _ßl3 . The surfaces 66, 53 and 54 are acted upon by the compressive forces F., Fj- and F _fi , the inner sealing collar 36 being subjected to a bending stress in the area of the web I. So that the gap width h _g on the input side is smaller than that Gap width h ^. "On the output side of the sealing gap 70 and a resulting pressure distribution approximately as in Fig. 7a is obtained. The sealing collar shifts to the right, h. _Q increases.

A comparison of the two FIGS. 9 and 10 shows that ^Ρ 3> ^ρ -ρ

h _n > - h _n and h ^ - ^ - ho is. Here, too, you get an automatic / IU ο

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Ge setting by a geometric dimensioning of the areas such that the area Y _{4 is} equal to the area Y ₃ , the sum of the areas Y ₃ and ^ ₃ . From this it can be seen that the width of the seal gap varies with fluid pressure in such a way that it is greater at high pressures than at low pressures. Here, as already mentioned, the annular groove 65 has to give the inner sealing collar 36 a certain flexibility, with the effect that the end face 48 delimiting the sealing gap recedes under the effect of the compressive forces acting on the device. These are the radial pressure forces F, F and F ₃ or F ₄ , F ₅ and F ^ acting on the cylindrical surfaces 66, 53 and 54, so that a print image with the force fields T _ß3 , T _ß5 , T _ß7 , T ₅₉ and T ₃₁₃ as shown in Figures 7, 8, 9 and 10 is obtained. If the opposite is the case, the pressure equalization becomes unstable, as described in Eig. 11 was shown.

This figure thus shows an example of an unfavorably designed inner sealing collar 71 which does not have an inner annular groove. The sealing gap 72 has the width h ^ on the side where the fluid pressure P. is applied and the width hp on _{the discharge side which is under the fluid pressure P 5.} The result is a print image with the force field T ₅₁₄ on the sealing surface 49, which differs from the to-

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before described differs in that the pressure forces corresponding to the force fields Τ _β ., T _ and T. try to tilt the sealing collar 71 in the wrong direction, so that a resulting force field Tg., - results, as shown in the diagram of FIG. 11a. The effect of this pressure distribution is a higher pressure acting on the sealing collar 71, as a result of which it is shifted in the direction of the sealing surface 49, which not only entails an uneven load but also the disadvantage of high wear.

In the embodiment shown in Fig. 4, the plastic ring 60 seals to the right, i.e. it seals the " Annular space 59 against the leakage between the surfaces 58 and 58 of the inner sealing collar 36 or the connecting flange 23 from. If the hydraulic machine runs in the opposite direction of rotation, the direction of flow is reversed of the fluid and thus also the pressurization of the inner Sealing collar 36 um. The fluid enters through the channel 24 and acts on the inner surface 64 of the inner Sealing collar 36. Here, the fluid pressure also acts on the rear side of the sealing collar via the rear gap 73 36, the plastic ring 60 now the annular space 59 opposite the surfaces 53 and 57 of the inner Sealing collar 36 or the connecting flange 23 seals.

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In addition to forces acting in the annular groove 65, the fluid pressure also produces forces on the inside of the sealing collar 36 which oppose the forces F, F_ and F_ shown in FIGS. 7, 8, 9 and 10. These forces result in a bending stress on the sealing collar 36 in the region of the web I, so that the sealing gap widens on the side of the application of pressure. Thus, in the case of the sealing gap 67 of FIG. 7 h ₄ > h- ,, in the case of the sealing gap 68 of FIG. 8 h _g > h _[ -, in the case of the sealing gap 69 of FIG. 9 h "> h _? and in the case of the sealing gap 70 of FIG. 10

The correctness of these statements was determined by computer calculations confirmed. The sealing gap always widens on the pressurizing side and you get one with regard to the application of pressure, the sealing collar 36 is fully or at least partially balanced regardless of whether from which side the pressure is applied. the The sealing arrangement is thus insensitive to axial displacements and there is no need to maintain close tolerances.

It should also be mentioned that the difference between the inlet and outlet width of the sealing gap is very small, in certain cases is only approx. 10 µm «

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If the fluid pressure acts only in one direction, such as, for example, the pressure P in the device of FIG. 4, the annular groove 65 can also be omitted. The geometric configuration of the pressure areas A .. and A. _? is somewhat different here, as will be described in more detail in the case of the sealing collar 37 of FIG.

In Figs. 12 and 13 a device is shown with a sealing collar 74 which is only partially balanced and thus a variant of the fully balanced sealing collar 36 of FIG. That of the sealing surface 49 of the distributor 28 opposite end face 75 of the sealing collar 74 has two annular grooves 76 and 77, which have a radially arranged groove 78 and 79 with the pressurized volume V. and V "on the outside and inside of the Sealing collar 74 are connected. As a result, the pressure difference between the groove 76 and the volume V. as well as the Pressure difference between the groove 77 and the volume V " equals zero.

For the embodiment of FIG. 12, FIG. 14 shows the size of the force fields T _{D acting on surfaces A 11 and A.} and T ₀₀ . The at the surfaces A_. and A _{00 of} the sealing gap 80 acting counterpressure indicates the size of the force field T _n . Since the area A ", the sum of A and

fcSlo 1 JLl

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A. "Is greater than the area A" (the sum of A _? And A "2) results in a force pressing the sealing collar 74 against the surface 49 of the sealing gap, as can be seen from the diagram of FIG. 14a showing _{the resulting force field T B17} can be seen.

The sealing gap 18 is narrower in the partially balanced sealing collar 74 than the sealing gap 69 of the fully balanced sealing collar 36 according to FIG. 9, whereby the leakage is less.

By changing the mutual radial distance between the two annular grooves 76 and 77, the degree of pressure equalization can be changed. Such a change in the ratio of the areas A _? . and A "" causes a change in the pressure acting on the sealing collar 74 in the direction of the sealing surface 49.

Reference numbers 81 to 88 correspond to those above indicated reference numbers 51 to 54 and 63 to 66.

15 shows in an enlarged section of the FIG. In detail the installation of the outer axial sealing collar 37, in particular in the area of the surface 89 of the sealing collar 37 delimiting the sealing gap 91 and of the surface.

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before 90 of the distributor 28. The sealing collar 37 has a stepped recess on its inner surface 92 with a radial shoulder surface 93 and a cylindrical surface 94. Between the surface 94 aes sealing collar 37 and an annular groove 95 in the surface 96 of the connecting flange there is an annular space 97 , which enables the sealing collar 37 to move axially in the connecting flange 23. A plastic ring 98 with a rectangular profile is inserted into this annular space for the purpose of static sealing, and a plastic ring with a square profile or an O-ring can also be used in its place. In the former case, a spring element in the form of an annular spring 99 is provided, which is arranged in an annular gap 100 between a recess 101 of the connecting flange 23 and the rear face 102 of the sealing collar 37 in order to bias the sealing collar 37 against the sealing surface 90 of the distributor 28 cause. In the connecting flange 23 a dowel pin 39 is inserted, which extends into a groove 103 of the sealing collar 37, whereby the latter is secured against rotation.

The outer surface 104 of the sealing collar 37 has a slightly smaller diameter than the inner surface of the cylinder block 30 to allow the fluid to be drained to the drain passage 106. The sealing collar also has an inclined surface on its front side

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107 to form a replacement oil chamber 108 when drained.

On the side of the pressurization exhibiting the pressure P, the sealing gap 91 has the width h.- ,, on the opposite _{side exhibiting the pressure P fi} , the width h ₁₄ . The oil pressure P also prevails in the opening between the radial shoulder surface 93 of the sealing collar 37 and the end face 109 of the connecting flange 23 and with a certain reduction in the spaces 97 and 100, which means that by appropriate dimensioning of the sealing collar 37 on this for the purpose of sealing a complete or at least partial pressure equalization can be achieved with respect to the sealing surface 90, as has already been explained above with regard to the inner axial sealing collar 36. The sealing collar 37 is also dimensioned so that when it is acted upon by the compressive forces F7 and F8 acting on the surfaces 92 and 94, the result is that the gap width h ^ _{3 is greater than ^ 14} ? which is advantageous for the resulting print image.

The outer sealing collar 37 does not need to have grooves, as the inner sealing collar 36 in the form of Grooves 65 or 87, since it is only from one direction and only in one direction of rotation of the hydraulic machine from Pressure is applied. With the opposite turning

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direction, channel 46-47 represents the drainage channel with the lower pressure.

There is no need for further explanations that the outer sealing collar 37 due to analogous, with respect to the inner Sealing collar 36 hired considerations can be carried out completely or partially balanced. Also can outer sealing collar 37 have annular grooves and radially arranged grooves opening into these, as is the case for the case of the inner sealing collar 74, FIGS. 12 and 13 show.

In FIGS. 6 to 11 as well as 14 and 15, for the sake of clarity, the hydraulic pressures on the cylinder _{surfaces of the sealing collars are shown by force arrows F to F fi} instead of partial pressure forces distributed over the entire surfaces. In FIGS. 6 to 11 and FIG. 14, the sealing element 60 has also been omitted.

The structural design of the device can differ from the embodiment shown in the figures, without affecting their function. For example, the rotation lock of the sealing collar 36 can also be on in another way, for example by means of projections of the sealing collar engaging in recesses in the connecting flange 23 36 can be effected.

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Claims (13)

DR.-ING. EUGEN MAIER DR.-ING. ECKHARD WOLF PATE NTAISi iAFAlTE APPROVED REPRESENTATIVE BEFORE THE EUROPEAN PATENT OFFICE DRESDNER BANK AQ TELEPHONE: (0711) 242761/2 STUTTGART N R. 1 920 534 TELEGRAMS: MENTOR 7 STUTTGART 1, P I S C H E K S TR. 1 9 POSTSCHECK STQT. 25200-7O8 A 12 469 i - dm October 2, 1980 Aktiebolaget Hägglund & Söner S-891 01 Örnsköldsvik Device for hydrodynamic sealing of rotating machine parts Expectations Ij device for hydrodynamic sealing of a stationary or rotatable first machine part under fluid pressure from a rotatable second machine part, for example a hydraulic machine, with at least one sealing element under static pressure of an elastic element, characterized in that the stationary or rotatable first machine part (23) has a have at least one ring shoulder (51,52,81,82,93) - 2 130013/08 5 9 - 2 - A 12 469 i - dm October 2, 1980 37.74)
send sealing member (36, / assigned and the ring shoulder surface or the ring shoulder surfaces are acted upon by an axial fluid pressure acting in the direction of the gap to be sealed (50, 67, 68, 69, 70, 80, 91), which is caused by the opposite those to be sealed 89) Gap delimiting surface (48.75, / of the sealing element (36.37, 74) acting axial pressure of the fluid is compensated. 2. Apparatus according to claim 1, characterized in that the sealing member consists of a sealing collar (36,37,74) which is elongated in the axial direction and is axially movable in or on the first machine part (23). 3. Apparatus according to claim 1 or 2, characterized in that the sealing member (36,37,74) by means of an annular spring element (61, 99) in the direction of the gap to be sealed (50,67, 68,69,70,80,91) delimiting surface (49,90) of the rotatable second machine part (28) is biased. 4. Apparatus according to claim 3, characterized in that the sealing member (36, 37,74) by means of a dowel pin (38,39) engaging in a groove (63,85,103) of the sealing member, and there- 130019/08 5 9 - 3 - A 12 469 i - dm October 2, 1980 with the ring-shaped spring element (61,99) and the static seal (60,98) secured against rotary movement are. 5. Device according to one of claims 1 to 4, characterized in that the first machine part (23) which is provided by at least one ring 74) shoulder (51,52,93) of the sealing member (36,37, / formed Areas (53,54,83,84,94) correspondingly designed and interacting with these areas, step-like arranged surfaces (57,58,96). 6. Apparatus according to claim 5, characterized in that between one through at least one cylindrical inner surface (57, 96) of the first machine part (23) and one bounded by an annular shoulder correspondingly limited cylindrical outer surface 37.74) (54,94) of the sealing member (36, / an annular space (59,97) is formed in which the static sealing element (60,98) for sealing either axially rearward facing surfaces (54.58; 58.84; 94.96) or axially forward facing surfaces (53.57; 83.57) is arranged. 7. Apparatus according to claim 5 or 6, characterized in that the stair step 1 3001 9/0859 -A- - 4 - A 12 469 i - dm October 2, 1980 shaped surfaces (57,58) in the first machine part (23) are recesses and that the step-shaped arranged surfaces (53,54; 83,84) of the sealing member (36,74) are rotations on the outside of the sealing member. 8. Apparatus according to claim 5 or 6, characterized in that the step-shaped arranged surfaces (96) of the first machine part are (23) a turn / and the step-like arranged The surface (94) of the sealing element (37) is an extension on the inside thereof. 9. Device according to one of claims 1 to 7, characterized in that the surface (75) of the sealing member (74) facing the gap (80) to be sealed has one or more annular grooves (76, 77) which, via radial grooves (78, 79) are each connected to a pressurized volume (V ₁ , V ") of the device. 10. Device according to one of claims 1 to 9, characterized in that the Sealing member (36,74) in its axially central area by recessing an annular groove (65,87) on its cylindri- 130019/0855 - 5 - A 12 469 i - dm October 2, 1980 see inner surface (64,86) a narrowed cross-sectional zone having. 11. The device according to claim 10, characterized in that optionally the cylindrical Outer surface (53,54,66; 83,84,88) or the cylindrical inner surface (64,86) of the sealing member (36,74) is acted upon by the fluid pressure. 12. Device according to one of claims 1 to 9, characterized by a shape an inner sealing collar (36,74) and one having the shape of an outer sealing collar (37) Sealing member, of which the inner sealing collar (36, 74) is the outside against the inside and vice versa seals, while the outer sealing collar (37) is only provided for sealing from one side. 13. The apparatus according to claim 12, characterized in that the outer sealing collar (37) has an inner recess (94) at its end facing away from the gap (91) to be sealed, the Pressurization causes deformation of the sealing collar (37) and causes the gap (91) to widen on the side where pressure is applied. 130019/0859