EP3140550B1 - Sealing assembly for a high-pressure pump and high-pressure pump with the same - Google Patents

Description

The invention relates to a sealing arrangement for sealing a pressure chamber in a high-pressure pump and a high-pressure pump with such a sealing arrangement.

The pressure chamber in a pump, in which the pressurized fluid to be pumped by the pump is located, must be sealed from its environment. In this case, the environment of the pressure chamber may be the usually under atmospheric pressure environment of the pump or-for example in the case of a multi-stage pump - another pressure chamber of the pump, in which the fluid to be delivered is at a higher or lower pressure.

The greater the pressure generated by the pump, the more difficult it becomes to provide efficient and reliable sealing arrangements. At high pressures, for example, up to 1000 bar delivery pressure, there are often pressure-related strains or deformations of the pump housing or other components. These can have the consequence that open between column, which limit the same pressure chamber, for example, between pump housing and pump cover, column. Such gaps, which incidentally may also occur due to different thermal expansions of the components, must then be reliably sealed in order to prevent leakage of the fluid through the gaps.

The pressure-induced opening of such gaps can be avoided, for example, or at least limited to an uncritical measure by the components between which the gap arises, so stiff - and that usually means so thick-walled - are designed so that even at very high pressures only small gaps arise that the functionality of the seal assembly is not compromised. But this has the disadvantage that much more material is needed for the thick-walled design and that the pump has considerably more mass. Both are rather disadvantageous economic consequences.

Therefore, efforts are being made to provide sealing arrangements which seal reliably and efficiently even at very high pressures. In many sealing arrangements, an O-ring is provided, which is typically inserted into a groove of a sealing surface. In the international (PCT) patent application PCT / EP2012 / 071654 For example, a seal arrangement is proposed in which in one of the components between which the seal is to take place, a groove-shaped recess is provided, which is aligned so that when a pressure is applied to the groove, a force is exerted in the direction of the sealing surface of this component, which presses this sealing surface against the sealing surface of its adjacent component. In this case, the pressurization of the groove cause elastic or plastic deformation of its wall, so as to avoid or reduce the pressure-induced opening of gaps between the components. In one of the two contacting sealing surfaces an existing of an elastomer O-ring is provided, which is arranged in a groove provided in this sealing surface. This O-ring is a reliable seal between the two contacting sealing surfaces.

Especially with sealing arrangements with O-rings there is a risk of extrusion of the O-ring. By this is meant that the O-ring is deformed under pressure such that a part of it is pressed into a pressure-opening gap, which may result in damage to the O-ring and thus a loss of sealing effect.

A generic seal arrangement for sealing a pressure chamber in a turbomachine is also in the US Pat. No. 4,239,124 and the DE 696 21 545 T2 shown.

Based on this prior art, it is therefore an object of the invention to propose a sealing arrangement for sealing a pressure chamber in a high-pressure pump, which operates reliably even at very high pressures and in particular an extrusion of a sealing ring, especially an O-ring in a pressure-opening gap is prevented. Furthermore, it is an object of the invention to propose a high-pressure pump with such a sealing arrangement.

The problem-solving objects of the invention are characterized by the features of the independent claims of each category.

According to the invention, therefore, a sealing arrangement is proposed for sealing a pressure chamber in a high-pressure pump, which is delimited by a first and a second limiting element, with a separate sealing element having a first sealing surface for cooperation with the first limiting element and a second sealing surface for cooperation with the second limiting element wherein the two sealing surfaces are inclined relative to each other and each having a groove for receiving a sealing ring, and wherein the sealing element is arranged and configured so that it is displaceable in total along one of the limiting elements when pressure is applied.

In this seal arrangement, consequently, the entire sealing element can move when pressurized along one of the limiting elements. This causes a pressure-opening gap between the two limiting elements to be reliably covered by the displacement of the sealing element by the sealing element, so that extrusion of a sealing ring into the opening gap is avoided. This ensures an efficient sealing effect even at very high pressures of, for example, up to 1000 bar.

The provision of a separate sealing element with the grooves for receiving sealing rings also has the advantage that for this Sealing element, a different material can be selected as, for example, the material from which the boundary elements are made. Therefore, a material can be selected for the sealing element whose mechanical properties, such. B. the elastic properties are as optimal as possible under the pressure load.

Preferably, the two sealing surfaces of the sealing element enclose an angle of substantially 90 °. This measure is particularly advantageous for the displaceability of the sealing element under pressure load.

An advantageous measure is when a support ring is provided for positioning the sealing element, in particular in the unpressurized state. This makes it possible to realize that the sealing element has a defined initial position or starting position, so that it reacts in the desired manner under pressure load.

In a preferred embodiment, the support ring is in the non-pressurized state on a support surface of the sealing element, wherein the support surface is different from the two sealing surfaces of the sealing element. In this way it is ensured that the sealing element can move when pressurized by the support ring without obstruction.

According to a particularly preferred embodiment, which has proven itself in practice, the sealing element has a substantially L-shaped cross section with a long leg, which forms the first sealing surface, and with a short leg, which forms the second sealing surface.

Preferably, the sealing element is arranged displaceably along the second limiting element. This is particularly preferred in the embodiment with the substantially L-shaped cross section. The pressurized surface of the sealing element formed by the long leg is larger than the pressure-applied area formed by the short leg. This results from the pressure of a greater force on the first leg formed by the long leg, so that the sealing element is reliably displaced by this larger force along the second limiting element, which cooperates with the sealing surface formed by the shorter leg.

It is particularly preferred if the sealing element is displaceably arranged along the first and the second limiting element, because this allows the sealing element to follow pressure-induced displacements or bulges of both the first and the second limiting element. Hereby, in a high-pressure pump, a reliable seal can be realized both in the radial direction and in the axial direction.

A further advantageous measure consists in that the first sealing surface between the groove provided in it and its end facing the second sealing surface is conical. By this is meant that the first sealing surface is designed bevelled starting from the groove provided in it starting in the direction of the contact line between the two sealing surfaces. As a result, the first sealing surface moves away from the groove in the direction of the contact line farther and farther from the first limiting element. This measure ensures that the edge which delimits the groove in the first sealing surface and is closer to the contact line first comes into contact with the first limiting element when pressure is applied, and that at this edge or in the region of this edge the highest Surface pressure occurs. This measure provides additional security that an inserted in the groove sealing ring, z. As an O-ring, undergoes an extrusion when pressurized.

For the same reason, it is advantageous if the second sealing surface between the groove provided in it and its end facing the first sealing surface is conical.

In practice, it has proven useful when the angle of the cone is at most 2 °, preferably at most 1 °.

According to a preferred embodiment, the seal assembly is configured as a radial seal arrangement.

The invention further proposes a high-pressure pump with a sealing arrangement according to the invention. By this seal arrangement, the high-pressure pump can be operated safely and reliably even at very high pressures of, for example, up to 1000 bar.

In a preferred embodiment, the high-pressure pump is provided with a pump cover and a pump housing, wherein the seal assembly is provided for sealing between the pump cover and the pump housing.

According to a preferred application, the high pressure pump is designed as a multi-stage pump.

In a preferred embodiment of the high-pressure pump, the sealing arrangement is provided for sealing between a pressure chamber and an intermediate pressure chamber.

Another preferred embodiment of the high pressure pump is when the seal assembly is provided for sealing between a separator and the pump housing or between the pump cover and the pump housing.

Further advantageous measures and embodiments of the invention will become apparent from the dependent claims.

Fig. 1:

eine Schnittdarstellung eines Ausführungsbeispiels einer erfindungsgemässen Dichtungsanordnung,

Fig. 2:

eine schematische Darstellung einer ersten Variante für die Anordnung des Dichtungselements,

Fig. 3:

eine schematische Darstellung einer zweiten Variante für die Anordnung des Dichtungselements,

Fig. 4:

eine schematische Darstellung einer dritten Variante für die Anordnung von Dichtungselementen,

Fig. 5:

eine schematische Darstellung einer vierten Variante für die Anordnung von Dichtungselementen, und

Fig.6:

eine schematische Darstellung eines Ausführungsbeispiels einer erfindungsgemässen Hochdruckpumpe.

In the following the invention will be explained in more detail by means of embodiments and with reference to the drawing. In the schematic drawing show, partly in section:

Fig. 1:

a sectional view of an embodiment of an inventive seal assembly,

Fig. 2:

a schematic representation of a first variant of the arrangement of the sealing element,

3:

a schematic representation of a second variant for the arrangement of the sealing element,

4:

a schematic representation of a third variant for the arrangement of sealing elements,

Fig. 5:

a schematic representation of a fourth variant for the arrangement of sealing elements, and

Figure 6:

a schematic representation of an embodiment of an inventive high-pressure pump.

Fig. 1 shows a schematic sectional view of an embodiment of an inventive seal assembly, which is generally designated by the reference numeral 1 and for sealing a pressure chamber 2 in a high-pressure pump 100 (see Fig. 6 ) serves. The pressure chamber 2 is bounded by a first limiting element 3 and a second limiting element 4. The sealing arrangement 1 further comprises a separate sealing element 5, which has a first sealing surface 51 for co-operation with the first limiting element 3 and a second sealing surface 52 for co-operation with the second limiting element 4. By the term "separate sealing element" is meant that the sealing element 5 is not an integral part of, for example, one of the limiting elements 3, 4, but is designed as a separate component.

As can be clearly seen, the illustration in Fig. 1 only a part of the seal assembly 1, namely, for example, the upper half. In a high-pressure pump 100, the sealing element 5 is generally designed rotationally symmetrical with respect to the pump shaft, which in Fig. 1 is indicated by a rotation axis A, around which rotate the rotating parts of the pump in the operating state. That is, the sealing element 5 is usually designed annular. In Fig. 1 Thus, only a cross section through the annular sealing element 5 is shown. Also, the pressure chamber 2 is usually designed as an annular space surrounding the pump shaft.

In each of the two sealing surfaces 51, 52 of the sealing element 5 is provided in each case a groove, namely a first groove 53 and a second groove 54, each of which serves to receive a sealing ring 55, which is configured for example as an O-ring. The sealing rings 55 are used in a manner known per se for sealing between the respective sealing surface 51 or 52 and the limiting element 3 or 4 cooperating therewith and are e.g. made of an elastomeric material.

It is understood that the sealing rings can be other known sealing means, for example metallic rings or washers or sealants made of a plastic such as PTFE or PEEK.

Like this Fig. 1 shows, the two sealing surfaces 51, 52 of the sealing member 5 are inclined towards each other and adjoin one another along a contact line 56. In particular, close in this embodiment, the two sealing surfaces 51, 52 an angle of substantially 90 °. The sealing element 5 according Fig. 1 has a substantially L-shaped cross section with a long leg 57, which forms the first sealing surface 51 and cooperates with the first limiting element 3, and with a short leg 58, which forms the second sealing surface 52 and cooperates with the second limiting element 4.

According to the invention, the sealing element 5 is arranged and designed so that it is displaceable overall at least along one of the limiting elements 3, 4 when pressure is applied. This will be explained below with reference to Fig. 1 explained.

In the unpressurized state, ie when there is no overpressure in the pressure chamber 2 relative to its surroundings, the first limiting element 3 rests on the boundary surface 43 of the second limiting element 4. This can be realized in a pump, for example, in that the component which forms the first limiting element 3, with the component which forms the second limiting element 4, is firmly screwed. If now in the pressure chamber 2, an ever higher pressure is generated, it can by Pressure-induced deformations, for example bulges, of the first or the second limiting element 3 or 4 happen that a gap 6 opens between the limiting elements 3, 4. This condition is in Fig. 1 shown. Since the pressure in the pressure chamber 3 also acts on the sealing element 5 and this is displaceable along the second limiting element 4, the entire sealing element 5 moves upward as shown and thereby closes the gap 6 with respect to the pressure chamber 2, so that no fluid from the pressure chamber 2 through can escape the gap 6, but the sealing effect is maintained even at very high pressures.

If the second limiting element 4 shifts under the action of the pressure in the pressure chamber 2 relative to the first limiting element 3 along the interface 43, for example as shown in FIG Fig. 1 to the left, the sealing element 5 can also follow this movement, namely, by the sealing element 5 shifting in its entirety along the first limiting element 3. During this displacement, the substantially annular sealing element 5 expands.

With reference to the axis of rotation A, the sealing element 5 can thus be positioned both in the radial direction and in the illustration in FIG Fig. 1 to the top (or bottom) - as well as in the axial direction - so in accordance with illustration in Fig. 1 move to the right (or to the left). The displacement in the axial direction is of course accompanied by a widening of the substantially annular sealing element 5.

By this displaceability in both the axial and in the radial direction not only column 6 between the boundary elements 3 and 4 are closed, but it is also advantageously avoided that between the first sealing surface 51 and the first limiting element 3 or between the second sealing surface 52 and the second limiting element 4 opens or forms a gap when pressure is applied.

By this displaceability of the sealing element 5 is thus ensured that even at very high pressures in the pressure chamber 2, for example, up to 1000 bar, a reliable sealing of the pressure chamber 2 is realized.

In particular, the radial displaceability of the sealing element 5 ensures that the pressure-opening gap 6 between the two limiting elements 3 and 4 is reliably closed by the sealing element 5. By closing the gap 6 through the sealing element 5, extrusion of the sealing rings 55, in particular the O-rings 55, into the gap 6 is effectively prevented.

When the sealing element 5 is pressurized, its displaceability is usually combined with a deformation of the sealing element 5, i. In addition to or during the displacement of the sealing element 5, this can also deform. This deformation is preferably an elastic deformation, i. a deformation that is completely reversible when depressurized. Since the sealing element 5 is configured as a separate component, that is, for example, is not an integral part of one of the limiting elements 3, 4, one has the greatest possible freedom with regard to the choice of material for the sealing element 5. Thus, a material can be selected for the sealing element 5, which is optimal in terms of its elastic properties for the particular application. As a particularly preferred material for the sealing element 5, titanium has been found.

In order to realize an even higher protection of the sealing rings 55 and the O-rings 55 against extrusion, the measures described below are advantageous.

The first sealing surface 51 is configured conically between the first groove 53 and the contact line 56, at which the two sealing surfaces 51, 52 abut one another such that in the pressureless state, the distance between the first sealing surface 51 and the first limiting element 3 at that Boundary edge of the first groove 53 closer to the contact line 56 (in FIG Fig. 1 the illustration according to the left Begrenzungskannte), is minimal and then enlarged in the direction of the contact line 56. This bevel of the first sealing surface 51 is in Fig. 1 shown and the associated angle of the cone is denoted by α. By this measure, it is ensured that of the long leg 57 at a pressurization of the sealing element 5 as the first of these according to the illustration, the left boundary edge of the first groove 53 or the region at this boundary edge comes into contact with the first delimiting element 3 and that there (based on the first sealing surface 51) the highest surface pressure prevails. This makes it even better possible to avoid extrusion of the sealing ring 55 from the first groove 53 between the first sealing surface 51 and the first limiting element 3.

Preferably, the second sealing surface 52 between the second groove 54 and the contact line 56, at which the two sealing surfaces 51, 52 abut each other, conical in such a way that in the pressureless state, the distance between the second sealing surface 52 and the second limiting element. 4 at the boundary edge of the second groove 54, which is closer to the contact line 56 (in Fig. 1 the upper bounded edge according to the illustration), is minimal and then increases in the direction of the contact line 56. This bevel of the second sealing surface 52 is in Fig. 1 shown and the associated angle of the cone is denoted by β. By this measure it is ensured that of the short leg 58 at a pressurization of the sealing element 5 as the first upper boundary edge of the second groove 54 and the area at this boundary edge comes into contact with the second limiting element 4 and that there (based on the second sealing surface 52), the highest surface pressure prevails. This makes it even better possible to avoid extrusion of the sealing ring 55 from the second groove 54 between the second sealing surface 52 and the second limiting element 4.

Another optional advantageous measure is when the long leg 57 or the short leg 58 or preferably both legs 57, 58 in the area between the first and second groove 53, 54 and the end facing away from the contact line 56 each cylindrical (that is not conical or not inclined) are designed and cut back. In Fig. 1 This is evident from the fact that these regions each extend parallel to the first or second limiting element 3, 4 and have a larger distance from the first or second limiting element 3, 4 than the respective boundary edge of the first and second groove 53, 54, the closer to the contact line 56 is located. This measure also supports the effect that the respectively greatest surface pressure of the first or second sealing surface 51, 52 occurs in the region of the boundary edge of the first and second groove 53, 54 which is closer to the contact line 56.

The two angles α and β of the respective cone of the first and the second sealing surface 51, 52 may be the same or different. In practice, it has proven useful if α and β are in each case at most 2 ° and preferably at most 1 °. In particular, values between 0.1 ° and 0.2 ° have also proven suitable for α and β.

It is understood that by the seal assembly 1 not only pressure-induced but in a similar manner also thermally induced gaps, such as may be caused by different thermal expansion coefficients of adjacent components, can be closed by the displacement of the sealing element 5.

In addition to the L-shaped cross section of the sealing element 5 described here, of course, other geometries for the cross section of the sealing element possible, for example, the two legs 57 and 58 may also have the same length, so that the cross-sectional area is an isosceles angle profile, or it may be rounded be.

In the following description of various variants for the arrangement of the sealing element 5 and an embodiment of a high-pressure pump according to the invention are equal in function to the same or equivalent parts with the same reference numerals as in Fig. 1 and have those related to Fig. 1 explained meaning. For the sake of better overview is in the Fig. 2-6 the description of various details has been omitted. Thus, for example, provided in the grooves 53 and 54 sealing ring 55, which are preferably configured as O-rings, not shown. Also related to Fig. 1 described conical configuration of the sealing surfaces 51, 52 is in the Fig. 2-6 not shown. It is understood, however, that all measures taken in the Related to Fig. 1 are described, such as the cutting back and the cylindrical configuration of the sealing surfaces 51, 52 in the region between the first and second groove 53, 54 and their end facing away from the contact line 56, in a manner similar to the in the Fig. 2-6 illustrated embodiments may each be realized individually or in any combination with each other. Conversely, those associated with the Fig. 2-6 Explanations made in the same way analogously for the embodiment according to Fig. 1 and for the other embodiments of the Fig. 2-6 ,

In Fig. 2 a first variant for the arrangement of the sealing element 5 is shown. In particular, this is an arrangement for the radial seal that can be used in a multi-stage pump. In multi-stage pumps, especially those with a so-called back-to-back arrangement (see also Fig. 6 ) exists between the pressure at the inlet of the pump, for example atmospheric pressure, and the highest pressure in the pressure chamber 2, which is usually connected to the outlet of the pump, at least one intermediate pressure, which in a back-to-back arrangement typically in the middle between the Pressure at the entrance and the highest pressure in the pressure chamber 2 is, so for example, the pressure at the entrance to be atmospheric pressure, the pressure in the pressure chamber 2 is about 1000 bar and the intermediate pressure is 500 bar. In Fig. 2 In addition to the pressure chamber 2, two intermediate pressure chambers 7 and 8 are provided, in which the pressure of the fluid to be delivered is in each case about half as large as in the pressure chamber 2 Fig. 2 the variant shown, the first limiting element 3 is designed as a pump housing 3 and the second limiting element 4 serves the separation between the two intermediate pressure chambers 7, 8 and the respective separation of each of the intermediate pressure chambers 7, 8 from the pressure chamber 2. There are two sealing elements 5, each part a radial sealing arrangement and of which one sealing element 5 of the seal between the pressure chamber 2 and the intermediate pressure chamber 7 and the other sealing element of the seal between the pressure chamber 2 and the intermediate pressure chamber 8 is used. In addition to the in Fig. 1 Components described in each case a support ring 9 is provided in these seal assemblies, whose function is the positioning of the respective Dichtungselemnts 5 is in the depressurized state. The Sützring 9 may for example be designed as a split ring, that is, consist of two or more segments, for example, placed in the pressure chamber 2 and bolted to its wall. In this case, the support ring 9 is screwed or fastened with respect to the sealing element 5 with play, because the support ring 9 is the sealing element 5 only position, but not jamming or prevent the displaceability of the sealing member 5 in an undesirable manner or affect. The support ring 9 does not have a sealing function, it should only ensure that the sealing element 5 is in the pressureless state in a defined position.

In the embodiment shown here, the support ring 9 each has a substantially L-shaped cross section. With one of the legs of the L, the support ring is supported on the inner wall of the pressure chamber 2, the other leg forms the surface which supports the sealing element 5 in the unpressurized state. The support surface of the sealing element 5, which rests against the support ring in the pressureless state, is in each case the end face of the long leg 57 of the sealing element 5.

Now, if the pressure chamber 2 is pressurized, it can lead to a buckling or other expansion of the pump housing 3, which can open a gap between the pump housing 3 and the second limiting element 4. This will be - as related to Fig. 1 explained by the displacement of the sealing elements 5 effectively closed.

It is understood that even in the Fig. 1 illustrated embodiment and in the embodiments according to Fig. 3-6 in a similar manner a support ring 9 may be provided.

In Fig. 3 a second variant of the arrangement of the sealing element 5 is shown. In this variant, the sealing element 5 serves for sealing between the pump housing, which here represents the first limiting element 3, and a pump cover, which here represents the second limiting element 4. Typically, the pump cover 4 is with a plurality of screws 41 screwed to the pump housing 3, of which in Fig. 3 only one is shown there is typically outside of the pump housing 3 atmospheric pressure, while in the pressure chamber 2, an elevated pressure prevails. At very high pressures in the pressure chamber 2, the pump cover 4 bulges, whereby a gap between the pump housing 3 and the pump cover 4 opens. Since the sealing element 5 in the axial direction - ie in the direction of the axis of rotation A - can move, the sealing element shifts under pressure as shown to the right and thus reliably closes the gap between the pump cover 4 and the pump housing 3. In addition, the pump housing 3 also stretch, so to speak expand. This movement can also follow the sealing element 5, because it is also displaceable with respect to the radial direction. This displacement with respect to the radial direction is generally accompanied by a widening of the sealing element 5, since the inner diameter also increases when the pump housing 3 expands in the radial direction.

The term that the sealing element is "displaceably arranged" is therefore to be understood in the context of this application as meaning also an expansion or expansion of an annular sealing element.

At the in Fig. 4 illustrated third variant, the sealing element 5 is used to seal the pressure chamber 2 of a pump against an intermediate pressure chamber 7. In the pressure chamber 2, the maximum pressure prevails, for example 1000 bar, and in the intermediate pressure chamber 7 there is any intermediate pressure which is between the atmospheric pressure or the ambient pressure and the pressure in the pressure chamber 2, for example, the intermediate pressure is half the pressure in the pressure chamber second In this variant, the pump housing forms the first limiting element 3. The second limiting element 4 is a component, for example a separating element 4, which delimits the intermediate pressure chamber 7 from the pressure chamber 2.

In the Fig. 5 illustrated fourth variant for the arrangement of sealing elements 5 is similar to the in Fig. 2 shown. This arrangement is especially suitable for multi-stage pumps in back-to-back arrangements. These pumps have two substantially identical blocks, each of which can contain multiple stages of pumps. These two blocks are mirror images - ie back to back - arranged to each other, so that the pressure chamber 2, in which the highest pressure prevails and which is connected to the outlet of the pump, is usually arranged as an annular space in the middle of the pump. In this variant, two sealing elements 5 are provided. The first limiting element 3 is formed by the pump housing 3, while the second limiting element 4 as a separating element is the dividing wall between the two blocks arranged back to back. Outside the pump housing 3, the atmospheric or ambient pressure prevails and in the two intermediate pressure chambers 7 and 8 there is substantially the same pressure, which is typically half as large is like the pressure in the pressure chamber 2.

In Fig. 6 is schematically and in section an embodiment of an inventive high-pressure pump shown, which is generally designated by the reference numeral 100. The high-pressure pump 100 is a multi-stage - here four-stage - high-pressure pump with back-to-back arrangement, which is designed as a radial centrifugal pump. The high-pressure pump 100 has a pump housing 103, a pump cover 112 for closing the pump housing 103, an inlet 110 through which the fluid to be delivered, for example, a liquid such as water or petroleum, enters the high-pressure pump 100 and an outlet 111 through which then pressurized fluid leaves the high pressure pump 100. For driving the high-pressure pump 100, a pump shaft 113 is provided, which rotates in the operating state about the axis of rotation A and is driven by a drive unit, not shown.

The high-pressure pump 100 has four essentially identically designed stages, namely a first stage 114, a second stage 115, a third stage 116 and a fourth stage 117. Each of these stages 114-117 has an impeller 120, respectively. Each impeller 120 is non-rotatable with the pump shaft 113 connected. The first and second stages 114, 115 belong to a first one Block 130. The third and fourth stages 116, 117 belong to a second block 140. The two blocks 130, 140 are separated from each other by a partition 104 which is fixed with respect to the pump housing 103. The two essentially identically configured blocks 130, 140 are arranged in mirror image with respect to the separating element 104, ie, back to back, which is why this structure is also referred to as a back-to-back arrangement.

The flow path of the fluid through the high-pressure pump 100 is in Fig. 6 represented by arrows, of which only the first at the inlet 110 is designated by the reference numeral 150. The fluid flows from the input 110 in the axial direction to the impeller 120 of the first stage 114 and is guided from the outlet in the axial direction to the impeller of the second stage 115. From the output of the second stage 115, which also forms the output of the first block 130, the fluid is passed through a flow connection 160, which is provided in the separating element 104, into an intermediate pressure chamber 108 of the second block 140, through which the fluid flows to the inlet of the second block 140 third stage 116 passes. From the output of the third stage 116, the fluid is conducted in the axial direction to the input of the fourth stage 117, which finally promotes the fluid to the high pressure with which it is available at the outlet 111 of the high-pressure pump 100. From the output of the fourth stage 117, a high pressure flow connection 170 leads to the pressure chamber 102, which is connected to the outlet 111 of the high pressure pump 100. The pressure chamber 102 is configured essentially as an annular space, which leads around the separating element 104 radially outward.

Also in the first block 130, an intermediate pressure chamber 107 is provided, which is designed substantially as an annular space and arranged on the inside of the pump housing 103. This intermediate pressure space 107 is connected via an in Fig. 6 Flow connection, not shown, connected to the output of the second stage 115, so that in the two intermediate pressure chambers 107 and 108, the same pressure prevails, which corresponds due to the substantially same configuration of the four stages 114-117, about half the pressure of the pressure in the pressure chamber 2.

Like this the arrows in Fig. 6 clarify flows through the fluid with respect to the axial direction of the second block 140 in the reverse direction as the According to the illustration, the first block 130 flows through from right to left, while the second block flows through from left to right.

The separating element 104 adjoins, on the one hand, the pressure chamber 102, in which the highest pressure acts, and, on the other hand, the two intermediate pressure chambers 107 and 108, in which an approximately half the pressure acts as in the pressure chamber 2 Fig. 2 illustrated configuration. For sealing the pressure chamber 102 against the intermediate pressure chambers 107 and 108, a sealing element 5 is provided in each case, which forms an embodiment of the inventive sealing arrangement 1 with the adjacent boundary elements. In Fig. 6 the pump housing 103 forms the first limiting element 3 and the separating element forms the second limiting element 4. This sealing arrangement 1 is suitable for very high pressures. For example, the pressure in the pressure chamber 102 may be 1000 bar. Then, the pressure in the intermediate pressure spaces 107 and 108 is about 500 bar each.

It is understood that the seal assembly 1 according to the invention can also be used in other places a high-pressure pump. At the in Fig. 6 illustrated embodiment, for example, at the boundary between the pump cover 112 and the pump housing 103, a sealing element 5 may be provided.

Claims (15)

1. A sealing arrangement for sealing a pressure chamber (2) in a high pressure pump, the pressure chamber (2) being bounded by a first and a second bounding element (3, 4), having a separate sealing element (5) which has a first sealing surface (51) for cooperating with the first bounding element (3), as well as having a second sealing surface (52) for cooperating with the second bounding element (4); wherein the two sealing surfaces (51, 52) are inclined with respect to one another; and wherein the sealing element (5) is arranged and configured in such a way that it can be displaced totally along one of the bounding elements (3, 4) on the application of a pressure characterized in that the two sealing surfaces (51, 52) each have a groove (53, 54) for the reception of a sealing ring (55).
2. A sealing arrangement in accordance with claim 1, in which the two sealing surfaces (51, 52) of the sealing element (5) include an angle of substantially 90°.
3. A sealing arrangement in accordance with any one of the preceding claims, in which a support ring (9) is provided for positioning the sealing element (5), in particular in the pressure-less state.
4. An apparatus in accordance with claim 3, in which the support ring (9) contacts a support surface of the sealing element (5) in the pressure-less state, wherein the support surface is different from the two sealing surfaces (51, 52) of the sealing element (5).
5. A sealing arrangement in accordance with any one of the preceding claims, wherein the sealing element (5) has a substantially L-shaped cross-section having a long shank (57) which forms the first sealing surface (51) and having a short shank (58) which forms the second sealing surface (52).
6. A sealing arrangement in accordance with any one of the preceding claims, wherein the sealing element (5) is arranged in a displaceable manner along the first and the second bounding elements (3, 4).
7. A sealing arrangement in accordance with any one of the preceding claims, in which the first sealing surface (51) is conically formed between the groove (53) provided therein and its end facing the second sealing surface (52).
8. A sealing arrangement in accordance with any one of the preceding claims, in which the second sealing surface (52) is conically formed between the groove (54) provided therein and its end facing the first sealing surface (51).
9. A sealing arrangement in accordance with claim 7 or claim 8, wherein the angle of the cone (α, β) respectively amounts to at most 2°, preferably to at most 1°.
10. A sealing arrangement in accordance with any one of the preceding claims, configured as a radial seal arrangement.
11. A high pressure pump having a sealing arrangement in accordance with any one of the preceding claims.
12. A high pressure pump in accordance with claim 11, comprising a pump cover (4) and a pump housing (3), wherein the sealing arrangement (1) is provided for sealing between the pump cover and the pump housing.
13. A high pressure pump in accordance with claim 11 or claim 12, configured as a multi-stage pump.
14. A high pressure pump in accordance with any one of the claims 11 to 13, wherein the sealing arrangement (1) is provided for sealing between a pressure chamber (102) and an intermediate pressure chamber (107, 108).
15. A high pressure pump in accordance with any one of the claims 11 to 14, wherein the sealing arrangement (5) is provided for sealing between a separation element (104) and the pump housing (103) or between the pump cover (112) and the pump housing (103).

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