Sealing system of a device for allowing the passage of a medium, in particular in the high pressure range

Abstract

Sealing system of a device for allowing the passage of a medium, in particular in the high pressure range, is provided with a housing that has a bore hole, a component mounted within the housing such as to oscillate and/or rotate and with a pressure chamber formed within the bore hole. A sealing element surrounding the component adjoins this pressure chamber which can be charged with the medium. An additional metal seal is formed here by the housing and a pressure disc surrounding the component. The outer region is thus tightly closed after the sealing element. In this way, the sealing element is completely tightly encapsulated on the outside.

Claims

1. A sealing system of a device for allowing the passage of a medium, comprising a housing that has a bore hole, a component mounted within the housing such as to oscillate and/or rotate and with a pressure chamber formed within the bore hole which can be charged with the medium, adjoining which is at least one sealing element which surrounds the component, wherein an additional metal seal is formed by the housing and a pressure disc surrounding the component, or that the housing itself surrounds the component, and so the outer region is tightly closed after the sealing element.

2. The sealing system according to claim 1, wherein the sealing element is pressed into the cylindrical bore hole of the housing and borders the pressure chamber with it one front side so that it is charged with medium in the operational state.

3. The sealing system according to claim 1, wherein the sealing element is formed annularly with conically tapering front sides, the conicity of which is such that the sealing element can be pressed against a correspondingly conically formed support surface of the pressure disc such as to form a seal.

4. The sealing system according to claim 1, wherein the sealing element is formed annularly with front sides aligned almost perpendicularly to the longitudinal axis of the bore hole and can be pressed against a support surface of the pressure disc that is inclined correspondingly perpendicularly to the longitudinal axis of the bore hole such as to form a seal.

5. The sealing system according to claim 1, wherein the sealing element is produced as a soft seal made of plastic material.

6. The sealing system according to claim 1, wherein the sealing element is provided on the outside with at least one 0-ring as an auxiliary seal.

7. The sealing system according to claim 1, wherein the housing, which itself surrounds the component, the sealing element is pushed through the pressure chamber into the bore hole, for this purpose the housing being able to be opened by a valve seat block in the bore hole.

8. The sealing system according to claim 1, wherein the metal seal is formed by two opposing sealing surfaces of the housing and of the pressure disc, the angle of inclination of the sealing surfaces differing from one another by a small angular amount, by means of which the formation of a circular sealing edge is brought about on the inside.

9. The sealing system according to claim 8, wherein the opposing sealing surfaces are inclined at an angle of 30? to 60? to the longitudinal axis of the bore hole.

10. The sealing system according to claim 8, wherein the opposing sealing surfaces of the metal seal are aligned at an angle of approximately 90? perpendicular to the longitudinal axis of the bore hole.

11. The sealing system according to claim 1, wherein a reinforcement element is assigned to the sealing element on the front side bordering the pressure chamber so that the outer region of the sealing element is protected from the high flow speed of the fluid flowing through.

12. The sealing system according to claim 11, wherein the reinforcement element comprises a metal ring.

13. The sealing system according to claim 1, wherein the moveably mounted component and/or the bore hole of the pressure disc or of the housing that guides the component is/are provided with a coating.

14. The sealing system according to claim 13, wherein the sleeve-shaped component of the shaft pipe is provided with a coating.

15. The sealing system according to claim 13, wherein a PVD- or PACVD-based coating is used.

16. The sealing system according to claim 1, wherein the sealing system of the device is configured to allow the passage of a medium in a high pressure range.

17. The sealing system according to claim 1, wherein the additional metal seal is formed by the housing and the pressure disc surrounding the component.

18. The sealing system according to claim 1, wherein the housing itself surrounds the component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In the following, the invention will be explained in more detail with reference to two exemplary embodiments with reference to the drawings. These show as follows:

[0019] FIG. 1 is a longitudinal section of a sealing system according to the invention of a high pressure valve as a device;

[0020] FIG. 2 is a partial longitudinal section of the sealing system of the high pressure valve according to FIG. 1;

[0021] FIG. 3 is a detail of the metal seal according to FIG. 2, shown enlarged;

[0022] FIG. 4 is a partial longitudinal section of a sealing system according to the invention of a cutting head as a device; and

[0023] FIG. 5 is a longitudinal section of a sealing system according to the invention of a swivel joint as a device.

DETAILED DESCRIPTION OF THE INVENTION

[0024] FIG. 1 and FIG. 2 show a device of a high pressure valve 1 operating as a spindle valve which can be used, for example, for a cutting head with a water nozzle for cutting materials with a water jet at high pressure.

[0025] This high pressure valve 1 comprises of a housing 2 with a pressure chamber 3, a spindle nut 6 with a component provided as a valve needle 5, as well as a spindle 4 that can be operated manually or mechanically, for example pneumatically, by means of which the valve needle 5 can be pressed against a valve seat 8 within the housing 2. Moreover, the housing 2 has a water inlet 9 and outlet 10 or vice versa, which, when the valve is open, can be connected to one another via a channel 11. In addition, a pressure disc 12 with a bore hole 13 for guiding the valve needle 5 when closing and opening the high pressure valve is disposed in the housing 2.

[0026] In the sealing system according to the invention, a sealing element 14 surrounding the valve needle 5 and in the form of an annular soft seal made of plastic is disposed between the pressure chamber 3 and the pressure disc 12 in the bore hole 13 provided in the housing, and in addition, the outer region 14 of the sealing element 14 is closed tightly by a metal seal 17.

[0027] This metal seal 17 is brought about with opposing sealing surfaces 15a, 15b of the housing and of the pressure disc 12 pressed against the housing. Therefore, the sealing point on the external diameter of the sealing element, which is normally required, is dispensed with, and the sealing function of the sealing element 14 is restricted primarily to the less problematic internal diameter of the soft seal.

[0028] These sealing surfaces 15a, 15b are advantageously arranged at an angle of inclination of preferably 30? to 60?, for example 45? as shown, to the longitudinal axis of the guide bore hole 13. The sealing element 14 has on its part conically tapering front sides, the conicity of which is formed such that they can be pressed against a correspondingly conically formed support surface 18 of the pressure disc 12 such as to form a seal. In this way, it is possible to re-adjust the seal within a larger range by the liquid pressure pressing further into the cone when the sealing element 14 is worn in order to preserve the sealing function. However, the angle of inclination may also vary within specific limits depending on the individual case.

[0029] According to FIG. 2, a reinforcement element, preferably a metal ring 7, is assigned to the sealing element 14 on the front side bordering the pressure chamber 3. The outer region 14 of the sealing element 14 is thus protected against the high flow speed of the fluid flowing through.

[0030] According to FIG. 3, the angles of inclination of the sealing surfaces 15a, 15b differ from one another by a small angular amount 16 so that the metal seal 17 is produced on the inside in the form of a circular sealing edge 17. By means of the metal seal produced in this way, plastic deformation of the materials can be achieved at this sealing edge 17, and so the sealing element 14 is completely tightly encapsulated on the outside, and a perfect seal is permanently guaranteed, even at the highest pressures.

[0031] The sealing system according to the invention according to FIG. 4 only differs from that according to FIG. 1 in that in the former, the housing 2 and the pressure disc are more or less produced from a single piece, and consequently the housing 2 itself surrounds and supports this valve needle 5 forming the component. This simplifies the production of these parts, and the function of the spindle nut 6 as a means of supporting and pressing the pressure disc 12 against the counter surface of the housing is also dispensed with. The sealing element 14 is designed annularly with conically tapering front sides 14a, 14b, the outer region on the front side 14b merging into the inner region on the valve needle 5, and so an optimal seal is achieved.

[0032] The sealing element 14 is advantageously pressed onto the component 5 in the cylindrical bore hole 13 of the housing 2 both on the outside and on the inside. With its lower front side 14a, it borders the pressure chamber 3 so that it is charged with medium in the operational state. A valve seat block 8 which can be removed from the housing 2 and be exchanged and which comprises the valve seat 8 for the valve needle makes it possible to push the sealing element 14 into the bore hole 13 when the latter is removed. This valve seat block 8 is only partially illustrated.

[0033] The swivel joint 20 shown in FIG. 5 is a component part of a device with a high pressure jet of water, preferably used for cleaning objects or for use with robots for cutting objects, in which frequent rotational movements take place. This swivel joint 20 consists essentially of a multi-part housing 22 with a housing cover 21, a water inlet 29 and a pressure chamber 24, as well as, moreover, a shaft pipe 26 with a ball bearing 27, guided within a bore hole 25, a pressure disc 28, a connector 23 and a sealing element 30 which is inserted in a widened region of the bore hole 25.

[0034] According to the invention, an additional metal seal 33 is formed by the housing 22 and this pressure disc 28 that surrounds the sleeve-shaped component 26, and so the outer region 30 is tightly closed after the sealing element 30.

[0035] The sealing element 30 is advantageously likewise produced as a soft seal made of plastic material. The metal seal 33 on its part is formed by two opposing sealing surfaces 31a, 31b of the cylindrical housing part and of the pressure disc 28. Advantageously, the angles of inclination of the sealing surfaces 31a, 31b are likewise arranged such that they differ from one another by a small angular amount so that a circular sealing edge is formed on the inside. In addition, the pressure disc 28 is formed conically to the outside.

[0036] Unlike the metal seal 17 according to FIG. 1, the sealing surfaces 31a, 31b run at approximately 90? to the longitudinal axis of the bore hole 25. Another difference is that the contact surfaces of the sealing element 30 and of the pressure disc 28 are not conical, but are also inclined approximately perpendicularly to the longitudinal axis of the bore hole 25.

[0037] The sealing element 30 is additionally equipped with an 0-ring 32 disposed on the outside as an auxiliary seal in order to alternatively form an outer seal in addition to the metal seal.

[0038] The sleeve-shaped component 26 of the shaft pipe is advantageously provided with a coating on the outside so that it slides better within the bore hole 25. Preferably, a PVD- or PACVD-(Plasma Assisted Chemical Vapor Deposition) based coating is used.

[0039] In principle, the component 5 provided as a valve needle and/or the borehole 13, 25, which guides this respective component, of the pressure disc 12, 28 or of the housing 2 could also be provided with this coating.

[0040] The invention is sufficiently displayed by the exemplary embodiments described above. However, it could, needless to say, also be explained by further versions, such as for example one for sealing the piston of a high pressure pump in which a piston that can be moved to and fro is provided as the component.

[0041] These sealing systems according to the invention are particularly suitable for moving components which have small diameters of only a few millimetres and must work with media which are allowed to pass through at a particularly high pressure of a several thousands bar. In practice, the sealing system has proven its worth, in particular at pressures of over 4000 bar. It can be charged with pressures over 6200 bar, and could theoretically be charged to over 10,000 bar.