VACUUM VALVE FOR CONTROLLING A FLOW AND FOR INTERRUPTING A FLOW PATH

Abstract

A vacuum valve, having a valve seat including a valve opening (axis (A)), and a first sealing surface around the valve opening and defines a first sealing plane (E.sub.S), having a valve disk with a second sealing surface corresponding to the first sealing surface and defining a second sealing plane (E.sub.T), additionally having a first coupling element, connected to the valve disk and comprising a receiving means and a drive unit coupled with the first coupling element and is configured to provide the valve disk adjustable from an open position to a closed position. The drive unit and the valve disk are configured to provide a fine control position, wherein the valve disk is tilted relative to the valve seat where E.sub.S and E.sub.T enclose a defined angle (α), and the seal abuts fully against one of the two sealing surfaces and in part against the other sealing surface.

Claims

1. A Vacuum valve, in particular a vacuum control valve, for controlling a volume flow or mass flow and for interrupting a flow path in a gas-tight manner, having a valve seat which comprises a valve opening, which defines an opening axis (A), and a first sealing surface which runs around the valve opening and defines a first sealing plane (E.sub.S), a valve disk for controlling the volume flow or mass flow and for interrupting the flow path, having a second sealing surface which corresponds to the first sealing surface, wherein the second sealing surface defines a second sealing plane (E.sub.T), the modifiable position of which is determined by a respective position and alignment of the valve disk, a first coupling element, which is connected to the valve disk and comprises a receiving means, for providing controlled guidance of the valve disk and a drive unit which is coupled with the first coupling element, in particular by means of the receiving means, and is configured in such a manner that the valve disk is adjustable from an open position, in which the valve disk and the valve seat are present in a contactless manner relative to one another, into a closed position, in which there is axially sealing contact between the first sealing surface and the second sealing surface as a result of a seal which lies between them, and in which the valve opening is closed in a gas-tight manner as a result, and back, at least substantially along a geometric longitudinal axis in a longitudinal closing direction, wherein the drive unit and the valve disk are configured and interact in such a manner, in particular are coupled in such a manner, that the valve disk is adjustable into a fine control position, wherein the valve disk is tilted in a defined manner relative to the valve seat in such a manner that the first sealing plane (E.sub.S) and the second sealing plane (E.sub.T) enclose a defined angle (α), and the seal abuts fully against the first or second sealing surface and abuts only in part against the respectively other sealing surface.

2. The vacuum valve according to claim 1, wherein the drive unit and the valve disk are configured and coupled in such a manner that when adjusting the valve disk from the open position into the closed position or from the closed position into the open position, the valve disk assumes the fine control position prior to reaching the closed position or rather prior to reaching the open position.

3. The vacuum valve according to claim 1, wherein the valve disk is positioned in the fine control position in such a manner that the second sealing plane (E.sub.T), which is defined by an extension of the second sealing surface, tilts to the opening axis (A) or to the longitudinal axis.

4. The vacuum valve according to claim 1, wherein the first sealing surface points in a direction parallel to the opening axis (A) or longitudinal axis and extends orthogonally to the opening axis (A) or longitudinal axis, or the first sealing surface points in a direction transversely to the opening axis (A) or longitudinal axis and tilted to a plane which extends orthogonally to the opening axis (A) or longitudinal axis.

5. The vacuum valve according to claim 1, wherein the first and the second sealing planes (E.sub.S, E.sub.T) enclose a defined angle (α) in the open position and in the fine control position, and the first and the second sealing planes (E.sub.S, E.sub.T) are aligned substantially parallel in the closed position.

6. The vacuum valve according to claim 1, wherein a second, several or a plurality of fine control positions of the valve disk are adjustable, in particular successively, wherein the angle (α.sub.n), which is enclosed in each case by the first and the second sealing planes (E.sub.S, E.sub.T), is different in each case, and the seal abuts fully in each case against one of the two sealing surfaces and abuts only in part against the other sealing surface.

7. The vacuum valve according to claim 6, wherein the fine control positions are adjustable in a controlled manner in each case individually or continuously and consequently an in particular continuous control of the volume flow or mass flow of a medium through the valve opening is providable.

8. The vacuum valve according to claim 1, wherein the first coupling element is configured as a cross member which extends transversely with respect to the opening axis (A) or to the longitudinal axis and is connected to the valve disk at the at least one connecting point on a rear side of the valve disk, wherein the receiving means provides a central coupling point for coupling the drive unit transversely with respect to a direction of extension of the cross member, and the cross member is connected to the drive unit by means of an adjustment arm which extends transversely with respect to the direction of extension.

9. The vacuum valve according to claim 8, wherein the connection between the cross member and the valve disk comprises a friction stir welding connection at the at least one connecting point.

10. The vacuum valve according to claim 8, wherein the cross member is connected to the valve disk on the rear side of the valve disk at least two lateral connecting points which are located on both sides of the central coupling point, is at a spacing from the rear side, in a central portion, which includes the central coupling point and portions which connect on both sides to said coupling point and extends between the lateral connecting points, is configured resiliently in such a manner that as a result of distortion of the cross member, the valve disk is pivotable relative to the adjustment arm about a pivot axis (S) which is at right angles to the opening axis (A) or to the longitudinal axis, and in particular is configured in one piece.

11. The vacuum valve according to claim 1, wherein the drive unit comprises at least one motor and at least one guide component, in particular guide rod, which is movable by means of the at least one motor in a controlled manner along or parallel to the longitudinal axis, and the valve disk is connected to the guide component by means of the receiving means and is movable relative to the valve seat.

12. The vacuum valve according to claim 11, wherein the drive unit comprises two guide components, in particular guide rods, which are movable by means of the at least one motor in a controlled manner parallel to the longitudinal axis.

13. The vacuum valve according to claim 12, wherein the valve disk comprises a second coupling element which is connected to it and has a receiving means, wherein the first and the second coupling elements are arranged directly on the valve disk, in particular are configured in one piece with the valve disk, and in each case a guide component is connected to a respective one of the receiving means of the first and of the second coupling elements.

14. The vacuum valve according to claim 12, wherein the drive unit comprises two motors and each of the two guide components is movable in a controlled manner by one of the motors, and the fine control position, in particular the plurality of fine control positions, is providable by means of a defined, in particular individual actuation of the two motors in such a manner that the tilt position of the first sealing plane relative to the second sealing plane can be brought about as a result.

15. The vacuum valve according to claim 12, wherein the vacuum valve comprises a bridge which connects the guide components, and the first coupling element is connected to the bridge and in particular is configured as a cross member.

Description

[0045] The device according to the invention is described in more detail below in a purely exemplary manner by way of specific exemplary embodiments which are shown schematically in the drawings, further advantages of the invention also being looked at. The figures are as follows:

[0046] FIGS. 1a-b show a first and a second embodiment of a vacuum valve according to the invention in an open position;

[0047] FIGS. 2a-b show the first and the second embodiments of a vacuum valve according to the invention in an fine control position;

[0048] FIGS. 3a-b show the first and the second embodiments of a vacuum valve according to the invention in a closed position;

[0049] FIGS. 4a-c show various perspectives of a third embodiment of a vacuum valve according to the invention in an open position and in a fine control position; and

[0050] FIGS. 5a-c show various perspectives of a fourth embodiment of a vacuum valve according to the invention in an open position and in a fine control position.

[0051] FIG. 1a shows a schematic view of a cross section through an embodiment of a vacuum valve 10 according to the invention in an open position. The valve 10 comprises a valve disk 11 as a closure element and a valve seat 12 which is situated opposite the valve disk 11. The valve seat 12 extends around and consequently defines a valve opening 16. The valve disk 11 is arranged so as to be movable relative to the valve seat 12, the mobility being provided at least along an opening axis A, which is defined by the opening 16, or along an axis B, which is defined by the alignment of the second sealing surface 14. The axes A and B coincide in the position shown on account of a parallel alignment of the disk 11 or rather of the sealing surface 14 thereof relative to the seat 12.

[0052] As an alternative to this, the valve disk 11 can also be aligned in the open position not parallel but at at an angle (tilt) relative to the valve seat 12.

[0053] Both the valve disk 11 and the valve seat 12 have in each case a sealing surface—a first sealing surface 13 and a second sealing surface 14. The first sealing surface 13 additionally comprises a seal 15. Said seal 15 can be cured onto the valve seat 12 for example as a polymer by means of vulcanization. As an alternative to this, the seal 15 can be configured, for example, as an O-ring seal in a groove of the valve seat 12. A sealing material can also be bonded onto the valve seat 12 and as a result embody the seal 15. In an alternative embodiment, the seal 15 can be arranged on the side of the valve disk 11, in particular on the second sealing surface 14. Combinations of said realizations are also conceivable.

[0054] The sealing surface 13 defines a first sealing plane E.sub.S for the valve seat 12 and the sealing surface 14 defines a second sealing plane E.sub.T for the valve disk 11. The position of the sealing planes E.sub.T and E.sub.S is consequently firstly dependent on the extension of the respective sealing surface and secondly on the current spatial alignment (and position) of the valve disk 11 or rather of the valve seat 12.

[0055] FIG. 1b shows a further embodiment of a valve 20 according to the invention in an open position. The valve 20 is designed in a similar manner to that from FIG. 1a.

[0056] In contrast, the seal 25 here is arranged on the side of the sealing surface 24 of the valve disk 21 and a corresponding sealing surface 23 is configured on the valve seat 22. The sealing surfaces 23 and 24 define, in turn, corresponding sealing planes E.sub.T and E.sub.S.

[0057] FIGS. 1a and 1b show respective valve realizations in a purely schematic manner. A drive unit for moving the valve disk 11 or rather 21 relative to the respective valve seat is not shown in either case. Such a drive unit typically comprises a motor, in particular a stepping motor or a servomotor. The valve disk can be coupled to the drive unit by means of a corresponding structure. Different realizations are possible for this according to the invention.

[0058] Firstly, the drive unit can comprise a push rod (guide rod) which is movable in a linear manner along a longitudinal axis by means of the motor. A first end of an adjustment arm is connected to the push rod, in particular angled transversely or orthogonally with respect to the rod. The connection between push rod and adjustment arm is configured in a rigid manner. A cross member, which extends transversely with respect to the adjustment arm and is connected, in turn, to the valve disk, is provided on a second, oppositely situated end. The cross member is configured resiliently in such a manner that the disk is pivotable about a pivot axis which is defined by the extension of the cross member. A desired pivotability of the disk and consequently the possibility of a desired tilt position and modification of the tilt of the disk relative to the valve seat are made possible, in this connection, as a result of the member being twisted.

[0059] A device with two guide components (push rods) can be configured as an alternative or also combinable design of the output for the valve disk. The disk has, in this connection, two receiving means which are arranged, in particular, on two oppositely situated sides with reference to the disk circumference. Each one of the receiving means has connected thereto one push rod. The drive of the push rods is effected in a preferred manner by means of two motors, but can also be implemented with at least one motor and one gearing unit. A tilt position and adjustment of the tilt position of the valve disk relative to the valve seat can also be provided in a controlled manner as a result of a linear movement of the push rods (with reference to the linear position of the push rods) which is not effected in parallel.

[0060] FIGS. 2a and 2b show the valve realizations according to FIGS. 1a and 1b not in the open position, but in a fine control position. In this connection, in each case the valve disks 11 or rather 21 are not aligned parallel to the valve seats 12 or rather 22, but are at a tilt relative to one another. The valves are configured (and where applicable controlled) such that such a fine control position can be reached and assumed in each case with a closing movement of the valve disk prior to reaching a closed position.

[0061] The sealing planes E.sub.T and E.sub.S are not present in parallel in this case and consequently intersect one another, an angle α being enclosed. Said desired tilt position, that is to say the opening angle α, can be varied by retaining at least partial contact with the seal 15 or rather 25 (here the left-hand side of the circumferential seal). Advantageous flow control is provided as a result. The smaller the angle α is adjusted to be, the smaller the possible flow rate per unit time of a medium. An advantage, in this case, is in particular that the angle α still remains adjustable in steps or continuously even in the case of relatively very small angles and a force, resulting from a pressure difference at the two valve disk sides (top and bottom), also varies continuously at the disk. As a result, a very precise closing or opening movement can be carried out, a continuously applied or interrupted flow of a medium being able to be controlled in particular when transitioning toward or from the closed position or into the control position.

[0062] In particular, when the angle is modified, the surface of the contacted seal also varies. As the angle becomes increasingly smaller, the contact surface of the sealing material becomes greater.

[0063] The control is advantageous in particular when a smaller pressure prevails at the bottom of the disk (in the direction of the valve seat) than at the top. As a result of the partial contacting between the valve disk and the valve seat (by means of the seal), part of the force acting on the disk (on account of the pressure difference) can already be absorbed by means of the contact surface and thus does not have to be absorbed by the valve drive or the disk mounting.

[0064] In the fine control position, the valve disk 11 or rather 21 can also be seen as a flap which, when contacting the valve seat 12 or rather 22, is turned or pivoted about an axis.

[0065] Different mechanical solutions are conceivable for providing the angled abutment of the valve disk 11 and 12 against the respective valve seats 12 and 22. As in vacuum technology in general and for vacuum valve solutions in particular, sealing solutions with an avoidance of or a clearly reduced risk of particle generation are to be preferred. To this end, an avoidance of a relative mobility of components, or, where such mobility is necessary, a bearing arrangement of components where possible without the occurrence of friction between the components is to be preferred.

[0066] Particle-avoiding driving and retaining solutions for the disk are consequently proposed according to the invention as in FIGS. 4 and 5 below. The linear mobility of the valve disk relative to the respective valve seat is, in this case, beyond doubt and has to be provided, however the aspect of the pivotability of the disk about a pivot axis for adjusting the tilt relative to the seat in the fine control position is, in this case, also to be considered and is achieved here according to the invention (avoidance of particle generation).

[0067] FIGS. 3a and 3b show the valves 10 and 20 in each case in a sealed closed position in which a flow of a medium through the valve opening 16 or 26 is completely interrupted on account of the sealing action which is provided fully by the seal 15 or rather 25. Each seal 15 or 25 is, in this case, in full contact with the oppositely situated corresponding sealing surface of the opposite side, i.e. over the entire circumference about the valve opening, and presses to a pre-determined degree. The sealing planes E.sub.T and E.sub.S are present in parallel.

[0068] FIGS. 4a and 4b show an embodiment according to the invention of a vacuum valve 30 in an open position. The valve disk 31 is positioned in a parallel manner at a spacing from the valve seat 32 and exposes the valve opening 36.

[0069] A seal 35 is mounted on the sealing surface 33 of the valve seat 32. The progression of the sealing surface 33 defines a sealing plane E.sub.S.

[0070] The valve disk 31 is connected to an adjustment arm 37 by means of a coupling element which is configured as a cross member 38. The progression of the sealing surface of the valve disk 31, which is located opposite the sealing surface 33 of the valve seat 32 and corresponds with the same as regards form and size, defines the sealing plane E.sub.T. In the open position, the sealing planes E.sub.T and E.sub.S are aligned parallel to one another.

[0071] The cross member 38 defines, by means of the extension thereof transversely with respect to the adjustment arm 37, a pivot axis S which also extends transversely with respect to the adjustment arm 37. The cross member 38 is connected fixedly (here: screw-connected) to the adjustment arm 37 in the center region of said cross member and fixedly to the valve disk 31 at the ends of said cross member. However, the respective fastenings can also be produced in an alternative manner, e.g. by means of bolts or a weld (e.g. friction stir weld). In particular, the adjustment arm 37 and the cross member 38 can be configured in one piece.

[0072] The cross member 38, itself, is formed in such a manner that it provides a certain material elasticity and, as a result, is twistable about the pivot axis S within a pre-defined range (e.g. with reference to an angle of twist and force absorption) in a substantially wear-free manner.

[0073] The adjustment arm 37 is connected to the drive unit 39 by means of a push rod or guide rod. The disk 31 can be moved in a linear manner along the extension of the push rod by means of the drive 39.

[0074] FIG. 4c shows the valve 30 in a fine control position. The valve disk 31 is partially in contact with the seal 35. On the shown right-hand side of the cross section through the disk 31, there is no contact between the disk 31 and the seal 35. The valve disk 31 is therefore not aligned parallel to the valve seat 32. The sealing planes E.sub.T and E.sub.S intersect at a defined angle α.

[0075] The shown fine control position can be produced as a result of the connection between the cross member 38 and the adjustment arm 37 being configured so as to be pivotable (in a controlled manner). When the valve disk 31 moves closer to the valve seat 32, a slight pivoting can be set up and maintained (fixed). As an alternative to this, the disk 31 can be fastened by means of the cross member 38 in such a manner that the disk 31 is not parallel to the valve seat 32 in the open position, but already comprises a relative tilt position. The sealing planes E.sub.T and E.sub.S, in this case, are correspondingly not parallel, but enclose a certain angle α.

[0076] The disk 31, as a result of the linear approaching movement, then abuts in a correspondingly tilted manner against the seat 32. As a result of further linear adjustment by means of the drive 39, the tilt of the disk 31 can be modified by twisting the cross member 38. If the push rod is therefore retracted further, the opening angle α becomes smaller. In this case, the cross member 38 is acted upon by way of an inner torsion, i.e. is twisted. As a result, a continuously modifiable and, in this case, homogeneously maintained pressing of the disk sealing surface on the seal 35 can be provided. This can result in the complete closure of the opening 36 such that, here too, with regard to the seal progression, the seal is pressed in a homogeneous manner.

[0077] The cross member consequently enables continuous (or stepwise) modification of the tilt position as a result of being twisted, the seal 35 being pressed in a homogenous manner. Particle generation is additionally minimized or completely prevented as a result of the seal being pressed in a homogeneous manner and as a result of consequently no transverse load being effected on the seal.

[0078] As an alternative to the tilt position at the connection between the adjustment arm 37 and the cross member 38, the tilt position of the disk 31 relative to the seat 32 can also be provided by means of pivoting or by means of a permanent tilt position of the push rod. The effect provided then by the cross member corresponds to the aforenamed variant.

[0079] FIGS. 5a and 5b show a further embodiment according to the invention of a vacuum valve 40 in an open position. The valve disk 41 is positioned in a parallel manner at a spacing to the valve seat 42 and exposes the valve opening 46.

[0080] In contrast to a realization according to FIGS. 4a-c, the valve disk 41 is arranged so as to be movable relative to the valve seat 42 by means of two guide rods 47 which can each be moved in a controlled manner by way of a motor of a drive unit 49. The seal 45 is situated on the bottom surface of the disk 41. The respective sealing surfaces define, in turn, the sealing planes E.sub.T and E.sub.S.

[0081] The guide rods 47 are connected to the receiving means of two coupling elements 48. The coupling elements 48 are configured here in one piece with the valve disk 41, however, it is obvious that the coupling elements 48 can also be designed as separate components, said coupling elements being able to be screw-connected or welded, e.g., to the disk 41.

[0082] For adjusting a certain fine control position as shown in FIG. 5c, the two driving parts 49a and 49b of the drive 49 can be actuated correspondingly in an individual manner. One of the two driving parts 49a, 49b, in this case, generates a distance travelled for one of the guide rods 47 which is greater than the distance provided by the second drive for the other guide rod 47 within the same time period. In other words, one of the guide rods 47 is retracted quicker than the other at least over a certain time period. As an alternative to this, the linear movement produced by way of the first drive can be started earlier than that produced by way of the second drive, the drives providing a substantially synchronous movement as a result.

[0083] A valve disk 41 which is tilted relative to the valve seat 42 is produced as a result. The valve disk 41 or rather the seal 45 thereof is contacted (in part) by the valve seat 42 with said tilt position which is adjustable in this manner (FIG. 5c). Once a first end position has been reached with the first guide rod 47, which is guided faster or rather further, the control of a flow or rather of a stream through the valve opening 46 can be provided just by displacing the second guide rod 47 further in a linear manner. The first end position can correspond substantially to the position of the disk 41 where there is contact between the seal 45 and the valve seat. It is obvious, however, that once contact has been made a further linear displacement can be effected in order to achieve a desired pressing of the sealing material 45. The first and also a second end position can therefore also correspond with a generating of a desired seal compression.

[0084] It is obvious that the figures shown only show possible exemplary embodiments in a schematic manner. According to the invention, the different approaches can also be combined with one another and with methods and devices for controlling a volume flow or pressure in a process volume under vacuum conditions of the prior art.