The invention relates to a vacuum valve comprising a valve housing which has a vacuum region in the interior, a closure unit which is arranged in the vacuum region of the valve housing and by which at least one valve opening is closable in a closed state of the vacuum valve, a longitudinal drive by which the closure unit is adjustable in a longitudinal direction for adjusting the closure unit between a position opening up the valve opening and a position covering the valve opening, a longitudinal guide for the displaceable guiding of the closure unit parallel to the longitudinal direction, said longitudinal guide having a guide rod extending parallel to the longitudinal direction, and at least one guide part, wherein the guide rod is attached to the valve housing, and the guide part to which the closure unit is attached is guided displaceably parallel to the longitudinal direction by the guide rod, or the at least one guide part is attached to the valve housing, and the guide rod to which the closure unit is attached is guided displaceably parallel to the longitudinal direction by the at least one guide part, and wherein the at least one guide part has at least one bearing element for the mounting of the guide part in relation to the guide rod so as to be displaceable parallel to the longitudinal direction or for the mounting of the guide rod in relation to the guide part so as to be displaceable parallel to the longitudinal direction.
U.S. Pat. No. 9,086,173 B2 reveals a vacuum valve, the closure unit of which has first and second valve plates which close opposite first and second valve openings in a valve housing in a closed state of the vacuum valve. The valve plates are supported by a supporting unit of the closure unit. The supporting unit is attached to a valve rod which is led out of the vacuum region of the valve housing. The valve openings are opened up in the open state of the vacuum valve.
In order to close the vacuum valve, the supporting unit is displaced by a longitudinal drive, which is arranged outside the vacuum region, in front of the valve opening by axial displacement of the valve rod, wherein the valve plates are still raised from the valve seats. The supporting unit is here guided displaceably in relation to the valve housing parallel to the longitudinal direction by longitudinal guides on opposite sides. The closure unit has transverse drive elements, by which the valve plates are consequently pressed against the valve seats.
Instead of transverse drive elements, spreading elements, such as wedge elements, rollers, etc., could also be present in order to press the two valve plates against the valve seats. This would then be brought about by the longitudinal drive after the supporting unit has run against an end stop during closing of the vacuum valve. Closure mechanisms of this type are known in diverse embodiments in the prior art.
Such vacuum valves are used in particular in vacuum systems for carrying out vacuum processes, especially in semiconductor technology or in coating technology, for example for producing screens. Substrates to be processed are guided here through such vacuum valves in order to transfer the substrates from one vacuum chamber into an adjacent vacuum chamber. In the case of relatively large plate-like substrates, the valve openings are of slot-shaped design, i.e. have a substantially greater length than width. With an increasing size of the substrates to be processed, transport of the substrates in a horizontal orientation becomes increasingly more difficult or no longer possible because of the risk of buckling. A vertical (upright or hanging) or approximately vertical transport of such substrates is therefore already known. For this purpose, the slot-shaped valve openings are oriented vertically or approximately vertically. The closure unit is oriented correspondingly for this purpose.
A vacuum valve of this type is revealed, for example, in AT 14814 U. In order to be able to carry out servicing of the valve in a simple manner, it is described in this document that the closure unit has at least one rail, by which the closure unit, hanging on the rail or standing on the rail, can be pulled out of the valve housing into a servicing position. For this purpose, either additional rails, along which the closure unit can be moved out of the valve housing, are fitted after removal of a housing part of the valve housing, or, for the longitudinal guidance of the closure unit in relation to the valve housing, there are telescopic rails, by which the closure unit can be pulled out of the valve housing.
A similar vacuum valve is also revealed in JP-3241456 B2.
U.S. Pat. No. 6,899,316 B2 reveals a vacuum valve in which the closure unit has only one valve plate in order to close a valve opening in the valve housing in the closed state of the vacuum valve. Analogously as in the case of the valve known from U.S. Pat. No. 9,086,173 B2, a longitudinal drive arranged outside the vacuum region, and transverse drive elements arranged on the closure unit are present. The closure unit is guided displaceably in the longitudinal direction in relation to the valve housing on opposite sides.
A closure of a valve opening of a valve housing could also be carried out merely by a linear movement of the closure member, in particular by a three-dimensional sealing surface, as is revealed, for example, in DE 37 17 724 A1 or U.S. Pat. No. 4,921,213 A.