Vacuum device

Abstract

To provide a vacuum device which comprises, e.g., a cartridge vacuum pump and a vacuum chamber, and in which a simple and efficient seal between sections having respective different pressure levels is achieved.SOLUTION: A vacuum device (100) comprises an inner wall 118 and an outer wall 122. The outer wall surrounds the inner wall such that a gap 130 is formed between the inner wall and the outer wall. The gap includes at least one sealing region 134, in which the gap has a predetermined distance between the inner wall and the outer wall. The at least one sealing region is arranged between two areas 132, 138 of the gap. In the two areas, the respective distances between the inner wall and the outer wall are greater than the predetermined distance between the inner wall and the outer wall in the sealing region.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vacuum appliance comprising an inner wall and an outer wall, the outer wall surrounding the inner wall such that a gap is formed between the inner wall and the outer wall, the gap forming at least one sealing area. [Background technology]

[0002] Vacuum pumps are usually stand-alone units. They have their own housing and can be connected to a vacuum chamber or to another vacuum pump, for example via a flange connection at the inlet opening of the housing. Furthermore, so-called cartridge vacuum pumps exist. Cartridge vacuum pumps can be fitted into the outer wall of a vacuum chamber such that this outer wall forms part of the housing of the so-called vacuum pump.

[0003] Such cartridge construction types are used, for example, in so-called split-flow turbomolecular pumps, which, in addition to the main intake, have further intake openings or ports, by which different pumps at different pressure levels can be realized. The additional ports are typically arranged laterally in such pumps, i.e. laterally with respect to the axis of rotation of the rotor of the turbomolecular pump.

[0004] However, various parts of such a vacuum pump, which are at different pressure levels during operation of the vacuum pump, must be sealed from one another to avoid or at least reduce backflow within the vacuum pump. To seal the parts of the vacuum pump, each with its respective intake opening or port, from one another, orbiting elastomeric seals are usually used. The elastomeric seals are configured, for example, as O-rings and are pressurized axially, i.e. parallel to the axis of rotation of the rotor of the vacuum pump.

[0005] Due to the circular elastomer seal, a relatively large gap width between the cartridge vacuum pump and the vacuum chamber can be selected in such a cartridge vacuum pump, so that a reliable and relatively simple assembly of such a cartridge vacuum pump is possible, since there is a sufficient gap between the cartridge vacuum pump and the vacuum chamber.

[0006] When using such axially pressurized elastomeric seals, a disadvantage is that a stepped "fir tree" shape of the cartridge housing of the vacuum pump is required, in which the diameter of each part of the vacuum pump increases in the axial direction starting from the low pressure side, so that various parts or sealing planes of the vacuum chamber are engaged with respective opposing surfaces in the vacuum chamber for sealing. Therefore, such a "fir tree" shape of the cartridge housing of the vacuum pump requires a relatively large construction space.

[0007] Radially pressurized seals between various parts of the cartridge vacuum pump at various pressure levels may be arranged at approximately the same diameter relative to the axis of rotation of the rotor, but such radially pressurized seals would require tangential displacement to engage the seals, resulting in relatively strong frictional forces during insertion of such a cartridge vacuum pump into a vacuum chamber, which are often too strong in practice and may even lead to pinching of the various parts of the vacuum pump and vacuum chamber.

[0008] However, since cartridge vacuum pumps with radially pressurized seals allow for a compact construction of the vacuum pump with reduced construction space, consideration has been given to a special coating of the elastomeric seals, for example with PTFE (Teflon®), as described, for example, in WO 2018 / 229473. However, the special coating of the elastomeric seals requires additional effort. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] International Publication No. 2018 / 229473 Summary of the Invention [Problem to be solved by the invention]

[0010] It is an object of the present invention to provide a vacuum device, for example comprising a cartridge vacuum pump and a vacuum chamber, which achieves a simple and efficient seal between parts at different pressure levels. [Means for solving the problem]

[0011] This problem is solved by a vacuum device having the features of claim 1. Advantageous developments of the invention are described in the dependent claims, the description and the drawings.

[0012] The vacuum device comprises an inner wall and an outer wall surrounding the inner wall such that a gap is formed between the inner wall and the outer wall, the gap having at least one seal area, the gap having a predetermined distance between the inner wall and the outer wall in the seal area, the seal area being disposed between two areas of the gap, the respective distances between the inner wall and the outer wall in the two areas being greater than the predetermined distance between the inner wall and the outer wall in the seal area.

[0013] A sealing area is arranged between two regions of the gap, and during operation of the vacuum equipment, a higher pressure exists in at least one of the two regions of the gap than in the other one of the two regions. The sealing area therefore represents a gap seal, which is formed simply by the inner and outer walls of the vacuum equipment and does not require an elastomeric seal, for example in the form of an O-ring, or other sealing material. The vacuum equipment therefore has at least one such gap seal. However, this does not exclude the vacuum equipment having further seals in addition to such a gap seal.

[0014] The predetermined spacing may have a value of up to one to two tenths of a millimeter, with values ​​of less than 50 micrometers being preferred, and may be approximately zero, so that the inner and outer walls at least partially meet around their circumference.

[0015] In the sealing area, the gap between the inner wall and the opposing outer wall has a width smaller than the width of the gap in the two outer areas of the sealing area. Since the gap seal or the sealing area of ​​the gap is formed by narrowing the gap or reducing the distance between the inner wall and the outer wall, the extension of the gap may continue continuously through the sealing area, without, for example, having to expand the circumference of the inner wall and / or the outer wall over the sealing area. If the inner wall is formed, for example, by a cartridge vacuum pump with a rotor having an axially extending axis of rotation, the sealing area may extend approximately parallel to the axial direction.

[0016] Thus, in the vacuum appliance according to the invention, the circumference of the inner wall does not need to be increased to form the sealing area, so that no additional constructional space is required for sealing between the areas between which the sealing area is located. In particular, the constructional space for the vacuum appliance is reduced, for example, in comparison with the vacuum appliance described at the beginning, which has a stepped "fir-tree" cartridge housing of the vacuum pump forming the inner wall of the vacuum appliance. Furthermore, no additional elements, such as, for example, specially coated elastomer seals, are required for the sealing area, since the sealing area is formed exclusively by the inner and outer walls as a gap seal.

[0017] According to an embodiment, the vacuum equipment may comprise a vacuum pump having an inner wall and a vacuum chamber having an outer wall. The outer wall of the vacuum chamber may be configured to accommodate the inner wall of the vacuum pump. In other words, the vacuum equipment may have a cartridge vacuum pump, which in this embodiment is fitted or inserted into the vacuum chamber. A sealing area may be provided between at least two pump stages of the vacuum pump. The sealing area thus forms a gap seal here, which is formed exclusively by the inner wall of the vacuum pump and the outer wall of the vacuum chamber, without the need for a separate sealing element. This allows an efficient seal between the pump stages of the vacuum pump. The seal requires only a small construction space relative to the vacuum pump.

[0018] The vacuum pump may further comprise a plurality of pump stages, for example three or more pump stages, and a respective sealing area may be provided between each two pump stages of the vacuum pump. Furthermore, an intermediate suction may be provided in the axial area between each two pump stages of the vacuum pump.

[0019] The intermediate suction may be arranged, for example, in the axial direction of the vacuum pump, near at least one sealing area or between two sealing areas separating two pump stages of the vacuum pump from each other, each at a different pressure level. Alternatively, the intermediate suction may be arranged between a gap seal having a sealing area formed by an inner wall and an outer wall of the vacuum equipment and an elastomeric seal defining a pump stage of the vacuum pump at a higher pressure level compared to at least one other pump stage. Such an elastomeric seal, unlike the gap seal, may be axially pressurized between the inner wall and the outer wall of the vacuum equipment.

[0020] According to another embodiment, a plurality of sealing areas may be arranged along the gap. The sealing areas, like the gap between the inner and outer walls, extend substantially axially, e.g. substantially parallel to the rotation axis of the rotor of the vacuum pump. Furthermore, the plurality of sealing areas may be centered with respect to such rotation axis of the rotor of the vacuum pump. The plurality of sealing areas allows, for example, a stepped transition between various pump stages of the vacuum pump, which are at different pressure levels, i.e., for example, from a high vacuum region to a medium vacuum region, which is at a very high pressure level.

[0021] A sealing area is arranged between two regions of the gap, and the sealing area may extend at an angle to at least one of the two regions of the gap, in which case the sealing area may extend, in particular outside the sealing area, perpendicular to at least one of the two regions or in the same direction as these two regions. The predetermined angle may therefore be 90° or 0° in this special case. Furthermore, an oblique or conical extension of the gap in the sealing area is possible, i.e. it may extend at an angle of approximately 45° to at least one of the regions outside the sealing area.

[0022] For example, when a cartridge vacuum pump is inserted into a vacuum chamber and the inner and outer walls of the vacuum equipment, e.g. the inner wall of the vacuum pump and the outer wall of the vacuum chamber, come into contact with each other, a conical arrangement of the sealing area, i.e. the sealing area extends perpendicularly in a step at about 45° to the axial direction, can be advantageous, which generates small or negligible shear forces and thus reduces the friction forces between the inner and outer walls.

[0023] Furthermore, an additional seal may be arranged between the gap and an external region of the vacuum equipment where atmospheric pressure is present. Such an additional seal may thus be located outside the sealing region forming the gap seal, for example in the axial direction of the vacuum pump, and seals the gap seal against atmospheric pressure. This additional seal may be, for example, an elastomeric seal in the form of an O-ring. However, in such an embodiment, the vacuum equipment only requires a single additional seal to insulate the gap seal or the sealing region at a lower pressure level.

[0024] According to another embodiment, at least one sealing area between the inner and outer walls of the vacuum device may have a metal contact between the inner and outer walls. Such a metal contact may be referred to as a "support point" of a cartridge vacuum pump in a vacuum chamber, for example. A metal contact may be advantageous if the vacuum device is provided for ultra-high vacuum regions, for example, since a metal seal has significantly better outgassing properties than an elastomer seal, for example. Furthermore, a metal contact may improve the transfer of heat, which may be advantageous, for example, when heating the vacuum device.

[0025] Alternatively, the inner and outer walls may not be provided with metal contacts. The sealing area or areas may be set in such an embodiment with respect to the spacing between the inner and outer walls such that the respective sealing area or the respective gap seal is adapted to the desired pressure difference through the respective sealing area. Additionally, an elastomeric seal may be provided to seal against ambient pressure, i.e. as a so-called last seal before the transition to the space outside the vacuum equipment. When the inner and outer walls of the vacuum equipment are not provided with metal contacts, vibration isolation may be achieved, for example, between the vacuum chamber of the vacuum equipment and the vacuum pump.

[0026] According to another embodiment, the ratio of the length of the sealing area along the gap to the predefined distance between the inner and outer walls in the sealing area is greater than 5, preferably greater than 10. The predefined distance may also be referred to as the height of the seal gap in the direction perpendicular to the inner and outer walls. The greater the length of the sealing area along the gap or gap in the sealing area in ratio to the predefined distance or gap height in the sealing area, the lower the vacuum-technical conductance of the sealing area and, conversely, the increased sealing action.

[0027] The gap height in the sealing area or the predetermined distance between the inner and outer walls in the sealing area may be 0.2MM or less, preferably 0.05MM or less. The required setting of the predetermined distance or gap height in the sealing area depends on the required seal, i.e., the pressure differential required through the respective sealing area, as well as on the backflow, type of gas, internal pumping speed of the pump and the resulting gas load.

[0028] However, it has been found that practical applications require narrow gap dimensions of 0.2MM or less in the sealing area. A very small predetermined spacing between the inner and outer walls in the sealing area, for example less than 0.05MM, can be achieved by reducing the tolerances of the components and improving the surface quality of the inner and outer walls. However, the smaller the predetermined spacing selected, the higher the manufacturing costs of the corresponding components of the vacuum equipment that form the inner and outer walls.

[0029] The predetermined clearance between the inner wall and the outer wall may occupy a value of, for example, 0.05MM to less than 0.1MM, 0.1MM to less than 0.15MM, or 0.15MM to less than 0.2MM in the sealing area. Since the outer wall surrounds the inner wall and the inner wall may orbit, for example in an annular manner, around the longitudinal axis of the vacuum pump, the actual clearance between the inner wall and the outer wall may vary, i.e. may not be of a constant size, around the circumference of the outer wall. Thus, the predetermined clearance between the inner wall and the outer wall may be an average value of the gap size around the circumference of the outer wall relative to the inner wall. The aforementioned ranges of the predetermined clearance or gap width in the sealing area therefore relate to the average value of this gap size around the circumference of the inner wall and the outer wall, respectively.

[0030] Furthermore, the length of the sealing area along the gap may be greater than 5MM, preferably greater than 40MM. Alternatively, the length of the sealing area along the gap may be less than 5MM, but in this case the predetermined distance between the inner and outer walls in the sealing area must be very small, for example less than 0.05MM, so as to provide the lowest possible vacuum-technical conductance for a sufficient seal across the sealing area. Furthermore, the length of the sealing area along the gap may occupy a value greater than 5MM and less than 10MM, greater than 10MM and less than 15MM, or greater than 15MM and less than 40MM, or may be greater than 40MM. However, in this case the predetermined distance between the inner and outer walls in the sealing area, respectively, must be selected so as to be able to achieve the required pressure difference across the sealing area.

[0031] Yet another object of the invention is a vacuum pump adapted to be fitted into a vacuum chamber and having a wall extending in an annular manner around a longitudinal axis of the vacuum pump, the wall of the vacuum pump having at least one portion having a predetermined distance relative to the longitudinal axis, said portion forming at least one sealing area with an opposing wall of the vacuum chamber, in which a gap between the wall of the vacuum pump and the opposing wall of the vacuum chamber has a width that is smaller than the width of the gap outside the sealing area.

[0032] In other words, the vacuum pump is intended to form at least one gap seal with a wall of the vacuum chamber when inserted into the vacuum chamber, and the seal area is therefore located between two areas of the gap between the vacuum pump and the vacuum chamber, in which the respective spacing between the wall of the vacuum pump and the wall of the vacuum chamber is greater than the predetermined spacing between these walls in the seal area.

[0033] The invention will now be described on the basis of exemplary advantageous embodiments with reference to the accompanying drawings, in which: FIG. [Brief description of the drawings]

[0034] [Figure 1] 1 illustrates an exemplary cartridge vacuum pump according to the prior art. [Diagram 2] 1 shows a vacuum apparatus according to the present invention having a vacuum pump and a vacuum chamber, with at least one gap seal provided between the vacuum pump and the vacuum chamber. [Diagram 3] 1 illustrates an embodiment having a conically extending gap seal between a vacuum pump and a vacuum chamber of a vacuum instrument. [Figure 4] 1 illustrates another embodiment having a radially extending gap seal between a vacuum pump and a vacuum chamber of a vacuum instrument. [Diagram 5] 1 illustrates another embodiment of a vacuum apparatus, where at least one of the gap seals forms a metal-to-metal contact between a vacuum pump and a vacuum chamber. [Figure 6] 13 illustrates another embodiment of a vacuum device having an intermediate suction section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Figure 1 shows an exemplary split-flow turbomolecular pump 10. The split-flow turbomolecular pump 10 has a circular so-called cartridge housing 20 and three inlet openings or ports 30, 32, 34. The cartridge housing 20 can be used to fit or insert the turbomolecular pump 10 into a vacuum chamber. Such fitting of the vacuum pump into a vacuum chamber is shown diagrammatically in cross section in Figure 2A.

[0036] The three intake openings 30, 32, 34 of the turbomolecular pump include intake opening 30 or port H0, which constitutes the main intake opening of turbomolecular pump 10 and is at the lowest pressure level P0 reached by turbomolecular pump 10 during operation. Port H0 is located at the axial end of turbomolecular pump 10 and at the same time is centered with respect to the longitudinal axis of turbomolecular pump 10, which represents the axis of rotation for the rotor of turbomolecular pump 10.

[0037] The two other intake openings 32, 34 of the turbomolecular pump 10 include two other ports H1 and H2 located laterally in the cartridge housing 20 of the turbomolecular pump 10. Port H1 is at a pressure level P1 higher than the pressure level P0 at port H0 when the turbomolecular pump 10 is in operation, while port H2 is at a pressure level P2 higher than the pressure level P1 at port H1 and thus greater than the pressure level P0 at port H0 when the turbomolecular pump 10 is in operation.

[0038] Due to the different pressure levels P0, P1 and P2 at ports H0, H1 or H2 of the turbomolecular pump 10, respectively, sealing between the respective areas or ports of the turbomolecular pump 10 is necessary during operation of the turbomolecular pump 10. Sealing between the various pressure levels P0, P1, P2 or ports H0, H1, H2 as well as between port H2 and the ambient pressure outside the turbomolecular pump 10 is provided by respective elastic seals 40, 42, 44. The seals 40, 42, 44 are each formed as an orbiting O-ring.

[0039] The elastic seals 40, 42, 44 are pressurized in the exemplary prior art turbomolecular pump 10 in an axial direction, i.e., parallel to the longitudinal axis of the turbomolecular pump 10. This gives the turbomolecular pump 10 a stepped "fir tree" shape, in which the diameter of each section of the turbomolecular pump 10 increases gradually from port H0 toward the opposite axial end of the turbomolecular pump 10. Similarly, the diameter of each of the O-rings forming the respective elastic seals 40, 42, 44 also increases axially from port H0. Due to the stepped "fir tree" shape with increasing diameters of each section, the prior art turbomolecular pump 10 requires a relatively large construction space when it is to be installed in a vacuum chamber.

[0040] In accordance with this, Fig. 2 shows a vacuum device 100 according to the invention, which has a vacuum pump 110 configured as a turbomolecular pump and a vacuum chamber 120. Similar to the turbomolecular pump 10 shown in Fig. 1, the vacuum pump 110 has a cartridge housing, by means of which the vacuum pump 110 can be fitted or inserted into the vacuum chamber 120. Furthermore, the vacuum pump 110 likewise has a first inlet opening 112 and two laterally arranged inlet openings 114, 116, the first inlet opening 112 being called port H0 and being arranged axially on the upper side of the vacuum pump 110, the inlet openings 114, 116 being called port H1 or port H2. Since the two lateral inlet openings 114, 116 allow for differential pumping by the vacuum pump 110, the vacuum pump 110 is here configured as a split-flow turbomolecular pump.

[0041] The vacuum pump 110 further has a longitudinal axis 117, which is at the same time the axis of rotation for a rotor, not shown, of the vacuum pump 110. When the vacuum pump 110 is inserted into the vacuum chamber 120, the vacuum pump 110 is further centered about the longitudinal axis 117.

[0042] The vacuum device 100 has an inner wall 118 formed by the cartridge housing of the vacuum pump 110 and an outer wall 122 of the vacuum chamber 120. A gap 130 is formed between the inner wall 118 and the outer wall 120, and the gap 130 is shown enlarged in Figures 2B and 2C. The gap 130 has two sealing regions 134, 140 along its extension from the inlet opening 112 or port H0 to the inlet opening 116 or port H2, where the gap 130 has a reduced width or a predetermined reduced spacing between the inner wall 118 and the outer wall 122.

[0043] 2B shows an enlarged drawing of portion "B" of FIG. 2A including the first sealing area 134 between ports H0 and H1. The first sealing area 134 is disposed between two regions 132, 138 of the gap 130, where the respective spacing between the inner wall 118 and the outer wall 122 in the two regions 132, 138 is greater than a predetermined spacing or gap width between the inner wall 118 and the outer wall 122 in the sealing area 134.

[0044] In other words, the sealing area 134 has a reduced width along its length 136 along the gap 130, i.e., the sealing area 134 is disposed between the regions 132, 138, where the width between the inner wall 118 and the outer wall 122 is smaller than the width of the gap 130 in the regions 132, 138. The same is true for the second sealing area 140 shown in FIG. 2A. The sealing area 140 is disposed between the ports H1 and H2 and between the region 138 of the gap 130 and another region 142, where the gap 130 has a larger width than in the sealing area 140.

[0045] At its axial end opposite the axial end of port H0, the vacuum pump 110 has an elastomeric seal 150 configured as an orbiting O-ring, which seals the gap 130 and thus the entire vacuum pump 110 against ambient pressure.

[0046] 2C, because the inner wall 118 and the outer wall 122 of the vacuum equipment 100 may deviate from an ideal coaxial shape, the gap 130 has a varying width at each position along the circumference of the vacuum pump 110, as illustrated by width 162 at position 160. Thus, the given spacing between the inner wall 118 and the outer wall 122 in the seal areas 134, 140 applies to the average gap size or width of the gap 130 over the circumference of the vacuum pump 110.

[0047] In the example shown in Figure 2A, the sealing area 134, 140 has a predetermined spacing between the inner wall 118 and the outer wall 122 of about 0.061 MM, where a range of 0.025 MM to 0.097 MM is set for the width of the gap 130 in the sealing area 134, 140 to allow for diameter tolerances. It has been found that the width of the gap 130 in the sealing area 134, 140 should be less than 0.2 MM. The length 136 of the sealing area 134 along the gap 130 ranges from 5 MM to about 40 MM, where a length 136 of about 15 MM was specifically used in the example of Figure 2A.

[0048] The sealing area 134 seals the pressure level P0 at the port H0 or the inlet opening 112 against a pressure level P1 at the port H1 or the inlet opening 114. The pressure level P1 is greater than the pressure level P0 at the port H0. Similarly, the second sealing area 140 seals the pressure level P1 at the port H1 against a pressure level P2 at the port H2 or the inlet opening 116. The pressure level P2 is here greater than the pressure level P1. The sealing action of the sealing areas 134, 140 is given by a vacuum-technical conductance along the respective sealing area 134, 140. The lower the vacuum-technical conductance, the better the sealing action of the respective sealing area or the respective gap seal 134, 140. The vacuum-technical conductance is here lower the greater the ratio of the length 136 of the sealing area 134 along the gap 130 to the width of the gap 130 in the sealing area 134, 140. In this example, the ratio is greater than five.

[0049] By means of both sealing areas 134, 140, sealing between the various pressure levels P0, P1, P2 is achieved in the vacuum pump 110 as a whole, without the need for an axially pressurized elastomeric seal. Based on the two axially extending sealing areas or gap seals 134, 140 in the example of FIG. 2A, the increase in the radial diameter of the vacuum pump 110 between the ports H0 and H2 is very small, i.e. much smaller than in the case of the turbomolecular pump 10 according to the background art shown in FIG. 1. This allows the vacuum pump 110, when inserted into the vacuum chamber 120, to require less construction space compared to the turbomolecular pump 10 of FIG. 1. However, to seal the vacuum pump 110 against the ambient pressure, an elastomeric seal 150, which is a single elastomeric seal in the example of FIG. 2A, is required, since the pressure difference between the pressure level P2 in the area of ​​the port H2 and the ambient pressure is too large for the gap seal.

[0050] 3 shows a part of an embodiment of the vacuum device 100. In this embodiment, unlike the embodiment shown in FIGS. 2A and 2B, the sealing area 134 does not extend axially, but obliquely or conically. Specifically, the sealing area 134 of the gap 130 between the vacuum pump 110 and the vacuum chamber 120 extends at an angle to the axial direction set by the longitudinal axis 117 of the vacuum pump 110 (see FIG. 2A). The sealing area 134 is disposed between the other regions 132, 138 of the gap 130, and similarly extends obliquely at an angle to the other regions 132, 138 of the gap 130, so that the sealing area 134 forms a conical annular surface.

[0051] The advantage of the oblique or conical extension of the sealing area 134 is that it generates less friction when the vacuum pump 110 is inserted into the vacuum chamber 112 compared to the axial extension shown in Figure 2A. However, the oblique or conical extension of the sealing area 134 also causes a radial diameter expansion of the vacuum pump 110 over the sealing area or gap seal 134, i.e. to a lesser extent than in the "fir tree" arrangement of the pump stages of a cartridge vacuum pump (see Figure 1).

[0052] Figure 4 shows another embodiment of the vacuum appliance 100, which is comparable to the embodiment of figure 3. However, in the embodiment of figure 4, the sealing area 134 extends almost completely radially and thus forms a step in the vacuum pump 110 in the inner wall 118 of the vacuum appliance 100. The embodiment of figure 4 has the advantage that, due to the approximately radial extension of the sealing area 134, the axial frictional forces occurring when the vacuum pump 110 is inserted into the vacuum chamber 120 are almost completely suppressed. However, the stepped extension of the gap 130 through the sealing area 134 results in a larger expansion of the diameter of the vacuum pump 110 through the sealing area 134 from the area 132 having the pressure level P0 of the port H0 to the area 138 of the gap 130 at the pressure level P1 of the port H1.

[0053] 5 shows another embodiment of the vacuum device 100. In this other embodiment, as in the embodiment shown in FIG. 2, a respective sealing area 134, 140 is provided between the pressure level P0 of the port H0 and the pressure level P1 of the port H1 or between the pressure level P1 and the pressure level P2 of the port H2. However, the sealing area 134 differs from the sealing area shown in FIG. 2 in that, on the one hand, the gap 130 of this sealing area extends obliquely or conically, i.e. at an angle greater than 0° and less than 90° with respect to the longitudinal axis 117 of the vacuum pump 110, as also shown in FIG. 3. Furthermore, in the sealing area 134, in the embodiment shown in FIG. 5, a metal contact occurs between the vacuum pump 110 and the vacuum chamber 120.

[0054] In other words, the gap 130 between the vacuum pump 110 and the vacuum chamber 120 at the sealing area 134 is pressed into contact in the embodiment shown in Fig. 5, so that the inner wall 118 of the vacuum pump 110 and the outer wall 122 of the vacuum chamber 120 are in direct contact or abutment. The contact point formed by the sealing area 134 between the vacuum pump 110 and the vacuum chamber 120 is used as a so-called support point when the vacuum pump 110 is inserted into the vacuum chamber 120. The position of the contact point formed by the sealing area 134 is selected in such a way that the vibration characteristics of the vacuum pump 110 are improved during operation of the vacuum pump 110.

[0055] Metal contact between the vacuum pump 110 and the vacuum chamber 120 in the sealing area 134 is even more advantageous if the vacuum device 110 is designed for the ultra-high vacuum range. Based on the metal contact in the sealing area 134, the outgassing characteristics of the vacuum device 100 are improved compared to the use of elastomeric seals, since no metallic material is required except for the elastomeric seal 150 to seal against atmospheric pressure.

[0056] Additionally, the metal contact 134 improves heat transfer between the vacuum chamber 120 and the vacuum pump 110, which is advantageous for warming the vacuum equipment 100 for operation in the ultra-high vacuum range.

[0057] 5 also includes an elastomeric seal 150 at the axial end of the vacuum pump 110 axially opposite port H0 to seal port H2 and the region 142 of the gap 130 adjacent port H2 against atmospheric pressure. A further gap 152 is provided between the elastomeric seal 150 and the exterior region of the vacuum apparatus 100.

[0058] FIG. 6 shows another embodiment of the vacuum apparatus 100. In this embodiment, an intermediate suction section via an additional port 180 is provided between a region 132 of the gap 130 having a pressure level P0 of the port H0 and a region 138 of the gap 130 having a pressure level P1 of the port H1. Specifically speaking, in order to seal the region 132 at the pressure level P0 against another region 138 at the pressure level P1 where the gap 130 has a larger gap width compared to the seal region 134, on the one hand, a seal region 134 with a narrowed or reduced width of the gap 130 is provided. Additionally, an elastomeric seal 170 for sealing between the pressure levels P0 and P1 is provided. An additional port 180 for intermediate suction of the gas load Q specifically indicated by the arrow is located in the region between the seal region 134 with the reduced width of the gap 130 and the elastomeric seal 170.

[0059] Based on the intermediate suction via the additional port 180, the gap 130 has a pressure PX that is lower than the pressure level P1 but higher than the pressure level P0 between the seal region 134 and the region 138 at the pressure level P1, or above or upstream of the elastomeric seal 170 in the axial direction. In other words, P0 < PX < P1 holds.

[0060] In the embodiment of the vacuum device 100 shown in FIG. 6, the seal area 134 may have a contact point or metal contact between the vacuum pump 110 and the vacuum chamber 120. However, alternatively, the seal area 134 may prevent metal contact between the vacuum pump 110 and the vacuum chamber 120. Thus, the vacuum device 100 may be constructed entirely without metal contact in the seal areas 134, 140 or gap seals formed therein in the embodiment shown in FIG. 6. In the absence of such metal contact, the vacuum pump 110 has improved thermal insulation with respect to the vacuum chamber 120. Such improved thermal insulation may be advantageous, such that heat flow of an application in the vacuum chamber 120 is not transferred to the vacuum pump 110, or vice versa, such that a warmed vacuum pump 110 does not cause unnecessary heat flow to the vacuum chamber 120 and the application located therein.

[0061] Metallic contact between the vacuum pump 110 and the vacuum chamber 120 can also be prevented in the area of ​​the elastomeric seal 150 and in the gap 152 adjacent to the elastomeric seal 150, for example by configuring the threaded connection between the vacuum pump 110 and the vacuum chamber 120 in the area of ​​the gap 152 as a threaded connection that has no metallic contact with the vacuum pump 110 (see FIG. 5). In the case of such a threaded connection, the shaft of the respective screw is metallically connected to the vacuum chamber 120, while the head of the respective screw is insulated from the vacuum chamber 110 by a plastic part. This allows the vacuum chamber 120 and the vacuum pump 110 to be electrically and thermally insulated from one another and also provides vibrational isolation between them. [Explanation of symbols]

[0062] 10 Split-flow turbomolecular pump 20 Cartridge housing 30, 32, 34 Intake opening, port H0, H1 or H2 40, 42, 44 Axially pressurized elastomer seals, O-rings 100 Vacuum equipment 110 Vacuum Pump 112, 114, 116 Intake opening, port H0, H1 or H2 117 Vacuum pump axial longitudinal axis 118 Inner Wall 120 Vacuum Chamber 122 Outer Wall 130 Gap 132 Area of ​​the gap at pressure level P 134 Sealing Area 136 Length of the seal area along the gap 137 Area of ​​the gap at pressure level PX 138 Area of ​​the gap at pressure level P1 140 Sealing Area 142 Area of ​​the gap at pressure level P2 150 Elastomer Seal 152 Gap between elastomer seal and exterior area 160 Position around the outer wall 162 Gap width 170 Elastomer Seal 180 additional ports

Claims

1. In a vacuum device (100), An inner wall (118); an outer wall (122) surrounding the inner wall (118) such that a gap (130) is formed between the inner wall (118) and the outer wall (122); the gap (130) has at least one sealing area (134), and in the sealing area (134), the gap (130) has a predetermined distance between the inner wall (118) and the outer wall (122); A vacuum device (100), wherein at least one of the sealing areas (134) is disposed between two areas (132, 138) of the gap (130), and in the two areas (132, 138), each of the spacings between the inner wall (118) and the outer wall (122) is greater than a predetermined spacing between the inner wall (118) and the outer wall (122) in the sealing area (134).

2. a vacuum pump (110) having said inner wall (118); a vacuum chamber (120) having an outer wall (122) configured to receive the inner wall (118) of the vacuum pump (110); The vacuum apparatus (100) of claim 1 further comprising:

3. The vacuum pump (110) has multiple pumping stages; a respective sealing area (134, 140) is provided between each two pump stages of the vacuum pump (110); The vacuum apparatus (100) of claim 2.

4. The vacuum equipment (100) of claim 3, wherein the vacuum pump (110) is provided with an intermediate suction section (180) in an axial region between two pump stages.

5. The vacuum apparatus (100) of any one of claims 1 to 4, wherein a plurality of sealing areas (134, 140) are disposed along the gap (130).

6. 6. The vacuum equipment (100) of claim 1, wherein the sealing area (134) is disposed between two areas (132, 138) of the gap (130), and the sealing area (134) extends at a predetermined angle with respect to at least one of the two areas (132, 138).

7. 7. The vacuum device (100) of claim 6, wherein the sealing area (134) is disposed between two regions (132, 138) of the gap (130), and the sealing area (134) extends perpendicular to at least one of the two regions (132, 138).

8. 7. The vacuum device (100) of claim 6, wherein the sealing area (134) is disposed between two regions (132, 138) of the gap (130), and the sealing area (134) extends in the same direction as the two regions (132, 138).

9. 9. The vacuum apparatus (100) of claim 1, wherein an additional seal (150) is disposed between the gap (130) and an exterior area of ​​the vacuum apparatus (100) where atmospheric pressure is present.

10. The vacuum apparatus (100) of any one of claims 1 to 9, wherein there is a metal contact between the inner wall (118) and the outer wall (134) in at least one sealing area (134, 140).

11. The vacuum apparatus (100) of any one of claims 1 to 9, wherein there is no metal contact between the inner wall (118) and the outer wall (122).

12. 12. The vacuum apparatus (100) of claim 1, wherein a ratio of a length (136) of the sealing area (134) along the gap (130) to a predetermined distance between the inner wall (118) and the outer wall (122) within the sealing area (134) is greater than 5, preferably greater than 10.

13. 13. The vacuum apparatus (100) of any one of claims 1 to 12, wherein the predetermined distance between the inner wall (118) and the outer wall (122) in the sealing area (134) is 0.2 mm or less, preferably 0.05 mm or less.

14. The vacuum apparatus (100) of any one of claims 1 to 13, wherein a length (136) of the sealing area (134) along the gap (130) is greater than 5 mm or more, preferably greater than 40 mm.

15. In the vacuum pump (110), The vacuum pump (110) is configured to be fitted into a vacuum chamber (120) and has a wall (118) extending annularly about a longitudinal axis (117) of the vacuum pump (110); the wall (118) has at least one portion having a predetermined distance relative to the longitudinal axis (117), the portion forming at least one sealing area (134) with an opposing wall (122) of the vacuum chamber (120), and in the sealing area (134), a gap (130) between the wall (118) of the vacuum pump (110) and the opposing wall (122) of the vacuum chamber (120) has a width that is smaller than a width of the gap (130) outside the sealing area (134); Vacuum pump (110).

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