vacuum system

Abstract

Vacuum system with a vacuum pump (1) and at least one receiver (2) to be evacuated, the receiver having a housing (3) and at least one outlet opening for evacuating the receiver (2), wherein the vacuum pump (1) is connected to the outlet opening of the receiver (2), wherein a projection (5) is arranged as an intermediate piece between the vacuum pump (1) and the housing (3) of the receiver (2), wherein the vacuum pump (1) is detachably fixed to the projection (5) at the end of the projection (5) opposite the receiver (2), wherein at least one O-ring (9) is provided for sealing between an end of the projection associated with the vacuum pump (1) and the vacuum pump (1), and wherein the O-ring seal is designed as an elastomer O-ring, characterized in that the projection (5) is fixedly and vacuum-tightly arranged on the housing (3) of the receiver (2), and that the projection (5) has a wall thickness of measures between one and ten millimeters.

Description

[0001] The invention relates to a vacuum system with a vacuum pump and at least one recipient to be evacuated.

[0002] A sealing element for vacuum applications is known from the prior art (DE 24 16 808 A1). This sealing element is made of metal because sealing elements made of an elastomeric material are not heat-resistant and therefore cannot be used at high temperatures. In particular, elastomeric seals cannot be used when the receiver is baked out, as these seals either outgas and thus "contaminate" the vacuum, or the elastomeric seals are damaged during baking, so that the sealing effect is no longer guaranteed.

[0003] Metal seals, which represent the state of the art, have the disadvantage that they can generally only be used once or at most a few times, since metal lacks the advantage of elastomer seals, namely their elastic deformability. After any significant deformation, a new sealing element must therefore be used. Because metal sealing rings are often made of expensive materials (copper, indium, gold, or the like), the cost of metal seals is relatively high.

[0004] According to the prior art (DE 24 16 808 A1), it is therefore proposed to design a sealing ring made of metal and the centering ring as a spring ring with a radial gap. This embodiment is also very complex and therefore very expensive.

[0005] Ultra-high vacuum (UHV) flanges are a well-known design. These flanges feature cutting edges and, for example, copper gaskets. A copper ring is placed between two flanges. The concentric cutting edges of the flanges penetrate the copper, forming a metallic seal characterized by extremely low leakage and permeation rates, as well as high temperature resistance. These flanges are also known as Conflat flanges (a registered trademark of Agilent Technologies Inc., USA) or CF flanges. However, these flanges also have the disadvantage of using cutting edges and metal gaskets. The metal gaskets cannot be reused due to permanent deformation after a single use. Furthermore, for strength reasons, stainless steel is required instead of, for example, aluminum.

[0006] The technical problem underlying the invention is to enable a weight-, cost-, and suction-capacity-optimized interface between a vacuum system and a preferably heatable ultra-high vacuum chamber. The invention aims to provide an O-ring seal for a vacuum system made of an elastomer, in which no contamination effects impede the ultra-high vacuum.

[0007] This technical problem is solved by a vacuum system having the features according to claim 1.

[0008] The vacuum system according to the invention, comprising a vacuum pump and at least one recipient to be evacuated, which has a housing and at least one outlet opening for evacuating the recipient, wherein the vacuum pump is connected to the outlet opening of the recipient, is characterized in that an extension is arranged as an intermediate piece between the vacuum pump and the housing of the recipient, that the extension is fixedly and vacuum-tightly arranged on the housing of the recipient, that the vacuum pump is detachably fixed to the extension at the end of the extension opposite the recipient, that at least one O-ring is provided for sealing between the end of the extension associated with the vacuum pump and the vacuum pump, and that the O-ring seal is designed as an elastomer O-ring.

[0009] The invention has the advantage that an inexpensive elastomer O-ring can be used as an O-ring seal, but that no contamination effects from the O-ring seal counteract the ultra-high vacuum.

[0010] The vacuum system according to the invention has the advantage that the seal is shifted towards the forevacuum at a higher pressure by the arrangement of the extension on the receiver housing. If the UHV area is baked out, the O-ring seal is not subjected to excessive stress due to the axial distance created by the inventive use of the extension between the receiver and the vacuum pump.

[0011] For this purpose, it is particularly advantageous to make the attachment from stainless steel or aluminum or another material which preferably has a lower thermal conductivity, so that the attachment does not transfer the heat to the O-ring seal.

[0012] The approach is advantageously designed as a tubular design, for example as a tube.

[0013] The vacuum pump housing is also advantageously made at least partially of aluminum. This makes the pump lighter, as the aluminum housing is lighter than the usual heavy stainless steel housings used in CF seals, as is common practice.

[0014] According to a further advantageous embodiment of the invention, at least the connection flange of the vacuum pump for the receiver is made of aluminum. This also results in a weight reduction. The use of aluminum is possible because no CF flanges with metal seals are required; instead, at least an O-ring seal with at least one elastomer O-ring is sufficient.

[0015] The attachment arranged between the housing of the receiver and the vacuum pump advantageously has a wall thickness of one to ten millimeters.

[0016] To achieve an airtight and secure connection between the nozzle and the receiver housing, the nozzle and housing are advantageously welded together. However, it is also possible to provide other vacuum-tight connections between the nozzle and housing.

[0017] According to a further advantageous embodiment of the invention, it is also possible to form the receiver's protrusion and housing in one piece.

[0018] The design advantageously features a flange on the side facing the vacuum pump for connection to the vacuum pump. At least one O-ring seal is provided in this area. The standard flange connection to the vacuum pump can be made here.

[0019] The flange of the attachment is advantageously designed to be screwed to the flange of the vacuum pump. This is a simple type of connection. It is also possible to provide clamps or other fasteners for a detachable connection of the flanges.

[0020] Advantageously, at least one O-ring is arranged as a seal between the flanges of the attachment and the vacuum pump. This has the advantage that the O-ring is axially displaced from the housing of the receiver towards the vacuum pump, and that heat-up of the receiver has no negative effects on the elastomer O-ring.

[0021] According to an advantageous embodiment of the invention, the vacuum pump has a pipe section which is at least partially arranged in the extension between the housing of the receiver and the vacuum pump. This pipe section additionally prevents outgassing and permeation leakage rates that can occur with an O-ring seal in a vacuum.

[0022] Furthermore, the higher pressure level in the area of ​​the O-ring seal offers the advantage that the O-ring seal emits significantly less or no outgassing at all.

[0023] For this purpose, a narrow gap is advantageously provided between the tube section of the vacuum pump and the extension arranged between the receiver and the vacuum pump. According to a particularly advantageous embodiment of the invention, intermediate extraction from this narrow gap is provided. For this purpose, the tube section of the vacuum pump advantageously has at least one opening for the extraction of gases. The number of particles arriving in the UHV area due to outgassing can thus be minimized.

[0024] Furthermore, a collection groove for extracting gases is advantageously provided. The extraction openings are advantageously arranged in this collection groove.

[0025] The pipe section arranged on the vacuum pump can advantageously be made of aluminum or stainless steel. The vacuum system according to the invention advantageously comprises a vacuum pump designed as a turbomolecular pump. Particularly preferably, the vacuum system comprises a pump designed as a split-flow pump. Turbomolecular pumps and split-flow pumps are particularly advantageously used in the UHV range.

[0026] The design according to the invention has the additional advantage that the pump can be positioned closer to the recipient overall, since the two CF flanges known from practical applications are eliminated along the axial length, and the space for the screw connection can also be accommodated within the pump housing. This reduces the installation space and increases the conductivity and / or the effective pumping speed. A further particular advantage of the invention lies in the reusability of the seal.

[0027] Further features and advantages of the invention will become apparent from the accompanying drawing, in which an embodiment of a vacuum system according to the invention is shown only by way of example. The drawing shows:

[0028] Fig. 1 a vacuum system with vacuum pump and receiver partially cut;

[0029] Fig. 2 a modified embodiment.

[0030] Fig. Figure 1 shows a vacuum pump 1 as well as a recipient 2 The recipient 2 a case 3 , which is shown in the view. The casing 3 has an outlet opening 4 on. On the casing 3 of the recipient 2 is the outlet opening 4 covering pipe 5 arranged. The pipe 5 is by means of a welded connection 6 on the case 3firmly and vacuum-tightly arranged. The pipe 5 has a flange 7 on, which has a flange 8 the vacuum pump 1 It is detachably connected. Between the flanges 7 , 8 is an O-ring seal 9 arranged.

[0031] Through the pipe 5 An axial displacement of the O-ring seal occurs. 9 towards the forevacuum, to a higher pressure. In the tube 5 is a piece of pipe 10 arranged, which is shown in view and which is part of the vacuum pump 1 is. Between the pipe section 10 and the pipe 5 is a narrow gap 11 provided for. In addition, the pipe section contains 10 Extraction openings 12 arranged for intermediate extraction. The extraction openings 12 are in grooves 14, which are designed as collecting grooves. This reduces outgassing and permeation leakage rates that occur with an O-ring seal. 9 can occur in a vacuum, from the UHV (ultra-high vacuum) of the recipient 2 sealed off. Through the extraction openings. 12 The escaping particles are transferred to the turbo section of the turbomolecular pump. 1 extracted. This minimizes the number of particles arriving in the UHV area.

[0032] Fig. 2 shows the vacuum system with the vacuum pump 1 and the recipient 2 . Identical parts are used with those in Fig. 1 reference numbers used.

[0033] The case 3 of the recipient 2 is one piece with the pipe 5 trained. Reference symbol list 1 vacuum pump 2 Recipient 3 Receiver housing 4 Outlet opening 5 pipe 6 welded joint 7 Flange of the pipe 8 Flange of the vacuum pump 9 O-ring seal 10 pipe sections 11 column 12 extraction openings 14 Collecting QUOTES INCLUDED IN THE DESCRIPTION

[0034] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0035] DE 2416808 A1 [0002, 0004]

Claims

[1] Vacuum system comprising a vacuum pump and at least one recipient to be evacuated, the recipient having a housing and at least one outlet opening for evacuating the recipient, wherein the vacuum pump is connected to the outlet opening of the recipient, characterized by that between the vacuum pump ( 1 ) and the housing ( 3 ) of the recipient ( 2 ) an approach ( 5 ) is arranged as an intermediate piece, so that the approach ( 5 ) firmly and vacuum-tight to the housing ( 3 ) of the recipient ( 2 ) is arranged that at the recipient ( 2 ) opposite end of the approach ( 5 ) the vacuum pump ( 1 ) detached, fixed to the attachment ( 5 ) is arranged so that between one of the vacuum pumps ( 1 ) associated attachment end and the vacuum pump ( 1 ) at least one O-ring ( 9 ) is intended for sealing, and that the O-ring seal ( 9) is designed as an elastomer O-ring. [2] Vacuum system according to claim 1, characterized by that the approach ( 5 ) is designed as a tubular extension or as a tube. [3] Vacuum system according to claim 1 or 2, characterized by that the approach ( 5 ) is made of stainless steel or aluminum. [4] Vacuum system according to any one of claims 1 to 3, characterized by that the housing of the vacuum pump ( 1 ) is at least partially made of aluminum. [5] Vacuum system according to claim 4, characterized by that at least one connection flange of the vacuum pump ( 1 ) for the recipient ( 2 ) is made of aluminum. [6] Vacuum system according to claim 3, characterized by that the approach ( 5 ) has a wall thickness of one to ten millimeters. [7] Vacuum system according to any one of the preceding claims, characterized by that the approach ( 5 ) with the housing ( 3) of the recipient ( 2 ) is welded together. [8] Vacuum system according to any one of claims 1 to 6, characterized by that the approach ( 5 ) one-piece with the housing ( 3 ) of the recipient ( 2 ) is trained. [9] Vacuum system according to any one of the preceding claims, characterized by that the approach ( 5 ) at the vacuum pump ( 1 ) facing side a flange ( 7 ) for connection to the vacuum pump ( 1 ) exhibits. [10] Vacuum system according to claim 9, characterized by that the flange ( 7 ) of the approach ( 5 ) with the flange ( 8 ) the vacuum pump ( 1 ) is designed to be screwed together. [11] Vacuum system according to claim 10, characterized by that between the flanges ( 7 , 8 ) of the approach ( 5 ) and the vacuum pump ( 1 ) which has at least one O-ring as a seal. [12] Vacuum system according to any one of the preceding claims, characterized by that a piece of pipe ( 10 ) the vacuum pump ( 1 ) at least partially in the housing ( 3 ) of the recipient ( 2 ) arranged approach ( 5 ) is arranged. [13] Vacuum system according to claim 12, characterized by that the pipe section ( 10 ) the vacuum pump ( 1 ) at least one opening ( 12 ) for the extraction of gases. [14] Vacuum system according to claim 13, characterized by that the pipe section ( 10 ) the vacuum pump ( 1 ) at least one collecting notch ( 14 ) has at least one opening ( 12 ) for the extraction of gases in at least one collecting groove ( 14 ) is arranged. [15] Vacuum system according to claim 12, characterized by that the pipe section ( 10 ) is made of aluminum or stainless steel. [16] Vacuum system according to any one of the preceding claims, characterized by that the vacuum pump ( 1 ) is designed as a turbomolecular pump. [17] Vacuum system according to any one of the preceding claims, characterized by that the vacuum pump ( 1 ) is designed as a split-flow pump.

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