EP3339652B1 - Vacuum pump with inner lining to receive deposits - Google Patents

Description

The present invention relates to a vacuum pump according to claim 1.

Vacuum pumps, such as turbomolecular pumps, are used in different areas of technology in order to create a vacuum necessary for a particular process. The problem can arise that deposits, such as process impurities, particles and / or liquid residues, accumulate or deposit from the fluid pumped by the pump in the vacuum pump and primarily there in its fore-vacuum region. These possibly also corrosive and toxic deposits have to be removed during maintenance with great effort, in particular by mechanical, physical and / or chemical cleaning. The housing of the vacuum pump and in particular the lower part of the housing enclosing the fore-vacuum region with the assemblies which may be arranged there, such as an electronic assembly, precision mechanical assemblies, seals, etc., are made more difficult cleaning because, for example, superheated steam, cleaning agents and the like can be harmful.

A vacuum pump according to the preamble of claim 1 is known from the US 2016/273552 A1 known. Another vacuum pump is disclosed US 2002/114695 A1 .

Against this background, the present invention has for its object to provide a vacuum pump that is easy to clean. In particular, deposits should be easy to remove from the fore-vacuum area of the vacuum pump.

The object is achieved by a vacuum pump with the features of claim 1. Preferred embodiments and developments of the invention are described in the dependent claims.

A vacuum pump according to the invention, in particular a turbomolecular pump, comprises a housing with at least one inlet and an outlet for fluid, in particular process gas or air, a recipient being connectable to the inlet. The vacuum pump according to the invention also comprises at least one pump stage arranged in the housing for conveying the fluid, in particular out of the recipient, through the vacuum pump from the inlet to the outlet, a chamber also being formed in the housing, and at least one insert for receiving in the chamber of deposits is arranged, which covers at least one side delimiting the chamber.

The chamber preferably opens into the outlet and preferably forms a discharge area of the vacuum pump. The chamber is therefore preferably in the fore-vacuum region of the pump. The chamber is preferably arranged downstream of the pump stage closest to the forevacuum in the housing, as seen in the pumping direction. The pump channel running through the vacuum pump through which the Fluid flowing in the pump extends through the chamber. The deposits drawn in by the pump and contained in the fluid can therefore deposit on the insert. The deposits can be removed by removing the insert from the pump. The insert can preferably be arranged in the chamber in such a way that it can be removed from the chamber, for example, during maintenance of the pump. The removed insert can be cleaned outside the pump and then reinserted into the pump. Alternatively, the dirty insert can be replaced with a new insert. The effort of cleaning the chamber from the deposits can be reduced by using the insert or, in the best case, saved entirely. This also reduces the risk of damaging sensitive components in the fore-vacuum area.

The term "deposition" is to be understood broadly and can include any type of substances, such as particles, liquids, gases or exotic states such as plasma or atomic gas, which are contained in the fluid conveyed by the vacuum pump and are found in the vacuum pump, for example can "settle down" through adhesion, condensation, resublimation, solidification or chemical reaction.

According to the invention, the insert has an outlet opening, which can be aligned in particular with the outlet on the housing of the vacuum pump. The fluid can thus pass through the volume of the insert into the outlet opening of the insert and further into the outlet of the vacuum pump. The outlet opening can have a diameter which corresponds at least substantially to the diameter of the outlet of the vacuum pump. The outlet opening can be formed, for example, by removing, in particular cutting out, material from the insert.

According to the invention, the outlet of the vacuum pump has a fore-vacuum nozzle in which the Chamber opens, and the insert has a mouth section which can be introduced or introduced into the fore-vacuum nozzle. The mouth section can at least partially cover the inner wall of the fore-vacuum nozzle and thus protect it from deposits.

According to the invention, the mouth section is formed by the part of the insert material which was removed or cut out from the insert to create the outlet opening, the mouth section preferably being connected in one piece to the insert. No additional material is therefore required for the mouth section. Rather, only the material of the insert is used, which has "become free" by creating the outlet opening.

The mouth section can be insertable into the fore-vacuum nozzle. The mouth section can be designed to match the fore-vacuum nozzle. The outer diameter of the mouth section can thus essentially correspond to the inner diameter of the fore-vacuum nozzle. Furthermore, the axial length of the mouth section can be adapted to the axial length of the fore-vacuum nozzle. The fitting mouth section inserted into the fore-vacuum nozzle can thus effectively protect the fore-vacuum nozzle from deposits.

The side delimiting the chamber, which at least partially covers the insert, can be a side wall and / or the bottom of the chamber. The insert can be designed such that it covers the largest possible surface area of the chamber or the chamber walls. As many deposits as possible can thus deposit on the insert and not on the chamber surfaces.

The insert can be designed like a bowl, a can or a container. The The insert can therefore have or define a volume that is accessible from the outside, in which the deposits can accumulate and accumulate.

The insert can be designed such that it covers, in particular at least largely completely, the bottom of the chamber and / or a side wall delimiting the chamber radially outwards and / or a side wall delimiting the chamber radially inwards.

The insert, in particular the bottom and side walls thereof, preferably surrounds a volume, at least one opening being provided on at least one side of the insert, in particular on the top of the insert, so that the deposits can be caught in the volume through the opening. The opening can be designed such that the insert has no wall on the corresponding side. The opening can alternatively be designed such that one or more openings, such as slots, are provided in a wall. The insert can thus be completely or at least partially opened on its upper side which is remote from the floor, so that the deposits can accumulate in the volume from above.

The insert is preferably designed and / or can be fitted in the chamber such that the at least one opening faces the pump stage upstream of the chamber. Deposits that are sucked in by the pump stage and conveyed towards the outlet can thus get directly into the volume of the insert and accumulate there. Possible contamination of the chamber walls by deposits can thus be further reduced.

The insert is preferably designed as a shell, the shape of which is particularly adapted to the shape of the chamber. Due to the shell shape, process impurities, deposits and other substances or particles can be captured particularly well and stored in the volume defined by the bowl. The shell is preferably at least partially open on one side, in particular on the side which, in the intended installation position, is directed in the direction of the upstream pump stage. The deposits can thus be accumulated particularly well in the volume formed by the shell.

The chamber can extend in a ring, in particular below the pump stage, about a central axis of the vacuum pump, in particular about an axis of rotation of a rotor of the pump stage. The chamber can thus form a kind of annular space under the pump stage, which among other things also has a favorable effect on the pumping speed of the pump stage.

The chamber preferably has an at least approximately rectangular cross section. This cross-sectional shape can be implemented particularly easily in terms of production technology.

The insert can be designed as a bowl-shaped shell with a bottom and, preferably vertically to the bottom, in particular upward, radially inside or radially outside, which is designed to correspond to the chamber and is at least partially open on its upper side. The insert can thus be inserted, in particular in a suitable manner, into the annular chamber. The shell, like the chamber, can preferably have an at least approximately rectangular cross section.

The insert can be fixed and / or fixable in the chamber by means of at least one fixation. The fixation can comprise, for example, at least one screw, by means of which the insert is fastened to the chamber or to an inner wall of the housing. The screw can, for example, be screwed in or screwed into the bottom of the insert and the chamber bottom underneath. Preferably a screw comes with a large one Head, such as a pan head screw or hexagon screw, because such a screw can be easily located on a floor covered with deposits and loosened with a tool.

The insert can also be designed and / or dimensioned in such a way that it can be fixed in the clamping assembly in the chamber with the stator package of the pump stage located above the chamber. I.e. the stator package mentioned can be used as a kind of fixation for the insert.

The insert can be brought from a first form into a second form, in particular by pressing on the insert, the insert in the second form having a larger outside diameter and / or a smaller inside diameter compared to the first form, and / or wherein the insert has plastic and / or elastic changes in shape in the second form compared to the first form. The insert can thus be inserted into the chamber in the first form and, in particular by pressing the insert or by inserting the insert into the chamber, the latter can be brought into the second form, as a result of which the outside diameter and / or the inside diameter of the Insert changes at least slightly, or as a result of plastic and / or elastic changes in shape of the insert. As a result of the change in shape, the insert can be "clamped" in the chamber to a certain extent, so that the insert can be fixed in the chamber.

The shape change of the insert can be reversible. To remove or after removing the insert, it can be brought back into the first shape.

The change in shape can be made possible in that at least one side of the insert, in particular the radially outer side wall of the insert, is designed such that, for example, by pressing on the insert, the dimensions of the Side, especially their radial extent, is adjustable. The change in shape can also be made possible in that at least one side of the insert, in particular the radially outer side wall of the insert, is designed such that the dimensioning of the side, in particular its axial extent, is adjustable, for example by pressing on the insert. This can be realized, for example, in that the side wall consists of at least two partial areas, which are connected by means of at least one peripheral deformation area with deformation elements and recesses, in particular in the axial direction, and is designed such that at least one deformation element is elastic or else by pressing on the insert is plastically deformed, with at least one recess being reduced and the axial extent of the side wall also being reduced.

It can also be provided that the insert can be brought from a first shape into a second shape, in particular by pressing the insert, in which the insert, in particular the radially outer side wall, has a greater or lesser axial height than the first shape . The axial extent of the insert can thus be adjustable.

At least one seal is preferably arranged between an outside of the insert and a side wall of the chamber. The chamber wall behind the outside of the insert can thus be effectively protected against deposits. The seal can also pinch the insert in the chamber and thus act as a fixation. The seal, which is preferably inserted between the upper edge of the insert and the side wall of the chamber behind it, can also act as a type of pressure distributor and distribute any existing tolerances or forces, in particular axial tolerances or forces, in such a way that the insert is firm on the one hand is fixed in the chamber and, on the other hand, a stator packet arranged upstream of the chamber is securely clamped.

The insert can be made from metal, in particular as sheet metal or foil, or from a, preferably inert, plastic, such as PTFE. PTFE stands for polytetrafluoroethylene.

The insert may have at least one coating, in particular an anti-stick layer, e.g. with nickel or PTFE, and / or a foil-like layer. The surfaces of the insert can be protected from aggressive deposits, for example. The coating can be such that it can be removed by means of a cleaning agent, in particular with the deposits, and in particular can be rinsed out of the chamber.

The insert can be formed or produced by spraying or applying at least one layer of a spray film or the like on the sides of the chamber to be covered. The layer can be removed from the chamber walls, in particular with the deposits accumulated thereon. The layer can be such that it can be removed by means of a cleaning agent, in particular with the deposits, and in particular can be rinsed out of the chamber. A new layer can then be formed by spraying or applying again.

The insert can be made in one or more parts. A backing pump, e.g. a rotary vane pump.

An alternative to the invention, and not part of the invention, is a vacuum pump, in particular a turbomolecular pump, comprising a housing with at least one inlet for fluid, in particular process gas or air, to which a recipient can be connected, and with at least one outlet for the fluid, and at least a pump stage arranged in the housing for conveying the fluid, in particular out of the recipient, through the vacuum pump from the inlet to the outlet, wherein in the housing, in particular a chamber opening into the outlet, preferably forming an ejection area of the vacuum pump, is formed, and wherein the chamber can be heated by means of at least one heating device. The chamber can thus be baked to remove the deposits from the chamber.

Fig. 1

eine perspektivische Ansicht einer Vakuumpumpe,

Fig. 2

eine Schnittansicht der Vakuumpumpe von Fig. 1,

Fig. 3

die Schnittansicht von Fig. 2 mit einer in der Vakuumpumpe angeordneten Einlage,

Fig. 4

einen Ausschnitt der Schnittansicht von Fig. 3, in welchem ein Teil einer Variante der Einlage im Querschnitt zu sehen ist,

Fig. 5

einen Ausschnitt der Schnittansicht von Fig. 3, in welchem ein Teil der erfindungsgemäßen Einlage im Querschnitt zu sehen ist,

Fig. 6

einen Ausschnitt der Schnittansicht von Fig. 3, in welchem ein Teil einer anderen Variante der Einlage im Querschnitt zu sehen ist,

Fig. 7

einen Ausschnitt der Schnittansicht von Fig. 3, in welchem ein Teil einer anderen Variante der Einlage im Querschnitt zu sehen ist,

Fig. 8

einen Ausschnitt der Schnittansicht von Fig. 3, in welchem ein Teil einer Variante der Einlage im Querschnitt zu sehen ist, und

Fig. 9

einen Ausschnitt der Schnittansicht von Fig. 3, in welchem ein Teil einer Variante der Einlage im Querschnitt zu sehen ist.

The invention is described below by way of example with reference to the accompanying figures. Each shows schematically

Fig. 1

a perspective view of a vacuum pump,

Fig. 2

a sectional view of the vacuum pump of Fig. 1 ,

Fig. 3

the sectional view of Fig. 2 with an insert arranged in the vacuum pump,

Fig. 4

a section of the sectional view of Fig. 3 , in which part of a variant of the insert can be seen in cross section,

Fig. 5

a section of the sectional view of Fig. 3 , in which a part of the insert according to the invention can be seen in cross section,

Fig. 6

a section of the sectional view of Fig. 3 , in which part of another variant of the insert can be seen in cross section,

Fig. 7

a section of the sectional view of Fig. 3 , in which part of another variant of the insert can be seen in cross section,

Fig. 8

a section of the sectional view of Fig. 3 , in which part of a variant of the insert can be seen in cross section, and

Fig. 9

a section of the sectional view of Fig. 3 , in which part of a variant of the insert can be seen in cross section.

The in the Fig. 1 and 2nd The vacuum pump 10 shown comprises a housing 16 with a pump inlet 14 surrounded by an inlet flange 12, in the housing 16 a plurality of pump stages for conveying the gas present at the pump inlet 14 to a pump outlet 74 provided on the lower part 90 of the housing. Between the lower part 90 and the housing 16 there is one Seal 81 arranged. The vacuum pump 10 comprises in the housing 16 or in the lower part 90 a stator and a rotor with a rotor shaft 20 which is rotatably mounted about an axis of rotation 18.

The vacuum pump 10 is designed as a turbomolecular pump and comprises a plurality of turbomolecular pump stages connected in series with one another with effective pumping, with a plurality of turbomolecular rotor disks 22 connected to the rotor shaft 20 and a plurality of turbomolecular stator disks 24 arranged in the axial direction between the rotor disks 22 and fixed in the housing 16, by spacer rings 26 are held at a desired axial distance from one another. The pump-active system implemented by means of the turbomolecular pump stages is therefore built up in a regular alternation of rotor disks 22 and stator disks 24. Only some of the components shown for legibility have been identified with numbers. The rotor disks 22 and stator disks 24 provide an axial pumping action in the direction of the arrow 30 in a scoop area 28.

The vacuum pump 10 can optionally have one or more Holweck pump stages, known per se, downstream of the turbomolecular pump stages, which are not shown. For example, three Holweck pump stages that are arranged one inside the other in the radial direction and have a pumping effect are connected in series with one another. The rotor-side part of the Holweck pump stages can have a rotor hub connected to the rotor shaft 20 and two cylindrical jacket-shaped Holweck rotor sleeves attached to and supported by the rotor hub, which are oriented coaxially to the rotor axis 18 and in a radial direction Are nested in one another. Furthermore, one, two or three cylindrical jacket-shaped Holweck stator sleeves can be provided, which are also oriented coaxially to the axis of rotation 18 and are nested in one another in the radial direction. The pump-active surfaces of the Holweck pump stages are each formed by the radial jacket surfaces, each opposing one another with the formation of a narrow radial Holweck gap, of a Holweck rotor sleeve and a Holweck stator sleeve. In each case, one of the pump-active surfaces is smooth, in particular that of the Holweck rotor sleeve, and the opposite pump-active surface, in particular the Holweck stator sleeve, has a structure with grooves running helically around the axis of rotation 18 in the axial direction, in which through the Rotation of the rotor propels the gas and is thereby pumped. In the vacuum pump 10 shown, however, the Holweck pump stages are not provided.

A sealing area 34 is formed by a special, in this case asymmetrically shaped stator disk 24, which keeps the remaining gaps to the rotor disks 22 minimal in order to achieve a better seal against unwanted backflows between the first and second pump stages.

A preload and sealing ring 32 is arranged between the inner wall of the housing 16 and the turbomolecular pump stages, in particular between two spacer rings 26. The preload and sealing ring 32 ensures that the stack of spacer rings 26, which is subject to tolerances, is securely axially preloaded between the housing 16 and the lower part 90. Furthermore, it additionally seals the gap between the stack of spacer rings 26 and the wall of the housing 16 against unwanted backflows from the fore-vacuum / ejection area into the high-vacuum / suction area.

A flood gas inlet 36 is arranged on the housing 16, via which the vacuum pump 10 can be flooded with flood gas. The flood gas inlet 36 is advantageously located Downstream of the pump or below the prestressing and sealing ring 32. The spacer ring 26 located at the level of the connection is preferably provided on its outer surface with a channel or a recess over the entire circumference, so that the flood gas is first distributed throughout the ring channel with a good conductance and then penetrates the gap or the recesses in the stator stack with a lower conductivity as uniformly as possible over the circumference and reaches the pumping stages that are mechanically more stable against flooding.

A coolant inlet 38 and a coolant outlet 40 are arranged on the lower part 90, between which runs a coolant line formed by at least one coolant pipe 76, which is guided in turns around the lower part 90. A coolant pump can be connected to the coolant inlet 38 and the coolant outlet 40, by means of which coolant can be pumped through the coolant line in order to cool the vacuum pump 10.

The coolant tube 76 can be in preformed recesses in the lower part 90, for example in accordance with EP 3 070 335 A1 , be pressed in. The pipe ends can either protrude from the contour of the pump 10 as a respective pipe section at any angle, for example to be connected to the inlet 38 or outlet 40 using insulation displacement screw connections or special plug connectors.

The pipe ends can also be accommodated in the connection blocks, which form the inlet 38 or the outlet 40 and in turn are fixed to the lower part 90. The tight connection of tube 76 and connection block 38, 40 can be established in different ways, e.g. by soldering, welding, clamping / pressing / stretching or with separate sealing elements, e.g. (cutting) sealing rings or bands or with special connectors with integrated Sealing system.

A coolant line is shown which, starting from the inlet 38, has three complete, spirally arranged wraps of the lower part 90 and then ends at the outlet 40. Alternatively, any number or parts of wraps can intersect one or more times at different radius and / or at different axial heights of the axis of rotation 18 or can also reverse one or more times in their direction of rotation, e.g. by means of U-shaped bends or arranged deflection blocks, which take up two pipe ends similar to the connection blocks and establish a connection between them. Such connection and deflection blocks can also contain a valve that regulates the coolant flow or can interrupt it if necessary. Alternatively, any block can also have a further connection, on which e.g. An additional, in particular parallel, coolant line or one or more valves for deflecting or distributing the coolant flow into different branches of the coolant pipe system, which can also serve as a bypass or diversion, depending on the need, is or are present.

The rotatable mounting of the rotor shaft 20 is effected by a roller bearing 42 in the area of the pump outlet 74 and a permanent magnet bearing 44 in the area of the pump inlet 14.

The permanent magnet bearing 44 comprises a bearing half 46 on the rotor side and a bearing half 48 on the stator side, each of which comprises an annular stack of a plurality of permanent magnetic rings 50, 52 stacked one on top of the other in the axial direction, the magnetic rings 50, 52 lying opposite one another to form a radial bearing gap 54.

Within the permanent magnet bearing 44, an emergency or catch bearing 56 is provided, which is designed as an unlubricated rolling bearing and runs empty during normal operation of the vacuum pump without contact and only comes into engagement with an excessive radial deflection of the rotor relative to the stator to form a radial stop for the rotor, which prevents a collision of the rotor-side structures with the stator-side structures. The emergency or catch bearing 56 is seized separately by an insert and can therefore be replaced independently of the permanent magnet bearing 44.

The roller bearing 42 is held by a ring holder which, in turn, is received in an axially and radially decoupled manner by elastomeric elements in a roller bearing holder or roller bearing suspension 84 which is securely fixed to the lower part 90. Mechanical stops limit the possible relative movements between the ring holder and rolling bearing suspension 84.

In the area of the roller bearing 42, a conical injection screw 58 is provided on the rotor shaft 20 with an external diameter increasing toward the roller bearing 42, which can receive operating fluid, in particular lubricant, supplied by means of a lubricant channel 60 and feed it to the roller bearing. The injection screw 58 can preferably according to EP 2 740 956 A2 be designed.

The operating medium is circulated by a lubricant pump 78. The lubricant pump 78 is preferably in accordance with EP 2 060 794 A2 built up. In particular, it can supply a lubricant feed channel, which according to at least one segment EP 2 801 725 A2 is constructed as an O-ring sealed round channel.

The lubricant pump 78 can be used to implement an active, regulated supply of operating media.

The vacuum pump 10 comprises a drive motor 62 for rotatingly driving the rotor, the rotor of which is formed by the rotor shaft 20. A control unit 64 controls the drive motor 62. The vacuum pump 10 and in particular the control unit 64 and the drive motor can be connected via an electrical connection 66 62 can be supplied with electrical current. The control unit 64 forms the lower region of the housing and is closed by the cover 80. The control unit 64 with the cover 80 closes the lower part 90. Depending on the design, one or more seals 77 can be inserted all round between the control unit 64, cover 80 and / or lower part 90 or the corresponding transitions with other sealants, such as liquid sealants, adhesives or, in particular, mold seals that can be applied be closed to gain security against the ingress of media and / or contaminants. By means of at least one electrical feedthrough 86, the current can be fed through the cover 80 into the housing and in particular fed to the drive motor 62.

Vacuum feedthrough 86 can be configured according to EP 1 843 043 A2 be configured, in the example described here a circuit board with a plurality of sealing rings, separate voltage potentials and signals separate from one another from the pump interior, that is to say from the vacuum region, to the outside, that is to say to the “atmosphere” and in particular to the control unit 64.

Depending on the application, the control unit 64 or the drive motor 62 or the pump-active components can mainly introduce undesirable heat into the pump via the housing 16. The coolant, such as water, advantageously flows from the inlet 38 to the outlet 40 since the control unit 64 is to be kept coolest.

A cover 88 can be arranged on the radial outer side of the lower part 90. The cladding 88, which can be designed in the form of a jacket as a sheet metal sleeve slotted along the axis of rotation 18 of the pump 10, is advantageously not shown in the external view of the pump 10 in order to obtain a better view of the solutions underneath. The cladding 88 can have one or more viewing windows or cutouts around any connections of the lower part 90, for example a sealing gas inlet 68, to the outside or to reveal the type data (type plate or engraving) of the pump 10, which are attached to the lower part in a non-detachable manner.

The sealing gas inlet 68 is also referred to as a purge gas connection. Purge gas can be introduced via the sealing gas inlet 68 to protect the engine 62 in the engine compartment in which the engine 62 is accommodated. The gas admitted in the area of the engine via the sealing gas inlet 68 protects the components located in the lower part 90 from corrosive and / or deposited media which can occur in the pump system, depending on the application. A seal 83 is arranged between the motor mount 82 and the lower part 90, so that a labyrinth seal 72, as the only remaining passage, on the one hand, with its low conductance, represents a lock against inflowing media in the motor and roller bearing area and furthermore an increased saturation of the roller bearing and motor area with lock - / inert gas secures.

The labyrinth seal 72 is provided between a motor mount 82 which delimits the motor space upwards and the lower rotor disk 22. The electric drive motor 62 is advantageously protected against corrosion by a casting compound. In the embodiment shown, the motor mount 82 is cast integrally with the drive motor, so that the entire unit, including the stator side of the labyrinth seal 72, which is made in one piece with the motor mount, can be optimally aligned or centered in one step with the lower part 90.

The forevacuum area is located radially outside of the labyrinth seal 72 and below the turbomolecular pump stages, in which, in particular, a chamber 70 is formed which surrounds the axis of rotation 18 and which, as in FIG Fig. 2 and 3rd can be seen has a substantially rectangular cross section. This cross-sectional shape can only be seen as an example, so that another cross-sectional shape, for example a square or circular cross-section, can also be realized. The chamber 70 can also be accommodated at another location in the housing 16 or in the lower part 90. Preferably, chamber 70 is where most of the deposits are, typically in the fore-vacuum area. The chamber 70 is thus particularly preferably between the last pump stage and the pump outlet 74.

In the variant shown, the chamber 70 opens into the pump outlet 74. The chamber 70 therefore forms an ejection area for the gas conveyed by the vacuum pump 10 from the inlet 14, which can reach a fore-vacuum pump (not shown) connected to it via the pump outlet 74. The backing pump can then deliver the gas further, for example into a line for exhaust gas, which is under normal pressure.

The sectional view of the Fig. 3 corresponds to the sectional view of Fig. 2 . It is according to Fig. 3 in the chamber 70 an insert 92 is arranged on which deposits can accumulate or accumulate, which get into the pump 10 via the gas sucked in by the pump 10 and which experience has shown to predominantly deposit in the chamber 70. Deposits 92, such as substances, particles and / or liquid droplets, are not deposited directly on the walls of chamber 70 covered or covered by insert 92, but rather on insert 92 maintenance of the pump 10 are removed from the chamber 70 and cleaned or replaced by a new insert 92. The deposits can therefore be easily removed from the pump 10.

In the example shown, the insert 92 is essentially designed to match the shape of the chamber 70. The insert 92 can thus be inserted into the chamber 70 in a suitable manner. The insert 92 can then lie directly in front of the chamber walls to be covered. The insert 92, like the chamber 70, a circular ring shape with a substantially rectangular cross section when viewed in the radial direction.

The insert 92 is preferably made of sheet metal. However, it can also be made of another material, such as plastic, in particular PTFE.

The insert 92 comprises a bottom 94, a radially inner side wall 96 and a radially outer side wall 98, which extend approximately or completely vertically away from the bottom 94. If, for example, the insert 92 is produced at least partially in a reshaping or original manner, one or more elements can advantageously have bevels. The bottom 94 and the side walls 96, 98 enclose a volume 100 which is open at the top. The insert 92 is therefore in the form of an annular shell or, more generally, the shape of an annular container.

With the insert 92 the Fig. 3 the upper side facing the upstream pump stage is open. Gas discharged from the pump stage can thus get into the volume 100 without being blocked by a wall or the like, so that deposits can accumulate particularly well in the volume 100.

The insert 92 also has an outlet opening 102 (cf. 4 and 5 ), the cross section of which preferably corresponds to the cross section of the pump outlet 74. The insert 92 is arranged in the chamber 70 such that the outlet opening 102 is aligned with the pump outlet 74. The gas can thus flow through the outlet opening 102 into the pump outlet 74 and thus out of the pump 10. The outlet opening 102 can in particular be created in that it is cut out of the insert 92 or otherwise separated out.

The insert 92 is fixed in the chamber 70, preferably by means of at least one fixation. The insert 92 can, for example, be fixed in the clamping association with the package of the stator disks 24. How Fig. 3 indicates that the radially outer side wall 98 can extend so far upwards that its upper end strikes the lowermost stator disk 24. The insert 92 can therefore be fixed in the chamber 70 by means of the lowest stator disk 24.

How Fig. 3 shows, the upper end of the radially inner side wall 96 can be directed radially inward. However, contrary to the illustration, it is preferably ensured that there is a small gap between the upper end of the side wall 96 and the lowermost rotor disk 22 located there, so that the rotor disk 22 can rotate about the axis of rotation 18 on the side wall 96 without abrasion.

Fig. 4 shows a section of the sectional view of Fig. 3 , in which part of a variant of the insert 92 can be seen in cross section. The part of the insert 92 is located in the region of the pump outlet 74 and has the outlet opening 102 already mentioned above.

As the Fig. 4 also shows, an orifice section 106 extends in the fore-vacuum connection 104 of the pump 10 having the pump outlet 74. The orifice section 106 can be designed as a separate part, in particular as a tubular part with an outer diameter which essentially corresponds to the inner diameter of the fore-vacuum connection 104. The mouth section 106 can be introduced into the fore-vacuum connection 104. The channel 108 formed by the mouth section 106 can connect to the outlet opening 102 of the insert 92. The mouth section 106 can also be formed in one piece with the insert 92.

Fig. 5 shows a section of the sectional view of Fig. 3 , in which in turn the part of the insert 92 can be seen in cross section, which is located in the region of the pump outlet 74 and has the outlet opening 102. At the in Fig. 5 Insert 92 shown in the invention, the mouth section 106 is formed according to the invention by the material which is obtained by cutting out the outlet opening 102.

As shown, the mouth section 106 can be formed by triangular pieces of material 110, which are formed by a kind of star-shaped opening or cutting out of the outlet opening 102. The pieces of material 110 remain connected to the insert 92. The pieces of material 110 can be pressed into the fore-vacuum nozzle 104 and in particular brought into contact with the inner wall of the fore-vacuum nozzle 104. The covered inner wall areas of the socket 104 are thus protected against deposits.

Fig. 6 shows a section of the sectional view of Fig. 3 , in which a part of another variant of the insert 92 can be seen in cross section. As shown, a screw 112 can be screwed into a hole in the bottom 94 of the insert 92 and into an underlying hole in the bottom of the chamber 70 in order to fix the insert 92. The screw 112, as shown, is preferably a pan head screw so that it is easy to find when the bottom 94 is covered with debris. In the direction of rotation of the axis of rotation 18 (cf. Fig. 3 ) As seen from one another, a plurality of screws 112 for fixing the insert 92 can be screwed into the bottom 94 of the insert 92 or into the chamber bottom.

Fig. 7 shows a section of the sectional view of Fig. 3 , in which a part of yet another variant of the insert 92 can be seen in cross section, which in comparison to the variant of FIG Fig. 6 has no screw 112 for fixation. In this variant, the insert 92 is again open on its top 114. However are provided in the side wall 98 along the circumferential direction of the side wall 98 offset, elongated, continuous openings 116, in particular slots or openings. The openings 116 are preferably as in FIG Fig. 7 is shown, arranged in the region of the upper edge of the side wall 98. The upper edge of the side wall 98 has a wavy structure due to the openings 116.

The insert 92 can be brought from a first shape into a second shape, in particular by pressing the side wall 98 from above, the insert 92 being reduced or compressed in the second shape as seen in the axial direction. The upper edge of the side wall 98 with the openings 116 forms a circumferential deformation area. By pressing the side wall 98, the openings 116 can be plastically or elastically deformed and reduced, so that the axial extension of the side wall 98 is reduced and the insert 92 is thus compressed in the axial direction. The openings 114 therefore allow the side wall 98 to be axially deflected to vary the overall height. The insert 92 can behave like a kind of spiral spring and can thus be clamped between the lowest stator disk 24 and the chamber bottom.

The insert 92 can also be designed such that the outer side wall 98 can be moved at least slightly radially outward and / or the inner side wall 96 radially inward by "pressing in" the insert 92, so that it lies in contact with the inner or reaches outer chamber wall. The insert 92 can thereby also be fixed or tensioned in the chamber 70. This can be made possible, for example, by the fact that the side wall 98 has a plurality of through openings 116 which are offset with respect to one another in the circumferential direction and which, starting from the upper edge of the side wall, run at least substantially in the axial direction downward (not shown). As a result, the side wall 98 has a number offset at its upper edge in the circumferential direction tabs lying opposite one another, which can tilt radially outward, for example, in order to clamp the insert 98 in the chamber 70.

How Fig. 7 also shows, in the radially outer wall of the chamber 70 one in the circumferential direction of the side wall 98 or in the direction of rotation of the axis of rotation 18 (cf. Fig. 3 ) circumferential groove 118 may be formed. The radially outward, upper end of the side wall 98 can engage in the groove 118, as a result of which the fixation of the insert 92 in the chamber 70 can be further improved. The groove 118 preferably runs directly below the lowermost stator disk 24. For this purpose, the radially outer side wall 98 also has a slightly cranked, raised edge which abuts the first or lowermost stator disk 24 axially and is under axial pressure.

Fig. 8 shows a section of the sectional view of Fig. 3 , in which part of a variant of the insert 92 can be seen in cross section. In this case, a seal 120 which extends around the axis of rotation 18 is arranged between the radially outer side wall 98 of the insert 92 and the outer wall of the chamber 70. The seal 120 is preferably inserted into a circumferential groove 118 which is introduced into the outer side wall 98. Between the radially inner side wall 96 and the radially inner wall of the chamber 70, a seal 122 is inserted which extends around the axis of rotation 18. The seals 120 and 122 act as a type of pressure distributor and fix the insert 92 in the chamber 70. In addition, they provide a sealing effect between the respective side wall 96, 98 of the insert 92 and the respective chamber wall located behind it.

Fig. 9 shows a section of the sectional view of Fig. 3 , in which part of a variant of the insert 92 can be seen in cross section. Between the outer, upper end of the side wall 98 and the outer wall of the chamber 70 or the lowermost stator disk 24, a seal 124 is inserted which surrounds the axis of rotation 18, as a result of which the insert 92 is fixed in the chamber 70.

The in the 8 and 9 Seals 120, 122 and 124 shown are preferably designed as O-ring seals.

Reference list

10th

Vacuum pump

12th

Inlet flange

14

Pump inlet

16

casing

18th

Axis of rotation

20

Rotor shaft

22

Rotor disc

24th

Stator disc

26

Spacer ring

28

Scoop area

30th

arrow

32

Preload and sealing ring

34

Sealing area

36

Flood gas inlet

38

Coolant inlet

40

Coolant outlet

42

roller bearing

44

Permanent magnet bearings

46

half of the bearing on the rotor side

48

stator side bearing half

50

permanent magnetic ring

52

permanent magnetic ring

54

radial bearing gap

56

Emergency or catch camp

58

conical spray screw

60

Lubricant channel

62

Drive motor

64

Control unit

66

Electrical connection

68

Sealing gas inlet

70

Discharge area, chamber

72

Labyrinth seal

74

Pump outlet

76

Coolant pipe

77

poetry

78

Lubricant pump

80

cover

81

poetry

82

Engine mount

83

poetry

84

Rolling bearing suspension

86

Electrical implementation

88

Cladding

90

Lower part

92

inlay

94

ground

96

Side wall

98

Side wall

100

volume

102

Outlet opening

104

Backing nozzle

106

Mouth section

108

channel

110

Piece of material

112

screw

114

Top

116

opening

118

Groove

120

poetry

122

poetry

124

poetry

Claims (12)

1. A vacuum pump, in particular a turbomolecular pump, comprising

   a housing (16, 90) having at least one inlet (14) for a fluid, in particular a process gas or air, to which a recipient can be connected and having at least one outlet (74) for the fluid; and

   at least one pump stage arranged in the housing (16, 90) for conveying the fluid, in particular from the recipient, through the vacuum pump (10) from the inlet (14) to the outlet (74),

   wherein a chamber (70) is formed in the housing (16, 90), and wherein at least one insert (92) for receiving deposits is arranged in the chamber (70) and covers at least one side of the chamber (70) bounding the chamber (70),
   wherein

   the insert (92) has an outlet opening (102) which can in particular be aligned with the outlet (74) at the housing (16, 90) of the vacuum pump (10);

   the outlet (74) of the pump (10) has a pre-vacuum stub (104) into which the chamber (70) opens; and the insert (92) comprises at least one opening section (106) which can be inserted or is inserted into the pre-vacuum stub (104),

   characterized in that
   the opening section (106) is formed, in particular solely formed, by the part of the material of the insert (92) which was separated from the insert (92) to provide the outlet opening (102).
2. A vacuum pump in accordance with claim 1,
   characterized in that
   the insert (92) is configured such that it covers, in particular at least largely completely covers, the base of the chamber (70) and/or a side wall of the chamber (70) radially outwardly bounding the chamber (70) and/or a side wall of the chamber (70) radially inwardly bounding the chamber (70).
3. A vacuum pump in accordance with claim 1 or claim 2,
   characterized in that
   the insert (92) at least partly surrounds a volume (100) and has at least one opening at at least one side, in particular an upper side (114), or is completely open at the side.
4. A vacuum pump in accordance with claim 3,
   characterized in that
   the insert (92) can be attached in the chamber (70) such that the side, in particular the upper side (114), faces the pump stage.
5. A vacuum pump in accordance with any one of the preceding claims,
   characterized in that
   the shape of the insert (92), which is in particular configured as a shell, is at least substantially adapted to the shape of the chamber (70).
6. A vacuum pump in accordance with any one of the preceding claims,
   characterized in that
   the chamber (70) extends, in particular beneath the pump stage, in ring shape about a central axis of the vacuum pump, in particular about an axis of rotation (18) of a rotor shaft (20) of the pump (10), with, preferably, the chamber (70) having an at least approximately rectangular cross-section.
7. A vacuum pump in accordance with any one of the preceding claims,
   characterized in that
   the insert (92) is designed as a shell, preferably a ring-shaped shell, which is designed in a manner corresponding to the chamber (70), which is at least partly open at the top and which has a base (94) and radially inwardly or radially outwardly disposed side walls (96, 98) which preferably extend vertically to the base (94).
8. A vacuum pump in accordance with any one of the preceding claims,
   characterized in that
   the insert (92) is fixed and/or can be fixed in the chamber (70) by means of at least one fixing (112, 120, 122, 124).
9. A vacuum pump in accordance with any one of the preceding claims,
   characterized in that
   the insert (92) can be moved, in particular by pressing onto the insert (92), from a first mold into a second mold in which the insert (92) has a larger outer diameter and/or a smaller inner diameter compared to the first mold and/or in which the insert (92) has plastic and/or elastic shape changes and/or in which the insert (92) has a larger or smaller axial height with respect to the first mold.
10. A vacuum pump in accordance with any one of the preceding claims,
    characterized in that
    at least one seal (120, 122, 124) is arranged between a wall (94, 96, 98) of the insert (92) and a wall of the chamber (70).
11. A vacuum pump in accordance with any one of the preceding claims,
    characterized in that
    the insert (92) is designed from metal, in particular in the manner of a metal sheet or a foil, or is designed from a plastic, preferably an inert plastic, such as PTFE.
12. A vacuum pump in accordance with any one of the preceding claims,
    characterized in that
    the insert (92) has at least one coating, in particular a non-stick layer, e.g. comprising nickel or PTFE, a foil-like layer or a layer formed by a spray film.

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