KR20120054061A - Vacuum pump system - Google Patents

Abstract

The vacuum pump system includes two vacuum pumps 12 and 35 connected to each other. In order to form a vacuum pump system of smaller size, the connection between the two vacuum pumps is carried out via connecting elements 22, 38 which are attached directly to the pump housing and form the connection site 34. The outlet flange 46 of the upper pump 35 lies directly on the inlet flange 14 of the lower pump 12 without causing a large force or moment transfer.

Description

Vacuum Pump System {VACUUM PUMP SYSTEM}

The present invention relates to a vacuum pump system comprising a plurality of vacuum pumps connected to each other.

Vacuum pump systems of the type described above usually comprise two or more vacuum pumps arranged in series. Thus, the medium to be transported which is usually gas will be transported through the inlet of the vacuum pump by the first pump and then through the pump outlet to the adjacent second vacuum pump. Normally, in a system comprising two vacuum pumps, the second vacuum pump will perform the transport process under atmospheric pressure. Optionally, it is also possible to arrange a plurality of vacuum pumps in series with one another or in part parallel to one another, in which case the last vacuum pump will normally perform compression under atmospheric pressure in the transport direction. In such arrangements, forward vacuum pumps for compression under atmospheric pressure are often provided in the form of rotary vane vacuum pumps, sliding vane vacuum pumps, claw vacuum pumps, multistage Roots vacuum pumps and screw vacuum pumps. In such pump systems, a Roots pump is often provided as the first pump in the transport direction, at which the lowest pressure is produced at the inlet of the first pump.

Known vacuum pump systems include a support rack or frame, on which individual vacuum pumps are arranged. Mounting vacuum pumps on the rack can be performed, for example, with the aid of feet provided on the pump housing. Thus, the inlet and outlet of the vacuum pumps will be connected to each other by rigid or flexible conduits or by special adapters. The weight force and gas force generated during pump operation will be largely accommodated by the rack. In such pump systems, the rack can be lifted and moved from the bottom by the use of a forklift or by the use of a crane with the aid of a crane eyelet. On the other hand, such vacuum pump systems of the type comprising a rack for the support of the individual pumps have the advantage that in most cases the individual pumps can be exchanged independently of one another. However, the inevitable disadvantage of such systems is that there is a significant space requirement for the rack. In addition, the required connection elements as well as the rack will incur additional costs.

In other types of known vacuum pump systems, a vacuum pump, usually two pumps, are directly connected to each other. In this case, no separate rack is provided. The connection of the two vacuum pumps is carried out by connecting the outlet flange of the first vacuum pump directly or via an adapter to the inlet flange of the second vacuum pump. In this embodiment, the weight and gas forces generated during operation must be received by the flange and transferred to the pump housing. Here, it is not normally possible to provide a crane eyelet for the transfer of the vacuum pump system, since the flanges are subjected to excessive stress during the transfer, exposing a great risk of damage. In addition, connecting two pumps through the inlet and outlet flanges can accommodate and transfer the corresponding forces, and above all, the flanges and the adapters must be very rigid in order to be able to assemble the arrangement and free space for screw connections. Has the disadvantage of being provided. This incurs additional costs. In addition, the appearance of two interconnected vacuum pumps does not coincide, which often results in one pump protruding beyond the other. This will result in significant space requirements.

It is an object of the present invention to provide a compact vacuum pump system with only minimal space requirements.

According to the invention, the above object is achieved by the features defined in claim 1.

The vacuum pump system of the present invention comprises two or more vacuum pumps. In the first case, the pump outlet of the first vacuum pump is arranged to be fluidly connected to the pump inlet of the second vacuum pump arranged downstream in the flow direction. This connection is effected by connecting the outlet flange to the inlet flange. Preferably, the connection is established directly through the flange. Alternatively, indirect connection via tube conduits or other intermediate elements is also possible. In the present invention, on both pump housings, three or more connection sites are mechanically connected to each other for force transmission and / or moment transmission. According to the invention, at least two of the connection sites are flange-independent.

It may also be provided that the pump inlet of the second vacuum pump is connected to the pump inlet of the first vacuum pump. In such an embodiment, one pump sucks fluid from the suction region of the other pump so that both pumps return to the same operating state, while the free suction flange of the other pump is another additional vacuum pump, optionally another Two identical vacuum pumps are connected to each other, arranged parallel to each other in such a way that they can be used to mount a vacuum pump of the type on top. Instead of using a direct flange connection, both suction regions of the same pumps can also be connected via the outer tube conduit.

Thus, according to a first preferred embodiment, the first mechanical connection is carried out-according to the state of the art-via two interconnected flanges, thereby providing a It will form a first connecting site for delivering a portion. In addition, according to the invention, two or more additional connection sites are provided in two pump housings. Here, the two connection sites preferably comprise one connection element each on both pump housings, wherein according to a preferred embodiment the two connection elements of the connection site are arranged to face each other. In addition, transfer of forces and / or moments will occur on two or more additional connecting sites. Compared with the direct connection of two vacuum pumps through the pump flange, the further provision of two or more additional connection sites has the advantage that only part of the force and moment are accommodated by the flange connection. This, in turn, offers the advantage that the flange itself may have less rigidity. In particular, it is possible to arrange three connecting sites at the greatest possible distance from each other to achieve an advantageous transfer of forces and / or moments. Thus, according to a particularly preferred embodiment, two or more connection sites are located outside of the flange surfaces, ie the surfaces on which the two flanges face each other and which are selectively connected to each other by screw connection or the like. Preferably, at least two of said connection sites are arranged outside the flange surfaces defined by the standard. In large flange systems, it may be sufficient to provide only one additional connection site to achieve sufficient distribution of force and moment.

Particularly preferably, the two or more flange-independent connection sites can each receive and transmit at least 25%, more preferably at least 40%, of the forces and moments generated during operation. Thus, the flanges on the pump inlet and the pump outlet connected to the flange can be given a smaller weight and therefore a less costly design.

According to a further preferred embodiment, three or more flange-independent connection sites are provided. In particular, this has the advantage that the fluid connection via the inlet and outlet flanges can be given in a simpler configuration. In particular, it becomes possible to design the flange to have the effect of substantially only acting as a fluid connection and without substantial force transmission. Such a design is particularly advantageous where only a difficult access is possible with the flange connection. In this embodiment, for example, the flange connection between the pump outlet and the pump inlet only achieves the sealing function and, if necessary, positioning via resistor pins or the like (eg housing sealing with centering ring). This can be designed in a further provided manner. This has the advantage that a mechanical connection between two vacuum pumps can be provided at a more convenient accessible site.

Thus, in this embodiment the pump outlet and the pump inlet are not connected to each other, in particular in a force-locking manner. In particular no screw connection is provided.

It is particularly preferred that the connecting elements are at least partially formed as outward projections of the housing wall of the corresponding vacuum pump. Advantageously, such protrusions are more easily accessible, in particular these protrusions can also be processed more easily. Thus, in particular, it becomes possible to treat the contact surfaces of the projections in an easy manner and to provide these contact surfaces with the flatst shape. Preferably, the two mutually facing connecting elements in this connection comprise two mutually plane-parallel contact surfaces at the connecting site. In this way, tension is prevented from being introduced into the housing of the individual vacuum pump, in particular as a result of the assembly process of the vacuum pump system. In addition, it is particularly advantageous in this connection that two or more-and more preferably all-of the contact surfaces of the vacuum pump are arranged in one plane. Preferably, this plane corresponds to the flange contact surface, which is particularly preferred in embodiments where the flange connection also serves as a transfer of force and moment. When using three or more connection sites, it is particularly desirable to maintain the flange faces of the outlet and inlet flanges at a distance of about 0.1 mm, provided that the flange system does not have any connection force or Will not accept the moment. The deformation of the pump housing can thus be prevented by the connecting force resulting in a possible result of a reduced straight gap for the pump rotor.

Preferably, the individual connecting sites are further provided with retaining elements. The retaining elements include, for example, screws, clamping elements and the like to ensure the mechanical connection of the individual vacuum pumps of the vacuum pump system. The individual retaining elements are formed integrally with the protrusions forming the connecting elements, for example. For example, the holding site may be configured in such a way that one of the two vacuum pumps to be connected to each other comprises a cylindrical protrusion, with the foot-shaped protrusion lying on top extending outwardly with respect to the second pump housing. . It is thus possible to use a screw as a retaining element, which will be screwed into the cylindrical projection of the lower pump through the foot-shaped projection of the upper pump. It is also possible to provide separate retaining elements, in which case, for example, two projections are arranged that are cylindrically arranged to face each other, which projections abut one another but are not mechanically connected to one another. With the aid of claw-like connection, eyelet connection and the like, the two housings of the vacuum pump can be connected to each other, preferably at their side walls, to the outside.

According to a further preferred embodiment, one or more connecting elements of the connecting site are configured to allow displacement of the two connecting elements relative to each other at this connecting site. Preferably, in this case, since one of the two connecting elements is in the form of a rail, the second connecting element of this connecting site can be displaced in the first connecting element in the form of a rail. Particularly preferably, the two connecting sites are configured in such a way that two displacement means are parallel to each other. This has the advantage that, for example, manufacturing tolerances can be easily compensated for and the occurrence of tensile forces due to the assembly process can be avoided. In addition, it is possible to connect vacuum pumps of different sizes to each other. By providing such rail-shaped connection elements, it also facilitates assembly and disassembly processes, especially under conditions of tight spaces. If the connecting element in the form of a rail is suitably configured, compensation for different thermal expansion of the two pumps is also possible.

It is also possible to provide spacer elements between the connecting elements for height balance. The provision of such spacer elements is particularly advantageous because the modular system can be compiled by providing the possibility of connecting different pumps to each other. Corresponding spacer elements may be rigid or elastic.

According to a particularly preferred embodiment, the position of the individual connection elements is at least partly selected due to the effect that the connection elements are arranged in the region of the side wall of the pump housing and / or in the region of the support flange. Advantageously, this allows good introduction of forces and / or moments into the pump housing. Thus, the forces and / or moments introduced ensure that only the smallest possible deformation of the pump housing can result. This is particularly advantageous due to the very narrow play between the pump housing and the pump element, for example the rotor.

According to a further preferred embodiment of the invention or a possible variant of the above-described embodiments, an adapter element is provided between two vacuum pumps to be connected. This makes it possible for example to connect very different vacuum pumps to each other. In particular, a vacuum pump without separate connecting elements can thus be connected to the further vacuum pump comprising a plurality of connecting elements, via an outlet flange. For this purpose, the adapter element preferably comprises two or more adapter feet. This type of connection is particularly possible when the flange of the upper pump is dimensioned sufficiently to accommodate the forces and / or moments. The lower pump will in turn be stressed in such a way that the two or more flange-independent connection sites receive at least 25%, preferably at least 40%, of the force generated during operation and deliver them separately.

The above-described individual embodiments of the vacuum pump system of the present invention having two or more vacuum pumps are unique in that a very small vacuum pump system can be realized by corresponding adaptation to the positions of the inlet and outlet flanges and the positions of the connection sites. Has an advantage. In particular, such a vacuum pump system makes it possible, for example, to arrange a small pump among two vacuum pumps within the appearance of a large vacuum pump, so that a smaller length configuration is not possible because the small pump does not protrude beyond the large pump. Have Particularly in the case of a roots pump, the position of the outlet flange can be freely chosen in the axial direction at least within any limit. Thus, corresponding shape adaptations can be performed, whereby the position of the pumps relative to each other can be improved to form a compact vacuum pump system.

In particular, it is possible to provide a modular system comprising different vacuum pumps, in particular forward vacuum pumps and high vacuum pumps, by providing the connection elements of the invention in individual vacuum pumps. By allowing different pumps of different performance levels to be combined with each other in a simple manner, it becomes easy to realize vacuum pump systems with very different performance ranges. Thus, the system cost can be kept very low. In addition, various embodiments of the present invention further have the advantage of allowing a very robust small vacuum pump system. In addition, the assembly process can be quite simple. With this preferred modular system, it is possible to achieve a high degree of adaptability so that a scalable modular system is realized. In addition, it is of course also possible to combine two or more pumps into each other in a vacuum pump system. In addition, it is possible to transfer the entire vacuum pump system with the aid of a crane or floor conveyor system (eg forklift) as a result of the transfer of advantageous forces and / or moments.

The invention will now be described in more detail with reference to the accompanying drawings.

In the drawings, the following drawings are shown.

1 to 5 are plan views of different embodiments of a vacuum pump of a vacuum pump system,
6 is an enlarged cross-sectional view as seen in the direction of arrow VI of FIG. 5,
7 is a schematic plan view of a preferred configuration of a connection site,
8 is a schematic cross-sectional view taken along the line VII of FIG. 7,
9 and 10 are schematic side views of preferred embodiments of a connection site,
11 is a schematic side view of one embodiment of a vacuum pump system,
12 is a bottom view of the upper vacuum pump shown in FIG. 11 as seen in the direction of arrow XII of FIG. 11,
13 is a schematic cross sectional view of an embodiment of a flange connection;
14 is a schematic side view of a further embodiment of a vacuum pump system provided with an adapter element.

1 to 5 are very schematic top views of vacuum pumps, for example screw-type vacuum pumps. Each upper side 10 of each vacuum pump housing will be connected to a first vacuum pump 12 (shown) and mounted with a second vacuum pump (not shown in the figure) of the vacuum pump system. In all the vacuum pumps shown in FIGS. 1-5, the upper side 10 is shown with an inlet flange 14 surrounding the inlet opening 16. In the illustrated embodiment the inlet flange 14 having a rectangular cross section can, of course, be circular. In the embodiment shown, the inlet flange 14 is provided with four fastening holes 18. The two flanges can be mechanically fastened to each other by means of a screw, in cooperation with the corresponding fastening holes on the outlet flange of the second vacuum pump lying on top of the first pump, which will be connected to the first pump 12. In addition, the vacuum pump 12 shown in FIGS. 1 to 5 includes a side outlet 20.

In order to form a connection site, the embodiment shown in FIG. 1 is provided with six cylindrical connection elements 22 extending upward from the housing side 10. Through these cylindrical cylindrical connection elements 22, the connection to the second or upper vacuum pump can be established by the use of a number of connection options, which will be further described with reference to FIGS. 6 to 10. Thus, in the embodiment shown in FIG. 1, six flange-independent connecting elements 22 are provided on the outside of the flange 14 to form up to six connecting sites. The connection of the second pump and the first pump 12 at the top can thus already be effected mechanically only by the connection site. This has the advantage that only small forces and / or moments can be transmitted through the flange 14. Therefore, there will be no need to design the flange 14 in a particularly robust and stable manner.

Especially in small vacuum pumps, it may be sufficient to provide only two connecting elements 22 (FIG. 2). The connection with the second vacuum pump arranged on top will then be carried out by the flanges 14 as well as the two connection elements 22.

According to a further possible embodiment, three flange-independent connection sites 22 are provided (FIG. 3). Thus, there is a three-point connection through three connecting elements 22. In this embodiment, the flange 14 does not have to accept forces and / or moments.

In the embodiments shown in FIGS. 1-3, the separate cylindrical connection site 22 comprises a toothed hole 24 for receiving the fastening screw. Also in these embodiments, different connections of the two pumps may be provided, which will be described later with reference to FIGS. 7 to 10.

One such alternative connection is shown schematically in FIG. 4. In this embodiment, the connection is not carried out via the connection element 22. Here, the connection site 22 comprises a flat surface 26 for positioning a cylindrical pit-shaped element of the vacuum pump arranged on top of the cylindrical shape, the pit-shaped elements being, for example, Corresponds to the connecting element 22. Thus, in this embodiment the connecting element 22 serves only as a support and does not serve to establish a mechanical fixed connection. Mechanical connection is carried out via a separate retaining element 28. In the embodiment shown, one retaining element 28 is provided for each connecting element 22, each arranged on the outer wall 30 of the pump housing. These retaining elements are designed as protrusions with U-shaped recesses, thereby enabling attachment to a corresponding retaining element located on the second vacuum pump by use of a toothed bar or the like (see FIG. 9 described below in this regard). .

According to a further preferred embodiment (FIG. 5), a rail-shaped connection element 32 is provided instead of the cylindrical connection element 22. The connecting element 32 comprises a rail 33 which is firmly connected to the housing of the lower pump 12 and has a rectangular cross section. On the rail 33, a carriage 37, which is firmly connected to the housing of the upper pump, is guided for displacement in the longitudinal direction 39 of the pump housing. For adjustment, a side guide 33a may be further provided. Thereby, the upper pump can be easily adjusted for the lower pump. In particular, in this way the tensile forces due to the assembly process are protected from being introduced into the flange 14. For the mechanical connection of the two pumps, in this embodiment a retaining element 28 is also provided on the side pump 30 of the lower pump as well as on the upper pump (the upper pump is not shown).

The connection between two or more pumps of the vacuum pump system may be provided in the manner described below with reference to FIGS. 7 to 10.

In the first embodiment of the connecting site 34 (FIGS. 7 and 8), the upper side 10 of the lower pump 12 is provided with a cylindrical connecting element 22. The housing 36 of the upper pump includes side eyelet shaped projections 38. The bottom of this projection is supported on the planar upper side 26 of the connecting element 22. In addition, the connecting element 38 of the upper pump housing 36 is formed with a hole 40 which is aligned with the toothed hole 24 of the lower connecting element 22. Therefore, the fixing can be performed by the screw 42 (FIG. 8) not shown in FIG.

In addition, it is possible to realize the connecting site 34 by connecting two lug-like connecting elements 38 to each other. In the embodiment shown in FIG. 9, the two lug connection elements 38 do not directly abut one another, but are provided with intervening spacer elements 44. The spacer element 44 may be rigid or elastic. Depending on the configuration of the connecting element, the connecting element can be omitted.

Preferably, two lug connection elements 38 arranged on the outer wall of the pump housing can also serve as retaining elements. These retaining elements will thus implement a substantial mechanical connection to the two pumps, as described above in connection with the retaining element 28 (FIGS. 4 and 5). In addition, connecting elements are provided, on which the two pumps abut one another but are not mechanically connected. These connecting elements can be designed, for example, as already described with reference to FIGS. 4 and 5.

In addition, the connection site 34 may also be designed in the manner shown in FIG. 10. Optionally, in this embodiment a spacer element 44 is arranged between the lug connection element 38 and the cylindrical connection element 22, which elements 38, 22 are fastened back to one another by means of a screw 42. do.

11 is a side view of one embodiment of a pump system according to the present invention. In the pump system, the lower first pump 12 is provided, for example, in the form of a screw type vacuum pump. The upper or second pump 35 is provided in the form of a Roots vacuum pump. The connection of the two pumps 12, 35 is provided in an intermodulating manner in which the vacuum pump system can be designed to be the smallest. In particular, in side view, the upper pump 35 does not protrude laterally beyond the lower pump 12. As shown on the right side of FIG. 11, the connection of the two pumps 12, 35 is carried out through two connection sites 34 arranged behind each other. These connecting sites 34 are designed as shown in FIGS. 9 and 10, with spacer elements 44 provided for height adjustment. Provided on the left side in FIG. 11 are also two additional linking sites 34 which are connected in turn, which are designed as shown in FIGS. 7 and 8. Here, no spacer element is provided.

Thus, in the bottom view of the Roots vacuum pump 35 (FIG. 12) one can see four connection elements 38 for four connection sites 34. Further visible in this bottom view is the outlet flange 46 connected to the inlet flange 14 of the lower pump 12. The connection can be carried out via a screw in a corresponding hole 18 provided for this purpose. However, it is also possible to provide a pure fluid connection with the corresponding seal element since it is absolutely not necessary to carry out the transfer of forces and / or moments through the flanges 46, 14. This has the advantage that it is not necessary to carry out the attachment by screws on the flanges 14 and 46 which was only difficult to access.

The flange connection between two flanges 14, 46 is shown by way of example in FIG. 13. In such a flange connection, no substantial transfer of force and / or moment occurs between the two flanges 14, 46. This connection is a pure fluid connection between the two flanges 14, 46. For this purpose, the flange 14 is provided with an annular groove 48 surrounding the inlet 16 of the lower pump 12. Arrangement of the seal element 52 on the annular groove 48 creates a seal effect on the upper flange 46. The two housings will be connected to each other and aligned with each other by screws 42 on the connection site 34. Thus alignment can also be performed through the register pin.

According to a further embodiment of the pump system, the upper or second pump 56 (FIG. 14) is uniquely fastened to the lower pump 12 via the outlet flange 46 of the lower pump. In order to realize good acceptance of the forces and / or moments that occur, the outlet flange 46 is not directly connected to the inlet flange 14. Instead, an adapter element 58 is provided. The adapter element is configured to realize a mechanical and fluid connection between two flanges 46, 14 and also includes two adapter feet 60. Thus, in plan view, the adapter element 58 of the illustrated embodiment has a substantially Y-shape so that the adapter feet 60 are arranged one after the other. Two adapter feet 60 are connected to the connecting element 22 of the lower pump 12, and according to the invention such a connection can be provided in the manner described in the various embodiments of the invention.

In order to mount the upper vacuum pump, perhaps with a heavier weight, on the pump housing of the lower pump and preferably without the transmission of forces and / or moments, the adapter element can be fixed in an X-shaped configuration over the four connection sites 22. It is particularly advantageous to design the adapter element 58 in such a way that the inlet flange 14 of the lower pump 12 remains almost stress free. Of course, the pump systems of the present invention may include two or more pumps as well as two pumps.

Claims (18)

A first vacuum pump 12 comprising a pump inlet 16 and a pump outlet 20, and
A second vacuum pump (35) comprising a pump inlet and a pump outlet (50),
The pump outlet 50 and / or pump inlet of the second vacuum pump 35 is fluidly connected to the pump inlet 16 of the first vacuum pump with the aid of flanges 14, 46. To
The first and second pump housings 11, 36 are mechanically connected to each other on three or more connecting sites 22, 34, 38; 14, 46 to enable the transfer of forces, and the connecting sites 22, 34. At least two of 38) are flange-independent,
Vacuum pump system.
The method of claim 1,
Each connection site 22, 34, 38 comprises two mutually facing connection elements 22, 38,
Vacuum pump system.
The method according to claim 1 or 2,
Characterized in that two or more connecting sites 22, 34, 38 are arranged outside the surface of the flange,
Vacuum pump system.
The method according to any one of claims 1 to 3,
The two or more flange-independent connection sites 22, 34, 38 are constructed in such a way that the flange-independent connection sites can deliver at least 25%, preferably at least 40%, of the forces and moments generated during operation. Or arranged,
Vacuum pump system.
The method according to any one of claims 1 to 4,
Three or more connection sites 22, 34, 38 are flange-independent,
Vacuum pump system.
The method of claim 5, wherein
Characterized in that the connection of the pump inlet 16 to the pump outlet 50 is substantially the only fluid connection,
Vacuum pump system.
The method according to claim 6,
Characterized in that there is no force-locking connection and in particular a screw connection between the pump inlet 16 and the pump outlet 50.
Vacuum pump system.
The method according to any one of claims 1 to 7,
Said connecting elements 22, 38 comprise protrusions extending from the housing walls 10, 30,
Vacuum pump system.
The method according to any one of claims 1 to 8,
Interfacing the connecting sites 22, 34, 38, the interconnecting connecting elements 22, 38 are characterized in that they comprise two mutually planar-parallel support faces 26,
Vacuum pump system.
The method of claim 9,
The support face 26 of the two or more connecting elements 22, 38 of the vacuum pump 12, 35 is characterized in that it is arranged in one plane, preferably in the plane of the flange abutment face,
Vacuum pump system.
11. The method according to any one of claims 1 to 10,
The connecting sites 22, 34, 38 comprise a retaining element 28, characterized in that the retaining element 28 is preferably provided integrally or separately inside the projections 22, 38.
Vacuum pump system.
12. The method according to any one of claims 2 to 11,
Characterized in that one or more of the connecting elements 33, 33a, 37 of the connecting site 34 are displaceable with respect to each other,
Vacuum pump system.
The method according to any one of claims 2 to 12,
A spacer element 44 is provided to compensate for the height difference between the mutually facing connecting elements 22, 38, in particular between the abutment faces of the mutually facing connecting elements,
Vacuum pump system.
The method according to any one of claims 2 to 13,
Said connecting elements 22, 38 are arranged at least partly in the region of the side walls 10, 30 of the pump housing and / or in the region of the support flanges,
Vacuum pump system.
The method according to any one of claims 2 to 14,
An adapter element 58 is arranged between the two vacuum pumps 12, 56 which are connected to each other for the connection of the connection elements 22, 38; 46, 14 which are not facing each other, wherein the vacuum pumps 56 are One of which optionally comprises only one connecting site 46 formed as a flange,
Vacuum pump system.
The method of claim 15,
The adapter element 58 comprises at least two adapter feet 60 to accommodate the weight of the upper vacuum pump 56,
Vacuum pump system.
The method of claim 15,
In order to accommodate the weight of the upper vacuum pump 56, the adapter element 58 comprises at least three, preferably four adapter feet 60, so that the inlet flange 14 is preferably free from stress. Characterized in that
Vacuum pump system.
The method according to any one of claims 1 to 17,
Characterized in that it comprises two or more vacuum pumps,
Vacuum pump system.

Images