EP3070335A1 - Housing for a vacuum pumping and/or for a piece of a vacuum pump - Google Patents

Abstract

The invention relates to a housing for a vacuum pump and / or for a part of a vacuum pump with at least one arranged in the housing cooling and / or heating tube and / or arranged on the housing component in which arranged at least one cooling and / or heating tube is, for tempering the housing, wherein in the housing and / or in the at least one component of the housing at least one groove for receiving the at least one cooling and / or heating tube is arranged, wherein the at least one groove at least partially at least one undercut and / or or at least one projection.

Description

The invention relates to a housing for a vacuum pump and / or for a part of a vacuum pump.

Vacuum pumps play an important role in vacuum technology and are used in various technical applications for the extraction of mainly gaseous media and for the evacuation of cavities. Among others, turbomolecular pumps are used which operate in the molecular, ie non-viscous, range and are capable of producing a vacuum of very high purity. Turbomolecular pumps usually include a rotating unit consisting of a stator and a rotor rotatable relative to the stator, the rotor being driven in rotation to produce the high-purity vacuum at usually very high speeds.

The development of vacuum pumps is moving towards vacuum pumps with a high power density and a compact pump housing. Due to the small outer surface of the case, the cooling of the pump housing and the lubricant via convection presents a particular challenge. While the housing components usually survive temperatures of more than 100 ° C. without damage, equipment such as the lubricants used for the lubrication of the shaft bearings encounters increased levels Temperatures to their limits. These age prematurely and components that are dependent on optimum lubrication properties, such as gear wheels, rolling bearings and also touching seals, have a shortened life and cause shorter service intervals.

From practice it is known to arrange cooling and / or heating pipes in the housing of a vacuum pump. For this purpose, grooves are introduced in the surface of the housing, which are arranged, for example, spirally in the housing surface. In these grooves, the cooling and / or heating pipes are arranged. This known from practice embodiment has the disadvantage that the tubes retain their elasticity and thus detach from the surface of the groove. As a result, the cooling or heating effect is greatly reduced because there is no contact between the pipes and the housing and thereby the heat transfer is significantly minimized. This release of the surface of the groove can also be done after a long time, so that the pump loses over a longer period of efficiency.

The technical problem underlying the invention is to provide a housing for a vacuum pump and / or for a part of a vacuum pump, which does not have the disadvantages mentioned in the prior art.

This technical problem is solved with a housing having the features according to claim 1.

The housing according to the invention for a vacuum pump and / or for a part of a vacuum pump with at least one cooling and / or heating tube arranged in the housing and / or a component arranged on the housing, in which at least one cooling and / or heating tube is arranged, for tempering the housing, wherein in the housing and / or in the at least one component of the housing at least one groove for receiving the at least one cooling and / or heating tube is arranged, characterized in that the at least one groove at least partially at least one Undercut and / or has at least one projection.

The invention is applicable to all vacuum pumps, such as Roots or screw pumps, turbomolecular pumps, rotary vane pumps, side channel pumps and the like.

By arranging at least one undercut and / or at least one projection in the groove, the embodiment according to the invention has the advantage that the at least one cooling and / or heating tube, which is arranged in the groove, through the at least one undercut and / or by the at least one projection is held in the groove. A release of the tube from the surface of the groove is of the at least one undercut and / or prevented by the at least one projection. This means that the contact between the tube wall of the at least one cooling and / or heating tube and a wall of the groove is maintained even with a long-term operation and with large heat fluctuations.

As a result, a permanent and reliable heat transfer from the at least one cooling and / or heating tube or in the reverse direction of the housing on the cooling and / or heating tube is possible.

According to a preferred embodiment of the invention, the at least one groove in cross section has at least one region which has a smaller width than a region with the greatest width of the groove. This means that the region with the smaller width keeps the cooling and / or heating tube in the predetermined position in which the cooling and / or heating tube is arranged during the assembly of the groove.

Usually, the cooling and / or heating tube is pressed in the groove, so that the cooling and / or heating tube over the entire surface, that is, ideally with the entire groove wall is connected to ensure the greatest possible heat transfer.

According to a further advantageous embodiment of the invention, it is provided that the at least one groove in a region adjacent to a surface of the housing has a smaller width than the region of the groove having the greatest width.

This means that the groove with the undercut, that is with the region which has a smaller width than the region of the groove with the largest width, the Cooling and / or heating tube prevents it due to the elasticity of the cooling and / or heating tube to be released from the groove wall and move away from a groove bottom.

A further advantageous embodiment of the invention provides that the at least one undercut and / or the at least one projection is arranged at a distance from an edge of the groove. By means of this embodiment, it is possible for the at least one undercut and / or the at least one projection to be superficially pressed into the cooling and / or heating tube during the compression of the cooling and / or heating tube in the groove and the cooling and / or heating tube is fixed thereby.

Such an undercut may be provided additionally or alternatively to the undercut in the edge region of the groove.

According to a further embodiment of the invention, it is possible that the at least one undercut and / or the at least one projection is arranged on both sides of the groove or only on one side in the groove. It may be provided a symmetrical or asymmetrical configuration. A symmetrical configuration is more advantageous in that the undercut and / or the projections are / is arranged on both sides of the edge region of the groove. However, a one-sided undercut and / or a projection arranged on one side, which is possibly larger than two individual undercuts on both sides and / or two projections arranged on both sides, is also possible.

A further advantageous embodiment of the invention provides that the at least one groove has a round or substantially round cross-section.

This embodiment has the advantage that the cooling and / or heating tube, which also has a round cross-section in commercial terms, abuts flat against the groove wall during compression. However, it is also possible to provide other cross sections of the groove. The cross section of the groove is advantageously adapted to the cross section of the pipe to be formed in order to achieve a surface contact of the cooling and / or heating tube on the groove wall and thus optimum heat transfer. In principle, rectangular cross sections or other cross sections are also conceivable.

A further advantageous embodiment provides that the groove has a groove base which is round or rounded in cross-section. This embodiment has the advantage that the cooling tubes and / or heating tubes, which are likewise round or approximately round in cross-section, rest against the groove base over the whole area during pressing in the groove in order to ensure optimum heat transfer.

If the tubes are round in cross-section, it makes sense to make the groove as well as the groove bottom edge-free.

According to a further advantageous embodiment of the invention, the cooling and / or heating tube is designed as a compressed in the groove cooling and / or heating tube. This embodiment has the advantage that the cooling and / or heating pipe is applied over the entire surface of the groove wall and / or the groove bottom during pressing and thereby optimal heat transfer is ensured. By pressing is simultaneously ensured that the at least one undercut and / or the at least one projection unfolds the retention effect on the cooling and / or heating tube.

According to a further advantageous embodiment of the invention it is provided that between at least one groove wall and / or a groove bottom and the cooling and / or heating tube, a heat conducting means and / or an adhesive is arranged.

The heat conducting means may be formed, for example, as a thermal paste. The effect of the heat conducting means and / or the adhesive is that no cavities with air inclusions remain between the cooling and / or heating tube and the groove wall, but that an optimum heat transfer between the cooling and / or heating tube and the groove wall and / or the groove base is ensured ,

It is advantageously provided that the at least one cooling and / or heating tube made of copper or stainless steel is formed and / or that the housing made of aluminum and / or stainless steel is formed.

Housings of vacuum pumps are often formed of aluminum and / or stainless steel because these materials are stable and heat resistant for the required applications. Cooling and / or heating pipes are often made of copper, since copper has a very good thermal conductivity. Stainless steel cooling and / or heating pipes can also be used, as they are cheaper and still have good thermal conductivity.

A further advantageous embodiment of the invention provides that the at least one arranged in the groove of the housing cooling and / or heating tube has a shape adapted to an outer housing shape.

According to a further advantageous embodiment of the invention, the at least one groove is arranged radially and / or axially in the housing. The guidance of the groove in the housing surface is preferably matched to the geometry of the housing.

The groove is arranged in the surface of the housing. The cooling and / or heating tube is advantageously arranged in this groove, so that the cooling and / or heating tube after assembly has a shape adapted to the outer housing shape. As a result, optimum heat transfer between the cooling and / or heating tube and the housing is possible. In addition, this training is space-saving.

However, there is also the possibility that the cooling and / or heating tube is arranged in a separate component, for example in a plate, and that this component is arranged as a cooling element on the housing. In this case, the component also has the grooves designed according to the invention, so that an optimum heat transfer between the cooling and / or heating tube and the component is ensured.

The formation of the undercut and / or the projections creates an optimal "gearing" of the cooling and / or heating pipes with the pump housing. The at least one cooling and / or heating tube is anchored with bias positively in the groove.

This gives a reliable and durable system, that is a kind of connection of the cooling and / or heating tube with the housing, whereby a creeping decreasing cooling performance is avoided in use. The invention can be used in all materials and components. A particularly advantageous application is in components with different coefficients of expansion, for example motor housing, pump housing, lower parts of a vacuum pump and the like.

By means of the invention, cooling and / or heating pipes made of different materials can be mounted in the best possible form-fitting manner radially or axially on housing components such as motor housings, pump housings, bottoms of vacuum pumps and the like.

As a result, the greatest possible heat transfer between the materials is produced. It is possible to generate or dissipate the highest possible energy density, in the smallest possible space.

The tube can deform plastically during pressing. As a result, the tube is supported and / or clawed and / or anchored by the at least one undercut and / or by the at least one projection. The better the groove or the bottom of the groove is adapted to the outer shape of the tube, the smaller is the necessary plastic deformation of the tube. As a result, a smaller force is required for the deformation.

Fig. 1

eine Vakuumpumpe in perspektivischer Ansicht;

Fig. 2

einen Längsschnitt durch ein Vakuumpumpengehäuse;

Fig. 3

einen Querschnitt durch eine Nut;

Fig. 4

ein geändertes Ausführungsbeispiel;

Fig. 5

eine Nut mit einem verpressten Kühlrohr im Querschnitt.

Further features and advantages of the invention will become apparent from the accompanying drawings, in which various embodiments of a vacuum pump according to the invention are shown by way of example only, without limiting the invention to these embodiments. In the drawings show:

Fig. 1

a vacuum pump in perspective view;

Fig. 2

a longitudinal section through a vacuum pump housing;

Fig. 3

a cross section through a groove;

Fig. 4

a modified embodiment;

Fig. 5

a groove with a compressed cooling tube in cross section.

Fig. 1 shows a designed as a turbomolecular pump vacuum pump 10 in a perspective view.

The vacuum pump 10 comprises a stator, which comprises a part of a multi-part pump housing 14, and a rotor 16, which is mounted to be driven to rotate with respect to the stator.

The vacuum pump 10 comprises on its high-vacuum side a suction opening 20 surrounded by a suction flange 18 for connection to a volume to be evacuated and a gas outlet opening 24 arranged in the region of the fore-vacuum side of the vacuum pump 10 and surrounded by a fore-vacuum flange 22 for connection to a pre-vacuum.

The stator and the rotor 16 together form a rotation unit 26 of the vacuum pump 10, which is detachably connected to a base portion or lower part 28 of the pump 10.

Fig. 2 shows the pump housing 14. In a surface 30 of the pump housing 14, a groove 32 is arranged. The groove 32 is arranged spirally in the pump housing 14. The groove 32 has a beginning 34 and an end 36.

In the groove, a cooling and / or heating pipe (not shown) is arranged and pressed to ensure heat transfer from the pump housing 14 to the cooling and / or heating pipe or vice versa.

According to Fig. 3 the groove 32 is shown. The groove 32 has an undercut 38. This means that a width B in the region of the undercut 38 is smaller than a region 40 with the greatest width of the groove 32.

The undercut 38 is arranged in the direction of the surface 30 of the housing 14.

If a cooling and / or heating tube (not shown) is arranged in the groove 32 and pressed there, the undercut 38 prevents detachment of the cooling and / or heating tube due to the elasticity of the cooling and / or heating tube. This means that the cooling and / or heating tube in the predetermined position of the groove 32 remains even during prolonged operation of the vacuum pump, and that a positive connection between the cooling and / or heating tube and the groove wall 42 is maintained.

The groove 32 has a rounded groove bottom 44.

According to Fig. 4 a modified embodiment 32 is shown. The groove 32 has projections 46, 48. These projections are spaced from the surface 30 of the housing 14. However, the projections 46, 48 may also be arranged directly in an edge region 50 of the groove 32.

The projections 46, 48 may be formed as individual projections. However, the projections 46, 48 can also be formed as running along the groove wall 42 projections. The projections 46, 48 have in this case an axial extent.

The projections 46, 48 take on the same task as in Fig. 3 illustrated undercut 38, namely a fixing of the arranged and grooved in the groove 32 cooling and / or heating pipe.

It is also possible to form a combination of the undercut 38 and the projections 46, 48.

By forming the undercut 38 and / or the projections 46, 48, a permanent hold of the cooling and / or heating pipes and thus a reliability of the particular cooling function is achieved when using a water cooling.

Fig. 5 shows the groove 32 with a compressed in the groove 32 cooling tube 52. The cooling tube 52 is the entire surface of the groove wall 42 at. The undercut 38 keeps the cooling tube 52 in the predetermined position, even over long periods of high temperature fluctuations.

The cooling tube 52 deforms plastically during pressing and is thereby supported by the at least one undercut 38 and / or the at least one projection 46, 48 and / or clawed and / or anchored. The better the groove bottom 44 is adapted to the outer shape of the cooling tube 52, the smaller the necessary plastic deformation of the tube 52 and thus a smaller force is necessary for the deformation.

reference numerals

10

vacuum pump

14

pump housing

16

rotor

18

suction flange

20

suction

22

fore-vacuum flange

24

Gas outlet

26

rotation unit

28

lower part

30

Surface of the pump housing 14

32

groove

34

Beginning of the spiral groove

36

End of the spiral groove

38

undercut

40

Area

42

groove wall

44

groove base

46

head Start

48

head Start

50

border area

52

cooling pipe

B

width

Claims (12)

Housing for a vacuum pump and / or for a part of a vacuum pump with at least one arranged in the housing cooling and / or heating tube and / or arranged on the housing component in which at least one cooling and / or heating tube is arranged, for tempering the housing, wherein in the housing and / or in the at least one component of the housing at least one groove for receiving the at least one cooling and / or heating tube is arranged,
characterized in that the at least one groove (32) at least in sections at least one undercut (38) and / or at least one projection (46, 48). Housing according to claim 1, characterized in that the at least one groove (32) has in cross-section at least one region (B) which has a smaller width than a region (40) with the greatest width of the groove (32). Housing according to claim 1 or 2, characterized in that the at least one groove (32) in an edge region (50) to a surface (30) of the housing (14) has a smaller width than the region (40) of the groove (32). with the largest width. Housing according to one of the preceding claims, characterized in that the at least one undercut (38) and / or the at least one projection (46, 48) is arranged at a distance from an edge (50) of the groove (32). Housing according to one of the preceding claims, characterized in that the at least one undercut (38) and / or the at least one projection (46, 48) is arranged on both sides or only on one side in the groove (32). Housing according to one of the preceding claims, characterized in that the at least one groove (32) has a round or substantially round cross-section. Housing according to one of the preceding claims, characterized in that the at least one groove (32) has a cross-sectionally round or rounded groove base (44). Housing according to one of the preceding claims, characterized in that the cooling and / or heating tube (52) as a in the groove (32) pressed cooling and / or heating tube (52) is formed. Housing according to one of the preceding claims, characterized in that between at least one groove wall (42) and the cooling and / or heating tube (52), a heat conducting means and / or an adhesive is arranged. Housing according to one of the preceding claims, characterized in that the at least one cooling and / or heating tube (52) made of copper or stainless steel is formed and / or that the housing (14) made of aluminum and / or stainless steel is formed. Housing according to one of the preceding claims, characterized in that the at least one in the groove (32) of the housing (14) arranged cooling and / or heating tube (52) has a shape adapted to an outer housing shape. Housing according to one of the preceding claims, characterized in that the at least one groove is arranged radially and / or axially in the housing.

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