U.S. patent application number 13/265093 was filed with the patent office on 2012-02-09 for vacuum pump housing and set of cooling elements for a vaccum pump housing.
Invention is credited to Thomas Dreifert, Wolfgang Giebmanns.
Application Number | 20120034110 13/265093 |
Document ID | / |
Family ID | 42779613 |
Filed Date | 2012-02-09 |
United States Patent
Application |
20120034110 |
Kind Code |
A1 |
Dreifert; Thomas ; et
al. |
February 9, 2012 |
VACUUM PUMP HOUSING AND SET OF COOLING ELEMENTS FOR A VACCUM PUMP
HOUSING
Abstract
A vacuum pump housing comprises a pump housing formed in a
pumping chamber. In the pumping chamber, pumping elements are
arranged. On a planar outer side of the pump housing, a cooling
element is arranged. The cooling element comprises at least one
cooling channel which is open towards the outer side of the pump
housing. The disclosure further relates to a set of cooling
elements comprising a plurality of cooling elements having
different outer dimensions.
Inventors: |
Dreifert; Thomas; (Kerpen,
DE) ; Giebmanns; Wolfgang; (Erftstadt, DE) |
Family ID: |
42779613 |
Appl. No.: |
13/265093 |
Filed: |
November 3, 2010 |
PCT Filed: |
November 3, 2010 |
PCT NO: |
PCT/US10/55196 |
371 Date: |
October 18, 2011 |
Current U.S.
Class: |
417/313 |
Current CPC
Class: |
F04C 29/04 20130101;
F04C 25/02 20130101; F04C 2240/30 20130101; F01C 21/007 20130101;
F01C 21/10 20130101; F04B 39/064 20130101; F04C 2230/21
20130101 |
Class at
Publication: |
417/313 |
International
Class: |
F04B 53/00 20060101
F04B053/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 21, 2009 |
DE |
102009018212.8 |
Claims
1. A core lifter for use in a drilling system, the core lifter
comprising: a tubular body including an exterior surface and an
interior surface; and a plurality of longitudinally-oriented
recesses formed in the exterior surface of the tubular body of the
core lifter.
2. The core lifter as in claim 1, wherein the core lifter has a
corrugated configuration.
3. The core lifter as in claim 2, further comprising a plurality of
longitudinally-oriented recesses formed in the interior surface of
the tubular body of the core lifter; wherein the corrugated
configuration of the core lifter is formed by the plurality of
longitudinally-oriented recesses formed in the interior surface of
the tubular body and plurality of longitudinally-oriented recesses
formed in the interior surface of the tubular body.
4. The core lifter as in claim 1, wherein the tubular body of the
core lifter is tapered.
5. The core lifter as in claim 1, wherein the plurality of
longitudinally-oriented recesses formed in the exterior surface of
the tubular body of the core lifter are tapered.
6. The core lifter as in claim 1, further comprising a plurality of
longitudinally-oriented projections formed in the exterior surface
of the tubular body of the core lifter.
7. The core lifter as in claim 6, wherein the plurality of
longitudinally-oriented recesses and projections formed in the
exterior surface of the tubular body of the core lifter
alternate.
8. The core lifter as in claim 1, wherein the core lifter has a
length; and wherein the plurality of longitudinally-oriented
recesses formed in the exterior surface of the tubular body of the
core lifter extend along at least 50 percent, 60 percent, 70
percent, 80 percent and/or 90 percent of the length of the core
lifter.
9. The core lifter as in claim 1, wherein at least one of a leading
edge or a trailing edge of the core lifter is at an oblique angle
relative to a central axis of the core lifter.
10. The core lifter as in claim 1, wherein at least one of a
leading edge or a trailing edge of the core lifter is perpendicular
to a central axis of the core lifter.
11. A core lifter for use in a drilling system, the core lifter
comprising: a tubular body including an exterior surface and an
interior surface, the interior surface including a gripping surface
configured to grip a core sample; and a raised contact feature that
extends inwardly away from the gripping surface.
12. The core lifter as in claim 9, wherein the raised contact
feature extends radially inwardly from the gripping surface.
13. The core lifter as in claim 9, wherein the gripping surface has
an inner diameter; and wherein the raised contact feature has an
inner diameter that is smaller than the inner diameter of the
gripping surface.
14. The core lifter as in claim 9, wherein the raised contact
feature has a generally rounded shape.
15. The core lifter as in claim 9, further comprising a flared
skirt that extends outwardly from the raised contact feature, the
flared skirt configured to limit movement of the core lifter
relative to a core lifter case.
16. The core lifter as in claim 15, wherein the flared skirt
extends radially outwardly from the raised contact feature.
17. The core lifter as in claim 15, wherein the flared skirt is
adjacent the raised contact feature.
18. The core lifter as in claim 9, wherein at least one of a
leading edge or a trailing edge of the core lifter is at an oblique
angle relative to a central axis of the core lifter.
19. The core lifter as in claim 9, wherein at least one of a
leading edge or a trailing edge of the core lifter is perpendicular
to a central axis of the core lifter.
20. A core lifter for use in a drilling system, the core lifter
comprising: a tubular body; and a flared skirt configured to limit
movement of the core lifter relative to a core lifter case.
21. The core lifter as in claim 20, wherein the flared skirt is
configured to limit movement of the core lifter relative to a core
lifter case by being disposed within and engaging a recess of the
core lifter case.
22. The core lifter as in claim 20, wherein the flared skirt
includes slots configured to facilitate resilient compression of
the flared skirt.
23. The core lifter as in claim 22, wherein the slots are
configured to facilitate resilient compression of the flared skirt
when a portion of a core sample is disposed within the core lifter
and a tapered inner wall of the core lifter case contacts and/or
exerts a force against the core lifter.
24. The core lifter as in claim 20, wherein the flared skirt forms
a leading edge of the core lifter.
25. The core lifter as in claim 20, wherein the flared skirt forms
a trailing edge of the core lifter.
26. The core lifter as in claim 20, further comprising: a gripping
surface of the tubular body of the core lifter, the gripping
surface being configured to grip a core sample; and a raised
contact feature that extends inwardly away from the gripping
surface.
27. The core lifter as in claim 26, wherein the raised contact
feature extends radially inwardly from the gripping surface.
28. The core lifter as in claim 26, wherein the gripping surface
has an inner diameter; and wherein the raised contact feature has
an inner diameter that is smaller than the inner diameter of the
gripping surface.
29. The core lifter as in claim 26, wherein the raised contact
feature has a generally rounded shape.
30. The core lifter as in claim 26, wherein the flared skirt
includes slots configured to facilitate resilient compression of
the flared skirt and the raised contact feature.
31. The core lifter as in claim 30, wherein the slots are
configured to facilitate resilient compression of the flared skirt
and the raised contact feature when a portion of the core sample is
disposed within the core lifter and a tapered inner wall of the
core lifter case contacts and/or exerts a force against the core
lifter.
32. The core lifter as in claim 20, wherein at least one of a
leading edge or a trailing edge of the core lifter is at an oblique
angle relative to a central axis of the core lifter.
33. The core lifter as in claim 20, wherein at least one of a
leading edge or a trailing edge of the core lifter is perpendicular
to a central axis of the core lifter.
34. A method of forming a core lifter for use in a drilling system,
the method comprising: forming a tubular body of the core lifter by
stamping a sheet of material.
35. The method as in claim 34, wherein the sheet of material
comprises a metallic sheet.
36. The method as in claim 34, further comprising: forming a
plurality of longitudinally-oriented recesses in an exterior
surface of the tubular body of the core lifter by stamping the
sheet of material.
37. The method as in claim 34, further comprising: forming a
plurality of longitudinally-oriented recesses in an exterior
surface of the tubular body of the core lifter by stamping the
sheet of material; and forming a plurality of
longitudinally-oriented recesses in an interior surface of the
tubular body of the core lifter by stamping the sheet of
material.
38. The method as in claim 34, wherein forming a tubular body of
the core lifter includes: forming a corrugated configuration of the
tubular body of the core lifter by stamping the sheet of
material.
39. The method as in claim 34, further comprising: forming a
gripping surface on an exterior surface of the tubular body of the
core lifter by stamping the sheet of material, the gripping surface
being configured to grip a core sample; and forming a raised
contact feature of the core lifter by stamping the sheet of
material, the raised contact feature extending inwardly away from
the gripping surface.
40. The method as in claim 39, further comprising: forming a flared
skirt of the core lifter by stamping the sheet of material, the
flared skirt extending outwardly from the raised contact feature,
the flared skirt configured to limit movement of the core lifter
relative to a core lifter case.
41. The method as in claim 40, wherein the flared skirt extends
radially outwardly from the raised contact feature.
42. The method as in claim 40, wherein the flared skirt is adjacent
the raised contact feature.
43. The method as in claim 40, further comprising: forming slots in
the flared skirt of the core lifter by stamping the sheet of
material, the slots configured to facilitate resilient compression
of the flared skirt and the raised contact feature.
44. The method as in claim 43, wherein the slots are configured to
facilitate resilient compression of the flared skirt and the raised
contact feature when a portion of the core sample is disposed
within the core lifter and a tapered inner wall of the core lifter
case contacts and/or exerts a force against the core lifter.
45. The method as in claim 34, further comprising: forming a flared
skirt of the core lifter by stamping the sheet of material, the
flared skirt configured to limit movement of the core lifter
relative to a core lifter case.
46. The method as in claim 45, further comprising: forming slots in
the flared skirt of the core lifter by stamping the sheet of
material, the slots configured to facilitate resilient compression
of the flared skirt.
47. The method as in claim 46, wherein the slots are configured to
facilitate resilient compression of the flared skirt when a portion
of a core sample is disposed within the core lifter and a tapered
inner wall of the core lifter case contacts and/or exerts a force
against the core lifter.
48. The method as in claim 34, wherein at least one of a leading
edge or a trailing edge of the core lifter is at an oblique angle
relative to a central axis of the core lifter.
49. The method as in claim 34, wherein at least one of a leading
edge or a trailing edge of the core lifter is perpendicular to a
central axis of the core lifter.
50. The method as in claim 34, further comprising: applying a
wear-resistant coating to at least a portion of the core
lifter.
51. The method as in claim 50, wherein the wear-resistant coating
comprises a metal and micro-diamond composite coating.
52. The method as in claim 51, wherein the wear-resistant coating
is bonded to the core lifter via an immersive electro-chemical
process.
Description
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present disclosure relates to a vacuum pump housing and
a set of cooling elements for a vacuum pump housing.
[0003] 2. Discussion of the Background Art
[0004] Vacuum pumps comprise pumping elements arranged in a pumping
chamber formed by a housing. Vacuum pumps are primarily configured
as screw pumps, one- or multi-stage Roots pumps, rotary vacuum
pumps and claw pumps. For generating a vacuum, it is required that
a gap of the smallest possible size is realized between the pumping
elements and the inner wall of the pumping chamber. For this
reason, it is required to operate vacuum pumps at an operating
temperature as uniform as possible, in order to avoid changes of
said gap which may happen to occur due to differences in the
thermal expansion of the pump housing and the pump elements.
[0005] It is known to provide vacuum pumps with cooling ribs and to
cool the pump housings by use of an air flow. With these
approaches, however, a uniform and well-aimed cooling of the
housings will normally be possible only with the aid of special
measures, e.g. by installation of an outer shell with well-aimed
guidance of the air and with an external ventilation system (driven
by one of the pump shafts or by a separate drive unit). Such an
arrangement has the disadvantage that the specific cooling
performance (heat flow per area unit) will be low. Further,
dissipation of heat into the ambience is often undesired.
Especially in clean room environments, an occurrence of air flows
has to avoided to the largest extent possible. Further, ventilator
units are undesirable sources of noise.
[0006] Further, it is known to effect the cooling of vacuum pump
housings with the aid of water or a cooling liquid. Cooling by
water will necessitate special constructive measures. On the one
hand, for achieving the highest possible cooling effect, the water
has to be guided as closely as possible to the regions which have
to be cooled. On the other hand, the corrosive effect of water on
most materials will make it impossible to use water without the
need of taking special protective measures. To avoid corrosion, it
would be possible to use corrosion-free materials such as e.g.
stainless steel or specific aluminum alloys. Such materials,
however, are expensive and do not meet other preconditions for
vacuum pump housings, such as e.g. resistance to high temperatures,
particularly of more than 250.degree. C. Further, it is possible to
apply lacquer onto those surfaces which will be contacted by the
water. However, reliably lacquering of corresponding channels
arranged internally of the housing would be very complex. The
lacquering process would have to be performed by immersion baths or
by rotating or tumbling movements for distributing the liquid
lacquer. Further known are galvanic surface treatment methods such
as e.g. zinc or nickel coating in case of steel and grey cast iron,
or hard anodizing in case of aluminum. Also these methods, however,
are very complex. A further known approach consists in the use of
consumable electrodes while, however, also this method is complex
and, especially in case of internal cooling channels, does not
allow for reliable prevention of corrosion.
[0007] Instead of using water as a cooling agent, use can also be
made of special cooling liquids. This, however, will be possible
only if the cooling circuits are closed in themselves, at the
penalty of increased complexity. Particularly, it is required to
cool the cooling agent by heat exchangers which have to be
additionally provided.
[0008] The provision of cooling channels in vacuum pump housings
made of cast iron is also possible by retrofitting the housings
with such channels by machining, particularly by milling and
drilling. The resultant need for time-consuming additional
processing steps will make this option extremely complex. It is
also possible to form the cooling channels already during the
casting process. For this purpose, sand cores are provided. This
method, too, is complex and even involves the risk that the cooling
water may suffer long-term contamination by sand residuals. Further
still, the provision of insert-molded channels shaped by sand
cores, although possible, will impose massive limitations on the
shape, the cross section and the course of the channels because the
molding is performed with the aid of sand cores which are required
to have a sufficient stability for the casting process. Thus, the
provision of cooling channels of this type will massively restrict
the range of possible shapes and possible operating conditions, the
latter including e.g. the stability, the operational temperatures
and the media compatibility.
[0009] It is an object of the disclosure to provide a vacuum pump
housing which can be cooled in a simple manner, particularly by use
of a liquid cooling medium. Further, an independent object of the
disclosure resides in providing a set of cooling elements for
vacuum pumps which has a high variability.
SUMMARY
[0010] A housing for a vacuum pump comprises a pump housing
defining a pumping chamber. Arranged in the pumping chamber are the
pump elements, such as e.g. helical rotors. According to the
disclosure, the pump housing comprises at least one planar outer
side. Said preferably flat, planar outer side is connected to a
cooling element. According to the disclosure, said cooling element
comprises at least one and optionally a plurality of cooling
channels which are open towards the outer side of the pump housing.
By connecting the cooling element, which preferably is formed as a
separate component, to the pump housing, so that a preferably
planar abutment face of the cooling element is facing towards the
planar outer side of the pump housing, there will be generated
cooling channels of a closed cross-sectional shape. Thus, in the
inventive arrangement of a cooling element which preferably is
formed as a separate component, it is not required to provide
cooling ribs or the like on the pump housing itself. Thereby, the
pump housing can be given a simpler configuration, thus lowering
the production costs. For cooling the pump housing, the cooling
element of the disclosure will then be connected to the planar
outer side. Particularly, this has the advantage that the cooling
element can be produced as a separate component.
[0011] Since the cooling element does not comprise internally
arranged cooling channels while, instead, its cooling channels are
open towards the outer side of the pump housing, production of the
cooling element is simple. The cooling elements can be provided as
cast components, it being preferred that the cooling channels will
not be formed at a later time in the production process but will
already have been provided beforehand in the cooling element as
corresponding grooves or recesses. The cooling channels herein can
have a suitable configuration for allowing the cooling element to
be produced in casting molds. The cooling channels preferably
comprise mold release slopes. As a result, it is not necessarily
required to generate the cooling channels by subsequent treatment
of the cooling element such as e.g. by milling the cooling
channels. In case of flat, wider cooling channels with larger mold
release slopes, it will also not be required to provide sand cores
or the like for generating the cooling channels. Preferably, the
cooling element comprises a planar abutment face which in the
assembled condition is facing towards the outer side of the pump
housing. In the assembled condition, said abutment face is thus
preferably parallel to the outer side of the pump housing.
[0012] It is possible to fasten the cooling element directly on the
outer side, e.g. by use of screws or other fastening means.
Preferably, a sealing element is arranged at least in the edge
region of the cooling element, again on the surface facing towards
the outer side of the pump housing. Said sealing element can be a
liquid sealing element, a sealing compound or the like. Preference
is given to an annular sealing element which is closed in itself
and preferably has a circular cross section; such a sealing element
preferably is an O-ring. It is preferred that a sealing groove is
provided in the outer side of the pump housing and/or in a side of
the cooling element opposite to said outer side, i.e.--according to
a particularly preferred embodiment--in the abutment face of the
cooling element. In this sealing groove, the sealing element is
arranged. It is possible to provide both surfaces with respectively
one sealing groove so that there will exist two sealing grooves
which preferably arranged opposite to each other. In addition
to--or in place of--such sealing elements, it is according to a
preferred embodiment provided that a sealing element, preferably of
an areal type, is located on the outer side of the pump housing.
Said sealing element preferably fully covers the outer side. In
addition to its sealing function, the sealing element can thus also
assume the function of protecting the outer side of the pump
housing from corrosion. This obviates the need to apply a coating
of an anti-corrosive agent such as e.g. lacquer onto a planar and
preferably treated outer side of the pump housing.
[0013] The at least one cooling channel provided in the cooling
element is preferably of a meandering configuration. Optionally,
also a plurality of cooling channels, e.g. having different cross
sections, can be provided in a cooling element. This makes it
possible to connect one and the selfsame cooling element in a
different manner and thus achieve a different cooling effect. Of
course, the different cooling channels can also be connected
together.
[0014] Each cooling channel comprises at least one inlet and at
least one outlet. With preference, a plurality of inlets and/or
outlets are provided, more preferably two of each. This
advantageously provides a plurality of connection options, making
it possible to select that connection which e.g. is better
accessible or allows for easier mounting.
[0015] Said at least one inlet and/or outlet is preferably arranged
in a lateral surface of the cooling element. Said lateral surface
is a side oriented at an angle relative to the abutment face of the
cooling element, i.e. relative to the side of the cooling element
facing towards the outer side. In a substantially parallelepipedic
cooling element, for instance, said lateral surface extends
vertically to the abutment face. Alternatively, an inlet and/or
outlet can be arranged on an outer side, i.e. particularly on that
side of the cooling element which is arranged opposite to the side
of the abutment face.
[0016] According to an especially preferred embodiment, said inlets
and/or outlets are arranged in such a manner that they are closed
towards the outer side of the pump housing. Thereby, the sealing
will be made considerably easier. Preferably, the inlets and/or
outlets are formed as bores. These bores, which preferably are
formed as a cylindrical opening, connect the cooling channels which
are open towards the outer side of the pump housing. Said
cylindrical opening is closed towards the outer side of the pump
housing, i.e. towards the abutment face of the cooling element.
[0017] Since, according to a particularly preferred embodiment, the
cooling medium used will be a cooling liquid such as e.g. water, a
risk of corrosion exists. To avoid such corrosion, it is possible
to provide the inner sides of the cooling channels with an
anti-corrosion layer. For this purpose, it is possible e.g. to
lacquer the corresponding surfaces or to subject them to a galvanic
treatment, e.g. zinc plating or nickel plating. Further, e.g. in
case of aluminum casting, a hard anodizing process can be applied.
Also a consumable electrode can be provided for protection from
corrosion. Preferably, the cooling element is made of a material
serving as a consumable electrode. Further, the cooling elements
can comprise a consumable electrode and be entirely or partially
made of a corresponding material.
[0018] According to an especially preferred embodiment, the cooling
element is produced as a grey-casting or spheroidal-casting
component or also from corrosion-resistant aluminum or
stainless-steel cast alloys. The resultant cast surfaces will not
be susceptible to corrosion when exposed to water. Producing such
component parts by grey-casting, spheroidal-casting or aluminum
casting will also be inexpensive. A further possibility resides in
producing the cooling elements from copper, brass or bronze
alloys.
[0019] The present disclosure further relates to a set of cooling
elements for vacuum pumps. Said set of cooling elements comprises a
plurality of cooling elements with different outer dimensions. Each
cooling element is provided with at least one cooling channel which
is open towards the abutment face of the cooling element. In the
assembled state, the abutment face of the cooling element is facing
towards an outer side of the vacuum pump housing and, together with
said outer side, forms a cooling channel having a closed cross
section. By designing a set of cooling elements comprising
different cooling elements, it is possible to provide different
pump types with the respective suitable cooling elements in a
highly variable manner.
[0020] The cooling elements of the set of cooling elements comprise
e.g. differently large, preferably rectangular abutment faces. When
designing the vacuum pump housings, one merely has to take care to
generate outer surfaces which correspond to the size of one or a
plurality of the cooling elements. It will thus not be required to
design different cooling elements for different vacuum pump
housings.
[0021] For instance, the set of cooling elements may comprise not
only cooling elements with differently large abutment faces and/or
with abutment faces of different geometric configurations, but also
cooling elements having cooling channels of different
cross-sectional shapes. Thus, for a given vacuum pump and a given
use of the vacuum pump, one can conveniently provide different
cooling elements having different cooling performances. According
to a preferred embodiment, the individual cooling elements are
designed in the manner described above in connection with the
vacuum pump housing. Particularly, the cooling elements, preferably
being of a parallelepipedic shape or comprising a parallelepipedic
base body, have at least one inlet and at least one outlet. These,
as already explained above, are preferably located in lateral
surfaces or on an outer side of the cooling elements. Consequently,
connecting the cooling channels to a cooling system via cooling
conduits is possible in an easy manner.
[0022] The disclosure will be described in greater detail hereunder
by way of preferred embodiments and with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In the drawings, the following is shown:
[0024] FIG. 1 is a schematic perspective view of a first embodiment
of a cooling element;
[0025] FIG. 2 is a schematic sectional view taken along the line
II-II in FIG. 1;
[0026] FIG. 3 is a partial view of a cooling element similar to the
cooling element shown in FIG. 2;
[0027] FIG. 4 is a schematic sectional view taken along the line
III-III in FIG. 4; and
[0028] FIG. 5 is a view of an example of a set of cooling
elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] A cooling element 10 which in the illustrated embodiment
(FIG. 1) is formed as a parallelepipedic cast component, comprises
a meander-shaped cooling channel 12. The cooling channel 12 is
shaped as a groove which is open towards an abutment face 14. Said
groove can be produced already during the casting process by using
a corresponding casting mold. Alternatively, the groove for forming
the cooling channel 12 can be produced e.g. by machining processes
such as milling, for instance. Cooling channel 12 has a U-shaped
cross section (FIG. 2) so that the cooling element is closed on its
outer face 16. In the illustrated embodiment, inlets 20 and outlets
22 for connection of the cooling channel to cooling conduits are
provided on outer sides 18. Said inlets 20 and outlets 22 are
formed as transverse bores (FIG. 4). The abutment face 14 is thus
closed in the region of these transverse bores 20,22. This has the
advantage that the provisions for sealing can be realized in a
simpler manner.
[0030] In the illustrated embodiment, two inlets 20 and two outlets
22 are provided. These are arranged respectively in different,
mutually vertically outer sides 18, each time in a corner region.
This arrangement has the advantage that the connection of the
cooling channel can be realized via one of the two inlet openings
20 and respectively one of the outlet openings 22, the connection
being freely selectable in accordance to the respective
requirements. This is advantageous because, depending on the pump
type for which the cooling element 10 is used, there will exist
different space conditions.
[0031] Further, pump element 10 is provided with a plurality of
through bores 24 for attachment, said bores extending from outer
face 16 to abutment face 14. Thereby, the cooling element 10 can be
easily fastened to a pump housing 26 (FIG. 2), e.g. by screws. This
is schematically outlined by the chain-dotted line 28 in FIG.
2.
[0032] In the illustrated embodiment, abutment face 14 is not in
immediate abutment on a planar, treated outer face 30 of pump
housing 26. Instead, an areal sealing 32 is provided between the
two components. Said sealing 32 fully covers the outer face 30 as
well as the abutment face 14. Thus, the sealing 32 does not only
serve for achieving a sealed arrangement of the cooling element 10
on the housing but is used also to seal the individual portions
(FIG. 2) of cooling channel 12 against each other. Further, by the
provision of such an areal sealing 32, the treated outer face 30 of
pump housing 26 is protected against corrosion. Further still, the
areal sealing 32 also serves for anti-corrosion protection of
abutment face 14 which in the embodiment shown in FIG. 2 has also
been given a full-surfaced treatment. An inner face 34 of cooling
channel 12 can be provided with an anti-corrosion protective
coating such as e.g. lacquer. Preferably, however, said inner face
34 is an untreated cast surface, wherein the cooling element 10 is
preferably produced by a grey-casting or spheroidal-casting process
or is made of corrosion-resistant aluminum or stainless-steel cast
alloys, so that the resultant cast surface is corrosion-resistant
towards the cooling agent, i.e. particularly to water.
[0033] In a further embodiment (FIG. 3), the cooling element 10 has
a configuration similar to that shown in FIG. 2. The only
difference resides in that web portions 36, arranged between
adjacent portions of cooling channel 12, have been left untreated
in a region 38 of abutment face 14. When providing a
correspondingly thick areal sealing element 32, a treatment of said
portions is not required because the sealing element 32 is
compressed in said region 38 and the sealing element 32 will thus
partially project into the lateral faces 34 of cooling channel 12
and thus will seal adjacent portions of cooling channel 12 against
each other.
[0034] When providing a correspondingly thick sealing element 32 in
the embodiment shown in FIG. 2, it is also not absolutely required
to use an anti-corrosion agent for protecting the abutment face 14
from corrosion. This is not required because, if a sealing 32 with
a suitable thickness is used, the sealing will project into the
lateral faces 34 and thus will prevent the cooling agent from
reaching the abutment face 14.
[0035] In embodiments which do not comprise an areal sealing
element 32, it is also possible to provide a sealing groove in an
outer edge region 40 (FIG. 2) of abutment face 14 for accommodating
a sealing element formed e.g. as an O-ring. Optionally, the
corresponding sealing groove can also be arranged in a
corresponding region opposite to the outer side 30 of pump housing
26.
[0036] FIG. 5 illustrates, by way of example, a set of cooling
elements comprising a plurality of cooling elements 42,44,46. Said
cooling elements 42,44,46 are designed substantially in the manner
of cooling element 10.
[0037] Thus, the two cooling elements 42,44 each comprise a
meander-shaped cooling channel 12 which, corresponding to the above
described cooling element 10, is open towards an abutment face 14.
Cooling element 42 is on its lateral faces 18 provided with inlets
20 and outlets 22, wherein also herein, two inlet and respectively
outlets are provided in the edge regions so as to safeguard a high
variability with respect to the connection options.
[0038] The cooling element 44 is of a design corresponding to
cooling element 10 wherein the parallelepipedic cooling element
does not comprise a quadratic but a rectangular abutment face 14.
The further cooling element 46, shown in FIG. 5, comprises two
cooling channels extending substantially parallel to each other.
Each of the two cooling channels 12 has an inlet 20 as well as an
outlet 22. The two cooling channels 12 can e.g. conduct flows in
different directions. Further, it is possible to connect only one
of the cooling channels 12, which will depend on the requirements
posed to the cooling of the vacuum pump.
[0039] By the above set of cooling elements comprising a plurality
of cooling elements as illustrated by way of example in FIGS. 5 to
7, it is rendered possible to create cooling elements for different
vacuum pumps. These cooling elements are designed in the manner of
a modular construction kit so that the individual cooling elements
of the set of cooling elements can be used for different vacuum
pumps. This has the advantage that the different vacuum pumps
merely must have correspondingly designed outer sides 30 and that,
depending on the size and the requirements, there can then be used
a corresponding cooling element of the set of cooling elements. In
this manner, an extremely high flexibility is achieved.
* * * * *