U.S. patent application number 12/376186 was filed with the patent office on 2010-02-25 for vacuum pump.
This patent application is currently assigned to OERLIKON LEYBOLD VACUUM GMBH. Invention is credited to Heinrich Englaender, Christian Harig.
Application Number | 20100047095 12/376186 |
Document ID | / |
Family ID | 38659353 |
Filed Date | 2010-02-25 |
United States Patent
Application |
20100047095 |
Kind Code |
A1 |
Englaender; Heinrich ; et
al. |
February 25, 2010 |
VACUUM PUMP
Abstract
A vacuum pump (10) has a vacuum-tight housing (12) and having a
gas-tight electrical leadthrough assembly (20) for producing an
electrical connection between an electrical component (14,16,18)
within the housing (12) and the exterior of the housing. The
leadthrough assembly (20) is formed by a housing opening (22), by a
sealing compound body (24) seated on the opening, by an electric
line in the sealing compound body (24), by a sealing ring (26)
between the opening edge of the housing opening (22) and the
sealing compound body (24), and by a fixing means (32) for
fastening the sealing compound body (24) to the housing (12).
Inventors: |
Englaender; Heinrich;
(Linnich, DE) ; Harig; Christian; (Koeln,
DE) |
Correspondence
Address: |
FAY SHARPE LLP
1228 Euclid Avenue, 5th Floor, The Halle Building
Cleveland
OH
44115
US
|
Assignee: |
OERLIKON LEYBOLD VACUUM
GMBH
KOELN
DE
|
Family ID: |
38659353 |
Appl. No.: |
12/376186 |
Filed: |
July 18, 2007 |
PCT Filed: |
July 18, 2007 |
PCT NO: |
PCT/EP2007/057436 |
371 Date: |
October 13, 2009 |
Current U.S.
Class: |
417/423.4 |
Current CPC
Class: |
F04D 19/04 20130101;
F04D 17/168 20130101; F04D 25/0693 20130101 |
Class at
Publication: |
417/423.4 |
International
Class: |
F04D 19/04 20060101
F04D019/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 4, 2006 |
DE |
102006036493.7 |
Claims
1. A vacuum pump comprising a vacuum-tight housing, an elastic
component arranged within said housing, a gas-tight electrical
leadthrough assembly for producing an electrical connection between
an electrical component within the housing and the exterior of the
housing, wherein said leadthrough assembly is formed by a housing
opening, a sealing compound body positioned on said housing opening
and enclosing an electric line extending between the interior of
the housing and the exterior of the housing, a sealing ring between
an opening edge of the housing opening and the sealing compound
body, and a fixing means for attachment of the sealing compound
body to the housing.
2. The vacuum pump according to claim 1, wherein said sealing
compound body is mounted to said housing opening from the
outside.
3. The vacuum pump according to claim 1, wherein said fixing means
is a sealing-compound housing.
4. The vacuum pump according to claim 1, wherein said electric line
comprises a circuit board arranged within the sealing compound
body.
5. The vacuum pump according to claim 1, wherein said electric line
comprises respectively one electric plug towards the interior and
towards the exterior.
6. The vacuum pump according to claim 4, wherein said circuit board
comprises electronic components.
7. The vacuum pump according to claim 6, wherein one of said
electronic components is configured as a readable pump-data
memory.
8. The vacuum pump according to claim 1, wherein the material of
the sealing compound body is an epoxy resin.
Description
BACKGROUND
[0001] The invention relates to a vacuum pump wherein the pump
housing is provided with a gas-tight electrical leadthrough
assembly.
[0002] Vacuum pumps normally comprise electrical components
arranged within a vacuum-tight housing, such as e.g. an electric
drive motor, electric sensors, a magnetic bearing etc. The
electrical components on the vacuum side have to be connected to
the outer side of the housing through electric lines. For this
purpose, electric lines have to be led from the interior of the
housing to the exterior of the housing via a gas-tight electrical
leadthrough assembly.
[0003] Known from the state of the art are leadthrough assemblies
consisting of a contact plate provided with contact pins passing
therethrough, said contact plate being configured to close a
corresponding opening of the housing. With the aid of a sealing
ring, the contact plate is sealed towards the edge of said housing
opening. The sealing of said contact pins in the contact plate can
be effected only with difficulties and will not be reliable in case
that mechanical stresses happen to act on the contact plate.
[0004] In view of the above, it is an object of the invention to
provide a vacuum pump whose housing is provided with a reliable
gas-tight electrical lead-through assembly.
SUMMARY
[0005] The vacuum pump according to the invention comprises a
vacuum-tight housing and an electrical component arranged within
the housing. The gas-tight electrical leadthrough assembly for
producing an electrical connection between said electrical
component and the exterior of the housing is formed by an opening
in the housing; a sealing compound body seated on the opening of
the housing, with an electric line, extending between the inner
side of the housing and the outer side of the housing, passing
through said sealing compound body; a sealing ring arranged between
the opening edge of the opening of the housing and the sealing
compound body; and a fixing means for fastening the sealing
compound body to the housing. Thus, the leadthrough assembly
substantially consists of three parts, namely the sealing compound
body having all of the electric lines cast into it, the sealing
ring for safeguarding a gas-tight and vacuum-tight sealing action
between the sealing compound body and the edge of the opening, and
a sealing-compound body fixing means which is effective to
permanently press the sealing compound body onto the opening edge
of the opening of the housing.
[0006] The sealing compound has a certain elasticity, safeguarding
the gas-tight and vacuum-tight passage of the electric line or
lines through the sealing compound body. Preferably, both
proximally and distally, the electric line or lines should at least
slightly project outwards from of the sealing compound body so as
to allow for the attachment of electric connection lines. The
sealing effect between the sealing compound body and the edge of
the opening is reliably obtained by a sealing ring.
[0007] The thickness of the sealing compound body should be at
least 5 mm and preferably 10 mm so as to guarantee a sufficiently
long sealing space between the electric line and the sealing
compound.
[0008] By casting all of the electric lines into a monolithic,
elastic sealing compound body, it is made possible to realize a
reliable, vacuum-tight passage in a relatively simple manner also
in case of a large number of electric lines. This is of relevance
particularly for vacuum pumps with magnetic bearings since these
pumps will often require a number of 50 or more electric conduits
to be led through the vacuum-tight housing.
[0009] According to a preferred embodiment, the sealing compound
body is seated from the outside onto the opening edge of the
opening of the housing. During operation, under the effect of the
differential pressure between the atmospheric air pressure acting
from the outside and the vacuum prevailing in the housing, the
sealing compound body will be pressed onto the edge of the opening
of the housing. In this manner, the sealing effect between the
sealing compound body and the edge of the opening of the housing
will be additionally intensified when the vacuum pump is
operated.
[0010] Preferably, the fixing means is a sealing-compound housing
configured to almost fully take up the sealing compound and to
press the sealing compound against the edge of the opening of the
housing. The sealing-compound housing comprises only one proximal
opening and one distal opening for the electric line or lines. The
primary function of the sealing-compound housing resides in fixing
the sealing compound body in place while, on the other hand, this
housing does not primarily have a sealing function. Nonetheless,
the sealing-compound housing may in fact have a sealing effect as
well.
[0011] According to a preferred embodiment, the electric line can
comprise a conductive board arranged in the sealing compound. Thus,
the electric line is partially realized in the form of a conductor
trace on a printed circuit board. The electric line can further
comprise respectively one plug projecting from the sealing compound
body towards the interior of the housing, and one plug projecting
from the sealing compound body towards the exterior of the housing.
Said two electric plugs can be connected to each other by the
printed circuit board but can also be electrically connected to
each other in another manner.
[0012] According to a preferred embodiment, the printed circuit
board comprises electronic components. Possible electronic
components in this regard are all electronic components which may
serve for amplification, interference suppression or another
manipulation of electric signals, i.e. components such as, for
instance, amplifiers, suppressor chokes and capacitors, integrated
circuits for signal processing, etc.
[0013] Preferably, the electronic component is a readable pump-data
memory adapted for storage therein of pump-specific functional
parameters, e.g. an error history of the respective vacuum pump,
and for retrieval therefrom of such functional parameters at any
time.
[0014] Preferably, the sealing compound material is an epoxy resin.
Epoxy resins are vacuum-tight and elastic and are castable at
relatively low temperatures which are not destructive to electronic
components.
[0015] The following is a detailed description of an embodiment of
the invention with reference to the drawing.
BRIEF DESCRIPTION OF THE DRAWING
[0016] The FIGURE schematically shows a vacuum pump and, in partly
sectional view, the vacuum pump housing provided with a gas-tight
electrical lead-through assembly.
DETAILED DESCRIPTION
[0017] Schematically shown in the FIGURE is a vacuum pump 10 which
can be configured as a displacement pump but preferably will be
configured as a high-vacuum turbomolecular pump with magnetic
bearing.
[0018] Vacuum pump 10 comprises a vacuum-tight metal housing 12
having a housing wall 13 and accommodating a plurality of
electrical components 14,16,18, notably an electric drive motor 14,
a magnetic bearing 16 as well as pump sensors 18. Drive motor 14 is
operative to drive a pump rotor of the turbomolecular pump via a
shaft 17.
[0019] Vacuum pump 10 is provided with a gas-tight electrical
leadthrough assembly 20 for establishing an electrical connection
between said electrical components 14,16,18 and the exterior of
said housing. Leadthrough assembly 20 is substantially formed by a
housing opening 22 in housing wall 13; a sealing compound body 24
seated on said housing opening 22 on the outside of the latter; an
elastic sealing ring 26 between an opening edge 28 of housing
opening 22 and the sealing compound body; a fixing means 32 formed
as a sealing-compound housing 30; and an electric line 34. Said
sealing ring 26 is seated in an annular groove 27 of sealing
compound body 24.
[0020] Electric line 34 is formed by a proximal electric plug 40, a
distal electric plug 42, and a printed circuit board 44 comprising
conductive traces and electrical components 46,47,48. Said
electrical components 46-48 are an integrated circuit 46 and
passive components 47,48. Said plugs 40,42 comprise more than 50
plug pins, each one of them individually connected to conductive
traces on circuit board 44.
[0021] Stored in integrated circuit 46 are functional parameters
and data of vacuum pump 10. The functional parameters are
pump-specific and include an error history of vacuum pump 10 which,
using a suitable reading device 50, can be read out via distal plug
42 through an electrical data line 52 adapted to be plugged onto
plug 42.
[0022] All parts of electric line 34 are enclosed in a gas-tight
manner within the sealing compound body 24 cast therearound. The
sealing compound material is an epoxy resin. The epoxy resin can be
provided with fine-granulated admixtures which have a positive
influence on thermal expansion, thermal conductivity and/or other
physical parameters.
[0023] Under the effect of the cup-shaped sealing-compound housing
30 forming a fixing means 32 and being fixed, e.g. screwed, to the
outside of housing 30, the sealing compound body 24 is pressed onto
said opening edge 28, resulting in a gas-tight and vacuum-tight
sealing condition between opening edge 28 and sealing compound body
24.
[0024] The invention has been described with reference to the
preferred embodiments. Modifications and alterations may occur to
others upon reading and understanding the preceding detailed
description. It is intended that the invention be construed as
including all such modifications and alterations insofar as they
come within the scope of the appended claims or the equivalents
thereof.
* * * * *