Title: Device for processing an electrically conductive component
Abstract: A device for processing an electrically conductive component includes positioning means that position the component to be processed in a processing position. The positioning means are provided with means for generating a magnetic field. The magnetic field generates forces that act contactless on the component and in this way bring about or support the positioning of the component.
Patent Number: 6,872,255 Issued on 03/29/2005 to Baumann, et al.
| Inventors:
|
Baumann; Thomas (Wettingen, CH);
Bock; Albrecht (Hohentengen, DE);
Oesterheld; Joerg (Birmenstorf, CH)
|
| Assignee:
|
Alstom Technology LTD (Baden, CH)
|
| Appl. No.:
|
996876 |
| Filed:
|
November 30, 2001 |
Foreign Application Priority Data
| Nov 30, 2000[DE] | 100 59 384 |
| Current U.S. Class: |
118/300; 361/144 |
| Intern'l Class: |
B05C 005//00 |
| Field of Search: |
118/300,323
148/103,108
294/65.5
361/144
335/285
|
References Cited [Referenced By]
| Foreign Patent Documents |
| 41 05 874 | Jul., 1992 | DE.
| |
| 42 10 188 | Oct., 1993 | DE.
| |
| 34 02 143 | May., 1994 | DE.
| |
| 195 01 570 | Sep., 1996 | DE.
| |
| 195 01 571 | Sep., 1996 | DE.
| |
| 196 11 801 | Oct., 1997 | DE.
| |
| 196 37 201 | Feb., 1998 | DE.
| |
| 44 36 651 | Aug., 1998 | DE.
| |
| 199 16 922 | Oct., 2000 | DE.
| |
| 0 790 623 | Aug., 1997 | EP.
| |
| 1035643 | Mar., 2000 | EP | .
|
| WO 99/17034 | Apr., 1999 | WO | .
|
Other References
Derwent, English Abstract of JP 02185975 (Vapour coating wafer at
sub-stmoshpheric pressure--with non-contact support e.g. with magnetic
force or gas lift), Jan. 11, 1989.
|
Primary Examiner: Fiorilla; Chris
Assistant Examiner: Lazor; Michelle Acevedo
Attorney, Agent or Firm: Burns, Doane, Swecker & Mathis, L.L.P.
Claims
What is claimed is:
1. A fixation and positioning device for fixing and positioning a component
while applying a process, wherein the component is one selected from the
group consisting of a direct current supplied component, a permanently
magnetic component, and a direct current supplied permanently magnetic
component, the component being subjectable to a first magnetic field, the
device comprising:
a first mechanical fixation means and a second mechanical fixation means,
spaced a distance apart from each other, and arranged and adapted to
receive the component between the first and the second mechanical fixation
means; and a magnetic field generation device arranged and adapted to
generate a second magnetic field, which, in co-action with the first
magnetic field, effects a force to support the component against its
gravitational force along a distance between the first mechanical fixation
means and the second mechanical fixation means.
2. The fixation and positioning device as claimed in claim 1, wherein the
magnetic field generation device is arranged and adapted such that the
forces co-effected by the magnetic fields comprise field components which
are oriented transversely to the gravitational force and act symmetrically
on the component, thus centering the component.
3. The fixation and positioning device as claimed in claim 1, wherein the
magnetic field generation device is constructed and dimensioned such that
the magnitude of the forces co-effected by the first and second magnetic
fields essentially compensate a gravity induced bending of the component
along the distance between the first and the second mechanical fixation
means.
4. The fixation and positioning device as claimed in claim 1, wherein the
magnetic field generation device is arranged essentially between the first
and second mechanical fixation means.
5. The fixation and positioning device as claimed in claim 1, the magnetic
field generation device extending essentially in the same direction as the
component to be held by the first and the second mechanical fixation
means.
6. The fixation and positioning device as claimed in claim 1, the magnetic
field generation device comprising a member made from a permanently
magnetic ferromagnetic material.
7. The fixation and positioning device as claimed in claim 1, the magnetic
field generation device comprising an electrically conductive member, said
member being provided with electrical connection means.
8. The fixation and positioning device as claimed in claim 7, wherein the
electrically conductive member comprises a coil arranged around a core of
ferromagnetic material.
9. The fixation and positioning device as claimed in claim 7, wherein the
electrically conductive member is connected to a power supply.
10. The fixation and positioning device as claimed in claim 9, wherein the
first and the second mechanical fixation means are connected to a power
supply.
11. The fixation and positioning device as claimed in claim 10, wherein the
first and second mechanical fixation means and a conductive member of the
magnetic field generation device are connected to a common power supply.
12. The fixation and positioning device as claimed in claim 10, wherein the
first and second mechanical fixation means are connected to a power
supply, and a conductive member of the magnetic field generation device is
arranged below the component, and extending essentially parallel with the
component, wherein the current direction in the component is opposite to
that in the conductive member.
13. The fixation and positioning device as claimed in claim 1, wherein
first and the second mechanical fixation means constitute electrical
connection means.
14. The fixation and positioning device as claimed in claim 1, further
comprising support members arranged and adapted to support the component
when the magnetic field forces are not active.
15. The fixation and positioning device as claimed in claim 1, comprising a
spraying member for producing a coating on the component.
Description
FIELD OF THE INVENTION
The invention relates to a device for processing an electrically conductive
or permanently magnetic component and to a method for producing a coating
on an electrically conductive or permanently magnetic component. Of
special interest in this context are components in the form of electric
conductors or conductor bundles that must be provided with electrical
insulation. Such insulated electrical conductors are used, in particular,
for rotating electrical machines, for example, generators, in the form of
stator coils, Roebel bars, and exciter conductors. Other examples of
possible uses include switching installations and transformers.
BACKGROUND OF THE INVENTION
In a standard procedure for insulating conductors or conductor bundles of a
rotating electrical machine, tapes, consisting, for example, of a
fiber-glass carrier and mica paper, are wrapped in layers in a spiral
shape around the conductor, for example, a stator conductor, until the
desired insulation thickness is achieved. Such an insulation tape and
associated method are described, for example, in EP 0 790 623 B1.
By using an impregnation, for example, with a suitable synthetic resin, any
remaining air can be purged from the resulting insulation winding, whereby
the tape layers are at the same time bonded to each other. The insulation
receives its final shape by hardening in a suitable mold.
In modern methods for producing an insulation, a suitable, powdered or
liquid insulation agent is applied to the component to be insulated. This
is done, for example, by a suitable spraying process or another suitable
coating process.
In larger components that must undergo such processing, the problem exists,
however, that these components bend as a result of their own weight, if
they are only supported at their end sections. However, if a coating, in
particular, an insulation, is applied when such a deformation is present,
the coating or insulation can be damaged in the installed condition of the
component. This problem is encountered, for example, with bar-shaped
conductors that may have a length of several meters.
To avoid the mentioned disadvantages, for example, winding robots that have
several holding pliers for holding the bar-shaped conductors at several
points, and in this way support it, are used. To permit the application of
a winding on the conductor at such holding pliers point, the respective
holdings pliers open and move away automatically. Once the respective
support point has been wound, the corresponding holding pliers returns to
its support position and closes again to restore the support of the
conductor. However, such a procedure is not suitable for coatings that
work with coating agents that must harden immediately after their
application. The reason for this is that the holding pliers can only
return to their holding positions and touch the component for support once
this hardening process at the respective holding point has been completed.
A numerical example will make this problem clear: A bar-shaped conductor
is supposed to be provided with insulation over a length of 10 meters. In
order to prevent bending of the bar, the bar is fixed over the length to
be coated with 10 holding pliers. The insulation is supposed to be applied
using a spraying method, working, for example, an application speed of 1
m/s. In the example, the hardening of the sprayed-on insulating agent
shall take 1 minute. Accordingly, the spray application must be
interrupted for approximately 1 minute after moving past each holding
point, or the application speed must be reduced to 1 m/min until the
released holding pliers is again able to assume its support function.
Overall, this results in a total application time of approximately 10
minutes. This means that the coating of such conductors takes much longer
than the actual spraying process with a speed of 1 m/s. The coating could
indeed be accelerated by providing fewer support points, but this again
would mean that a greater bending would have to be tolerated. Such a
coating, applied by using such a frequently interrupted spraying process,
also does not have an especially high quality, in particular with respect
to homogeneity.
SUMMARY OF THE INVENTION
The present invention attempts to disclose possibilities for permitting a
quick processing or coating of the component with respect to the
processing of an electrically conductive or permanently magnetic
component, in particular for the production of a coating on such a
component.
The invention is based on the idea that the component is positioned
contactless, at least in the section to be processed, by means of magnetic
field or, specifically, by the forces that cause these magnetic fields.
Since the position in the section to be processed does not require a
physical contact between the component and any support device, such as,
for example, holding pliers, an application of a coating that must be
hardened also is not able to cause an interfering interaction between
these support device and the applied, but not yet hardened coating. The
advantage of the invention becomes especially clear with respect to the
above numerical example: A coating of a 10 m long conductor now takes only
approximately 1 minute. The coating also can be realized with high quality
in the section that is positioned contactless.
The physical principle of contactless, magnetic positioning is the fact
that bodies that generate a magnetic field exert forces attracting or
repelling each other. The forces hereby are oriented vertically to the
magnetic fields. Parallel-oriented magnetic fields generate attractive
forces, anti-parallel-oriented magnetic fields generate repelling forces.
The occurrence of forces between the bodies requires that both bodies
generate a magnetic field. The contactless positioning according to the
invention therefore requires that the object itself is able to generate a
magnetic field. The positioning of the object then takes place--in
general--by superimposing the magnetic field generated by the object with
a magnetic field generated by one or more suitably shaped magnetic field
generation device(s). It is preferred that these external magnetic field
generation devices (MGM) are designed so that they counteract the weight
force of the component. This measure reduces a gravity-induced bending of
the component.
In an especially advantageous embodiment, the MGM can be constructed so
that the sizes of the forces generated by the magnetic fields are such
that they essentially compensate the gravity-induced bending of the
component at least in the part to be processed. In this embodiment,
optimum values can be achieved for a coating to be applied.
Magnetic fields are generated on the one hand by magnetization of
ferromagnetic materials (permanent magnets), and on the other hand by
energizing electrically conductive materials. Since there are many more
electrically conductive materials then permanently magnetic materials,
this is the more important technical application. The present invention
therefore preferably is used for objects made from electrically conductive
materials. It is hereby useful that time-constant magnetic fields and
direct current are used, since this is the only way to achieve a
positioning constant over time. Naturally, it is also possible with direct
current to control the object position suitably by adjusting the current
intensity.
According to a further development, the magnetic field generation device
can be constructed so that the forces generated by the magnetic field have
components that are oriented transversely to the force of gravity, act
symmetrically on the component, and center it. These measures realize a
lateral guidance and stabilization of the component in its processing
position.
According to an alternative embodiment of the present invention, the
magnetic field generation device may be provided with an electrical
conductor arrangement of at least one electrical conductor, whereby the
conductor arrangement is connected to a power supply and extends below or
above the respective component in the same direction as the component,
whereby the magnetic field generation devices are also provided with
electrical connection means with which the component can be connected to a
power supply, whereby for the positioning of the component in its
processing position the electrical conductor arrangement and the component
are energized in such a way that between the component and the conductor
arrangement a repelling force or attractive force that brings about or
supports the positioning of the component is created. Such an embodiment
is particularly useful if the component to be processed is a relatively
long component, in particular, a bar-shaped component, such as an
electrical conductor or conductor bundle of, for example, a rotating
electrical machine. If the conductor arrangement is located above the
component, component and conductor arrangement are energized with currents
oriented in the same direction, i.e., parallel currents, in order to
create an attractive force. If, however, the conductor arrangement is
located below the component, component and conductor arrangement are
energized with currents oriented in the opposite directions, i.e.,
anti-parallel currents, in order to create a repelling force.
In an another embodiment of the present invention, the MGM includes a
conductor arrangement of a coil system of the above described type, which
is constructed on a core of ferromagnetic material, for example ferritic
steel. The high magnetic permeability causes the magnetic field of the MGM
to be significantly increased, which means that the forces are
significantly increased.
The invention hereby is based on the general idea of bringing about the
positioning of the component, at least in a section to be coated, by
magnetic forces with sizes that cause the component to freely float at
least in the section to be coated, so that it can be coated without
physical contact. The advantage hereby is again that the section to be
coated can be coated completely using a continuous coating process, which
permits a coating with a higher quality.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are disclosed in the following
description and illustrated in the accompanying drawings, in which:
FIG. 1 shows a lateral view of a greatly simplified device according to the
invention, with disabled magnetic field generation devices,
FIG. 2 shows a view according to FIG. 1, but with enabled magnetic field
generation devices,
FIG. 3 shows a view according to FIG. 2, but with disabled support devices,
FIG. 4 shows a principal view of the field line progression in a plane
transversely to the longitudinal direction of a component to be processed,
for a first embodiment of an electrical conductor arrangement with an
anti-parallel power flow extending parallel to the component,
FIG. 5 shows a view corresponding to FIG. 4, but for a second embodiment of
the conductor arrangement,
FIG. 6 shows a view corresponding to FIG. 4, but for a third embodiment of
the conductor arrangement,
FIG. 7 shows a view corresponding to FIG. 4, but for a fourth embodiment of
the conductor arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to FIG. 1 to 3, a device 1 according to the invention is provided
with positioning device 2, with which a component 3 can be positioned in a
processing position. This processing position is shown in FIG. 2 and 3.
Component 3 is made of an electrically conductive material and, in the
present embodiment, is formed by a tape- or bar-shaped electrical
conductor used, for example, in a rotating electrical machine, for
example, a turbo generator. Component 3 may be, for example, a so-called
Roebel bar. In the present embodiment, component 3 is constructed so that
a center section 14 to be processed is connected at its ends via an angled
section 15 with end sections 5.
The positioning devices 2 are provided with holding members 4 that hold the
end sections 5 of the component 3 in order to fix it there. The holding
members 4 therefore form a holder for the component 3 and can be
constructed, for example, of pliers or similar devices. The holding
members 4 in the present embodiment are constructed at the same times as
electrical connections that are connected via corresponding power lines 6
with a power supply 7. The power supply 7 is provided with a control 8
that permits a supply of the connections or holding members 4 with power.
The current flow direction is hereby symbolized for a certain time by
arrows.
The positioning members 2 also have support members 9 that support the
component 3 from below in relation to an electrical conductor arrangement
10. The support members 9 are made of an electrically insulated material
and are sized so that the component 3 does not contact the conductor
arrangement 10 in the case of gravity-induced bending. This bending of the
component 3 caused by gravity is shown in FIG. 1.
The electrical conductor arrangement 10 includes one or more electrical
conductors that, in the shown embodiment, are formed by one or more
parallel bars resting on a bottom 17. The conductor arrangement 10 is
hereby oriented in the same direction as the component 3, so that in the
embodiment the longitudinal directions of the component 3 and of the
conductor arrangement 10 extend horizontally and are located in the
drawing plane.
The conductor arrangement 10 is also connected at its ends 12 via suitable
power lines 11 with power supply 7. It should be noted hereby that the
ends 12 of the conductor arrangement 10 and the ends 5 of the component 3
are connected in opposite direction, i.e., anti-parallel, to the power
supply 7.
The device 1 according to the invention functions as follows:
The component 3 to be processed is placed onto the support members 9 and is
fixed at its ends 5 to the holding members 4. Since the holding members 4
are constructed as connection members, the ends 5 are connected by the
attachment automatically to the power supply 7. Because of the weight of
the component 3, a gravity-induced bending according to FIG. 1 occurs
between its ends 5.
The positioning members 2 are provided with magnetic field generation
devices 13, the essential components of which are the conductor
arrangement 10, component 3, and power supply 7. FIG. 1 shows these
magnetic field generation devices 13 disabled, so that the component 3
takes on the sagging or bending shape shown in FIG. 1, which is however
not suitable for the intended processing of the component 3.
In FIG. 2, the magnetic field generation devices 13 are enabled. For this
purpose, the control 8 supplies the component 3 and conductor arrangement
10 with power. As a result of the applicable laws of physics, this
generates a magnetic field that results in a mutual repulsion between
component 3 and conductor arrangement 10. The positioning of the conductor
arrangement 10 and the applied currents have hereby been chosen so that
the component 3 in the section 14 to be processed is oriented essentially
horizontally.
The number of conductors in the conductor arrangement 10, their spatial
arrangement, and their power supply are preferably chosen so as to
compensate the gravity-induced bending of the component 3. Hereby it is
not necessary that the magnetic field generation devices 13 absorb the
complete force of the weight, since part of the force of the weight is
taken up by the holding members 4.
According to FIG. 3, the support members 9 are constructed so that they can
be disabled or removed so that the component 3 is supported in its section
14 to be supported exclusively by the magnetic forces. FIG. 3 expressly
shows that a floating state for the component 3 quasi occurs when the
magnetic field generation devices 13 are enabled and the support members 9
are disabled; in this state, the component 3 is supported contactless in
its section 14 to be processed. In this state, the desired processing of
the component 3 now can be performed. For example, the component 3 should
be provided with an insulated coating applied, for example, by a spraying
process. For this, a hardening insulation material that only can be
exposed to mechanical stresses following a hardening time can be used.
After the respective coating has hardened, the support members 9 can be
activated again. Once the magnetic field generation device 13 have been
disabled again, the processed or coated component 3 can be removed from
the device 1 again.
While the support members 9 in the embodiment described here comprise only
two support points, another embodiment provides that support constructions
as complicated and complex as desired may be provided, the support members
preventing a gravity-induced bending of the component 3 especially also
when the magnetic field generation devices 13 are disabled.
In the case of the embodiment shown here, the component 3, as described
above, is a long, electrical conductor of an electrical machine that is
straight in the section to be processed. However, the invention also can
be used for other electrically conductive components with any desired
shapes. A suitable conductor arrangement 10 that generates a magnetic
field whose forces compensate the gravity-induced bending of this
component 3 with its complex shape also can be found for components 3 of
any desired shape. In order to find a suitable conductor arrangement 10,
the component 3 can be divided into infinitesimal parts, which are then
associated with corresponding sections of the conductor arrangement 10.
The suitable magnetic field hereby also can be generated by corresponding
shape and/or spatial positioning of the conductor arrangement 10.
According to FIG. 4, the conductor arrangement 10 in an especially simple
embodiment includes a single conductor constructed in a bar shape, which
principally may have any kind of cross-section. However, in the embodiment
at hand a rectangular cross-section has been chosen, since the component 3
located above it also has a corresponding rectangular cross-section. In a
single conductor 10, the repelling forces acting between the conductor 10
and the component 3 extend only exactly vertical in a vertical
longitudinal center plane. The resulting field line progression of the
induced magnetic field is shown symbolically with individual field lines
18. As a result, the magnetic repelling forces are therefore, with respect
to the positioning of the component 3 vertically above the conductor 10,
relatively unstable, so that a lateral support of the component 3 may be
necessary. In shorter components 3, this lateral support can be realized
in a simple manner with holding members 4. In longer components 3,
additional measures may be necessary.
According to FIG. 5, the conductor arrangement 10 may be constructed of an
arrangement of two bar-shaped conductors arranged next and parallel to
each other. This conductor arrangement 10 is energized consistently in the
same direction, i.e., parallel. The resulting field lines 18 extend
flatter above the conductor arrangement 10 than is the case for the single
conductor according to FIG. 4. In this way, the instability of the
component 3 held floating above the conductor arrangement 10 is reduced,
and the stability is increased. The component 3 is not shown in FIG. 5.
In FIG. 6, the distance between the two conductors of the conductor
arrangement 10 also has been increased. This measure causes a magnetic
field to be generated w hose field lines 18 form a dip in the area of a
vertical longitudinal center plane. The area of this dip is designated as
16 in FIG. 6. With an arrangement of the component in the area of this dip
16, magnetic forces with components that gave a centering effect are
applied to the component 3. This centering results from forces that are
symmetrically applied transversely to the longitudinal direction of the
component 3 and transversely to the force of gravity at both sides of the
component 3. Accordingly, this results in a stable positioning of the
component 3 that does not require mechanical lateral supports.
FIG. 7 shows a further embodiment in which the design of the dip 16 above
the conductor arrangement 10 is additionally reinforced. This
reinforcement is hereby realized with the help of two additional conductor
bars that are arranged in relation to the horizontal longitudinal center
plane further outward, and in relation to the conductor bars located
further inward, are located further up. This measure reinforces the stable
position of the component 3 that is in a floating state above the
conductor arrangement 10.
The principles, preferred embodiments and manner of use of the present
invention have been described in the foregoing specification. However, the
invention which is intended to be protected is not to be construed as
limited to the particular embodiments described. Further, the embodiments
described herein are to be regarded as illustrative rather than
restrictive. Variations and changes may be made by others, and equivalents
employed, without departing from the spirit of the present invention.
Accordingly, it is expressly intended that all such variations, changes
and equivalents which fall within the spirit and scope of the invention be
embraced thereby.
*
