The present invention relates to a linear motor comprising
a stationary part provided with electromagnetic coils and a movable part provided
with a device interacting with said coils and generating an electromagnetic field,
wherein the stationary part is provided with a guide for said movable part, said
guide having seats for accommodating wheels arranged on either side of said device.
Such a linear motor is disclosed in WO 02/27900. In this
publication a construction is described that consists of a number of sections that
have to be arranged on a separate supporting construction. One aim of the present
invention is to make a linear motor more compact, less expensive, more stable and
This aim is realised with a linear motor as described above
in that said stationary part comprises a compound section that is (self-)supporting.
The basic concept is based on making use of a compound
(for example produced by shearing and forming operations) or rolled or extruded
section of any nature, shape, length or type of material suitable for this whatsoever,
in which and/or through which a so-called translator (transport carriage, lifting
device or support provided with permanent magnets) is able to move or can be guided
on command. The sections can easily be infinitely coupled and/or clicked together
in any form whatsoever. That is to say, the section according to the present invention
is a complete construction that, on the one hand, can be joined directly to the
surroundings without special structural measures being needed for this and where,
on the other hand, the movable part can be fitted therein/thereon without further
structural operations being needed. The stationary part can optionally be fitted
separately during the installation, but the positioning of the stationary part is
unambiguously determined by means of facilities such as grooves or raised edges,
as a result of which complex adjustment operations are dispensed with. Preferably,
there are separate tracks in the section for accommodating separate rollers/wheels
for the movable part. These wheels are preferably perpendicular to one another.
The construction is made such that the movable part, with the rollers/wheels described
above, can be fitted in the compound section without radical adjustment operations
and thus all-round enclosure of the movable part with respect to the stationary
part takes place, except, of course, in the linear direction in which the motor
operates. Preferably, the enclosure of the movable part in the stationary part is
such that dust and the like are not able to penetrate into the space delimited inside
the section in which the movable part has been fitted. That is to say, the section
according to the invention also serves as enclosing housing for the movable part,
the housing, of course, being provided with a slot or the like through which a portion
of the movable part can extend.
One of the most important main points on which the concept
is based is also to make use of a compound (for example produced by shearing and
forming operations) or rolled or extruded section of any nature, shape, length or
type of material suitable for this whatsoever, in which and/or on which the permanent
magnets and/or components generating a magnetic field are located and together with
the so-called translator form the entirety of the linear motor. As a result the
translator is variable in length and in fact can be made and/or supplied as an endless
part. Preferably, the compound section consists of an extruded section that is provided
with a centring construction for the stationary electromagnetic coils, tracks for
the various rollers/wheels and accommodation for cables and the like. Preferably
this extruded section is in one piece. More particularly, this extruded section
is made of an aluminium material.
It is, however, also possible to build up the compound
section from a number of plate sections and to join these to one another by welding
and flanging, as a result of which a positive unit is produced.
Likewise it is possible to build up the compound section
from two section halves and to connect these at the stationary part generating the
magnetic field. After all, the support for the magnetic coils will be relatively
rigid and it is possible to connect the two section halves to one another in an
effective manner using this.
The stators (coils and/or magnetic field generator) are
mounted in line on or in said section on and/or along specially marked lines and/or
grooves. As a result the alignment of the components of the linear motor (stators
and translators) is guaranteed in the correct manner. Guiding of the roller wheels
in the vertical and/or horizontal direction is guaranteed in a simple manner by
the profiling. An extruded section made of a type of steel or, for example, aluminium
is preferred. The dimensional stability and continuity of an extruded section in
combination with the shaping and possibility for fitting a wide variety of quick-fit
or click connectors or sections for detectors, cabling, cold bridge breaks, dust
seals, etc. creates an appreciable improvement. The vertical running wheels are
of a large diameter (120 - 280 mm) with as wide as possible a running surface so
as to produce a high bearing capacity and a lower circumferential speed or fewer
revolutions per moved/running metre of the translator. The running wheels are also
vulcanised with a plastic that is wear-resistant but runs silently. The horizontal
running, pilot and tracking wheels are also of large diameter (70 - 120 mm) with
as wide as possible a running surface, the aim of this being the same as that for
the vertical running wheels.
The track, rail, i.e. guide section is also suitable for
accommodating the requisite cabling in the length of the section, both for supplying
voltage and/or current and the cabling required for detectors to be mounted and/or
snugly fitted as desired.
By means of the presence of additional co-formed and/or
extruded fingers/lips and/or grooves, the track, rail or guide section can easily
be provided with a length and/or position measurement system based on, for example,
existing rack, tooth-feeler, hole strip, hole/barcode, laser technology, etc.
The track, rail, i.e. guide section can also be used as
a self-supporting assembly. The section can thus also be used as support or suspender
with the linear motor integrated therein. The track, rail, i.e. guide section can
be used lying flat and/or sideways, upright, suspended, radially and diagonally
with the linear motor integrated therein, optionally clamped between and/or on and/or
to an additional beam and/or support made of any type of material whatsoever.
Because there is the option with the track, rail, i.e.
guide section to supply the whole as a closed system, complete with an integrated
linear motor therein, there can be said to be a dust-tight housing. The corollary
of this is that attraction of metal particles from the surroundings by the strong
permanent magnets is thus virtually completely prevented. This risk is also made
much smaller by working with an extruded aluminium section.
By providing the track, rail or guide section with this
closed characteristic it is no longer necessary to embed the stators or components
generating a magnetic field (for example coils); this is associated with a substantial
saving in costs. Personal safety is appreciably better guaranteed by this means.
As a result of the closed system it is also easy to cool
or to ventilate the system.
In the description and claims the closed system is referred
to at various points by U-shaped or upturned U-shaped. It will be understood that
this relates to orientations in specific positions which can be different depending
on the use.
An extractor or ventilator can be fitted to, for example,
the end faces of the track, rail or closed guide section. The warm air liberated
can also be re-used in a recovery or recycling system.
The track, rail, i.e. guide section, but also the compound
(for example produced by shearing and forming operations) or rolled or extruded
section for the translator is made up to a variable length on a project basis. The
length is determined by the market segment or application for which it is used.
The required specific characteristics with regard to force, power, etc. also have
an influence on the length of the translator section. The stators together with
the translator, i.e. the linear motor, are thus integrated in the track, rail, i.e.
guide section. The linear motor with the track, rail and/or guide and translator
section together form a quick-fit component.
The track, rail and/or guide section can, for example easily
be bolted or welded to or on, for example, a steel structure and/or embedded in
the foundations or supporting construction of a structural whole.
The production, assembly and fitting of the section in
practice is appreciably shortened as a result. The section provided with stators,
cabling, detectors and optionally a translator can also already be tested in the
factory before delivery.
From the logistics or transport technology standpoint the
complete system is thus easier to handle and easier to stack. The risk of damage
in the subsequent handling route is appreciably reduced.
In the explanation of this invention and/or this patent
a choice has been made to take an aluminium extruded section contained between two
steel uprights or supports as an example.
However, the invention and/or this patent is in no way
restricted to the embodiments described as an example and shown in the drawing,
but such embodiments can be implemented in a wide variety of methods, work sequences,
procedures, shapes, lengths and/or dimensions, types of material without going beyond
the scope of the invention.
The aluminium extruded section taken as an example is made
up of several parts (parts 1 to 3). Part 1 of the section is the mirror image of
part 3. Part 2 is intended as a spacer and snap-fit section for housing cabling
for, for example, controlling the stators and/or components generating a magnetic
field. In the heart of the compound track, rail and/or guide section for the linear
motor the stators and/or components generating a magnetic field are mounted against
a raised edge (A in Fig. 1) and/or groove. This is done on two sides; as a result
the alignment and the mounting of the stators and/or components generating a magnetic
field in the correct position is easily guaranteed. In this example (Fig. 1) fixing
is effected by means of a bolt/nut joint. The requisite air gap (B in Fig. 1) between
the permanent magnets of the translator and the stators is guaranteed by this means.
The track, rail and/or guide section continues this. The large, vertically positioned
running wheels (C in Fig. 1) are attached to a so-called separate slide section
(E in Fig. 1). This creates the possibility for being able to adjust the various
components subsequently and, moreover, being able to replace these easily. Matching
of the running wheel diameter to the required carrying capacity and/or lifting or
suspending capacity for a required application is also simplified as a result. After
all, the slide section contains the two large vertical running wheels, but also
the two horizontal running, pilot and tracking wheels. There is an eccentric clamping
facility for these horizontal wheels so as to be able to adjust and/or align this
setting as well. The slide section is mounted both on the left-hand side and on
the right-hand side of the translator. The vertical and horizontal running wheels
are all provided with vulcanised plastic that is wear-resistant but runs silently
(D in Fig. 1).
The extruded aluminium section shown as an example in Fig.
1 has a variable length. This is determined by the application and/or the market
segment in which the linear motor is sold. By providing a facility (G in Fig. 1)
at the top, i.e. open, side of the track, rail and/or guide section (Fig. 1) for
the fixing of and/or the ability to fit, for example, two rubber flaps (F in Fig.
1), a closed track, rail and/or guide section is created. A driver (K in Fig. 1)
or point of attachment will be visible only at the location of the translator of
the linear motor. All other locations in the section are closed in the longitudinal
direction. The linear motor can be cooled with air by ventilating and/or extracting
at the front of the track, rail and/or guide section. Furthermore, this system can
also be used for recovery of heat from the air heated by the linear motor. Because
the track, rail and/or guide section is closed, the linear motor can also be simplified
with regard to the necessary personal safety. Embedding of the stators and/or the
components generating a magnetic field (J in Fig. 1) can be dispensed with. This
saves appreciable costs.
Parts 1 to 3 in Fig. 1 can also serve independently as
self-supporting beam, support and/or rail. Finally, the present invention is in
no way restricted to the embodiments described as an example and shown in the drawing,
but such embodiments can be implemented in a wide variety of shapes and dimensions
without going beyond the scope of the invention.
The sizing used is unrestricted. The system is universal
and, moreover, modular to such an extent that it can easily be expanded and/or provided
with one or more options.
As a result of its modular construction, the system can
also easily be combined with the Netherlands patent, number 1016282, International
PCT Application No. PCT/01/00681 ("Transport System") respectively.