Receiving device with coil of electric line for receiving a magnetic field and for producing
electric energy by magnetic induction and with magnetizable material
The invention relates to a receiving device for receiving a magnetic field and for producing
electric energy by magnetic induction, in particular for use by a vehicle. The invention also
relates to a method of manufacturing such a receiving device. In particular, the invention
can be applied in the field of wireless transfer of energy to vehicles, such as road
automobiles, busses, vans, trucks, but also load carriers, e.g. forklift trucks, and rail
vehicles. The receiving device shall be adapted to produce electric power at least at rates
in the kilowatt range, e.g. 20 kW.
WO 201 2/010649 A2 discloses an arrangement for receiving an electromagnetic field, for
producing electric energy from the electromagnetic field by induction and for providing a
load with the electric energy, in particular for providing a rail vehicle (e.g. a tram) or a road
vehicle with energy. For producing electric energy by induction, the receiving arrangement
comprises at least one inductor which may be realized by one or more windings of an
electrical conductor. While a load is provided with electric energy from the receiving
arrangement, the resulting alternating current produced by the inductor is rectified. An
output side of the rectifier is connected to the load. The receiving arrangement may have
three phases for receiving the electromagnetic field and the rectifier may be connected to
the three phase lines of the receiving arrangement. Each phase comprises an inductance
and a capacitance, which may be realized by in each case at least one capacitor.
There is a demand for the integration of such a receiving device or a different receiving
device in existing motor vehicles, such as road automobiles. The weight of the receiving
device should be small, since the maximum revenue load of the vehicle should be
affected as little as possible. In addition, the construction of the receiving device and the
mounting of the receiving device should be stable and also easy to assemble. Existing
spaces especially in the region of the bottom of the vehicle's car body should be utilized.
Typically, the magnetic field (as part of an alternating electromagnetic field) is produced
by a device below the vehicle's bottom. Therefore, the receiving device which is typically
mounted at the bottom of the vehicle receives the magnetic field from below, i.e. from the
bottom side. However, it is possible to orient the receiving device in a different direction
(such as the horizontal direction) if the magnetic field generating device is located in this
direction. Generally speaking, the receiving device has a receiving side and, during
operation, the magnetic field enters the receiving device or its case on the receiving side.
EP 2081792 B 1 discloses a cladding element having a receiving unit integrated therein.
The receiving unit comprises a receiver coil for contactless transmission of electrical
energy and a plurality of flow conducting elements that are allocated to the receiver coil
and designed to concentrate the field strength and are made from a material having high
permeability compared with air.
Magnetizable material, such as iron or ferrite, can be used to shape the field lines of the
magnetic field. This may enhance field intensity at the location of the coil or coils of the
receiving device. Furthermore, the magnetizable material shields the surroundings of the
receiving device, in particular the area beyond the magnetizable material if viewed from
the coil or coils. However, magnetizable material is typically heavy material which
consequently increases the weight of the receiving device.
It is an object of the present invention to provide a receiving device and a method of
manufacturing a receiving device which comprises magnetizable material, wherein the
weight of the receiving device is small. In particular, the receiving device shall be
mechanically stable and producible at small costs.
According to a basic idea of the present invention, the thickness of the magnetizable
material, which is located behind the coil or coils, varies. "Behind" means that the
magnetizable material is located in between the coil or coils and the side of the receiving
device which is opposite to the receiving side. Alternatively, the thickness can be named
"depth". The direction, in which the thickness or depth is to be measured, is the direction
from the receiving side of the receiving device to the side of the receiving device opposite
to the receiving side.
By varying the depth of the magnetizable material, weight can be saved. In particular, the
depth of the magnetizable material can be chosen so that the magnetizable material is
deeper where necessary and less deep where sufficient. In particular, the depth of the
magnetizable material is designed to be larger at locations, if viewed from the receiving
side, behind regions of the coil where the electromagnetic field produced by electric
currents through the at least one coil is larger compared to locations behind regions of the
coil where the electromagnetic field produced by electric currents through the at least one
coil is smaller. Provided that the field intensity of the magnetic field, which is produced by
a generating device for transferring energy to the receiving device by induction and which
enters the receiving device on the receiving side, is essentially constant along the
extensions of the coil or coils, only the electric currents which are induced in the coil or
coils are responsible for variations of the field intensity behind the coil or coils.
In particular, the magnetizable material is arranged above the coil or coils, if the receiving
side is the bottom side. In any case, the field lines of the magnetic field enter the receiving
device on the receiving side, penetrate the area covered by the coil or coils and are re
directed and bundled within the magnetizable material so as to return to the field
generating device.
Preferably, in the case of coils arranged to produce different phases of an alternating
current, the depth of the magnetic layer is larger behind a first region where coils of
different phases overlap, and in particular where electric lines of different coils overlap
each other, compared to a second region where there is no overlap of coils of different
phases or electric lines of different coils.
In particular, the outline of the field shaping arrangement, which is formed by the
magnetizable material, may have a hat-like shape with a deeper central region and two
less deep peripheral regions. In particular, the deeper central region is located behind
regions of the coil or coils having more parallel electric lines, thereby producing a larger
electromagnetic field than the peripheral regions. In particular, the central region and the
two less deep peripheral regions may form a planar outline (i.e. an outline having no
recesses or protrusions, except for gaps in between field shaping elements) on the side
facing the coil or coils.
In particular, the following is proposed: A receiving device for receiving a magnetic field
and for producing electric energy by magnetic induction, in particular for use by a vehicle,
wherein
- the receiving device comprises at least one coil of at least one electric line and
wherein the magnetic field induces an electric voltage in the at least one coil during
operation,
- the receiving device and the at least one coil are adapted to receive the magnetic
field from a receiving side of the receiving device,
- the receiving device comprises a field shaping arrangement comprising
magnetizable material adapted to shape magnetic field lines of the magnetic field,
- the field shaping arrangement is placed behind the at least one coil, if viewed from
the receiving side of the receiving device,
- a depth, to be measured in the direction from the receiving side of the receiving
device to the side of the receiving device opposite to the receiving side, of the field
shaping arrangement varies.
Furthermore, proposed is: A method of manufacturing a receiving device for receiving a
magnetic field and for producing electric energy by magnetic induction, in particular for
use by a vehicle, wherein
- at least one coil of at least one electric line is provided, wherein the at least one coil
comprises an inductance, so that the magnetic field induces an electric voltage in
the at least one coil during operation of the receiving device,
- the coil is arranged to receive the magnetic field from a receiving side of the
receiving device,
- a field shaping arrangement, comprising magnetizable material adapted to shape
magnetic field lines of the magnetic field, is placed behind the at least one coil, if
viewed from the receiving side of the receiving device,
so that a depth, to be measured in the direction from the receiving side of the receiving
device to the side of the receiving device opposite to the receiving side, of the field
shaping arrangement varies.
In particular, the receiving device may comprise a plurality of electric lines for carrying
different phases of an alternating electric current. In addition or alternatively, the receiving
device may comprise a plurality of coils, wherein coils of the same phase line may be
arranged next to each other and wherein coils of different phase lines may overlap each
other. Overlap" means that the magnetic field lines, which enter the receiving device on
the receiving side and which penetrate one coil towards the side opposite to the receiving
side, also penetrate the overlapping coil(s).
In the following the expression "magnetic material" is used as a synonym of "magnetizable
material", although the magnetic state of the material may change. Preferably, the coil or
coils of the receiving device is/are combined with ferromagnetic and/or ferrimagnetic
material (such as a ferrite), which is arranged behind the coil or coils.
In particular, the area covered by the at least one coil includes the whole area around
which any winding of the coil or coils circulates.
In particular, a layer of electrically insulating material and/or of elastic material can be
arranged between the coil or coils and the magnetic material. In case of electrically
conducting magnetic material, this layer insulates and in case of an elastic layer,
mechanic vibrations and wear of the coils and the magnetic material is prohibited.
In particular, the field shaping arrangement is formed by a plurality of field shaping
elements made of the magnetizable material. Using field shaping element facilitates
forming the field shaping arrangements. More or less field shaping elements can be
stacked so as to vary the depth of the field shaping arrangement. In particular, different
field shaping elements can be placed next to each other, but leaving a gap in between the
neighboring field shaping elements, wherein the gap extends in a direction transverse to
the direction of the depth. Consequently, magnetizable material can be saved and the
weight is further reduced. Preferably, the gap or gaps are sized and are adapted to the
depth of the field shaping arrangement according to the desired shielding effect of the
magnetizable material. For example, the desired shielding effect can be defined by a
maximum value of the magnetic field behind the field shaping arrangement, if viewed from
the coil or coils.
In particular, the field shaping elements may have equally large depths and the depth of
the field shaping arrangement varies, because different numbers of the field shaping
elements are stacked upon each other in the direction from the receiving side to the side
opposite to the receiving side. Using field shaping elements having equally large depths
facilitates forming the desired variation of the depth of the field shaping arrangement.
Preferably, variations of the depth of the field shaping arrangement are compensated by
at least one compensating element made of non-magnetizable material. It is preferred that
the material of the compensating element(s) is lighter in weight per volume compared to
the magnetic material. "Compensation" means that the total depth of the combined
arrangement consisting of the field shaping arrangement and of the at least one
compensating element varies less than the depth of the field shaping arrangement. It is
possible, but not preferred, that at least one compensating element is arranged in
between field shaping elements so as to form a combined stack of field shaping elements
and at least one compensating element. In this case, the depth of the field shaping
arrangement is equal to the total depth reduced by the depth of the at least one
compensating element. For example, the compensating element may be made of plastic,
for example a polymer.
Compensating variations of the depth of the field shaping arrangement facilitates the
assembly of the receiving device. In particular, the receiving device may comprise
different layers and/or modules which are stacked upon each other. Similarly to the layer
of electrically insulating material and/or of elastic material mentioned above, such a layer
can be arranged behind the field shaping arrangement, if viewed from the coil or coils.
Further layers may be a shield made of electrically conducting material for shielding an
electric field and a module comprising capacitors. Examples are given below. If the
variations of the depth of the field shaping arrangement would not be compensated, these
layers and modules needed to be adapted to the depth profile of the field shaping
arrangement. Otherwise, mechanical stability is at risk. Since it should be possible to
produce receiving devices with different depth profiles of the field shaping arrangement,
this would require individually shaped parts for the respective receiving device. Therefore,
the same type of additional layers and modules can be used for different depth profiles, if
the depth variations are compensated.
Preferably, the variations of the depth are compensated so that the depth of a combined
arrangement consisting of the field shaping arrangement and of the at least one
compensating element is constant. Due to this depth compensation it is possible to use
planar layers, elements and modules in regions of the receiving device beyond the
magnetic layer (if viewed from the coil or coils) and hollow spaces are avoided. Therefore,
the receiving device can be compact and stable. For example, a layer of elastic material
and/or a layer of electrically conducting material (which therefore shields electromagnetic
radiation) and/or a layer of electrically insulating material (which might be the base plate of
an electric circuit arrangement comprising the at least one capacitor and connecting
electric lines for connecting the capacitor(s) and/or the coils to an external device may be
placed on the region which is formed by the magnetic material and the height
compensating material.
In particular, the coil or coils comprise in each case at least one winding of the electric line
(in case of at least two phases: the phase lines) and the winding or windings of the
respective coil defines a central axis around which the electric line is wound. In particular,
the windings of the respective coil may circulate around an area in each case, wherein the
area is substantially the same for each winding of the respective coil. Furthermore, it is
preferred that all coils of the receiving device have areas enclosed by the windings, which
areas have substantially (with variations of only a few percent) the same size. The central
axis mentioned above penetrates the area at its center. Preferably, the coil or coils of the
receiving device is/are flat, i.e. the winding or windings of each coil extend(s) in a plane
and the planes of any different windings of the same coil are identical or parallel to each
other. In case of plural phases, sections of the electric lines of at least one of the coils
may extend outside of the plane due to the fact that electric lines of different coils and/or
phases overlap each other if viewed from the receiving side.
Preferably, not only the planes of different windings of the same coil, but also the planes
of the windings of different coils are identical or parallel to each other so that the complete
arrangement of the coils is flat, which means that the coils cover an area, which is
penetrated by the magnetic field during operation and which is significantly wider and
longer compared to the total height of the coil arrangement. In particular, the height may
be smaller than 1/3, preferably one 1/5 and most preferred 1/10 of the width and length of
the covered area. Consequently, the coil arrangement can be housed by a housing (or
case) that is shaped like a flat box, i.e. a box having a small height compared to its width
and length.
More generally speaking, the case has a flat configuration defining a first surface on the
receiving side and a second surface on the side opposite to the receiving side, wherein
the first surface and the second surface are connected by surface areas of the case which
are oriented in each case to another side than the receiving side and the side opposite to
the receiving side and which are smaller than the first surface and the second surface.
In particular, at least one fastening and/or stiffening element in the shape of a column
(preferably a plurality of columns) extending from the receiving side to the opposite side
may be part of the receiving device. The column(s) may be used to fix and/or separate
different regions (in particular the field shaping elements) of the magnetizable material of
the field shaping arrangement. This facilitates mounting of the magnetic material and
guarantees that the magnetic material remains in predetermined desired positions and/or
regions. Preferably, the at least one column separates the different regions of magnetic
material with respect to a first direction (e.g. the transverse direction) and separates
different electric lines and/or bundles of electric lines with respect to a second direction
(e.g. the longitudinal direction), wherein the first direction and the second direction may
extend transverse to each other, in particular perpendicularly to each other. The first and
second direction may extend perpendicularly to the direction from the receiving side to the
opposite side of the receiving device.
At least one column of the separating structure may extend through a cut out of a material
layer, which material layer is arranged on the side opposite to the receiving side if viewed
from the at least one coil. This layer may be made of elastic material. Alternatively or in
addition, the material of the layer may be electrically conducting or electrically insulating.
In any case, the column either holds the layer or, at least, limits movement of the layer.
At least one column of the fixing and/or separating structure may be fixed to a base plate
of the separating structure or of a case of the receiving device, the base plate being
preferably arranged on the receiving side if viewed from the at least one coil. By fixing the
at least one column to the base plate, the column can be fixed in a desired, stable
position. This facilitates assembling of the receiving device, since the column can be used
for the assembly of other components of the receiving device as separator or holding
element.
Embodiments of the method of manufacturing the receiving device follow from the
description of the embodiments of the receiving device.
Examples of the invention will be described with reference to the attached drawing. The
figures of the drawing show:
Fig. 1 an example of a case of a receiving device in a three dimensional view,
Fig. 2 a view of a side face of the case shown in Fig. 1,
Fig. 3 an exploded view of the case shown in Fig. 1 and Fig. 2 with the interior
components of the receiving device, according to a specific embodiment, i.e. the
interior components may be varied,
Fig. 4 an example of an arrangement of coils, in particular the arrangement shown in
Fig. 3,
Fig. 5 a base part of the case shown in Fig. 1 and Fig. 2 with a specific embodiment of
an arrangement of components for positioning and/or fixing interior components
of the receiving device,
Fig. 6 a layer of electrically insulating elastic material for covering the coil arrangement
of a receiving device,
Fig. 7 schematically an intermediate layer of the interior of a receiving device, such as
the layer shown in Fig. 6, and a plurality of blocks made of magnetic material in
an exploded view,
Fig. 8 schematically a side view of an arrangement of interior components of a
receiving device, comprising a plurality of coils, an intermediate layer and an
arrangement of magnetic material elements as well as height compensating
elements,
Fig. 9 a base plate made of electrically insulating material and an arrangement of
capacitors and connecting lines in an exploded view, wherein the capacitors and
connecting lines are to be positioned within a protruding portion of a case,
Fig. 10 an arrangement of the case shown in Fig. 1 and a rectifier,
Fig. 11 schematically a road vehicle and an arrangement for inductively transferring
energy to the road vehicle, wherein a receiving device for receiving a magnetic
field is integrated at the bottom of the vehicle,
Fig. 12 schematically a cross section through a part of an arrangement similar to the
arrangement shown in Fig. 5 in combination with the arrangement shown in Fig.
7 and
Fig. 13 schematically a cross section through a part of an arrangement similar to the
arrangement shown in Fig. 4 and 5 in combination with the arrangement shown
in Fig. 7, wherein the image plane of Fig. 13 extends perpendicularly to the
image plane of Fig. 12.
The receiving device 1 shown in Fig. 1 and Fig. 2 comprises a case having a base plate 2
and a top part or cover 3. While the base plate 2 forms a planar surface on the underside
(the receiving side of the receiving device to be housed by the case), the top surface
formed by the cover 3 is not planar as a whole, but only comprises planar regions. The
cover 3 has three elongated protruding portions 5, 6a, 6b which protrude to the top side
(the side opposite to the receiving side of the case or receiving device).
In the embodiment shown in Fig. 1 and Fig. 2, the cover 3 forms the main sections of the
side surfaces of the case 1. In alternative embodiments, the case may comprise more
than two parts forming the outer surfaces and/or larger parts of the side surfaces may be
formed by the base part which corresponds to the base plate 2 in Fig. 1 and Fig. 2.
As shown in Fig. 1, the side surfaces of the case comprise a plurality of means for fixing
the case 1 to a vehicle, in particular to a frame construction of the vehicle. For example,
the fixing means 8 may be threaded holes for screwing the case to the vehicle.
The protruding portions 5, 6a, 6b of the cover 3 are elongated, i.e. in each case comprise
a longitudinal axis along which they extend. Preferably, the protruding portions extend
along the whole length of the case and preferably have the same profile along their
extension in longitudinal direction.
The protruding portion 5 is located in the center of the case (if viewed in width direction)
and extends along the center line of the case, i.e. in lengthwise direction of the case. The
cross section of the protruding portion 5 is trapezoidal, wherein the cross section tapers to
the free top end of the protruding portion 5.
According to the specific embodiment shown in Fig. 1 and Fig. 2, the central protruding
portion 5 has an opening in the side face shown in Fig. 2 which opens to a tubular
connecting part 7 that can be used for receiving electric connection lines or cables.
Variations of the embodiment shown in Fig. 1 and Fig. 2 are possible, such as a case
having the protruding portion 5 along the center line, but does not have the side protruding
portions 6a, 6b or only having one of these side protruding portions.
The exploded view of Fig. 3 shows a specific embodiment of a receiving device, wherein
the components of the receiving device are housed by the case shown in Fig. 1 and Fig 2.
The base part 2 of the case carries a holding device 12 for holding other interior
components of the receiving device, in particular electric lines that form in each case two
coils of three phases. In addition, the holding device 12 comprises a plurality of columns
for separating, holding and/or fixing components of the receiving device which are located
above the coils. In particular, at least one intermediate layer of insulating and/or elastic
material, magnetic material, a layer of electrically conducting shield material and/or a base
plate for an electric circuit arrangement can be separated, held and/or fixed using one or
more than one of the columns.
When the cover 3 of the case is mounted to the base plate 2 of the case, the outer rim of
the cover 3 abuts on a sealing 11 which is positioned in the periphery of the holding
device 12 and is supported by the rim of the base plate 2.
A coil arrangement 3 1 is positioned within pre-defined receiving spaces of the holding
device 12. Since the different electric lines (phase lines) for producing the different phases
of an alternating current form coils which overlap each other if viewed from the top (from
the cover 3), the phase lines of at least two of the phases rise nearby the longitudinal
sides of the coil arrangement so that they extend along the longitudinal side one upon the
other, where they overlap. Details of a specific embodiment of this kind are shown in Fig.
4 and will be described later.
The coil arrangement 3 1 is covered by a layer 5 1 of elastic material which is preferably
also electrically insulating. The layer 5 1 may be formed by a single piece of material or by
a plurality of pieces.
An arrangement 6 1 of magnetizable material, in particular ferrimagnetic material or
alternatively ferromagnetic material, is placed on the intermediate layer 5 1. Preferably, the
height (i.e. the depth) of the magnetic material differs and is larger above (i.e. behind)
regions where the density (number per length) of the electric lines of the coil arrangement
3 1 is higher.
Preferably, compensating material 7 1 is placed where the height of the magnetic material
6 1 is smaller so that the height of the total arrangement of magnetic material 6 1 and
compensating material 7 1 is constant or, at least, varies less than the height of the
magnetic material 6 1.
In the specific embodiment shown in Fig. 3, a second intermediate layer 8 1, which may be
have the features described above for the intermediate layer 5 1, is placed on top of the
magnetic material 6 1 or the compensating material 7 1.
A shielding layer 9 1 made of electrically conducting material, for example aluminum, is
placed on top of the second intermediate layer 8 1. The shielding layer 9 1 has cut outs 95
so that at least some of the columns of the holding device 12 can extend through the cut
outs 95. Some cut outs or regions 96 of the cut outs can be used for placing sections of
electric connections between the coil arrangement 3 1 and the electric circuit 111 that is
placed above the shielding layer 9 1.
The circuit arrangement 111 is placed on a sheet-like carrier 10 1, such as a conventional
circuit board. There is a cut out 100 in the carrier 101 so that electric connections between
the circuit arrangement 111 and the coil arrangement 3 1 can extend through the cut out
100.
In the specific embodiment shown in Fig. 3, the carrier 111 and the shielding layer 9 1
comprise bores 97 or other cut outs which allow for fixing the carrier 101 to columns of the
holding device 12 so that the complete arrangement of interior components of the
receiving device is fixed to the holding device 12. In particular, the electric circuit
arrangement 111 can be fixed to the carrier, for example by soldering, and the holding
device 12 can be fixed to the base plate 2 of the case, such as by gluing or screwing.
Preferably, screws are also used to fix the carrier 101 to the columns of the holding device
12.
A preferred embodiment of the coil arrangement 3 1 is shown in Fig. 4. The coil
arrangement consists of six coils 33a, 33b, 35a, 35b, 37a, 37b, two coils per phase line
32, 34, 36. The coils of each phase line are placed next to each other on the same height
level of the receiving device. Fig. 4 shows an exploded view of the coil arrangement 3 1 .
To form the two coils of one phase, the respective phase line 32, 34, 36 is wound starting
at one end of a first coil around the area to be covered so as to form the first coil and
further extends around the area to be covered by the second coils so as to form the
second coil. In the example shown in Fig. 4, each coil may comprise two to five windings.
The number of the windings of the phase lines 32, 34, 36 is not shown in the figures.
As mentioned before, the coils of the different phases overlap each other partially in the
middle region of the coil arrangement 3 1. The phase lines 32, 34, 36 are placed one upon
the other where the coils overlap. Since transversally extending sections of the different
phase lines 32, 34, 36, which sections connect the longitudinal sides, are placed on the
same height level in the finished coil arrangement 3 1 , at least the phase lines 34, 36 rise
along their extension next to the longitudinal sides of the coils. The holding device 12
defines spaces for receiving these transversely extending sections of the phase lines,
wherein the spaces are on the same height level.
Although the phase lines 32, 34, 36 are preferably electrically insulated at their surfaces,
the coils 33, 35, 37 of the different phases are preferably placed upon each other using
distance pieces 4 1, 42, 43. These pieces are placed in between the phase lines 32, 34, 36
where they are placed one upon the other. In particular, there are three types of distance
pieces. The first type 4 1 is used where the phase line 34 of the second phase is placed
above the phase line 32 of the first phase along the longitudinal side of the coil
arrangement 3 1. The first type 4 1 of distance pieces is elongated and extends along the
longitudinal side and, at the same time, along the phase lines 32, 34 so as to form a
distance between the phase lines 32, 34. The first type 4 1 of the distance pieces has a
constant cross section. It is used for the second coil 33b of the first phase.
The second type 42 of distance pieces does not have a constant cross section, but the
end region shown on the right hand side of Fig. 4 is significantly higher than the other
sections. Where the distance pieces 42 are higher, the first coil 33a of the first phase
supports the first coil 37a of the third phase. Where the height of the distance pieces 42 is
smaller, the first coil 33a of the first phase supports the first coil 35a of the second phase.
The third type 43 of the distance pieces also has a non-constant, varying cross section.
The end regions of the distance pieces 43 are higher than the other regions. Where the
height is larger, the second coil 35b of the second phase supports other components of
the receiving device which are placed above the coil arrangement 3 1. Where the height of
the distance pieces 43 is smaller, the second coil 35b or the first coil 35a of the second
phase supports the first or second coil 37a, 37b of the third phase.
In particular, the number of the distance pieces 4 1, 42, 43 depends on the number of
windings per coil. Since the number of windings may differ in different embodiments of the
arrangement, Fig. 4 shows different numbers of the different types of the distance pieces
4 1, 42, 43. However, in practice, it is preferred that all coils comprise the same number of
windings and, consequently, that the numbers of the different types of distance pieces are
equal.
The longitudinal section of the coil 33b of the first phase is fully overlapped by the coils
35a, 35b of the second phase. If the coils 35a, 35b are placed on top of the coils 33a, 33b,
the transversely extending section at the side face of coil 35b is placed outside of the area
which is covered by the second coil 33b of the first phase. The transversely extending
section of the second phase which comprises sections of the first coil 35a and the second
coil 35b is placed in the area around which the phase line 32 of the second coil 33b of the
first phase extends. The transversely extending section of the first coil 35a of the second
phase is placed in the area around which the phase line 32 of the first coil 33a of the first
phase extends. The corresponding arrangement can be perceived from Fig. 3: the
transversely extending sections of the coils are separated from the neighbouring
transversely extending section of another coil in each case by at least one of the columns.
In the example shown, there are five columns in each case in between two neighbouring
transversely extending sections.
The coils 35 of the second phase and the coils 37 of the third phase are shifted in a
similar manner relative to each other as the first phase and the second phase, but the shift
length in longitudinal direction is twice as large as the shift length of the first and second
phase. As a result, the transversely extending section at the side face of the first coil 37a
of the third phase is placed outside of the area around which the phase line 32 of the first
coil 33a of the first phase extends. On the other hand, the shift length in longitudinal
direction of the third phase relative to the first phase has the same amount as the shift
length of the first phase and the second phase, but is oriented in the opposite direction if
viewed from the first phase coil arrangement.
At least one end of the phase line 32, 34, 36 which forms the coils of the respective phase
is connected to a line section or forms a line section that extends upwards from the coils.
Respective upwardly extending sections 38, 39, 40 are shown in Fig. 4. The other ends of
the phase lines 32, 34, 36 can directly be connected to each other (not shown in Fig. 4) so
as to form an electrical star point. Since at least one end of each phase line 32, 34, 36 is
connected to an upwardly extending section 38, 39, 40, the coil arrangement can be
electrically connected in a different region (in particular on a higher level) of the receiving
device, in particular to components which are located in the protruding portion of the case.
In particular, the upwardly extending sections 38, 39, 40 are connected to in each case at
least one capacitor of the circuit arrangement 111 shown in Fig. 3 and Fig. 9.
The enlarged view of the base plate 2 and the holding device 12 shown in Fig. 5
comprises a plurality of columns 13, 14, 15 which extend upwards from the basis of the
holding device. A preferred material of the holding device 12 is plastic, such as a polymer.
Preferably, the basis of the holding device 12 is sheet-like forming a planar or merely
planar outer surface facing to the base plate 2. Preferably, the columns 13, 14, 15, the
basis and optionally further portions (e.g. holding portions for holding electric lines or
bundles of electric lines) of the holding device 12 are formed as an integral part, for
example by injection moulding. Alternatively, at least one of the columns 13, 14, 15 can be
manufactured as a separate piece and can be fixed to the basis.
The holding device 12 comprises holding portions 16, 17 for holding electric lines or
bundles of electric lines. Depending on the number of the electric lines or bundles of
electric lines to be held by the individual holding portion 16, 17, the holding portions are
wider or narrower (with respect to the longitudinal direction). In the example shown in Fig.
5, the first three holding portions 16 from the left and from the right in the figure are
narrower than the three holding portions 17 in the middle.
The columns 13, 14, 15 are arranged in lines extending in the longitudinal direction (from
left to right in Fig. 5) and rows extending in transverse direction (from front to back in Fig.
5). There are spaces in between the rows of columns and beyond the first and last row,
wherein these spaces are adapted to receive the respective transversely extending
sections of the coils of the coil arrangement, in particular the coil arrangement 3 1 as
shown in Fig. 4. In the specific embodiment shown in Fig. 5, the width of these spaces as
measured in the longitudinal direction differs corresponding to the number of sections of
electric lines which are to be placed side by side to each other on the same height level.
Consequently, in view of the coil arrangement 3 1 shown in Fig. 4, the first three spaces
have a smaller width which is in particular half as wide as the width of the three spaces in
the middle of the holding device 12.
The lines of the columns 13, 14, 15 are spaced so that pieces of magnetic material and
optionally compensating material can be placed in between in each case two of the
columns.
In addition, at least one of the columns 13, 14, 15 can be used for fixing other components
of the receiving device to the column and thereby to the holding device 12.
Therefore, the columns combine different functions, in particular separating different
transversely extending sections of coil, separating different pieces of material, such as
magnetic material and compensating material, and/or fixing other components to the
respective column. A further possible function is separating components of the receiving
device from the basis of the holding device and/or from the basis of the receiving device at
the receiving side. "Separating" means that the respective components or parts cannot
contact each other. The respective dimension of the column, either in longitudinal
direction, in transverse direction or in height direction, defines the minimum distance
between the two parts or components which are separated.
In addition, as mentioned before, the specific embodiment of the holding device 12 shown
in Fig. 5 comprises elevated rims 18 along the longitudinal sides. In any case, the rims of
the holding device along the longitudinal sides are adapted to receive the corresponding
sections of the coil arrangement.
Preferably, the spaces for receiving the phase lines of the coil arrangement have shaped
surfaces, in particular grooved surfaces, so that the phase lines are held in place and do
not slip. In particular, these spaces can be provided by holding portions of the holding
device.
In particular, two columns 15 of the holding device 12 are higher than the other columns
13, 14 and serve to position and/or fix the carrier 10 1 and the circuit arrangement 111
shown in Fig. 3 and Fig. 9.
The intermediate layer 5 1 (and optionally the intermediate layer 7 1) shown in Fig. 3 are
shaped as shown in Fig. 6. The layer 5 1 may be made of an elastic material, such as
silicone. The layer 5 1 comprises a plurality of cut outs 23, 24, 25 which are arranged in
lines and rows similarly to the lines and rows of the columns 13, 14, 15 of the holding
device 12. Preferably, the cut outs 23, 24, 25 are sized so that the columns may extend
through the cut outs while abutting to the surfaces of the cut outs 23, 24, 25. It is preferred
that the surfaces of the cut outs 23, 24, abut to the surface of the respective column 13,
14 all around the column. In the center line of the receiving device and, therefore, of the
layer 5 1, there is the cut out 25 which has a length that is larger than the length of the
columns 15. This allows for passing other components through the cut out 25. In
particular, the upwardly extending line sections 38, 39, 40 shown in Fig. 4 may extend
through the cut out 25.
Fig. 7 and Fig. 8 schematically show the arrangement of a plurality of magnetic material
pieces 62 (e.g. pieces having the shape of a cuboid) which is to be placed on an
intermediate layer 5 1 which may be the intermediate layer 5 1 shown in Fig. 6. However,
the number of cut outs 23, 24 and their shapes may vary from embodiment to
embodiment. In addition, the arrangement can be used with a different type of receiving
device as described with reference to the figures. Fig. 7 and Fig. 8 show the principle of
placing magnetic material above the coil arrangement of a receiving device, independent
of the interior components used in the receiving device and independent of the specific
dimensions of the interior components of the receiving device.
In Fig. 7, areas 63 where magnetic material pieces 62 are to be placed are indicated by
dashed outlines. For a first line of such areas 63, the pieces 62 are shown in the exploded
view of Fig. 7. There are four pieces 62 to be placed on top of the two areas 63 in the
middle of the line and there are only two pieces 62 to be placed on the two areas 63 at the
end of the line. The resulting stacked arrangement of pieces 62 is schematically shown in
Fig. 8. Since all pieces 62 have the same dimensions, the two stacks in the middle are
twice as high as the two stacks at the opposite ends of the line. The motivation for these
different total heights of magnetic material is the overlap of the different phase lines 32,
34, 36 which form the coils of the different phases, for example as shown in Fig. 4. Higher
magnetic field strengths caused by more electric lines require more magnetic material.
In order to compensate for the different heights of the magnetic material, compensating
material 72 is placed as shown in Fig. 8.
Fig. 7 also shows the cut outs 23, 24 and that the lines of areas where the magnetic
material is to be placed are located in between the lines of the cut outs 23, 24. In
longitudinal direction, it is preferred that the magnetic material pieces 62 abut to each
other (in contrast to the small distances shown in Fig. 8). As preferred, at least one
column (not shown in Fig. 7) and preferably a plurality of columns extend(s) in each case
through one of the cut outs 23, 24, thereby separating the lines of the magnetic material
pieces 62.
Variations of the embodiment of a field shaping arrangement shown in Fig. 7 and Fig. 8
are possible. In particular, it is not necessary to combine the arrangement with one of the
intermediate layers or any of the intermediate layers shown in Fig. 6. Furthermore, the
columns can be omitted. In addition, the shape of the elements made of magnetizable
material may be different. However, shapes are preferred which allow for producing a
mosaic of elements having seams between the elements, but no other hollow spaces.
Fig. 9 shows an enlarged view of the carrier 101 and of the electric circuit arrangement
111 which is carried and preferably fixed on the carrier 10 1 . There is a plurality of blockshaped
capacitors 115, some of which are electrically connected to each other by plate
like electrical connectors 116. In addition, the capacitors 115 are electrically connected to
the respective coil in particular via the upwardly extending connecting sections 38, 39, 40
shown in Fig. 4 and are electrically connected via connection lines 112, 113, 114 to an
external device, in particular to the rectifier 120 shown in Fig. 10. These external
connection lines 112, 113, 114 can be guided through the connecting part 7 shown in
Fig. 1 and Fig. 2.
At least the upper part of the circuit arrangement 111 shown in Fig. 9 can be placed within
the protruding portion 5 of the cover 3 of the case shown in Fig. 1 and Fig. 10. The
protruding portions 6a, 6b of the cover 3 along the longitudinal sides are preferably used
for receiving at least sections of the phase lines and optionally of the spacing pieces of the
coil arrangement, such as the circuit arrangement 3 1 shown in Fig. 4.
Fig. 10 shows the receiving device 1 of Fig. 1 and a rectifier 120 which is housed by a
housing 12 1. In particular, the connecting lines 112, 113, 114 shown in Fig. 9 connect the
receiving device 1 with the rectifier 120.
The central protruding portion 5 of the receiving device 1 is elongated and extends along
a longitudinal axis which is also the longitudinal axis of the housing 121 of the rectifier
120. This arrangement can be placed in corresponding recesses formed by the bottom
surface of the car body of a road vehicle. Such a road vehicle 141 is shown in Fig. 11. The
location of the receiving device is schematically indicated by a block with reference
numeral 143 and the location of the rectifier is schematically indicated by a block with
reference numeral 144.
During energy transfer to the vehicle, a generating device 142 generates the magnetic
field, in particular by generating an alternating electromagnetic field. The magnetic field is
indicated by three curved lines. The generating device 142 is provided with electric current
from corresponding equipment 145, which may include an inverter and/or an AC/AC
converter.
Figure 12 shows five columns 13, 15 which extend upwards from a base plate of a
separating structure 12, wherein the receiving side of the receiving device is at the bottom
of the figure. A layer 5 1 of elastic material extends at a distance and parallel to the base
plate. In a similar manner as shown in the exploded view of Fig. 8, pieces of magnetic
material 62 are laid on the layer 5 1 in between the columns 13, 15. Consequently, the
columns 13, 15 separate the pieces of magnetic material 62. In addition, the columns 13,
15 extend through cut outs of the layer 5 1.
Figure 13 shows three columns 13, 14, 15 which extend upwards from a base plate of a
separating structure 12, wherein the receiving side of the receiving device is at the bottom
of the figure. In the same manner as shown in figure 12, the layer 5 1 of elastic material
extends at a distance and parallel to the base plate. While Fig. 12 shows a region of the
arrangement where no electric lines of the coil arrangement are positioned in between the
base plate and the layer 5 1, Fig. 13 shows a region of the arrangement where bundles of
electric lines, in particular the phase lines 34, 36 of the arrangement shown in Fig. 4, of
the coil arrangement are positioned in between the base plate and the layer 5 1. The
bundles are held by holding portions 16, 17 of the separating structure 12. The holding
portions 16, 17 in each case form a groove for receiving the electric lines 34, 36. In case
of the receiving portions 16, there are three electric lines 36 side-by-side in the groove. In
case of the receiving portions 17, there are five electric lines 34 side-by-side in the
groove. In alternative embodiments, the electric lines may be held in a different manner,
for example using a groove for each single electric line and/or with electric lines not or not
only side-by-side in the longitudinal direction (horizontal direction in Fig. 13), but stacked.
Consequently, the column 15 separates the holding portions 16, 17 and thereby the
bundles of electric lines 34, 36. In addition, the column 15 extends through a cut out of the
layer 5 1.
Modifications of the arrangement shown in Fig. 12 and Fig. 13 are possible. For example,
the numbers and/or dimensions of the elements and components shown in the figures
may vary. In addition, the columns may be used for separating, holding and/or fixing other
components of the receiving device in addition to the components shown in the figures or
alternatively to the at least a part of the components shown in the figures.

Claims
1. A receiving device ( 1) for receiving a magnetic field and for producing electric
energy by magnetic induction, wherein
- the receiving device (1) comprises at least one coil (33, 35, 37) of at least one
electric line and wherein the magnetic field induces an electric voltage in the at
least one coil (33, 35, 37) during operation,
- the receiving device (1) and the at least one coil (33, 35, 37) are adapted to
receive the magnetic field from a receiving side of the receiving device ( 1 ) ,
- the receiving device ( 1) comprises a field shaping arrangement (61 )
comprising magnetizable material adapted to shape magnetic field lines of the
magnetic field,
- the field shaping arrangement (61) is placed behind the at least one coil (33,
35, 37), if viewed from the receiving side of the receiving device (1),
- a depth, to be measured in the direction from the receiving side of the
receiving device ( 1 ) to the side of the receiving device (1) opposite to the
receiving side, of the field shaping arrangement (61) varies.
2. The receiving device of claim 1, wherein the depth of the magnetizable material is
larger at locations, if viewed from the receiving side, behind regions of the coil
where the electromagnetic field produced by electric currents through the at least
one coil (33, 35, 37) is larger compared to locations behind regions of the coil
where the electromagnetic field produced by electric currents through the at least
one coil (33, 35, 37) is smaller.
3. The receiving device of claim 1 or 2, wherein the field shaping arrangement (61) is
formed by a plurality of field shaping elements (62) made of the magnetizable
material.
4. The receiving device of claim 3, wherein the field shaping elements (62) have
equally large depths and wherein the depth of the field shaping arrangement (61)
varies, because different numbers of the field shaping elements (62) are stacked
upon each other in the direction from the receiving side to the side opposite to the
receiving side.
5. The receiving device of one of claims 1 to 4, wherein variations of the depth of the
field shaping arrangement (61 ) are compensated by at least one compensating
element (72) made of non-magnetizable material.
6. The receiving device of claim 5, wherein the variations of the depth are
compensated so that the depth of a combined arrangement consisting of the field
shaping arrangement (61) and of the at least one compensating element (72) is
constant.
7. A method of manufacturing a receiving device ( 1 ) for receiving a magnetic field
and for producing electric energy by magnetic induction, wherein
- at least one coil (33, 35, 37) of at least one electric line is provided, wherein
the at least one coil (33, 35, 37) comprises an inductance, so that the
magnetic field induces an electric voltage in the at least one coil (33, 35, 37)
during operation of the receiving device ( 1 ) ,
- the coil (33, 35, 37) is arranged to receive the magnetic field from a receiving
side of the receiving device,
- a field shaping arrangement (61 ) , comprising magnetizable material adapted
to shape magnetic field lines of the magnetic field, is placed behind the at
least one coil (33, 35, 37), if viewed from the receiving side of the receiving
device (1),
so that a depth, to be measured in the direction from the receiving side of the
receiving device (1) to the side of the receiving device ( 1 ) opposite to the receiving
side, of the field shaping arrangement (61) varies.
8. The method of claim 7, wherein the depth of the magnetizable material is designed
to be larger at locations, if viewed from the receiving side, behind regions of the
coil where the electromagnetic field produced by electric currents through the at
least one coil (33, 35, 37) is larger compared to locations behind regions of the coil
where the electromagnetic field produced by electric currents through the at least
one coil (33, 35, 37) is smaller.
9. The method of claim 7 or 8, wherein the field shaping arrangement (61) is formed
by a plurality of field shaping elements (62) made of the magnetizable material.
10. The method of claim 9, wherein field shaping elements (62) are used which have
equally large depths and wherein the depth of the field shaping arrangement (61)
is varied by stacking different numbers of the field shaping elements (62) upon
each other in the direction extending from the receiving side to the side opposite to
the receiving side.
11. The method of one of claims 7 to 10, wherein variations of the depth of the field
shaping arrangement (61) are compensated by at least one compensating element
(72) made of non-magnetizable material.
12. The method of claim 11, wherein the variations of the depth are compensated so
that the depth of a combined arrangement consisting of the field shaping
arrangement (61) and of the at least one compensating element (72) is constant.