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(11) | EP 2 363 866 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Coil arrangement |
| (57) The invention relates to a coil arrangement for an electronic device, comprising
a core, a coil (7) arranged around said core, and a cooling element (1) comprising
an inlet (2) for receiving a cooling fluid and an outlet (3) for forwarding the cooling
fluid from said cooling element (1). In order to obtain an efficient coil arrangement
with an adequate cooling said core comprises at least two core elements (6) arranged
at a distance from each other. The cooling element (1) is arranged between said at
least two core elements (6).
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BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
[0001] The present invention relates to a coil arrangement of an electronic device and in particular to a solution for cooling such a coil arrangement.
DESCRIPTION OF PRIOR ART
[0002] A heat load generated in a coil of an electric device can be significant. In order to avoid that the temperature of the coil rises too high there are prior art solutions where a cooling element is arranged in connection with the coil. This cooling element comprises an inlet for receiving a cooling fluid and an outlet for forwarding the cooling fluid from said cooling element. Heat generated by the coil is therefore passed to the cooling fluid.
[0003] The above described prior art solutions are, however, complicated and in addition they fail to provide a sufficient cooling for all implementations.
SUMMARY OF THE INVENTION
[0004] An object of the present invention is to provide a novel and efficient coil arrangement with an adequate cooling. This object is achieved with the coil arrangement of independent claim 1.
[0005] To utilize a cooling element between two core elements makes it possible to obtain a simple and efficient solution for cooling the core of a coil arrangement. In this way, the temperature of the coil arrangement can be controlled efficiently.
BRIEF DESCRIPTION OF DRAWINGS
[0006] In the following, the present invention will be described in closer detail by way of example and with reference to the attached drawings, in which
DESCRIPTION OF AT LEAST ONE EMBODIMENT
[0010] Figures 1 to 3 illustrate a cooling element 1 for an embodiment of a coil arrangement. Figures 1 and 2 illustrate a front and side view of the cooling element 1, and Figure 3 is a cross section of the cooling element along line III - III in Figure 1.
[0011] In the illustrated embodiments, the cooling element 1 comprises an inlet 2, an outlet 3 and a plurality of conduits 4 providing parallel fluid paths for passing fluid from said inlet 2 to said outlet 3. The term "parallel fluid paths" does not require that all conduits are exactly parallel with each other, though this is probably the case in many implementations, but instead it is sufficient that the conduits 4 provide alternative fluid paths for passing fluid from the inlet to the outlet. However, it should be observed that it is not necessary in all implementations to utilize a cooling element with parallel fluid paths. Instead in some implementations, it may be advantageous to utilize a cooling element with only one single fluid path between the inlet and the outlet.
[0012] In the illustrated embodiment, the conduits 4 are connected to each other with pipe sections 5 at the opposite ends of the cooling element 1 for providing a fluid path between the conduits 4 to the inlet 2 and outlet 3, respectively. The cooling element 1 may be manufactured from aluminum, for instance, and it can be relatively thin, which has the advantage that the width of the coil arrangement can be kept small.
[0013] Figures 4 to 5 illustrate a first embodiment of a coil arrangement. In Figures 4 and 5 it is assumed, by way of example, that the cooling element of Figures 1 to 3 is utilized. The illustrated coil arrangement may be a choke for an electronic apparatus, such as a frequency converter, for instance.
[0014] In Figures 4 and 5 two core elements 6 are arranged on opposite sides of the cooling element 1. The core elements may be of a ferromagnetic or ferrite material, for instance. Each core element may be a single element or consist of a plurality of thinner elements (such as plates) arranged on top of each other.
[0015] Outermost in Figures 4 and 5 there is a coil 7. This coil 7 is arranged to surround the cooling element 1 and the core elements 6. The coil may consist of an electric conductor, such as a wire, wound in several turns around the cooling element 1 and the core elements 6. Alternatively, the coil 7 may consist of a band or a plate.
[0016] In Figures 4 and 5 it can be seen that the cooling element 1 extends past the coil 7 and the core elements 6 at both ends (below and above). In this way, the inlet 2 and outlet 3 of the cooling element 1 are easily accessible in order to carry out the necessary pipe attachments for passing the cooling fluid to and from an external device where the cooling fluid is cooled before reintroduction into the cooling element 1.
[0017] Figures 6 and 7 illustrate a second embodiment of a coil arrangement. Figure 6 is an end view and Figure 7 a side view of the coil arrangement. The embodiment of Figures 6 and 7 is very similar to the one described in connection with Figures 4 and 5, and therefore this embodiment will mainly be described by pointing out the differences between these embodiments.
[0018] In the embodiment of Figures 6 and 7, three pairs of cooling elements 1 are utilized. Each pair of cooling elements comprises a core element 6 arranged between the two cooling elements 1, and a second and a third core element 6 is arranged against the respective outer surfaces of the cooling elements 1. Finally, for each pair of cooling elements 1 and the three respective core elements 6 a coil 7 is arranged to surround the two cooling elements 1 and the three core elements 6.
1. A coil arrangement for an electronic device, comprising:
a core,
a coil (7) arranged around said core, and
a cooling element (1) comprising an inlet (2) for receiving a cooling fluid and an outlet (3) for forwarding the cooling fluid from said cooling element(1),characterized in
that said core comprises at least two core elements (6) arranged at a distance from each other, and
said cooling element (1) is arranged between said at least two core elements (6).
2. A coil arrangement according to claim 1, characterized in that said coil arrangement is a coil arrangement for a choke or a transformer.
3. A coil arrangement according to claim 1 or 2, characterized in that said core is of a ferromagnetic or ferrite material.
4. A coil arrangement according to one of claims 1 to 3, characterized in that said coil arrangement comprises:
at least two cooling elements (1),
at least two core elements (6) arranged on opposite sides of each respective cooling element (1),
at least one coil (7) arranged around each respective two core elements (6) and said respective cooling element (1), and
at least two core elements (8) on each side of said cooling elements (1), which core elements (8) extend between said at least two cooling elements (1).
5. A coil arrangement according to one of claims 1 to 3, characterized in
that said coil arrangement comprises at least two cooling elements (1),
that said cooling elements (1) are arranged against each other with a core element (6) between them,
that a second and a third core element (6) is arranged against a respective outer surface of said cooling elements (1), and
a coil (7) is arranged around said cooling elements (1) and core elements (6).
that said coil arrangement comprises at least two cooling elements (1),
that said cooling elements (1) are arranged against each other with a core element (6) between them,
that a second and a third core element (6) is arranged against a respective outer surface of said cooling elements (1), and
a coil (7) is arranged around said cooling elements (1) and core elements (6).
6. A coil arrangement according to one of claims 1 to 5, characterized in that said coil arrangement is a coil arrangement of a choke in a frequency converter.
7. A coil arrangement according to one of claims 1 to 6, characterized in that at least one of said cooling elements (1) comprises a plurality of conduits (4) providing
parallel fluid paths for passing said fluid from said inlet (2) to said outlet (3).