COOLING COMPONENT FOR ELECTRIC MOTOR

Abstract

A component of electric motor configured to cool windings mounted therein is described, wherein the component is made of a material formed by an aggregate of granules coated with an electrically insulating layer, wherein the granules are substantially in contact with each other.

Claims

1. Component of electric motor configured to cool windings mounted therein, wherein the component is made of a material formed by an aggregate of granules coated with an electrically insulating layer, wherein the granules are substantially in contact with each other.

2. Component according to claim 1, wherein the material making up the granules has thermal conductivity λ [W.Math.m.sup.−1.Math.K.sup.−1]>15, more preferably λ [W.Math.m.sup.−1.Math.K.sup.−1]>100, even more preferably λ [W.Math.m.sup.−1.Math.K.sup.−1]>300.

3. Component according to claim 1, wherein the material composing the granules is selected from: copper, aluminum or iron, magnesium oxide or boron nitride; diamond, silver, gold, laminated aluminum, brass, platinum, laminated steel, lead, stainless steel.

4. Component according to claim 1, wherein the insulating layer is a plastic material or a resin.

5. Component according to claim 1, wherein the insulating layer is a layer of oxide, enamel or alumina.

6. Component according to claim 1, wherein the granules are immersed in a binder matrix.

7. Component according to claim 6, wherein the binder matrix is selected from: glue, plastic, or a polymer or a resin or a technopolymer.

8. Component according to claim 1, characterized by being an electric motor's stator configured to cool windings mounted therein, the stator comprising an outer ring, an inner ring concentric to the outer ring, segments that extend radially from the inner ring to the outer ring, wherein the rings and the segments are internally hollow and are joined to form a continuous channel inside them capable of carrying a cooling fluid along a path that passes from one ring to the other, the rings and the segments being arranged to form or delimit pass-through openings able to receive and surround the windings.

9. Component according to claim 8, wherein the stator belongs to an axial-flow electric motor, the stator comprising a circular series of windings, arranged around the rotation axis of a rotor, to generate a magnetic flux with a polar axis parallel to the rotation axis of the rotor, the rotor being equipped with permanent magnets for interacting with the generated magnetic field.

10. Method for constructing an electric motor's stator, wherein the stator is made of a material formed by an aggregate of metallic granules coated with an electrically insulating layer.

11. Component according to claim 2, wherein the insulating layer is a plastic material or a resin.

12. Component according to claim 3, wherein the insulating layer is a plastic material or a resin.

13. Component according to claim 2, wherein the insulating layer is a layer of oxide, enamel or alumina.

14. Component according to claim 3, wherein the insulating layer is a layer of oxide, enamel or alumina.

15. Component according to claim 2, wherein the granules are immersed in a binder matrix.

16. Component according to claim 3, wherein the granules are immersed in a binder matrix.

17. Component according to claim 15, wherein the binder matrix is selected from: glue, plastic, or a polymer or a resin or a technopolymer.

18. Component according to claim 16, wherein the binder matrix is selected from: glue, plastic, or a polymer or a resin or a technopolymer.

Description

[0043] The advantages of the invention will be clearer from the following description of a preferred embodiment of stator, referring to the attached drawing in which

[0044] FIG. 1 shows a three-dimensional view of a stator.

[0045] FIG. 1 shows a stator 10 of an electric motor, consisting of an outer circular ring 30, an inner circular ring 40 concentric to the outer ring 30, and straight segments or spokes 50 radially joining the two rings 30, 40. The outer ring 30 and the inner ring 40 have center on the rotation axis of a rotor (not shown).

[0046] Two adjacent segments 50 and the arches of rings 30, 40 bounded by them delimit pass-through cavities 36 having perimeter complementary to windings mounted on the stator 10.

[0047] The number of segments or spokes 50 may vary, thus varying the number of windings.

[0048] The rings 30, 40 and the segments 50 are preferably hollow shells and overall they form inside them a continuous channel to carry a cooling fluid, which enters the stator 10 from an inlet and exits from an outlet.

[0049] The fluid circulation inside the stator 10 occurs along a path that involves at least once the two rings 30, 40 and at least two segments 50. In other words, the fluid circulates inside the stator 10 passing from the ring 30 to the ring 40 through a segment 50 and then passing from the ring 40 to the ring 30 through a different segment 50. During the flowing, the fluid skims the windings and subtracts heat from them.

[0050] The number of channels for the cooling fluid inside the component, in particular the number of independent channels, may vary. Two or more separate channels can better remove heat from the windings, providing a more uniform working temperature to the motor.

[0051] The stator 10 is made of a particular material, see zoom in FIG. 1.

[0052] The material is composed of compacted granules, or embedded in a binder 60. Each granule is formed by a metal core 62 coated with an electrically insulating layer or film 64.

[0053] The density of granules in the binder 60 is such that the distance between the granules is minimal, preferably all or almost all of them touching each other.

[0054] Thus the agglomerate of granules behaves overall as a good heat conductor, thanks to the continuity offered by the metal material that forms the close granules.

[0055] On the other hand, the agglomerate of granules behaves as a bad conductor of electric current, thanks to the insulating properties of the layer 64.

[0056] Therefore the stator 10 is able to remove well the heat generated by the windings without incurring significant losses caused by eddy currents.