ELECTRICAL CONDUCTOR COOLED BY PHASE CHANGE MATERIAL AND METHOD FOR THE MANUFACTURE THEREOF

Abstract

A method for manufacturing a conductor of a winding of a coil, includes manufacturing a heat-sink preform including a phase-change material, depositing a conductive element by layer deposition of electrically conductive material on the heat-sink preform, including inserting the heat-sink preform into an electrolytic solution of the electrically conductive material, and; electrodeposition for depositing the electrically conductive material on the heat-sink preform.

Claims

1. A method for manufacturing a conductor of a winding of a coiling comprising: manufacturing a heat sink preform comprising a phase change material, and depositing a conductor element by depositing a layer of electrically conductive material onto the heat sink preform by comprising: inserting the heat sink preform into an electrolytic solution of the electrically conductive material, carrying out an electrodeposition for depositing the electrically conductive material onto the heat sink preform.

2. The method for manufacturing a conductor of a winding of a coiling according to claim 1, wherein the electrically conductive material is copper.

3. The method for manufacturing a conductor of a winding of a coiling according to claim 1, wherein the manufacturing of the heat sink preform forms a plurality of portions having a cross-section in a first shape and a plurality of second portions in a second shape different from the first shape and wherein the depositing of the conductive material onto the preform forms a conductor having first portions each having a cross-section with a shape different from a cross-section shape of a plurality of second portions of the conductor.

4. The method for manufacturing a conductor of a winding of a coiling according to claim 1, further comprising: adjusting a volume of the phase change material of the heat sink comprising: of changing phase from the solid phase to the liquid phase of the phase change material and discharging the volume of the phase change material through at least one end of the heat sink generated by thermal expansions of the phase change material, enclosing the phase change material of the heat sink, and performing an insulation step comprising a sub-step of electrophoretically deposition of an electric insulator layer which is of AlN, Boron Nanotubes, BN or Alumina onto the conductive material.

5. The method for manufacturing a conductor of a winding of a coiling according to claim 1, comprising enclosing the phase change material of the heat sink comprising a substep of inserting plug into at least one end of a conductor preform.

6. The method for manufacturing a conductor of a winding of a coiling according to claim 5, wherein each plug comprises a circuitry necessary to supply the coil of the coiling.

7. The method for manufacturing a conductor of a coil of a coiling according to claim 5, wherein: manufacturing a conductor element by depositing a layer of electrically conductive material onto the heat sink preform further comprises: removing a conductor preform from the electrolytic solution of the electrically conductive material, the conductor preform comprising the heat sink preform and a layer of conductive material for electrodeposition by electrolysis onto the heat sink preform forming a part of the conductor element and second inserting the conductor preform with the plugs into the electrolytic solution of the electrically conductive material, performing an electrolysis electrodeposition step of depositing the electrically conductive material onto the conductor preform and the plugs, the inserting of the plug onto the conductor preform is performed after the removing and before the second inserting, the method further comprises an insulation step after the manufacturing of a conductor element by depositing a layer of conductive material, the insulation step comprising a sub-step of electrophoretically deposition of an insulating layer which is of AlN, Boron Nanotubes, BN or Alumina, onto the layer of conductive material deposited onto the preform.

8. The method for manufacturing a conductor of a winding of a coiling according to claim 1, wherein the heat sink preform is a cable.

9. The method for manufacturing a conductor of a winding of a coiling according to claim 1, wherein the heat sink preform is made by an additive method in order to have a conductor with an irregular cross-section.

10. The method for manufacturing a conductor of a winding of a coiling according to claim 1, wherein manufacturing a heat sink preform comprises a chemical metallisation sub-step onto the phase change material.

11. The method for manufacturing a conductor of a winding of a coiling according to claim 10, wherein the chemical metallisation sub-step is a chemical deposition of copper or silver.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0092] The figures are set forth by way of indicating and are in no way limiting purposes of the invention.

[0093] FIG. 1 represents a flow diagram of a grafcet of a method for manufacturing a conductor according to a first implementation.

[0094] FIG. 2 represents a block diagram of a grafcet of a method for manufacturing a conductor according to a second implementation.

[0095] FIG. 3 represents a block diagram of a grafcet of a method for manufacturing a conductor according to a third implementation.

[0096] FIG. 4 represents a block diagram of a grafcet of a method for manufacturing a conductor according to a fourth implementation.

DETAILED DESCRIPTION

[0097] The figures are set forth by way of indicating and in no way limiting purposes of the invention.

[0098] FIG. 1 represents a flow diagram of a grafcet of a first implementation of a method for manufacturing a bare conductor S2 of a winding of a coiling comprising a conductor element and a heat sink comprising the phase change material inside the conductor element.

[0099] In the application, by “conductor element”, it is meant the main electrically conductive part of the conductor.

[0100] As used in the application, by “heat sink”, it is meant the part of the conductor for cooling the conductor element.

[0101] As used in the application, by “phase change material”, it is meant a material that is capable of changing physical state within a given temperature range and that will absorb a large amount of heat energy from its surrounding environment to change from a solid to a liquid state, and that releases some of the heat energy as the material cools from the liquid to the solid state.

[0102] The method comprises a step of manufacturing E1 a heat sink preform S1 comprising a phase change material.

[0103] The conductive phase change material may be either electrically conductive metal, for example a eutectic bismuth-lead alloy, or conductive non-metal, for example in the form of a salt such as iron fumarate, or it may be, for example, a hydrated salt such as nitrates or hydroxides (LiNO.sub.3, NaNO.sub.3, Li.sub.2CO.sub.3 etc.) preferably with graphite.

[0104] In this first implementation, the conductive phase change material is non-conductive and the step of manufacturing E1 a heat sink preform S1 comprises a first sub-step of manufacturing e10 a phase change material preform s10.

[0105] The first sub-step of manufacturing e10 the phase change material preform s10 may be carried out by an additive method or moulding or machining. According to one example of this first implementation, the first sub-step of manufacturing e10 the phase change material preform s10 is arranged to make a phase change material preform with an irregular cross-section.

[0106] This allows the heat sink preform to have an irregular cross-section and thus a conductor with an irregular cross-section. This may allow a coiling to have less material in the winding head or overhang of a stator. Indeed, the restriction of conventional conductors in terms of radius of curvature results in an increase in the size of the winding overhangs, and therefore the weight of the machine. The winding overhangs do not participate in the creation of torque in the machine, so having a heat sink preform with an irregular cross-section can have a shape to limit the size of this region. According to one example, the cross-section of the conductor may vary with the length of the conductor. For example, the conductor has portions with different cross-sectional shapes for the winding overhangs than those of the portions for the active parts, but without reducing the cross-sectional area of the conductors at the winding overhangs so as not to increase Joule losses.

[0107] The step of manufacturing a heat sink preform S1 further comprises a second chemical metallisation sub-step e11, for example chemical deposition of copper or silver, onto the phase change material preform s10 to form the heat sink preform S1.

[0108] The method further comprises a step of depositing E2 a conductor element by depositing layer of electrically conductive material onto the heat sink preform. The electrically conductive material is copper in this example.

[0109] The deposition step E2 comprises a first sub-step of inserting e20 the heat sink preform S1 into an electrolytic solution of the electrically conductive material S20′ and a second electrodeposition sub-step e21 for depositing the electrically conductive material onto the heat sink preform. The electrolytic solution may be an acidic copper sulphate solution for example.

[0110] The electrodeposition substep e21 may be an electroforming step.

[0111] When the electrodeposition substep e21 has deposited enough conductive material onto the heat sink preform, for example until a predetermined cross-sectional area, for example a cross-sectional area of the conductor assembly equal to 200 mm.sup.2, the bare conductor S2 is formed and can be removed from the electrolytic solution of the electrically conductive material S20.

[0112] The method according to this example of this first implementation may further comprise an insulation step comprising adding an insulating resin to the bare conductor S2 by, for example, bathing the bare conductor S2 in an insulating resin bath to impregnate and insulate it and thereby form an insulating conductor.

[0113] For example, the insulation step comprises a step of electrophoretically deposition of an insulating layer which is of type of AlN, Boron

[0114] Nanotubes, BN or Alumina for the insulation of turns. The insulating layer can be made by electrophoretic deposition of an electrically insulating and thermally conductive ceramic (AlN, BN, boron nanotubes, alumina etc.). This insulation step is carried out before the coiling is inserted into the motor.

[0115] FIG. 2 represents a schematic diagram of a grafcet of a method for manufacturing an insulating conductor S3 of a winding of a coiling according to a second implementation.

[0116] This method is identical to the first manufacturing method except that the phase change material is conductive metal, for example a eutectic bismuth-lead alloy, and therefore the step of manufacturing E1′ a heat sink preform S1 comprising a phase change material is different in that it does not include a chemical metallisation sub-step e11. Of course, the method may include this metallisation step to increase conductivity.

[0117] In this second implementation, the step E1′ of manufacturing a heat sink preform S1′ can be carried out by an additive method or moulding or machining or by extrusion. Herein, in this example, the conductor S3 is a cable with a regular cross-sectional area of, for example, 300 mm.sup.2 and the step of manufacturing E1′ a heat sink preform S1′ is carried out by extrusion of the conductive metal phase change material directly forming the heat sink preform S1′.

[0118] The step of depositing E2′ a conductor element by depositing a layer of electrically conductive material onto the heat sink preform S1′ may be performed in an identical manner to the depositing step E2 of the first implementation. The bare conductor S2′ is formed and can be removed from the electrolytic solution of the electrically conductive material S20 when the cross-sectional area of the conductor assembly equals 300 mm.sup.2.

[0119] The bare conductor S2′ may further be impregnated with an insulating resin. Herein, in this example, the method of this first implementation may further comprise an insulation step E3 comprising adding an insulating resin to the bare conductor S2′ by, for example, bathing the bare conductor S2′ in an insulating resin bath to impregnate and insulate it and thereby form an insulating conductor S3.

[0120] According to one example of the first, second implementation, the method comprises a step of enclosing the phase change material comprising a substep of inserting a plug at the end of the preform comprising an expansion chamber facing the phase change material to allow the phase change material to expand into this chamber upon its first phase change from solid to liquid phase. The enclosing step may be performed between the preform manufacture step E1, E1′ and the conductor element deposition step E2, E2′, or after the conductor element deposition step E2, E2′, by cutting off at least one end of the bare conductor or during the deposition step E2, E2′, E2″ as, for example, in a fourth implementation described later without or with an adjustment step described later.

[0121] FIG. 3 represents a block diagram of a grafcet of a method for manufacturing a conductor S32 of a winding of a coiling according to one example of a third implementation.

[0122] This method comprises a step of manufacturing E1′ a heat sink preform S1′ identical to that of the second implementation and further comprises a sub-step e210 of electrodepositing the heat sink preform, a second sub-step e211 of electrodepositing a conductor preform S4 adjusted and further a step E4 of adjusting a volume of phase change material S4 of the conductor preform S4 adjusted during the first electrodeposition sub-step e210 by electrolysis.

[0123] According to another example of this third implementation, not represented, the step of manufacturing a heat sink preform is identical to that of the first implementation.

[0124] The step of depositing E2″ a conductor element by depositing a layer of electrically conductive material onto the heat sink preform S1′ comprises, in an identical manner to the second implementation, the first sub-step of inserting e20′ the heat sink preform in an electrolytic solution of the electrically conductive material.

[0125] The step of adjusting E4 the volume of phase change material S4 comprises a substep of changing phase e40 from the solid phase to the liquid phase S40 of the phase change material and a substep of discharging e41 the volume of the phase change material through at least one end generated by thermal expansions of the phase change material until the volume of the phase change material reaches a predetermined volume in the adjusted conductive preform S4.

[0126] In this example, in order to perform the adjustment step E4, it is necessary for a conductor preform S210′ comprising the heat sink preform S1′ and a part of the conductor element surrounding the heat sink preform S1′, to be sufficiently covered with the conductive material by the electrodeposition substep e21′ to be sealed in order to perform the adjustment step E4.

[0127] In this example of this third implementation, the adjustment step E4 is performed during the electrodeposition substep e21′, for example by covering the ends of the conductive preform S210′, cutting at least one of the sealed ends to open the ends of the conductive preform, and raising the temperature of the solution to the melting temperature of the phase change material to perform the phase change step s40 and then the step of discharging e41 a part of the phase change material up to the predetermined volume.

[0128] In this example, when the conductor preform is adjusted S4, the ends of the conductor preform including the predetermined volume of phase change material S4 are reinserted into the electrolytic solution and the electrodeposition sub-step e21′ by electrolysis comprises a second electrodeposition step e211′ continuing the addition of the conductor material onto the conductor preform S4 until there is a bare conductor S20″ comprising the predetermined cross-sectional area, for example 400 mm.sup.2 and thus comprising the predetermined volume of phase change material.

[0129] According to another example not represented, the conductor preform S210′ is removed, the adjustment step E4 is performed, and the conductor preform with the predetermined volume S4 is reintegrated into the solution to perform the last second electrodeposition step e211′. This example makes it possible to have a uniform conductor since the electrolysis of the conductor preform S210′ is stopped during the adjustment step E4 whereas in the example represented, the part of the preform S210′ immersed in the solution continues to be electrolysed and thus to have an addition of conductive material.

[0130] According to one alternative not represented, the method performs the adjustment step E4 on the bare conductor, and further comprises a step of enclosing the conductive material by inserting at least one plug onto the open end (by cutting off the end of the conductor preform S210′). The plug may be sealed by welding or soldering for example.

[0131] The method may include an insulation step E3 as in the previous embodiments by impregnating the bare conductor S20″ in an insulating resin bath and thus emerging an insulated conductor S32.

[0132] FIG. 4 represents a schematic diagram of a method for manufacturing a conductor S35 of a winding of a coiling according to one example of a fourth implementation.

[0133] This method comprises a step of manufacturing E1′ a heat sink preform S1′ identical to that of the method of the third implementation and a step of depositing E2″ a conductor element by depositing a layer of electrically conductive material onto the heat sink preform S1′, which is different from this third implementation in that it further comprises a sub-step of removing e22 the conductor preform S210′ from the electrolytic solution of the electrically conductive material and a second sub-step of inserting 205 a conductor preform S5 having plug into the solution and in that the method further includes a step of adjusting E4 the volume of phase change material S4 and a step of enclosing E5 this phase change material performed between the removal sub-step e22 and the second insertion step e205.

[0134] In this fourth implementation, the method thus comprises after the electrodeposition sub-step e210 until the deposition of electric conductor onto the heat sink preform seals it forming a conductor preform S210′ as in the third implementation, a step of removing e22 the conductor preform S210′ from the solution.

[0135] The method further includes an adjustment step e4 comprising a sub-step of changing phase e40 from the solid phase to the liquid phase S40 but unlike the third implementation, this sub-step is performed outside the electrolytic solution. The adjustment step e4 comprises, as in the third implementation, a sub-step of discharging e41 the volume of the phase change material through at least one end generated by thermal expansions of the phase change material until the volume of the phase change material reaches a predetermined volume in the conductive preform S4 adjusted.

[0136] Then, the method of this fourth implementation comprises a step of enclosing E5 the phase change material of at least the open end for the adjustment step E4. Herein, in this example of this implementation, the step of enclosing E5 the phase change material comprises a sub-step of inserting plug at both ends of the conductor preform S4. In particular, according to this example, each plug comprises the circuitry necessary to supply the coil of the coiling.

[0137] The method then comprises the second sub-step of inserting 205 the conductor preform S5 comprising the plugs and the sub-step of electrodepositing the conductor preform S5 by electrolysis.

[0138] Unless otherwise specified, a same element appearing in different figures has a single reference.