CCA wire coil

Abstract

An induction coil for electric motors and / or actuators for use in pumps comprises a plurality of turns made by means of at least one improved CCA-type wire, a central portion made of aluminium, and a peripheral portion made of copper, with an overall diameter comprised between 0.17 mm and 0.34 mm; the peripheral portion is coaxial to said central portion and the amount of material forming the peripheral portion corresponds to 10% of the overall composition of the CCA wire.

Description

[0001] CCA WIRE COIL DESCRIPTION

[0002] The present invention provides an induction coil for electric motors and / or actuators which can be used in small electric pumps, which can be used in hot and humid environments, comprising a plurality of turns made from at least one improved CCA-type wire.

[0003] In the prior art, it is common to use copper wire to make inductive AC coils used to make electric motors and / or actuators for electric pumps used in hydraulic circuits to manage water flows in equipment such as vending machines for dispensing hot beverages, coffee machines and the like, where the water flow is at varying temperatures depending on the various possible technical applications,

[0004] Copper wires are excellent conductors and can be drawn in very small diameters, so as to form coils for electric motors which can be used in very small high-pressure pumps.

[0005] Disadvantageously, due to the high cost of copper and in anticipation of a risk of increased scarcity of international suppliers and the incremental rise in the cost of the material itself, there is a growing urgency to obtain alternative solutions of coils for small electric pumps which could be less expensive in terms of manufacture fabrication but still ensure good performance.

[0006] A first alternative is "FM"-type coils, which with respect to pure copper coils have higher inductive capacities and require less material (about half as much), therefore allowing savings in overall material costs as well as savings in transport and storage costs.

[0007] Disadvantageously, FM coils are instead expensive to manufacture. Moreover, the cost of supplying the materials forming them is also rising steadily.

[0008] Furthermore, ferrite-based materials are prone to rapid oxidation when exposed to high humidity and high temperatures.

[0009] A further alternative solution known in the state of the art with respect to the traditional solutions mentioned above is coils consisting of aluminium wire.

[0010] Some of the main advantages of aluminium are its lower cost and lower overall weight with respect to copper, making it economically advantageous.

[0011] Aluminium is a relatively abundant and readily available material at low cost.

[0012] Furthermore, aluminium is a relatively light material which not only allows to obtain savings in terms of the overall weight of the coils, but also in terms of savings in transport and storage costs.

[0013] Disadvantageously, the low conductivity of aluminium (1 / 3 with respect to copper) means that coils made of copper wire require a higher amount of material for their manufacture (in particular, in terms of wire diameter) so as to obtain an effective passage of current, thus rendering it ineffective for the manufacture of coils below a predetermined size.

[0014] A further disadvantage is that aluminium wires are difficult to weld and when they oxidise, they lose conductivity, making this material not entirely suitable for use in systems / devices of this type.

[0015] Another disadvantage is that aluminium wires have very low mechanical strength, making it difficult to process to obtain wires having very small diameters, which implies the need to drastically change the current pump designs, both in terms of metal brackets, bushings and the overall size of the coils.

[0016] Similarly, the low mechanical strength of aluminium wire implies low compatibility with the drawing processes currently used to make the above-mentioned coils, making it incompatible with some of the current production technologies for induction coils for electric pumps.

[0017] In the case of coils made of small-diameter aluminium wire compatible with the above-mentioned uses, it is necessary to reduce the working cycles of the coils from a ratio of 2 / 1 to 1 / 1 or 1 / 1.5 with respect to a coil made of copper and to increase the insulation class of the wires to class 'H' due to the high resistivity of aluminium.

[0018] A further disadvantage is that aluminium wires have poor compatibility in terms of welding operations generally used in the prior art, thus requiring complex and expensive welding techniques and processes.

[0019] The task of the present invention is to provide a coil made using an improved metal wire for the formation of electric pumps which can be used in various application contexts, such as vending machines for dispensing hot beverages and the like.

[0020] The technical aim of the present invention is therefore to provide a coil compatible with use inside pump motors or actuators, and in particular with small high-pressure pumps, e.g., 15 bar or 20 bar, which can ensure operation at a reduced manufacturing cost with respect to a traditional coil using pure copper wire or FM copper coils.

[0021] A further technical aim is to provide a reel compatible for use in different operating contexts such as vending machines or coffee machines.

[0022] A further technical aim is to provide a coil having a lower coil weight with respect to a traditional coil using pure copper wire or FM copper coils and involving a lower quantity of raw material required for its manufacture, thus allowing savings in material, procurement, storage and / or transport costs.

[0023] The technical task and the technical aim are essentially achieved by an induction coil for electric motors and / or actuators which can be used in electric pumps, comprising a plurality of turns made from at least one improved CCA-type wire.

[0024] The wire comprises a central portion, made of aluminium, and a peripheral portion or cover, made of copper, with an overall diameter comprised between 0.17 mm and 0.34 mm, wherein the peripheral portion is positioned coaxially to the central portion and the material forming the peripheral portion corresponds to 10% of the overall composition of the wire.

[0025] Further features and advantages of the present invention will become clearer from the indicative, and therefore non-limiting, description of an induction coil design for electric motors and / or actuators which can be used in small electric pumps comprising at least one CCA-type wire.

[0026] Such description will be set forth herein below with reference to the accompanying drawings, provided for merely indicative and therefore nonlimiting purposes, wherein:

[0027] - Figure 1 illustrates an induction coil using a CCA wire;

[0028] - Figure 2 illustrates a detail of the inner section of the CCA wire illustrated in Figure 1 ;

[0029] - Figure 3 illustrates a detail of the wire in Figure 1 ;

[0030] - Figure 4 illustrates the difference in the volume occupied by a coil using a copper wire and a coil using a CCA wire.

[0031] An induction coil for electric motors and / or actuators which can be used in electric pumps, comprising a plurality of turns made by means of at least one improved CCA-type wire 2, has been illustrated with 1 .

[0032] Wire 2 comprises a central portion 3, made of aluminium, and a peripheral portion 4 or cover, made of copper, which entirely surrounds central portion 3.

[0033] Peripheral portion 4 is coaxial to central portion 3.

[0034] Lastly, wire 2 can comprise an insulating coating 5, made of insulating material commonly used in the state of the art.

[0035] According to an aspect of the present finding, the overall diameter of wire 2 is comprised between 0.16 mm and 0.34 mm, preferably between 0.17 mm and 0.335 mm.

[0036] Preferably, CCA wire 2 comprises a peripheral portion 4 made by using an amount of copper corresponding to a range comprised between 9% and 15% of the total composition of CCA wire 2.

[0037] Even more preferably, CCA wire 2 comprises a peripheral portion 4 made using an amount of copper corresponding to 10% of the total composition of CCA wire 2.

[0038] Embodiment variants can include a peripheral portion corresponding to a different percentage. For example, it has been shown experimentally that the wire forming the coil has good performance inside a pump even at higher percentages, such as above 15% of the overall CCA wire 2 composition.

[0039] However, it has been shown experimentally that the use of a CCA wire 2 comprising a peripheral portion 4 in copper corresponding to around 10% in composition allows to save both the cost of the overall material used to make coil 1 and the overall weight of coil 1 itself while ensuring the proper functioning of coil 1 inside the high-pressure electric pump.

[0040] As the preponderant portion of CCA wire 2 is made of aluminium, which has a lower cost and density with respect to than an equivalent pure copper wire, CCA wire 2 has a lower overall cost and weight with respect to an equivalent pure copper wire.

[0041] The use of increasing higher percentages with respect to 9%-10%, e.g., 15%, means that the overall manufacturing cost of the coil increases significantly in proportion to a point where the trade-off between the overall cost of making a coil 1 out of CCA wire 2 is equal if not higher with respect to a coil made with pure copper wire or an FM coil.

[0042] Coil 1 made from CCA wire 2 has several advantages with respect to the use of copper-only or aluminium-only wire.

[0043] Overall, the weight of CCA wire 2 is lower with respect to an equivalent wire made entirely of copper.

[0044] With respect to copper, the price / kg of CCA wire 2 is more expensive than copper in terms of manufacturing costs, but due to the lower density of aluminium, the total weight of a coil 1 using CCA wire 2 is lower, ensuring on the one hand coil 1 with a lower overall weight and on the other hand economies of scale in terms of overall material use, as well as savings in terms of the cost of transport and storage of the individual materials.

[0045] In particular, given the lower cost of aluminium, aluminium being used in greater proportions with respect to copper, the overall cost of a CCA wire according to the present finding is significantly reduced.

[0046] Moreover, advantageously, a CCA wire 2, thanks to peripheral portion 4 in copper, has the same behaviour as a wire made entirely of copper in the case of spot welding, thus allowing the same equipment to be used as is currently used for the production of pure copper wire coils.

[0047] Furthermore, again thanks to peripheral portion 4 made of copper, a CCA wire 2 has greater corrosion resistance when coil 1 is used in electric pumps operating in hot and humid environments.

[0048] According to an aspect of the present finding, preferably, coil 1 comprises a number of turns inversely proportional to the overall diameter of CCA wire 2.

[0049] Advantageously, such a feature allows good inductive properties of coil 1 to be maintained, while at the same time, it allows the overall weight of coil 1 to be kept low, thus a lower overall product cost with respect to a copper wire coil.

[0050] According to an aspect of the present finding, preferably, coil 1 comprises between 1650 turns and 5550 turns.

[0051] Advantageously, it has been experimentally verified that for such values, the features of coil 1 remain compatible with a proper operational functioning of small high-pressure electric pumps while a lower overall product cost is maintained with respect to a copper coil.

[0052] According to an aspect of the present finding, preferably, coil 1 comprises a CCA wire 2 having an average conductivity of approximately 2 / 3 with respect to an equivalent coil using a copper wire.

[0053] Preferably, coil 1 comprises a CCA wire 2 having an average conductivity of approximately 37.5 S*m / mm2.

[0054] An aluminium wire covered with copper foil has better conductivity than a pure aluminium wire (albeit worse with respect to copper). CCA wire 2 used in coil 1 , according to the present finding, has sufficient electrical conductivity to allow a good conductivity compatible with the proper operation of small high-pressure pumps, in particular used in hot and humid environments such as vending machines for dispensing hot beverages and the like. According to an aspect of the present finding, preferably, coil 1 comprises a CCA wire 2 with an average resistivity of 0.0265 Ohm*mm2 / m.

[0055] Advantageously, it was experimentally verified that for such a value, the features of CCA wire 2 does not exhibit excessive heating in use, and is therefore compatible with the use within a high-pressure electric pump configured to comprise a coil 2.

[0056] According to an aspect of the present invention, preferably, coil 1 comprises a CCA wire 2 having a tensile strength comprised between 120- 180 N / mm2.

[0057] Advantageously, such a feature allows the coil turns to be manufactured using similar machinery used for the manufacture of coils consisting of pure copper or FM coils and, most importantly, at the maximum process speeds currently used in the winding processes for coils made of allcopper wire, allowing production costs to be kept low with respect to turns made of pure aluminium wire.

[0058] A CCA wire 2 has a lower mechanical resistance with respect to a wire made entirely of copper. However, during the process of winding the wire into turns and similarly to a pure copper wire, CCA wire 2 can be subjected to an electrical voltage at the ends, which increases the resistance thereof during the process and prevents breakage during winding.

[0059] A CCA wire 2 manufactured according to the present finding requires only slightly more electrical voltage applicable at the ends with respect to that required for a pure copper wire, and is therefore fully compatible with the same production processes as FM or pure copper coils.

[0060] According to a first embodiment, a coil 1 comprises between 1600 turns and 1800 turns, preferably 1700 turns.

[0061] Coil 1 according to the first embodiment further comprises a wire having an overall diameter comprised between 0.32 mm and 0.40 mm, preferably 0.335 mm.

[0062] According to a second embodiment, a coil 1 comprises between 3600 turns and 3800 turns, preferably 3700 turns. The coil according to the second embodiment further comprises a wire having an overall diameter comprised between 0.22 mm and 0.30 mm, preferably 0.25 mm.

[0063] According to a third embodiment, a coil 1 comprises between 3700 turns and 3900 turns, preferably 3800 turns

[0064] Coil 1 according to the third embodiment further comprises a total diameter comprised between 0.23 mm and 0.31 mm, preferably 0.265 mm.

[0065] According to a fourth embodiment, coil 1 comprises between 5400 turns and 5550 turns, preferably 5500 turns.

[0066] Coil 1 according to the fourth embodiment further comprises a total diameter between 0.15 mm and 0.20 mm, preferably 0.17 mm.

[0067] According to an aspect of the present finding, the weight of coil 1 made by means of a CCA wire 2 corresponds to a range between 45% and 70% of the weight of a coil made of equivalently dimensioned FM wire and to a range between 22% and 35% of the weight of a coil made from equivalently dimensioned pure copper wire.

[0068] In particular, take a coil made with a FM wire as an example. Assume that such an FM wire coil has a wire diameter of 0.2 mm and 3800 turns. Such a coil has a total weight of 102.4g. (for the same dimensions and number of turns, a coil made of pure copper wire would have a total weight of 200g).

[0069] A coil 1 made with a CCA wire 2 according to the first embodiment comprises a total weight of 48.0 g, of which 12.9 g copper and 35.1 g aluminium, viz., 46.9% with respect to the FM copper coil.

[0070] A coil 1 made with a CCA wire 2 according to the second embodiment comprises a total weight of 61.5 g, of which 16.5 g copper and 45.0 g aluminium, viz., 60.1 with respect to the FM copper coil.

[0071] A coil 1 made with a CCA wire 2 according to the third embodiment comprises a total weight of 69.4 g, of which 18.7 g copper and 50.7 g aluminium, viz., 67.8% with respect to the FM copper coil. A coil 1 made with a CCA wire 2 according to the fourth embodiment comprises a total weight of 57.0 g, of which 15.3 g copper and 41.7 g aluminium, viz., 60.1% with respect to the FM copper coil.

[0072] A coil 1 made with a CCA wire 2 according to the first embodiment comprises a total weight of 62.5 g, of which 16.5 g copper and 45 g aluminium, viz., 55.7% with respect to the FM copper coil.

[0073] An electric pump made by means of a coil 1 according to the present finding results in a negligible overall increase in coil volume in comparison with respect to a copper coil with the same inductive response.

[0074] For example, with reference to Figure 4, the different embodiments mentioned above involve different dimensions. However, in the worst case, a coil made with CCA wire according to the present finding has a coil radius no greater than 15% with respect to an equivalent in a copper coil or an FM coil.

[0075] Figure 4 illustrates two examples of coils (an FM coil "B1" and a CCA wire coil "B2") inserted into equivalent metal brackets "S".

[0076] FM coil "B1", having the features mentioned in the above example, would have a coil body "C1 " having a diameter "D1 " equal to 37.55 mm.

[0077] Metal bracket "S" in the FM coil has an overall width "D2" of 50.00 mm.

[0078] For comparison, coil "B2" has the same bracket "S" with width "D2" of 50.00 mm.

[0079] The body "C2" of CCA wire coil "B2" according to the first embodiment has a diameter of 43.56 mm.

[0080] It can be seen that the difference in diameter between FM coil "B1 " and CCA wire coil "B2" according to the present finding is negligible, as in both cases, the coils fit into the metal cage used.

[0081] The present invention solves all the shortcomings of the solutions currently described in the prior art in that it provides available a coil 1 made of CCA wire 2 of small dimensions, which is resistant to use in humid and hot environments such as in pumps for hot beverage vending machines and coffee machines. Coil 1 according to the present invention is also lighter in size with respect to the known art, requiring less material; therefore, it ensure slower costs in terms of both materials and logistics.

[0082] Finally, coil 1 according to the present finding is compatible with the production processes currently used to make coils from known traditional materials.

Claims

CLAIMS1. Induction coil (1 ) for electric motors and / or actuators usable in pumps, comprising a plurality of turns made by means of at least one CCA-type wire (2), comprising a central portion (3), made of aluminium, and a peripheral portion or cover (4), made of copper, of a total diameter comprised between 0.17 mm and 0.34 mm, wherein said peripheral portion (4) is coaxial to said central portion (3) and the amount of material making said peripheral portion (4) corresponds to 10% of the total composition of the CCA wire (2).

2. Induction coil (1 ) according to one or more of the preceding claims, comprising a number of turns inversely proportional to the overall diameter of the CCA wire (2).

3. Induction coil (1 ) according to one or more of the preceding claims, comprising between 1650 turns and 5550 turns.

4. Induction coil (1 ) according to one or more of the preceding claims, wherein said CCA wire (2) has an average conductivity of 37.5 S*m / mm2.

5. Induction coil (1 ) according to one or more of the preceding claims, wherein said CCA wire (2) has an average resistivity of 0.0265 Ohm*mm2 / m.

6. Induction coil (1 ) according to one or more of the preceding claims, wherein said CCA wire (2) has a tensile force comprised between 120 N / mm2and 180 N / mm2.

7. Induction coil (1 ) according to one or more of the preceding claims, comprising between 1600 turns and 1800 turns, preferably 1700 turns, wherein the CCA wire (2) has an overall diameter comprised between 0.32mm and 0.40 mm, preferably 0.335 mm.

8. Induction coil (1 ) according to one or more of the preceding claims, comprising between 3600 turns and 3800 turns, preferably 3700 turns, wherein the CCA wire (2) has an overall diameter comprised between 0.22 mm and 0.30 mm, preferably 0.25 mm.

9. Induction coil (1 ) according to one or more of the preceding claims, comprising between 3700 turns and 3900 turns, preferably 3800 turns, wherein the CCA wire (2) has an overall diameter comprised between 0.23 mm and 0.31 mm, preferably 0.265 mm.

10. Induction coil (1) according to one or more of the preceding claims, comprising between 5400 turns and 5550 turns, preferably 5500 turns, wherein the CCA wire (2) has an overall diameter comprised between 0.15 mm and 0.20 mm, preferably 0.17 mm.

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