The invention relates to electric coils and methods of making electric coils.
For over 100 years, electric coils have been constructed using wire coated with insulation, usually termed “magnet wire”. This wire is wound onto bobbins to achieve the various benefits of coils. The number of solenoids, motors, transformers, inductors, etc. in use every day is enormous.
Electric coils are disclosed herein which do not require a magnet wire. Spiral conductors are disclosed which provide a coil producing a magnetic flux. The spiral conductors disclosed herein may include only a single spiral conductor layer, or plural layers. The spiral conductors may be circular, square, rectangular or any other suitable shape. The spiral conductor layer or layers include(s) a central air core to accommodate a solid core, plunger and/or other element depending on the application.
Traditional coils are made by starting near the center and making a complete coil, with subsequent coils outside the first coil. Such traditional coils are fixed and not flexible. The presently disclosed methods provide an end-to-end method in which the conductor may be spiral and as desired for a particular application, subsequent layers of spirals are built lengthwise. The spiral method disclosed herein provides a flexible coil that may be built out to any desired length. Coils as described and used herein may also be helical, overlapping rings, etc. Methods are also provided for making electric coils without a magnet wire. The devices and methods disclosed herein not only eliminate the need for winding, but also eliminate the costs associated with making magnet wire. A tremendous amount of work is involved in making a fine wire, including the gradual drawing down from larger originally-cast rod, reduction by reduction (about 20% per reduction), subsequent annealing of the copper after the copper is work-hardened and then further reduction, using big machinery occupying a lot of space. Even then, when the wire is finally at the size required, it has to be coated with insulating lacquer. The presently disclosed methods and devices eliminate all of these steps and the associated expense.
In accordance with some embodiments, a magnetic flux-inducing conductor may be formed into a spiral or other shape with suitable air spacing and molding an insulating structure around the conductor. The spiral magnetic flux-inducing conductor may be square, rectangular or other shape depending on the application. The conductor may be a single spiral layer or a plurality of stacked spiral layers. It is possible to make such a conductor when the size of the conductor makes it rigid enough to support its own weight. The magnetic flux-inducing conductor may be made using for example a 3-D printer, computer numerical control (CNC) machines such as mills, lathes, plasma cutters, electric discharge machining (EDM), water jet cutters, laser cutting, etc. A mold may be employed to support the conductor, wherein melted insulator material such as plastic is used to fill the mold to occupy the air space and insulate the conductor. It will be apparent that the process of insulating the conductor is intended to coat the conductor and the air spaces while leaving the air core open.
In accordance with other embodiments, methods are disclosed for making coils producing a magnetic flux which involve forming an insulation body, for example a single piece of insulating material of the type typically used to coat a wire to form a magnet wire, with a cavity, which cavity is formed for the purpose of receiving conductor material. In one embodiment, 3-dimensional (3D) printers and 3D printing techniques may be employed to produce a single or multi-layer insulator body having a cavity or groove that can be filled with conductive material to form a flux inducing coil. Laser cutting techniques may also be used. Coils as described and used herein may be helical, spiral, overlapping rings, etc.
In embodiments in which a conductive material is introduced to a cavity or groove formed in an insulator, a conductor material may include any suitable material such as a powder, granulate, liquid or any form which lends itself to filling into a cavity. The material may be tamped or otherwise settled using various techniques such as vibration until the desired level of compactness is achieved. The material may be introduced via suction, pressure or the like, and filtered if desired. The ends of the cavity may be sealed. Connectors such as brass connectors or the like positioned at the ends of the coils may likewise be filled and soldered. In another embodiment, a lead wire may be joined directly to the filler material, obviating the need for a connector. The composition of the material used to fill the cavity may be selected to provide desired coil properties depending on the application.
In some embodiments a conductor coil which induces a magnetic field includes at least one layer of conductive material formed in a spiral, the spiral having an inner portion forming an air core.
In some embodiments conductor coils are disclosed including at least two spiral layers of conductive material wherein the first spiral layer has a configuration in which a first end terminates at an exterior periphery of the first spiral layer and extends spirally inward toward an inner portion of the first spiral layer terminating at a second end, wherein the second spiral layer has a configuration in which a first end terminates at an interior periphery of the first spiral layer and extends spirally outward toward an exterior periphery of the first spiral layer, wherein the second spiral layer first end is conductively connected to the first spiral layer second end. The conductor coils are magnetic flux-inducing. The conductor coils may include plural spiral layers. At least one of the spiral layers is generally planar in cross-section. In some embodiments all of the spiral layers are generally planar in cross-section as shown in the accompanying FIGs.
Successive spiral layers of the conductor coil are connected by at least one bridge. The successive spirals may have the same or different number of turns. The spiral layers may have the same or different radii, and the pitch of the conductors may be the same or different as between successive layers. The spiral layers may be configured to extend spirally clockwise or counterclockwise, but either way, typically extend in the same direction.
The conductor coil may include in some embodiments a power connector extending from at least one of the spiral layers. The conductor coil may include an insulation layer coating the conductor coil and filling air spaces defined by the conductor coil.
In one embodiment a methods of making a conductor coil as described above may include simply forming a first spiral layer and connecting the first spiral layer to one or more successive spiral layers.
In another embodiment a method of making a conductor coil as described above may involve providing a mold having a configuration corresponding to a conductor coil as described above, filling the mold with conductive material, and casting the conductor coil from a conductive material in the mold.
In still a further embodiment a method of making a conductor coil as described above involves constructing an insulation body having an internal cavity having a configuration corresponding to the configuration of the conductor coil described above and introducing conductive material into the insulation body. The step of constructing the insulation body having an internal cavity may include printing the insulation body with an internal cavity using a three-dimensional printer. The method may involve forming plural layers of insulation material having spiral grooves, each of the grooves having at least one aperture formed therein, superimposing the plural layers such that the respective grooves of adjacent layers are configured to form a continuous cavity corresponding to the configuration of the conductor coil and the at least one aperture of each of the grooves is in communication with an a groove of an adjacent layer.
In other embodiments, the method involves forming a spiral groove on a first insulation layer, the spiral groove having an aperture, filling the groove with a conductor material such that a first spiral layer is formed and a first bridge of conductive material is formed in the aperture, superimposing a further insulation layer comprising a spiral groove formed therein and an aperture formed in the groove, and filling the groove with a conductor material such that the conductive material forms a second spiral layer and a conductive connection with the first bridge and forms a second bridge that may be conductively connected to a subsequent spiral layer. Successive spiral layers may be added as needed for a particular application.
In other embodiments an insulation body includes an opening formed therein and a continuous spiral groove formed in the insulation body along an outer perimeter of the opening. The opening may provide the region defining an air core of a conductor coil.
In other embodiments, an insulation body is provided having an internal cavity with a continuous cavity having at least two spiral layers wherein the first spiral layer has a configuration including a first end terminating at an exterior periphery of the first spiral layer and extending spirally inward toward an inner portion of the first spiral layer terminating at a second end, wherein the second spiral layer has a configuration having a first end terminating at an interior periphery of the first spiral layer and extending spirally outward toward an exterior periphery of the first spiral layer, wherein the second spiral layer first end is in open communication with the first spiral layer second end. The insulation body may include a central bore. A sidewall of the central bore may include an aperture formed therein to receive conductive material.
In still further embodiments, solenoids having a conductor coil as described above are disclosed herein.
In yet still further embodiments, an atomizer system having a solenoid employing a conductor coil as described above are disclosed, the system having a valve operably connected to the solenoid, wherein the valve is operably connectable to a fluid supply and a spray orifice.
In another embodiment, a solenoid is disclosed having a plunger with a flange configured and operable to remove air gaps and obtain intimate contact between elements of a magnetic circuit of the solenoid. The solenoid may include a return spring operable to serve as a shading ring, wherein the return spring is positioned between the flange of the plunger and a magnetic circuit pot of the solenoid.
In addition to the other advantages listed above, a major advantage of the presently disclosed magnetic flux inducing conductor coils is that the magnetic flux concentration can be controlled and adjusted. For, example normal wound coils have a concentration of magnetic flux at the center of their length. This is why the usual juncture of core to plunger is positioned at the center of their length. By contrast, the number of turns of each conductor layer, conductor thickness, and insulation thickness of the presently disclosed embodiments can all be varied to locate the higher concentration of flux at a different point than the center. This enables lighter weight, faster moving plungers in solenoids and increases the speed of operation.
For the purposes of illustration, there are forms shown in the drawings that are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown.
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the invention are shown. In the drawings, the relative sizes of regions or features may be exaggerated for clarity. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
It will be understood that when an element is referred to as being “coupled” or “connected” to another element, it can be directly coupled or connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly coupled” or “directly connected” to another element, there are no intervening elements present. Like numbers refer to like elements throughout. As used herein the term “and/or” includes any and all combinations of one or more of the associated listed items.
In addition, spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
Well-known functions or constructions may not be described in detail for brevity and/or clarity.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The phrase “magnet wire” as defined and used herein refers to a wire coated with insulation.
Electric coils are described herein which do not require a magnet wire. Spiral conductors are disclosed which provide a coil producing a magnetic flux. Such coils may be employed in devices such as solenoids, motors, transformers, inductors, etc. Various methods of making such coils are disclosed herein.
With reference to
With reference to
An example of a single-layer magnetic flux-inducing spiral coil is shown in
The cross-section of the conductor 10 may be any suitable dimension and shape. For example, and not by way of limitation, in one embodiment the largest cross sectional diameter of the conductor is in the range of 0.001 mm to 10 mm. In another embodiment the largest cross sectional diameter of the conductor is in the range of about 0.05 mm to about 8 mm. In another embodiment the largest cross sectional diameter of the conductor is from about 0.1 mm to about 0.5 mm. In another embodiment the largest cross sectional diameter of the conductor is about 0.2 mm. In one embodiment the conductor includes a square cross section having dimensions on one side of about 0.001 mm to about 10 mm and on another side of about 0.001 mm to about 10 mm. In one embodiment the dimensions are 0.2 mm×0.2 mm.
The foregoing figures and description can be applied by using prior art manufacturing methods such as metal die casting, metal stamping and automatic assembly etc.
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Another method for making a conductor coil, such as a solenoid coil, is disclosed in which the insulation is a solid body with an internal cavity. The solid body insulator can be built using a 3D printer or other methods such as laser cutting, CNC, etc. 3-dimensional (3D) printers are used to print thin layers of computer-controlled deposits of various materials and build these layers into solid three dimensional objects. By using various available materials, this technique can be employed to build assemblies. The cavity may be formed by the superposition of multiple printed layers of insulation material. In some embodiments the cavity so formed may be helical, spiral, maze-like, in the form of stacked, off-center circles, or any shape adequate to provide a coil producing a magnetic flux. In some embodiments the cavity includes a long, small cross-sectioned path. Once the cavity is formed, material such as conductive material may be introduced into the cavity to form a coil.
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The thickness of walls between grooves is from about 0.001 mm to about 8 mm. The same range applies to the wall thickness between adjacent layers.
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It will be recognized by those skilled in the art that the methods of inserting the conducting material may be selected to suit the application and the complexity of the coil. These methods could utilize for example pressure and vacuum, gravity, centrifugal force, etc. The insertion of the conductor could be via a single point or multiple points.
It is expected that further developments in 3D printing of metals will enable a practical construction of the entire coil, including the insulation, the conducting coil and the power connecting points.
The finished conductor coil can be tested for continuity by any means known in the art.
It will be recognized by those skilled in the art the foregoing assemblies and devices can be produced using known methods such as plastic molding, die casting, stamping, automatic assembly, etc.
Any suitable material may be employed to fill the insulator body 40. Conductive materials such as copper, silver, etc. may be used to fill the cavity. The conductive material may be provided in solid, powdered form or in liquid form. When the grooves or internal cavity (as the case may be, depending on the method of incorporating the conductor material and the structure) of the insulator body 40 are/is filled with an electrically conductive material, it becomes a magnetic flux-causing coil. One of the advantages of coil structures made in accordance with the present disclosure using powdered or liquid conductive materials to fill pre-formed cavities/grooves is that it is easy to change the resistance simply by mixing the conductive filling material with a material having a higher or lower conductivity. For example, copper filling material may be mixed with a less conductive material such as but not limited to carbon, or a more conductive material such as silver. Adjusting the conductivity of the filling material as described enables one to change the current, power and temperature without changing the coil structure, configuration, and/or physical shape.
In addition, low melting metals and/or fusible alloys can be mixed with conductive powder such as copper powder to make rigid coil structures. Examples of such low melting metals/alloys include mercury-containing alloys, alkali metal-containing alloys, gallium-containing alloys, and alloys containing bismuth, lead, tin, cadmium, zinc, indium, or thallium. In some embodiments the low melting metal may be Wood's metal, Field's metal, Rose metal, or Galinstan.
The filling of the cavity can be accomplished in one embodiment by introducing a finely powdered conductor, such as copper, or a conductive fluid, and upon completion of the filling, joining the ends of the cavity to solid connectors to make power connection easy. This process may be enhanced by pressurizing the powder going into the cavity and vacuuming the powder coming out of the cavity, and using vibration and jerky orientation changes, until the cavity is solidly filled. Insulated coils formed in accordance with the methods disclosed herein eliminate the need for winding magnet wire.
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Regardless of the method employed to fill the insulator cavity, in the case in which a powder filler is employed, it is generally desirable to conduct the filling operation in conditions of low humidity to enhance powder flow. In addition, particle size relative to cavity cross section size will impact filling efficiency. Employing a conductor with higher resistance permits a cavity having a larger cross section to be used, which enhances the ability to fill the cavity.
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In some embodiments, a lead wire may be joined directly to the filler material, obviating the need for a connector.
Any suitable insulator material may be employed in connection with the disclosed embodiments, such as but not limited to any non-conductive material such as plastic, ceramic, silk, fiberglass, paper, wood, etc.
In case of electrical conductive material having a melting temperature which is lower than the insulator maximum distortion-free temperature, disclosed are methods which can be utilized to make very reliable coils. There are 3D printable insulator materials which can withstand high temperatures. The following are maximum temperatures of selected common insulator materials:
There are metals and metal alloys which melt below some or all of the foregoing temperatures. For example, tin/silver solder melts at 430° F.; tin melts at 450° F.; tin/lead (63%/37%) melts at 361° F., etc. Any metal or alloy having a melting point below the melting point of the selected insulator material may be employed.
It will be apparent to the skilled artisan that low temperature metal alloys may be used if a lower temperature insulating material such as ceramic is desired. In one embodiment, a conductor which melts below 300 F but does not melt when powdered is a desirable fill material. Various such materials are available from Belmont Metals, Inc. of Brooklyn, N.Y., including but not limited to Belmont 2562 Base (MP 255° F.) and 2581 Tru (MP 281° F.).
In one embodiment, a method of making an electric coil includes introducing the conductor material into the cavity as a powder and subsequently subjecting the assembly to heat treatment to melt the conductor, and solidifying the conductor in a cooling step. In another embodiment, a method of making an electric coil includes introducing the conductor material into the cavity in molten form, and solidifying the conductor in a cooling step. In addition, it is expected that once 3D printing equipment and technology is advanced enough to print metals, the coil can be built as an assembly of insulator and conductor layer by layer.
Embodiments of the presently disclosed subject matter provide several advantages. For example, coils made according to the methods are neat and compact. Coils made according to one or more of the methods, when used in motor rotors, minimize unbalance. Regardless of the device in which such coils may be used, the coils can be designed for better cooling. Moreover, in a fixed insulation, the conductor can be a mixture to give a specified resistance. In addition, end terminals can be applied automatically to make power connection easy. A lead wire may be joined directly to the filler material, obviating the need for a connector.
Specialty coils can be made more readily than manual winding. Coils can be changed easily in diameter and length. Also, the conductor cross sectional area and the number of turns can be changed easily.
With advances in 3D printing technology, the presently disclosed methods are expected to yield reduced costs, and the productivity to cost ratio will approach or surpass that of current traditional wire winding operations.
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In the prior art, a solenoid plunger moves within the coil and is part of the magnetic circuit. Also, in the prior art, the magnetic circuit could be made up, in addition to the plunger, of a core, which is also within the coil, and a magnetic conductive structure, which is outside of the coil. When in the de-energized plunger “out” position, there are two gaps: a gap between the core face and the plunger face, and a gap between the plunger and the outer magnetic conductive structure, which is clearance to allow movement. When air is added to the magnetic circuit, there is reduced total magnetic permeance, depending on the total air gap. When the permeance is low, as would be when there is a large air gap, the current necessary to operate and hold a solenoid's force is increased. Conversely, when the permeance is high, as would be when there is zero air gap, the current is reduced.
The plunger 125 shown in
Also, solenoids which are operated with alternating current require a shading ring to keep the plunger from separating from the core during main coil zero flux moments. Otherwise, the solenoid will have an annoying and destructive vibration. The prior art locates this shading ring at the end of the core, at the juncture with the plunger face.
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Although the devices and systems of the present disclosure have been described with reference to exemplary embodiments thereof, the present disclosure is not limited thereby. Indeed, the exemplary embodiments are implementations of the disclosed systems and methods are provided for illustrative and non-limitative purposes. Changes, modifications, enhancements and/or refinements to the disclosed systems and methods may be made without departing from the spirit or scope of the present disclosure. Accordingly, such changes, modifications, enhancements and/or refinements are encompassed within the scope of the present invention.
This application is a divisional of U.S. patent application Ser. No. 14/812,467 filed Jul. 29, 2015, which claims the benefit of U.S. Provisional Patent Application No. 62/030,169 filed Jul. 29, 2014, the entireties of which are incorporated herein by reference.
Number | Date | Country | |
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62030169 | Jul 2014 | US |
Number | Date | Country | |
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Parent | 14812467 | Jul 2015 | US |
Child | 16111708 | US |