Patent Description:
Magnetic-cores are widely used in electric machines such as electric motors and generators. For example, a magnetic-core may be used in a rotor core assembly and/or in a stator core assembly. An electric machine utilizes a magnetic field to convert electrical energy to mechanical energy, or vice versa. The magnetic field may be provided by an array of permanent magnets and/or an electromagnetic coil. The use of a magnetic-core increases the strength of a magnetic field by orders of magnitude from what it would be without the core. Typically steel alloys such as silicon steel are used for the magnetic-core because these materials have a high relative permeability, which reflects the material's magnetic flux carrying capacity or the degree of magnetization that the material obtains in response to an applied magnetic field. However, magnetic-cores made of steel alloys are susceptible to forming eddy currents as a result of the alternating flux induced during operation of the electric machine. These eddy currents generate resistive losses, generating heat which, among other things, reduces the efficiency of the electric machine.

Eddy currents can be minimized to an extent relative to solid magnetic-cores by using magnetic-cores made of stacks of thin sheets of steel alloy coated or laminated with a thin film of non-ferromagnetic insulating material. Each individual laminated sheet is commonly referred to as a lamination. The film of insulating material coating the thin sheet of steel alloy serves as a barrier to eddy currents, such that eddy currents can only flow in narrow loops within the thickness of the individual laminations. The current in an eddy current loop is proportional to the area of the loop, so thinner laminations generally correspond to relatively lower eddy current losses. As such, it is generally desirable to provide thinner laminations so as to minimize eddy current losses.

A typical magnetic-core may have hundreds of even thousands of laminations tightly clamped together between compression plates to minimize the amount of space between the laminations. Proper operation and performance of a magnetic-core depends on having precisely stacked laminations, including having uniform alignment and compression throughout the magnetic-core. Imprecisions in a lamination stack, such as imprecisions introduced when stacking the laminations can lead to performance issues, premature wear, and even critical failures due to electrical, mechanical, and thermal stresses. For example, improper alignment or clamping can cause movement and vibration between the laminations, leading to settling of laminations, imbalances, excessive temperatures, buckling, and even meltdown of the magnetic-core. These issues may arise even with minute imprecisions. For example, even minute imprecisions may cause variations in the electromagnetic flux. Variations in the electromagnetic flux may cause magnetostrictive strain, which may oscillate at twice the frequency of the magnetic field. This magnetostrictive strain may cause movement and vibration between the laminations. When laminations move relative to each other, the film of insulating material coating the laminations may wear, leading to shorts, magnetic field imbalances, overheating, and potentially catastrophic failures.

Specialized assembly tools have been provided for assembling magnetic-cores. However, imprecisions and corresponding issues nevertheless persist. Efforts to address these issues include applying adhesives across the face of laminations to adhere them to one another, as well as welding laminations together. However, these approaches are not often ideal because they increase manufacturing time and cost, and add material that does not contribute to the magnetic flux carrying capacity of the magnetic-core.

Accordingly, there exists a need for improved methods for assembling a laminated magnetic-core.

<CIT> describes an interior core magnet manufacturing device.

Aspects and advantages will be set forth in part in the following description, or may be obvious from the description, or may be learned through practicing the presently disclosed subject matter.

In one aspect, the present disclosure embraces methods of assembling a magnetic-core assembly. Methods according to the invention include assembling a plurality of lamination stacks, staging the plurality of lamination stacks to provide a magnetic-core assembly, assembling a magnetic-core assembling-tool around the magnetic-core assembly, and injecting magnet retention adhesive into a plurality of magnet retention slots in the magnetic-core assembly housed in the magnetic-core assembling tool.

In another aspect, the present disclosure embraces magnetic-core assembling tools. A magnetic-core assembling tool includes a first compression plate alignment guide configured to be fitted to a first compression plate of a magnetic-core assembly, a second compression plate alignment guide configured to be fitted to a second compression plate of the magnetic-core assembly, a plurality of semiannular tension bars, and a clamping plate. Each of the plurality of semiannular tension bars have a first end and a second end, with the first end configured to attach to the first compression plate alignment guide and the second end configured to attach to the clamping plate. The clamping plate may include a plurality of compression shoes, each of the plurality of compression shoes configured to apply a variable amount of compression to the magnetic-core assembly.

In another aspect, the present disclosure embraces magnetic-core assemblies. Exemplary magnetic-core assemblies may include a magnetic-core comprising a plurality of laminations clamped between a first compression plate and a second compression plate, a plurality of permanent magnets within a plurality of magnet retention slots in the laminations, and a magnet retention adhesive adhering the plurality of permanent magnets within the plurality of magnet retention slots. The magnet retention adhesive may be applied with the lamination stacks under axial compression applied by a magnetic-core assembling tool, substantially preventing magnet retention adhesive from flowing across the face of the laminations.

These and other features, aspects and advantages will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments and, together with the description, serve to explain certain principles of the presently disclosed subject matter.

A full and enabling disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended Figures, in which:.

Reference now will be made in detail to exemplary embodiments of the presently disclosed subject matter, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation and should not be interpreted as limiting the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope of the present disclosure. Thus, it is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims.

It is understood that terms "upstream" and "downstream" refer to the relative direction with respect to fluid flow in a fluid pathway. It is also understood that terms such as "top", "bottom", "outward", "inward", and the like are words of convenience and are not to be construed as limiting terms. The terms "a" and "an" do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

Here and throughout the specification and claims, range limitations are combined and interchanged, and such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.

The present disclosure generally provides improved magnetic-core assemblies, magnetic-core assembling tools, and systems and methods for assembling a magnetic-core assembly. The presently disclosed tools, systems, and methods help to improve staging and alignment with of a magnetic-core assembly and to maintain proper compression and alignment of the magnetic-core assembly, thereby reducing the possibility of warping, shifting of laminations, or damage to the magnetic-core assembly. The presently disclosed magnetic-core assembling tools provide systems for staging, assembling, aligning, and compressing the components of the magnetic-core assembly with improved precision and tighter tolerances. Additionally, the presently disclosed magnetic-core assembling tools provide systems for performing assembly steps to a magnetic-core assembly housed in a magnetic-core assembling tool, such as injecting magnet retention adhesive into magnet retention slots of a magnetic-core assembly, performing machining operations upon a magnetic-core assembly, and/or coupling a rotor shaft to a magnetic-core assembly. These assembly steps can be performed without removing the magnetic-core assembly from the magnetic-core assembling tool. Additionally, these assembly steps can be performed while maintaining the magnetic-core assembly under constant axial pressure.

With the presently disclosed tools, systems, and methods, a magnetic-core assembly can be provided that has an improved relative permeability. The relative permeability of a magnetic-core depends on how closely and uniformly the laminations that make up the magnetic-core are clamped together. This closeness and uniformity of the laminated magnetic-core can be characterized by a lamination factor, S, in accordance with ASTM <NUM>, Standard Test Method for Lamination Factor of Magnetic Materials. Lamination factor may also be referred to as a space factor or stacking factor. Lamination factor indicates the deficiency of effective steel volume due to the presence of oxides, roughness, insulating coatings, and other conditions affecting the steel surface of the laminations making up a magnetic-core. Accordingly, the presently disclosed tools, systems, and methods can provide magnetic-core assemblies that have an improved lamination factor. By way of example, magnetic-core assemblies may have a lamination factor of greater than <NUM>, such as at least <NUM>, such as at least <NUM>, such as at least <NUM>, such as at least <NUM>, such as at least <NUM>, such as at least <NUM>.

<FIG> schematically depicts a magnetic-core assembly <NUM> for an electric machine. The magnetic-core assembly <NUM> includes a magnetic-core <NUM> made up of a plurality of laminations clamped between compression plates <NUM>. The plurality of laminations making up the magnetic-core <NUM> are provided as a plurality of lamination stacks <NUM>. The magnetic-core <NUM> may include a plurality of permanent magnets <NUM>, or electromagnetic windings. As discussed with reference to <FIG>, each lamination stack <NUM> may include a plurality of lamination sub-stacks, and each lamination sub-stack may include a plurality of individual laminations. As shown, the magnetic-core assembly <NUM> may be a rotor core assembly for an electric machine, since the magnetic-core assembly <NUM> includes a rotor shaft <NUM> operably coupled to the rotor core. However, the present disclosure embraces any magnetic-core assembly <NUM>, including rotor core assemblies and stator core assemblies, among others, and the inclusion of the rotor shaft <NUM> should not be interpreted as limiting the present disclosure. For example, it will be appreciated that by elimination of the rotor shaft <NUM>, the exemplary magnetic-core assembly <NUM> as shown may additionally or alternatively reflect a stator core assembly, among other magnetic-core assemblies.

Another embodiment of an exemplary magnetic-core assembly <NUM> is shown in <FIG>. As shown in <FIG>, the exemplary magnetic-core assembly <NUM> includes a magnetic-core <NUM> made up of a plurality of laminations (e.g., lamination stacks and/or lamination sub-stacks) clamped between compression plates <NUM>. The laminations making up the magnetic-core <NUM> include one or more outward facing surfaces <NUM>, and one or more inward facing surfaces <NUM>. <FIG> shows the exemplary magnetic-core assembly <NUM> of <FIG>, but with the compression plates <NUM> removed to show a plurality of magnet retention slots <NUM> which hold a plurality of permanent magnets <NUM> and/or a plurality of permanent magnet segments <NUM>. As shown in <FIG>, exemplary compression plates <NUM> include one or more injection ports <NUM>, which lead to an adhesive conduit <NUM> that defines a pathway for flowing magnet retention adhesive into the plurality of magnet retention slots <NUM> in the magnetic-core <NUM>. In some embodiments, the adhesive conduit <NUM> includes a plurality of magnet retention grooves <NUM>. The plurality of magnet retention grooves <NUM> may be interconnected, defining at least a portion of the adhesive conduit <NUM>. Alternatively, the plurality of magnet retention grooves <NUM> may each separately define at least a portion of an adhesive conduit <NUM>. The one or more injection ports <NUM> may be used to inject magnet retention adhesive, as discussed below with reference to <FIG>.

<FIG> shows flowchart depicting an exemplary method <NUM> of assembling a magnetic-core assembly <NUM> at least in part using a magnetic-core assembling tool <NUM>. <FIG> and <FIG> respectively show an exemplary magnetic-core assembling tool <NUM> with the magnetic-core assembly <NUM> of <FIG> housed therein. As shown in <FIG>, a magnetic-core assembling tool <NUM> used in the method according to the invention includes a first compression plate alignment guide <NUM>, a plurality of semiannular tension bars <NUM>, a second compression plate alignment guide <NUM>, and a clamping plate <NUM>. As shown in <FIG>, an exemplary magnetic-core assembling tool <NUM> may additionally include a plurality of semiannular compression bars <NUM> disposed between the plurality of semiannular tension bars <NUM> and the clamping plate <NUM>. The magnetic-core assembling tool <NUM> may be assembled using the method depicted in <FIG>. The exemplary method <NUM> may include assembling a plurality of lamination stacks <NUM> (block <NUM>). The method according to the invention includes staging a plurality of lamination stacks <NUM> to provide a magnetic-core assembly <NUM> (<FIG>) (block <NUM>). The method <NUM> according to the invention includes assembling a magnetic-core assembling tool <NUM> around a magnetic-core assembly <NUM> (block <NUM>). For example, the magnetic core assembling tool <NUM> may be assembled around a staged magnetic core assembly <NUM>. Additionally, or in the alternative, the magnetic core assembling tool <NUM> may be assembled while concurrently staging the magnetic core assembly <NUM>. The exemplary method <NUM> may include injecting magnet retention adhesive into a plurality of magnet retention slots <NUM> in the magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM> (block <NUM>). The exemplary method <NUM> may optionally include performing a machining operation on the magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM> (block <NUM>), and/or coupling a rotor shaft <NUM> to the magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM> (block <NUM>). The exemplary method <NUM> may include removing the magnetic-core assembly <NUM> from the magnetic-core assembling tool <NUM> (block <NUM>). The exemplary magnetic-core assembling tool <NUM> and the exemplary method <NUM> are discussed in further detail below with reference to <FIG>, <FIG>, <FIG>, and <FIG>.

Typically a magnetic-core <NUM> includes a plurality of lamination stacks <NUM> tightly clamped together between compression plates <NUM>. An exemplary method <NUM> of assembling a magnetic-core assembly <NUM> may include assembling a plurality of lamination stacks <NUM> (block <NUM>), for example, as discussed below with reference to <FIG>. The lamination stacks <NUM> can be subsequently combined together to assemble a magnetic-core assembly <NUM> as described herein. A magnetic-core <NUM> may include thousands of individual laminations. As shown in <FIG>, a method <NUM> of assembling a plurality of lamination stacks <NUM> (block <NUM> of <FIG>) includes assembling a plurality of lamination sub-stacks from a plurality of laminations (block <NUM>), and then assembling a plurality of lamination stacks <NUM> from the plurality of lamination sub-stacks (block <NUM>).

As shown in <FIG>, a lamination sub-stack <NUM> may be assembled using a stack assembling-tool <NUM>. The stack assembling-tool <NUM> includes a first clamping member <NUM>, a second clamping member <NUM>, and a compression member <NUM> configured to apply compression force to a plurality of laminations <NUM> clamped between the first clamping member <NUM> and the second clamping member <NUM>. The compression member <NUM> may be driven by a hydraulic press, manual actuation, or the like, applying clamping pressure to the plurality of laminations <NUM>.

A plurality of laminations <NUM> are placed in the stack assembling-tool <NUM>, and optionally a small bead of tacking adhesive <NUM> may be applied at select locations. For example, as shown in <FIG>, tacking adhesive <NUM> may be applied at one or more locations at the inward facing surfaces <NUM> of the laminations <NUM>. Any suitable thermoplastic material may be used as a tacking adhesive <NUM> may be used. The tacking adhesive <NUM> temporarily holds the laminations <NUM> in position, and may be removed at subsequent points in the assembly of the magnetic-core assembly <NUM>. The plurality of laminations <NUM> are aligned using a micrometer or the like and clamped tightly together in the stack assembly-tool <NUM>. The clamping pressure applied to the plurality of laminations <NUM> may range from <NUM> to <NUM> megapascal. After the tacking adhesive <NUM> has set, the plurality of laminations <NUM> are removed from the stack assembly-tool <NUM>, providing a lamination sub-stack <NUM>. A lamination sub-stack <NUM> may include any number of laminations <NUM>. For example, a lamination sub-stack <NUM> may include between <NUM> to <NUM> laminations <NUM>, between <NUM> to <NUM> laminations <NUM>, between <NUM> to <NUM> laminations <NUM>, or between <NUM> to <NUM> laminations <NUM>.

A plurality of lamination sub-stacks <NUM> can be formed, which can be subsequently combined together to form a lamination stack <NUM> as shown in <FIG>. A lamination stack <NUM> may be assembled using a stack assembling-tool <NUM> as shown in <FIG>. A plurality of lamination sub-stacks <NUM> are placed in the stack assembling-tool <NUM>, and optionally a small bead of tacking adhesive <NUM> may be applied at select locations. For example, as shown in <FIG>, tacking adhesive <NUM> may be placed at one or more locations at the inward facing surface <NUM> of the lamination sub-stacks <NUM>. Any suitable thermoplastic material may be used as a tacking adhesive <NUM> may be used, such as the same thermoplastic material used as a tacking adhesive <NUM> used to adhere the laminations <NUM> when assembling the lamination sub-stacks <NUM>. The tacking adhesive <NUM> temporarily holds the lamination sub-stacks <NUM> in position, and may be removed at subsequent points in the assembly of the magnetic-core assembly <NUM>.

The plurality of laminations sub-stacks <NUM> can be aligned using a micrometer or the like and clamped tightly together in the stack assembly-tool <NUM>. The clamping pressure applied to the plurality of lamination sub-stacks <NUM> may range from <NUM> to <NUM> megapascal. After the tacking adhesive <NUM> has set, the plurality of lamination sub-stacks <NUM> can be removed from the stack assembly-tool <NUM>, providing a lamination stack <NUM>. A lamination stack <NUM> may include any number of lamination sub-stacks <NUM>. For example, a lamination stack <NUM> may include between <NUM> to <NUM> lamination sub-stacks <NUM>, between <NUM> to <NUM> lamination sub-stacks <NUM>, between <NUM> to <NUM> lamination sub-stacks <NUM>, between <NUM> to <NUM> lamination sub-stacks <NUM>, between <NUM> to <NUM> lamination sub-stacks <NUM>, or between <NUM> to <NUM> lamination sub-stacks <NUM>.

In an exemplary embodiment, the lamination sub-stacks <NUM> can be measured at various locations, using a micrometer or the like. These measurements may be recorded, for example, in a database associating the measurement values to the lamination sub-stack <NUM> and the location on the lamination sub-stack <NUM> corresponding to the measurement. For example, a lamination sub-stack may be measured for thickness, alignment, cylindricity, concentricity, perpendicularity, parallelism, and/or angularity, and the like. Lamination stacks <NUM> may be selectively assembled from a plurality of lamination sub-stacks <NUM> selected based at least in part on such measurement values. The lamination sub-stacks <NUM> may be selectively added to a lamination stack <NUM> being assembled such that variations in the lamination sub-stacks <NUM> at least partially offset one another. For example, a plurality of lamination sub-stacks <NUM> with a variation in thickness may be added to the lamination stack <NUM> such that the variations in thickness are distributed throughout the lamination stack <NUM>. Such variations may be distributed periodically, uniformly, or evenly throughout the lamination stack <NUM>. Such distributed variations may at least partially offset one another, keeping variation in the resulting lamination stack <NUM> within an acceptable tolerance range <NUM>. In some embodiments, variations in the lamination sub-stacks <NUM> may become unapparent in the resulting lamination stack <NUM>.

Referring to <FIG>, an exemplary method <NUM> of assembling a magnetic-core assembly <NUM> may include staging the magnetic-core assembly <NUM> (block <NUM>). An exemplary method <NUM> may include assembling a magnetic-core assembling tool <NUM> around the magnetic-core assembly <NUM> (block <NUM>). In some embodiments, a magnetic-core assembly <NUM> can be staged as discussed below with reference to <FIG>. A magnetic-core assembling tool <NUM> can be assembled around a staged magnetic-core assembly <NUM>. Additionally, or in the alternative, a magnetic-core assembling tool <NUM> can be assembled around a magnetic-core assembly <NUM> while concurrently staging the magnetic core assembly <NUM>, as discussed below with reference to <FIG>. The magnetic core assembly <NUM> may be compressed using the magnetic-core assembling tool <NUM> as discussed below with reference to <FIG>.

As shown in <FIG>, a method <NUM> of staging a plurality of lamination stacks <NUM> to provide a magnetic-core assembly <NUM> (block <NUM> of <FIG>) may include fitting a first compression plate alignment guide <NUM> to a first compression plate <NUM> (block <NUM>), stacking and at least partially aligning a plurality of lamination stacks on the first compression plate <NUM> fitted to the first compression plate alignment guide <NUM> (block <NUM>), and stacking a second compression plate <NUM> on the plurality of lamination stacks (block <NUM>).

As shown in <FIG>, a magnetic-core assembling tool <NUM> includes a first compression plate alignment guide <NUM> configured to mate with a compression plate <NUM>. The compression plates <NUM> of a magnetic-core assembly <NUM> are fabricated with precise dimensions. For example, typical tolerances for compression plates <NUM> may be from <NUM> to <NUM> mils (<NUM>,<NUM>) such as from <NUM> to <NUM> mils (<NUM>,<NUM>), such as from <NUM> to <NUM> mils (<NUM>,<NUM>) , such as from <NUM> to <NUM> mils (<NUM>,<NUM>). In the case of a rotor core, the compression plates <NUM> rotate with the rotor core assembly. Precise fabrication of the compression plates <NUM> helps assure that the compression plates <NUM> do not contribute to imbalances in the magnetic-core assembly <NUM>. This precision allows the compression plates <NUM> to serve as a reference point for aligning the plurality of lamination stacks <NUM> when staging and assembling the magnetic-core assembly <NUM> using the magnetic-core assembling tool <NUM>. The magnetic-core assembling tool <NUM> may be similarly fabricated with precise dimensions at least at surfaces that contact and align the compression plates <NUM> and/or the lamination stacks <NUM>. For example, typical tolerances for the magnetic-core assembling tool <NUM> may be from <NUM> to <NUM> mils (<NUM>,<NUM>) such as from <NUM> to <NUM> mils (<NUM>,<NUM>), such as from <NUM> to <NUM> mils (<NUM>,<NUM>) , such as from <NUM> to <NUM> mils (<NUM>,<NUM>).

As shown, a compression plate <NUM> may include at least one compression plate mating surface <NUM>, and the first compression plate alignment guide <NUM> may include at least one alignment guide mating surface <NUM> configured to precisely mate with the at least one compression plate mating surface <NUM>. For example, a compression plate mating surface <NUM> and an alignment guide mating surface <NUM> may mate with one another with a tolerance of from <NUM> to <NUM> mils (<NUM>,<NUM>) such as from <NUM> to <NUM> mils (<NUM>,<NUM>), such as from <NUM> to <NUM> mils (<NUM>,<NUM>) , such as from <NUM> to <NUM> mils (<NUM>,<NUM>). The compression plate mating surface <NUM> and the alignment guide mating surface <NUM> may include one or more annular mating surfaces and/or one or more lateral mating surfaces. For example, the compression plate <NUM> may include an inward-facing annular mating surface <NUM> that precisely mates with an outward-facing annular mating surface <NUM> on the first compression plate alignment guide <NUM>. Additionally, or in the alternative, the compression plate <NUM> may include an outward-facing annular mating surface <NUM> that precisely mates with an inward-facing annular mating surface <NUM> on the first compression plate alignment guide <NUM>. Additionally, the compression plate <NUM> may include a first lateral mating surface <NUM> that precisely mates with a second lateral mating surface <NUM> on the first compression plate alignment guide <NUM>. The compression plate <NUM> may additionally include a third lateral mating surface <NUM> that precisely mates with a fourth lateral mating surface <NUM> on the compression plate alignment guide. The mating surfaces help to align the compression plate <NUM> and the first compression plate alignment guide <NUM> within required tolerances for cylindricity, concentricity, perpendicularity, parallelism, and/or angularity, and the like. Using a compression plate <NUM> as a reference point, such alignment helps to similarly align the lamination stacks <NUM> of the magnetic-core assembly <NUM> within required tolerances for cylindricity, concentricity, perpendicularity, parallelism, and/or angularity, and the like.

When fitting a compression plate <NUM> to a first compression plate alignment guide <NUM>, one or more mating surfaces may be measured, and one or more shims may be used to compensate for a deviation from one or more tolerances. For example, a first axial distance <NUM> between the first lateral mating surface <NUM> and the third lateral mating surface <NUM> may be compared to a second axial distance <NUM> between the second lateral mating surface <NUM> and the fourth lateral mating surface <NUM>. One or more shims <NUM> may be utilized in the event of a deviation between the first axial distance <NUM> and the second axial distance <NUM>, for example, to bring the deviation within an applicable tolerance.

Referring to <FIG>, with the compression plate <NUM> fitted to a first compression plate alignment guide <NUM>, the method <NUM> of staging the magnetic-core assembly may continue with stacking and at least partially aligning a plurality of lamination stacks <NUM> on the first compression plate alignment guide <NUM> (block <NUM>). As shown in <FIG>, a plurality of guideposts <NUM> may be used to help at least partially align the plurality of lamination stacks <NUM> during stacking. The guideposts <NUM> may be configured to fit within magnet retention grooves <NUM> (<FIG>) in the compression plate <NUM>. Magnet retention slots <NUM> (<FIG>) in the lamination stacks <NUM> are configured to fit around the guideposts <NUM>. The guideposts <NUM> are removed and replaced with permanent magnets <NUM> and/or a permanent magnet segments <NUM> when stacking the plurality of lamination stacks <NUM>. The plurality of lamination stacks <NUM> can be stacked and aligned using the guideposts <NUM>, and the guideposts <NUM> can be removed and replaced with permanent magnets <NUM> and/or a permanent magnet segments <NUM> in any desired sequence. In some embodiments, a plurality of lamination stacks <NUM> and a first plurality of permanent magnets <NUM> can be stacked sequentially in layers using the guideposts <NUM>. An exemplary sequence is shown in <FIG>. The exemplary sequence begins with placing a plurality of guideposts <NUM> in in a plurality of magnet retention grooves <NUM> in a first compression plate <NUM> (<FIG>), and stacking a first plurality of lamination stacks <NUM> on the first compression plate <NUM>, with the magnet retention slots <NUM> in the first plurality of lamination stacks <NUM> fitting around the guideposts <NUM> (<FIG>). The exemplary sequence continues with removing the guideposts <NUM> and inserting a first plurality of permanent magnets <NUM> in the magnet retention slots <NUM> (<FIG>). The sequence may be continued until a desired stack height is reached.

In some embodiments, a combination of long guideposts <NUM> and short guideposts <NUM> may be used so as to provide interlocking guideposts <NUM> and lamination stacks <NUM>. The long guideposts <NUM> may have a length selected so as to exceed the height of a lamination stack <NUM>, so that the long guidepost <NUM> may provide a guide for adding one or more subsequent lamination stacks <NUM> and aligning adjacent lamination stacks <NUM> with one another. The short guideposts <NUM> may have a length selected to correspond to the height of a lamination stack <NUM>. Additionally, or in the alternative, a combination of long permanent magnets <NUM> and short permanent magnets <NUM> may be used, so as to provide interlocking permanent magnets <NUM> and guideposts <NUM>. The long permanent magnets <NUM> may have a length selected so as to exceed the height of a lamination stack <NUM>, so that the long permanent magnets <NUM> may interlock with adjacent lamination stacks <NUM>. The short permanent magnets <NUM> may have a length selected to correspond to the height of a lamination stack <NUM>.

Additional lamination stacks may be added by placing a plurality of guideposts <NUM> in a plurality of magnet retention slots <NUM> in the first plurality of lamination stacks <NUM> already stacked on the first compression plate <NUM> and adding one or more additional lamination stacks <NUM> to the stack, with the magnet retention slots <NUM> in the one or more additional lamination stacks <NUM> fitting around the guideposts <NUM> (<FIG>). The guideposts <NUM> may again be removed and a second plurality of permanent magnets <NUM> inserted in the plurality of magnet retention slots <NUM> in the one or more additional lamination stacks <NUM> (<FIG>). This sequence may be continued (<FIG>) until a desired stack height is obtained (<FIG>). A second compression plate <NUM> is placed in position on the end of the stack opposite to the first compression plate <NUM>, providing a staged magnetic-core assembly <NUM> (<FIG>).

Now turning to <FIG>, an exemplary method <NUM> of assembling a magnetic-core assembling tool <NUM> will be described. As shown with reference to <FIG>, a magnetic-core assembling tool <NUM> may be assembled around a staged magnetic-core assembly <NUM> (block <NUM> of <FIG>). Additionally, or in the alternative, as shown with reference to <FIG>, a magnetic-core assembling tool <NUM> may be assembled while concurrently staging the magnetic core assembly <NUM> (block <NUM> of <FIG>). A method of <NUM> of assembling a magnetic-core assembling tool <NUM> includes attaching a plurality of semiannular tension bars <NUM> to the first compression plate alignment guide <NUM> with a first end of each semiannular tension bar attached to the first compression plate alignment guide <NUM> (block <NUM>). A method <NUM> according to the invention includes fitting a second compression plate alignment guide <NUM> to a second compression plate <NUM> and/or within a spaced surrounded by the plurality of semiannular tension bars <NUM> (block <NUM>). A method <NUM> according to the invention includes attaching a clamping plate <NUM> to the plurality of semiannular tension bars <NUM> with a second end of each semiannular tension bar <NUM> attached to the clamping plate <NUM> (block <NUM>).

<FIG> show an embodiment of a magnetic-core assembling tool <NUM>. As shown in <FIG>, a magnetic-core assembling tool <NUM> includes a first compression plate alignment guide <NUM>, a plurality of semiannular tension bars <NUM>, a second compression plate alignment guide <NUM>, and a clamping plate <NUM>. The magnetic-core assembling tool <NUM> shown in <FIG> may be utilized to assemble a magnetic core assembly <NUM> that has been staged as described with reference to <FIG>. The plurality of semiannular tension bars <NUM> are each attached to the first compression plate alignment guide <NUM> at one or more attachment points <NUM> with a plurality of bolts or the like. Each semiannular tension bar <NUM> surrounds a semiannular portion of the magnetic-core assembly <NUM>. Attachment points <NUM> where the semiannular tension bars <NUM> attach to the first compression plate alignment guide <NUM> are precisely located. When attached to the first compression plate alignment guide <NUM>, the plurality of semiannular tension bars <NUM> together define an annulus <NUM> with an internal annular surface that surrounds the lamination stacks <NUM> of the magnetic-core assembly <NUM>. A magnetic-core assembling tool <NUM> may include any number of semiannular tension bars <NUM>.

The semiannular tension bars <NUM> include one or more lamination stack aligning surfaces <NUM>. The lamination stack aligning surfaces <NUM> are defined at least in part by an internal annular surface of an annulus <NUM> defined by the semiannular tension bars <NUM>. The lamination stack aligning surfaces <NUM> are configured to precisely abut one or more outward facing surfaces <NUM> of the lamination stacks <NUM>, thereby further aligning the lamination stacks <NUM> with one another and/or with the compression plates <NUM>, in each case within required tolerances for cylindricity, concentricity, perpendicularity, parallelism, and/or angularity, and the like. For example, the lamination stack aligning surfaces <NUM> may abut the one or more outward facing surfaces <NUM> of the lamination stacks <NUM> with a tolerance of from <NUM> to <NUM> mils (<NUM>,<NUM>) such as from <NUM> to <NUM> mils (<NUM>,<NUM>), such as from <NUM> to <NUM> mils (<NUM>,<NUM>) , such as from <NUM> to <NUM> mils (<NUM>,<NUM>).

Referring to <FIG> and <FIG>, the second compression plate alignment guide <NUM> includes at least one alignment guide mating surface <NUM> configured to precisely mate with at least one compression plate mating surface <NUM> of the second compression plate <NUM> at one or more annular mating surfaces and/or one or more lateral mating surfaces. The second compression plate alignment guide <NUM> may be inserted axially into the internal annular space of the annulus <NUM> defined by the plurality of semiannular tension bars <NUM> and mated with the second compression plate <NUM>, for example, after the semiannular tension bars <NUM> have been attached to the first compression plate alignment guide <NUM>. Alternatively, the second compression plate alignment guide <NUM> may be mated with the second compression plate <NUM> prior to attaching the semiannular tension bars <NUM> to the first compression plate alignment guide <NUM>. The one or more lamination stack aligning surfaces <NUM> may be configured to precisely abut one or more outward facing surfaces <NUM> of the second compression plate alignment guide <NUM>, thereby helping to align the second compression plate <NUM> and/or the lamination stacks <NUM> within required tolerances for cylindricity, concentricity, perpendicularity, parallelism, and/or angularity, and the like. For example, the lamination stack aligning surfaces <NUM> may abut the one or more outward facing surfaces <NUM> of the second compression plate alignment guide <NUM> with a tolerance of from <NUM> to <NUM> mils (<NUM>,<NUM>) such as from <NUM> to <NUM> mils (<NUM>,<NUM>), such as from <NUM> to <NUM> mils (<NUM>,<NUM>) , such as from <NUM> to <NUM> mils (<NUM>,<NUM>). In some embodiments, the combination of the first compression plate alignment guide <NUM>, the plurality of semiannular tension bars <NUM>, and the second compression plate alignment guide <NUM> provides a system for aligning the lamination stacks <NUM> with one another and/or with the compression plates <NUM> with improved precision and tighter tolerances.

Referring to <FIG>, the clamping plate <NUM> may be attached to the semiannular tension bars <NUM> after the semiannular tension bars <NUM> have been attached to the first compression plate alignment guide <NUM> and the second compression plate alignment guide <NUM> has been inserted axially into the internal annular space of the annulus <NUM> defined by the plurality of semiannular tension bars <NUM> and mated with the second compression plate <NUM>. The clamping plate <NUM> may be attached to the semiannular tension bars <NUM> at one or more attachment points <NUM> with a plurality of bolts or the like. The clamping plate <NUM> includes a plurality of compression shoes <NUM>, each configured to apply a variable amount of compression to the magnetic-core assembly <NUM> by adjusting a compression bolt <NUM> corresponding a respective compression shoe <NUM>.

Any number of compression shoes <NUM> may be provided. For example, the number of compression shoes <NUM> in a magnetic-core assembling tool <NUM> may range from <NUM> to <NUM> shoes, from <NUM> to <NUM> shoes, from <NUM> to <NUM> shoes, from <NUM> to <NUM> shoes, from <NUM> to <NUM> shoes, or from <NUM> to <NUM> shoes. As the compression shoes are tightened, compressive force is applied to the magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM>. The compressive force may be adjusted separately for each compression shoe <NUM>. Such separate adjustment may be utilized to apply a more uniform compression to the lamination stacks <NUM>.

<FIG> show another exemplary embodiment of a magnetic-core assembling tool <NUM>. The magnetic-core assembling tool <NUM> shown in <FIG> may be utilized to assemble a magnetic core assembly <NUM> that has been staged as described with reference to <FIG>. Additionally, or in the alternative, the magnetic-core assembling tool <NUM> shown in <FIG> may be utilized to assemble a magnetic core assembly <NUM> while concurrently staging the magnetic core assembly <NUM>, such as while concurrently staging the magnetic core assembly <NUM> within the magnetic-core assembling tool <NUM>. As shown in <FIG>, a magnetic-core assembling tool <NUM> includes a first compression plate alignment guide <NUM>, a plurality of semiannular tension bars <NUM>, a plurality of semiannular compression bars <NUM>, a second compression plate alignment guide <NUM>, and a clamping plate <NUM>. The plurality of semiannular tension bars <NUM> are each attached to the first compression plate alignment guide <NUM> at one or more attachment points <NUM> with a plurality of bolts or the like. When attached to the first compression plate alignment guide <NUM>, the plurality of semiannular tension bars <NUM> together define an annulus <NUM>.

As shown in <FIG>, a plurality of lamination stacks <NUM> are inserted within an internal annular space of the annulus <NUM> defined by the plurality of semiannular tension bars. The semiannular tension bars <NUM> respectively surround a semiannular portion of the lamination stacks <NUM>. The semiannular tension bars <NUM> include one or more lamination stack aligning surfaces <NUM> The lamination stack aligning surfaces <NUM> are defined at least in part by an internal annular surface of an annulus <NUM> defined by the semiannular tension bars <NUM>. The lamination stack aligning surfaces <NUM> are configured to precisely abut one or more outward facing surfaces <NUM> of the lamination stacks <NUM>, thereby further aligning the lamination stacks <NUM> with one another and/or with the compression plates <NUM>, in each case within required tolerances for cylindricity, concentricity, perpendicularity, parallelism, and/or angularity, and the like. For example, the lamination stack aligning surfaces <NUM> may abut the one or more outward facing surfaces <NUM> of the lamination stacks <NUM> with a tolerance of from <NUM> to <NUM> mils (<NUM>,<NUM>) such as from <NUM> to <NUM> mils (<NUM>,<NUM>), such as from <NUM> to <NUM> mils (<NUM>,<NUM>) , such as from <NUM> to <NUM> mils (<NUM>,<NUM>). A magnetic-core assembling tool <NUM> may include any number of semiannular tension bars <NUM>.

As shown in <FIG>, a plurality of permanent magnets <NUM> may be inserted into the magnet retention slots <NUM>. The permanent magnets <NUM> may be inserted into the magnet retention slots <NUM> after the lamination stacks <NUM> have been positioned within the annular space of the annulus <NUM> defined by the plurality of semiannular tension bars <NUM>. Additionally, or in the alternative, the permanent magnets <NUM> and the lamination stacks <NUM> may be inserted sequentially within the annular space of the annulus <NUM> defined by the plurality of semiannular tension bars <NUM> as described with reference to <FIG>. However, in some embodiments, the lamination stacks <NUM> may be inserted sequentially within the annular space of the annulus <NUM> defined by the plurality of semiannular tension bars <NUM> without the use of guideposts <NUM>. For example, the guideposts <NUM> may be unnecessary at least in part because of the degree of tolerance with which the lamination stacks <NUM> may be aligned by the lamination stack aligning surfaces <NUM> of the plurality of semiannular tension bars <NUM>. As shown in <FIG>, a second compression plate <NUM> may be added to the plurality of lamination stacks <NUM>.

As shown in <FIG>, the plurality of semiannular tension bars <NUM> may be configured with a height such that each of the plurality of lamination stacks <NUM> may have a protruding portion <NUM> that extend outward beyond the annular space of the annulus <NUM> defined by the plurality of semiannular tension bars <NUM>. The plurality of lamination stacks <NUM> may be compressed by the plurality of semiannular compression bars <NUM> by least a portion of the distance that the protruding portion <NUM> extends beyond the annular space of the annulus <NUM>.

Referring now to <FIG> and <FIG>, the plurality of semiannular compression bars <NUM> may be respective attached to one or more of the plurality of semiannular tension bars <NUM> at one or more attachment points <NUM> with a plurality of bolts or the like. As shown in <FIG>, in some embodiments, an exemplary method <NUM> of assembling a magnetic-core assembling tool <NUM> may include fitting a plurality of lamination stacks <NUM> within a space surrounded by the plurality of semiannular tension bars, such as prior to staging the plurality of lamination stacks <NUM> (block <NUM>). For example, the magnetic core assembly <NUM> may be staged within a partially assembled magnetic-core assembling tool <NUM>.

An exemplary method <NUM> may include attaching a plurality of semiannular compression bars <NUM> to the plurality of semiannular tension bars <NUM> (block <NUM>). A first end of the respective ones of the plurality of semiannular compression bars <NUM> may be attached to a second end of one or more of the plurality of semiannular tension bars <NUM>. An exemplary method <NUM> may include fitting a second compression plate alignment guide to a second compression plate <NUM> and/or within a spaced surrounded by the plurality of semiannular compression bars <NUM> (block <NUM>). An exemplary method <NUM> may include attaching a clamping plate <NUM> to the plurality of semiannular compression bars <NUM> with a second end of each semiannular compression bar <NUM> attached to the clamping plate <NUM> (block <NUM>).

As shown in <FIG>, by attaching the respective semiannular compression bars <NUM> to the plurality of semiannular tension bars <NUM>, a plurality of lamination stacks <NUM> surrounded by the plurality of semiannular tension bars <NUM> by the plurality of semiannular compression bars <NUM>. For example, the plurality of lamination stacks <NUM> may be at least partially compressed such that at least part of the protruding portion <NUM> of the plurality of lamination stacks <NUM> may be moved within the annular space of the annulus <NUM> defined by the plurality of semiannular tension bars <NUM>. In some embodiments, the protruding portion <NUM> of the plurality of lamination stacks <NUM> may be aligned with an end portion of the plurality of semiannular tension bars <NUM>, such as an end portion of the plurality of semiannular tension bars that faces the plurality of semiannular compression bars <NUM>. Attachment points <NUM> where the semiannular compression bars <NUM> attach to the semiannular tension bars <NUM> are precisely located. When attached to the plurality of semiannular tension bars <NUM>, the plurality of semiannular compression bars <NUM> may together define an annulus <NUM> with an internal annular surface that surrounds the second compression plate <NUM>. A magnetic-core assembling tool <NUM> may include any number of semiannular compression bars <NUM>.

The semiannular compression bars <NUM> may include one or more compression plate aligning surfaces <NUM>. The compression plate aligning surfaces <NUM> may be defined at least in part by an internal annular surface of an annulus <NUM> defined by the semiannular compression bars <NUM>. The compression plate aligning surfaces <NUM> may be configured to precisely abut one or more outward facing surfaces <NUM> of the second compression plate <NUM>, thereby contributing to alignment of the second compression plate <NUM> with the magnetic-core assembly <NUM>, for example, within required tolerances for cylindricity, concentricity, perpendicularity, parallelism, and/or angularity, and the like. For example, the compression plate aligning surfaces <NUM> may abut the one or more outward facing surfaces <NUM> of the second compression plate <NUM> with a tolerance of from <NUM> to <NUM> mils (<NUM>,<NUM>) such as from <NUM> to <NUM> mils (<NUM>,<NUM>), such as from <NUM> to <NUM> mils (<NUM>,<NUM>) , such as from <NUM> to <NUM> mils (<NUM>,<NUM>).

Referring to <FIG> and <FIG>, the second compression plate alignment guide <NUM> includes at least one alignment guide mating surface <NUM> configured to precisely mate with at least one compression plate mating surface <NUM> of the second compression plate <NUM> at one or more annular mating surfaces and/or one or more lateral mating surfaces. The second compression plate alignment guide <NUM> may be inserted axially into the internal annular space of the annulus <NUM> defined by the plurality of semiannular compression bars <NUM> and mated with the second compression plate <NUM>, for example, after the plurality of semiannular compression bars <NUM> have been attached to the plurality of semiannular tension bars <NUM>. Alternatively, the second compression plate alignment guide <NUM> may be mated with the second compression plate <NUM> prior to inserting the second compression plate <NUM> into the axially into the internal annular space of the annulus <NUM> defined by the plurality of semiannular compression bars <NUM> and mated with the second compression plate <NUM>. The one or more compression plate aligning surfaces <NUM> may be configured to precisely abut one or more outward facing surfaces <NUM> of the second compression plate alignment guide <NUM>, thereby helping to align the second compression plate <NUM> and/or the lamination stacks <NUM> within required tolerances for cylindricity, concentricity, perpendicularity, parallelism, and/or angularity, and the like. For example, the compression plate aligning surfaces <NUM> may abut the one or more outward facing surfaces <NUM> of the second compression plate alignment guide <NUM> with a tolerance of from <NUM> to <NUM> mils (<NUM>,<NUM>) such as from <NUM> to <NUM> mils (<NUM>,<NUM>), such as from <NUM> to <NUM> mils (<NUM>,<NUM>) , such as from <NUM> to <NUM> mils (<NUM>,<NUM>). In some embodiments, the combination of the first compression plate alignment guide <NUM>, the plurality of semiannular tension bars <NUM>, the plurality of semiannular compression bars <NUM>, and the second compression plate alignment guide <NUM> provides a system for aligning the lamination stacks <NUM> with one another and/or with the compression plates <NUM> with improved precision and tighter tolerances.

Referring to <FIG>, the clamping plate <NUM> may be attached to the plurality of semiannular compression bars <NUM> after the plurality of semiannular compression bars <NUM> have been attached to the plurality of semiannular tension bars <NUM> and the second compression plate alignment guide <NUM> has been inserted axially into the internal annular space of the annulus <NUM> defined by the plurality of semiannular compression bars <NUM> and mated with the second compression plate <NUM>. The clamping plate <NUM> may be attached to the semiannular compression bars <NUM> at one or more attachment points <NUM> with a plurality of bolts or the like. The clamping plate <NUM> includes a plurality of compression shoes <NUM>, each configured to apply a variable amount of compression to the magnetic-core assembly <NUM> by adjusting a compression bolt <NUM> corresponding a respective compression shoe <NUM>.

Referring now to <FIG>, in some embodiments, the clamping plate <NUM> may include a witness slot <NUM> to observe the position of a compression shoe <NUM>, and a compression shoe may include position markings <NUM> observable through the witness slot <NUM> to indicate the location of the compression shoe <NUM>. Some or all of the compression shoes <NUM> may include a witness slot <NUM>. The witness slots <NUM> may be used to confirm that each compression shoe <NUM> has compressed the lamination stacks <NUM> in the magnetic-core assembly <NUM> an axial distance within a required tolerance. Additionally, in some embodiments a compression shoe <NUM> may include a pressure sensor <NUM> such as a load cell to confirm that each compression shoe <NUM> has applied an axial compression pressure within a require tolerance. For example, a typical axial compression pressure tolerance may be from <NUM> to <NUM> megapascal, such as from <NUM> to <NUM> megapascal, such as from <NUM> to <NUM> megapascal, such as from <NUM> to <NUM> megapascal, or such as from <NUM> to <NUM> megapascal.

As shown in <FIG>, a magnetic-core assembling tool <NUM> may include three semiannular tension bars <NUM>. Alternatively, a magnetic-core assembling tool <NUM> may include two semiannular tension bars <NUM>, or more than three semiannular tension bars <NUM>, such as from <NUM> to <NUM> semiannular tension bars <NUM>. In various embodiments, annular gaps may exist between the respective semiannular tension bars <NUM>. As shown in <FIG>, a magnetic-core assembling tool <NUM> may include three semiannular compression bars <NUM>. Alternatively, a magnetic-core assembling tool <NUM> may include two semiannular compression bars <NUM>, or more than three semiannular compression bars <NUM>, such as from <NUM> to <NUM> semiannular tension bars <NUM>. In various embodiments, annular gaps may exist between the respective semiannular compression bars <NUM>. As shown in <FIG>, a plurality of semiannular tension bars <NUM> and a plurality of semiannular compression bars <NUM> may be configured to overlap one another. For example, a semiannular tension bar <NUM> may overlap two semiannular compression bars <NUM>, and a semiannular compression bar <NUM> may overlap two semiannular tension bars <NUM>.

It is preferable that the magnetic-core assembly <NUM> remain under constant axial compression compressed once the magnetic-core assembling tool <NUM> has been assembled and the magnetic-core assembly <NUM> axially compressed. Accordingly, the magnetic-core assembling tool <NUM> is configured such that subsequent assembly steps, such as those discussed below with respect to <FIG>, may be performed with the magnetic-core assembly <NUM> housed within the magnetic-core assembling tool <NUM>. For example, referring to <FIG>, an exemplary method <NUM> of assembling a magnetic-core assembly <NUM> may further include injecting magnet retention adhesive into a plurality of magnet retention slots <NUM> in a magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM> (block <NUM>). Additionally, the exemplary method <NUM> also optionally includes performing a machining operation on a magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM> (block <NUM>), and/or coupling a rotor shaft <NUM> to a magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM> (block <NUM>).

Referring now to <FIG>, exemplary methods of injecting magnet retention adhesive into a plurality of magnet retention slots <NUM> in the magnetic-core assembly <NUM> (block <NUM> of <FIG>) will be described. As shown in <FIG>, an exemplary method <NUM> of injecting magnet retention adhesive into a magnetic-core assembly <NUM> (block <NUM> of <FIG>) may include injecting magnet retention adhesive into one or more adhesive injection ports <NUM> in a compression plate <NUM> (block <NUM>). An exemplary method <NUM> may include flowing the magnet retention adhesive through an adhesive conduit <NUM> in the compression plate <NUM> and into one or more magnet retention slots <NUM> passing through a plurality of lamination stacks <NUM> of the magnetic-core assembly <NUM> (block <NUM>).

<FIG> shows magnet retention adhesive <NUM> being injected into a magnetic-core assembly <NUM>. As shown, the magnet retention adhesive <NUM> flows through one or more injection ports <NUM> leading to an adhesive conduit <NUM> in a compression plate <NUM>. The adhesive conduit <NUM> may include one or more magnet retention grooves <NUM>. The magnet retention adhesive <NUM> flow into one or more magnet retention slots <NUM> passing through a plurality of lamination stacks <NUM> of the magnetic-core assembly <NUM>. The magnet retention adhesive <NUM> is applied while permanent magnets are present in the magnet retention slots <NUM>. The magnet retention adhesive <NUM> flows through the space between the permanent magnets and the edges of the magnet retention slots <NUM> across the axial length of the magnet retention slots <NUM>. In some embodiments, a witness slot (not shown) may be provided to confirm full penetration of the magnet retention adhesive <NUM>. The magnet retention adhesive <NUM> is applied while the lamination stacks <NUM> are under axial compression applied by the magnetic-core assembling tool <NUM>. As such, in contrast with adhesives that may be applied across the face of laminations, the magnet retention adhesive <NUM> remains substantially within the magnet retention slots <NUM>. It will be appreciated that although an insignificant amount of magnet retention adhesive <NUM> may contact the interface between the edges and faces of the lamination stacks <NUM>, the axial compression applied by the magnetic-core assembling tool <NUM> would prevent magnet retention adhesive <NUM> from flowing across the face of the laminations (e.g., across the face of the lamination stacks <NUM>, the lamination sub-stacks <NUM>, and/or the individual laminations <NUM>). The magnet retention adhesive <NUM> may include any suitable adhesive or combination of adhesives.

Referring to <FIG>, in some embodiments, injecting the magnet retention adhesive (block <NUM>) concludes the exemplary method <NUM> of assembling a magnetic-core assembly <NUM>, in which case the assembled magnetic-core assembly <NUM> may be removed from the magnetic-core assembling tool <NUM> after the magnet retention adhesive <NUM> has sufficiently cured. However, in other embodiments the exemplary method <NUM> may additionally include performing a machining operation on the magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM> (block <NUM>), and/or coupling a rotor shaft <NUM> to a magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM> (block <NUM>). The machining operation (block <NUM>) and/or the coupling of the rotor shaft <NUM> (block <NUM>) to the magnetic-core assembly <NUM> are performed while the magnetic-core assembly <NUM> remains housed in the magnetic-core assembling tool <NUM>. The magnetic-core assembling tool <NUM> helps to maintain proper compression and alignment of the magnetic-core assembly <NUM> and reduces the possibility of warping, shifting of laminations <NUM>, or damage when performing these steps. Preferably, the magnetic-core assembly <NUM> is maintained under constant axial compression in the magnetic-core assembling tool <NUM> until each step in the assembly process has been completed and the magnetic-core assembly <NUM> is at ambient temperature.

As shown in <FIG>, an exemplary method <NUM> of performing a machining operation on a magnetic-core assembly <NUM> (block <NUM> of <FIG>) includes passing a machining tool through an annular passageway defined by an inner surface of the magnetic-core assembling tool <NUM> (block <NUM>), machining an inward facing surface of the magnetic-core assembly <NUM> using the machining tool (block <NUM>), and optionally removing the magnetic-core assembly <NUM> from the magnetic-core assembling tool <NUM> with the magnetic-core assembly <NUM> at an ambient temperature (block <NUM>). <FIG> schematically depicts a machining tool performing a machining operation (arrow <NUM>) on an inward facing surface <NUM> of a magnetic-core assembly <NUM> housed in a magnetic-core assembling tool <NUM>. The machining operation (block <NUM>) provides an annular inner surface <NUM>, which for example may define an annular rotor shaft receiving space <NUM> for receiving a rotor shaft <NUM>. The machining operation may include boring, turning, drilling, reaming, milling, cutting, combinations thereof, or the like. The machining operation may smoothen and or apply a texture to the annular inner surface <NUM> and/or may conform the diameter of the annular rotor shaft receiving space <NUM> to accommodate a rotor shaft <NUM> that has a particular outer diameter.

As shown in <FIG>, the machining tool removes a portion of the inner surface <NUM> of the lamination stacks <NUM>. In some embodiments, the portion of the inner surface <NUM> removed by the machining tool includes the tacking adhesive <NUM> placed at one or more locations of the one or more inward facing surfaces <NUM> of the laminations <NUM>, as discussed with respect to <FIG>. As such, the machining tool may remove the tacking adhesive <NUM> used to temporarily hold the laminations <NUM> in position when assembling the lamination stacks <NUM> and the lamination sub-stacks <NUM>. With the tacking adhesive <NUM> removed by the machining operation, the magnet retention adhesive <NUM> may be the only adhesive in the assembled magnetic-core assembly <NUM>.

Referring to <FIG>, in some embodiments, performing a machining operation on the magnetic-core assembly <NUM> (block <NUM>) concludes the exemplary method <NUM> of assembling a magnetic-core assembly <NUM>, in which case the assembled magnetic-core assembly <NUM> may be removed from the magnetic-core assembling tool <NUM> after the machining operation (block <NUM>) has been completed. When removing the magnetic-core assembly <NUM> after performing the machining operation (block <NUM>), it is preferable to remove the magnetic-core assembling tool <NUM> when the magnetic-core assembly <NUM> is at ambient temperature to reduce the possibility of warping or shifting of laminations <NUM> due to changes in temperature. For example, the machining operation (block <NUM>) may generate heat in various regions of the magnetic-core assembly <NUM>, which may or may not be uniformly distributed. Even a partial release of compression on the magnetic-core assembly <NUM> before such heat dissipates or when the magnetic-core assembly <NUM> is not at ambient temperature may cause warping or shifting of laminations <NUM>. Accordingly, the magnetic-core assembly <NUM> preferably remains under constant axial compression until each step in the exemplary method <NUM> have been completed and the magnetic-core assembly <NUM> is at ambient temperature and ready to be removed from the magnetic-core assembling tool <NUM>.

The exemplary method <NUM> of assembling a magnetic-core assembly <NUM> may additionally or alternatively include coupling a rotor shaft <NUM> to a magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM> (block <NUM>). As shown in <FIG>, an exemplary method <NUM> of coupling a rotor shaft <NUM> to a magnetic-core assembly <NUM> housed in the magnetic-core assembling tool <NUM> (block <NUM> of <FIG>) includes heating the magnetic-core assembly <NUM> and the magnetic-core assembling tool <NUM> to a prescribed thermal expansion temperature (block <NUM>) and/or cooling a rotor shaft <NUM> to a prescribed thermal contraction temperature (block <NUM>), inserting the rotor shaft <NUM> through an annular rotor shaft receiving space <NUM> of the magnetic-core assembly <NUM> (block <NUM>), and removing the magnetic-core assembly <NUM> from the magnetic-core assembling tool <NUM> with the magnetic-core assembly <NUM> and the rotor shaft <NUM> at an ambient temperature (block <NUM>).

<FIG> schematically depicts a magnetic-core assembly <NUM> and a magnetic-core assembling tool <NUM> heated to a prescribed thermal expansion temperature, and a rotor shaft <NUM> cooled to a prescribed thermal contraction temperature. The prescribed thermal expansion temperature, the prescribed thermal contraction temperature, or a combination thereof are selected so as to allow the rotor shaft <NUM> to pass through the annular rotor shaft receiving space <NUM> without excessive interference from contact between the rotor shaft <NUM> and the annular inner surface <NUM> defining the annular rotor shaft receiving space <NUM>. The magnetic-core assembly <NUM> and the magnetic-core assembling tool <NUM> may be heated in a furnace or the like until the prescribed thermal expansion temperature is reached. The rotor shaft <NUM> may be cooled in a freezer or with a cryogenic fluid such as liquid nitrogen until the prescribed thermal cooling temperature is reached. In some embodiments, the magnetic-core assembling tool <NUM> may include one or more flange-receiving grooves or recesses <NUM> configured to receive a flange <NUM> on the driveshaft.

Referring to <FIG>, some embodiments, coupling the rotor shaft <NUM> to the magnetic-core assembly <NUM> (block <NUM>) concludes the exemplary method <NUM> of assembling a magnetic-core assembly <NUM>, in which case the assembled magnetic-core assembly <NUM> may be removed from the magnetic-core assembling tool <NUM> after the coupling step (block <NUM>) has been completed. Preferably the magnetic-core assembly <NUM> remains under constant axial compression until the magnetic-core assembly <NUM> returns to ambient temperature following heating and/or cooling performed for inserting the rotor shaft <NUM> through the annular rotor shaft receiving space <NUM>. Accordingly, preferably the magnetic-core assembly <NUM> is allowed to cool to ambient temperature and/or the rotor shaft <NUM> is allowed to warm to ambient temperature before removing the magnetic-core assembly <NUM> from the magnetic-core assembling tool <NUM>.

Various components of the magnetic-core assembling tool <NUM> and/or various components of the stack assembling-tool <NUM> may be manufactured using any desired technology, including casting, subtractive manufacturing (e.g., machining, drilling, etc.), additive manufacturing, a combination thereof, or any other technique. In an exemplary embodiment, a machining process may be used to form one or more components of the of the magnetic-core assembling tool <NUM>, including the first compression plate alignment guide <NUM>, the plurality of semiannular tension bars <NUM>, second compression plate alignment guide <NUM>, and/or the clamping plate <NUM>.

As shown in <FIG>, an exemplary method <NUM> of fabricating a magnetic-core assembling tool <NUM> includes fabricating a first compression plate alignment guide <NUM> (block <NUM>), attaching a workpart to the first compression plate alignment guide <NUM> (block <NUM>), machining a plurality of lamination stack aligning surfaces into the workpart (block <NUM>), and machining the workpart into a plurality of semiannular tension bars <NUM> (block <NUM>). <FIG> shows a workpart <NUM> attached to a first compression plate alignment guide <NUM>. <FIG> shows a plurality of lamination stack aligning surfaces <NUM> having been machined into the workpart <NUM>. <FIG> shows a portion of the workpart <NUM> having been machined into a plurality of semiannular tension bars <NUM>.

An exemplary method <NUM> of fabricating a magnetic-core assembling tool <NUM> may additionally or alternatively include machining a plurality of compression plate aligning surfaces into the workpart (block <NUM>), and machining the workpart into a plurality of semiannular compression bars <NUM> (block <NUM>). <FIG> shows a portion of the workpart <NUM> having been machined into a plurality of semiannular compression bars <NUM>.

In another exemplary embodiment, a magnetic-core assembling tool <NUM> may be manufactured at least in part using an additive manufacturing process, which may include any process that involves layer-by-layer construction or additive fabrication (as opposed to material removal as with subtractive manufacturing processes). Such processes may also be referred to as "rapid manufacturing processes". Additive manufacturing processes include, but are not limited to: Direct Metal Laser Melting (DMLM), Laser Net Shape Manufacturing (LNSM), electron beam sintering, Selective Laser Sintering (SLS), 3D printing, such as by inkjets and laserjets, Sterolithography (SLA), Electron Beam Melting (EBM), Laser Engineered Net Shaping (LENS), and Direct Metal Deposition (DMD).

Claim 1:
A method (<NUM>) of assembling a magnetic-core assembly (<NUM>), the magnetic-core assembly (<NUM>) including a magnetic-core (<NUM>) made up of a plurality of lamination stacks (<NUM>) clamped between a first and a second compression plate (<NUM>), the method (<NUM>) comprising:
assembling a plurality of lamination stacks (<NUM>);
staging the plurality of lamination stacks (<NUM>) to provide a magnetic-core assembly (<NUM>);
assembling a magnetic-core (<NUM>) assembling-tool around the magnetic-core assembly (<NUM>); and
injecting magnet retention adhesive (<NUM>) into a plurality of magnet retention slots (<NUM>) in the magnetic-core assembly (<NUM>) housed in the magnetic-core assembling tool (<NUM>);
wherein assembling the magnetic-core (<NUM>) assembling-tool around the magnetic-core assembly (<NUM>) comprises:
fitting a first compression plate alignment guide (<NUM>) to the first compression plate (<NUM>) of the magnetic-core assembly (<NUM>);
attaching a plurality of semiannular tension bars (<NUM>) to the first compression plate alignment guide (<NUM>), a first end of each semiannular tension bar (<NUM>) attached to the first compression plate alignment guide (<NUM>);
fitting a second compression plate alignment guide (<NUM>) to the second compression plate (<NUM>) of the magnetic-core assembly (<NUM>) and/or within a space surrounded by the plurality of semiannular tension bars (<NUM>); and
attaching a clamping plate (<NUM>) to the plurality of semiannular tension bars (<NUM>), a second end of each semiannular tension bar (<NUM>) attached to the clamping plate (<NUM>);
wherein the semiannular tension bars (<NUM>) include one or more lamination stack aligning surfaces (<NUM>) defined by an internal annular surface of an annulus (<NUM>) defined by the semiannular tension bars (<NUM>) and configured to precisely abut the outward facing surfaces (<NUM>) of the lamination stacks (<NUM>), thereby further aligning the lamination stacks (<NUM>) with one another and/or with the compression plates (<NUM>).