Patent Description:
Currently, electric motor rotor and stators utilize cores created from laminations produced from a multitude of stamped electrical sheet steel stacked vertically together. A stamping press is fed a single sheet and is used to punch individual single sheets via progressive stamping. It is preferable to create the laminations from coated electrical sheet steel which is as thin as possible (< <NUM>) to maintain electromagnetic isolation between the sheets to improve the electric motor performance and efficiency. These individual sheets are then stacked and assembled to from a multiple layer lamination. The method known to connect the individual sheets into laminations includes mechanically mating via welding or interlock. Bonding the sheets together with epoxy adhesives, backlack bonding varnish, or other adhesives to form the rotor or stator core have also been utilized. The thinness of the material results in limitations to the effectiveness for mechanical mating or welding techniques, so adhesives are now preferred. Currently utilized epoxy-based adhesives or backlack bonding varnish require significant heat curing processes which increase the energy usage and cycle time to form a finished lamination stack. Therefore, there is a need to improve the rotor or stator lamination production process.

<CIT> discloses a method for manufacturing a laminated core, comprising: a punching, laminating and fixing step; a step of impregnating the laminate obtained by the punching, laminating and fixing step with a thermosetting adhesive; and a step of drying and baking the laminated body, wherein the punching, laminating and fixing step comprises that a fixed laminated body is obtained by continuously punching a soft magnetic steel strip and simultaneously laminating and fixing a plurality of soft magnetic steel plates obtained by the punching step.

<CIT> discloses a punching method, comprising the steps of preparing a wound body of at least two electromagnetic steel sheets; supplying a workpiece consisting of at least two electromagnetic steel sheets pulled out from each of the wound bodies and fixed to each other in a stacked state to a die; and punching the workpiece in the die, wherein the widths of the two electromagnetic steel sheets constituting the two wound bodies are different from each other.

<CIT> discloses a Method for producing a sheet metal stack, in particular an electrical sheet metal package, the method comprising the following: coating one or more sheets with a connecting material; connecting a plurality of sheets to form a sheet metal laminate by a first activation of the connecting material; dividing the sheet metal laminate to produce a plurality of sheet metal laminate units and/or dividing a plurality of sheet metal laminate units out of the sheet metal laminate; and connecting the plurality of sheet metal laminate units to form a sheet metal stack by a second activation of the connecting material, wherein one or more parameters differ from one another in the first activation and the second activation.

It is an object of the disclosure to provide an improved rotor or stator lamination process. In one aspect, the process includes stamping more than a single layer with each stroke of the press and joining the layers together with an improved adhesive technology and application method.

The object is achieved by a method of producing a lamination stack assembly for electrical components as disclosed in claim <NUM>.

The method disclosed relates to creating a multilayer arrangement of thin sheet material joined together by adhesive prior to further processing in line with a stamping press for creation of a lamination stack for rotors and stators of an electric motor. The disclosure further describes alternative adhesive types, application methods, and adhesive application geometries to form the multilayer sheet component and to construct the final lamination stack assembly using two or three adhesive application stations.

The sheet steel materials proposed are electrical steel which is a soft magnetic material with enhanced electrical properties. Electrical steel can also be referred to as silicon steel due to the increased silicon content. Typical thickness of the electrical steel used in lamination applications is between <NUM> and <NUM> thickness. The sheet material is received with a coating (i. e AISI-ASTM A <NUM>-<NUM> standard C3, C5, or C7) utilized to insulate the electrical steel sheets to increase electrical resistance between laminations, reduce eddy currents, provide resistance to corrosion, and to act as a lubricant during the stamping process. The adhesives and activators proposed in this disclosure are functional with the coatings typically used as described above and require no additional backlack. The electrical sheet steel utilized in this process can either be non-grain-oriented electrical steel (NGOES) or grain-oriented electrical steel (GOES), but non-grain-orientated electrical steel (NGOES) is preferred in rotor and stator laminations as specifically described in this disclosure. Optionally, an iron-based low loss amorphous material may be utilized when in a form with similar thickness to the silicon steels described.

The adhesives for creating the bonds between the layers to form the multilayer construction, and later in the process to produce the lamination stack, are of either anaerobic or cyanoacrylate technology. The anaerobic adhesives cure in the absence of oxygen and may be, as an example, dimethacrylate ester, urethane acrylate, or urethane methacrylate chemical types. The cyanoacrylate adhesive is derived from ethyl cyanoacrylate and related esters. Activators to improve the bond of the anaerobic adhesives can also be optionally used to further promote curing effectiveness in a reduced timeframe. These adhesives and optional activators are chosen because they form strong bonds without the need to introduce significantly higher temperatures than room temperature, as seen in backlack or epoxy based adhesive systems. Due to the work and movement of the material through the multilayer forming device and lamination forming device processes, heating upwards of <NUM> Degrees C is naturally created within the formation of the multilayer lamination device. Further curing improvements may be accomplished if additional heat up to <NUM> Degrees C is added, which can be added via chambers surrounding the multilayer forming device prior to the stamping tool or surrounding the lamination assemblies. These temperatures and durations are well below those required for curing thermosetting epoxies and polyester resins used in other lamination assemblies. The adhesives disclosed are applied directly to the face of the coated sheet material or laminations prior to joining, and can be applied with a variety of dispersion methods. Dispersion of the adhesive onto the surface can be via contact or contactless methods. Contactless methods including spraying, applying a thin amount over a larger area, or discharging a specific amount from a nozzle in the form of a dot for localized application. Contact methods including rolling, depositing, screen printing, or wiping, and can also be used if larger areas are required to be covered by adhesive.

In another aspect, in combination with the anaerobic adhesives, an optional activator may be utilized to improve curing times, eliminate the need of elevated heat curing, and improve adhesive effectiveness between the coating layers. The activators proposed are solvent based, as an example methacrylate or acetone, which will clean the surface, activate the surfaces in preparation for contact with the anaerobic adhesive, and evaporate quickly. The activator may be applied to a separate surface than the anaerobic adhesive, and then the surfaces can be brought together under pressure. The pressure may be applied from the roll feeder when forming the multilayer material sheet, or the activation of the press when creating the lamination assemblies. As the activator and the adhesive application are done at different locations in the process, the activator applicator can be positioned in a manner to provide a time delay between when the activator is applied to the first surface and the adhesive is applied to the second surface to further promote adhesion when the surfaces are brought together. For instance, the activator application may be positioned prior to the single layer roll feeder, while the adhesive applicator of the first application station is positioned later in the process. For instance, the adhesive applicator could be located between the single layer roll feeder and the multilayer roll feeder, just prior to when the surfaces of the upper and lower layers are joined. The application of the activator can be the same contacting and non-contacting methods as described for the adhesive. The area where the activator is applied aligns with the area where adhesive is applied when the material faces are brought together for a proper bond.

Two processes to form a multilayer lamination assembly for a rotor and/or stator are provided. In both non-limiting examples, the multilayer sheet component formed has two layers, but the equipment and processes described can be expanded in parallel operations within the multilayer lamination device to create a multilayer material sheet with additional layers beyond two. For a two-layer design, a parallel process is utilized in a first section where two long, separate sheets of wound coil material are processed to ensure the material is flat and unwound using standard techniques. Each layer of material enters a first adhesive application station where adhesive is applied to the upper surface of the lower material layer while, optionally, an activator is applied to the lower surface of the upper later of material. Due to the thin viscosity of the adhesive, it is preferable to apply the adhesive to the upper surface of the lower layer, but if viscosity were to be increased, or the application method allows, the adhesive could potentially be applied to the lower surface of the upper layer as well. In such an arrangement, the optional activator application surface would change to the opposite surface of where the adhesive is applied. The separate layers are brought together and compressed between rollers which results in the adhesive bonding the layers tightly together to create the multilayer material sheet. At this point, curing has begun within the ambient temperature of the environment. This multilayer material sheet is received in the form of a single combined sheet by the lamination forming device, which includes a second and third adhesive application station, as well as the stamping press to stamp and blank the single multilayer sheet into individual rotor and stator laminations, which are then assembled into rotor and stator lamination assemblies or stacks.

In a comparative example not belonging to the invention, a process includes two adhesive application stations. A first adhesive application station is used to bond the multilayer sheet component together while the second adhesive application station dispenses adhesive to form a lamination stack from lamination plates blanked from the multilayer sheets. The second adhesive application station applies adhesive prior to any stamping or blanking operations to create the stator or rotor lamination plates, and applies adhesive and an optional activator to the surface of the multilayer sheet in a variety of patterns further described.

The process according to the invention uses the same first adhesive application station for bonding of the multilayer sheet, but a second and third adhesive application stations are positioned within the stamping tool. The second adhesive application occurs immediately prior to the blanking of the rotor lamination plate, while the third adhesive application occurs immediately prior to the blanking of the stator lamination plate. Blanking shall be understood as the final stamping operation to separate the rotor or stator lamination plate from the combined multilayer material sheet. Further according to the invention, adhesive is applied immediately prior to the blanking operation to specific areas that become the rotor or stator lamination plates to reduce contamination with the stamping tool. This adhesive applied at stations two and three is done in preparation for creating a stack of laminations to form the rotor and/or stator lamination assembly. The method of applying the adhesive and optional activator to the various surfaces will be described in further detail, but the intention is to apply adhesive in order to bond the individual blanked sheets together to form the lamination stack of the rotor and stator. Because the remaining unused scrap material of the multilayer sheet leaves the lamination forming device, the overall process creates a fully bonded stator lamination stack assembly and a rotor lamination stack assembly in an optimized manner.

In one aspect, the adhesive application stations apply the adhesive and the optional activator in a variety of ways. It was previously described how the application system can deposit adhesives onto the surfaces of the electrical steel in different methods, but the pattern that is utilized by the application system can also be varied at the different adhesive application stations. In each of the pattern designs, which will be described in further detail herein, there is a balance between the amount of adhesive used, the accuracy requirement of the adhesive application location, and potential adhesive contamination on the punching tools. Each pattern may also have a different influence on the final functionality of the electrical motor, due to impacts to the electromagnetic performance if there is a loss of isolation between layers at the edges of the laminations. This effect is due to the creation of a burr on the cut edge. The adhesive patterns range from full-face bonding, where the entire surface of the coil has adhesive applied, to a dot bonding approach where adhesive is only applied to select local areas within the final stator or rotor lamination. In one aspect, there can be a difference to the amount and pattern of the adhesive applied at each of the adhesive application stations. Also, an optional activator may be applied in a similar patterned approach as the adhesive, varying between full coverage or localized application. In the case of a localized application, such as dots, the activator and the adhesive are deposited on the separate surfaces in a controlled positional manner that will result in an alignment and interaction when the separate layers are brought together. If a particular adhesive, which requires activator to cure, contacts the opposite layer and no activator is present proper bonding will not occur. However, adhesive that does not require an activator to cure, but that may still use an activator, may still bond in the event the activator is not present in a matching area.

Utilizing these adhesive compositions and application methods without requiring elevated curing temperatures to create a multilayer sheet prior to introduction into a stamping press provides an efficient and cost-effective approach to producing lamination stacks for rotors and stators. Utilizing the method described, overall production time is reduced with reduced operational costs due to creating and utilizing a multilayer material sheet as the blank material for the laminations, and not requiring significantly increased temperatures to bond the layers of the lamination assembly together.

It is a related aspect of the present disclosure to form the multilayer material component in line with and to feed it directly to the stamping press to form the final lamination assembly.

It is a related aspect of the present disclosure to utilize existing high-speed stamping techniques to stamp a multiple layer construction, reducing the overall cycles required and reducing handling to produce a complete lamination stack assembly.

It is a related aspect of the present disclosure that the multilayer construction can be formed from two, three, four or more individual layers depending on the stamping process and overall thickness of the single sheet material.

It is a related aspect of the present disclosure to form the multilayer construction from layers of differing material thicknesses or material types to create a non-homogeneous structure.

It is an aspect of the present disclosure to utilize an adhesive technology that cures at room temperature or at a slightly elevated temperature sufficiently enough to form a multiple layer sheet product in line with and between a decoiler and the stamping press.

It is a related aspect of the present disclosure to utilize anaerobic or cyanoacrylate adhesive technology types.

It is a related aspect of the present disclosure to utilize a single adhesive type through the full process of creating a rotor and/or stator lamination.

It is a related aspect of the present disclosure to utilize an optional activator applied to the sheet steel material prior to the application of the adhesive to initiate curing action, improve curing times, reduce the need of high heat curing, and improve adhesive effectiveness.

It is a related aspect of this disclosure for the adhesive to be applied prior to the roll feeder that joins the individual sheets to create a stable single combined multilayer metal sheet construction for further pressing operations.

It is a related aspect of this disclosure for the optional activator to be applied earlier in the process than the adhesive to improve bonding in the formation of the multilayer metal sheet.

It is a related aspect of this disclosure to apply the adhesive above the individual sheet material and the optional activator from below the individual sheet material prior to the formation of the multilayer material.

It is a related aspect of this disclosure to apply the adhesive and/or optional activator for the lamination construction from above or below the combined multilayer material depending on tool design, and accuracy of the adhesive application.

It is a related aspect of this disclosure that the adhesive and/or activator may be applied by non-contacting spray, non-contacting or contact depositing, and/or brush or roll application methods.

It is an aspect of the present disclosure that the adhesive application for rotor and stator lamination construction can be applied to all required surfaces prior to any stamping operations at an adhesive application station positioned prior to the stamping tool or within the stamping tool.

It is an aspect of the present disclosure that the adhesive application for the rotor and the stator lamination construction can occur within the stamping tool immediately prior to a blanking operation of the rotor and stator lamination plates.

It is a related aspect of the present disclosure to apply adhesive immediately prior to the blanking operation of the rotor and stator lamination plates to reduce contamination to the stamping tool from the adhesive.

It is an aspect of this disclosure to provide a method of optimized adhesive application geometries to create a stable multilayer metal sheet, which may vary from the adhesive application geometries and adhesive volumes utilized to further create the lamination stack in order to optimize the amount of adhesive used.

It is a related aspect of this disclosure to apply the adhesive and/or activator in application geometries which vary from full face bonding to localized bonding positions including rings or dots of adhesive.

It is a related aspect of this disclosure to position the application of the optional activator on the first sheet layer in such a way that it will align with the adhesive applied in a similar position on the second sheet layer when they are brought together to form the multilayer sheet.

It is a related aspect of this disclosure that the location of the adhesive and/or optional activator application system can be adjusted in the X/Y plane to optimize the adhesive application location on the coil material.

According to the invention, the rotor and stator will be produced from same area of the sheet material, wherein the rotor lamination geometry will be formed from the material radially inward of the material utilized to form the stator lamination geometry.

It is a related aspect of the present disclosure to utilize butt welding to connect lengths of electrical sheet steel between the decoiler and the straightening machine to further improve throughput and reduce material handling.

These and other features and advantages of the present invention will become more readily appreciated when considered in connection with the following detailed description and appending drawings.

The drawings described herein are for illustrative purposes only of selected embodiments and are not intended to limit the scope of the present disclosure. The inventive concepts associated with the present disclosure will be more readily understood by reference to the following description in combination with the accompanying drawings, in which:.

It is to be recognized the example embodiments only are provided so that this disclosure will be thorough, and will fully convey the scope, which is ultimately defined by the claims, to those who are skilled in the art. Numerous specific details are set forth, such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that certain specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure or the claims. In some example embodiments, well-understood processes, well-understood device structures, and well-understood technologies are not described in detail. It will be further appreciated that reference made to particular aspects being optional does not imply that other aspects are not also optional in the absence of such a designation. It will be further appreciated that reference made to particular aspects being preferred does not imply that other aspects are not also preferred in the absence of such a designation.

<FIG> provides an overview of one comparative example of a multilayer lamination device <NUM>, which includes a multilayer forming device <NUM> followed directly by the lamination forming device <NUM>. The multilayer forming device <NUM> is shown in this example to join two layers of sheet material to create the multilayer material sheet <NUM>. Multilayer forming device <NUM> in this two-layer example includes an upper layer processing device <NUM> and a lower layer processing device <NUM>. If additional layers beyond two are required, additional layer processing devices as described would be positioned in parallel (for example above or below the two shown) prior to the lamination forming device <NUM> to create a multilayer material sheet <NUM> of three, four, or more layers.

For the two-layer multilayer material sheet <NUM> in this example, the upper layer processing device <NUM> receives the upper electrical sheet coil material <NUM>, removed from coil <NUM> by the decoiler <NUM> in conjunction with the single layer roll feeder <NUM> and coil puller <NUM> positioned at the end of the process. Note, the lower layer processing device <NUM> will receive the lower electrical sheet coil material <NUM> in a similar manner. The width of the electrical sheet coil materials <NUM> and <NUM> will be at minimum similar to the outside diameter of the stator and rotor stacks being manufactured. The material length will be significantly longer than the width allowing for a continuous feed of strip-like material to both the upper and lower layer processing devices <NUM> and <NUM>. To further increase production capability, a coil sheet welder may be included to butt weld <NUM> end portions of the coil material together to a starting portion of a replacement coil. In one aspect, the butt welding location may be between the decoiler <NUM> and the straightening machine <NUM>. This butt welding process can result in an endless strip of coil material provided to both the upper <NUM> and lower devices <NUM> of multilayer lamination device <NUM>, thereby increasing production and reducing handling requirements. The upper electrical sheet coil material <NUM> and lower electrical sheet coil material <NUM> are each fed into separate straightening machines <NUM> to flatten the material (due to being wound around the coil) to provide that the final lamination layers can lay parallel and tightly against each other when joined. The straightening machine <NUM> and the single layer roll feeder <NUM> for each layer may be positioned and operated at a feed rate to allow a strip loop <NUM> of loose material to hang freely in between. Each individual electrical sheet coil material <NUM> and <NUM> may pass thru a single layer roll feeder <NUM> to continue to move the material towards the first adhesive application station <NUM>. Up to this point in the process, the upper electrical sheet coil material <NUM> and lower electrical sheet coil material <NUM> have been processed thru the processing devices <NUM> and <NUM> in similar parallel processing steps. The above-described straightening machine <NUM> may also be optional, depending on the needs and performance of the process.

Continuing to refer to <FIG>, as each electrical sheet coil material <NUM> and <NUM> enters the first adhesive application station <NUM>, adhesive <NUM> is applied to the upper surface <NUM> of the lower electrical sheet coil material <NUM> by applicator <NUM>. The adhesive <NUM> is applied to the upper surface because it is easier to deposit the adhesive in the direction of gravity due to the viscosity of the adhesive. Optionally, at this location, activator <NUM> may be applied to the lower surface <NUM> of the upper electrical sheet coil material <NUM> via applicator <NUM> to improve bonding performance of adhesive <NUM>. It is possible the surfaces adhesive <NUM> and activator <NUM> could be applied to surfaces opposite of those described in this example as well. A predetermined distance "X" between the adhesive applicator <NUM> and multilayer roll feeder <NUM> will allow sufficient time for any chemical reactions required in preparation of bonding to occur before the optional activator <NUM>, adhesive <NUM>, and the surfaces <NUM> and <NUM> of the electrical sheet coil material <NUM> and <NUM> are brought together at the multilayer roll feeder <NUM>. If additional time is required for the optional activator <NUM> to prepare the surface and evaporate from the lower surface <NUM> of the upper electrical sheet coil material <NUM>, the activator applicator <NUM> may be positioned earlier in the process, for instance prior to the single layer roll feeder <NUM> as shown by 72A. After the adhesive <NUM> and the optional activator <NUM> are applied, the multilayer roll feeder <NUM> compresses each electrical sheet coil material <NUM> and <NUM> tightly together to create the multilayer material sheet <NUM>. The adhesive volume dispensed is selected to accomplish proper bonding between the layers without resulting in excessive adhesive oozing out between the layers, as this would be detrimental to further pressing operations. At this stage, curing begins and the materials are received by the lamination forming device <NUM> as a single piece combined multilayer material sheet <NUM> that provides the base material for forming the rotor and stator laminations, with bare coated electrical steel on the top <NUM> and bottom surface <NUM> of the multilayer material sheet <NUM>.

The adhesive applicator <NUM> may be X/Y adjustable relative to the layers, to ensure that the adhesive is applied within the projected final location of the lamination stamping that occurs. For instance, in adhesive applications in which the location of the adhesive is desired to be controllable, the goal is to apply the adhesive to functional areas of the resulting rotor and stator plates rather than across the entire surfaces. Thus, X/Y adjustment can be used to control the precise area where the adhesive is applied. Some example options for controlled adhesive application locations can be seen in <FIG>. For example, <FIG> illustrates an example of precise control of adhesive dots that avoid areas of windings or magnets.

Multilayer roll feeder <NUM> is illustrated as having a pair of opposing rollers feed and combine the two layers of material together following application of adhesive therebetween. However, it will be appreciated that this illustration is schematic, and that the illustration may also be applicable to a multi-layer roll feeder unit that includes a separate feeder and a separate <NUM> in <NUM> combiner. In this aspect, the feeder or feeders of multilayer roll feeder <NUM> may convey the layers forward in the process, with the <NUM>-in-<NUM> combiner applying force to put the layers together. While the main function of the <NUM>-in-<NUM> combiner is to apply the force, the rolling action will also provide the ability to advance the layers, in combination the other feeding mechanisms, at the same speed. The feeder mechanism of multilayer roll feeder <NUM> may be before or after the <NUM>-in-<NUM> combiner mechanism.

To precisely control the position of the coil material, in particular the lower electrical sheet coil material <NUM> upon which adhesive is applied at adhesive applicator <NUM>, the lower electrical sheet coil material <NUM> is held in tension during the process. This tensioning and controlled positioning of the lower electrical sheet coil material <NUM> ensures that the location of the applied adhesive <NUM> is correct relative to the actual location of the rotor lamination plate <NUM> and stator lamination plate <NUM> that are stamped out of the material. To achieve this tension and precise positioning, the feeder mechanism within multilayer roll feeder <NUM> acts as a master control, from which other feeders and/or pullers follow, including the bottom single-roll feeder <NUM>, the <NUM>-in-<NUM> combiner of the multilayer roll feeder <NUM>, and coil puller <NUM>. This arrangement ensures tension in the lower electrical sheet coil material <NUM> and a synchronized advancement of material through the process, which limits instances of curling up/down of the material, which could lead to separating of the electrical sheet coil materials <NUM>, <NUM> or slipping of the electrical sheet coil materials <NUM>, <NUM> relative to each other due to the differences in rolling forces between upper and lower electrical sheet coil materials <NUM>, <NUM>.

Moving to the right side of <FIG>, the multilayer material sheet <NUM> is received by the lamination forming device <NUM> positioned in line with the multilayer forming device <NUM>. The function of the lamination forming device <NUM> is to process the multilayer material sheet <NUM> into a bonded stack of a final rotor lamination assembly <NUM> and a final stator lamination assembly <NUM>. The lamination forming device <NUM> includes a second application station <NUM>, a stamping tool <NUM> positioned within a stamping press, and two separate stackers <NUM> for the final formation of the rotor and stator lamination assemblies <NUM> and <NUM>. Stamping tool <NUM> will progressively form features via stamping into the multilayer material sheet <NUM> via the vertical movement of punch <NUM> into a die (not depicted), resulting in an operation of blanking out an individual rotor lamination plate <NUM> from the center portion of the multilayer material sheet <NUM>, and then subsequently stamping features and then blanking out an individual stator lamination plate <NUM> from the surrounding remaining multi-layer material sheet <NUM> radially outward of the removed rotor portion.

<FIG> shows a simplified arrangement of a single stamping station to form the rotor and stator plates, but it should be understood the stamping tool <NUM> may include multiple stamping stations, each forming a variety of specific features, such as magnet pockets or winding slots, into the individual rotor and stator lamination plates <NUM> and <NUM> as the multilayer material sheet <NUM> is indexed thru the stamping tool <NUM>.

Continuing to refer to <FIG> details of the second application station <NUM> will be provided. Second application station <NUM> is positioned in the process line to be prior to any stamping operations. This positioning can include physically positioning the second application station <NUM> prior to the stamping tool <NUM> or integrating station <NUM> into stamping tool <NUM>. In this aspect, the multilayer material sheet <NUM> receives a second treatment of adhesive 62A and optional activator 68A from second application station <NUM>. This adhesive 62A and (optional) activator 68A are may be the same type and chemical composition as used earlier in the process. The adhesive 62A and (optional) activator 68A are applied in preparation for creating a combined stack of rotor and stator lamination assemblies <NUM> and <NUM> from rotor and stator lamination plates <NUM>, <NUM>. The rotor lamination assembly <NUM> is made of several dozen individually stamped ring-shaped rotor lamination plates <NUM>, with adhesive 62A located in between each layer of rotor lamination plates <NUM>. As the rotor lamination plates <NUM> are placed into stacker <NUM>, force from the stamping tool <NUM> is utilized to apply pressure to the stack as it is built from the bottom up in the stacker <NUM>, thereby bonding each rotor lamination plate <NUM> together. Once the targeted height of rotor lamination assembly <NUM> is achieved, the stack is removed from stacker <NUM> and the process of building up a new rotor lamination assembly <NUM> may begin again. The stator lamination assembly <NUM> is assembled in the same way. Creating and utilizing a multilayer material sheet <NUM> decreases the number of stamping operations to produce a given height lamination assembly, because multiple layers are processed via each stroke of the press rather than using a single layer material. In one aspect, heat may be utilized within the stackers <NUM> to form the stacked assemblies (for instance <NUM> degrees C). Otherwise, heat is generally not applied prior to this stage.

In this <FIG> comparative example, the second adhesive applicator <NUM> applies adhesive 62A to the top surface <NUM> of the multilayer material sheet <NUM> prior to the stamping operations of the rotor or stator lamination plates <NUM> and <NUM>. If an optional activator 68A is used, it is applied to the bottom surface <NUM> of the multilayer material sheet <NUM> via the second activator applicator <NUM>. The application of the adhesive 62A and activator 68A can be performed in a similar manner as described for the first adhesive application station <NUM>. Depending on the press configuration and environment for locating the second adhesive application station <NUM>, the surfaces which the adhesive 62A and activator 68A are applied to may be reversed. For instance, adhesive 62A could instead be applied to the bottom surface <NUM> of the multilayer material sheet <NUM>, particularly if during press operation the multilayer material sheet <NUM> is displaced in the vertical direction as it enters the stamping press, because this could facilitate easier displacement of adhesive 62A in a contacting method, because the applicator <NUM> could remain stationary while the multilayer material sheet <NUM> is brought into contact with the applicator. On the other hand, if the multilayer material sheet <NUM> has no vertical displacement as it travels towards the stamping press, it may facilitate applying the adhesive 62A on the surface via a spray or droplet in an easier manner from above. There will also be situations where adhesive 62A or (optional) activator 68A will be purposely not applied to the multilayer surface <NUM>, particularly when the stamped lamination from the multilayer material sheet 26is the starting bottom piece of a rotor and/or stator lamination assembly <NUM> and/or <NUM> or is the finishing top piece of the rotor and/or stator lamination assembly <NUM> and/or <NUM>.

The lamination forming device <NUM> described above (and modified lamination forming device <NUM>' described below) is preferably isolated from the structure of the roll feeders <NUM> and <NUM> and also isolated from the structure of coil puller <NUM>. This isolation increases accuracy of the lamination forming by reducing vibrations from the press that may otherwise propagate to the feeders/pullers.

In addition to the above-described controlled feeding and vibration isolation to improve accuracy, the upper and lower electrical sheet coil materials <NUM>, <NUM> may be mechanically interlocked with each other prior to the punching/stamping/blanking. This mechanical interlocking connection may be provided via a punch, such as an additional punch <NUM>, disposed prior to the punch <NUM> that creates rotor lamination plates <NUM>. This further punch <NUM> may be disposed within lamination forming device <NUM>, <NUM>' or outside of lamination forming device <NUM>, <NUM>' after multilayer roll feeder <NUM>. The mechanical interlocking connection 120a may be provided in a scrap portion <NUM> or <NUM> (See <FIG>), that does not become part of the final rotor or stator. This mechanical connection further maintains the locations of the electrical sheet coil materials <NUM>, <NUM> relative to each other.

provides an overview of an embodiment according to the invention of the multilayer lamination device <NUM> which again includes the multilayer forming device <NUM> followed directly by a modified lamination forming device <NUM>'. In this embodiment the function and features of the multilayer lamination device <NUM> as previously described remains unchanged, including the activator being optional. Lamination forming device <NUM>' is modified to position the second application station <NUM>' immediately prior to the blanking operation of the rotor lamination plate <NUM> and adding a third application station <NUM> immediately prior to the blanking operation of the stator lamination plate <NUM>. The application stations each include adhesive applicators and optional activator applicators. Stamping operations to form various features into the rotor and stator lamination plates <NUM> and <NUM> occur prior to the adhesive application. Second application station <NUM>' differs from second application station <NUM> of the first embodiment as it applies adhesive 62A and optional activator primarily to the area on multilayer material sheet <NUM> that becomes rotor lamination plate <NUM>, rather than to both rotor and stator areas. The third application station <NUM> applies adhesive 62B and optional activator 68B to the remaining material of multilayer material sheet <NUM> or specifically applied to the ring-shaped portion of material from which the stator lamination plate <NUM> is blanked or both areas.

It is preferred that adhesive 62A and 62B is applied in a manner which will result in minimal contact with punch <NUM> during the blanking process to reduce contamination. As described in the original embodiment, adhesives in the second and third application stations <NUM>' and <NUM> can apply adhesive and optional activator to either the top surface <NUM> or bottom surface <NUM> of multilayer material sheet <NUM> in the second application station <NUM>. In a similar manner, adhesive 62B and activator 68B are proposed to be of the same type and chemical composition as 62A and 68A. Due to the arrangement of alternating layers of bonding agent and lamination plates, the surfaces on which the second application station <NUM>' applies adhesive 62A will be the same surfaces as the third application station <NUM> applies adhesive 62B. The positioning of the second adhesive application station <NUM>' prior to the rotor blanking and the third adhesive application station <NUM> prior to the blanking of stator lamination plate <NUM> provides the benefit of reduced risk of glue contamination onto the tooling, because adhesive is applied immediately prior to the blanking operation. If adhesive 62A and 62B were to be applied by the applicators prior to the multiple pressing operations to form the magnet pockets and stator wire winding slots in the rotor lamination plates <NUM> and stator lamination plate <NUM>, it is likely punch <NUM> would be contaminated by the adhesives. Separating the second application station <NUM>' from the third application station <NUM> can also provide flexibility in the optional application of activator <NUM>, potentially staggering the time from activator application to adhesive application within the process, improving cure times at room temperatures. Other features previously described in the second application station <NUM> can also apply to the third application station <NUM>.

In one aspect, the system preferably does not include application of an activator at stations <NUM>, <NUM>, <NUM>', or <NUM> via applicators <NUM>, 72A, 68A, 68B. <FIG> and <FIG> each include illustrations of these applicators and applied activators in the event that application of the activator is desirable, but it will be appreciated that the provided illustration is not limiting and that such application is not required. Preferably, only adhesive is applied at the stations <NUM>, <NUM>, <NUM>' and <NUM>.

Each of the <FIG> depict a short length of coil material overlaid by an outline of rotor lamination plate <NUM> surrounding stator lamination plate <NUM>, and further show a variety of patterns that the adhesive <NUM> may applied to the coil material. These adhesive patterns can be applied at first adhesive application station <NUM> to form the multilayer material sheet <NUM>, or at the second application station <NUM> and third application station <NUM> to form the lamination assemblies <NUM> and <NUM>. As an example, the figures will each show how different patterns of adhesive <NUM> can be applied at the first adhesive application station <NUM> to the upper surface <NUM> of lower electrical sheet coil material <NUM>. It should be understood these figures can also describe patterns which the optional activator <NUM> would be applied in a similar arrangement as well, or where adhesive <NUM> can be applied at later stages in the process at application stations <NUM>, <NUM>' and <NUM>. Each figure will be representative of a short length <NUM> of the longer strip of lower electrical sheet coil material <NUM>. The width <NUM> of the material can be selected to be slightly wider than the outer diameter <NUM> of stator lamination plate <NUM> to utilize as much material as possible. Ring shaped stator lamination plate <NUM> includes a stator outer diameter <NUM> and a stator inner diameter <NUM>. The stator inner diameter <NUM> is slightly larger than the rotor outer diameter <NUM> of the rotor lamination plate <NUM>. Rotor lamination plate <NUM> will further include rotor inner diameter <NUM> that, when formed, will result in a circular scrap portion <NUM> removed from the center of the rotor lamination plate <NUM>. After the formation of the stator and rotor laminations <NUM> and <NUM>, the remaining portion of excess coil material <NUM>, with multiple circular shaped cutouts resulting from the stamping operation, will exit the lamination forming device <NUM> by the actions of coil puller <NUM>. The designs of the rotor lamination plate <NUM> and stator lamination plate <NUM> should not be considered limiting designs or arrangements, only an example to further explain the various patterns of adhesive applied. Features such as magnet pockets and stator wire winding slots can vary from application to application, and illustrations of such example designs herein shall not be limiting.

<FIG> represents a full-face bonding application of adhesive <NUM>. In this illustrated aspect, adhesive <NUM> is applied to substantially the full extent of the coil material <NUM> with consistent and complete coverage substantially entirely along length <NUM> and across width <NUM>. Advantages of this technique include, but are not limited to, that the highest strength and the stamping position of the stator and the rotor lamination plates <NUM> and <NUM> does not have to be as tightly controlled, because there is no positional relationship of the adhesive <NUM>, because it is covering the entire surface of the material from which the stator and the rotor lamination plates <NUM> and <NUM> are blanked. The compete coverage arrangement also improves isolation between the layers, because there is guaranteed to be adhesive across the entire face of the rotor or stator lamination plates <NUM> and <NUM>. Because adhesive <NUM> is applied to the scrap material portions <NUM> and <NUM>, excessive adhesive is used. One drawback is, because adhesive <NUM> is applied across the entire surface, the punch <NUM> could become contaminated with adhesive <NUM> because it will cut into areas which have been covered by adhesive.

<FIG> represents a full-face bonding application of adhesive <NUM>, similar to <FIG>, except with adhesive not applied within the circular scrap portion <NUM>. Adhesive <NUM> has been applied nearly to the full extent of the coil material covering the surface along length <NUM> and across width <NUM>, with the exception of the portion inward of the rotor inner diameter <NUM> that will become the scrap portion <NUM>. Because the circular scrap portion <NUM> is not included in the final lamination assembly the lack of adhesive <NUM> has no impact on functionality. Advantages of this technique include, but are not limited to, maintaining the highest strength, because within the lamination the layers are fully bonded; however, some alignment is required to ensure that the rotor lamination plate <NUM> is stamped from the area where adhesive <NUM> has been applied. Isolation between layers is still guaranteed because adhesive covers the entire face of the rotor and stator lamination plates <NUM> and <NUM>. Because adhesive <NUM> is not applied to scrap portions <NUM>, some adhesive material is saved, but adhesive <NUM> is still applied to the outer scrap material portion <NUM>. Punch <NUM> may still become contaminated when stamping through the adhesive in areas outward of rotor inner diameter <NUM>.

<FIG> represents an optimized pattern of applied adhesive which maintains the full face contact across the areas of the final stamped portion of the rotor and stator lamination plate <NUM> and <NUM>, but eliminates the waste of adhesive <NUM> on surfaces which become scrap later in the process. Adhesive <NUM> is applied fully from the rotor inner diameter <NUM> to the stator outer diameter <NUM>.

Because areas where adhesive <NUM> is not applied are not included in the final lamination assembly, there is no negative impact on functionality in the final product. Advantages of this technique include, but are not limited to, maintaining the highest strength because within the lamination the layers are fully bonded, but alignment is required to ensure the rotor lamination plate <NUM> and stator lamination plate <NUM> are stamped from the areas where adhesive <NUM> has been applied. Isolation between layers is still guaranteed because adhesive is covering the entire face of the rotor or stator lamination plates <NUM> and <NUM>. Because adhesive <NUM> is not applied to scrap material portions <NUM> or <NUM>, the adhesive material applied is fully utilized in the final rotor and stator lamination assemblies <NUM> and <NUM>. Punch <NUM> has less potential to become contaminated when stamping, because punch <NUM> will generally only intersect adhesive when forming stator outer diameter <NUM> and rotor outer diameter <NUM> and other internal features of the rotor and stator lamination plates. When the third adhesive application station <NUM> is utilized in the process as in <FIG>, adhesive 62A will be applied to the rotor lamination plate <NUM> area prior to blanking plate <NUM> at adhesive application station <NUM>', and adhesive 62B is applied to the stator lamination plate <NUM> areas at the third station <NUM> prior to blanking plate <NUM>. Separating the application of adhesives 62A and 62Bcan further minimize contamination to punch <NUM>.

<FIG> illustrates the use of rings of adhesive to provide a bonding area around <NUM> degrees of given widths <NUM> onto the face of the rotor lamination plate <NUM> and stator lamination plate <NUM>. In the example provided, a single ring of adhesive <NUM> is applied to each of the areas which align with the final position of the rotor or stator. A rotor adhesive ring <NUM> is applied onto the area which would align with the rotor lamination plate <NUM> while a second, stator adhesive ring <NUM> would be applied onto the area that aligns with stator lamination plate <NUM>. Rings <NUM> and <NUM> are concentrically positioned with respect to each other and positioned centrally to the diameters that are stamped later in the process to form the rotor <NUM> and stator <NUM> lamination plates. Although two rings are shown in this example additional rings could be included, with an adjustment in width <NUM> to allow more rings of adhesive <NUM> to fit between the rotor inner diameter <NUM> and the stator outer diameter <NUM>. It is proposed that the stator adhesive ring <NUM> be positioned towards the stator outer diameter <NUM> because this position has full face contact, because the stator slots <NUM> that cause an interruption in the face of the lamination are inward of the stator adhesive ring <NUM>, providing no contamination to punch <NUM>. Rotor adhesive ring <NUM> may be positioned centrally between the rotor inner diameter <NUM> and the rotor outer diameter <NUM>. Relatively precise alignment may be used to ensure the rotor and stator adhesive rings <NUM> and <NUM> are positioned correctly and are aligned with the rotor and stator lamination plates <NUM> and <NUM> that are stamped out later in the process. This ringed arrangement of adhesive reduces waste when compared to the previous full face adhesive arrangements. Because there are areas on the faces of the laminations without adhesive, there may be a potential of reduced isolation and metal connection, particularly on the cut edge of the diameters and other features stamped within the laminations. Alternatively, paired rings of adhesive could be positioned at the stator outer diameter <NUM>, stator inner diameter <NUM>, and rotor inner diameter <NUM> to improve electrical isolation at these cut edges. If a third adhesive application station <NUM> is utilized in the process, the stator adhesive ring <NUM> may be applied at the third station <NUM>, while the rotor adhesive ring <NUM> may be applied prior to stamping out the rotor lamination plate <NUM> at adhesive application station <NUM>'. It is proposed that both the stator adhesive ring <NUM> and rotor adhesive ring <NUM> are applied together at the first adhesive application station <NUM> for forming the multilayer material sheet <NUM>, or in the first embodiment at the single second adhesive application station <NUM>.

<FIG> represents application of adhesive <NUM> in a grid pattern of dots <NUM> applied onto the surface of the lower electrical sheet coil material <NUM>. These dots <NUM> of adhesive can be applied in a uniform manner across the surface of the lower electrical sheet coil material <NUM>, independent of the location where the rotor and stator lamination plates <NUM> and <NUM> would be stamped from. An arrangement of four dots <NUM> of a given dot outer diameter <NUM> are shown placed across width <NUM> of the coil material, but the arrangement, number of dots, and outer diameter of dots <NUM> can be varied to increase or decrease the number of dots <NUM> in a given area, or the percentage of the surface covered by dots <NUM>. The advantage of such arrangement is that the application of the dots <NUM> can be applied by various contacting and non-contacting methods.

These methods are typically very quick and have a high level of controllability related to location and the amount of adhesive <NUM> applied. Because a grid arrangement is utilized that is independent of the final rotor and stator lamination plates <NUM> and <NUM> that are formed from the strip of material, alignment is less of a concern. Edge isolation due to a lack of adhesive fully between the faces of laminations and contamination of punch <NUM> may be drawbacks as described previously in other adhesive application methods. There may also be some usage of adhesive <NUM> that is applied to surfaces that became scrap, because they are not within the extents of the final lamination areas.

<FIG> represents another optimized application of adhesive <NUM>, because it applies dots <NUM> to specific locations within the final rotor and stator lamination plate areas <NUM> and <NUM>. This illustration also represents a process requiring relatively precise control in the location and quantity of adhesive <NUM> applied to the surface of the coil material. Dots <NUM> may be applied only in strategic areas. For instance, in the area of material which will become the stator lamination plate <NUM>, dots <NUM> may be located between the stator outer diameter <NUM> but radially outside of the extents of the stator slots <NUM>. Similarly, in the area which will become the rotor lamination plate <NUM>, dots <NUM> may be positioned in a way to avoid the areas formed for the magnet pockets <NUM>. The number of dots <NUM> and the amount of adhesive <NUM> applied may be based on functional and structural requirements of the final lamination stack. The complete arrangement of dots <NUM> as shown in <FIG> may be applied at the first adhesive application station <NUM> to bond the layers together to create the multilayer material sheet <NUM>. In the second application station <NUM>, all dots <NUM> may be applied to the rotor lamination plate <NUM> and the stator lamination plate <NUM> prior to stamping operations. When the second <NUM>' and third adhesive application station <NUM> are utilized in the process as in <FIG>, the dots <NUM> applied to the area of the stator lamination plate <NUM> may be applied at the third station <NUM> prior to stamping, while the area of the rotor lamination plate <NUM> may have the dots <NUM> applied prior to stamping out the rotor lamination plate <NUM> at the second adhesive application station <NUM>'. Edge isolation due to a lack of adhesive fully between the faces of the laminations may be more of a concern than other methods proposed, but applying dots <NUM> in any of the adhesive application stations in such a specific location results in reduced concerns of contamination to punch <NUM> and optimized usage of adhesive material.

It is proposed the adhesive patterns previously described do not need to be utilized uniformly across all adhesive application stations within the process. For instance, the optimized full-face bonding shown in <FIG> may be utilized to create the bonding of multilayer material sheet <NUM>, while the optimized dot bonding of <FIG> could be utilized to create bonding between the blanked plates of multilayer material sheet <NUM> when forming rotor and stator lamination assemblies <NUM> and <NUM>. Other combinations of adhesive patterns may also be utilized.

Claim 1:
A method of producing a lamination stack assembly for electrical components, the method comprising:
providing an upper electrical sheet coil material (<NUM>) and a lower electrical sheet coil material (<NUM>);
applying a first adhesive (<NUM>) between the upper electrical sheet coil material (<NUM>) and the lower electrical sheet coil material (<NUM>);
bonding the upper electrical sheet coil material (<NUM>) and the lower electrical sheet coil material (<NUM>) together and creating a bonded multilayer material sheet (<NUM>), wherein the upper electrical sheet coil material (<NUM>) and lower electrical sheet coil material (<NUM>) are joined together by the adhesive (<NUM>);
applying a second adhesive (62A) to the multilayer material sheet (<NUM>) for creation of a final lamination stack;
stamping (<NUM>) multiple lamination plates from the multilayer material sheet (<NUM>) arrangement;
arranging the multiple lamination plates vertically in at least one stack;
wherein the multiple lamination plates include multiple rotor lamination plates (<NUM>) and multiple stator lamination plates (<NUM>),
pressing the rotor and stator lamination plates (<NUM>, <NUM>) together and constructing a final bonded stack of rotor and stator lamination assembly (<NUM>, <NUM>), wherein the at least one stack includes a rotor lamination assembly (<NUM>) and a stator lamination assembly (<NUM>), wherein the stack of rotor and stator lamination assembly (<NUM>, <NUM>) is bonded by the second adhesive (62A) disposed between vertically adjacent ones of the rotor and stator lamination plates (<NUM>, <NUM>) in the stack,
wherein the stator lamination plates (<NUM>) and the rotor lamination plates (<NUM>) are stamped from a common length and width of the multilayer material sheet (<NUM>), wherein the rotor lamination plate (<NUM>) is stamped from material that is disposed radially within the material for the stator lamination plate (<NUM>),
wherein the rotor lamination plate (<NUM>) is stamped prior to the stator lamination plate (<NUM>),
wherein a third adhesive (62B) is applied to the multilayer material sheet (<NUM>) after stamping the rotor lamination plate (<NUM>) and before stamping the stator lamination plate (<NUM>),
wherein the third adhesive (62B) is applied to areas corresponding to the stator lamination plate (<NUM>), and the second adhesive (62A) is applied to areas corresponding to the rotor lamination plate (<NUM>).