WO2025073474A1

WO2025073474A1 - Linear application of adhesive for laminated cores

Info

Publication number: WO2025073474A1
Application number: PCT/EP2024/076102
Authority: WO
Inventors: Rainer Hofkirchner; Bradley R. Larkin
Original assignee: Magna Powertrain GmbH and Co KG
Current assignee: Magna Powertrain GmbH and Co KG
Priority date: 2023-10-05
Filing date: 2024-09-18
Publication date: 2025-04-10
Anticipated expiration: 2026-04-05

Abstract

The invention relates to a method of producing a lamination stack assembly by a lamination assembly device for electrical components, the method comprising: providing a strip of electrical sheet steel; providing a valve to apply an adhesive to the strip of electrical sheet steel; providing relative motion between an outlet nozzle of a valve and the strip of electrical sheet steel; dispensing adhesive from said outlet nozzle onto the electrical sheet steel during period of time when there is relative motion between the outlet nozzle and electrical sheet to form a series of adhesive dots.

Description

LINEAR APPLICATION OF ADHESIVE FOR LAMINATED CORES

The present disclosure is generally related to a method of applying adhesive to a strip of electrical sheet steel to produce a laminated stack assembly for electrical components, specifically for a rotor and stator core of an electric motor. More particularly, the method relates to using relative motion in the direction of the length of the strip of material to apply dots of adhesive in multiple locations using a single adhesive applicator valve. This disclosure will include various methods, where relative motion will be provided between the adhesive dispensing outlet of the valve and the strip of material. To further optimize the adhesive dispensing, the adhesive dots are applied in a row aligned with the outlet of the valve and its path.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

Electric motor rotor and stators utilize cores created from laminations punched from a strip of electrical sheet steel. These laminations may be formed using a multiple station progressive punching press, where features including magnet pockets, winding slots, cooling channels, and mass reduction holes are removed from the sheet steel in several consecutive punching operations. Prior to the final punch operation which separates the rotor or stator from the strip of electrical sheet steel, adhesive is applied to the top or bottom surface of the sheet steel. In order to have an efficient press operation, the adhesive should be applied in the same duration of time allotted to a single press stroke or cycle. In the example of the rotor, in the final press operation, the punched-out rotor form will drop into a stacker, where a previous rotor lamination resides with the exposed upper surface including the previously applied adhesive. When the current rotor lamination is dropped into the stacker, the bottom surface makes contact with the upper surface of the previous lamination which includes adhesive resulting in the laminated core being created. Subsequent laminations continue to fill the stacker until a complete multiple layer rotor core is produced. In a similar manner, a multiple layer stator core will be produced after the rotor from the same strip of remaining electrical sheet steel material.

Current lamination stacks are formed using a precise amount of adhesive applied to the rotor and stator laminations where a dot form is preferred. A dot of adhesive is applied with a specific quantity and precise location that ensures proper connection strength without adhesive flowing into areas such as magnet pockets, cooling channels, or winding slots. The dot may be circular or elliptical. Due to the surface area of a larger diameter rotor or stator used in traction motors of electric vehicles, often dozens of dots must be applied to achieve proper strength to form the lamination stack. It is advantageous to apply dots of adhesive in different diameters, sizes, or volumes depending on the location where the dot is located on the laminate to optimize the core design. Normally a dispensing valve is utilized to precisely control the amount of adhesive deposited onto the strip of material. These dispensing valves are designed to provide precise fluid dispensing depending on applications. There are different types of precision dispensing valves may include piezoelectric actuated valves, diaphragm valves, micro-dispensing valves, needle or spool dispensing valves, pinch valves, spray valves, or positive displacement precision valves. Multiple valves may used to distribute adhesive to single dot locations directly from the nozzle of the valve or assist in distributing adhesive from a single valve to multiple dot locations via a multiple nozzle arrangement in an applicator head. In these typical arrangements, the nozzle location from where the adhesive is distributed is located at the same location as where the dot of adhesive is applied on the strip of material when the strip of material is stationary. As rotor and stator size and designs change, the positional arrangement and diameter of dots may greatly vary from application to application requiring a very specific applicator head design, valve, and nozzle arrangement. Therefore, there is a need to develop a new adhesive applicator design and method for producing laminated rotor and stator stack assemblies for electrical components where the method to apply the adhesive can have greater flexibility, provide a simplified valve placement and supporting structure, and utilize relative linear movement between the valve nozzle and the strip of material to assist in depositing adhesive in several locations using the same valve.

SUMMARY

The purpose of this disclosure is to describe and provide an improved adhesive application method for the construction of rotor and stator lamination cores. Four overall embodiments of the adhesive application method will be provided. All embodiments will arrange a multitude of valves above a strip of material where each valve deposits dots of adhesive in multiple locations, positioned in a manner to utilize the relative linear movement between the strip and the valve nozzle. This linear movement will be aligned with the length of the strip which may also be considered as the Y axis direction. This may be achieved by fixing a valve or multitude of valves in position and having the strip move below the respective valve nozzles depositing adhesive accordingly. Another alternative is to use the movement of a valve or multitude of valves and the respective valve nozzles above the stationary strip while depositing adhesive to a stationary strip. A combination of valve and strip movements together will also be described.

The overall design of a rotor and stator laminate may be considered to be a sector or pie shape design which is repeated to achieve a complete 360 degree design. In other words, the magnet pockets, cooling channels, or winding slots are features which are repeated in position, size, and design in a clocked arrangement around a rotor or stator lamination. In the rotor example provided in this disclosure, eight repeating sectors of the same design are used to create a complete rotor laminate. Due to the sector type design, adhesive dots are typically positioned in an arrangement which is also repeating within these common sectors. The adhesive dot locations are often set where the center of the dot is located on a diameter set at a given radial distance from the center of the stator or rotor. The locating of the adhesive dots in this manner makes sense due to the symmetrical repeated sector design but is not a fixed requirement to achieve proper adhesion between the layers to create the laminated stack.

In this disclosure it is advantageous, but not absolutely required, to arrange the adhesive dots in an alternative manner. As the adhesive application solutions provided in this disclosure utilize relative movement between the valve nozzle and strip material it would be beneficial to align the dots of adhesive with this motion in mind, therefore in the direction of the relative movement. Locating the adhesive dots aligned with the valve outlet will optimize the number of valve outlets required to produce a plurality of dots. For the method described the dots would be aligned along the long axis of sheet strip or along the Y axis. In this approach a rotor or stator lamination may be considered to have an upper half portion and a lower half portion, as defined across the top surface of the material strip. In other words, if the lengthwise portion of the strip is the Y axis, the width of the strip may be considered the X axis. The material thickness of the strip itself would be the Z axis. At least one rotor laminate with a surrounding stator laminate portion may be removed from the sheet of strip steel where rotor and stator are positioned concentrically with each other, and the center position of the rotor/stator laminate would be shared between the rotor and the stator. This center position of the rotor/stator would be considered the zero point of the X axis.

The adhesive dots may be arranged in an optimized manner in rows, where adhesive dots positioned across the rotor or stator laminations, i.e. Y axis, are placed at the same distance from the zero point of the X axis to form a row of dots. These dots would be positioned on a given X axis, but vary in position along the Y axis. Locating the dots fixed on or offset from the X zero point, and therefore in the same row, allows a single valve nozzle fixed on or offset from the X axis to deposit multiple dots of adhesive as relative motion between the material strip and the valve outlet in the Y direction occurs. Multiple valves or valve nozzles may be positioned at variable offsets relative to the zero point of the X axis to effectively provide a grid of dots applied to the lamination surface. The timing of the valve opening and closing will dictate the location of where the adhesive is deposited along the Y axis. Changes in valve opening duration may be controlled to precisely provide the appropriate amount of adhesive and appropriately sized dot onto the surface. The valve may be further controlled to vary the dot size within a given row, adding further optimization to pack strength or ensuring no adhesive interference with cut out features within the lamination by using a smaller dot of adhesive.

It is an aspect of the present disclosure to provide a method for the applying adhesive in the construction of rotor and stator lamination cores where relative motion between an outlet nozzle of a valve and the strip of material is used to deposit adhesive in multiple locations on an axis aligned along the length of the material.

It is a related aspect of the present disclosure where the relative motion is created by movement of the valve nozzle while the strip is stationary.

It is a related aspect of the present disclosure where the relative motion is created by movement of the strip while the valve nozzle is stationary.

It is a related aspect of the present disclosure where the valve nozzle and the strip both move during the application of the adhesive.

It is a related aspect of the present disclosure to apply the adhesive while the valve is moving or stationary.

It is a related aspect of the present disclosure to apply the adhesive while the strip of material is moving or stationary.

It is a related aspect of the present disclosure to provide the adhesive applicator a separate dedicated space and operation step between punching operations. It is a related aspect of the present disclosure to position the adhesive applicator in between punching operations without a dedicated separate operation step in a compact arrangement.

It is a related aspect of the present disclosure where the multiple locations applied by a single valve may be of different diameters and/or adhesive discharge volumes.

It is a related aspect of the present disclosure that a single valve may supply a single nozzle to form a row of adhesive dots.

It is a related aspect of the present disclosure where each valve will be controlled independently.

It is a related aspect of the present disclosure where a pair of valves each supplying a separate outlet nozzle positioned equidistant from the X axis zero point in an upper half of a rotor or stator lamination and a lower half of a rotor or stator lamination may share a control system where each valve is actuated together in time.

It is a related aspect of the present disclosure where a single valve may supply two outlet nozzles distributing adhesive equally to form a first row of adhesive dots in the upper half of a rotor or stator lamination and a second row of adhesive dots in the lower half of a rotor or stator lamination which are equidistant from the center of the lamination.

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.

BRIEF DESCRIPTION OF THE 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:

FIG. 1A provides an overview of the lamination assembly device;

FIG. 1 B shows the progression of features formed and adhesive applied onto the material strip by the lamination assembly device;

FIG. 2 depicts a rotor lamination with adhesive dots applied in an optimal manner to utilize the linear adhesive application method;

FIG. 3 provides a representation of the method where the material strip moves under stationary valve outlets to dispense adhesive onto the rotor lamination where a separate dedicated space and operational step is provided between punching operations;

FIG. 4 provides a representation of the method where the material strip is stationary while the valve outlets are moved over the material strip to dispense adhesive onto the rotor lamination;

FIG. 5 provides a representation of the method where both the material strip and the valve outlets move during the adhesive application cycle to dispense adhesive onto the rotor lamination;

FIG. 6 provides a representation of the method where the material strip moves under stationary valve outlets located between punching operations to dispense adhesive onto the rotor lamination in a compact arrangement;

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings. 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. 1 provides an overview of a lamination assembly device 10. The upper FIG. 1A shows the lamination assembly device 10 in a view from the side of electrical steel strip material 12, while the lower FIG. 1 B shows the top surface of electrical steel strip material 12 and the features formed or applied by lamination assembly device 10. The lamination assembly device 10 shown will create a rotor lamination stack 14 and then a stator lamination stack 16 from a strip of material 12. Strip material 12 will be fed into lamination assembly device 10 with a roll feeder 18 and further brought thru lamination assembly device 10 by an optional coil puller 20. Strip material 12 may be considered an endless strip in the length wise or Y axis direction and having a width, as shown in the X direction, slightly larger than the outer diameter of the stator lamination stack 16. Roll feeder 18 in combination with coil puller 20 will move strip thru lamination assembly device in the direction of the Y axis from left to right as shown in the figure at a controlled rate. As the strip material 12 is processed thru the lamination assembly device 10 overall, strip material 12 will be move or index a given distance in the Y axis, then stop, and again move or index. The movement is roughly equivalent to the width of strip material 12 based on the stator outer diameter. During each movement either a punching operation, adhesive application, or blanking operation will occur to strip material 12 dependent on location. How the strip material 12 changes from the punching, blanking and adhesive processes from station to station may be understood from FIG 1 B. In this description, one portion of strip material 12 will be focused on depicting how this specific portion or area of the material will transfer from station to station and transform along the way in the Y axis direction. In this non-limiting example, rotor feature punch 22 will include two stations where various features of the rotor lamination 24 will be punched out of strip material 12 including magnet pockets, weight saving cutouts, center bore, etc. in a progressive punching operation. For these two stations, strip material 12 will advance in two separate steps. Strip material 12 will again advance to the right where adhesive 26 will be applied to the top surface 28 of strip material 12 by rotor adhesive applicator 30 in the form of a series of dots. Adhesive 26 may be anaerobic or cyanoacrylate technology. Once adhesive 26 is applied to the top surface 28 of strip material 12 in multiple dot form 52, strip material 12 is again advanced where rotor blanking punch 32 will separate rotor lamination 34 from strip material 12. Rotor lamination 32 will drop into rotor stacker 35 where a previously blanked rotor lamination 32 already resides. The previous rotor lamination 36 will be located in the rotor stacker 35 with adhesive 26 exposed on the top surface of rotor lamination 36. The most recently blanked rotor lamination 32 will then drop onto the top surface of rotor lamination 36 resulting in an adhesive connection between the two rotor laminations. The stacking of rotor laminations 34 and 36 with adhesive 26 in between each lamination layer will continue to create rotor lamination stack 14 of a given height.

With rotor lamination 34 removed from strip material 12, strip material 12 will again index towards the right to the next location within lamination assembly device 10 where the stator features punch 38 includes two punching operations in this nonlimiting example to provide stator features such as winding slots or cooling channels. Similar to the rotor feature punch 22, strip material 12 will index two times representative of the two punching operations of stator feature punch 38. With the portion of strip material now having had rotor lamination 34 removed from the center and many of the features of stator lamination 44 formed into the strip material 12 the portion of material in focus now enters the stator adhesive applicator 42 where adhesive 26 is applied to the top surface 28 of material strip 12 in the form of multiple adhesive dots 52. It is proposed that adhesive 26 is the same as used for creating the rotor lamination stack 14 but this is not necessary as stator adhesive applicator 42 is proposed as a stand-alone system. Once adhesive 26 is applied to strip material 12 in the area of the stator lamination 44, strip material 12 will again advance. At this point stator blanking punch 46 will separate stator lamination 44 with adhesive applied on the top surface from material strip 12. Similar in the description of creating the rotor lamination stack 14, stator lamination stack 16 will be built up by layering stator lamination 44 on top of a previously blanked stator lamination 48 within stator stacker 50. At this point, material strip 12 is indexed an additional time and the focused area of strip material 12 has fully passed thru lamination assembly device 10 and only the scrap portion of the material remains.

Rotor adhesive applicator 30 and stator adhesive applicator 42 are shown in FIG. 1 to be provided as a dedicated station. This arrangement allows either adhesive applicator 30 or 42 to occupy a space generally equivalent to the size of the stator lamination 44. Alternatively, a compact sized rotor adhesive applicator 30’ and stator adhesive applicator 42’ may be utilized without the need for a dedicated station when the valve outlets are positioned in a linear arrangement and the strip material 12 moves fully under the valve outlets when strip material 12 is advanced. As will be further described in the fourth embodiment as an example for rotor lamination 34, rotor adhesive applicator 30’ may be positioned between rotor features punch 22 and rotor blanking punch 32 without a separate dedicated operation step. Such an arrangement will reduce the overall length of lamination assembly device 10 as a dedicated footprint for rotor adhesive applicator 30’ and stator adhesive applicator 42’will no longer be required.

Roll feeder 18 and coil puller 20 may be controlled to have operational conditions which result in the roll feeder 18 and coil puller 20 to be in synch or operate at different speeds. This may be beneficial as this may provide fine adjustment of the speed, acceleration, deacceleration, and tension which strip material 12 transitions thru lamination assembly device 20. This is specifically beneficial for the first, third, and fourth embodiments where the strip material 12 is moving under the adhesive applicator 30 and 42 as adhesive 26 will be applied during situations where the strip material 12 is slowing to a stop, stopped, and moving again to maximize the time available to dispense the adhesive 26.

FIG. 2 provides a non-limiting example of a rotor lamination 34 which includes a plurality of adhesive 26 deposited on the surface at specific locations in a dot form. The adhesive dots 52 provided are merely an example of possible placement and additional adhesive dots 52 and/or positions different than those shown should be understood as possibilities. Also, although the rotor lamination 34 is specifically shown here, the same overall concept of adhesive dots 52 arranged in a manner described would be applicable to the stator lamination 44. Note the rotor lamination may be considered to have a X axis and a Y axis in the same manner as described for the strip material 12. The center of the rotor lamination, positioned on the strip material 12, is considered the X axis zero point 54. One important characteristic of the location of the adhesive dots 52 are they are arranged in a manner where they are aligned together along the Y axis of the lamination at various offsets from the X axis zero point 54. In this example four adhesive dots 52 are positioned along the X axis zero point 54, where the inward pair of dots 52C are larger in diameter than the outer pair of dots 52B. The size of the dots are important as it directly correlates to the adhesion strength between the laminations. The size of the dots, and therefore the volume of adhesive 26 dispensed is precisely controlled. If the adhesive dots 52 are too large it is possible adhesive 26 will flow towards and into features removed from the lamination such as magnet pocket 56 and cutout 58. This may result in contamination within the press, wasted adhesive, and a lower quality lamination stack. If the adhesive dots 52 are too small, a lack of adhesion between the laminations may result. Also included in this example elsewhere on the surface of the lamination are adhesive dots 52A with a smaller diameter, located in areas closer to magnet pockets 56 and cutouts 58 or in areas where reduced adhesion is required. Actual rotor laminations 34 or stator laminations 44 in practice can have no limitation in the number or size of adhesive dots 52 and a simplified arrangement has been shown in this disclosure to easily explain the concept. Continuing to refer to FIG. 2, the plurality of adhesive dots 52 are arranged in this example in seven spaced apart rows. The center row as previously described is aligned with the X axis zero point 54. Three rows offset each a different distance from the X axis zero point 54 are located on the upper half 60 of rotor lamination 34 and three rows offset each a different distance from the X axis zero point 54 are located on the lower half 62 of rotor lamination 34. The distances do not necessarily need to be equal but instead aligned based upon where adhesive dots 52 are required in the application. Note if additional adhesive dots 26 are required, they would be positioned along the Y axis but at a different offset than the seven rows shown in this example in between the seven rows shown. The arrangement of the adhesive dots 52 aligned in the direction of the Y axis is important as this defines the location of the valve outlet nozzle path in the X axis for rotor adhesive applicator 30 in this example. Rotor adhesive applicator 30 is proposed to include seven valves with each valve providing one nozzle to dispense adhesive 26. The center of valve nozzle outlet will be positioned at a location with an X axis offset which match the center location of the adhesive dots 52 in the seven rows of this example. This is depicted in FIG. 2 by the seven nozzle paths aligned with the adhesive dots 52. Valves or the valve nozzle outlets do not need to be positioned in a linear arrangement aligned in the X axis direction, only appropriately set at the required position offset from X axis zero point 54. Valve 0 outlet will be positioned to align with the X axis zero point 54 of rotor lamination 34. Valve 1A outlet will be positioned at a first offset and apply adhesive dots 26 to the row closest to the X axis zero point 54 in the upper half 60 of rotor lamination 34. Valve 2A outlet will be positioned at a second offset at a position further away from X axis zero point 54 than Valve 1A outlet and apply adhesive dots 26 to the second row in the upper half 60 of rotor lamination 34. Valve 3A outlet will be located to be aligned with the final row in the upper half 60 of rotor lamination 34, furthest from the X axis zero point 54. In a similar manner, the lower half 62 of rotor lamination 34 will include valve outlets 1 B, 2B, and 3B positioned at different offsets from X axis zero point 54 to apply adhesive dots 26 in three different rows along the Y axis. In this arrangement these seven valve outlets will apply twenty-eight adhesive dots 52 to the rotor lamination 34. Additional adhesive dots 52 of any size may be applied along the seven rows as described in this example using the same seven valve outlets (0, 1A-3A, 1 B-3B) with only a change in the number of times and/or duration of valve opening providing flexibility without a significant change to the rotor adhesive applicator 30.

FIG. 3 provides an overview of the method describing the timing, actuation, and motion of various components when applying adhesive dots 52 to strip material 12 which will become rotor lamination 34. In this first embodiment the adhesive 26 will be deposited to the strip material 12 by rotor adhesive applicator 30 where the seven valve outlets of this example (0, 1 A-3A, 1 B-3B) as previously described are in a fixed in position within the adhesive applicator 30. Adhesive applicator may utilize any type of dispensing valve which can precisely control the amount of adhesive deposited onto the strip of material. This dispensing valve receives a supply of adhesive 26 and is controllable to deposit the adhesive 26 precisely and quickly in a specific quantity and/or adhesive dot 52 size based on the duration of time the actuator is actuated from a nozzle outlet. FIG. 3 defines a period of time where a portion of strip material 12 enters and exits adhesive applicator 30. Strip material 12 will move into the adhesive applicator 30 space based on the operation of roll feeder 18 and coil puller 20 as described previously. Strip material 12 will initially enter adhesive applicator 30 moving at speed S at the start of the cycle (Time = 0). Strip material 12 velocity will slow until becoming standstill in the middle of the cycle (Time =0.5T). At this point of time lamination assembly device 10 will be conducting punching and/or blanking operations on other portions of strip material 12. When the punching and/or blanking operation is completed strip material 12 will then begin to advance, accelerating again to speed S at the end of the cycle (Time =T). A representation of the distance D strip material 12 travels is shown in FIG. 3 as it enters and exits rotor adhesive applicator 30. Distance D will change at different rates over period T due to the change in speed S of the strip material 12. This is shown to provide a graphical representation of the strip of material 12 moving relative to a fixed valve outlet position. It is proposed that the seven valve outlet positions will be located at the center of the rotor lamination 34 when at its stopped position in rotor adhesive applicator 30 and arranged in a linear manner aligned with the X axis. This will result in the strip material 12 fully passing below each of the valve outlets during one cycle. This will result in the right portion 70 of rotor lamination 34 to be applied with twelve adhesive dots 52 as the strip material 12 enters rotor adhesive applicator 30. These will be applied from right to left onto the rotor lamination 34 by each of the seven valves as strip material 12 passes under each valve nozzle. Once strip material 12 stops, the four center adhesive dots 52 located in central area 72 will be applied only by valves 2A, 3A, 2B and 3B. Strip material 12 will then again move to the right and the remaining twelve adhesive dots 52 in area 74 will be applied by the seven valves before strip material exits rotor adhesive applicator 30. The adhesive dots 52 in area 74 will be applied right to left to coincide with the movement of material strip 12. Alternatively valve outlets may be arranged in an array, where valve outlets are positioned appropriately on the given X axis offset to deposit adhesive dots 52 in the correct position, but may vary in position in the Y axis relative to other valve outlets. As long as the portion of the strip material 12 which becomes the rotor lamination 34 fully passes under each valve outlet during a cycle, an array or other undefined alternative arrangement of valves is also suitable. Only the timing of the valve actuation would need to be adjusted due to the different position on the Y axis relative to the strip material 12.

Referring to the lower portion of FIG. 3 and assuming a linear arrangement of valve outlets, a rotor lamination 34 with the same arrangement of twenty-eight adhesive dots 52 as previously described in FIG. 2 is shown. Overlaid onto the rotor lamination 34 is a representation of the when a valve is actuated to dispense adhesive 26 for each of the seven valves outlets over period T. This assumes a single valve is dedicated to each of the valve outlets. The valve will have a portion of time when it is not actuated during period T, therefore no adhesive 26 is dispensed and is shown as a flat line 64 for each valve. When the valve is actuated and adhesive 26 is deposited onto the material strip 12, this is shown by a solid bar 66 for each valve. Using valve 0 as an example, the valve will actuate four times over period T. Assuming Valve 0 is positioned in the center of rotor adhesive applicator 30, valve 0 will actuate the area 70 enters the center of rotor adhesive applicator 30 to deposit first a medium dot 52B and then larger dot 52C. Adhesive dots 52 deposited by valve 0 are of two different sizes, represented by the length of solid bar 66, where the longest bar 66C represents depositing adhesive 26 to create the largest dot 52C onto the surface of the material strip 12. Valve 0 will also deposit a medium dot 52B onto the surface of the material strip 12 with a slightly shorter actuation of the valve represented by a shorter bar 66B. Note the first two adhesive dots 52 deposited by valve 0 will occur when strip material 12 is moving. Strip material 12 will then stop for a short period of time. At this point area 72 will be directly below the outlet of valve 0 but as no adhesive dot 52 is required on the rotor lamination 34 in the center, valve 0 will not actuate. Strip material 12 will again begin to move exiting the rotor adhesive applicator 30. As strip material 12 is exiting, valve 0 will actuate two more times to deposit adhesive 26 in the form of first a large dot 52C and then a medium dot 52B. Meanwhile, valve 3B will produce three dots via three actuation events during the same cycle, where two outer dots are small dots 52A which is achieved by a reduced duration of valve opening shown by the shortest solid bar 66A. Valve 3B will open a slightly longer period of time to create adhesive dot 52B as it is slightly larger than small dot 52A. Valve 3B will first deposit the small dot 52A while strip material 12 is moving, then deposit medium dot 52B when strip material is stationary. At this point of time as the strip material 12 is stationary valve 3B (as well as valve 3A, 2A, 2B) will actuate. Each of these four valves may actuate for a different period of time to deposit adhesive of a varying quantity resulting in a different size adhesive dot 52. For instance, valves 3A and 3B will create a medium dot 52B while valves 2A and 2B will produce a larger dot 52C by using a longer actuation time. Material strip 12 will again start to move, where valve 3B will apply the small dot 52A in area 74. Note as the material strip 12 is traveling a different strip speeds S during the overall cycle, the duration each valve is actuated may need to be adjusted to coincide and correct for the speed of material strip 12 to maintain a properly sized adhesive dot 52. As material strip 12 passes thru rotor adhesive applicator 30 the seven valves in this example will actuate twenty-eight times of varying actuation duration to deposit twenty-eight adhesive dots 52 onto the material strip 12. In this embodiment, as the adhesive 26 is deposited while the material strip 12 is moving and stationary, the overall period of time allotted to applying adhesive 26 may be maximized as the entire period T may be utilized. As should be understood, the same method described in this embodiment are applicable to be used in the stator adhesive applicator 42 to deposit adhesive 26 onto the surface of material strip 12 which becomes stator lamination 50.

FIG. 4 provides an overview of the method describing the timing, actuation, and motion of various components when applying adhesive dots 52 to strip material 12 which will become rotor lamination 34 in a second embodiment. In this second embodiment the adhesive 26 will be deposited to the strip material 12 by rotor adhesive applicator 30 using an alternative method. Within the adhesive applicator 30 the seven valves as previously described are located offset from each other in the X axis but now mounted in an apparatus which allows them to move together over the strip material 12 along the Y axis while the strip material 12 is stationary. FIG. 4 again defines a period of time T where a portion of strip material 12 enters and exits adhesive applicator 30. Strip material 12 will move into the adhesive applicator 30 space based on the operation of roll feeder 18 and coil puller 20. Strip material 12 will initially enter moving at speed S at the start of the cycle (Time = 0). Strip material 12 velocity will slow, becoming standstill during the majority of defined time T. Time T of the second method does not need to equate to the time T of the first method. At this point of time, lamination assembly device 10 will be conducting punching and/or blanking operations on other portions of strip material 12. When the punching and/or blanking operation is completed strip material 12 will then begin to advance, accelerating again to speed S at the end of the cycle (Time =T). A representation of the movement of the valves using valve position VP is shown in FIG. 4 providing a graphical representation of the valve position VP relative to the strip material 12 over time T. Note that strip material 12 speed S is zero while the valves are moved from a starting location at distance 0 on the far right of the rotor adhesive applicator 30 to an ending location VP on the opposite side, representing a length of travel along the Y axis generally equivalent to the diameter of rotor lamination 34. In the bottom portion of FIG. 4, a rotor lamination 34 with the same arrangement of twenty-eight adhesive dots 52 as previously described in FIG. 2 is shown including a representation of the when a valve is actuated to dispense adhesive 26 for each of the seven valves over period T. The description of valve actuation in this second method assumes all seven of the valve outlets are positioned aligned along the X axis within the moving apparatus. The outlets of the seven valves must travel across, in the Y axis direction, fully over the rotor lamination 34 to apply the adhesive dots 52. The valve outlets are shown in this example to move left to right to deposit adhesive 26, although they may also move right to left. The valve will have a portion of time when it is not actuated during period T, therefore no adhesive 26 is dispensed and is shown as a flat line 64. When the valve is actuated and adhesive 26 is deposited onto the material strip 12, this is shown by a solid bar 66. Using valve 0 as an example, the valve will actuate four times over period T. Adhesive dots 52 deposited by valve 0 are of two different sizes, represented by the length of solid bar 66, where the longest bar 66C represents depositing adhesive 26 to create the largest dot 52C onto the surface of the material strip 12. Valve 0 will also deposit a medium dot 52B onto the surface of the material strip 12 with a slightly shorter actuation of the valve represented by a shorter bar 66B. Valve 3B on the other hand will produce three dots via three actuation events, where two of the dots are small dots 52A which is achieved by a reduced duration of valve opening shown by the shortest solid bar 66A. The central medium sized dot 52B will require a slightly longer valve actuation as depicted by bar 66B. Other size adhesive dots 52 based on an adjustment in actuation time may be achieved as required. Unlike in the first embodiment, material strip 12 is stationary while adhesive 26 is applied, so the duration each valve is actuated will not need to be adjusted to correct for the speed variability of material strip 12 to maintain a properly sized adhesive dot 52. As the arrangement of seven valve outlets pass over the material strip 12, the valves will actuate twenty-eight times of varying actuation duration to deposit twenty-eight adhesive dots 52 onto the material strip 12. As should be understood, the same method described in this embodiment is applicable to be used in the stator adhesive applicator 42 to deposit adhesive 26 onto the surface of material strip 12 which becomes stator lamination 50.

FIG. 5 provides an overview of the method describing the timing, actuation, and motion of various components when applying adhesive dots 52 to strip material 12 which will become rotor lamination 34 in a third method. In this third embodiment the adhesive 26 will be deposited to the strip material 12 by rotor adhesive applicator 30 using a combination of the first and second methods described. Within the adhesive applicator 30 the seven valve outlets as previously described are located offset from each other in the X axis and again mounted in an apparatus similar to the second embodiment which allows the valve outlets to move together over the strip material 12 along the Y axis. In this embodiment strip material 12 will move in the same manner described in the first embodiment, from left to right. FIG. 5 again defines a period of time T where a portion of strip material 12 enters and exits adhesive applicator 30. This results in both the valve outlets moving and the strip material 12 moving at various speeds relative to each other over time T. In the example provided, strip material will move left to right thru the rotor adhesive applicator 30 while the valve outlet movement will be right to left. A representation of the distance D strip material 12 travels over period T is shown in FIG. 5 as it enters and exits rotor adhesive applicator 30. Distance D will change at different rates over period T due to the change in speed S of the strip material 12. A representation of the movement of the valve and valve position VP is also shown in FIG. 5 providing a graphical representation of the valve position VP over time T. The starting location of valve outlets within rotor adhesive applicator 30 maybe flexible, as long as the valve outlets travel over the entire rotor lamination 34 surface while strip material 12 advances within a given cycle. Note while strip material 12 speed S is decreasing, valves begin to move from a starting location at distance 0 over the moving strip material 12. Strip material 12 continues to decrease in speed until stationary at time 0.5T. The valves continue to move at the same speed while the strip material 12 is stationary without stopping, finally ending at location VP when strip material 12 returns to speed S after being stationary and the lamination assembly device 10 completes a full cycle.

To the right in FIG. 5, a rotor lamination 34 with the same arrangement of twenty-eight adhesive dots 52 as previously described is shown including a representation of when a valve is actuated to dispense adhesive 26 for each of the seven valves over period T. The previously described actuation characteristics to develop adhesive dots 52 are carried over to this third embodiment. In this method, material strip 12 is either moving or stationary while the valves which are applying adhesive 26 are moved over material strip 12. This does add some complexity to the timing and actuation duration of each valve to ensure the proper amount of adhesive 26 is applied to form adhesive dots 52 as the relative speed is increased versus the other two methods previously described. The benefit of this arrangement is time devoted to adhesive application may be reduced over alternative methods. As the arrangement of seven valve outlets pass over the moving material strip 12, the valves will actuate twenty-eight times of varying actuation duration to deposit twenty-eight adhesive dots 52 onto the material strip 12. As should be understood, the same method described in this third embodiment are applicable to be used in the stator adhesive applicator 42 to deposit adhesive 26 onto the surface of material strip 12 which becomes stator lamination 50.

FIG. 6 provides an overview of a fourth method describing the timing, actuation, and motion of various components when applying adhesive dots 52 to strip material 12 which will become rotor lamination 34. In this fourth embodiment the adhesive 26 will be deposited to the strip material 12 by rotor adhesive applicator 30’ as the strip material 12 moves under the applicator. Rotor adhesive applicator 30’ is a reduced size rotor adhesive applicator 30 which is achieved by locating the valve outlets offset each other in the X axis but also aligning the seven valve outlets along the Y axis. This may be achieved when the valve outlets may be positioned closely together in the Y axis. This allows rotor adhesive applicator 30’ to have a small X axis footprint which may allow rotor adhesive applicator 30’ be positioned between rotor feature punch 22 and rotor blanking punch 32 without dedicated space and the additional operational step as in previous embodiments. In the example provided, strip material 12 will move left to right thru the rotor adhesive applicator 30’ while the arrangement of valves stand still. FIG. 6 defines a period of time T where a portion of strip material 12 enters and exits rotor adhesive applicator 30’. A representation of the distance D strip material 12 travels over period T is shown in FIG. 6 as it passes under rotor adhesive applicator 30’. Distance D will be equivalent to the distance strip material 12 moves under the valve outlets from rotor feature punch 22 to rotor blanking punch 32. Adhesive 26 will be deposited onto strip material 12 as it passes under rotor adhesive applicator 30’. It is proposed that the rotor adhesive applicator 30’ and the seven valve outlet positions provided in this example will be located immediately prior to rotor blanking punch 32. Adhesive 26 will be applied onto the area which becomes rotor lamination 34 by each of the seven valves as strip material 12 passes under each valve nozzle with the same arrangement of twenty-eight adhesive dots 52 as previously described. FIG. 6 is shown including a representation of when a valve is actuated to dispense adhesive 26 for each of the seven valves over period T is provided, while strip material 12 moves distance D. The previously described actuation characteristics to develop adhesive dots 52 of various sizes are carried over to this fourth embodiment. In this method, material strip 12 is moving while the valves which are applying adhesive 26 are fixed in position over material strip 12. As the arrangement of seven valve outlets pass over the moving material strip 12, the valves will actuate twenty-eight times of varying actuation duration to deposit twenty-eight adhesive dots 52 onto the material strip 12. As should be understood, the same method described in this fourth embodiment are applicable to provide a compact stator adhesive applicator 42’ to deposit adhesive 26 onto the surface of material strip 12 which becomes stator lamination 44. The timing and actuation duration of each valve to ensure the proper amount of adhesive 26 is applied to form adhesive dots 52 will be controlled relative to the speed of material strip 12. This fourth embodiment may reduce the overall length of lamination assembly device 10 as a dedicated footprint and operational step for rotor adhesive applicator 30 and stator adhesive applicator 42 of previous embodiments will no longer be required.

A further consideration for applying adhesive 26 when the material strip 12 is moving and/or stopped may also be required. Material strip 12 raises and lowers slightly in the Z axis as it transitions from operational to operation due to the dynamics within lamination assembly device 10. This movement up and down of material strip 12 is due to the operation of roll feeder 18 and coil puller 20 as well as the various punching operations occurring while adhesive 26 is being applied. As the valve outlet location in the Z axis is proposed to be fixed, when material strip 12 is stationary it will be slightly further from the valve outlets of the adhesive applicators than when moving. Therefore, an adhesive method as described in the first embodiment of FIG. 3 which applies adhesive 26 to the strip 12 when it is moving, stationary, and again moving may be more complicated to control the size of the adhesive dot 52 than methods where adhesive 26 applied during only stationary or moving of material strip 12. The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varies in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of disclosure.

Claims

1. A method of producing a lamination stack assembly by a lamination assembly device for electrical components, the method comprising: providing a strip of electrical sheet steel; providing a valve to apply an adhesive to the strip of electrical sheet steel; providing relative motion between an outlet nozzle of a valve and the strip of electrical sheet steel; dispensing adhesive from said outlet nozzle onto the electrical sheet steel during period of time when there is relative motion between the outlet nozzle and electrical sheet to form a series of adhesive dots.

2. The method of claim 1 where the relative motion between an outlet nozzle of an adhesive dispensing valve and the strip of electrical sheet steel is due to advancing the electrical sheet steel thru the lamination assembly device.

3. The method of claim 1 where the relative motion between an outlet nozzle of an adhesive dispensing valve and the strip of the electrical sheet steel is due to movement of the valve outlets over a stationary electrical sheet stee.;

4. The method of claim 1 where the relative motion between an outlet nozzle of an adhesive dispensing valve and the strip of electrical sheet steel is due to the advancement of the strip of electrical sheet steel thru the lamination assembly device and the movement of the valve outlets over the advancing strip of electrical sheet steel.

5. A method of producing a lamination stack assembly by a lamination assembly device for electrical components, the method comprising: providing a strip of electrical sheet steel; providing a valve to apply an adhesive to the strip of electrical sheet steel; providing a first period of time where relative motion between an outlet nozzle of a valve and the strip of electrical sheet steel occurs; dispensing adhesive from said outlet nozzle onto the electrical sheet steel during said first period of time when there is relative motion between the outlet nozzle and electrical sheet to form a series of adhesive dots; providing a second period of time where no relative motion between an outlet nozzle of a valve and the strip of electrical sheet steel occurs; dispensing adhesive from said outlet nozzle onto the electrical sheet steel during said second period of time when there is no relative motion between the outlet nozzle and electrical sheet to form a series of adhesive dots; providing a third period of time where relative motion between an outlet nozzle of a valve and the strip of electrical sheet steel occurs; dispensing adhesive from said outlet nozzle onto the electrical sheet steel during said third period of time when there is relative motion between the outlet nozzle and electrical sheet to form a series of adhesive dots.