MXPA98006726A - Engine with interlocks in rotor and stator nucleus pairs and its formac method - Google Patents

Abstract

A rotor or motor stator core is formed of a plurality of stacked laminations, generally circular. The stack defines at least one internal lamination having laminations positioned adjacent to both sides of the lamination. Each lamination has a predetermined number of circumferential and equally spaced grooves or bar elements extending radially around its edge. The internal laminations include at least one interlock projection formed on one side of the surfaces at a predetermined radial distance from the center of the lamination. The laminations further define at least one projection receiving region formed therein for coupling the projections when the laminations are in the stacked formation. The region of reception of interlocking projection by an angle that is a multiple of integer from where it is an angle defined as a ratio of 360 degrees to the number of slots. It also describes a method to make the core stack

Description

ENGINE WITH THERMAL BLOCKS IN ROTOR AND STATOR NUCLEO COUPONS AND ITS TRAINING METHOD FIELD OF THE ITION The present ition relates generally to electric motors, more particularly to interlocks in pairs for rotor and stator cores that are formed from a stack of laminations, and to a method for making said cores BACKGROUND OF THE ITION The electric motors are in a vast use. They have an impact on every aspect of industry, commercial and residential life. Such motors can vary from small fractional motors that can be found, for example in washing machines and refrigerators, to large industry applications for activating manufacturing equipment, fans and the like. L OI motors are commonly used to cot electrical energy into rotational energy or rotational force Typically, a motor includes a rotating central portion called a rotor and a fixed external portion called a stator. The stator and the rotor are housed in a housing containing the motor. Both e! rotor like e! stator condemn electrical conductor elements Loe core? of rotors v > Lices can be formed with a variable number of slots, which are the openings that receive the electrical conductive elements. A rotor core is the central portion of the rotor that contains the electrical conductive elements. The number of rods in the rotor cores can vary considerably. For smaller, fractional rotor rotor motors, for example, those with rotor diameters of approximately 5 08 centimeters, the number of rods is generally between 8 and 52. The core structure is typically formed as a plurality of stacked plates or laminations. The laminations, which are made of metal, can be punched in a press, and subsequently stacked one on top of the other to form the core. Due to the possible asymmetries in the lamination material the laminations can be rotated, so that the core, on the final assembly, forms a straight pile instead of twisted The laminations are interlocked with each other to form a rigid core structure and prevent the laminations from moving with relationship to each other Stator cores are formed in a similar way In one arrangement known interlocking each lamination has a concavity or depression stamped on the surface which forms a corresponding projection on the opposite side of the lamination The laminations are then stacked on top of each other with the projections of a lamination engaging and resting on the Depression in the next adjacent lamination In this nested layout, the laminations are maintained in alignment with each other through the coupling of the projections and depressions This is a common and accepted method for interlocking laminations Although such methods are in common practice, they have their disadvantages First, there is a mathematical dependence between the number of slots in the rotor or stator and the number of interlocks. Typically, the number of rotor slots and the number of interlocks are selected so that both can be divided by 3, 4 or 5 to produce rotations of 120, 90 and 72.5 degrees, respectively. Although this may be suitable when the rotor or stator has a number of slots that is easily divisible between said numbers, it is unacceptable when the number of slots in the rotor > The number of interlocks can be sufficient (for example, when the number of slots is 12 15, 16, 20 24, 28, 30, 32 36, 40, 42, 45 or 48). , between 3 and 4j and the rotational angles are easily determined by dividing the number of interlocks by 360. As an example a rotor having 12 slots can include 2, 3 or 6 interlocks and will have rotational angles of 180, 120 and 60 degrees, respectively However, it will be readily apparent that when the number of bars varies from these easily divisible numbers the incorporation of spheroids into a spinning core can be absolute complex if not impossible. they have, for example, a prime number of bars (for example, 13, 17, 19, 23, 29, 31, 37, 41, 43 or 47 bars) can not be manufactured using the known method for interlocking laminations. Furthermore, it has been observed that rotor and stator cores having laminations with a number of grooves that can only be turned 180 degrees, can be susceptible to the formation of a twisted pile or core. That is, cores that include laminations that only rotate 180 degrees can produce an undesirable oval shape in the finished core if there is a deviation in the punched holes that are intended to be concentric with each other. Accordingly, there remains a need for a rotor and stator core lamination interlocking arrangement that is independent of the number of slots, whose configuration is adapted to the rotations of the lamination, and further suits the twisting of the core laminations. of rotor to each other. In addition, there continues to be a need for a method for making said rotor and stator core laminations, said method does not increase, or preferably reduce, the number of steps required in core formation.

COMPENDIUM OF THE INVENTION A core formed from a stack of laminations, which can be used for a rotor or electric motor stator, is formed of a plurality of generally circular laminations stacked to define a core. Each lamination defines an axis therethrough which is collinear. with one axis of another lamination The laminations have first and second surfaces The stacked formation is configured to define at least one internal lamination having laminations positioned adjacent to both first and second surfaces and external laminations having laminations positioned adjacent to one of the surfaces Each lamination defines a predetermined number of circumferential and equally spaced openings or slots that extend radially around its edge. The slots are separated from the adjacent slots through teeth. The tears are adapted to receive conductive elements. Internal laminations include by or less an interlocking projection extending from one of the first and second surfaces at a predetermined radial distance from the axis. Each lamination further defines at least one projection receiving region that is positioned at the same radial distance from the axis to which the projection is positioned. The receiving region is circumferentially separated from the projection by an angle f which is a complete plural number < - f a r1 guio ß which is defined as a ratio of 360 degrees to the number of grooves Other characteristics and advantages of the invention will be apparent from the following DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective, exploded view of an illustrative engine, showing a rotor and stator, each having a core formed in accordance with the principles of the present invention, Figure 2 is a perspective view of a core of rotor formed from a stacked plurality of laminations including one embodiment of a paired interlocking system, Figure 3 is a top perspective view of one of the laminations of the core of Figure 2; Figure 4 is a bottom view in perspective of the lamination of Figure 3 Figure 5 is an enlarged view of the lamination of Figure 4, illustrating an interlocking projection Figure 6 is an enlarged perspective view of a portion of an illustrative stator core having the interblocks in pairs Figure 7 is a partial cross-sectional view taken along line 1-1 of Figure 5, Figure 8 is a partial perspective view of a Mining including an alternative mode of the interlocking system in pairs, and Figures 9a-9e illustrate various forms of projections of the interlock mode in Figure 8 DETAILED DESCRIPTION OF THE INVENTION Since the present invention is susceptible to modality in various forms, it is shown in the drawings and the presently preferred embodiments and methods will be described hereinafter with the understanding that the present description should be considered as an illustration of the invention and not It is intended to limit the invention to the specific embodiments illustrated and methods described. Referring now to the Figures and in particular to the Figure 1 shows a motor generally illustrated in 10. The motor 10 is enclosed within a housing 12 and includes a rotor 14 and a stator 16 The stator 16 is the fixed portion of the motor 10 that is mounted to and within the housing 12 The stator 16 defines a longitudinal axis, indicated at 18, through it. The rotor 16 is the rotation portion of the motor 10 that is placed inside the stator 16. The rotor 14 defines a longitudinal axis indicated at 20 and is aligned with the stator 16, so that the axes 18 20 of the rotor 14 and the stator 16 are cohneal. The rotor 14 is placed inside the stator 16 to define a gap, designated as an air gap, indicated at 22, between them. The recess 22 allows the rotor 14 to freely rotate within the stator 16, without the rotor 14 and the stator 16 inadvertently making contact with each other. In a small fractional motor, typical, for example less than one horsepower, the gap 22 may be about 254 microns. Those skilled in the art will recognize that the gap 22 between the rotor 14 and the stator 16 must be maintained in order to prevent the rotor and the stator 16 make contact with each other as the rotor 14 rotates. Since the rotor 14 can rotate at speeds exceeding 3,600 revolutions per minute (RPM) said contact can damage both the rotor 14 and the stator 16 thereby causing that the motor 10 is inoperable On the one hand, the gap 22 must be small enough so that the electric field that is created in the stator 16 can in turn induce an electric field in the rotor 14 This is the field electrical induced in the rotor 14 which is converted to mechanical energy and results in rotation of the rotor 14 On the other hand, the gap 22 must be sufficient to prevent contact between the rotor 14 and the stator 16 As the gap 22 is increased between the rotor 14 and the stator 16 the electric field induced in the rotor 14 is reduced In this way, the size of the gap 22 between the rotor 14 and the stator 16 must be determined by balancing the need to maintain a critical space between the components while keeping the components sufficiently close to decrease and preferably minimize field losses The rotor 14 and the stator 16 each include a core 24 26 respectively, which is formed of a plurality of plates or laminations 28 which They are stacked together one above the other. For purposes of the present discussion, reference may be made to the rotor 14, rotor core 24, rotor laminations, and the like. However, it should be understood that this discussion is equally applicable to stators 16 as to the stator components, and that said stators 16 and their components are within the scope of the present invention. The laminations 28 are secured in place in relation to one to the other. another through an interlocking system The interlocking system 30 prevents the laminations 28 from rotating and moving relative to one another and separating from each other, and thus maintains the rotational nude 24 as a unitary member during the As illustrated in FIG. 2, the core 24 includes a predetermined number of grooves 36 formed therein at one edge or periphery of each lamination 28. The grooves 36 are defined by teeth 32a-32gg separating the grooves 36 one from the other. the other In a typical rotor core lamination 28 the teeth 32a-32gg are integral with the central portion of the lamination The spaces between the teeth 32a-32gg is dec slots 36 are configured to receive and secure the conductive elements 34 in them In a motor 10 fractional I | J ÍG <; IL O ios conduccrc c oA cao? it is formed as an individual mass from for example aluminum which has been injected into the grooves 36 in molten form This type of rotor manufacture 14 is commonly referred to as a short-circuited rotor motor In an illustrative stator 16 best seen in the figure 6 the stator slots 36 extends outwardly from an inner edge of the stator laminations 28 Unlike the opposite orientation the stator 16 is formed in almost the same manner as the rotor 14 It would be appreciated by one skilled in the art that all the circular shape "of the stator 16 is necessary only as an inner periphery adjacent the rotor 14 The plates or laminations 28 are generally formed from a sheet material such as sheet steel which has been stamped in the form of the laminations 28 The laminations 28 are then stacked, one on top of the other, to form the core 24 As with the much more commercially available sheet material available material characteristics such as material thickness can not be uniform across the entire sheet. That is, the thickness of the material can vary. Although such variation may not be critical for many applications it can be critical for the manufacture of rotor cores and stator 24, 26 since the stacked core 24, 26 may exhibit asymmetries for example twisting due to the varying thicknesses of the lamination 28 As previously provided the core 24 must be straight is to be aerated, it must have a right cylindrical shape, so that the rotor 14 rotates within the stator 16 in a coaxial form without contacting the sides of the stator 16 An effective way to represent or adapt the variation in the thicknesses of the lamination 28 has been observed to rotate the laminations 28 a predetermined number of times. degrees (for example, 60, 90, 120) as they are formed, to distribute the asymmetries around all the 360 degrees of the core 24 This is referred to as the "rotation" of the core 24 The angle at which the laminations 28 rotate is termed as the index angle which includes the angle of rotation (or angle of rotation) and any additional angle representing a twist In core configurations Known, the angle of rotation depends on the number of interlocks and the number of grooves in the core. For example, a core that has 24 slots can have two intei locks and a rotation angle of 180 degrees (or a multiple of! same), three interlocks and a rotation angle of 120 degrees (or a multiple of it), or four marbling and a rotation angle of 90 degrees (or a multiple of it) Since this seems to provide sufficient flexibility in the design of the nucleus, it should be noted that this configuration does not allow the manufacture of rotated nuclei that have a prime number (for example 13 17 19 23 29, 37 41 43, and 47) of bars Also, as stated above problems have been observed with laminations that g > only at 180 graccc For example, nuclei that rotate only at 180 degrees, can exhibit an eccentricity, which is an undesirable characteristic for a nucleus. In addition, large rotational angles, for example 180 degrees, result in slower compression speeds due to the "communication" time between the manufacturing control system and the servo motors of the system and servo-driven systems. The present invention uses a system interlock 30 allowing the use of any number of interlocks in the cores 24, 26 having any number of slots 36. Each interlock 30 includes a raised projection or tab 38 that is formed on a surface 40 of the lamination 28. In an embodiment preferred, the projection 38 has a front portion 42 and a rear portion 44. The front portion 42 can be stepped, as shown in Figure 5. Essentially, the front portion 42 is the uppermost raised portion from the surface 40 of the lamination 38 The rear portion 44 may be tapered or ramped down from the front portion 42. leaning toward the surface 40 of the lamination 28 As best seen in Figure 4, preferably, the projection 38 defines an arcuate shape along its circumferential length as indicated by Lp, such that the center line as indicated at 46, remains at a fixed radial distance from the axis 20 of the lamination 38 A Unlike the known interlocks, which use a series of projections that lock or nest with each other in a fixed relationship and in fixed positions, the projections 38 of the present invention are received in projection receiving apertures or regions 48, which are formed in the lamination 28 The reception regions 48 are elongated to receive the projections 38 along the length L0 of the region and thus allow the projection 38 to be completely housed within the region 48. Similar to the projection 38, the The receiving region 48 is preferably arcuate such that a central line, indicated at 50, of the receiving region 48, is at a fixed radial distance from the The rolling axis 20 In a preferred embodiment the projections 38 and the receiving regions 48 are in pairs with each other and each receiving region 48 has a circumference length 'L' which is a little longer than the length Lp of its projection 38 As discussed more fully herein, the elongation of the receiving region 48 is adapted to coincide with a twisting angle in, for example, the rotor core 24, if desired. As is evident from the Figures, the central centers of the projections and the receiving regions 46, 50, they are at the same radial distance from the rolling axis 20, when they are in a stacked formation, the projection or projections 38 of a lamination 28 will reside fully within the receiving region or regions 48 of an adjacent lamination 28 Advantageously, the interlocking configuration of the present can be used to form ictor and stator 24 24 having any number of slots 36, including a prime number of slots 36 Each receiving opening 48 and its corresponding projection 38 are separated from each other through an angle? which is a multiple of an angle ß that is defined by 360 degrees / S, where S is the number of slots 36 in the lamination 28 Mathematically expressed, the relationship is as follows F = nß, and ß = 360 ° / S, wherein f is the separation angle between the projection 38 and its corresponding receiving aperture 48, n is a whole number integer ß is the base angle and S is the number of slots 36 For example in a lamination 28 having thirty and six slots 36 a projection 38 and its corresponding receiving region 48 are separated by an angle f which is a multiple of 360 degrees / 36 or 10 degrees In this way, the projection 38 and its corresponding receiving region 48 can be separated by any 10-degree multiple such as 20 degrees 30 degrees and 40 degrees Advantageously any multiple of 10 degrees can be used This provides extreme flexibility in the design of rotor and stator core 24, 26 Likewise in a lamination 28 having twenty slots 36 the projections 38 and the receiving regions 48 are separated by an angle f which is a multiple of 360 degrees / 20 or 18 degrees Thus, the projection 38 and its corresponding receiving region 48 can be separated by any multiple of 18 degrees ta as 36 degrees 54 degrees and 72 degrees Any multiple of 18 degrees can be used. The rotational spacing between each projection 38 and its corresponding receiving aperture 48 must be constant for each lamination 28 of the core 24, 26. The core 24, 26 which modalizes the interlocking configuration of the present, can have any practical number of interbranches. Each lamination 28 can include a single projection 38 and a receiving aperture 48, or multiple projections 38 and receiving apertures 48. However, it is anticipated that for use in small motors 10, such as those having core diameters 24 less than about 508 centimeters can be used up to nine pairs of interlocks, ie projections and corresponding reception regions, 38, 48 It will be evident that as the size, the diameter say, of the Motor 10 increases the number of interlocks may be increased. Said cores 24 may have any practical number of slots, including more than about 59 and less than about 7 slots. It is also contemplated that laminations 28 may be formed that do not have equal numbers of projections 38 and of receiving openings 48 That is, each lamination 28 is a group of aminations 28 for a core 24, 26 may include, for example, two projections 38 and four receiving openings 48 As stated above, in said contemplated laminating configuration 28, the projections 38 and the openings 48 are separated from one another by an angle? which is a multiple of an angle β which is defined as 360 degrees / S, where S is the number of slots 36 Referring now to Figure 2, the core 24 illustrated includes a misalignment, indicated at 56, in the slots 36 Those skilled in the art will recognize that such misalignment 56 may be included to, for example, reduce the loss of torque in the engine 10 or to reduce the "noise" of the engine 10 The misalignment 56 is effected by deviating the laminations 28 one of the other by a relatively small angle (laminating misalignment angle) relative to the angle of rotation. That is, the misalignment angle is relatively small compared to the angle that the laminations 28 are rotated relative to one another to represent the Asymmetries of the lamination 28 Typically, the misalignment angle is equal to approximately 360 degrees / T, where T is the number of stator slots 58 For example , in a motor 10 having a stator 16 with twenty-four slots 58, the desalting angle may be approximately 360 degrees / 24 or 15 degrees. It will be appreciated by those skilled in the art that the rolling misalignment angle for each lamination 28 is the total deflection angle divided by the total number of laminations 28 in the stator 16 Thus, for the illustrative stator 16 having a deflection angle of 15 degrees and having 30 laminations, the misalignment angle for each lamination is 14 degrees The interlock system 30 of the present facilitates the provision of said deflection angle in the rotor core 24 without considering the number of slots 36 or the number of interlocks 30. As discussed above, the reception regions 48 are a bit longer circumferentially (as indicated in L0) than their corresponding projections (indicated in Lp), to adapt to the slight deviation n to effect the misalignment of core 56 In this manner, adjacent laminations 28 can be positioned relative to each other to accommodate both the angle of rotation and the smallest misalignment angle since the projections 3e can be received within the receiving regions 8 with a small amount of freedom for placement, the misalignment angle can be easily adapted between the adjacent laminations 28. Thus, both the twisted and non-twisted cores 24 can be manufactured using common rotor tool and a Common Rotor Design Figures 8 and 9a-9e illustrate several alternative embodiments of projections that can be formed having various shapes. Each of the projections is formed without the rear portion as shown in the embodiment of the projection 38 in Figures 2- 7 For example, as shown in Figures 8 and 9a, the projection 138 may have a circular shape. The corresponding receiving aperture 148 in said embodiment may have a circular shape or, alternatively, may be formed having an elongated arched shape (not shown) to allow a degree of freedom of placement of the projection 138 within the aperture Other shapes may also be used, such as a square projection 238 (Figure 9b), rectangle 338 (Figure 9c), elongate 438 (Figure 9d) and a double projection triangle end in opposite oriented or arc shape 538 (Figure 9e) Each of these embodiments of the projection can be formed with a ramp rear portion or the projection can be formed as a tongue extended fully downwardly. Corresponding reception can be formed with a clear or sufficient tolerance to allow a tight fit ", the openings can be configured to allow n degree of freedom to place the projection into the opening As is evident from Figures 9a-9e the projections 238 338 438 and 538 can be formed by punching "a surface or side 140 of the lamination 28 forming the respective projection onto the other side or surface 142 of the lamination 28 The respective projections can be formed with square or straight sides or the projections can be formed with angled or ramp sides, as illustrated All of these shapes and their corresponding aperture configurations are within range OF THE PRESENT INVENTION Referring now to Figure 2 it will be apparent that laminations 28e must be formed so that they engage or are coupled only by an adjacent lamination 28. That is, although the inner laminations 28 couple two adjacent laminations 28, the end laminations 28e engage or are coupled only by their respective inner lamination 28. In a preferred embodiment, the end lamination 28e is required only to receive the projections 38 from its adjacent lamination 28. This is easily achieved by forming only receiving regions 48 in lamination 28e. However, end laminations can be formed in a variety of configurations. For example, end laminations 28e can be formed with projections 38 and receiving portions 48, and lamination. 28 can be rotated through its axis (so that the projections 38 are in an open orientation to those of the stack laminations 28) In this arrangement, the projections 38 extend toward the adjacent lamination 28, and the receiving regions 48 receive the projections 38 of the adjacent lamination 28. Alternatively, the end lamination 28e can be oriented relative to its adjacent lamination 28 so that the projections 38 are pushed back into the lamination body 28 As previously provided, although the interlock system 30 of the present has been, in part, described and illustrated with respect to a motor rotor core 24, the interlock system 30 can be easily used to manufacture stator cores 26 as well as other cores that are formed as a stack of rolling mills. interlocking 30 to other cores is within the scope of the present invention The methods for making laminations 28 having the interlock system 30, and for making rotor cores 24 and stator cores 26 including laminations 28 having the interlock projections 38 and reception openings 48 are anticipated to be less expensive, less time consuming and with less traffic down intensive than the known core manufacturing methods. One method contemplated to form, for example, rotor laminations 28 includes placing a stock material, such as sheet steel, in a die cutting apparatus. The reserve material is centralized and the rotor slots 36 (for example, conductor reception regions) are cut, such as by punching. If desired, ventilation holes can also be cut, such as guide holes for aligning the workpiece as it travels through the apparatus. Interlocking protections 38 are formed, such as by perforation or partial cutting through the reserve material The projection receiving regions 48 and a central hole 60 for an arrow 62 are also cut or punched. The end laminations 28e are formed for the purpose of engaging or being coupled only by an adjacent, individual lamination 28. In a preferred method, the end lamination 28e is formed by omitting the projection formation step however the reception regions 48 and the hole Arrow 60 are formed in the material as are any other openings, penetrations or holes in the lamination 28. Other extreme lamination forming steps 28e can be used For example, the end lamination 28e can be formed by rotating the end lamination 28e transversally about its axis (for example, turning over) so that the projections 38 on the end lamination 28e are oriented opposite to each other in relation to the other projections 38 of the lamination 28 Alternatively, the projections 38 can be formed, such as by punching in its opposite direction. The end laminations may also be formed by punching all the projections 38, instead of a combination of projections 38 and receiving regions 48. The rotor lamination 28 is then cut from the reserve mate and stacked for alignment. The lamination 28 is rotated at a predetermined angle, i.e. the index angle, of the cutting position. The index angle is selected to make the core rotated. The index angle is equal to the angle of rotation if there is no twisting, and is equal to the angle of rotation plus the misalignment angle of the lamination if a twist is desired. The laminations 28 are subsequently stacked one on top of the other to form the rotor core 24. The stator laminations can be formed from the stock of immediately adjacent sheet material and outward from the rotor formation after the rotor has been cut. the matter! and, if desired, the inner portion of the stator can be shaved to establish the necessary space for the air gap. The stator slots are cut or punched in a manner similar to the cutting of the rotor slots. Interlocking projections are formed. as perforating or partially cutting through the reserve material The projection receiving regions can also be cut or punched Stator laminations are then cut from the stock and stacked for alignment The laminations can be rotated at a predetermined angle from the position cutting to rotate the stator laminations The laminations are then stacked, one on top of the other, to form the stator The remaining steps necessary to form the motor such as to form the electrical conductive elements and the assembly of the components to manufacture the motor can be carried out using methods known to those skilled in the art It will be noted from the foregoing that numerous modifications and variations can be made without departing from the true spirit and scope of the novel concepts of the present invention. It should be understood that no limitation with respect to the specific embodiments illustrated or methods presented is intended or should be inferred The description is intended to cover all these modifications by way of the appended claims as they fall within the scope of the claims

Claims (18)

1 - . 1 - A core formed from a stack of rotating laminations, which comprises a plurality of generally circular laminations in a stacked formation one soore the other, each lamination defining an axis therethrough which is collinear with an axis of each of the laminations in the stacked formation, each lamination having first and second surfaces and being configured to define at least one internal lamination having an adjacent lamination on both the first and second sides and external laminations having laminations adjacent to one of The first and second sides each lamination having a predetermined number of equally spaced circumferential grooves formed thereon around one edge of said lamination each groove being separated from the grooves adjacent thereto in order to define conductor receiving regions each internal lamination including at least one projection of i terbloq It is formed on one of the first and second surfaces at a predetermined radial distance from the axis, at least one projection including a front portion extending from the surface, each lamination further defining at least one projection receiving region formed in the same, at least that region of projection reception being at a distant rad? predetermined from the axis and being separated from at least said interlocking projection by an angle f which is a multiple of integer of ß where ß is an angle defined as a ratio of 360 degrees to the number of slots

2 - The core according to claim 1, wherein at least one internal lamination includes at least two interlock projections

3 - The core according to claim 1, wherein each lamination defines between 7 and 59 slots

4 - The core according to claim 1, wherein said projection has an elongated shape and includes a back region contiguous with the front portion, said back region tapering the surface from which the projection 5 extends - the core according to claim 1, in where the front portion has a circular shape 6 - The core according to claim 1 wherein said laminations are placed in a torc formation going in relation to one another 7 - The core according to claim 1 wherein at least one projection has a circumferential length, and wherein said projection receiving region has a circumferential length that is greater than the length of the projection. projection 8 - An electric motor comprising a housing, a stator having a core, said stator being disposed within the housing and a rotor having a core and being arranged coaxially within the stator, wherein one of the rotor core and the Stator core is formed of a plurality of generally circular laminations in a stacked formation on each other, each lamination defining an axis therethrough which is collinear with one axis of each lamination in the stacked formation, each lamination having first and second surfaces and being configured to define at least one internal lamination having laminations placed adjacent s both to the first and second sides and external laminations having laminations positioned adjacent to one of the first and second sides, each lamination defining a predetermined number of circumferential and equally spaced slots extending around one edge of said lamination, each slot being separated of the slots adjacent thereto in order to define conductor receiving regions each internal lamination including at least one interlock projection formed in one of the first and second surfaces at a predetermined radial distance from the axis, said projection including a front portion and further defining at least one projection receiving region formed therein, by at least one projection receiving region being at a predetermined radial distance from said axis and being separated from at least one interlocking projection by an angle? which is a multiple of the whole number of an angle ß which is defined as a ratio of 360 degrees to the number of slots 9 - The electric motor according to claim 8 wherein at least one internal lamination includes at least two interlock projections 10 - The electric motor according to claim 8, wherein each lamination defines between 7 and 59 slots 11 - The electric motor according to claim 8, wherein said projection has an elongated shape and includes a rear region contiguous with the front portion, said back region tapering the surface from which the projection 12 extends - The electric motor according to claim 8, wherein said projection has a circular shape 13 - The electric motor according to the rei indication 8 , wherein at least one projection has a circumferential length, and wherein said projection receiving region has a circumferential length. unferential that is greater than the length of the projection 14 - A method for making a core for one of a rotor and a stator for use in an electric motor the core being formed from a plurality of laminations comprising the steps of forming a predetermined number of grooves through the material in a reserve material form at least one angled interlocking projection in the reserve material said projection having a circumferential length and being formed such that at least a portion of said projection remains integral with the reserve material and a portion of the projection extends transverse! to the reserve material, cutting said reserve material to define a reception opening corresponding to the projection of interblocks, said opening of leception having a circumference length! and being positioned relative to said projection at an angle f which is a multiple of integer of ß, where ß is an angle defined as a ratio of 360 degrees to the number of slots, cutting said reserve material in a circular manner to forming a substantially circular lamination, forming MI at the second lamination, rotating the second lamination relative to the first lamination of the rotor, and placing the second lamination on the first lamination so that the projection of the first lamination engages the receiving aperture in the second lamination to form said core 1

5 - The method according to claim 14, wherein it includes the step of forming a plurality of interlock projections in each lamination and forming at least one reception opening corresponding to each projection, said projections and said corresponding receiving openings being positioned in relation to each other to a angle f which is a whole number word of ß where ß is an angle defined as a ratio of 360 ° to the number of rotor slots 1

6 - The method according to claim 14 wherein it includes the step of forming an extreme lamination and interlocking said extreme lamination with a lamination adjacent thereto 1

7 - The method according to claim 16 wherein said extreme lamination is formed only with receiving openings 1

8 - The method according to claim 16 wherein said extreme lamination is form through the step of rotating the end lamination transversely about an axis to orient its respective projections in an opposite relationship to projections of an adjacent lamination