Abstract: An amorphous magnetic core is produced by wrapping cut strips of amorphous metal about a mandrel to form a distributed gap core. The cut strips are secured to the mandrel during assembly by wrapping the strips with amorphous metal ribbons that have been weakened in predetermined areas but not fully parted. After the core has been built to its desired size, the weakened ribbons are completely parted. This method of making an amorphous magnetic core produces a tightly wound distributed gap core without the need for a belt winder or specialized strip holding devices.

Abstract: The present invention relates to a method of fabricating electromagnetic coil vanes. The method utilizes laser machining to provide high resolution, dense coil wire patterns on both sides of a ceramic vane substrate. A firing operation is first performed that eutectically bonds the copper to the ceramic. Laser machining is then used to produce a coil pattern in the copper. The substrate is drilled to provide a through hole which, when filled or partially filled with a conducting material, forms an electrical connection between the two coil patterns.

Abstract: An electric motor including a permanent-magnet rotor having embedded magnets held in place by several segments. The embedded magnets are secured by segments including non-circular openings near their centers. Several non-magnetic, non-conductive bars extend through the non-circular openings of the segments to secure the segments in relation to the shaft. The motor is capable of producing high torque while only requiring a minimum amount of space.

Abstract: In a manufacturing method and apparatus for manufacturing sheet metal packets in punch-packeting technology with a round or oval iron cross section. laminations are punched from a ribbon and are provided with depressions at one side and with elevations at the other side that coincide with the depressions and lie opposite them, with the elevations being in the form of at least two circular nipples being pressed into the depressions upon assembly of each packet. In one lamination per packet, serving as a separating lamination, cylindrical holes are punched instead of the depressions, the nipples of the neighboring lamination engaging into these holes. Laminations are thereby punched from the strip that respectively exhibit different outside contours, particularly different widths, and are joined with one another to form a packet that has a cross-section that is at least partially round, by virtue of the sheet metal packet having graduated edges.

Abstract: The method provides an electromagnetic assembly in the form of a magnet pole or of a stator packet of an extended stator linear motor for a magnetic levitation train. The assembly includes a sheet stack (8) made of ferromagnetic material and at least one additional component (12,13,14). The sheet stack (8) is assembled from raw magnetic steel sheets and is positioned in a shaping tool. Thereafter by feeding a hardenable mixture into the tool and hardening or hardening out the mixture, the sheets are surrounded with the mixture and connected to each other in a single working step to form the finished sheet stack. In the same working step, the sheet stack (8) is connected to the additional component (12,13,14) and the assembly as a whole is provided with its final electrical, magnetic, mechanical and/or geometric properties.

Abstract: A segmented core for an electric machine includes segments stamped from coated electric steel. The segments each have a first end, a second end, and winding openings. A predetermined number of segments are placed end-to-end to form layers. The layers are stacked such that each of the layers is staggered from adjacent layers by a predetermined rotation angle. The winding openings of each of the layers are in vertical alignment with the winding openings of the adjacent layers. The stack of layers is secured to form the segmented core.

Abstract: There is provided a copper clad laminate which makes laser beam drilling extremely easy and is suitable for forming an interlayer connection microhole by improving a surface of its copper foil, which is to be used as the surface which a laser beam enters, in the production of printed circuit boards. Specifically, the copper clad laminate is such that it includes electrodeposited copper foil for use in the laser beam drilling and is characterized in that the matte side of the above electrodeposited copper foil is used as the surface which the laser beam enters.

Abstract: When layering a no. 2 partial magnetic core lamination furnishing an axis inserted on one side of a magnetic pole extending inward from a partial yoke and a partial yoke lamination onto a no. 1 partial magnetic core lamination furnishing a circular hole partially opening to one side of a magnetic pole extending inward from a partial yoke and a partial yoke lamination, the no. 1 and no. 2 partial magnetic core laminations are connected to rotate freely.

Abstract: The magnetic performance, rigidity and mechanical precision of an iron core assembly can be improved. A plurality of plate-shaped core segments are disposed in succession to form a plurality of first and second core members respectively. Edge portions of adjacent core segments of the first and second core members are coupled with each other. The first and second core members are alternately laminated one over another in such a manner that first inter-segment positions each defined between adjacent two first core segments of the first core member are offset from second inter-segment positions each defined between adjacent two second core segments of the second core member in a longitudinal direction of the first and second core members, with those edge portions of the respective first and second core segments which adjoin each other in a laminating direction in which the first and second core members are laminated being overlapped each other.

Abstract: An indexing system for a die assembly for manufacturing a stack of laminae from sheet stock material in a punch press, the stack having a desired stack height and a skew angle, the stock material having a nominal thickness. The indexing system includes indexing means for producing a first indexing input movement in response to movement of the punch press, a motor for producing a second indexing input movement in response to a control signal, and differential means for combining the first and second indexing input movements into an indexing output movement and having first and second input means for respectively receiving the first and second indexing input movements. The first input means is coupled to the indexing means, and the second input means is coupled to the motor. The differential means also has output means for transmitting the indexing output movement; a rotatable choke barrel in which laminae are received and stacked.

Abstract: A center core laminated part and a side core laminated part are formed separately from each other. The center core laminated part is integrated with the side core laminated part by engaging depressed engaging portions with projected engaging portions, wherein the depressed engaging portions and the projected engaging portions are formed relatively on the corresponding opposite surfaces, to form a laminated core part for forming a magnetic path.

Abstract: A motor stator is constructed from loose laminations which are aligned and secured to the compressor housing at the time of assembling the compressor unit. The loose lamination stator is first attached to the compressor housing to initially locate the stator. A solid sizing mandrel is pushed through the rotor accommodating bore to remove any burrs and initially size the bore. An expanding mandrel is then positioned within the rotor accommodating bore and expanded to finalize the sizing of the bore and the alignment with the compressor housing. Once the final size and alignment have been achieved, the stator is secured to the motor housing.

Abstract: In accordance with the invention, a magnetic device is made by providing magnetic sheet layers with reactive joining materials that will react to join the layers into a unitary body. The joining materials are reacted, and the device is formed. In a preferred embodiment, the magnetic material is a soft magnetic material such as FeCo alloy, and the reactive joining materials are aluminum and FeCoOx which react to form nonconducting alumina layers between magnetic regions.

Abstract: A manufacturing method of an MR sensor includes a step of stacking an anti-ferromagnetic layer made of an electrically conductive anti-ferromagnetic material, a step of stacking a pinned layer on the anti-ferromagnetic layer, a step of stacking a nonmagnetic spacer layer on the pinned layer, a step of exposing at least one time a surface of the nonmagnetic spacer layer to an atmosphere containing an oxygen, a step of stacking a free layer on the nonmagnetic spacer layer, a magnetization direction of the free layer being free depending upon a magnetic filed applied thereto, and a step of providing the pinned layer a magnetization direction fixed by an exchange coupling between the anti-ferromagnetic layer and the pinned layer.

Abstract: A progressive stamping die assembly apparatus and method in which strip stock material advances in a first direction through the apparatus and substantially simultaneously with the strip stock movement, a transversely moveable die station moves in opposite second and third directions substantially perpendicular to the first direction to one of a plurality of predetermined positions.

Abstract: There is disclosed a method of making transformer core laminates with bent corners from magnetic strip material having a predetermined thickness and power loss in the manufacture of a low-stress polyhedral core for a power transformer. The method includes mechanically bending corners in each laminate about predetermined bending lines while limiting the zone in each corner where the laminate is subject to plastic deformation to <5 times laminate thickness so that the specific power loss in the transformer core will equal that of the magnetic strip material except within the distance from the bending lines, where the power loss is higher due to plastic deformation of the magnetic strip material.

Abstract: A stacked layered core includes a core body formed from a plurality of core, plates stacked in layers, each of the core plates having a connection base section formed in a circular shape and a plurality of salient pole sections radially extending from an external peripheral surface or an internal peripheral surface of the connection base. The circular connection base section has a fixing-side peripheral surface on the opposite side of the salient pole sections. At least one retaining recessed section is provided in the fixing-side peripheral surface of the connection base section. A dielectric film may be formed over an external surface of the core body. The retaining recessed section has a depth greater than a thickness of a bump portion of the dielectric film formed in the retaining recessed section such that the bump portion of the dielectric film is contained inside the retaining recessed section.

Abstract: An electric motor including a permanent-magnet rotor having embedded magnets held in place by several segments. The embedded magnets are secured by segments including non-circular openings near their centers. Several non-magnetic, non-conductive bars extend through the non-circular openings of the segments to secure the segments in relation to the shaft. The motor is capable of producing high torque while only requiring a minimum amount of space.

Abstract: The object of the present invention is to provide an Fe-based amorphous alloy thin strip capable of realizing an excellent soft magnetic property for use in alternating current applications while keeping a high magnetic flux density even in a composition range with a high Fe content, and an Fe-based amorphous alloy thin strip with which a core having an excellent soft magnetic property can be manufactured, even if there occurs a temperature difference among different portions of the core during annealing. The present invention is an Fe-based amorphous alloy thin strip having a high magnetic flux density, consisting of the main component elements of Fe, Si, B, C, and P and unavoidable impurities, characterized by having: a composition, in atomic %, of 82<Fe≦90, 2≦Si<4, 5<B≦16, 0.02≦C≦4, and 0.2≦P≦12; Bs of 1.74 T or more after annealing; B80 exceeding 1.5 T; and a low core loss of 0.12 W/kg or less.

Abstract: A distributed gap core is prepared by a process comprising the steps of inter-wrapping a plurality of amorphous metal strips with a continuous amorphous metal ribbon having at least one weakened area and separating the at least one weakened area to form a joint region. The strips may comprise one or more groups of cut ribbon having substantially aligned longitudinal edges and substantially aligned transverse edges.

Abstract: A laminate tile pole piece for an MRI, a method and a mold for manufacturing laminate tile metal pole pieces for an MRI. Each laminate tile has a trapezoidal or annular sector shape. The trapezoidal shape allows the tiles to be attached side by side to form a multiple concentric annular array pole piece without using oddly shaped edge filler tiles needed to fill a circular pole piece with square tiles. The pole piece is made by placing a plurality of tiles into a mold and filling the mold with an adhesive substance to bind the plurality of tiles into a unitary tile body. The unitary tile body is then removed from the mold and attached to a pole piece base to form the pole piece. The mold cavity surface preferably has a non-uniform contour. The bottom surface of the unitary tile body forms a substantially inverse contour of the mold cavity surface contour.

Abstract: A process for the production of an inductor device comprising the steps of forming a green sheet to form an insulating layer; forming a plurality of conductive coil pattern units on the surface of the green sheet in order that a plurality of unit sections each including a single coil pattern unit are arranged on the surface of the green sheet and each two coil pattern units adjoining in the substantially perpendicular direction to the longitudinal direction of the unit sections are arranged centro-symmetrically with respect to a center point of a boundary line of adjoining unit sections; stacking a plurality of green sheets formed with the plurality of coil pattern units arranged in centro-symmetry and connecting the upper and lower coil pattern units separated by the green sheets to form a coil shape; and sintering the stacked green sheets. It is possible to obtain an inductor device able to suppress the stack deviation without complicating the production process even if the device is made small in size.

Abstract: A stator assembly method is disclosed for constructing a generator stator in the field. For stator assembly, the method includes the steps of positioning a stator frame on an assembly site; inserting a plurality of stator core modules into the stator frame; clamping the stator core modules together to form a stator core, attaching the stator core to the stator frame; and, winding a plurality of coil windings into the stator core. The stator may be positioned substantially vertically or horizontally at various steps in the method. The stator assembly method may also employ an assembly base to facilitate construction of the stator in the field.

Abstract: In a method for producing a stator of an alternating current dynamo-electric machine, a laminated assembly with a roughly rectangular parallelopiped shape is produced, and a stator coil assembly is disposed in slots of the laminated assembly. Thereafter, a cylindrical stator core is produced by bending the laminated assembly. The stator coil assembly can thereby be easily disposed in the slots at a higher density, and damage to the conductors of the stator coil assembly can be prevented.

Abstract: A method of manufacturing a noise-cut filter having distributed inductances and distributed capacitances is produced wherein conductive spiral coil patterns are formed on the opposite surfaces of a dielectric sheet, such that the spiral coil patterns are aligned with each other in a direction perpendicular to the plane of the dielectric sheet, and a main circuit pattern is constructed by bonding a main circuit conductor to the spiral coil pattern formed on one of the opposite surfaces of the dielectric sheet. The main circuit conductor is formed by stamping with a punch press so that the conductor has a cross sectional area large enough to allow the passage of current of a main circuit, and has substantially the same shape as the spiral coil pattern.

Abstract: A method for manufacturing a motor core having a plurality of metallic plate-like laminations includes the steps of a) juxtaposing the laminations in a stacked relation, b) placing the laminations over an alignment post of an alignment fixture, c) flowing at least one bead of hardenable adhesive material along the outer peripheral surface of the laminations where the adhesive material, when cured, fixes the laminations in a predetermined non-moving orientation, d) removing the laminations from the alignment fixture; and e) applying windings to the laminated stack.

Abstract: A permanent magnet micro-rotor comprises a cylinder of magnetic material having a plurality of spaced-apart slots disposed around the periphery of the magnetic material. The magnetic material is magnetized by placing conductors in the spaced apart slots and energizing the conductors so that magnetic poles are formed between the spaced-apart slots.

Abstract: A thin metal sheet is laminated to form in advance a plurality of core units (of a circular cylinder shape) having the thickness of 1/N (N is a natural number of more than 2) of a predetermined thickness in the laminating direction and this plurality of core units is laminated again for securing so that the whole stator does not cause any mode of oscillation in the diametric direction.

Abstract: A laminate tile pole piece for an MRI. Each laminate tile has a trapezoidal or annular sector shape. The trapezoidal shape allows the tiles to be attached side by side to form a multiple concentric annular array pole piece without using oddly shaped edge filler tiles needed to fill a circular pole piece with square tiles. The pole piece is made by placing a plurality of tiles into a mold and filling the mold with an adhesive substance to bind the plurality of tiles into a unitary tile body. The unitary tile body is then removed from the mold and attached to a pole piece base to form the pole piece. The mold cavity surface preferably has a non-uniform contour. The bottom surface of the unitary tile body forms a substantially inverse contour of the mold cavity surface contour.

Abstract: A magnetic material is continuously wound in and through openings formed in a pair of bobbins to form a wound core of an electrical transformer by inserting the pair of bobbins into a cavity formed in a winding fixture, feeding the magnetic material into the winding fixture so that the magnetic material is fed into a circular winding action such that a leading edge of the magnetic material is continuously threaded into the openings formed in the pair of bobbins to form a wound transformer core, cutting the magnetic material to form a trailing edge, securing the trailing edge to underlying wound transformer core material, and shaping the wound transformer core to a predetermined shape.

Abstract: An indexing system for a die assembly for manufacturing a stack of laminae from sheet stock material in a punch press, the stack having a desired stack height and a skew angle, the stock material having a nominal thickness. The indexing system includes indexing means for producing a first indexing input movement in response to movement of the punch press, a motor for producing a second indexing input movement in response to a control signal, and differential means for combining the first and second indexing input movements into an indexing output movement and having first and second input means for respectively receiving the first and second indexing input movements. The first input means is coupled to the indexing means, and the second input means is coupled to the motor. The differential means also has output means for transmitting the indexing output movement; a rotatable choke barrel in which laminae are received and stacked.

Abstract: A stator core which assures a favorable workability for coupling core segments and has favorable magnetic characteristics even when made by coupling core segments that are formed by laminating core division sheets. A method of manufacturing a core for rotary electric machines includes forming a coupling convexity having an arc-like planar shape and a coupling concavity engageable with the coupling convexity on core segments, forming a serial core segment assembly by engaging the coupling convexity on one of the core segments with the coupling concavity formed on an adjacent core segment so as to be rotatable by more than 180 degrees, and forming a magnetic circuit by bending the serial core segment assembly into an annular form.

Abstract: Rotor for electric motors, in which the laminations of two types and arranged alternately, are made in a manner that a first type is provided with a plurality of protrusions formed by respective protruding tabs, a plurality of perforations being punched in the lamination near the edge of a respective tab with the same orientation pattern thereof so as to create an alternate sequence of tabs and respective perforations, wherein a respective cavity is provided in the respective lamination in correspondence of the tabs of said first type, whereas the second type of laminations is provided with a plurality of different tabs adapted to engage the cavities formed by the association of said recesses corresponding to said first tabs with said respective perforations, wherein the tabs of the second type are produced without any removal of material.

Abstract: The invention relates to a method of manufacturing a sheet stack (8) consisting of ferromagnetic material, and/or an assembly including such a sheet stack (8) and at least one further component (12, 13, 14). According to the invention, the sheet stack (8) is assembled from raw magnetic steel sheets, and is positioned in a shaping tool. Thereafter, by means of introducing a mixture into the tool and hardening or hardening out of the mixture, the sheets are surrounded by the mixture and connected together to form the finished sheet stack (8) in a single working step. In order to manufacture the assembly, the sheet stack (8) can be connected in the same working step with the components (12,13,14), and the assembly as a whole can be provided with its final electrical, magnetic, mechanical and/or geometric properties (FIG. 2).

Abstract: Progressive die assembly for forming a centrally interlocked stack of laminations for rotors, the stack of laminations having a central stack axis. The die assembly includes a punch which forms a centrally located, circular indentation in each lamination, the indentations each having a cental axis which is substantially coaxial with the stack axis. The indentation provides corresponding projections and depressions in the laminas which may be interlocked by engaging adjacent depressions and projections. The station of the die assembly which includes the punch for forming the indentation may also include a counterforce which is applied when punching the indentation so that the stock material is relatively flat. The die assembly also includes a rotating and stacking station in which the laminations are blanked, then rotated, and finally stacked together to form a lamination stack.

Abstract: A stator core which assures a favorable workability for coupling core segments and has favorable magnetic characteristics even when made by coupling core segments that are formed by laminating core division sheets. A method of manufacturing a core for rotary electric machines includes forming a coupling convexity having an arc-like planar shape and a coupling concavity engageable with the coupling convexity on core segments, forming a serial core segment assembly by engaging the coupling convexity on one of the core segments with the coupling concavity formed on an adjacent core segment so as to be rotatable by more than 180 degrees, and forming a magnetic circuit by bending the serial core segment assembly into an annular form.

Abstract: The present invention involves a method and apparatus for forming a centrally interlocked stack of laminations for rotors. A centrally located, circular indentation is formed in each lamination. The indentation provides corresponding projections and depressions in the laminas which may be interlocked by engaging adjacent depressions and projections. Using a progressive die assembly, laminas are blanked from stock sheet material and punched to form the projection/depression. The machine for manufacturing the laminations includes a blanking station including a punch for forming the projections/depressions, and a rotating and stacking station. The projection/depression forming station includes a counterforce which is applied when punching the projection/depression so that the stock material is relatively flat. The laminations are blanked, then rotated, and finally stacked together to form a lamination stack.

Abstract: 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, includes forming a predetermined number of through-material slots in a first portion of a material stock, forming at least one angled interlocking projection in the material stock, the projection having a circumferential length and being formed so that at least a portion of the projection remains integral with the material stock, cutting the material stock to define a receiving opening corresponding to the interlocking projection, the receiving opening positioned relative to the projection at an angle &phgr; that is a whole number multiple of &bgr;, where &bgr; is an angle defined as a ratio of 360 degrees to the number of slots and cutting the material stock to form a first substantially circular lamination. Second and third laminations are formed in kind.

Abstract: A dual action indexing system and method for relatively rotating a lamina and a partial lamina stack in a progressive die assembly. The dual action indexing system includes a mechanical indexer which provides a large indexed rotational movement to correct for thickness inconsistencies in the laminas and a relatively small and fast servo motor to provide a small indexed rotational movement to provide a desired skew angle. The rotational movements of the mechanical indexer and servo motor are combined by a differential such as a zero velocity gear mesh differential or a step-up differential. The combined rotational movement is used to rotate a choke barrel into which the laminas are punched to form a lamina stack. The operation of the servo motor is regulated by a controller and may thereby be conveniently and rapidly adjusted.

Abstract: Magnetic materials which are divided into a plurality of blocks or divided corresponding to respective magnetic pole teeth are connected by means of thin portions. The respective magnetic pole teeth are wound continuously with wire without cutting the wire at the positions in which the thin portions are connected. When a stator is assembled, a plurality of blocks or magnetic pole teeth are disposed on a substrate by separating or bending the thin portions.

Abstract: A laminated magnetic core assembly and method of manufacture having at least one notch formed along opposite sides of a strip material from which the laminations are formed. The notches on the opposite sides of the strip are punched out and separated from each other by a fixed distance. The notches minimize the amount of scrap material by avoiding the need for increasing the width of the strip from which a narrower strip having precision cut sides is formed.

Abstract: A laminate tile pole piece for an MRI, a method and an apparatus for manufacturing laminate tile metal pole pieces for an MRI. Each laminate tile has a trapezoidal or annular sector shape. The trapezoidal shape allows the tiles to be attached side by side to form a multiple concentric ring pole piece without using oddly shaped edge filler tiles needed to fill a circular pole piece with square tiles. The laminate tiles are formed by unwinding a metal ribbon, guiding the ribbon through an adhesive bath, winding the ribbon on a polygonal bobbin, such as a rectangular bobbin, to form a coil with at least one flat side, removing the coil from the bobbin, cutting the coil into laminate bars and shaping the laminate bars into trapezoidal or annular sector shaped laminate tiles. The apparatus contains an adhesive bath, a polygonal shaped bobbin, bobbin side plates for guiding the ribbon onto the bobbin and pressure plates for controlling the thickness of the coil.

Abstract: Methods of manufacturing a magnetic device and a manufacturing tool employing the methods. One of the methods includes the steps of: (1) providing a planar winding assembly and (2) employing an automated pick and placement tool adhesively to secure a first core-portion of a magnetic core to a second core-portion thereof proximate the planar winding assembly, the magnetic core adapted to impart a desired magnetic property to the planar winding assembly, the first and second core-portions being secured to said planar winding assembly without substantial compressive forces.

Abstract: A laminated stack having a lamina layer comprised of a plurality of discrete lamina segments and which may also have laminas which define a plurality of outer perimeter configurations. The invention provides a method and apparatus for manufacturing such stacks. Lamina layers comprising a plurality of discrete lamina segments are automatically stacked by positioning the uppermost lamina in a choke barrel near the lower die bed surface and engaging the interlock tabs of the discrete lamina segments with the interlock slots of an uppermost lamina layer in the choke barrel prior to the complete separation of the discrete lamina segments from the remaining portion of the strip stock material. Each of the outer perimeter configurations has at least one common choke surface.

Abstract: An apparatus and method for manufacturing laminated parts from a plurality of laminas, in which the laminas for forming the laminated parts are blanked from strip stock material. The laminas and are then cut and stacked to form the laminated part. The apparatus includes a measuring device placed with the die element of the press, for accurately measuring the thickness of successive sections of the strip stock. A controller, such as a computer or a programmable logic controller, receives the thickness value of the strip stock sections from the measuring device. Means are also included which is activated by the controller to provide a compensation adjustment at selected locations upon the strip stock sections to counteract the measured thickness variations, and to control the stack height.

Abstract: In a method of making a pencil core having a plurality of substantially flat laminations wherein at least one lamination at the center of the core is wider than the other laminations, a flat strip of core steel is fed into a progressive die, and a plurality of scrap region blanking stations is provided each of which blank out two spaced parallel regions from the strip, but with each of the scrap region blanking stations blanking out the regions at a different spacing. At an embossing station, at least one embossment is provided in at least each of the laminations preceding the last lamination.

Abstract: Ballast for a discharge lamp, which can make a sustained power supply to the discharge lamp, and method and apparatus for manufacturing the same, are disclosed. The ballast having a core assembly (4) with one pair of stacks of a plurality of cores (3) symmetrically inserted into a bobbin (2) wound with copper wire (1), and the ballast including one retainer (9) for surrounding and fixing the entire core assembly (4).

Abstract: A quiet transformer includes a laminated core having each laminate formed as a flat layer from highly grain oriented silicon steel which is fabricated by laser cutting techniques with each layer including five segments in intimate contact with each other via mitered butt lap joints having increased length and asymmetrical angles at opposite ends for reducing the reluctance of the gaps between adjacent lamination segments. The center segment has V joints of different angles on opposite ends. Clamping holes formed in the element of said lamination having the largest cross section at the location in the segment away from said gaps to prevent magnetic flux crowding and increased local flux density. Indexing pins on opposite faces of the segments close and lock in the gaps of the core with each layer being 100% interleaved for producing low joint reluctance and to minimize magnetostrictive forces. The core is pressurized by clamping brackets and bolts connected to opposite ends of the core.

Abstract: A ballast stabilizer includes a stack of annular silicon steel plates defining a center through hole, a perforated bottom-open casing mounted within the center through hole of the stack of annular silicon steel plates, a winding holder mounted within the casing, the winding holder having a center open chamber, a peripheral wire groove, and a winding mounted in the peripheral wire groove around the winding holder, a stack of I-shaped silicon steel plates received in the open chamber of the winding holder, and a varnish coating covered over the stack of annular silicon steel plates and filled up the gaps in the casing, the winding holder and the stack of I-shaped silicon steel plates.

Abstract: A squirrel cage rotor includes a cage, lamination sheets provided with a plurality of slots, and short circuit rings arranged at the axial ends of said lamination sheets and connected by short circuit rods disposed within said slots. In one aspect, said lamination sheets comprise sheets made of an amorphous magnetic material, especially of an amorphous metal with high saturation magnetization. In another aspect, said slots are formed with a convex base portion. In a further aspect, said short circuit rings are made of a metal matrix composite material with high electrical conductivity, preferably of a fiber reinforced aluminum matrix composite material.