Abstract: A high speed electromagnetic rotating machine is arranged to avoid heat generation due to mutual inductance between a stator and rotor and has a stator provided with drive windings for generating a rotating magnetic field to rotate the rotor and position control windings fitted to the stator for generating a magnetic field having a different number of poles than that of the drive windings for controlling the axial or radial position of the rotor when an electric current sufficient to unbalance the magnetic field applied to the rotor by the drive windings is supplied to the position control windings. The rotor has a cage conductors interconnected to form a plurality of closed circuits mounted to the rotor, the closed circuits having a number of poles set so that there is no mutual inductance between the position control windings and the cage conductors.

Abstract: An electric motor including a stator having a stator core, a start winding and first and second main windings is described. The first main winding and the start winding are configured to form a lower number of poles than the second main windings. The stator core forms a stator bore. The motor also includes a rotor having a rotor shaft concentrically arranged axially of the stator core and a rotor core positioned concentrically with the rotor shaft. Secondary conductors are arranged axially of the rotor shaft and extend through the rotor core. A plurality of permanent magnets are located at an outer periphery of the rotor core and are magnetized to form a number of poles equal to the number of poles formed by the second main winding.

Abstract: In a cage rotor for an induction motor, a end ring (22) for connecting conductive rods (20) to one another is covered with a reinforcing member (24). The reinforcing member (24) is obtained by integrally forming a tube-like portion (26) having an inner diameter which is substantially equal to the diameter of a central through hole (14) of a laminated core (26), an annular end wall (28) extending radially outward from one end of the tube-like portion (26) in an axial direction, and an annular engagement wall (30) extending radially outward from the other end of the tube-like portion (26) in the axial direction.

Abstract: A method of making a squirrel-cage rotor employs a forging die assembly including a receiving die receiving one end of a rotor core and having a first annular concavity corresponding to one of two end rings and a pressing die movable relative to the other end of the rotor core to form a second annular concavity corresponding to the other end ring. The one end of the rotor core is set in the receiving die, and a forging material such as aluminum is set at the other end of the rotor core. Subsequently, the pressing die is moved relative to the other end of the rotor core so that the forging material is pressurized to be plastically deformed. The forging material is caused to enter the first concavity through slots of the rotor core. Consequently, the first and second concavities and the slots of the rotor core are filled by the forging material such that a squirrel-cage conductor is formed.

Abstract: An electric motor comprises a stator having a plurality of conductive windings radially spaced about a central axis. The motor includes a rotor located radially inward of the stator and rotationally fixed with respect to a shaft disposed along the central axis. The rotor defines an area in which, upon rotation of the rotor, a low pressure vacuum is created drawing air radially outward, with respect to the rotor, from the area. The rotor also includes an annular plate disposed at a transverse end of the rotor coaxial with the shaft. The annular plate defines at least one hole extending axially through the annular plate and in pneumatic communication with the area. The hole is configured so air is drawn by the low pressure vacuum through the hole to the area.

Abstract: The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced.

Abstract: A variable-speed dynamotor has a stator having a first set of windings that provide a number of poles for rotating a rotor and a second set of windings that provide a number of poles different from the number of poles provided by the first set of windings. Voltages or currents supplied to the second set of windings are controlled to generate radial forces acting on the rotor for thereby controlling a radial position of the rotor, suppressing vibrations of the rotor, adjusting rotational balancing of the rotor, and controlling radial damping of the rotor.

Abstract: An electric motor for an x-ray tube of a medical imaging system is described herein. The electric motor includes a stator and a substantially cylindrical rotor. The stator includes stator winding slots and stator windings injected into the stator winding slots. The stator also has a stator bore. The rotor is rotatably mounted within a stator bore so that the rotor is coaxial with the stator bore. The rotor includes a rotor core, a plurality of rotor bars, and end rings. The rotor bars are at located in rotor bar openings at a periphery of the rotor. At least one of the rotor bars has a different cross-sectional area than one of the other rotor bars.

Abstract: A rotating electrical machine has openings (105) in its stator teeth (101) occupying a substantial part of the surface area of each tooth so that the stator windings (103) have only a short thermal path to axial cooling ducts created by the openings. In another embodiment, each rotor tooth (109) is provided with a recess (110) at one corner of the tooth to form a recess axial cooling duct; the recess may be of such a depth as to expose part of an adjacent slot (118) to the recess duct. Cooling is by air, either in a single-ended or a double-ended axial ventilation system.

Abstract: A rotor for a motor which can provide a great supply of mechanical power using only slightly more input power, because magnetization is sped up when the rotor is rotated by a rotating magnetic field from a stator. The rotor includes laminated sheets of silicon steel. The weight of the rotor is separated into several pieces by inserting a non-magnetic plate between laminated sheets of silicon steel which make up the rotor. The phase angle of the rotor therefore remains synchronized with the rotating magnetic field from the stator.

Abstract: A synchronous reluctance electrical motor, including a stator having an even number of slots per pair of poles equal to n.sub.s, a rotor of the transverse lamination type having an even number n.sub.r of equivalent slots per pair of poles, and an air gap separating the stator from the rotor, wherein, in order to minimize the torque ripple, between the number n.sub.s of the stator slots and the number n.sub.r of the rotor equivalent slots the following relationships are satisfied: n.sub.s -n.sub.r .noteq.0, +2, -2; n.sub.r >6; n.sub.s .noteq.m.multidot.n.sub.r, m being an integer, and preferably also the following relationship: n.sub.s -n.sub.r =.+-.4 . The rotor of this motor may have insulating layers open to the air gap and/or insulating layers closed towards the air gap by iron ribs suitable for being magnetically saturated; other iron ribs may traverse some insulating layers in intermediate positions thereof.

Abstract: A squirrel cage type electric motor rotor assembly includes first and sec end plates of circular configuration, rigid tubes extending from the first plate to the second plate, the tubes being closed at either end thereof to define enclosed chambers therein, and granules of magnetic material disposed in the chambers, the granules being packed therein with a density leaving them readily movable to align with magnetic fields.

Abstract: An induction motor includes a stator defining stator inner and outer diameters extending about a longitudinal axis, the stator includes a plurality of windings extending longitudinally and circumferentially about the longitudinal axis between the stator inner diameter and the outer diameter and passing an electric current therethrough to create a magnetic field, a rotor extends along the longitudinal axis having a rotor length and a rotor outer diameter less than the stator inner diameter, the rotor being rotatable about the longitudinal axis relative to the stator, the rotor includes at least one electrically conductive bar having a radial outer end and an inner end, the outer end having a notch, the at least one electrically conductive bar extending parallel to the longitudinal axis adjacent the rotor outer diameter for receiving an induced current due to the magnetic field.

Abstract: An induction motor includes a stator defining stator inner and stator outer diameters extending about a longitudinal axis, the stator includes a plurality of windings extending longitudinally and circumferentially about the longitudinal axis between the stator inner diameter and the stator outer diameter, passing an electric current therethrough to create a magnetic field, a rotor extending along the longitudinal axis having a rotor length and a rotor outer diameter less than the stator inner diameter, the rotor being rotatable about the longitudinal axis relative to the stator in response to the magnetic field, the rotor including a hoop portion disposed adjacent the rotor outer diameter and extending radially inwardly toward the longitudinal axis, the hoop portion being a solid unitary structure.

Abstract: An induction motor includes a stator defining stator inner and outer diameters extending about a longitudinal axis, the stator includes a plurality of windings extending longitudinally and circumferentially about the longitudinal axis between the stator inner diameter and the stator outer diameter and passing an electric current therethrough to create a magnetic field, a rotor extends along the longitudinal axis having a rotor length and a rotor outer diameter less than the stator inner diameter, the rotor being rotatable about the longitudinal axis relative to the stator, the rotor including at least one electrically conductive bar extending parallel to the longitudinal axis adjacent the rotor outer diameter for receiving an induced current due to the magnetic field, an end cap at each end of the rotor contacting the at least one electrically conductive bar and a capture ring attached to each end of the rotor to prevent movement between the end caps and the rotor.

Abstract: A method for fabricating a motor component comprises forming a plurality of substantially parallel electrical current conductors and molding magnetic flux conductive material around at least a portion of each of the plurality of electrical current conductors. In one embodiment the motor component comprises a stator, and the step of forming a plurality of slot liners comprises positioning multi-turn wire coils on a mandrel. In another embodiment, the motor component comprises a rotor, and the step of forming the plurality of substantially parallel electrical current conductors comprises fabricating a rotor cage.

Abstract: An electric motor generates a large torque despite its small size, causes small torque ripples, and is able to perform field-weakening control when the number of revolutions is large. The electric motor comprises a stator having m portions where large magnetic resistance and small magnetic resistance exist in the radial direction around the entire circumference, and a rotor having n portions where large magnetic resistance and small magnetic resistance exist in the radial direction around the entire circumference. The value .vertline.m-n.vertline. is an integer less than 3, m and n are large numbers. The stator is provided with two-pole, multi-phase stator windings. The structure such that the salient poles of the stator and rotor are shifted slightly from each other enables the motor to generate large torque and cause only small torque ripples.

Abstract: A conductor bar configuration includes a multiplicity of conductor bars extending along a longitudinal axis, stacked on one another along a vertical axis and each having four cooling ducts aligned parallel to the longitudinal axis, disposed next to one another in pairs in the direction of a transverse axis perpendicular to the longitudinal axis and to the vertical axis and disposed one behind another in pairs along the longitudinal axis. Each cooling duct has an associated orifice in the vicinity of one end of the configuration and reaches into one of two gas outlet zones disposed approximately in the middle relative to the longitudinal axis, where it merges into an outlet duct directed at an acute angle to the vertical axis. For each pair of cooling ducts situated next to one another in the case of each conductor bar, the orifice of one cooling duct is disposed directly at one end and the orifice of the other cooling duct is spaced from that end.

Abstract: A high starting torque induction motor with simultaneously reduced starting current adapted to be associated with a drive having a high load torque on starting that includes a stator, a rotor, a first end ring fixed on said rotor, a second movable end ring associated with said rotor and having a lower electrical resistance than the first ring, and a centrifugal device associated with the second ring and operable upon the rotation of the rotor at a predetermined speed such that, when the motor is electrically energized, the high resistance of the first ring produces a high starting torque at reduced starting current, and when the motor achieves a predetermined speed, the second ring is moved into engagement with the first ring reducing the effective resistance and permitting normal operation of the electric motor.

Abstract: Disclosed is a Segmented Coil Array ("SCA") for use in rotary electromotive devices, such as motors and generators, which employ multiple coils operating within an axial gap magnetic structure. Individual conductor coils have offset circumferentially extending portions so as to allow interlocking of adjacent coils radially extending portions to form a circular array in which all of the coils' working conductors, which are those in the axial magnetic field, can be oriented in the same plane. This construction allows minimum magnet gap spacing, thus, maximizing the available magnetic flux. The resulting SCA may easily be commuted as a three-phase motor, actuator, or generator. The invention also provides a structure whereby multiple coil arrays and associated magnetic rotors may be alternately stacked in layers so as to further increase the total coil working area within a motor or generator of a given diameter.

Abstract: A method of fabricating rotors for induction motors. In a first aspect, arcuately spaced apart rotor bars pass through channels the magnetic core of the motor. The rotors are formed of an elongate portion having a constant cross section parallel to the magnetic core laminations and include two portions protruding beyond the end laminations at opposite ends of the magnetic core. The protruding portions are, at one end, a head much like the head of a "T", and at the other end, a straight continuation of the elongate portion. The rotor bars are formed to fit closely with one another in an interleaving arrangement. The protruding portions form an end ring assembly which is subjected to a consolidation process. In this way, for a rotor having N rotor bars, there will only be N braze joints in each end ring.

Abstract: In a squirrel-cage rotor for an asynchronous machine, having a laminated core (2) which is mounted on the shaft (1), held together at both ends by press rings and is intended for accommodating the cage bars (3), the latter are respectively permanently connected to a short-circuiting ring (4) outside the laminated core (2). Each short-circuiting ring (4) is supported in the radial direction by a support ring (6) fixed on the shaft. In order to couple the cage head to the rotor body over the entire speed range of the machine for the purpose of suppressing natural vibrations, the two press rings are axially spaced from the laminated core (2) and simultaneously form the support ring (6) for the short-circuiting ring (4). In order to ensure the ventilation of the winding overhang, there are provided between the end face of the laminated core (2) and the support ring (6) spacer webs (7) which are preferably constructed in one piece with the support ring (6).

Abstract: A brushless resolver having a stator and a rotor, and a resolver part axially displaced to one another and a transformer part and having associated windings is provided. An additional short-circuited winding arranged parallel with the transformer rotor winding with few turns on the iron core thereof is also provided. A lowpass filter is thereby formed, which compensates the unwanted frequency-dependent phase displacement between the input voltage and the output voltages for the respective frequency.

Abstract: An electric motor for an electrically powered vehicle provides the power necessary for rotating a plurality of vehicle wheels. The motor is constructed of light weight and corrosion resistant metals and includes a cooling system for supplying cooling oil to the rotor and stator core and stator windings such that high speed operation of larger electric motors for electric cars and buses is achievable.

Abstract: The present invention pertains to an improved rotor bar design and method of fabrication of asynchronous motors using such rotor bars. The rotor bar design employs "T"-shaped rotor bars that are interleaved around a magnetic core forming a rotor having a minimum amount of bonding interfaces between the rotor bars and end ring portions. The "T"-shaped rotor bars may either be formed from a single piece or from multiple pieces of copper. The single piece rotor bar method provides N bonding interfaces per end ring, where N is the number of rotor bars used. Where the "T"-shaped rotor bars are formed from three pieces for a rotor having N rotor bars, there will be 2N bonding interfaces for each end ring. Also, the "T" shape of the rotor bars may be added after straight rotor bars have been installed in the rotor bar channels in the magnetic core with their end portions extending beyond the rotor bar channels.

Abstract: A dynamoelectric machine constructed for speed and accuracy of manufacturing has a stator core constructed of 90.degree. symmetrical stator laminations and the windings have differing numbers of poles which overlap in slots of the stator core are wound of the core formed by the laminations in unique fashion. The rotor bars of the machine are skewed to optimize performance of the machine when in the form of a single phase induction motor. Magnet wire leads of the windings are connected directly to terminals on a plug and terminal assembly which is formed for positive location on an end frame of the machine without welding or other fastening to the end frame. The end frames of the machine and stator laminations forming the stator core are formed so as to increase the precision of the final position of the stator relative to the rotor assembly of the dynamoelectric machine. The end frames are constructed for grounding without the use of fasteners or wire.

Abstract: In a squirrel-cage rotor, the theoretical ideal groove cross section is divided radially into at least two zones, which are displaced relative to each other alternatively in and against the direction of rotation of the rotor, the groove cross section including protuberances that extend into the theoretical ideal groove cross section and bulges that extend from the theoretically ideal groove cross section in a manner that the width of a tooth between the individual grooves remains the same as the theoretical ideal groove cross section, thus preventing the conductor rods from shifting either as they cool after aluminum has been introduced into the grooves or at high rotational rotor speeds.

Abstract: A rotor in an asynchronous electrical machine used in high speed applications, comprises an electrically conductive conductor surrounding a rotor shaft and located substantially adjacent to a stator of the asynchronous electrical machine, a coating layer made of a ferromagnetic particulate material having an electric conductivity substantially lower than that of the conductor, the coating layer being placed between the rotor shaft and the conductor and a metallic intermediate layer between the coating layer and rotor shaft, the metallic intermediate layer having yield point lower than that of the coating layer and the rotor shaft.

Abstract: An electroconductive material has at least one portion in which the electrical resistance varies continuously along a gradient. Accordingly, since the material is not formed by directly bonding different elements, it does not have a weak joint portion. Further, since other material characteristics besides electrical resistance also vary along a gradient, for instance, when the material is used at a high or low temperature, a large thermal stress does not generate at an interface between different elements of the material due to a difference of thermal expansion coefficients of such elements. A motor uses the above electroconductive material as a conductor provided in a plural slots. Consequently, starting characteristics of the motor are improved due to the skin effect, and internal stress of the motor due to the thermal expansion of the conductor is decreased. Moreover, the reliability of the motor is improved.

Abstract: A high-frequency motor comprises a squirrel-cage rotor. The rotor comprises an iron core having a plurality of circular slots, a plurality of conductive rods inserted into the slots, and short-circuit rings disposed at both ends of the conductive rods. The conductive rods are made of copper. A ratio of a product of the number N2 of the conductive rods and a diameter d2 of each conductive rod to an outer diameter D of the rotor is in an optimized range of 1.1 to 1.5, namely, 1.1.ltoreq.N2.multidot.d2/D.ltoreq.1.5. With this optimization, it becomes possible to achieve a maximum rotational speed of more than 120,000 min.sup.-1 and obtain an excellent motor efficiency.

Abstract: Slot wedges, electrically-conductive, used in rotor slots, between rotor teeth, and overlying the rotor coils, are serially arranged in the slots and have arcuate grooves in opposite ends thereof. Inserts, also electrically-conductive, are spring-loaded in the grooves to effect electrical continuity fully therealong, lengthwise of the rotor, from wedge to wedge.

Abstract: The present invention is applicable to any a.c. electromagnetic reduction device which is used to change voltage or current levels or to transfer energy between mechanical and electrical systems and includes, for each phase, a combined pair of windings which are conductively and inductively dependent. The dominant winding of each combined pair is electrically connected to an input/output phase, while the reflux winding of each pair is electrically connected in additive or subtractive series with the dominant winding by means of a variable capacitive reactance. The capacitive reactance is then adjusted to minimize the net reactive factor of the coupled windings and the net reflected impedance of the input/output circuitry.

Abstract: A squirrel-cage rotor 10 includes a plurality of slots 16 for accommodating secondary conductors 18 along the outer circumferential surface of a laminated core 14 fixed to a rotor shaft 12. Each slot 16 is defined by a wall having a generally elliptical profile in which a maximum circumferential distance D is larger than a maximum radial distance d in a given section orthogonal to an axis and axially penetrates near the outer circumferential surface of the laminated core 14. The radial inner profile of the slot 16 has a shape in which the tangents on given two points adjacent to the radial innermost portion of each slot wall do not cross at an acute angle in a section orthogonal to the axis, in order to prevent a stress concentration.

Abstract: A high efficiency salient pole reluctance synchronous motor comprises a rotor and at least two poles having polar surfaces with a substantially constant gap through the central region thereof and increasing toward the side regions thereof, so that the gap .delta.m, measured in the central region, and the gap .delta.M measured on the pole horns, meet the relationship ##EQU1## In the rotor there is provided a cage secondary assembly which is shorted by front rings.

Abstract: A rotor for use in a line start permanent magnet motor comprises a rotor core having a shaft and including teeth defining slots; a rotor cage, at least a portion of which extends through the slots; and a layer of composite permanent magnet material at least partially coating the rotor core.

Abstract: For a squirrel-cage rotor of an electric machine, having a cage that passes through the stack axially and is made of electrically well-conductive short-circuit rods that are connected by short-circuit rings at the ends projecting from the stack, oscillation problems that result during operation with frequency converters are intended to be solved. In addition, higher natural torsion frequencies are intended to be achieved on the rotor, that is, the construction is to be made less sensitive by simple modifications to the squirrel cage in order to prevent the resonance effects. This object is attained in that respectively two, three or more short-circuit rods are guided together to rod assemblies at their ends, and these are connected to the short-circuit rings with material-to-material bonding.

Abstract: The present invention relates to an electric motor with high power and high rotational speed consisting of a stator and of a rotor, in which the rotor comprises a laminated magnetic mass (1) consisting of a stack of armature core disk laminations (11) and a squirrel cage consisting of two short circuiting rings (2) located on either side of the laminated magnetic mass (1) and of a plurality of bars (3) joining the two short circuiting rings (2) together and which are distributed uniformly at the periphery of the magnetic mass (1), this rotor being one wherein the armature core disk laminations (11) do not have a central hole.

Abstract: The invention relates to a rotor for an electric machine, particularly to a rotor for a hermetic refrigerating compressor. The rotor core contains a number of axial slots, containing the electric conductors of the rotor, which are short-circuited by short-circuiting rings. The rotor has a spindle hole with at least one increased internal diameter for accommodating the bearing neck of the motor. The increased internal diameter of the core results in increased magnetic field strength in the area with increased internal diameter. The invention reduces the magnetic field strength in the area with increased internal diameter by the axial slots having varying profiles in their longitudinal direction.

Abstract: A brushless DC motor in which increased rotor resistance is used to facilitate very frequent reversals. The rotor endcap is thinned down to the point where the resistance seen by the path of the current loop through one of said endcaps, is at least one-half as much as the resistance seen by the portion of said current loop which flows along the length of one of said rotor bars.

Abstract: A squirrel cage type rotor for a high speed electric motor comprises longitudinally extending bars which are in electrical contact with, but not affixed to, conductive end rings of the rotor. The bars are electrically conductive and are each affixed to the armature core at a single point located intermediate the end rings.

Abstract: A method of producing a squirrel-cage rotor for an induction motor, which includes a plurality of secondary conductors arranged respectively in through holes (16) of a laminated core (14), and a pair of end rings connecting the secondary conductors with one another at both axial ends of the laminated core (14). Each of a pair of reinforcing members (22) includes a cylindrical wall (26), an annular multi-aperture wall (28) provided with apertures (32) and extending in a radial inward direction from one edge of the cylindrical wall (26), and an annular end wall (30) extending generally parallel to the multi-aperture wall (28) in a radial inward direction from another edge of the cylindrical wall (26). Each reinforcing member (22) is arranged in a manner in which the multi-aperture wall (28) is brought into contact with one of the axial end faces of the laminated core (14) while the apertures (32) communicate with the through holes (16).

Abstract: A squirrel-cage rotor (10) includes a laminated core (14) fixed to a rotor shaft (12), a plurality of secondary conductors (18) arranged respectively in a plurality of through holes (16) formed through the laminated core (14), a pair of end rings (20) connected to the secondary conductors (18) at axial ends of the laminated core (14), and a pair of reinforcing members (22, 23) respectively covering the end rings (20). The secondary conductors (18) and the end rings (20) are integrally formed through a casting process, and are connected with the laminated core (14) and the reinforcing members (22, 23).

Abstract: An induction motor rotor unit adapted to support and rotate an X-ray target anode in an X-ray tube comprises a stacked array of very thin highly magnetic annular laminations on a cylindrical carrier. Gold plated copper conductor bars are placed in longitudinal coaxial slots in the circumference of the rotor. Gold plated end rings on the carrier abut each end of the stacked array and conductor bars. In a vacuum furnace the gold plating is caused to melt and diffuse into contiguous components to bond the rotor as an integral unit.

Abstract: The core of the secondary for use in a linear or other induction motor is a ladder-like stamping with two spaced apart rails and a number of bars extending between and having end portions of one piece with the rails. The bars of the cage can be inserted into the recesses of a core, and such recesses can be provided in one side or in two opposite sides of the core. Each recess can receive a single bar or the bars of two or more discrete cores. The bars can be confined in their recesses by slidable closures or by plugs of a hardened adhesive, a synthetic resin or an impregnating agent.

Abstract: An electric motor possesses a motor housing, preferably a pressure-resistant one, wherein a stator is installed and a rotor is journaled for rotation. The pressure-resistant motor housing is preferably filled with gas, more particularly a gas under high pressure of preferably between 5 and 150 bar or greater. In order to reduce heat dissipation in the interior of the electric motor, a capsule is provided, which surrounds the rotor rods at the drive end and/or at the non-drive end.

Abstract: A method for brazing end rings to rotor bars for a squirrel cage rotor assembly comprises assembling the rotor in a brazing fixture with a braze shim between the rotor bars and the end rings; preheating the rotor and brazing fixture to a temperature that is below the aged temperature of the rotor bars and end rings and which is sufficiently high so that the difference in thermal expansion of the rotor bars and brazing fixture applies a predetermined amount of pressure on the brazing joint such that after the joint is brazed and has cooled, a braze filler having a predetermined thickness inches will bond the rotor bar end faces to the end ring, and brazing each joint to bond the rotor bar end faces to the end ring.

Abstract: An asynchronous salient pole induction motor having a stator core with equally-spaced teeth with inner ends having equal angular extent and defining a bore whereat a squirrel cage rotor is provided. A main field winding includes serially connected coils embracing alternate stator teeth and connected across a single phase source of alternating current. An auxiliary field winding includes serially connected coils embracing consecutive teeth intermediate the teeth having the main winding coils thereon. The auxiliary winding coils are phase displaced from the main winding coils. Each of the teeth faces at their inner ends are shaped for increasing the air gaps on both sides of the center line longitudinal plane of each tooth thereby increasing the magnetic reluctance between each of the teeth and the rotor on both sides of the center line plane.

Abstract: An improved method of manufacture of a shorted turn copper bar rotor which is amenable to high volume production and which provides a copper-to-copper electrical bond among the conductor bar end turn portions at each end of the rotor core. Once the rotor core laminations have been assembled on the rotor shaft, and the conductor bars have been inserted into the core slots, a cylinder or spool element is positioned in abutment with each axial end of the core to define annular cavities into which the conductor bar end turn portions extend. Each cavity has a continuous opening for permitting access to the end turn portions lying therein, and a molten copper plasma is sprayed into the opening of each cavity, thereby forming a copper-to-copper electrical bond among the end turn portions extending from each end of the core. The ends of the assembly are then shortened as necessary by machining to provide the required current carrying capacity.

Abstract: A squirrel-cage rotor includes a rotor core composed of steel sheets. Each steel sheet has in the outer circumference a number of slot-forming punched portions along the outer circumference thereof, each punched portion including a main portion and an additional portion inclined toward one of two sides along the outer circumference of the rotor relative to the position of the main portion, such that each punched portion has an unsymmetrical shape. The units include those formed by laminating the steel sheets having the respective additional portions inclined in the direrction of one side, and those formed by laminating the steel sheets having the respective additional portions inclined toward the other side. Slots are formed so as to be parallel with the rotor axis.

Abstract: A small rotor assembly for an alternating current motor and method of assembly are disclosed. The rotor assembly includes a squirrel cage winding which is die-cast onto a rotor subassembly of a shaft, a hollow, elongated hub, and a stack of rotor laminations. This squirrel cage winding does double duty of providing a short-circuited winding for the rotor and a unifying and rigidifying portion along a considerable length of the shaft for the rotor assembly in a unit-bearing motor. The single bearing of the unit-bearing motor extends inside the elongated hub, and the considerable length of die-cast sleeve along the shaft assures a rigid rotor assembly structure which permits the journal portion of the shaft to be very nearly perfectly concentric with the outside diameter of the rotor lamination. The result is considerably less eccentricity than in the prior art, resulting in a smaller air gap and a more efficient motor.