Abstract: Induction motors may have a rotor that includes a shaft and a plurality of rotor laminations. The plurality of rotor laminations may have a central bore sized to receive the shaft, and the shaft may have a laminated portion that extends throughout the central bore. In other embodiments, the plurality of rotor laminations may have a very small or no central bore, and the shaft may include first and second end pieces respectively attached on opposite sides of the plurality of rotor laminations. In some embodiments, the first and second end shaft pieces may be attached to the rotor laminations with a through bolt that passes through the rotor laminations via a central bore sized no larger than needed to receive the through bolt, allowing each of the rotor laminations to have a larger laminated surface area. Methods of assembling a rotor are also provided, as are other aspects.

Abstract: An electric machine stator is provided and includes laminations consolidated along an axial direction to form a core element such that the core element includes an end lamination at an axial end of the core element. The end lamination includes a body extending in a plane and a plurality of spacer protrusions protruding along the axial direction from the plane. Each of the spacer protrusions of the plurality of spacer protrusions is configured for consolidation with another core element to define a radial vent between the core element and the another core element.

Abstract: A stator of an electric machine is provided and includes laminations arranged to form a core packet. Each lamination is formed to define an annular array of teeth at an inner radial portion thereof and an annular array of annular sectors at an outer radial portion thereof.

Abstract: A rotor of an electric machine is provided and includes first and second core elements formed to define annular arrays of axial slots and rotor bar openings, each axial slot being fluidly communicative with a corresponding one of the rotor bar openings and a spacer element interposed between the first and second core elements to define a rotor vent opening fluidly communicative with the axial slots.

Abstract: Method and apparatus for insulating induction machine conductive connectors by sliding a closed-end insulating sheath over the connector. The sheath is circumferentially secured to the conductive connector with a biasing element, such as an elastomeric stretchable fabric, stretch tape or heat shrink material. Additional insulative materials as well as resin curing catalysts or accelerants may be added to the sheath.

Abstract: A method for forming rotor bar slots in an induction machine rotor includes providing a rotor body having an outer circumference, a central axial axis and a radial axis and forming opposed first and second rotor slot sidewalls having profiles diverging outwardly in opposite directions from the rotor radial axis. The opposed first and second rotor slot sidewalls are formed using a cutting tool having a first rotational axis oriented at a first angle outwardly diverging from the radial axis and with a second cutting tool having a second rotational axis oriented at a second angle outwardly diverging from the radial axis that is opposed from the first angle.

Abstract: A bearing support assembly adapted to support and damp radial vibration of a rotor shaft of a vertical motor is disclosed. The bearing support assembly has a thrust bearing adapted to couple to a rotor shaft and carry axial thrust loads along an axial axis, and a radial magnetic damping apparatus having one or more magnetic field-producing members adapted to provide a radially-acting magnetic force to act upon the rotor shaft to reduce radial vibration thereof. Vertical motors and methods of operating the vertical motors are disclosed, as are other aspects.

Abstract: A permanent magnet bearing supports part of thrust loads of a vertical shaft induction motor, or the thrust loads of other types of rotation machinery regardless of shaft rotational axis orientation, in parallel with a lubricated mechanical bearing. The permanent magnet has a stationary magnet portion coupled to a bearing bracket and a rotating portion adapted for coupling to a rotor shaft. The permanent magnet bearing exerts a directional magnetic force that generates a preload support force on the rotor shaft that is selectively varied by varying air gap between the stationary and rotating magnet portions. Air gap between the magnet portions is varied with an air gap adjustment mechanism. The gap adjustment mechanism may be coupled to a control system that in some embodiments causes the permanent magnet bearing to vary the air gap based on external load applied on the motor.

Abstract: Induction motors may have a rotor that includes a shaft and a plurality of rotor laminations. The plurality of rotor laminations may have a central bore sized to receive the shaft, and the shaft may have a laminated portion that extends throughout the central bore. In other embodiments, the plurality of rotor laminations may have a very small or no central bore, and the shaft may include first and second end pieces respectively attached on opposite sides of the plurality of rotor laminations. In some embodiments, the first and second end shaft pieces may be attached to the rotor laminations with a through bolt that passes through the rotor laminations via a central bore sized no larger than needed to receive the through bolt, allowing each of the rotor laminations to have a larger laminated surface area. Methods of assembling a rotor are also provided, as are other aspects.

Abstract: An air-cooled electric machine, such as an alternating current motor, having a housing containing a rotating shaft and a housing airflow cooling path has cooling vents on the housing periphery. An external cooling system having a duct enclosure is coupled to the housing exterior, and defines a duct airflow cooling path that is in communication with the housing airflow cooling vent and housing airflow cooling path. A duct fan within the duct enclosure external the housing is coupled to and driven by the shaft. The duct fan circulates air at above ambient pressure into the housing airflow cooling path.

Abstract: Induction motors may have a rotor core assembly that includes a plurality of rotor laminations having an arrangement of vents therein. The arrangement of vents may provide increased airflow through the induction motor without adversely affecting the electromagnetic properties of the motor. The arrangement of vents includes first and second circular rows of vents, wherein each vent of the first row may be radially aligned with a respective vent of the second row, and each radially aligned pair of first and second row vents may be radially aligned with a respective conductor bar slot in the rotor lamination. The number of rotor bar slots may equal the number of first row vents and the number of second row vents. Systems and methods of facilitating ventilation in an induction motor are provided, as are other aspects.

Abstract: A heat sink apparatus for induction motors and other dynamoelectric machines. The heat sink has a mounting portion adapted for coupling to a motor housing. A first heat sink portion is adapted for insertion into a motor housing interior, such as through an aperture in the frame or bearing bracket, and is thermally coupled to a second heat sink portion that is adapted for orientation outside the housing. The heat sink apparatus first heat sink portion may be inserted within an air channel of a TEFC induction motor. The heat sink preferably has a higher heat transfer rate than the motor housing.

Abstract: A computer implemented method for evaluating quality control data of a product manufactured by a partially automated manufacturing process. In the method, a database is generated which includes design specifications for the product. Manufacturing data generated from inspection of the product at each stage of the partially automated process is then received. The manufacturing data is then compared with the design specifications to determine whether the manufacturing data meets the design specifications. In one embodiment, the product is an induction coil used in electric motors.

Abstract: Machines and motors with multiple three-phase AC power connections. A motor includes first, second, and third windings arranged to drive a rotator shaft. A first end of each winding is connected to a respective power input of a three-phase alternating current (AC) power source and a second end of each winding is connected to a neutral. The motor includes at least one intermediate tap connected to each of the first, second, and third windings at substantially equal respective distances between the neutral and the respective power inputs. The intermediate taps together provide a three-phase AC power output at a voltage that is less than the voltage of the three-phase AC power source.

Abstract: A rotor bar slot having diverging sidewall profiles that are analogous to a dovetail cut is formed within an induction machine rotor body by cutting into the rotor body with a cutting head. The rotor slot diverging sidewall profile enables the rotor body to constrain a rotor bar inserted into the slot, against centrifugal forces imparted on the rotor bar during the induction machine operation.

Abstract: Permanent magnet bearings are incorporated into rotating equipment, such as induction machines, in addition to active magnetic or lubricated primary shaft support bearings. The passive magnetic bearings incorporate permanent magnets that generate directionally oriented magnetic fields of selective intensity. The magnetic field directions are aligned with a desired shaft support bearing preload direction and intensity, for example to exert axial thrust or radial preloads on the support bearings. A plurality of magnetic bearings may be oriented in opposed relationship with neutral or offsetting resultant forces. The passive magnetic force preload may be utilized to offset rotor vertical weight during induction startup or stopping cycles. Passive magnetic force preload may be applied to lubricated bearings to assure their operational stability.

Abstract: Method and apparatus for insulating induction machine conductive connectors by sliding a closed-end insulating sheath over the connector. The sheath is circumferentially secured to the conductive connector with a biasing element, such as an elastomeric stretchable fabric, stretch tape or heat shrink material. Additional insulative materials as well as resin curing catalysts or accelerants may be added to the sheath.

Abstract: An alternating current (AC) induction machine, such as a medium voltage induction motor, includes an auxiliary electrical connection box that is incorporated in the terminal box or within separate auxiliary electrical connection boxes that, are coupled to the machine's incoming power source. The box includes power conversion transformers or bridges that respectively convert the incoming AC power to other AC voltages or direct current (DC) useful for operating auxiliary devices proximal the machine. The connection box avoids the need to run separate power lines to induction machines necessary for operating auxiliary devices. Exemplary auxiliary devices include external auxiliary AC powered cooling fans for medium voltage AC motors. The auxiliary connection box may reconfigurable in the field and/or be pre-configured to provide one or more common auxiliary device output power sources.

Abstract: Machines and motors with multiple three-phase AC power connections. A motor includes first, second, and third windings arranged to drive a rotator shaft. A first end of each winding is connected to a respective power input of a three-phase alternating current (AC) power source and a second end of each winding is connected to a neutral. The motor includes at least one intermediate tap connected to each of the first, second, and third windings at substantially equal respective distances between the neutral and the respective power inputs. The intermediate taps together provide a three-phase AC power output at a voltage that is less than the voltage of the three-phase AC power source.

Abstract: An air-cooled electric machine, such as an alternating current motor, having a housing containing a rotating shaft and a housing airflow cooling path has cooling vents on the housing periphery. An external cooling system having a duct enclosure is coupled to the housing exterior, and defines a duct airflow cooling path that is in communication with the housing airflow cooling vent and housing airflow cooling path. A duct fan within the duct enclosure external the housing is coupled to and driven by the shaft. The duct fan circulates air at above ambient pressure into the housing airflow cooling path.