Abstract: A dynamoelectric machine includes a stator having teeth fabricated from a non-magnetic material and containing at least one embedded conductor. The teeth are unitary with a back portion that is mounted to a stator back iron. Permeance variations induced by a stator winding mounted on the non-magnetic stator teeth are low which facilitates a reduction of motor noise. Specifically, since the non-magnetic teeth reduce production of permeance variations, changes in air gap forces between the rotor and the stator are decreased.

Abstract: A differential probe is scanned along a stator core tooth portion to detect lamination faults. The probe utilizes two magnetic flux injection yokes arranged side-by-side in relatively close proximity, each yoke having two arm portions and two core-tooth flux-injection surfaces, each yoke being wound with an excitation coil winding and at least one yoke-arm of each yoke having a magnetic flux sensor. Current is supplied to the excitation coil windings on each yoke to inject magnetic flux into the stator core laminations while the probe is moved in a scanning process along the core teeth across the laminations. The magnetic flux differential detected at adjacent regions in the core by flux sensors on each of the two yokes is used to incrementally evaluate the core for laminations faults. The output produced by the differential probe may be converted to a digital signal and provided to a computer system for storage and future analysis.

Abstract: A core contact (meaning core fault or keybar contact) detection method comprises: positioning at least two electrically conductive plates near at least two respective laminations of a laminated core; supplying an excitation signal to the at least two electrically conductive plates; and using a resulting signal to detect variations in capacitance between the at least two electrically conductive plates representative of a core contact.

Abstract: A direct current machine monitoring system includes a sensor configured to monitor a load current of the machine and provide a signal indicative of an alternating current component of the load current; and a computer configured for: transforming the signal to provide a time domain transformation of the alternating current component of the load current, identifying features in the time domain transformation corresponding to sparking, and assessing a condition of the direct current machine using the features. The transform may be performed using a wavelet transform. The features may be used to determine a sparking intensity and a sparking frequency in the direct current machine, which may be used to determine a sparking index for assessing the condition of the direct current machine. The sparking index may be compared to a limit value, and statistical analysis may be performed on the sparking index.

Abstract: A probe for use in detecting abnormalities in an electrical device having a wedge depression of no more than 100 mils. The probe includes a solid core surrounded by a sense coil. The ends of the core are arranged in a contact-free, spaced relationship between and at least partially above opposed surfaces of adjacent lamination teeth of a stator. Air gaps are maintained between the ends of the probe core and the opposed surfaces. The total of the two air gaps is constant. The probe is supported on a carriage arrangement and moved along the teeth. Variations in leakage flux produced with the stator energized with an energization winding to produce a flux which is a few percent of a normal energization level, are monitored.

Abstract: An apparatus for estimating the time to failure acceleration factor of a large industrial motor includes a sensor, a clock for controlling sensor sampling times, and a memory address calculator for mapping output signals of the sensor to a memory address. A unit is provided for incrementing the content of a specified memory address by unity.

Abstract: A method of making a permanent magnet body is provided. The method includes providing a first precursor body comprising a plurality of blocks and magnetizing the first precursor body to form a first permanent magnet body. A recoil magnetization pulse may be applied to the permanent magnet body after the magnetization. The precursor body may be heated during magnetization. A power supply containing a battery may be used to energize a pulsed magnet used to magnetize the precursor body.

Abstract: A rotor assembly is provided in which the rotor assembly comprises a first core portion, wherein the first core portion has at least one first core protrusion, and a second core portion, wherein the second core portion has at least one second core protrusion. The first core portion and the second core portion are configured to be matingly coupled to each other so as to form an assembled rotor assembly. In addition, the rotor assembly comprises a plurality of magnetizable members wherein respective ones of the plurality of magnetizable members are coupled to each of the first core protrusions and coupled to each of the second core protrusions. The plurality of magnetizable members are adapted to be coupled to a magnetizing fixture prior to mating the first and second core portions so as to magnetize the magnetizable members.

Abstract: A probe includes at least one core and at least one sense coil associated with the core. The ends of the core are arranged in a contact-free, spaced relationship between opposed surfaces of adjacent lamination teeth of a stator. Air gaps are maintained between the ends of the probe core and the opposed surfaces. The total of the two air gaps is constant. The probe is supported on a carriage arrangement and moved along the teeth. Variations in leakage flux produced with the stator energized with an energization winding to produce a flux which is a few percent of is normal energization level, are monitored.

Abstract: A method comprises: sampling a current waveform of an induction machine to obtain sampled points; characterizing the sampled current over a selected first time window to obtain characterized points; subtracting the characterized points from respective sampled points to obtain a residual signal comprising residual points; obtaining a frequency spectrum representative of the residual signal over a selected second time window; and identifying a rotor bar pass frequency from the frequency spectrum. The method is typically carried out by a system comprising a computer, a computer-readable medium, or combinations thereof.

Abstract: A coated ferromagnetic particle comprises a ferromagnetic core and a coating. The coating comprises a residue resulting from a thermal treatment of a coating material comprising a polymer selected from the group consisting of polyorganosiloxanes, polyorganosilanes, and mixtures thereof. A composite magnetic article comprises a compacted and annealed article of a desired shape. The composite magnetic article comprises a plurality of coated ferromagnetic articles. Each coated ferromagnetic particle comprises a ferromagnetic core and a coating. The coating comprises a residue resulting from a thermal treatment of a coating material comprising a polymer selected from the group consisting of polyorganosiloxanes, polyorganosilanes, and mixtures thereof.

Abstract: A method of making a permanent magnet body is provided. The method includes providing a first precursor body comprising a plurality of blocks and magnetizing the first precursor body to form a first permanent magnet body. A recoil magnetization pulse may be applied to the permanent magnet body after the magnetization. The precursor body may be heated during magnetization. A power supply containing a battery may be used to energize a pulsed magnet used to magnetize the precursor body.

Abstract: A rotor assembly is provided in which the rotor assembly comprises includes a first core portion, wherein the first core portion has at least one first core protrusion, and a second core portion, wherein the second core portion has at least one second core protrusion. The first core portion and the second core portion are configured to be matingly coupled to each other so as to form an assembled rotor assembly. In addition, the rotor assembly comprises includes a plurality number of magnetizable members wherein respective ones of the plurality of magnetizable members are coupled to each of the first core protrusions and coupled to each of the second core protrusions. The plurality of magnetizable members are adapted to be coupled to a magnetizing fixture prior to mating the first and second core portions so as to magnetize the magnetizable members.

Abstract: A method for evaluating core stack pressure includes: positioning a magnetic yoke near the core, the magnetic yoke being wound by an excitation winding; supplying current to the excitation winding to inject magnetic flux into the core; measuring a signal resulting from the injected magnetic flux; and using the measured signal to evaluate the core stack pressure. A system for implementing the method includes the magnetic yoke; a current supply for supplying the current; a sensor for measuring the signal; and a computer for using the measured signal to evaluate core stack pressure.

Abstract: Permanent magnets, devices including permanent magnets and methods for manufacture are described with the permanent magnet comprising, for example: iron-boron-rare earth alloy particulate having an intrinsic coercive force of at least about 1591 kiloamperes/meter (about 20 kiloOersteds) and a residual magnetization of at least about 0.8 tesla (about 8 kiloGauss), wherein the rare earth content comprises praseodymium, a light rare earth element selected from the group consisting of cerium, lanthanum, yttrium and mixtures thereof, and balance neodymium; and a binder bonding the particulate.

Abstract: An electrical machine stator core and method for reducing electromagnetic losses and the consequent heating of the core. The stator core makes use of laminations made from an iron-aluminum alloy at the core-ends of the core, while laminations between the core-ends are formed of a ferromagnetic alloy different from the iron-aluminum alloy. Use of iron-aluminum alloy laminations at the core-ends makes possible a relatively simple technique for generator uprate, by removing laminations located at the core-ends of the stator core, and then installing replacement laminations formed of the iron-aluminum alloy at the core-end, again with the result that the laminations located at the core-ends are formed of an Fe—Al alloy that is different from the alloy of the laminations between the core ends.

Abstract: A machine stator is fabricated by positioning pre-wound stator windings with respect to a laminated stator yoke and directly molding composite tooth tips into contact with respective teeth of the laminated stator yoke, or by positioning pre-wound stator windings around respective stator teeth and then coupling the stator teeth and a stator yoke, wherein the stator yoke radially surrounds the stator teeth.

Abstract: Permanent magnets, devices including permanent magnets and methods for manufacture are described with the permanent magnet comprising, for example: iron-boron-rare earth alloy particulate having an intrinsic coercive force of at least about 1591 kiloamperes/meter (about 20 kiloOersteds) and a residual magnetization of at least about 0.8 tesla (about 8 kiloGauss), wherein the rare earth content comprises praseodymium, a light rare earth element selected from the group consisting of cerium, lanthanum, yttrium and mixtures thereof, and balance neodymium; and a binder bonding the particulate.

Abstract: A method of fabricating a motor-pump combination with the motor including a stator including a plurality of teeth extending between opposite stator end faces and a plurality of tooth tips defining a generally axial bore, the method including: forming a magnetic portion of a generally annular sleeve by compression molding a plurality of axially extending ferromagnetic strips using a plastic binder; forming a non magnetic portion of the annular sleeve by injection molding plastic material between adjacent ferromagnetic strips; molding a resin material casing member for the pump with the casing member having a generally annular cylindrical section and including the annular sleeve in part in the annular cylindrical section; and inserting the annular cylindrical section into the bore of the stator and aligning the ferromagnetic strips of the annular sleeve in abutting engagement with the tooth tips on the teeth of the stator.

Abstract: The present invention provides an actuated seal assembly for controlling flow in a fluid path in turbomachinery comprising a seal and a seal carrier coupled to the seal. A displacement apparatus is coupled to the seal carrier for positioning the seal so as to control the flow in the fluid path. In addition, a drive system is provided for powering the displacement apparatus.