Abstract: A method of determining the rotational speed of a rotating shaft from machine vibration data. The vibration produced by the shaft is sensed to produce a test vibration signal at an unknown rotational speed of the shaft, which test vibrational signal is converted to a test frequency spectrum. A reference frequency spectrum, corresponding to a known rotational speed of the shaft, is provided, and a stretch factor is determined. The stretch factor provides optimum correlation between the test frequency spectrum and the reference frequency spectrum. The unknown speed of the rotating shaft is calculated using the known speed of the reference frequency spectrum and the stretch factor.

Abstract: A method for nonintrusive detection of anomalies in electric machines. A flux coil is positioned external to the motor to obtain magnetic leakage flux measurements, which are transformed to the frequency domain to obtain a flux spectrum. Asymmetry-producing faults, such as turn-to-turn stator winding shorts, produce changes in the amplitudes of individual frequencies and groups of frequencies within a defined slot pass family of frequencies of the flux spectrum. The measured amplitudes of the slot pass family of frequencies are compared to reference and trend data. Significant changes in the slot pass frequency amplitudes indicate the presence of a machine fault or other anomalous condition. Significant changes are determined by comparing individual amplitudes and groups of amplitudes of the slot pass family of frequencies to an absolute or delta threshold value.

Abstract: Apparatus which automates the collection of motor temperature, flux and shaft current data for proactive motor maintenance. Motor speed is determined by an analysis of the flux frequency spectrum, and motor load is determined based on speed, from which a normalized thermal parameter is then determined. From a spectrum analysis of magnetic flux signals a set of peaks each characterized by a frequency and an amplitude is found, and a subset of peaks is identified in accordance with predetermined identity criteria for purposes of comparison. Temperature, magnetic flux and shaft current data are trended to provide early indications of degradation, as well as for recognizing faults.

Abstract: A highly portable infrared thermography system automates the collection, display, analysis, annotation, and recording of thermographic data and facilitates the efficient generation of reports. The system includes an infrared camera and a digital video data collector (VDC) having an embedded PC with an internal hard drive. The VDC also includes a VGA color LCD display with touch screen overlay for displaying images, presenting information to a thermographer, and for receiving data and command inputs from the thermographer. The system can be carried with a custom vest and battery belt, or it can be mounted to a hand truck. Thermographic images captured by the infrared camera are received by the VDC and displayed in real time at rates of at least thirty frames per second to eliminate flicker. The VDC also interfaces with a videotape recorder for displaying and recording images. Other interfaces include a visible image camera interface, a digital video interface, and a base station computer interface.

Abstract: A system for managing the alignment of a plurality of machine sets includes a portable alignment analyzer for calculating machine moves tending to bring the shafts of a machine set into alignment, and a base computer. A database of alignment documentation for the machine set is maintained in the base computer, the database including alignment fixture setup data, machine dimensions and tolerances, by way of example. A data link at least periodically enables communication between the base computer and the portable alignment analyzer. When the data link is active, alignment documentation for the machine set may be selectively Loaded into the portable alignment analyzer, and measured misalignment data may be selectively Dumped to the base computer for storage in the database. The system allows previously entered and stored machine-specific setup information to be used for a current alignment job, requiring only minor changes in the field.

Abstract: A portable, hand-held, battery-powered rotor balancing calculator has a data port, which includes a host communications port to down-load set-up data from, and upload collected data to a host computer. A rotation sensor communications port receives data from the rotation sensor, and a vibration sensor communications port receives data from vibration sensors. An angle sensor communications port receives data from an angle sensor, and the calculator determines how far and in what direction the rotor has been rotated. The calculator also employs a power supply, a processor, and an operator interface. There is also a memory for data storage, menus with check-off lists, and procedures, including raw data screening procedures and collected data analysis procedures. A display is provided which depicts gathered data in a graphical form which is easily reconfigured for rotor viewing orientation.

Abstract: Apparatus for determining the rotational speed of an AC induction motor based on a spectrum analysis of a magnetic flux signal. For a Phase I analysis, which is usually sufficient, three sets of families of peaks indicative of possible rotational speeds are defined, and the flux frequency spectrum is searched for peaks meeting the family definitions to determine candidate speeds, and to assign scores. If there is a candidate speed with an overall score which exceeds a predetermined threshold, the motor rotational speed is determined as that candidate speed. A Phase II analysis, employing a more exhaustive set of five additional family definitions, is applied when Phase I fails to reach a result.

Abstract: An alignment analyzer for facilitating the alignment of a machine set including co-rotatable in-line shafts includes a display device on which separate offset misalignment and angle misalignment components are displayed as a single point in an x-y coordinate system. The coordinates of the point are the individual misalignment components. Also displayed on the display device are curves representing "acceptable" and "excellent" tolerance ranges. The displayed point and the curves together indicate whether the combined offset and angular misalignment is within or without the "acceptable" tolerance range, and whether the combined offset and misalignment is within or without the "excellent" tolerance range.

Abstract: A viscosity tester includes a free standing magnetic object disposed in fluid in a stationary receptacle. A magnetic force drives the object in an orbit and the magnetic force, the speed of the object and the lag angle between the magnetic field and the object are either measured or controlled and, based on at least one of these three parameters, the viscosity of the fluid is determined. In one embodiment, a magnetic ball is driven by four electromagnets, with proximity sensors detecting the presence of the ball and controlling the electromagnets. In another embodiment, a free standing magnet is driven in an orbital pattern by a rotating field that is coaxial with the orbital pattern and is produced by a rotating magnet or a stator.

Abstract: A system including a mobile infrared thermography unit and a base station for automating the collection of thermographic data and for facilitating the efficient generation of reports. The mobile infrared thermography unit includes an infrared camera, a storage device such as a videotape recorder for at least recording thermographic images captured by the infrared camera, and a mobile unit computer. The mobile unit computer includes a touch screen display for presenting information to a thermographer and for receiving data and command inputs from the thermographer. The mobile unit computer is interfaced to the infrared camera or the videotape recorder for maintaining a record, either by tape position or date/time stamp, where thermographic images of particular equipment are recorded.

Abstract: The specification discloses apparatus for aligning rotatable in-line machine shafts. In a preferred embodiment, the invention provides an alignment system having a sensed point positioned for rotation with the shaft to be aligned to provide a reference point against which misalignment is measured. The position of the sensed point is adjustable in three-dimensional space by an adjustment system so that the sensed point may be easily secured in a desired location to eliminate errors attributable to movement of the sensed point or improper location of the sensed point. In addition, the alignment system provides a capacitive displacement system to more accurately sense the sensed point, binary blocks to facilitate proper vertical positioning of the sensed point, and an improved chain assembly to facilitate mounting of the alignment system and to reduce errors of the type common to conventional alignment systems.

Abstract: Methods and systems for acquiring offset data for aligning co-rotatable in-line machine shafts. Two sets of offset data, each set for example representing relative displacement in a radial direction between a reference point referenced to one of the shafts and a particular point on the other of the shafts at given angular positions, are collected at a plurality of measurement angular positions. The measurement angular positions are not necessarily the 0.degree., 90.degree., 180.degree. and 270.degree. angular positions at which measurements are traditionally taken. Preferably, measured offset data is collected during continuous rotation of the shafts in their normal direction of rotation or at convenient positions where the rotation is halted. Measured offset data may be collected at as few as three angular positions, but preferably is collected at more than three angular positions, and typically at a multiplicity of angular positions such as thirty or forty.

Abstract: The specification describes a system for analyzing and processing an input analog signal. This invention provides an analog signal preprocessor which is operated in conjunction with a main instrument for measuring any defects or wear of machinery parts. The analog signal preprocessor operates to preprocess an analog signal by filtering and amplifying a signal from the analog signal to allow a more accurate reading by the main instrument. The preprocessor will adjust itself for optimum operation and communicate the operation modes to the main instrument. Also, the preprocessor can be addressed by the main instrument to setup the operation of the preprocessor according to a program or input entered into the main instrument.

Abstract: Methods for verifying the mechanical integrity of an alignment bracket, particularly a multi-configurable alignment bracket, used for aligning co-rotatable in-line machine shafts, and for determining the amount of alignment bracket "sag" to be accounted for when subsequently employing readings taken with the alignment bracket. The invention employs a previously-established relationship between sag and deflection of the alignment bracket under the influence of a known force to determine sag and to verify mechanical integrity of the alignment bracket in situ, avoiding the need for the usual prealignment sag determination on a separate straight pipe or mandrel. In the practice of the method, the alignment bracket is set up in a position for use, on the actual shafts being aligned. The extension bar of the alignment bracket is positioned above the centerlines of the shafts, and a known force is applied by hanging a known weight at a predetermined point on the alignment bracket.

Abstract: A portable vibration monitoring device (10) for use in connection with a base computer (11) which stores data regarding the nature and parameters of vibration measurements to be made on preselected machines for predictive maintenance purposes. The device includes a power module (36) which energizes the various components. A vibration sensor (14) produces an analog signal which is representative of selected vibration parameters. The signal generated by the vibration monitor is conditioned by a signal conditioning module (16) which includes anti-aliasing filters which enhance the accuracy of the data collected. A multiple function module (18) includes various selectively energized modules which enhance the speed and reliability of the data collected. This data is analyzed by a microprocessor and displayed as desired.