Abstract: A scanning device for automated eddy current inspection of retaining rings is disclosed. The scanning device supports an eddy current probe inside the retaining rings and moves the probe automatically in an axial and rotational path within the rings to scan the entire surface of the rings.

Abstract: The present invention includes a bore mapping system that includes one or more high resolution ultrasonic mapping transducers that are used to measure the diameter of a bore. The travel time for a normally incident pulse to reach the bore surface and return for each transducer is used with a reference reflection time measured in a calibration bore to determine the measured diameter from a mechanically measured reference diameter using a known velocity of the ultrasonic pulse in an immersion fluid. The diameter measured by each of the transducers is averaged to obtain an average measured diameter which is produced for plural axial rotor positions. The present invention also includes a surface time measurement system that uses at least one ranging transducer measuring the ranging time required for a ranging beam to reach and return from the bore surface.

Abstract: An immersion base ultrasonic inspection system for interrogating the bore and near bore material of turbine and generator rotors by passing ultrasonic search units through the rotor bore. This system utilizes variable focus array inspection transducers in a shear mode inspection of the near bore material. The system includes a positioning assembly for a transducer which includes carriage means for supporting the transducer and a first positioning means for tilting one end of the carriage means in a radial axial plane whereby the transducer may be positioned at an angle to a longitudinal axis of the system. A second positioning means is provided for circumferentially rotating the transducer to a known and repeatable angular position. Position resolver means are coupled to the first and second positioning means.

Abstract: An array of SQUID detectors to map the magnetic field associated with test currents flowing in the component to be tested. The SQUID is an ultrasensitive, miniature device that transduces a faint magnetic field to a measurable voltage. Perturbation occurs in the test currents and the associated magnetic field at physical defects or inhomogeneities. Multi-dimensional test currents are injected into the component being tested; the injection being made between specific electrodes by varying the direction of the current until it is normal to the direction of the defect to maximize and amplify the effect of the perturbation. The perturbation is detected by the SQUID grid which pinpoints the location, orientation, and size of the defect. The frequency of the injected current can be made to sweep the spectrum from DC to the highest response limit of the SQUID to scan for defects at various depths.

Abstract: The present invention includes a bore mapping system that includes one or more high resolution ultrasonic mapping transducers that are used to measure the diameter of a bore. The travel time for a normally incident pulse to reach the bore surface and return for each transducer is used with a reference reflection time measured in a calibration bore to determine the measured diameter from a mechanically measured reference diameter using a known velocity of the ultrasonic pulse in an immersion fluid. The diameter measured by each of the transducers is averaged to obtain an average measured diameter which is produced for plural axial rotor positions. The present invention also includes a surface time measurement system that uses at least one ranging transducer measuring the ranging time required for a ranging beam to reach and return from the bore surface.

Abstract: An immersion based ultrasonic inspection system is disclosed which is used to interrogate the bore and near bore material of turbine and generator rotors by passing ultrasonic search units through the rotor bore. This system utilizes variable focus array inspection transducers in a shear mode inspection of the near bore material. The flaw location method includes recording calibration transit times and transducer locations for calibration holes from which refraction angles, and material velocities are determined. When a flaw is detected the surface time for a bore surface reflection, the flaw reflection time and transducer position are used to determine the position of the flaw.

Abstract: An ultrasonic signal processing system that includes flaw gates that process signals from an inspection transducer is disclosed. The flaw gates operate in pairs where each pair is dedicated to a time window corresponding to, for example, flaw depth or transducer angle. The time window for a pair of flaw gates is indicated by a channel code produced by a timing control unit. One flaw gate in each pair processes incoming digitized transducer signals during a scan to produce reflector indications while the other gate in each pair transfers data from a previous different position scan to a main computer. The main computer determines flaw locations from the reflector indications and transducer positions provided by the flaw gate.

Abstract: An immersion based ultrasonic inspection system is disclosed which is used to interrogate the bore and near bore material of turbine and generator rotors by passing ultrasonic search units through the rotor bore. This system utilizes variable focus array inspection transducers in a shear mode inspection of the near bore material. A ranging transducer is provided which is used to correct the surface time of the inspection beam. A mapping transducer and blind bore sensor allow diameter mapping of the rotor bore as well as a blind rotor end sensing as the scan head carrying the transducers enters the bore. A scan head centering device or chuck deploys four radial arms to center and support the scan head. Each arm has a roller attached to the end which contacts the bore and rolls along so that the bore will not be damaged as the scan head passes through the bore.

Abstract: A shipping and storage enclosure for an ultrasonic inspection system used to inspect turbine and generator rotors from the bore which is flooded with water and which enclosure can be expanded into an operating enclosure in which the environment is controlled to provide for affective operation of the equipment and provide for alignment of the ultrasonic sensing head with the bore of the rotor shaft.

Abstract: A system for deaerating water utilized to flood a bore of a turbine rotor which is to be ultrasonically inspected in which the bore is inclined and evacuated and heated water enters the bore and impinges on a surface that breaks up the influent stream of water to substantially increase its surface area to assist in the deaeration, the bore being connected to a trough partially filled with heated water to a level above the bore to maintain the flooded condition of the bore during the ultrasonic inspection.

Abstract: Herein presented and claimed is a removable sleeve-to-shaft interlock for a dynamoelectric machine. The invention comprises: a shaft having a groove about its outer circumferential surface; a sleeve having a central bore for receiving said shaft therethrough, said sleeve having an eccentric groove about its inner circumferential surface; at least one detent, said detent being an arcuate spring having an associated radius smaller than the radius of the shaft and an associated height greater than the depth of the shaft groove, said detent depressible during assembly and disassembly; and means for circumferentially positioning said detent in the shaft groove, for example at least one spacer having at least one protrusion which mates with a similarly shaped channel in the non-eccentric groove. After assembly the detent straddles the interface between the shaft and the sleeve, being within both of the grooves simultaneously, thereby preventing axial movement of the sleeve relative to the shaft.

Abstract: Herein presented and claimed is a removable sleeve-to-shaft interlock for a dynamoelectric machine. The invention comprises: a shaft having a groove about its outer circumferential surface; a sleeve having a central bore for receiving said shaft therethrough, said sleeve having an eccentric groove about its inner circumferential surface; at least one detent, said detent being an arcuate spring having an associated radius smaller than the radius of the shaft and an asociated height greater than the depth of the shaft groove, said detent depressible during assembly and disassembly; and means for circumferentially positioning said detent in the shaft groove, for example at least one spacer having at least one protrusion which mates with a similarly shaped channel in the non-eccentric groove. After assembly the detent straddles the interface between the shaft and the sleeve, being within both of the grooves simultaneously, thereby preventing axial movement of the sleeve relative to the shaft.

Abstract: A connector assembly for joining gas-cooled conductors of a dynamoelectric machine. Conductor compression in two mutually perpendicular directions is provided by a pair of plate members which are slideably engaged with a pair of wedge members. A compressive force applied to the plate members is transmitted directly to overlapping conductor end portions in a first direction, and a component of the compressive force is also transmitted to the conductors in a direction normal to the first direction by means of an inclined surface engaging arrangement between the wedge and plate member. The positive, controllable biaxial compression feature provides high mechanical strength and good electrical conductivity. Bolts for securing the plate and wedge members together are inserted from only one side of the connector, thereby providing easy assembly and clearance for induction soldering and ultrasonic inspection.