Abstract: A portable vibration monitoring probe is provided which comprises a housing, a probe and a transducer is provided. An analog to digital converter is coupled to the transducer output. The vibration monitor comprises an interface configured to transmit digital data comprising vibration parameters derived from the digitized analog signal to processing circuitry external to the housing. In some embodiments of the present invention, vibration monitors may be configured to store information in a memory located near the measuring point.

Abstract: A ring-shaped bearing failure sensor constructed of insulation and electrically conductive material utilizing printed circuit board technology. Because of its construction, high dimensional tolerances can be achieved and the ring can be easily assembled as a component of a generator. Further, the bearing sensor is equipped with a resistor so that the operational readiness of the sensor can be monitored.

Abstract: An ultrasonic leak detector with a wide dynamic bandwidth and repeatable fixed attenuation reference points includes a transducer which receives ultrasonic energy and converts it into an electrical output signal related in intensity and frequency to the received ultrasonic energy. A high gain charge preamplifier is connected to the transducer and generates an amplified version of the transducer's electrical output signal. The amplified signal is then passed through a multi-level logarithmic attenuator having at least one fixed attenuation reference point to create an attenuated version of the detected and amplified ultrasonic signal. The output of the logarithmic attenuator is connected to a frequency shift circuit which converts the ultrasonic frequency signal into an audio frequency signal related in magnitude and frequency to the attenuated signal.

Abstract: An ultrasonic stroboscope is used to inspect an object rotating at a first frequency to determine if the rotating object has any defects. The ultrasonic stroboscope includes a first acoustic transducer spaced apart from the rotating object. The first transducer is configured to radiate ultrasonic energy at the rotating object at a second frequency. The second frequency is substantially related to a sub-harmonic of the first frequency so that the rotating object appears acoustically substantially still. A second acoustic transducer is used to sense a reflection of the ultrasonic energy from a defect in the rotating object. The second transducer translates the sensed reflection into at least one reflection signal. A user interface is coupled to the reflection signal.

Abstract: Apparatus for detecting a dry bearing condition utilizes an ultrasonic transducer which is intermittently pulsed a certain number of times by a microprocessor and associated circuitry. The number of return pulses received by the ultrasonic transducer is detected by the microprocessor and is used to determine whether a dry bearing condition exists.

Abstract: In the ball bearing inspection apparatus and method, the butting portion 7c of a skew drive shaft 7 rotatable coaxially with a spindle rotary shaft 1 is butted against steel balls 3 which are respectively held between the respective grooves of the inner ring 4b and outer ring 4a of a ball bearing 4 to be inspected, the spindle rotary shaft 1 is rotated while applying a pre-load to the outer ring 4a by a pre-load ring 5, and the skew drive shaft 7 is rotated while controlling the rotation speed of the skew drive shaft 7 in such a manner that the respective steel balls 3, which are being rotated on their own axes and around the spindle rotary shaft 1 due to the rotation of the spindle rotary shaft 1, is caused to make a skew movement due to the butting portion 7c.

Abstract: A device for testing mechanical devices using acoustic signature analysis of the sonic signature of such devices by filtering out the frequencies of interest, recreating such frequencies from their respective harmonics, and then correlating the recreated frequencies to pre-determined known characteristics or parameters developed from valid devices to predict the long term operability of other unknown devices in a noisy environment like a factory or an airport wherein other sources of sound and/or vibration are present.

Abstract: A noise measuring device for a differential gear assembly which measures a noise generated from a differential gear under simulated driving conditions. The noise measuring device for the differential gear assembly includes: a driving motor for rotating a differential gear in a differential assembly; a braking apparatus comprised of a brake drum, a brake lining, and a brake operation knob, for providing a load of a driving condition to the differential gear; and sound sensing apparatus comprised of a sound level meter and a frequency analyzer, for measuring a noise from the differential assembly; and a driving condition sensing apparatus comprised of a torque sensor, an RPM sensor, and an A/D converter, for sensing the driving condition through the differential gear.

Abstract: A vibration sensing apparatus including an acceleration sensor 2 for outputting a sensing signal corresponding to a vibrating acceleration, a level discriminator 3 for generating an output when the output level of the signal from the acceleration sensor 2 exceeds a preset reference level, a display unit 4 for displaying the output of the level discriminator 3, a piezoelectric ceramic power generating unit 5 using piezoelectric ceramics for generating a charge when it is subjected to vibration, and a conversion unit 6 for converting the charge generated by the piezoelectric ceramic power generating unit 5 into DC power, the DC power being supplied to the level discriminator and to the display unit as power to be consumed by them.

Abstract: A method for analysing regularly recurring mechanical vibrations comprises the steps of plotting an amplitude/time spectrum associated with the vibrations, dividing the amplitude/time spectrum into time intervals shorter than the shortest time lapse between two consecutive excitations, subjecting those parts of the amplitude/time spectrum defined by each time interval to a Fourier transformation in order to obtain an amplitude/vibration-frequency interval spectrum associated with each time interval, and subjecting those amplitudes in each amplitude/vibration frequency interval spectrum associated with certain vibration frequencies to a Fourier transformation in order to obtain an excitation-frequency spectrum associated with the respective vibration frequency.

Abstract: A vibration detecting and condition monitoring system for the press section, including felts, rollers and presses, employing a feature extracting circuit having a selectable plurality of Bessel type bandpass filters and an enveloping circuit to square the bandpassed signal output prior to FFT analysis of the signal. The system enables the enhancement and detection of highly impulsive signals in the frequency domain, that are indicative of defects in machinery operation.

Abstract: An in-use rolling element bearing monitoring system which uses a piezoelectric film transducer on either a bearing, bearing support structure, or on a separate washer in close proximity to a bearing for monitoring bearing performance. One embodiment provides a bearing monitoring system for detecting and predicting bearing failure. Another embodiment provides a system configured for detecting rotational speed of a rolling element bearing. Each embodiment of the invention entails maintaining a piezoelectric film transducer in contiguous pressure wave responsive communication with a bearing for detecting bearing performance, and provides the system in a compact configuration for in-use operation on a variety of machinery and vehicle components heretofore previously not compatible.

Abstract: A current feed means is connected to an armature coil of a motor. Current is fed from the current feed means to the armature coil while the frequency of the current is gradually varied from a preset frequency to another preset frequency, thereby to vibrate the motor. The amplitudes of the frequencies are measured by a frequency analyzer means, which is brought into contact with the motor. The frequency at which the amplitude of the vibration of the motor is peaked indicates the natural frequency of the motor.

Abstract: An apparatus for detecting drive line system imbalances in an automotive vehicle includes an angular position and speed sensor located at a preselected position spaced from, but associated with the drive shaft in non-contacting relationship therewith, the sensor generates a signal responsive to the speed and angular position of the drive shaft relative to the preselected reference point. The apparatus also includes at least one vibration sensor located at a preselected position, spaced from, but associated with, the drive line in non-contacting relationship therewith. The vibration sensor detects the drive line vibration and generates a signal responsive thereto. A signal analyzer receives the signals generated by the angular position and speed sensor as well as the vibration sensor and calculates any imbalance in the drive line system and presents counterweight and position parameters for correcting any system imbalance.

Abstract: An apparatus in which ultrasonic vibrations or acoustic emissions are detected includes a rotating shaft 21 having a dressing wheel 31 mounted on one end, and a detection liquid supply unit 41 disposed at the end face of the wheel and/or shaft so as to form a gap S therebetween and to supply detection liquid toward the rotational center of the wheel to form a detection liquid membrane in the gap. An AE sensor 43 is provided integrally with the detection liquid supply unit and detects the ultrasonic vibrations or acoustic emissions of the wheel and/or shaft through the detection liquid membrane formed in the gap.

Abstract: An apparatus compares the torque from an MOV motor with the valve displacement, and from the comparison assesses MOV operating condition. A transducer measures the vibration of the housing of an MOV. The vibrations are due to the motions of the rotating elements within the housing, which motions are directly related to the motion of the valve relative to its seat. Signal processing apparatus analyzes the vibrations to recover the rotations of the rotating elements and thus the motion of the valve plug. Lost motion can also be determined (if a lost motion connection exists) by demodulating the vibration signal and thus taking into account also the lost motion. Simultaneously, the forces applied to the valve are estimated by estimating the torque between the stator and the rotor of the motor. Such torque can be estimated from measuring the input current and voltage alone, using a forgetting factor and a correction for the forgetting factor.

Abstract: The present invention relates to a process for the early detection of a crack in a rotating shaft, particularly in a shaft of a turbo generator used in a power plant. Signals that represent flexural vibrations of the shaft are measured--as a function of the rotational angle, continuously or at time intervals by means of vibration sensors in at least two radial, preferably perpendicular, directions with respect to each other. These signals are transmitted to a signal processor which uses the signals to ascertain the harmonic vibration components with single and/or double and/or triple rotational frequencies and then the processor forms single and/or double and/or triple rotational-frequent vibration orbits by means of a vectorial combination of these vibration components.

Abstract: While maintaining a shaft in a fixed state, an outer ring is rotated. Vibrations of the shaft are detected by a first vibration pickup and a second vibration pickup. Detection signals of both the vibration pickups are delivered to a frequency converter via amplifier, respectively. The frequency converter determines, by Fourier transformation, the rotation frequency of the outer ring, the revolution frequency of balls and the resonance frequency of the double-row ball bearing. A first computing assembly then calculates the contact angle and bearing rigidity, and a second computing assembly calculates the preload.

Abstract: The present invention provides a method and system for analyzing signals from rotating machines containing rotating components that slip and, thereby, to detect faults in those components. The signals are processed by a series of steps to generate coherently averaged spectra and derived features that indicate defects in, or certain other features of, machine components that slip or rotate asynchronously.

Abstract: A vibration measurement system 1 comprises a shrink-type chuck 5, a spindle 14, and a servo motor 16 as mechanical elements, and has a vibration pickup 41 attached to the outer peripheral surface of a jaw 5a holding an outer ring 4 of a roller bearing 2. A ring groove 5b is formed on the inner face of the jaw 5a holding the bearing 2, and a shell 18 with oil pressure as back pressure is fitted into the ring groove 5b. When vibration is measured, the oil pressure of the shell 18 is raised to bring bearing clearance to zero, thereby preventing so-called roller drop from causing impulsive vibration.

Abstract: A two-wire constant current powered transducer (10) for detecting, integrating and transmitting an acceleration signal (50) received from a piezoelectric crystal (12). The crystal is operatively coupled to rotating machinery (M) such that rotating anomalies correlative of wear or potential failure can be detected early enough for preventative maintenance. The transducer (10) includes two stages (30, 40). The first stage (30) is an integrator which integrates the acceleration to velocity. The second stage (40) is a gain stage. The gain stage operates with a PNP transistor emitter follower to control the output DC bias level and route the integrated acceleration signal back to the control system.

Abstract: The rolling element bearing condition testing method uses acceleration signals at frequencies over 1000 Hertz and employs band-pass and digital filtering and envelope detecting techniques. The testing method measures the vibration signals generated by the rolling element bearing in the frequency range containing the majority of the rolling bearing energy, typically from 2,000 Hertz to 15,000 Hertz, next optionally de-modulates those signals, and then uses digital filter techniques to remove the interference, either from the de-modulated acceleration signal or from the raw acceleration signal.

Abstract: A system for measuring the magnitude component corresponding to the once-per-revolution frequency or a multiple thereof of the vibration signal generated by a body rotating at a non-uniform rate. The output of a sensor detecting the acceleration of the vibration motion of the rotating body is decomposed into its frequency components. Simultaneously, the information contained in the output of a tachometer sensor for detecting the rotational speed of the rotating body is used to determine the variation of the rotational speed during the measurement interval. The speed variation information is selectively combined with the frequency components of the acceleration spectrum to yield the magnitude result that would be measured if the rotating body had a constant rotational speed. This method yields vibration information in select frequency bands that is corrected for the non-uniform rate of rotation of the body.

Abstract: In a method for the early detection and location of a change in a component of a turbine, in particular in a turbine blade, in the event of a deviation from a standard value in at least one measured value determined during operation of the turbine, an acoustic spectrum generated by the component is measured in the interior of the turbine and compared with a reference spectrum. In order to increase the intensity of signals in the acoustic spectrum, the components of the turbine, preferably runner blades, are excited from outside to acoustic emission (resonance test). An apparatus has a number of sensors for recording operating parameters of the turbine. The sensors are connected to a device for measured value conditioning. In order to detect and locate changes, an acoustic measurement probe which can be inserted from the outside into the interior of the turbine, is connected to the device.

Abstract: Apparatus for detecting defective conditions associated with a set of railway vehicle wheels and with a railtrack upon which a given railway vehicle travels comprises a rotation measurement unit for generating data indicative of rotational rate of the set of wheels; a motion sensor, such as an accelerometer or vibration sensor, for generating data indicative of motion along a vertical axis relative to the railtrack; and a data processor coupled to the motion sensor and to the rotation measurement unit for receiving the rotational rate and motion data. The data processor is designed for detecting, based on the received rotational rate and motion data, a defective condition associated with the wheel set and for detecting, based on the received motion data, a defective condition associated with the railtrack. The apparatus can be operatively combined with a mobile tracking unit for a vehicle tracking system.

Abstract: A method and system for balancing an automotive vehicle driveline (10) after it has been installed into a vehicle (8). An impact hammer and a system analyzer (36) are used to determine a frequency response function at each end of a driveshaft (16). From this, a critical frequency of rotation is determined for the driveshaft (16) for that particular model of vehicle (8) and driveline (10). Each vehicle (8) that comes off of an assembly line can now have a balance test performed on it using accelerometers (44 and 46) and a phase angle measurement. Combining the measurement with the frequency response function, the imbalance of the driveline is determined and compared to a predetermined limit to determine if correction masses need to be added. If so, a determination of the amount of mass needed and the orientation is made.

Abstract: While maintaining an outer ring in a fixed state, an inner ring is rotated. Radial vibrations of the outer ring are detected by a vibration pickup, and detection signals are delivered to a frequency converter via an amplifier. The frequency converter determines, by Fourier transformation, the rotation frequency of the inner ring and the revolution frequency of balls. The processor then calculates the contact angle of a rolling bearing on the basis of these rotation frequency and revolution frequency.

Abstract: A microphone, coupled to the machinery under test, is connected via a blanking amplifier to a headset speaker. A sync generator, coupled to the machinery, generates a pulse each time the machinery passes through a reference position. This sync pulse sequence is the input to a phase locked loop which produces an internal representation of the instantaneous phase position of the machinery. Each time this phase position reaches an operator designated phase position, the blanking amplifier is unblanked for a duration designated by the operator so that only the operator designated segment of the machinery cycle is audible.

Abstract: An ultrasonic testing method for detection of flaws in a ball-shaped material to be tested using an ultrasonic probe, wherein a test frequency f (MHz) of the probe and a radius of curvature r (mm) of a tip portion of the probe satisfy the relationship 50 mm.ltoreq.r.sqroot.f.ltoreq.60 mm, and wherein the radius of curvature r (mm) of the tip portion and the diameter D (mm) of an oscillator of the probe satisfy the relationship 0.35 mm.ltoreq.D/r.ltoreq.0.50 mm. The method enables detection of surface and internal flaws in materials, particularly ceramic ball hearings having a diameter ranging from several tens of millimeters down to 10 mm or below.

Abstract: A bearing assembly monitoring system provides continuous, real time monitoring of the operating condition of a powertrain support bearing assembly and real time alarm signals indicative of degradation and/or impending catastrophic failure thereof. One embodiment of the monitoring system includes a vibration sensing device, first and second primary temperature sensing devices, an ambient temperature sensing device, vibration and temperature signal processing subcircuits, and an alarm subsystem. The vibration sensing device monitors complex vibration signals emanating from the bearing assembly and provides signals corresponding thereto. The vibration signal processing circuit filters such complex vibration signals to provide a predetermined bandwidth thereof that are converted to stabilized DC voltage signals which are compared to reference voltages corresponding to higher than normal and excessive vibration levels. Exceedance of such reference voltages generates a corresponding vibration alarm signal.

Abstract: The device includes a stand, a rail for supporting the wheel fixed to a horizontal part of the stand, longitudinal guide members fixed to a vertical part of the stand and extending in a direction parallel to the rail, slideways fixed to the horizontal part of the stand and extending in a direction parallel to the rail, and a carriage movable along the slideways. The carriage carries a grinding device and a hardness measuring device. Means permit applying a force on the hardness measuring device. An ultrasonic inspection device carried by the carriage may also be provided.

Abstract: The present invention is directed to methods and apparatus relating to an accelerometer electrical signal recorder and playback module. The recorder module may be manufactured in lightweight configuration and includes analog memory components to store data. Signal conditioning circuitry is incorporated into the module so that signals may be connected directly from the accelerometer to the recorder module. A battery pack may be included for powering both the module and the accelerometer. Timing circuitry is included to control the time duration within which data is recorded or played back so as to avoid overloading the analog memory components. Multiple accelerometer signal recordings may be taken simultaneously without analog to digital circuits, multiplexing circuitry or software to compensate for the effects of multiplexing the signals.

Abstract: A device for monitoring vibration of a bearing to assess whether other service is required. The device is adaptable for use with conventional grease guns and can be used simultaneously with lubrication of a bearing. The device includes an electric circuit and headphones which enable the wearer to "listen" to the bearing. Depending on the "bearing noise" that is heard, maintenance personnel can assess what further lubrication is required and what service is needed.

Abstract: A submerged motor pump is provided in a piping system or connected to a pressure vessel, and a pump and a motor are immersed in the fluid. A rotor rotatable together with a pump impeller is fixed to a rotor shaft. The rotor shaft is supported by a thrust bearing. A cover is provided facing the end of the rotor shaft and carries an ultrasonic sensor on its outside surface. The ultrasonic sensor projects ultrasonic wave toward the end of the rotor shaft and detects the echo therefrom so as to measure the distance between the end of the rotor shaft and the inside surface of the cover, i.e. the surface thereof in contact with the fluid. The inside surface of the cover includes a concave spherical surface which faces the end of the rotor shaft and substantially converges the main beam of the ultrasonic wave to the end of the rotor shaft, preventing reduction of sound pressure of the ultrasonic wave.

Abstract: While maintaining a shaft in a fixed state, an outer ring is rotated. Vibrations of the shaft are detected by a first vibration pickup and a second vibration pickup. Detection signals of both the vibration pickups are delivered to a frequency converter via amplifier, respectively. The frequency converter determines, by Fourier transformation, the rotation frequency of the outer ring, the revolution frequency of balls and the resonance frequency of the double-row ball bearing. The first computing device then calculates the contact angle and bearing rigidity, and the second computing device calculates the preload.

Abstract: The present invention provides for an inspection system and method for detecting defects in test objects which includes means for generating expansion inducing energy focused upon the test object at a first location, such expansion being allowed to contract, thereby causing pressure wave within and on the surface of the test object. Such expansion inducing energy may be provided by, for example, a laser beam or ultrasonic energy. At a second location, the amplitudes and phases of the acoustic waves are detected and the resonant frequencies' quality factors are calculated and compared to predetermined quality factor data, such comparison providing information of whether the test object contains a defect. The inspection system and method also includes means for mounting the bearing ball for inspection.

Abstract: An ultrasonic testing method for detecting flaws of balls for structural members comprises rotating a ball to be tested in an ultrasonic wave transmitting medium. At least two focus-type ultrasonic probes are provided and arranged so as to cover nonoverlapping flaw-detecting regions on and/or inside the ball. Flaws in the ball are detected by sending ultrasonic waves from the probes toward the ball. An apparatus for detecting flaws of balls comprises a ball holding portion for rotatably holding the ball to be tested, at least two focus-type probes for detecting flaws and at least two probe mounting portions for mounting the probes thereof so that respective axes of the probes are each capable of being set eccentrically relative to the center of the ball and wherein the focal positions of the probes are variable.

Abstract: An apparatus for detecting machining conditions in a machine tool has a magnetic bearing for magnetically supporting a work spindle or a tool spindle. An exciting current detector is provided for detecting an exciting current of an electromagnet of the magnetic bearing. The exciting current corresponds to various machining conditions including the conditions when the machine tool starts operating, the tool contacts the workpiece to follow various unfinished faces, and a machining face condition of the workpiece during machining. The detection signals from the exciting current detector are inputted to a plurality of frequency band pass filters to discriminate the machining conditions. Comparators are provided to compare the output signals from the frequency band pass filters with a predetermined set of reference values, and comparative judgment signals are inputted to a control unit, thereby controlling the machine tool to automatically perform appropriate machining operations.

Abstract: An immersion type automatic ultrasonic testing apparatus for detecting flaws of balls comprising a tank for containing a liquid medium of transmitting ultrasonic wave, a ball rotating device for rotating a ball to be tested, an ultrasonic flaw detection device for detecting flaws in the ball while swiveling a probe around the ball rotated by the ball rotating device or rotating the ball spirally by the ball rotating device with or without swiveling the probe, and a ball feeding and removing device for feeding the ball to the position of the ball rotating device and removing the tested ball from the ball rotating device to a predetermined position. The ball feeding device comprises a holding device having an air cylinder and a tip with a pair of holder claws and a pair of side support claws for holding the ball.

Abstract: A method for predicting destruction of a bearing preliminarily finds frequency range of acoustic emission signals indicating fatigue of bearings. In order to find the fatigue-related frequency range, frequency components of electrical noise, mechanical noise, acoustic emissions (AE) due to slip of a bearing, and AE due to plastic-deformation of the bearing are respectively obtained under corresponding conditions, using a test equipment. Then, under a certain condition, combined AE signals of electrical noise, mechanical noise, slip-related AE, plastic-deformation-related AE and rolling-fatigue-related AE are generated. By subtracting the frequency components of electrical noise, mechanical noise, slip-related AE, plastic-deformation-related AE from frequency components of the combined AE signals, the fatigue-related frequency range is obtained. This frequency range is used to predict destruction of a bearing.

Abstract: An ultrasonic rotational speed sensor in which all of the various electronic devices of the sensor are arranged compactly on one side of a rotational member to be measured, while maintaining a high precision in a rotational speed measurement. In this sensor, the transmitter microphone and the receiver microphone as well as other electronic devices associated with them are arranged on the same one side of the rotational member, where the rotational speed of the rotational member is determined from a period of the ultrasonic signals transmitted from the transmitter microphone, reflected at non-notch portions of the rotational member, and received by the receiving microphone, while a direct transmission from the transmitter microphone to the receiver microphone without an interaction with the rotational member is prevented by the use of a high frequency ultrasonic signals at MHz level.

Abstract: An apparatus and method for detecting defects in moving parts having a central rotating shaft, in particular shaft bearings, with the aid of an acoustic-electric transducer converting the mechanical acoustic vibrations received into electric signals to be processed in a signal processing circuit to signals indicative of the status of the parts, the improvement wherein the acoustic-electric transducer is centrally disposed on one end of the shaft so that it rotates therewith and receives vibrations therefrom, and wherein the acoustic-electric transducer comprises a piezoelectric element, and an amplifier having its control terminal coupled to the pass filter.

Abstract: An immersion type automatic ultrasonic testing apparatus for detecting flaws of balls comprising a tank for containing a liquid medium of transmitting ultrasonic wave, a ball rotating device for rotating a ball to be tested, an ultrasonic flaws detection device for detecting surface flaws in the ball while swiveling a probe around the ball rotated by the ball rotating device or rotating the ball spirally by the ball rotating device with or without swiveling the probe, and a ball feeding device for feeding the ball to the position of the ball rotating device. The ball feeding device comprises an air cylinder for holding the ball by suction at the tip thereof. For the suction holding of the ball at the tip of the air cylinder, a level regulating device is additionally provided for setting a level of the liquid medium of transmitting ultrasonic wave in the tank wherein the ball rotating device and the ultrasonic flaws detection device are placed.

Abstract: An ultrasonic testing method for detection of flaws in a material to be tested having a curved surface portion by use of an ultrasonic probe, wherein a center axis of curvature of the curved surface portion of the material to be tested and the center axis of the probe are set in an eccentric relationship so that the angle of refraction of an ultrasonic wave is 90.degree., and the probe comprises a tip portion having a curved surface of the same kind as the curved surface portion of the material to be tested and a radius of curvature of from 1.0 to 3.0 times the radius of curvature of the curved surface portion of the material to be tested. The method enables detection of internal flaws in, particularly, a spherical or cylindrical body formed of a ceramic and used as a bearing member.

Abstract: A method and an apparatus for observing operating state of a mechanical seal are disclosed. The apparatus comprises a sensor 1, amplifier 2,4, a root mean square value voltmeter 5 and a computer 7. Root mean square values of outputs of high frequency acoustic emission generated by a mechanical seal provided on a rotary machine are inputted in the computer 7 which performs operations to obtain a maximum value, a minimum value, a mean value and deviation of the continously measured root mean square values. The computer also computes the magnitude of each of the values, any tendency for variation thereof and their mutual relationships, whereby the operating state of the mechanical seal is judged in terms of damage of and the possibility of leakage of sealed fluid from the sliding surfaces of the mechanical seal.

Abstract: The diametral variations around the circumference of a bearing roller are measured by mechanical-to-electrical transducers which convert the diametral variations into electrical signals which are functions of the variations. The frequencies of the electric signals are converted into electric spikes which are proportional to the actual effect on roller noise of the frequency represented by each spike. The spikes are electrically added and a print is made of a value which is proportional to the expected noise the roller will produce when used in a roller bearing.

Abstract: In a method of detecting defects formed in a surface or in the vicinity thereof of a ball of a bearing by means of an ultrasonic wave, the ball and a probe for projecting an ultrasonic wave toward the ball and receiving an ultrasonic wave reflected from the detects are arranged in water in such a manner that a center axis of the probe is deviated from a normal axis of the ball which passes through a center of the ball and extends in parallel with the center axis of the probe by such a displacement amount that the ultrasonic wave refracted by the ball propagates along the surface of ball. The ball is rotated about a horizontal axis perpendicular to the normal axis, and the ball and probe are rotated relative to each other about a center axis of the ball which is perpendicular both to the normal axis and horizontal axis of the ball, so that the whole surface of the ball is scanned automatically with the ultrasonic wave.

Abstract: Method for predicting destruction of a rolling bearing using an apparatus which has a sensor for detecting acoustic emission signals from a rolling bearing, a plurality of band-pass filters which have different specific frequency pass bands within the range of 150-400 KHz, first comparators for comparing outputs from the band-pass filters with their respective reference values for the specific frequency bands, time-measuring devices for measuring time during which the outputs from the band-pass filters exceed the reference values, and second comparators for comparing the time measured with a further reference value. Of all signals detected by the sensor, only those that have frequencies of 150-400 KHz pass the corresponding band-pass filters, and then are compared with their respective reference values. The first comparators signal to the time-measuring devices when the outputs from the band-pass filters exceed the reference values.

Abstract: An acoustic microscope surface inspection system and method in which pulses of high frequency electrical energy are applied to a transducer which forms and focuses acoustic energy onto a selected location on the surface of an object and receives energy from the location and generates electrical pulses. The phase of the high frequency electrical signal pulses are stepped with respected to the phase of a reference signal at said location. An output signal is generated which is indicative of the surface of said selected location. The object is scanned to provide output signals representative of the surface at a plurality of surface locations.

Abstract: Each bearing of an aligned line-shaft has vibration responses which differ from the vibration responses of a misaligned system in which at least one of the bearings is statically displa=ced. Computed static displacement values for each bearing are derived from the equation of motion of the system employing mass, stiffness and damping coefficients of the system. The static displacement value of each bearing is computed from the vibration responses of all of the bearings. Accelerometers sense the vibration response of each bearing. A computer computes the magnitude of misalignment of each bearing from the sensed responses. The computed results provide an indication of the magnitude of static displacement of each bearing of the system causing the sensed vibration response.