The experiments that imitate wear in pump impellers were performed, in which various physical values such as outlet pressure, suction pressure, flow rate and motor current were acquired simul taneously. Three impellers with various wear amount and a normal one were tested. Similarity Based Modeling (SBM) was applied to the data for detection of the abnormality. SBM is a non-parame tric modeling method that makes a model of a certain state by sampling vectors that consists of various physical values at the ...
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Investigation of multivariate analysis for detection of wear in pump impellers

A method that applies the neural network to acoustic data to detect abnormalities of horizontal pumps is proposed. In the experiments, running sound of a pump with bearing damage or misalignment was acquired from various distance while another pump in the same room was running or not running as a possible noise source. By applying the neural network to the appropriately processed frequency spectrum of acquired data, abnormality can be accurately detected regardless of the distance between the sensor and ...
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Detection of abnormality of pumps by acoustic diagnosis using neural network

A new electromagnetic method for the nondestructive evaluation of electric pumps with ball bearings is proposed. A permanent m agnet generates a static magnetic field and a coil of several hundred turns wrapped around it is used to pick up eddy currents induced inside rotating ball bearings and impellers. First, a method that make use of the autocorrelation is applied to the si gnals of the ball bearings. A relation between the processed signals and the size of the defects in the bearings is obtained....
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Electromagnetic Nondestructive Detection for Wounded Bearings andCorrelation of Size of Defect and Signal

A new electromagnetic method for the nondestructive evaluation of electric pumps with ball bearings is proposed. A permanent magnet generates a static magnetic field and a coil of several hundred turns wrapped around it is used to pick up eddy currents induced inside rotating ball bearings and impellers. First, a method that makes use of the autocorrelation is applied to the signals of the ball bearings. A relation between the processed signals and the size of the defects in the bearings is obtained....
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Electromagnetic Nondestructive Detection for Wounded Bearings and Correlation of Size of Defect and Signal

new electromagnetic method for the nondestructive evaluation of electric pumps with ball bearings is roposed. A permanent magnet generates a static magnetic field and a coil of several hundred turns wrapped round it is used to pick up eddy currents induced inside rotating ball bearings and impellers. First, a method hat make use of the autocorrelation is applied to the signals of the ball bearings. A relation between therocessed signals and the size of the defects in the bearings is obtained. In a second...
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Electromagnetic Nondestructive Detection for Wounded Bearings and Impellers andCorrelation of Size of Defect and Signal

This work investigates the effective method for detecting structural abnormality such as misalignment or unbalance in rotating machines. Experiments are performed which acquire vibration acceleration data of a horizontal pump under various structural abnormality. In order to detect abnormality comparing to the normal state, feature vector is defined as a set of magnitude of rotational frequency and its harmonics of vibration signal, then change of it is evaluated with SBM (Similarity Based Modeling). W...
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Study of the capability of detection of structural abnormality in rotating machines with multipoint analysis

In order to investigate effective methods to detect the abnormality of pipe supports, vibration data of piping was acquired under various operating pressure and conditions of supports. Single feature value such as RMS of vibration acceleration, vibration velocity, vibration displacement, was not always able to detect the abnormality. To make the feature value more informative, the feature vector was defined as the combination of 3 aforementioned feature value. Then the difference of feature vectors compa...
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Multivariate analysis method to detect abnormality of pipe supports

This study aimed to establish the method for evaluating the amount of bearing flaking in balls. We performed 5 accelerated aging tests of ball bearing s that expedite the occurance of flaking in balls and analyzed the vibraion signal. Some characteristic features for initial stage of flaking in balls are revealed such as sudden decrease of vibarion level or pulse vibration once per several revolutions of a ball. Those knowledge can be used for diag nosing the severity of bearings that indicate the existanc...
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A Study on Evaluating the Amount of Bearing Flaking in Balls

A new electromagnetic method for the nondestructive evaluation of electric pumps with sliding bearings is proposed. A permanent magnet gen erates a static magnetic field and a coil of several hundred turns wrapped around it is used to pick up eddy currents induced inside rotat ing impellers. This electromagnetic nondestructive evaluation method is applied to the canned pump. By monitoring the movement of the impe ller in a canned pump, the rotation speed, the variance of the impeller position as well as th...
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Study of Evaluation Method for the Amount of Wear-Out of Plain bearingswith Electromagnetic Sensor

The epochal electromagnetic nondestructive detection method was proposed. In that method a permanent magnet is zed to generate static magnetic field and a several hundred turn coil is used to detect the eddy currents induced inside ball bea rings. In the present study the signal procedure method of a autocorrelation method is also proposed in tion to that detection method and these methods are applied to observe and evaluate ball bearings wounded by grinder. erimental validatio ns are carried out using a c...
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Lectromagnetic Nondestructive Detection for Wounded Bearings and Proposalof the Signal Procedure Method for Estimating the Wound Width