Entity

Time filter

Source Type


Yusa N.,Tohoku University | Yusa N.,IIU Corporation | Miya K.,IIU Corporation | Komura I.,Japan Power Engineering and Inspection Corporation | Chen Z.,Xian Jiaotong University
International Journal of Applied Electromagnetics and Mechanics | Year: 2010

This paper introduces a research project the authors have proposed. The project aims to gather non-destructive testing data of stress corrosion cracking specimens and present them as benchmark data freely available to researchers in the field. Round-robin test using seven austenitic stainless steel plate specimens with artificial stress corrosion cracking is carried out, and they are measured using various non-destructive testing methods. The data measured are made available together with the results of destructive tests to confirm the true profile of the cracking. © 2010 - IOS Press and the authors. All rights reserved. Source


Mawatari S.,Japan Nuclear Fuel Limited | Takase K.,IIU Corporation | Tsunokai M.,IIU Corporation | Kayata R.,IIU Corporation | And 2 more authors.
COMADEM 2010 - Advances in Maintenance and Condition Diagnosis Technologies Towards Sustainable Society, Proc. 23rd Int. Congr. Condition Monitoring and Diagnostic Engineering Management | Year: 2010

The continuous monitoring of the condition of a ball bearing is very useful to accurately determine its lifetime. In this paper, two methods to continuously monitor the growth of a defect on the outer race of ball bearings with an electromagnetic or a vibration sensor are presented. The first method makes use of the autocorrelation to size relatively small defects. The second method makes use of particularities in the variation of the root mean square (RMS) value to size relatively large defects. Experimental results are presented that show that the methods allow monitoring continuously the size of outer race defects with very good accuracy. Source


Mawatari S.,Japan Nuclear Fuel Limited | Takase K.,IIU Corporation | Tsunokai M.,IIU Corporation | Kayata R.,IIU Corporation | And 2 more authors.
COMADEM 2010 - Advances in Maintenance and Condition Diagnosis Technologies Towards Sustainable Society, Proc. 23rd Int. Congr. Condition Monitoring and Diagnostic Engineering Management | Year: 2010

Replacing a bearing on a rotating machine is a costly process. By accurately monitoring the condition of the bearing, replacements can be optimally scheduled to lower the cost. Life equations exist for determining the average life span of a bearing (for example, the L 10 life formula). Optimal replacement of a bearing can be scheduled only if the actual lifetime of a given bearing is known. In this paper, the results obtained with a simple method to monitor the growth of a defect on the outer race of ball bearings with an electromagnetic or vibration sensor are used to predict the life expectancy of these bearings once a defect appeared on the outer race. Source


Perrin S.,IIU Corporation | Mawatari S.,Japan Nuclear Fuel Limited | Kayata R.,IIU Corporation | Tsunokai M.,IIU Corporation
Studies in Applied Electromagnetics and Mechanics | Year: 2016

This paper introduces a new monitoring technique for detecting the presence of wear-out in friction bearings with an electromagnetic sensor. This new method detects the presence of wear-out indirectly, through the detection of airgap eccentricity. Firstly, the electromagnetic sensor and the airgap eccentricity are introduced. Then, the effectiveness of the method is illustrated by experimental results on a pump with a 3-phase induction motor. © 2016 The authors and IOS Press. All rights reserved. Source


Tsunokai M.,IIU Corporation | Takase K.,IIU Corporation | Kayata R.,IIU Corporation | Nakano K.,Tohoku Electric Power Co.
International Journal of Applied Electromagnetics and Mechanics | Year: 2012

This paper proposes a new non-destructive method for evaluating the size of the flaking in ball bearing with an electromagnetic sensor. This method focuses on the variation of the magnitude of the characteristic frequency of a defect on the outer race. Through the presence of local maximums and minimums, the length of the flaking is evaluated while the bearing is in operation. The applicability and accuracy of this method is confirmed through several accelerated aging tests. It is shown that the growth of the length of the flaking in ball bearings is linear. © 2012 - IOS Press and the authors. All rights reserved. Source

Discover hidden collaborations