• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.905-906
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.553-554
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1021-1022
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• 2010

• Journal of Drive and Control
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• v.7 no.1
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• pp.33-37
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.399-400
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.77-78
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• 2007

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.5
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• pp.30-36
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• 2018

Automotive fuel efficiency regulations and air pollution control are hot issues of recent years in the automotive industry. To solve these regulation problems, many studies are continuing to improve the transmission efficiency of transmissions. Tapered roller bearings are useful to improve the transmission efficiency in the recent automobile parts. The frictional losses in the tapered roller bearings are mainly composed of the rolling friction and the sliding friction, and are dependent upon the load, the lubrication, the rotation speed of bearings, and etc. In this paper, the operating conditions of the transmission are defined and then the power losses of each bearing are calculated. In addition, improvement options are suggested after identifying the design factors influenced much by the improvement effect of power loss under the operating conditions of each bearing. We compare the power losses of the entire transmission system due to bearing improvements by comparing the friction losses between the original design and the improved design. Lastly, it is shown that the calculated power losses are valid by comparing the test values and the theoretical values for the frictional torque characteristics of the original and improved bearings.

• Journal of the Korean Society of Safety
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• v.11 no.2
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• pp.42-51
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• 1996

Taper roller bearing is used on rotating shaft where radial and thrust loads are attended. To avoid the sudden failure and maintain the good condition of rotating machinery it is necessary to monitor the condition of bearing and diagnose the defect of bearing. In this study the diagnosis program of taper roller bearing which is used on the lower bearing of V.A.W.T. (Vertical Axis Wind Turbine) is developed. By plenty of test the database is constructed and by Gaussian distribution obtained from database the defect probability of bearing is calculated.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.2
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• pp.181-191
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• 2014

This study aims to evaluate cutter acting forces as well as axial stresses and torques in the shaft of two kinds of disc cutters including a single disc cutter and a double disc cutter with the same cutter ring geometry in a series of linear cutting tests. From the tests, the mean values of normal forces and rolling forces acting on the double disc cutter were approximately twice as high as those from the single disc cutter. Similarly, the mean values of axial stresses in the shaft of the double disc cutter were also twice as high as those from the single disc cutter even though the comparisons of torques from two kinds of disc cutters were insignificant since they showed very low values. However, it is necessary to take the durability of a tapered roller bearing used for the double disc cutter into high consideration since the average normal force from the double disc cutter exceeds the allowable force for a disc cutter with the diameter of 432 mm (17 inches). Finally, there is no practical problem in terms of axial stresses in the shaft of the double disc cutter since they are much lower than the yielding stress of the cutter shaft material, even though the axial stresses in the shaft of the double disc cutter are approximately twice as high as those from the single disc cutter.