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Moonho Choi,Yoon Chul Rhim IEEE 2011 IEEE transactions on magnetics Vol.47 No.7
<P>A herringbone groove pattern is applied to a plane disk damper of a hard disk drive to reduce the axial vibration of the disk rotating at high speed. According to the design parameters such as mean radius r<SUB>m</SUB>, ridge-groove ratio B, and spiral angle β , the performance of the herringbone groove disk damper is studied numerically in terms of the stiffness and the damping coefficients and the ratio of the axial stiffness to the frictional torque. The dynamic coefficients are calculated from the result of computational fluid dynamics solution of a simple hard disk drive model using four-point central difference scheme. To confirm the numerical results, the nonrepeatable run-out of the disk is measured when a plane or a herringbone groove disk damper is used. It is found that a herringbone groove disk damper increases the stiffness as well as the damping coefficient of the air film by 20% more than those of a plane disk damper.</P>
체결조건에 따른 휠볼트 축력 변동 및 파손 원인 해석적 분석
양문호(Moonho Yang),정진호(Jinho jung),최동영(Dongyoung Choi),김재한(Jaehan Kim),이준하(Joonha Lee),최수교(Sukyo Choi) 한국자동차공학회 2018 한국자동차공학회 부문종합 학술대회 Vol.2018 No.6
As the vehicle becomes increasingly high performance, it may happen that the wheel nuts are loosen or the wheel bolts are broken during the endurance test. This paper examined the variation in the bolt clamping force and the bolt teeth stress in relation to the clamping conditions of the wheel nuts.