| Project/Area Number |
63460106
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械力学・制御工学
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| Research Institution | Nagoya University |
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Principal Investigator |
OTA Hiroshi Nagoya Univ. Mechanical Eng. Professor, 工学部, 教授 (80023050)
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| Co-Investigator(Kenkyū-buntansha) |
MITSUYA Yasunaga Nagoya Univ. Electronic-Mechanical Eng. Professor, 工学部, 教授 (10200065)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1989: ¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1988: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Keywords | Flying Head / Thin Film Hydrodynamic Lubrication / Reynolds Equation / Surface Roughness / Slip Flow / Transient Response / Laser Measuring / Magnetic Storage System / 動特性 / 平均すきま / レーザ測長 |
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| Research Abstract |
TO analyze the head crash phenomena, which are the most significant concern in the head-medium interface problem, experimental apparatus for accurately measuring flying head dynamic characteristics was realized, and analytic methods which enable to simulate the flying head dynamics in a ultra thin spacing were established.
1. Experimental apparatus: Stable flying operation of a flying head down to 0.03 mum was confirmed using newly designed experimental apparatus, which comprises high stiffness air spindle, air circulating dust filtering system and vibration control table. A high accuracy of down to 1 or 2 nm and a minimum measurement limit of 0.03 mum were achieved utilizing spacing measurement system based on laser interferometry which successfully eliminated undesirable interference fringes in beam spot and resonance noise in laser output.
2. Analytic method: The average film thickness theory was tended to gas lubrication possessing surface roughness in the slip flow regime. A simplif
… More
ied averaged Reynolds equation was derived and its applicability to determining the surface roughness effects in the slip flow regime was confirmed through comparing with experiments. The compressibility effects of lubricating films incurring a roughness on film thickness averaging were studied numerically.
Averaged static and dynamic lubrication equations were derived in the general form containing anisotropic film thickness dependent on roughness orientation. Solving these equations leads to a presentation of the dynamic characteristics of lubricating films existing between computer flying heads and textured media. Transient responses of head sliders flying over a bump were demonstrated indicating the effects of roughness orientation and roughness movement. It is interesting to note that longitudinal roughness serves to de crease damping coefficients and inversely affects moving transverse roughness. Thus, slider excursion immediately flying over a bump is minimum for longitudinal roughness and the damping speed of residual vibration is maximum for moving transverse roughness. Less
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