• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.272-280
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• 2009

In this study is performed to investigate the pumping characteristics of three-stage disk-type molecular drag pump (DTDP). The experiments are measured using five vacuum pressure gauges in the positions for rotors of DTDP. The experimented DTDP is consisted of three rotors and four stator. In the DTDP, spiral channels of three rotors are cut on the both upper surface and lower surface of a rotating disk, and corresponding stator is a planar disk. The experiments are performed in the outlet pressure range of $0.2{\sim}533\;Pa$. The pressure of each rotors are measured under the various condition of outlet pressure and throughputs, and nitrogen gas is used for test gas. In the numerical study, the pumping characteristics of each rotor are studied for the variation of throughputs in the all rotating channel. Pressure contour and velocity are obtained by the numerical simulation.

• Proceedings of the Korean Vacuum Society Conference
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• 2006.02a
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• pp.61-61
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• 2006

• Proceedings of the Korean Vacuum Society Conference
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• 2007.02a
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• pp.56-56
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• 2007

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.121-121
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• 2007

• Proceedings of the Korean Vacuum Society Conference
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• 2004.02a
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• pp.34-34
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• 2004

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.12
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• pp.1501-1510
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• 2004

The pumping characteristics of a single-stage disk-type drag pump (DTDP) are calculated for the variation of the vertical clearance between a rotor and stator by the three-dimensional direct simulation Monte Carlo (DSMC) method. The gas flow mainly belongs to the molecular transition flow region. Spiral channels of a DTDP are cut on the both the upper and lower sides of a rotating disk, but a stationary disk is planar. The interaction between molecules is described by the variable hard-sphere model. The no time counter method is used as a collision sampling technique. The vertical clearance has a significant effect on the pumping performance. Experiments are performed under the outlet pressure range of 0.4∼533 Pa. When the numerical results are compared with the experimental data, the numerical results agree well quantitatively

• Proceedings of the Korean Magnestics Society Conference
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• 2012.05a
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• pp.129-130
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• 2012

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1703-1708
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• 2004

In this study, we are investigated experimentally the pumping characteristics about the pumping channel shapes of disk-type drag pump (DTDP). We are experimented the pumping performance about the rotors which have channel or do not exist. The channel disk-type rotor has spiral channels both upper and lower part, and stator is planar. The planar disk-type rotor hasn't channel and stator has spiral channels both upper and lower part. The flow-meter method is adopted to calculate the pumping speed. Compression ratio and pumping speeds for the nitrogen gas are measured under the inlet pressure range of 0.001 ${\sim}$ 4 Torr. The maximum of compression ratio was about 3300 for three-stage DTDP (channel disk-type rotor), 1000 for four-stage (planar disk-type rotor) and two-stage DTDP (channel disk-type rotor) at zero throughput. The ultimate pressure was $1.6{\times}10^{-6}$ Torr for three-stage DTDP (channel disk-type rotor), $2.5{\times}10^{-6}$ Torr for four-stage DTDP (planar disk-type rotor).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.935-940
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• 2005

In this paper, dual rotor disk configuration with a coreless stator is proposed for the Lorentz force type integrated motor bearing system. An experimental compensation for the effects of high order harmonics is performed using the digital controller of the experimental setup. The runout profile and rotor unbalance are also identified by the extended influence coefficient method. The experimental results confirm that this compensation method effectively attenuates the rotor vibration all over the operating range of rotational speed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.9 s.102
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• pp.1045-1052
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• 2005

Tn this paper. dual rotor disk configuration with a coreless stator is proposed for the Lorentz force type integrated motor hearing system. An experimental compensation for the effects of high order harmonics is performed using the digital controller of the experimental setup. The runout profile and rotor unbalance are also identified by the extended influence coefficient method. The experimental results confirm that this compensation scheme effectively attenuates the rotor vibration all over the operating range of rotational speed.