发明名称 |
Magnetic bearing, rotating machine mounting the same, and method for driving rotating machine |
摘要 |
In a rotating machine with employment of a sensor-less DC brushless motor, a terminal voltage of a motor is corrected in a phase corrector by using a motor phase current signal. At this time, the terminal voltage is processed in an integrator and a comparator so as to be converted into an ON/OFF signal having a duty ratio of 1:1. Then, a rotation signal is produced based on an induced voltage which is generated by rotating a permanent magnet rotor, so that a rotation sensor is no longer required. On the other hand, an output derived from the phase corrector is entered as a 1-pulse/1-rotation output signal into a PLL circuit. The PLL circuit contains a phase comparator, a low-pass filter, an oscillator, and a counter. The PLL circuit frequency-divides the 1-pulse/1-rotation output signal. The sine wave data are stored into a ROM with respect to each of the frequency-divided signal positions. The unbalance vibrations of the magnetic bearing are controlled every frequency-divided signal.
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申请公布号 |
US6111333(A) |
申请公布日期 |
2000.08.29 |
申请号 |
US19990261237 |
申请日期 |
1999.03.03 |
申请人 |
HITACHI, LTD. |
发明人 |
TAKAHASHI, NAOHIKO;ENDO, TSUNEHIRO;MIURA, HARUO;YOSHIHARA, MINORU;FUKUSHIMA, YASUO;TAKAHASHI, KAZUKI |
分类号 |
F16C32/04;F16C39/06;H02K7/09;H02P6/08;(IPC1-7):H02K7/09;H02K11/00;G05B1/02 |
主分类号 |
F16C32/04 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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