JPH03318U

JPH03318U -

Info

Publication number: JPH03318U
Application number: JP6011889U
Authority: JP
Priority date: 1989-05-24
Filing date: 1989-05-24
Publication date: 1991-01-07

Description

[Brief explanation of drawings]

第１図はこの考案の一実施例の構成を示すブロ
ツク図、第２図は磁気軸受の一部の構造を示す斜
視図、第３図は従来の磁気軸受の制御回路の構成
を示すブロツク図、第４図は同制御回路の動作を
説明するための波形図、第５図は磁気軸受を真空
ポンプに適用した場合の構成を示す概略構成図で
ある。Ｍ_１，Ｍ_２……電磁石、Ｃ_１，Ｃ_２……コイル
、Ｓ_１，Ｓ_２……変位センサ、２……ロータ、５
……変位検出回路、６……電流指令信号発生器（
電流指令手段）、７ａ，７ｂ……電流制御回路（
電流制御手段）、９ａ，９ｂ，９ｃ……加算点、
１０……無停電電源装置、１１……停電検出器（
停電検出手段）、１２……リレー、１３…バイア
ス電流設定器、１４…バイアス電流増加分設定器
、（９ｃと１２〜１４がバイアス電流調整手段）
。 Fig. 1 is a block diagram showing the structure of an embodiment of this invention, Fig. 2 is a perspective view showing the structure of a part of a magnetic bearing, and Fig. 3 is a block diagram showing the structure of a conventional magnetic bearing control circuit. , FIG. 4 is a waveform diagram for explaining the operation of the control circuit, and FIG. 5 is a schematic configuration diagram showing the configuration when a magnetic bearing is applied to a vacuum pump. M ₁ , M ₂ ... Electromagnet, C ₁ , C ₂ ... Coil, S ₁ , S ₂ ... Displacement sensor, 2 ... Rotor, 5
...Displacement detection circuit, 6...Current command signal generator (
current command means), 7a, 7b... current control circuit (
current control means), 9a, 9b, 9c... addition points,
10...Uninterruptible power supply, 11...Power outage detector (
power failure detection means), 12...relay, 13...bias current setter, 14...bias current increment setter, (9c and 12 to 14 are bias current adjustment means)
.

Claims

[Claims for Utility Model Registration] A plurality of pairs of electromagnets that attract a rotor in opposite directions, a plurality of pairs of displacement sensors that detect displacement of each of the electromagnets of the rotor in the attraction direction, and an output of each of the displacement sensors. a displacement detection circuit that detects the amount of displacement of the rotor from the equilibrium position based on the above, and current command means that determines the value of the excitation current to be supplied to each coil according to the output of the displacement detection circuit.
Excitation power is supplied from the battery backed up power supply device, and the excitation current supplied to each of the coils is controlled in accordance with a signal obtained by adding a bias current value to the current command signal output from the current command means. A control circuit for a magnetic bearing, comprising: a power failure detection means for detecting a power failure in a power supply supplied to a motor that rotationally drives a rotating part including the rotor; and a power failure detection means for detecting a power failure by the power failure detection means. A control circuit for a magnetic bearing, comprising: bias current adjusting means for increasing the bias current value when the bias current value is detected.