JP2000266117A - Rotary magnetic damper - Google Patents
Rotary magnetic damperInfo
- Publication number
- JP2000266117A JP2000266117A JP11111274A JP11127499A JP2000266117A JP 2000266117 A JP2000266117 A JP 2000266117A JP 11111274 A JP11111274 A JP 11111274A JP 11127499 A JP11127499 A JP 11127499A JP 2000266117 A JP2000266117 A JP 2000266117A
- Authority
- JP
- Japan
- Prior art keywords
- disk
- shaft
- magnet
- permanent magnet
- conductor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Vibration Prevention Devices (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は軸のふれまわり振動と
くに共振乗り越しに関するものである。この発明は振動
を発生する高速回転軸の振動を低減させるものであり、
回転軸を有する各種の機器に利用できる。とくに非接触
を特徴とするので、磁気軸受、高温超電導軸受等の非接
触回転軸の振動抑制に用いられる。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to whirling vibration of a shaft, and more particularly to overrunning of a resonance. The present invention reduces vibration of a high-speed rotating shaft that generates vibration,
It can be used for various devices having a rotation axis. Particularly, since it is characterized by non-contact, it is used for suppressing vibration of non-contact rotating shafts such as magnetic bearings and high-temperature superconducting bearings.
【０００２】[0002]
【従来の技術】高速回転を行う軸は通常いくつかの共振
点を乗り越し、高次モードで回転させる。このとき共振
点を乗り越す一般の方法は強力なモータを用いて加速
し、共振点を速やかに通過する方法が取られる。それで
も共振点近傍では、他の回転数に比べでかなり振動が大
きくなる。そこで減衰力を軸受等から取り入れる方法が
用いられてきたが、振動抑制に十分な減衰力を取り入れ
るためには、軸受間隔を必要に応じて狭めなければなら
ない欠点があった。一方磁気軸受、高温超電導軸受を用
いた非接触回転軸は、軸受摩擦が無いためと潤滑の必要
が無いため、数万ｒｐｍで回転させることができる。し
かしこの場合は非接触のため、減衰が少なく、共振点を
無制御で通過することが困難となる。そこ整で一般に
は、磁気アクチュエータを用いて共振をアクティブ制御
で抑制する方法が用いられる。しかしアクティブ制御は
複雑な構成となり、高価でランニングコスト（エネル
ギ）も必要とし、かつメンテナンスも無制御のときに比
べ格段に難しい等の欠点があった。2. Description of the Related Art A shaft rotating at high speed usually jumps over several resonance points and rotates in a higher mode. At this time, a general method of jumping over the resonance point is to accelerate by using a powerful motor and quickly pass the resonance point. Nevertheless, near the resonance point, the vibration becomes considerably larger than at other rotational speeds. Therefore, a method of taking damping force from a bearing or the like has been used. However, in order to take in damping force sufficient for suppressing vibration, there is a disadvantage that the bearing interval must be reduced as necessary. On the other hand, a non-contact rotating shaft using a magnetic bearing and a high-temperature superconducting bearing can be rotated at tens of thousands of rpm because there is no bearing friction and no need for lubrication. However, in this case, since there is no contact, attenuation is small, and it is difficult to pass through the resonance point without control. Therefore , generally, a method of suppressing resonance by active control using a magnetic actuator is used. However, the active control has a complicated structure, is expensive, requires a running cost (energy), and has a drawback that maintenance is much more difficult than when no control is performed.
【０００３】[0003]
【発明が解決しようとする課題】本発明は上記の欠点を
解消するもので、本ダンパを組み込むことにより容易に
大きな減衰を回転損失無しに与える。とくに無制御で非
接触回転軸の共振乗り越しを行い、かつ目標とする共振
以外の高次振動に対しても振動を抑制するものである。SUMMARY OF THE INVENTION The present invention solves the above-mentioned disadvantages, and can easily provide a large damping without rotation loss by incorporating the damper. In particular, it is intended to control over the resonance of the non-contact rotary shaft without control, and to suppress vibration even for higher-order vibrations other than the target resonance.
【０００４】[0004]
【課題を解決するための手段】回転軸に磁石を取り付
け、その磁石に対向するように適当な間隙を置いて電気
導体の回転円板を配し、その円板を軸の回転方向と反対
方向に回転させる。または回転軸に電気導体円板を取り
付け、その円板に対向するように適当な間隙を置いて磁
石を配し、その磁石を軸の回転方向と反対方向に回転さ
せる。このような構成とすることで、軸の相対速度を増
加させることができる。磁石からわずかに離して電気導
体を置き、磁石あるいは導体を動かすと、導体内に渦電
流が流れ、それと磁場とが作用し、ローレンツ力と呼ば
れる抵抗力が発生する。すなわち導体あるいは磁石の動
く方向と反対方向の抵抗力が発生する。この磁気ダンパ
を回転軸等の振動系に取り付けると、抵抗力はとりもな
おさず振動の減衰力となる。このときの減衰力は速度に
比例することが知られている。すなわち、速度が大きけ
れば、抵抗力も大となる。したがって、本装置のような
構成とすることで、軸の回転数にかかわらず、外部磁石
あるいは外部円板の回転数を増大させることで減衰力を
増大させることができる。また導体円板の回転数を制御
することで減衰量も制御することができる。Means for Solving the Problems A magnet is attached to a rotating shaft, and a rotating disk of an electric conductor is arranged at an appropriate gap so as to face the magnet, and the rotating disk is oriented in a direction opposite to the rotating direction of the shaft. Rotate to. Alternatively, an electric conductor disk is attached to the rotating shaft, a magnet is arranged at an appropriate gap so as to face the disk, and the magnet is rotated in a direction opposite to the rotation direction of the shaft. With such a configuration, the relative speed of the shaft can be increased. When an electric conductor is placed slightly away from a magnet and the magnet or the conductor is moved, an eddy current flows in the conductor, and a magnetic field acts on the eddy current to generate a resistance called Lorentz force. That is, a resistance force is generated in the direction opposite to the direction in which the conductor or the magnet moves. When this magnetic damper is attached to a vibration system such as a rotating shaft, the resistance becomes a damping force of the vibrations. It is known that the damping force at this time is proportional to the speed. That is, as the speed increases, the resistance increases. Therefore, by adopting a configuration like this device, the damping force can be increased by increasing the rotation speed of the external magnet or the external disk regardless of the rotation speed of the shaft. In addition, the amount of attenuation can be controlled by controlling the number of rotations of the conductor disk.
【０００５】[0005]
【実施例】図１は超電導浮上軸を示したもので、クライ
オスタット底部に高温超電導円板８が置かれている。軸
は非磁性材で、永久磁石円盤７が下端部に、中間に円盤
ロータ６、ファン５および上端部に永久磁石４が取り付
けられている。またハウジングに永久磁石２が磁石４の
Ｎ極とＳ極が対向するように取り付けられ、磁石２と４
の間に電気導体の円板３が配され、モータ１により円板
３が回転できるようになっている。このような構成とす
ることで、軸は高温超電導円板８のピン留め力で非接触
で浮上する。この時ピン留め力は軸方向および軸直角方
向の２方向に作用する。また軸上端に取り付けられた磁
石の吸引力で軸上端に軸直角方向の復元力が作用し、軸
方向の不安定力は高温超電導体の軸方向ピン留め力によ
り安定化される。したがってこの軸は無制御で非接触で
安定に浮上する。この軸のファン５に圧縮空気を接線方
向に当てることで軸を回転させ、共振点を通過させ、定
常回転数まで加速させることを考える。FIG. 1 shows a superconducting levitation shaft, in which a high-temperature superconducting disk 8 is placed at the bottom of a cryostat. The shaft is made of a non-magnetic material, and a permanent magnet disk 7 is attached to a lower end portion, a disk rotor 6, a fan 5 and a permanent magnet 4 are attached to an upper end portion in the middle. Further, the permanent magnet 2 is attached to the housing such that the north pole and the south pole of the magnet 4 face each other.
A disk 3 of an electric conductor is disposed therebetween, so that the disk 3 can be rotated by the motor 1. With such a configuration, the shaft floats in a non-contact manner by the pinning force of the high-temperature superconducting disc 8. At this time, the pinning force acts in two directions: an axial direction and a direction perpendicular to the axis. In addition, a restoring force in the direction perpendicular to the axis is applied to the upper end of the shaft by the attractive force of the magnet attached to the upper end of the shaft, and the unstable force in the axial direction is stabilized by the axial pinning force of the high-temperature superconductor. Therefore, this shaft floats stably without control and without contact. It is considered that the shaft is rotated by applying compressed air to the fan 5 of the shaft in a tangential direction to allow the fan to pass through a resonance point and accelerate to a steady rotation speed.
【０００６】図１で磁石２、磁石３および電気導体の円
板４の部分が本発明の構成図である。すなわちモータ１
で導体円板３を軸の回転方向と逆向きに回転させること
で、軸側の磁石４の回転方向と導体円板の回転方向が逆
となり、相対速度が増加する。このときの軸の回転数ω
に対する本ダンパの等価減衰係数をｃとすると ｃ＝ｃ０（１＋ω１／ω） （１） となる。ここにｃは本ダンパの減衰係数、ｃ０は導体円
板を回転させないときの磁気減衰による減衰係数であ
り、ω’は導体円板の回転数を、またωは軸の回転数を
表す。式（１）より導体円板の回転数をω’を増加させ
ることにより減衰係数ｃが増大することがわかる。なお
本実験では、２個の磁石２，４の間に導体円板３を配置
しているので、減衰力は大きくなっているが、磁石４と
導体円板３だけでも導体円板の回転による減衰効果が得
られる。In FIG. 1, the magnet 2, the magnet 3, and the disk 4 of the electric conductor are structural diagrams of the present invention. That is, the motor 1
By rotating the conductor disk 3 in the direction opposite to the rotation direction of the shaft, the rotation direction of the magnet 4 on the shaft and the rotation direction of the conductor disk are reversed, and the relative speed increases. The shaft rotation speed ω at this time
Is c = c 0 (1 + ω 1 / ω) (1) where c is the equivalent damping coefficient of the present damper with respect to Here, c is the damping coefficient of the present damper, c 0 is the damping coefficient due to magnetic attenuation when the conductor disk is not rotated, ω ′ is the rotation speed of the conductor disk, and ω is the rotation speed of the shaft. From the equation (1), it can be seen that the damping coefficient c increases by increasing the rotational speed of the conductor disk ω ′. In this experiment, the conductor disk 3 is arranged between the two magnets 2 and 4, so that the damping force is large. However, the magnet 4 and the conductor disk 3 alone cause rotation of the conductor disk. A damping effect is obtained.
【０００７】[0007]
【発明の効果】本発明の効果を表したものが図２であ
る。図２中には図１の上端磁石４の位置の軸直角方向の
第一次共振（６．５Ｈｚ）における軸の変位振幅と導体
円板３の回転周波数の関係が示されている。この図よ
り、導体円板３の回転数（軸の回転方向と逆向きに回
転）とともに共振点における軸の振動振幅が減少してい
る。その効果は大きく、軸の振幅は導体円板を約３０Ｈ
ｚで回転させたとき、回転させないときの約１／３以下
に抑制されている。このことより本発明の効果を列記す
ると次のようである。 （１）本ダンパにより非接触かつ無制御で相当大きな減
衰を回転軸のふれまわり振動に与えることができる。 （２）本ダンパで磁石を厚み方向に一様に磁化した円板
あるいは円筒磁石を用いると、回転方向に対する磁気減
衰はなくなるの。したがって原理的には本ダンパによる
回転エネルギ損失はない。もちろんふれまわりに対する
エネルギ損失を有する。 （３）本ダンパは、導体円板を回転させるエネルギを必
要とするが、目的の共振を乗り越したあと、回転を静止
させることで、それ以後のエネルギを必要としない。ま
た円板の回転を静止した後も磁石の間に導体円板が介在
するので、ふれまわりに対する通常の磁気ダンパとして
の減衰を与える。したがって高次の振動抑制には静止時
も相当の減衰効果を有する。FIG. 2 shows the effect of the present invention. FIG. 2 shows the relationship between the displacement amplitude of the shaft and the rotation frequency of the conductor disk 3 at the primary resonance (6.5 Hz) in the direction perpendicular to the axis at the position of the upper end magnet 4 in FIG. From this figure, the vibration amplitude of the shaft at the resonance point decreases with the rotation speed (rotation in the direction opposite to the rotation direction of the shaft) of the conductor disk 3. The effect is great, and the shaft amplitude is about 30H
When rotated at z, it is suppressed to about 1/3 or less of that when not rotated. From this, the effects of the present invention are listed as follows. (1) The present damper can apply considerable damping to the whirling vibration of the rotating shaft without contact and without control. (2) If a disk or a cylindrical magnet in which the magnet is uniformly magnetized in the thickness direction is used by the present damper, the magnetic attenuation in the rotation direction is eliminated. Therefore, in principle, there is no rotational energy loss due to the damper. Of course, it has energy loss for whirling. (3) The present damper requires energy to rotate the conductor disk, but does not require any further energy by stopping the rotation after overcoming the desired resonance. In addition, even after the rotation of the disk is stopped, the conductor disk is interposed between the magnets, so that the whirling is damped as a normal magnetic damper. Therefore, high-order vibration suppression has a considerable damping effect even at rest.
【図１】 この発明の実施例における装置の側面図FIG. 1 is a side view of an apparatus according to an embodiment of the present invention.
【図２】 本装置の軸の先端磁石４の点における軸直角
方向の共振振幅と導体円板３の回転数の関係FIG. 2 shows the relationship between the resonance amplitude in the direction perpendicular to the axis at the point of the tip magnet 4 of the shaft of the apparatus and the rotational speed of the conductor disk 3;
１ モータ ２ 円筒型永久磁石 ３ 導体円板
（アルミニウム製） ２ 円筒型永久磁石 ５ ファン ６ 円板ロータ
７ 円板型永久磁石 ８ 高温超電導円板DESCRIPTION OF SYMBOLS 1 Motor 2 Cylindrical permanent magnet 3 Conductor disk (made of aluminum) 2 Cylindrical permanent magnet 5 Fan 6 Disk rotor 7 Disk permanent magnet 8 High-temperature superconducting disk
Claims (1)
向するように適当な間隙を置いて電気導体の回転円板を
配し、その円板を軸の回転方向と反対方向に回転させ
る。または回転軸に電気導体円板を取り付け、その円板
に対向するように適当な間隙を置いて磁石を配し、その
磁石を軸の回転方向と反対方向に回転させることで、軸
のふれまわり振動を抑制することを特徴とする磁気ダン
パ。1. A magnet is attached to a rotating shaft, and a rotating disk of an electric conductor is arranged at an appropriate gap so as to face the magnet, and the disk is rotated in a direction opposite to the rotating direction of the shaft. Alternatively, an electric conductor disk is attached to the rotating shaft, a magnet is arranged with an appropriate gap facing the disk, and the magnet is rotated in the direction opposite to the rotation direction of the shaft, so that the shaft rotates. A magnetic damper characterized by suppressing vibration.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11111274A JP2000266117A (en) | 1999-03-15 | 1999-03-15 | Rotary magnetic damper |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11111274A JP2000266117A (en) | 1999-03-15 | 1999-03-15 | Rotary magnetic damper |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000266117A true JP2000266117A (en) | 2000-09-26 |
Family
ID=14557077
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11111274A Pending JP2000266117A (en) | 1999-03-15 | 1999-03-15 | Rotary magnetic damper |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000266117A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003247600A (en) * | 2002-02-26 | 2003-09-05 | Nok Corp | Torque fluctuation absorbing damper |
| WO2012157572A1 (en) * | 2011-05-16 | 2012-11-22 | 財団法人生産技術研究奨励会 | Viscosity/resilience measurement device and measurement method |
| US8669589B2 (en) | 2005-09-07 | 2014-03-11 | Cree, Inc. | Robust transistors with fluorine treatment |
| US9041064B2 (en) | 2006-11-21 | 2015-05-26 | Cree, Inc. | High voltage GaN transistor |
| US9240473B2 (en) | 2007-03-23 | 2016-01-19 | Cree, Inc. | High temperature performance capable gallium nitride transistor |
| US9419124B2 (en) | 2001-07-24 | 2016-08-16 | Cree, Inc. | Insulating gate AlGaN/GaN HEMT |
-
1999
- 1999-03-15 JP JP11111274A patent/JP2000266117A/en active Pending
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9419124B2 (en) | 2001-07-24 | 2016-08-16 | Cree, Inc. | Insulating gate AlGaN/GaN HEMT |
| US10224427B2 (en) | 2001-07-24 | 2019-03-05 | Cree, Inc. | Insulting gate AlGaN/GaN HEMT |
| JP2003247600A (en) * | 2002-02-26 | 2003-09-05 | Nok Corp | Torque fluctuation absorbing damper |
| US8669589B2 (en) | 2005-09-07 | 2014-03-11 | Cree, Inc. | Robust transistors with fluorine treatment |
| US9041064B2 (en) | 2006-11-21 | 2015-05-26 | Cree, Inc. | High voltage GaN transistor |
| US9450081B2 (en) | 2006-11-21 | 2016-09-20 | Cree, Inc. | High voltage GaN transistor |
| US9240473B2 (en) | 2007-03-23 | 2016-01-19 | Cree, Inc. | High temperature performance capable gallium nitride transistor |
| WO2012157572A1 (en) * | 2011-05-16 | 2012-11-22 | 財団法人生産技術研究奨励会 | Viscosity/resilience measurement device and measurement method |
| JP2012242137A (en) * | 2011-05-16 | 2012-12-10 | Foundation For The Promotion Of Industrial Science | Viscosity and elasticity measuring device, and method therefor |
| CN103534572A (en) * | 2011-05-16 | 2014-01-22 | 财团法人生产技术研究奖励会 | Viscosity/resilience measurement device and measurement method |
| US10184872B2 (en) | 2011-05-16 | 2019-01-22 | The Foundation For The Promotion Of Industrial Science | Viscosity/elasticity measurement device and measurement method |
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