JPH08210352A - Magnetic bearing device - Google Patents

Magnetic bearing device

Info

Publication number
JPH08210352A
JPH08210352A JP7288096A JP28809695A JPH08210352A JP H08210352 A JPH08210352 A JP H08210352A JP 7288096 A JP7288096 A JP 7288096A JP 28809695 A JP28809695 A JP 28809695A JP H08210352 A JPH08210352 A JP H08210352A
Authority
JP
Japan
Prior art keywords
bearing
touchdown
magnetic bearing
rotor
touch
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.)
Granted
Application number
JP7288096A
Other languages
Japanese (ja)
Other versions
JP3061168B2 (en
Inventor
Yasukazu Fujimoto
靖一 藤本
Hirotomo Kiyoutani
拓知 京谷
Kazuo Rokkaku
和夫 六角
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koyo Seiko Co Ltd
Original Assignee
Koyo Seiko Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
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Application filed by Koyo Seiko Co Ltd filed Critical Koyo Seiko Co Ltd
Priority to JP7288096A priority Critical patent/JP3061168B2/en
Publication of JPH08210352A publication Critical patent/JPH08210352A/en
Application granted granted Critical
Publication of JP3061168B2 publication Critical patent/JP3061168B2/en
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Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C39/00—Relieving load on bearings
    • F16C39/02—Relieving load on bearings using mechanical means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C32/00—Bearings not otherwise provided for
    • F16C32/04—Bearings not otherwise provided for using magnetic or electric supporting means
    • F16C32/0406—Magnetic bearings
    • F16C32/044—Active magnetic bearings
    • F16C32/0442—Active magnetic bearings with devices affected by abnormal, undesired or non-standard conditions such as shock-load, power outage, start-up or touchdown
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2240/00—Specified values or numerical ranges of parameters; Relations between them
    • F16C2240/40—Linear dimensions, e.g. length, radius, thickness, gap
    • F16C2240/70—Diameters; Radii
    • F16C2240/80—Pitch circle diameters [PCD]
    • F16C2240/82—Degree of filling, i.e. sum of diameters of rolling elements in relation to PCD
    • F16C2240/84—Degree of filling, i.e. sum of diameters of rolling elements in relation to PCD with full complement of balls or rollers, i.e. sum of clearances less than diameter of one rolling element
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2300/00—Application independent of particular apparatuses
    • F16C2300/40—Application independent of particular apparatuses related to environment, i.e. operating conditions
    • F16C2300/62—Application independent of particular apparatuses related to environment, i.e. operating conditions low pressure, e.g. elements operating under vacuum conditions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2360/00—Engines or pumps
    • F16C2360/44—Centrifugal pumps
    • F16C2360/45—Turbo-molecular pumps

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Magnetic Bearings And Hydrostatic Bearings (AREA)
  • Motor Or Generator Frames (AREA)
  • Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

Abstract

PURPOSE: To provide a magnetic bearing device capable of improving the wear resistance and the seizure resistance of a raceway surface of a touch-down bearing and a side circumferential surface of a touch-down, and turnably supporting a rotor when the power of the magnetic bearing is shut off. CONSTITUTION: A magnetic bearing device supports a rotor 3 by a magnetic bearing in a levitating manner, and turnably supports the rotor 3 by a rolling bearing 12 for touch-down when the power of the magnetic bearing is shut off. The rolling bearing for touch-down is of the total ball type, and a first metallic solid lubrication film layer A is formed on a touch-down side circumferential surface 151 of a rotary wheel 15 of the rolling bearing for touch-down, and second metallic solid lubrication film layer A are formed on the raceway surfaces 152, 161 of the roller bearing for touch-down.

Description

【発明の詳細な説明】 【０００１】 【発明の属する技術分野】本発明は、真空用機器等に用
いる磁気軸受装置、特に、磁気軸受のロータを支承する
タッチダウン軸受を有する磁気軸受装置に関する。 【０００２】 【従来の技術】例えば、ターボ分子ポンプなどの真空用
機器に組込まれる磁気軸受装置においては、ロータはそ
の高速回転中磁気軸受にて非接触状態に支承され、回転
停止時にはロータが磁気軸受のステータやモータ等に接
触して破損せぬようタッチダウン軸受を設けている。と
ころで、通常の磁気軸受装置の使用停止時には、ロータ
がその回転速度を除々に落とされ、かなり低速になって
からタッチダウン軸受に接触させられるようにしている
ためタッチダウン軸受等の損傷はない。しかし、磁気軸
受装置の使用中に停電等の原因にて瞬時に磁気軸受が作
動しなくなった場合、ロータは高速回転を続けた状態で
タッチダウン軸受に接触し、回転停止するまでタッチダ
ウン軸受にて支承されることにより、ロータの損傷や軸
受寿命が短くなる等の問題がある。これは、タッチダウ
ン軸受の回転輪の瞬時の急加速性が悪いことに起因す
る。上述の問題点を解消するため、特に真空中で使用す
る磁気軸受装置のタッチダウン軸受では、転動体表面に
銀などの金属膜層を形成したのちに二硫化モリブデンな
どの固体潤滑剤を被膜することにより軸受寿命を延長す
る磁気軸受装置（特開昭６１−１６５０２１号）などが
考案されている。 【０００３】 【発明が解決しようとする課題】しかしながら、上述の
場合も、固体潤滑剤の磨耗、剥離が進行するにつれ、タ
ッチダウン軸受の回転トルクが高くなり、タッチダウン
側周面でのすべりの増大、軌道部でのころがり運動のす
べり率の増大により、特に真空中においては上記部材が
容易に高温になり、転動体表面や軌道面あるいはタッチ
ダウン側周面に焼付けが発生し、早期に軸受寿命に到達
してしまう。本発明は、上述の問題点を解消するもので
あり、その目的とするところは、タッチダウン軸受の軌
道面およびタッチダウン側周面の耐摩耗強度および耐焼
付性を向上させ、長期にわたり磁気軸受の電源断時の際
のロータを回転可能に支持しうるようにした磁気軸受装
置を提供することにある。 【０００４】 【課題を解決するための手段】本発明の磁気軸受装置
は、ロータを磁気軸受で浮揚状態に支持し、かつ磁気軸
受の電源断時にタッチダウン用転がり軸受によりロータ
を回転可能に支持するようにした磁気軸受装置におい
て、前記タッチダウン用転がり軸受を総ボール型式と
し、該タッチダウン用転がり軸受の回転輪のタッチダウ
ン側周面に第１の金属系固体潤滑被膜層を形成するとと
もに、該タッチダウン用転がり軸受の軌道面に第２の金
属系固体潤滑被膜層を形成することにより上記目的を達
成するものである。 【０００５】 【作用】例えば、電源断時のように急激な回転トルクが
磁気軸受装置のタッチダウン軸受に作用する場合でも、
タッチダウン軸受の軌道面およびタッチダウン側周面に
ＴｉＣもしくはＴｉＮ等の金属系固体潤滑被膜層を形成
しているため、完全ドライな潤滑を保持して耐摩耗強度
と耐焼付性を向上させることができる。よって、タッチ
ダウン軸受あるいはロータを損傷することなく、長期に
わたりロータに良好に追従して磁気軸受装置の寿命を向
上させうる。 【０００６】 【発明の実施の形態】以下に本発明を実施例について詳
述する。例えば、第１図に示すように、本発明の磁気軸
受装置１は、有底円筒状のケース２内に下端部が細軸４
となる段付き軸受に形成され、かつ該細軸４の下端に円
盤部５を有するロータ３を挿入している。前記ロータ３
の上部は、ケース２の内壁２ａに固定された磁気軸受６
にて支承され、前記ロータ３の下部の円盤部５は、ケー
ス２の底壁２ｂに固定された磁気軸受７と該磁気軸受７
より若干上方でケース２の内壁２ａに固定された磁気軸
受８との間に位置して両磁気軸受７、８にて支承され
る。前記上方の磁気軸受６は、ロータ３の軸線に直交す
る方向に磁力を出すラジアル軸受として作用し、下方の
二個の磁気軸受７、８は、ロータ３の軸線方向すなわち
円盤部５の上下面５ａ、５ｂに直交する方向に磁力を出
すスラスト軸受として作用する。９は高周波モータでロ
ータ３を回転させるためのものである。また磁気軸受６
の上方のケース２の内壁２ａからは半径方向にフランジ
１０が一体に設けられ、該フランジ１０の端部１０ａに
形成した周状凹溝１１内に、タッチダウン軸受として総
ボール形式の深みぞ玉軸受１２が装着固定され、ロータ
３の回転停止時のラジアル負荷を受ける。 【０００７】さらに下方の両磁気軸受７、８のうち、円
盤部５の上面側に配置された磁気軸受８のコアー８ｂの
ロータ３に対向する側面８ａには、タッチダウン軸受と
して二個の総ボール形式のアンギュラ玉軸受１３、１４
が上下に正面組合わせで装着固定されている。この両タ
ッチダウン軸受１３、１４のうち上部の軸受１３により
ロータ３の段付き面３ａおよび細軸４が支承され、下部
の軸受１４によりロータ３の細軸４のみが支承される。
ここで第１図の実施例はロータ３の回転中の状態を示し
ているが、ロータ３の回転停止時にはロータ３はタッチ
ダウン軸受１２、１３、１４のみにて支承され、磁気軸
受６、７、８には非接触状態を保つよう、寸法関係が考
慮されていることはもちろんである。 【０００８】次に前記タッチダウン軸受について詳述す
る。なお、ここでは便宜上タッチダウン軸受１２を代表
して説明するが、他の軸受１３、１４の構成についても
同様であることはいうまでもない。第２図に示すよう
に、タッチダウン軸受１２は、軸受鋼を素材とした内輪
１５、外輪１６、および、内外輪１５、１６の間に介装
された転動体１７である。Ａは、膜厚約数μｍのＴｉＮ
薄膜層であり、タッチダウン時の回転輪となる内輪１５
のタッチダウン側周面すなわち内周面１５１、内輪１５
の軌道面１５２、および外輪１６の軌道面１６１に、ス
パッタリング法、イオンプレーティング法あるいはＣＶ
Ｄ法等のコーティングにより形成されている。前記Ｔｉ
Ｎの薄膜層Ａは、従来の二流化モリブデン等の固体潤滑
剤層に比べ、機械的摩耗に対して強く、長期にわたりタ
ッチダウンに耐えられ、しかも高温での摩耗係数が小さ
く、タッチダウン時の内輪内周面１５１および内外輪の
軌道面１５２、１６１での摩擦係数を小さく、すなわち
摩擦トルクを小さくさせることができ、高温での安定性
と耐焼付性は数段に優れたものとなる。もちろん、真空
中で使用されるタッチダウン軸受に要求される完全ドラ
イ潤滑性も失われることがない。 【０００９】上記薄膜層Ａとしては、ＴｉＮの他ＴｉＣ
なども同等の効果が得られる。さらに、これらを複数積
層にして用いることも可能である。第３図には、従来技
術である銀膜上に二硫化モリブデンを被覆したタッチダ
ウン軸受と、本発明のＴｉＮ層を被覆したタッチダウン
軸受との低真空中３００℃での摩擦係数の変化状態を示
す比較グラフである。第３図から明らかなように、本発
明の軸受の方が、長期間にわたり摩擦係数を小さく維持
できることが明らかである。これは、Ａｇ、ＭO Ｓ2 が
低真空中であっても、わずかに存在する酸素のため、高
温中で酸化が進み、潤滑性を失って行くが、ＴｉＮ層は
高温条件下においても劣化しないことと、高速回転によ
っても剥離しにくいからである。したがって、高温条件
下において高速回転で使用しても、支障なく長期にわた
って軸受機能を発揮することができる。 【００１０】上記実施例では、総ボール形式の玉軸受に
ついて説明したが、保持器付きの玉軸受でもよい。ま
た、他の形式のころがり軸受でもよい。また、本発明の
他の実施例として、前記実施例において内輪１５と外輪
１６との間に介装される転動体１７をセラミックス製と
してもよい。この場合には、セラミックスの潤滑性によ
り転動体１７と軌道面１５２、１６１間の摩擦を効果的
に小さくできるばかりでなく、異種材料の使用による焼
付性の向上が得られる。さらにまた、本発明の他の実施
例として第１図および第２図の実施例において、タッチ
ダウン軸受の回転輪１５の内周面１５１に対向するロー
タ３の外周面３１にＴｉＮ薄膜層をコーティングにより
形成してもよい。 【００１１】 【発明の効果】本発明は、ロータを磁気軸受で浮揚状態
に支持し、かつ磁気軸受の電源断時にタッチダウン用転
がり軸受によりロータを回転可能に支持するようにした
磁気軸受装置において、前記タッチダウン用転がり軸受
を総ボール型式とし、該タッチダウン用転がり軸受の回
転輪のタッチダウン側周面に第１の金属系固体潤滑被膜
層を形成するとともに、該タッチダウン用転がり軸受の
軌道面に第２の金属系固体潤滑被膜層を形成した構成で
あるから、急激な回転トルクが負荷されても、初期トル
クの低減を長時間にわたり可能とし、しかも磁気軸受の
信頼性を向上させ、回転軸や軸受の損傷を防止でき、磁
気軸受装置の寿命を向上させうる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic bearing device for use in vacuum equipment and the like, and more particularly to a magnetic bearing device having a touchdown bearing for supporting a rotor of the magnetic bearing. 2. Description of the Related Art For example, in a magnetic bearing device incorporated in vacuum equipment such as a turbo molecular pump, the rotor is supported in a non-contact state by a magnetic bearing during its high-speed rotation, and the rotor is magnetically stopped when the rotation is stopped. Touchdown bearings are provided to prevent damage to the bearings such as the stator and motor. By the way, when the normal magnetic bearing device is not used, the rotation speed of the rotor is gradually decreased and the rotor is brought into contact with the touchdown bearing after the rotor speed becomes considerably low. Therefore, the touchdown bearing is not damaged. However, if the magnetic bearing momentarily stops operating due to a power failure or the like while using the magnetic bearing device, the rotor contacts the touchdown bearing while continuing to rotate at high speed, and the rotor continues to operate until it stops rotating. However, there is a problem that the rotor is damaged and the life of the bearing is shortened. This is because the rotary wheel of the touchdown bearing has poor momentary rapid acceleration. In order to solve the above-mentioned problems, particularly in a touchdown bearing of a magnetic bearing device used in a vacuum, a metal film layer of silver or the like is formed on the surface of the rolling element, and then a solid lubricant such as molybdenum disulfide is coated. As a result, a magnetic bearing device (Japanese Patent Laid-Open No. 61-165021), which extends the life of the bearing, has been devised. However, also in the case described above, as the wear and peeling of the solid lubricant progresses, the rotating torque of the touchdown bearing increases, and the slippage on the peripheral surface of the touchdown side is increased. Due to the increase in the rolling rate and the increase in the sliding rate of the rolling motion in the raceways, the above components easily become hot, especially in a vacuum, and seizure occurs on the rolling element surface, raceway surface or touchdown side peripheral surface, resulting in early bearing. It will reach the end of its life. The present invention solves the above-mentioned problems, and an object of the present invention is to improve the wear resistance and seizure resistance of the raceway surface of the touchdown bearing and the peripheral surface of the touchdown side, and to improve the magnetic bearing for a long time. Another object of the present invention is to provide a magnetic bearing device capable of rotatably supporting the rotor when the power source is cut off. In the magnetic bearing device of the present invention, the rotor is supported in a levitated state by the magnetic bearing, and the rotor is rotatably supported by the touch-down rolling bearing when the magnetic bearing is powered off. In the magnetic bearing device configured as described above, the rolling bearing for touchdown is of a full ball type, and the first metal-based solid lubricating coating layer is formed on the touchdown side peripheral surface of the rotary wheel of the rolling bearing for touchdown. The above object is achieved by forming a second metallic solid lubricating coating layer on the raceway surface of the touchdown rolling bearing. For example, even when a sudden rotation torque acts on the touchdown bearing of the magnetic bearing device, such as when the power is cut off,
Since a metal solid lubricant coating layer such as TiC or TiN is formed on the raceway surface of the touchdown bearing and the peripheral surface of the touchdown side, it is necessary to maintain complete dry lubrication and improve wear resistance and seizure resistance. You can Therefore, it is possible to favorably follow the rotor for a long period of time without damaging the touchdown bearing or the rotor, and improve the life of the magnetic bearing device. BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to Examples. For example, as shown in FIG. 1, a magnetic bearing device 1 of the present invention has a cylindrical case 2 having a bottom and a lower end portion having a thin shaft 4.
A rotor 3 which is formed into a stepped bearing and has a disk portion 5 at the lower end of the thin shaft 4 is inserted. The rotor 3
The upper part of the magnetic bearing 6 is fixed to the inner wall 2a of the case 2.
The disk portion 5 at the bottom of the rotor 3 is supported by a magnetic bearing 7 fixed to the bottom wall 2b of the case 2 and the magnetic bearing 7
Located slightly above and between the magnetic bearing 8 fixed to the inner wall 2a of the case 2, both magnetic bearings 7, 8 are supported. The upper magnetic bearing 6 acts as a radial bearing that produces a magnetic force in a direction orthogonal to the axial line of the rotor 3, and the lower two magnetic bearings 7 and 8 are the axial direction of the rotor 3, that is, the upper and lower surfaces of the disk portion 5. It acts as a thrust bearing that produces a magnetic force in a direction orthogonal to 5a and 5b. Reference numeral 9 is a high-frequency motor for rotating the rotor 3. Also magnetic bearing 6
A flange 10 is integrally provided in a radial direction from an inner wall 2a of the case 2 above the casing 2, and a deep groove ball of a full ball type is used as a touchdown bearing in a circumferential groove 11 formed at an end 10a of the flange 10. The bearing 12 is mounted and fixed, and receives a radial load when the rotor 3 stops rotating. Of the two magnetic bearings 7 and 8 located further below, the core 8b of the magnetic bearing 8 arranged on the upper surface side of the disk portion 5 has a side surface 8a facing the rotor 3 and two touch-down bearings. Ball type angular contact ball bearings 13, 14
Are mounted and fixed on the top and bottom in frontal combination. Of the two touchdown bearings 13 and 14, the upper bearing 13 supports the stepped surface 3a and the thin shaft 4 of the rotor 3, and the lower bearing 14 supports only the thin shaft 4 of the rotor 3.
Here, the embodiment of FIG. 1 shows a state in which the rotor 3 is rotating, but when the rotation of the rotor 3 is stopped, the rotor 3 is supported only by the touchdown bearings 12, 13 and 14, and the magnetic bearings 6 and 7 are used. Needless to say, the dimensional relations are taken into consideration so as to maintain a non-contact state. Next, the touchdown bearing will be described in detail. Although the touchdown bearing 12 will be described as a representative for convenience here, it goes without saying that the same applies to the configurations of the other bearings 13 and 14. As shown in FIG. 2, the touchdown bearing 12 is an inner ring 15 and an outer ring 16 made of bearing steel, and rolling elements 17 interposed between the inner and outer rings 15 and 16. A is TiN with a film thickness of about several μm
Inner ring 15 that is a thin film layer and serves as a rotating wheel during touchdown
Touchdown side peripheral surface, that is, inner peripheral surface 151, inner ring 15
On the raceway surface 152 of the outer ring 16 and the raceway surface 161 of the outer ring 16 by the sputtering method, the ion plating method or the CV method.
It is formed by coating such as the D method. The Ti
The thin film layer A of N is more resistant to mechanical wear than conventional solid lubricant layers such as molybdenum disulfide, can withstand touchdown for a long time, and has a small wear coefficient at high temperature. The friction coefficient at the inner ring inner peripheral surface 151 and the raceway surfaces 152, 161 of the inner and outer rings can be made small, that is, the friction torque can be made small, and the stability at high temperature and the seizure resistance are remarkably excellent. Of course, the complete dry lubricity required for the touchdown bearing used in vacuum is not lost. As the thin film layer A, TiC is used in addition to TiN.
The same effect can be obtained. Furthermore, it is also possible to use a plurality of these in a laminated form. FIG. 3 shows the state of change in friction coefficient at 300 ° C. in a low vacuum between a touchdown bearing in which molybdenum disulfide is coated on a silver film, which is a conventional technique, and a touchdown bearing in which the TiN layer of the present invention is coated. 7 is a comparative graph showing As is clear from FIG. 3, it is apparent that the bearing of the present invention can keep the friction coefficient small over a long period of time. This is because even if Ag and M O S 2 are present in a low vacuum, a small amount of oxygen is present, so that oxidation progresses at high temperature and loses lubricity, but the TiN layer deteriorates even under high temperature conditions. This is because it is difficult to peel off even if it is rotated at a high speed. Therefore, even if it is used at high speed under high temperature conditions, the bearing function can be exerted for a long time without any trouble. In the above embodiment, the full ball type ball bearing has been described, but a ball bearing with a retainer may be used. Also, other types of rolling bearings may be used. Further, as another embodiment of the present invention, the rolling element 17 interposed between the inner ring 15 and the outer ring 16 in the above-described embodiment may be made of ceramics. In this case, not only can the friction between the rolling elements 17 and the raceway surfaces 152, 161 be effectively reduced by the lubricity of the ceramics, but seizure can be improved by using different materials. Further, as another embodiment of the present invention, in the embodiment of FIGS. 1 and 2, the outer peripheral surface 31 of the rotor 3 facing the inner peripheral surface 151 of the rotating wheel 15 of the touchdown bearing is coated with a TiN thin film layer. You may form by. The present invention provides a magnetic bearing device in which a rotor is supported by a magnetic bearing in a levitated state, and a rotor is rotatably supported by a touch-down rolling bearing when the magnetic bearing is powered off. The touch-down rolling bearing is of a full ball type, and the first metal-based solid lubricating coating layer is formed on the touch-down side peripheral surface of the rotating ring of the touch-down rolling bearing, and the touch-down rolling bearing Since the second metal-based solid lubricating coating layer is formed on the raceway surface, the initial torque can be reduced for a long time even when a sudden rotation torque is applied, and the reliability of the magnetic bearing is improved. It is possible to prevent damage to the rotary shaft and the bearing, and improve the life of the magnetic bearing device.

【図面の簡単な説明】 【図１】本発明の一実施例の縦断面図である。 【図２】第１図の実施例におけるタッチダウン軸受の要
部拡大断面図である。 【図３】本発明のタッチダウン軸受と従来のタッチダウ
ン軸受の摩擦係数の変化状態を示す比較グラフである。 【符号の説明】 ３ ロータ ６、７、８ 磁気軸受 １２、１３、１４ タッチダウン軸受 Ａ 固体潤滑膜BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional view of an embodiment of the present invention. FIG. 2 is an enlarged sectional view of a main part of the touchdown bearing in the embodiment of FIG. FIG. 3 is a comparative graph showing changes in friction coefficient between the touchdown bearing of the present invention and a conventional touchdown bearing. [Explanation of Codes] 3 rotors 6, 7, 8 magnetic bearings 12, 13, 14 touchdown bearing A solid lubricant film

Claims (1)

【特許請求の範囲】 （１）ロータを磁気軸受で浮揚状態に支持し、かつ磁気
軸受の電源断時にタッチダウン用転がり軸受によりロー
タを回転可能に支持するようにした磁気軸受装置におい
て、 前記タッチダウン用転がり軸受を総ボール型式とし、該
タッチダウン用転がり軸受の回転輪のタッチダウン側周
面に第１の金属系固体潤滑被膜層を形成するとともに、
該タッチダウン用転がり軸受の軌道面に第２の金属系固
体潤滑被膜層を形成してなる磁気軸受装置。 （２）前記タッチダウン用転がり軸受の転動体がセラミ
ックスでなる特許請求の範囲第１項に記載の磁気軸受装
置。Claims: (1) A magnetic bearing device in which a rotor is supported by a magnetic bearing in a levitated state, and a rotor is rotatably supported by a touchdown rolling bearing when the magnetic bearing is powered off. The down rolling bearing is a full ball type, and a first metal-based solid lubricating coating layer is formed on the touchdown side peripheral surface of the rotary wheel of the touchdown rolling bearing,
A magnetic bearing device in which a second metal-based solid lubricating coating layer is formed on the raceway surface of the touchdown rolling bearing. (2) The magnetic bearing device according to claim 1, wherein the rolling element of the touchdown rolling bearing is made of ceramics.
JP7288096A 1995-10-09 1995-10-09 Magnetic bearing device Expired - Fee Related JP3061168B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7288096A JP3061168B2 (en) 1995-10-09 1995-10-09 Magnetic bearing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7288096A JP3061168B2 (en) 1995-10-09 1995-10-09 Magnetic bearing device

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
JP10827087A Division JPS63275815A (en) 1987-04-30 1987-04-30 Magnetic bearing device

Related Child Applications (1)

Application Number Title Priority Date Filing Date
JP9265012A Division JPH10176714A (en) 1997-09-10 1997-09-10 Magnetic bearing device

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JPH08210352A true JPH08210352A (en) 1996-08-20
JP3061168B2 JP3061168B2 (en) 2000-07-10

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109322918A (en) * 2018-11-05 2019-02-12 南京航空航天大学 A kind of magnetic suspension bearing radial protection structure
CN109322917A (en) * 2018-11-05 2019-02-12 南京航空航天大学 A kind of radial and axial protection structure of magnetic suspension bearing
CN109356933A (en) * 2018-11-05 2019-02-19 南京航空航天大学 A kind of radial protection ring structure that cooperation magnetic suspension bearing uses

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58174718A (en) * 1982-04-05 1983-10-13 Ulvac Corp Ball-and-roller bearing
JPS61165021A (en) * 1985-01-11 1986-07-25 Koyo Seiko Co Ltd Roller bearing
JPS61197487A (en) * 1985-02-22 1986-09-01 株式会社　陶研産業 Antiabrasive sintered sphere
JPS61215813A (en) * 1985-03-18 1986-09-25 Toyota Central Res & Dev Lab Inc Rolling bearing made of ceramics

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58174718A (en) * 1982-04-05 1983-10-13 Ulvac Corp Ball-and-roller bearing
JPS61165021A (en) * 1985-01-11 1986-07-25 Koyo Seiko Co Ltd Roller bearing
JPS61197487A (en) * 1985-02-22 1986-09-01 株式会社　陶研産業 Antiabrasive sintered sphere
JPS61215813A (en) * 1985-03-18 1986-09-25 Toyota Central Res & Dev Lab Inc Rolling bearing made of ceramics

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109322918A (en) * 2018-11-05 2019-02-12 南京航空航天大学 A kind of magnetic suspension bearing radial protection structure
CN109322917A (en) * 2018-11-05 2019-02-12 南京航空航天大学 A kind of radial and axial protection structure of magnetic suspension bearing
CN109356933A (en) * 2018-11-05 2019-02-19 南京航空航天大学 A kind of radial protection ring structure that cooperation magnetic suspension bearing uses

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