JPS63289319A - Radial ball bearing for protection in magnetic bearing device - Google Patents
Radial ball bearing for protection in magnetic bearing deviceInfo
- Publication number
- JPS63289319A JPS63289319A JP62123216A JP12321687A JPS63289319A JP S63289319 A JPS63289319 A JP S63289319A JP 62123216 A JP62123216 A JP 62123216A JP 12321687 A JP12321687 A JP 12321687A JP S63289319 A JPS63289319 A JP S63289319A
- Authority
- JP
- Japan
- Prior art keywords
- ball
- bearing
- balls
- ceramics
- outer ring
- 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
Links
- 239000000919 ceramic Substances 0.000 claims abstract description 24
- 229910000831 Steel Inorganic materials 0.000 abstract description 6
- 239000010959 steel Substances 0.000 abstract description 6
- 238000010438 heat treatment Methods 0.000 abstract 1
- 230000001681 protective effect Effects 0.000 description 23
- 230000000052 comparative effect Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000000314 lubricant Substances 0.000 description 5
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 5
- 229910052982 molybdenum disulfide Inorganic materials 0.000 description 5
- 230000020169 heat generation Effects 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
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
- 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
- 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
- F16C19/00—Bearings with rolling contact, for exclusively rotary movement
- F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
- F16C19/04—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly
- F16C19/06—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly with a single row or balls
-
- 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
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Sliding-Contact Bearings (AREA)
- Magnetic Bearings And Hydrostatic Bearings (AREA)
- Rolling Contact Bearings (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
この発明は、たとえば真空ポンプなどの磁気軸受装置に
おける保護用ラジアル玉軸受に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a protective radial ball bearing in a magnetic bearing device, such as a vacuum pump.
従来の技術とその問題点
第４図は従来の磁気軸受装置の１例を示し、垂直固定軸
（１）の周囲に円筒状のロータ（２）が配置されている
。ロータ（２）は、固定軸（１）に設けられたラジアル
磁気軸受（３）（４）およびアキシャル磁気軸受（５）
（６）で非接触状態に支持され、たとえば３００００
ｒｐｍ程度の高速で回転する。Prior art and its problems FIG. 4 shows an example of a conventional magnetic bearing device, in which a cylindrical rotor (2) is arranged around a vertical fixed shaft (1). The rotor (2) has radial magnetic bearings (3) (4) and axial magnetic bearings (5) provided on the fixed shaft (1).
(6) is supported in a non-contact state, for example, 30,000
It rotates at a high speed of about rpm.
固定軸（１）の上下２箇所に、ロータ（２）の停止時に
これを受けるための保護用ラジアル玉軸受（７） （８
）が設けられている。各保護用軸受（７） （８）には
負荷能力を増すため総圧軸受が使用され、その内輪（７
ａ） （８ａ）が固定軸（１）に固定されている。ロー
タ（２）が正常に回転しているときは、ロータ（２）と
保護用軸受（７） （８）との間にはたとえば０．１〜
数１１１１１１程度のすきまがある。そして、ロータ（
２）が停止するときには、ロータ（２）が保護用軸受（
７）（８）の外輪（７ｂ） （８ｂ）に接触してこれに
受けられ、ロータ（２）が磁気軸受（３） （４） （
５）（６）などに接触してこれらを損傷しないようにな
っている。なお、このようにロータが保護用軸受に受け
られて停止する動作をタッチダウンという。Protective radial ball bearings (7) (8) are installed at two locations above and below the fixed shaft (1) to receive the rotor (2) when it is stopped.
) is provided. For each protective bearing (7) (8), a total pressure bearing is used to increase the load capacity, and its inner ring (7)
a) (8a) is fixed to the fixed shaft (1). When the rotor (2) is rotating normally, the distance between the rotor (2) and the protective bearings (7) and (8) is, for example, 0.1 to
There is a gap of about 111111. And the rotor (
When the rotor (2) stops, the rotor (2) is mounted on the protective bearing (
7) The rotor (2) contacts and is received by the outer rings (7b) (8b) of (8), and the rotor (2) is mounted on the magnetic bearings (3) (4) (
5) It is designed to prevent damage to items such as (6) by contacting them. Note that this operation in which the rotor is stopped by being received by the protective bearing is called touchdown.
ところで、磁気軸受装置が正常な状態で停止する場合、
ロータ（２）は徐々に減速され、かなり低速になってか
ら保護用軸受（７）（８）に接触して低速でタッチダウ
ンするため、保護用軸受（７）（８）が損傷することは
ない。これに対し、停電その他の故障により磁気軸受（
３） （４） （５） （Ｂ）が作動しなくなった場合
は、高速で回転しているロータ（２）が保護用軸受（７
） （８）に接触して高速でタッチダウンするため、と
くに真空ポンプの磁気軸受装置の場合、保護用軸受（７
） （８）が真空中（たとえば１０ ”−２〜１０−”
Ｔｏｒｒ） で高速回転（たとえばｄｍｎ＞３００Ｘ１
０’ ）することになる。このため、鋼製の玉（７ｃ）
（８ｃ）を使用した従来の保護用軸受（７） （８）
では、玉（７ｃ）（８ｅ）が摩耗しやすく、耐久性か劣
っており、１回の高速タッチダウンの途中で保護用軸受
（７） （８）が損傷するというような問題があった。By the way, if the magnetic bearing device stops under normal conditions,
Since the rotor (2) is gradually decelerated and reaches a fairly low speed, it contacts the protective bearings (7) and (8) and touches down at a low speed, so the protective bearings (7) and (8) will not be damaged. do not have. However, due to power outages and other failures, magnetic bearings (
3) (4) (5) If (B) stops working, the rotor (2) rotating at high speed will
) (8) and touch down at high speed, especially in the case of a magnetic bearing device for a vacuum pump, the protective bearing (7)
) (8) in vacuum (e.g. 10"-2 to 10-"
Torr) and high speed rotation (for example, dmn>300X1
0'). For this reason, a steel ball (7c)
Conventional protective bearings using (8c) (7) (8)
However, there were problems in that the balls (7c) and (8e) were easily worn and had poor durability, and the protective bearings (7) and (8) were damaged during one high-speed touchdown.
磁気軸受装置には、」二記のように固定軸の周囲を筒状
のロータが回転する形式の他に、筒状の固定ケースの内
側をロータ軸が回転する形式もある。この場合、ケース
の上下２箇所に保護用軸受が設けられ、軸が停止すると
きに、軸が保護用軸受の内輪に接触してこれに受けられ
るが、上記と同様の問題がある。In addition to the type of magnetic bearing device in which a cylindrical rotor rotates around a fixed shaft as described in ``2'', there is also a type in which a rotor shaft rotates inside a cylindrical fixed case. In this case, protective bearings are provided at two locations on the upper and lower sides of the case, and when the shaft stops, the shaft contacts and is received by the inner ring of the protective bearing, but there is a problem similar to that described above.
この発明の目的は、上記のような問題を解決した耐久性
の高い保護用ラジアル玉軸受を提供することにある。An object of the present invention is to provide a highly durable protective radial ball bearing that solves the above problems.
問題点を解決するための手段
この発明による保護用ラジアル玉軸受は、固定部分に対
し回転部分を磁気軸受で非接触状態に支持して回転させ
る磁気軸受装置において、回転部分の停止時に回転部分
を受けるために固定部分の複数箇所に設けられる保護用
ラジアル玉軸受であって、
少なくとも一部の玉がセラミック製であることを特徴と
するものである。Means for Solving the Problems The protective radial ball bearing according to the present invention is a magnetic bearing device in which a rotating part is supported and rotated by a magnetic bearing in a non-contact state with respect to a fixed part, and when the rotating part is stopped, the rotating part is This is a protective radial ball bearing that is provided at a plurality of locations on a fixed part for receiving, and is characterized in that at least some of the balls are made of ceramic.
作 用
高速タッチダウン時に回転部分が高速回転状態のまま保
護用ラジアル玉軸受の軌道輪に接触すると、この軌道輪
も高速で回転を開始するが、保護用ラジアル玉軸受の少
なくとも一部の玉がセラミック製であるから、耐久性が
高く、損傷を受けにくい。すなわち、玉がセラミック製
であるから、硬さが高く、耐摩耗性が向上する。Operation During high-speed touchdown, if the rotating part contacts the raceway of the protective radial ball bearing while still rotating at high speed, this raceway also starts rotating at high speed, but at least some of the balls of the protective radial ball bearing Made of ceramic, it is highly durable and resistant to damage. That is, since the balls are made of ceramic, they have high hardness and improved wear resistance.
セラミックは密度が小さいので、玉に作用する遠心力が
小さく、玉と軌道輪の間の接触面圧か小さくなる。セラ
ミックは線膨張係数が小さいため、発熱による軸受すき
ま変化が鋼製の玉に比べて小さい。また、セラミックは
弾性係数が大きいため、玉の変形が小さく、回転がなめ
らかとなる。したがって、玉をセラミック製にすること
により、保護用ラジアル玉軸受の耐久性が向上する。Since ceramic has a low density, the centrifugal force acting on the balls is small, which reduces the contact pressure between the balls and the raceway. Ceramic has a small coefficient of linear expansion, so the change in bearing clearance due to heat generation is smaller than that of steel balls. Furthermore, since ceramic has a large elastic modulus, the ball deforms little and rotates smoothly. Therefore, by making the balls made of ceramic, the durability of the protective radial ball bearing is improved.
実 施 例
第１図は、磁気軸受装置の保護用ラジアル玉軸受の１具
体例を示す。Embodiment FIG. 1 shows a specific example of a protective radial ball bearing for a magnetic bearing device.
この軸受（１０）は総圧軸受であり、玉（１１）は全て
セラミック製である。また、通常のラジアル玉軸受に比
べて玉（１１）の直径Ｄａは小さく、内輪（１２）の肉
厚ｔｉは薄く、外輪（１３）の肉厚ｔｅは厚くなってい
る。したがって、玉（１１）の中心（０）を通る円の直
径（ピッチ円径）ｄｐは内輪（１２）の内径（軸受内径
）ｄと外輪（１３）の外径（軸受外径）Ｄの和の半分（
平均径）ｄ’ｍよりかなり小さくなっている。これらの
寸法の１例を挙げれば、軸受内径ｄを９０ｍｍ、軸受外
径りを１１５＋ｎｕ、平均径ｄｍを１０２．５ｎ＋ｍ、
内輪（１２）の肉厚ｔｉを３ｍｍ５外輪（１３）の肉厚
ｔｅを６ｍｖａ、ピッチ円径ｄｐを平均径ｄｍより２．
５ｍｍ小さくして１００■とし、玉（１１）の直径Ｄａ
を通常の６．７４７ｍｍより小さく設定している。This bearing (10) is a total pressure bearing, and all balls (11) are made of ceramic. Moreover, compared to a normal radial ball bearing, the diameter Da of the balls (11) is small, the wall thickness ti of the inner ring (12) is thin, and the wall thickness te of the outer ring (13) is thick. Therefore, the diameter (pitch circle diameter) dp of the circle passing through the center (0) of the ball (11) is the sum of the inner diameter (bearing inner diameter) d of the inner ring (12) and the outer diameter (bearing outer diameter) D of the outer ring (13). half of (
The average diameter) is considerably smaller than d'm. To give an example of these dimensions, the bearing inner diameter d is 90mm, the bearing outer diameter is 115+nu, the average diameter dm is 102.5n+m,
The wall thickness ti of the inner ring (12) is 3 mm, the wall thickness te of the outer ring (13) is 6 mva, and the pitch circle diameter dp is 2.
Reduce the diameter by 5mm to 100mm and set the diameter Da of the ball (11).
is set smaller than the normal 6.747mm.
内輪（１２）の軌道みぞ（１４）の曲率半径（みぞ半径
）ｒｉは通常のものより大きく、たとえば約０．５５Ｄ
ａとなっている。また、内輪（１２）および外輪（１３
）の全表面に固体潤滑剤たとえば二硫化モリブデンがコ
ーティングされている。The radius of curvature (groove radius) ri of the raceway groove (14) of the inner ring (12) is larger than normal, for example about 0.55D.
It is a. In addition, the inner ring (12) and the outer ring (13
) is coated with a solid lubricant such as molybdenum disulfide.
この軸受（１０）を第４図のような固定軸の周囲を筒状
のロータが回転する形式の磁気軸受装置に使用する場合
、内輪（１２）が固定軸に固定される。When this bearing (10) is used in a magnetic bearing device of the type in which a cylindrical rotor rotates around a fixed shaft as shown in FIG. 4, the inner ring (12) is fixed to the fixed shaft.
ロータか正常に回転している場合、ロータは磁気軸受に
より非接触状態に支持され、ロータと軸受（ｌＯ）の外
輪（１３）との間には適当なすきまがあり、外輪（１３
）は停止している。When the rotor is rotating normally, the rotor is supported by the magnetic bearing in a non-contact state, and there is an appropriate clearance between the rotor and the outer ring (13) of the bearing (lO).
) has stopped.
高速タッチダウンの場合、高速で回転しているロータが
軸受（１０）の外輪（１３）に接触し、外輪（１３）も
高速で回転を開始する。このため、従来の軸受では、外
輪は第２図に破線（Ａ）で示すように非常に急激な立上
りで高速回転を開始し、外輪の最高回転数（ａ）はロー
タの回転数（ｃ）に近くなる。このため、前述のように
、軸受が損傷する。なお、第２図において、鎖線（Ｃ）
はロータの回転数の変化を示す。In the case of high-speed touchdown, the rotor rotating at high speed contacts the outer ring (13) of the bearing (10), and the outer ring (13) also starts rotating at high speed. For this reason, in conventional bearings, the outer ring starts rotating at high speed with a very sudden rise as shown by the broken line (A) in Figure 2, and the maximum rotation speed (a) of the outer ring is equal to the rotation speed of the rotor (c). It becomes close to. As a result, the bearing is damaged as described above. In addition, in Fig. 2, the chain line (C)
indicates the change in the rotation speed of the rotor.
ところが、上記の軸受（１０）の場合、次に説明するよ
うに、耐久性が高く、このような損傷を防止することが
できる。However, in the case of the above-mentioned bearing (10), as explained below, it has high durability and can prevent such damage.
すなわち、まず、玉（１１）がセラミック製であるから
、硬さが高く、耐摩耗性が向上する。セラミックは密度
か小さいので、玉（１１）に作用する遠心力が小さく、
玉（１１）と外輪（１３）の間の接触面圧が小さくなる
。セラミックは線膨張係数が小さいため、発熱による軸
受すきま変化が鋼製の玉に比べて小さい。また、セラミ
ックは弾性係数が大きいため、玉（１１）の変形が小さ
く、回転がなめらかとなる。したがって、玉（１１）を
セラミック製にすることにより、耐久性が向上する。That is, first, since the balls (11) are made of ceramic, they have high hardness and improved wear resistance. Since ceramic has a low density, the centrifugal force acting on the ball (11) is small.
The contact pressure between the balls (11) and the outer ring (13) is reduced. Ceramic has a small coefficient of linear expansion, so the change in bearing clearance due to heat generation is smaller than that of steel balls. Furthermore, since ceramic has a large elastic modulus, the ball (11) is less deformed and rotates smoothly. Therefore, by making the balls (11) made of ceramic, durability is improved.
このことを証明するため、内輪、外輪および玉が軸受鋼
製の通常のラジアル玉軸受（比較例）と、比較例と寸法
、形状が同一で玉だけがセラミック製のラジアル玉軸受
（実施例）とを準備し、これらを使用した磁気軸受装置
について、 、高速タッチダウンを行なった。その結
果を第３図に示す。この試験より、比較例のものは１回
のタッチダウンでしかも３分程度で損傷したが、実施例
のものは、数回のタッチダウンで合計６０分以上の作動
が可能であ′す、比較例に比べて２０倍以上の耐久性の
あることが明らかになった。To prove this, we used a normal radial ball bearing (comparative example) in which the inner ring, outer ring, and balls are made of bearing steel, and a radial ball bearing (example) that has the same dimensions and shape as the comparative example but only the balls are made of ceramic. A high-speed touchdown was performed on a magnetic bearing device using these devices. The results are shown in FIG. From this test, it was found that the comparative example was damaged after one touchdown and took about 3 minutes, but the example was able to operate for a total of more than 60 minutes after several touchdowns. It was revealed that the durability was 20 times more than that of the example.
上記の軸受（１０）では、内輪（１２）および外輪（１
３）の全面に二硫化モリブデンがコーティングされてい
るので、次のような効果を奏する。まず、外輪（１３）
の外面にコーティングされた二硫化モリブデンがロータ
と外輪（１３）の間のすべりを助長するため、第２図に
実線（Ｂ）で示すように高速タッチダウン時の外輪（１
３）の立上りは緩やかになり、外輪（１３）の最高回転
数（ｂ）も小さくなる。そして、このように外輪（１３
）の最高回転数が小さくなるため、外輪（１３）および
玉（１１）の遠心力が小さくなる。内輪（１２）および
外輪（１３）の軌道みぞ（１４） （１５）の二硫化モ
リブデンは玉（１１）との間の潤滑剤となる。したがっ
て、軸受（１０）の損傷の度合が小さくなる。また、修
理などのために内輪（１２）を固定軸から抜取るような
場合、内輪（１２）の内面にも二硫化モリブデンがコー
ティングされていて、固定軸との間の摩擦力が小さくな
っているので、抜取りが容易である。The above bearing (10) has an inner ring (12) and an outer ring (1
Since the entire surface of 3) is coated with molybdenum disulfide, the following effects are achieved. First, the outer ring (13)
Molybdenum disulfide coated on the outer surface of the outer ring (13) promotes slippage between the rotor and the outer ring (13).
3), the rise becomes gradual and the maximum rotational speed (b) of the outer ring (13) also becomes small. Then, like this, the outer ring (13
) becomes smaller, so the centrifugal force of the outer ring (13) and balls (11) becomes smaller. Molybdenum disulfide in the raceway grooves (14) (15) of the inner ring (12) and outer ring (13) serves as a lubricant between the balls (11). Therefore, the degree of damage to the bearing (10) is reduced. In addition, when the inner ring (12) is removed from the fixed shaft for repairs etc., the inner surface of the inner ring (12) is also coated with molybdenum disulfide, which reduces the frictional force between it and the fixed shaft. It is easy to remove.
また、上記の軸受（１０）では、内輪（１２）のみぞ半
径ｒ ｉ （−０，５５Ｄａ）が大きくなっているの
で、次のような効果を奏する。まず、タッチダウン時に
ロータが軸受（１０）の外輪（１３）に接触する場合、
軸受（１０）に傾きが生じるが、みぞ半径ｒｉを大きく
することにより許容傾き角が大きくなり、軸受（１０）
内部に過大な応力が発生しなくなる。そして、同じ傾き
角の場合では、みぞ半径ｒｉが大きい方が玉（１１）の
公転速度差が小さく、回転が滑らかとなる。また、みぞ
半径ｒｉを大きくすることにより、玉（１１）と軌道み
ぞ（１４）との接触面圧が大きくなり、高速回転への立
上り時に玉（１１）が最初から正常な回転をしやすくな
る。なお、みぞ半径ｒｉは０．５３〜０．５８Ｄａ程度
であれば上記の効果を奏する。Furthermore, in the bearing (10) described above, since the groove radius r i (-0.55 Da) of the inner ring (12) is large, the following effects are achieved. First, when the rotor contacts the outer ring (13) of the bearing (10) during touchdown,
The bearing (10) is tilted, but by increasing the groove radius ri, the allowable tilt angle becomes larger, and the bearing (10)
Excessive stress will no longer occur inside. In the case of the same inclination angle, the larger the groove radius ri, the smaller the difference in revolution speed of the ball (11) and the smoother the rotation. In addition, by increasing the groove radius ri, the contact surface pressure between the ball (11) and the raceway groove (14) increases, making it easier for the ball (11) to rotate normally from the beginning when starting up to high-speed rotation. . Note that the above effect can be achieved if the groove radius ri is approximately 0.53 to 0.58 Da.
また、上記の軸受（１０）では、外輪（１３）の肉厚ｔ
ｅが厚くなっているので、回転時の遠心力による外輪（
１３）自身の膨張が小さく、軸受内部すきま（ラジアル
すきま）の変化が小さいので、回転が滑らかである。そ
して、外輪（１３）の肉厚ｔｅが厚くなっていることに
より、ロータと接触したときの外輪（１３）の変形が小
さくなり、玉（１１）に無理な力が作用しないので、回
転か滑らかとなる。しかも、玉（１１）の直径Ｄａを小
さくして玉数を増しているので、外輪（１３）の剛性が
高くなる。また、ピッチ円径ｄｐが小さくなっているの
で、玉（１１）の公転速度が小さくなり、回転時に玉（
１１）に作用する遠心力も小さくなる。In addition, in the above bearing (10), the outer ring (13) has a wall thickness t
Since e is thicker, the outer ring (
13) Rotation is smooth because its own expansion is small and changes in bearing internal clearance (radial clearance) are small. Since the wall thickness te of the outer ring (13) is increased, the deformation of the outer ring (13) when it comes into contact with the rotor is reduced, and no excessive force is applied to the balls (11), so the rotation is smooth. becomes. Moreover, since the diameter Da of the balls (11) is reduced to increase the number of balls, the rigidity of the outer ring (13) is increased. In addition, since the pitch circle diameter dp is small, the revolution speed of the ball (11) becomes small, and the ball (11) during rotation becomes small.
The centrifugal force acting on 11) also becomes smaller.
このため、軸受（１０）の耐久性か向上する。Therefore, the durability of the bearing (10) is improved.
上記の軸受（１０）は、筒状の固定ケースの内側をロー
タ軸が回転する形式の磁気軸受装置にも使用できる。こ
の場合、外輪（１３）が固定ケースに固定され、ロータ
軸は内輪（１２）の内面に接触する。そして、この場合
も、上記とほぼ同様の効果が奏される。The above bearing (10) can also be used in a magnetic bearing device in which the rotor shaft rotates inside a cylindrical fixed case. In this case, the outer ring (13) is fixed to the fixed case, and the rotor shaft contacts the inner surface of the inner ring (12). In this case as well, substantially the same effects as above are achieved.
上記実施例では、玉（１１）が全てセラミック製である
が、セラミック製の玉と鋼製の玉を組合わせて使用する
ようにしてもよい。また、上記実施例には総圧軸受を示
したが、この発明は保持器付玉軸受にも適用できる。上
記実施例では、内輪（１２）および外輪（１３）に潤滑
剤をコーティングしているが、これは必ずしも必要では
ない。In the above embodiment, all the balls (11) are made of ceramic, but a combination of ceramic balls and steel balls may be used. Further, although a total pressure bearing is shown in the above embodiment, the present invention can also be applied to a ball bearing with a cage. In the above embodiment, the inner ring (12) and outer ring (13) are coated with a lubricant, but this is not necessarily necessary.
潤滑剤をコーティングする場合でも、軌道みぞ（１４）
（１５）およびタッチダウン時に回転体と接触する面
だけにしてもよい。そして、潤滑剤を軌道みぞ（１４）
（１５）にコーティングするかわりに玉（１１）の表
面にコーティングしてもよい。また、玉（１１）の直径
Ｄａ、内輪（１２）および外輪（１３）の肉厚ｔｉ、ｔ
ｅならびにピッチ円径ｄｐは通常のラジアル玉軸受と同
程度にしてもよい。Even when coated with lubricant, the raceway groove (14)
(15) Alternatively, only the surface that comes into contact with the rotating body at the time of touchdown may be used. Then, apply the lubricant to the orbital groove (14).
Instead of coating (15), the surface of ball (11) may be coated. In addition, the diameter Da of the ball (11), the wall thickness ti of the inner ring (12) and the outer ring (13), t
e and the pitch circle diameter dp may be made comparable to those of a normal radial ball bearing.
発明の効果
この発明の磁気軸受装置における保護用ラジアル玉軸受
によれば、少なくとも一部の玉がセラミック製であるか
ら、上述のように、耐久性が高く、高速タッチダウン時
の損傷を防止することができる。Effects of the Invention According to the protective radial ball bearing in the magnetic bearing device of the present invention, at least some of the balls are made of ceramic, so as mentioned above, it is highly durable and prevents damage during high-speed touchdown. be able to.
第１図はこの発明の実施例を示す保護用ラジアル玉軸受
の主要部縦断面図、第２図は高速タッチダウン時の外輪
の回転速度の変化を示すグラフ、第３図は比較例と実施
例の比較試験結果を示すグラフ、第４図は従来の保護用
ラジアル玉軸受を組込んだ磁気軸受装置を示す縦断面図
−１１＝
である。
（１０）・・・保護用ラジアル玉軸受、（１１）・・・
玉。
以 上
０８等間
第２図
ロックＪで′のＢ岑Ｍ Ｃ分）Fig. 1 is a longitudinal cross-sectional view of the main parts of a protective radial ball bearing showing an embodiment of the present invention, Fig. 2 is a graph showing changes in the rotational speed of the outer ring during high-speed touchdown, and Fig. 3 is a comparative example and an embodiment. FIG. 4 is a graph showing the comparative test results of the example, and is a vertical cross-sectional view -11= showing a magnetic bearing device incorporating a conventional protective radial ball bearing. (10)... Radial ball bearing for protection, (11)...
ball. Above 08 equidistant figure 2 lock J 'B MC minutes)
Claims (1)
して回転させる磁気軸受装置において、回転部分の停止
時に回転部分を受けるために固定部分の複数箇所に設け
られる保護用ラジアル玉軸受であって、 少なくとも一部の玉がセラミック製であることを特徴と
する磁気軸受装置における保護用ラジアル玉軸受。[Scope of Claims] In a magnetic bearing device that supports and rotates a rotating part in a non-contact state with a magnetic bearing with respect to a fixed part, protection is provided at multiple locations on the fixed part to receive the rotating part when the rotating part stops. A radial ball bearing for protection in a magnetic bearing device, characterized in that at least some of the balls are made of ceramic.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62123216A JP2821592B2 (en) | 1987-05-20 | 1987-05-20 | Radial ball bearings for protection in magnetic bearing devices |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62123216A JP2821592B2 (en) | 1987-05-20 | 1987-05-20 | Radial ball bearings for protection in magnetic bearing devices |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63289319A true JPS63289319A (en) | 1988-11-25 |
| JP2821592B2 JP2821592B2 (en) | 1998-11-05 |
Family
ID=14855073
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62123216A Expired - Lifetime JP2821592B2 (en) | 1987-05-20 | 1987-05-20 | Radial ball bearings for protection in magnetic bearing devices |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2821592B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002542436A (en) * | 1999-04-16 | 2002-12-10 | エスケイエフ フランス | Hard ball bearings |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5037704U (en) * | 1973-08-02 | 1975-04-19 | ||
| JPS57142872U (en) * | 1981-02-28 | 1982-09-07 | ||
| JPS6088828U (en) * | 1983-11-24 | 1985-06-18 | トヨセツト株式会社 | desk |
| JPS60176630U (en) * | 1984-05-01 | 1985-11-22 | コクヨ株式会社 | desk |
| JPS6278128U (en) * | 1986-10-31 | 1987-05-19 |
-
1987
- 1987-05-20 JP JP62123216A patent/JP2821592B2/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5037704U (en) * | 1973-08-02 | 1975-04-19 | ||
| JPS57142872U (en) * | 1981-02-28 | 1982-09-07 | ||
| JPS6088828U (en) * | 1983-11-24 | 1985-06-18 | トヨセツト株式会社 | desk |
| JPS60176630U (en) * | 1984-05-01 | 1985-11-22 | コクヨ株式会社 | desk |
| JPS6278128U (en) * | 1986-10-31 | 1987-05-19 |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002542436A (en) * | 1999-04-16 | 2002-12-10 | エスケイエフ フランス | Hard ball bearings |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2821592B2 (en) | 1998-11-05 |
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