JPH11201153A - Rotating machine - Google Patents
Rotating machineInfo
- Publication number
- JPH11201153A JPH11201153A JP1511098A JP1511098A JPH11201153A JP H11201153 A JPH11201153 A JP H11201153A JP 1511098 A JP1511098 A JP 1511098A JP 1511098 A JP1511098 A JP 1511098A JP H11201153 A JPH11201153 A JP H11201153A
- Authority
- JP
- Japan
- Prior art keywords
- rotating
- gravity
- center
- ball bearing
- vibration
- 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
Landscapes
- Rolling Contact Bearings (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、光ディスクや磁気
ディスク等の円盤状記録媒体を高精度に回転駆動するに
好適なスピンドルモータ等の、高精度の回転の実現に好
適な回転機械に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating machine suitable for realizing high-precision rotation, such as a spindle motor suitable for driving a disc-shaped recording medium such as an optical disk or a magnetic disk with high precision.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】近年、
ハードディスク等の円盤状記録媒体を回転駆動するスピ
ンドルモータ（回転機械の一例）においては、その高速
化が進む一方で、高精度化つまりＮＲＲＯと呼ばれる回
転非同期成分による振動の低減が求められている。2. Description of the Related Art In recent years,
In a spindle motor (an example of a rotating machine) that rotationally drives a disk-shaped recording medium such as a hard disk, the speed of the spindle motor has been increased, and at the same time, higher accuracy, that is, reduction of vibration due to a rotation asynchronous component called NRRO is required.
【０００３】スピンドルモータにおける軸受として最も
よく用いられる玉軸受は、内輪と外輪との間に複数個の
転動球体を周方向等間隔に配置して構成され、理想的に
は振動の発生はない。しかし実際には、軸受部品の加工
公差やモータ組立時の内外輪の歪み等により、僅かに振
れながら（振動しながら）回転する。A ball bearing most often used as a bearing in a spindle motor is configured by arranging a plurality of rolling spheres at equal circumferential intervals between an inner ring and an outer ring, and ideally does not generate vibration. . However, in reality, the bearing rotates while slightly oscillating (vibrating) due to a processing tolerance of a bearing part, a distortion of an inner and outer ring at the time of motor assembly, and the like.
【０００４】従来では、玉軸受による励振を極力避ける
目的で、内外輪、転動球体、リテーナの寸法精度向上を
追求していたが、未解決になっている。即ち、軸受によ
る振動の原因としては、（１）内輪の歪、（２）外輪の
歪、（３）転動球体の相互差、（４）リテーナの不等配
等が挙げられ、このうち、（３）及び（４）は、転動球
体及びリテーナの製作精度を上げることにより対応する
ことができる。しかし、（１）及び（２）については、
スピンドルモータの軸受ハウジング形状の内外輪への転
写や内外輪の相対的な傾き差、或いは内外輪を接着した
場合の接着剤の熱収縮等により、内輪又は外輪が組立時
に歪んでしばしば軌道面に周方向のうねりを生じ、この
周方向のうねりにより引き起こされるＮＲＲＯによっ
て、ロータにピッチング振動、パラレル振動及びアキシ
ャル振動等が生じていたため、単品の製作精度を上げる
だけでは対応できないのが現状である。Hitherto, in order to minimize the excitation by the ball bearings, the dimensional accuracy of the inner and outer rings, the rolling spheres, and the retainer has been sought, but this has not been solved. That is, the causes of the vibration caused by the bearing include (1) distortion of the inner ring, (2) distortion of the outer ring, (3) mutual difference between the rolling spheres, (4) unequal distribution of the retainer, and the like. (3) and (4) can be dealt with by increasing the manufacturing accuracy of the rolling sphere and the retainer. However, for (1) and (2),
Due to the transfer of the bearing housing shape of the spindle motor to the inner and outer rings, the relative inclination difference of the inner and outer rings, or the heat shrinkage of the adhesive when the inner and outer rings are bonded, the inner or outer ring is distorted during assembly and often becomes distorted on the raceway surface. At present, pitching vibration, parallel vibration, axial vibration, and the like have occurred in the rotor due to NRRO caused by circumferential undulation, and the NRRO caused by the circumferential undulation is not sufficient to improve the manufacturing accuracy of a single product.
【０００５】本発明は、従来技術に存した上記のような
問題点に鑑み行われたものであって、その目的とすると
ころは、玉軸受の軌道面の周方向のうねりに起因する回
転部のピッチング振動、パラレル振動及びアキシャル振
動等が、何れも効果的に抑制され、高精度の回転を実現
し得る、記録媒体駆動用のスピンドルモータ等の回転機
械を提供することにある。The present invention has been made in view of the above-mentioned problems in the prior art, and an object of the present invention is to provide a rotary unit which is caused by circumferential waviness of a raceway surface of a ball bearing. It is an object of the present invention to provide a rotating machine such as a spindle motor for driving a recording medium, which can effectively suppress the pitching vibration, the parallel vibration, the axial vibration, and the like, and can realize high-precision rotation.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成する本発
明の回転機械は、 固定部と、回転軸線上に重心を
有する回転部を有し、回転軸線方向における２以上の箇
所に配装された玉軸受を介して前記固定部に対し前記回
転部が回転自在に支持されてなる回転機械であって、各
玉軸受において、転動球体は周方向等間隔に配置され、
回転部の重心との回転軸線方向距離が比較的に長い位置
の玉軸受における転動球体の数が合成数であり、前記重
心との回転軸線方向距離が比較的に短い位置の玉軸受に
おける転動球体の数が素数であることを特徴とする（請
求項１）。According to the present invention, there is provided a rotating machine having a fixed portion and a rotating portion having a center of gravity on a rotation axis, and is provided at two or more locations in the direction of the rotation axis. A rotating machine in which the rotating portion is rotatably supported with respect to the fixed portion via a ball bearing, in each of the ball bearings, rolling spheres are arranged at equal intervals in a circumferential direction,
The number of rolling spheres in the ball bearing at a position where the distance in the rotation axis direction from the center of gravity of the rotating portion is relatively long is a composite number, and the number of rolling spheres in the ball bearing at a position where the distance in the rotation axis direction from the center of gravity is relatively short is relatively large. The number of moving spheres is a prime number (claim 1).
【０００７】回転部は、例えば、固定部に対し玉軸受に
よって支持された回転軸を有するものであってもよく、
また例えば、固定部における固定軸部に対し玉軸受を介
して回転部が支持されたものでもよい。前記の回転軸を
有する回転部の場合、回転部の重心は通常回転軸の軸心
線（その延長線を含む）上に位置し、前記の固定部にお
ける固定軸部に対し玉軸受を介して支持された回転部の
重心は、通常固定軸部の軸心線（その延長線を含む）上
に位置することとなる。なお、回転機械によって駆動さ
れる被駆動体等が回転部と一体に回転する場合において
は、被駆動体等を含めた全体を回転機械として捉え、回
転部及びその被駆動体等を含む全回転部の重心の位置を
上述の重心の位置とすることが望ましい。The rotating portion may have, for example, a rotating shaft supported by a ball bearing with respect to the fixed portion.
Further, for example, a rotating part may be supported by a fixed shaft part in a fixed part via a ball bearing. In the case of the rotating part having the rotating shaft, the center of gravity of the rotating part is usually located on the axis of the rotating shaft (including an extension thereof), and the fixed shaft part of the fixed part is connected to the fixed shaft via a ball bearing. The center of gravity of the supported rotating part is usually located on the axis of the fixed shaft (including the extension thereof). When a driven body driven by a rotating machine rotates integrally with a rotating part, the whole body including the driven body is regarded as a rotating machine, and the entire rotation including the rotating part and the driven body is performed. It is desirable that the position of the center of gravity of the part be the above-described position of the center of gravity.
【０００８】上記回転機械は、玉軸受を２個有し、その
各玉軸受が異なる回転軸線方向位置に配装されたものと
することができる（請求項２）。但し、玉軸受の数はこ
れに限るものではなく、３個以上であってもよい。３個
以上の場合、回転軸線方向における位置は必ずしも全て
の玉軸受が互いに離隔していることを要せず、例えば２
個の玉軸受が回転軸線方向に隣接して１組の玉軸受を形
成するものであってもよい。[0008] The rotary machine may include two ball bearings, each of which is disposed at a different rotational axis position. However, the number of ball bearings is not limited to this, and may be three or more. In the case of three or more, the position in the rotation axis direction does not necessarily require that all ball bearings are separated from each other.
The ball bearings may be adjacent to each other in the rotation axis direction to form a set of ball bearings.
【０００９】下記表１に、玉軸受の軌道面（固定軌道輪
又は回転軌道輪）に周方向のうねりを有する場合のうね
りの山数と、その玉軸受の転動球体の数（玉数）と、ラ
ジアルＮＲＲＯ振幅との関係を示す。また、下記表２
に、玉軸受の軌道面（固定軌道輪又は回転軌道輪）に周
方向のうねりを有する場合のうねりの山数と、その玉軸
受の転動球体の数（玉数）と、アキシャルＮＲＲＯ振幅
との関係を示す。Table 1 below shows the number of undulations in the case where the raceway surface (fixed raceway or rotating raceway) of the ball bearing has a circumferential undulation, and the number of rolling spheres (ball number) of the ball bearing. And the radial NRRO amplitude. Table 2 below
In the case where the raceway surface (fixed raceway ring or rotating raceway ring) of the ball bearing has a circumferential undulation, the number of undulations, the number of rolling spheres of the ball bearing (number of balls), the axial NRRO amplitude and Shows the relationship.
【００１０】なお、表１及び表２は、一定条件下におけ
る解析結果を示すものであり、表１及び表２中、「大」
は０．５μｍを超える振幅、「中」は０．０１μｍ乃至
０．５μｍの振幅、「小」は０．０１μｍ未満の振幅、
「／」は振動が発生しないことをそれぞれ示す。[0010] Tables 1 and 2 show the results of analysis under certain conditions.
Is an amplitude exceeding 0.5 μm, “medium” is an amplitude of 0.01 μm to 0.5 μm, “small” is an amplitude of less than 0.01 μm,
“/” Indicates that no vibration occurs.
【００１１】[0011]
【表１】 [Table 1]
【００１２】[0012]
【表２】 表１に示されるように、転動球体の数が合成数（非素
数、すなわち因数を２以上有する数）であるとき、軌道
面の周方向のうねりの山数が、前記の合成数（転動球体
の数）若しくはその整数倍の数よりも１大きい数又は１
小さい数である場合を除けば、ラジアルＮＲＲＯは転動
球体の数が素数の場合よりも小さくなる。[Table 2] As shown in Table 1, when the number of rolling spheres is a composite number (non-prime number, that is, a number having a factor of 2 or more), the number of peaks in the circumferential direction of the track surface is the composite number (rolling number). Number of moving spheres) or a number greater than or an integer multiple of 1 or 1
Except when the number is small, the radial NRRO is smaller than when the number of rolling spheres is a prime number.
【００１３】また、表２に示されるように、転動球体の
数が素数であるとき、軌道面の周方向のうねりの山数
が、前記の素数（転動球体の数）又はその整数倍の数で
ある場合を除けば、アキシャルＮＲＲＯは転動球体の数
が合成数の場合より小さくなる。As shown in Table 2, when the number of rolling spheres is a prime number, the number of undulations in the circumferential direction of the raceway surface is the prime number (the number of rolling spheres) or an integral multiple thereof. Except for the number of rolling spheres, the axial NRRO is smaller than when the number of rolling spheres is the composite number.
【００１４】回転部の重心との回転軸線方向距離が比較
的に長い位置においては、ラジアル振動が比較的大きく
なり易い。従って、その位置の玉軸受は転動球体の数を
合成数とし、ラジアル振動を小さくするものとする。ま
た、回転部の重心との回転軸線方向距離が比較的短い
（０の場合も含む）位置においては、ラジアル振動の振
幅が比較的小さいため、その位置の玉受軸は転動球体の
数を素数とする。At a position where the distance between the rotating portion and the center of gravity in the direction of the rotation axis is relatively long, the radial vibration tends to be relatively large. Accordingly, the number of rolling spheres in the ball bearing at that position is set as a composite number, and the radial vibration is reduced. Also, at a position where the distance between the center of gravity of the rotating portion and the center of gravity in the direction of the rotation axis is relatively short (including 0), the amplitude of the radial vibration is relatively small. Let it be a prime number.
【００１５】なお、この回転機械は電動機とすることが
でき、この電動機は、ハードディスク等の磁気ディス
ク、光磁気ディスク、ＣＤ−ＲＯＭ、ＣＤ−Ｒ、ＣＤ−
ＲＷ、ＤＶＤ等の光ディスクを始めとする記録媒体、特
に円盤状記録媒体を駆動するためのスピンドルモータの
他、種々の電動機として用いることができる。The rotating machine may be an electric motor, and the electric motor may be a magnetic disk such as a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-ROM.
It can be used as various electric motors, in addition to a spindle motor for driving a recording medium such as an optical disk such as RW and DVD, particularly a disk-shaped recording medium.
【００１６】転動球体の数が合成数である上記玉軸受、
すなわち回転部の重心との回転軸線方向距離が比較的に
長い位置の玉軸受において、軌道面の周方向のうねりの
山数が、前記の合成数（転動球体の数）若しくはその整
数倍の数よりも１大きい数又は１小さい数である場合を
除けば、表１に示されるように、その位置における回転
部のラジアル振動は転動球体が素数の場合よりも小さく
抑えることができる。The above ball bearing, wherein the number of rolling spheres is a composite number;
That is, in a ball bearing at a position where the distance in the rotation axis direction from the center of gravity of the rotating portion is relatively long, the number of undulations in the circumferential direction of the raceway surface is equal to the composite number (the number of rolling spheres) or an integral multiple thereof. Except for the case where the number is one number larger or one number smaller than the number, as shown in Table 1, the radial vibration of the rotating part at that position can be suppressed smaller than when the rolling sphere is a prime number.
【００１７】転動球体の数が素数である上記玉軸受、す
なわち回転部の重心との回転軸線方離が比較的に短い位
置の玉軸受において、軌道面の周方向のうねりの山数
が、前記の合成数（転動球体の数）若しくはその整数倍
の数である場合を除けば、表２に示されるように、その
位置における回転部のアキシャル振動は転動球体が合成
数の場合よりも小さく抑えることができる。In the above-described ball bearing in which the number of rolling spheres is a prime number, that is, a ball bearing at a position relatively short of the rotation axis from the center of gravity of the rotating portion, the number of circumferential undulations on the raceway surface is As shown in Table 2, the axial vibration of the rotating part at that position is larger than that of the case where the number of rolling spheres is composite, except for the case where the number of rolling spheres is a multiple of the number of rolling spheres or an integer multiple thereof. Can also be kept small.
【００１８】[0018]
【発明の実施の形態】本発明の実施の形態を、図面を参
照しつつ説明する。Embodiments of the present invention will be described with reference to the drawings.
【００１９】図１は、ハードディスク（記録媒体の一
例）が装着された軸回転型のハードディスク駆動用スピ
ンドルモータ（回転機械の一例）の断面図、図２は、そ
のスピンドルモータの上玉軸受の拡大平面図、図３は、
そのスピンドルモータの下玉軸受の拡大平面図である。FIG. 1 is a sectional view of a spindle motor (an example of a rotating machine) for driving a shaft-rotating hard disk on which a hard disk (an example of a recording medium) is mounted, and FIG. 2 is an enlarged view of an upper ball bearing of the spindle motor. The plan view and FIG.
It is an enlarged plan view of the lower ball bearing of the spindle motor.
【００２０】このスピンドルモータは、ハードディスク
駆動装置の基盤に固定されるブラケット１０の環状凹部
１０ａの内周側に立設された略円筒形状の軸受ハウジン
グ部１０ｂに対し、軸心方向に同軸状に配列された上下
ラジアル玉軸受１２・１４を介して、ロータハブ１６と
一体をなす回転軸１８が回転自在に支持されてなる。な
お、ブラケットはハードディスク駆動装置の基盤に一体
に形成されていてもよい。This spindle motor is axially coaxial with a substantially cylindrical bearing housing portion 10b erected on the inner peripheral side of an annular concave portion 10a of a bracket 10 fixed to a base of a hard disk drive. A rotating shaft 18 integral with the rotor hub 16 is rotatably supported via the arranged upper and lower radial ball bearings 12 and 14. The bracket may be formed integrally with the base of the hard disk drive.
【００２１】ブラケット１０の軸受ハウジング部１０ｂ
の外周部には、ステータコイル２０が巻回されたステー
タコア２２が外嵌固定されている。環状凹部１０ａの上
部外周側には、環状張出部１０ｃを有する。Bearing housing portion 10b of bracket 10
A stator core 22 around which a stator coil 20 is wound is externally fitted and fixed to the outer peripheral portion. An annular protrusion 10c is provided on the upper outer peripheral side of the annular concave portion 10a.
【００２２】ロータハブ１６は、略椀形状をなし、その
外周壁の外周部に、円筒面部１６ｂ１と環状の外方突部
１６ｂ２を備えた記録媒体保持部１６ｂを有する。ロー
タハブ１６の中央部には、下向きに突出する回転軸１８
が同軸状に内嵌固定されている。回転軸１８の外径は、
実質上一定である。ロータハブ１６の外周壁には、ロー
タマグネット２４が内嵌固定されてステータコア２２に
相対している。The rotor hub 16 has a substantially bowl shape, and has a recording medium holding portion 16b provided with a cylindrical surface portion 16b1 and an annular outward projection 16b2 on the outer peripheral portion of the outer peripheral wall. A rotating shaft 18 projecting downward is provided at the center of the rotor hub 16.
Are coaxially fitted and fixed. The outer diameter of the rotating shaft 18 is
Substantially constant. A rotor magnet 24 is internally fixed to the outer peripheral wall of the rotor hub 16 and faces the stator core 22.
【００２３】円筒面部１６ｂ１には２枚のハードディス
ク２６が環状スペーサ２８を挟んで外嵌され、ロータハ
ブ１６に取り付けられたクランプ部材３０と外方突部１
６ｂ２の間にそれらのハードディスク２６が挟圧固定さ
れている。Two hard disks 26 are externally fitted to the cylindrical surface portion 16b1 with an annular spacer 28 interposed therebetween, and a clamp member 30 attached to the rotor hub 16 and the outward protrusion 1 are provided.
The hard disks 26 are clamped and fixed between 6b2.
【００２４】上下ラジアル玉軸受１２・１４の外輪１２
ａ・１４ａは、軸受ハウジング部１０ｂの内周部に圧入
され、外輪１２ａ・１４ａの外周面と軸受ハウジング部
１０ｂの内周面は、圧接状態で接着剤により固定されて
いる。Outer ring 12 of upper and lower radial ball bearings 12 and 14
a and 14a are press-fitted into the inner peripheral portion of the bearing housing portion 10b, and the outer peripheral surfaces of the outer rings 12a and 14a and the inner peripheral surface of the bearing housing portion 10b are fixed by an adhesive in a press-contact state.
【００２５】上下ラジアル玉軸受１２・１４における外
輪１２ａ・１４ａの軌道面と内輪１２ｂ・１４ｂの軌道
面の間には、それぞれ複数個の転動球体３２・３４がリ
テーナ（図示を略す）によって等間隔に配置されてい
る。なお、実際には、転動球体の円滑な回転のために、
そのリテーナの適個所にグリースが適量充填されてお
り、さらに外輪１２ａ・１４ａと内輪１２ｂ・１４ｂの
間の軸心方向両端面或いは一方の端面にグリースの流出
を防止する円環状シールド板が設けられている。Between the raceways of the outer races 12a, 14a and the raceways of the inner races 12b, 14b in the upper and lower radial ball bearings 12, 14, a plurality of rolling spheres 32, 34 are respectively provided by retainers (not shown). It is arranged at intervals. In addition, actually, for smooth rotation of the rolling sphere,
An appropriate amount of grease is filled in an appropriate place of the retainer, and an annular shield plate for preventing grease from flowing out is provided on both axial end surfaces or one end surface between the outer ring 12a, 14a and the inner ring 12b, 14b. ing.
【００２６】なお、軸受ハウジング部１０ｂの下方開口
部は、シール部材８０により密封されている。The lower opening of the bearing housing 10b is sealed by a seal member 80.
【００２７】ロータハブ１６、ロータマグネット２４、
ハードディスク２６、環状スペーサ２８、クランプ部材
３０、及び上下ラジアル玉軸受１２・１４の内輪１２ｂ
・１４ｂによって構成される全回転部の重心Ｇ１は、回
転軸１８の軸心線における中央よりも上方に位置する。The rotor hub 16, the rotor magnet 24,
Hard disk 26, annular spacer 28, clamp member 30, and inner ring 12b of upper and lower radial ball bearings 12 and 14
The center of gravity G <b> 1 of the entire rotating unit constituted by 14 b is located higher than the center of the axis of the rotating shaft 18.
【００２８】重心Ｇ１との回転軸線方向距離が比較的に
短く、ラジアル振動の振幅が比較的小さい位置に位置す
る上ラジアル玉軸受１２は、図２に示すように転動球体
３２の個数を１１、すなわち素数としている。従って、
上ラジアル玉軸受１２のアキシャルＮＲＲＯは小さく抑
えられる。As shown in FIG. 2, the upper radial ball bearing 12 having a relatively short distance from the center of gravity G1 in the direction of the rotational axis and having a relatively small amplitude of radial vibration has the number of rolling spheres 32 as shown in FIG. That is, it is a prime number. Therefore,
The axial NRRO of the upper radial ball bearing 12 is kept small.
【００２９】一方、重心Ｇ１との回転軸線方向距離が比
較的に長く、ラジアル振動の振幅が比較的大きくなり易
い位置に位置する下ラジアル玉軸受１４は、図３に示す
ように転動球体３４の個数を１２、すなわち２種以上の
因数を有する合成数としている。従って、下ラジアル玉
軸受１４のラジアルＮＲＲＯは小さく抑えられる。On the other hand, as shown in FIG. 3, the lower radial ball bearing 14 is located at a position where the distance from the center of gravity G1 in the direction of the rotation axis is relatively long and the amplitude of the radial vibration tends to be relatively large. Is 12, ie, a composite number having two or more types of factors. Therefore, the radial NRRO of the lower radial ball bearing 14 can be kept small.
【００３０】こうして、回転部のピッチング振動、パラ
レル振動及びアキシャル振動等が何れも抑えられる。Thus, pitching vibration, parallel vibration, axial vibration, and the like of the rotating portion are all suppressed.
【００３１】図４は、ハードディスク（記録媒体の一
例）が装着された軸固定型のハードディスク駆動用スピ
ンドルモータ（回転機械の一例）の断面図である。FIG. 4 is a sectional view of a fixed-shaft hard disk drive spindle motor (an example of a rotating machine) to which a hard disk (an example of a recording medium) is mounted.
【００３２】このスピンドルモータは、ハードディスク
駆動装置の基盤に固定されるブラケット５０の中央嵌合
孔に下端部が圧入固定されて立設された固定軸体５２に
対し、軸心方向に同軸状に配列された上下ラジアル玉軸
受５４・５６を介して、ロータハブ５８が回転自在に支
持されてなる。This spindle motor is axially coaxial with a fixed shaft 52 having a lower end press-fitted and fixed in a central fitting hole of a bracket 50 fixed to a base of a hard disk drive and standing upright. A rotor hub 58 is rotatably supported via the arranged upper and lower radial ball bearings 54 and 56.
【００３３】ブラケット５０における、ロータハブ５８
の内周壁部５８ａの外方側には、円筒状壁部５０ａが立
設され、その外周部にステータコイル６２が巻回された
ステータコア６４が外嵌固定され、ロータハブ５８の外
周壁に内嵌固定されたロータマグネット６６と相対して
いる。ロータハブ５８にはハードディスク６８が外嵌さ
れ、ロータハブ５８に取り付けられたクランプ部材７０
とロータハブ５８のデイスク受け部５８ｂの間に挟圧固
定されている。The rotor hub 58 of the bracket 50
A cylindrical wall portion 50a is erected on the outer side of the inner peripheral wall portion 58a, and a stator core 64 around which a stator coil 62 is wound is fixed on the outer peripheral portion thereof. It is opposed to the fixed rotor magnet 66. A hard disk 68 is externally fitted to the rotor hub 58, and a clamp member 70 attached to the rotor hub 58.
And a disk receiving portion 58b of the rotor hub 58.
【００３４】上下ラジアル玉軸受５４・５６の外輪５４
ａ・５６ａは、ロータハブ５８の内周壁部５８ａに圧入
され、外輪５４ａ・５６ａの外周面とロータハブ５８の
内周壁部５８ａの内周面は、圧接状態で接着剤により固
定されている。また、上下ラジアル玉軸受５４・５６の
内輪５４ｂ・５６ｂには、固定軸体５２が圧入され、内
輪５４ｂ・５６ｂの内周面と固定軸体５２の外周面は圧
接状態で接着剤により固定されている。Outer ring 54 of upper and lower radial ball bearings 54 and 56
a and 56a are press-fitted into the inner peripheral wall 58a of the rotor hub 58, and the outer peripheral surfaces of the outer rings 54a and 56a and the inner peripheral surface of the inner peripheral wall 58a of the rotor hub 58 are fixed by an adhesive in a press-contact state. The fixed shaft 52 is press-fitted into the inner rings 54b and 56b of the upper and lower radial ball bearings 54 and 56, and the inner peripheral surfaces of the inner rings 54b and 56b and the outer peripheral surface of the fixed shaft 52 are fixed by an adhesive in a press-contact state. ing.
【００３５】上下ラジアル玉軸受５４・５６における外
輪５４ａ・５６ａの軌道面と内輪５４ｂ・５６ｂの弧状
断面の軌道面の間には、図１のスピンドルモータと同様
に、それぞれ複数個の転動球体がリテーナ（図示を略
す）によって等間隔に配置されている。In the upper and lower radial ball bearings 54 and 56, between the raceways of the outer rings 54a and 56a and the raceways of the arc-shaped cross sections of the inner rings 54b and 56b, a plurality of rolling spheres are provided as in the spindle motor of FIG. Are arranged at equal intervals by a retainer (not shown).
【００３６】ロータハブ５８、ロータマグネット６６、
ハードディスク６８、クランプ部材７０、及び上下ラジ
アル玉軸受５４・５６の外輪５４ａ・５６ａによって構
成される全回転部の重心Ｇ２は、固定軸体５２の軸心線
における中央に位置する。The rotor hub 58, the rotor magnet 66,
The center of gravity G <b> 2 of all the rotating parts formed by the hard disk 68, the clamp member 70, and the outer rings 54 a and 56 a of the upper and lower radial ball bearings 54 and 56 is located at the center of the axis of the fixed shaft 52.
【００３７】重心Ｇ２との回転軸線方向距離が比較的に
長く、ラジアル振動の振幅が比較的大きくなり易い位置
に位置する上ラジアル玉軸受５４は、転動球体７２の個
数を１２、すなわち２種以上の因数を有する合成数とし
ている。従って、表１に示されるようにその回転軸線方
向位置における回転部のラジアルＮＲＲＯが小さく抑え
られる。The upper radial ball bearing 54, which is located at a position where the distance from the center of gravity G2 in the direction of the rotation axis is relatively long and the amplitude of the radial vibration tends to be relatively large, has 12 rolling balls 72, that is, two types. It is a composite number having the above factors. Therefore, as shown in Table 1, the radial NRRO of the rotating portion at the position in the rotation axis direction can be suppressed to a small value.
【００３８】一方、重心Ｇ２との回転軸線方向距離が比
較的に短く、ラジアル振動の振幅が比較的小さい位置に
位置する下ラジアル玉軸受５６は、転動球体７４の個数
を１１、すなわち素数としている。従って、表２に示さ
れるように、その回転軸線方向位置における回転部のア
キシャルＮＲＲＯが小さく抑えられる。On the other hand, the lower radial ball bearing 56, which is located at a position where the distance from the center of gravity G2 in the rotation axis direction is relatively short and the amplitude of the radial vibration is relatively small, has 11 rolling balls 74, that is, a prime number. I have. Therefore, as shown in Table 2, the axial NRRO of the rotating portion at the position in the rotation axis direction can be suppressed to a small value.
【００３９】こうして、回転部のピッチング振動、パラ
レル振動及びアキシャル振動等が何れも抑えられる。Thus, pitching vibration, parallel vibration, axial vibration and the like of the rotating portion are all suppressed.
【００４０】なお、以上の実施の形態についての記述に
おける上下位置関係は、単に図に基づいた説明の便宜の
ためのものであって、実際の使用状態等を限定するもの
ではない。It should be noted that the vertical positional relationship in the description of the above embodiment is merely for convenience of explanation based on the drawings, and does not limit the actual use state and the like.
【００４１】[0041]
【発明の効果】本発明の回転機械においては、回転部の
重心との回転軸線方向距離が比較的に長いためラジアル
振動の振幅が比較的大きくなり易い回転軸線方向位置に
おける回転部のラジアルＮＲＲＯが抑えられ、回転部の
重心との回転軸線方向距離が比較的に短いためラジアル
振動の振幅が比較的小さい回転軸線方向位置における回
転部のアキシャルＮＲＲＯが抑えられる。そのため、玉
軸受の軌道面の周方向のうねりに起因する回転部のピッ
チング振動、パラレル振動及びアキシャル振動等が、何
れも効果的に抑制され、高精度の回転が実現される。In the rotating machine of the present invention, the radial NRRO of the rotating portion at the position in the rotating axis direction where the amplitude of the radial vibration tends to be relatively large since the distance in the rotation axis direction from the center of gravity of the rotation portion is relatively long is small. The axial NRRO of the rotating part at a position in the rotating axis direction where the amplitude of the radial vibration is relatively small because the distance in the rotation axis direction from the center of gravity of the rotation part to the center of gravity is relatively short is suppressed. Therefore, pitching vibration, parallel vibration, axial vibration, and the like of the rotating portion due to circumferential undulation of the raceway surface of the ball bearing are all effectively suppressed, and high-precision rotation is realized.
【００４２】従って、例えば本発明の回転機械が記録媒
体駆動用のスピンドルモータである場合、記録媒体、特
に円盤状記録媒体の回転精度を向上させてエラー発生を
確実に防止しつつ記録密度を向上させる上で効果が高
い。Therefore, for example, when the rotating machine of the present invention is a spindle motor for driving a recording medium, the recording density is improved while improving the rotational accuracy of the recording medium, especially the disk-shaped recording medium, thereby reliably preventing the occurrence of errors. The effect is high in making it.
【００４３】請求項３の回転機械においては、回転部の
重心との回転軸線方向距離が比較的に長いためラジアル
方向の振動の振幅が比較的大きくなり易い位置における
回転部のラジアルＮＲＲＯがより確実性高く抑えられる
ので、回転部のピッチング振動及びパラレル振動が、何
れもより効果的に抑制される。In the rotating machine according to the third aspect, the radial NRRO of the rotating part at a position where the amplitude of the vibration in the radial direction tends to be relatively large because the distance between the rotating part and the center of gravity of the rotating part in the rotation axis direction is relatively long is more reliable. Therefore, both the pitching vibration and the parallel vibration of the rotating part are more effectively suppressed.
【図１】軸回転型のハードディスク駆動用スピンドルモ
ータの断面図である。FIG. 1 is a sectional view of a spindle motor for driving a hard disk of a rotating shaft type.
【図２】スピンドルモータの上玉軸受の拡大平面図であ
る。FIG. 2 is an enlarged plan view of an upper ball bearing of a spindle motor.
【図３】スピンドルモータの下玉軸受の拡大平面図であ
る。FIG. 3 is an enlarged plan view of a lower ball bearing of a spindle motor.
【図４】軸固定型のハードディスク駆動用スピンドルモ
ータ）の断面図である。FIG. 4 is a sectional view of a fixed shaft type hard disk drive spindle motor.
１２ 上ラジアル玉軸受 １４ 下ラジアル玉軸受 １６ ロータハブ ２６ ハードディスク ３０ クランプ部材 ３２ 転動球体 ３４ 転動球体 12 Upper Radial Ball Bearing 14 Lower Radial Ball Bearing 16 Rotor Hub 26 Hard Disk 30 Clamp Member 32 Rolling Sphere 34 Rolling Sphere
Claims (3)
部を有し、回転軸線方向における２以上の箇所に配装さ
れた玉軸受を介して前記固定部に対し前記回転部が回転
自在に支持されてなる回転機械であって、各玉軸受にお
いて、転動球体は周方向等間隔に配置され、回転部の重
心との回転軸線方向距離が比較的に長い位置の玉軸受に
おける転動球体の数が合成数であり、前記重心との回転
軸線方向距離が比較的に短い位置の玉軸受における転動
球体の数が素数であることを特徴とする回転機械。A rotating portion having a center of gravity on a rotating axis, wherein the rotating portion rotates with respect to the fixed portion via ball bearings disposed at two or more locations in the rotating axis direction. A rotating machine freely supported, wherein in each ball bearing, the rolling spheres are arranged at regular intervals in the circumferential direction, and the rolling sphere in the ball bearing at a position relatively long in the rotation axis direction with respect to the center of gravity of the rotating portion. A rotating machine wherein the number of moving spheres is a composite number, and the number of rolling spheres in a ball bearing at a position relatively short in the rotation axis direction from the center of gravity is a prime number.
回転軸線方向位置に配装された請求項１記載の回転機
械。2. The rotary machine according to claim 1, comprising two ball bearings, each of which is disposed at a different position in the direction of the rotation axis.
的に長い位置の玉軸受における転動球体の数が、２種以
上の因数を有する合成数である請求項１、２、３又は４
記載の回転機械。3. The number of rolling spheres in a ball bearing at a position where a distance from the center of gravity of the rotating portion to the center of gravity of the rotating portion in the rotation axis direction is relatively long is a composite number having two or more factors. Or 4
The rotating machine as described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01511098A JP4118993B2 (en) | 1998-01-08 | 1998-01-08 | Rotating machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01511098A JP4118993B2 (en) | 1998-01-08 | 1998-01-08 | Rotating machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11201153A true JPH11201153A (en) | 1999-07-27 |
| JP4118993B2 JP4118993B2 (en) | 2008-07-16 |
Family
ID=11879704
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP01511098A Expired - Fee Related JP4118993B2 (en) | 1998-01-08 | 1998-01-08 | Rotating machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4118993B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005027186A1 (en) * | 2005-06-07 | 2006-12-14 | Getrag Getriebe- Und Zahnradfabrik Hermann Hagenmeyer Gmbh & Cie Kg | Retainer for e.g. loose wheel bearing of motor vehicle gear, has rows of rolling body slots and empty slots formed at base body, where number of empty slots is prime number and number of rolling body slots is not prime number or vice versa |
| US8104968B2 (en) * | 2006-03-27 | 2012-01-31 | Ntn Corporation | Rolling contact bearing |
| JP2013036578A (en) * | 2011-08-10 | 2013-02-21 | Ntn Corp | Thrust bearing |
-
1998
- 1998-01-08 JP JP01511098A patent/JP4118993B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005027186A1 (en) * | 2005-06-07 | 2006-12-14 | Getrag Getriebe- Und Zahnradfabrik Hermann Hagenmeyer Gmbh & Cie Kg | Retainer for e.g. loose wheel bearing of motor vehicle gear, has rows of rolling body slots and empty slots formed at base body, where number of empty slots is prime number and number of rolling body slots is not prime number or vice versa |
| DE102005027186B4 (en) * | 2005-06-07 | 2007-04-12 | Getrag Getriebe- Und Zahnradfabrik Hermann Hagenmeyer Gmbh & Cie Kg | Rolling bearing cage and idler gear bearing |
| US8104968B2 (en) * | 2006-03-27 | 2012-01-31 | Ntn Corporation | Rolling contact bearing |
| JP2013036578A (en) * | 2011-08-10 | 2013-02-21 | Ntn Corp | Thrust bearing |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4118993B2 (en) | 2008-07-16 |
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