JPH0610945A - Dynamic pressure bearing and rotating polygon mirror device using this - Google Patents
Dynamic pressure bearing and rotating polygon mirror device using thisInfo
- Publication number
- JPH0610945A JPH0610945A JP1364993A JP1364993A JPH0610945A JP H0610945 A JPH0610945 A JP H0610945A JP 1364993 A JP1364993 A JP 1364993A JP 1364993 A JP1364993 A JP 1364993A JP H0610945 A JPH0610945 A JP H0610945A
- Authority
- JP
- Japan
- Prior art keywords
- bearing
- rotating body
- resistant member
- mirror device
- dynamic pressure
- 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.)
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- Mechanical Optical Scanning Systems (AREA)
- Sliding-Contact Bearings (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、回転体を滑らかに回転
させるための動圧軸受と、これを用いた回転多面鏡装置
に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic pressure bearing for smoothly rotating a rotating body and a rotary polygon mirror device using the same.
【０００２】[0002]
【従来の技術】動圧軸受は、回転体を高速で滑らかに回
転するため、多面鏡回転モータの支持部としてよく使わ
れている。図７に従来の多面鏡回転モータの断面図を示
す。図に示すように、回転体４には多面鏡５と回転子６
とが取り付けてあり、固定子７に通電すると、回転子６
は図中矢印Ａ方向に回転する。回転体が回転すると周囲
の空気が巻き込まれ、軸受基材２に接合された耐磨耗性
プラスチツク材３で構成した上下２組の軸受１と回転体
４とは非接触状態となる。2. Description of the Related Art A dynamic pressure bearing is often used as a support portion of a polygon mirror rotation motor because it rotates a rotating body smoothly at high speed. FIG. 7 shows a sectional view of a conventional polygon mirror rotation motor. As shown in the figure, the rotating body 4 includes a polygon mirror 5 and a rotor 6.
Are attached, and when the stator 7 is energized, the rotor 6
Rotates in the direction of arrow A in the figure. When the rotating body rotates, the surrounding air is entrained, and the upper and lower two sets of bearings 1 and the rotating body 4 formed of the wear-resistant plastic material 3 joined to the bearing base material 2 are in a non-contact state.
【０００３】このモータは立軸なので回転体４の全重量
を支えるスラスト側は、永久磁石８，９の極性が互いに
同じ極性で向かい合うことによつて生じる反発力で、非
接触状態で浮上している。Since this motor is a vertical shaft, the thrust side, which supports the total weight of the rotating body 4, is levitated in a non-contact state by the repulsive force generated by the permanent magnets 8 and 9 facing each other with the same polarity. .
【０００４】上記モータは、高速時、ラジラル方向およ
びスラスト方向は非接触のため滑らかに回転するはずだ
が、実際は振動を発生する。この振動の主な原因とし
て、幾つか考えられる。１つは回転体の不釣合いによる
振動であるが、これは釣り合い試験機によつて不釣合い
を検出して、修正することによつて取り除くことが可能
である。これに対して軸受より発生する不安定振動は、
上記試験機による修正はできない。At the time of high speed, the above-mentioned motor should rotate smoothly because it is non-contact in the radial direction and the thrust direction, but actually it generates vibration. There are several possible causes of this vibration. One is vibration due to imbalance of the rotating body, which can be removed by detecting and correcting the imbalance by the balance testing machine. On the other hand, the unstable vibration generated from the bearing is
It cannot be corrected by the above tester.
【０００５】この不安定振動は、上下軸受１の芯ずれに
よるものと、軸受の形状により発生するものがある。前
記上下軸受１の芯ずれによる振動は、回転体４の回転軸
が芯ずれにより斜めに倒れた形で回転し、軸受の空隙が
不均一になり発生するものであるが、この芯ずれを無く
すため、従来は一方の軸受１を３方向からのねじにより
他方の軸受１の中心に合うべく調整することによつて解
決していた。This unstable vibration may be caused by the misalignment of the upper and lower bearings 1 or may be caused by the shape of the bearing. The vibration caused by the misalignment of the upper and lower bearings 1 is caused by the rotational axis of the rotating body 4 being tilted and tilted due to the misalignment, resulting in uneven bearing gaps. However, this misalignment is eliminated. Therefore, conventionally, the problem has been solved by adjusting one bearing 1 so as to match the center of the other bearing 1 with screws from three directions.
【０００６】また、軸受の形状より発生する振動はホワ
ールと呼ばれ、このホワールは一般に図８、図９に示す
ような多円弧の軸受によつて解決されると考えられてい
たが、多円弧の軸受においても発生するのが実情であ
る。Further, the vibration generated by the shape of the bearing is called a whirl, and this whirl was generally thought to be solved by a multi-circle bearing as shown in FIGS. The reality is that it also occurs in bearings.
【０００７】即ち、図８、図９に示すように、回転体４
の移動方向に隙間が段々狭くなつて、この時、面の相対
的な移動により気体が粘性で引きずられ、隙間に押し込
められて回転体４を浮上させる圧力（正圧）が生じる。
その後、回転体４の移動方向に隙間は段々広くなつてく
るが、この時、気体の粘性によつて回転体を引つ張る力
（負圧）が発生し、この力によつて回転軸が角速度ωで
自転しながら、偏心量ｅの半径で回転軸の回転方向に触
れ回りの角速度ω0 で軸受の中心のまわりを回転する。
ここで、触れ回りの角速度ω0 は角速度ωの１／２〜１
／3 となつている。That is, as shown in FIG. 8 and FIG.
The gap is gradually narrowed in the moving direction of, and at this time, the gas is viscous dragged by the relative movement of the surfaces, and the pressure (positive pressure) that is pushed into the gap and floats the rotating body 4 is generated.
After that, the gap gradually widens in the moving direction of the rotating body 4, but at this time, a force (negative pressure) pulling the rotating body is generated due to the viscosity of the gas, and this force causes the rotating shaft to move. While rotating at the angular velocity ω, the bearing rotates about the center of the bearing at the angular velocity ω 0 , which touches the rotation direction of the rotating shaft with the radius of the eccentricity e.
Here, the angular velocity ω 0 around the touch is 1/2 to 1 of the angular velocity ω.
It is / 3.
【０００８】また、前記振動の他に軸受１と回転体４の
空隙が温度によつて変化することによつても振動が生じ
る。これは、軸受１と回転体４の熱膨張係数が異なるこ
とによつて生じていた。In addition to the above-mentioned vibration, vibration also occurs when the gap between the bearing 1 and the rotating body 4 changes due to temperature. This was caused by the difference in thermal expansion coefficient between the bearing 1 and the rotating body 4.
【０００９】従来、軸受基材は銅系およびプラスチツク
材で形成し、回転体は鉄系の鋼材で形成していた。ここ
で回転体が回転することで温度が上昇し、軸受基材の熱
膨張系数が高いため、回転体４の直径膨張量より大きく
なり、空隙が大きくなる。Conventionally, the bearing base material is made of copper-based and plastic materials, and the rotating body is made of iron-based steel material. Here, as the rotating body rotates, the temperature rises and the coefficient of thermal expansion of the bearing base material is high, so that it becomes larger than the diameter expansion amount of the rotating body 4 and the void becomes large.
【００１０】このため、動圧が下がり剛性が弱くなつて
振動が生じる。また、軸受基材に取り付けてある耐磨耗
性のプラスチツク材の肉厚が厚いと、前記プラスチツク
材が軸受基材の熱膨張係数より小さい場合は、前記のよ
うに空隙は大きくなるが、大きいか同等の場合は、空隙
が小さくなるため、軸受のロスが増し、温度上昇が大と
なる。For this reason, the dynamic pressure is lowered and the rigidity is weakened, so that vibration occurs. Further, if the thickness of the wear-resistant plastic material attached to the bearing base material is large, if the plastic material is smaller than the coefficient of thermal expansion of the bearing base material, the voids become large as described above, but large. If the values are the same, the air gap becomes small, so that the loss of the bearing increases and the temperature rises significantly.
【００１１】[0011]
【発明が解決しようとする課題】前述したように、従来
の軸受には、不安定振動が発生するという問題がある
が、上下の２つの軸受の芯ずれによる振動は芯合わせの
調整をすることによつて解決する。しかしこれでは調整
する時間がかかる、部品点数が増える、等の問題があつ
た。As described above, the conventional bearing has a problem that unstable vibration occurs, but the vibration due to the misalignment of the upper and lower two bearings requires the alignment of the center. To solve it. However, this involves problems such as time required for adjustment and increase in the number of parts.
【００１２】また、回転数を高くするとロスが増すた
め、温度上昇による軸受空隙が変化し、振動が生じて回
転数を高速域（２００００ｍｉｎ-1以上）まで達するこ
とができないため、外部からの冷却を十分に行う必要が
ある等の問題があつた。Further, since the loss increases as the number of revolutions increases, the bearing air gap changes due to temperature rise, and vibrations occur to prevent the number of revolutions from reaching the high speed range (20,000 min-1 or more), so cooling from the outside is required. There was a problem that it was necessary to fully perform.
【００１３】本発明の目的は、上記の問題点をなくし、
広い回転領域にわたって安定した回転を得ることが可能
な動圧軸受及び回転多面鏡装置を提供することである。The object of the present invention is to eliminate the above problems,
An object of the present invention is to provide a dynamic pressure bearing and a rotary polygon mirror device capable of obtaining stable rotation over a wide rotation region.
【００１４】[0014]
【課題を解決するための手段】上記の目的は、 （１）軸受部の芯ずれを少なくするため、複数の軸受面
をもつ場合、あるいは、回転軸方向に軸受面が幅をもつ
場合の両方に対して、単一の軸受基材を用い、この軸受
基材の内面に耐磨耗性部材のプラスチツク材などを接合
し、このプラスチツク材の内面に軸受形状を同時加工す
ることにより達成される。The above objects are (1) In order to reduce the misalignment of the bearing portion, both when the bearing surface has a plurality of bearing surfaces or when the bearing surface has a width in the rotational axis direction. To achieve this, a single bearing base material is used, a plastic material such as a wear-resistant member is joined to the inner surface of the base material, and the bearing shape is simultaneously processed on the inner surface of the plastic material. .
【００１５】（２）また、軸受の多円弧形状におけるホ
ワール抑制のためには、負圧の力をなくすことが必要で
ある。そのため、軸受面は、回転体の一部をほぼ同心的
に覆うように配置され、回転体の移動方向に対し、前記
回転体との間に形成される空隙が徐々に狭くなり、ある
特定位置で、最小空隙から最大空隙に急激に変化させる
ことによつて、空気の粘性力が急激に失われて、負圧が
発生しない。しかし、最大空隙と最小空隙の比があまり
小さすぎると、高速域で負圧が生じやすくなるので、広
い回転域で使用するため、その比を６倍以上取ることに
よつて安定化が達成される。(2) Further, in order to suppress the whirl in the multi-arc shape of the bearing, it is necessary to eliminate the negative pressure force. Therefore, the bearing surface is arranged so as to cover a part of the rotating body substantially concentrically, and the gap formed between the rotating surface and the rotating body becomes gradually narrower with respect to the moving direction of the rotating body. Then, by rapidly changing from the minimum gap to the maximum gap, the viscous force of air is rapidly lost, and negative pressure is not generated. However, if the ratio of the maximum air gap to the minimum air gap is too small, negative pressure is likely to occur in the high speed range, so for use in a wide rotation range, stabilization is achieved by taking the ratio 6 times or more. It
【００１６】（３）また、多面鏡を有する回転体と、前
記回転体の一部をほぼ同心的に覆うように配置され、か
つ、前記回転体に対向する面に耐磨耗性部材が配置され
た流体動圧軸受を有し、前記軸受に覆われた回転体部位
がモータ磁束の通路である回転多面鏡装置において、前
記回転体に対向する軸受面形状が、回転方向に対して前
記回転体との間に形成される空隙が徐々に狭くなり、あ
る特定位置で急激に広くなる軸受を設けたことによつて
安定に回転する回転多面鏡装置が達成される。(3) Further, a rotating body having a polygonal mirror is arranged so as to cover a part of the rotating body substantially concentrically, and an abrasion resistant member is arranged on a surface facing the rotating body. In a rotary polygon mirror device in which a rotating body portion covered with the bearing is a passage of a motor magnetic flux, the shape of the bearing surface facing the rotating body is the rotation direction with respect to the rotation direction. A rotary polygon mirror device that stably rotates is achieved by providing a bearing in which the gap formed between the body and the body gradually narrows and rapidly widens at a specific position.
【００１７】（４）また、（３）において、前記軸受
は、対向する回転体部と同一の材料を基材とし、その内
面に耐磨耗性部材を配置すると共に、前記耐磨耗性部材
の厚さが、前記基材の厚さよりも薄いものであることに
よつて対温度特性の安定化が達成される。(4) Further, in (3), the bearing is made of the same material as that of the rotating body portion facing the base material, and the wear resistant member is disposed on the inner surface of the base material. Since the thickness of the base material is smaller than the thickness of the base material, stabilization of temperature characteristics is achieved.
【００１８】（５）また、（４）において、前記耐磨耗
性部材の厚さが、０．５ｍｍ以下であることが対温度特
性上好ましい。(5) Further, in (4), the thickness of the abrasion resistant member is preferably 0.5 mm or less in view of temperature characteristics.
【００１９】（６）また、（４）において、前記軸受を
ハウジング部に直接固定したことによつて効率の良い冷
却が達成される。(6) Further, in (4), since the bearing is directly fixed to the housing portion, efficient cooling is achieved.
【００２０】[0020]
【作用】上記の（１）で構成された軸受は、１つの軸受
基材の内面に耐磨耗性部材を接合し、この耐磨耗性部材
に軸受形状を同時加工することによつて、軸受形状の芯
がずれることなく加工されるため、組立時、芯ずれが発
生することがない。In the bearing constructed in the above (1), the wear resistant member is joined to the inner surface of one bearing base material, and the bearing shape is simultaneously machined on the wear resistant member. Since the core of the bearing shape is machined without deviation, no misalignment occurs during assembly.
【００２１】また、上記（２）で構成された軸受は、隙
間が急激に広くなるため、隙間が段々広くなることによ
つて発生する負圧部がなくなる。しかし、最小空隙と最
大空隙の差が小さくなつてくれば、前記負圧の発生が生
じやすくなるため、最小と最大の空隙比は少なくとも６
倍以上必要となる。Further, in the bearing constructed in the above (2), since the gap is suddenly widened, the negative pressure portion generated due to the widening of the gap is eliminated. However, if the difference between the minimum void and the maximum void becomes smaller, the negative pressure is more likely to occur, so the minimum and maximum void ratio is at least 6%.
You need more than twice.
【００２２】また、上記（３）で構成された回転多面鏡
装置は、芯合わせ等の調整が不要で、ホワール振動も発
生しない。Further, in the rotary polygon mirror device constructed in the above (3), adjustment such as centering is unnecessary, and whirl vibration does not occur.
【００２３】また、上記（４），（５）で構成された軸
受は、熱膨張係数が、軸受基材と回転体とで同一のた
め、空隙が温度で変化することがない。また、軸受基材
で接合された耐磨耗性プラスチツク材を薄肉としている
ので、前記プラスチツクの熱膨張の影響を小さくするこ
とができる。Further, in the bearing constituted by the above (4) and (5), since the thermal expansion coefficient of the bearing base material is the same as that of the rotating body, the air gap does not change with temperature. Further, since the abrasion-resistant plastic material joined by the bearing base material is thin, the influence of thermal expansion of the plastic material can be reduced.
【００２４】また、上記（６）で構成された軸受は、ハ
ウジングに直接軸受を接合することによつて冷却効果を
上げて温度上昇を防ぐことができる。Further, in the bearing constructed in the above (6), by directly joining the bearing to the housing, the cooling effect can be enhanced and the temperature rise can be prevented.
【００２５】[0025]
【実施例】以下、本発明の実施例を図面に基づいて説明
する。Embodiments of the present invention will be described below with reference to the drawings.
【００２６】図１は長手方向に平行に縦断した動圧軸受
の斜視図、図２は径方向に平行に縦断した動圧軸受の断
面図である。FIG. 1 is a perspective view of a dynamic pressure bearing longitudinally cut in parallel to the longitudinal direction, and FIG. 2 is a sectional view of a dynamic pressure bearing longitudinally cut in parallel to the radial direction.
【００２７】軸受１は図１（ａ）に示されるように、硬
い材料で作られた軸受基材２の内面に、耐磨耗性部材と
してプラスチツク材３が接着剤によつて接合されてい
る。このプラスチツク材３は図１（ｂ）に示すように２
個以上でもよい。プラスチツク材３の内面は図２のよう
な形状、即ち、多円弧形状に形成されている。前記形状
は軸受基材２を保持し、プラスチツク材３の内面をＮＣ
加工機などで加工することにより完成する。この時、２
個のプラスチツク材３は同時に加工されている。As shown in FIG. 1 (a), the bearing 1 has an inner surface of a bearing base material 2 made of a hard material, and a plastics material 3 as an abrasion resistant member joined by an adhesive. . As shown in FIG. 1 (b), this plastic material 3 is
It may be more than one. The inner surface of the plastic material 3 has a shape as shown in FIG. 2, that is, a multi-arc shape. The shape holds the bearing base material 2 and the inner surface of the plastic material 3 is NC.
It is completed by processing with a processing machine. At this time, 2
The individual plastic materials 3 are processed at the same time.
【００２８】図３に、図１、図２の軸受を使用した多面
鏡回転モータの断面図を示す。図に示すように、回転体
４には多面鏡５と回転子６とが取り付けてあり、軸受１
の外周部に取り付けた固定子７に通電すると、回転子６
は図中矢印Ａ方向に回転する。回転子６が回転すると、
軸受１によつて回転体４と非接触状態となる。この時、
軸受１のプラスチツク材３は芯が合致しているので、上
下の芯が合わないことによる振動がなく、また、芯合わ
せの調整も不要となる。FIG. 3 shows a sectional view of a polygon mirror rotating motor using the bearings of FIGS. As shown in the figure, a polygonal mirror 5 and a rotor 6 are attached to the rotating body 4, and the bearing 1
When electricity is applied to the stator 7 attached to the outer periphery of the rotor 6,
Rotates in the direction of arrow A in the figure. When the rotor 6 rotates,
The bearing 1 makes a non-contact state with the rotating body 4. At this time,
Since the cores of the plastic material 3 of the bearing 1 are aligned, there is no vibration due to the alignment of the upper and lower cores, and the alignment adjustment is also unnecessary.
【００２９】図４は、図２の最小空隙Ｇa と最大空隙Ｇ
b の比（ε＝Ｇb ／Ｇa ）を横軸とし、縦軸に回転数を
取り、ホワールの発生する有無を表したものである。図
に示すように、空隙比εが６より小さいと、ある特定の
回転領域でホワールが発生し、それ以上だとホワールは
どの回転数でも発生していないことが分かる。FIG. 4 shows the minimum gap G a and the maximum gap G of FIG.
The horizontal axis represents the ratio of b (ε = G b / G a ), and the vertical axis represents the number of revolutions, representing the presence or absence of whirl. As shown in the figure, it can be seen that when the void ratio ε is less than 6, whirl occurs in a certain specific rotation region, and when it is more than that, the whirl does not occur at any rotation speed.
【００３０】ここで、動圧軸受に振動計を付設し、一次
の回転時の振動（１２０００ｒｐｍの速度で回転する時
に、周波数２００Ｈｚの振動を生じる）よりも低い周波
数の振動が測定されるとホワール有と判断している。Here, a vibrometer is attached to the dynamic pressure bearing, and when a vibration of a frequency lower than the vibration at the time of the primary rotation (a vibration of frequency 200 Hz is generated when rotating at a speed of 12000 rpm) is measured, the whirl It is judged that there is.
【００３１】なお、軸受基材２としてアルミニウムや銅
などの非磁性材あるいは鋼などの磁性材が使用される。A non-magnetic material such as aluminum or copper or a magnetic material such as steel is used as the bearing base material 2.
【００３２】また、プラスチツク材３として、ポリイミ
ド樹脂、ポリアミド樹脂、ポリアセタール樹脂などが使
用可能で、特にポリイミド樹脂は硬度が高く、耐磨耗性
に優れているため好適である。As the plastic material 3, a polyimide resin, a polyamide resin, a polyacetal resin or the like can be used. Particularly, the polyimide resin is preferable because it has high hardness and excellent abrasion resistance.
【００３３】また、１つの軸受基材２の内面に２つ以上
のプラスチツク材３を接合すると、軸受１の軸方向に沿
つて加工部材を移動させることにより、上下のプラスチ
ツク材３に位置ずれなく段差が形成できるので、芯ずれ
がなく回転状態が安定する。When two or more plastic materials 3 are joined to the inner surface of one bearing base material 2, the working member is moved along the axial direction of the bearing 1 so that the upper and lower plastic materials 3 are not displaced. Since a step can be formed, there is no misalignment and the rotating state is stable.
【００３４】そして、２つ以上のプラスチツク材３が同
時に加工できるから作業性が良好なものとなる。Further, since two or more plastic materials 3 can be processed at the same time, the workability becomes good.
【００３５】図５は図１、図２の軸受を使用した多面鏡
回転モータの断面図を示す。FIG. 5 shows a sectional view of a polygon mirror rotating motor using the bearings of FIGS.
【００３６】図に示すように、回転体４には多面鏡５と
回転子６とが取り付けてあり、回転子６は、モータの磁
束を発生する２極の永久磁石１１と磁束を通すために磁
性材料で形成されたヨーク１０で構成されている。永久
磁石１１とヨーク１０との間にコイル７が固定され、コ
イル７に電流を流すことにより、回転体４を回転させる
ことが可能となる。As shown in the figure, a polygonal mirror 5 and a rotor 6 are attached to the rotating body 4, and the rotor 6 passes through a two-pole permanent magnet 11 for generating a magnetic flux of the motor and a magnetic flux. The yoke 10 is made of a magnetic material. The coil 7 is fixed between the permanent magnet 11 and the yoke 10, and the rotating body 4 can be rotated by passing a current through the coil 7.
【００３７】図５のヨーク１０の外周面は、軸受１と対
面している。回転体４が図中矢印方向に回転することに
より、軸受１によつて回転体４と非接触状態となる。こ
の時、軸受形状が図２に示す形となつているため、高速
まで滑らかに回転することが可能となる。The outer peripheral surface of the yoke 10 in FIG. 5 faces the bearing 1. When the rotor 4 rotates in the direction of the arrow in the figure, the bearing 1 brings the rotor 4 out of contact with the rotor 4. At this time, since the bearing has the shape shown in FIG. 2, it is possible to smoothly rotate at a high speed.
【００３８】軸受１の軸受基材２は、回転子６のヨーク
１０と同じ材料で形成されており、高速回転時に発生す
る発熱で材料が等熱膨張した時、軸受１と回転子６との
空隙が常に同一となる。The bearing base material 2 of the bearing 1 is made of the same material as that of the yoke 10 of the rotor 6, and when the material is subjected to equal thermal expansion due to heat generated during high speed rotation, the bearing 1 and the rotor 6 are separated from each other. The voids are always the same.
【００３９】さらに、軸受１に接合されている耐磨耗性
プラスチツク材３は、熱膨張の影響を避けるため、極力
薄く接合されている。Further, the wear-resistant plastic material 3 bonded to the bearing 1 is bonded as thinly as possible in order to avoid the influence of thermal expansion.
【００４０】図６はプラスチツク材３の肉厚を変化させ
た時の空隙の変化を計算した結果を、回転体よりも軸受
基材の熱膨張係数が大きい例（二点鎖線で示す）と回転
体と軸受基材の熱膨張係数が等しい例（実線で示す）と
を比較して示す図である。横軸に耐磨耗性プラスチツク
材３の厚さを、また、縦軸に軸受空隙に軸方向の変化量
を示している。FIG. 6 shows the calculation results of the change of the air gap when the wall thickness of the plastic material 3 is changed, with an example in which the coefficient of thermal expansion of the bearing base material is larger than that of the rotating body (shown by a chain double-dashed line). It is a figure which compares and shows an example (indicated by a solid line) where a body and a bearing base material have the same coefficient of thermal expansion. The horizontal axis shows the thickness of the abrasion-resistant plastics material 3, and the vertical axis shows the amount of change in the axial direction in the bearing gap.
【００４１】図に示すように、プラスチツク材３の肉厚
を０．５ｍｍ以下とすることにより、熱による空隙の変
化を少なくすることができる。また、この場合、変化量
が１μｍ以下となり、ロスがなく回転性が良好となる。
また、軸受基材２の熱膨張係数をヨーク１０の１．７倍
とした時、プラスチツク材３の肉厚を２．５ｍｍとして
も可能であるが（二点鎖線でしめす）、材料が高くなり
好ましくはない。このようなことから、プラスチツク材
３の厚さは、０．１〜０．５ｍｍの範囲が好適である。As shown in the figure, by changing the thickness of the plastic material 3 to 0.5 mm or less, it is possible to reduce the change in the air gap due to heat. Further, in this case, the change amount is 1 μm or less, and there is no loss, and the rotatability is good.
Further, when the coefficient of thermal expansion of the bearing base material 2 is 1.7 times that of the yoke 10, the thickness of the plastic material 3 can be 2.5 mm (indicated by a chain double-dashed line), but the material becomes high. Not preferred. Therefore, the thickness of the plastic material 3 is preferably in the range of 0.1 to 0.5 mm.
【００４２】軸受１は高速回転によつて生じる発熱を外
部へ放熱させるため、ハウジング１２に直接接着されて
いる。The bearing 1 is directly bonded to the housing 12 in order to radiate the heat generated by the high speed rotation to the outside.
【００４３】[0043]
【発明の効果】請求項１ないし５記載の発明によれば、
軸受の単一軸受基材に耐磨耗性部材としてのプラスチツ
ク材を接合し、その内面に多円弧形状を同時加工するこ
とにしたので、軸受の形状の芯合わせができ、調整する
ことが不要となる。また軸受の最大空隙と最小空隙の比
を６以上としたので、振動を抑えることができる。According to the inventions of claims 1 to 5,
Since a single bearing base material of the bearing is joined with a plastic material as an abrasion resistant member and the inner surface of the bearing is processed into a multi-arc shape at the same time, the bearing shape can be centered and no adjustment is required. Becomes Further, since the ratio of the maximum gap to the minimum gap of the bearing is 6 or more, vibration can be suppressed.
【００４４】請求項６ないし９記載の発明によれば、軸
受の軸受基材に１つの耐磨耗性プラスチツク材を接合
し、その内面を多円弧のくさび形状とするのみならず、
また、軸受基材と回転体との材料を同一とし、プラスチ
ツク材を軸受基材より薄くし、軸受を直接ハウジングに
接合したので、熱による軸受空隙の変化を小さく抑える
ことができる。According to the sixth to ninth aspects of the invention, not only one wear-resistant plastic material is joined to the bearing base material of the bearing, and the inner surface of the bearing material is formed into a multi-arc wedge shape.
Further, since the bearing base material and the rotating body are made of the same material, the plastic material is made thinner than the bearing base material, and the bearing is directly joined to the housing, it is possible to suppress a change in the bearing gap due to heat.
【００４５】上記のような構成により、広い回転速度を
領域にわたって安定動作する回転多面鏡装置を実現する
ことができる。また、本発明が、回転多面鏡装置のみな
らず、他の高速・高精度の回転体の実現にも適用できる
ことは明らかである。With the above-described structure, it is possible to realize a rotary polygon mirror device which operates stably over a wide range of rotation speeds. Further, it is obvious that the present invention can be applied not only to the rotary polygon mirror device but also to the realization of other high-speed and high-precision rotary bodies.
【図１】本発明の実施例に係る、長手方向に平行に縦断
した動圧軸受の斜視図である。FIG. 1 is a perspective view of a dynamic pressure bearing according to an embodiment of the present invention, which is longitudinally cut in parallel with a longitudinal direction.
【図２】本発明の実施例に係る、径方向に平行に縦断し
た動圧軸受の断面図である。FIG. 2 is a sectional view of a dynamic pressure bearing according to an embodiment of the present invention, which is longitudinally cut in parallel with a radial direction.
【図３】本発明の動圧軸受を組み込んだ多面鏡回転モー
タの縦断面図である。FIG. 3 is a vertical cross-sectional view of a polygon mirror rotation motor incorporating the dynamic pressure bearing of the present invention.
【図４】本発明の動圧軸受のギヤツプ比を変化させた時
のホワール発生の有無を表す図である。FIG. 4 is a diagram showing the presence or absence of whirl when the gear ratio of the dynamic pressure bearing of the present invention is changed.
【図５】本発明の他の実施例に係る回転多面鏡装置の長
手方向に平行に縦断したときの斜視図である。FIG. 5 is a perspective view of a rotary polygon mirror apparatus according to another embodiment of the present invention when the rotary polygon mirror apparatus is longitudinally cut parallel to the longitudinal direction.
【図６】プラスチツク材の肉厚を変化させた時の空隙の
変化を示す図である。FIG. 6 is a diagram showing changes in voids when the thickness of the plastic material is changed.
【図７】従来の多面鏡回転モータの縦断面図である。FIG. 7 is a vertical sectional view of a conventional polygon mirror rotation motor.
【図８】従来の軸受形状図である。FIG. 8 is a conventional bearing shape diagram.
【図９】従来の軸受形状図である。FIG. 9 is a conventional bearing shape diagram.
１ 軸受 ２ 軸受基材 ３ プラスチツク材 ４ 回転体 1 bearing 2 bearing base material 3 plastic material 4 rotating body
───────────────────────────────────────────────────── フロントページの続き (72)発明者 和田 聡 茨城県勝田市武田1060番地 日立工機株式 会社勝田工場内 (72)発明者 菊池 隆広 茨城県勝田市武田1060番地 日立工機株式 会社勝田工場内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Wada 1060 Takeda, Katsuta, Ibaraki Prefecture Katsuta Factory, Hitachi Koki Co., Ltd. (72) Takahiro Kikuchi, 1060 Takeda, Katsuta, Ibaraki Hitachi Koki Co., Ltd. Katsuta Factory Within
Claims (13)
が接合された動圧軸受において、 前記耐磨耗性部材が所定の軸受形状に加工されて軸受が
構成されることを特徴とする動圧軸受。1. A dynamic pressure bearing in which a wear resistant member is joined to an inner surface of a bearing base material on the side of a rotating body, wherein the wear resistant member is processed into a predetermined bearing shape to form a bearing. And dynamic pressure bearing.
れ、その形状が回転体との移動方向に対して、回転体と
の間に形成される空隙が徐々に狭くなり、特定位置で最
小空隙から最大空隙に急激に変化し、かつ最小空隙と最
大空隙の比が６〜１１であることを特徴とする請求項１
記載の動圧軸受。2. The wear-resistant member is formed in a multi-arc shape, and the shape thereof is gradually narrowed with respect to the moving direction with respect to the rotating body, so that the gap formed between the rotating body and the rotating body becomes narrower. 2. A rapid change from the minimum void to the maximum void at, and the ratio of the minimum void to the maximum void is 6 to 11.
The described dynamic pressure bearing.
ることを特徴とする請求項１記載の動圧軸受。3. The dynamic pressure bearing according to claim 1, wherein the wear resistant member is a polyimide resin.
以下であることを特徴とする請求項１記載の動圧軸受。4. The wear resistant member has a thickness of 0.5 mm.
The dynamic pressure bearing according to claim 1, wherein:
耗性部材が接合され、前記耐磨耗性部材が所定の軸受形
状の同時加工されてなることを特徴とする請求項１記載
の動圧軸受。5. A single bearing base material has two or more wear resistant members joined to the inner surface thereof, and the wear resistant members are simultaneously machined into a predetermined bearing shape. Item 5. The dynamic pressure bearing according to item 1.
一部をほぼ同心的に覆うように配置され、かつ、前記回
転体に対向する面に耐磨耗性部材が配置された流体動圧
軸受を有し、前記軸受に覆われた回転体部位がモータ磁
束の通路である回転多面鏡装置において、 前記回転体に対向する軸受面形状が、回転方向に対して
前記回転体との間に形成される空隙が徐々に狭くなり、
ある特定位置で急激に広くなる動圧軸受を設けたことを
特徴とする回転多面鏡装置。6. A rotating body having a polygonal mirror, and a fluid arranged to cover a part of the rotating body substantially concentrically, and an abrasion resistant member arranged on a surface facing the rotating body. In a rotary polygonal mirror device having a dynamic pressure bearing, and a rotating body portion covered with the bearing is a path of a motor magnetic flux, a bearing surface shape facing the rotating body has The voids formed between them gradually narrow,
A rotary polygon mirror device, characterized in that a dynamic pressure bearing is provided that widens rapidly at a specific position.
材料を基材とし、その内面に耐磨耗性部材を配置すると
共に、前記耐磨耗性部材の厚さが、前記基材の厚さより
も薄いことを特徴とする請求項６記載の回転多面鏡装
置。7. The bearing has a base material made of the same material as that of the facing rotating body, and an abrasion resistant member is disposed on an inner surface of the bearing, and the thickness of the abrasion resistant member is the base material. 7. The rotating polygonal mirror device according to claim 6, wherein the polygonal mirror device is thinner than the thickness of.
以下であることを特徴とする請求項７記載の回転多面鏡
装置。8. The wear-resistant member has a thickness of 0.5 mm.
The rotating polygon mirror device according to claim 7, wherein:
ことを特徴とする請求項６記載の回転多面鏡装置。9. The rotary polygon mirror apparatus according to claim 6, wherein the bearing is directly fixed to the housing portion.
の一部をほぼ同心的に覆うように配置され、かつ、前記
回転体に対向する面に耐磨耗性部材が配置された流体動
圧軸受を有し、前記軸受に覆われた回転体部位がモータ
磁束の通路である回転多面鏡装置において、 前記回転体に対向する軸受面が、回転方向に対して前記
回転体との間に形成される空隙が徐々に狭くなり、ある
特定位置で急激に広くなる形状を有し、かつ、単一の軸
受基材内面に前記軸受面を複数個設けたことを特徴とす
る回転多面鏡装置。10. A rotating body having a polygonal mirror, and a fluid arranged to cover a part of the rotating body substantially concentrically, and an abrasion resistant member arranged on a surface facing the rotating body. A rotary polygonal mirror device having a dynamic pressure bearing, wherein a rotating body portion covered with the bearing is a passage of a motor magnetic flux, wherein a bearing surface facing the rotating body is between the rotating body and the rotating body. The rotary polygon mirror having a shape in which the void formed in the inner wall gradually narrows and rapidly widens at a specific position, and a plurality of bearing surfaces are provided on the inner surface of a single bearing base material. apparatus.
の材料を基材とし、その内面に耐磨耗性部材を配置する
と共に、前記耐磨耗性部材の厚さが、前記基材の厚さよ
りも薄いことを特徴とする請求項１０記載の回転多面鏡
装置。11. The bearing comprises a base material made of the same material as that of the facing rotating body, and an abrasion resistant member is disposed on an inner surface of the bearing, and the thickness of the abrasion resistant member is the base material. 11. The rotary polygon mirror device according to claim 10, wherein the polygonal mirror device is thinner than the thickness of.
ｍ以下であることを特徴とする請求項１１記載の回転多
面鏡装置。12. The wear resistant member has a thickness of 0.5 m.
The polygonal mirror device according to claim 11, wherein the polygonal mirror device has a thickness of m or less.
たことを特徴とする請求項１０記載の回転多面鏡装置。13. The rotary polygon mirror device according to claim 10, wherein the bearing is directly fixed to the housing portion.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1364993A JPH0610945A (en) | 1992-04-27 | 1993-01-29 | Dynamic pressure bearing and rotating polygon mirror device using this |
| US08/048,185 US5434695A (en) | 1992-04-21 | 1993-04-20 | Dynamic pressure bearing and rotary polygon mirror device with the bearing |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10773992 | 1992-04-27 | ||
| JP4-107739 | 1992-04-27 | ||
| JP1364993A JPH0610945A (en) | 1992-04-27 | 1993-01-29 | Dynamic pressure bearing and rotating polygon mirror device using this |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0610945A true JPH0610945A (en) | 1994-01-21 |
Family
ID=26349476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1364993A Pending JPH0610945A (en) | 1992-04-21 | 1993-01-29 | Dynamic pressure bearing and rotating polygon mirror device using this |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0610945A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0732517A1 (en) * | 1995-03-13 | 1996-09-18 | Sumitomo Electric Industries, Limited | Dynamic-pressure gas bearing structure and optical deflection scanning apparatus |
| CN110594287A (en) * | 2019-09-17 | 2019-12-20 | 福建福清核电有限公司 | Main pump integrated three-liquid-tank radial water guide bearing bush |
| CN114786801A (en) * | 2019-12-11 | 2022-07-22 | 阿法拉伐股份有限公司 | Shaft bearing for bearing a stirrer shaft and stirrer |
-
1993
- 1993-01-29 JP JP1364993A patent/JPH0610945A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0732517A1 (en) * | 1995-03-13 | 1996-09-18 | Sumitomo Electric Industries, Limited | Dynamic-pressure gas bearing structure and optical deflection scanning apparatus |
| US5731831A (en) * | 1995-03-13 | 1998-03-24 | Canon Kabushiki Kaisha | Dynamic-pressure gas bearing structure and optical deflection scanning apparatus |
| CN110594287A (en) * | 2019-09-17 | 2019-12-20 | 福建福清核电有限公司 | Main pump integrated three-liquid-tank radial water guide bearing bush |
| CN114786801A (en) * | 2019-12-11 | 2022-07-22 | 阿法拉伐股份有限公司 | Shaft bearing for bearing a stirrer shaft and stirrer |
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