JP2635981B2 - Thin motor - Google Patents
Thin motorInfo
- Publication number
- JP2635981B2 JP2635981B2 JP62310674A JP31067487A JP2635981B2 JP 2635981 B2 JP2635981 B2 JP 2635981B2 JP 62310674 A JP62310674 A JP 62310674A JP 31067487 A JP31067487 A JP 31067487A JP 2635981 B2 JP2635981 B2 JP 2635981B2
- Authority
- JP
- Japan
- Prior art keywords
- stator
- magnetic
- rotor shaft
- view
- rotor
- 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.)
- Expired - Fee Related
Links
Landscapes
- Permanent Magnet Type Synchronous Machine (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、回転子の軸振れが厳しく規制される薄型電
動機に関し、特に磁気記録装置やデジタルオーディオデ
ィスク装置のダイレクトドライブスピンドルモータとし
て用いられる薄型電動機に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin motor in which shaft runout of a rotor is strictly controlled, and in particular, a thin motor used as a direct drive spindle motor of a magnetic recording device or a digital audio disk device. Related to electric motors.
［従来の技術］ 従来、この種の薄型電動機では、第９図に示すよう
に、固定子１が径及び軸方向で対称になっている。その
ため、含油合金軸受を用いた場合、回転子軸は、磁気
的、機械的不釣り合いやわずかな外乱によって軸受との
嵌合寸法隙間の範囲内で倒れや、スリコギ運動を起し易
く、また薄型のため軸受有効長が短く設計されているこ
とから、その影響を強く受ける。[Prior Art] Conventionally, in a thin motor of this type, as shown in FIG. 9, the stator 1 is symmetrical in the radial and axial directions. Therefore, when oil-impregnated alloy bearings are used, the rotor shaft is likely to fall down or slip over within the fitting dimension gap with the bearing due to magnetic or mechanical imbalance or slight disturbance, and is thin. For this reason, the bearing is designed to have a short effective length, which is strongly affected.
また、前述の嵌合寸法隙間は、回転子軸の倒れを少な
くするため通常より狭く設計される結果、含油合金の潤
滑油の温度による粘度変化の影響を受け、特に低温時に
は軸受損失が増大する結果となっていた。In addition, the above-mentioned fitting gap is designed to be narrower than usual in order to reduce the inclination of the rotor shaft. As a result, the gap is affected by the viscosity change of the oil-containing alloy due to the temperature of the lubricating oil, and the bearing loss increases particularly at low temperatures. The result was.
また、１個あるいは２個の玉軸受と含油合金軸受を組
合せて用いる場合、余圧を与える関係から玉軸受内輪と
回転子軸の嵌合部、あるいは玉軸受外輪とその筐体の嵌
合部はスキマバメとしていたため、量的には少ないもの
の回転子軸の倒れやスリコギ運動が存在していた。When one or two ball bearings and an oil-impregnated alloy bearing are used in combination, the fitting portion between the ball bearing inner ring and the rotor shaft, or the fitting portion between the ball bearing outer ring and its housing, due to the application of excess pressure. Because of the skim, there was a small amount of rotor shaft tilting and squatting motion, although in small quantities.
［発明が解決しようとする問題点］ 上述した従来の含油合金軸受を用いた薄型電動機は、
軸受と軸との嵌合寸法隙間が狭く設定されているため、
特に低温時の潤滑油の粘度変化による損失が増大する。
このため、電動機としてのトルク余裕を大きくしなけれ
ばならず、消費電流の増加となって省電力化に逆行す
る。加えて、回転子軸の倒れやスリコギ運動をより少な
くするため、前述の嵌合寸法隙間をより狭くすれば焼付
きの危険が増す。従って、回転子の回転中に生じる回転
子軸の倒れやスリコギ運動を無くすことはできなかっ
た。[Problems to be Solved by the Invention] The above-described thin motor using the conventional oil-impregnated alloy bearing,
Because the fitting dimension gap between the bearing and the shaft is set narrow,
In particular, the loss due to the change in the viscosity of the lubricating oil at low temperatures increases.
For this reason, it is necessary to increase the torque margin as the electric motor, which increases current consumption and goes against power saving. In addition, the risk of seizure increases if the above-mentioned fitting dimension gap is made narrower in order to reduce the rotation of the rotor shaft and the sliding motion. Therefore, it has not been possible to eliminate the tilting of the rotor shaft and the sliding motion that occur during the rotation of the rotor.
［問題点を解決するための手段］ 上記従来の問題点を解決する本発明は、メディアディ
スクを回転子軸に直接装着駆動する薄型電動機におい
て、固定子の回転子磁石と対向する固定子磁極面の磁気
的中心を半周ごとに軸方向上下に変位させ、かつ固定子
の中心に対して点対称に配置した構成としている。Means for Solving the Problems According to the present invention for solving the above-mentioned conventional problems, in a thin motor in which a media disk is directly mounted on a rotor shaft and driven, a stator magnetic pole surface facing a rotor magnet of a stator is provided. The magnetic center is displaced up and down in the axial direction every half circle, and is arranged point-symmetrically with respect to the center of the stator.
［実施例］ 次に、本発明の実施例について図面を参照して詳細に
説明する。Example Next, an example of the present invention will be described in detail with reference to the drawings.
第１図は本発明の一実施例の断面図、第２図は第１図
のＡ部分における拡大断面図、第３図は第１図のＢ部分
における拡大断面図、第４図は第１図に示されている磁
気集束ヨークの平面図、第５図は第４図の断面図であ
る。1 is a cross-sectional view of one embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of a portion A of FIG. 1, FIG. 3 is an enlarged cross-sectional view of a portion B of FIG. 1, and FIG. FIG. 5 is a plan view of the magnetic focusing yoke shown in FIG. 5, and FIG. 5 is a sectional view of FIG.
本実施例の固定子１は、ほぼ半周に位置する磁極2aの
磁極先端部を軸方向に折り曲げ立ち上げて形成した磁気
集束面2bを有する２枚の磁気集束ヨーク２を、前記磁気
集束面2bが互いに対角に位置するように固定子鉄心３の
両面に配置挟持し、ハトメ４により固定した構成となっ
ている。The stator 1 of the present embodiment includes two magnetic focusing yokes 2 each having a magnetic focusing surface 2b formed by bending a magnetic pole tip of a magnetic pole 2a located substantially half way around in the axial direction and raising the magnetic pole 2a. Are arranged and sandwiched on both sides of the stator core 3 so as to be located diagonally to each other, and are fixed by eyelets 4.
上記固定子１とマグネットヨーク５との磁気的位置関
係を第２図及び第３図に示す。図中、Ｃはマグネットヨ
ーク５に保持された回転子磁石６の軸方向における磁気
中心、Ｄは固定子１のＡ部分の軸方向における磁気中
心、Ｅは固定子１のＢ部分の軸方向における磁気中心で
ある。The magnetic positional relationship between the stator 1 and the magnet yoke 5 is shown in FIG. 2 and FIG. In the figure, C is the magnetic center in the axial direction of the rotor magnet 6 held by the magnet yoke 5, D is the magnetic center in the axial direction of the A portion of the stator 1, and E is the axial center of the B portion of the stator 1. Magnetic center.
このような構成の固定子１とマグネットヨーク５によ
って保持された回転子磁石６の軸方向の磁気的位置関係
によって生ずる磁気的吸引力P1,P2によって、マグネッ
トヨーク５は偶力P0＝P1＋P2によって常に一定方向に傾
いて回転する第６図はその時のマグネットヨーク５を支
える回転子軸７と含油合金軸受８との状態を示す図であ
る。Due to the magnetic attraction forces P 1 and P 2 generated by the axial magnetic relationship between the stator 1 and the rotor magnet 6 held by the magnet yoke 5 having such a configuration, the magnet yoke 5 couples P 0 = FIG. 6 is a view showing the state of the rotor shaft 7 supporting the magnet yoke 5 and the oil-impregnated alloy bearing 8 at that time, the rotor being always inclined in a fixed direction by P 1 + P 2 .
本発明の他の実施例を第７図及び第８図に示す。この
実施例では、上記のような磁気集束ヨーク２を使用せ
ず、半裁鉄心3aを固定子鉄心３の上下に対角に位置する
ように配置した構成となっている。Another embodiment of the present invention is shown in FIG. 7 and FIG. In this embodiment, the half core 3a is arranged diagonally above and below the stator core 3 without using the magnetic focusing yoke 2 as described above.
この場合も、固定子１と回転子磁石６の軸方向におけ
る磁気的位置関係が、第２図、第３図と同様の位置関係
となる。その結果、一定の偶力が回転軸７に働き、回転
子軸７は常に一定方向に傾いて回転する。Also in this case, the magnetic positional relationship between the stator 1 and the rotor magnet 6 in the axial direction is the same as that in FIGS. 2 and 3. As a result, a constant couple acts on the rotating shaft 7, and the rotor shaft 7 always rotates in a certain direction.
なお、上記実施例では、回転子軸７と含油合金軸受８
との嵌合寸法隙間を６〜30μｍに設定した。In the above embodiment, the rotor shaft 7 and the oil-impregnated alloy bearing 8
Is set to 6 to 30 μm.
［発明の効果］ 以上説明したように本発明は、メディアディスクを回
転子軸に直接装着駆動する薄型電動機において、固定子
の回転子磁石と対向する固定子磁極面の磁気的中心を半
周ごとに軸方向上下に変位させ、かつ固定子の中心に対
して点対称に配置したことにより、マグネットヨークは
常に一定方向に傾いて回転しかつそれを支える回転子軸
も傾いて回転し回転子軸を受ける含油合金軸受との接触
点も一定するため、従来この種の薄型電動機にみられた
軸受と回転子軸との嵌合寸法隙間の範囲内での回転中の
倒れやスリコギ運動を防止できる。また、そのため上記
嵌合寸法隙間を通常の適正値あるいはそれ以上に設定で
きるようになり、低温時の損失増を補う電流増加の必要
もなく、焼付きの危険もないなどの効果がある。[Effects of the Invention] As described above, the present invention relates to a thin motor in which a media disk is directly mounted on a rotor shaft, and a magnetic center of a stator magnetic pole surface facing a rotor magnet of a stator is disposed every half a circle. Displaced vertically in the axial direction, and arranged symmetrically with respect to the center of the stator, the magnet yoke always rotates in a certain direction and rotates, and the rotor shaft that supports it also rotates in a tilted manner, thus rotating the rotor shaft. Since the contact point between the bearing and the oil-impregnated alloy bearing is also constant, it is possible to prevent the falling and the sliding motion during rotation within the range of the fitting dimension gap between the bearing and the rotor shaft, which is conventionally seen in this type of thin motor. In addition, the fitting dimension gap can be set to a normal appropriate value or more, so that there is no need for an increase in current to compensate for an increase in loss at low temperature, and there is no danger of seizure.
また、固定子磁極面を点対称に配置したことにより、
各磁極の有効磁束が均一化してコッキングが減少し、従
って磁気振動やトルクリップルも低減しかつ回転ムラも
減少する等の効果がある。In addition, by arranging the stator pole faces symmetrically,
The effective magnetic flux of each magnetic pole is made uniform and cocking is reduced. Therefore, there are effects such as reduction in magnetic vibration and torque ripple and reduction in rotation unevenness.
また、玉軸受を用いた場合でも、前述同様の効果が得
られる。Further, even when a ball bearing is used, the same effect as described above can be obtained.
第１図は本発明の一実施例の断面図、第２図は第１図の
Ａ部分の拡大断面図、第３図は第１図のＢ部分の拡大断
面図、第４図は第１図に示した磁気集束ヨークの平面
図、第５図は第４図の断面図、第６図は第１図の回転子
軸と軸受部の関係を示す拡大図、第７図は本発明の他の
実施例を示す断面図、第８図は第７図に示した実施例の
半裁された固定子鉄心の平面図、第９図は従来例の断面
図である。 1:固定子、2:磁気集束ヨーク 2a:磁極、2b:磁気集束面 3:固定子鉄心、3a:半裁鉄心 5:マグネットヨーク 6:回転子磁石 7:回転子軸、8:含油合金軸受1 is a sectional view of an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a portion A in FIG. 1, FIG. 3 is an enlarged sectional view of a portion B in FIG. 1, and FIG. FIG. 5 is a plan view of the magnetic focusing yoke shown in FIG. 5, FIG. 5 is a cross-sectional view of FIG. 4, FIG. 6 is an enlarged view showing the relationship between the rotor shaft and the bearing of FIG. 1, and FIG. FIG. 8 is a cross-sectional view showing another embodiment, FIG. 8 is a plan view of a half-cut stator core of the embodiment shown in FIG. 7, and FIG. 9 is a cross-sectional view of a conventional example. 1: stator, 2: magnetic focusing yoke 2a: magnetic pole, 2b: magnetic focusing surface 3: stator core, 3a: half-cut core 5: magnet yoke 6: rotor magnet 7: rotor shaft, 8: oil-impregnated alloy bearing
Claims (1)
動する薄型電動機において、固定子の回転子磁石と対向
する固定子磁極面の磁気的中心を半周ごとに軸方向上下
に変位させ、かつ固定子の中心に対して点対称に配置し
たことを特徴とする薄型電動機。1. A thin motor in which a media disk is directly mounted and driven on a rotor shaft, and a magnetic center of a stator magnetic pole surface opposed to a rotor magnet of the stator is axially displaced up and down every half circle and fixed. A thin electric motor characterized by being arranged point-symmetrically with respect to the center of a child.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62310674A JP2635981B2 (en) | 1987-12-08 | 1987-12-08 | Thin motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62310674A JP2635981B2 (en) | 1987-12-08 | 1987-12-08 | Thin motor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01152947A JPH01152947A (en) | 1989-06-15 |
| JP2635981B2 true JP2635981B2 (en) | 1997-07-30 |
Family
ID=18008088
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62310674A Expired - Fee Related JP2635981B2 (en) | 1987-12-08 | 1987-12-08 | Thin motor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2635981B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4900965A (en) * | 1988-09-28 | 1990-02-13 | Fisher Technology, Inc. | Lightweight high power electromotive device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5495307A (en) * | 1978-01-13 | 1979-07-27 | Rhythm Watch Co | Small motor |
-
1987
- 1987-12-08 JP JP62310674A patent/JP2635981B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01152947A (en) | 1989-06-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |