JP3656686B2

JP3656686B2 - Electric motor

Info

Publication number: JP3656686B2
Application number: JP02605397A
Authority: JP
Inventors: 斉浦上; 一広武田
Original assignee: Nidec Corp
Current assignee: Nidec America Corp
Priority date: 1997-01-24
Filing date: 1997-01-24
Publication date: 2005-06-08
Anticipated expiration: 2017-01-24
Also published as: JPH10210699A

Description

【０００１】
【発明の属する技術分野】
本発明は、スリーブ軸受と、スリーブ部から軸部が離脱するのを防ぐ抜け止め手段を備えており、且つ薄型化に適した電動機に関する。
【０００２】
【従来の技術及び発明が解決しようとする課題】
スリーブ軸受を有するモータとしては、例えば図６に示すようなファンモータがある。このモータにおいては、スリーブ部ａによって回転軸ｂを径方向に支持し、スラスト受部ｃによって回転軸ｂの下端部を上向きに受けると共に、ロータマグネットｄの磁気センタをステータｅの磁気センタよりもやや上方に位置させることによりロータに下向きの磁気吸引力を作用させて回転軸ｂの下端部をスラスト受部ｃ押圧させている。
【０００３】
しかしながら、この磁気吸引力だけでは回転軸ｂがスリーブ部ａから離脱するおそれがあるので、別に何らかの抜け止め手段が必要となる。その抜け止め手段として、この種のモータでは、ロータにおける回転軸ｂの基部外周に径方向外方に突起する合成樹脂製の外方突起部ｆを設けると共に、スリーブ部ａの上方に径方向内方に突起する合成樹脂製の内方突起部ｇを設け、ロータ側の外方突起部ｆをスリーブ部側の内方突起部ｇの下方に位置させて回転軸ｂの離脱を防いでいる。ロータの回転軸ｂをスリーブ部ａに挿入して回転軸ｂにスリーブ部ａをスリーブ嵌合させると、その過程において、外方突起部ｆと内方突起部ｇが接触して両者が弾性変形することにより、相互に相手方を乗り越えるので、外方突起部ｆを内方突起部ｇの下方に位置させることができる。
【０００４】
ところが、このような従来の抜け止め構造はスリーブ部ａの上方に位置するので、モータの回転軸線方向の高さが増大する。それ故、この種の抜け止め構造を、例えば記録用ディスク駆動のためのモータ等の緻密で薄型のモータに適用しようとすると、回転軸線方向の寸法の要求に応えられないという問題があった。
【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、回転部の抜け止めを、内部のスペースを有効に利用して達成することにより、全体を薄型化することができる電動機を提供することにある。
【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電動機は、
回転部と固定部の一方に有する軸部に、他方に有するスリーブ部がスリーブ嵌合する際に、回転部に設けられた回転抜け止め部と固定部に設けられた固定抜け止め部が接触して回転部及び固定部の一方の一部又は両方の一部が弾性変形することにより、前記回転抜け止め部が前記固定抜け止め部よりも下方に達して回転部が固定部から回転軸線方向上方に離脱することが防がれてなり、
固定部と回転部が径方向の軸受隙間を隔てて相対する径方向軸受部の径方向外方に、ステータコイルが巻回されたステータコアを有する電動機であって、
回転軸線方向における前記径方向軸受部の上下端の間で、径方向における前記ステータコアに巻回されたステータコイルと径方向軸受部の間に、前記回転抜け止め部及び固定抜け止め部が位置することを特徴とする。
【０００７】
回転部に軸部を有する場合、スリーブ部は固定され、軸部が回転する。回転部にスリーブ部を有する場合、軸部が固定され、スリーブ部が回転する。
【０００８】
回転部及び固定部の一方の一部又は両方の一部の弾性変形というのは、回転部に設けられた回転抜け止め部又は固定部に設けられた固定抜け止め部自体が弾性変形するものの他、例えば、回転抜け止め部又は固定抜け止め部が支持部により支持されていて、主としてその支持部が弾性変形するものや、そのような支持部と回転抜け止め部又は固定抜け止め部の全体が弾性変形するものであってもよい。
【０００９】
回転抜け止め部及び固定抜け止め部は、例えば一方を径方向内方突起部とし他方を径方向外方突起部とすることができる。金属薄板製又は合成樹脂製の断面略Ｌ字形状部又は略Ｊ字形状部の先端部を、そのような径方向内方突起部及び径方向外方突起部として利用することもできる。
【００１０】
回転部と固定部の一方に有する軸部に、他方に有するスリーブ部をスリーブ嵌合させて電動機を組み立てる際に、回転抜け止め部と固定抜け止め部が接触して回転部及び固定部の一方の一部又は両方の一部が弾性変形することにより、回転抜け止め部が固定抜け止め部よりも下方に達する。回転部が固定部から回転軸線方向上方に離脱しようとすると、それに伴い回転抜け止め部が上方に移動するが、上方に位置する固定抜け止め部がそれ以上の上方移動を阻止することにより、回転部の離脱が防がれる。
【００１１】
回転抜け止め部及び固定抜け止め部は、回転軸線方向における前記径方向軸受部の上下端の間で、径方向における前記ステータコアに巻回されたステータコイルと径方向軸受部の間に位置するので、その部分のスペースが回転部の抜け止めのために利用される。
【００１２】
この電動機は、回転抜け止め部及び固定抜け止め部が、回転軸線方向におけるステータコアの上面と径方向軸受部の上端の間に位置するものとすることができる。
【００１３】
この場合、ステータコアの上面と径方向軸受部の上端の間のスペース、すなわちステータコアに巻回されたステータコイルのうちステータコアの上側突出する高さにほぼ相当する高さのスペースが、回転抜け止め部及び固定抜け止め部による回転部の抜け止めのために利用される。
【００１４】
また、本発明の電動機は、ステータコアが固定される基盤と、そのステータコアを基盤に固定する固定用部材とを有してなる電動機であって、前記固定用部材により、固定抜け止め部を構成するための固定抜け止め部材を同時に固定部に固定したものとすることができる。
【００１５】
固定用部材としては、例えば、リベットやネジを用いることができる。また固定抜け止め部材は、例えば、固定用部材としてのリベットやネジの頭部とステータコアの上面との間に挟圧固定することができる。
【００１６】
この場合、固定抜け止め部を構成するための固定抜け止め部材が、固定用部材によりステータコアが基盤に固定されると同時に固定部に固定される。
【００１７】
また、本発明の電動機は、ステータコアが固定される基盤と、そのステータコアを基盤に固定する固定用部材とを有してなる電動機であって、前記固定用部材のうちステータコアの上側に突出した部分に、固定抜け止め部を有するものとすることができる。
【００１８】
固定用部材としては、例えば、固定抜け止め部となる突起部を頭部に形成したリベットやネジを用いることができる。
【００１９】
この場合、固定用部材によりステータコアが基盤に固定されることにより、その固定用部材が有する固定抜け止め部が固定部に設けられる。
【００２０】
【発明の実施の形態】
本発明の実施の形態を、図１乃至図５を参照しつつ説明する。
【００２１】
図１乃至図３は、本発明の実施の形態の一例としての電動機に関するものであって、図１は電動機の半断面図である。
【００２２】
この電動機の固定部１０は、主として、平板状の基盤１２と、スリーブ部材１４（スリーブ部の一例）と、スラスト受板１６と、ステータコイル２０が巻回されたステータコア２２と、金属薄板製の固定抜け止め部材２４と、固定抜け止め部材２４とステータコア２２とスリーブ部材１４を同時に基盤１２に固定するネジ２６からなる。
【００２３】
スリーブ部材１４の内周面は、下端部を除き一定内径であり、スリーブ部材１４の下端内側部は拡径され、基盤１２との間にスラスト受板１６を収容固定している。スリーブ部材１４の下端外側部は、ネジ２６が位置する部分を切り欠いた状態で外方へ張り出した外方張出部１４ａに形成されている。
【００２４】
図２は、固定抜け止め部材２４の要部斜視図である。
【００２５】
固定抜け止め部材２４は、環状平板部２４ａの外周部に断面略Ｊ字形状の上方突起部２４ｂを等間隔に有してなる。各上方突起部２４ｂの上端部の、上に凸に湾曲しつつ径方向外方に突起した部分が、固定抜け止め部２４ｃを構成する。環状平板部２４ａには、等中心角毎の３箇所にネジ挿通孔２４ｄを有する。
【００２６】
外方張出部１４ａの上部の小外径部にステータコア２２が外嵌され、ステータコア２２の上面内周部上に固定抜け止め部材２４の環状平板部２４ａの下面が位置した状態で、固定抜け止め部材２４、ステータコア２２及びスリーブ部材１４が、等中心角毎の３箇所においてネジ２６により一括的に基盤１２に対し固定されている。基盤１２とステータコア２２及びステータコイル２０の間には、それらをスリーブ部材１４の外周部と共に固定して振動を防止することができる合成樹脂２８が充填固化されている。
【００２７】
電動機の回転部４０は、回転軸４２（軸部の一例）と、回転軸４２の上部に外嵌固定された環状体４４と、内周部が環状体４４の下面側の径方向中間位置に設けられた環状下方突部４４ａに外嵌固定された略椀形状の強磁性材料製のロータフレーム４６と、ロータフレーム４６の外周壁部の内周面に固定されてステータコア２２と径方向に相対するロータマグネット４８からなり、記録用ディスクを駆動する場合のターンテーブルとして利用される金属製の環状体４４の外周部には、記録用ディスクを保持するための環状板状のクランプ用マグネット５０が外嵌固定されている。
【００２８】
図３は、ロータフレーム４６の要部斜視図である。
【００２９】
ロータフレーム４６の上板の内周側における等中心角毎の４箇所に、プレス加工により、断面略Ｌ字形状の下方突起部４６ａが設けられ、各下方突起部４６ａの下端部の、径方向内方に突起した部分が、回転抜け止め部４６ｂを構成する。
【００３０】
回転軸４２の下端面は、中心がその回転軸線に一致した下に凸の球面状に形成されている。
【００３１】
回転部４０を組み立てた後、回転軸４２をスリーブ部材１４に挿入して回転軸４２にスリーブ部材１４をスリーブ嵌合させると、回転軸４２の外周面はスリーブ部材１４の内周面に相対して径方向軸受部を構成し、回転軸４２の下端面はスラスト受板１６の平坦な上面上に支持される。ロータマグネット４８の磁気センタがステータの磁気センタよりもやや上方に位置するので、回転部４０に下向きの磁気吸引力が作用して回転軸４２の下端面がスラスト受板１６に押圧される。
【００３２】
スリーブ嵌合の過程において、回転抜け止め部４６ｂと固定抜け止め部２４ｃが接触し、固定部１０の上方突起部２４ｂ及び回転部４０の下方突起部４６ａの両方、特に、金属薄板製の上方突起部２４ｂが弾性変形することにより、相互に相手方を乗り越えて回転抜け止め部４６ｂが固定抜け止め部２４ｃよりも下方に達する。通常、電動機の回転中は、回転抜け止め部４６ｂと固定抜け止め部２４ｃは非接触状態である。回転部４０が固定部１０から回転軸線方向上方に離脱しようとすると、それに伴い回転抜け止め部４６ｂが上方に移動するが、その上方に位置する固定抜け止め部２４ｃが、回転部４０のそれ以上の上方移動を阻止するので、回転部４０の離脱が防がれる。なお、固定部１０の上方突起部２４ｂ同士の間隔は、回転部４０の下方突起部４６ａの径方向幅よりも小さく設定されているので、回転部４０の回転角度の如何によらず有効に離脱防止される。
【００３３】
回転抜け止め部４６ｂ及び固定抜け止め部２４ｃは、回転軸線方向におけるステータコア２２の上面とスリーブ部材１４の内周面の上端（径方向軸受部の上端）の間で、径方向におけるステータコイル２０とスリーブ部材１４の間に位置するので、その部分のスペースが回転部４０の抜け止めのために有効に利用され、電動機全体の薄型化が達成されている。特に、この例のように金属薄板を固定抜け止め部２４ｃ又は回転抜け止め部４６ｂとして用いると、強度を確保しつつ必要スペースを低減することができるので好適である。
【００３４】
なお、ステータコア必要箇所を、ステータコイルに対し電気的に絶縁するためのインシュレータにより被覆する場合は、そのインシュレータの一部により固定抜け止め部を形成することもできる。
【００３５】
図４は、本発明の実施の形態の別の例としての電動機の断面図である。
【００３６】
この電動機の固定部６０は、主として、平板状の基盤６２と、スリーブ部材６４（スリーブ部の一例）と、スラスト受板６６と、ステータコイル６８が巻回されたステータコア７０と、金属薄板製の固定抜け止め部材７２と、ステータコア７０とスリーブ部材６４を同時に基盤６２に固定するリベット７４からなる。
【００３７】
スリーブ部材６４の内周面は、下端部を除き一定内径であり、スリーブ部材６４の下端内側部は拡径され、基盤６２との間にスラスト受板６６を収容固定している。
【００３８】
固定抜け止め部材７２は、ステータコア７０の上面内周部の数箇所に等中心角毎に固定されている。各固定抜け止め部材７２は、下板の内端部に断面略Ｌ字形状の上方突起部７２ａが設けられ、その上端部の、径方向外方に突起した部分が、固定抜け止め部７２ｂを構成する。
【００３９】
ステータコア７０は、スリーブ部材６４の小外径部に外嵌され、そのステータコア７０の内周部と、スリーブ部材６４の下端の外方張出部が、等中心角毎の位置においてリベット７４により基盤６２に対し固定されている。各固定抜け止め部材７２の固定をリベット７４により同時に行って製造工程数を削減することもできる。
【００４０】
電動機の回転部８０は、回転軸８２（軸部の一例）と、回転軸８２の上部に外嵌固定された環状体８４と、内周部が環状体８４に外嵌固定された略椀形状の強磁性材料製のロータフレーム８６と、ロータフレーム８６の外周壁部の内周面に固定されてステータコア７０と径方向に相対するロータマグネット８８からなり、ロータフレーム８６の上板の内周部上には、環状板状のクランプ用マグネット９０が外嵌固定されている。
【００４１】
記録用ディスクを駆動する場合のターンテーブルとして利用される金属製の環状体８４の外周部は、全周にわたり下方に突出し、更にその下端内周部に、全周にわたり径方向内方に突起した回転抜け止め部８４ａが設けられている。この回転抜け止め部８４ａは切削加工により形成されている。
【００４２】
回転軸８２の下端面の中央部には、中心がその回転軸８２線に一致した下に凸の球面凸部８２ａが設けられている。
【００４３】
回転部８０を組み立てた後、回転軸８２をスリーブ部材６４に挿入して回転軸８２にスリーブ部材６４をスリーブ嵌合させると、回転軸８２の外周面はスリーブ部材６４の内周面に相対して径方向軸受部を構成し、回転軸８２の下端面中央部の球面凸部８２ａは、スラスト受板６６の上面中央部の、球面凸部８２ａの曲率よりも小さい曲率の球面凹部６６ａ上に支持される。ロータマグネット８８の磁気センタがステータの磁気センタよりもやや上方に位置するので、回転部８０に下向きの磁気吸引力が作用して回転軸８２の下端面がスラスト受板６６に押圧される。
【００４４】
スリーブ嵌合の過程において、回転抜け止め部８４ａと固定抜け止め部７２ｂが接触し、主として固定部６０の上方突起部７２ａが弾性変形することにより、相互に相手方を乗り越えて回転抜け止め部８４ａが固定抜け止め部７２ｂよりも下方に達し、回転部８０の離脱が防がれる。
【００４５】
回転抜け止め部８４ａ及び固定抜け止め部７２ｂは、回転軸線方向におけるステータコア７０の上面とスリーブ部材６４の内周面の上端（径方向軸受部の上端）の間で、径方向におけるステータコイル６８とスリーブ部材６４の内周面（径方向軸受部）の間に位置するので、その部分のスペースが回転部８０の抜け止めのために有効に利用され、電動機全体の薄型化が達成されている。この場合、回転抜け止め部８４ａを切削加工により形成していて寸法精度を出しやすいので、より小型化・薄型化された寸法精度の厳しい電動機として好適である。
【００４６】
図５は、本発明の実施の形態の更に別の例としての電動機の断面図である。
【００４７】
この例においては、金属薄板製の固定抜け止め部材１００が、その環状下板において、ステータコア７０及びスリーブ部材６４と共にリベット７４によりステータコア７０の上面内周部に固定されている。固定抜け止め部材１００の内周部の数箇所に、等中心角毎に断面略Ｌ字形状の上方突起部１００ａが設けられ、その上端部の、径方向内方に突起した部分が、固定抜け止め部１００ｂを構成する。なお、この固定抜け止め部材は、金属製のものよりもやや肉厚にして十分な強度を持たせれば、合成樹脂により形成することもできる。その場合、金属製の固定抜け止め部材をプレス加工により得るのが困難な形状のものでも、成形しやすい。
【００４８】
また、金属製の環状体１１０の径方向中間部が、全周にわたり下方に突出し、更にその下端外周部に、全周にわたり径方向外方に突起した回転抜け止め部１１０ａが設けられている。この回転抜け止め部は切削加工により形成されており、径方向外方に突起しているので切削加工が容易である。
【００４９】
その他の点は、図４の例と同様である。
【００５０】
なお、固定抜け止め部材１００に替えて、リベット７４の上端内周部に径方向内方に突起した固定抜け止め部７４ａを設ければ、部品点数及び製造工程数が削減される。
【００５１】
以上は、何れも、回転部に回転軸を有し、固定部にスリーブ部を有する電動機の例であるが、回転部にスリーブ部を有し、固定部に固定軸部を有するものであっても勿論差し支えない。
【００５２】
【発明の効果】
本発明の電動機においては、回転軸線方向における径方向軸受部の上下端の間で、径方向におけるステータコイルと径方向軸受部の間の部分のスペースを、回転部の抜け止めのために有効に利用し、抜け止めのための回転抜け止め部及び固定抜け止め部が占めるべき高さ分を薄型化することができる。
【００５３】
本発明の電動機においては、回転軸線方向における径方向軸受部の上下端の間で、径方向におけるステータコイルと径方向軸受部の間の部分のスペースを、回転部の抜け止めのために有効に利用し、抜け止めのための回転抜け止め部及び固定抜け止め部が占めるべき高さ分を薄型化することができる。加えて、固定抜け止め部を構成するための固定抜け止め部材を、ステータコアを基盤に固定すると同時に固定部に固定することができるので、製造工程数を削減することができる。
【００５４】
請求項２の電動機においては、前述と同様に、回転軸線方向における径方向軸受部の上下端の間で、径方向におけるステータコイルと径方向軸受部の間の部分のスペースを、回転部の抜け止めのために有効に利用し、抜け止めのための回転抜け止め部及び固定抜け止め部が占めるべき高さ分を薄型化することができる。加えて、固定用部材によりステータコアを基盤に固定することにより、その固定用部材が有する固定抜け止め部を固定部に設けることができるので、部品点数及び製造工程数を削減することができる。
【００５５】
請求項３の電動機においては、ステータコアに巻回されたステータコイルのうちステータコアの上側突出する高さにほぼ相当する高さのスペースを、回転部の抜け止めのために有効に利用し、抜け止めのための回転抜け止め部及び固定抜け止め部が占めるべき高さ分を薄型化することができる。
【図面の簡単な説明】
【図１】電動機の半断面図である。
【図２】固定抜け止め部材の要部斜視図である。
【図３】ロータフレームの要部斜視図である。
【図４】別の電動機の断面図である。
【図５】更に別の電動機の断面図である。
【図６】従来の電動機の断面図である。
【符号の説明】
１４スリーブ部材
２０ステータコイル
２２ステータコア
２４ｂ上方突起部
２４ｃ固定抜け止め部
４２回転軸
４６ロータフレーム
４６ａ下方突起部
４６ｂ回転抜け止め部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric motor that is provided with a sleeve bearing and retaining means for preventing a shaft portion from being detached from a sleeve portion, and is suitable for thinning.
[0002]
[Prior art and problems to be solved by the invention]
An example of a motor having a sleeve bearing is a fan motor as shown in FIG. In this motor, the rotating shaft b is supported in the radial direction by the sleeve portion a, the lower end portion of the rotating shaft b is received upward by the thrust receiving portion c, and the magnetic center of the rotor magnet d is more than the magnetic center of the stator e. By being positioned slightly above, a downward magnetic attraction force is applied to the rotor, and the lower end portion of the rotating shaft b is pressed against the thrust receiving portion c.
[0003]
However, since the rotating shaft b may be detached from the sleeve portion a only by this magnetic attraction force, some kind of retaining means is required separately. In this type of motor, as an anti-removal means, an outer protrusion f made of a synthetic resin projecting radially outward is provided on the outer periphery of the base of the rotating shaft b of the rotor, and the radially inner portion is provided above the sleeve a. An inward protruding portion g made of a synthetic resin protruding in the direction is provided, and an outer protruding portion f on the rotor side is positioned below the inner protruding portion g on the sleeve portion side to prevent the rotation shaft b from being detached. When the rotating shaft b of the rotor is inserted into the sleeve portion a and the sleeve portion a is fitted into the rotating shaft b, the outer protruding portion f and the inner protruding portion g come into contact with each other in the process, and both are elastically deformed. By doing so, since the other party is overcome, the outer projection f can be positioned below the inner projection g.
[0004]
However, since such a conventional retaining structure is located above the sleeve portion a, the height of the motor in the rotational axis direction increases. Therefore, when this type of retaining structure is applied to a dense and thin motor such as a motor for driving a recording disk, there is a problem in that it cannot meet the requirements for the dimension in the rotational axis direction.
[0005]
The present invention has been made in view of the above-described problems existing in the prior art, and the object of the present invention is to achieve the prevention of the rotation part from being effectively utilized in the internal space. Thus, an object of the present invention is to provide an electric motor that can be thinned as a whole.
[0006]
[Means for Solving the Problems]
The electric motor of the present invention that achieves the above object is as follows.
When the sleeve part of the rotating part and the fixed part are fitted to the shaft part of one of the rotating part and the fixed part, the rotational retaining part provided in the rotating part and the fixed retaining part provided in the fixed part come into contact with each other. As a result, one or both of the rotating part and the fixed part are elastically deformed, so that the rotation retaining part reaches below the fixed retaining part, and the rotating part is above the fixing part in the rotational axis direction. Will be prevented from leaving,
An electric motor having a stator core around which a stator coil is wound, radially outward of a radial bearing portion where the fixed portion and the rotating portion face each other across a radial bearing gap,
Between the upper and lower ends of the radial bearing portion in the rotation axis direction, the rotation retaining portion and the fixed retaining portion are positioned between the stator coil wound around the stator core and the radial bearing portion in the radial direction. It is characterized by that.
[0007]
When the rotating portion has a shaft portion, the sleeve portion is fixed and the shaft portion rotates. When the rotating portion has a sleeve portion, the shaft portion is fixed and the sleeve portion rotates.
[0008]
The elastic deformation of a part of one or both of the rotating part and the fixing part means that the rotation retaining part provided in the rotating part or the fixed retaining part itself provided in the fixing part is elastically deformed. For example, the rotation retaining portion or the fixed retaining portion is supported by the support portion, and the support portion is mainly elastically deformed, or the support portion and the rotation retaining portion or the fixed retaining portion as a whole are It may be elastically deformed.
[0009]
For example, one of the rotation retaining portion and the fixed retaining portion can be a radially inward protruding portion and the other can be a radially outward protruding portion. The tip of the substantially L-shaped section or the substantially J-shaped section made of a thin metal plate or synthetic resin can be used as such a radially inward projection and a radially outward projection.
[0010]
When assembling the electric motor by fitting the sleeve portion of the other portion to the shaft portion of one of the rotating portion and the fixed portion and assembling the motor, one of the rotating portion and the fixed portion comes into contact. As a result of elastic deformation of a part or both, the rotational retaining part reaches below the stationary retaining part. When the rotating part tries to detach from the fixed part upward in the rotational axis direction, the rotational retaining part moves upward accordingly, but the fixed retaining part located above prevents further upward movement, thereby rotating. Part separation is prevented.
[0011]
Since the rotation retaining portion and the fixed retaining portion are located between the upper and lower ends of the radial bearing portion in the rotational axis direction and between the stator coil wound around the stator core in the radial direction and the radial bearing portion. The space of the part is used for preventing the rotating part from coming off.
[0012]
In this electric motor, the rotation retaining portion and the fixed retaining portion may be located between the upper surface of the stator core and the upper end of the radial bearing portion in the rotation axis direction.
[0013]
In this case, the space between the upper surface of the stator core and the upper end of the radial bearing portion, that is, the space having a height substantially corresponding to the height of the stator coil wound around the stator core and protruding upward from the stator core is the rotation retaining portion. And is used to prevent the rotating part from coming off by the fixed retaining part.
[0014]
The electric motor of the present invention is an electric motor having a base to which the stator core is fixed and a fixing member for fixing the stator core to the base, and the fixing member constitutes a fixed retaining portion. Therefore, it is possible to fix the fixing retaining member for fixing to the fixing portion at the same time.
[0015]
For example, a rivet or a screw can be used as the fixing member. Further, the fixed retaining member can be clamped and fixed between, for example, a rivet or a screw head as a fixing member and the upper surface of the stator core.
[0016]
In this case, the fixed retaining member for constituting the fixed retaining portion is fixed to the fixing portion at the same time that the stator core is fixed to the base by the fixing member.
[0017]
The electric motor of the present invention is an electric motor having a base to which the stator core is fixed and a fixing member for fixing the stator core to the base, and a portion of the fixing member protruding above the stator core. In addition, it may have a fixed retaining portion.
[0018]
As the fixing member, for example, a rivet or a screw formed with a protrusion on the head serving as a fixed retaining portion can be used.
[0019]
In this case, when the stator core is fixed to the base by the fixing member, a fixing retaining portion included in the fixing member is provided in the fixing portion.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
[0021]
1 to 3 relate to an electric motor as an example of an embodiment of the present invention, and FIG. 1 is a half sectional view of the electric motor.
[0022]
The electric motor fixing portion 10 is mainly composed of a flat base 12, a sleeve member 14 (an example of a sleeve portion), a thrust receiving plate 16, a stator core 22 around which a stator coil 20 is wound, and a metal thin plate. The fixed retaining member 24 includes a fixed retaining member 24, a screw 26 that simultaneously fixes the stator core 22 and the sleeve member 14 to the base 12.
[0023]
The inner peripheral surface of the sleeve member 14 has a constant inner diameter except for the lower end portion. The inner end portion of the lower end of the sleeve member 14 is expanded in diameter, and the thrust receiving plate 16 is accommodated and fixed between the base member 12 and the base member 12. The outer side of the lower end of the sleeve member 14 is formed in an outwardly projecting portion 14a that projects outwardly in a state where a portion where the screw 26 is located is cut out.
[0024]
FIG. 2 is a perspective view of a main part of the fixed retaining member 24.
[0025]
The fixed retaining member 24 has upper protrusions 24b having a substantially J-shaped cross section at equal intervals on the outer periphery of the annular flat plate portion 24a. A portion of the upper end portion of each upper protruding portion 24b that protrudes radially outward while curving convexly constitutes a fixed retaining portion 24c. The annular flat plate portion 24a has screw insertion holes 24d at three locations for each equal central angle.
[0026]
The stator core 22 is fitted over the small outer diameter portion on the upper portion of the outward projecting portion 14a, and the bottom surface of the annular flat plate portion 24a of the stationary retaining member 24 is positioned on the inner peripheral portion of the top surface of the stator core 22. The stop member 24, the stator core 22, and the sleeve member 14 are collectively fixed to the base 12 by screws 26 at three locations for each equal central angle. Between the base 12, the stator core 22, and the stator coil 20, a synthetic resin 28 that can be fixed together with the outer peripheral portion of the sleeve member 14 to prevent vibration is filled and solidified.
[0027]
The rotating portion 40 of the electric motor includes a rotating shaft 42 (an example of a shaft portion), an annular body 44 that is externally fitted and fixed to the upper portion of the rotating shaft 42, and an inner peripheral portion at a radially intermediate position on the lower surface side of the annular body 44. A rotor frame 46 made of a substantially bowl-shaped ferromagnetic material that is externally fitted and fixed to the provided annular lower protrusion 44a, and is fixed to the inner peripheral surface of the outer peripheral wall portion of the rotor frame 46 and is relative to the stator core 22 in the radial direction. An annular plate-like clamping magnet 50 for holding the recording disk is provided on the outer periphery of the metal annular body 44 that is used as a turntable for driving the recording disk. The outer fitting is fixed.
[0028]
FIG. 3 is a perspective view of a main part of the rotor frame 46.
[0029]
Lower projections 46a having a substantially L-shaped cross section are provided by pressing at four locations on the inner peripheral side of the upper plate of the rotor frame 46, and the radial direction of the lower end of each lower projection 46a The portion protruding inward constitutes the rotation retaining portion 46b.
[0030]
The lower end surface of the rotating shaft 42 is formed in a convex spherical shape whose center coincides with the rotating axis.
[0031]
After the rotating portion 40 is assembled, when the rotating shaft 42 is inserted into the sleeve member 14 and the sleeve member 14 is fitted into the rotating shaft 42, the outer peripheral surface of the rotating shaft 42 faces the inner peripheral surface of the sleeve member 14. A radial bearing portion is formed, and a lower end surface of the rotating shaft 42 is supported on a flat upper surface of the thrust receiving plate 16. Since the magnetic center of the rotor magnet 48 is located slightly above the magnetic center of the stator, a downward magnetic attractive force acts on the rotating portion 40 and the lower end surface of the rotating shaft 42 is pressed against the thrust receiving plate 16.
[0032]
In the sleeve fitting process, the rotation retaining portion 46b and the fixed retaining portion 24c come into contact with each other, and both the upper projecting portion 24b of the fixed portion 10 and the lower projecting portion 46a of the rotating portion 40, particularly the upper projection made of a thin metal plate. Due to the elastic deformation of the part 24b, the rotation retaining part 46b reaches below the stationary retaining part 24c by overcoming the other party. Normally, during rotation of the electric motor, the rotation retaining portion 46b and the fixed retaining portion 24c are in a non-contact state. When the rotating part 40 tries to detach from the fixed part 10 upward in the rotation axis direction, the rotational retaining part 46b moves upward accordingly, but the fixed retaining part 24c positioned above the rotational retaining part 46c is more than that of the rotating part 40. Is prevented from being detached. Since the interval between the upper protrusions 24b of the fixed part 10 is set smaller than the radial width of the lower protrusion 46a of the rotating part 40, it is effectively separated regardless of the rotation angle of the rotating part 40. Is prevented.
[0033]
The rotation retaining portion 46b and the fixed retaining portion 24c are arranged between the stator coil 20 in the radial direction between the upper surface of the stator core 22 and the upper end of the inner peripheral surface of the sleeve member 14 (upper end of the radial bearing portion) in the rotational axis direction. Since it is located between the sleeve members 14, the space in that portion is effectively used for preventing the rotating portion 40 from coming off, and the overall thickness of the electric motor is reduced. In particular, the use of a thin metal plate as the fixed retaining portion 24c or the rotational retaining portion 46b as in this example is preferable because the necessary space can be reduced while ensuring the strength.
[0034]
In addition, when a stator core required part is coat | covered with the insulator for electrically insulating with respect to a stator coil, a fixed removal prevention part can also be formed with a part of the insulator.
[0035]
FIG. 4 is a sectional view of an electric motor as another example of the embodiment of the present invention.
[0036]
The fixing portion 60 of the electric motor is mainly composed of a flat base 62, a sleeve member 64 (an example of a sleeve portion), a thrust receiving plate 66, a stator core 70 around which a stator coil 68 is wound, and a thin metal plate. It comprises a fixed retaining member 72 and a rivet 74 that simultaneously fixes the stator core 70 and the sleeve member 64 to the base 62.
[0037]
The inner peripheral surface of the sleeve member 64 has a constant inner diameter except for the lower end portion, the inner diameter of the lower end portion of the sleeve member 64 is increased, and the thrust receiving plate 66 is accommodated and fixed between the base member 62 and the base member 62.
[0038]
The fixed retaining members 72 are fixed at several equal central angles at several locations on the inner peripheral portion of the upper surface of the stator core 70. Each fixed retaining member 72 is provided with an upper protrusion 72a having a substantially L-shaped cross section at the inner end portion of the lower plate, and a portion of the upper end portion protruding radially outwardly forms the fixed retaining member 72b. Constitute.
[0039]
The stator core 70 is externally fitted to the small outer diameter portion of the sleeve member 64, and the inner peripheral portion of the stator core 70 and the outer protruding portion of the lower end of the sleeve member 64 are formed by a rivet 74 at a position for each equicentral angle. 62 is fixed. The fixing members 72 can be fixed simultaneously by the rivets 74 to reduce the number of manufacturing steps.
[0040]
The rotating portion 80 of the electric motor has a rotating shaft 82 (an example of a shaft portion), an annular body 84 fitted and fixed to the upper portion of the rotating shaft 82, and a substantially bowl shape whose inner peripheral portion is fitted and fixed to the annular body 84. A rotor frame 86 made of a ferromagnetic material, and a rotor magnet 88 fixed to the inner peripheral surface of the outer peripheral wall portion of the rotor frame 86 and opposed to the stator core 70 in the radial direction, and the inner peripheral portion of the upper plate of the rotor frame 86 On the top, an annular plate-like clamping magnet 90 is fitted and fixed.
[0041]
The outer peripheral portion of the metal annular body 84 used as a turntable when driving a recording disk protrudes downward over the entire periphery, and further protrudes radially inward over the entire periphery of the lower end inner peripheral portion. A rotation retaining portion 84a is provided. The rotation retaining portion 84a is formed by cutting.
[0042]
A spherical convex portion 82a is provided at the central portion of the lower end surface of the rotating shaft 82 so that the center is coincident with the rotating shaft 82 line.
[0043]
After assembling the rotating portion 80, when the rotating shaft 82 is inserted into the sleeve member 64 and the sleeve member 64 is fitted into the rotating shaft 82, the outer peripheral surface of the rotating shaft 82 faces the inner peripheral surface of the sleeve member 64. The spherical convex portion 82a at the central portion of the lower end surface of the rotating shaft 82 is formed on the spherical concave portion 66a having a curvature smaller than the curvature of the spherical convex portion 82a at the central portion of the upper surface of the thrust receiving plate 66. Supported. Since the magnetic center of the rotor magnet 88 is located slightly above the magnetic center of the stator, a downward magnetic attractive force acts on the rotating portion 80 and the lower end surface of the rotating shaft 82 is pressed against the thrust receiving plate 66.
[0044]
In the process of fitting the sleeve, the rotation retaining portion 84a and the fixed retaining portion 72b come into contact with each other, and the upper protrusion 72a of the fixing portion 60 is mainly elastically deformed. It reaches below the fixed retaining portion 72b and prevents the rotating portion 80 from being detached.
[0045]
The rotation retaining portion 84a and the fixed retaining portion 72b are connected to the stator coil 68 in the radial direction between the upper surface of the stator core 70 in the rotational axis direction and the upper end of the inner peripheral surface of the sleeve member 64 (the upper end of the radial bearing portion). Since the sleeve member 64 is located between the inner peripheral surfaces (radial bearing portions) of the sleeve member 64, the space in that portion is effectively used for preventing the rotating portion 80 from coming off, and the overall thickness of the electric motor is reduced. In this case, since the rotation retaining portion 84a is formed by cutting and it is easy to obtain dimensional accuracy, it is suitable as an electric motor with strict dimensional accuracy that is smaller and thinner.
[0046]
FIG. 5 is a cross-sectional view of an electric motor as still another example of the embodiment of the present invention.
[0047]
In this example, a fixed retaining member 100 made of a thin metal plate is fixed to the inner periphery of the upper surface of the stator core 70 by a rivet 74 together with the stator core 70 and the sleeve member 64 in the annular lower plate. Upper protrusions 100a having a substantially L-shaped cross section are provided for each equi-center angle at several locations on the inner peripheral portion of the fixed retaining member 100, and the portion of the upper end projecting radially inward is fixed A stopper 100b is configured. The fixed retaining member can be made of a synthetic resin as long as it is thicker than a metal member and has sufficient strength. In that case, even if it is difficult to obtain a metal fixed retaining member by pressing, it is easy to mold.
[0048]
In addition, a radially intermediate portion of the metallic annular body 110 protrudes downward over the entire circumference, and a rotation retaining portion 110a that protrudes radially outward over the entire circumference is provided at the outer periphery of the lower end thereof. This rotation retaining portion is formed by cutting, and since it protrudes outward in the radial direction, cutting is easy.
[0049]
Other points are the same as in the example of FIG.
[0050]
If the fixed retaining member 74a projecting radially inward is provided on the inner periphery of the upper end of the rivet 74 instead of the fixed retaining member 100, the number of parts and the number of manufacturing steps can be reduced.
[0051]
The above is an example of an electric motor having a rotating shaft in the rotating portion and a sleeve portion in the fixed portion, but has a sleeve portion in the rotating portion and a fixed shaft portion in the fixed portion. Of course.
[0052]
【The invention's effect】
In the electric motor according to the present invention, the space between the stator coil and the radial bearing portion in the radial direction between the upper and lower ends of the radial bearing portion in the rotational axis direction is effectively used to prevent the rotary portion from coming off. It is possible to reduce the height by which the rotation retaining portion and the fixed retaining portion for retaining can be occupied.
[0053]
In the electric motor according to the present invention, the space between the stator coil and the radial bearing portion in the radial direction between the upper and lower ends of the radial bearing portion in the rotational axis direction is effectively used to prevent the rotary portion from coming off. It is possible to reduce the height by which the rotation retaining portion and the fixed retaining portion for retaining can be occupied. In addition, since the fixed retaining member for constituting the fixed retaining portion can be fixed to the fixing portion at the same time as fixing the stator core to the base, the number of manufacturing steps can be reduced.
[0054]
In the electric motor according to claim 2, similarly to the above, the space between the stator coil and the radial bearing portion in the radial direction is removed between the upper and lower ends of the radial bearing portion in the rotation axis direction. It can be effectively used for stopping, and the height to be occupied by the rotation retaining portion and the stationary retaining portion for retaining can be reduced in thickness. In addition, by fixing the stator core to the base with the fixing member, it is possible to provide the fixing part with a fixing retaining portion that the fixing member has, so that the number of parts and the number of manufacturing steps can be reduced.
[0055]
In the electric motor according to claim 3, a space having a height substantially corresponding to a height protruding upward of the stator core of the stator coil wound around the stator core is effectively used for preventing the rotating portion from being detached. Therefore, it is possible to reduce the height of the rotation retaining portion and the fixed retaining portion for the purpose.
[Brief description of the drawings]
FIG. 1 is a half sectional view of an electric motor.
FIG. 2 is a perspective view of a main part of a fixed retaining member.
FIG. 3 is a perspective view of a main part of a rotor frame.
FIG. 4 is a cross-sectional view of another electric motor.
FIG. 5 is a sectional view of still another electric motor.
FIG. 6 is a sectional view of a conventional electric motor.
[Explanation of symbols]
14 Sleeve member 20 Stator coil 22 Stator core 24b Upper projecting portion 24c Fixed retaining portion 42 Rotating shaft 46 Rotor frame 46a Lower projecting portion 46b Rotating retaining portion

Claims

When the sleeve portion of the rotating portion and the fixed portion are fitted into the shaft portion of the rotating portion and the fixed portion, the rotational retaining portion provided in the rotating portion and the fixed retaining portion provided in the fixed portion come into contact with each other. As a result, one or both of the rotating part and the fixing part are elastically deformed, so that the rotation retaining part reaches below the fixed retaining part, and the rotating part is above the fixing part in the rotational axis direction. Will be prevented from leaving,
A stator core around which a stator coil is wound, and a stator core on which the stator core is fixed. An electric motor having a fixing member for fixing to a base ,
With the fixing member, a fixing retaining member for constituting a fixing retaining portion is fixed to the fixing portion simultaneously with the stator core,
Between the upper and lower ends of the radial bearing portion in the rotation axis direction, the rotation retaining portion and the fixed retaining portion are located between the stator coil wound around the stator core and the radial bearing portion in the radial direction. An electric motor characterized by that.

When the sleeve portion of the rotating portion and the fixed portion are fitted into the shaft portion of the rotating portion and the fixed portion, the rotational retaining portion provided in the rotating portion and the fixed retaining portion provided in the fixed portion come into contact with each other. As a result, one or both of the rotating part and the fixing part are elastically deformed, so that the rotation retaining part reaches below the fixed retaining part, and the rotating part is above the fixing part in the rotational axis direction. Will be prevented from leaving,
A stator core around which a stator coil is wound is provided on the radially outer side of the radial bearing portion where the fixed portion and the rotating portion face each other across a radial bearing gap. An electric motor having a fixing member for fixing to a base,
A portion of the fixing member that protrudes above the stator core has a fixed retaining portion,
Between the upper and lower ends of the radial bearing portion in the rotation axis direction, the rotation retaining portion and the fixed retaining portion are located between the stator coil wound around the stator core and the radial bearing portion in the radial direction. An electric motor characterized by that.

The electric motor according to claim 1 , wherein the rotation retaining portion and the fixed retaining portion are located between the upper surface of the stator core and the upper end of the radial bearing portion in the rotational axis direction .