JP3791570B2

JP3791570B2 - Abduction motor

Info

Publication number: JP3791570B2
Application number: JP35288397A
Authority: JP
Inventors: 啓宇川崎; 誠鵜飼; 幸典竹腰; 健一東; 裕治中原; 昭彦今城; 鋼希木枝; 学出口; 泰成高田; 康浩遠藤
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1997-12-22
Filing date: 1997-12-22
Publication date: 2006-06-28
Anticipated expiration: 2017-12-22
Also published as: JPH11187605A

Description

【０００１】
【発明の属する技術分野】
この発明は、回転子と固定子の外側に配置した外転形電動機に関するものでものである。
【０００２】
【従来の技術】
図６は特開昭６３−２５７４４０号公報に開示された従来の外転形電動機を、スリーブ軸受を玉軸受に置換したものを示す断面図である。図６において、外転形電動機１０は回転磁界を発生させる内孔１２ａを有する固定子１２と、前記回転磁界に基づき回転する回転子１４と、固定子１２を支持し、同心円状の中空部を有する断面がＬ字形状の枠１７と、前記枠１７の円柱状の内側面に外輪が嵌合された軸受１８、２０と、前記軸受１８、２０の内輪に装着されるとともに回転子１４にも装着された軸２２とから構成されている。
【０００３】
次に上記のように構成された外転形電動機１０の動作について説明する。
いま、外転形電動機１０の固定子１２に図示しない電源が投入されると、固定子１２で発生した回転磁界により外側の回転子１４が回転する。
【０００４】
【発明が解決しようとする課題】
しかしながら、従来の外転形電動機１０は、以下の問題点があった。
第１に、Ｌ字形状の枠１７が、円柱状に形成された中空部の内側面、同様な形状の外側面の旋盤等による機械加工が煩雑であった。加えて、枠１７の内側面を軸受１８、２０の外輪と嵌合させ、前記外側面が固定子１２の内孔１２ａと密着固定されるので、枠１７の内側面および外側面の高い同軸度加工精度が必要となり、機械加工の作業時間を増大させていた。
【０００５】
第２に、枠１７の製作誤差、組付け誤差のために固定子１２の外周面と、軸受１８、２０との同軸度が悪くなり、固定子１２と回転子１４との空隙１４ｇが不均一となり溝高調波による騒音が増大し、加えて、回転子１４の軸受１８、２０の外径が小さくなって軸受１８、２０の許容荷重が小さくなっていた。
【０００６】
この発明は、上記のような課題を解決するためになされたもので、製作時間を短縮しつつ、固定子と回転子との空隙を均一にして騒音を抑制し、回転子の軸受の外径を増大し、軸受の許容荷重を増大し得る外転形電動機を提供することを目的とするものである。
【０００７】
【課題を解決するための手段】
この発明に係る第１の発明の外転形電動機は、固定子の外側へ配置されて回転磁界で回転する回転子の軸を保持する第１の軸受および第２の軸受が固定子に設けられた外転形電動機において、第１の軸受および第２の軸受の外径よりも大きい内径を有する円管に、樹脂が均一な肉厚になるようにモールド成形し、第１の軸受および第２の軸受のそれぞれの外輪とコイルとの間で、第１の軸受および第２の軸受のそれぞれの外輪を嵌合させて各軸受を保持する第１の軸受保持部および第２の軸受保持部を配設したものである。
【０００８】
また、第２の発明の外転形電動機は、円管をコア部とコイルとを絶縁する板状の絶縁カバーと一体にしたものである。
【００１３】
【発明の実施の形態】
実施の形態１．
図１はこの発明の実施の形態１の外転形電動機を示す断面図である。図中、従来と同一または相当部分は説明を省略する。図１において、外転形電動機１００は、回転磁界を発生させる複数枚の鋼板から成るコア部１１２ｃを有すると共に、コア部１１２ｃに円筒状の内孔１１２ａを有し、コイル１１２ｗを収納した断面Ｌ字形状にモールドして形成されたケース１１６を有する固定子１１２と、前記固定子１１２と所定の空隙１１４ｇを有して、外側に配置された回転子１１４とを備えている。また、前記固定子１１２のコア部１１２ｃの一端側（図面上左側）には、円筒状の内孔１１２ａより大径になっている第１の軸受保持部１１２ｘに外輪が嵌合された第１の軸受１１８と、コア部１１２ｃの他端側（図面上右側）には、同様な形状の第２の軸受保持部１１２ｚに外輪が嵌合された第２の軸受１２０とを有している。そして、前記第１の軸受１１８および第２の軸受１２０の内輪が、前記回転子１１４の中心へ嵌め込まれた軸１２２に装着されている。
【００１４】
前記第１の軸受１１８と、第２の軸受１２０との内側面間の距離値Ｐａを近接させることで、回転子１１４の固有振動周波数を高くし、溝高調波の低次成分との共振を避けるように構成されている。
【００１５】
上記のように構成された外転形電動機においては、固定子１１２の複数の鋼板が積層されたコア部１１２ｃに巻かれたコイル１１２ｗをモールドして収納した断面Ｌ字形状のケース１１６は、コア部１１２ｃの一端側に第１の軸受保持部１１２ｘおよび他端側に第２の軸受保持部１１２ｚを円筒状の内孔１１２ａより大径に切削して形成する。前記第１の軸受保持部１１２ｘおよび第２の軸受保持部１１２ｚにそれぞれ第１の軸受１１８、第２の軸受１２０の外輪を嵌合するとともに、内輪を回転子１１４の中心へ嵌め込まれた軸１２２に貫装して、第１の軸受１１８、第２の軸受１２０の装着が完了する。全体が一体化された固定子１１２のコア部１１２ｃに軸受保持部１１２ｘ、軸受保持部１１２ｚを形成して第１の軸受１１８、第２の軸受１２０の外輪を嵌合するので、組付け誤差が減少して空隙１１４ｇを全周に渡ってより均一となし得るので溝高調波成分の騒音を低減でき、軸受の保持に枠等が不要となり、第１の軸受１１８、第２の軸受１２０の外径を大きくし、あるいは電動機の外径を小さくするとができる。
【００１６】
前記外転形電動機１００の固定子１１２に図示しない電源を加えると、回転磁界が発生し、回転子１１４が回転する。この場合、第１の軸受１１８と第２の軸受１２０との内側面間の距離値Ｐａを短くしたので、回転子１１４の固有振動周波数を高くし、溝高調波の低次成分との共振をさけることができる効果もあり、騒音を減少することができる。
【００１７】
実施の形態２．
図２はこの発明の実施の形態２の外転形電動機を示す断面図である。図中、従来または上記実施の形態１と同一または相当部分は説明を省略する。図２において、外転形電動機２００は、回転磁界を発生させる複数枚の鋼板から成るコア部２１２ｃを有すると共に、このコア部２１２ｃに円筒状の内孔２１２ａを有し、コイル２１２ｗを収納した断面Ｌ字形状にモールドして形成されたケース２１６を有する固定子２１２と、前記固定子２１２と所定の空隙２１４ｇを有して、外側に配置された回転子２１４とを備えている。また、前記固定子２１２のコア部２１２ｃの一端側（図面上左側）の第１の軸受保持部２１２ｘに外輪が嵌合された第１の軸受２１８と、固定子２１２の他端側（図面上右側）のモールドで形成されたケース２１６には、同様な形状の第２の軸受保持部２１６ｚに外輪が嵌合された第２の軸受２２０とを有している。そして、前記第１の軸受２１８および第２の軸受２２０の内輪が、前記回転子２１４の中心へ嵌め込まれた軸２２２に装着されている。
【００１８】
前記第１の軸受２１８の内側面から第２の軸受２２０の内側面までの距離値Ｐｂを上記実施の形態１よりも長くして、第２の軸受２２０の内側面から回転子２１４の垂直部の内面までの距離値Ｑを上記実施の形態１よりも短くして回転子２１４の振れ回りを抑えるように構成されている。
【００１９】
上記のように構成された外転形電動機においては、実施の形態１と同様に全体が一体化された固定子２１２のケース２１６を切削して、コア部２１２ｃの一端側（図面上左側）の内孔２１２ａに第１の軸受保持部２１２ｘを形成しすると共に、ケース２１６の他端側（図面上右側）のモールドに同様な形状の第２の軸受保持部２１２ｚを形成して、各々に第１の軸受２１８、第２の軸受２２０の外輪を嵌合するので、組付け誤差が減少して空隙２１４ｇを全周に渡ってより均一となし得るので溝高調波成分の騒音を低減でき、軸受の保持に枠等が不要となり、第１の軸受２１８、第２の軸受２２０の外径を大きくし、あるいは電動機の外径を小さくすることができる。また、上記のように軸受内側面間の距離値Ｐｂが長くなり、上記距離値Ｑが短いので、回転子２１４の振れ回りを抑制できる。
【００２０】
実施の形態３．
図３はこの発明の実施の形態３の外転形電動機を示す断面図である。図中、従来または上記実施の形態１と同一または相当部分は説明を省略する。図３において、外転形電動機３００は、回転磁界を発生させる複数枚の鋼板から成るコア部３１２ｃを有すると共に、このコア部３１２ｃに円筒状の内孔３１２ａを有し、コイル３１２ｗを収納した断面Ｌ字形状にモールドして形成されたケース３１６を有する固定子３１２と、前記固定子３１２と所定の空隙３１４ｇを有して、外側に配置された回転子３１４とを備えている。また、前記固定子３１２の一端側（図面上左側）のモールドで形成されたケース３１６の第１の軸受保持部３１２ｘに外輪が嵌合された第１の軸受３１８と、固定子３１２のコア部３１２ｃの他端側（図面上右側）には、同様な形状の第２の軸受保持部３１２ｚに外輪が嵌合された第２の軸受３２０とを有している。そして、前記第１の軸受３１８および第２の軸受３２０の内輪が、前記回転子３１４の中心へ嵌め込まれた軸３２２に装着されている。
【００２１】
ここで、特徴的なことは、回転子３１４の中心部に形成された水平部３１４ａが軸３２２と固着されている固着部の距離値Ｌを長くして、軸３２２と回転子３１４の固定強度を増加させるように構成していることである。
【００２２】
上記のように構成された外転形電動機においては、実施の形態１と同様に全体が一体化された固定子３１２のケース３１６を切削して、前記ケース３１６の一端側（図面上左側）のモールドに第１の軸受保持部３１２ｘを形成すると共に、同様な形状の第２の軸受保持部３１２ｚを形成して、各々に第１の軸受３１８、第２の軸受３２０の外輪を嵌合したので、組付け誤差が減少して空隙３１４ｇを全周に渡ってより均一となし得るので溝高調波成分の騒音を低減でき、軸受の保持に枠等が不要となり、第１の軸受３１８、第２の軸受３２０の外径を大きくし、あるいは電動機の外径を小さくすることができることは前記実施の形態１と同様である。また、上記のように水平部３１４ａが軸３２２と固着されている固着部の距離値Ｌを長くして軸３２２と回転子３１４の固定強度を増加し、且つ第１の軸受３１８と、第２の軸受３２０との内側面間の距離Ｐｃを上記実施の形態１よりも長くしたので回転子３１４の振れ精度が向上する。
【００２３】
実施の形態４．
図４はこの発明の実施の形態４の外転形電動機を示す断面図である。図中、従来または上記実施の形態１と同一または相当部分は説明を省略する。図４において、外転形電動機４００は、回転磁界を発生させる複数枚の鋼板からなるコア部４１２ｃを有すると共に、このコア部４１２ｃに円筒状の内孔４１２ａを有し、コイル４１２ｗを収納した断面Ｌ字形状に樹脂モールドして形成されたケース４１６を有する固定子４１２と、前記固定子４１２と所定の空隙４１４ｇを有して、外側に配置された回転子４１４とを備えている。また、前記固定子４１２の一端側（図面上左側）のモールドで形成されたケース４１６の第１の軸受保持部４１６ｘの端面となっているコア部４１２ｃの端面４１６ｙと、外輪の端面が当接するように嵌合された第１の軸受４１８と、同じくモールドで形成されたケース４１６の他端側（図面上右側）の第２の軸受保持部４１６ｚに外輪が嵌合された第２の軸受４２０とを有している。そして、前記第１の軸受４１８および第２の軸受４２０の内輪が前記回転子４１４の中心へ嵌め込まれた軸４２２に装着されている。
【００２４】
ここで特徴的なことは、コア部４１２ｃの内孔４１２ａの内径Ｄｃよりも第１の軸受保持部４１６ｘおよび第２の軸受保持部４１６ｚの内径Ｄｂを大きくし、かつ第１の軸受４１８の端面がコア部４１２ｃの端面４１６ｙに接する構造としたことである。
【００２５】
上記のように構成された外転形電動機においては、実施の形態１と同様に全体が一体化された固定子４１２のケース４１６の一端側（図面上左側）のモールドに、第１の軸受保持部４１６ｘの端面がコア部４１２ｃの端面４１６ｙとなるように、コア部４１２ｃの端面を露出させて形成すると共に、ケース４１６の他端側（図面上右側）のモールドに第２の軸受保持部４１２ｚを、後加工することなく樹脂モールドにて形成する。この第１の軸受保持部４１６ｘおよび第２の軸受保持部４１６ｚの両方の内径、すなわち軸受の外輪径を大きくすることにより、軸受の許容荷重が大きくできるばかりでなく、軸４２２の外径Ｄｓも太くできて回転子４１４の固有振動周波数を高くできて、低次の溝高周波からずらして低騒音化が図れ、また、第１の軸受４１８を上に、第２の軸受４２０を下向きに使用すると回転子の重量を強度的に強いコア部４１２ｃの端面４１６ｙで支えることができ、信頼性を向上することができる。また、第１の軸受保持部４１６ｘおよび第２の軸受保持部４１６ｚの両方には、コア部４１２ｃの外径を基準として、後加工することなく樹脂モールドにて成形できるので、コア部４１２ｃの外径と第１の軸受保持部および第２の軸受保持部の内径との同軸度精度がよく、空隙４１４ｇも均一にできて、溝高調波成分の騒音を低減できる。
【００２６】
なお、上記実施の形態においては、ケース４１６の第１の軸受保持部４１６ｘの端面となっているコア部４１２ｃの端面４１６ｙと第１の軸受４１８の外輪の端面とが当接するように構成したが、第２の軸受保持部４１６ｚをコア部４１２ｃと隣接させて設け、第２の軸受４２０の外輪の端面とが当接するように構成して、第２の軸受４２０を上に、第１の軸受４１８を下向きに使用するようにしてもよい。
【００２７】
実施の形態５．
図５はこの発明の実施の形態５の外転形電動機を示す断面図である。図中、従来または上記実施の形態１と同一または相当部分は説明を省略する。図５において、外転形電動機５００は、回転磁界を発生させる複数枚の鋼板からなるコア部５１２ｃを有し、コア部５１２ｃには板状の絶縁カバー３により電気絶縁されてコイル５が巻かれており、コイル５に交番電圧を印可すると、回転磁界が発生し、所定空隙５１４ｇを有して外側に配置された回転子５１４に印可され、回転力が発生する。コア５１２ｃ、コイル５および絶縁カバー３は樹脂にてモールドされている。モールドに第１の軸受保持部５１６ｘおよび第２の軸受保持部５１６ｚを同時に形成しているが、その際第１の軸受１８および第２の軸受２０の外径よりも大きい円管９を設けてモールドしており、第１の軸受保持部５１６ｘおよび第２の軸受保持部５１６ｚを形成している樹脂部５１６ｍおよび樹脂部５１６ｎは全周に渡ってほぼ均一な樹脂肉厚となっている。
【００２８】
上記のように構成された外転形電動機においては、コア部５１２ｃの両側に第１の軸受１８および第２の軸受２０の外径よりも大きい円管９を配設してモールドすることにより、成形時の樹脂の収縮による軸受保持部５１６ｘおよび軸受保持部５１６ｚの変形が少なく、真円度やコア５１２ｃとの同軸度の高精度化が図れ、空隙５１４ｇを均一にできて、溝高調波成分の騒音を低減できる。
【００２９】
なお、前記円管９は板状の絶縁カバー３と鍔状に一体化されたものでもよいし、別部品であってもよい。また、樹脂肉厚が均等であれば成形時の樹脂の収縮による軸受保持部５１６ｘおよび軸受保持部５１６ｚの変形が少なく、円管９は全周に渡ってつながっている必要はなく、円管９の外周方向から軸受保持部５１６ｘおよび軸受保持部５１６ｚへの樹脂の流れがよくなるように、複数箇所にスリットや穴を設けてもよい。
【００３０】
また、上記の各実施の形態において、固定子の軸受保持部を後からの切削加工によって形成したものにおいても、これに限定されるものではなく、モールドした状態で形成されるようにしてもよい。
【００３１】
【発明の効果】
本発明の外転形電動機によれば、コイルの巻き方に関わらず軸受保持部の樹脂肉厚を均一にでき、成形時の樹脂の収縮による軸受保持部の変形を少なくでき、真円度およびコアとの同軸度のよい軸受保持部を形成でき、空隙を均一にできて溝高調波成分の騒音を低減できる。
【図面の簡単な説明】
【図１】この発明の外転形電動機の実施の形態１を示す断面図である。
【図２】この発明の外転形電動機の実施の形態２を示す断面図である。
【図３】この発明の外転形電動機の実施の形態３を示す断面図である。
【図４】この発明の外転形電動機の実施の形態４を示す断面図である。
【図５】この発明の外転形電動機の実施の形態５を示す断面図である。
【図６】従来の外転形電動機の実施の形態を示す断面図である。
【符号の説明】
１０，１００，２００，３００，４００外転形電動機、１２，１１２，２１２，３１２固定子、１４，１１４，２１４，３１４，４１４回転子、１６，１１６，２１６，３１６，４１６ケース、１８，１１８，２１８，３１８，４１８第１の軸受、２０，１２０，２２０，３２０，４２０第２の軸受。[0001]
BACKGROUND OF THE INVENTION
The present invention also relates to an abduction motor disposed outside the rotor and the stator.
[0002]
[Prior art]
FIG. 6 is a sectional view showing a conventional abduction motor disclosed in Japanese Patent Laid-Open No. 63-257440 in which a sleeve bearing is replaced with a ball bearing. In FIG. 6, an external rotation type motor 10 supports a stator 12 having an inner hole 12a that generates a rotating magnetic field, a rotor 14 that rotates based on the rotating magnetic field, and the stator 12, and has a concentric hollow portion. The frame 17 having an L-shaped cross section, bearings 18 and 20 in which outer rings are fitted to the columnar inner surface of the frame 17, and the rotor 14 are mounted on the inner rings of the bearings 18 and 20. The shaft 22 is mounted.
[0003]
Next, the operation of the abduction motor 10 configured as described above will be described.
Now, when a power source (not shown) is turned on to the stator 12 of the outer motor 10, the outer rotor 14 is rotated by the rotating magnetic field generated by the stator 12.
[0004]
[Problems to be solved by the invention]
However, the conventional abduction motor 10 has the following problems.
First, the L-shaped frame 17 is complicated to machine by a lathe on the inner surface of the hollow portion formed in a columnar shape, the outer surface of the same shape, or the like. In addition, the inner surface of the frame 17 is fitted to the outer rings of the bearings 18 and 20, and the outer surface is closely fixed to the inner hole 12a of the stator 12, so that the inner surface and the outer surface of the frame 17 have high coaxiality. Machining accuracy was required, which increased the machining work time.
[0005]
Secondly, the coaxiality between the outer peripheral surface of the stator 12 and the bearings 18 and 20 deteriorates due to manufacturing errors and assembly errors of the frame 17, and the gap 14g between the stator 12 and the rotor 14 is not uniform. As a result, the noise due to the groove harmonics increased, and in addition, the outer diameter of the bearings 18 and 20 of the rotor 14 was reduced, and the allowable load of the bearings 18 and 20 was reduced.
[0006]
The present invention has been made to solve the above-described problems, and while reducing the manufacturing time, the gap between the stator and the rotor is made uniform to suppress noise, and the outer diameter of the rotor bearing The object of the present invention is to provide an abduction motor that can increase the allowable load of the bearing.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, the outer motor is provided with a first bearing and a second bearing which are disposed outside the stator and hold the shaft of the rotor rotating by a rotating magnetic field. In the abduction motor, the first bearing and the second bearing are molded into a circular pipe having an inner diameter larger than the outer diameter of the first bearing and the second bearing so that the resin has a uniform thickness. A first bearing holding part and a second bearing holding part for holding the respective bearings by fitting the respective outer rings of the first bearing and the second bearing between the outer rings and the coils of the bearings; It is arranged.
[0008]
According to a second aspect of the present invention, the outer motor is formed by integrating a circular tube with a plate-like insulating cover that insulates a core portion and a coil.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
1 is a cross-sectional view showing an abduction motor according to Embodiment 1 of the present invention. In the figure, the description of the same or corresponding parts as in the prior art is omitted. In FIG. 1, an outer rotation type electric motor 100 has a core portion 112 c made of a plurality of steel plates that generate a rotating magnetic field, a cylindrical inner hole 112 a in the core portion 112 c, and a cross section L in which a coil 112 w is accommodated. A stator 112 having a case 116 formed by molding in a letter shape, and a rotor 114 arranged outside and having the stator 112 and a predetermined gap 114g. In addition, on one end side (the left side in the drawing) of the core portion 112c of the stator 112, a first bearing holding portion 112x having a larger diameter than the cylindrical inner hole 112a is fitted with a first outer ring. The other end of the core portion 112c (the right side in the drawing) has a second bearing 120 in which an outer ring is fitted to a second bearing holding portion 112z having a similar shape. The inner rings of the first bearing 118 and the second bearing 120 are mounted on a shaft 122 fitted into the center of the rotor 114.
[0014]
By bringing the distance value Pa between the inner surfaces of the first bearing 118 and the second bearing 120 close to each other, the natural vibration frequency of the rotor 114 is increased, and resonance with the lower-order component of the groove harmonic is caused. Configured to avoid.
[0015]
In the abduction motor configured as described above, a case 116 having an L-shaped cross section in which a coil 112w wound around a core portion 112c in which a plurality of steel plates of the stator 112 are stacked is housed is stored in a core. A first bearing holding portion 112x is formed on one end side of the portion 112c and a second bearing holding portion 112z is formed on the other end side by cutting to a larger diameter than the cylindrical inner hole 112a. The first bearing holding portion 112x and the second bearing holding portion 112z are fitted with the outer rings of the first bearing 118 and the second bearing 120, respectively, and the shaft 122 is fitted into the center of the rotor 114. And the mounting of the first bearing 118 and the second bearing 120 is completed. Since the bearing holding portion 112x and the bearing holding portion 112z are formed in the core portion 112c of the stator 112 which is integrated as a whole and the outer rings of the first bearing 118 and the second bearing 120 are fitted, there is no assembly error. Since the gap 114g can be made uniform over the entire circumference, the noise of the groove harmonic component can be reduced, and a frame or the like is not required for holding the bearing, and the outside of the first bearing 118 and the second bearing 120 is eliminated. The diameter can be increased or the outer diameter of the motor can be reduced.
[0016]
When a power source (not shown) is applied to the stator 112 of the abduction motor 100, a rotating magnetic field is generated and the rotor 114 rotates. In this case, since the distance value Pa between the inner surfaces of the first bearing 118 and the second bearing 120 is shortened, the natural vibration frequency of the rotor 114 is increased, and resonance with the lower-order component of the groove harmonic is caused. There is also an effect that can be avoided, and noise can be reduced.
[0017]
Embodiment 2. FIG.
FIG. 2 is a cross-sectional view showing an abduction motor according to Embodiment 2 of the present invention. In the figure, the description of the same or corresponding parts as those of the conventional or the first embodiment is omitted. In FIG. 2, the outer rotation type electric motor 200 has a core part 212 c made of a plurality of steel plates for generating a rotating magnetic field, and has a cylindrical inner hole 212 a in the core part 212 c and a cross section in which a coil 212 w is accommodated. A stator 212 having a case 216 formed by molding in an L-shape, and a rotor 214 arranged outside and having the stator 212 and a predetermined gap 214g are provided. Also, a first bearing 218 having an outer ring fitted to a first bearing holding portion 212x on one end side (left side in the drawing) of the core portion 212c of the stator 212, and the other end side (on the drawing side) of the stator 212. A case 216 formed of a mold on the right side has a second bearing 220 in which an outer ring is fitted to a second bearing holding portion 216z having a similar shape. The inner rings of the first bearing 218 and the second bearing 220 are attached to a shaft 222 that is fitted into the center of the rotor 214.
[0018]
The distance value Pb from the inner surface of the first bearing 218 to the inner surface of the second bearing 220 is made longer than that in the first embodiment, so that the vertical portion of the rotor 214 extends from the inner surface of the second bearing 220. The distance value Q to the inner surface of the rotor 214 is made shorter than that of the first embodiment to suppress the swing of the rotor 214.
[0019]
In the abduction motor configured as described above, the case 216 of the stator 212 integrated as a whole is cut in the same manner as in the first embodiment, and the one end side (left side in the drawing) of the core portion 212c is cut. A first bearing holding portion 212x is formed in the inner hole 212a, and a second bearing holding portion 212z having a similar shape is formed in the mold on the other end side (the right side in the drawing) of the case 216, and the first bearing holding portion 212x is formed in each of the first holes. Since the outer rings of the first bearing 218 and the second bearing 220 are fitted, the assembly error is reduced and the gap 214g can be made more uniform over the entire circumference, so that the noise of the groove harmonic component can be reduced, and the bearing A frame or the like is not necessary for holding the first bearing 218, the outer diameter of the first bearing 218 and the second bearing 220 can be increased, or the outer diameter of the electric motor can be decreased. Further, as described above, the distance value Pb between the bearing inner surfaces becomes long and the distance value Q is short, so that the swinging of the rotor 214 can be suppressed.
[0020]
Embodiment 3 FIG.
FIG. 3 is a sectional view showing an abduction motor according to Embodiment 3 of the present invention. In the figure, the description of the same or corresponding parts as those of the conventional or the first embodiment is omitted. In FIG. 3, the outer rotation type electric motor 300 has a core portion 312 c made of a plurality of steel plates for generating a rotating magnetic field, and has a cylindrical inner hole 312 a in the core portion 312 c, and a cross section in which a coil 312 w is accommodated. A stator 312 having a case 316 formed by molding in an L shape, and a rotor 314 having the stator 312 and a predetermined gap 314g and disposed outside. In addition, a first bearing 318 in which an outer ring is fitted to a first bearing holding portion 312x of a case 316 formed by a mold on one end side (left side in the drawing) of the stator 312; and a core portion of the stator 312 The other end side (right side in the drawing) of 312c has a second bearing 320 in which an outer ring is fitted to a second bearing holding portion 312z having a similar shape. The inner rings of the first bearing 318 and the second bearing 320 are mounted on a shaft 322 fitted into the center of the rotor 314.
[0021]
Here, what is characteristic is that the distance L between the fixing portion where the horizontal portion 314a formed at the center portion of the rotor 314 is fixed to the shaft 322 is increased, and the fixing strength between the shaft 322 and the rotor 314 is increased. It is configured to increase.
[0022]
In the outer rotation type electric motor configured as described above, the case 316 of the stator 312 integrated as a whole is cut in the same manner as in the first embodiment, and one end side (left side in the drawing) of the case 316 is cut. Since the first bearing holding portion 312x is formed in the mold, and the second bearing holding portion 312z having the same shape is formed, and the outer rings of the first bearing 318 and the second bearing 320 are fitted into each. Since the assembly error is reduced and the gap 314g can be made more uniform over the entire circumference, the noise of the groove harmonic component can be reduced, and a frame or the like is not required for holding the bearing, and the first bearing 318, second bearing As in the first embodiment, the outer diameter of the bearing 320 can be increased or the outer diameter of the motor can be reduced. Further, as described above, the distance L between the fixing portion where the horizontal portion 314a is fixed to the shaft 322 is increased to increase the fixing strength between the shaft 322 and the rotor 314, and the first bearing 318 and the second bearing 318 Since the distance Pc between the inner surfaces of the bearing 320 and the bearing 320 is longer than that in the first embodiment, the deflection accuracy of the rotor 314 is improved.
[0023]
Embodiment 4 FIG.
4 is a sectional view showing an abduction motor according to Embodiment 4 of the present invention. In the figure, the description of the same or corresponding parts as those of the conventional or the first embodiment is omitted. In FIG. 4, the outer rotation type electric motor 400 has a core portion 412c made of a plurality of steel plates for generating a rotating magnetic field, and has a cylindrical inner hole 412a in the core portion 412c, and a cross section in which a coil 412w is accommodated. A stator 412 having a case 416 formed by resin molding in an L-shape, and a rotor 414 disposed outside with the stator 412 and a predetermined gap 414g are provided. In addition, the end surface 416y of the core portion 412c, which is the end surface of the first bearing holding portion 416x of the case 416 formed by a mold on one end side (left side in the drawing) of the stator 412, abuts the end surface of the outer ring. The first bearing 418 fitted in this manner and the second bearing 420 in which the outer ring is fitted to the second bearing holding portion 416z on the other end side (the right side in the drawing) of the case 416 also formed of a mold. And have. The inner rings of the first bearing 418 and the second bearing 420 are mounted on a shaft 422 fitted into the center of the rotor 414.
[0024]
What is characteristic here is that the inner diameter Db of the first bearing holding portion 416x and the second bearing holding portion 416z is made larger than the inner diameter Dc of the inner hole 412a of the core portion 412c, and the end face of the first bearing 418 is used. This is a structure in contact with the end face 416y of the core portion 412c.
[0025]
In the abduction motor configured as described above, the first bearing is held in the mold on one end side (the left side in the drawing) of the case 416 of the stator 412 which is integrated as in the first embodiment. The end surface of the core portion 412c is exposed so that the end surface of the portion 416x becomes the end surface 416y of the core portion 412c, and the second bearing holding portion 412z is formed on the mold on the other end side (right side in the drawing) of the case 416. Are formed by resin molding without post-processing. By increasing the inner diameter of both the first bearing holding portion 416x and the second bearing holding portion 416z, that is, the outer ring diameter of the bearing, not only the allowable load of the bearing can be increased, but also the outer diameter Ds of the shaft 422 is increased. The natural vibration frequency of the rotor 414 can be increased, the noise can be reduced by shifting from the lower-order groove high frequency, and when the first bearing 418 is used upward and the second bearing 420 is used downward. The weight of the rotor can be supported by the end face 416y of the core part 412c which is strong in strength, and the reliability can be improved. In addition, since both the first bearing holding portion 416x and the second bearing holding portion 416z can be formed by resin molding without post-processing on the basis of the outer diameter of the core portion 412c, the outside of the core portion 412c. The coaxiality accuracy between the diameter and the inner diameter of the first bearing holding part and the second bearing holding part is good, the gap 414g can be made uniform, and the noise of the groove harmonic component can be reduced.
[0026]
In the above embodiment, the end surface 416y of the core portion 412c, which is the end surface of the first bearing holding portion 416x of the case 416, and the end surface of the outer ring of the first bearing 418 are in contact with each other. The second bearing holding portion 416z is provided adjacent to the core portion 412c, and is configured so as to abut the end surface of the outer ring of the second bearing 420. 418 may be used downward.
[0027]
Embodiment 5. FIG.
FIG. 5 is a sectional view showing an abduction motor according to Embodiment 5 of the present invention. In the figure, the description of the same or corresponding parts as those of the conventional or the first embodiment is omitted. In FIG. 5, the outer rotation type electric motor 500 has a core portion 512 c made of a plurality of steel plates that generate a rotating magnetic field, and the core portion 512 c is electrically insulated by a plate-shaped insulating cover 3 and is wound with a coil 5. When an alternating voltage is applied to the coil 5, a rotating magnetic field is generated and applied to the rotor 514 disposed outside with a predetermined gap 514g to generate a rotational force. The core 512c, the coil 5, and the insulating cover 3 are molded with resin. The first bearing holding portion 516x and the second bearing holding portion 516z are formed at the same time in the mold. At this time, a circular tube 9 larger than the outer diameter of the first bearing 18 and the second bearing 20 is provided. The resin part 516m and the resin part 516n forming the first bearing holding part 516x and the second bearing holding part 516z have a substantially uniform resin thickness over the entire circumference.
[0028]
In the abduction motor configured as described above, by disposing and molding the circular tubes 9 larger than the outer diameters of the first bearing 18 and the second bearing 20 on both sides of the core portion 512c, There is little deformation of the bearing holding portion 516x and the bearing holding portion 516z due to resin shrinkage during molding, high accuracy of roundness and coaxiality with the core 512c can be achieved, the gap 514g can be made uniform, and the groove harmonic component Noise can be reduced.
[0029]
The circular tube 9 may be integrated with the plate-like insulating cover 3 in a bowl shape or may be a separate part. Further, if the resin wall thickness is uniform, deformation of the bearing holding portion 516x and the bearing holding portion 516z due to resin shrinkage during molding is small, and the circular tube 9 does not have to be connected over the entire circumference. In order to improve the flow of resin from the outer peripheral direction to the bearing holding portion 516x and the bearing holding portion 516z, a plurality of slits and holes may be provided.
[0030]
Further, in each of the above embodiments, the bearing holding portion of the stator formed by subsequent machining is not limited to this, and may be formed in a molded state. .
[0031]
【The invention's effect】
According to the abduction motor of the present invention, the resin thickness of the bearing holding portion can be made uniform regardless of how the coil is wound, the deformation of the bearing holding portion due to the shrinkage of the resin during molding can be reduced, and the roundness and A bearing holding portion having good coaxiality with the core can be formed, the gap can be made uniform, and the noise of the groove harmonic component can be reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a first embodiment of an abduction motor of the present invention.
FIG. 2 is a cross-sectional view showing a second embodiment of the abduction motor of the present invention.
FIG. 3 is a cross-sectional view showing Embodiment 3 of the abduction motor of the present invention.
FIG. 4 is a sectional view showing Embodiment 4 of an abduction motor according to the present invention.
FIG. 5 is a cross sectional view showing Embodiment 5 of an abduction motor according to the present invention.
FIG. 6 is a cross-sectional view showing an embodiment of a conventional abduction motor.
[Explanation of symbols]
10, 100, 200, 300, 400 External rotating motor, 12, 112, 212, 312 Stator, 14, 114, 214, 314, 414 Rotor, 16, 116, 216, 316, 416 Case, 18, 118 , 218, 318, 418 First bearing, 20, 120, 220, 320, 420 Second bearing.

Claims

In an abduction motor in which a first bearing and a second bearing that are arranged outside the stator and hold a rotor shaft that rotates in a rotating magnetic field are provided in the stator,
A circular pipe having an inner diameter larger than the outer diameter of the first bearing and the second bearing is molded so that the resin has a uniform thickness, and the outer rings of the first bearing and the second bearing are respectively between the coils, and characterized in that arranged first bearing holding portion and the second bearing holding portion for holding the bearings by fitting each of the outer ring of the first bearing and the second bearing An abduction-type electric motor.

2. An abduction motor according to claim 1, wherein the circular tube is integrated with a plate-like insulating cover for insulating the core portion and the coil.