JP2004328963A

JP2004328963A - Manufacturing method of rotor for electric motor, and the rotor for electric motor

Info

Publication number: JP2004328963A
Application number: JP2003123767A
Authority: JP
Inventors: Masahide Kimura; 真秀木村
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 2003-04-28
Filing date: 2003-04-28
Publication date: 2004-11-18

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor manufacturing method and a rotor that can achieve high output for an electric motor. <P>SOLUTION: A rotor 20 has a rotor core 21 formed by stacking disc-shaped thin plates. In this rotor core 21, four slits 22 are formed that are arranged virtually at equal intervals along the circumferential direction and that passes through in the axial direction. Each slit 22 has a cross section, having a first outside surface 22a, a first inside surface 22b inclined with respect to the first outside surface 22a, and gaps 22c positioned at both ends of these surfaces 22a, 22b. A permanent magnet 23, which has a cross section, having a second outside surface 23a and a second inside surface 23b that corresponds to the first inside surface 22b, is inserted into the slit 22 along the axial direction and moved with respect to the slit 22, and the magnet 23 is moved in a direction where the gap between the first outside surface 22a and the first inside surface 22b is narrower, and by making each surface 23a, 23b of the permanent magnet 23 contacts each surface 22a, 22b of the slit 22, the permanent magnet 23 is made to come into close contact with the slit 22 and fixed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【技術分野】
本発明は、永久磁石埋込型の電動機に用いて好ましい回転子の製造方法及び回転子に関する。
【０００２】
【背景技術】
小型高出力化が要求されるモータにおいて、ロータコアの内部に永久磁石を配置したロータと、前記回転子の外周に配置され、巻線が巻装されたステータとを備え、マグネットトルクのみならずリアクタンストルクを利用して小型高出力化を実現した永久磁石埋込型モータ（以下、単に「ＩＰＭ（ＩｎｔｅｒｉｏｒＰｅｒｍａｎｅｎｔＭａｇｎｅｔ）モータ」と称する。）が知られている。
【０００３】
このようなＩＰＭモータに用いられるロータは、当該ロータの内部に配置される永久磁石より大きな断面形状のスリット孔をロータコアに形成し、当該スリット孔に永久磁石を挿入した後に、接着剤やバネを用いて、永久磁石をロータコアに対して固定している（例えば、特許文献１、２及び３参照）。
【０００４】
しかしながら、このような永久磁石の固定方法では、ロータコアに形成されたスリット孔と永久磁石との間に接着層や空気層が介在し、ロータコアと永久磁石との密着性に劣るため、永久磁石からロータコアの外周方向への磁束が通過し難くなり、ＩＰＭモータの高出力化を図ることができない。
【０００５】
また、このような固定方法では、スリット孔と永久磁石との間に介在する接着層や空気層の熱伝導率がロータコアより低く、永久磁石で発生した熱がロータコアに伝熱し難くなり、当該永久磁石の抜熱性に劣るため、ＩＰＭモータの高出力運転時に永久磁石が減磁し、出力を制限する必要があった。
【０００６】
【特許文献１】
特開２００２−５８１８５号公報
【特許文献２】
特開２０００−１７５３８８号公報
【特許文献３】
特開２０００−３４１９２０号公報
【０００７】
【発明の開示】
本発明は、電動機の高出力化を図ることが可能な回転子の製造方法及び回転子を提供することを目的とする。
【０００８】
上記目的を達成するために、本発明によれば、永久磁石埋込型の電動機に用いられる、回転子コアに軸方向に沿って形成された磁石挿入孔に永久磁石が配置された回転子の製造方法であって、前記磁石挿入孔は、前記永久磁石より大きく形成されており、相互に非平行である第１の外側面及び第１の内側面を少なくとも有し、前記永久磁石は、前記第１の外側面及び前記第１の内側面にそれぞれ対応した第２の外側面及び第２の内側面を少なくとも有しており、前記永久磁石を前記磁石挿入孔に軸方向に沿って挿入するステップと、前記第１の外側面及び前記第２の外側面と、前記第１の内側面及び第２の内側面とをそれぞれ当接させるように、前記永久磁石を前記磁石挿入孔に対して軸方向に直交する方向に相対的に移動させ、前記永久磁石を前記回転子コアに固定するステップとを少なくとも備えた回転子の製造方法が提供される。
【０００９】
また、本発明によれば、永久磁石埋込側の電動機に用いられる、回転子コアに軸方向に沿って形成された磁石挿入孔に永久磁石が配置された回転子であって、前記磁石挿入孔は、相互に非平行である第１の外側面及び第１の内側面を少なくとも有し、前記永久磁石は、前記第１の外側面及び前記第１の内側面にそれぞれ対応した第２の外側面及び第２の内側面を少なくとも有しており、前記第１の外側面及び前記第２の外側面と、前記第１の内側面及び前記第２の内側面とがそれぞれ当接するように、前記永久磁石が前記磁石挿入孔に挿入され、前記永久磁石が前記回転子コアに固定されている回転子が提供される。
【００１０】
本発明では、回転子コアに形成された磁石挿入孔に永久磁石が埋め込まれた電動機に用いられる回転子において、前記磁石挿入孔に少なくとも一つの傾斜面を形成すると共に、前記磁石挿入孔の少なくとも一つの傾斜面に対応した傾斜面を前記永久磁石に形成し、磁石挿入孔への永久磁石の挿入時に、これら傾斜面を相互に当接させて、当該永久磁石を回転子コアに固定する。
【００１１】
これにより、永久磁石が磁石挿入孔に対して楔のように作用して密着することとなるので、永久磁石から回転子コアの外周方向への磁束の通過性が向上し、電動機の高出力化を図ることが可能となる。
【００１２】
また、永久磁石と回転子コアとが密着することにより、永久磁石から回転子コアへの伝熱が向上し、当該永久磁石の抜熱性が向上するので、電動機の高速運転時における永久磁石の減磁を防止することが可能となり、電動機の高出力化を図ることが可能となる。
【００１３】
さらに上記目的を達成するために、本発明によれば、永久磁石埋込型の電動機に用いられる、回転子コアに軸方向に沿って形成された磁石挿入孔に永久磁石が配置された回転子の製造方法であって、前記磁石挿入孔は、前記永久磁石より大きく形成されており、第１の外側面及び第１の内側面を少なくとも有し、前記永久磁石は、径方向外側に位置する第１の永久磁石と、前記第１の永久磁石に対して径方向内側に位置する第２の永久磁石とを有し、前記第１の永久磁石は、前記第１の外側面に対応した第２の外側面と、前記第２の外側面に軸方向に直交する方向に沿って非平行である第２の内側面とを少なくとも有し、前記第２の永久磁石は、前記第２の内側面に対応した第３の外側面と、前記第１の内側面に対応した第３の内側面とを少なくとも有しており、前記第１の永久磁石を前記磁石挿入孔に軸方向に挿入するステップと、前記第２の内側面と前記第３の外側面とが相互に対向するような姿勢で、前記第２の永久磁石を前記磁石挿入孔に軸方向に挿入するステップと、前記第２の内側面と前記第３の外側面とを当接させるように、前記第１の永久磁石及び前記第２の永久磁石を前記磁石挿入孔に対して軸方向に直交する方向に相対的に移動させ、前記第１の永久磁石及び前記第２の永久磁石を前記回転子コアに固定するステップとを少なくとも備えた回転子の製造方法が提供される。
【００１４】
また、本発明によれば、永久磁石埋込型の電動機に用いられる、回転子コアに軸方向に沿って形成された磁石挿入孔に永久磁石が配置された回転子の製造方法であって、前記磁石挿入孔は、第１の外側面及び第１の内側面を少なくとも有し、前記永久磁石は、径方向外側に位置する第１の永久磁石と、前記第１の永久磁石に対して径方向内側に位置する第２の永久磁石とを有し、前記第１の永久磁石は、前記第１の外側面に対応した第２の外側面と、前記第２の外側面に軸方向に沿って非平行である第２の内側面とを少なくとも有し、前記第２の永久磁石は、前記第２の内側面に対応した第３の外側面と、前記第１の内側面に対応した第３の内側面とを少なくとも有しており、前記第１の永久磁石を前記磁石挿入孔に軸方向に挿入するステップと、前記第２の内側面と前記第３の外側面とが相互に対向するような姿勢で、前記第２の永久磁石を前記磁石挿入孔に軸方向に挿入して、前記第１の永久磁石及び前記第２の永久磁石を前記回転子コアに固定するステップとを少なくとも備えた回転子の製造方法が提供される。
【００１５】
さらに、本発明によれば、永久磁石埋込型の電動機に用いられる、回転子コアに軸方向に沿って形成された磁石挿入孔に永久磁石が配置された回転子であって、前記磁石挿入孔は、第１の外側面及び第１の内側面を少なくとも有し、前記永久磁石は、径方向外側に位置する第１の永久磁石と、前記第１の永久磁石に対して径方向内側に位置する第２の永久磁石とを有し、前記第１の永久磁石は、前記第１の外側面に対応した第２の外側面と、前記第２の外側面に非平行である第２の内側面とを少なくとも有し、前記第２の永久磁石は、前記第２の内側面に対応した第３の外側面と、前記第１の内側面に対応した第３の内側面とを少なくとも有しており、前記第２の内側面と前記第３の外側面とが当接するように、前記永久磁石が前記磁石挿入孔に挿入され、前記第１の永久磁石及び前記第２の永久磁石が前記回転子コアに固定されている回転子が提供される。
【００１６】
本発明では、回転子コアに形成された磁石挿入孔に永久磁石が埋め込まれた電動機に用いられる回転子において、前記永久磁石を第１の永久磁石と第２の永久磁石とに分割し、当該第１及び第２の永久磁石において相互に対向する面をそれぞれ傾斜面とし、磁石挿入孔への永久磁石の挿入時に、これら傾斜面を相互に当接させて、第１及び第２の永久磁石を回転子コアに固定する。
【００１７】
これにより、第１の永久磁石と第２の永久磁石とが楔のように作用して第１及び第２の永久磁石と磁石挿入孔と密着することとなるので、永久磁石から回転子コアの外周方向への磁束の通過性が向上し、電動機の高出力化を図ることが可能となる。
【００１８】
また、永久磁石と回転子コアとが密着することにより、永久磁石から回転子コアへの伝熱が向上し、当該永久磁石の抜熱性が向上ので、電動機の高速運転時における永久磁石の減磁を防止することが可能となり、電動機の高出力化を図ることが可能となる。
【００１９】
【発明の実施の形態】
以下、本発明の実施形態を図面に基づいて説明する。
【００２０】
［第１実施形態］
図１は本発明の実施形態に係るＩＰＭモータの横断面図であり、図２は図１のＩＩ−ＩＩ線に沿う断面図、図３は本発明の第１実施形態における図２のＩＩＩ部の詳細図であり、図３（Ａ）は、永久磁石を挿入している状態を示す図であり、図３（Ｂ）は永久磁石を挿入した状態を示す図である。
【００２１】
まず、本実施形態に係る方法により製造されるロータが用いられるＩＰＭモータの構造について説明する。
【００２２】
図１及び図２に示すように、本実施形態におけるＩＰＭモータ１は、ハウジング３、及び第１及び第２のブラケット４、５から成るモータカバー２と、当該第１及び第２のブラケット４、５にそれぞれ取り付けられたベアリング６に回動自在に支持されたシャフト７と、前記モータカバー２のハウジング３の内周面に固定されたステータ１０と、前記シャフト７の外周に固定され、空隙（エアギャップ）を介在させて前記ステータ１０に対して相対的に回動自在に設けられ、永久磁石２３が埋め込まれたロータ（回転子）２０とから構成されている。
【００２３】
このＩＰＭモータ１のステータ１０は、円環形状の内部に向かって突出し、互いの間にスロットが形成された２４個のティース１１を有しており、各ティース１１には巻線１２が巻装されている。
【００２４】
このＩＰＭモータ１のロータ２０は、例えば珪素鋼板などから成る円盤形状の磁性体薄板を積層して形成されたロータコア（回転子コア）２１と、当該ロータコア２１に形成された４つのスリット孔（磁石挿入孔）２２に挿入されている永久磁石２３と、当該永久磁石２３がそれぞれ挿入された各スリット孔２２を塞ぐように、ロータコア２１の両端部に取り付けられたエンドプレート２７とを有している。
【００２５】
このロータ２０のロータコア２１には、その中心に前記シャフト７が挿入される貫通孔が軸方向に沿って形成されていると共に、円周方向に沿って実質的に等間隔に配置され、軸方向に沿って貫通している４つのスリット孔（磁石挿入孔）２２が形成されている。
【００２６】
このスリット孔２２は、図３（Ａ）及び図３（Ｂ）に示すように、挿入される永久磁石２３より大きな断面形状を有しており、径方向外側に位置する第１の外側面２２ａと、当該第１の外側面２２ａに対して径方向内側に位置しており、当該第１の外側面２２ａに非平行である第１の内側面２２ｂと、当該第１の外側面２２ａ及び第１の内側面２２ｂの両端部に位置して、磁束の短絡を防止するフラックスバリアとして機能すると共に、永久磁石２３の円滑な挿入作業を実現するために形成された隙間部２２ｃとを持つ断面形状を有している。
【００２７】
この各スリット孔２２の第１の内側面２２ｂは、図３（Ｂ）に示すように、第１の外側面２２ａ及び第１の内側面２２ｂの一方の端部の間の距離と、第１の外側面２２ａ及び第１の内側面２２ｂの他方の端部の間の距離との差がｈ_１となるように、第１の外側面２２ａに対して傾斜している。
【００２８】
この各スリット孔２２にそれぞれ挿入される各永久磁石２３は、上記のスリット孔２２の断面形状に対応した断面形状を有しており、径方向外側に位置する第２の外側面２３ａと、当該第２の外側面２３ａに対して径方向内側に位置しており、スリット孔２２の第１の内側面２２ｂに対応して、当該第１の内側面２２ｂに実質的に平行であり、第２の外側面２３ａに非平行である第２の内側面２３ｂとを持つ断面形状を有している。この各永久磁石２３の第２の内側面２３ｂは、スリット孔２２の第１の内側面２２ｂと同様に、図３（Ｂ）に示すように、第２の外側面２３ａに対して傾斜している。
【００２９】
上記の各スリット孔２２には、接着剤（不図示）等が塗布された４つ（２対）の永久磁石２３がそれぞれ挿入されている。そして、これら永久磁石２３は、第２の外側面２３ａと第２の内側面とがそれぞれ磁極となっており、互いに隣接する永久磁石２３が相互に異極となるように、ロータコア２１の内部にそれぞれ配置されている。
【００３０】
この永久磁石２３に用いられる材料としては、錆止めの観点から、例えばネオジウムマグネットが好ましい。また、永久磁石２３は既に着磁しており、スリット孔２２への挿入時に永久磁石２３の磁気吸引力によりロータコア２１に接触しながら挿入されるため、当該永久磁石２３の表面に、例えば、ニッケルメッキやエポキシ系塗装などの表面処理を施して強度を向上させ、永久磁石２３の割れ、欠け及び剥離などを防止すると共に、錆止めを行うことが好ましい。
【００３１】
以上のように構成されるＩＰＭモータ１は、ステータ１０に巻装された巻線１２に電流が流れると回転磁界が発生し、この回転磁界によってステータ１０とロータ２０との間にトルクが発生して、シャフト７に固定されたロータ２０がステータ１０に対して相対的に回転する。このとき発生するトルクは、ステータ１０の巻線１２とロータ２０の永久磁石２３とが反発・吸引することによるマグネットトルクと、永久磁石２３を透磁率とロータコア２１の透磁率との差により発生するリアクタンストルクとから成る。
【００３２】
以下に、上記のような構造を有するロータの製造方法について説明する。
【００３３】
まず、図３（Ａ）に示すように、表面処理が施され、接着剤が塗布された永久磁石２３を、積層されたロータコア２１に形成されたスリット孔２２に軸方向に沿って挿入する。この際、永久磁石２３の第２の外側面２３ａとスリット孔２２の第１の外側面２２ａとが実質的に平行となり、永久磁石２３の第２の外側面２３ｂとスリット孔２２の第１の内側面２２ｂとが実質的に平行となり、さらに、スリット孔２２の第１の外側面２２ａと第１の内側面２２ｂとの間隔が広くなっている側の隙間部２２ｃに永久磁石２３を寄せた姿勢で、永久磁石２３をスリット孔２２に挿入する。
【００３４】
次に、スリット孔２２内において、挿入された永久磁石を、スリット孔２２の第１の外側面２２ａと第１の内側面２２ｂとの間の間隔が狭くなっている方向に、即ち、図３（Ａ）に示す矢印の方向に移動させ、永久磁石２３の第２の外側面２３ａとスリット孔２２の第１の外側面２２ａとを当接させると共に、永久磁石２３の第２の内側面２３ｂとスリット孔２２の第１の内側面２２ｂとを当接させて、永久磁石２３をスリット孔２２の内壁面２２ａ、２２ｂに密着させて固定する。
【００３５】
同様に、ロータコア２１に形成された他の３つのスリット孔２２に永久磁石２３をそれぞれ挿入して移動させて、永久磁石２３をロータコア２１に対して固定することにより、図１及び図２に示すような４つ（２対）の永久磁石が埋め込まれたロータ２０が製造される。
【００３６】
以上のように、ロータコアのスリット孔に少なくとも一つの傾斜面を形成すると共に、当該スリット孔の少なくとも一つの傾斜面に対応した傾斜面を永久磁石に形成し、スリット孔への永久磁石の挿入時に、これら傾斜面を相互に当接させて、当該永久磁石をロータコアに固定することにより、永久磁石がスリット孔に対して楔のように径方向に密着するので、永久磁石からロータコアの外周方向への磁束の通過性が向上し、ＩＰＭモータの高出力化を図ることが可能となる。
【００３７】
また、ロータコアと永久磁石とが密着することにより、永久磁石からロータコアへの伝熱が向上し、当該永久磁石の抜熱性が向上するので、ＩＰＭモータの高出力運転時における永久磁石の減磁を防止することが出来、ＩＰＭモータの高出力化を図ることが可能となる。
【００３８】
また、本実施形態では、永久磁石の枚数を増加させることなく、上記効果を得ることが出来る。
【００３９】
さらに、本実施形態に係るロータは、永久磁石の楔の作用により当該永久磁石がスリット孔に密着して固定されるので、ロータのアンバランスやトルクリプルなどの問題も解消される。
【００４０】
［第２実施形態］
図４は本発明の第２実施形態における図２のＩＩＩ部の詳細図、図５は図４のＶ部の拡大図、図６は異形環状断面形状の弾性部材を用いた場合の図４のＶ部の拡大図、図７は略弓状断面形状の弾性部材を用いた場合の図４のＶ部の拡大図、図８は略Ｖ字状断面形状の弾性部材を用いた場合の図４のＶ部の拡大図である。
【００４１】
本実施形態に係るＩＰＭモータ１は、ロータ２０のスリット孔２２及び永久磁石２３の断面形状と、永久磁石２３のロータコア２１への固定のために接着剤の代わりに弾性部材２６ａを用いている以外は、第１実施形態の構造と同様である。
【００４２】
スリット孔２２の断面形状は、第１実施形態と同様に、第１の外側面２２ａ、第１の内側面２２ｂ及び隙間部２２ｃを有する断面形状であるが、本実施形態においては、図４に示すように、第１の外側面２２ａ及び第１の内側面２２ｂが非平行であり、第１の外側面２２ａの両端部の間の傾斜による差がｈ_２であり、第１の内側面２２ｂの両端部の間の傾斜による差がｈ_１であり、従って、第１の外側面２２ａ及び第１の内側面２２ｂの一方の端部と第１の外側面２２ａ及び第１の内側面２２ｂの他方の端部との間の傾斜による差がｈ_１＋ｈ_２となるように、第１の外側面２２ａ及び第１の内側面２２ｂのいずれもが傾斜している。また、図５に示すように、第１の外側面２２ａと第１の内側面２２ｂとの間の間隔が広くなっている側の隙間部２２ｃには、後述する弾性部材２６ａを位置決めするための凹部２２ｄが形成されている。
【００４３】
この各スリット孔２２にそれぞれ挿入される永久磁石２３の断面形状は、第１実施形態と同様に、第２の外側面２３ａ及び第２の内側面２３ｂを有する断面形状であるが、本実施形態においては、図４に示すように、第２の外側面２３ａが第１の外側面２２ａに対応して、第１の外側面２２ａに実質的に平行となるように傾斜しており、第２の内側面２３ｂが第１の内側面２２ｂに対応して、第１の内側面２２ｂに実質的に平行となるように傾斜しており、上記のスリット孔２２の断面形状に対応するような断面形状となっている。
【００４４】
さらに、本実施形態においては、スリット孔２２の第１の外側面２２ａと第２の内側面２２ｂとの間の間隔が広くなっている側の隙間部２２ｃに、例えば合成樹脂等から成る非磁性の環状断面状を有する弾性部材２６ａが長手方向に沿って挿入されており、当該弾性部材２６ａは、隙間部２２ｃに形成された凹部２２ｄで位置決めされている。この弾性部材２６ａの弾性力により、接着剤を用いることなく、永久磁石２３がロータコア２１に固定されている。
【００４５】
なお、この弾性部材の断面形状は、上記のような環状断面形状に限定されず、他の断面形状をすることも可能である。例えば、当該弾性部材の断面形状を、図６に示す弾性部材２６ｂのように、異形環状の断面形状としても良い。このような断面形状の弾性部材２６ｂを採用した場合には、断面の四方において、当該弾性部材２６ｂがスリット孔２２の内壁面に当接するため、スリット孔２２の隙間部２２ｃに上記のような凹部２２ｄを設ける必要がない。また、当該弾性部材の断面形状を、図７に示す弾性部材２６ｃのような略弓状の断面形状や図８に示す弾性部材２６ｄのような略Ｖ字状の断面形状としても良い。これらの弾性部材２６ｃ、２６ｄを採用した場合には、当該弾性部材２６ｃ、２６ｄの一部が係合して効果的に弾性力を得るために、当該隙間部２２ｃに係合部２２ｅを形成する必要がある。また、弾性部材として、例えば合成樹脂等の非磁性の材料から成る棒状体やバネ等を用いても良い。
【００４６】
以下に、上記のような構造を有するロータの製造方法について説明する。
【００４７】
まず、第１実施形態と同様に、表面処理が施された永久磁石２３を、積層されたロータコア２１に形成されたスリット孔２２に軸方向に沿って挿入する。この際、永久磁石２３の第２の外側面２３ａ及び第２の内側面２３ｂと、スリット孔２２の第１の外側面２２ａ及び第１の内側面２２ｂとがそれぞれ平行となり、さらに、スリット孔２２の第１の外側面２２ａと第１の内側面２２ｂとの間隔が広くなっている側の隙間部２２ｃに永久磁石２３を寄せた姿勢で、永久磁石２３をスリット孔２２に挿入する。
【００４８】
次に、第１実施形態と同様に、スリット孔２２内において、挿入された永久磁石２３を、スリット孔２２の第１の外側面２２ａと第１の内側面２２ｂとの間の間隔が狭くなっている方向に移動させ、永久磁石２３の第２の外側面２３ａ及び第２の内側面２３ｂを、スリット孔２２の第１の外側面２２ａ及び第１の内側面２２ｂに当接させて、永久磁石２３をスリット孔２２の内壁面２２ａ、２２ｂに密着させる。
【００４９】
次に、図４に示すように、永久磁石２３が挿入されたスリット孔２２の第１の外側面２２ａと第１の内側面２２ｂとの間の間隔が広くなっている側の隙間部２２ｃに弾性部材２６ａを軸方向に挿入し、永久磁石２３をロータコア２１に固定する。
【００５０】
同様に、ロータコア２１に形成された他の３つの各スリット孔２２に永久磁石２３をそれぞれ挿入して移動させて、永久磁石２３をロータコア２１に対して固定することにより、図１及び図２に示すような４つ（２対）の永久磁石が埋め込まれたロータ２０が製造される。
【００５１】
以上のように、ロータコアのスリット孔に少なくとも一つの傾斜面を形成すると共に、当該スリット孔の少なくとも一つの傾斜面に対応した傾斜面を永久磁石に形成し、スリット孔に永久磁石を挿入し、これら傾斜面が相互に当接するように移動させて、弾性部材の弾性力により、永久磁石をロータコアに固定することにより、永久磁石がスリット孔に対して楔の作用して径方向に密着するので、永久磁石からロータコアの外周方向への磁束の通過性が向上し、ＩＰＭモータの高出力化を図ることが可能となる。
【００５２】
また、ロータコアと永久磁石とが密着することにより、永久磁石からロータコアへの伝熱が向上し、当該永久磁石の抜熱性が向上するので、ＩＰＭモータの高出力運転時における永久磁石の減磁を防止することが出来、ＩＰＭモータの高出力化を図ることが可能となる。
【００５３】
また、本実施形態では、永久磁石の枚数を増加させることなく、上記効果を得ることが出来る。
【００５４】
さらに、本実施形態に係るロータは、永久磁石の楔の作用により当該永久磁石がスリット孔に密着して固定されるので、ロータのアンバランスやトルクリプルなどの問題も解消される。
【００５５】
［第３実施形態］
図９は本発明の第３実施形態における図２のＩＩＩ部の詳細図であり、図９（Ａ）は永久磁石を挿入している状態を示す図、図９（Ｂ）は永久磁石を挿入した状態を示す図、図１０は本発明の第３実施形態の他の例を示す詳細図である。
【００５６】
本実施形態に係るＩＰＭモータ１は、ロータ２０のスリット孔２２の断面形状及び永久磁石２３の構造と、永久磁石２３のロータコア２１への固定のために接着剤の代わりに、弾性部材２６ａを用いている以外は、第１実施形態の構造と同様である。
【００５７】
本実施形態のロータコア２１に形成されたスリット孔２２の断面形状は、第１実施形態と同様に、第１の外側面２２ａ、第１の内側面２２ｂ及び隙間部２２ｃを有する断面形状であるが、本実施形態においては、図９（Ａ）及び図９（Ｂ）に示すように、第１の外側面２２ａと第１の内側面２２ｂとが実質的に平行となっている。また、本実施形態においては、第１の外側面２２ａ及び第１の内側面２２ｂの両端部に位置するいずれの隙間部２２ｃにも、弾性部材２６ａを位置決めするための凹部２２ｄが形成されている。
【００５８】
この各スリット孔２２にそれぞれ挿入される永久磁石２３は、図９（Ａ）及び図９（Ｂ）にように、径方向外側に位置する第１の永久磁石２４と、当該第１の永久磁石２５に対して径方向内側に位置する第２の永久磁石２５とから構成されている。
【００５９】
第１の永久磁石２４は、径方向外側に位置し、スリット孔２２の第１の外側面２２ａに対応した第２の外側面２４ａと、当該第２の外側面２４ａに対して径方向内側に位置し、当該第２の外側面２４ａに非平行である第２の内側面２４ｂとを持つ断面形状を有している。
【００６０】
第２の永久磁石２５は、径方向内側に位置し、スリット孔２２の第１の内側面２２ｂに対応して、当該第１の内側面２２ｂに実質的に平行な第３の内側面２５ｂと、当該第３の内側面２５ｂに非平行であり、第１の永久磁石２４の第２の内側面２４ｂに対応して、当該第２の内側面２４ｂに実質的に平行な第３の外側面２５ａとを持つ断面形状を有している。
【００６１】
これら第１及び第２の永久磁石２４、２５は、第１の永久磁石２４の第２の内側面２４ｂと、第２の永久磁石２５の第３の外側面２５ａとが相互に異極となっており、当該第２の内側面２４ｂと第３の外側面２５ａとが相互に対向するようにスリット孔２２に挿入されている。
【００６２】
さらに、本実施形態においては、スリット孔２２のいずれの隙間部２２ｃにも、例えば合成樹脂等から成る非磁性の環状断面状を有する弾性部材２６ａが長手方向に沿って挿入され、当該隙間部２２ｃに形成された凹部２２ｄにより位置決めされている。この弾性部材２６ａの弾性力により、接着剤を用いることなく、第１及び第２の永久磁石２４、２５から構成される永久磁石２３が、ロータコア２１に固定されている。
【００６３】
なお、スリット孔２２の隙間部２２ｃに挿入される弾性部材の断面形状は、上記のような環状断面形状に限定されず、第２実施形態と同様に、例えば弾性部材２６ｂ、２６ｃ、２６ｄのように、異形環状の断面形状、略弓状の断面形状、又は略Ｖ字状の断面形状としても良い。また、弾性部材として、例えば合成樹脂等の非磁性の材料から成る棒状体やバネ等を用いても良い。
【００６４】
さらに、本実施形態においては、図１０に示すように、スリット孔２２の断面形状を、第２の永久磁石２５の第３の外側面２５ａと第３の内側面２５ｂとの間の間隔が広くなっている側の隙間部２２ｃ’を小さく形成し、第２の永久磁石２５をスリット孔２２の内壁面に付き当てることにより位置決め及び固定し、第１の永久磁石２４の第２の外側面２４ａと第２の内側面２４ｂとの間の間隔が広くなっている側の隙間部２２ｃのみに弾性部材２６ａを挿入することにより、第１及び第２の永久磁石２４、２５をロータコア２１に固定しても良い。
【００６５】
以下に、上記のような構造を有するロータの製造方法について説明する。
【００６６】
まず、図９（Ａ）に示すように、表面処理が施された第１の永久磁石２４を、積層されたロータコア２１に形成されたスリット孔２２に軸方向に沿って挿入する。この際、第１の永久磁石２４の第２の外側面２４ａと、スリット孔２２の第１の外側面２２ａとが実質的に平行となり、さらに、第１の永久磁石２４の第２の外側面２４ａと第２の内側面２４ｂとの間の間隔が広くなっている側に、当該第１の永久磁石２４をスリット孔２２に対して寄せた姿勢で、第１の永久磁石２４をスリット孔２２に挿入する。
【００６７】
次に、表面処理が施された第２の永久磁石２５を、スリット孔２２に軸方向に沿って挿入する。この際、第２の永久磁石２５の第３の外側面２５ａと、第１の永久磁石２４の第２の内側面２４ｂとが実質的に平行となり、第２の永久磁石２５の第３の内側面２５ｂとスリット孔２２の第１の内側面２２ｂとが実質的に平行となり、さらに、第２の永久磁石２５の第３の外側面２５ａと第３の内側面２５ｂとの間の間隔が広くなっている側に、当該第２の永久磁石２５をスリット孔２２に対して寄せた姿勢で、第２の永久磁石２５をスリット孔２２に挿入する。
【００６８】
次に、スリット孔２２内において、第１の永久磁石２４の第２の内側面２４ｂと第２の永久磁石２５の第３の外側面２５ａとが当接するように、図９（Ａ）に示す矢印の方向に第１及び第２の永久磁石２４、２５を移動させて、第１及び第２の永久磁石２４、２５同士を密着させると共に、当該第１及び第２の永久磁石２４、２５をスリット孔２２の内壁面２２ａ、２２ｂに密着させる。
【００６９】
次に、図９（Ｂ）に示すように、第１及び第２の永久磁石２４、２５が挿入されたスリット孔２２の各隙間部２２ｃに弾性部材２６ａを軸方向に沿ってそれぞれ挿入し、第１及び第２の永久磁石２４、２５をロータコア２１に固定する。
【００７０】
同様に、ロータコア２１に形成された他の３つのスリット孔２２に第１及び第２の永久磁石２４、２５をそれぞれ挿入して、これらを当接させるように移動させ、永久磁石２３（第１及び第２の永久磁石２４、２５）をロータコア２１に対して固定することにより、図１及び図２に示すような４つ（２対）の永久磁石が埋め込まれたロータ２０が製造される。
【００７１】
なお、一方の隙間部に、図１０に示すような突当構造の隙間部２２ｃ’を採用した場合には、先に第２の永久磁石２５をスリット孔２２に挿入し、次に第１の永久磁石２４を挿入し、最後に他方の隙間部２２ｃにのみ弾性部材２６ａを挿入すれば良い。
【００７２】
以上のように、永久磁石を第１の永久磁石と第２の永久磁石とに分割し、当該第１及び第２の永久磁石において相互に対向する面をそれぞれ傾斜面とし、スリット孔への永久磁石の挿入時に、これら傾斜面を相互に当接させて、第１及び第２の永久磁石をロータコアに固定することにより、第１の永久磁石と第２の永久磁石とが楔のように作用して、第１の永久磁石と第２の永久磁石同士、及び、第１及び第２の永久磁石とスリット孔とが径方向に密着するので、永久磁石からロータコアの外周方向への磁束の透過性が向上し、ＩＰＭモータの高出力化を図ることが可能となる。
【００７３】
また、ロータコアと永久磁石とが密着することにより、永久磁石からロータコアへの伝熱が向上し、当該永久磁石の抜熱性が向上するので、ＩＰＭモータの高出力運転時における永久磁石の減磁を防止することが出来るので、ＩＰＭモータの高出力化を図ることが可能となる。
【００７４】
また、本実施形態では、ロータに埋め込まれた永久磁石の厚みを長手方向に沿って実質的に均一とすることが出来るので、実質的に均一な磁束を発生させることが可能となる。さらに、本実施形態では、永久磁石を２つに分割してそれぞれに傾斜面を具備させる構造としているため、スリット孔の形状を変更する必要がない。
【００７５】
さらに、本実施形態に係るロータは、永久磁石の楔の作用により当該永久磁石がスリット孔に密着して固定されるので、ロータのアンバランスやトルクリプルなどの問題も解消される。
【００７６】
［第４実施形態］
図１１は本発明の第４実施形態におけるロータの横断面図であり、図１１（Ａ）は永久磁石を挿入している状態を示す図、図１１（Ｂ）は永久磁石を挿入した状態を示す図、図１１（Ｃ）はエンドプレートを取り付けた状態を示す図、図１２は本発明の第４実施形態におけるロータの端部の要部断面図、図１３は図１２に示す弾性部材及びエンドプレートの分解斜視図、図１４は本発明の第４実施形態の他の例におけるロータの端部の要部断面図、図１５は図１４に示す弾性部材及びエンドプレートの分解斜視図である。
【００７７】
本実施形態に係るＩＰＭモータ１は、第１の永久磁石２４及び第２の永久磁石２５の形状、スリット孔２２の断面形状、及び、弾性部材２６ａの挿入位置が異なる以外は、第３実施形態の構造及び作用と同様である。
【００７８】
本実施形態の永久磁石２３を構成する第１の永久磁石２４及び第２の永久磁石２５は、第３実施形態と異なり、軸方向に沿った傾斜面を有している。
【００７９】
即ち、図１１（Ａ）〜（Ｃ）に示すように、本実施形態においては、第１の永久磁石２４の第２の内側面２４ｂが、第２の外側面２４ａに長手方向に沿って非平行となっている。
【００８０】
また、同図に示すように、第２の永久磁石２５の第３の外側面２５ａが、第２の内側面２４ｂに対応して、当該第２の内側面２４ｂに長手方向に沿って実質的に平行となっている。
【００８１】
これら第１及び第２の永久磁石２４、２５は、第３実施形態と同様に、第１の永久磁石２４の第２の内側面２４ｂと、第２の永久磁石２５の第３の外側面２５ａとが相互に異極となっており、当該第２の内側面２４ｂと第３の外側面２５ｂとが相互に対向するようにスリット孔２２に挿入されている。
【００８２】
なお、特に図示しないが、本実施形態においては、上述の第１〜第３実施形態と異なり、スリット孔２２に隙間部２２ｃを設けて、当該スリット孔２２の断面形状を永久磁石２３より大きく形成する必要はなく、磁束の短絡を防止するために必要なフラックスバリアを設けるだけで良い。
【００８３】
さらに、本実施形態においては、図１１（Ｃ）、図１２及び図１３に示すように、ロータコア２１の端部に取り付けられた一方のエンドプレート２７ａの内壁面に、例えば合成樹脂等から成る非磁性の、環状の断面形状であり、さらに全体として環状形状の環状弾性部材２９ａが挿入される円周状の溝２８が形成されている。これに対し、他方のエンドプレート２７ｂには、円周状の溝２８が形成されておらず、環状弾性部材２９ａが挿入されていない。そして、他方のエンドプレート２７ｂと、この弾性部材２９ａが挿入された一方のエンドプレート２７ａとがロータコア２１の端部にそれぞれ取り付けられている。この弾性部材２９ａの弾性力により、接着剤を用いることなく、第１及び第２の永久磁石２４、２５がロータコア２１に固定されている。なお、図１２に示すように、上記一方のエンドプレート２７ａの溝２９ａには、環状の弾性部材２９ａを位置決めするための凹部が形成されている。
【００８４】
この第１及び第２の永久磁石２４、２５をロータコア２１に固定するための弾性部材の断面形状は、上記のような環状の断面形状に限定されず、例えば、図１４及び図１５に示す環状弾性部材２９ｂのように、円周方向に沿って実質的に等間隔に配置され、一方の側に突出する複数の爪部を有するような断面形状としても良い。また、環状弾性部材として、一方のエンドプレート２７ａにバネ等を円周方向に沿って実質的に等間隔に配置しても良い。
【００８５】
以下に、上記のような構造を有するロータの製造方法について説明する。
【００８６】
まず、図１１（Ａ）及び図１１（Ｂ）に示すように、第１の永久磁石２４と第２の永久磁石２５とをスリット孔２２の相互に異なる側の開口から挿入する。この際、第１の永久磁石２４の第２の外側面２４ａとスリット孔２２の第１の外側面２２ａとが実質的に平行となり、第２の永久磁石２５の第３の内側面２５ｂとスリット孔２２の第１の内側面２２ｂとが実質的に平行となり、さらに、第１の永久磁石２４の第２の内側面２４ｂと第２の永久磁石２５の第３の外側面２５ａとが実質的に平行となるように、第１及び第２の永久磁石２４、２５をスリット孔２２にそれぞれ挿入する。同様に、ロータコア２１に形成された他の３つのスリット孔２２に第１及び第２の永久磁石２４、２５をそれぞれ挿入する。
【００８７】
全てのスリット孔２２に第１及び第２の永久磁石２４、２５が挿入されたら、図１１（Ｃ）に示すように、ロータコア２１の両端部にエンドプレート２７ａ、２７ｂをそれぞれ取り付ける。この際、まず、環状弾性部材２９ａが挿入されていないエンドプレート２７ｂを、ロータコア２１の端部に取り付ける。次に、環状弾性部材２９ａが挿入されたエンドプレート２７ａをロータコア２１の反対側の端部に取り付ける。このような順序の取付により、環状弾性部材２９ａが取り付けられていないエンドプレート２７ｂに、第１及び第２の永久磁石２４、２５が突き当てられ、エンドプレート２７ａに挿入された環状弾性部材２９ａの弾性力により、第１の永久磁石２４の第２の外側面２４ａとスリット孔２２の第１の外側面２２ａとが密着し、第２の永久磁石２５の第３の内側面２５ｂとスリット孔２２の第１の内側面２２ｂとが密着し、さらに、第１の永久磁石２４の第２の内側面２４ｂと第２の永久磁石２５の第３の外側面２５ａとが密着し、全ての第１及び第２の永久磁石２４、２５がロータコア２１に固定される。なお、エンドプレート２７ａ、２７ｂは、シャフト７に対し、圧入や接着、カシメなどの手法により固定される。
【００８８】
以上のように、永久磁石を第１の永久磁石と第２の永久磁石とに分割し、当該第１及び第２の永久磁石において相互に対向する面をそれぞれ傾斜面とし、スリット孔への永久磁石の挿入時に、これら傾斜面を相互に当接させて、第１及び第２の永久磁石をロータコアに固定することにより、第１の永久磁石と第２の永久磁石とが楔のように作用して、第１の永久磁石と第２の永久磁石同士、及び、第１及び第２の永久磁石とスリット孔とが径方向に密着するので、永久磁石からロータコアの外周方向への磁束の透過性が向上し、ＩＰＭモータの高出力化を図ることが可能となる。
【００８９】
また、ロータコアと永久磁石とが密着することにより、永久磁石からロータコアへの伝熱が向上し、当該永久磁石の抜熱性が向上するので、ＩＰＭモータの高出力運転時における永久磁石の減磁を防止することが出来、ＩＰＭモータの高出力化を図ることが可能となる。
【００９０】
また、本実施形態では、ロータに埋め込まれた永久磁石の厚みを長手方向に沿って実質的に均一とすることが出来るので、実質的に均一な磁束を発生させることが可能となる。さらに、本実施形態では、永久磁石を２つに分割してそれぞれに傾斜面を具備させる構造としているため、スリット孔の形状を変更する必要がない。
【００９１】
さらに、本実施形態に係るロータは、永久磁石の楔の作用により当該永久磁石がスリット孔に密着して固定されるので、ロータのアンバランスやトルクリプルなどの問題も解消される。
【００９２】
なお、以上説明した実施形態は、本発明の理解を容易にするために記載されたものであって、本発明を限定するために記載されたものではない。したがって、上記の実施形態に開示された各要素は、本発明の技術的範囲に属する全ての設計変更や均等物をも含む趣旨である。例えば、第２及び第３実施形態において、弾性部材を用いて永久磁石をロータコアに固定するように説明したが、本発明においては特にこれに限定されることなく、弾性部材を用いずに例えば第１実施形態のように接着剤を用いて永久磁石をロータコアに固定しても良い。
【図面の簡単な説明】
【図１】図１は、本発明の実施形態に係るＩＰＭモータの横断面図である。
【図２】図２は、図１のＩＩ−ＩＩ線に沿う断面図である。
【図３】図３は、本発明の第１実施形態における図２のＩＩＩ部の詳細図であり、図３（Ａ）は、永久磁石を挿入している状態を示す図であり、図３（Ｂ）は、永久磁石を挿入した状態を示す図である。
【図４】図４は、本発明の第２実施形態における図２のＩＩＩ部の詳細図である。
【図５】図５は、図４のＶ部の拡大図である。
【図６】図６は、異形環状断面形状の弾性部材を用いた場合の図４のＶ部の拡大図である。
【図７】図７は、略弓状断面形状の弾性部材を用いた場合の図４のＶ部の拡大図である。
【図８】図８は、略Ｖ字状断面形状の弾性部材用いた場合の図４のＶ部の拡大図である。
【図９】図９は、本発明の第３実施形態における図２のＩＩＩ部の詳細図であり、図９（Ａ）は、永久磁石を挿入している状態を示す図であり、図９（Ｂ）は永久磁石を挿入した状態を示す図である。
【図１０】図１０は、本発明の第３実施形態の他の例を示す図である。
【図１１】図１１は、本発明の第４実施形態におけるロータの横断面図であり、図１１（Ａ）は永久磁石を挿入している状態を示す図であり、図１１（Ｂ）は、永久磁石を挿入した状態を示す図であり、図１１（Ｃ）は、エンドプレートを取り付けた状態を示す図である。
【図１２】図１２は、本発明の第４実施形態におけるロータの端部の要部断面図である。
【図１３】図１３は、図１２に示す弾性部材及びエンドプレートの分解斜視図である。
【図１４】図１４は、本発明の第４実施形態の他の例におけるロータの端部の要部断面図である。
【図１５】図１５は、図１４に示す弾性部材及びエンドプレートの分解斜視図である。
【符号の説明】
１…ＩＰＭモータ
２…モータカバー
３…ハウジング
４…第１のブラケット
５…第２のブラケット
６…ベアリング
７…シャフト
１０…ステータ
１１…ティース
１２…巻線
２０…ロータ
２１…ロータコア
２２…スリット孔
２２ａ…第１の外側面
２２ｂ…第１の内側面
２２ｃ…隙間部
２２ｄ…凹部
２２ｅ…係合部
２３…永久磁石
２３ａ…第２の外側面
２３ｂ…第２の外側面
２４…第１の永久磁石
２４ａ…第２の外側面
２４ｂ…第２の内側面
２５…第２の永久磁石
２５ａ…第３の外側面
２５ｂ…第３の内側面
２６…弾性部材
２７…エンドプレート
２８…溝
２９…環状弾性部材[0001]
【Technical field】
The present invention relates to a rotor manufacturing method and a rotor that are preferable for use in a motor with embedded permanent magnets.
[0002]
[Background Art]
In a motor required to have a small size and high output, a rotor having a permanent magnet disposed inside a rotor core, and a stator having windings wound around an outer periphery of the rotor are provided. 2. Description of the Related Art A permanent magnet embedded motor (hereinafter simply referred to as an “IPM (Interior Permanent Magnet) motor”) that realizes a small size and high output by using a torque is known.
[0003]
The rotor used in such an IPM motor has a slit hole having a larger cross-sectional shape than a permanent magnet arranged inside the rotor, and a slit or a permanent magnet is inserted into the slit hole. The permanent magnet is fixed to the rotor core using such a method (see, for example, Patent Documents 1, 2, and 3).
[0004]
However, in such a method of fixing the permanent magnet, an adhesive layer or an air layer is interposed between the slit hole formed in the rotor core and the permanent magnet, and the adhesion between the rotor core and the permanent magnet is inferior. It becomes difficult for the magnetic flux in the outer circumferential direction of the rotor core to pass, and the output of the IPM motor cannot be increased.
[0005]
Further, in such a fixing method, the heat conductivity of the adhesive layer and the air layer interposed between the slit hole and the permanent magnet is lower than that of the rotor core, so that the heat generated by the permanent magnet is less likely to be transferred to the rotor core. Due to the poor heat removal of the magnet, the permanent magnet was demagnetized during high-power operation of the IPM motor, and it was necessary to limit the output.
[0006]
[Patent Document 1]
JP-A-2002-58185
[Patent Document 2]
JP 2000-175388 A
[Patent Document 3]
JP 2000-341920 A
[0007]
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a rotor manufacturing method and a rotor capable of increasing the output of an electric motor.
[0008]
In order to achieve the above object, according to the present invention, there is provided a rotor having a permanent magnet disposed in a magnet insertion hole formed in a rotor core along an axial direction, which is used in a permanent magnet embedded type electric motor. In the manufacturing method, the magnet insertion hole is formed to be larger than the permanent magnet, and has at least a first outer surface and a first inner surface that are not parallel to each other, and the permanent magnet is It has at least a second outer surface and a second inner surface respectively corresponding to a first outer surface and the first inner surface, and inserts the permanent magnet into the magnet insertion hole along the axial direction. Step, the permanent magnet is inserted into the magnet insertion hole such that the first outer surface and the second outer surface are brought into contact with the first inner surface and the second inner surface, respectively. The permanent magnet is moved relatively in the direction orthogonal to the axial direction. Method of manufacturing a rotor having at least a step of fixing to the rotor core is provided with.
[0009]
Further, according to the present invention, there is provided a rotor in which a permanent magnet is disposed in a magnet insertion hole formed in a rotor core along an axial direction, which is used for an electric motor on a permanent magnet embedded side, wherein the magnet insertion is performed. The hole has at least a first outer surface and a first inner surface that are non-parallel to each other, and the permanent magnet has a second outer surface and a second inner surface corresponding to the first inner surface, respectively. At least an outer side surface and a second inner side surface so that the first outer side surface and the second outer side surface are in contact with the first inner side surface and the second inner side surface, respectively. A rotor is provided in which the permanent magnet is inserted into the magnet insertion hole and the permanent magnet is fixed to the rotor core.
[0010]
In the present invention, in a rotor used for an electric motor in which a permanent magnet is embedded in a magnet insertion hole formed in a rotor core, at least one inclined surface is formed in the magnet insertion hole, and at least one of the magnet insertion holes is formed. An inclined surface corresponding to one inclined surface is formed on the permanent magnet, and when the permanent magnet is inserted into the magnet insertion hole, these inclined surfaces are brought into contact with each other to fix the permanent magnet to the rotor core.
[0011]
As a result, the permanent magnet acts as a wedge in close contact with the magnet insertion hole, so that the permeability of the magnetic flux from the permanent magnet to the outer peripheral direction of the rotor core is improved, and the output of the motor is increased. Can be achieved.
[0012]
In addition, since the permanent magnet and the rotor core are in close contact with each other, heat transfer from the permanent magnet to the rotor core is improved, and the heat removal of the permanent magnet is improved. It is possible to prevent magnetism and to increase the output of the electric motor.
[0013]
In order to further achieve the above object, according to the present invention, there is provided a rotor in which permanent magnets are arranged in magnet insertion holes formed in a rotor core along an axial direction and used in a permanent magnet embedded type electric motor. Wherein the magnet insertion hole is formed larger than the permanent magnet, has at least a first outer surface and a first inner surface, and the permanent magnet is located radially outward. A first permanent magnet; and a second permanent magnet located radially inward with respect to the first permanent magnet, wherein the first permanent magnet is a first permanent magnet corresponding to the first outer surface. 2 and at least a second inner surface that is non-parallel along a direction perpendicular to the axial direction of the second outer surface, wherein the second permanent magnet is A third outer surface corresponding to the side surface and a third inner surface corresponding to the first inner surface; Inserting the first permanent magnet into the magnet insertion hole in the axial direction, and positioning the second permanent magnet and the third outer surface so as to face each other. Inserting the second permanent magnet into the magnet insertion hole in the axial direction, and causing the first permanent magnet and the third permanent magnet to contact the second inner surface and the third outer surface. Moving the second permanent magnet relative to the magnet insertion hole in a direction orthogonal to the axial direction, and fixing the first permanent magnet and the second permanent magnet to the rotor core. At least a method for manufacturing a rotor is provided.
[0014]
Further, according to the present invention, there is provided a method for manufacturing a rotor in which permanent magnets are arranged in a magnet insertion hole formed in a rotor core along an axial direction, which is used for a permanent magnet embedded type electric motor, The magnet insertion hole has at least a first outer side surface and a first inner side surface, and the permanent magnet has a first permanent magnet located radially outward, and a diameter relative to the first permanent magnet. A second permanent magnet positioned on the inner side in the direction, wherein the first permanent magnet has a second outer surface corresponding to the first outer surface, and an axially extending second permanent magnet on the second outer surface. And a second non-parallel second inner surface, wherein the second permanent magnet has a third outer surface corresponding to the second inner surface and a third outer surface corresponding to the first inner surface. And a step for axially inserting the first permanent magnet into the magnet insertion hole. And inserting the second permanent magnet in the magnet insertion hole in the axial direction with the second inner side surface and the third outer side surface facing each other. Fixing the magnet and the second permanent magnet to the rotor core.
[0015]
Further, according to the present invention, there is provided a rotor used in an electric motor of a permanent magnet embedded type, in which a permanent magnet is arranged in a magnet insertion hole formed in a rotor core along an axial direction, wherein the magnet is inserted. The hole has at least a first outer side surface and a first inner side surface, and the permanent magnet includes a first permanent magnet positioned radially outward and a radially inner side relative to the first permanent magnet. A second permanent magnet located on the second permanent magnet, wherein the first permanent magnet has a second outer face corresponding to the first outer face and a second non-parallel to the second outer face. At least an inner side surface, wherein the second permanent magnet has at least a third outer side surface corresponding to the second inner side surface and a third inner side surface corresponding to the first inner side surface. And the permanent magnet is inserted into the magnet so that the second inner surface and the third outer surface come into contact with each other. It is inserted into a rotor of the first permanent magnet and said second permanent magnet is fixed to the rotor core is provided.
[0016]
According to the present invention, in a rotor used for an electric motor in which a permanent magnet is embedded in a magnet insertion hole formed in a rotor core, the permanent magnet is divided into a first permanent magnet and a second permanent magnet. The surfaces facing each other in the first and second permanent magnets are respectively inclined surfaces, and when the permanent magnets are inserted into the magnet insertion holes, these inclined surfaces are brought into contact with each other to form first and second permanent magnets. To the rotor core.
[0017]
As a result, the first permanent magnet and the second permanent magnet act like wedges and come into close contact with the first and second permanent magnets and the magnet insertion holes. The permeability of the magnetic flux in the outer peripheral direction is improved, and the output of the electric motor can be increased.
[0018]
Further, since the permanent magnet and the rotor core are in close contact with each other, heat transfer from the permanent magnet to the rotor core is improved, and the heat removal of the permanent magnet is improved, so that the permanent magnet is demagnetized during high-speed operation of the motor. Can be prevented, and the output of the electric motor can be increased.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
[First Embodiment]
FIG. 1 is a cross-sectional view of an IPM motor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1, and FIG. 3 is a section III of FIG. 3A is a diagram showing a state where a permanent magnet is inserted, and FIG. 3B is a diagram showing a state where a permanent magnet is inserted.
[0021]
First, the structure of an IPM motor using a rotor manufactured by the method according to the present embodiment will be described.
[0022]
As shown in FIGS. 1 and 2, the IPM motor 1 according to the present embodiment includes a motor cover 2 including a housing 3 and first and second brackets 4 and 5, and the first and second brackets 4 and 4. 5, a shaft 7 rotatably supported by bearings 6 attached to the motor 5, a stator 10 fixed to the inner peripheral surface of the housing 3 of the motor cover 2, and a gap fixed to the outer periphery of the shaft 7. A rotor (rotor) 20 is provided rotatably relative to the stator 10 with an air gap therebetween, and has a permanent magnet 23 embedded therein.
[0023]
The stator 10 of the IPM motor 1 has 24 teeth 11 projecting toward the inside of an annular shape and having slots formed therebetween, and each tooth 11 is wound with a winding 12. Have been.
[0024]
The rotor 20 of the IPM motor 1 has a rotor core (rotor core) 21 formed by laminating disk-shaped magnetic thin plates made of, for example, a silicon steel plate, and four slit holes (magnets) formed in the rotor core 21. It has a permanent magnet 23 inserted in the insertion hole 22 and end plates 27 attached to both ends of the rotor core 21 so as to cover each slit hole 22 in which the permanent magnet 23 is inserted. .
[0025]
The rotor core 21 of the rotor 20 has a through hole in the center of the rotor core 21 in which the shaft 7 is inserted. The through hole is arranged at substantially equal intervals along the circumferential direction. Are formed along with four slit holes (magnet insertion holes) 22.
[0026]
As shown in FIGS. 3A and 3B, the slit hole 22 has a larger cross-sectional shape than the permanent magnet 23 to be inserted, and the first outer surface 22a located radially outward. A first inner side surface 22b positioned radially inward with respect to the first outer side surface 22a and non-parallel to the first outer side surface 22a; a first inner side surface 22a; A cross-sectional shape which is located at both ends of the inner side surface 22b of the first inner surface 22b, functions as a flux barrier for preventing short-circuit of magnetic flux, and has a gap portion 22c formed for realizing a smooth insertion work of the permanent magnet 23. have.
[0027]
As shown in FIG. 3B, the first inner side surface 22b of each slit hole 22 has a distance between one end of the first outer side surface 22a and one end of the first inner side surface 22b, and The difference between the distance between the other end of the outer side surface 22a and the other end of the first inner side surface 22b is h. ₁ So as to be inclined with respect to the first outer surface 22a.
[0028]
Each of the permanent magnets 23 inserted into each of the slit holes 22 has a cross-sectional shape corresponding to the cross-sectional shape of the slit hole 22, and includes a second outer surface 23a located radially outside, It is located radially inward with respect to the second outer side surface 23a, and is substantially parallel to the first inner side surface 22b corresponding to the first inner side surface 22b of the slit hole 22; And a second inner side surface 23b that is not parallel to the outer side surface 23a. As shown in FIG. 3B, the second inner side surface 23b of each of the permanent magnets 23 is inclined with respect to the second outer side surface 23a, like the first inner side surface 22b of the slit hole 22. I have.
[0029]
Four (two pairs) permanent magnets 23 coated with an adhesive (not shown) or the like are inserted into each of the slit holes 22. The permanent magnets 23 have a magnetic pole on the second outer surface 23a and a magnetic pole on the second inner surface, and the inside of the rotor core 21 is such that the adjacent permanent magnets 23 have mutually different polarities. Each is arranged.
[0030]
As a material used for the permanent magnet 23, for example, a neodymium magnet is preferable from the viewpoint of rust prevention. Further, since the permanent magnet 23 is already magnetized and is inserted into the slit hole 22 while being in contact with the rotor core 21 due to the magnetic attraction of the permanent magnet 23, for example, nickel It is preferable to improve the strength by performing a surface treatment such as plating or epoxy coating, to prevent the permanent magnet 23 from cracking, chipping and peeling, and to perform rust prevention.
[0031]
In the IPM motor 1 configured as described above, when a current flows through the winding 12 wound on the stator 10, a rotating magnetic field is generated, and a torque is generated between the stator 10 and the rotor 20 by the rotating magnetic field. Thus, the rotor 20 fixed to the shaft 7 rotates relatively to the stator 10. The torque generated at this time is generated by the magnet torque due to the repulsion and attraction of the winding 12 of the stator 10 and the permanent magnet 23 of the rotor 20 and the difference between the magnetic permeability of the permanent magnet 23 and the magnetic permeability of the rotor core 21. And reactance torque.
[0032]
Hereinafter, a method of manufacturing the rotor having the above-described structure will be described.
[0033]
First, as shown in FIG. 3A, a permanent magnet 23 which has been subjected to a surface treatment and to which an adhesive has been applied is inserted along an axial direction into a slit hole 22 formed in the laminated rotor core 21. At this time, the second outer surface 23a of the permanent magnet 23 and the first outer surface 22a of the slit hole 22 become substantially parallel, and the second outer surface 23b of the permanent magnet 23 and the first The inner surface 22b is substantially parallel to the inner surface 22b, and the permanent magnet 23 is moved to the gap 22c on the side where the distance between the first outer surface 22a and the first inner surface 22b of the slit hole 22 is increased. In the posture, the permanent magnet 23 is inserted into the slit hole 22.
[0034]
Next, in the slit hole 22, the inserted permanent magnet is moved in the direction in which the distance between the first outer surface 22 a and the first inner surface 22 b of the slit hole 22 is reduced, that is, FIG. (A), the second outer side surface 23a of the permanent magnet 23 is brought into contact with the first outer side surface 22a of the slit hole 22, and the second inner side surface 23b of the permanent magnet 23 is moved. And the first inner side surface 22b of the slit hole 22 is brought into contact, and the permanent magnet 23 is fixed to the inner wall surfaces 22a and 22b of the slit hole 22 in close contact.
[0035]
Similarly, by inserting and moving the permanent magnets 23 into the other three slit holes 22 formed in the rotor core 21 and fixing the permanent magnets 23 to the rotor core 21, as shown in FIGS. The rotor 20 in which four (two pairs) permanent magnets are embedded is manufactured.
[0036]
As described above, at least one inclined surface is formed in the slit hole of the rotor core, and an inclined surface corresponding to at least one inclined surface of the slit hole is formed in the permanent magnet, and when the permanent magnet is inserted into the slit hole. By contacting these inclined surfaces with each other and fixing the permanent magnet to the rotor core, the permanent magnet comes into close contact with the slit hole in a radial direction like a wedge. Of the IPM motor can be improved, and the output of the IPM motor can be increased.
[0037]
In addition, since the rotor core and the permanent magnet are in close contact with each other, the heat transfer from the permanent magnet to the rotor core is improved, and the heat removal of the permanent magnet is improved, so that the demagnetization of the permanent magnet during high-power operation of the IPM motor is reduced. Thus, the output of the IPM motor can be increased.
[0038]
Further, in the present embodiment, the above effects can be obtained without increasing the number of permanent magnets.
[0039]
Furthermore, in the rotor according to the present embodiment, the permanent magnet is fixed in close contact with the slit hole by the action of the wedge of the permanent magnet, so that problems such as imbalance and torque ripple of the rotor are also eliminated.
[0040]
[Second embodiment]
4 is a detailed view of a part III in FIG. 2 according to a second embodiment of the present invention, FIG. 5 is an enlarged view of a part V in FIG. 4, and FIG. 6 is a view in FIG. FIG. 7 is an enlarged view of the V portion, FIG. 7 is an enlarged view of the V portion in FIG. 4 when an elastic member having a substantially arcuate cross section is used, and FIG. It is an enlarged view of the V section of FIG.
[0041]
The IPM motor 1 according to the present embodiment is different from the cross-sectional shape of the slit hole 22 of the rotor 20 and the permanent magnet 23 in that the elastic member 26a is used instead of the adhesive for fixing the permanent magnet 23 to the rotor core 21. Is the same as the structure of the first embodiment.
[0042]
Similar to the first embodiment, the cross-sectional shape of the slit hole 22 is a cross-sectional shape including a first outer surface 22a, a first inner surface 22b, and a gap portion 22c. As shown, the first outer surface 22a and the first inner surface 22b are non-parallel, and the difference due to the inclination between both ends of the first outer surface 22a is h. ₂ And the difference due to the inclination between both ends of the first inner side surface 22b is h. ₁ Therefore, the difference due to the inclination between one end of the first outer surface 22a and the first inner surface 22b and the other end of the first outer surface 22a and the first inner surface 22b is h ₁ + H ₂ Both the first outer surface 22a and the first inner surface 22b are inclined so that As shown in FIG. 5, the gap 22c on the side where the distance between the first outer side surface 22a and the first inner side surface 22b is wider is used to position an elastic member 26a described later. A recess 22d is formed.
[0043]
The cross-sectional shape of the permanent magnet 23 inserted into each of the slit holes 22 is a cross-sectional shape having a second outer side surface 23a and a second inner side surface 23b as in the first embodiment. In FIG. 4, as shown in FIG. 4, the second outer surface 23a is inclined so as to correspond to the first outer surface 22a and to be substantially parallel to the first outer surface 22a. Is inclined so as to be substantially parallel to the first inner surface 22b corresponding to the first inner surface 22b, and has a cross section corresponding to the cross-sectional shape of the slit hole 22 described above. It has a shape.
[0044]
Further, in the present embodiment, a non-magnetic material such as a synthetic resin or the like The elastic member 26a having an annular cross-sectional shape is inserted along the longitudinal direction, and the elastic member 26a is positioned by the concave portion 22d formed in the gap portion 22c. Due to the elastic force of the elastic member 26a, the permanent magnet 23 is fixed to the rotor core 21 without using an adhesive.
[0045]
Note that the cross-sectional shape of the elastic member is not limited to the above-described annular cross-sectional shape, and may have another cross-sectional shape. For example, the elastic member may have a modified annular cross-sectional shape, such as an elastic member 26b shown in FIG. When the elastic member 26b having such a cross-sectional shape is employed, since the elastic member 26b abuts on the inner wall surface of the slit hole 22 on all four sides of the cross section, the above-described concave portion is formed in the gap portion 22c of the slit hole 22. There is no need to provide 22d. Further, the cross-sectional shape of the elastic member may be a substantially arcuate cross-sectional shape like the elastic member 26c shown in FIG. 7 or a substantially V-shaped cross-sectional shape like the elastic member 26d shown in FIG. When these elastic members 26c and 26d are adopted, an engaging portion 22e is formed in the gap portion 22c in order to engage a part of the elastic members 26c and 26d to effectively obtain an elastic force. There is a need. Further, as the elastic member, for example, a rod-shaped body or a spring made of a non-magnetic material such as a synthetic resin may be used.
[0046]
Hereinafter, a method of manufacturing the rotor having the above-described structure will be described.
[0047]
First, similarly to the first embodiment, the surface-treated permanent magnet 23 is inserted along the axial direction into the slit hole 22 formed in the laminated rotor core 21. At this time, the second outer side surface 23a and the second inner side surface 23b of the permanent magnet 23 and the first outer side surface 22a and the first inner side surface 22b of the slit hole 22 are parallel to each other. The permanent magnet 23 is inserted into the slit hole 22 in such a manner that the permanent magnet 23 is moved closer to the gap 22c on the side where the distance between the first outer surface 22a and the first inner surface 22b is wider.
[0048]
Next, as in the first embodiment, the gap between the first outer side surface 22a and the first inner side surface 22b of the slit hole 22 is reduced in the inserted permanent magnet 23 in the slit hole 22. The permanent magnet 23 is brought into contact with the second outer surface 23a and the second inner surface 23b of the permanent magnet 23 with the first outer surface 22a and the first The magnet 23 is brought into close contact with the inner wall surfaces 22a and 22b of the slit hole 22.
[0049]
Next, as shown in FIG. 4, the gap portion 22 c on the side where the interval between the first outer side surface 22 a and the first inner side surface 22 b of the slit hole 22 in which the permanent magnet 23 is inserted is increased. The elastic member 26a is inserted in the axial direction, and the permanent magnet 23 is fixed to the rotor core 21.
[0050]
Similarly, by inserting and moving the permanent magnets 23 into the other three slit holes 22 formed in the rotor core 21, respectively, and fixing the permanent magnets 23 to the rotor core 21, FIGS. The rotor 20 in which four (two pairs) permanent magnets are embedded as shown is manufactured.
[0051]
As described above, at least one inclined surface is formed in the slit hole of the rotor core, and an inclined surface corresponding to at least one inclined surface of the slit hole is formed in the permanent magnet, and a permanent magnet is inserted into the slit hole. By moving these inclined surfaces so as to abut each other and fixing the permanent magnet to the rotor core by the elastic force of the elastic member, the permanent magnet comes into close contact with the slit hole in the radial direction by acting as a wedge. In addition, the permeability of the magnetic flux from the permanent magnet to the outer peripheral direction of the rotor core is improved, and the output of the IPM motor can be increased.
[0052]
In addition, since the rotor core and the permanent magnet are in close contact with each other, the heat transfer from the permanent magnet to the rotor core is improved, and the heat removal property of the permanent magnet is improved. Thus, the output of the IPM motor can be increased.
[0053]
Further, in the present embodiment, the above effects can be obtained without increasing the number of permanent magnets.
[0054]
Furthermore, in the rotor according to the present embodiment, the permanent magnet is fixed in close contact with the slit hole by the action of the wedge of the permanent magnet, so that problems such as imbalance and torque ripple of the rotor are also eliminated.
[0055]
[Third embodiment]
FIG. 9 is a detailed view of a part III in FIG. 2 according to the third embodiment of the present invention. FIG. 9A shows a state where a permanent magnet is inserted, and FIG. 9B shows a state where a permanent magnet is inserted. FIG. 10 is a detailed view showing another example of the third embodiment of the present invention.
[0056]
The IPM motor 1 according to the present embodiment uses an elastic member 26 a instead of an adhesive for fixing the cross-sectional shape of the slit hole 22 of the rotor 20 and the structure of the permanent magnet 23 and the permanent magnet 23 to the rotor core 21. Except for this, the structure is the same as that of the first embodiment.
[0057]
The cross-sectional shape of the slit hole 22 formed in the rotor core 21 of the present embodiment is a cross-sectional shape having a first outer side surface 22a, a first inner side surface 22b, and a gap portion 22c, as in the first embodiment. In the present embodiment, as shown in FIGS. 9A and 9B, the first outer side surface 22a and the first inner side surface 22b are substantially parallel. In the present embodiment, a concave portion 22d for positioning the elastic member 26a is formed in each of the gap portions 22c located at both ends of the first outer side surface 22a and the first inner side surface 22b. .
[0058]
As shown in FIGS. 9A and 9B, the permanent magnets 23 inserted into the respective slit holes 22 include a first permanent magnet 24 located on the radially outer side and the first permanent magnet And a second permanent magnet 25 located radially inward with respect to the second permanent magnet 25.
[0059]
The first permanent magnet 24 is located radially outward, and has a second outer surface 24a corresponding to the first outer surface 22a of the slit hole 22, and a radially inner side with respect to the second outer surface 24a. It has a cross-sectional shape having a second inner side surface 24b that is located and is non-parallel to the second outer side surface 24a.
[0060]
The second permanent magnet 25 is located radially inward, and corresponds to the first inner surface 22b of the slit hole 22, and has a third inner surface 25b substantially parallel to the first inner surface 22b. A third outer surface that is non-parallel to the third inner surface 25b and that is substantially parallel to the second inner surface 24b, corresponding to the second inner surface 24b of the first permanent magnet 24; 25a.
[0061]
In the first and second permanent magnets 24 and 25, the second inner surface 24b of the first permanent magnet 24 and the third outer surface 25a of the second permanent magnet 25 have mutually different polarities. The second inner side surface 24b and the third outer side surface 25a are inserted into the slit holes 22 such that they face each other.
[0062]
Further, in this embodiment, an elastic member 26a having a non-magnetic annular cross section made of, for example, a synthetic resin is inserted into any of the gaps 22c of the slit hole 22 along the longitudinal direction. Is positioned by the concave portion 22d formed at the bottom. Due to the elastic force of the elastic member 26a, the permanent magnet 23 including the first and second permanent magnets 24 and 25 is fixed to the rotor core 21 without using an adhesive.
[0063]
Note that the cross-sectional shape of the elastic member inserted into the gap portion 22c of the slit hole 22 is not limited to the above-described annular cross-sectional shape, and for example, like the elastic members 26b, 26c, and 26d as in the second embodiment. Alternatively, a modified annular cross section, a substantially arcuate cross section, or a substantially V-shaped cross section may be used. Further, as the elastic member, for example, a rod-shaped body or a spring made of a non-magnetic material such as a synthetic resin may be used.
[0064]
Further, in the present embodiment, as shown in FIG. 10, the cross-sectional shape of the slit hole 22 is set such that the distance between the third outer surface 25a and the third inner surface 25b of the second permanent magnet 25 is large. The second permanent magnet 25 is positioned and fixed by abutting the second permanent magnet 25 against the inner wall surface of the slit hole 22, and the second outer surface 24a of the first permanent magnet 24 is formed. The first and second permanent magnets 24 and 25 are fixed to the rotor core 21 by inserting the elastic member 26a only into the gap portion 22c on the side where the distance between the first and second inner side surfaces 24b is wider. May be.
[0065]
Hereinafter, a method of manufacturing the rotor having the above-described structure will be described.
[0066]
First, as shown in FIG. 9A, the first permanent magnet 24 having been subjected to the surface treatment is inserted in the slit hole 22 formed in the laminated rotor core 21 along the axial direction. At this time, the second outer surface 24a of the first permanent magnet 24 and the first outer surface 22a of the slit hole 22 become substantially parallel, and further, the second outer surface of the first permanent magnet 24 The first permanent magnet 24 is moved toward the slit hole 22 while the first permanent magnet 24 is moved toward the slit hole 22 on the side where the distance between the first permanent magnet 24 and the second inner side surface 24b is increased. Insert into
[0067]
Next, the surface-treated second permanent magnet 25 is inserted into the slit hole 22 along the axial direction. At this time, the third outer surface 25a of the second permanent magnet 25 and the second inner surface 24b of the first permanent magnet 24 become substantially parallel, and the third inner surface 24b of the second permanent magnet 25 The side surface 25b and the first inner side surface 22b of the slit hole 22 are substantially parallel, and the distance between the third outer side surface 25a and the third inner side surface 25b of the second permanent magnet 25 is wide. The second permanent magnet 25 is inserted into the slit hole 22 with the second permanent magnet 25 approaching the slit hole 22 on the side where the second permanent magnet 25 is located.
[0068]
Next, FIG. 9A shows a state in which the second inner side surface 24b of the first permanent magnet 24 and the third outer side surface 25a of the second permanent magnet 25 abut in the slit hole 22. The first and second permanent magnets 24 and 25 are moved in the direction of the arrow to bring the first and second permanent magnets 24 and 25 into close contact with each other, and the first and second permanent magnets 24 and 25 are It is brought into close contact with the inner wall surfaces 22a and 22b of the slit hole 22.
[0069]
Next, as shown in FIG. 9B, the elastic members 26a are inserted along the axial direction into the respective gaps 22c of the slit holes 22 into which the first and second permanent magnets 24 and 25 are inserted, respectively. The first and second permanent magnets 24 and 25 are fixed to the rotor core 21.
[0070]
Similarly, the first and second permanent magnets 24 and 25 are inserted into the other three slit holes 22 formed in the rotor core 21, respectively, and are moved so as to abut each other. By fixing the second permanent magnets 24 and 25) to the rotor core 21, the rotor 20 in which four (two pairs) permanent magnets are embedded as shown in FIGS. 1 and 2 is manufactured.
[0071]
In the case where a gap 22c 'having a striking structure as shown in FIG. 10 is employed in one of the gaps, the second permanent magnet 25 is inserted into the slit hole 22 first, and then the first permanent magnet 25 is inserted. The permanent magnet 24 may be inserted, and finally, the elastic member 26a may be inserted only into the other gap 22c.
[0072]
As described above, the permanent magnet is divided into the first permanent magnet and the second permanent magnet, and the surfaces facing each other in the first and second permanent magnets are respectively inclined surfaces, and the permanent When the magnets are inserted, the inclined surfaces are brought into contact with each other to fix the first and second permanent magnets to the rotor core, so that the first and second permanent magnets act like wedges. Since the first permanent magnet and the second permanent magnet and the first and second permanent magnets and the slit hole are in close contact with each other in the radial direction, the transmission of magnetic flux from the permanent magnet to the outer peripheral direction of the rotor core is performed. Performance is improved, and the output of the IPM motor can be increased.
[0073]
In addition, since the rotor core and the permanent magnet are in close contact with each other, the heat transfer from the permanent magnet to the rotor core is improved, and the heat removal of the permanent magnet is improved. This can prevent the IPM motor from increasing its output.
[0074]
Further, in the present embodiment, since the thickness of the permanent magnet embedded in the rotor can be made substantially uniform along the longitudinal direction, it is possible to generate a substantially uniform magnetic flux. Furthermore, in the present embodiment, since the permanent magnet is divided into two and each has a slope, it is not necessary to change the shape of the slit hole.
[0075]
Furthermore, in the rotor according to the present embodiment, the permanent magnet is fixed in close contact with the slit hole by the action of the wedge of the permanent magnet, so that problems such as imbalance and torque ripple of the rotor are also eliminated.
[0076]
[Fourth embodiment]
FIG. 11 is a cross-sectional view of a rotor according to a fourth embodiment of the present invention. FIG. 11A shows a state where a permanent magnet is inserted, and FIG. 11B shows a state where a permanent magnet is inserted. 11C is a diagram showing a state where an end plate is attached, FIG. 12 is a cross-sectional view of a main part of an end portion of a rotor according to a fourth embodiment of the present invention, and FIG. FIG. 14 is an exploded perspective view of an end plate, FIG. 14 is a sectional view of a main part of an end of a rotor in another example of the fourth embodiment of the present invention, and FIG. 15 is an exploded perspective view of an elastic member and an end plate shown in FIG. .
[0077]
The IPM motor 1 according to the present embodiment is different from the third embodiment except that the shapes of the first permanent magnet 24 and the second permanent magnet 25, the cross-sectional shape of the slit hole 22, and the insertion position of the elastic member 26a are different. The structure and operation are the same.
[0078]
Unlike the third embodiment, the first permanent magnet 24 and the second permanent magnet 25 that constitute the permanent magnet 23 of the present embodiment have inclined surfaces along the axial direction.
[0079]
That is, as shown in FIGS. 11A to 11C, in the present embodiment, the second inner side surface 24 b of the first permanent magnet 24 is not connected to the second outer side surface 24 a along the longitudinal direction. It is parallel.
[0080]
As shown in the figure, the third outer side surface 25a of the second permanent magnet 25 corresponds to the second inner side surface 24b and substantially extends along the longitudinal direction on the second inner side surface 24b. It is parallel to.
[0081]
These first and second permanent magnets 24 and 25 are, as in the third embodiment, a second inner side surface 24b of the first permanent magnet 24 and a third outer side surface 25a of the second permanent magnet 25. Have mutually different polarities, and are inserted into the slit holes 22 such that the second inner side surface 24b and the third outer side surface 25b face each other.
[0082]
Although not particularly shown, in the present embodiment, unlike the above-described first to third embodiments, a gap portion 22c is provided in the slit hole 22 so that the cross-sectional shape of the slit hole 22 is larger than that of the permanent magnet 23. It is only necessary to provide a flux barrier necessary for preventing a short circuit of the magnetic flux.
[0083]
Further, in the present embodiment, as shown in FIGS. 11 (C), 12 and 13, on the inner wall surface of one end plate 27a attached to the end of the rotor core 21, a non-conductive material such as synthetic resin is used. A circumferential groove 28 having a magnetic, annular cross-sectional shape and into which an annular elastic member 29a as a whole is inserted is formed. On the other hand, the circumferential groove 28 is not formed in the other end plate 27b, and the annular elastic member 29a is not inserted. The other end plate 27b and one end plate 27a into which the elastic member 29a is inserted are attached to the ends of the rotor core 21, respectively. The first and second permanent magnets 24 and 25 are fixed to the rotor core 21 by the elastic force of the elastic member 29a without using an adhesive. As shown in FIG. 12, a recess for positioning the annular elastic member 29a is formed in the groove 29a of the one end plate 27a.
[0084]
The cross-sectional shape of the elastic member for fixing the first and second permanent magnets 24 and 25 to the rotor core 21 is not limited to the above-described annular cross-sectional shape. Like the elastic member 29b, a cross-sectional shape having a plurality of claw portions arranged at substantially equal intervals along the circumferential direction and protruding to one side may be used. Further, as an annular elastic member, springs and the like may be arranged on one end plate 27a at substantially equal intervals along the circumferential direction.
[0085]
Hereinafter, a method of manufacturing the rotor having the above-described structure will be described.
[0086]
First, as shown in FIGS. 11A and 11B, the first permanent magnet 24 and the second permanent magnet 25 are inserted from openings of the slit holes 22 on different sides. At this time, the second outer surface 24a of the first permanent magnet 24 and the first outer surface 22a of the slit hole 22 become substantially parallel, and the third inner surface 25b of the second permanent magnet 25 is The first inner side surface 22b of the hole 22 becomes substantially parallel, and further, the second inner side surface 24b of the first permanent magnet 24 and the third outer side surface 25a of the second permanent magnet 25 become substantially parallel. The first and second permanent magnets 24 and 25 are respectively inserted into the slit holes 22 so as to be parallel to. Similarly, the first and second permanent magnets 24 and 25 are inserted into the other three slit holes 22 formed in the rotor core 21, respectively.
[0087]
When the first and second permanent magnets 24 and 25 are inserted into all the slit holes 22, end plates 27a and 27b are attached to both ends of the rotor core 21 as shown in FIG. At this time, first, the end plate 27b into which the annular elastic member 29a is not inserted is attached to the end of the rotor core 21. Next, the end plate 27a into which the annular elastic member 29a is inserted is attached to the opposite end of the rotor core 21. By the mounting in this order, the first and second permanent magnets 24 and 25 are abutted against the end plate 27b to which the annular elastic member 29a is not attached, and the annular elastic member 29a inserted into the end plate 27a is Due to the elastic force, the second outer surface 24a of the first permanent magnet 24 and the first outer surface 22a of the slit hole 22 come into close contact with each other, and the third inner surface 25b of the second permanent magnet 25 and the slit hole 22 The first inner side surface 22b of the first permanent magnet 24 and the third outer side surface 25a of the second permanent magnet 25 are in close contact with each other. And the second permanent magnets 24 and 25 are fixed to the rotor core 21. The end plates 27a and 27b are fixed to the shaft 7 by a method such as press-fitting, bonding, or caulking.
[0088]
As described above, the permanent magnet is divided into the first permanent magnet and the second permanent magnet, and the surfaces facing each other in the first and second permanent magnets are respectively inclined surfaces, and the permanent When the magnets are inserted, the inclined surfaces are brought into contact with each other to fix the first and second permanent magnets to the rotor core, so that the first and second permanent magnets act like wedges. Since the first permanent magnet and the second permanent magnet and the first and second permanent magnets and the slit hole are in close contact with each other in the radial direction, the transmission of magnetic flux from the permanent magnet to the outer peripheral direction of the rotor core is performed. Performance is improved, and the output of the IPM motor can be increased.
[0089]
In addition, since the rotor core and the permanent magnet are in close contact with each other, the heat transfer from the permanent magnet to the rotor core is improved, and the heat removal of the permanent magnet is improved, so that the demagnetization of the permanent magnet during high-power operation of the IPM motor is reduced. Thus, the output of the IPM motor can be increased.
[0090]
Further, in the present embodiment, since the thickness of the permanent magnet embedded in the rotor can be made substantially uniform along the longitudinal direction, it is possible to generate a substantially uniform magnetic flux. Furthermore, in the present embodiment, since the permanent magnet is divided into two and each has a slope, it is not necessary to change the shape of the slit hole.
[0091]
Furthermore, in the rotor according to the present embodiment, the permanent magnet is fixed in close contact with the slit hole by the action of the wedge of the permanent magnet, so that problems such as imbalance and torque ripple of the rotor are also eliminated.
[0092]
The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention. For example, in the second and third embodiments, the permanent magnet is fixed to the rotor core using the elastic member. However, the present invention is not particularly limited to this. The permanent magnet may be fixed to the rotor core using an adhesive as in one embodiment.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an IPM motor according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along the line II-II in FIG.
3 is a detailed view of a part III in FIG. 2 according to the first embodiment of the present invention, and FIG. 3A is a view showing a state where a permanent magnet is inserted; (B) is a diagram showing a state where a permanent magnet is inserted.
FIG. 4 is a detailed view of a part III in FIG. 2 according to a second embodiment of the present invention.
FIG. 5 is an enlarged view of a portion V in FIG. 4;
FIG. 6 is an enlarged view of a portion V in FIG. 4 when an elastic member having a modified annular cross-sectional shape is used.
FIG. 7 is an enlarged view of a portion V in FIG. 4 when an elastic member having a substantially arcuate cross-sectional shape is used.
FIG. 8 is an enlarged view of a portion V in FIG. 4 when an elastic member having a substantially V-shaped cross section is used.
9 is a detailed view of a part III in FIG. 2 according to a third embodiment of the present invention, and FIG. 9A is a view showing a state where a permanent magnet is inserted; (B) is a diagram showing a state where a permanent magnet is inserted.
FIG. 10 is a diagram showing another example of the third embodiment of the present invention.
11 is a cross-sectional view of a rotor according to a fourth embodiment of the present invention, FIG. 11 (A) is a view showing a state where a permanent magnet is inserted, and FIG. 11 (B) is And FIG. 11C is a diagram showing a state where a permanent magnet is inserted, and FIG. 11C is a diagram showing a state where an end plate is attached.
FIG. 12 is a sectional view of a main part of an end portion of a rotor according to a fourth embodiment of the present invention.
FIG. 13 is an exploded perspective view of the elastic member and the end plate shown in FIG.
FIG. 14 is a sectional view of a main part of an end of a rotor in another example of the fourth embodiment of the present invention.
FIG. 15 is an exploded perspective view of the elastic member and the end plate shown in FIG.
[Explanation of symbols]
1: IPM motor
2 ... Motor cover
3 ... Housing
4. First bracket
5 Second bracket
6 ... Bearing
7 ... Shaft
10 ... Stator
11 ... Tees
12 ... winding
20 ... rotor
21 ... Rotor core
22 ... Slit hole
22a: first outer surface
22b: First inner surface
22c ... gap
22d ... recess
22e ... engaging part
23 ... permanent magnet
23a: Second outer surface
23b: second outer surface
24 ... first permanent magnet
24a: second outer surface
24b 2nd inner surface
25 ... second permanent magnet
25a: Third outer surface
25b: Third inner surface
26 ... elastic member
27 ... End plate
28 ... groove
29 ... Circular elastic member

Claims

A method for manufacturing a rotor in which permanent magnets are arranged in magnet insertion holes formed along the axial direction in a rotor core, which is used for a permanent magnet embedded type electric motor,
The magnet insertion hole is formed larger than the permanent magnet, and has at least a first outer surface and a first inner surface that are not parallel to each other,
The permanent magnet has at least a second outer surface and a second inner surface corresponding to the first outer surface and the first inner surface, respectively.
Inserting the permanent magnet into the magnet insertion hole along the axial direction;
The permanent magnet is axially moved relative to the magnet insertion hole such that the first outer surface and the second outer surface are brought into contact with the first inner surface and the second inner surface, respectively. Relatively moving in a direction orthogonal to each other and fixing the permanent magnet to the rotor core.

The first outer surface and the first inner surface of the magnet insertion hole are non-parallel along a direction orthogonal to the axial direction,
An elastic member is inserted between the second outer side surface and the second inner side surface of the permanent magnet, and the surface on the side where the gap between the surface of the magnet insertion hole is widened, The method for manufacturing a rotor according to claim 1, further comprising a step of fixing a permanent magnet to the rotor core.

A method for manufacturing a rotor in which permanent magnets are arranged in magnet insertion holes formed along the axial direction in a rotor core, which is used for a permanent magnet embedded type electric motor,
The magnet insertion hole is formed larger than the permanent magnet, and has at least a first outer surface and a first inner surface,
The permanent magnet has a first permanent magnet located radially outward, and a second permanent magnet located radially inward with respect to the first permanent magnet,
The first permanent magnet has a second outer surface corresponding to the first outer surface, and a second inner surface that is non-parallel to the second outer surface along a direction orthogonal to the axial direction. Has at least
The second permanent magnet has at least a third outer surface corresponding to the second inner surface, and a third inner surface corresponding to the first inner surface.
Axially inserting the first permanent magnet into the magnet insertion hole;
Inserting the second permanent magnet into the magnet insertion hole in the axial direction with the second inner surface and the third outer surface facing each other;
The first permanent magnet and the second permanent magnet are moved relative to the magnet insertion hole in a direction perpendicular to the axial direction so that the second inner surface and the third outer surface come into contact with each other. And fixing the first permanent magnet and the second permanent magnet to the rotor core.

A surface on the side where the distance between the second outer surface of the first permanent magnet and the second inner surface is wider, or the third outer surface of the second permanent magnet; An elastic member is inserted between at least one of the surfaces on the side where the distance between the third inner surface is wide and the surface of the magnet insertion hole, and the first permanent magnet and the 4. The method for manufacturing a rotor according to claim 3, further comprising the step of fixing the two permanent magnets to the rotor core.

A method for manufacturing a rotor in which permanent magnets are arranged in magnet insertion holes formed along the axial direction in a rotor core, which is used for a permanent magnet embedded type electric motor,
The magnet insertion hole has at least a first outer surface and a first inner surface,
The permanent magnet has a first permanent magnet located radially outward, and a second permanent magnet located radially inward with respect to the first permanent magnet,
The first permanent magnet has at least a second outer surface corresponding to the first outer surface, and a second inner surface that is non-parallel to the second outer surface along the axial direction. ,
The second permanent magnet has at least a third outer surface corresponding to the second inner surface, and a third inner surface corresponding to the first inner surface.
Axially inserting the first permanent magnet into the magnet insertion hole;
Inserting the second permanent magnet in the magnet insertion hole in the axial direction with the second inner surface and the third outer surface facing each other, Fixing the second permanent magnet to the rotor core.

The rotor further has an end plate attached to both ends in the axial direction of the rotor, and closes the magnet insertion hole,
The surface on the side where the distance between the second outer surface of the first permanent magnet and the second inner surface is wider, or the third outer surface of the second permanent magnet and the third outer surface The method for manufacturing a rotor according to claim 5, further comprising a step of inserting an elastic member between at least one of the surfaces on the side where the distance between the third inner surface and the third inner surface is wide and the end plate. .

A rotor in which a permanent magnet is arranged in a magnet insertion hole formed along an axial direction in a rotor core, which is used for a motor on a permanent magnet embedded side,
The magnet insertion hole has at least a first outer surface and a first inner surface that are not parallel to each other,
The permanent magnet has at least a second outer surface and a second inner surface corresponding to the first outer surface and the first inner surface, respectively.
The permanent magnet is inserted into the magnet insertion hole such that the first outer surface and the second outer surface are in contact with the first inner surface and the second inner surface, respectively, and the permanent magnet is inserted into the permanent magnet. A rotor having a magnet fixed to the rotor core.

The second outer surface and the second inner surface of the permanent magnet are non-parallel along a direction orthogonal to the axial direction,
The rotor is inserted between a surface of the permanent magnet, on the side where the distance between the second outer surface and the second inner surface is increased, and a surface of the magnet insertion hole. The rotor according to claim 7, further comprising an elastic member.

A rotor in which permanent magnets are arranged in a magnet insertion hole formed in a rotor core along an axial direction, which is used for a permanent magnet embedded type electric motor,
The magnet insertion hole has at least a first outer surface and a first inner surface,
The permanent magnet has a first permanent magnet located radially outward, and a second permanent magnet located radially inward with respect to the first permanent magnet,
The first permanent magnet has at least a second outer surface corresponding to the first outer surface and a second inner surface that is non-parallel to the second outer surface.
The second permanent magnet has at least a third outer surface corresponding to the second inner surface, and a third inner surface corresponding to the first inner surface.
The permanent magnet is inserted into the magnet insertion hole such that the second inner surface and the third outer surface are in contact with each other, and the first permanent magnet and the second permanent magnet are connected to the rotor core. Rotor fixed to.

The second outer surface and the second inner surface of the first permanent magnet are non-parallel along a direction orthogonal to the axial direction,
The rotor has a surface on the side where the distance between the second outer surface and the second inner surface of the first permanent magnet is widened, or the third permanent magnet has a third surface. 10. An elastic member inserted between at least one of the surfaces on the side where the distance between the outer surface of the magnet and the third inner surface is widened and the surface of the magnet insertion hole. Rotor.

The second outer surface and the second inner surface of the first permanent magnet are non-parallel along the axial direction,
The rotor,
An end plate attached to both ends in the axial direction to close the magnet insertion hole,
The surface on the side where the distance between the second outer surface of the first permanent magnet and the second inner surface is wider, or the third outer surface of the second permanent magnet and the third outer surface The rotor according to claim 9, further comprising: an elastic member inserted between at least one of the surfaces on the side where the interval between the third inner surface and the third inner surface is wide, and the end plate.