JP2004274814A

JP2004274814A - Rotary electric machine

Info

Publication number: JP2004274814A
Application number: JP2003058622A
Authority: JP
Inventors: Hiroshi Ikeda; 浩池田; Hidekazu Shiomi; 英一塩見
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2003-03-05
Filing date: 2003-03-05
Publication date: 2004-09-30
Anticipated expiration: 2023-03-05
Also published as: JP3967275B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary electric machine having a ventilating system which straightens inflow velocity distribution to an axial fan and which can reduce leakage loss at a chip gap between the tip of the blade of the axial fan and an inside fan guide. <P>SOLUTION: The rotary electric machine includes the axial fan provided at the end of a rotor shaft for supplying and circulating a cooling medium toward a stator and a rotor, the inside fan guide having a cylinder disposed concentrically with the rotor shaft and surrounding the tip of the blade of the axial fan via the chip gap and an annular plate connected to the opening edge of the cylinder via an intermediate connecting tube, an outside fan guide for forming the suction channel of the axial fan together with the inside fan guide, and a cooler provided in the channel from an exhaust duct formed on the back surface of the stator to the suction channel of the axial fan for cooling the cooling medium. The rotary electric machine further includes a leakage control means for suppressing the leakage of the cooling medium from the pressure surface of the blade of the axial fan toward the negative pressure surface of the blade at the cylinder surrounding the tip of the blade of the axial fan at the inside fan guide. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、回転子軸端に設けた軸流ファンにより固定子コイルおよび回転子コイルを冷却するようにした通風システムを備えた回転電機に関する。
【０００２】
【従来の技術】
図１１は、横軸形の回転電機例えばタービン発電機の冷却システムを模式化して示す断面図である。
図１１において、１は回転子であり、回転子軸２と一塊に形成された回転子鉄心３と、この回転子鉄心３の周方向に切削加工して設けたスロット内に納めた回転子コイル（図示せず）とから構成され、回転子軸２は軸受４（軸受自体の構成は省略する）を介して回転自在に支持されている。
回転子鉄心３の両端に張り出した回転子コイル端部は、回転子１の回転による強大な遠心力で変形しないように保持環５で覆い保護している。
【０００３】
また、６は固定子全体を示すものであり、固定子枠７に固定された固定子鉄心８とその内径の周方向に設けたスロット内に納めた固定子コイル９とから構成されている。そして固定子鉄心９の外径側すなわち背面側と固定子枠７との間に形成された空間部を環状仕切り部１０によって２つの給気セクションと、３つの排気セクションとに区分している。なお、前記固定子鉄心８は固定子コイル９を冷却するための通風ダクト１１を軸方向に適当な間隔で挿入した間隔片によって多数形成しており、これらの通風ダクト１１は設けられている位置によって、給気セクションまたは排気セクションに連通するようになっている。
【０００４】
ところで、このタービン発電機通風システムは、回転子軸２両端に対称的に設けた押し込み形の軸流ファン１２と、回転子鉄心３内に形成した回転子通風ダクト１３と、固定子鉄心８の積層面に形成した前記固定子通風ダクト１１と、この固定子通風ダクト１１に連通する前記給気セクションおよび排気セクションと、この排気セクションから排気された温まった冷却媒体を冷却するクーラ１４と、このクーラ１４で冷却された冷却媒体を前記軸流ファン１２に導く流路１５とから構成している。
【０００５】
前記軸流ファン１２で加圧された冷却媒体は矢印の如く固定子通風ダクト１１、回転子通風ダクト１３、固定子６および回転子１の間のエアギャップ１６側に分岐して流れる。固定子６側に送気された冷却媒体は、固定子６の給気セクションの固定子通風ダクト１１を流れる過程で固定子コイル９を冷却し、エアギャップ１６を介して排気セクションの固定子通風ダクト１１を通ってクーラ１４に送られる。また、回転子１側への冷却媒体は、保持環５内の回転子コイル端部の隙間に流れ込み、回転子通風ダクト１３を通って固定子６、回転子１間のエアギャップ１６に排出される過程で、回転子コイル端部を含む回転子コイルを冷却し、回転子１の外周側の回転子１、固定子６間のエアギャップ１６部で固定子の給気セクションを通過した冷却媒体と合流し、固定子排気セクションの固定子通風ダクト１１を通って排気ダクト１７からクーラ１４に送られる。
【０００６】
一方、エアギャップ１６部への直接流入した冷却媒体は、エアギャップ１６で固定子側の給気セクションから流入した流れと、回転子１側を通過した流れと合流し、固定子７の排気セクションの固定子通風ダクト１１を通って排気ダクト１７からクーラ１４に送られる。
【０００７】
図１２は、タービン発電機の従来の軸流ファンまわりの冷却構造を示す断面図であり、（ａ）は回転子の軸線上半部を示す側面図であり、（ｂ）は同正面図である。
【０００８】
図１２において、クーラ１４で冷却された冷却媒体は流路１５を構成する内側ファンガイド１８および外側ファンガイド１９によって、軸中心部に向かって流れていた冷却媒体の流れの向きを軸方向へ変える。前記内側ファンガイド１８は、軸流ファン１４の翼先端部を囲繞する円筒部２０と、前記固定子枠７に直接または間接的に固定される環状板部２１と、両者間を接続する中間接続間２２とから構成されている。円筒部２０と環状板部２１とはなるべく滑らかに接続されるような構造にすることが望ましく、そのためは中間接続管２２を円弧状にしている例もあるが、多くは製造上の面から中間接続管２２としては、両端で口径の異なる複数個の中間接続管２２−１、２２−２…を溶接して円筒部２０と環状板部２１との間を接続し、内側ファンガイド１８を構成している。すなわち、円筒部２０と中間接続管２２−１、中間接続管２２−１と２２−２、中間接続管２２−２と環状板部２１とをそれぞれ溶接して接続している。
【０００９】
外側ファンガイド１９は、内側ファンガイド１８の環状板部２１に対して所定の距離を隔てて配置された環状板部２３と、軸受４の外周部を覆い軸流ファン１２側へ冷却媒体を導く部品２４とから構成されている。環状板部２３と冷却媒体を導く部品２４とは弧形状に滑らかに接続される場合もあるが、多くは前記内側ファンガイド１８と同様に、製造上の面から溶接により構成している。すなわち軸受４の外周部を覆う外側ファンガイド部品２４−１と２４−２、２４−２と環状板部２３とをそれぞれ溶接して接続している。
【００１０】
内側ファンガイド１８のコーナ部１８ｘ_３となる中間接続管２２−２と環状板部２１との溶接部では、冷却媒体の流れが図示破線のように、内側ファンガイド１８の壁面から剥離し、剥離位置から離れた個所で再び壁面に付着する。この再付着距離は冷却媒体流速、コーナ部の形状に依存する剥離の大きさの程度によって異なってくるが、発電機のコンパクト化にともなってコーナ部１８ｘ_３と軸流ファン１２の距離が短くなっており、軸流ファン１２の外周端近傍には再付着する前の剥離流れが流入する場合がある。
【００１１】
軸流ファン１２の理論ファンヘッドは軸流ファン前縁における相対速度ベクトルと周速度ベクトルと絶対速度ベクトルから成る速度三角形と軸流ファン後縁における相対速度ベクトルと周速度ベクトルと絶対速度ベクトルから成る速度三角形によって決まり、圧力損失としては形状に依存した損失のほか、軸流ファン１２の翼先端部と、対向する内側ファンガイド１８の円筒部２０との間に形成されたチップギャップ２５における冷媒漏れ現象による漏れ損失およびそれによって誘起される軸流ファン１２の翼間内２次流れ損失が大きな割合を占めている。
【００１２】
漏れ損失は翼圧力面側から負圧面側に向かった方向２６に圧力勾配が大きくなり、チップギャップ２５を通過して負圧面側に流れ込む冷却媒体が生じることに起因するため、チップギャップ２５の幅を通常５ｍｍのところ、これよりも狭くするなどチップギャップ２５の流れ抵抗を大きくして抑制することが現在試みられている。
【００１３】
しかし、チップギャップ２５幅を狭くすることは軸流ファン１２およびファンガイド１８の加工精度および組立精度を向上させなければならず、製造上高コストになるので、ギャップ幅が翼高さに対して大きい機種も多い。
【００１４】
軸流ファン１２に流入する流れが剥離している場合には、前縁における速度三角形の絶対速度ベクトル（軸流速）が小さくなるので迎え角が大きくなり、前縁でも流れが剥離し、翼間内の圧力損失増大につながるため、軸流ファン１２への流入速度分布を整流することがファン高効率化に必要である。
【００１５】
【発明が解決しようとする課題】
以上述べたように、固定子および回転子を冷却する軸流ファンに冷却媒体を導くための流路を外側ファンガイドおよび内側ファンガイドによって形成した従来の回転電機においては、回転電機のコンパクト化にともなって軸流ファン上流側のダクト直線部が短くなり、ファンへの流入速度分布の整流状態が悪化した場合、軸流ファンの翼先端部と内側ファンガイドの円筒部間のチップギャップにおける翼圧力面側から翼負圧面側への漏れ損失またはそれに誘起される２次流れ損失が大きくなるという課題を抱えている。
【００１６】
本発明は上記従来技術の課題を解決するためになされたもので、冷媒の軸流ファンへの流入速度分布を整流し、軸流ファンの翼先端部と内側ファンガイドとの間のチップギャップでの漏れ損失を低減することが可能な通風システムを備えた回転電機を提供することを目的とする。
【００１７】
【課題を解決するための手段】
上記の目的を達成するため、請求項１に係る回転電機の発明は、回転子軸の端部に設けられ冷却媒体を固定子および回転子に向けて送気し循環させる軸流ファンと、回転子軸に同心状に配置され前記軸流ファンの翼先端部をチップギャップを介して囲繞する円筒部およびこの円筒部の開口縁部に中間接続管を介して接続した環状板部からなる内側ファンガイドと、この内側ファンガイドとともに前記軸流ファンの吸込み流路を形成する外側ファンガイドと、前記固定子背面に形成された排気ダクトから前記軸流ファンの吸込み流路までの流路に設けられ前記冷却媒体を冷却するクーラとを備えた回転電機において、前記内側ファンガイドの軸流ファンの翼先端部を囲繞する円筒部に、前記軸流ファンの翼圧力面から翼負圧面に向かう冷媒漏れを抑制する漏れ抑制手段を設けたことを特徴とする。
【００１８】
また、請求項８に係わる回転電機の発明は、回転子軸の端部に設けられ冷却媒体を固定子および回転子に向けて送気し循環させる軸流ファンと、回転子軸に同心状に配置され前記軸流ファンの翼先端部をチップギャップを介して囲繞する円筒部およびこの円筒部の開口縁部に中間接続管を介して接続した環状板部からなる内側ファンガイドと、この内側ファンガイドとともに前記軸流ファンの吸込み流路を形成する外側ファンガイドと、前記固定子背面に形成された排気ダクトから前記軸流ファンの吸込み流路までの流路に設けられ前記冷却媒体を冷却するクーラとを備えた回転電機において、前記軸流ファンの吸込み流路を構成する内側ファンガイドのコーナ部を形成する軸流ファン直前の中間接続管を０〜３０度以内に傾斜させ、かつ傾斜させた円筒部と中間接続管の接続コーナ部から軸方向に５０ｍｍ以内の位置に軸流ファンを取付けることを特徴とする。
【００１９】
さらに、請求項９に係わる回転電機の発明は、回転子軸の端部に設けられ冷却媒体を固定子および回転子に向けて送気し循環させる軸流ファンと、回転子軸に同心状に配置され前記軸流ファンの翼先端部をチップギャップを介して囲繞する円筒部およびこの円筒部の開口縁部に中間接続管を介して接続した環状板部からなる内側ファンガイドと、この内側ファンガイドとともに前記軸流ファンの吸込み流路を形成する外側ファンガイドと、前記固定子背面に形成された排気ダクトから前記軸流ファンの吸込み流路までの流路に設けられ前記冷却媒体を冷却するクーラとを備えた回転電機において、前記内側ファンガイドの環状板部の軸流ファンの吸込み流路のコーナ部近傍に電機内部空間部に貫通する微小孔を設けたことを特徴とする。
【００２０】
さらにまた、請求項１０に係わる回転電機の発明は、回転子軸の端部に設けられ冷却媒体を固定子および回転子に向けて送気し循環させる軸流ファンと、回転子軸に同心状に配置され前記軸流ファンの翼先端部をチップギャップを介して囲繞する円筒部およびこの円筒部の開口縁部に中間接続管を介して接続した環状板部からなる内側ファンガイドと、この内側ファンガイドとともに前記軸流ファンの吸込み流路を形成する外側ファンガイドと、前記固定子背面に形成された排気ダクトから前記軸流ファンの吸込み流路までの流路に設けられ前記冷却媒体を冷却するクーラとを備えた回転電機において、内側ファンガイド部の軸流ファンの吸込み流路のコーナ部よりも回転子軸側に外側ファンガイド部を設置したことを特徴とする。
【００２１】
【発明の実施の形態】
以下、本発明に係わる回転電機の実施の形態について図面を参照して説明する。なお、各図を通じて同一要素には同一符号をつけることにより重複する説明を省略し、異なる部分を中心に説明する。
【００２２】
（第１の実施の形態）
図１は本発明に係わる回転電機の第１の実施の形態における要部の構造を示す断面図である。本実施の形態と、図１１および図１２に示す従来の技術との主な相違点は、本実施の形態では、軸流ファン１２の翼先端部を囲繞する内側ファンガイド１８の円筒部２０にチップギャップを通って冷媒が漏れるのを抑制する冷媒漏れ抑制手段を設けた点にある。
【００２３】
本実施の形態の冷媒漏れ抑制手段は、軸流ファン１２の翼圧力面から翼負圧面への冷媒漏れを抑制するために、内側ファンガイド１８の円筒部２０に微小孔２７を設け、軸流ファン１２の送気によって気圧の高まった発電機の内部空間部２８からチップギャップ２５に向けて冷却媒体を噴射させることによって、チップギャップ２５の圧力を発電機の内部空間部２８と連続させるようにしたものである。この冷却媒体の噴射量の調整は、微小孔２７の口径を調整することによって行う。微小孔２７の口径は大きすぎると、噴射量が多くなって効率が悪くなるので、ファンガイド円筒部２０からチップギャップ２５への冷媒噴射量が翼圧力面から翼負圧面への冷媒漏れを抑制するのに必要にして十分な量となるような大きさに選定する必要がある。このためには、内部空間部２８の圧力値からの圧力降下を見込んで、チップギャップ２５の幅よりも口径を小さくすることが望ましい。例えば、チップギャップ２５が２ｍｍの軸流ファンの場合、微小孔２７の口径は２ｍｍよりも小さい寸法（１．５ｍｍとか１ｍｍ）が好ましい。なお、微小孔２７は円筒部２０の軸方向および円周方向に複数個設けることが好ましい。
【００２４】
本実施の形態では、微小孔２７からのわずかな冷媒の流れによって通風損失が発生するが、チップギャップ２５の圧力が上昇するため、翼圧力面からこのチップギャップ２５への漏れ流れが抑制され、漏れ損失およびそれに誘起される翼間内２次流れ損失が低減される。
【００２５】
以上述べたように、本実施の形態によれば、軸流ファン１２の翼先端部をチップギャップ２５を介して囲繞する内側ファンガイド１８の円筒体２０に微小孔２７を設けて、電機内部空間部２８から冷媒をわずか噴射させることによって、内部空間部２８とチップギャップ２５の圧力が連続的になるので、チップギャップ２５の圧力は内部空間部２８の圧力から内側ファンガイド１８に設けた孔の通風損失を差し引いた圧力となり、チップギャップ２５の圧力は翼圧力面の圧力より局所的に大きくなる。
【００２６】
これにより、軸流ファン１２の翼圧力面から翼負圧面への周方向漏れ流れが抑制され、チップギャップでの漏れ損失が低減し、さらに漏れ流れの影響によるファン中央部の流れの二次損失を抑制することから、ファン効率を向上することができる。
【００２７】
また、チップギャップ２５幅が軸流ファン１２の翼高さに対して大きい場合にも過大な漏れ損失および翼間内２次流れを低減できるため、製造上のコストを低減できるという効果を得ることができる。
【００２８】
（第２の実施の形態）
図２は本発明に係わる回転電機の第２の実施の形態における要部の構造を示す断面図である。
第２の実施の形態は、第１の実施の形態を改良したもので、軸流ファンの翼間では軸方向に沿って圧力上昇するため、内側ファンガイドに設ける口径を軸方向に電機内部に向かって大きくなるように変化させ、軸流ファンの翼間での軸方向圧力上昇に対応した圧力分布となるようにしたものである。
【００２９】
すなわち、内側ファンガイド１８の円筒部２０に、電機内部に向かって口径が大きくなるように複数個の微小孔２７−１、２７−２、…２７−ｎを設けたものである。
【００３０】
微小孔２７の口径によって微小孔２７−１、２７−２、…２７−ｎにおける圧力損失を調整することができるため、翼間内の圧力上昇に対応させて翼前縁近傍では内部空間部２８からの圧力降下が大きくなるような小さな孔、翼後縁近傍では内部空間部２５と翼圧力面の圧力が同程度になるので前縁近傍より大きな孔を設けるのが望ましい。微小孔２７−１、２７−２、…２７−ｎの列は１列だけではなく、周方向に複数列設けるようにしてもよい。
【００３１】
本実施の形態によれば、微小孔２７−１、２７−２、…２７−ｎからのわずかな流れによる通風損失が発生するものの、内側ファンガイド円筒部２０に設ける微小孔２７−１、２７−２、…２７−ｎの径を軸方向に変化させることで各微小孔における通風損失が異なるため、軸流ファン１２の翼間内軸方向圧力上昇に対応した圧力分布とすることができる。この結果、翼圧力面からチップギャップ２５を介した漏れ流れをより一層抑制することができ、漏れ損失およびそれに誘起される翼間内２次流れ損失を低減させることができる。
【００３２】
（第３の実施の形態）
図３は本発明に係わる回転電機の第３の実施の形態における要部構造を示す断面図である。
第３の実施の形態は、第２の実施の形態を更に改良したもので、軸流ファン１２先端に対向する内側ファンガイド１８の円筒部２０に口径の異なる微小孔２７ａ−１、２７ａ−２、…２７ａ−ｎを複数翼負圧面から翼圧力面方向に傾斜させて設けたものである。なお、この微小孔２７ａ−１、２７ａ−２、…２７ａ−ｎは周方向にも複数設けることができる。
【００３３】
本実施の形態の場合、微小孔２７ａ−１、２７ａ−２、…２７ａ−ｎからのわずかな流れによる通風損失が発生するが、内部空間部２５から軸流ファン１２の翼先端部と内側ファンガイドの円筒部２０の間のチップギャップ２５への流入方向を、翼圧力面から翼負圧面への漏れ流れと逆の翼負圧面から翼圧力面としているので、一層漏れ流れを抑制する効果が大きい。
【００３４】
（第４の実施の形態）
図４は本発明に係わる回転電機の第４の実施の形態における要部構造を示す断面図である。
第４の実施の形態は、軸流ファン１２の翼先端部に対向する内側ファンガイド１８の円筒部２０に微小孔２７を設け、さらにこの微小孔２７を挟むように、チップギャップ２５側の周方向に凹凸部を形成するように複数の突条（または溝）２９を設けたものである。言い換えれば、微小孔２７は突条２９相互の溝に開けられているということである。
【００３５】
本実施の形態の場合、軸流ファン１２の翼先端部と内側ファンガイド１８の円筒部２０間のチップギャップ２５が周方向に凹凸部となる流路になるので、翼圧力面から翼負圧面に向かう漏れ流れ方向への通風抵抗（拡大縮小損失）が大きくなる。また、微小孔２７を通って内部空間部２５から流入してくる冷却媒体にとっても通風抵抗となるので、翼面内に微小孔２７からの流れが入り込みづらくなり、通風効果を上げることができる。
【００３６】
（第５の実施の形態）
図５は本発明に係わる回転電機の第５の実施の形態における要部構造を示す断面図である。
この第５の実施の形態は、前記第４の実施の形態を改良したものであり、翼弦線の傾きに対応して周方向に凹凸となるような傾斜した突条２９ａを設けたものである。
【００３７】
本実施の形態の場合、軸流ファン１２の翼先端部と内側ファンガイド１８の円筒部２０間のチップギャップ２５が翼先端近傍の翼断面の翼弦線の９０°方向に凹凸状の流路となるので、漏れ流れ方向への通風抵抗（拡大縮小損失）が第５の実施の形態よりも大きくなる。
【００３８】
しかも、突条２９ａまたは溝が翼弦線に沿っているため、軸流ファン１２先端と内側ファンガイド１８のチップギャップ２５の幅が翼弦線に沿って均一になり、翼圧力面から翼負圧面への漏れ流れが一層抑制される。
【００３９】
（第６の実施の形態）
図６は本発明に係わる回転電機の第６の実施の形態における要部構造を示す断面図である。
この第６の実施の形態は、前記第５の実施の形態を更に改良したものであり、内側ファンガイド１８の円筒部２０のチップギャップ２５側に翼先端近傍の翼断面の平均反り線の９０°方向に対応して周方向に凹凸部を形成するように、複数の曲がり突条２９ｂを設けたものである。
【００４０】
本実施の形態の場合、軸流ファン１２の先端と内側ファンガイド１８の円筒部２０間のチップギャップ２５が翼先端近傍の翼断面の平均反り線の９０°方向に凹凸する流路になるので、漏れ流れ方向への通風抵抗（拡大縮小損失）が大きくなり、突条２９ｂまたな溝が平均反り線に沿っているため、軸流ファン１２先端と内側ファンガイド１８の円筒部２０間のチップギャップ２５の幅が平均反り線に沿って均一になり、翼圧力面から翼負圧面への漏れ流れが抑制される。
【００４１】
（第７の実施の形態）
図７は本発明に係わる回転電機の第７の実施の形態における要部構造を示す断面図である。
第７の実施の形態は、流路１５内において前記円筒部２０とこれに接続される中間接続管２２−１とのコーナ部１８ｘ１から軸方向内部に向かって５０ｍｍ以内の位置に軸流ファン１２を設置するという条件のもとで、冷媒層流の壁面からの剥離が軸流ファン１２の効率に影響を及ぼさないように円筒部２０と中間接続管２２−１とのなす角度θ１を選定したものである。
【００４２】
図８はファンガイド傾斜角θ１とチップギャップ２５における冷媒層流の剥離領域δとの関係をシミュレーションした結果を表したグラフである。
図８は、シミュレーションによって軸流ファン１２の設置位置Ｘをコーナ部１８ｘ１から電機内部に向かって５０ｍｍとしたとき、ファンガイド傾斜角θ１をいろいろ変えていった場合の剥離領域（境界層厚さ）δの変化の様子を示す図である。この図８から明らかなように、θ１が３０度の前後で剥離領域（境界層厚さ）δが大きく変化することが確かめられた。剥離領域（境界層厚さ）δがチップギャップ２５の幅（通常、２〜５ｍｍ）よりも厚くなると、軸流ファン１２の効率が悪くなることから、効率を悪くしないためには剥離領域（境界層厚さ）δをチップギャップ２５の幅と同等にする必要がある。そのためには、ファンガイド傾斜角θ１を３０度以下にすれば良いことがわかる。
【００４３】
なお、図７において中間接続管２２−２を省略し、中間接続管２２−１と環状板部２１とが直接接続される構造の場合でも同様であり、逆に中間接続管２２−２と環状板部２１との間にさらにコーナ部があっても軸流ファン１２直前の中間接続管２２−１と円筒部２０とのなす角度θ１に関しては同様である。
【００４４】
以上述べたように、本実施の形態によれば、チップギャップ２５に冷却媒体が軸方向から流入しないので漏れ損失およびそれに誘起される翼間内２次流れ損失が低減され、軸流ファン１２効率を向上することができる。また、軸流ファン１２上流側の流れを整流するための助走距離（言い換えれば、剥離した流れが再付着するための助走距離）を長くとる必要がないのでコンパクト化につながるとともに、ファン上流側流路のコーナ部を形成する内側ファンガイド１８を流れの剥離が小さい弧形状とする必要がないので製造上のコストを低減するメリットが得られる。
【００４５】
（第８の実施の形態）
図９は本発明に係わる回転電機の第８の実施の形態における要部構造を示す断面図である。
第８の実施の形態は、軸流ファン１２上流側の流路にあるコーナ部１８ｘを形成する内側ファンガイド１８において流れが大きく剥離することが予測されるコーナ部（環状板部２１と中間接続管２２−２とのなす角度θ２が中間接続管２２−２と中間接続管２２−１とのなす角度θ３や中間接続管２２−１と円筒部２０のなす角度θよりも大きいコーナ部）の上流側位置する環状板部２１において、上流側に傾斜させた微小孔３０を設けるものである。この傾斜微小孔３０は環状板部２１の周方向に複数個設けるか、あるいは複数の中間接続管２２−１、２２−２および環状板部２１の軸方向に複数設けるようにしてもよい。
【００４６】
この実施の形態の場合、傾斜微小孔３０からのわずかな冷媒の噴射によって、流路１５内を流れる冷却媒体が環状板部２１の壁面で撹乱されるので、その壁面に沿った流れにはならなくなり、コーナ部での剥離が緩和される。環状板部２１の壁面近傍での流れの乱れは大きくなるが剥離の程度が緩和されるため、軸流ファン１２先端のファン性能が急激に低下することを回避することができる。
【００４７】
以上述べたように、本実施の形態によれば、軸流ファンの吸込み流路のコーナ部で大きく流れが剥離した場合にも翼先端近傍の性能低下を抑制できるので、軸流ファン１２上流側の流れを整流するための助走距離（剥離した流れが再付着するための助走距離）を長くとる必要がなくコンパクト化につながるとともに、軸流ファン上流側流路のコーナ部を形成する内側ファンガイド１８を流れの剥離が小さい弧形状とする必要がないので製造上のコストを低減できるメリットが得られる。
【００４８】
（第９の実施の形態）
図１０は本発明に係わる回転電機の第９の実施の形態における要部構造を示す断面図である。
第９の実施の形態は、外側ファンガイド１９の環状板部２３と軸受４の外周部を覆う外側ファンガイド部品２４−２との接続部であるコーナ部１９ｘを、内側ファンガイド１８の環状板部２１と中間接続管２２−２とを接続するコーナ部１８ｘ３よりも回転子軸２に近づけるようにしたものである。すなわち、回転軸２表面からコーナ部１９ｘまでの距離Ｌ２と、回転軸２表面からコーナ部１８ｘ３までの距離Ｌ１とはＬ１＞Ｌ２という関係にする。
【００４９】
流路１５は半径方向に向いているので外径側から内径側（回転子軸２側）に向かって流路断面積が小さくなる縮流になっており、冷却媒体流速が徐々に速くなる。内側ファンガイド１８における流れの剥離はまず環状板部２１と中間接続管２２−２とを接続するコーナ部１８ｘ３で生じるため、剥離の程度を抑制するために流速が小さいことが望ましい。
【００５０】
この実施の形態の場合、外側ファンガイドのコーナ部を内側ファンガイドのコーナ部よりも回転子軸側に配置するようにしたので、軸流ファン上流側流路断面の急縮流が内側ファンガイドのコーナ部の後流となり、内側ファンガイドのコーナ部での流れの大きな剥離を抑制することができる。
なお、この実施の形態の場合も、内部ファンガイド１８の円筒部２０に微小孔２７を設けているが、微小孔２７を設けることは必須要件ではない。
【００５１】
【発明の効果】
以上述べたように、本発明によれば、軸流ファンによって圧力上昇した内側ファンガイドの外径側の内部空間部２８と、軸流ファン先端周縁部および内側ファンガイド間のチップギャップ２５の圧力を連続的にすることができ、その結果、翼圧力面から翼負圧面への周方向への冷媒漏れを抑制することができるので、チップギャップ２５の漏れ損失およびそれに誘起される２次流れ損失が低減された高効率ファンを有する通風システムを備えた回転電機を提供することができる。
【図面の簡単な説明】
【図１】本発明による回転電機の第１の実施の形態における要部構造を示す断面図。
【図２】本発明による回転電機の第２の実施の形態における要部構造を示す断面図。
【図３】本発明による回転電機の第３の実施の形態における要部構造を示す断面図。
【図４】本発明による回転電機の第４の実施の形態における要部構造を示す断面図。
【図５】本発明による回転電機の第５の実施の形態における要部構造を示す断面図。
【図６】本発明による回転電機の第６の実施の形態における要部構造を示す断面図。
【図７】本発明による回転電機の第７の実施の形態における要部構造を示す断面図。
【図８】内側ファンガイドの傾斜角と境界層の厚さの関係を示す図。
【図９】本発明による回転電機の第８の実施の形態における要部構造を示す断面図。
【図１０】本発明による回転電機の第９の実施の形態における要部構造を示す断面図。
【図１１】タービン発電機全体の冷却構造を示す断面図。
【図１２】従来のタービン発電機の要部構造を示す断面図。
【符号の説明】
１…回転子、２…回転子軸、３…回転子鉄心、４…軸受、５…保持環、６…固定子、７…固定子枠、８…固定子鉄心、９…固定子コイル、１０…環状仕切り部、１１…固定子通風ダクト、１２…軸流ファン、１３…回転子通風ダクト、１４…クーラ、１５…流路、１６…エアギャップ、１７…排気ダクト、１８…内側ファンガイド、１８ｘ…流れの剥離個所、１９…外側ファンガイド、２０…円筒部、２１…環状板部、２２−１，２２−２…中間接続管、２３…環状板部、２４−１，２４−２…外側ファンガイド部品、２５…チップギャップ、２６…翼圧力面側から負圧面側に向かう冷媒漏れ、２７…微小孔、２８…回転電機の内部空間、２９，２９ａ，２９ｂ…周方向の凹凸部、３０…傾斜微小孔。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rotating electric machine including a ventilation system configured to cool a stator coil and a rotor coil by an axial fan provided at an end of the rotor shaft.
[0002]
[Prior art]
FIG. 11 is a cross-sectional view schematically illustrating a cooling system for a horizontal-axis type rotating electric machine, for example, a turbine generator.
In FIG. 11, reference numeral 1 denotes a rotor, a rotor core 3 formed integrally with the rotor shaft 2, and a rotor coil housed in a slot formed by cutting the rotor core 3 in the circumferential direction. (Not shown), and the rotor shaft 2 is rotatably supported via a bearing 4 (the configuration of the bearing itself is omitted).
The ends of the rotor coil projecting from both ends of the rotor core 3 are covered and protected by a retaining ring 5 so as not to be deformed by a strong centrifugal force due to the rotation of the rotor 1.
[0003]
Reference numeral 6 denotes the whole stator, which comprises a stator core 8 fixed to a stator frame 7 and a stator coil 9 housed in a slot provided in a circumferential direction of an inner diameter of the stator core. The space formed between the outer diameter side, that is, the rear side of the stator core 9 and the stator frame 7 is divided into two air supply sections and three exhaust sections by an annular partitioning section 10. The stator core 8 is formed by a plurality of ventilation ducts 11 for cooling the stator coils 9 at appropriate intervals in the axial direction, and the ventilation ducts 11 are provided at positions where the ventilation ducts 11 are provided. Thus, it is connected to the air supply section or the exhaust section.
[0004]
By the way, this turbine generator ventilation system includes a push-type axial fan 12 symmetrically provided at both ends of the rotor shaft 2, a rotor ventilation duct 13 formed in the rotor core 3, and a stator core 8. The stator ventilation duct 11 formed on the lamination surface, the air supply section and the exhaust section communicating with the stator ventilation duct 11, a cooler 14 for cooling a warmed cooling medium exhausted from the exhaust section, The cooling medium is cooled by the cooler 14 and the flow path 15 guides the cooling medium to the axial fan 12.
[0005]
The cooling medium pressurized by the axial fan 12 branches and flows toward the air gap 16 between the stator ventilation duct 11, the rotor ventilation duct 13, the stator 6, and the rotor 1 as shown by arrows. The cooling medium supplied to the stator 6 cools the stator coil 9 in the process of flowing through the stator ventilation duct 11 in the air supply section of the stator 6, and the stator ventilation in the exhaust section through the air gap 16. It is sent to the cooler 14 through the duct 11. Further, the cooling medium to the rotor 1 side flows into the gap between the ends of the rotor coils in the holding ring 5 and is discharged to the air gap 16 between the stator 6 and the rotor 1 through the rotor ventilation duct 13. In the process of cooling, the rotor coil including the rotor coil end is cooled, and the cooling medium that has passed through the air supply section of the stator at the air gap 16 between the rotor 1 and the stator 6 on the outer peripheral side of the rotor 1. And is sent from the exhaust duct 17 to the cooler 14 through the stator ventilation duct 11 of the stator exhaust section.
[0006]
On the other hand, the cooling medium that has flowed directly into the air gap 16 merges with the flow that has flowed in from the air supply section on the stator side in the air gap 16 and the flow that has passed through the rotor 1 side, and the exhaust section of the stator 7 has Is sent from the exhaust duct 17 to the cooler 14 through the stator ventilation duct 11.
[0007]
12A and 12B are cross-sectional views showing a conventional cooling structure around an axial fan of a turbine generator. FIG. 12A is a side view showing an upper half of an axis of a rotor, and FIG. is there.
[0008]
In FIG. 12, the cooling medium cooled by the cooler 14 changes the direction of the flow of the cooling medium flowing toward the axial center portion in the axial direction by the inner fan guide 18 and the outer fan guide 19 constituting the flow path 15. . The inner fan guide 18 includes a cylindrical portion 20 surrounding the blade tip of the axial fan 14, an annular plate portion 21 fixed directly or indirectly to the stator frame 7, and an intermediate connection for connecting the two. And an interval 22. It is desirable that the cylindrical portion 20 and the annular plate portion 21 be connected as smoothly as possible. For this purpose, there is an example in which the intermediate connecting pipe 22 is formed in an arc shape. As the connecting pipe 22, a plurality of intermediate connecting pipes 22-1, 22-2... Having different diameters at both ends are welded to connect between the cylindrical portion 20 and the annular plate portion 21, thereby forming the inner fan guide 18. are doing. That is, the cylindrical portion 20 and the intermediate connection tube 22-1, the intermediate connection tubes 22-1 and 22-2, and the intermediate connection tube 22-2 and the annular plate portion 21 are connected by welding.
[0009]
The outer fan guide 19 covers the outer peripheral portion of the bearing 4 and guides the cooling medium to the axial fan 12 side, with the annular plate portion 23 disposed at a predetermined distance from the annular plate portion 21 of the inner fan guide 18. And a component 24. In some cases, the annular plate portion 23 and the component 24 for guiding the cooling medium are smoothly connected in an arc shape, but in many cases, like the inner fan guide 18, they are formed by welding from the viewpoint of manufacturing. That is, the outer fan guide parts 24-1 and 24-2 and 24-2 covering the outer peripheral portion of the bearing 4 are welded and connected to the annular plate portion 23, respectively.
[0010]
Corner portion 18x of inner fan guide 18 ₃ In the welded portion between the intermediate connecting pipe 22-2 and the annular plate portion 21, the flow of the cooling medium separates from the wall surface of the inner fan guide 18 as shown by the broken line in FIG. Adhere to. The reattachment distance varies depending on the flow rate of the cooling medium and the degree of separation which depends on the shape of the corner portion. ₃ The distance between the axial fan 12 and the axial fan 12 is short, and a separation flow before re-adhesion may flow into the vicinity of the outer peripheral end of the axial fan 12.
[0011]
The theoretical fan head of the axial fan 12 comprises a speed triangle consisting of a relative velocity vector, a peripheral velocity vector, and an absolute velocity vector at the leading edge of the axial fan, and a relative speed vector, a peripheral velocity vector, and an absolute velocity vector at the trailing edge of the axial fan. The pressure loss is determined by the speed triangle, and the pressure loss is not only a shape-dependent loss, but also a refrigerant leakage in a tip gap 25 formed between the blade tip of the axial fan 12 and the cylindrical portion 20 of the inner fan guide 18 facing the same. The leakage loss due to the phenomenon and the secondary flow loss in the space between the blades of the axial flow fan 12 induced by the phenomenon account for a large proportion.
[0012]
The leakage loss is caused by the fact that the pressure gradient increases in the direction 26 from the blade pressure surface side to the suction surface side, and a cooling medium that flows through the chip gap 25 and flows into the suction surface side is generated. It is currently attempted to increase the flow resistance of the chip gap 25 by, for example, making it smaller than 5 mm at a distance of 5 mm.
[0013]
However, reducing the width of the chip gap 25 requires improving the machining accuracy and the assembly accuracy of the axial fan 12 and the fan guide 18 and increasing the manufacturing cost. There are many large models.
[0014]
When the flow flowing into the axial fan 12 is separated, the absolute velocity vector (axial flow velocity) of the velocity triangle at the leading edge is reduced, so that the angle of attack is increased. Therefore, it is necessary to rectify the inflow velocity distribution to the axial fan 12 in order to increase the efficiency of the fan.
[0015]
[Problems to be solved by the invention]
As described above, in the conventional rotating electric machine in which the flow path for guiding the cooling medium to the axial fan for cooling the stator and the rotor is formed by the outer fan guide and the inner fan guide, the size of the rotating electric machine is reduced. If the straight section of the duct on the upstream side of the axial fan becomes shorter and the commutation state of the inflow velocity distribution into the fan deteriorates, the blade pressure at the tip gap between the tip of the axial fan and the cylindrical section of the inner fan guide There is a problem that the leakage loss from the surface side to the blade suction side or the secondary flow loss induced by the leakage loss increases.
[0016]
The present invention has been made in order to solve the above-mentioned problems of the prior art, and rectifies the distribution of the inflow velocity of the refrigerant into the axial flow fan, so that the tip gap between the blade tip of the axial flow fan and the inner fan guide can be used. It is an object of the present invention to provide a rotating electric machine provided with a ventilation system capable of reducing a leakage loss of a motor.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, an invention of a rotating electric machine according to claim 1 includes an axial fan provided at an end portion of a rotor shaft for feeding and circulating a cooling medium toward a stator and a rotor, and a rotating fan. An inner fan comprising a cylindrical portion disposed concentrically with the slave shaft and surrounding the blade tip of the axial flow fan via a tip gap and an annular plate portion connected to an opening edge of the cylindrical portion via an intermediate connecting pipe. A guide, an outer fan guide that forms a suction flow path for the axial fan together with the inner fan guide, and a flow path from an exhaust duct formed on the back of the stator to a suction flow path for the axial flow fan. In a rotating electric machine having a cooler for cooling the cooling medium, refrigerant leakage from a blade pressure surface of the axial flow fan toward a blade negative pressure surface to a cylindrical portion surrounding a blade tip of the axial flow fan of the inner fan guide. Characterized in that a suppressing leakage suppressing means.
[0018]
Further, the invention of the rotating electric machine according to claim 8 is an axial fan provided at an end of the rotor shaft for feeding and circulating the cooling medium toward the stator and the rotor, and concentrically with the rotor shaft. An inner fan guide comprising a cylindrical portion arranged to surround the blade tip of the axial flow fan via a tip gap, and an annular plate portion connected to an opening edge of the cylindrical portion via an intermediate connecting pipe; An outer fan guide that forms a suction flow passage of the axial fan together with the guide; and a flow passage from an exhaust duct formed on the back of the stator to a suction flow passage of the axial flow fan to cool the cooling medium. In the rotating electric machine having the cooler, the intermediate connecting pipe immediately before the axial fan forming the corner portion of the inner fan guide constituting the suction flow path of the axial fan is inclined within 0 to 30 degrees, and And wherein the mounting the axial fan from the connecting corners of the cylindrical portion and the intermediate connecting pipe that is positioned within 50mm in the axial direction.
[0019]
Furthermore, the invention of the rotating electric machine according to claim 9 is an axial fan provided at the end of the rotor shaft for feeding and circulating the cooling medium toward the stator and the rotor, and concentrically with the rotor shaft. An inner fan guide comprising a cylindrical portion arranged to surround the blade tip of the axial flow fan via a tip gap, and an annular plate portion connected to an opening edge of the cylindrical portion via an intermediate connecting pipe; An outer fan guide that forms a suction flow passage of the axial fan together with the guide; and a flow passage from an exhaust duct formed on the back of the stator to a suction flow passage of the axial flow fan to cool the cooling medium. In a rotary electric machine having a cooler, a minute hole penetrating into an electric machine internal space is provided in the annular plate portion of the inner fan guide near a corner of a suction flow passage of an axial fan.
[0020]
Furthermore, the invention of a rotating electric machine according to claim 10 is an axial fan provided at the end of the rotor shaft for feeding and circulating the cooling medium toward the stator and the rotor, and concentric with the rotor shaft. An inner fan guide comprising a cylindrical portion disposed around the tip of the axial flow fan via a tip gap and an annular plate portion connected to an opening edge of the cylindrical portion via an intermediate connecting pipe; An outer fan guide that forms a suction flow path of the axial fan together with a fan guide, and a cooling medium that is provided in a flow path from an exhaust duct formed on a back surface of the stator to a suction flow path of the axial flow fan and cools the cooling medium. In the rotating electric machine having the cooler, the outer fan guide portion is provided closer to the rotor shaft than the corner portion of the suction flow path of the axial fan of the inner fan guide portion.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a rotating electric machine according to the present invention will be described with reference to the drawings. In the drawings, the same elements will be denoted by the same reference numerals, without redundant description, and different parts will be mainly described.
[0022]
(First Embodiment)
FIG. 1 is a sectional view showing a structure of a main part of a rotating electric machine according to a first embodiment of the present invention. The main difference between this embodiment and the prior art shown in FIGS. 11 and 12 is that, in this embodiment, the cylindrical portion 20 of the inner fan guide 18 surrounding the tip of the blade of the axial flow fan 12 is provided. The present invention is characterized in that a refrigerant leakage suppressing means for suppressing leakage of the refrigerant through the chip gap is provided.
[0023]
The refrigerant leakage suppressing means of the present embodiment is provided with a minute hole 27 in the cylindrical portion 20 of the inner fan guide 18 in order to suppress refrigerant leakage from the blade pressure surface of the axial fan 12 to the blade negative pressure surface. The pressure of the chip gap 25 is made to be continuous with the internal space 28 of the generator by injecting the cooling medium from the internal space 28 of the generator whose pressure has been increased by the air supply of the fan 12 toward the chip gap 25. It was done. The adjustment of the injection amount of the cooling medium is performed by adjusting the diameter of the minute holes 27. If the diameter of the micro holes 27 is too large, the injection amount increases and the efficiency deteriorates. Therefore, the refrigerant injection amount from the fan guide cylindrical portion 20 to the tip gap 25 suppresses the refrigerant leakage from the blade pressure surface to the blade negative pressure surface. It is necessary to select a size that is necessary and sufficient for the process. To this end, it is desirable to make the diameter smaller than the width of the tip gap 25 in consideration of the pressure drop from the pressure value of the internal space 28. For example, in the case of an axial fan having a chip gap 25 of 2 mm, the diameter of the minute holes 27 is preferably smaller than 2 mm (1.5 mm or 1 mm). It is preferable that a plurality of micro holes 27 are provided in the axial direction and the circumferential direction of the cylindrical portion 20.
[0024]
In the present embodiment, ventilation loss occurs due to a small flow of the refrigerant from the minute holes 27, but since the pressure in the tip gap 25 increases, leakage flow from the blade pressure surface to the tip gap 25 is suppressed, Leakage loss and secondary flow loss between blades induced thereby are reduced.
[0025]
As described above, according to the present embodiment, the minute hole 27 is provided in the cylindrical body 20 of the inner fan guide 18 surrounding the tip of the blade of the axial flow fan 12 via the tip gap 25, and Since the pressure in the internal space 28 and the chip gap 25 becomes continuous by slightly injecting the refrigerant from the portion 28, the pressure in the chip gap 25 is reduced from the pressure in the internal space 28 by the pressure of the hole provided in the inner fan guide 18. As a result, the pressure in the tip gap 25 is locally larger than the pressure on the blade pressure surface.
[0026]
Thereby, the circumferential leakage flow from the blade pressure surface to the blade suction surface of the axial flow fan 12 is suppressed, the leakage loss at the tip gap is reduced, and the secondary loss of the flow at the center of the fan due to the influence of the leakage flow. , The fan efficiency can be improved.
[0027]
Further, even when the width of the tip gap 25 is larger than the blade height of the axial fan 12, an excessive leakage loss and a secondary flow between blades can be reduced, so that an effect that manufacturing cost can be reduced can be obtained. Can be.
[0028]
(Second embodiment)
FIG. 2 is a sectional view showing a structure of a main part of a rotary electric machine according to a second embodiment of the present invention.
The second embodiment is an improvement of the first embodiment. Since the pressure increases along the axial direction between the blades of the axial fan, the bore provided on the inner fan guide is axially provided inside the electric machine. The pressure distribution is changed so as to increase toward the center, so that a pressure distribution corresponding to an increase in the axial pressure between the blades of the axial fan is obtained.
[0029]
That is, a plurality of micro holes 27-1, 27-2,... 27-n are provided in the cylindrical portion 20 of the inner fan guide 18 so that the diameter increases toward the inside of the electric machine.
[0030]
Since the pressure loss in the minute holes 27-1, 27-2,... 27-n can be adjusted by the diameter of the minute holes 27, the internal space 28 near the leading edge of the blade corresponds to the rise in pressure between the blades. It is desirable to provide a small hole that increases the pressure drop from the blade, and a hole larger than the vicinity of the leading edge because the pressure in the internal space 25 and the blade pressure surface near the trailing edge of the blade becomes almost the same. The rows of the micro holes 27-1, 27-2,... 27-n are not limited to one row, and a plurality of rows may be provided in the circumferential direction.
[0031]
According to the present embodiment, although the ventilation loss occurs due to the slight flow from the minute holes 27-1, 27-2,..., 27-n, the minute holes 27-1, 27 provided in the inner fan guide cylindrical portion 20 are formed. By changing the diameters of −2,..., 27-n in the axial direction, the ventilation loss in each of the minute holes is different, so that a pressure distribution corresponding to the pressure increase in the axial direction between the blades of the axial flow fan 12 can be obtained. As a result, the leakage flow from the blade pressure surface through the tip gap 25 can be further suppressed, and the leakage loss and the secondary flow loss between blades induced by the leakage loss can be reduced.
[0032]
(Third embodiment)
FIG. 3 is a cross-sectional view showing a main structure of a rotating electric machine according to a third embodiment of the present invention.
The third embodiment is a further improvement of the second embodiment. Micro holes 27a-1 and 27a-2 having different diameters are formed in the cylindrical portion 20 of the inner fan guide 18 facing the tip of the axial fan 12. , ... 27a-n are provided so as to be inclined from the blade negative pressure surface in the blade pressure surface direction. .. 27a-n can be provided in the circumferential direction.
[0033]
In the case of the present embodiment, although a ventilation loss occurs due to a slight flow from the minute holes 27a-1, 27a-2,... 27a-n, the blade tip of the axial fan 12 and the inner fan Since the direction of flow into the tip gap 25 between the cylindrical portions 20 of the guides is set to the blade pressure surface from the blade suction surface opposite to the leakage flow from the blade pressure surface to the blade suction surface, the effect of further suppressing the leakage flow is improved. large.
[0034]
(Fourth embodiment)
FIG. 4 is a cross-sectional view illustrating a main structure of a rotary electric machine according to a fourth embodiment of the present invention.
In the fourth embodiment, a minute hole 27 is provided in the cylindrical portion 20 of the inner fan guide 18 facing the tip of the blade of the axial flow fan 12, and a peripheral hole on the chip gap 25 side is sandwiched so as to sandwich the minute hole 27. A plurality of ridges (or grooves) 29 are provided so as to form uneven portions in the directions. In other words, the micro holes 27 are formed in the grooves between the ridges 29.
[0035]
In the case of the present embodiment, the tip gap 25 between the blade tip of the axial flow fan 12 and the cylindrical portion 20 of the inner fan guide 18 becomes a flow path that becomes an uneven portion in the circumferential direction. , The ventilation resistance (expansion / reduction loss) in the direction of the leak flow toward the air flow increases. In addition, since the cooling medium flowing from the internal space portion 25 through the minute holes 27 also serves as ventilation resistance, the flow from the minute holes 27 does not easily enter the blade surface, and the ventilation effect can be improved.
[0036]
(Fifth embodiment)
FIG. 5 is a cross-sectional view showing a main structure of a rotary electric machine according to a fifth embodiment of the present invention.
The fifth embodiment is an improvement of the fourth embodiment, and is provided with an inclined ridge 29a which becomes uneven in the circumferential direction corresponding to the inclination of the chord line. is there.
[0037]
In the case of the present embodiment, the tip gap 25 between the blade tip of the axial flow fan 12 and the cylindrical portion 20 of the inner fan guide 18 has an uneven flow path in the 90 ° direction of the chord line of the blade cross section near the blade tip. Therefore, the ventilation resistance (expansion / reduction loss) in the leak flow direction is larger than that in the fifth embodiment.
[0038]
Moreover, since the ridges 29a or grooves are along the chord line, the width of the tip gap 25 between the tip of the axial fan 12 and the inner fan guide 18 is uniform along the chord line, and the blade pressure is reduced from the blade pressure surface. The leakage flow to the pressure surface is further suppressed.
[0039]
(Sixth embodiment)
FIG. 6 is a cross-sectional view showing a main structure of a rotary electric machine according to a sixth embodiment of the present invention.
The sixth embodiment is a further improvement of the fifth embodiment. The sixth embodiment has an average warpage of 90% near the tip of the blade near the tip gap 25 of the cylindrical portion 20 of the inner fan guide 18. A plurality of bent ridges 29b are provided so as to form uneven portions in the circumferential direction corresponding to the ° direction.
[0040]
In the case of the present embodiment, the tip gap 25 between the tip of the axial fan 12 and the cylindrical portion 20 of the inner fan guide 18 becomes a flow path that is uneven in the 90 ° direction of the average warpage of the blade section near the blade tip. Since the ventilation resistance (expansion / reduction loss) in the leak flow direction is increased and the ridges 29b or grooves are along the average warpage, the tip between the tip of the axial fan 12 and the cylindrical portion 20 of the inner fan guide 18 is formed. The width of the gap 25 becomes uniform along the average warpage line, and leakage flow from the blade pressure surface to the blade suction surface is suppressed.
[0041]
(Seventh embodiment)
FIG. 7 is a cross-sectional view showing a main structure of a rotary electric machine according to a seventh embodiment of the present invention.
The seventh embodiment is different from the first embodiment in that the axial fan 12 is positioned within 50 mm inward in the axial direction from the corner portion 18x1 of the cylindrical portion 20 and the intermediate connection pipe 22-1 connected to the cylindrical portion 20 in the flow path 15. Under the condition that the laminar flow of the refrigerant is separated from the wall surface, the angle θ1 between the cylindrical portion 20 and the intermediate connection pipe 22-1 is selected so that the efficiency of the axial fan 12 is not affected. Things.
[0042]
FIG. 8 is a graph showing the result of simulating the relationship between the fan guide inclination angle θ1 and the separation region δ of the laminar refrigerant flow in the chip gap 25.
FIG. 8 shows a peeling area (thickness of a boundary layer) when the installation position X of the axial fan 12 is set to 50 mm from the corner 18x1 toward the inside of the electric machine by simulation, and the fan guide inclination angle θ1 is variously changed. FIG. 7 is a diagram illustrating a state of change of δ. As is clear from FIG. 8, it was confirmed that the peeling region (boundary layer thickness) δ greatly changed around θ1 of about 30 degrees. If the separation region (boundary layer thickness) δ is greater than the width of the tip gap 25 (usually 2 to 5 mm), the efficiency of the axial fan 12 deteriorates. (Layer thickness) δ needs to be equal to the width of the chip gap 25. It can be seen that the fan guide inclination angle θ1 should be set to 30 degrees or less for that purpose.
[0043]
In FIG. 7, the intermediate connecting pipe 22-2 is omitted, and the same applies to a structure in which the intermediate connecting pipe 22-1 and the annular plate portion 21 are directly connected. The same applies to the angle θ1 formed by the intermediate connecting pipe 22-1 just before the axial flow fan 12 and the cylindrical part 20, even if there is a corner part between the cylindrical part 20 and the plate part 21.
[0044]
As described above, according to the present embodiment, since the cooling medium does not flow into the chip gap 25 from the axial direction, the leakage loss and the secondary flow loss between blades induced by the leakage loss are reduced, and the efficiency of the axial fan 12 is improved. Can be improved. In addition, it is not necessary to increase the approach distance for rectifying the flow on the upstream side of the axial flow fan 12 (in other words, the approach distance for the separated flow to reattach). Since it is not necessary to form the inner fan guide 18 forming the corner of the road into an arc shape with small flow separation, there is an advantage of reducing manufacturing costs.
[0045]
(Eighth embodiment)
FIG. 9 is a cross-sectional view showing a main structure of a rotary electric machine according to an eighth embodiment of the present invention.
In the eighth embodiment, the corner portion (the annular connection between the annular plate portion 21 and the intermediate connection portion 21) where the flow is expected to largely separate in the inner fan guide 18 that forms the corner portion 18 x in the flow path on the upstream side of the axial flow fan 12. The angle θ2 formed by the pipe 22-2 and the angle θ3 formed by the intermediate connection pipe 22-2 and the intermediate connection pipe 22-1 and the angle θ formed by the intermediate connection pipe 22-1 and the cylindrical section 20 are larger. In the annular plate portion 21 located on the upstream side, a minute hole 30 inclined toward the upstream side is provided. A plurality of the inclined minute holes 30 may be provided in the circumferential direction of the annular plate portion 21, or a plurality of the inclined minute holes 30 may be provided in the axial direction of the plurality of intermediate connecting pipes 22-1 and 22-2 and the annular plate portion 21.
[0046]
In the case of this embodiment, since the cooling medium flowing in the flow path 15 is disturbed by the wall surface of the annular plate portion 21 due to the slight injection of the refrigerant from the inclined minute holes 30, the flow along the wall surface does not occur. As a result, peeling at corners is eased. The turbulence of the flow near the wall surface of the annular plate portion 21 increases, but the degree of separation is reduced, so that the fan performance at the tip of the axial fan 12 can be prevented from sharply lowering.
[0047]
As described above, according to the present embodiment, even when the flow largely separates at the corner of the suction flow path of the axial fan, the performance degradation near the blade tip can be suppressed. It is not necessary to increase the approach distance for rectifying the flow of air (the approach distance for the separated flow to reattach), leading to compactness and an inner fan guide that forms the corner of the axial fan upstream flow path Since it is not necessary to form the arc 18 into an arc shape with a small flow separation, there is an advantage that the manufacturing cost can be reduced.
[0048]
(Ninth embodiment)
FIG. 10 is a cross-sectional view showing a main part structure of a rotary electric machine according to a ninth embodiment of the present invention.
In the ninth embodiment, the corner portion 19x, which is a connection portion between the annular plate portion 23 of the outer fan guide 19 and the outer fan guide component 24-2 covering the outer peripheral portion of the bearing 4, is changed to the annular plate of the inner fan guide 18. It is configured to be closer to the rotor shaft 2 than the corner portion 18x3 that connects the portion 21 and the intermediate connection pipe 22-2. That is, the distance L2 from the surface of the rotating shaft 2 to the corner portion 19x and the distance L1 from the surface of the rotating shaft 2 to the corner portion 18x3 have a relationship of L1> L2.
[0049]
Since the flow path 15 is oriented in the radial direction, the flow path has a contraction in which the flow path cross-sectional area decreases from the outer diameter side toward the inner diameter side (the rotor shaft 2 side), and the flow velocity of the cooling medium gradually increases. Since the separation of the flow in the inner fan guide 18 first occurs at the corner portion 18x3 connecting the annular plate portion 21 and the intermediate connection pipe 22-2, it is desirable that the flow velocity is small in order to suppress the degree of separation.
[0050]
In the case of this embodiment, the corner portion of the outer fan guide is arranged closer to the rotor shaft than the corner portion of the inner fan guide. At the corner portion of the inner fan guide, and large separation of the flow at the corner portion of the inner fan guide can be suppressed.
In this embodiment as well, the minute holes 27 are provided in the cylindrical portion 20 of the internal fan guide 18, but the provision of the minute holes 27 is not an essential requirement.
[0051]
【The invention's effect】
As described above, according to the present invention, the pressure of the tip space 25 between the outer peripheral portion of the axial fan and the inner fan guide and the inner space portion 28 on the outer diameter side of the inner fan guide whose pressure is increased by the axial fan. And as a result, it is possible to suppress the refrigerant leakage in the circumferential direction from the blade pressure surface to the blade suction surface, so that the leakage loss of the tip gap 25 and the secondary flow loss induced thereby It is possible to provide a rotating electric machine including a ventilation system having a high-efficiency fan with reduced noise.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a structure of a main part of a rotary electric machine according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view illustrating a main structure of a rotary electric machine according to a second embodiment of the present invention;
FIG. 3 is a sectional view showing a main structure of a rotating electric machine according to a third embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a main structure of a rotary electric machine according to a fourth embodiment of the present invention.
FIG. 5 is a sectional view showing a main structure of a rotary electric machine according to a fifth embodiment of the present invention.
FIG. 6 is a sectional view showing a main structure of a rotary electric machine according to a sixth embodiment of the present invention.
FIG. 7 is a sectional view showing a main structure of a rotary electric machine according to a seventh embodiment of the present invention.
FIG. 8 is a diagram showing the relationship between the inclination angle of the inner fan guide and the thickness of the boundary layer.
FIG. 9 is a sectional view showing a structure of a main part of an electric rotating machine according to an eighth embodiment of the present invention;
FIG. 10 is a sectional view showing a main part structure of a rotating electric machine according to a ninth embodiment of the present invention.
FIG. 11 is a sectional view showing a cooling structure of the entire turbine generator.
FIG. 12 is a cross-sectional view showing a main structure of a conventional turbine generator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... rotor, 2 ... rotor shaft, 3 ... rotor core, 4 ... bearing, 5 ... holding ring, 6 ... stator, 7 ... stator frame, 8 ... stator core, 9 ... stator coil, 10 ... annular partition part, 11 ... stator ventilation duct, 12 ... axial flow fan, 13 ... rotor ventilation duct, 14 ... cooler, 15 ... flow path, 16 ... air gap, 17 ... exhaust duct, 18 ... inner fan guide, 18x: flow separation point, 19: outer fan guide, 20: cylindrical portion, 21: annular plate portion, 22-1, 22-2: intermediate connecting pipe, 23: annular plate portion, 24-1, 24-2 ... Outer fan guide parts, 25: chip gap, 26: refrigerant leakage from the blade pressure surface side to the negative pressure surface side, 27: minute holes, 28: internal space of the rotating electric machine, 29, 29a, 29b: circumferential irregularities, 30 ... inclined micropores.

Claims

An axial fan provided at an end of the rotor shaft for supplying and circulating a cooling medium toward the stator and the rotor, and a tip gap which is concentrically arranged on the rotor shaft and has a blade tip portion of the axial fan. And an inner fan guide comprising an annular plate portion connected to an opening edge of the cylindrical portion through an intermediate connecting pipe, and together with the inner fan guide, form a suction flow passage for the axial flow fan. An outer fan guide, and a rotating electric machine including a cooler provided in a flow path from an exhaust duct formed on the stator back surface to a suction flow path of the axial fan to cool the cooling medium,
A rotating portion provided on a cylindrical portion surrounding a tip of the blade of the axial fan of the inner fan guide, for suppressing a refrigerant leak from a blade pressure surface of the axial fan to a blade negative pressure surface. Electric machine.

2. The leak suppressing means according to claim 1, wherein the cylindrical portion surrounding the tip of the blade of the axial fan of the inner fan guide is provided with a minute hole communicating the internal space of the rotating electric machine with the gap. The rotating electric machine as described.

The rotating electric machine according to claim 2, wherein a plurality of the micro holes are arranged in the axial direction by increasing the diameter of the inside of the rotating electric machine.

The rotary electric machine according to claim 2, wherein the minute holes are inclined in a direction from a blade negative pressure surface of the axial fan to a blade pressure surface.

2. The rotating electric machine according to claim 1, wherein the leakage suppressing unit is configured by a concave and convex portion in a circumferential direction of a cylindrical portion of the inner fan guide surrounding a blade tip of the axial fan. 3.

The rotating electric machine according to claim 5, wherein the circumferential irregularities correspond to the inclination of a chord line of a blade section near the blade tip.

The rotating electric machine according to claim 5, wherein the concave and convex portions in the circumferential direction are curved corresponding to an average warpage of a blade section near the blade tip.

An axial fan provided at an end of the rotor shaft for supplying and circulating a cooling medium toward the stator and the rotor, and a tip gap which is concentrically arranged on the rotor shaft and has a blade tip portion of the axial fan. And an inner fan guide comprising an annular plate portion connected to an opening edge of the cylindrical portion through an intermediate connecting pipe, and together with the inner fan guide, form a suction flow passage for the axial flow fan. An outer fan guide, and a rotating electric machine including a cooler provided in a flow path from an exhaust duct formed on the stator back surface to a suction flow path of the axial fan to cool the cooling medium,
The intermediate connecting pipe immediately before the axial fan that forms the corner of the inner fan guide that forms the suction flow path of the axial fan is inclined within 0 to 30 degrees, and the inclined cylindrical part is connected to the intermediate connecting pipe. A rotating electric machine having an axial fan mounted at a position within 50 mm in an axial direction from a corner.

An axial fan provided at an end of the rotor shaft for supplying and circulating a cooling medium toward the stator and the rotor, and a tip gap which is concentrically arranged on the rotor shaft and has a blade tip portion of the axial fan. And an inner fan guide comprising an annular plate portion connected to an opening edge of the cylindrical portion through an intermediate connecting pipe, and together with the inner fan guide, form a suction flow passage for the axial flow fan. An outer fan guide, and a rotating electric machine including a cooler provided in a flow path from an exhaust duct formed on the stator back surface to a suction flow path of the axial fan to cool the cooling medium,
A rotating electric machine having a small hole penetrating into an electric machine internal space near a corner of a suction flow path of an axial fan in an annular plate portion of the inner fan guide.

An axial fan provided at the end of the rotor shaft to supply and circulate the cooling medium toward the stator and the rotor, and a gap between the blade tip of the axial fan arranged concentrically with the rotor shaft. An inner fan guide composed of a cylindrical portion surrounding the cylindrical portion and an annular plate portion connected to an opening edge of the cylindrical portion through an intermediate connecting pipe; and an outer portion that forms a suction flow passage of the axial flow fan together with the inner fan guide. In a rotating electric machine including a fan guide and a cooler provided in a flow path from an exhaust duct formed on the stator back surface to a suction flow path of the axial fan to cool the cooling medium,
A rotating electric machine characterized in that an outer fan guide section is provided closer to a rotor shaft than a corner section of a suction flow path of an axial fan of an inner fan guide section.