JP4010212B2

JP4010212B2 - Supercharger having rotating electrical machine lubricating oil discharging means

Info

Publication number: JP4010212B2
Application number: JP2002270425A
Authority: JP
Inventors: 修五十嵐
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2002-09-17
Filing date: 2002-09-17
Publication date: 2007-11-21
Anticipated expiration: 2022-09-17
Also published as: DE10342808A1; DE10342808B4; FR2844550A1; FR2844550B1; JP2004108213A

Description

【０００１】
【発明の属する技術分野】
本発明は内燃機関の過給機に係り、特にタービンと圧縮機の組合せに電動機または電動発電機の如き回転電機が組み込まれた回転電機付き過給機に係る。
【０００２】
【従来の技術】
【特許文献１】
特表２００１−５２７６１３
【特許文献２】
特開平４−１７８１４７
【特許文献３】
特開昭６３−１２９８２９
回転電機付き過給機は、例えば上記特許文献１に記載されている如く公知である。この公報に記載の過給機に於いては、回転電機である電動機は過給機のロータを支持する２つの軸受装置の間に設けられた電動機室内に配置されており、これら２つの軸受装置へ供給された潤滑油のうち電動機室内へ流出した分は電動機室内に軸受装置に沿って形成されたドレーン空間に集められて排出されるようになっている。
【０００３】
特許文献２には、電動機に於いて、回転子と固定子の間に異物が侵入することを防止するため、回転子の一端部に設けられたフランジの外縁を固定子上に重なるよう拡径することが提案されている。
【０００４】
特許文献３には、発電機と真空ポンプとが共通の駆動軸により駆動される構造に於いて、真空ポンプの摺動部の潤滑のために供給された潤滑油が発電機の側へ侵入するのを防止するため、両者の境界に於いて駆動軸にディスクを取り付け、該ディスクの外周円部を真空ポンプの側へ傾斜させ、その回りに潤滑油を集める環状溝を形成することが提案されている。
【０００５】
【発明が解決しようとする課題】
過給機は、全力運転時には、毎分２０万回転を越えるような高速にて運転される。一方、電動機や電動発電機の如き回転電機は、その作動効率を高めるためには回転子と固定子の間の間隙ができるだけ小さいことが望まれる。そのため過給機に組み込まれた回転電機の回転子と固定子の間の間隙が小さくされたとき、この間隙に潤滑油が侵入すると、この部分で回転子の回転に対する摩擦抵抗が増大することにより、過給機の作動効率が大きく損なわれるという問題がある。
【０００６】
本発明は、回転電機付き過給機に於ける上記の問題に着目し、この問題を解決するよう回転電機付き過給機を改良することを課題としている。
【０００７】
【課題を解決するための手段】
上記の課題を解決するものとして、本発明は、タービンと圧縮機の組合せに回転電機が組み込まれた回転電機付き過給機にして、前記回転電機の回転子と固定子の間の間隙より潤滑油を排出する手段を有することを特徴とする過給機を提供するものである。
【０００８】
前記潤滑油排出手段は前記回転子の少なくとも一方の軸端部に設けられた拡径部であってその上に付着した潤滑油液膜に該回転子の回転に伴い遠心力が作用したとき該遠心力により該液膜に前記間隙外へ向かう軸線方向力を作用させる拡径部を含んでいてよい。この場合、前記拡径部の半径は回転子の軸端へ向けて漸増されていてよい。また、前記拡径部には拡径方向に延在する溝が設けられていてよい。
【０００９】
或いはまたは、前記潤滑油排出手段は回転子の外周面に沿って設けられた螺旋溝を含み、該螺旋溝は該回転子が回転するとき該回転子の軸端へ向けて流れる方向に傾斜していてよい。また、前記螺旋溝は外周面の軸線方向中央部から両軸端へ向けて対称に傾斜していてよい。
【００１０】
或いはまた、前記潤滑油排出手段は前記間隙に空気を噴き込む手段を含んでいてよい。この場合、空気噴き込み手段は前記間隙の軸線方向中央部に空気を噴き込むようになっていてよい。
【００１１】
尚、上記の軸端部の拡径、回転子外周面に沿った螺旋溝の形成、固定子と回転子間の間隙への空気の噴込みは、それぞれ単独で行なわれても、或は適宜に組み合わせて行われてもよい。
【００１２】
【発明の作用及び効果】
上記の如くタービンと圧縮機の組合せに回転電機が組み込まれた回転電機付き過給機に於いて、回転電機の回転子と固定子の間の間隙より潤滑油を排出する手段が設けられるときには、回転子と固定子の間に潤滑油が侵入するようなことがあってもそれを該間隙外へ積極的に排除することができ、回転子と固定子の間の小さな間隙に潤滑油が侵入した状態で過給機ロータが高速回転することにより大きな摩擦損失が生ずるような事態を確実に回避することができる。
【００１３】
前記潤滑油排出手段が回転電機の回転子の少なくとも一方の軸端部に設けられた拡径部を含み、該拡径部がその上に付着した潤滑油液膜に該回転子の回転に伴い遠心力が作用したとき該遠心力により該液膜に前記間隙外へ向かう軸線方向力を作用させるようになっていれば、過給機の停止中に潤滑油が前記間隙内へ侵入したとしても、過給機の作動開始により回転子が回転すれば、それを間隙外へ引き出して排出することができ、また過給機の作動中には潤滑油が前記間隙内へ向けて移動することを阻止することができる。
【００１４】
回転子の端部に拡径部を設けることにより回転子の軸端部にてその周りに付着した潤滑油に対し前記間隙より離れる方向の力を及ぼす作用は、回転子の円筒状部から拡径部にかけてその壁面に付着する形に形成された潤滑油の液膜に拡径部に於いて遠心力による放射方向の力が作用し、それが液膜を伝わって円筒状部に及ぶことによるが、この場合、拡径部が軸端へ向けて半径を漸増させるよう円錐状或いは円弧錐状に形成されていれば、遠心力による放射方向の力が液膜を通じて円筒状部に及ぶ作用をより効果的に達成することができる。
【００１５】
更にこの場合、拡径部に拡径方向に延在する溝が設けられていれば、かかる溝によって液膜を保持して拡径部の回転によりよく追従させ、拡径部に於ける液膜により強い遠心力を作用させることにより、円筒状部に於ける液膜に対する軸線方向の引っ張り力をさらに高めることができる。
【００１６】
また、前記潤滑油排出手段が回転子の外周面に沿って設けられた螺旋溝を含み、該螺旋溝が該回転子の回転に連れて該回転子の軸端へ向けて流れる方向に傾斜するよう形成されていれば、前記間隙に存在する潤滑油は、回転子の回転で連れてかかる螺旋溝により捉えられ、それに沿って順次回転子の軸端へ向けて送られ、該間隙外へ排出される。この場合、該螺旋溝が回転子外周面の軸線方向中央部から両軸端へ向けて対称に傾斜していれば、前記間隙内に存在する潤滑油を回転子の軸長の半分以下というできるだけ短い距離の移動により該間隙外へ排出することができ、しかもそれを回転子の両軸端側へ分けて排出することにより、該間隙外への潤滑油の排出をより容易にすることができる。
【００１７】
前記潤滑油排出手段が前記間隙に空気を噴き込む手段として構成されるときには、潤滑油排出の作用を行った後には自由に大気へ放出されてよい空気という媒体を用いて潤滑油の排出を行うことができ、作動媒体の処理が容易であるという利点が得られる。この場合、空気噴き込み手段が前記間隙の軸線方向中央部に空気を噴き込むようになっていれば、上記の傾斜溝を回転子外周面の軸線方向中央部から両軸端へ向けて対称に傾斜させる場合と同様に、前記間隙内に存在する潤滑油を回転子の軸長の半分以下というできるだけ短い距離の移動により該間隙外へ排出することができ、しかもそれを回転子の両軸端側へ分けて排出することにより、該間隙外への潤滑油の排出をより容易にすることができるという利点が得られる。
【００１８】
【発明の実施の形態】
添付の図１は本発明による回転電機潤滑油排出手段を有する過給機の一つの実施例を示す幾分解図的縦断面図である。図に於いて、１０はタービン部であり、１２は圧縮機部であり、１４は回転電機部である。タービン部のタービンロータ１６と圧縮機部の圧縮機インペラ１８と回転電機部の回転子２０とが一体に連結された過給機ロータは、タービンロータと回転子との間の軸部２２にて軸受２４により回転式に支持されており、圧縮機インペラと回転子との間の軸部２６にて軸受２８により回転式に支持されている。回転電機１４は回転子２０の周りに設けられた固定子３０を有している。尚、図１に於いては、固定子はコアの部分にてのみ示されており、コイルは図を簡単にするため省略されている。
【００１９】
軸受２４は、油路３２より油路３４を経て供給され油路３６を経て排出される潤滑油により潤滑され、また軸受２８は、油路３８より油路４０を経て供給され油路４２を経て排出される潤滑油により潤滑されるようになっている。
【００２０】
図２の（Ａ）は図１に於ける回転電機１４の部分を取り出し、幾分拡大して示す図である。（但し、コア３０の直径は図示の都合上幾分縮小されている。）図１および２に於いては、回転子２０と固定子３０のコアの間の環状の間隙４４は図を明瞭にする目的で拡大して示されているが、実際には回転電機の作動効率を高めるべく回転子と固定子コアの間に接触を生じない範囲で可及的に小さくされている。従って、そのような小さな間隙に潤滑油が侵入した状態で過給機ロータが高速にて回転されると、過給機ロータには大きな制動力が作用し、それだけ過給機の作動効率が低下する。尚、回転電機の固定子と回転子の間の間隙への潤滑油の侵入に対しては、固定子および回転子を液密にされたケース内に配置して該間隙への潤滑油の侵入を防ぐことも考えられるが、その場合、ケースを設ける分だけ過給機ロータの軸長が増大し、その剛性が低下するので好ましくない
【００２１】
そこで図２の（Ａ）に示す実施例に於いては、回転子２０はその少なくとも一方の軸端（但し、図示の実施例では両方の軸端）に拡径部４６が形成されている。間隙４４内に潤滑油が侵入し或いは侵入しつつあるような状態では、当然軸端部上には潤滑油の油膜が形成されているので、このとき軸端部が拡径されていると、回転子の回転に伴って油膜に遠心力が作用し、油膜には放射方向の力が作用するので、拡径部より間隙へ向けて延在する油膜にはこれを間隙外へ引き戻そうとする引き戻し力が作用する。これは拡径部が一種の遠心ポンプ作用を行うことに相当している。
【００２２】
上記の如き拡径部による遠心ポンプ作用を得るには、拡径部の表面に形成された液膜に作用する放射方向の力を間隙４４へ向けてより効果的に作用させるべく、拡径部４６は、その径が漸増するよう、図２の（Ａ）に示されている如く円錐状に形成されるか、或いは図２の（Ｂ）に示されている如く円弧錐状に形成されるのが好ましい。
【００２３】
更にまた、図２の(Ａ)または(Ｂ)に示す如く形成された拡径部４６に図３に示す如く拡径方向に延在する溝４８が設けられれば、拡径部の表面に形成された油膜が溝４８により捕捉されることによって該油膜は回転子の回転と共に確実に回転し、拡径部上の油膜より間隙４４へ向けて及ぼされる吸引力はより一層強くなる。かかる溝４８は図３に示す如く、拡径部の内周縁より外周縁へ向かうにつれて回転子の回転方向（図中矢印）に見て後方へ傾斜するよう螺旋状に湾曲して形成されるのが好ましく、また図示の如く拡径部の周方向に沿って適当な間隔を置いて複数個設けられるのが好ましい。
【００２４】
図４は本発明による回転電機の間隙より潤滑油を排出させる手段の更に他の一つの実施例を示す回転子の外周面の解図的平面図である。この実施例に於いては、回転子２０の外周面には、回転子が回転するときその軸端へ向けて流れる方向に傾斜して設けられた螺旋溝５０が形成されている。かかる螺旋溝が設けられていると、回転子の外周面に付着した潤滑油は回転子がその外周面を図の矢印方向に移動させるよう回転するとき、螺旋溝５０により捕捉されて軸端へ向けて移動され、間隙４４外へ排出される。
【００２５】
この場合、特に図に示す実施例の如く、螺旋溝５０が回転子の軸線方向中央部から両軸端へ向けて対称に傾斜していると、間隙４４より潤滑油を押し出す距離は回転子の軸長の半分以下になると同時に、間隙内の潤滑油は間隙の両端へ向けて２つに分かれて排出されるので、間隙４４よりの潤滑油の排出がより容易になる。
【００２６】
尚、図示の実施例では螺旋溝５０は回転子の軸線方向中央部より両軸端へ向けて対称に１本ずつ設けられているが、かかる螺旋溝は周方向の位置をずらせて複数本設けられてもよい。
【００２７】
図５は本発明による回転電機の間隙より潤滑油を排出させる手段の更に他の一つの実施例を示す図１と同様の過給機の幾分解図的縦断面図である。図５に於いて、図１に示した部分と同じ部分は図１に於けると同じ符号により示されている。
【００２８】
この実施例に於いては、間隙４４内へ空気を噴き込むことによって潤滑油が間隙４４内へ侵入すること或いは間隙内に侵入した潤滑油を間隙外へ押し出すことが図られている。特に図示の実施例に於いては、導管５２の先端部に設けられた空気噴出口５４は間隙４４の軸線方向中央部に位置しており、空気を間隙４４の軸線方向中央部に噴き出すことが図られている。このように間隙の軸線方向中央部にて空気を噴き出すことにより、間隙内に存在する潤滑油は空気によって間隙の奥へ押しやられることなく必ず間隙の開口端へ向かう方向に押しやられ、より効率的に間隙外へ排出される。固定子３０のコア５６には、図５の矢印６−６方向に見た固定子の断面を示す図６に示されている如くコイル５８を装着するための溝６０が星形に形成されているので、かかる溝の開口端に沿って導管５２の先端部を配置することにより、その空気噴出口５４を間隙４４の軸線方向中央部に位置させることができる。
【００２９】
導管５２によりその空気噴出口５４を経て間隙４４の中央部に噴き出された空気は、間隙の両軸端へ向けて流れた後、そこに残された適当な空隙を経て排出管６２および６４（排出管６４は図５にて導管５２の向こう側に偏倚して配置されている）を経て機外へ排出されればよい。
【００３０】
以上に於いては本発明をいくつかの実施例について詳細に説明したが、これらの実施例について本発明の範囲内にて種々の変更が可能であることは当業者にとって明らかであろう。
【図面の簡単な説明】
【図１】本発明による回転電機潤滑油排出手段を有する過給機の一つの実施例を示す幾分解図的縦断面図。
【図２】図の（Ａ）は図１に於ける回転電機１４の部分を取り出し、幾分拡大して示す図であり、図の（Ｂ）はその変更例を示す同様の図。
【図３】図２の（Ａ）または（Ｂ）に示す拡径部４６に溝４８を設ける実施例を示す回転子の一部断面による軸線方向図。
【図４】回転電機の間隙より潤滑油を排出させる手段の更に他の一つの実施例を示す回転子外周面の解図的平面図。
【図５】回転電機の間隙より潤滑油を排出させる手段の更に他の一つの実施例を示す図１と同様の幾分解図的縦断面図。
【図６】図５の矢印６−６方向に見た固定子の断面図。
【符号の説明】
１０…タービン部、１２…圧縮機部、１４…回転電機部、１６…タービンロータ、１８…圧縮機インペラ、２０…回転子、２２…軸部、２４…軸受、２６…軸部、２８…軸受、３０…固定子、３２，３４，３６，３８，４０，４２…油路、４４…間隙、４６…拡径部、４８，５０…溝、５２…導管、５４…空気噴射口、５６…コア、５８…コイル、６０…溝、６２，６４…排出管[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a supercharger for an internal combustion engine, and more particularly to a supercharger with a rotating electric machine in which a rotating electric machine such as an electric motor or a motor generator is incorporated in a combination of a turbine and a compressor.
[0002]
[Prior art]
[Patent Document 1]
Special table 2001-527613
[Patent Document 2]
JP-A-4-178147
[Patent Document 3]
JP 63-1229829 A
A supercharger with a rotating electrical machine is known as described in Patent Document 1, for example. In the supercharger described in this publication, an electric motor that is a rotating electric machine is disposed in an electric motor chamber provided between two bearing devices that support a rotor of the supercharger. Of the lubricating oil supplied to, the oil that has flowed into the motor chamber is collected in a drain space formed along the bearing device in the motor chamber and discharged.
[0003]
In Patent Document 2, in an electric motor, in order to prevent foreign matter from entering between the rotor and the stator, the diameter of the flange is increased so that the outer edge of the flange provided at one end of the rotor overlaps the stator. It has been proposed to do.
[0004]
In Patent Document 3, in a structure in which a generator and a vacuum pump are driven by a common drive shaft, lubricating oil supplied for lubrication of the sliding portion of the vacuum pump enters the generator side. In order to prevent this, it has been proposed to attach a disk to the drive shaft at the boundary between the two, tilt the outer circumference of the disk toward the vacuum pump, and form an annular groove around it to collect the lubricating oil. ing.
[0005]
[Problems to be solved by the invention]
The supercharger is operated at a high speed exceeding 200,000 revolutions per minute during full power operation. On the other hand, in a rotating electrical machine such as an electric motor or a motor generator, it is desired that the gap between the rotor and the stator be as small as possible in order to increase the operating efficiency. Therefore, when the gap between the rotor and the stator of the rotating electrical machine incorporated in the supercharger is reduced, if the lubricating oil enters the gap, the frictional resistance against the rotation of the rotor increases at this part. There is a problem that the operating efficiency of the supercharger is greatly impaired.
[0006]
An object of the present invention is to improve the supercharger with a rotating electrical machine so as to solve this problem by paying attention to the above-mentioned problem in the supercharger with a rotating electrical machine.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a turbocharger with a rotating electrical machine in which a rotating electrical machine is incorporated in a combination of a turbine and a compressor, and lubricates from a gap between the rotor and the stator of the rotating electrical machine. The present invention provides a supercharger characterized by having means for discharging oil.
[0008]
The lubricating oil discharging means is a diameter-enlarged portion provided at at least one shaft end of the rotor, and when a centrifugal force is applied to the lubricating oil film adhering thereto on the lubricating oil film as the rotor rotates. A diameter-enlarged portion that causes an axial force to move out of the gap to the liquid film by centrifugal force may be included. In this case, the radius of the enlarged diameter portion may be gradually increased toward the shaft end of the rotor. Moreover, the said enlarged diameter part may be provided with the groove | channel extended in an enlarged diameter direction.
[0009]
Alternatively, the lubricating oil discharging means includes a spiral groove provided along the outer peripheral surface of the rotor, and the spiral groove is inclined in a direction of flowing toward the axial end of the rotor when the rotor rotates. It may be. Further, the spiral groove may be symmetrically inclined from the axial center portion of the outer peripheral surface toward both axial ends.
[0010]
Alternatively, the lubricating oil discharging means may include means for injecting air into the gap. In this case, the air injecting means may inject air into the central portion in the axial direction of the gap.
[0011]
The above-mentioned diameter expansion of the shaft end, the formation of the spiral groove along the outer peripheral surface of the rotor, and the injection of air into the gap between the stator and the rotor may be performed independently or as appropriate. It may be performed in combination.
[0012]
[Action and effect of the invention]
In the turbocharger with a rotating electrical machine in which the rotating electrical machine is incorporated in the combination of the turbine and the compressor as described above, when a means for discharging the lubricating oil from the gap between the rotor and the stator of the rotating electrical machine is provided, Even if lubricating oil enters between the rotor and the stator, it can be positively excluded from the gap, and the lubricating oil enters the small gap between the rotor and the stator. In this state, it is possible to reliably avoid a situation in which a large friction loss is caused by the high speed rotation of the supercharger rotor.
[0013]
The lubricating oil discharge means includes an enlarged diameter portion provided at at least one shaft end portion of the rotor of the rotating electric machine, and the enlarged diameter portion adheres to the lubricating oil liquid film on the lubricant oil film as the rotor rotates. If the centrifugal force causes the liquid film to act on the liquid film in the axial direction toward the outside of the gap, the lubricating oil may enter the gap while the turbocharger is stopped. If the rotor rotates due to the start of operation of the supercharger, it can be drawn out and discharged out of the gap, and the lubricating oil can move toward the gap during operation of the supercharger. Can be blocked.
[0014]
By providing an enlarged diameter portion at the end of the rotor, the effect of exerting a force in the direction away from the gap on the lubricant oil adhering to the periphery of the shaft end of the rotor is expanded from the cylindrical portion of the rotor. Radial force due to centrifugal force acts on the liquid film of the lubricating oil formed in a shape that adheres to the wall surface over the diameter part, and it is transmitted through the liquid film and reaches the cylindrical part. However, in this case, if the enlarged-diameter portion is formed in a conical shape or an arc-conical shape so as to gradually increase the radius toward the shaft end, the radial force due to the centrifugal force acts on the cylindrical portion through the liquid film. It can be achieved more effectively.
[0015]
Furthermore, in this case, if a groove extending in the diameter expansion direction is provided in the diameter-expanded portion, the liquid film is held by the groove and is made to follow the rotation of the diameter-expanded portion better, and the liquid film in the diameter-expanded portion By applying a stronger centrifugal force, it is possible to further increase the tensile force in the axial direction against the liquid film in the cylindrical portion.
[0016]
The lubricating oil discharging means includes a spiral groove provided along the outer peripheral surface of the rotor, and the spiral groove is inclined in a direction of flowing toward the shaft end of the rotor as the rotor rotates. If it is formed in this way, the lubricating oil present in the gap is caught by the spiral groove along with the rotation of the rotor, and is sequentially sent along the axial direction of the rotor, and discharged out of the gap. Is done. In this case, if the spiral groove is symmetrically inclined from the central portion in the axial direction of the outer peripheral surface of the rotor toward both shaft ends, the lubricating oil existing in the gap can be less than half of the axial length of the rotor. The oil can be discharged out of the gap by a short distance movement, and the oil can be easily discharged out of the gap by discharging the oil separately to both shaft end sides of the rotor. .
[0017]
When the lubricating oil discharging means is configured as means for injecting air into the gap, the lubricating oil is discharged using a medium of air that may be freely released to the atmosphere after the lubricating oil discharging action is performed. And the advantage that the working medium is easy to handle is obtained. In this case, if the air injection means is configured to inject air into the central portion in the axial direction of the gap, the inclined groove is symmetrically directed from the central portion in the axial direction of the outer peripheral surface of the rotor toward both axial ends. As in the case of inclining, the lubricating oil existing in the gap can be discharged out of the gap by moving as short as possible, that is, less than half of the axial length of the rotor, and it can be discharged to both ends of the rotor shaft. By discharging separately to the side, there is an advantage that the lubricating oil can be easily discharged out of the gap.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 attached herewith is a partially exploded longitudinal sectional view showing one embodiment of a supercharger having rotating electrical machine lubricating oil discharging means according to the present invention. In the figure, 10 is a turbine section, 12 is a compressor section, and 14 is a rotating electrical machine section. A turbocharger rotor in which a turbine rotor 16 of a turbine section, a compressor impeller 18 of a compressor section, and a rotor 20 of a rotating electrical machine section are integrally connected is formed by a shaft section 22 between the turbine rotor and the rotor. The bearing 24 is rotatably supported, and the shaft portion 26 between the compressor impeller and the rotor is rotatably supported by the bearing 28. The rotating electrical machine 14 has a stator 30 provided around the rotor 20. In FIG. 1, the stator is shown only at the core portion, and the coil is omitted for the sake of simplicity.
[0019]
The bearing 24 is lubricated by lubricating oil supplied from the oil passage 32 through the oil passage 34 and discharged through the oil passage 36, and the bearing 28 is supplied from the oil passage 38 through the oil passage 40 and passed through the oil passage 42. It is lubricated by the discharged lubricating oil.
[0020]
FIG. 2A is a view showing a part of the rotating electrical machine 14 in FIG. (However, the diameter of the core 30 is somewhat reduced for the sake of illustration.) In FIGS. 1 and 2, the annular gap 44 between the core of the rotor 20 and the stator 30 makes the figure clear. However, in order to increase the operating efficiency of the rotating electrical machine, it is actually made as small as possible without causing contact between the rotor and the stator core. Therefore, if the turbocharger rotor rotates at a high speed with the lubricant intruding into such a small gap, a large braking force acts on the turbocharger rotor, and the operating efficiency of the turbocharger decreases accordingly. To do. In addition, with respect to the intrusion of the lubricating oil into the gap between the stator and the rotor of the rotating electrical machine, the lubricating oil enters the gap by arranging the stator and the rotor in a liquid-tight case. However, in this case, the axial length of the supercharger rotor increases and the rigidity of the turbocharger rotor decreases, so this is not preferable.
Therefore, in the embodiment shown in FIG. 2A, the rotor 20 has a diameter-expanded portion 46 formed on at least one shaft end (both shaft ends in the illustrated embodiment). In the state where the lubricating oil has entered or is invading into the gap 44, naturally, since the oil film of the lubricating oil is formed on the shaft end portion, the diameter of the shaft end portion is expanded at this time. As the rotor rotates, centrifugal force acts on the oil film, and radial force acts on the oil film, so that the oil film that extends from the enlarged diameter part toward the gap pulls it back out of the gap. Force acts. This corresponds to the enlarged diameter portion performing a kind of centrifugal pump action.
[0022]
In order to obtain the centrifugal pump action by the above-mentioned enlarged-diameter part, the enlarged-diameter part is more effectively applied to the gap 44 by applying a radial force acting on the liquid film formed on the surface of the enlarged-diameter part. 46 is formed in a conical shape as shown in FIG. 2A so that its diameter gradually increases, or is formed in an arc-conical shape as shown in FIG. 2B. Is preferred.
[0023]
Furthermore, if a groove 48 extending in the diameter-expanding direction as shown in FIG. 3 is provided in the diameter-expanded portion 46 formed as shown in FIG. 2 (A) or (B), it is formed on the surface of the diameter-expanded portion. When the oil film formed is captured by the groove 48, the oil film surely rotates together with the rotation of the rotor, and the suction force exerted toward the gap 44 from the oil film on the enlarged diameter portion becomes even stronger. As shown in FIG. 3, the groove 48 is formed in a spiral curve so as to incline backward as viewed from the rotation direction of the rotor (arrow in the figure) from the inner periphery to the outer periphery. It is preferable that a plurality of them are provided at appropriate intervals along the circumferential direction of the enlarged diameter portion as shown in the drawing.
[0024]
FIG. 4 is an illustrative plan view of the outer peripheral surface of the rotor showing still another embodiment of means for discharging lubricating oil from the gap of the rotating electrical machine according to the present invention. In this embodiment, a spiral groove 50 is formed on the outer peripheral surface of the rotor 20 so as to be inclined in the direction of flowing toward the shaft end when the rotor rotates. When such a spiral groove is provided, the lubricating oil adhering to the outer peripheral surface of the rotor is captured by the spiral groove 50 to the shaft end when the rotor rotates so as to move the outer peripheral surface in the direction of the arrow in the figure. It is moved toward and discharged out of the gap 44.
[0025]
In this case, in particular, as in the embodiment shown in the figure, when the spiral groove 50 is symmetrically inclined from the central portion in the axial direction of the rotor toward both shaft ends, the distance for pushing out the lubricating oil from the gap 44 is the distance of the rotor. At the same time as the axial length becomes less than half, the lubricating oil in the gap is discharged in two parts toward both ends of the gap, so that the lubricating oil can be easily discharged from the gap 44.
[0026]
In the illustrated embodiment, one spiral groove 50 is provided symmetrically from the center in the axial direction of the rotor toward both ends, but a plurality of such spiral grooves are provided with their circumferential positions shifted. May be.
[0027]
FIG. 5 is a partially exploded longitudinal sectional view of a turbocharger similar to FIG. 1, showing still another embodiment of means for discharging lubricating oil from the gap of the rotating electrical machine according to the present invention. In FIG. 5, the same parts as those shown in FIG. 1 are denoted by the same reference numerals as in FIG.
[0028]
In this embodiment, by injecting air into the gap 44, the lubricating oil enters the gap 44 or the lubricating oil that has entered the gap is pushed out of the gap. In particular, in the illustrated embodiment, the air outlet 54 provided at the tip of the conduit 52 is located in the axial center of the gap 44, and air can be ejected to the axial center of the gap 44. It is illustrated. By blowing out air at the axial center of the gap in this way, the lubricating oil present in the gap is always pushed toward the opening end of the gap without being pushed into the gap by the air, making it more efficient. To the outside of the gap. In the core 56 of the stator 30, grooves 60 for mounting the coils 58 are formed in a star shape as shown in FIG. 6, which shows a cross section of the stator seen in the direction of the arrow 6-6 in FIG. 5. Therefore, by arranging the distal end portion of the conduit 52 along the opening end of the groove, the air jet port 54 can be positioned at the center portion in the axial direction of the gap 44.
[0029]
The air blown out to the central portion of the gap 44 through the air outlet 54 by the conduit 52 flows toward both axial ends of the gap, and then passes through appropriate gaps remaining therein to discharge pipes 62 and 64. The discharge pipe 64 may be discharged out of the machine via (displaced on the other side of the conduit 52 in FIG. 5).
[0030]
While the invention has been described in detail with reference to several embodiments, it will be apparent to those skilled in the art that various modifications can be made to these embodiments within the scope of the invention.
[Brief description of the drawings]
FIG. 1 is an exploded longitudinal sectional view showing one embodiment of a supercharger having rotating electrical machine lubricating oil discharging means according to the present invention.
FIG. 2A is a view showing a part of the rotating electrical machine 14 in FIG. 1 taken out and is somewhat enlarged, and FIG. 2B is a similar view showing a modification example thereof.
FIG. 3 is an axial direction view with a partial cross section of a rotor showing an embodiment in which a groove 48 is provided in the enlarged diameter portion 46 shown in FIG. 2 (A) or (B).
FIG. 4 is an illustrative plan view of a rotor outer peripheral surface showing still another embodiment of means for discharging lubricating oil from the gap of the rotating electrical machine.
FIG. 5 is an exploded longitudinal sectional view similar to FIG. 1, showing still another embodiment of means for discharging lubricating oil from the gap of the rotating electrical machine.
6 is a cross-sectional view of the stator as seen in the direction of arrow 6-6 in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Turbine part, 12 ... Compressor part, 14 ... Rotary electric machine part, 16 ... Turbine rotor, 18 ... Compressor impeller, 20 ... Rotor, 22 ... Shaft part, 24 ... Bearing, 26 ... Shaft part, 28 ... Bearing , 30 ... Stator, 32, 34, 36, 38, 40, 42 ... Oil passage, 44 ... Gap, 46 ... Expanded portion, 48, 50 ... Groove, 52 ... Conduit, 54 ... Air injection port, 56 ... Core 58 ... Coil, 60 ... Groove, 62, 64 ... Discharge pipe

Claims

A turbocharger with a rotating electric machine in which a rotating electric machine is incorporated in a combination of a turbine and a compressor. The radius is gradually increased toward the shaft end of the rotor provided at at least one shaft end of the rotor. When the centrifugal force accompanying the rotation of the rotor acts on the lubricating oil film adhering to the enlarged diameter portion, the centrifugal force causes the liquid film to move between the rotor and the stator of the rotating electric machine. A supercharger comprising means for applying an axial force outward from the gap and discharging lubricating oil from the gap between the rotor and the stator of the rotating electric machine.

The supercharger according to claim 1 , wherein a groove extending in the diameter expansion direction is provided in the diameter expansion portion.

As a means for discharging lubricating oil from a gap between a rotor and a stator of the rotating electric machine, a spiral groove provided along the outer peripheral surface of the rotor is further included, and the spiral groove is rotated when the rotor rotates. supercharger according to claim 1 or 2, characterized in that it is inclined in the direction of flow towards the axial end of the rotor.

4. The supercharger according to claim 3 , wherein the spiral groove is symmetrically inclined from the axially central portion of the outer peripheral surface toward both axial ends. 5.

The supercharging according to any one of claims 1 to 4 , further comprising means for injecting air into the gap as means for discharging lubricating oil from a gap between a rotor and a stator of the rotating electrical machine. Machine.

The supercharger according to claim 5, wherein the air injection means is configured to inject air into an axially central portion of the gap.