.201030237 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種利用旋轉軸來旋轉轉子以運送泵室 內的氣體，並進行抽吸作用的旋轉式真空栗。 【先前技術】 專利文獻1揭露一種屬旋轉式真空栗之一的多段式魯 式泵。該多段式魯式泵在外殼內平行地設置有兩個旋轉 0 軸’且分別藉由軸承可旋轉地支承各旋轉軸之兩端。具有 設於各旋轉軸的複數個轉子，分別被收容於在外殼內與該 旋轉軸呈直角方向並設的複數個栗室內的構成。 具體來說，設於一旋轉軸的複數個轉子與設於另一旋 轉軸的複數個轉子各自成對，並以嚙合狀態收容於該各泵 室中。各泵室具有吸入領域與排出領域，一個泵室的排出 領域透過連通路與鄰接之泵室的吸入領域相連。又，位於 一端側的泵室的吸入區域和與外部連通的吸入孔相連，位 ® 於另一端的泵室的排出區域和與外部連通的排出口相連。 該一旋轉軸的一端連結至驅動源，且設置於該旋轉軸 之齒輪係與設於該另一旋轉軸之齒輪嚙合，使得各旋轉軸 同步地朝相反方向旋轉。雖然專利文獻1並沒有明確記 載’但所實施之多段式魯式泵中，由於該一旋轉軸和另一 旋轉軸爲了限制該泵室內之轉子的位置，故構成爲藉由鎖 定螺帽、或者該旋轉軸一端側之徑向軸承與旋轉軸的壓入 等的手段以禁止其朝向旋轉軸線方向的移動。 -4- 201030237 以前述方式構成之多段式魯式泵，藉由驅動該一轉 軸，該另一旋轉軸亦會跟著被旋轉，使得收容於該各泵室 的一對轉子旋轉。透過該吸入口被吸入至該一端側泵室的 氣體，藉該一對轉子之旋轉一邊被壓縮，一邊依序被吸入 至鄰接之泵室內，依此方式被運送。從其他端泵室將被壓 縮之氣體經排出口排出到外部。 〔專利文獻〕 〔專利文獻1〕日本特開第2008-51116號公報 '0 【發明內容】 〔發明所欲解決之課題〕 以前述方式構成之多段式魯式泵於運轉中，特別是因 爲在該排出口側會產生高熱，所以該外殼、轉子以及旋轉 軸會產生熱膨脹。又，多段式魯式泵在停止時，因爲該外 殻、轉子以及旋轉軸會被空氣冷卻，故會產生熱收縮。但 是，於運轉中，該外殻會與空氣直接接觸而呈現容易受到 φ 冷卻效果的狀態，然而該轉子及旋轉軸係位於外殻內故不 會受到空氣冷卻效果。所以，該外殼與該轉子以及旋轉軸 之間會產生熱膨脹量差異，該轉子以及旋轉軸自該外殻大 幅位移。因此，在屬該外殼之一部分的泵室壁面與該轉子 壁面之間會產生推力方向的大間隙。 另一方面，由於被吸入泵室內的氣體中混合有粉麈 等，故容易於該推力方向的大間隙處產生因粉塵等的堆積 所形成的異物。在有堆積異物狀態停止多段式魯式泵，且 201030237 產生熱收縮的情況下，該轉子以及該旋轉軸會因異物的存 在而無法回復到初期設定位置，而成爲強力地壓抵於該異 物的狀態。因此，當多段式魯式泵重新啓動時，該轉子與 異物之間將產生很大的摩擦阻力，恐怕無法重新啓動。 本發明係提供一種旋轉式真空泵，其可減輕於重新啓 動時堆積在泵室內的異物所造成之摩擦阻力。 〔解決課題之手段〕 ©申請專利範圍第1項記載之本發明係將泵室設置於外 殻內，且將設置於該泵室內的轉子設於複數根旋轉軸上， 藉由該複數根旋轉軸的旋轉來運送該泵室內的氣體以產生 抽吸作用，該旋轉式真空泵的特徵在於，該旋轉軸係具備： 推力方向移動限制機構，係將因該旋轉式真空泵運轉時所 產生的該轉子與該旋轉軸之推力方向的熱膨脹所致之位移 限制於僅能朝一方向；以及第一彈性構件，係朝容許該熱 膨脹方向之相反方向對該旋轉軸賦予彈推力。根據申請專 φ 利範圍第1項記載之本發明，該旋轉式真空泵在運轉時， 即使在因該外殻與該轉子和該旋轉軸之間的熱膨脹量差異 而於該泵室內產生推力方向的間隙處堆積異物，亦可藉該 第一彈性構件的變形吸收該旋轉式真空栗於停止時的熱收 縮所伴隨產生之該外殼與該轉子間的摩擦力，可使該旋轉 式真空泵能夠沒有阻礙地重新啓動。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary vacuum pump that uses a rotary shaft to rotate a rotor to transport gas in a pump chamber and perform suction. [Prior Art] Patent Document 1 discloses a multi-stage Lu pump which is one of the rotary vacuum pumps. The multi-stage Lu pump is provided with two rotating 0-axis 'parallelly in the outer casing and rotatably supports both ends of each of the rotating shafts by bearings. Each of the plurality of rotors provided on each of the rotating shafts is housed in a plurality of chestnut chambers provided in the casing at right angles to the rotating shaft. Specifically, a plurality of rotors provided on one rotating shaft are paired with a plurality of rotors provided on the other rotating shaft, and are housed in the respective pump chambers in an engaged state. Each pump chamber has an area of suction and discharge, and a discharge area of a pump chamber is connected to an intake area of an adjacent pump chamber through a communication path. Further, the suction region of the pump chamber on the one end side is connected to the suction port communicating with the outside, and the discharge region of the pump chamber at the other end is connected to the discharge port communicating with the outside. One end of the one rotating shaft is coupled to the driving source, and the gear train provided on the rotating shaft meshes with the gear provided on the other rotating shaft such that the respective rotating shafts rotate in opposite directions in synchronization. Although Patent Document 1 does not explicitly describe 'however, in the multi-stage Lu pump, the one rotating shaft and the other rotating shaft are configured to be locked by a nut, in order to limit the position of the rotor in the pump chamber. A means for pressing the radial bearing and the rotating shaft on one end side of the rotating shaft to prohibit its movement in the direction of the rotation axis. -4- 201030237 The multi-stage Lu pump constructed in the foregoing manner, by driving the one shaft, the other rotating shaft is also rotated to rotate a pair of rotors accommodated in the pump chambers. The gas sucked into the pump chamber at the one end through the suction port is compressed while being rotated by the pair of rotors, and is sequentially sucked into the adjacent pump chamber and transported in this manner. The compressed gas is discharged to the outside through the discharge port from the other end pump chamber. [Patent Document 1] [Patent Document 1] JP-A-2008-51116A SUMMARY OF THE INVENTION [Problems to be Solved by the Invention] The multi-stage Lu pump configured as described above is operated, particularly because High heat is generated on the discharge port side, so the outer casing, the rotor, and the rotating shaft are thermally expanded. Further, when the multi-stage Lu pump is stopped, since the outer casing, the rotor, and the rotating shaft are cooled by air, heat shrinkage occurs. However, during operation, the outer casing is in direct contact with the air and is in a state of being easily subjected to the φ cooling effect. However, the rotor and the rotating shaft are located in the outer casing and are not subjected to air cooling. Therefore, a difference in the amount of thermal expansion occurs between the outer casing and the rotor and the rotating shaft, and the rotor and the rotating shaft are largely displaced from the outer casing. Therefore, a large gap in the thrust direction is generated between the wall surface of the pump chamber which is a part of the outer casing and the wall surface of the rotor. On the other hand, since the powder sucked into the pump chamber is mixed with powder or the like, it is easy to generate foreign matter formed by the accumulation of dust or the like in the large gap in the thrust direction. When the multi-stage Lu pump is stopped in the state of accumulated foreign matter, and the heat shrinkage occurs in 201030237, the rotor and the rotating shaft cannot return to the initial setting position due to the presence of foreign matter, and become strongly pressed against the foreign matter. status. Therefore, when the multi-stage Lu pump is restarted, there will be a large frictional resistance between the rotor and the foreign object, which may not be restarted. SUMMARY OF THE INVENTION The present invention provides a rotary vacuum pump which can alleviate the frictional resistance caused by foreign matter accumulated in a pump chamber during restart. [Means for Solving the Problem] The present invention described in claim 1 is that the pump chamber is disposed in the casing, and the rotor provided in the pump chamber is disposed on the plurality of rotating shafts, and the plurality of rotating shafts are rotated by the plurality of rotating shafts Rotating the shaft to transport the gas in the pump chamber to generate a suction function, the rotary vacuum pump having: a thrust direction movement restricting mechanism for the rotor generated when the rotary vacuum pump is operated The displacement due to thermal expansion in the thrust direction of the rotating shaft is limited to only one direction; and the first elastic member imparts a spring force to the rotating shaft in a direction opposite to the direction in which the thermal expansion is allowed. According to the invention as recited in claim 1, the rotary vacuum pump generates a thrust direction in the pump chamber even during a difference in thermal expansion amount between the outer casing and the rotor and the rotary shaft during operation. The foreign matter is deposited at the gap, and the friction between the outer casing and the rotor caused by the thermal contraction of the rotary vacuum pump during the stop can be absorbed by the deformation of the first elastic member, so that the rotary vacuum pump can be unobstructed. Restart the ground.
‘申請專利範圍第2項記載的本發明中，由於設置有第 二彈性構件，其對該旋轉軸賦予容許該熱膨脹方向的彈A 201030237 力，故可藉具有相反方向的兩個彈性構件定位該旋轉軸， 同時可減輕因熱膨脹而堆積在泵室內的異物所產生的摩擦 阻力。 申請專利範圍第3項記載的本發明中，由於該推力方 向移動限制機構係由形成於該旋轉軸之階差部與支持該旋 轉軸的軸承所組成，且藉由該階差部與該軸承的直接或間 接抵接，可限制推力方向的移動，故可利用簡易的手段達 ^ 成本發明之目的。 〇 申請專利範圍第4項記載的本發明中，由於該第一彈 性構件係設置於該階差部與該軸承之間，故可適當地對旋 轉軸賦予推壓力。 申請專利範圍第5項記載的本發明中，由於該旋轉式 真空係爲多段式魯式泵，故可適當地實施本發明。 申請專利範圍第6項記載的本發明中，由於該第一彈 性構件對該旋轉軸賦予彈推力的方向係與該多段式魯式泵 G 中氣體的運送出方向相同’且該推力方向移動限制機構係 設置於該多段式魯式泵的最末端側，故可限制多段式魯式 泵最末端側推力方向的移動’並且可有效地防止氣體自最 末端泵室1 4洩露。 〔發明的效果〕 本發明無論泵室內是否有堆積異物皆可滑順地重新啓 動旋轉式真空泵。 【實施方式】 .201030237 (第1實施形態） 以下，參照第1圖〜第6圖說明本發明之多段式魯式 泵所實施的第1實施形態。又，本發明說明書中，關於多 段式魯式泵的方向，係將第1圖〜第4圖的左方作爲前側、 右方作爲後側、上方作爲上方、下方作爲下方，將第5圖 以及第6圖的右方作爲正面、左方作爲背面來說明。 形成多段式魯式泵外形的外殻1係由前側依序接合有 A 前殼2、轉子殼3、後殼4以及齒輪殻5，且在將內部密封 〇 狀態下藉由例如螺絲（圖中未顯示）等形成一體。各外殼 2〜5係如第5圖和第6圖槪略外觀般，係構成爲將具有大 致呈橢圓形內部空間之筒狀體上下分割成兩部分。此種二 分割構成在可有效地組合成多段式魯式泵，例如將後述各 機構的構件安裝於下方側之分割筒狀體之後，再以上方側 之分割筒狀體加以覆蓋而形成密封狀態，進而組合成一 體。又，由於各外殼2〜5的二分割構成與本發明沒有密切 〇 關係，所以省略詳細說明。又，多段式魯式泵的各構成係 如各圖般，依組合後狀態作說明。 於轉子殻3內部，以成爲橢圓形的方式自前側依序以 狹窄間隔安裝有上下分割爲兩部分的分隔壁6〜9，且於分 隔壁6與前殼2之間、各分隔壁6〜9之間以及分隔壁9與 後殼4之間分別形成有泵室10〜14。因此，各分隔壁6〜9 係構成作爲用以形成泵室10〜14的轉子殼3的一部分。 又，各泵室10〜14具有自前側依序縮減的容積。 201030237 各分隔壁6〜9於內部具有連通空間15〜18。 空間1 5〜1 8係如第1圖所示，於下方具有朝前側開 出通道19〜22，於上方具有朝後側開口之吸入通發 26 » 第1圖中，各泵室10〜14係於上方空間形成秦 入領域，於下方空間形成氣體的排出領域。泵室1C 入領域連通至吸入口 27，使排出領域連通至分隔壁 出通道19，而該吸入口 27係設於轉子殼3上方且 〇 連接。於分隔壁6〜9之間形成的各泵室11〜13係 領域各自連通至各分隔壁6〜9之吸入通道23〜25 排出領域各自連通至各分隔壁6〜9之排出通道19 泵室14將吸入領域連通至分隔壁9之吸入通道26 將排出通道連通至設置在轉子殼3下方且與外部相 排出口 2 8。 在以上構成中，吸入口 27以及吸入通道23〜 〇 構成各泵室10〜14的氣體抽吸部，排出通道19〜 排出口 28各自構成各泵室10〜14的氣體排出部。 在外殼1內的約中央部處，平行設置有自前側 後側的兩根旋轉軸29、30，旋轉軸29、30各自具 個在周面上呈一體化之十字形（參考第5圖）轉子3 轉子31、36成對嚙合並且可旋轉地收容於栗室10 下同樣地，轉子32、39可旋轉地收容於栗室11中 33、38可旋轉地收容於泵室12中，轉子34、39 各連通 目口之排 ! 23〜 I體的吸 >係使吸 5 6的排 與外部 將吸入 ，並將 〜2 2。 ，並且 連結之 26各自 22以及 :貫通至 有複數 1 〜4 0。 中，以 ，轉子 丁旋轉地 .201030237 收容於泵室13中，轉子35、40可旋轉地收容於泵室14中。 旋轉軸29、30的前側端部係分別利用軸承41、42可 旋轉地支承於前殼2。軸承41、42可對前殼2朝推力方向 移動。於旋轉軸29、30周面固定有環構件43、44，且於 環構件43、44與前殻2之間介設有作爲第二彈性構件的盤 簧45、46。因此，旋轉軸29、30構成爲藉由盤簧45、46, 透過軸承41、42、環構件43、44,接承朝向前側的彈推力。 ▲ 又’構成爲在環構件43、44外周面與前殼2內周面之間安 〇 裝有密封構件47、48，使得泵室10內的氣體不會漏到外 部。又’符號65係用於覆蓋旋轉軸29、30之前側端部的 外蓋。 旋轉軸29、30的後側係藉由軸承51、52可旋轉地支 承，軸承51、52則藉由安裝在後殼4內周面的保持器49、 5 0來加以支撐。在比軸承5 1、5 2更靠後側位置處，設置 有藉由螺入而固定於旋轉軸29、30周面的彈簧承環53、 φ 54。彈簧承環53、54在調整安裝位置後，可利用適當的手 段固定於旋轉軸29、30,其中利用雙螺帽等即可，構成簡 單。 在軸承51、52的內座圏與彈簧承環53、54之間，安 裝有構成爲壓縮彈簧之作爲本發明之第一彈性構件的螺旋 彈簧55、56，並且對旋轉軸29、30賦予朝向後側的彈推 力。旋轉軸29、30係相對於軸承51、52容許朝向推力方 向移動之構成。較佳爲，相對於盤簧45、46，將螺旋彈簧 -10- .201030237 55、56的彈力設成較強，藉此旋轉軸29、30可成爲位於 最後側位置的狀態。 在位於軸承5 1、5 2前側之後殻4內的空間中，於旋轉 軸29、30上設置有曲徑機構57、58，以密封泵室14內與 軸承5 1、5 2側的空間之間。突出於齒輪殼5內部空間的旋 轉軸29、30之後側端部各自具備齒輪59、60，藉由兩齒 輪59、60的嚙合進行旋轉傳動。旋轉軸29係藉由接頭62 ^ 與固定於齒輪殻5後側外端面的馬達之馬達軸61連結，並 ❹ 接收馬達Μ的驅動力。 與作爲最末端之泵室14排出領域連通的排出口 28， 係連結至消音器63以及排出機構64，自泵室14排出的氣 體會透過排出機構64排出至圖中未顯示之排氣處理裝置。 具有以上構成的多段式魯式栗進行下述之動作。藉由 馬達Μ的驅動力使旋轉軸29旋轉，並經由齒輪59、60使 旋轉軸30旋轉。旋轉軸29之轉子31〜35以及旋轉軸30 〇 之轉子36〜40各自成對並以嚙合狀態於栗室10〜14中旋 轉。隨著旋轉軸29、30的旋轉，可自吸入口 27抽吸氣體。 自吸入口 27被抽吸至第1段栗室10之吸入領域的氣 體藉由轉子31、36被運送至排出領域，然後透過分隔壁6 之排出通道19、連通空間15和吸入通道23被抽吸至鄰接 的第二段泵室11的吸入區域。被抽吸至泵室11中的氣體， 藉由轉子32、37被運送至排出領域，然後藉由分隔壁7之 排出通道20、連通空間16以及吸入通道24被抽吸到第三 -11- .201030237 段泵室12。以下同樣地’泵室12內的氣體依序被運送至 第四段的泵室13以及最末端的泵室14。 自吸入口 27被吸入的氣體，在從泵室1〇送至泵室14 的期間，依序被壓縮，而成爲高溫、高壓的氣體，並朝排 出口 28排出。所以，含有分隔壁6〜9的轉子殻3以及含 有轉子31〜40的旋轉軸29、30會產生熱膨脹，並朝推力 方向以及徑向位移。旋轉軸29、30對於轉子殼3、後殼4 的安裝係構成爲可容許因該熱膨脹所產生朝推力方向之位 〇 移。在位於後殻4內之旋轉軸29、30，形成爲階差部之凸 緣部29a、3 0a的後側側面，係抵接於曲徑機構57、58的 前側端面。因此，旋轉軸29、30藉由屬一端側支持部的軸 承51、52而被限制朝向後側移動，且旋轉軸29、30之凸 緣部29a、30a、曲徑機構57、58、軸承51、52係構成推 力方向移動限制機構。旋轉軸29、30之凸緣部29a、30a 亦可由扣環（circlip)形成。又，將多段式魯式泵的外殻1 ❹ 透過防震橡膠（圖中未顯示）固定於圖中未顯示之安裝基 座，由於馬達Μ係以懸掛於外殼1之後側端面的狀態構 成，所以外殻1的熱膨脹會被防震橡膠吸收。 以上述方式構成之第1實施形態係如下所述般地作 動。 關於多段式魯式泵運轉時的各部位的狀態’參照顯示 有以旋轉軸30的轉子36〜40爲代表的第3圖和第4圖進 行說明。將透過多段式魯式泵的運轉被抽吸至第一段栗室 -12- 201030237 10的氣體依序壓縮並運送至最末端的泵室14。於栗室14 中將被高度壓縮而變成高溫的氣體排出。因此，含有分隔 壁6〜9的轉子殼3以及含有轉子36〜40的旋轉軸3〇會因 熱膨脹而朝徑向以及推力方向產生熱膨脹。 其中，由於推力方向之熱膨脹僅容許朝一方向位移， 所以會在前側的氣體抽吸部側產生位移（參考第3圖的箭頭 方向）。因熱膨脹所致之位移量，以泵室14的周圍爲最大。 但是，由於轉子殼3的外周圍部會暴露於外部空氣，因此 包含分隔壁6〜9在內會經常呈現受到冷卻效果的狀態。相 對地，與轉子殼3分離且包含收容於內部之轉子36〜40的 旋轉軸30’不會受到因外部空氣而所致之冷卻效果。因此， 如第3圖之箭頭長短所示，熱膨脹量會產生外殼側熱膨脹 «<旋轉軸側熱膨脹β的關係。 特別是在構成泵室14的後殼4的前側壁面與轉子40 的後側壁面之間，會產生了很大的間隙66。運送於泵室1 0 〇 〜14之氣体中所混入的粉麈，特別容易堆積於大的間隙66 中，並於此處產生異物67(參考第4圖）塊。由於多段式魯 式泵在運轉中間隙66較大，所以不會特別造成問題。但 是，當多段式魯式泵停止時，因高溫氣體所致之加熱源會 消失，故整體會急速地冷卻。 第4圖係顯示多段式魯式泵於停止時的狀態。含有分 隔壁6〜9的轉子殼3以及含有轉子36〜40的旋轉軸30, 會因熱收縮位移至後側而回到初期設定位置。含熱膨脹量 -13- 201030237 較大之轉子36〜40之旋轉軸30，其熱收縮量也較大，如 第4圖的箭頭的長短所示，會產生外殼側熱收縮γ<旋轉 軸側熱收縮δ的關係。但是，於泵室14的間隙66’存有 運轉時堆積之異物67。 當轉子40即將回到初期設定位置時，異物67會藉由 螺旋彈簧56的彈力而在泵室14內被夾在轉子40與後殼4 的前側壁面之間。雖然異物67對轉子40有很大的旋轉阻 力，但本實施形態中可藉由螺旋彈簧56的伸長使旋轉軸 〇 30維持稍微朝前側位移的狀態。因此，可避免因轉子40 的熱收縮而造成異物67被強力推壓在轉子40與後殼4的 前側壁面之間所致之卡住問題。又，即便異物67堆積在泵 室10〜14的任一間隙，均可防止異物67卡在轉子36〜40、 後殻4的前側壁面、分隔壁6〜9、前殼2的後側壁面之間。 多段式魯式泵於其後被命令重新啓動的情況下，由於 轉子4 0對異物6 7的推壓力較小，摩擦阻力較小，所以可 Q 滑順地啓動。又，期盼在多段式魯式泵重新運轉時，異物 67可藉由氣體的壓力與轉子40的旋轉而逐漸被除去。即 使在堆積有異物67的情況下，轉子40也不會因螺旋彈簧 56的伸長而強力地壓抵於異物67,所以不會妨礙多段式魯 式栗的運轉。 前述第1實施形態具有以下的作用效果。 (1)藉由透過螺旋彈簧55、56彈推，將旋轉軸29、30 設成可朝旋轉軸線方向位移的簡單構造，可抑制因異物67 -14- .201030237 的堆積所致之大摩擦阻力的發生。 (2) 藉由分別使盤簧45、46以及螺旋彈簧55、56介設 於外殼1的前側和後側，可易於進行泵室1 〇〜1 4中之轉子 36〜40的初期設定位置的定位。 (3) 螺旋彈簧55、56對旋轉軸29、30施加彈推力的方 向，係與多段式魯式泵中氣體的運送方向相同，旋轉軸29、 30的凸緣部29a、30a、曲徑機構57、58和軸承51、52, 可在多段式魯式栗的最末端側限制推力方向的移動，可有 〇 效地防止氣體自最末端泵室14洩露出。 本發明並不限定於前述實施形態的構成，於本發明之 旨趣的範圍內亦可進行各種變更，可如下地實施。 (1) 本發明的第一彈性構件不限於螺旋彈簧5 5、5 6，可 使用盤簧或是樹脂、橡膠等的彈性構件。 (2) 螺旋彈簧55、56等第一彈性構件並不限設置於後 側，亦可設置於前側或後側與前側的中間位置。 〇 (3)如第1實施形態所示，以螺旋彈簧55、56爲代表 的第一彈性構件，不限設置在旋轉軸29、30上，只要是可 將旋轉軸29、30朝旋轉軸線方向彈推的構成，則亦可設置 於其他位置。又，在以下各實施形態的說明中，以括號表 示之數字爲第2圖顯示之旋轉軸3 0側的組成構件。例如， 第7圖顯示之第2實施形態，係構成爲使軸承51(5 2)可與 旋轉軸29(3 0)—體地滑動，並且將軸承51(52)的外座圈抵 接於安裝在保持器49(5 0)之限制板68(69)上。因此，雖然 -15- .201030237 旋轉軸29(3 0)以及軸承51(5 2)會被限制往後側（第7圖的右 側）之移動，卻可被允許因熱膨脹而往前側（第7圖的左側） 之移動。作爲本發明之第一彈性構件的螺旋彈簧70(71)， 係設置在保持器49(50)前側所形成之突起部72(73)與軸承 51(52)的外座圈之間。螺旋彈簧70(71)係使旋轉軸29(3 0) 以及軸承51 (5 2)朝向與因熱膨脹而移動之方向相反的方向 (第7圖的右側）彈推。第2實施形態可期盼具有與第1實 施形態同樣的作用效果。 〇 (4) 第8圖所示之第3實施形態，係構成爲可使軸承 51(52)以及保持器49(50)與旋轉軸29(30)—體地滑動。藉 由第1圖和第2圖所示之旋轉軸29(30)之凸緣部29a、30a 與曲徑機構57、58相抵接，可限制軸承51(52)、保持器 49(50)以及旋轉軸29(3 0)朝向後側（第8圖的右側）的移 動’並可允許因熱膨脹而朝向前側（第8圖的左側）的移動。 本發明之第一彈性構件的螺旋彈簧74(75)係設置在保持器 〇 49(50)的後側突起部76(77)與後殼4的後側缺口部7 8(79) 之間。螺旋彈簧74(75)係將旋轉軸29(30)、軸承51(52)以 及保持器49(50)朝向因熱膨脹而移動之方向相反的方向 (第8圖的右側）彈推。第3實施形態可期盼具有與第1實 施形態相同的作用效果》 (5) 設置可限制因螺旋彈簧55、56而朝向旋轉軸29、 3 〇之後側移動之具剛性的限制構件來取代作爲第二彈性構 件的盤簧45、46 ’亦可獲得本發明之作用效果。 -16- .201030237 (6) 含分隔壁6〜9的轉子殼3以及含轉子31〜40的旋 轉軸29、30因熱膨脹而位移的方向，不限於如第1實施形 態的吸入部側，亦可構成爲僅朝排出部側位移》 (7) 外殻1並非一定是分割成兩部分的構成，亦可爲一 體成型或分割成三部分以上之分割構成。 (8) 本發明不限於多段式魯式泵，亦可實施於具有單一 泵室的魯式栗。 (9) 本發明不限於魯式泵，可爲在例如使用螺旋式泵或 ❹ 齒輪泵等之旋轉式真空泵中實施。 【圖式簡單說明】 第1圖係多段式魯式泵的前視剖面圖。 第2圖係多段式魯式栗的俯視剖面圖。 第3圖係顯示熱膨脹時的部分俯視剖面圖。 第4圖係顯示熱收縮時的部分俯視剖面圖。 第5圖係第2圖之A-A線剖面圖。 Q 第6圖係第2圖之B-B線剖面圖。 第7圖係顯示第2實施形態的部分剖面圖。 第8圖係顯示第3實施形態的部分剖面圖。 【主要元件符號說明】 1 外殼 2 前殼 3 轉子殼 4 後殼 17- 201030237In the invention described in the second aspect of the patent application, since the second elastic member is provided, the spring A 201030237 that allows the thermal expansion direction is applied to the rotating shaft, so that the two elastic members having the opposite directions can be positioned. By rotating the shaft, it is possible to reduce the frictional resistance generated by foreign matter accumulated in the pump chamber due to thermal expansion. In the invention described in claim 3, the thrust direction movement restricting mechanism is composed of a step portion formed on the rotating shaft and a bearing supporting the rotating shaft, and the step portion and the bearing are Direct or indirect contact can limit the movement of the thrust direction, so it can be achieved by simple means. In the invention according to the fourth aspect of the invention, since the first elastic member is disposed between the step portion and the bearing, the pressing force can be appropriately applied to the rotating shaft. In the invention described in claim 5, since the rotary vacuum system is a multi-stage Lu pump, the present invention can be suitably carried out. In the invention according to claim 6, the direction in which the first elastic member imparts a spring force to the rotating shaft is the same as the direction in which the gas in the multi-stage Lu pump G is carried out, and the thrust direction is restricted. The mechanism is disposed at the extreme end side of the multi-stage Lu pump, so that the movement of the most end side thrust direction of the multi-stage Lu pump can be restricted and the gas can be effectively prevented from leaking from the most end pump chamber 14. [Effects of the Invention] The present invention can smoothly restart the rotary vacuum pump regardless of whether or not foreign matter accumulates in the pump chamber. [Embodiment] 201030237 (First embodiment) Hereinafter, a first embodiment of a multi-stage Lu pump according to the present invention will be described with reference to Figs. 1 to 6 . Further, in the present specification, the direction of the multi-stage Lu pump is the left side of the first to fourth figures as the front side, the right side as the rear side, the upper side as the upper side, and the lower side as the lower side, and the fifth figure and the fifth figure and The right side of Fig. 6 is described as the front side and the left side as the back side. The outer casing 1 forming the multi-stage Lu pump shape is sequentially joined with the front casing 2, the rotor casing 3, the rear casing 4, and the gear casing 5 from the front side, and is sealed by, for example, a screw in the state of being sealed inside (in the figure) Not shown) and so on. Each of the outer casings 2 to 5 is configured such that the cylindrical body having the substantially elliptical inner space is divided into two parts up and down as in the fifth and sixth views. The two-part splitting structure can be effectively combined into a multi-stage Lu-type pump. For example, the members of the mechanisms described below are attached to the divided cylindrical body on the lower side, and then the upper divided cylindrical body is covered to form a sealed state. And then combined into one. Further, since the two-division configuration of each of the outer casings 2 to 5 is not closely related to the present invention, detailed description thereof will be omitted. Further, the respective configurations of the multi-stage Lu pump are described in the state after the combination as in the respective drawings. Inside the rotor case 3, partition walls 6 to 9 which are divided into two parts up and down are attached to the front side in a narrow manner from the front side, and between the partition wall 6 and the front case 2, and the partition walls 6 to Pump chambers 10 to 14 are formed between 9 and between the partition wall 9 and the rear casing 4, respectively. Therefore, each of the partition walls 6 to 9 is formed as a part of the rotor case 3 for forming the pump chambers 10 to 14. Further, each of the pump chambers 10 to 14 has a volume that is sequentially reduced from the front side. 201030237 Each of the partition walls 6 to 9 has a communication space 15 to 18 inside. As shown in Fig. 1, the space 1 5 to 18 has a passage 19 to 22 toward the front side and a suction passage 26 which is open to the rear side at the top. » In the first drawing, each pump chamber 10 to 14 It is formed in the upper space to form the Qin into the field, forming a gas discharge field in the space below. The pump chamber 1C is connected to the suction port 27, and the discharge area is communicated to the partition wall outlet passage 19, and the suction port 27 is provided above the rotor casing 3 and connected to the crucible. Each of the pump chambers 11 to 13 formed between the partition walls 6 to 9 is connected to the suction passages 23 to 25 of the partition walls 6 to 9 respectively. The discharge passages are respectively connected to the discharge passages 19 of the partition walls 6 to 9 The suction passage 26 that connects the suction field to the partition wall 9 communicates the discharge passage to a discharge port 28 disposed below the rotor casing 3 and externally. In the above configuration, the suction port 27 and the suction passages 23 to 构成 constitute the gas suction portions of the pump chambers 10 to 14, and the discharge passage 19 to the discharge port 28 constitute the gas discharge portions of the pump chambers 10 to 14, respectively. At the center portion of the outer casing 1, two rotating shafts 29, 30 are provided in parallel from the front side rear side, and the rotating shafts 29, 30 each have a cross shape which is integrated on the circumferential surface (refer to Fig. 5). The rotor 3 rotors 31, 36 are meshed in pairs and rotatably received in the chest chamber 10. Similarly, the rotors 32, 39 are rotatably received in the chest chambers 11, 33, 38 rotatably received in the pump chamber 12, the rotor 34 , 39 rows of connected eyes! 23 ~ I body suction > so that the suction of 5 6 rows and the outside will be inhaled, and will be ~ 2 2 . And each of the links 26 and 22: through to the plural 1 to 4 0. The rotors 35 and 40 are rotatably housed in the pump chamber 14 in the pump chamber 13 . The front end portions of the rotary shafts 29, 30 are rotatably supported by the front case 2 by bearings 41, 42, respectively. The bearings 41, 42 are movable toward the thrust direction of the front case 2. Ring members 43, 44 are fixed to the circumferential surfaces of the rotating shafts 29, 30, and coil springs 45, 46 as second elastic members are interposed between the ring members 43, 44 and the front housing 2. Therefore, the rotating shafts 29 and 30 are configured to transmit the projectile thrust toward the front side through the bearings 41 and 42 and the ring members 43 and 44 by the coil springs 45 and 46. ▲ Further, the sealing members 47 and 48 are mounted between the outer circumferential surfaces of the ring members 43 and 44 and the inner circumferential surface of the front casing 2 so that the gas in the pump chamber 10 does not leak to the outside. Further, the symbol 65 is an outer cover for covering the front end portions of the rotary shafts 29 and 30. The rear sides of the rotary shafts 29, 30 are rotatably supported by the bearings 51, 52, and the bearings 51, 52 are supported by the retainers 49, 50 mounted on the inner peripheral surface of the rear casing 4. Spring retaining rings 53 and φ 54 which are fixed to the circumferential surfaces of the rotating shafts 29 and 30 by screwing are provided at positions on the rear side of the bearings 5 1 and 5 2 . After adjusting the mounting position, the spring retaining rings 53, 54 can be fixed to the rotating shafts 29, 30 by appropriate means, and the double nut or the like can be used to form a simple structure. Between the inner seat of the bearings 51, 52 and the spring retainers (53, 54), coil springs 55, 56 which are the first elastic members of the present invention which are configured as compression springs are attached, and the rotating shafts 29, 30 are oriented. The elastic thrust on the back side. The rotating shafts 29 and 30 are configured to be allowed to move in the thrust direction with respect to the bearings 51 and 52. Preferably, the elastic forces of the coil springs -10.201030237 55, 56 are set to be strong with respect to the coil springs 45, 46, whereby the rotary shafts 29, 30 can be in the state of being located at the rearmost position. In the space inside the casing 4 on the front side of the bearings 5 1 and 5 2, the radial shafts 29, 30 are provided with labyrinth mechanisms 57, 58 to seal the space in the pump chamber 14 and the bearings 5 1 and 5 2 between. The rear end portions of the rotary shafts 29, 30 projecting from the inner space of the gear case 5 are each provided with gears 59, 60, and are rotationally driven by the meshing of the two gears 59, 60. The rotary shaft 29 is coupled to the motor shaft 61 of the motor fixed to the rear outer end surface of the gear housing 5 via a joint 62^, and receives the driving force of the motor cymbal. The discharge port 28 that communicates with the discharge area of the pump chamber 14 as the end is connected to the muffler 63 and the discharge mechanism 64, and the gas discharged from the pump chamber 14 is discharged to the exhaust gas treatment device (not shown) through the discharge mechanism 64. . The multi-stage Lu type pump having the above configuration performs the following operations. The rotary shaft 29 is rotated by the driving force of the motor cymbal, and the rotary shaft 30 is rotated via the gears 59, 60. The rotors 31 to 35 of the rotary shaft 29 and the rotors 36 to 40 of the rotary shaft 30 各自 are each paired and rotated in the engagement state in the chest chambers 10 to 14. As the rotating shafts 29, 30 rotate, gas can be sucked from the suction port 27. The gas sucked into the suction region of the first stage chest chamber 10 from the suction port 27 is transported to the discharge area by the rotors 31, 36, and then drawn through the discharge passage 19 of the partition wall 6, the communication space 15, and the suction passage 23. Suction into the suction region of the adjacent second pump chamber 11. The gas sucked into the pump chamber 11 is transported to the discharge area by the rotors 32, 37, and then sucked to the third -11 by the discharge passage 20 of the partition wall 7, the communication space 16, and the suction passage 24. .201030237 Stage pump chamber 12. Similarly, the gas in the pump chamber 12 is sequentially transported to the pump chamber 13 of the fourth stage and the pump chamber 14 at the end. The gas sucked from the suction port 27 is sequentially compressed while being sent from the pump chamber 1 to the pump chamber 14, and is a high-temperature, high-pressure gas, and is discharged to the discharge port 28. Therefore, the rotor case 3 including the partition walls 6 to 9 and the rotary shafts 29, 30 including the rotors 31 to 40 are thermally expanded and displaced in the thrust direction and the radial direction. The mounting shafts of the rotating shafts 29, 30 for the rotor case 3 and the rear case 4 are configured to allow the positional displacement in the thrust direction due to the thermal expansion. The rotating shafts 29, 30 located in the rear casing 4 are formed as the rear side faces of the flange portions 29a, 30a of the step portions, and abut against the front end faces of the labyrinth mechanisms 57, 58. Therefore, the rotating shafts 29, 30 are restricted from moving toward the rear side by the bearings 51, 52 belonging to the one end side supporting portion, and the flange portions 29a, 30a of the rotating shafts 29, 30, the labyrinth mechanisms 57, 58, and the bearing 51 The 52 series constitutes a thrust direction movement restricting mechanism. The flange portions 29a, 30a of the rotating shafts 29, 30 may also be formed by a circlip. Further, the outer casing 1 多 of the multi-stage Lu pump is fixed to a mounting base (not shown) through a shock-proof rubber (not shown), and the motor is configured to be suspended from the rear end surface of the outer casing 1 The thermal expansion of the outer casing 1 is absorbed by the anti-vibration rubber. The first embodiment configured as described above operates as follows. The state of each part in the operation of the multi-stage Lu pump is shown in Fig. 3 and Fig. 4, which are represented by the rotors 36 to 40 of the rotating shaft 30. The gas pumped to the first stage chest chamber -12-201030237 10 through the operation of the multi-stage Lu pump is sequentially compressed and transported to the pumping chamber 14 at the extreme end. The gas which is highly compressed and becomes high temperature is discharged in the chest chamber 14. Therefore, the rotor case 3 including the partition walls 6 to 9 and the rotating shaft 3〇 including the rotors 36 to 40 are thermally expanded in the radial direction and the thrust direction due to thermal expansion. Among them, since the thermal expansion in the thrust direction is only allowed to be displaced in one direction, displacement occurs on the gas suction portion side on the front side (refer to the arrow direction in Fig. 3). The amount of displacement due to thermal expansion is maximized around the pump chamber 14. However, since the outer peripheral portion of the rotor case 3 is exposed to the outside air, the partition walls 6 to 9 often exhibit a cooling effect. Conversely, the rotating shaft 30' separated from the rotor case 3 and including the rotors 36 to 40 housed inside is not subjected to the cooling effect due to the outside air. Therefore, as indicated by the length of the arrow in Fig. 3, the amount of thermal expansion causes a relationship between the thermal expansion of the outer casing side «<the thermal expansion of the rotating shaft side β. In particular, a large gap 66 is generated between the front side wall surface of the rear case 4 constituting the pump chamber 14 and the rear side wall surface of the rotor 40. The whitefly mixed in the gas sent to the pump chambers 10 to 14 is particularly likely to accumulate in the large gap 66, and a foreign matter 67 (refer to Fig. 4) is generated therein. Since the multi-stage Lu pump has a large gap 66 during operation, it does not pose a particular problem. However, when the multi-stage Lu pump stops, the heating source due to the high temperature gas will disappear, so the whole will be rapidly cooled. Figure 4 shows the state of the multi-stage Lu pump when it is stopped. The rotor case 3 including the partition walls 6 to 9 and the rotating shaft 30 including the rotors 36 to 40 are displaced to the rear side by thermal contraction and returned to the initial setting position. The amount of thermal expansion -13 - 201030237 The rotating shaft 30 of the larger rotors 36 to 40 has a large heat shrinkage amount. As shown by the length of the arrow in Fig. 4, the outer casing side heat shrinkage γ < rotary shaft side heat is generated. The relationship of shrinkage δ. However, the foreign matter 67 accumulated during the operation is present in the gap 66' of the pump chamber 14. When the rotor 40 is about to return to the initial set position, the foreign matter 67 is sandwiched between the rotor 40 and the front side wall surface of the rear case 4 in the pump chamber 14 by the elastic force of the coil spring 56. Although the foreign matter 67 has a large rotational resistance to the rotor 40, in the present embodiment, the rotation axis 〇 30 can be maintained slightly displaced toward the front side by the elongation of the coil spring 56. Therefore, the jamming problem caused by the foreign matter 67 being strongly pressed between the rotor 40 and the front side wall surface of the rear case 4 due to the heat shrinkage of the rotor 40 can be avoided. Further, even if the foreign matter 67 is deposited in any of the gaps of the pump chambers 10 to 14, the foreign matter 67 can be prevented from being caught on the rotors 36 to 40, the front side wall surface of the rear case 4, the partition walls 6 to 9, and the rear side wall surface of the front case 2. between. In the case where the multi-stage Lu pump is commanded to be restarted thereafter, since the thrust of the rotor 40 against the foreign matter 67 is small and the frictional resistance is small, the Q can be smoothly started. Further, it is expected that the foreign matter 67 can be gradually removed by the pressure of the gas and the rotation of the rotor 40 when the multi-stage Lu pump is operated again. Even when the foreign matter 67 is deposited, the rotor 40 is not strongly pressed against the foreign matter 67 by the elongation of the coil spring 56, so that the operation of the multi-stage lube is not hindered. The first embodiment described above has the following effects. (1) By rotating the coil springs 55, 56, the rotating shafts 29, 30 are set to a simple structure that can be displaced in the direction of the rotation axis, and the large frictional resistance due to the accumulation of the foreign matter 67 - 14 - . 201030237 can be suppressed. happened. (2) By initially arranging the coil springs 45, 46 and the coil springs 55, 56 on the front side and the rear side of the outer casing 1, the initial setting positions of the rotors 36 to 40 in the pump chambers 1 to 14 can be easily performed. Positioning. (3) The direction in which the coil springs 55, 56 apply the elastic thrust to the rotating shafts 29, 30 is the same as the direction in which the gas is transported in the multi-stage Lu pump, the flange portions 29a, 30a of the rotating shafts 29, 30, and the labyrinth mechanism 57, 58 and the bearings 51, 52, the movement of the thrust direction can be restricted at the extreme end side of the multi-stage lug, which can effectively prevent the gas from leaking from the most end pump chamber 14. The present invention is not limited to the configuration of the above-described embodiment, and various modifications can be made within the scope of the present invention, and can be carried out as follows. (1) The first elastic member of the present invention is not limited to the coil springs 5 5 and 5 6, and a coil spring or an elastic member such as resin or rubber may be used. (2) The first elastic members such as the coil springs 55, 56 are not limited to the rear side, and may be provided at the intermediate position between the front side or the rear side and the front side. (3) As shown in the first embodiment, the first elastic members typified by the coil springs 55 and 56 are not limited to the rotating shafts 29 and 30, and the rotating shafts 29 and 30 may be oriented in the direction of the rotation axis. The structure of the pusher can also be set at other locations. Further, in the following description of the respective embodiments, the numbers indicated by the parentheses are the constituent members on the side of the rotating shaft 30 shown in Fig. 2 . For example, in the second embodiment shown in Fig. 7, the bearing 51 (52) is slidable integrally with the rotating shaft 29 (30), and the outer race of the bearing 51 (52) is abutted. Mounted on the limiting plate 68 (69) of the retainer 49 (50). Therefore, although the -15-.201030237 rotating shaft 29 (30) and the bearing 51 (52) are restricted to move to the rear side (the right side of Fig. 7), they can be allowed to move forward due to thermal expansion (the first The movement of the left side of the figure 7). The coil spring 70 (71) as the first elastic member of the present invention is disposed between the projection 72 (73) formed on the front side of the retainer 49 (50) and the outer race of the bearing 51 (52). The coil spring 70 (71) springs the rotating shaft 29 (30) and the bearing 51 (52) in a direction opposite to the direction of movement due to thermal expansion (the right side of Fig. 7). The second embodiment can be expected to have the same operational effects as those of the first embodiment. (4) In the third embodiment shown in Fig. 8, the bearing 51 (52) and the retainer 49 (50) are slidably engaged with the rotary shaft 29 (30). The flange portions 29a and 30a of the rotating shaft 29 (30) shown in Figs. 1 and 2 abut against the labyrinth mechanisms 57 and 58 to restrict the bearing 51 (52) and the retainer 49 (50). The movement of the rotating shaft 29 (30) toward the rear side (the right side of Fig. 8) can allow the movement toward the front side (the left side of Fig. 8) due to thermal expansion. The coil spring 74 (75) of the first elastic member of the present invention is disposed between the rear side protrusion portion 76 (77) of the retainer 〇 49 (50) and the rear side notch portion 78 (79) of the rear case 4. The coil spring 74 (75) springs the rotating shaft 29 (30), the bearing 51 (52), and the retainer 49 (50) in a direction opposite to the direction of movement due to thermal expansion (the right side of Fig. 8). The third embodiment is expected to have the same operational effects as those of the first embodiment. (5) Instead of being provided as a restricting member that can restrict the movement of the coil springs 55 and 56 toward the rear side of the rotating shafts 29 and 3, The coil springs 45, 46' of the second elastic member can also obtain the effects of the present invention. -16-.201030237 (6) The direction in which the rotor case 3 including the partition walls 6 to 9 and the rotating shafts 29 and 30 including the rotors 31 to 40 are displaced by thermal expansion is not limited to the suction portion side of the first embodiment. The outer casing 1 may be configured to be divided into two or more portions. (8) The present invention is not limited to a multi-stage Lu pump, but can also be implemented in a Lu pump having a single pump chamber. (9) The present invention is not limited to the Lu pump, and may be implemented in a rotary vacuum pump using, for example, a screw pump or a 齿轮 gear pump. [Simple description of the diagram] Figure 1 is a front cross-sectional view of a multi-stage Lu pump. Figure 2 is a top cross-sectional view of a multi-stage Lu chestnut. Fig. 3 is a partial plan sectional view showing a state of thermal expansion. Fig. 4 is a partial plan sectional view showing the heat shrinkage. Fig. 5 is a cross-sectional view taken along line A-A of Fig. 2. Q Fig. 6 is a cross-sectional view taken along line B-B of Fig. 2. Fig. 7 is a partial cross-sectional view showing the second embodiment. Fig. 8 is a partial cross-sectional view showing a third embodiment. [Main component symbol description] 1 Housing 2 Front housing 3 Rotor housing 4 Rear housing 17- 201030237
5 6、7、7、9 10、 11、 12、 13、 15、 16、 17、 18 19、 20 、 21、 22 23 、 24 、 25 ' 26 27 28 29、30 31、 32 、 33 、 34 、 41 、 42 、 51、 52 45、46 53、54 55、 56、 70、 71、 64 66 67 72 、 73 、 76 、 77 78、79 Μ 齒輪殼 分隔壁 14 泵室 連通空間 排出通道 吸入通道 吸入口 排出口 旋轉軸 35 、 36 、 37 ' 38 、 39 、 軸承 盤簧 彈簧承環 74、75螺旋彈簧 排出機構 間隙 異物 突起部 缺口部 馬達 40 轉子 -18-5 6, 7, 7, 9 10, 11, 12, 13, 15, 16, 17, 18 19, 20, 21, 22 23, 24, 25 ' 26 27 28 29, 30 31, 32, 33, 34, 41, 42 , 51 , 52 45 , 46 53 , 54 55 , 56 , 70 , 71 , 64 66 67 72 , 73 , 76 , 77 78 , 79 齿轮 Gear housing partition wall 14 pump chamber communication space discharge passage suction passage suction port Exhaust shaft rotating shaft 35, 36, 37' 38, 39, bearing coil spring retaining ring 74, 75 coil spring discharge mechanism clearance foreign matter protrusion notch motor 40 rotor-18-