201000771 六、發明說明： 【發明所屬之技術領域】 本發明是關於例如搬運超臨界co2流體或液體c〇2用 的泵浦。 【先前技術】 例如：搬運超臨界co2流體或液體c〇2用的泵浦，有 半導體洗淨用的循環泵浦。隨著近年來半導體設備的高集 成化’晶圓的加工線寬度也被要求微細化，針對現在爲主 流的〇 · 1 8 // m，預估將來會成爲0 · 1 0 // m以下。然而，先前 使用超純水等液體進行半導體洗淨的方式，於晶圓乾燥時 ，氣體和液體的界面張力因素造成的毛細力，有時會導致 形成在晶圓的抗鈾劑產生倒壞現象（抗蝕劑倒壞）。 爲了解決上述不利因素，已開發有使用超臨界流體的 半導體洗淨裝置取代先前的超純水等液體。超臨界流體， 相較於液體，其具有非常高的浸透性，能夠浸透任何微細 的構造。此外，氣體和液體之間並沒有界面存在，因此具 備所謂乾燥時不產生毛細力的特徵。 超臨界流體，主要是使用二氧化碳（co2)。二氧化 碳，相較於其他的液體溶媒是在比較穩健的條件，即在臨 界溫度31.2°C、臨界壓力7.38MPa’就會達到臨界密度468 kg/m3。此外，因二氧化碳在常溫、常壓狀態下是爲氣體 ，所以當恢復成常溫、常壓狀態時二氧化碳就會氣化，能 夠容易分離被洗淨物和污染物’因此洗淨後的被洗淨物不 -5- 201000771 需要乾燥等，能夠簡略洗淨流程和降低成本。 上述使用超臨界€〇2流體的半導體洗淨裝置，其超臨 界C02流體通常是加壓成約20MPa，因此可使其循環做爲 晶圓洗淨用的循環泵浦是使用能夠耐高壓所謂非密封型屏 蔽電動泵浦形式的循環泵浦。另外，軸承是使用滾珠軸承 ，其是在半導體洗淨劑的揚液（超臨界C02 )中使用。 該滾珠軸承承受著作用在轉子的徑向載重及軸向載重 。此外，以葉輪側相反側的設置在軸端側軸承的軸承預壓 彈簧控制預壓載重，藉此達到能夠防止滾珠軸承的公轉滑 動（橫向滑動）。另外，以軸承預壓載重控制滾珠軸承的 徑向剛性（彈簧常數），同時也執行轉子固有振動數的調 整。 上述泵浦有下述專利文獻1記載的泵浦。 [專利文獻1]日本特開2007-23 1 95 8號公報 【發明內容】 [發明欲解決之課題] 然而，上述先前的泵浦，其滾珠軸承是使用在黏性低 的超臨界co2流體內（或液體co2)，所以無法期望揚液 的潤滑。因此，在滾珠軸承會產生磨損，使主軸及葉輪沿 著旋轉軸心的方向移動。葉輪是利用其旋轉使吸入口吸入 的流體昇壓從吐出口吐出，爲了防止流體從吐出口往吸入 口逆流’機殼和葉輪之間的軸方向間隙是設定成非常狹窄 。然而’當滾珠軸承的磨損造成主軸及葉輪沿著旋轉軸心 -6- 201000771 的方向移動時，葉輪和機殻之間會產生干涉，導致有使用 壽命降低的問題。 本發明是爲了解決上述課題所硏創的發明，目的是提 供一種能夠延長使用壽命的泵浦。 [用以解決課題之手段] 爲了達成上述目的，申請專利範圍第1項發明記載的 泵浦，其具備：具吸入口和吐出口的機殼；在該機殼內利 用滾珠軸承支撐成旋轉自如的主軸；連結於該主軸的軸端 部的葉輪；及透過上述主軸可驅動旋轉上述葉輪的屏蔽馬 達，構成爲利用上述葉輪的旋轉使上述吸入口吸入的流體 昇壓從上述吐出口吐出，其特徵爲，在上述葉輪的軸心方 向前側設有前部覆緣的同時，在上述葉輪的軸心方向後側 設有後部覆緣，在上述機殼和上述前部覆緣之間設有在軸 方向相向的指定間隙的同時，在上述機殼和上述前部覆緣 之間設有在徑方向相向的密封部。 申請專利範圍第2項發明記載的泵浦，其特徵爲，上 述密封部是排列在上述葉輪的軸心方向設置成複數。 申請專利範圍第3項發明記載的泵浦，其特徵爲，於 上述機殼，使來自於上述葉輪的流體出口透過擴散器及渦 室連通於上述吐出口，在上述擴散器設有縮口部。 申請專利範圍第4項發明記載的泵浦，其特徵爲，上 述縮口部的形狀是根據上述擴散器出口的流體流出角，和 上述擴散器出口與上述渦室的通道面積比進行設定。 201000771 申請專利範圍第5項發明記載的泵浦，其特徵爲，設 有對上述滾珠軸承施加預壓的預壓彈簧，該預壓彈簧是由 環狀的波板材複數層疊所構成。 申請專利範圍第6項發明記載的泵浦，其特徵爲，上 述葉輪是藉由旋轉驅動就能夠搬運超臨界co2流體或液體 co2’能夠做爲半導體洗淨用循環泵浦使用。 [發明效果] 根據申請專利範圍第1項發明的泵浦時，在具有吸入 口和吐出口的機殼內利用滾珠軸承使主軸支撐成旋轉自如 ，於該主軸的軸端部連結著葉輪，構成爲利用屏蔽馬達透 過主軸就能夠驅動旋轉葉輪，在該葉輪的軸心方向前側設 有前部覆緣的同時，在軸心方向後側設有後部覆緣’在機 殼和前部覆緣之間設有在軸方向相向的指定間隙的同時’ 在機殼和前部覆緣之間設有在徑方向相向的密封部。因此 ’利用密封部就能夠防止流體從吐出口往吸入口逆流’此 外，即使滾珠軸承的磨損造成主軸及葉輪沿著旋轉軸心方 向移動，但因葉輪和機殼之間設有指定間隙，所以兩者不 會彼此干涉，因此能夠延長泵浦壽命。 根據申請專利範圍第2項發明的泵浦時，因是將密封 部排列在葉輪的軸心方向設置成複數，所以利用複數的密 封部就能夠降低葉輪和機殼之間的流體洩漏，能夠適當防 止流體從吐出口往吸入口逆流。 根據申請專利範圍第3項發明的泵浦時，因是將來自 -8- 201000771 於葉輪的流體出口透過擴散器及渦 散器設有縮口部，所以就能夠使擴 形成較大，藉此能夠降低擴散器出 ，同時能夠容許葉輪的移動防止干 根據申請專利範圍第4項發明 狀，因是根據擴散器出口的流體流 渦室的通道面積比進行設定，所以 適當形狀，使從擴散器出口流出至 度和圓周方向速度的合計速度減速 擴散器效果，即能夠充分確保流體 換成壓力能量（靜壓），能夠提昇i 根據申請專利範圍第5項發明 滾珠軸承施加預壓的預壓彈簧，由 構成預壓彈簧，所以利用預壓彈簧 預壓，藉此能夠抑制滾珠軸承的公 的同時，藉由將波板材複數層疊構 彈簧受壓尺寸變化量相對的載重變 預壓。 根據申請專利範圍第6項發明 葉輪就能夠搬運超臨界C02流體或 導體洗淨用循環泵浦使用，所以洗 要乾燥，因此能夠使洗淨程序簡化 【實施方式】 室連通於吐出口，在擴 散器出口的流體流出角 口至擴散器入口的損耗 涉。 的泵浦時，縮口部的形 出角，和擴散器出口與 就能夠將縮口部設定成 渦室的流體其徑方向速 ，藉此就能夠充分確保 的速度能量（動壓）轉 栗浦效率。 的泵浦時，因是設有對 環狀的波板材複數層疊 就能夠對滾珠軸承施加 轉滑動可延長使用壽命 成預壓彈簧，能夠減少 化量，能夠施加適當的 的泵浦時，以旋轉驅動 液體C〇2，能夠做爲半 淨後的被洗淨物就不需 及削減成本。 -9- 201000771 [發明之最佳實施形態] 以下是參照附圖，對本發明相關的泵浦最佳實施例進 行詳細說明。另’本發明並不限於該實施例。 [實施例] 第1圖爲表示本發明一實施例相關的泵浦爲半導體洗 淨裝置用循環泵浦時的剖面圖，第2圖爲表示本實施例的 半導體洗淨裝置用循環栗浦要部放大圖。 本實施例的半導體洗淨裝置用循環栗浦，如第1圖及 第2圖所示，其具備：具吸入口 11和吐出口12的機殼13; 在該機殼13內利用滾珠軸承14、15支撐成旋轉自如的主軸 16;連結於該主軸16軸端部的葉輪17;及透過主軸16可驅 動旋轉葉輪17的屏蔽馬達18’構成爲利用葉輪17的旋轉就 能夠使吸入口 1 1吸入的流體昇壓從吐出口丨2吐出。 該機殼1 3 ’是構成爲’環狀的吐出暨吸入側機殼2 i和 沖洗側機殻2 2配置成夾著圓筒形狀的外筒2 3，利用連結螺 栓2 4連結著’在吐出暨吸入側機殻2 1的外側固定著岐管2 5 ，利用連結螺栓26連結著。接著，該岐管25是在主軸16的 軸心延長軸線上形成有揚液的吸入口 1 1，該吸入口〗丨的外 圍側形成有吐出口 1 2。 滾珠軸承I4、15是斜角滾珠軸承，其是安裝在吐出暨 吸入側機殻21和沖洗側機殼22 ’將主軸16支撐成旋轉自如 。接著’該主軸16的軸端部嵌合著葉輪17，利用連結螺栓 27固定著。 -10- 201000771 另外，本實施例中，滾珠軸承Μ、15’爲了提昇耐磨 損性及耐蝕性及降低高速旋轉時的離心載重，對於內外輪 及滾珠是採用陶瓷材料（例如：氮化矽SisN4、鋁Al2〇3、 碳化矽S i C等）。如上述，將軸承材料全部爲陶瓷，能夠 連帶提昇其相對於外來微粒的耐磨損性。此外，將{呆f寺^ 設計成能夠減少阻力損耗（旋轉阻力）。如此一來，，就肯g 夠防止公轉滑動及降低預壓載重（推力軸承載重），fg多句 達到滾珠軸承I4、15的長壽命化。保持器的材料，基於其 對洗淨劑的耐蝕性、耐磨損性、確保其對高速旋轉的纟茧g 之觀點，是使用PEEK材（聚醚酮醚）。另，也可取代 PEEK材使用不銹鋼或纖維複合材料。 屏蔽馬達18，是由：固定在外筒23內圍部的定子28; 及與該定子28成相向設置在主軸16外圍部的轉子29所構成 〇 另一方面’於沖洗側機殼2 2，是在主軸1 6的軸心延長 軸線上形成有能夠吐出所吸入之揚液一部份的沖洗口 3 0。 此外’沖洗側機殻2 2和斜角滾珠軸承〗5之間，夾持著預壓 彈簧31。該預壓彈簧31是位於主軸16另一端周邊位置由環 狀波板彈簧複數層疊構成，以定壓彈簧方式對滾珠軸承15 施加軸方向的預壓。 因此，當對屏蔽馬達1 8通電時，轉子2 9會對定子2 8形 成旋轉’主軸16會和該轉子29 —起旋轉，連動於該旋轉使 葉輪17旋轉。如此一來，揚液就會從吸入口 η吸入，由葉 輪1 7的離心力昇壓引導至吐出口 1 2側朝外部吐出。此外， 201000771 從吸入口 1 1吸入的揚液一部份是通過滾珠軸承1 4、1 5及屏 蔽馬達18內，對該等進行冷卻後以沖洗流從沖洗口 30吐出 〇 於上述構成的循環泵浦，本實施例中，葉輪17爲封閉 式，相對於機殼13使主軸16及葉輪17支撐成對軸心方向只 以指定量移動自如同時，以機殼1 3和葉輪1 7的徑方向形成 密封。 即，機殼1 3構成用的吸入暨吐出側機殼2 1是在其中心 部形成有可連通於吸入口 1 1的收容孔4 1 ’在該收容孔4 1的 內圍面固定著外圍環42及外圍環43。另一方面’葉輪口’ 是構成爲，於設置在軸心方向前側的環狀前部覆緣44和設 置在軸心方向後側的圓板形狀後部覆緣4 5之間’在圓周方 向以等間隔設有複數的葉片46。 於該狀況時，前部覆緣44具有與葉輪17徑方向水平的 圓板部44a和與軸方向水平的筒部Wb。接著’在外圍環43 (機殼1 3 )的一端部和前部覆緣4 4的圓板部4 4 a的表面部 之間，設有在軸方向相向的指定間隙47。此外’在外圍環 43 (機殼13)的內圍部和前部覆緣44的筒部44b的外圍部 之間，設有在徑方向相向的密封部4 8、4 9。該密封部4 8、 4 9是偏離葉輪1 7的徑方向，排列設置在葉輪1 7的軸、方向 。另，密封部48、49是以複數設置爲佳’並不限於2個’ 也可設置成3個以上。 此外，於機殼1 3，從葉輪1 7的流體出口 1 7a是透過擴 散器51、渦室52、連通道53連通於吐出口 12°即’吸入暨 -12- 201000771 吐出側機殼2 1和岐管2 5的接合部，形成有來自於葉輪1 7的 流體出口 17a，連通於該流體出口 17a形成有岐管25。該擴 散器5 1可使流體的速度能量（動壓）轉換成壓力能量（靜 壓）。渦室52是在吸入暨吐出側機殼21和岐管25的接合部 形成爲渦卷狀，一端部連通於擴散器5 1，另一端部連通於 連通道53。 接著，該擴散器51設有縮口部。即，擴散器51是將朝 往渦室52側的出口部的流路寬度W2 (流路面積）相對於來 自葉輪1 7的流體出口 1 7側的入口部的流路寬度Wi (流路面 積）形成較爲狹窄（小），藉此構成縮口部。即，將擴散 器5 1的入口部相對於出口部形成較大，藉此容許指定間隙 47造成葉輪17往軸心方向的移動，能夠將壓力流體適當導 入至擴散器5 1。 該擴散器5 1的縮口部形狀，即傾斜角度，是根據從擴 散器5 1出口部的流體流出角α和擴散器5 1的出口部通道面 積與渦室52面積的面積比Υ進行設定。從擴散器5 1流至渦 室52的流體是對擴散器5 1的接線具有流體流出角α，其速 度V是分成圓周方向速度V0和徑方向速度Vm。渦室52的 面積比Y，是擴散器51的出口部通道面積Ad和渦室52的面 積Αν的比率（Y= Ad/Av )。 一般，就擴散器51的出口部至渦室52的入口部爲止的 摩擦損失，和擴散器5 1的吐出速度與渦室5 2的流入速度之 速度差所造成的損失而言，流體流出角α爲1 5 °程度，能 夠確保泵浦最大效率。此外，渦室5 2舌端損失是在渦室5 2 •13- 201000771 的舌端安裝角和流體流出角的差太大時產生 渦室52的舌端厚度太厚則渦室52的舌端安裝 數度（小的角度）。 其結果，本實施例是以擴散器5 1設有縮 器5 1出口部的流體流出角α形成爲較大’藉 此外，將擴散器51的入口部寬度爲較大’能 的軸方向移動。於該狀況’將擴散器5 1縮口 度Vm會上昇，但圓周方向速度ΥΘ是經由角 爲減速（自由渦流）°因此’擴散器51是形 向速度乂111和圓周方向速度νθ的合計速度達 止的縮口形狀。 因此，當葉輪17旋轉時，從吸入口 11吸 葉輪1 7的離心力使揚液昇壓。該昇壓的揚液 口 1 7 a通過擴散器5 1，藉此使流體的速度能 能量，然後流至渦室5 2 ’通過連通道5 3從吐 外部。此時，機殻1 3和葉輪1 7是利用密封部 向形成爲密封著，所以利用葉輪1 7昇壓的揚 吸入口，能夠從流體出口 1 7a適當流入擴散器 另外，即使主軸1 6及葉輪1 7利用指定間 向移動，但密封部4 8、4 9能夠讓外圍環4 3和 位置關係不變，所以揚液就不會洩漏至吸入 當流入擴散器5 1。 如上述，本實施例的栗浦是利用滾珠軸 軸16旋轉自如支撐在具有吸入口 11和吐出口 。其原因是若 角就難以成爲 口部，使擴散 此降低損耗。 夠容許葉輪1 7 時，徑方向速 運動量保存成 成可使該徑方 到減速程度爲 入揚液，利用 是從液體流出 量轉換成壓力 出部1 2吐出至 4 8、4 9在徑方 液不會浅漏至 5 1° 隙47朝軸心方 前部覆緣44的 口 1 1，能夠適 承1 4、1 5使主 1 2的機殼1 3內 -14- 201000771 ’在該主軸1 6的軸端部連結著葉輪1 7，構成爲利用屏蔽馬 達1 8透過主軸1 6就能夠驅動旋轉葉輪1 7，在葉輪1 7的軸心 方向前側設有前部覆緣44的同時，在軸心方向後側設有後 部覆緣45，在機殼13和前部覆緣44之間設有在軸方向相向 的指定間隙47的同時，在機殼13和前部覆緣44之間設有在 徑方向相向的密封部4 8、4 9。 因此，利用密封部48、49就能夠防止流體從吐出口 1 2 往吸入口 1 1逆流，此外，即使滾珠軸承1 4、1 5等的磨損造 成主軸1 6及葉輪1 7沿著旋轉軸心方向移動，但因葉輪1 7和 機殼1 3之間設有指定間隙47，所以兩者不會彼此干涉，因 此能夠延長栗浦壽命。 此外，本實施例的泵浦，因是將密封部48、49排列在 葉輪1 7的軸心方向設置成複數。因此，利用複數的密封部 4 8、4 9就能夠降低葉輪1 7和機殼1 3之間的流體洩漏，能夠 適當防止流體從吐出口 1 2往吸入口 1 1的逆流。 另外，本實施例的泵浦，因是將來自葉輪1 7的流體出 口 17a透過擴散器51及渦室52連通於吐出口 12’在擴散器 5 1設有縮口部。因此’從葉輪1 7的流體出口 1 7a流出至擴 散器5 1的流體其圓周方向的速度和徑方向的速度之合計就 會減速，藉此能夠在擴散器5 1將流體的速度能量（動壓） 適當轉換成壓力能量（靜壓）。 此時，在擴散器5 1設有縮口部’所以就能夠使擴散器 5 1出口部的流體流出角α形成爲較大’藉此就能夠降低損 耗。此外，將擴散器5 1的入口部寬度形成較大’藉此能夠 -15- 201000771 降低葉輪17軸方向移動造成的葉輪出口之擴散器入口的損 耗。 此外，擴散器51的縮口部形狀是根據來自擴散器51出 口部的流體流出角，和擴散器5 1出口部與渦室52入口部的 通道面積比進行設定。因此’將縮口部設定成適當形狀’ 可使擴散器51的徑方向速度加速’但圓周方向速度是會減 速，基於該合計速度爲減速’其結果能夠以擴散器5 1減速 將流體的速度能量適當轉換成壓力能量’此外’將渦室5 2 的流體速度成爲適當的速度’能提昇泵浦效率。 另外，本實施例的泵浦，設有對滾珠軸承1 4、1 5施加 預壓的預壓彈簧31，由環狀的波板材複數層疊構成該預壓 彈簧3 1。因此，利用預壓彈簧3 1對滾珠軸承1 4、1 5施加預 壓，能夠抑制滾珠軸承1 4、1 5的公轉滑動可延長使用壽命 的同時，藉由將波板材複數層疊構成預壓彈簧3 1，能夠減 少彈簧受壓尺寸變化量相對的載重變化量，能夠施加適當 的預壓。 此外，本實施例的泵浦，以旋轉驅動葉輪1 7就能夠搬 運超臨界co2流體或液體co2，能夠做爲半導體洗淨用循 環泵浦使用，因此洗淨後的被洗淨物就不需要乾燥，能夠 使洗淨程序簡化及削減成本。 另，上述的實施例是將本發明的泵浦以半導體洗淨用 循環泵浦爲例子進行的說明，但本發明的泵浦也可應用在 通常的離心栗浦。 -16- 201000771 [產業上之可利用性] 本發明相關的泵浦是在機殼和前部覆緣之間設有在軸 方向相向的指定間隙的同時，在機殼和前部覆緣之間設有 在徑方向相向的密封部，藉此構成爲能夠抑制流體的浅漏 和構成構件的磨損且能夠延長使用壽命的泵浦’也可應用 在任何泵浦。 【圖式簡單說明】 第1圖爲表示本發明一實施例相關的泵浦作爲半導體 洗淨裝置用循環泵浦的剖面圖。 第2圖爲表示本實施例的半導體洗淨裝置用循環泵浦 要部放大圖。 【主要元件符號說明】 11 :吸入口 1 2 :吐出口 13 :機殻 1 4、1 5 :滾珠軸承 1 6 :主軸 17 :葉輪 1 8 :屏蔽馬達 31 :預壓彈簧 44 :前部覆緣 45 :後部覆緣 -17- 201000771 46 : 47 : 48、 5 1 ： 5 2 ： 葉片 指定間隙 4 9 :密封部 擴散器 渦室201000771 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to, for example, a pump for carrying a supercritical co2 fluid or a liquid c〇2. [Prior Art] For example, a pump for carrying a supercritical co2 fluid or a liquid c〇2 has a circulation pump for semiconductor cleaning. With the recent high integration of semiconductor devices, the processing line width of wafers has also been required to be miniaturized. For the current main stream of 〇 · 1 8 // m, it is estimated that it will become 0 · 1 0 // m or less in the future. However, in the past, the method of semiconductor cleaning using a liquid such as ultrapure water, the capillary force caused by the interfacial tension of the gas and the liquid during the drying of the wafer sometimes causes the anti-uranium agent formed on the wafer to be spoiled. (The resist is broken). In order to solve the above disadvantages, a semiconductor cleaning apparatus using a supercritical fluid has been developed in place of a liquid such as ultrapure water. Supercritical fluids have a very high permeability compared to liquids and are capable of saturating any fine structure. Further, there is no interface between the gas and the liquid, and therefore there is a feature that the capillary force is not generated when it is dried. Supercritical fluids, mainly using carbon dioxide (co2). Carbon dioxide is a relatively stable condition compared to other liquid solvents, ie, a critical density of 468 kg/m3 at a critical temperature of 31.2 ° C and a critical pressure of 7.38 MPa'. In addition, since carbon dioxide is a gas at normal temperature and normal pressure, carbon dioxide vaporizes when it is returned to normal temperature and normal pressure, and it is possible to easily separate the washed matter and the contaminant. Things do not -5 - 201000771 Need to dry, etc., can simplify the cleaning process and reduce costs. In the above semiconductor cleaning device using supercritical fluid, the supercritical CO 2 fluid is usually pressurized to about 20 MPa, so that the circulation can be recycled as a recirculating pump for wafer cleaning. Type shielded electric pump in the form of a circulating pump. In addition, the bearing uses a ball bearing, which is used in the liquid detergent (supercritical CO 2 ) of the semiconductor detergent. The ball bearing is subjected to the radial load and axial load of the rotor. Further, the bearing preloading spring provided on the opposite side of the impeller side on the shaft end side bearing controls the preloading load, thereby preventing the revolution of the ball bearing from being slid (lateral sliding). In addition, the radial stiffness (spring constant) of the ball bearing is controlled by the bearing preload load, and the number of natural rotor vibrations is also adjusted. The pump described above has the pump described in Patent Document 1 below. [Patent Document 1] JP-A-2007-23 1 95 8 SUMMARY OF THE INVENTION [Problem to be Solved by the Invention] However, in the above prior pump, the ball bearing is used in a supercritical co2 fluid having low viscosity. (or liquid co2), so the lubrication of the liquid can not be expected. Therefore, the ball bearing wears and the spindle and the impeller move in the direction of the rotation axis. The impeller is pressurized by the rotation of the suction port to be sucked out from the discharge port, and the fluid is prevented from flowing backward from the discharge port to the suction port. The axial gap between the casing and the impeller is set to be extremely narrow. However, when the wear of the ball bearing causes the spindle and the impeller to move in the direction of the rotational axis -6-201000771, interference occurs between the impeller and the casing, resulting in a problem of reduced service life. The present invention has been made to solve the above problems, and an object of the invention is to provide a pump capable of extending the service life. [Means for Solving the Problem] In order to achieve the above object, the pump according to the first aspect of the invention is characterized in that the pump includes a casing having a suction port and a discharge port, and is supported by the ball bearing in the casing so as to be rotatable a main shaft; an impeller coupled to the shaft end portion of the main shaft; and a shield motor that is rotatable through the main shaft and configured to rotate the impeller, wherein the fluid sucked into the suction port is boosted and discharged from the discharge port by rotation of the impeller. A front edge is provided on a front side of the impeller in the axial direction, and a rear edge is provided on a rear side of the axial direction of the impeller, and a gap is provided between the casing and the front edge. At the same time as the specified gap in the axial direction, a seal portion facing in the radial direction is provided between the casing and the front edge. The pump according to the second aspect of the invention is characterized in that the sealing portion is arranged in a plurality of directions in the axial direction of the impeller. The pump according to the third aspect of the invention is characterized in that, in the casing, a fluid outlet from the impeller is communicated to the discharge port through a diffuser and a volute, and a shrunken portion is provided in the diffuser. . The pump according to the fourth aspect of the invention is characterized in that the shape of the neck portion is set based on a fluid outflow angle of the diffuser outlet and a passage area ratio between the diffuser outlet and the scroll chamber. The pump according to the fifth aspect of the invention is characterized in that the pump is provided with a preloading spring that applies a preload to the ball bearing, and the preloading spring is formed by laminating a plurality of annular wave plates. The pump according to the sixth aspect of the invention is characterized in that the impeller is capable of transporting the supercritical co2 fluid or the liquid co2' by rotational driving, and can be used as a cyclic pump for semiconductor cleaning. [Effect of the Invention] According to the pump of the first aspect of the invention, in the casing having the suction port and the discharge port, the main shaft is rotatably supported by a ball bearing, and the impeller is coupled to the shaft end of the main shaft. In order to transmit the rotary impeller through the main shaft by the shield motor, a front flange is provided on the front side in the axial direction of the impeller, and a rear flange edge is provided on the rear side in the axial direction on the casing and the front flange. A sealing portion that faces in the radial direction is provided between the casing and the front edge of the casing while providing a predetermined gap in the axial direction. Therefore, 'the sealing portion can prevent the fluid from flowing back from the discharge port to the suction port'. Further, even if the wear of the ball bearing causes the main shaft and the impeller to move in the direction of the rotation axis, since the specified gap is provided between the impeller and the casing, The two do not interfere with each other, thus prolonging the pump life. According to the pumping method of the second aspect of the invention, since the sealing portion is arranged in a plurality of axial directions of the impeller, the fluid leakage between the impeller and the casing can be reduced by using a plurality of sealing portions. Prevent fluid from flowing back from the spout to the suction port. According to the pump of the third aspect of the invention, since the fluid outlet of the impeller from -8 to 201000771 is provided through the diffuser and the vortexer, the expansion portion can be formed, whereby the expansion can be made large. It is possible to reduce the diffusion of the diffuser while allowing the movement of the impeller to prevent dryness. According to the invention of the fourth aspect of the patent application, since the passage area ratio of the fluid flow vortex chamber at the outlet of the diffuser is set, an appropriate shape is obtained from the diffuser. The total speed of the outlet outflow and the circumferential speed reduces the effect of the diffuser, that is, it can fully ensure that the fluid is exchanged for pressure energy (static pressure), and can improve the preloading spring that applies preload to the ball bearing according to the invention of claim 5 Since the preloading spring is formed, it is preloaded by the preloading spring, whereby the load of the ball bearing can be suppressed, and the load of the plurality of laminated plates can be preloaded by the load relative to the amount of change in the size of the spring. According to the sixth aspect of the invention, the impeller can be used for transporting the supercritical CO 2 fluid or the circulating pump for conductor cleaning, so that the washing is dry, so that the washing procedure can be simplified. [Embodiment] The chamber is connected to the discharge port and is diffused. The loss of fluid exiting the outlet of the outlet to the diffuser inlet is involved. At the time of pumping, the angle at which the neck portion is formed and the outlet of the diffuser can set the speed at which the neck portion is set to the vortex chamber in the radial direction, whereby the speed energy (dynamic pressure) can be sufficiently ensured. Pu efficiency. In the case of pumping, it is possible to apply a turning slip to the ball bearing by a plurality of layers of the annular wave plate to extend the service life into a preload spring, which can reduce the amount of conversion, and can rotate when an appropriate pump can be applied. Driving the liquid C〇2 can eliminate the cost and can be used as a semi-cleaned material. -9- 201000771 BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a preferred pumping embodiment of the present invention will be described in detail with reference to the accompanying drawings. Further, the present invention is not limited to the embodiment. [Embodiment] FIG. 1 is a cross-sectional view showing a pump for a semiconductor cleaning apparatus according to an embodiment of the present invention, and FIG. 2 is a view showing a circulating pump for a semiconductor cleaning apparatus according to the present embodiment. Enlarged picture. As shown in FIGS. 1 and 2, the recirculating pump for a semiconductor cleaning apparatus of the present embodiment includes a casing 13 having a suction port 11 and a discharge port 12, and a ball bearing 14 is used in the casing 13. a spindle 16 that is rotatably supported; an impeller 17 coupled to the shaft end of the spindle 16; and a shield motor 18' that can drive the rotary impeller 17 through the spindle 16 so that the suction port 1 can be made by the rotation of the impeller 17 The inhaled fluid is boosted and discharged from the discharge port 丨2. The casing 1 3 ′ is a ring-shaped discharge and suction side casing 2 i and a flushing side casing 2 2 are disposed so as to sandwich a cylindrical outer casing 2 3 and are connected by a connecting bolt 24 The manifold 2 5 is fixed to the outside of the discharge and suction side casing 21, and is connected by a joint bolt 26. Next, the manifold 25 is a suction port 1 1 in which a rising liquid is formed on the axial extension axis of the main shaft 16, and a discharge port 1 2 is formed on the outer side of the suction port. The ball bearings I4, 15 are bevel ball bearings which are mounted on the discharge cum suction side casing 21 and the flush side casing 22' to support the main shaft 16 so as to be rotatable. Then, the impeller 17 is fitted to the shaft end of the main shaft 16, and is fixed by a joint bolt 27. -10- 201000771 In addition, in this embodiment, the ball bearings Μ, 15' are made of ceramic materials for inner and outer wheels and balls in order to improve wear resistance and corrosion resistance and to reduce centrifugal load during high-speed rotation (for example, tantalum nitride). SisN4, aluminum Al2〇3, niobium carbide S i C, etc.). As described above, the bearing material is entirely ceramic, and it is possible to improve the wear resistance with respect to foreign particles. In addition, the design of the staying temple is designed to reduce the drag loss (rotational resistance). In this way, it is possible to prevent the revolution from slipping and reduce the preload load (thrust axle load), and the long life of the ball bearings I4 and 15 can be achieved. The material of the retainer is a PEEK material (polyether ketone ether) based on its viewpoint of corrosion resistance and abrasion resistance to the detergent and ensuring its high-speed rotation. Alternatively, stainless steel or fiber composites can be used in place of PEEK. The shield motor 18 is composed of a stator 28 fixed to the inner circumference of the outer cylinder 23, and a rotor 29 disposed at a peripheral portion of the main shaft 16 opposite to the stator 28, and on the other hand, the flushing side casing 22 is A flushing port 30 capable of discharging a portion of the sucked liquid is formed on the axis extending axis of the spindle 16. Further, between the flushing side casing 22 and the bevel ball bearing 5, a preload spring 31 is held. The preload spring 31 is formed by laminating a plurality of annular wave plate springs at a position around the other end of the main shaft 16, and applies a preload in the axial direction to the ball bearing 15 by a constant pressure spring. Therefore, when the shield motor 18 is energized, the rotor 29 will form a rotation of the stator 28. The spindle 16 will rotate with the rotor 29, and the rotation will cause the impeller 17 to rotate. As a result, the liquid is sucked from the suction port η, and is boosted by the centrifugal force of the impeller 17 to the discharge port 1 2 side and discharged to the outside. In addition, 201000771 part of the liquid suctioned from the suction port 11 is passed through the ball bearings 14 and 15 and the shield motor 18, and after cooling, the flushing flow is discharged from the flushing port 30 to circulate the above-mentioned composition. In the present embodiment, the impeller 17 is of a closed type, and the main shaft 16 and the impeller 17 are supported relative to the casing 13 so as to move freely by a predetermined amount in the axial direction, and the diameter of the casing 13 and the impeller 17 are simultaneously The direction forms a seal. In other words, the suction and discharge side casing 21 for the casing 13 is formed with a receiving hole 4 1 ' at its center portion that is connectable to the suction port 1 1 , and a peripheral portion is fixed to the inner peripheral surface of the receiving hole 4 1 Ring 42 and peripheral ring 43. On the other hand, the 'impeller port' is configured such that the annular front edge flange 44 provided on the front side in the axial direction and the disk-shaped rear edge flange 45 provided on the rear side in the axial direction are 'in the circumferential direction A plurality of vanes 46 are provided at equal intervals. In this case, the front flange 44 has a disk portion 44a horizontal to the radial direction of the impeller 17, and a tubular portion Wb horizontal to the axial direction. Next, between the one end portion of the peripheral ring 43 (the casing 13) and the surface portion of the disc portion 440a of the front flange 44, a predetermined gap 47 that faces in the axial direction is provided. Further, between the inner peripheral portion of the outer ring 43 (the casing 13) and the outer peripheral portion of the tubular portion 44b of the front flange 44, sealing portions 48, 49 which face in the radial direction are provided. The seal portions 48, 49 are offset from the radial direction of the impeller 17 and are arranged in the axis and direction of the impeller 17. Further, the sealing portions 48 and 49 are preferably set in a plural number, and are not limited to two, and may be provided in three or more. Further, in the casing 13, the fluid outlet 17a from the impeller 17 is transmitted through the diffuser 51, the volute 52, and the passage 53 to communicate with the discharge port 12°, that is, 'inhalation cum-12-201000771 discharge side casing 2 1 A joint portion of the manifold 25 is formed with a fluid outlet 17a from the impeller 17 and a manifold 25 is formed in communication with the fluid outlet 17a. The diffuser 51 converts the velocity energy (dynamic pressure) of the fluid into pressure energy (static pressure). The vortex chamber 52 is formed in a spiral shape at the joint portion between the suction and discharge side casing 21 and the manifold 25, and the one end portion communicates with the diffuser 151, and the other end portion communicates with the connecting passage 53. Next, the diffuser 51 is provided with a necking portion. In other words, the diffuser 51 is a flow path width Wi (flow path area) of the outlet portion toward the vortex chamber 52 side with respect to the flow path width Wi (flow path area) of the inlet portion from the fluid outlet 17 side of the impeller 17 The formation is relatively narrow (small), thereby forming a necking portion. That is, the inlet portion of the diffuser 51 is formed larger with respect to the outlet portion, thereby allowing the specified gap 47 to cause the impeller 17 to move in the axial direction, and the pressure fluid can be appropriately guided to the diffuser 51. The shape of the neck portion of the diffuser 51, i.e., the angle of inclination, is set based on the fluid outflow angle α from the outlet portion of the diffuser 51 and the area ratio of the outlet portion of the diffuser 51 to the area of the scroll 52. . The fluid flowing from the diffuser 51 to the vortex chamber 52 has a fluid outflow angle α to the wiring of the diffuser 51, and its velocity V is divided into a circumferential direction velocity V0 and a radial direction velocity Vm. The area ratio Y of the vortex chamber 52 is the ratio (Y = Ad / Av) of the outlet portion passage area Ad of the diffuser 51 and the area Α ν of the vortex chamber 52. In general, the fluid discharge angle is the loss due to the friction loss from the outlet portion of the diffuser 51 to the inlet portion of the vortex chamber 52, and the speed difference between the discharge speed of the diffuser 51 and the inflow velocity of the vortex chamber 52. The α is 15 ° level to ensure maximum pump efficiency. In addition, the loss of the tongue end of the vortex chamber 5 2 is such that when the difference between the tongue end mounting angle of the vortex chamber 5 2 •13-201000771 and the fluid outflow angle is too large, the tongue end of the vortex chamber 52 is too thick to be the tongue end of the vortex chamber 52. Install a few degrees (small angle). As a result, in the present embodiment, the fluid outflow angle α at which the diffuser 51 is provided with the outlet portion of the reducer 5 1 is formed to be larger, thereby shifting the width of the inlet portion of the diffuser 51 to a larger axis. . In this case, the divergence Vm of the diffuser 5 1 is increased, but the circumferential velocity ΥΘ is decelerated (free vortex) via the angle. Therefore, the diffuser 51 is the total velocity of the velocity 乂 111 and the circumferential velocity νθ. The shape of the shrinkage. Therefore, when the impeller 17 rotates, the centrifugal force of the impeller 17 is sucked from the suction port 11 to raise the lift liquid. The boosted riser port 17a passes through the diffuser 51, thereby enabling the velocity of the fluid to be energized, and then flows to the vortex chamber 5 2 ' from the venting chamber 5 3 from the outside of the spout. At this time, since the casing 13 and the impeller 17 are sealed by the sealing portion, the suction port that is pressurized by the impeller 17 can be appropriately flowed into the diffuser from the fluid outlet 17a, even if the main shaft 16 and The impeller 17 is moved by the specified inter-directional direction, but the sealing portions 48, 49 can make the peripheral ring 43 and the positional relationship constant, so that the liquid does not leak to the suction when flowing into the diffuser 51. As described above, the chestnut of the present embodiment is rotatably supported by the ball shaft 16 with the suction port 11 and the discharge port. The reason is that if the corner is difficult to become the mouth, the diffusion will reduce the loss. When the impeller is allowed to be 7 7 , the amount of radial direction movement is saved so that the diameter can be reduced to the level of the liquid, and the amount is converted from the liquid outflow to the pressure outlet. 1 2 discharge to 4 8 , 4 9 in the radial direction The liquid does not leak to the 5 1 ° gap 47 toward the shaft side of the front edge of the flange 44 of the shaft 1 1, can accommodate 1 4, 1 5 so that the main 1 2 of the casing 1 3 -14- 201000771 'in the The shaft end of the main shaft 16 is coupled to the impeller 17 and is configured to be capable of driving the rotary impeller 17 by the shield motor 18 through the main shaft 16 and providing the front flange 44 on the front side of the impeller 17 in the axial direction. a rear cover 45 is provided on the rear side in the axial direction, and a predetermined gap 47 facing in the axial direction is provided between the casing 13 and the front cover 44, and the casing 13 and the front cover 44 are provided. Sealing portions 48, 49 which face each other in the radial direction are provided. Therefore, it is possible to prevent the fluid from flowing back from the discharge port 1 2 to the suction port 1 by the seal portions 48 and 49, and further, the wear of the ball bearings 14 and 15 causes the spindle 16 and the impeller 17 to follow the axis of rotation. The direction moves, but since the specified gap 47 is provided between the impeller 17 and the casing 13, the two do not interfere with each other, so that the life of the pump can be prolonged. Further, the pumping of this embodiment is provided in a plurality of positions in which the sealing portions 48, 49 are arranged in the axial direction of the impeller 17. Therefore, fluid leakage between the impeller 17 and the casing 13 can be reduced by the plurality of sealing portions 48, 49, and the backflow of the fluid from the discharge port 1 2 to the suction port 1 can be appropriately prevented. Further, in the pumping of this embodiment, the fluid outlet 17a from the impeller 17 is communicated to the discharge port 12' through the diffuser 51 and the volute 52, and the diffuser 51 is provided with a neck portion. Therefore, the sum of the velocity in the circumferential direction and the velocity in the radial direction of the fluid flowing out from the fluid outlet 17a of the impeller 17 to the diffuser 51 is decelerated, whereby the velocity energy of the fluid can be made in the diffuser 51. Pressure) Properly converted to pressure energy (static pressure). At this time, since the diffuser portion is provided in the diffuser 51, the fluid outflow angle α at the outlet portion of the diffuser 5 1 can be made large, whereby the loss can be reduced. Further, the width of the inlet portion of the diffuser 51 is made larger, whereby the loss of the diffuser inlet of the impeller outlet caused by the movement of the impeller 17 in the axial direction can be reduced by -15-201000771. Further, the shape of the neck portion of the diffuser 51 is set in accordance with the fluid outflow angle from the outlet portion of the diffuser 51, and the passage area ratio of the outlet portion of the diffuser 51 and the inlet portion of the swirl chamber 52. Therefore, 'setting the neck portion to an appropriate shape' accelerates the radial speed of the diffuser 51, but the speed in the circumferential direction is decelerated, and the speed is decelerated based on the total speed. As a result, the speed of the fluid can be decelerated by the diffuser 51. Proper conversion of energy into pressure energy 'in addition' to the fluid velocity of the vortex chamber 5 2 to an appropriate speed' can improve pump efficiency. Further, in the pumping of the present embodiment, a pre-compression spring 31 for preloading the ball bearings 14 and 15 is provided, and the pre-compression spring 31 is formed by laminating a plurality of annular wave plates. Therefore, the preloading of the ball bearings 14 and 15 by the preloading spring 3 1 can suppress the revolution of the ball bearings 14 and 15 and prolong the service life, and the plurality of wave plates are laminated to form a preload spring. 3 1. It is possible to reduce the amount of change in the load relative to the amount of change in the spring pressure, and to apply an appropriate preload. Further, in the pump of the present embodiment, the supercritical co2 fluid or the liquid co2 can be transported by rotationally driving the impeller 17 and can be used as a circulating pump for semiconductor cleaning, so that the washed laundry does not need to be used. Drying simplifies the cleaning process and cuts costs. Further, the above embodiment is an example in which the pump of the present invention is circulated for semiconductor cleaning, but the pump of the present invention can also be applied to a conventional centrifugal pump. -16- 201000771 [Industrial Applicability] The pump according to the present invention is provided with a specified gap in the axial direction between the casing and the front rim, and at the same time as the casing and the front rim A seal portion that faces in the radial direction is provided therebetween, whereby the pump that can suppress the shallow leak of the fluid and the wear of the constituent members and can extend the service life can be applied to any pump. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing a pump for use as a semiconductor cleaning device in accordance with an embodiment of the present invention. Fig. 2 is an enlarged view showing a circulating pump portion of the semiconductor cleaning apparatus of the present embodiment. [Main component symbol description] 11 : Suction port 1 2 : Discharge port 13 : Case 1 4, 1 5 : Ball bearing 1 6 : Spindle 17 : Impeller 1 8 : Shield motor 31 : Preload spring 44 : Front flange 45: rear margin -17- 201000771 46 : 47 : 48, 5 1 : 5 2 : blade specified clearance 4 9 : seal diffuser vortex