200839104 九、發明說明： 【發明所屬之技術領域】 本發明係有關於一種離心泵耆。 【先前技術】 如第八圖所示般，曰本公開專利第2 0 0 6-2 0 〇 4 2 7號公報揭示有離心泵。此離心栗係具有定子塊1，而 疋子塊1係由··鐵芯及線圈所成的定子2、控制電路3、 及隔間板4以嵌件成型的模樹脂所構成。隔間板4位於定 子2^内周側，又在其中央部具有凹部4 〇，軸5的一端 被凹=40所支撐。軸5的外周裝配有轉子6。轉子6係 部之軸承6 0及外周側之永久磁鐵6 1形成為一體， 同4在軸向的一端侧與葉輪7形成一體。 古^此離心泵更具備有機殼8。機殼8係藉由小螺釘而被 ^疋於定子塊1，且在機殼8與隔間板4之間形成有收容 茱輪7的泵室。機殼8，係外周侧具有吐出口 8 1、中央 =有吸人π 8 0。又，機殼8係具備用來支撐軸5的另 端之軸支撐部1 〇 〇，軸支撐部i 〇 〇，係被從吸入口 〇周圍之機殼8朝向機殼8内部延伸設置的支撐肋工〇 1所支撑。在軸支撐部i 00之吸入口侧的面，形成 有圓錐體狀之突出部1 〇 〇 a，用以將水流導引於葉 側。 ’、 在此離心泵中，因為是將用以支撐轴5的另一端的轴 支撐部10 0-體形成於機殼8，所以具有僅需運用少量 零件即可解決問題優點。然而，在轴支撐部工〇 〇的外周 200839104200839104 IX. Description of the invention: [Technical field to which the invention pertains] The present invention relates to a centrifugal pump. [Prior Art] As shown in the eighth drawing, a centrifugal pump is disclosed in Japanese Laid-Open Patent Publication No. 2000-62. The centrifugal pump system has a stator block 1, and the stator block 1 is composed of a stator 2 composed of a core and a coil, a control circuit 3, and a partition plate 4, which are formed by insert molding. The partition plate 4 is located on the inner peripheral side of the stator 2, and has a recess 4 在 at its central portion, and one end of the shaft 5 is supported by the recess = 40. The outer periphery of the shaft 5 is fitted with a rotor 6. The bearing 60 of the rotor 6 and the permanent magnet 61 of the outer peripheral side are integrally formed, and the same end 4 is integrally formed with the impeller 7 at one end in the axial direction. The ancient centrifugal pump has an organic shell 8 . The casing 8 is clamped to the stator block 1 by means of a small screw, and a pump chamber for accommodating the weir wheel 7 is formed between the casing 8 and the partition plate 4. The casing 8 has a discharge port 8 1 on the outer peripheral side, and has a suction π 8 0 at the center. Further, the casing 8 is provided with a shaft support portion 1 for supporting the other end of the shaft 5, and the shaft support portion 〇〇 is supported by the casing 8 around the suction port toward the inside of the casing 8. Supported by the ribs 〇1. On the surface of the suction port side of the shaft support portion i 00, a conical projection 1 〇 〇 a is formed for guiding the water flow to the blade side. In the centrifugal pump, since the shaft support portion 10-body for supporting the other end of the shaft 5 is formed in the casing 8, there is an advantage that the problem can be solved by using only a small number of parts. However, in the outer periphery of the shaft support work 2008 2008 200839104
面與葉輪7的内周面之間具有A 氣在此部分積存而難輯出的.問題/ ^^成所謂的空 【發明内容】 本發明乃有馨於上述問題點而完成者，其 供-種空氣難以積存在機殼内，且能有效率、 氣泡之液體的離心泵。 出此‘有 本發明之離心泵係具備：機殼，具有吸入 :固定在前述機殼内侧^，被前述軸支撐部所= 面朝外周面打的流路，將從前述吸人口流人4機2 的液體藉由前述流路排出外部；及驅動部，用以使前= 輪旋轉。本發明特徵點為，前述軸支禮部具有：形成= =吸=Π侧的面且朝向前述吸人σ突出的圓錐體狀= 述突出部的底部之周圍的周緣部，且前： 、ΐ:=Γ 側的面’係從前述突出部之底部朝向前 的内周面側之開口延伸，且外徑比前述吸入 徑退大。 心円 μ 明之n絲利用躲部來填㈣往存在於 的外面與葉輪的内周面之間的間隙，使得空難 於機殼内。而且，從吸入口朝向葉輪的流路之液體難 引：動狀之突出部與周緣部之吸入口側的面而被導 i灶里!1輪流路之入口（流路的内周面侧之開口）附近， ，、、、”果，能有效率地排出混雜有氣泡之液體。 為，刖述轴支撐部，係由··與前述機殼形成一 且前述圓錐體狀之突出部的轴支撐部本體 雨遂軸支撐部本體之外周心構減述周緣部的環戶^ 200839104 成。 在此情況，藉由將環裝配於軸支撐部本體 容易地形成前述周緣部。 。，此Between the surface and the inner peripheral surface of the impeller 7, there is a gas accumulated in this portion and it is difficult to assemble. The problem / ^^ becomes so-called empty [invention] The present invention is completed by the above problems, and is provided for - A centrifugal pump that is difficult to accumulate in the casing and that is efficient and has a liquid of bubbles. In the centrifugal pump system of the present invention, the casing is provided with a casing, and is provided with a suction passage that is fixed to the inside of the casing, and is flown by the shaft support portion toward the outer peripheral surface. The liquid of the machine 2 is discharged to the outside through the flow path; and the driving portion is used to rotate the front = wheel. According to a feature of the present invention, the shaft edge portion has a conical shape that forms a surface of the == suction=Π side and protrudes toward the suction σ; a peripheral portion around the bottom of the protruding portion, and the front: The surface on the side of the Γ side extends from the bottom of the protruding portion toward the opening on the inner peripheral surface side of the front portion, and the outer diameter is larger than the suction diameter. The heart 円 μ 之 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝 丝Further, the liquid from the suction port toward the flow path of the impeller is hard to be drawn: the protruding portion of the movable portion and the surface on the suction port side of the peripheral portion are guided to the inlet of the one-pass flow path (the inner peripheral surface side of the flow path) In the vicinity of the opening, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , The support body main body of the rain cover shaft support portion has a peripheral core structure and a lower peripheral portion of the ring portion. In this case, the peripheral portion is easily formed by fitting the ring to the shaft support portion body.
或者亦可為，前述轴支撐部係與前述機夂 且在W述機殼之内面被固定於前述吸入口之端部^ 同前述，在欲將機殼及軸支撐部本體形成—體時y7二 機殼時之起模方便上，係難以將吸入口之口徑（内秤= 成比軸支撐部本體之外徑還小。於是，藉由將轴支^ 機殼各別形成，可無關乎轴支撐部的大小而將吸入口之口、 徑自由地設小。藉此可提供例如仍舊保持軸支撐部之強= 下將吸入口之口徑設小之對應於低流量的離心泵。 又 —較佳為，前述周緣部之前述吸入口側的面，係位於护 述葉輪的流路朝向葉輪中心側延長的領域内。 引 此％，就算因為軸承之磨耗等因素使葉輪的位置偏移 於機殼侧時，亦能順暢地將來自吸入口的水流導引到葉^ 較佳為，在前述圓錐體狀之突出部的外面形成有螺於 狀之階段部。 ’、疋 此日守，可賦予從吸入口流入的水旋轉，能更有效率地 排出液體。 【實施方式】 以下’茲一邊參照所附圖式一邊詳細說明本發明。 (第一實施形態） 本實施形態之離心泵的基本構造係與第八圖所示之習 知例相同’乃如第一圖所示，具備有：定子塊1 ;機殼8， 7 200839104 具有吸入口 8 〇 ;軸支撐部8 4，固定在機殼8内側；軸 5，其一端被軸支撐部8 4支撐而另一端被定子塊1之凹 邓4 0所支撐；及葉輪7，被支撐成可藉轉子6而在軸5 上旋轉自如。 定子塊1，係由··鐵心及線圈所成的定子2、控制電 路3、及隔間板4以嵌件成型的模樹脂所構成。定子2、 控制電路3，係構成用以旋轉葉輪7之驅動部，隔間板4 係位於定子2之内周侧，其底面之中央部形成有凹部4〇 、支撐韵述軸5的另一&。軸5的外周裝配有轉子6。 孝=6係-體形成關部之軸承6 Q及外周側之永久磁鐵 b 1，同時在軸向之機殼8侧一體形成有葉輪7。 ^機殼8，係藉由固定小螺絲而被固定於定子塊丄，在 與隔間板4之間形成有收容葉輪7的泵室。機 具備吐出口81 (參照第二心），中央具備有吸 軸支撐部8 4，係配置於在泵室之内部而*吸入 〇相對的位置。針對軸支撐部8 4之構成，詳㈣述。 =7係由·_部所驅動且連同轉子6 具備有從其内周面朝外周面貫=路 而從吐出=:二8卜，^ 以下，兹針對輛支撐部8 4作詳細說明。 係由==;=部84如第二A，圖所示， 的環◦、及裝配在軸切部外周 200839104 緣的0，係透過從吸人口 8 〇< 係3根)支又數根(圖== ’在吸人σ 8 Q側之該面，支稽部本 出的圓錐體狀的突出部8 朝吸入〇8〇 環“==的，承部“Ο反 成在突出部8 4J、广心本體8 4 0之外裡，用、 1具有與支#之周圍擴展的周緣部者。2構 q 8 3對應的複數槽8 4 ^84 3 了甘欠e於槽8 4 2之中般地裝配 且从支撐肋8 :環8 4 ―!係藉由支撐肋8 3及in，8 4 0 部β疋轉，又’藉由設在軸支撐部本體8 4 η山之卡合而 二8 5與設在環8 4 1底面的階段部之卡人，的階段 ί订季由向定位。環8 4 1係例如依超音圖示）而 定於輛支標部本體8 4 〇的周圍。（曰仏接方式而被固 當環8 41被裝配在軸支撐部本 環8 41之吸入口側的一面8 4工：體！2的周圍後， a之底部朝向葉輪7的流路7 〇之内出部8 4 〇 緩地延伸，而該面841a之外^ 係大於吸入口 8 0之内徑。環8 4]之冰田…之外搜） 間隙與葉輪7的内周面呈相對。 卜周面係隔著微小 本實施形態的離心泵，因為是在轴支撐部本體8 4 〇 的周圍裝配有環8 41 ’所以能以環8 4 i來填補轴支 部本體840的外面與葉輪7的内周面之間的間隙，使* 氣變得難以積存在機殼内。而且，從吸入口8〇朝向葉輪 之流路7 0的水，係藉由圓錐體狀之突出部8 4 〇 a及^ 9 200839104 8 4 1的吸入口側的面8 4 1 a而順暢地引導至流路7 0 的開口 7 1附近，其結果，能有效率地排出混雜有氣泡之 液體。Alternatively, the shaft support portion may be fixed to the end portion of the suction port on the inner surface of the casing and the inner surface of the casing, and when the casing and the shaft support body are to be formed into a body, y7 may be used. When the two casings are easy to lift, it is difficult to make the diameter of the suction port (the inner scale = the outer diameter of the main body of the shaft support is smaller). Therefore, by forming the shafts separately, it is irrelevant. The size of the shaft support portion is small, and the diameter and the diameter of the suction port are freely set. This makes it possible to provide, for example, a centrifugal pump that keeps the diameter of the suction port and that has a small diameter corresponding to a low flow rate. Preferably, the surface of the peripheral edge portion on the suction port side is located in a region in which the flow path of the impeller is extended toward the center of the impeller. In this case, the position of the impeller is shifted due to factors such as wear of the bearing. On the side of the casing, it is also possible to smoothly guide the flow of water from the suction port to the blade. Preferably, a stepped portion is formed on the outer surface of the protruding portion of the conical shape. It is more efficient to impart water rotation from the suction port. [Embodiment] The present invention will be described in detail below with reference to the drawings. (First Embodiment) The basic structure of the centrifugal pump of the present embodiment is the same as the conventional example shown in FIG. 'As shown in the first figure, there is: stator block 1; casing 8, 7 200839104 has suction port 8 〇; shaft support portion 8 4 is fixed inside the casing 8; shaft 5, one end of which is supported by the shaft 8 4 is supported and the other end is supported by the concave Deng 40 of the stator block 1; and the impeller 7 is supported to be rotatable on the shaft 5 by the rotor 6. The stator block 1 is formed by a core and a coil. The stator 2, the control circuit 3, and the partition plate 4 are formed by insert molding resin. The stator 2 and the control circuit 3 constitute a driving portion for rotating the impeller 7, and the partition plate 4 is located in the stator 2. On the inner peripheral side, a central portion of the bottom surface is formed with a recessed portion 〇 and another amp that supports the rhombic axis 5. The rotor 6 is attached to the outer circumference of the shaft 5. The chobe = 6-body-formed bearing 6 Q and the outer periphery The side permanent magnet b 1 is integrally formed with an impeller 7 on the side of the casing 8 in the axial direction. A small screw is fixed to the stator block, and a pump chamber for accommodating the impeller 7 is formed between the partition plate 4. The machine has a discharge port 81 (see the second center), and the center has a suction shaft support portion 84. It is disposed in the pump chamber and is in the position opposite to the suction 。. The configuration of the shaft support portion 84 is described in detail in (4). The =7 is driven by the _ section and is provided with the rotor 6 from the inner circumferential surface thereof. The outer peripheral surface is the same as the road and is discharged from the spout =: two 8 b, ^ The following is a detailed description of the support portion 84. The portion of the support portion 84 is as shown in the second A, the figure, and 0, which is attached to the edge of the shaft cut portion at the periphery of 200839104, is transmitted through a population of 8 〇<3) and several branches (Fig. == 'on the side of the suction σ 8 Q side, the branch is issued by the branch The conical projection 8 is in the direction of the suction 〇 8 “ ring "==, the bearing portion" is reversed to the outside of the projection portion 8 4J, the center of the wide-body body 804, with the extension of 1 and the branch # The peripheral department. The complex groove 8 4 ^ 84 3 corresponding to the structure q 8 3 is assembled in the groove 8 4 2 and is supported from the support rib 8 : the ring 8 4 -- by the support rib 8 3 and in, 8 4 0 疋 疋 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Positioning. The ring 8 4 1 is defined around the body of the branch portion 8 4 例如, for example, according to a supersonic diagram. (The splicing method is applied to the side of the suction port side of the shaft support portion 816 of the shaft support portion 81, and the bottom portion of the a is directed toward the flow path 7 of the impeller 7 〇 The inner portion 8 4 extends gently, and the outer surface of the surface 841a is larger than the inner diameter of the suction port 80. The ice field of the ring 8 4] is opposite to the inner circumferential surface of the impeller 7 . The circumferential surface is separated from the centrifugal pump of the present embodiment. Since the ring 8 41 ' is attached around the shaft support portion body 4 4 ′, the outer surface of the shaft branch body 840 and the impeller 7 can be filled with the ring 8 4 i. The gap between the inner peripheral surfaces makes it difficult for the gas to accumulate in the casing. Further, the water from the suction port 8〇 toward the flow path 70 of the impeller is smoothly smoothed by the surface 8 4 1 a of the projections on the suction side of the conical projections 8 4 〇 a and 9 9 200839104 8 4 1 It is guided to the vicinity of the opening 7 1 of the flow path 70, and as a result, the liquid mixed with the bubble can be efficiently discharged.
^此外’欲將機殼8及轴支撐部8 4形成一體時，在起 _方便ί L係難以將軸支撐部8 4之外徑作成比吸入口 8 〇之廷大（換言之，難以將吸入口 8 0之内徑作成比 〆 筹f 8 4之外挺還小）。於是，如同本實施形態，藉由 i格支撐°卩8 4建構成轴支撐部本體8 4 0 ’及裝配在車由 2部本體840周圍的環841，使得就算吸入口80 、小亦可容易地擴張軸支撐部8 4的外徑。 如第 口侧的面841示，環（亦即周緣部）841之吸入 心側延長的侧Ϊ I/纽位在葉輪的流路7 Q朝向葉輪中 4 I 2内者為宜。換言之，環吸入口侧的面8 千者為^=路7 ◦之底面7 ◦ a還要靠近機殼8側若 你罟:且*日t，就鼻是因軸承6 0之磨耗等而使荦輪之 3 =殼側時，亦能順獅從吸入口 8二 水W導於茱輪之流路7〇。 外_成^^所示，宜在圓錐體狀之突出部8 4 0 a 荦之階段部8 8。階段部8 8係形成為輿 f狀之突出部84〇a賊予自吸入口 8〇流入== =¾至葉輪7側’可更有效率地將絲有氣朗水引^ 葉輪7。 、 (弟二貫施形態） 除了軸支撐部8 4 對相同部分附予相 本實施形態的離心泵之基本構造， 以外，其餘是與第一實施形態相同，茲 200839104 同標號並省略重覆的說明。 如第五、六圖所示In addition, when the casing 8 and the shaft support portion 84 are integrally formed, it is difficult to make the outer diameter of the shaft support portion 8 4 larger than the suction port 8 (in other words, it is difficult to inhale). The inner diameter of the mouth 80 is better than that of the f 8 4 . Therefore, as in the present embodiment, the shaft support portion main body 8 4 0 ' is constructed by the i-frame support and the ring 841 is assembled around the two body portions 840, so that the suction port 80 can be easily made small. The outer diameter of the shaft support portion 84 is expanded. As indicated by the face 841 on the side of the mouth, it is preferable that the side Ϊ I/nucleus of the suction side of the ring (i.e., the peripheral portion) 841 is oriented toward the flow path 7 Q of the impeller. In other words, the surface of the ring suction side is 8 = ^= 7 of the road 7 ◦ a is also close to the side of the casing 8 if you 罟: and * day t, the nose is caused by the wear of the bearing 60 When the wheel 3 = shell side, it is also possible to pass the lion from the suction port 8 and the water to the raft wheel 7 〇. As shown in the outer _ ^ ^ ^, it is preferable to be in the stage portion 8 8 of the conical protrusion 8 8 0 a 。. The stage portion 8 8 is formed into a 舆 f-shaped projection 84 〇 a thief from the suction port 8 〇 inflow == = 3⁄4 to the impeller 7 side' to more efficiently introduce the wire into the impeller 7 . (Different configuration) The same as the first embodiment except that the shaft support portion 8 4 is attached to the same portion of the basic structure of the centrifugal pump of the present embodiment, the same reference numerals are given to the same reference numerals, and the repeated description is omitted. . As shown in the fifth and sixth figures
底部周圍的周緣部841，j部84〇a，之 8 5 0’。轴支標部84、=，5的-端之轴承部 外徑D1大於吸入口 8 〇之:=’周緣部84 1，的 係在機殼8之内面沿軸向安二口 ==缘: 且利用超音波溶接等方式來固定。 0之w周緣 當軸支撐部8 4,被固定於機殼8時，周緣部84 1之吸入口侧的面8 4 1a，，係自突出部8 4 〇 a， 之底部朝向流路7 Q之内周面侧的開口 7 1平緩地延伸， 周緣部8 4 1，之外周面係隔著微小間隙與葉輪7之内周 面呈相對。 本實施形態的離心泵，係能利用周緣部841，來填 補軸支撐部8 4’的外面與葉輪7的内周面之間的間隙， 所以空氣難以積存在機殼内。而且，從吸入口 8 〇朝向葉 輪之流路7 0的水，係籍由圓錐體狀之突出部8 4 〇 a， 及周緣部8 4 1，之吸入口侧的面8 4 1 a’ ，而順暢地 引導至流路7 0的開口 71附近，其結果，能有效率地排 出混雜有氣泡之液體。 如第-實施形賴述，欲將機殼8及軸支樓部形成-體時，在起模方便ΐ，係難以將=2内經作成比 軸支樓部之外徑還小。’本^^^之離心系，因為 200839104 是分Z成軸切部84，肖機殼8 例如第七圖所示般=二，大小無關地自由地設小。 内徑D3維持與第五圖_ 孕y85〇之 ^ η 9 ^ I - 奴的大小，且使吸入口 8 0的内 二泵，、’猎提供—種維持軸強度且能對應更低流量 此：f貫施形態亦與第一實施形態同樣地，周緣部8The peripheral portion 841 around the bottom portion, the j portion 84〇a, is 85'. The outer diameter D1 of the bearing portion at the end of the shaft support portion 84, =, 5 is larger than the suction port 8 :: = 'the peripheral portion 84 1 is axially closed on the inner surface of the casing 8 == edge: And it is fixed by means of ultrasonic welding or the like. When the peripheral support portion 84 of the 0 is fixed to the casing 8, the surface 8 4 1a of the peripheral portion 84 1 on the suction port side is from the protruding portion 8 4 〇a, and the bottom portion faces the flow path 7 Q. The opening 7 1 on the inner peripheral side thereof gently extends, and the outer peripheral surface of the peripheral portion 841 is opposed to the inner peripheral surface of the impeller 7 with a small gap therebetween. In the centrifugal pump of the present embodiment, the peripheral portion 841 can be used to fill the gap between the outer surface of the shaft support portion 8 4' and the inner peripheral surface of the impeller 7, so that it is difficult to accumulate air in the casing. Further, the water from the suction port 8 〇 toward the flow path 70 of the impeller is a conical-shaped projecting portion 8 4 〇a and a surface 8 4 1 a' on the suction port side of the peripheral edge portion 814. Further, it is smoothly guided to the vicinity of the opening 71 of the flow path 70, and as a result, the liquid mixed with the bubble can be efficiently discharged. As for the first embodiment, when the casing 8 and the shaft branch portion are to be formed into a body, it is difficult to make the inner diameter of the inner wall of the shaft portion smaller than the outer diameter of the shaft branch portion. In the centrifugation system of the present invention, since the 200839104 is divided into the Z-axis cut portion 84, the crank case 8 is, for example, as shown in the seventh figure, and is freely small in size. The inner diameter D3 is maintained with the fifth figure _ pregnant y85 〇 ^ η 9 ^ I - the size of the slave, and the inner two pump of the suction port 80, the 'hunting provides a kind of maintaining the shaft strength and can correspond to the lower flow rate. In the same manner as in the first embodiment, the peripheral portion 8 is the same as the first embodiment.
〇上在=口：的面84la’，係以使葉輪之流路7 0位在於茱輪之中心側延伸的領域内者為宜。 又，在圓錐體狀之突出部8 4 〇 a， 螺旋狀的階段部。 ，，以上所述，僅林發明最佳之—的频實施形態 m兄贿圖式，惟本發明之特徵並不侷限於此，並非 本發明，本發明之所有範圍應以下述之中請專利 1L圍為準’凡合於本發明申請專利祕 施例’皆應包含於本發明之㈣中，任何熟二= 技蟄者在本發明之賴思及之變化祕飾皆可 /函皇在以下本案之專利範圍。 【圖式簡單說明】 第一圖係本發明之第一實施形態所涉及之離心泵的剖面 圖〇 =二A圖係第一圖的離心泵之機殼與環之局部分離前視 圖〇 昂二B圖係表示將環裝配於第二a圖的機殼之狀態的局部 分離前視圖。 12 200839104 第三圖係第一圖之要部放大圖。 第四圖係表示在第一圖的突出部形成螺旋狀的階段部之一 例的局部前視圖。 第五圖係本發明之第二實施形態所涉及的離心泵之剖面 圖。 第六圖係第五圖的離心泵之機殼與轴支撐部之剖面圖。 第七圖係表示使第五圖之離心泵中的吸入口作成小口徑的 變形例之剖面圖。 第八圖係習知例的離心泵之剖面圖。 【主要元件符號說明】 1定子塊 2定子 3控制電路 4隔間板 4 0凹部 5轴 Θ轉子 Θ 0軸承 61永久磁鐵 7葉輪 7 0流路 7 1開口 8機殼 8 0吸入口 13 200839104 8 3支撐肋 8 4、8 4’軸支撐部 8 4 0軸支撐部本體 840a、840a’ 突出部 8 4 1環 8 4 Γ周緣部 841a、841a’吸入口侧的面 8 5 0、8 5 0 ’轴承部It is preferable that the surface 84la' of the = port is in a field in which the impeller flow path 70 is located on the center side of the crucible. Further, in the conical projection portion 8 4 〇 a, a spiral step portion. According to the above description, only the embodiment of the present invention is the best embodiment of the present invention, but the features of the present invention are not limited thereto, and the present invention is not limited to the scope of the present invention. 1L is the standard of the patent application of the present invention, which should be included in (4) of the present invention, and any skilled person who is skilled in the invention can change the secrets of the invention. The scope of the patent in this case below. BRIEF DESCRIPTION OF THE DRAWINGS The first drawing is a cross-sectional view of a centrifugal pump according to a first embodiment of the present invention. 〇=2A is a partial separation of the casing and the ring of the centrifugal pump of the first figure. B is a partially separated front view showing a state in which the ring is fitted to the casing of the second a figure. 12 200839104 The third picture is an enlarged view of the main part of the first picture. The fourth figure is a partial front view showing an example of a stage portion in which the protruding portion of the first figure is formed in a spiral shape. Fig. 5 is a cross-sectional view showing a centrifugal pump according to a second embodiment of the present invention. The sixth drawing is a cross-sectional view of the casing and the shaft support portion of the centrifugal pump of the fifth drawing. Fig. 7 is a cross-sectional view showing a modification in which the suction port in the centrifugal pump of the fifth embodiment is formed into a small diameter. The eighth figure is a cross-sectional view of a centrifugal pump of a conventional example. [Description of main components] 1 stator block 2 stator 3 control circuit 4 compartment board 4 0 recess 5 shaft Θ rotor Θ 0 bearing 61 permanent magnet 7 impeller 7 0 flow path 7 1 opening 8 casing 8 0 suction port 13 200839104 8 3 support ribs 8 4, 8 4' shaft support portion 8 40 shaft support portion body 840a, 840a' protrusion portion 8 4 1 ring 8 4 Γ peripheral portion 841a, 841a' suction port side surface 8 5 0, 8 5 0 'bearing department
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