200918760 九、發明說明 【發明所屬之技術領域】 本發明係關於—種用於電氣機器之內部冷卻等的雙重 反轉式軸流鼓風機。 【先前技術】 曰本特開2004-278370號公報（專利文獻1)及美國 專利第7156611號（專利文獻2)中，揭示一種具備外殼 雙重反轉式軸流鼓風機，該外殼係具備外殼本體以及馬 達支搏框’其中該外殼本體係在內部具有風洞，該風洞係 於軸線方向之其中一方具有吸入口且於軸線方向之另一方 具有吐出口 ’而該馬達支撐框係配置於風洞之中央部。該 雙重反轉式軸流鼓風機，係於外殼內的馬達支撐框與吸入 口之間的第1空間內’配置有藉由第1馬達而旋轉的第1 動葉輪（impeller )。又，在與外殼內的馬達支撐框與吐 出口之間的第2空間內，配置有藉由第2馬達而旋轉的第 2動葉輪。第1動葉輪，係朝第2動葉輪之相反方向旋轉 。該雙重反轉式軸流鼓風機中，外殼係藉由依結合構造而 連結的第1及第2分割外殼單元所構成。第丨分割外殼單 兀’係具有：％ 1外殼本體半部’其係具備於內部具有第 1二間之主3c η卩分的第1筒狀風洞半部；以及第1支撐框 半部，其係馬達支撐框沿著朝與軸線方向正交的徑方向延 二個。第2分割外殻單元 其係具備於內部具有第2 伸之虛擬基準分割面而分割取得 ，係具有：第2外殼本體半部， -5- 200918760 空間之主要部分的第2筒狀風洞半部；以及第2支撐框半 部’其係馬達支撐框沿著虛擬基準分割面而分割取得二個 〇 (專利文獻1)日本特開2004-278370號公報 (專利文獻2 )美國專利第7 1 5 66 1 1號 【發明內容】 (發明所欲解決之問題） 然而’以往的雙重反轉式軸流鼓風機中，一旦增加第 1及第2馬達之旋轉速度’則會出現複數個震動變大的震 動增加區域（共振區域）。尤其是，一旦雙重反轉式軸流 鼓風機之使用旋轉速度設定於該震動增加區域內，則雙重 反轉式軸流鼓風機所產生的震動會變大，結果有噪音增大 的問題。 本發明之目的在於’提供一種在較寬的旋轉速度範圍 內’可比習知還降低震動之發生的雙重反轉式軸流鼓風機 (解決問題之手段） 本案發明的雙重反轉式軸流鼓風機，係具備外殼；第 1動葉輪及第1馬達；以及第2動葉輪及第2馬達。外殼 係具備：於內部具有風洞的外殻本體以及配置於風洞之中 央部的馬達支撐框，該風洞係於軸線方向之其中一方具有 吸入口且於軸線方向之另一方具有吐出口。第1動葉輪， -6 - 200918760 係配置於外殼內之馬達支撐框與吸入口之間的第1空間內 ，且具備複數片的葉片（blade )。第1馬達，係具備固 定第1動葉輪的第1旋轉軸，使第1動葉輪在第1空間內 朝第1旋轉方向旋轉。第2動葉輪，係配置於外殼內之馬 達支撐框與吐出口之間的第2空間內，且具備複數片的葉 片。第2馬達，其係具備固定第2動葉輪的第2旋轉軸， 使第2動葉輪在第2空間內朝與第1旋轉方向相反的第2 旋轉方向旋轉。 馬達支撐框，係具備：位於風洞之中央部的支撐框本 體；以及複數支的腹板（web )，其係在旋轉軸之周方向 隔開預定的間隔配置於支撐框本體與外殻本體之間，用以 連結支撐框本體與外殼本體。 外殼，係由藉由機械性的結合構造而連結的第1及第 2分割外殼單元所構成。第1分割外殻單元，係具有：第 1外殼本體半部以及第1支撐框半部，該第1外殼本體半 部係具備於一端具有吸入口且於內部具有第1空間之主要 部分的第1筒狀風洞半部，該第1支撐框半部係馬達支撐 框沿著朝與軸線方向正交之徑方向延伸的分割面被分割取 得二個。又第2分割外殼單元，係具有：第2外殼本體半 部以及第2支撐框半部，該第2外殻本體半部係具備於一 端具有吐出口且於內部具有第2空間之主要部分的第2筒 狀風洞半部，該第2支撐框半部係將馬達支撐框沿著分割 面分割取得二個。 本發明中所採用的結合構造’係具備：複數個卡合部 200918760 以及複數個被卡合部，該複數個卡合部係與第1外殼本體 半部形成一體並於周方向隔開間隔而配置，該複數個被卡 合部係與第2外殼本體半部形成一體並於周方向隔開間隔 而配置，並與複數個卡合部相卡合。結合構造以及第1及 第2分割外殼單元’係當複數個卡合部與複數個被卡合部 處於完全結合後的狀態時，第1支撐框半部與第2支撐框 半部之各個的相對向面以全體性地接觸的方式所構成。本 案中所謂「對向面全體性地接觸」，微觀的話係指對向面 藉由多數的點接觸來接觸之意。 本發明中’尤其是’在第1支撐框本體半部與第2支 撐框本體半部之間’配置有複數個卡合部與複數個被卡合 部在完全卡合的狀態下成爲壓縮狀態的軟質之緩衝材。本 發明中’作爲軟質之緩衝材，係採用複數個獨立氣泡分散 存在於內部的軟質之緩衝材。在此的獨立氣泡，並非僅爲 單獨的氣泡’亦可爲包含複數個氣泡聯繫而形成的較大之 獨立氣泡。一旦使用如此的緩衝材，則可在從旋轉速度較 低的範圍至較高的範圍，遍及於較寬的轉數範圍內整體地 降低震動之增加。作爲複數個獨立氣泡分散存在於內部的 軟質之緩衝材，具體而言較佳爲，丙烯酸泡棉的薄片。在 使用丙烯酸泡棉的薄片作爲軟質之緩衝材的情況，較佳爲 ，將丙烯酸泡棉的薄片之厚度設爲0.4mm以上至0.8mm 以下。另外，當丙烯酸泡棉的薄片之厚度未滿〇 · 4 m m時 ，由於緩衝材本身的厚度尺寸較小，所以無法獲得充分的 震動吸收效果。又，當丙烯酸泡棉的薄片之厚度超過 -8- 200918760 0.8mm時，就必須另外設置在第1支撐框半部與第2支撐 框半部之間配置丙烯酸泡棉的薄片用之間隙。然而設置如 此的間隙，由於會產生震動之共振頻率的位移，且使震動 對策複雜化故而不佳。 本發明中所採用之特定的軟質之緩衝材，亦扮演降低 在第1支撐框半部與第2支撐框半部之間產生的震動之功 能。結果’依據本發明，與習知相較可遍及於從低速旋轉 區域至高速旋轉區域之較寬的旋轉速度範圍整體地降低震 動之增加。 又軟質之緩衝材，亦可整體地配置於第1支撐框半部 與第2支撐框半部之間。 另外’第1及第2分割外殼單元，可爲由合成樹脂材 料所形成，且可爲由鋁等之金屬材料所形成。 【實施方式】 以下，參照圖式詳細地說明本發明的實施形態。第！ 圖係將本發明實施形態的雙重反轉式軸流鼓風機經分解的 狀!之半部剖視圖。又’第2圖係雙重反轉式軸流鼓風機 之分解立體圖。如此等圖所示，本例的雙重反轉式軸流鼓 風機，係具有外殼1、第1馬達3、第1動葉輪5、第2 馬達7及弟2動葉輪9。桌1動葉輪5，係配置於外殼1 內之後述的馬達支撐框（23、53 )與吸入口丨la之間的第 1空間S1內，且具備複數片的葉片6。第丨馬達3，係具 備固定第1動葉輪5的第1旋轉軸4，用以使第1動葉輪 -9- 200918760 5在第1空間S1內朝第！旋轉方向旋轉。第2動葉輪9, 係配置於外殻1內之馬達支撐框（23、53)與吐出口 之間的第2空間S2內，且具備複數片的葉片ι〇。第2馬 達7,係具備固定第2動葉冑9的第2旋轉軸8,用以使 第2動葉輪9在第2空間S2內朝與第〗旋轉方向相反之 第2旋轉方向旋轉。 外殻1 ’係第1分割外殻單元n與第2分割外殼單 元1 3夾介結合構造組合所構成。第1分割外殼單元丨工， 係藉由合成樹脂材料或鋁等之金屬製材料所形成。另外如 第1圖所示’第1分割外殼單元H，係一體地具有第1 外殻本體半邰15與第1支撐框半部17。第1外殼本體半 部15’係具有第1及第2凸緣部19及20與第1筒狀風 洞半部21。第1凸緣部1 9，係具有並列於第1及第2馬 達3、7之共通軸線A上所排列的旋轉軸4之周方向（以 下，簡稱爲周方向）的第1〜第4角隅19a〜19d。又，第1 凸緣部19，係在共通軸線A之其中一端具有吸入口 lla。 在第1凸緣部19之四角隅（第1〜第4角隅19a〜19d)， 係分別形成有四個孔部1 9e用以各別作爲當在與第2分割 外殼單元13之間形成結合構造時所使用的被卡合部。此 等的孔部1 9e之形狀的詳細以及構成後述之卡合部的鉤部 4 9與孔部1 9 e之卡合關係的詳細’由於與日本特開2 0 0 4 -27 8 3 70號公報（美國專利第7 1 5 66 1 1號）中所示之構成 結合構造的孔部與鉤部之關係相同故而省略說明。在第2 凸緣部2 0，形成有貫穿孔2 0 a俾可插入將雙重反轉式軸 -10- 200918760 流鼓風機安裝於電氣機器的安裝具。在第1筒狀風洞半部 21之兩端’一體地形成有第1及第2凸緣部19及20。該 第1筒狀風洞半部2 1，係朝共通軸線a上所排列的旋轉 軸4、8之軸線方向（以下，簡稱爲軸線方向）延伸。 第1支撐框半部17，係具有：固定有第丨馬達3的 第1支撐框本體半部23 ;以及三支的第1腹板半部25。 第1支撐框本體半部23，係具有在中央部具有筒狀之突 面（b 〇 s s )部2 3 a的圓板部2 3 b ;以及從該圓板部2 3 b之 外周部朝軸線方向延伸的周壁部2 3 c。在突面部2 3 a內， 嵌合並固定有由黃銅所製成的金屬製之第1軸承座（ bearing holder) 27。又以閉塞由圓板部23b與周壁部23c 所包圍的空間之方式，配置有第1馬達3之定子的基板 29。在軸承座27’嵌合有具備複數個線圈部31的定子鐵 心33。 三支的第1腹板半部25，係在周方向隔開預定的間 隔’配置於第1支撐框本體半部23的周壁部23c與第1 外殻本體半部1 5的內周面之間，用以連結第1支撐框本 體半部23與第1外殻本體半部1 5。 在旋轉軸4之其中一端，固定有用以支撐具備複數個 葉片6的動葉輪5之由導磁性材料所構成的杯狀構件3 5 。在杯狀構件3 5之內周部固定有複數個永久磁鐵3 7。 第2分割外殻單元13’也是藉由合成樹脂材料或鋁 等之金屬材料所形成。如第1圖所示，第2分割外殻單元 13，係一體地具有第2外殼本體半部39與第2支撐框半 -11 - 200918760 部41。第2外殻本體半部39,係具有第1及第2凸緣部 43及45與第2筒狀風洞半部47。第1凸緣部43，係具 有由並列於第1及第2馬達3、7之共通軸線A上所排列 的旋轉軸8之周方向（以下，簡稱爲周方向）的第1〜第4 角隅43 a〜43d所構成之四角隅。在第1凸緣部43之四角 隅（第1〜第4角隅43 a〜43d )，係分別一體地形成有四個 飽部49與四個突起51用以各別作爲當在與第1分割外殼 單元Π之間形成結合構造時所使用的卡合部。此等的鉤 部49與突起51和孔部19e卡合之卡合關係的詳細，係與 日本特開2004-2783 7〇號公報中所示之構成結合構造的孔 部與鉤部之關係相同。如日本特開2004-278370號公報（ 美國專利第73 966 1 1號）所示，在將鉤部49嵌合於孔部 1 9e之一部分之後，一旦使第2分割外殼單元1 3以共通 軸線A爲中心，旋轉預定的角度，突起5 1就成爲嵌入於 弟1分割外殼單兀1 1之第1凸緣部1 9之端面所形成之未 圖示的被嵌合用凹部的狀態。結果，可謀求第2分割外殼 單元13之旋轉停止，又藉由和鉤部49與孔部19纟之周圍 的緣部之卡合，就可阻止第2分割外殼單元13從第1分 割外殼單元11朝軸線方向脫離。在第2凸緣部45，形成 有貫穿孔45a俾可插入將雙重反轉式軸流鼓風機安裝於電 氣機器的安裝具。在第2筒狀風洞半部47之兩端，一體 地形成有第1及第2凸緣部4 3及4 5。該第2筒狀風洞半 部47，係朝軸線方向（共通軸線A上所排列的旋轉軸4 、8之軸線方向）延伸。 -12- 200918760 第2支撐框半部41，係具有：固定有第2馬達7的 第2支撐框本體半部53;以及三支的第2腹板半部55。 第2支撐框本體半部53，係具有在中央部具有筒狀之突 面部5 3 a的圓板部5 3 b ;以及從該圓板部5 3 b之外周部朝 軸線方向延伸的周壁部5 3 c。在突面部5 3 a內，嵌合並固 定有由黃銅所製成的金屬製之第2軸承座57。又以閉塞 由圓板部53b與周壁部53c所包圍的空間之方式，配置有 第2馬達7之定子的基板59。在軸承座57，嵌合有具備 複數個線圈部6 1的定子鐵心63。 三支的第2腹板半部5 5，係在周方向隔開預定的間 隔，配置於第2支撐框本體半部5 3的周壁部5 3 c與第2 外殻本體半部3 9的內周面之間，用以連結第2支撐框本 體半部23與第2外殼本體半部39。另外在三支的第2腹 板半部5 5之中的一支腹板半部，形成有可讓導線進入的 溝槽5 5 A。 在旋轉軸8之其中一端，固定有用以支撐具備複數個 葉片1 〇的動葉輪9之由導磁性材料所構成的杯狀構件65 。在杯狀構件65之內周部固定有複數個永久磁鐵67。 另外本實施形態中，第1及第2支撐框半部1 7及41 ，係被組合而構成馬達支撐框（23、53 )。換言之，馬達 支撐框（23、5 3 )沿著朝與共通軸線A所延伸之軸線方 向正交的徑方向延伸之分割面被分割成二個來構成第1及 第2支撐框半部1 7及4 1。藉由如此的構成，本例中的結 合構造以及第1及第2分割外殼單元1 1及1 3，係以當四 -13- 200918760 個卡合部（四個鉤部49)與四個被卡合部（四個孔部19e )處於完全地卡合的狀態時，第1支撐框半部17及第2 支撐框半部41之各自的對向面會整體地接觸的方式而構 成。 本實施形態中，在第1支撐框半部17與第2支撐框 半部41之間，尤其是在第1支撐框本體半部2 3的圓板部 2 3 b與第2支撐框本體半部5 3的圓板部5 3 b之間，配置 複數個獨立氣泡分散存在於內部的圓板狀的軟質之緩衝材 7 1。作爲軟質之緩衝材7 1，較佳爲，可採用丙烯酸泡棉 的薄片。緩衝材7 1，係構成複數個卡合部的四個鉤部49 與構成複數個被卡合部的四個孔部1 在完全地卡合的狀 態下，以被壓縮的狀態配置。成爲壓縮狀態的複數個獨立 氣泡分散存在於內部的緩衝材7 1，係整體大致均等地產 生欲在被壓縮的狀態下回到原來狀態的復原力。該復原力 ，係成爲朝欲將複數個卡合部（四個鉤部49)與複數個 被卡合部之卡合予以脫離的方向之力。結果，複數個卡合 部（四個鉤部49)與複數個被卡合部（四個孔部19e之 周邊的緣部）之間的結合力會變強’且可抑制成爲在第1 及第2分割外殼單元11及13間所產生的震動之發生原因 之較大的間隙發生’並可縮小實際產生的震動。又緩衝材 7 1，也扮演吸收在第1支撐框半部1 7與第2支撐框半部 4 1之間所產生的震動’並降低該震動的功能。結果’依 據本發明，則與習知相較可整體地降低在較寬的旋轉速度 範圍內震動之增加。 -14 - 200918760 上述實施形態中，軟質之緩衝材7 1，因只配置於第1 支撐框本體半部23的圓板部23b與第2支撐框本體半部 53的圓板部53b之間故可獲得良好的結果。但是若亦在 第1腹板半部25與第2腹板半部55之間配置軟質之緩衝 材，則可更進一步地提高震動抑制效果。 以下，爲了確認本發明的效果而進行震動測定試驗。 弟3圖至弟5圖係顯不震動測定試驗之結果的圖表。另外 ，震動測定試驗中，測定周方向之測定部位Μ 1 (第2分 割外殼單元1 3側之第1凸緣部43的一部分）的震動加速 度（m / s2 )、與軸線方向之吐出口側的測定部位Μ 2 (第1 分割外殼單元U側之第2凸緣部20的貫穿孔20a附近） 的震動加速度（m/s2 )，且描繪作爲經合成此等的震動加 速度（m/s2 )之結果。首先，第3圖（A )係顯示經申請 人（山洋電氣股份有限公司）測定將本發明應用於以製品 編號9CRA0412P5J03販售的雙重反轉式軸流鼓風機之情 況、與不應用之情況的旋轉速度（高速旋轉的第2馬達之 旋轉速度）與所產生之震動的震動加速度之關係的結果之 圖表。第3圖（A)中，X係顯示加入軟質之緩衝材71的 雙重反轉式軸流鼓風機（實施例1 )之震動加速度的變化 ’ Y係顯示未加入緩衝材7 1的雙重反轉式軸流鼓風機（ 比較例1 )之震動加速度的變化。所使用的軟質之緩衝材 ’係採用住友3M股份有限公司以製品編號Y-4615之名 稱市售者。從測定結果中，可明白在從較低的轉數區域至 較高的轉數區域之較寬的轉數區域中，可抑制震動之發生 -15- 200918760 又第3圖（B)係顯示測定將本發明應用於申請人（ 山洋電氣股份有限公司）所販售的雙重反轉式軸流鼓風機 之中，尺寸及型式與第3圖（A)不同的雙重反轉式軸流 鼓風機（製品編號9 C R A 0 4 1 2 P 4 J 0 3 )之情況、與不應用之 情況的旋轉速度（高速旋轉的第2馬達之旋轉速度）與戶斤 產生之震動的震動加速度之關係的結果之圖表。第3圖（ B )中’ X係顯示加入緩衝材71的雙重反轉式軸流鼓風機 (實施例2 )之震動加速度的變化，γ係顯示未加入緩衝 材7 1的雙重反轉式軸流鼓風機（比較例2)之震動加速 度的變化。所使用的軟質之緩衝材，係與第3圖（A)之 情況相同。此例中’從測定結果來看，也可明白在從較低 的轉數區域至較尚的轉數區域之較寬的轉數區域中，可相 當地抑制所產生的較大之震動。 第4圖（A )係顯示測定將本發明應用於申請人以外 之其他公司所製造販售的雙重反轉式軸流鼓風機之情況、 與不應用之情況的旋轉速度（高速旋轉的第2馬達之旋轉 速度）與所產生之震動的震動加速度之關係的結果之圖表 。第4圖（A )中’ X係顯不加入緩衝材71的雙重反轉式 軸流鼓風機（實施例3 )之震動加速度的變化，γ係顯示 未加入緩衝材7 1的雙重反轉式軸流鼓風機（比較例3 ) 之震動加速度的變化。所使用的軟質之緩衝材，係採用與 第3圖（A )之情況相同者。從測定結果來看，可明白在 所有的轉數區域中，可整體地抑制震動之發生。 -16- 200918760 第4圖（B )係與第4圖（A)同樣地顯示測定將本 發明應用於其他公司的雙重反轉式軸流鼓風機之情況、與 不應用之情況的旋轉速度（高速旋轉的第2馬達之旋轉速 度與所產生之震動的震動加速度之關係的結果之圖表。第 4圖（B )中，X係顯示加入緩衝材7 1的雙重反轉式軸流 鼓風機（實施例4 )之震動加速度的變化，γ係顯示未加 入緩衝材7 1的雙重反轉式軸流鼓風機（比較例4 )之震 動加速度的變化。所使用的軟質之緩衝材，係採用與第3 圖（A )之情況相同者。從測定結果來看，可明白在所有 的轉數區域中，可整體地抑制震動之發生。 從以上之震動測疋的結果（第3圖及第4圖）來看， 由於可明白能獲得採用作爲獨立氣泡之緩衝材的丙烯酸泡 棉爲佳的結果’所以可更進一步確認作爲丙烯酸泡棉之緩 衝材的較佳之厚度’就丙烯酸泡棉以外的材料而言也能一 倂確認作爲緩衝材的適當性。第5圖係顯示經測定在與第 3圖相同的雙重反轉式軸流鼓風機中，以與第3圖相同的 測定條件，改變丙烯酸泡棉的薄片之厚度的情況、採用丙 烯酸泡棉以外之緩衝材的情況、以及未採用緩衝材的情況 、積極地設置間隙以取代緩衝材的情況之旋轉速度（高速 旋轉的第2馬達之旋轉速度）與所產生的震動之震動加速 度之關係的結果之圖表。 第5圖中，「點線」係顯示加入0.4 m m之丙烧酸泡 棉的薄片作爲軟質之緩衝材7 1的雙重反轉式軸流鼓風機 (實施例5 )之震動加速度的變化。「虛線」係顯示加入 -17- 200918760 〇.8mm之丙烯酸泡棉的薄片作爲軟質之緩衝材71的雙重 反轉式軸流鼓風機（實施例6 )之震動加速度的變化。「 粗實線」係顯不未加入緩衝材7 1的雙重反轉式軸流鼓風 機（比較例5 )之震動加速度的變化。「粗虛線」係顯示 在第1支撐框本體半部23與第2支撐框本體半部53之間 積極地設置〇 . 2 mm之間隙的雙重反轉式軸流鼓風機（比 較例6 )之震動加速度的變化。通常「實線」係顯示加入 0.46mm之鋁的薄片作爲緩衝材的雙重反轉式軸流鼓風機 (比較例7 )之震動加速度的變化。「一點虛線」係顯示 加入〇 . 5 mm之塑膠的薄片作爲緩衝材的雙重反轉式軸流 鼓風機（比較例8 )之震動加速度的變化。 作爲該測定結果，首先在未採用緩衝材的情況（比較 例5)，出現複數個震動加速度之共振點（峰値）。尤其 是，在14000〔轉/分鐘〕附近之較筒的轉數區域中發現非 常高的震動加速度之峰値。又在採用鋁的薄片作爲緩衝材 的情況（比較例7 )及採用塑膠的薄片作爲緩衝材的情況 (比較例8)，較高的轉數區域中的複數個震動加速度之 共振點（峰値）也會稍微減少。但是，在1 4000〔轉/分鐘 〕附近之較高的轉數區域中所比較的情況之震動加速度之 共振點（峰値）雖然非爲未使用緩衝材7 1的情況（比較 例5 )程度，但是會留下比較高的震動加速度之峰値。 相對於此，在使用〇.4mm之丙烯酸泡棉的薄片作爲 緩衝材7 1的情況（實施例5 )，係在較高的轉數區域中 之複數個震動加速度之峰値減少之後，在1 4000〔轉/分鐘 -18- 200918760 〕附近，與比較例比較後之情況的震動加速度之峰値’係 對於未使用緩衝材7 1的情況（比較例5 )降低40% ’而 對於使用鋁的薄片及塑膠的薄片作爲緩衝材71的情況（ 比較例7、8)降低30%。又在使用0.8mm之丙烯酸泡棉 作爲緩衝材7 1的情況（實施例6 )，係在較高的轉數區 域中之複數個震動加速度之峰値減少之後，在1 4000〔轉/ 分鐘〕附近，與比較例比較後之情況的震動加速度之峰値 ，係對於未使用緩衝材71的情況（比較例5 )降低60% ，而對於使用鋁的薄片及塑膠的薄片作爲緩衝材71的情 況（比較例7、8 )降低50%。即使與使用0.4mm之丙烯 酸泡棉的情況（實施例5 )相較，使用0.8mm之丙烯酸泡 棉的情況（實施例6 )，1 4000〔轉/分鐘〕附近的震動加 速度之峰値降低了 3 0 %。 另外，在不使用緩衝材而設置〇 . 2 m m之間隙的情況 (比較例6 )，在1 4000〔轉/分鐘〕附近並未發現震動加 速度較高的峰値，而在1 20 0 0〔轉/分鐘〕附近，卻發現比 未使用緩衝材71的情況（比較例5 )之最大峰値還高的 震動加速度度之峰値。此外，較高的震動加速度之峰値數 ’係比未使用緩衝材71的情況（比較例5 )還增加。從 此結果可明白，較高的轉數區域中之震動，雖然不配置緩 衝材而只要設置間隙，即可藉由震動加速度之最大峰値移 動至較低的轉數區域（發生位移現象）來抑制，但是在從 較低的轉數區域至較高的轉數區域之較寬的轉數區域中， 卻無法降低震動之發生。 -19- 200918760 從以上結果來看’一旦將使用作爲緩衝材71的丙烯 酸泡棉之厚度設定在0 4 m m〜0.8 m m之範圍’不僅可抑制 在較高的轉數區域中發生之較大的震動，也可在較寬的轉 數範圍整體地降低震動之增加。另外’當丙烯酸泡棉的薄 片之厚度未滿〇.4mm時’由於緩衝材本身的厚度尺寸較 小，所以可預想到無法獲得必要充分的震動吸收效果。又 ，當丙稀酸泡棉的薄片之厚度超過〇.8mm時’會發生要 另外設置用以在第1支撐框半部與第2支撐框半部之間配 置厚度較厚之丙烯酸泡棉的薄片之間隙的必要。一旦積極 地設置間隙，由於會出現設置前述0 · 2 m m之間隙時的位 移現象之影響故而不佳。 另外在上述實施形態中，雖然只在第1支撐框本體半 部2 3的圓板部2 3 b與第2支撐框本體半部5 3的圓板部 53b之間配置緩衝材71，但是亦可在第1腹板半部25與 第2腹板半部5 5之間配置緩衝材7 1是無庸置疑的。 (產業上之可利用性） 依據本發明，則由於在第1支撐框半部與第2支撐框 半部之間，配置有複數個卡合部與複數個被卡合部在完全 地卡合的狀態下成爲壓縮狀態的複數個獨立氣泡分散存在 於內部的軟質之緩衝材，所以與習知相較，可在較寬的轉 數範圍整體地降低震動之增加。 【圖式簡單說明】 -20- 200918760 第1圖係本發明實施形態的雙重反轉式軸流鼓風機之 分解半部剖視圖。 第2圖係本發明實施形態的雙重反轉式軸流鼓風機之 分解立體圖。 第3圖（A)及（B)係顯示爲了確認本發明之效果 而進行的震動測定之結果的圖表。 第4圖（A)及（B)係顯示爲了確認本發明之效果 而進行的震動測定之結果的圖表。 第5圖係顯示爲了確認本發明之效果而進行的震動測 定之詳細結果的圖表。 【主要元件符號說明】 1 :外殼 3 :第1馬達 4、8 :旋轉軸 5 :第1動葉輪 6、1 〇 :葉片 7 :第2馬達 9 :第2動葉輪 1 1 :第1分割外殼單元 1 1 a :吸入口 1 3 :第2分割外殼單元 1 3 b :吐出口 1 5 :第1外殼本體半部 -21 - 200918760 1 7 :第1支撐框半部 1 9、4 3 :第1凸緣部 19a〜19d、43a~43d :第1〜第4角隅 1 9 e :孔部 2 0、4 5 :第2凸緣部 20a、45a:貫穿孔 21 :第1筒狀風洞半部 23 :第1支撐框本體半部 23a、53a:突面部 2 3 b、5 3 b :圓板部 23c、 53c:周壁部 2 5 :第1腹板半部 2 7 :第1軸承座 29 、 59 :基板 3 1、6 1 :線圈部 3 3、6 3 :定子鐵心 3 5、6 5 :杯狀構件 3 7、6 7 :永久磁鐵 3 9 :第2外殻本體半部 41 :第2支撐框半部 47 :第2筒狀風洞半部 4 9 :鉤部 5 1 :突起 5 3 :第2支撐框本體半部 -22- 200918760 5 5 :第2腹板半部 5 5 A :溝槽 57 :第2軸承座 7 1 :緩衝材 A :共通軸線 S 1 :第1空間 S2 :第2空間BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double reverse axial flow blower for internal cooling of an electric machine or the like. [Prior Art] In Japanese Patent No. 2004-278370 (Patent Document 1) and U.S. Patent No. 7,576,181 (Patent Document 2), a double-reverse axial flow blower having a casing is provided, and the casing is provided with a casing body and a motor pitch frame in which the outer casing has a wind tunnel inside, the wind tunnel has a suction port in one of the axial directions and a discharge port in the other of the axial directions, and the motor support frame is disposed at a central portion of the wind tunnel . In the double reverse axial flow fan, a first impeller that is rotated by the first motor is disposed in the first space between the motor support frame and the suction port in the casing. Further, a second impeller that is rotated by the second motor is disposed in the second space between the motor support frame and the discharge port in the casing. The first impeller is rotated in the opposite direction to the second impeller. In the double reverse axial flow fan, the outer casing is constituted by the first and second divided outer casing units connected by the joint structure. The first divided housing unit 具有 has a: % 1 housing body half portion, which is provided with a first tubular wind tunnel half having a main 3c η split of the first two compartments; and a first support frame half. The motor support frame is extended by two in a radial direction orthogonal to the axial direction. The second divided outer casing unit includes a second outer casing main half having a second outer casing main half, and a second cylindrical wind tunnel half of a main portion of the space of the second outer casing; And the second support frame half portion 'the motor support frame is divided into two along the virtual reference division surface. (Patent Document 1) Japanese Laid-Open Patent Publication No. 2004-278370 (Patent Document 2) US Patent No. 7 1 5 66 1 No. 1 [Summary of the Invention] (Problems to be Solved by the Invention) However, in the case of the conventional double-reverse axial flow blower, when the rotational speeds of the first and second motors are increased, a plurality of vibrations are generated. Increase the area (resonance area). In particular, if the rotational speed of the double reverse axial flow blower is set in the vibration increase region, the vibration generated by the double reverse axial flow blower becomes large, and as a result, there is a problem that noise increases. SUMMARY OF THE INVENTION The object of the present invention is to provide a double reverse axial flow blower (which is a means for solving the problem) in the wide range of rotational speeds, which can reduce the occurrence of vibration. The housing includes a housing, a first impeller and a first motor, and a second impeller and a second motor. The outer casing includes a casing body having a wind tunnel therein and a motor support frame disposed at a central portion of the wind tunnel, the wind tunnel having a suction port in one of the axial directions and a discharge port in the other axial direction. The first impeller, -6 - 200918760 is disposed in the first space between the motor support frame and the suction port in the casing, and has a plurality of blades. The first motor includes a first rotating shaft that fixes the first moving impeller, and rotates the first moving impeller in the first rotating direction in the first space. The second impeller is disposed in a second space between the motor support frame and the discharge port in the casing, and includes a plurality of blades. The second motor includes a second rotating shaft that fixes the second moving impeller, and rotates the second moving impeller in a second rotating direction opposite to the first rotating direction in the second space. The motor support frame includes: a support frame body located at a central portion of the wind tunnel; and a plurality of webs disposed on the support frame body and the outer casing body at a predetermined interval in a circumferential direction of the rotary shaft The connection between the support frame body and the outer casing body. The outer casing is composed of first and second divided outer casing units that are coupled by a mechanical joint structure. The first divided casing unit includes a first casing main body half and a first support frame half, and the first casing main half has a main portion having a suction port at one end and a first space inside. In the one tubular wind tunnel half, the first support frame half motor support frame is divided into two along a split surface extending in a radial direction orthogonal to the axial direction. Further, the second divided casing unit includes a second casing main body half and a second support frame half, and the second casing main half has a main portion having a discharge port at one end and a second space inside. In the second tubular wind tunnel half, the second support frame half is divided into two by dividing the motor support frame along the dividing surface. The coupling structure used in the present invention includes a plurality of engaging portions 200918760 and a plurality of engaged portions, and the plurality of engaging portions are integrally formed with the first casing body half and spaced apart in the circumferential direction. In the arrangement, the plurality of engaged portions are integrally formed with the second outer casing main portion, and are disposed at intervals in the circumferential direction, and are engaged with the plurality of engaging portions. The joint structure and the first and second divided outer casing units' are each of the first support frame half and the second support frame half when the plurality of engagement portions and the plurality of engaged portions are completely coupled. The opposing faces are formed in such a manner as to be in total contact. In this case, the so-called "opposite contact with the entire face", the microscopic term refers to the intention of the opposite face to be contacted by a large number of points. In the present invention, in particular, a plurality of engaging portions are disposed between the first support frame main body half and the second support frame main body half, and a plurality of engaged portions are in a compressed state in a state of being completely engaged. Soft cushioning material. In the present invention, as a soft cushioning material, a plurality of soft foaming materials in which a plurality of independent cells are dispersed and dispersed therein are used. The closed cells here are not only individual bubbles, but also larger independent bubbles formed by a plurality of bubble contacts. Once such a cushioning material is used, the increase in vibration can be reduced overall over a wide range of revolutions from a range of lower rotational speeds to a higher range. As the soft cushioning material in which a plurality of independent cells are dispersed and dispersed inside, specifically, a sheet of acrylic foam is preferable. In the case where a sheet of acrylic foam is used as the soft cushioning material, the thickness of the sheet of the acrylic foam is preferably 0.4 mm or more and 0.8 mm or less. Further, when the thickness of the sheet of the acrylic foam is less than 4 m m , since the thickness of the cushioning material itself is small, a sufficient shock absorbing effect cannot be obtained. Further, when the thickness of the sheet of the acrylic foam exceeds -8 - 200918760 0.8 mm, it is necessary to additionally provide a gap for the sheet in which the acrylic foam is disposed between the first support frame half and the second support frame half. However, the provision of such a gap is not preferable because the displacement of the resonance frequency of the vibration is generated and the vibration countermeasure is complicated. The specific soft cushioning material used in the present invention also functions to reduce the vibration generated between the first support frame half and the second support frame half. As a result, according to the present invention, the increase in vibration can be reduced as a whole as compared with the wide range of rotational speeds from the low-speed rotation region to the high-speed rotation region. Further, the soft cushioning material may be disposed integrally between the first support frame half and the second support frame half. Further, the first and second divided outer casing units may be formed of a synthetic resin material, and may be formed of a metal material such as aluminum. [Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The first! The figure is a half cross-sectional view showing a double reverse type axial flow blower according to an embodiment of the present invention. Further, Fig. 2 is an exploded perspective view of the double reverse axial flow blower. As shown in the figures, the double reverse type axial flow blower of this embodiment includes a casing 1, a first motor 3, a first impeller 5, a second motor 7, and a second impeller 9. The table 1 movable impeller 5 is disposed in the first space S1 between the motor support frame (23, 53) and the suction port 丨la, which will be described later in the casing 1, and includes a plurality of blades 6. The first motor 3 is provided with a first rotating shaft 4 for fixing the first movable impeller 5, so that the first moving impeller -9-200918760 5 faces the first space S1! Rotate in the direction of rotation. The second impeller 9 is disposed in the second space S2 between the motor support frame (23, 53) in the casing 1 and the discharge port, and includes a plurality of blades. The second motor 7 has a second rotating shaft 8 that fixes the second bucket 9 so that the second rotor 9 rotates in the second space S2 in the second rotation direction opposite to the first rotation direction. The outer casing 1' is composed of a combination of a first divided outer casing unit n and a second divided outer casing unit 1 sandwiching structure. The first divided outer casing unit is formed by a synthetic resin material or a metal material such as aluminum. Further, the first divided casing unit H as shown in Fig. 1 integrally includes the first casing main body half 15 and the first support frame half portion 17. The first outer casing main portion 15' has first and second flange portions 19 and 20 and a first cylindrical wind chamber half portion 21. The first flange portion 197 has first to fourth angles in the circumferential direction (hereinafter, simply referred to as the circumferential direction) of the rotary shaft 4 arranged in parallel on the common axis A of the first and second motors 3 and 7.隅19a~19d. Further, the first flange portion 19 has a suction port 11a at one end of the common axis A. In the four corners of the first flange portion 19 (the first to fourth corners 19a to 19d), four hole portions 19e are formed to be formed between the second and second divided outer casing units 13, respectively. The engaged portion used in combination with the structure is combined. The details of the shape of the hole portion 19e and the details of the engagement relationship between the hook portion 49 and the hole portion 19e constituting the engaging portion to be described later are due to the Japanese Patent Publication No. 2 0 0 4-27 8 3 70 The relationship between the hole portion and the hook portion of the joint structure shown in the Japanese Patent No. 7 1 5 66 1 1 is the same, and the description thereof is omitted. In the second flange portion 20, a through hole 20a is formed, and a mounting tool for attaching the double reverse shaft -10-200918760 flow blower to the electric machine can be inserted. The first and second flange portions 19 and 20 are integrally formed at both ends ′ of the first tubular wind tunnel half 21 . The first tubular wind tunnel half portion 2 1 extends in the axial direction (hereinafter, simply referred to as the axial direction) of the rotating shafts 4 and 8 arranged on the common axis a. The first support frame half portion 17 has a first support frame main body half 23 to which the second motor 3 is fixed, and three first web half portions 25. The first support frame main body half 23 has a circular plate portion 2 3 b having a cylindrical projecting surface (b 〇ss) portion 2 3 a at the center portion; and a peripheral portion from the outer peripheral portion of the circular plate portion 2 3 b A peripheral wall portion 2 3 c extending in the axial direction. A first bearing holder 27 made of brass made of brass is fitted and fixed in the convex portion 2 3 a. Further, the substrate 29 of the stator of the first motor 3 is disposed so as to close the space surrounded by the circular plate portion 23b and the peripheral wall portion 23c. A stator core 33 having a plurality of coil portions 31 is fitted to the bearing housing 27'. The first web half 25 of the three branches is disposed at a predetermined interval in the circumferential direction at the inner peripheral surface of the peripheral wall portion 23c of the first support frame main body half 23 and the first outer casing main portion 15 The first support frame body half 23 and the first case body half 15 are connected. At one end of the rotary shaft 4, a cup-shaped member 35 made of a magnetically permeable material for supporting the movable impeller 5 having a plurality of blades 6 is fixed. A plurality of permanent magnets 3 7 are fixed to the inner circumference of the cup member 35. The second divided outer casing unit 13' is also formed of a synthetic resin material or a metal material such as aluminum. As shown in Fig. 1, the second divided casing unit 13 integrally includes a second casing main body half 39 and a second support frame half -11 - 200918760 portion 41. The second casing main body half 39 has first and second flange portions 43 and 45 and a second tubular wind tunnel half portion 47. The first flange portion 43 has first to fourth corners in the circumferential direction (hereinafter, simply referred to as the circumferential direction) of the rotary shaft 8 arranged in parallel on the common axis A of the first and second motors 3 and 7.四43 a~43d constitutes the four corners. Four corners 49 and four protrusions 51 are integrally formed in each of the four corners (first to fourth corners 43 a to 43d ) of the first flange portion 43 for use as the first and the first The engaging portion used when forming the joint structure between the split casing units 。 is formed. The details of the engagement relationship between the hook portion 49 and the projection 51 and the hole portion 19e are the same as those of the hook portion and the hook portion shown in Japanese Laid-Open Patent Publication No. 2004-2783. . As shown in Japanese Laid-Open Patent Publication No. 2004-278370 (U.S. Patent No. 73 966 1-1), after the hook portion 49 is fitted to a portion of the hole portion 19e, once the second divided housing unit 13 is made to have a common axis When A is rotated at a predetermined angle, the projections 5 1 are in a state of being fitted into the fitting recesses (not shown) formed on the end faces of the first flange portions 119 of the divided housing unit 1 1 . As a result, the rotation of the second divided outer casing unit 13 can be stopped, and the second divided outer casing unit 13 can be prevented from being separated from the first divided outer casing unit by the engagement with the peripheral portion of the hook portion 49 and the hole portion 19纟. 11 is detached toward the axis. In the second flange portion 45, a through hole 45a is formed, and a mounting tool for attaching the double reverse type axial flow blower to the electric device can be inserted. The first and second flange portions 43 and 45 are integrally formed at both ends of the second tubular wind tunnel half 47. The second tubular wind tunnel half 47 extends in the axial direction (the axial direction of the rotating shafts 4 and 8 arranged on the common axis A). -12- 200918760 The second support frame half 41 has a second support frame main body half 53 to which the second motor 7 is fixed, and three second web half portions 55. The second support frame main body half portion 53 has a disk portion portion 5 3 b having a cylindrical projecting surface portion 5 3 a at the center portion, and a peripheral wall portion extending from the outer peripheral portion of the disk portion portion 5 3 b in the axial direction. 5 3 c. In the projecting portion 5 3 a, a second bearing seat 57 made of metal made of brass is fitted and fixed. Further, the substrate 59 of the stator of the second motor 7 is disposed so as to close the space surrounded by the circular plate portion 53b and the peripheral wall portion 53c. A stator core 63 having a plurality of coil portions 61 is fitted to the bearing housing 57. The three second web halves 5 5 are disposed at a predetermined interval in the circumferential direction, and are disposed in the peripheral wall portion 53 c of the second support frame main body half 53 and the second outer casing main portion 39. Between the inner peripheral surfaces, the second support frame main body half 23 and the second outer casing main half 39 are coupled. Further, in one of the three web halves 5 of the three webs, a groove 55 5 A for allowing a wire to enter is formed. At one end of the rotary shaft 8, a cup-shaped member 65 made of a magnetically permeable material for supporting the movable impeller 9 having a plurality of blades 1 固定 is fixed. A plurality of permanent magnets 67 are fixed to the inner peripheral portion of the cup member 65. Further, in the present embodiment, the first and second support frame halves 17 and 41 are combined to constitute a motor support frame (23, 53). In other words, the motor support frames (23, 5 3 ) are divided into two along the dividing surface extending in the radial direction orthogonal to the axial direction in which the common axis A extends to form the first and second support frame halves 17 And 4 1. With such a configuration, the joint structure and the first and second divided casing units 1 1 and 1 3 in this example are four- 13-200918760 engaging portions (four hook portions 49) and four When the engaging portion (four hole portions 19e) is completely engaged, the opposing faces of the first support frame half 17 and the second support frame half 41 are integrally contacted. In the present embodiment, between the first support frame half portion 17 and the second support frame half portion 41, in particular, the disk portion 2 3 b of the first support frame main body half 23 and the second support frame body half Between the disc portions 5 3 b of the portion 53 is disposed a plurality of disk-shaped soft cushioning members 71 which are dispersed in a plurality of independent cells. As the soft cushioning material 171, it is preferable to use a sheet of acrylic foam. The cushioning material 171 is disposed in a compressed state in a state in which the four hook portions 49 constituting the plurality of engaging portions are completely engaged with the four hole portions 1 constituting the plurality of engaged portions. The cushioning material 711 which is a plurality of independent bubbles which are in a compressed state is dispersed in the interior, and is substantially equal to the restoring force which is intended to return to the original state in a compressed state. This restoring force is a force in a direction in which the engagement of the plurality of engaging portions (four hook portions 49) and the plurality of engaged portions is released. As a result, the bonding force between the plurality of engaging portions (four hook portions 49) and the plurality of engaged portions (edge portions around the four hole portions 19e) becomes strong, and can be suppressed to be in the first and A large gap occurs due to the occurrence of the vibration generated between the second divided outer casing units 11 and 13, and the actual generated vibration can be reduced. Further, the cushioning material 7-1 also functions to absorb the shock generated by the first support frame half portion 17 and the second support frame half portion 41, and to reduce the vibration. As a result, according to the present invention, the increase in vibration over a wide range of rotational speeds can be reduced as a whole. -14 - 200918760 In the above embodiment, the soft cushioning material 711 is disposed only between the disc portion 23b of the first support frame main body half 23 and the disc portion 53b of the second support frame main body half 53. Good results are obtained. However, if a soft cushioning material is also disposed between the first web half 25 and the second web half 55, the vibration suppressing effect can be further improved. Hereinafter, a vibration measurement test was performed in order to confirm the effect of the present invention. Figure 3 to Figure 5 shows a graph showing the results of the non-vibration measurement test. In the vibration measurement test, the vibration acceleration (m / s2 ) of the measurement site Μ 1 in the circumferential direction (a part of the first flange portion 43 on the second divided casing unit 13 side) and the discharge port side in the axial direction are measured. The vibration acceleration (m/s2) of the measurement site Μ 2 (near the through hole 20a of the second flange portion 20 on the first divided casing unit U side), and is depicted as a vibration acceleration (m/s2) synthesized. The result. First, Fig. 3(A) shows the case where the applicant (Sanyo Electric Co., Ltd.) measures the case where the present invention is applied to the double reverse type axial flow blower sold under the product number 9CRA0412P5J03, and the case where it is not applied. A graph showing the relationship between the rotational speed (the rotational speed of the second motor that rotates at a high speed) and the vibration acceleration of the generated vibration. In Fig. 3(A), X shows the change in the vibration acceleration of the double-reverse axial flow blower (Example 1) to which the soft cushioning material 71 is added. Y shows the double reverse type in which the cushioning material 7 1 is not added. The change in the vibration acceleration of the axial flow blower (Comparative Example 1). The soft cushioning material used is made by Sumitomo 3M Co., Ltd. under the name of product number Y-4615. From the measurement results, it can be understood that the occurrence of vibration can be suppressed in a wide number of revolutions from a lower number of revolutions to a higher number of revolutions -15-200918760 and Fig. 3(B) shows the measurement The present invention is applied to a double reverse axial flow blower (products of a double reverse type axial flow blower sold by the applicant (Shanyang Electric Co., Ltd.), which is different in size and type from the third figure (A). No. 9 CRA 0 4 1 2 P 4 J 0 3 ) The graph of the relationship between the rotation speed (the rotation speed of the second motor rotating at a high speed) and the vibration acceleration of the vibration generated by the household. . In Fig. 3(B), the 'X series shows the change in the vibration acceleration of the double-reverse axial flow blower (Example 2) to which the cushioning material 71 is added, and the γ-system shows the double reversed axial flow to which the cushioning material 71 is not added. The change in the vibration acceleration of the blower (Comparative Example 2). The soft cushioning material used is the same as in the case of Fig. 3(A). In this example, it can be understood from the measurement results that in the wide rotation area from the lower number of revolutions to the higher number of revolutions, the large vibration generated can be locally suppressed. Fig. 4(A) shows the measurement of the case where the present invention is applied to a double reverse type axial flow blower which is manufactured by a company other than the applicant, and the rotation speed (the second motor which rotates at a high speed) when it is not applied. A graph of the results of the relationship between the rotational speed and the vibrational acceleration of the generated vibration. In Fig. 4(A), the X-ray shows a change in the vibration acceleration of the double-reverse axial flow blower (Example 3) in which the cushioning material 71 is not added, and the γ-system shows the double inverted shaft to which the cushioning material 71 is not added. The change in the vibration acceleration of the flow blower (Comparative Example 3). The soft cushioning material used is the same as that in the case of Fig. 3(A). From the measurement results, it can be understood that the occurrence of vibration can be suppressed as a whole in all the number of revolutions. -16- 200918760 Fig. 4(B) shows the same as Fig. 4(A) showing the case where the present invention is applied to a double reverse axial flow blower of another company, and the rotational speed (high speed) when it is not applied. A graph showing the relationship between the rotational speed of the rotating second motor and the vibration acceleration of the generated vibration. In Fig. 4(B), X shows a double reverse axial flow blower to which the cushioning material 71 is added (Example 4) The change in the vibration acceleration, the γ system shows the change in the vibration acceleration of the double-reverse axial flow blower (Comparative Example 4) to which the cushioning material 71 is not added. The soft cushioning material used is the same as the third figure. The case of (A) is the same. From the measurement results, it can be understood that the occurrence of vibration can be suppressed as a whole in all the number of revolutions. From the results of the above vibration measurement (Fig. 3 and Fig. 4) In view of the fact that it is possible to obtain an acrylic foam which is used as a cushioning material for the closed cells, it is possible to further confirm that the preferred thickness of the cushioning material as the acrylic foam is in terms of materials other than acrylic foam. It is also possible to confirm the suitability as a cushioning material at a glance. Fig. 5 shows that the acrylic foam is changed in the double reverse axial flow blower which is the same as that in Fig. 3 by the same measurement conditions as in Fig. 3. In the case of the thickness of the sheet, the case where the cushioning material other than the acrylic foam is used, and the case where the cushioning material is not used, and the rotation speed in which the gap is actively provided instead of the cushioning material (the rotation speed of the second motor which rotates at a high speed) A graph showing the results of the relationship between the vibration accelerations of the generated vibrations. In Fig. 5, the "dotted line" shows a double inverted axial flow of a sheet of a 0.4 mm amalgamated foam as a soft cushioning material 71. The change in the vibration acceleration of the blower (Example 5). The "dashed line" is a double reverse axial flow blower in which a sheet of acrylic foam of -17-200918760 〇.8 mm is added as a soft cushioning material 71 (Example 6). The change of the vibration acceleration. The "thick solid line" shows the change of the vibration acceleration of the double reverse axial flow blower (Comparative Example 5) which is not added to the cushioning material 71. A change in the vibration acceleration of the double-reverse axial flow blower (Comparative Example 6) in which the gap between the first support frame main body half 23 and the second support frame main body half 53 is positively provided. The solid line shows the change in the vibration acceleration of the double-reverse axial flow blower (Comparative Example 7) in which a sheet of 0.46 mm aluminum is added as a cushioning material. The "dotted line" shows a sheet of plastic added as 5. 5 mm as a solid sheet. The change in the vibration acceleration of the double reverse axial flow blower (Comparative Example 8) of the cushioning material. As a result of the measurement, first, in the case where the cushioning material was not used (Comparative Example 5), a plurality of resonance points of the vibration acceleration occurred (peak)値). In particular, a very high peak of vibration acceleration is found in the region of the number of revolutions in the vicinity of 14000 [rev/min]. In the case of using a sheet of aluminum as a cushioning material (Comparative Example 7) and a sheet using a plastic sheet as a cushioning material (Comparative Example 8), resonance points of a plurality of vibration accelerations in a high number of revolutions (peaks) ) will also be slightly reduced. However, the resonance point (peak 値) of the vibration acceleration in the case where the higher number of revolutions in the vicinity of 1 4000 [rev/min] is not the case where the buffer material 7 1 is not used (Comparative Example 5) However, it will leave a relatively high peak of vibration acceleration. On the other hand, in the case where a sheet of 丙烯酸.4 mm acrylic foam is used as the cushioning material 71 (Example 5), after the peak of the plurality of vibration accelerations in the higher number of revolutions is reduced, at 1 In the vicinity of 4000 [rev/min -18-200918760], the peak of the vibration acceleration in the case of comparison with the comparative example was reduced by 40% for the case where the buffer material 71 was not used (Comparative Example 5), and for the use of aluminum. The sheet and the plastic sheet were reduced by 30% as the cushioning material 71 (Comparative Examples 7 and 8). Further, in the case where a 0.8 mm acrylic foam is used as the cushioning material 71 (Example 6), after the peak of the plurality of vibration accelerations in the higher number of revolutions is reduced, at 1 4000 [rev/min] In the vicinity, the peak of the vibration acceleration in the case of comparison with the comparative example was reduced by 60% in the case where the cushioning material 71 was not used (Comparative Example 5), and in the case where the sheet using aluminum and the sheet of plastic were used as the cushioning material 71. (Comparative Examples 7, 8) were reduced by 50%. Even in the case of using a 0.8 mm acrylic foam (Example 6), the peak of the vibration acceleration near 1 4000 [rev/min] was lowered compared to the case of using a 0.4 mm acrylic foam (Example 5). 30%. In addition, in the case where a gap of 〇. 2 mm was not used without using a cushioning material (Comparative Example 6), a peak of high vibration acceleration was not found in the vicinity of 1 4000 [rev/min], but at 1 20 0 0 [ In the vicinity of rpm, it was found that the peak of the vibration acceleration was higher than the maximum peak 未 of the case where the cushioning material 71 was not used (Comparative Example 5). Further, the peak number of peaks of the higher vibration acceleration was increased as compared with the case where the cushioning material 71 was not used (Comparative Example 5). From this result, it can be understood that the vibration in the higher number of revolutions can be suppressed by setting the gap without disposing the cushioning material, by moving the maximum peak of the vibration acceleration to the lower number of revolutions (displacement phenomenon). However, in a wide number of revolutions from a lower number of revolutions to a higher number of revolutions, the occurrence of vibration cannot be reduced. -19- 200918760 From the above results, 'when the thickness of the acrylic foam used as the cushioning material 71 is set to be in the range of 0 4 mm to 0.8 mm', it is possible to suppress a large occurrence in a higher number of revolutions. Vibration can also reduce the overall increase in vibration over a wide range of revolutions. Further, when the thickness of the acrylic foam sheet is less than 4 mm, the thickness of the cushioning material itself is small, so that it is expected that a sufficient shock absorption effect is not obtained. Further, when the thickness of the sheet of the acrylic foam exceeds 〇8 mm, it may occur that an acrylic foam having a relatively thick thickness is disposed between the first support frame half and the second support frame half. The need for a gap between the sheets. Once the gap is actively set, it is not preferable because of the influence of the displacement phenomenon when the gap of 0 · 2 m m described above is set. Further, in the above-described embodiment, the cushioning material 71 is disposed only between the disc portion 233b of the first support frame main body half 23 and the disc portion 53b of the second support frame main body portion 53. It is undoubted that the cushioning material 7 1 can be disposed between the first web half 25 and the second web half 55. (Industrial Applicability) According to the present invention, a plurality of engaging portions and a plurality of engaged portions are completely engaged between the first support frame half and the second support frame half. In the state in which the plurality of independent bubbles in the compressed state are dispersed in the soft cushioning material inside, the increase in vibration can be reduced as a whole in a wide range of revolutions. BRIEF DESCRIPTION OF THE DRAWINGS -20- 200918760 Fig. 1 is an exploded half cross-sectional view showing a double reverse axial flow fan according to an embodiment of the present invention. Fig. 2 is an exploded perspective view showing a double reverse type axial flow blower according to an embodiment of the present invention. Fig. 3 (A) and (B) are graphs showing the results of vibration measurement performed to confirm the effects of the present invention. Fig. 4 (A) and (B) are graphs showing the results of vibration measurement performed to confirm the effects of the present invention. Fig. 5 is a graph showing the detailed results of the vibration measurement performed to confirm the effect of the present invention. [Description of main component symbols] 1 : Case 3 : First motor 4 , 8 : Rotary shaft 5 : First rotor impeller 6 , 1 〇 : Blade 7 : 2nd motor 9 : 2nd rotor 1 1 : 1st split case Unit 1 1 a : suction port 1 3 : second divided casing unit 1 3 b : discharge port 1 5 : first casing body half 21 - 200918760 1 7 : first support frame half 1 9 , 4 3 : 1 flange portions 19a to 19d, 43a to 43d: first to fourth corners 隅1 9 e : hole portions 20, 4 5 : second flange portions 20a and 45a: through hole 21: first cylindrical wind tunnel half Part 23: First support frame main body halves 23a, 53a: convex surface portions 2 3 b, 5 3 b : disc portions 23c, 53c: peripheral wall portion 2 5 : first web half portion 2 7 : first bearing housing 29 59: substrate 3 1 , 6 1 : coil portion 3 3 , 6 3 : stator core 3 5 , 6 5 : cup member 3 7 , 6 7 : permanent magnet 3 9 : second case body half 41 : 2 support frame half 47: second tubular wind tunnel half 4 9 : hook portion 5 1 : protrusion 5 3 : second support frame body half 22 - 200918760 5 5 : second web half 5 5 A : Groove 57: second bearing housing 7 1 : cushioning material A: common axis S 1 : first space S2 : second space