圓形管道風機系列主要由外殼，葉輪，電機和接線盒組成 The GDF series are consisted of casing, propeller, motor and wiring box. （1）外殼：采用優質冷軋板或鍍鋅板，具有優良的耐大氣腐蝕性能.進風口設計呈符合空氣動力學的形狀，便于氣流進入葉輪。進風口和出風口外形尺寸相同，以便于安裝。進風蓋和出風蓋采用螺釘連接，便于維修與清潔。 （1）Shell: the shell is made of cold-rolled sheet or galvanized sheet, which has good atmospheric corrosion resistance performance. The shape of air inlet is designed in conformity to aerodynamics. Air is easy to go into the impeller. Air inlet’s size is the same air outlet’s. It’s easy for installation. The inlet cover connects with outlet cover by bolt which is easy for repairing and cleaning. （2）葉輪：GDF 100A、GDF125A、GDF150A、GDF160A圓形管道風機采用新型塑料葉輪，直徑為190mm；GDF200A、GDF250采用新型塑料葉輪或金屬葉輪，直徑為250mm;GDF315A圓形管道風機采用金屬制成，直徑為280mm。均設計成后向式葉輪，在正常運轉的情況下，均能與外殼良好配合，風量大、效率高、噪音低。葉輪與外轉子電機構成整體，成為葉輪輪轂的驅動電機被氣流高效地冷卻，可以延長風機壽命。 (2) Impeller: fans in the mode of GDF100A, GDF125A, GDF150A, and GDF160A adopt new plastic impeller with the diameter of 190mm: fans in the mode of GDF200A and GDF250A adopt new plastic impeller and metal impeller with the diameter of 250mm; fans in the mode of GDF315A adopt (3)電機：采用外轉子單相異步電動機，該電機的特點是葉輪直接壓裝在電機外殼上，由電機外殼旋轉直接驅動，電機與風輪一體，結構合理，體積小，節省安裝空間；重量輕,運行平穩，效率高，壽命長。 (4)接線盒：采用加有阻燃成分的ABS材料制成，防火性能較好。安裝在整機外表面接線、拆裝非常方便。