An aerator includes a floating platform, an oxygen dissolving mechanism, and a driving device. The pontoon includes two spaced apart axle seats and two bearings. The bearings are respectively disposed on the axle seat. The dissolved oxygen mechanism includes an axle set and two impellers. The axle set shaft is provided on the bearings. The impellers are respectively disposed at opposite ends of the axle set. The driving device is disposed on the floating platform and connected to the axle assembly for driving the axle assembly to rotate. The aerator adopts the bearings to carry the axle set to prevent the axle set from rubbing against the axle seat to generate vibration and noise, thereby improving the smoothness and service life of the dissolved oxygen mechanism.一種增氧機，包含一浮檯、一溶氧機構，及一驅動裝置。該浮檯包括二相間隔的軸座，及二軸承。該等軸承分別設置在該軸座。該溶氧機構包括一輪軸組及二葉輪。該輪軸組軸設在該等軸承。該等葉輪分別設置在該輪軸組的兩相反端部。該驅動裝置設置在該浮檯，並連接該輪軸組，用以驅使該輪軸組旋轉。該增氧機採用該等軸承來承載該輪軸組，避免該輪軸組與該軸座相摩擦而產生震動及噪音，藉此提高該溶氧機構運作的流暢度及使用壽命。
