It is a cooler for internal air water cooling when the temperature rises due to the generator and motor’s heat generation in the rotation. It is used in the large generator, motor and other rotary machines in the power generation, power transmission, industry and other fields. It is the cooling elements developed based on the reliable exclusive technologies. The cooling tube may adopt stainless steel and copper alloy tube with excellent corrosion resistance. Fin may adopt copper and aluminum plate fin with air grid. The cooling tube and fin undergo the close combination of expanded tube by expanded joint, so as to improve the heat transfer efficiency. The cooling tubemay adopt single tube or doubletube structure. The double tube structure can detect the water leakage due to the cooling tube corrosion in advance. Aiming at the large capacity, small wind resistance, compact and lightweight design, based on the customer needs, the product adopts the stepless design and is an excellent air cooler.