The air cooler is a kind of heat exchanger with air as cooling source, the heat is taken away by the air,we also called it oil cooler or air-cooled oil cooler. In general, the heat dissipation effect of the air cooler mainly depends on the heat exchange area and air volume of its component. At present, the air cooler used widely is made of aluminum alloy with good thermal conductivity, the fluid channel and the wind channel are advanced plate fin structure, the core is made of vacuum brazing, and the fluid channel is provided with internal fins. In a nutshell, when the heat transfer area is the same, the greater the air volume, the better the heat dissipation effect. When the air volume is the same, the larger the heat transfer area, the better the heat dissipation effect. The air cooler is commonly used as an auxiliary part of the hydraulic transmission system to cool the hydraulic oil, in order to obtain the normal working temperature and improve the stability of the hydraulic system and the service life of the parts.