Air cleaner assembly refers to the whole set of intake system of the engine, including intake pipe, air cleaner housing, air cleaner element and exhaust pipe (referring to the part connecting the housing and the engine). It is generally installed on the pipe in front of the engine throttle, mainly to filter the dust and sand in the air, so as to ensure that the air entering the cylinder is sufficient and clean. If the air is not filtered, the dust suspended in the air will be sucked into the cylinder, which will accelerate the wear of the piston bank and cylinder and gradually cause engine failure.