A separator has a first inlet arranged to receive a fluid stream, and first and second separation stages coupled together in series; A pump coupled to the second separation stage generates an area of reduced pressure to draw the fluid stream through the first and second separation stages. One of the stages includes a variable impactor separator comprising a first chamber arranged to receive the fluid stream, and a second chamber coupled to the first chamber through an aperture to accelerate the first fluid stream. The stream is incident upon an impaction surface to separate contaminants from the fluid stream. An actuator adjusts the open area of the aperture according to a pressure differential between fluid pressure in the first chamber and a reference fluid pressure in a third chamber. The other of the separation stages is a second variable impactor separator or a filter media.

An air cleaner may include a container body having a first end and a second end and defining an air flow chamber and a dust flow chamber each defining separate internal cavities within the container body. The air cleaner may also include an intake arranged at the first end of the container body and comprising a wall system for receiving air from outside the container body through an inlet in the side of the container body. The intake may include a dust flow path in fluid communication with and in general alignment with the inlet and extending from the inlet to a dust opening leading to the dust flow chamber. The intake may also include an airflow path abruptly and angularly diverging from the dust flow path at a point downstream of the inlet and extending from the dust flow path to an air opening leading to the air flow chamber.

An inlet air filter device including: at least one passage for delivering an air mass from an inlet section to an outlet section of the inlet air filter device, a water separator in the at least one passage for separating water in the air mass, the water separator positioned between the inlet section and the outlet section, a bypass element movable between a first open position in which the air mass is forced to cross the water separator and a second closed position in which the air mass flows from the inlet to the outlet section without crossing the water separator; a shutter element which is actuatable to co-operate with the bypass element for isolating the water separator from the air mass when the bypass element is in the second closed position.

An inertial separator including an inlet tube with an undercut, an outlet tube with a spiral ramp, and a scavenge flow outlet, is disclosed.

A multiple stage separation vortex flow air filter includes an air filter housing (AFH) having a central axis; a cylindrical helical plate located within the AFH proximate an upper shell bottom of the AFH; an air inlet eccentrically connected to the AFH to cause air flowing through the air inlet to create a vortex around the cylindrical helical plate; an perforated conical element in which the air flows through, the perforated conical element within the cylindrical helical plate around the central axis; an oblong conical casing that forms a conical passage and located along the central axis and partially within the perforated conical element, wherein air enters the conical passage through a whirling ring; and an air filter element within the oblong conical casing, wherein air flows through the air filter element and enters into an engine through an outlet pipe.