Self-cleaning rotary filter for the cooling air inlet of an engine enclosure

In a mobile agricultural machine having a body and a power unit including an internal combustion engine supported by the body, the engine generating waste heat energy in operation, the combination therewith of an improved enclosure and cooling system for the power unit comprising:

• an enclosure mounted on the body for enclosing at least part of the power unit and having walls;
• an air inlet in one of said enclosure walls;
• a rotatable air filter including a foraminous filter element mounted on said enclosure wall over the air inlet for filtering foreign material from air moving inwards through the air inlet;
• drive means for rotating the filter;
• an air outlet in the enclosure;
• a heat exchanger mounted within the enclosure and connected to the engine so as to receive at least a portion of the waste heat energy, for cooling the engine;
• a blower mounted and operatively connected to and driven by the engine for moving air inwards through the filter element and at least a portion of the air through the heat exchanger so as to receive waste heat energy from the heat exchanger and discharging the air through the air outlet;
• cleaning means for cleaning the filter element as the air filter rotates including a partial vacuum chamber mounted on the enclosure disposed adjacent the external side of the filter element and having an inlet opening closely adjacent and opposite a limited area of the filter element and an outlet connected to the blower so that air is drawn through the outlet creating a partial vacuum in the chamber, said area changing as the air filter rotates so that substantially the entire filter element moves past the inlet opening during each revolution of the air filter, the chamber blanking off the area of the filter element instantaneously opposite the inlet opening and the partial vacuum in the chamber causing an air flow outwards through the filter element area opposite the chamber inlet opening to clean foreign material from said area of the filter element and carry it into the vacuum chamber and through the vacuum chamber outlet;
• and
• agitating means operatively associated with the rotatable air filter for engaging at least a portion of the foreign material adjacent the vacuum chamber outlet to facilitate the movement of material being carried through the outlet.

In an agricultural machine having a mobile body and a power unit carried by the body, the power unit including a wall having an air inlet, an internal combustion engine, a heat exchanger for cooling the engine and a blower operable to draw cooling air through the inlet and over the heat exchanger, an improved air filter for removing foreign material from the cooling air comprising:

• a spindle carried by the wall;
• a rotatable filter element carrier including means for rotatably mounting the carrier on the spindle and having a rim concentric with the spindle;
• a generally circular filter element of flexible foraminous material spanning the exterior side of the carrier and secured to said rim for intercepting foreign material carried by the cooling air, the filter element and carrier substantially covering the inlet;
• and
• means for tensioning the filter element engaging the element near its center and urging it axially away from the carrier so as to shape and hold the filter element in a nearly flat generally conical form concentric with the spindle.