1. Field of the Invention
The present invention generally relates to agricultural vehicles, and, more specifically, to fluid cooling systems used with such vehicles. Particularly, the invention relates to air flow into, through and out of the fluid cooling system.
2. Description of the Related Art
An agricultural vehicle known as a “combine” is historically termed such because it combines multiple harvesting functions, such as picking, threshing, separating and cleaning in a single harvesting unit. A typical combine includes a header, which removes a crop from a field, and a feeder housing, which transports the crop matter into a threshing rotor. The threshing rotor rotates within a perforated housing, which may be in the form of adjustable concaves, and performs a threshing operation on the crop to remove the grain. Once the grain is threshed, the grain falls through perforations in the concaves onto a grain pan. From the grain pan, the grain is cleaned using a cleaning system. The grain is then transported to a grain tank onboard the combine. A cleaning fan blows air through sieves to discharge chaff and other debris toward the rear of the combine. Non-grain crop material, such as straw from the threshing section, proceeds through a residue system, which may utilize a straw chopper to process the non-grain material and direct it out the rear of the combine. When the grain tank becomes full, the combine is positioned adjacent a vehicle into which the grain is to be unloaded, such as a semi-trailer, gravity box, straight truck, or the like; and an unloading system on the combine is actuated to transfer the grain into the vehicle.
More particularly, a rotary threshing or separating system includes one or more rotors which can extend axially (front to rear) or transversely within the body of the combine, and which are partially or fully surrounded by a perforated concave. The crop material is threshed and separated by the rotation of the rotor within the concave. Coarser non-grain crop material such as stalks and leaves are transported to the rear of the combine and discharged back to the field. The separated grain, together with some finer non-grain crop material such as chaff, dust, straw, and other crop residue are discharged through the concaves and fall onto a grain pan where they are transported to a cleaning system. Alternatively, the grain and finer non-grain crop material may also fall directly onto the cleaning system itself.
A cleaning system further separates the grain from non-grain crop material, and typically includes a fan directing an airflow stream upwardly and rearwardly through vertically arranged sieves which oscillate in a fore and aft manner. The airflow stream lifts and carries the lighter non-grain crop material towards the rear end of the combine for discharge to the field. Clean grain that is heavier, and larger pieces of non-grain crop material that are not carried away by the airflow stream, fall onto a surface of an upper sieve (also known as a chaffer sieve) where some or all of the clean grain passes through to a lower sieve (also known as a cleaning sieve). Grain and non-grain crop material remaining on the upper and lower sieves are physically separated by the reciprocating action of the sieves as the material moves rearward. Any grain and/or non-grain crop material remaining on the top surface of the upper sieve are discharged at the rear of the combine. Grain falling through the lower sieve lands on a bottom pan of the cleaning system, where it is conveyed forwardly toward a clean grain auger.
The clean grain auger conveys the grain to a grain tank for temporary storage. The grain accumulates to the point where the grain tank is full and is discharged to an adjacent vehicle such as a semi trailer, gravity box, straight truck or the like by an unloading system on the combine that is actuated to transfer grain into the vehicle.
Agricultural combines tend to become larger and more sophisticated over time. As the size of the combines increase, the power requirements also increase. More power means more heat generated onboard the combine. Onboard components such as an internal combustion (IC) engine, hydraulic circuits, an air conditioning (A/C) circuit, etc. have internal fluids that require cooling. To this end, combines typically include several discrete fluid coolers located at various convenient locations onboard the combine. Such coolers are effective to cool the respective components, but take up additional room onboard the combine, and may not be located at the best location to avoid chaff, dust, etc. from plugging the screen or radiator.
An agricultural combine operating in a field generates significant dust, dirt, debris and crop residue, etc., which are referred to herein collectively as “contaminants”. Dirt and dust are raised simply from the movement of the equipment across the field. The cutting, threshing, screening and cleaning processes generate more airborne contaminants. Release of the non-grain crop material generates further contaminants. The contaminants can settle on surfaces throughout the combine, including areas that are generally quite hot during operation as well as areas that must be accessed frequently for servicing.
An operating combine also generates noise which must be abated under some standards and requirements.
What is needed in the art is a better way to manage air flow through a cooling system of an agricultural harvester that effectively uses the air flow and protects the system under various operating and non-operating conditions.