Hydraulic fan assembly for an engine ventilation system

#The present disclosure generally relates to ventilation systems for engines, engine enclosures, and engine compartments, and more particularly to hydraulic powered fans used in such systems.

#Aftertreatment systems are often utilized to reduce emissions associated with operation of engines. The State of California and the United States Environmental Protection Agency have imposed stricter emissions requirements over time, adopting increasingly stringent standards for criteria pollutants, such as NOx, unburned hydrocarbons, carbon monoxide, sulfur dioxide, ozone, lead, and particulate matter. In addition to heat produced by engines themselves, aftertreatment systems incorporated in order to meet such requirements have contributed to excessive heat in the operation of such machines. Excessive heat associated with the engine or the aftertreatment systems may be further increased due to insulating structures designed to minimize noise transmitted to the surroundings, including the passenger compartment.

#Various arrangements have been proposed for cooling the engine and related components. For example, U.S. Pat. No. 4,114,714 to Fachbach, et al. discloses a forced draft ventilation system that includes a first fan that pulls air through front grill and the radiator, and a second fan that receives air from an external inlet port directed forward the vehicle and forces the air across the engine, a portion of the heated air then being directed out of the engine compartment, and a portion of the heated air then being directed across the exhaust system and out of the vehicle. Inasmuch as the second fan is driven by the engine and is depicted as a relatively small device, and the inlet to the second fan is directed forward the vehicle, it would appear that second fan is dependent, at large in part, upon the forward movement of the vehicle to force fresh air to the second fan. Accordingly, the second fan may be unable to reduce adequately the engine compartment temperatures during idling situations, or when the machine travels in a direction such that the cab or other structure blocks ambient air flow into the engine compartment. Moreover, the air that is directed over the exhaust system has already been heated by moving over the engine itself, minimizing any resultant cooling of the exhaust components.

#FIG. 1 is a schematic side elevational view of a wheel loader including an exemplary hydraulic fan assembly.

#FIG. 2 is an enlarged fragmentary side view of an engine compartment, a secondary compartment, and the exemplary fan assembly utilized in the wheel loader of FIG. 1.

#FIG. 3 is a fragmentary isometric view of the secondary compartment, the sound wall, and the ventilation system of FIG. 2, the engine compartment being cut away.

#Embodiments of a ventilation fan are disclosed for use in a ventilation system provided for an engine compartment. The engine compartment may house the engine and one or more aftertreatment systems. For some machines, such as wheel loaders and hydraulic excavators, the ventilation fan is operated using hydraulic power. The ventilation fan includes a stationary baffle and a rotating deflector disc to prevent hydraulic fluid from becoming entrained in the air stream exiting the ventilation fan. More specifically, the ventilation fan includes a housing defining an interior chamber. The stationary baffle divides the interior chamber into an impeller chamber and a collection chamber. The deflector disc is configured to divert fluid from its normal leak path by directing the fluid away from the impeller chamber and toward the collection chamber. The collection chamber may include a reservoir in which diverted fluid collects. A drain conduit fluidly communicates with the reservoir to allow the fluid to be discharged from the reservoir. The drain conduit may include a clear conduit section or drain reservoir that provides a visual indication to the user that fluid is leaking from the hydraulic fan.

#Turning to the illustrated embodiments, FIG. 1 shows a ventilation system 100 for an engine compartment 102 of a machine, such as a wheel loader 108. While the ventilation system 100 is illustrated in connection with a wheel loader 108, the ventilation system 100 disclosed herein has universal applicability in various other types of machines. The term “machine” may refer to any machine that performs some type of operation associated with an industry such as mining, construction, farming, transportation, or any other industry known in the art. For example, the machine may be a wheel loader 108, an excavator, a motor grader, a landfill or other type of compactor, or a wheel dozer. Moreover, one or more implements may be connected to the machine. Such implements may be utilized for a variety of tasks, including, for example, brushing, compacting, grading, lifting, loading, plowing, ripping, and include, for example, augers, blades, breakers/hammers, brushes, buckets, compactors, cutters, forked lifting devices, grader bits and end bits, grapples, blades, rippers, scarifiers, shears, snow plows, snow wings, and others.

#The illustrated wheel loader 108 includes a body 110 that includes the engine compartment 102. The engine compartment 102 houses an engine 112 and aftertreatment equipment 114 which receives exhaust from engine 112 (each of these items being shown generally in FIGS. 1 and 2). The wheel loader 108 additionally includes a hydraulic system 116 that may include a plurality of components such as pumps, valves, and conduits, along with a hydraulic fluid reservoir (components not shown in detail). The hydraulic system 116, as well as other systems in the machine, may include its own cooling arrangement.