Integrated fluid reservoir and heat exchanger ducts

A combined liquid tank and fan air flow housing is molded as a unit to combine needed functions in a compact preassembled unit. Separate spaced side tank portions are formed that are joined together with a front end tank to form a central opening with upper and lower ends. The opening is closed with a top plate that defines a plenum chamber and a lower fan support plate that forms a fan chamber in the central opening. A fan in the fan chamber creates an airflow from the exterior through the plenum chamber and out lateral ducts formed in the side tank portions. The inlet air flows through an oil cooler, water radiator and if desired, an air conditioner condenser in the plenum chamber. The tank formed is used for storage of hydraulic fluid.

BACKGROUND OF THE INVENTION

The present invention relates to a unitarily molded fluid reservoir tank for a skid steer loader that forms a fan housing or shroud having passageways for cooling airflow across a hydraulic fluid cooler, an engine radiator if the loader the engine is not air cooled, and when installed, an air conditioner condenser, as well as drawing air from an engine compartment, and for discharging the air laterally out of the loader. The tank is hollow to form the hydraulic fluid reservoir or chamber and is designed to provide sound insulation between the fan and an operator's cab. Fill, inlet and outlet pipes, and a dipstick passage are molded in place.

It has been desirable to make molded tanks that are formed to include cooling ducts or a partial fan shroud as part of a molded unit. U.S. Pat. No. 5,649,587 illustrates a fan shroud that uses a molded housing with twin fan ducts in it, and also outlet connection pipes for a vehicle radiator cooling system.

In a skid steer loader adequate engine and hydraulic system cooling and optional air conditioning heat exchange, as well as a hydraulic reservoir with suitable capacity must be provided in a limited space combining the function efficiently is caused out with the present invention.

SUMMARY OF THE INVENTION

The present invention relates to a unitary, molded tank forming a reservoir for hydraulic fluid and configured to provide a center fan mounting chamber and shroud having airflow ducts for cooling air moved by the fan. Locating holes and inlet and outlet connections to the reservoir are molded unitarily as well. The tank has front and rear tank sections and connecting chambers on lateral sides that are formed by walls which connect the tank sections. The fan is mounted in the center portions of the molded tank on a plate that locates the fan in spacial relationship to the molded duct portions of the tank.

The molded tank surrounds heat exchangers, such as a hydraulic oil cooler or radiator, and when required an engine coolant radiator. Space for mounting an air conditioning condenser is reserved so when a condenser is needed, it can be installed. The integrated reservoir, heat exchanger, fan and duct assembly will mount easily as a unitary assembly into a space behind the operator's cab of a skid steer loader.

Because the tank is molded, the outer shape can be contoured or rounded as desired for aesthetic purposes, as well as for smoothly guiding airflow in the desired directions through the formed ducts.

The molded tank with ducts shape reduces the size of the combined fluid reservoir and loader cooling system that is necessary for operation of the loader, and permits modular assembly of the components that are added within the center portions of the tank, such as heat exchangers, a fan support and a fan, before being installed in the skid steer loader frame. The side tanks or chambers and the connecting chambers are shaped and sized to reduce sloshing of the hydraulic oil to help keep the hydraulic oil from becoming aerated. Because the reservoir extends for a substantial length along the loader frame's longitudinal and latitudinal axes, the locations of hose connections can be distributed so that hydraulic oil contained inside flows considerable distances to promote de-aeration.

The molded tank with ducts is formed by spaced walls around a perimeter of the fan. The double walls and the filling of hydraulic fluid dampen noise from the fan. The molded tank compartment that is positioned adjacent the rear cab wall is full height to provide a substantial reduction in noise and vibration between the fan and the cab. The hydraulic fluid in the tank also dampens noise harmonics for more operator comfort.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A skid steer loader indicated at10inFIG. 1includes wheels12, that are supported on the frame28of the loader and are driven to move the loader in a normal manner. An operator's cab14is located at a forward end of the loader. The skid steer loader10, as shown, has a rear engine compartment16with an engine18in the compartment. The engine can either be air cooled or liquid cooled. The present invention provides a molded tank with ducts forming a combined cooling fan and heat exchanger support assembly with airflow ducts, and hydraulic fluid reservoir. The integrated assembly will accommodate a fan that works with either air or liquid cooling for the engine.

The skid steer loader10includes a hydraulic pump illustrated schematically at20, which is driven by the engine18and connected to provide hydraulic fluid under pressure to ground drive motors and to components such as lift arm cylinders24, or other hydraulic components. The hydraulic components are represented at22. A boom lift cylinder is outlined in dotted lines at24. The pump20is connected to a suitable valve26, for operating the hydraulic components.

The length of the frame28of the skid steer loader10is limited in order to provide maneuverability and thus the mounting space for all of the components is limited. There is a need for providing cooling airflow for the hydraulic oil cooler, sometimes an engine radiator and if installed, an air conditioner condenser. Also a hydraulic reservoir is needed for providing hydraulic fluid for the pump20to accommodate these needs. The present invention comprises a integrated assembly30that combines an air inlet plenum, a heat exchanger, a fan, a fan shroud, a fan mount, a pair of air outlet ducts and a fluid reservoir. The integrated assembly30is mounted just ahead of the forward end32of the engine compartment16, and behind the rear wall15of the cab14.

The integrated assembly30, as can be seen, is mounted in place on the frame of the skid steer loader using suitable pivot brackets and pivot stops that pivotally support the tank on the frame as a unit. The tank will swing up for access to components below the tank, as shown in FIG.1A.

Referring specifically toFIGS. 2,3and4, exploded views of the integrated assembly30are illustrated. The combined component or integrated assembly30shown inFIGS. 2 and 3has a number of components that are vertically stacked and secured together.

The integrated assembly30includes a molded, unitary tank31with ducts which is rotationally molded from a suitable plastic material. The tank31with ducts is formed with hollow compartments and curved or contoured walls. The tank31with ducts forms a cooling air fan shroud and has a first side tank portion38, a second side tank portion40, a front wall tank portion42, and a rear cross over connector tube44.

The side tank portions38and40are spaced apart in lateral direction (side to side) on the loader and are joined by the front tank portion and rear cross connector over44. The cross over connector tube44forms a structural support or connection to hold the side tank portions as a unit, as well as forming a fluid passageway between the interior chambers of the side tank portions. The side tank portions, front tank portion and the cross over portion are all hollow and form interior chambers. The chambers of the tank portions are all fluidly open to each other. The side tank portions are formed to define laterally diverted channels38A and40A that form airflow outlet ducts, and together with the wall82of tank portion42and cross over44define a central fan chamber66. A fan support plate68closes the lower side of the fan chamber66, and a formed, bath tub shaped fan inlet plate69is supported above the fan chamber and forms a top wall over the walls38A and40A to form air discharge ducts38B and40B leading from the fan chamber66.

The inlet plate69is recessed in the center and provides the bottom for a plenum chamber50between the upper parts of the front and side tank portion in which cooling components are mounted in a suitable manner. The sides of plenum chamber50are enclosed with upwardly extending, accurate side panels69A formed as part of the inlet plate69. The inlet plate and other walls forming the plenum chamber can be made of individual components as shown or can be die formed or molded as a unitary structure.

The heat exchanger components include a hydraulic oil cooler or radiator46, which fits within the plenum chamber50between the side panels69A. The inlet plate69and an engine coolant radiator48is mounted below and spaced from the hydraulic oil cooler46. An air conditioning condenser47can be installed above as well, when an air conditioning system is used for the cab14. These cooling components are all nested within the plenum chamber50between the upper parts of the side tank portions38and40and the front wall tank portion42and crossover44. The condenser47, hydraulic46oil cooler and radiator48components can be fastened or secured to panels69B and69C of the fan inlet plate69, which in turn is secured to side shields71, panel wall85, plate106or plate108, and then to mounting plate68with cap screws or other fasteners in a desired manner.

The tank31with ducts has interior chambers that hold hydraulic fluid including chambers52A and52B in the side tank portions38and40(FIG.5), chamber52C in the front wall tank portion42and chamber52D in the cross over44(FIG.7). The chambers are formed by enclosing walls, as shown. The front wall tank portion42extends from the fan mounting or support plate68all the way to the top of the plenum chamber50(FIG.7). The wall82of the front tank portion42thus is adjacent to the front wall of plenum chamber50. The walls82and42A, and hydraulic fluid or oil shown in the tanks provides sound insulation from the fan chamber66.

The fan inlet plate69forms the bottom wall of the plenum chamber50and has a central opening62that provides an air inlet to the center63of a radial blade fan64, which is mounted in the fan chamber66. The fan64has a base plate64A that is drivably mounted onto a shaft70A of a fan drive motor70, which is mounted to the fan mounting plate68. Output shaft70A drives the fan64. The fan64is a radial fan having the base fan plate64A and main generally radial blades64B extending upwardly from plate64A, as presently used for skid steer loader engine cooling, as shown in U.S. Pat. No. 4,962,825.

Referring toFIGS. 7,8and9the fan64and motor70are shown in place on the mounting plate68. The mounting plate68has openings92under the fan plate62A. The tank31is supported by mounting plate68. Shields71(FIG. 2) that are on the right and left-hand sides of the tank31and have air discharge grates73(seeFIGS. 1 and 2) formed thereon. The side shields71are mounted on the frame28of the skid steer loader10. Suitable brackets are used for pivotally mounting the side shields71to the frame at pivot points71A so the entire integrated assembly can be pivoted up for service.

As shown inFIG. 8, the fan chamber66is defined by the scroll type wall82formed as the interior wall of the front tank portion42. An air deflector wall84is mounted on the rear side of the fan below cross over44. There is a space or gap86between the side tank portions38and40at the rear of the tank31and below the tubular cross over44. This space86is closed with a panel wall85that has an opening85A in the center (see FIG.5). The air deflector wall84aligns with opening85A. The air deflector wall84is a formed plate that has openings88that provide a controlled airflow into the engine compartment. The air deflector wall84is preferably metal, as are the fan support or mounting plate68and the fan inlet plate69. The air deflector wall84is fastened to mounting plate68in a suitable manner to enclose the fan chamber. The deflector wall84is supported on the fan mounting plate68.

Inlet opening62from plenum chamber50to fan chamber66for the fan has an annular flow guide ring62A that provides a smooth flow path for the incoming air. Incoming air is drawn down through the air conditioning condenser47(if used), the hydraulic fluid cooler46, and the engine coolant radiator48so that cool exterior air comes in from the top of the skid steer loader, and then through the plenum chamber50to the fan64. The air that is warmed or heated after passing through the heat exchangers is discharged by the fan out through side air outlet ducts38B and40B which are formed by the molded channel walls38A and40A.

The fan64has lower radial blades65fixed to and positioned below the fan plate64A, which will draw air from the engine compartment16through openings92in fan support or mounting plate68and will discharge hot engine compartment air out through ducts38B and40B.

The hot air is discharged through the outlet openings comprising grates73formed in side shields71. The outlet openings face laterally, so there is a lateral or sideways discharge from the fan.

It should be noted, as shown inFIG. 9, for example, that the lower walls of ducts38B and40B and the side walls69A of the fan inlet plate69are inclined or swept upwardly. This means that the hot air will be discharged laterally and upwardly.

Thus, when the fan motor70is running, the fan blades rotate and air will flow from the exterior down through the plenum chamber50for cooling the components such as the hydraulic oil radiator46, and the engine coolant radiator48, and will pass into the fan chamber66where it will be discharged laterally out through one or both of the side discharge ducts38B and40B.

As can be seen inFIG. 3, the tank31with ducts shroud has a suitable fill opening covered by a fill cap94and a dipstick98that is used for determining the level of the hydraulic oil in the tank. The breather element is in a molded support95at the front of the tank to vent the tank chamber52. The front wall of the tank extends upwardly to near the top of the plenum so it not only reduces noise, but raises the support for the vent up so a long tube is not required to bring the breather above the normal liquid level in the tank. The tank with shroud31has outlets100(FIG. 5) that connect to inlet of suction hoses102(FIG. 2) that connect to the pump20(FIG.1). The pump inlet hoses102are close to the hydraulic pump. The hydraulic fluid return line or hose104from hydraulic components returns flow to the bottom of the tank31.

The integrated assembly30can thus be put into place on the loader frame after the fan64and the heat exchangers have been installed. The assembly can be supported on the frame of the loader in a desired convenient manner.

The integrated assembly30is provided with a metal front shield between the rear wall of the cab and the front tank portion42. Two forms of the front shield are illustrated. When no air conditioning system is provided, a plate106(FIG. 2) that covers the entire front tank wall is used. The plate has an opening for the molded vent (breather) support95.

When an air conditioning system is used, a front plate108, shown inFIG. 3, that is recessed at the top is used. Also as shown inFIG. 5, openings110for filters112for cab inlet air can be provided.

The tank with ducts31can be rotationally molded or blow molded from a homogeneous plastic material of suitable composition to avoid degradation under the conditions of operation of a skid steer loader, and also to avoid degradation from hydraulic fluids. As shown inFIGS. 2 and 5, there is a recess for a coolant recovery bottle116. A fuel fill inlet118can be mounted adjacent to the tank assembly and is connected with a suitable pipe to a fuel tank located below the integrated assembly30.

The tank with ducts31and attached components, including the fan and the side guards can be preassembled and then mounted in the skid steer loader. As shown inFIG. 1A, the tank assembly can be rotated about pivot mounting at71A for access to components mounted below the tank assembly. The entire tank assembly pivots out of the way, and latches can be used to hold it closed. Also, a support such as a precharged gas cylinder can be used to aid in raising the tank assembly and it can be propped up when opened.

The compact cooling system of the present invention is enabled by integration of both the hydraulic fluid reservoir and the cooling system fan housing or shroud into one molded or cast component. The cooling fan chamber is defined as two scroll wipers, namely walls82and84, and two expansion scrolls or ducts38B and48B, and two scroll outlets which direct flow upwardly.

An air inlet plenum50directs airflow through a stack of heat exchangers to an inlet opening to the fan defined by a smooth ring62A that maintains a smooth airflow. The molded tank has space for a coolant recovery bottle, and forms a fill cap neck and a dipstick socket, as well as a reservoir vent port111(see FIG.5). Hydraulic flow outlet and return ports such as those shown at100can be integrally molded.

The molded tank can provide hydraulic return baffles on the interior, and hydraulic outlets sumps as well. As shown there are hydraulic fluid and/air separation surfaces so that the tanks are actually subjected to the cooling air as well.

This one component thus is a housing for a cooling fan and its drive, and for mounting air conditioner condensers, hydraulic fluid coolers, an engine cooler, and a coolant recovery bottle as well as the components mentioned above.

The assembly provides a reduced number of components which in turn means a reduced number of tooling developments. The assembly is modular, with the main component being the molded tank, and then the fan support, and the fan inlet plate being added easily. It should be noted that the cooling airflow ducts leading to the outlet serve as internal integrated hydraulic return flow baffles, because of the differences in the shapes of the chambers in the tank. A reservoir for the hydraulic fluid actually wraps around the heat exchangers to provide large areas for separating air from the hydraulic fluid, while the molded or cast shape of the component provides for rounded or smooth edges on surfaces to exchange airflow for cooling on both the inlet and outlet sides of the cooling fan inlet, and the walls defining the fan chamber. The tank mounts closely to the components that are used, so their hose extensions to a remote fill cap and a reservoir vent and dipstick are not needed. Integration of the cooling air duct work allows for compact packaging of the cooling system and hydraulic reservoir components, which allows efficient space utilization in a loader vehicle where space is at a premium.

The double wall construction of the front tank in particular, as well as the other tanks, provide sound barriers between the fan noise and the loader operator or bystanders. Hydraulic fluid between the double walls of the tank dampens the noise harmonics to aid in reducing noise levels.