The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Automotive vehicles typically utilize an internal combustion engine to provide the power to operate the vehicle. Internal combustion engines generate heat due to the combustion process and it is necessary to continuously remove the excess heat from the vehicle's engine in order to maintain the operating temperature of the vehicle's engine at a specified level.
The usual method of removing this excess heat is an automotive cooling system. The cooling system utilizes a coolant pump which pumps coolant through the vehicle's engine to absorb the excess heat and then this heated fluid is pumped to a heat exchanger or radiator which removes the excess heat by performing a heat exchange process with ambient air. The coolant which has been cooled by the radiator is returned to the engine and the process continuously repeats itself. Typically, the temperature of the coolant is maintained at a minimum level using a thermostat or some other type of control system.
In order to reduce the size and thus the costs of the radiator, the automotive designer strives to have the radiator operate in the most efficient manner. One method used to maximize the efficiency of the radiator is to control the flow of ambient air through the radiator. This is accomplished by providing a fan which draws the ambient air through the radiator and then providing a fan shroud which ensures that the maximum amount of air is drawn through the radiator.
Automotive fans for the cooling system can be electrically driven or they can be driven by the vehicle's engine. Regardless of how they are driven, the maximization of ambient air flow requires that the fan be located within the fan shroud. The use of a fan that is driven by the engine and a fan shroud which is attached to the radiator presents problems during the assembly of the vehicle. In many cases, the vehicle frame, drive train and suspension are constructed first and the fan is attached to the driving component of the engine such as a coolant pump pulley or the crankshaft of the engine. The vehicle's body, including the radiator and fan shroud, is not assembled to the frame, drive train and suspension assembly until near the end of the assembly line. Since the fan needs to be located within the fan shroud, an interference/clearance issue is created when the body, including the radiator and fan shroud are lowered onto the frame.
This interference/clearance issue has been addressed by designing the fan shroud such that it has a removable portion at the bottom of the shroud in order to provide clearance for the fan during the assembly of the body to the frame. Once the body has been assembled to the frame, the removable portion is attached to the fixed portion of the shroud to avoid significant air loss through the radiator.
The connection between the removable portion and the fixed portion must be very secure. If it were to become detached during the life of the vehicle, it could lead to undercooling of the vehicle's engine due to a loss of ambient air through the radiator, or it could come loose and interfere with and possibly damage the fan itself. While it is necessary to adequately secure the removable portion to the fixed portion of the shroud, it still needs to be removable for any service required to the fan. Typically, the only access to the fan is through the removable portion of the fan shroud. Finally, the assembly of the removable portion to the fixed portion of the fan shroud has to be a simple and rapid assembly process in order to accommodate the vehicle as it moves down the assembly line.