Vehicle engines commonly utilize cooling assemblies to remove excess heat from the engine and maintain an optimal operating temperature. The cooling assembly pumps a coolant through the engine and other components in order to control engine temperature. Heat generated within the engine and other components is absorbed by the coolant and dispersed into the surrounding atmosphere through the use of a radiator. In order to improve dispersal by the radiator, it is common to utilize fan assemblies to draw or force air past the radiator to assist in temperature transmission.
It is not always desirable for such fan assemblies to be run continuously. At times, it is desirable for the temperature within the coolant to increase rather than decrease. Additionally, continuous operation when unnecessary places a non-required draw on the engine and thereby reduces efficiency. To compensate for this, present fan assemblies utilize fan clutch assemblies that allow for the selective engagement of the fan to the engine such that the fans are engaged only when necessary. The fan clutch assemblies may be operated in a host of configurations including hydraulic and air-pressure actuated. It is common for these systems to be biased towards fan operation such that when failure occurs in the clutch assembly, the fan continuously operates to keep the engine cool.
An issue with these fan assemblies and associated clutch assemblies relates to their capacity and longevity. Since space is often limited in vehicle engine compartments, it is important to supply a fan clutch which has as much capacity as possible for the size and space allowed in the component in the vehicle. Also due to warranty requirements and the expense required to replace components in a vehicle, it is important to provide a fan clutch which has increased durability and longevity—perhaps to last to the life of the engine or vehicle.
Another issue with current fan clutch assemblies relates to the amount of heat generated during use which also affects durability and longevity. In many known clutch assemblies, the heat generated from the friction clutch mechanism is internalized in the assembly. This can reduce the life of the friction member and the entire clutch assembly.
It would therefore be highly desirable to have an improved pneumatic clutch fan assembly with increased capacity and durability and without significantly changing its external size or shape. Another object would be to provide a fan assembly which operates in a cooler manner.