All-Terrain Vehicle - Three wheeled ATV - Four wheeled ATV - Personal ATV - ATV Racing model - Multipurpose ATV - ATV attachment - Cooling arrangement for ATV - Criticisms of ATVs - ATV Development - ATV Enclosure - Flying ATV - ATV Tire - All-terrain wheeled vehicle - Power transmission device of ATV

Cooling arrangement for all terrain vehicle

1. Field of the Invention

The present invention generally relates to a cooling arrangement for all terrain vehicles. More particularly, the present invention relates to an engine cooling arrangement for use in all terrain vehicles.

2. Related Art

All terrain vehicles are often operated in open terrain under difficult running conditions. While such vehicles often may have unrestricted size, it is desirable to decrease the size and weight of the vehicle. For instance, a smaller vehicle allows its operator to maneuver into locations previously unreachable by the larger vehicles. Moreover, decreasing the size and weight of the vehicle increases the power to weight ratio of the vehicle as well as increases the fuel economy of the vehicle.

In the past, in some all terrain vehicles, the cooling systems have employed a cooling pump that is positioned under a forward portion of the crankcase. The cooling pump is used to circulate coolant between a radiator and an engine. The cooling pump was, in such applications, driven by connecting an input shaft to a crankshaft. The connection of the input shaft to the crankshaft might include a reduction gear train.

With the introduction of variable belt drive transmissions to all terrain vehicles, the transmission was positioned to a side of the engine and extended between the crankshaft and the engine output shaft. Because of the positioning of the transmission components, the crankcase had to be enlarged to accommodate both the transmission components and the cooling pump input shaft and its drive. Therefore, it became difficult to reduce the size of the crankcase while employing both a cooling pump and a variable speed transmission.

Moreover, due to the environments in which all terrain vehicles are used, the water pump had to be located in a protected location. Accordingly, the pump had to be positioned in locations that would not subject the water pump to abuse by environmental elements. For instance, the water pump would be positioned low within the crankcase to reduce the likelihood of inadvertent contact with passing elements. This position, however, led to maintenance difficulties.