Structure for mounting a water pump, water pump, and cooling system

摘要

A structure for mounting a water pump to a water-cooled internal combustion engine in an easy manner. A water-cooled internal combustion engine in which the water pump is removably mounted to a side wall of the water-cooled internal combustion engine, is driven by power transmitted from a crank shaft to the water pump through a transmission mechanism, wherein a water pump driving member is arranged closer to a center of the internal combustion engine than an output driving member of the crank shaft. A water pump following member is driven by accepting the power from the water pump driving member and is rotatably mounted to a side wall of the internal combustion engine. A drive shaft of the water pump is removably spline fitted to splined aperture of the water pump following member.