Water pump apparatus in an internal combustion engine

摘要

A water pump apparatus in an integral combustion engine of a water cooling type having a driving pulley fixed to one end of a crankshaft, and a driven pulley fixed to one end of a valve camshaft for driving the movable valve camshaft from the crankshaft via a timing belt has a water pump eccentrically providing a pump shaft axis relative to the valve camshaft axis, a pair of drive and driven gears provided with a suitable rotational ratio and respectively mounted on an end of the valve camshaft and one end of the pump shaft and engaged with each other, and a sliding bearing supporting the pump shaft and being inserted in a cylinder head.