US Patent 7225792 Valve device for internal combustion engine

A valve device for an internal combustion engine is provided with two flange portions, each of which is arranged at the outer periphery of a valve and has a larger outer diameter than a shaft. Annular valve-side end surfaces of the flange portions obstruct water flowing toward bearings and the inner surface of a cylindrical portion of a house along the surface of the shaft. Thus, water can be restricted from flowing into annular gaps between the shaft and the housing and annular gaps between the shaft and bearing members. Accordingly, water is not frozen in the annular gaps, thus restricting the shaft and the valve from freezing/sticking.