Abstract: An apparatus is provided for preventing emission of fuel vapor generated in a fuel tank during fuel supply, including a fuel supplying canister for absorbing the fuel vapor and desorbing the absorbed fuel vapor by an intake air flow in the operation of an internal combustion engine. The fuel supplying canister is provided, on one side of its vessel, with a tank port connected to the fuel tank and a purge port connected to an air intake passage of the internal combustion engine, and also provided with an atmospheric air port for introducing air on the other side thereof. The atmospheric air port includes a switching device for controlling the cross-sectional area of an atmospheric air passage in a manner that the switching device is fully opened during fuel supply, and that at other times a predetermined restriction hole is defined therein.

Abstract: A water pump including a pump housing having a central axial through-hole; a pump shaft inserted in the through-hole; a pulley fixed on the pump shaft at one end thereof; an impeller fixed on the pump shaft at the other end thereof; a bearing fitted with the through-hole for rotatably supporting the pump shaft in the vicinity of the pulley; a water seal provided between the impeller and the bearing for sealing water in a pump chamber where the impeller is installed, wherein an intermediate chamber is defined among the pump housing, the bearing and the water seal. A first ventilation passage is formed in a wall of the pump housing so as to induce an atomspheric air into the intermediate chamber. A second ventilation passage is formed in the wall of the pump housing so as to discharge a water vapor in the intermediate chamber to an outside of the pump housing.