WATER PUMP

PROBLEM TO BE SOLVED: To provide a water pump preventing a foreign matter such as rainwater from entering a pump from the outside via through-holes, the through-holes being provided in a sidewall of a pulley opposed to a bearing.SOLUTION: In this water pump 1, a plurality of discharge holes 15 being through-holes for connecting the inside and outside of a pump housing 2, is arranged in a sidewall part 4e opposed to the bearing 6 in a cylindrical base part 4a of the pulley 4. The rainwater or the like flowing along an outside surface of the cylindrical base part 4a from the outside, is made to flow down along the outer periphery of hole edge projection parts 16 by forming the hole edge projection parts 16 of projecting the hole edges of the discharge holes 15 outward.