WATER PUMP

PROBLEM TO BE SOLVED: To provide a water pump capable of restraining the sticking of abrasion powder by forcibly supplying cooling water to a clutch spring side from an impeller.SOLUTION: A water pump 1 includes a driving shaft 6 rotatably supported in a pump room 3 arranged in a pump housing 2, and an impeller 7 stored in the pump room and relatively rotatably arranged in a small diameter shaft 6b on the tip side of the driving shaft via a bearing 15 and a driven ring 16, and includes a clutch spring 20 on respective outer peripheral surfaces of a driving ring 14 of the driving shaft and a driven member. The impeller has a base 7a formed in a disk shape and six blades 7b arranged in a radial shape from the rotational center side on the front side of the base, and water guiding holes 26 and 27 for guiding cooling water in the clutch spring direction are formed in positions opposed from the axial direction to one end side of the clutch spring of the base.