ELECTRICALLY-DRIVEN WATER PUMP

摘要

PROBLEM TO BE SOLVED: To provide an electrically-driven water pump capable of improving a low flow rate performance while keeping a high flow rate performance.SOLUTION: A rotor 9 and an impeller 10 are arranged in such a way that they can axially move between an initial position and a prescribed position in a positive direction at x-axis in respect to a housing HSG. There are provided a wall part 15 overlapping a part of a discharging part 10e when the impeller 10 is placed at an initial position in a direction of the rotating shaft and releasing the overlapped state when the impeller 10 is placed at a position where it is moved from a prescribed position by a prescribed distance and a coil spring 30 for biasing the impeller 10 in a negative direction of x-axis at the position oppositely facing against the discharging part 10e of the housing HSG.