Abstract: A magnetically driven pump includes a pump chamber, an impeller held in the pump chamber so as to be rotatable about a central axis, a drive unit for rotatively driving the impeller, and a magnetic attraction system provided on the drive unit and impeller for rotating the impeller by mutual magnetic force. At least one of the first and second magnetic attraction devices is provided in parallel with the central axis and being provided also in front of and in back of the pump in the axial direction.

Abstract: A water pump for an internal combustion engine includes a body, a driving shaft held rotatably in the body, an impeller fixed on the driving shaft, a volute chamber formed in the body and including a deflecting portion adapted for introducing a coolant to an outlet port, a chamber formed in the body on a back side of the impeller and including an inner circumferential portion and an outer circumferential portion, and at least two ribs disposed so as to connect the inner circumferential portion and the outer circumferential portion of the chamber, one of the ribs disposed adjacent to the deflecting portion of the volute chamber, whereby inibiting foreign matters contained in the coolant from being left in a space formed between the inner circumferential portion and the outer cicumferential portion of the chamber. When foreign matters are contained in the coolant and when the foreign matters intrude into the chamber, the foreign matters collide with the ribs.