Pump for circulating water

A pump for circulating water, comprising:

• an upper housing formed with an inlet and an outlet for a flow of fluid;
• a lower housing installed to fit in a lower side of the upper housing, the lower housing having a receiving space formed therein;
• an inner housing having an edge part interposed between the upper housing and the lower housing, an impeller receiving groove formed at the center of the inner housing, and a shaft support part formed at the center of the bottom of the impeller receiving groove;
• an impeller received in the impeller receiving groove to be rotatably installed, so as to form a flow pathway between the impeller and an inner surface of the inner housing for the flow of fluid;
• a rotor installed inside the impeller;
• and
• a stator installed in the lower housing to be positioned to face the rotor,
• wherein the pump for circulating water is formed with a plurality of pressure alleviating through holes in a base plate in which a wing piece of the impeller is formed, a plurality of vertical discharge holes in a body of the impeller, interconnected with the flow pathway, so that the fluid inside the flow pathway is discharged to the upper side, and a plurality of horizontal discharge holes at a side of the impeller body between a lower part of the base plate and an upper part of a rotor receiving part having a rotor receiving space, wherein the pressure alleviating through holes, the plurality of vertical discharge holes and the plurality of horizontal discharge holes are formed to be interconnected with each other, and the fluid inside the flow pathway rising through the vertical discharge hole and the horizontal discharge hole and the fluid introduced through the inlet are mixed in a mixture space and discharged through the outlet.