Electric pump with relief valve

An electric pump comprising:

• a housing;
• an outer rotor accommodated in the housing and rotated around a first axis by a magnetic field produced by the housing;
• an inner rotor rotated around a second axis displaced to the first axis in a manner where an outer circumference thereof contacts an inner circumference of the outer rotor;
• a base member facing one side surface of the outer rotor and one side surface of the inner rotor;
• a side plate member having a facing surface facing the other side surface of the outer rotor and the other side surface of the inner rotor and a non-facing surface opposed to the facing surface;
• a shaft rotatably supporting the inner rotor and extending from the base member through the side plate member in a direction of the second axis;
• a suction port provided at the base member and sucking fluid;
• a discharge port provided at the base member and discharging fluid to an exterior of the housing;
• a negative pressure applied region provided between the outer rotor and the inner rotor and communicating to the suction port;
• a positive pressure applied region provided between the outer rotor and the inner rotor and communicating to the discharge port;
• and
• a relief valve discharging the fluid from the positive pressure applied region to a non-facing surface side of the side plate member when a pressure applied at the positive pressure applied region exceeds a predetermined value.