PUMP FOR LIQUID REFRIGERANT CIRCULATION

PROBLEM TO BE SOLVED: To provide a pump for a liquid refrigerant circulation, which has an outer gear and so on shaped in a cylinder with a bottom and still prevented from inclination during operation, thereby preventing generation of abrasion, vibration, and noise caused by increase of a friction coefficient of the gear.SOLUTION: A pump 1 circulating liquid refrigerant in a refrigerant circuit, includes: a main body 2 including a cylindrical gear accommodation chamber 2a having a bottom portion, and a suction port 2d and a discharge port 2e each opening in the gear accommodation chamber; an outer gear 4 rotatably arranged in the gear accommodation chamber; an inner gear 3 which has external teeth meshing with the internal teeth of the outer gear, and a rotational axis of which is provided eccentrically from a rotational axis of the outer gear; a motor 6 discharging liquid refrigerant from the suction port to the discharge port by rotating the outer gear; and a magnetic coupling 5 connecting the outer gear and a drive shaft 6a of the motor. The outer gear has a through hole 4c positioned between the adjacent internal teeth and close to a bottom portion of the gear accommodation chamber, and penetrating between an inner and an outer surface of the outer gear.