Electric coolant pump and manufacturing method for movable unit of the same

An electric coolant pump, comprising

• a pump house;
• a motor connected to the pump house and comprising:
• a stator with a fixed central shaft;
• and
• a movable unit rotatably mounted within the stator, the movable unit comprising a support body, a bearing assembly connected to the support body, a rotor core fixed to the support body and a plurality of permanent magnets attached to the rotor core, the bearing assembly comprising a cylindrical positioning sleeve and two bearings positioned at opposite ends of the positioning sleeve, the positioning sleeve and the bearings are sleeved on the central shaft, the positioning sleeve is in clearance fit with the central shaft, the two bearings rotatably supported on the central shaft, wherein the support body is formed by an injection-molding process to wrap the bearing assembly and fixedly connecting bearing assembly and the rotor core, the bearings are fixedly connected to the positioning sleeve through the support body being directly overmolded by the injection-molding process on both the bearings and the positioning sleeve;
• an impeller housed in the pump house and driven by the motor.