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 , a plurality of permanent magnets attached to the rotor core , the bearing assembly comprising at least one bearing rotatably supported on the central shaft ; and an impeller housed in the pump house and driven by the motor ; wherein the support body is formed by an injection-molding process with the bearing assembly and fixedly connecting with the rotor core , the bearing assembly comprises 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 , an inner diameter of the positioning sleeve is larger than that of the bearings , the two bearings are in friction fit with the central shaft , and the positioning sleeve is in clearance fit with the central shaft to prevent the positioning sleeve from interfering with the central shaft . 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 , a plurality of permanent magnets attached to the rotor core , the bearing assembly comprising at least one bearing rotatably supported on the central shaft ; and an impeller housed in the pump house and driven by the motor ; wherein the support body is formed by an injection-molding process with the bearing assembly and fixedly connecting with the rotor core , the bearing assembly comprises 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 , an inner diameter of the positioning sleeve is larger than that of the bearings , the two bearings are in friction fit with the central shaft , and the positioning sleeve is in clearance fit with the central shaft to prevent the positioning sleeve from interfering with the central shaft . 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 , a plurality of permanent magnets attached to the rotor core , the bearing assembly comprising at least one bearing rotatably supported on the central shaft ; and an impeller housed in the pump house and driven by the motor ; wherein the support body is formed by an injection-molding process with the bearing assembly and fixedly connecting with the rotor core , the bearing assembly comprises 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 , an inner diameter of the positioning sleeve is larger than that of the bearings , the two bearings are in friction fit with the central shaft , and the positioning sleeve is in clearance fit with the central shaft to prevent the positioning sleeve from interfering with the central shaft . <EOS>