A motor assembly, comprising: a rotating shaft; an impeller mounted on the rotating shaft; a rotor mounted on the rotating shaft and axially spaced apart from the impeller along a rotational axis of the rotating shaft; a stator surrounding a circumferential surface of the rotor and spaced apart from the rotor radially relative to the rotational axis of the rotating shaft; a first bearing mounted on the rotating shaft between the impeller and the rotor and configured to rotatably support a first support part of the rotating shaft; a second bearing mounted on the rotating shaft between the impeller and the rotor and configured to rotatably support a second support part of the rotating shaft, wherein the first bearing is positioned closer to the impeller than the second bearing, and the second bearing is positioned closer to the rotor than the first bearing; a bearing bracket that receives the first and second bearings therein; an elastic member disposed between the first bearing and the bearing bracket or between the second bearing and the bearing bracket and biasing one of the first bearing and the second bearing toward the other of the first beating and the second bearing; and a separation preventing holder mounted on the bearing bracket and fixing the first bearing, the second bearing and the elastic member within the bearing bracket such that at least a portion of the separation preventing holder covers at least one of the first bearing, the second bearing or the elastic member axially along the rotational axis of the rotating shaft, characterized in that the first bearing comprises a first outer ring contacting with an inner surface of the bearing bracket, and the second bearing comprises a second outer ring contacting with the inner surface of the bearing bracket, and wherein one of the first outer ring and the second outer ring is press-fit onto the inner surface of the bearing bracket, and wherein the other (152, 162) is attached to the inner surface of the bearing bracket by an adhesive. a rotating shaft; an impeller mounted on the rotating shaft; a rotor mounted on the rotating shaft and axially spaced apart from the impeller along a rotational axis of the rotating shaft; a stator surrounding a circumferential surface of the rotor and spaced apart from the rotor radially relative to the rotational axis of the rotating shaft; a first bearing mounted on the rotating shaft between the impeller and the rotor and configured to rotatably support a first support part of the rotating shaft; a second bearing mounted on the rotating shaft between the impeller and the rotor and configured to rotatably support a second support part of the rotating shaft, wherein the first bearing is positioned closer to the impeller than the second bearing, and the second bearing is positioned closer to the rotor than the first bearing; a bearing bracket that receives the first and second bearings therein; an elastic member disposed between the first bearing and the bearing bracket or between the second bearing and the bearing bracket and biasing one of the first bearing and the second bearing toward the other of the first beating and the second bearing; and a separation preventing holder mounted on the bearing bracket and fixing the first bearing, the second bearing and the elastic member within the bearing bracket such that at least a portion of the separation preventing holder covers at least one of the first bearing, the second bearing or the elastic member axially along the rotational axis of the rotating shaft, characterized in that the first bearing comprises a first outer ring contacting with an inner surface of the bearing bracket, and the second bearing comprises a second outer ring contacting with the inner surface of the bearing bracket, and wherein one of the first outer ring and the second outer ring is press-fit onto the inner surface of the bearing bracket, and wherein the other (152, 162) is attached to the inner surface of the bearing bracket by an adhesive.