Patent ID: 8089186
Filing Date: 2012-01-03
Classification: H02K

Abstract:
1. A spindle motor comprising: a base; a bearing housing installed on the base; a bearing fixed inside the bearing housing; a rotation shaft rotatably installed into the bearing; a stator disposed around the bearing housing; a bushing coupled to the rotation shaft; a rotor coupled to the bushing to rotate through interaction with the stator, wherein the rotor comprises a rotor yoke coupled to the bushing and a magnet coupled to the rotor yoke, wherein the rotor yoke contacts the outermost periphery of the bushing; and a clamp coupled to the rotor yoke, wherein the bearing is coupled to a lower portion of the rotation shaft and the bushing is coupled to an upper portion of the rotation shaft, wherein the thickness of the bushing is thinner than a diameter of the rotation shaft wherein a first area over which the upper portion of the rotation shaft and the bushing contact extends vertically over a length of between 0.8 mm and 1.5 mm, wherein a second area over which the lower portion of the rotation shaft and the bearing contact is greater than the first area, wherein a portion of the rotor yoke is disposed between the bushing and the clamp, wherein an inner surface of the portion of the rotor yoke is in contact with the bushing and an outer surface of the portion of the rotor yoke is in contact with the clamp, wherein the clamp is spaced from the bushing by the portion of the rotor yoke.