Abstract: Disclosed herein is a spindle motor which is capable of more easily controlling an axial gap and levelness between the thrust plate of a rotating shaft and a sealing cap. The spindle motor includes a rotating shaft having a thrust plate which is perpendicularly inserted into the upper portion of the rotating shaft. A sleeve accommodates the rotating shaft and rotatably supports the rotating shaft. The sleeve is secured to a plate. A sealing cap is secured to the sleeve through laser welding in such a way as to face the upper surface of the thrust plate. At least part of the sealing cap is stepped towards the thrust plate to correspond to a degree of deformation occurring during the laser welding.

Abstract: Disclosed herein is a spindle motor which is capable of more easily controlling an axial gap and levelness between the thrust plate of a rotating shaft and a sealing cap. The spindle motor includes a rotating shaft having a thrust plate which is perpendicularly inserted into the upper portion of the rotating shaft. A sleeve accommodates the rotating shaft and rotatably supports the rotating shaft. The sleeve is secured to a plate. A sealing cap is secured to the sleeve through laser welding in such a way as to face the upper surface of the thrust plate. At least part of the sealing cap is stepped towards the thrust plate to correspond to a degree of deformation occurring during the laser welding.

Abstract: A system and method for filling hydrodynamic bearings with fluid. The fluid filling system includes a vacuum vessel for receiving the hydrodynamic bearing therein, a pump hermetically connected to the vacuum vessel and exhausting air from the vacuum vessel to the outside, an ultrasonic generator for generating vibrations in the vacuum vessel, and a fluid dispenser for dripping the fluid into the hydrodynamic bearing. When air is exhausted from the vacuum vessel to the atmosphere by the pump, the hydrodynamic bearing is vibrated by the ultrasonic generator and air is exhausted from a micro-gap between the shaft and sleeve of the bearing the atmosphere.

Abstract: Disclosed herein is a spindle motor which prevents a sleeve from being deformed because of residual stress during the welding of a stopper for preventing the removal of a rotating shaft to which a thrust plate is coupled. The spindle motor includes a rotating shaft having a thrust plate which is fitted over the upper portion of the rotating shaft to be perpendicular to the rotating shaft. A sleeve accommodates the rotating shaft to rotatably support the rotating shaft. A stopper is coupled to the sleeve to support the upper surface of the thrust plate, thus preventing the removal of the rotating shaft. A stress-blocking groove is formed in the sleeve in such a way as to be adjacent to the stopper, and prevents the sleeve from being deformed by residual stress generated when the stopper is coupled to the sleeve.

Abstract: A motor is disclosed. The motor in accordance with an embodiment of the present invention includes: a rotor, a shaft, which is coupled to the rotor; a plate, which is coupled to an outer circumference of the shaft; a bearing, which supports the shaft such that the shaft can rotate; a cap, which is coupled to the bearing such that an edge of the plate is covered; a lubricant, which is filled between the shaft and the bearing; and a sealing part, which is coupled to an inner side of the cap and in which the sealing part is made of a transparent material such that an amount of the lubricant filled can be checked. Therefore, the amount of the lubricant filled between the shaft and the bearing can be directly checked.

Abstract: A spindle motor having a hydrodynamic pressure bearing includes a stator, a rotor, and a dynamic pressure generating unit including a sleeve having an upper plate disposed opposite to the rotor and at least one thrust dynamic pressure groove formed either at the upper plate of the sleeve or at the rotor. Inside width from a neutral radius to an innermost radius of the thrust dynamic pressure groove is larger than outside width from the neutral radius to an outermost radius of the thrust dynamic pressure groove such that the neutral radius is biased to the outside of the thrust dynamic pressure groove. Dynamic pressure at the inside width of the thrust dynamic pressure groove is higher than dynamic pressure at the outside width of the thrust dynamic pressure groove such that fluid supplied into the thrust dynamic pressure groove is guided to the outer diameter side.

Abstract: A system and method for filling hydrodynamic bearings with fluid is disclosed. The fluid filling system 100 of the present invention includes a vacuum vessel 110 for receiving the hydrodynamic bearing 10 therein, a pump 111 hermetically connected to the vacuum vessel 110 and exhausting air from the vacuum vessel 110 to the outside, an ultrasonic generator 140 for generating vibrations in the vacuum vessel 110, and a fluid dispenser 120 for dripping the fluid into the hydrodynamic bearing 10. When air is exhausted from the vacuum vessel 110 to the atmosphere by the pump 111, the hydrodynamic bearing 10 is vibrated by the ultrasonic generator 140 and air is exhausted from a micro-gap 13 between the shaft 11 and sleeve 12 of the bearing 10 to the atmosphere.