SPINDLE MOTOR AND HARD DISK DRIVE INCLUDING THE SAME

摘要

The present invention relates to a spindle motor and a hard disk drive including the same. The spindle motor includes: a lower thrust member fixed and installed on a base member; a shaft which is fixed and installed to at least one of the lower thrust member and the base member; and a sleeve forming lower sealing unit by being arranged on top of the lower thrust member to form a gas-liquid interface of a lubricant fluid with the lower thrust member while being rotatably installed on the shaft; a rotor hub which is coupled to the sleeve and is rotated while being connected to the sleeve; and an upper thrust member which is fixed and installed on the upper end of the shaft and forms the gas-liquid interface of the lubricant fluid with the sleeve to form an upper sealing unit. A circulation hole is arranged on the sleeve to link the upper and lower surfaces in the shaft direction. One of the surfaces facing the rotor hub and the upper thrust member in a radial direction has a secondary upper pumping groove. One of the surfaces facing the lower thrust member and the sleeve in the shaft direction has a secondary lower pumping groove. The lubricant liquid pumping force of the secondary upper pumping groove can be larger than that of the secondary lower pumping groove.