Hydrodynamic bearing and seal

A hydrodynamic bearing unit and lubricant seal comprising a shaft and a sleeve rotating relative to the shaft, the shaft and the sleeve defining a plurality of spaced apart hydrodynamic journal bearings, the shaft further defining a radial shoulder outwardly adjacent to one of the journal bearings and having a reduced cross-sectional dimension axially beyond the shoulder, a thrust plate secured to the shaft and registered by the radial shoulder and having a first radial surface in facing confrontation with a shoulder of the sleeve and defining a first hydrodynamic thrust bearing, a thrust bushing secured to the sleeve and having a bearing surface in overlying facing engagement with a second radial surface of the thrust plate and defining a second hydrodynamic thrust bearing, an annular Vee groove defined by diverging annular wall surfaces of the thrust plate and the thrust bearing and having a base facing the shaft outwardly adjacent to the radial shoulder and having an apex in substantial alignment with the second hydrodynamic thrust bearing, and hydrodynamic lubricant within the annular Vee groove which is retained in place by capillary force and by centrifugal force during relative rotation between the thrust plate and the thrust bushing.

A hydrodynamic spindle assembly for a hard disk drive spindle including a base, a shaft secured to the base, and a sleeve overlying the shaft and rotating relative to the shaft and base, the sleeve carrying a disk hub, the shaft and sleeve defining a plurality of spaced apart hydrodynamic journal bearings, a thrust plate secured to the shaft and having a first radial surface in facing confrontation with a shoulder of the sleeve and defining a first hydrodynamic thrust bearing, a thrust bushing secured to the sleeve and having a bearing surface in overlying facing engagement with a second radial surface of the thrust plate and defining a second hydrodynamic thrust bearing, a first lubricant seal axially beyond the thrust plate and formed by an annular Vee groove defined by diverging annular wall surfaces of the thrust plate and the thrust bearing and having a base facing the shaft and having an apex converging toward the second hydrodynamic thrust bearing, a second lubricant seal formed between the shaft and the sleeve at an axial location oppositely away from the first lubricant seal for retaining lubricant by capillary force and by centrifugal force, and lubricant emplaced within the first seal and the second seal and operative at the plurality of spaced apart hydrodynamic journal bearings and at the first and second thrust bearings.