Asymmetry pressure regulation and check valve device for fluid dynamic bearing

A fluid dynamic bearing system comprising a shaft, a sleeve defining a bore, a fluid dynamic bearing located in the bore between the sleeve and the shaft for supporting relative rotation, the fluid dynamic bearing comprising at least one grooved surface asymmetrically biased to create pressure gradient and fluid flow toward an end of the shaft, at least one fluid recirculation path, a preloaded obstruction located in the fluid recirculation path, and a constant pressure region downstream of the obstruction, the fluid flow established by the asymmetrical bearing grooves acting to displace the obstruction until force equilibrium is reached, thereby regulating pressure in the recirculation path.