Both ends open fluid dynamic bearing with multiple thrust plates

摘要

A hydrodynamic fluid bearing cartridge having a fixed central shaft (59) carrying first and second thrust plates (90, 92) separated by a circular shaft portion (94), each of the thrust plates having first and second radial surfaces connected by an axial surface and a sleeve (72) which rotates relative to the fixed shaft around a central axis of rotation defined by a central axis of the shaft. The sleeve supports a counterplate (105, 107) opposing each exposed face of the thrust plate and defines recesses for each of the first and second thrust plates. The recesses each include radial surfaces joined by an axial surface and face each radial and axial surface of the thrust plate to define a continuous gap (102) around each thrust plate. The gap includes lubricating fluid between the shaft and the sleeve and the thrust plates and between the sleeve and the counterplate in order to allow the sleeve to rotate relative to the fixed shaft while maintaining increased stiffness of the sleeve relative to the shaft.