Abstract: A pair of threadably engaged sleeves are supported around a shaft, and engage the outer races of a pair of shaft mounted tapered roller bearings to apply a tensile preload on the outer races.

Abstract: A hydrodynamic bearing assembly including a shaft and surrounding bushing which define a journal, the shaft and bushing defining at the end thereof which is open to the ambient atmosphere a shelf-like surface. An absorbent washer, preferably formed of a very clean, particle free absorbent paper is placed on this surface, and preferably held in place by a plastic or metal retainer. Typically, the retainer is pressed in place and held in place by spring force or the like, so that the washer is held tightly against the surface.

Abstract: The disclosure describes a passive lubrication system for use in a high speed print hammer mechanism to provide continuous lubrication to all print hammer elements. Channels are formed along the length of a pivot pin and filled with a porous material having a finer porosity than the sintered print hammer block serving as the principal reservoir. Fins located at each side of print hammer elements also are of the same porosity as the print hammer block and communicate lubricant to the material in the pivot pin channels. From the channels, lubricant is conveyed to the interface between each print hammer element and the pivot pin by capillary action.