Abstract: A preload system for bearings in a waterjet propulsion apparatus, the apparatus including a water intake section and a pumping unit including a bearing cartridge. The bearing cartridge is designed such that during operation a preload system provides tailoring between radial and axial thermal growths of a plurality of bearing components that comprise the bearing cartridge and such that an initial ambient temperature preload condition can be maintained or reduced during normal water mode operation conditions. The preload system includes a plurality of spacers that when positioned relative to the bearing components of the bearing cartridge prevent relative motion between the bearing components during land mode operation and maintain or reduce the initial ambient room temperature preload condition during normal water mode operation.

Abstract: The present invention provides for outer diameter piloting of a nut that secures stacked components to a tie-shaft or other threaded components used to axially secure one or more rotating components. Unlike conventional inner diameter piloting methods, machining a precise inner diameter of the nut is not needed. The nut face of the present invention has superior perpendicularity with the tie-shaft and the radial pilot is not lost when the nut is loaded. Outer diameter nut piloting may be conducted by using a nut alone or a nut in combination with a nut spacer, a pocket in the rotor, a nut spacer seat, or a nut piloting insert.