Combined anti-friction/hydrodynamic common shaft bearing system and methods of application

A method of preventing degradation of the theoretical L10 life of an anti-friction bearing subjected to axial forces within an anti-friction/hydrodynamic common shaft system, comprising:

• providing a housing comprising a lower housing member having a plurality of oil passageways and an upper housing member for placement on the lower housing member;
• providing a rotating shaft comprising an upstream portion having a first end, a downstream portion having a second end, and an input/output section therebetween;
• securing a first anti-friction bearing to the rotating shaft upstream portion or downstream portion;
• placing the rotating shaft on the lower housing member;
• securing a first hydrodynamic thrust bearing to the lower housing member and/or upper housing member and adjacent the first anti-friction bearing;
• securing a first thrust-collar to the rotating shaft and adjacent to the first hydrodynamic thrust bearing such that the first anti-friction bearing, the first hydrodynamic thrust bearing, and the first thrust-collar form a bearing assembly having an axial gap between the first hydrodynamic thrust bearing and the first thrust-collar;
• securing the upper housing member to the lower housing member to encapsulate the bearing assembly within the housing;
• and
• providing a lubricating medium to provide hydrodynamic lubrication to the bearing assembly via the plurality of oil passageways.

An anti-friction/hydrodynamic common shaft, comprising:

• a rotating shaft comprising an upstream portion having a first end, a downstream portion having a second end, and an input/output section therebetween;
• a first anti-friction bearing secured to the rotating shaft upstream portion;
• a second anti-friction bearing secured to the rotating shaft downstream portion;
• a housing carrying said rotating shaft comprising a lower housing member having a plurality of oil passageways and an upper housing member for placement on the lower housing member;
• a first hydrodynamic thrust bearing secured to the lower housing member and adjacent the first anti-friction bearing;
• a second hydrodynamic thrust bearing secured to the lower housing member and/or upper housing member and adjacent the second anti-friction bearing;
• a first thrust-collar secured to the rotating shaft and adjacent to the first hydrodynamic thrust bearing;
• a second thrust-collar secured to the rotating shaft and adjacent to the second hydrodynamic thrust bearing;
• and
• a lubricating medium for hydrodynamic lubrication of the first and second anti-friction bearings, the first and second hydrodynamic thrust bearings, and the first and second thrust-collars via the plurality of oil passageways.