Abstract: A turbocharger ball-bearing assembly incorporates a cageless set of ceramic bearing balls operating within outer and inner bearing raceways, wherein the outer bearing raceway is on the inside of a fractured outer race. The fractured outer race is located in a counterbore of a center body of a turbocharger. The center body, in cooperation with the ball-bearing assembly, provides for rotationally supporting, and axially restraining, a rotor shaft of the turbocharger. The outside diameter of the fractured outer bearing race is less than a corresponding inside diameter of the counterbore, and the center body provides for supplying lubricant to an isolation annulus therebetween, so as to provide fir squeeze-film damping the ball-bearing assembly within the counterbore.

Abstract: An aftwardly-extending internally-threaded boss of a boreless-hub compressor rotor of a turbocharger engages a corresponding externally-threaded forward end portion of an associated rotor shaft of the turbocharger, wherein an internal surface of an inner race of an associated rolling-element bearing of the turbocharger is in engagement with both an external surface of the rotor shaft and an external surface of the internally-threaded boss of the boreless-hub compressor rotor, wherein the rotor shaft extends through the inner race of the rolling-element bearing.

Abstract: An aftwardly-extending internally-threaded boss of a boreless-hub compressor rotor of a turbocharger engages a corresponding externally-threaded forward end portion of an associated rotor shaft of the turbocharger, wherein an internal surface of an inner race of an associated rolling-element bearing of the turbocharger is in engagement with both an external surface of the rotor shaft and an external surface of the internally-threaded boss of the boreless-hub compressor rotor, wherein the rotor shaft extends through the inner race of the rolling-element bearing.

Abstract: Lubrication fluid is discharged through an axial gap between a outer bearing race and a bearing housing from a cavity bounded in part by a forward surface of the outer bearing race that is axially slideable within the bearing housing so as to provide for changing the axial gap. The pressure in the cavity is automatically controlled responsive to an axial force on outer bearing race by an axial position of the outer bearing race that determines a size of the axial gap, so as to provide for increasing the pressure responsive to increasing axial force over at least a portion of an operating range. The lubrication fluid in the axial gap provides for isolating axial vibrations of the outer bearing race relative to the bearing housing.

Abstract: A turbocharger ball-bearing assembly incorporates a cageless set of ceramic bearing balls operating within outer and inner bearing raceways, wherein the outer bearing raceway is on the inside of a fractured outer race.

Abstract: Lubrication fluid is discharged through an axial gap between a outer bearing race and a bearing housing from an enclosed volume bounded in part by a forward surface of the outer bearing race that is axially slideable within the bearing housing so as to provide for changing the axial gap. The pressure in the enclosed volume is automatically controlled responsive to an axial force on outer bearing race by an axial position of the outer bearing race that determines a size of the axial gap, so as to provide for increasing the pressure responsive to increasing axial force over at least a portion of an operating range. The lubrication fluid in the axial gap provides for isolating axial vibrations of the outer bearing race relative to the bearing housing.