An improved turbocharger for railway locomotive sized engines includes, in a preferred embodiment, first and second axially spaced ball bearings supporting a rotor with the first bearing being a hybrid ceramic ball bearing mounted to accept both radial and axial loads acting on the shaft at the compressor end. The first bearing is mounted on a reduced diameter portion of the shaft, providing reduced bearing diameter to acceptably limit centrifugal loading of ceramic balls in the bearing against a surrounding bearing race. The first bearing has dual rows of ceramic ball bearings mounted to share all axial thrust loads on the shaft. The second bearing is also a ball bearing. Lubrication of the bearings is preferably by direct impingement on the inner race to minimize oil churning causing heating and power loss. Additional features and advantages are disclosed.
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