Turbocharger with oil-free hydrostatic bearing
A turbocharger for an internal combustion engine, the turbocharger being supported by hydrostatic bearings in both a radial and an axial direction by a compressed air supplied from a compressor of the turbocharger and boosted in pressure by a separate boost pump to a high enough pressure to support the rotor of the turbocharger. The turbocharger hydrostatic bearings are damped using wire mesh or dispersed friction dampers.
1. A turbocharger for an internal combustion engine comprising:
a compressor to compress air for burning in the internal combustion engine;
a turbine to drive the compressor using hot gas exhaust from the internal combustion engine;
a rotor connected between the compressor and the turbine of the turbocharger;
first and second hydrostatic bearings to rotatably support the rotor in a radial direction;
a vibration damper positioned between a bearing housing and the hydrostatic journal bearing;
a boost pump having an inlet connected to the compressor and an outlet connected to the first and second hydrostatic bearings to support the rotor; and,
the boost pump increasing a pressure of the compressed air from the compressor to a higher pressure capable of supporting the rotor.
2. The turbocharger of claim 1 , and further comprising:
the rotor includes a hydrostatic axial thrust bearing supplied with compressed air from the boost pump.
3. The turbocharger of claim 1 , and further comprising:
the boost pump is driven by a power takeoff from the internal combustion engine.
4. The turbocharger of claim 1 , and further comprising:
the boost pump is driven by an electric motor.
5. The turbocharger of claim 1 , and further comprising:
the boost pump is an extra compression cylinder within the internal combustion engine.
6. The turbocharger of claim 1 , and further comprising:
the vibration damper is a wire mesh damper.
7. The turbocharger of claim 1 , and further comprising:
the vibration damper comprises a plurality of elements that are enclosed within a cavity formed between the journal bearing and the bearing housing.
8. The turbocharger of claim 7 , and further comprising:
the plurality of elements are ceramic balls.
9. The turbocharger of claim 7 , and further comprising:
the plurality of elements are metallic balls.
10. The turbocharger of claim 6 , and further comprising:
the wire mesh damper is a doughnut shaped damper.
11. The turbocharger of claim 6 , and further comprising:
the dampers are multiple segmented dampers arranged circumferentially around the bearing journal.
12. The turbocharger of claim 6 , and further comprising:
the wire mesh damper is cooled using cooling air that is also used to cool the hydrostatic bearing.
13. The turbocharger of claim 1 , and further comprising:
the compressed air used for the hydrostatic bearing is also used to cool a hub side of the turbine rotor.