Thrust Bearing System And Method For Operating The Same

A method of operating a fluid machine comprising:

• communicating fluid from a pump outlet to a distribution groove disposed in a center bearing;
• communicating fluid from the distribution groove to a thrust bearing formed between a stationary end surface of a center bearing and an end surface of a pump shroud that is coupled to a shaft;
• rotating the shaft to generate a first axial force;
• and
• generating a second axial force counter to the first axial force in response to communicating fluid from the distribution groove to the thrust bearing.

A fluid machine assembly comprising:

• a casing comprising a pump portion having a pump impeller chamber, a pump inlet and a pump outlet;
• a pump impeller disposed in the pump impeller chamber;
• said casing further comprising a turbine portion having a turbine inlet, a turbine outlet and a turbine impeller chamber;
• a turbine impeller disposed in the turbine impeller chamber, said turbine impeller comprising a turbine shroud comprising a rotating thrust face;
• a shaft extending between the pump impeller and the turbine impeller, said shaft comprising a center axial shaft passage, a first radial shaft passage and a second radial shaft passage;
• a turbine wear ring disposed around the turbine outlet comprising a stationary thrust face opposite the rotating thrust;
• a center bearing disposed around the shaft between the pump impeller chamber and turbine impeller chamber, said center bearing and the shaft comprising a bearing clearance therebetween;
• a land disposed between the stationary thrust face and the rotating thrust face;
• a thrust bearing comprising a thrust bearing cavity defined between the stationary thrust face, the rotating thrust face and the land, said thrust bearing receiving filtered fluid from the pump outlet;
• a lubricant supply coupling lubricant to the thrust bearing cavity;
• an impeller passage communicating lubricant from the thrust bearing cavity to the center axial shaft passage;
• said axial shaft passage communicating lubricant to said bearing clearance through the first radial shaft passage and the second radial shaft passage;
• said bearing clearance communicating lubricant to the pump impeller chamber and the turbine impeller chamber.

A method comprising:

• communicating lubricant to a thrust bearing cavity disposed between a turbine impeller and a thrust wear ring;
• communicating lubricant from the thrust bearing cavity to a center axial shaft passage of a shaft through an impeller passage of the turbine impeller;
• communicating lubricant through the axial shaft passage to a bearing clearance between a shaft and a center bearing through a first radial shaft passage and a second radial shaft passage;
• and
• communicating lubricant through the bearing clearance to a pump impeller chamber and a turbine impeller chamber.