A rotary assembly for a centrifugal pump includes a housing, an impeller, a first opening formed in one of the housing or the impeller, a first bushing disposed in the first opening, and a first shaft projection projecting axially from one of the housing or the impeller. The first bushing extends annularly around a central opening thereof and is formed from an elastomeric material. The first shaft projection is received within the central opening of the first bushing. One of the first shaft projection or the first bushing is configured to rotate relative to the other of the first shaft projection or the first bushing during operation of the centrifugal pump.

The present invention provides a rotary blood pump with both an attractive magnetic axial bearing and a hydrodynamic bearing. In one embodiment according to the present invention, a rotary pump includes an impeller assembly supported within a pump housing assembly by a magnetic axial bearing and a hydrodynamic bearing. The magnetic axial bearing includes at least two magnets oriented to attract each other. One magnet is positioned in the spindle of the pump housing while the other is disposed within the rotor assembly, proximate to the spindle. In this respect, the two magnets create an attractive axial force that at least partially maintains the relative axial position of the rotor assembly. The hydrodynamic bearing is formed between sloping surfaces that form tight clearances below the rotor assembly.

Various contactless bearing mechanisms including hydrodynamic and magnetic bearings are provided for a rotary pump as alternatives to mechanical contact bearings. In one embodiment, a pump apparatus includes a pump housing defining a pumping chamber. The housing has a spindle extending into the pumping chamber. A spindle magnet assembly includes first and second magnets disposed within the spindle. The first and second magnets are arranged proximate each other with their respective magnetic vectors opposing each other. The lack of mechanical contact bearings enables longer life pump operation and less damage to working fluids such as blood.

A multi-stage pump featuring different stages configured to pump a fluid from a pump suction and to a pump discharge; and a center bushing configured between the different stages, having a center bushing side configured with pockets to balance axial forces between the different stages of the multistage pump. The pockets are configured as curved rib pockets, extruded circle or circular pockets, or full length rib pockets.

A magnetically driven centrifugal pump has a pump case, an open vane impeller in the pump case, a stuffing box including a stuffing box outer being fixed relative to the pump case and a stuffing box inner threadedly engaged with the stuffing box outer, and a rotor axially fixed and rotatably mounted in the stuffing box inner. Bushings are arranged between the rotor and the stuffing box inner. A drive is fixed relative to the pump case and includes a drive output extending into the rotor. There is a magnetic coupling between the rotor and the drive and a canister fixed to the stuffing box and extending through the magnetic coupling to isolate the rotor from the drive. A rub ring closes the end of the stuffing box inner and constrains the drive output from damaging the cannister under catastrophic bearing failure.

A magnetically driven centrifugal pump has a pump case, an open vane impeller in the pump case, a stuffing box including a stuffing box outer being fixed relative to the pump case and a stuffing box inner threadedly engaged with the stuffing box outer, and a rotor axially fixed and rotatably mounted in the stuffing box inner. Bushings are arranged between the rotor and the stuffing box inner. A drive is fixed relative to the pump case and includes a drive output extending into the rotor. There is a magnetic coupling between the rotor and the drive and a canister fixed to the stuffing box and extending through the magnetic coupling to isolate the rotor from the drive. A rub ring closes the end of the stuffing box inner and constrains the drive output from damaging the canister under catastrophic bearing failure.

A rotary blood pump includes a casing defining a pumping chamber. The pumping chamber has a blood inlet and a tangential blood outlet. One or more motor stators are provided outside of the pumping chamber. A rotatable impeller is within the pumping chamber and is adapted to cause blood entering the pumping chamber to move to the blood outlet. The impeller has one or more magnetic regions. The impeller is radially constrained in rotation by magnetic coupling to one or more motor stators and is axially constrained in rotation by one or more hydrodynamic thrust bearing surfaces on the impeller.

A system includes a hydraulic energy transfer system configured to exchange pressures between a first fluid and a second fluid, wherein the first fluid has a pressure higher than the second fluid. The hydraulic transfer system includes a cylindrical rotor configured to rotate circumferentially about a rotational axis and having a first end face and a second end face disposed opposite each other, a first end cover having a first surface that interfaces with the first end face of the cylindrical rotor, and a hybrid hydrodynamic-hydrostatic bearing system configured to resist axial displacement of the cylindrical rotor.

A blood pump includes a housing and a rotor within the housing configured to rotate along an axis. The rotor may include a hub, the hub having regions with blades and regions without blades. The regions without blades may have a constant outer diameter and may extend along at least one fourth the length of the hub. The regions with blades may have an increasing outer diameter. Blades may be disposed on a downstream end region of the hub and extend downstream of the hub. Blades may begin approximately halfway along the axial length of a motor stator located about a hub and extend downstream of the motor stator. Blades may have portions that produce axial fluid flow and radial fluid flow with improved flow characteristics.

Aspects of the invention disclosed herein generally provide a heat engine system, a turbopump system, and methods for lubricating a turbopump while generating energy. The systems and methods provide proper lubrication and cooling to turbomachinery components by controlling pressures applied to a thrust bearing in the turbopump. The applied pressure on the thrust bearing may be controlled by a turbopump back-pressure regulator valve adjusted to maintain proper pressures within bearing pockets disposed on two opposing surfaces of the thrust bearing. Pocket pressure ratios, such as a turbine-side pocket pressure ratio (P1) and a pump-side pocket pressure ratio (P2), may be monitored and adjusted by a process control system. In order to prevent damage to the thrust bearing, the systems and methods may utilize advanced control theory of sliding mode, the multi-variables of the pocket pressure ratios P1 and P2, and regulating the bearing fluid to maintain a supercritical state.