Apparatus comprising and methods are described including a blood pump that includes an axial shaft, and an impeller disposed on the axial shaft. The impeller is configured to pump blood of the subject by rotating. The impeller and the axial shaft are configured to undergo axial back-and-forth motion during operation of the impeller. A distal tip element is disposed at a distal end of the blood pump. The distal tip element defines an axial-shaft-receiving tube, configured to receive at least a portion of the axial shaft during forward motion of the axial shaft. The distal tip element additionally defines an atraumatic distal tip portion disposed distally of the axial-shaft-receiving tube. Other applications are also described.

A first fluid rotor that has a first fluid intake end and a first fluid discharge end. A second fluid rotor that has a second fluid intake end and a second fluid discharge end. The second fluid rotor is rotatably coupled to the first fluid rotor to rotate in unison with the first fluid rotor along a shared rotational axis. The first fluid intake end and the second fluid intake end are facing opposite directions. A first fluid stator surrounds the first fluid rotor. The first fluid rotor and the first fluid stator form a first fluid stage. The second fluid stator is aligned along the rotational axis. The second fluid stator and the second fluid rotor form a second fluid stage. A flow crossover sub is positioned between the first fluid stage and the second fluid stage.

A system and methodology are provided for enhancing the life and usefulness of a thrust bearing assembly in a submersible pumping system component. The technique utilizes a thrust runner positioned adjacent a thrust bearing in the submersible pumping system component. The thrust runner is rotated relative to the thrust bearing via a shaft. Gas that may accumulate in a lower region beneath the thrust runner is vented through a passageway from the lower region to an upper region above the thrust runner. The gas is vented to help maintain a hydrodynamic fluid film between the thrust runner and the thrust bearing.

Bearing assemblies, apparatuses, systems, and methods include bearing assemblies having one or more bearing element in a bearing housing for supporting a shaft extending through at least a portion of the bearing housing. The bearing assembly including a recirculation line for delivering fluid into the bearing housing at a location separate from a fluid inlet of the bearing housing to at least partially thermally regulate, lubricate, and/or flush the one or more bearing elements during operation of the shaft.

Bearing assemblies, apparatuses, systems, and methods include bearing assemblies having one or more bearing element in a bearing housing for supporting a shaft extending through at least a portion of the bearing housing. The bearing assembly including a recirculation line for delivering fluid into the bearing housing at a location separate from a fluid inlet of the bearing housing to at least partially thermally regulate, lubricate, and/or flush the one or more bearing elements during operation of the shaft.

A blood pump includes a housing having an inlet. A rotor disposed in the housing and configured to rotate substantially about the axis to pump blood from the inlet to the outlet. A stator is disposed within the housing and configured to drive rotation of the rotor about the axis. A bearing mechanism for supporting the rotor inside the housing includes a magnetic bearing configured to magnetically support the rotor inside the housing in a radial direction from the axis. The bearing mechanism includes a sliding bearing configured to physically support the rotor inside the housing in an axial direction along the axis of the housing and allow rotation of the rotor substantially about the axis, the sliding bearing comprising at least one point of contact where the rotor is configured to physically contact a trunnion affixed to the housing.

A shaftless rotary machine includes an impeller, a motor positioned radially outward from the impeller, and a housing. The impeller includes a hub, blades connected to the hub, and a shroud connected to the blades. The motor includes a rotor connected to the shroud and a stator. The housing includes an inlet, an outlet, and a duct. The duct extends from the inlet to the outlet. The duct partially surrounds the motor and the impeller.

A thrust balancing apparatus for a pump includes a housing, a balancing chamber, a connecting tube, a balancing disk, a bushing, a washer, and a pair of upthrust washers. The balancing chamber defines an upper cavity and a lower cavity. The connecting tube is configured to establish fluid communication between the balancing chamber and an exterior of the housing. A first portion of the balancing disk is disposed within the upper cavity. A second portion of the balancing disk passes through the lower cavity. A third portion of the balancing disk is external to the balancing chamber. The washer is disposed between the balancing disk and the bushing. The pair of upthrust washers are disposed between the balancing disk and the balancing chamber.

A thrust balancing apparatus for a pump includes a housing, a balancing chamber, a connecting tube, a balancing disk, a bushing, a washer, and a pair of upthrust washers. The balancing chamber defines an upper cavity and a lower cavity. The connecting tube is configured to establish fluid communication between the balancing chamber and an exterior of the housing. A first portion of the balancing disk is disposed within the upper cavity. A second portion of the balancing disk passes through the lower cavity. A third portion of the balancing disk is external to the balancing chamber. The washer is disposed between the balancing disk and the bushing. The pair of upthrust washers are disposed between the balancing disk and the balancing chamber.

A pump arrangement includes an axial-flow machine and a drive to convey fluid mounted in a housing. The axial-flow machine is formed by at least one first rotor having permanent magnets, a shaft connected to the first rotor and a stator arrangement with stator teeth distributed concentrically around the shaft axis circumferentially and axially separated from the first rotor by an air gap. The stator teeth have axially-opposite end portions and a tooth core therebetween wound with at least one coil winding. The second end portion, turned away from the first rotor, of each stator tooth forms a tooth root joined to a back plate. The first rotor is an eccentric disk and on the side away from the stator arrangement has an eccentric cam, radially spaced from the shaft axis, and rotatably and torque-transmittingly connected to the drive. An axial-flow machine and a compressor includes the pump arrangement.