The foot spa has a rotating drive hub and a pump. The hub has North and South pole domains encircling a rotation axis in alternating relation. The pump includes a housing and an impeller, the housing having a pair of sides and defining: a cavity having a center and a periphery; an intake that communicates with the cavity center; and one or more ports communicating with the periphery. The impeller is mounted in the cavity and: defines blades which are adapted, upon rotation of the impeller in the cavity, to draw water through the intake and eject water through the one or more ports; and includes a portion that is ferromagnetic and a portion that is not ferromagnetic, the portions: being adapted such that rotation of the drive hub causes rotation of the impeller and abutting one another, one being axially displaced from the other.

The foot spa has a rotating drive hub and a pump. The hub has North and South pole domains encircling a rotation axis in alternating relation. The pump includes a housing and an impeller, the housing having a pair of sides and defining: a cavity having a center and a periphery; an intake that communicates with the cavity center; and one or more ports communicating with the periphery. The impeller is mounted in the cavity and: defines blades which are adapted, upon rotation of the impeller in the cavity, to draw water through the intake and eject water through the one or more ports; and includes a portion that is ferromagnetic and a portion that is not ferromagnetic, the portions: being adapted such that rotation of the drive hub causes rotation of the impeller and abutting one another, one being axially displaced from the other.

An electrical submersible pump (ESP) for use in a high viscosity pumping system includes a pump shaft, at least one rotating impeller including an impeller hub and one or more impeller vanes projecting from the impeller hub. Each of the one or more impeller vanes includes an impeller vane edge, and at least one stationary diffuser positioned below the at least one rotating impeller. A diffuser includes a diffuser hub and a diffuser shroud including a diffuser shroud surface. The impeller vane edge and the diffuser shroud surface are separated only by a clearance gap.

An electrical submersible pump (ESP) for use in a high viscosity pumping system includes a pump shaft, at least one rotating impeller including an impeller hub and one or more impeller vanes projecting from the impeller hub, each of the one or more impeller vanes including an impeller vane edge, and at least one stationary diffuser positioned below the at least one rotating impeller, the diffuser including a diffuser hub and a diffuser shroud including a diffuser shroud surface, where the impeller vane edge and the diffuser shroud surface are separated only by a clearance gap.

The foot spa has a rotating drive hub and a pump. The hub has North and South pole domains encircling a rotation axis in alternating relation. The pump includes a housing and an impeller, the housing having a pair of sides and defining: a cavity having a center and a periphery; an intake that communicates with the cavity center; and one or more ports communicating with the periphery. The impeller is mounted in the cavity and: defines blades which are adapted, upon rotation of the impeller in the cavity, to draw water through the intake and eject water through the one or more ports; and includes a portion that is ferromagnetic and a portion that is not ferromagnetic, the portions: being adapted such that rotation of the drive hub causes rotation of the impeller and abutting one another, one being axially displaced from the other.

A rotor structure for a centrifugal flow machine includes working vanes attached to the hub of the rotor without any support disc or shroud. Additionally, the vane has a device for efficiently flushing the sealing chamber behind the rotor.