The present invention relates to a motor pump. The motor pump (MP) includes a first impeller (1A), and a second impeller (1B) connected to a communication shaft (270). A boss portion (281) of the first impeller (1A) has a larger size than that of the boss portion (282) of the second impeller (1B).

A method for filtering a fluid that includes collecting contaminates in the fluid, passing the fluid from inside an internal cavity of a first shaft through a tight clearance at a spline connection between the first shaft and a second shaft such that the fluid is filtered of contaminates as a result of the tight clearance, and delivering the filtered fluid to a delivery location.

A subsea fluid pressure-increasing machine includes an elongated member that is rotatable about a longitudinal axis. The machine also may include a plurality of impellers each having a leading edge, a trailing edge, a suction side, and a chord line defined by a line between the leading and trailing edges. Each impeller is fixedly mounted to the member such that a chord angle defined by an angle between the chord line and the rotation direction is less than or equal to a stall angle at which a maximum force is exerted on a fluid in a direction primarily parallel to the longitudinal axis when the member is rotated in the rotation direction. At least some of the impellers comprise one or more features that effectively reduce a pressure peak or specific loading of the suction side such that the axial length of the impeller is configured to be reduced without exceeding a desired specific load.

A method for filtering a fluid that includes collecting contaminates in the fluid, passing the fluid from inside an internal cavity of a first shaft through a tight clearance at a spline connection between the first shaft and a second shaft such that the fluid is filtered of contaminates as a result of the tight clearance, and delivering the filtered fluid to a delivery location.

A multi-stage horizontal centrifugal pump for conveying a fluid has a rotor including a rotatably arranged shaft and a plurality of impellers for conveying the fluid and a stator. All the impellers are arranged in a rotatably fixed manner on the shaft. The stator includes a plurality of stage casings, which are arranged consecutively one after another with respect to an axial direction determined by a central axis. The stator encompasses the rotor, and each stage casing is designed and arranged centrically with respect to the central axis. A plurality of wear rings is disposed between the rotor and the stator, each of which is fixed with respect to the stator, and surrounds the rotor with a clearance. At least one of the wear rings is designed eccentrically.

An assembly for filtering a fluid includes a first rotatable shaft with a first set of splines. The first rotatable shaft has an internal cavity containing the fluid. Also included is a second rotatable shaft with a second set of splines mated to the first set of splines. The second rotatable shaft includes at least a portion of a supply hole. The first rotatable shaft and the second rotatable shaft are configured to convey the fluid from the internal cavity through a tight clearance between the first set of splines and the second set of splines, to filter the fluid, and then out the supply hole.

A magnetic drive, seal-less combination axial air and water pump includes a housing having an inlet and an outlet at least one impeller mounted for rotation within the housing, and a magnetic drive surrounding the first rotor and the second rotor, the magnetic drive being configured to transmit torque to the first rotor and a second rotor at a location radially spaced from a central axis of the first rotor and the second rotor.

An electrical submersible pump (ESP) assembly. The ESP assembly comprises an electric motor having a first drive shaft; a seal section having a second drive shaft that is coupled to the first drive shaft; a third drive shaft that is coupled to the second drive shaft; and an axial flow centrifugal pump stage, wherein the centrifugal pump stage comprises an impeller coupled to the third drive shaft and a diffuser, wherein the impeller defines a plurality of impeller vanes attached between an impeller hub and an impeller shroud, wherein the impeller shroud is a straight-walled cylindrical shape, wherein the diffuser defines a plurality of diffuser vanes attached between a diffuser hub and a diffuser shroud, and wherein the diffuser shroud is a straight-walled cylindrical shape.

An impellor assembly for a liquid hydrogen pump. The assembly comprises a shaft, one or more impellors mounted to the shaft, a fastener configured to engage with the shaft at a first engagement point and with the one or more impellor at a second engagement point to axially clamp the one or more impellor to the shaft, an axially unconstrained length of the fastener being defined by an axial distance between the first and second engagement points. An axial extent of a clamped portion of the one or more impellors corresponds to the axially unconstrained length of the fastener. The fastener and the impellor comprise a material having a first coefficient of thermal expansion and the shaft comprises a material having a second coefficient of thermal expansion, wherein the first and second coefficients of thermal expansion are different.

In this pump apparatus, each of plural gate marks formed in a second blade member is formed at an intermediate position in a circumferential direction of a rotor between two blades that are adjacent to each other in the circumferential direction of the rotor, and the even number of blades are disposed between the gate marks in the circumferential direction of the rotor. The plural gate marks are disposed on an outer side, in the radial direction of the rotor, of an outer circumferential surface of a portion, which is connected to the second blade member, in a magnet holding member formed in a tubular shape.