Abrasion resistant centrifugal pump

In a centrifugal pump having a housing, a driven shaft extending along a longitudinal axis, a plurality of pumping stages, each stage having a diffuser mounted stationarily in the housing and an impeller having a hub through which the shaft extends for rotating the impeller, the improvement comprising in combination:

• a stationary member on at least one of the diffusers, having an upward facing stationary bearing surface and a bore;
• a runner having a cylindrical portion which is rotatably carried in the bore of the stationary member and an upper flange which has a lower surface which engages the stationary bearing surface;
• key means for causing the runner and impellers to rotate with the shaft but allowing axial movement relative to the shaft;
• and
• a tension member having a downward facing shoulder on an upper end which engages the runner and extends downward through a selected number of the stages, the tension member having a plurality of upward facing load shoulders spaced along its length, each of the upward facing load shoulders extending radially outward between two of the hubs and supporting one of the hubs against downthrust, whereby downthrust on each of the impellers transfers to the tension member and through the tension member to the runner and stationary bearing surface.

In a centrifugal pump having a housing, a driven shaft extending along a longitudinal axis, a plurality of pumping stages, each stage having a diffuser mounted stationarily in the housing and an impeller having a hub through which the shaft extends for rotating the impeller, the pump having at least one module having a selected number of the stages and comprising in combination:

• at least one stationary member on one of the diffusers, having an upward facing stationary bearing surface;
• a runner having a bore which receives the shaft for rotation with the shaft and a lower surface which engages the stationary bearing surface;
• and
• a tension sleeve extending from the runner downward through the stages, the tension sleeve having a plurality of upward facing load shoulders spaced along its length, each of the upward facing load shoulders extending radially outward between two of the hubs and supporting one of the hubs against downthrust, whereby downthrust on each of the impellers transfers to the tension member and through the tension member to the runner and stationary bearing surface.

In a centrifugal pump having a driven shaft extending along a longitudinal axis and a plurality of pumping stages, each stage having an impeller mounted to the shaft for rotation therewith and a stationary diffuser, the pump having at least one module containing a plurality of the stages and comprising in combination:

• an upward facing stationary bearing surface supported by one of the diffusers of the module;
• a runner which rotates with the shaft and has a downward facing bearing surface which engages the stationary bearing surface;
• and
• a load transfer member in engagement with the runner and having a plurality of upward facing load shoulders spaced along its length, each of the load shoulders supporting one of the impellers, whereby downthrust on each of the impellers transfers through one of the load shoulders to the load transfer member, and through the load transfer member to the runner and the stationary bearing surface.

In a centrifugal pump having a driven shaft extending along a longitudinal axis, a plurality of pumping stages, each stage having a stationary diffuser and a rotatable impeller, the improvement comprising in combination:

• a counterbore formed in at least one of the diffusers;
• a stationary thrust bearing mounted stationarily in the counterbore, the stationary thrust bearing having a bore and an upper bearing surface;
• a runner having a cylindrical portion which is rotatably carried in the bore and a flange which has lower surface which engages the upper bearing surface of the stationary thrust bearing;
• a plurality of keys located between the shaft and the runner and the shaft and the impellers for causing the runner and the impellers to rotate with the shaft but allowing axial movement relative to the shaft;
• and
• a load transfer member having a downward facing shoulder which engages the runner, the load transfer member extending through a selected number of the stages, the load transfer member having a plurality of upward facing load shoulders spaced along its length, each of the upward facing load shoulders extending radially outward between two of the impellers and supporting one of the impellers against thrust, whereby thrust on each of the impellers transfers to the load transfer member and through the load transfer member to the runner and thrust bearing.

In a centrifugal pump having a driven shaft extending along a longitudinal axis, a plurality of pumping stages, each stage having a stationary diffuser and a rotatable impeller mounted to the shaft for rotation therewith, the pump having at least one thrust module having a selected number of the stages and comprising in combination:

• at least one stationary thrust bearing mounted stationarily to one of the diffusers and having an upper bearing surface;
• a runner having a bore which receives the shaft for rotation with the shaft and a lower surface which engages the upper bearing surface of the stationary thrust bearing;
• and
• a load transfer sleeve extending from the runner through the stages, the load transfer sleeve having a plurality of upward facing load shoulders spaced along its length, each of the upward facing load shoulders extending radially outward between two of the impellers and supporting one of the impellers against thrust, whereby thrust on each of the impellers transfers to the load transfer sleeve and through the load transfer sleeve to the runner and thrust bearing.