Stepped Balance Ring for a Submersible Well Pump

摘要

An electrical submersible pump assembly includes a centrifugal pump having stages. Each of the stages has an impeller in cooperative engagement with a downstream diffuser. The impeller is axially movable relative to the downstream diffuser between a downthrust and an upthrust position. The downstream diffuser has an annular downstream wall surface, relative to the impeller, defining a downstream cavity. The impeller has a downstream balance ring that locates alongside the downstream wall surface. An annular clearance between the downstream balance ring and the downstream wall surface increases in response to the impeller moving from the downthrust to the upthrust position.

主权项

1. A submersible pump assembly, comprising:
a submersible motor; a centrifugal pump operatively connected to the motor, the pump having a longitudinal axis and a plurality of stages, each of the stages comprising: an impeller in cooperative engagement with a downstream diffuser, the impeller being axially movable relative to the downstream diffuser between a downthrust and an upthrust position; the downstream diffuser having an annular downstream wall surface, relative to the impeller, defining a downstream cavity; the impeller having a downstream balance ring that locates alongside the downstream wall surface; and an annular clearance between the downstream balance ring and the downstream wall surface that increases in response to the impeller moving from the downthrust to the upthrust position.