Metal Bellows with Guide Rings

摘要

A well pump assembly has a pump driven by an electrical motor. A seal section reduces a pressure difference between a dielectric lubricant in the motor and a hydrostatic well fluid Pressure. The seal section has a housing containing a guide tube concentric with the axis. Contractible and extensible inner and outer bellows surround the guide tube. An inner bellows guide ring is secured to the inner bellows between ends and has an inner surface with an inner diameter smaller than a minimum inner diameter of the inner bellows for sliding engagement with an outer surface of the guide tube as the inner bellows lengthens and contracts. The outer bellows has a guide ring secured between ends and having an outer surface with an outer diameter larger than a maximum outer diameter of the outer bellows for sliding engagement with an inner surface of the housing.

主权项

1. A well pump assembly for pumping well fluid from a well, comprising:
a pump; an electrical motor operatively coupled to the pump for driving the pump; a seal section operatively coupled to the motor for reducing a pressure difference between a dielectric lubricant in the motor and a hydrostatic well fluid pressure on an exterior of the motor, the seal section comprising: a guide member having a longitudinal axis and a cylindrical guide surface; a bellows coaxial with the guide member and having a flexible corrugated wail that is closely spaced to the guide surface and moves axially relative to the guide surface when the bellows contracts and extends; and a guide ring secured to the wall of the bellows between ends of the bellows, the guide ring having a contacting surface protruding slightly from the wall and slidingly engaging the guide surface as the bellows contracts and extends.