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Patent Searching and Data


Title:
PRESSURE COMPENSATION SYSTEM FOR AN OIL-SEALED MUD MOTOR BEARING ASSEMBLY
Document Type and Number:
WIPO Patent Application WO/2012/094460
Kind Code:
A3
Abstract:
In an oil-sealed bearing assembly in the bearing section of a mud motor, in which a mandrel (20) is rotatably disposed within a cylindrical housing (30), a cylindrical sleeve (90) is disposed coaxially and rotatably around the mandrel (20), with the sleeve (90) being non-rotatably mounted to an inner surface of the housing, thereby fonning an annular piston chamber (70) forming part of a generally annular oil reservoir. The sleeve (90) provides radial support to the mandrel (20) along the length of the piston chamber by virtue of the flexural stiffness of the sleeve (90). The mandrel (20) rotates within the sleeve (90), with a radial bearing being provided between the sleeve and the mandrel. An annular piston (80) is axially movable within the piston chamber (70) in response to variations in the volume of oil in the reservoir. The piston (80) slides within the piston chamber (70) without rotation relative to either the housing or the sleeve.

Inventors:
MARCHAND NICHOLAS (CA)
Application Number:
PCT/US2012/020279
Publication Date:
August 01, 2013
Filing Date:
January 05, 2012
Export Citation:
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Assignee:
NAT OILWELL VARCO LP (US)
MARCHAND NICHOLAS (CA)
International Classes:
E21B4/00; E21B4/02; F03C2/08; F04C2/107; F04C13/00; F04C15/00; F16C17/02; F16C33/74; F16C43/02
Foreign References:
US6250806B12001-06-26
US4577704A1986-03-25
US5385407A1995-01-31
US5248204A1993-09-28
Attorney, Agent or Firm:
FALESKI, Thaddeus J. (P.C.P.O. Box 326, Houston Texas, US)
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