Drilling turbine
AssigneeSmith International, Inc.
InventorsAndrew McPherson Downie, Guido Ernesto Pezzani, Edward Docherty Scott
Life of this patent
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Abstract
A turbine is disclosed which includes a turbine blade housing having an inner facing portion of a first material having a first coefficient of expansion, and a turbine blade body having an outer facing portion of a second coefficient of expansion greater than said first coefficient. In a preferred embodiment, the blade housing comprises a number of steel shroud rings and the turbine blade body comprises a number of stators and rotors of a thermoplastic material. An interference fit between stator blades and the shroud rings is enhanced in use due to the difference in thermal and/or hydrophilic coefficients of expansion of the first and second materials.
Claims17
A turbine as claimed in claim 1, wherein the first and second coefficients of expansion are hydrophilic coefficients of expansion of the materials.
A turbine as claimed in claim 1, wherein the outer facing portion of the turbine blade body comprises part of one or more of the turbine blades.
A turbine as claimed in claim 1, wherein the outer facing portion of the turbine blade body comprises a circumferential skirt around a plurality of the turbine blades.
A turbine as claimed in claim 1, wherein the turbine blade housing and the turbine blade body are entirely of said first and second materials, respectively.
A turbine as claimed in claim 1, wherein the turbine blade housing is of a first material comprising a steel, and wherein the turbine blade body is of a second material comprising an at least partly polymeric material.
A turbine as claimed in claim 1, wherein the turbine blade body is of a second material comprising a glass fibre filled nylon (GFFN).
A turbine as claimed in claim 1, wherein the turbine blade body is of a second material comprising a glass fibre filled polyetheretherketone (PEEK).
A turbine as claimed in claim 1, wherein the turbine blade body is of a second material comprising a glass fibre polyphenylenesulfide (PPS).
A turbine as claimed in claim 1, wherein the turbine is an axial flow fluid driven turbine of a downhole drilling assembly.
A turbine as claimed in claim 1, wherein the turbine blade body further comprises a stator, the stator including a stator ring having a tubular blade skirt from which stator turbine blades extend substantially radially outwardly to be disposed against the inner facing portion of the turbine blade housing.
A turbine as claimed in claim 1, wherein the turbine blade body further comprises a rotor, the rotor including a rotor blade skirt from which rotor turbine blades extend substantially radially outwardly.
A turbine as claimed in claim 1, wherein the turbine comprises a plurality of stator and rotor rings located alternately along the turbine blade housing.
A turbine as claimed in claim 1, wherein the turbine blade housing comprises a number of tubular shroud rings of the second material.
A turbine as claimed in claim 1, wherein the turbine blade body is disposed against the turbine blade housing in an interference fit.
A drilling assembly including a turbine as defined in claim 1.
An at least partly polymeric rotor and stator for use in a turbine as claimed in claim 1.
Dependencies are inferred from the claim text.