# US 8,147,187 B2 · Control of variable-pitch blades > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,147,187 B2 - Document ID: US8147187B2 - Status: Granted - Kind: B2 - Application number: 12/035,254 - Filed: 2008-02-21 - Published: 2008-08-28 - Granted: 2012-04-03 - Earliest claimed: 2007-02-22 - Assignees: Snecma - Inventors: Christelle Foucher - Web page: https://patentgrep.com/patent/US8147187B2 ## CPC - F01D 17/162: {for axial flow, i.e. the vanes turning around axes which are essentially perpendicular to the rotor centre line (F01D17/167 takes precedence)} - F02C 9/22: by adjusting turbine vanes - F04D 29/563: {specially adapted for elastic fluid pumps} - F05D 2250/241: spherical - F05D 2260/74: by turning around an axis perpendicular the rotor centre line - F05D 2260/79: Bearing, support or actuation arrangements therefor - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A device for controlling a pivot of a variable-pitch blade in a stator of a turbomachine compressor is disclosed. The device for controlling a pivot of a variable-pitch blade includes a control lever and a pivot with a bottom end and a top end. The top end is connected to the control lever. The device also includes a first swivel bearing placed at the bottom end of the pivot and a second swivel bearing placed at the top end of the pivot. ## Claims ### Claim 1 A device for controlling a pivot of a variable-pitch blade comprising: a control lever; a blade pivot with a bottom end and a top end, said top end being connected to the control lever; and first and second swivel bearings, the first swivel bearing being placed at the bottom end of the pivot and the second swivel bearing being placed at the top end of the pivot, wherein each of the first and second swivel bearings includes an inner race with a spherical outer surface and an outer race with a spherical inner surface, the spherical outer surface of the inner race cooperating with the spherical inner surface of the outer race to form a swivel connection, wherein the inner race of the swivel bearings and the pivot are prevented from rotating relative to one another. ### Claim 2 (depends on 1) The device for controlling a pivot of a variable-pitch blade as claimed in claim 1, wherein the pivot comprises at least one flat on its outer surface, the inner surface of the inner race comprising a matching shape. ### Claim 3 (depends on 1) The device for controlling a pivot of a variable-pitch blade as claimed in claim 1, wherein the pivot has a tenon shape and the inner shape of the inner race has a mortice shape. ### Claim 4 (depends on 1) The device for controlling a pivot of a variable-pitch blade as claimed in claim 1, wherein the pivot and the inner race of the swivel bearings have matching square-shaped sections. ### Claim 5 (depends on 2, 3, 4) The device for controlling a pivot of a variable-pitch blade as claimed in one of claims 2 to 4, wherein a plastic film is interposed between the pivot and an inner surface of the inner race of the swivel bearings. ### Claim 6 (depends on 1) A stator comprising a casing with an axis of revolution comprising at least one bore made along a radial axis oriented perpendicularly to said axis of revolution, which also comprises: at least one control device as claimed in claim 1, and at least one blade oriented along the radial axis placed inside the casing, said blade being fixedly attached to the pivot via the bottom end of said pivot, the swivel bearings being placed inside the bore. ### Claim 7 (depends on 6) The stator as claimed in claim 6, wherein the bore comprises at least one facing designed to receive a swivel bearing. ### Claim 8 (depends on 6, 7) The stator as claimed in one of claim 6 or 7, wherein the attachment of a swivel bearing in the bore may be carried out by shrink-fitting, welding or brazing. ### Claim 9 (depends on 6) The stator as claimed in claim 6, wherein the bottom end of the pivot has an increasing diameter. ### Claim 10 A compressor comprising: a stator including: a casing with an axis of revolution comprising at least one bore made along a radial axis oriented perpendicularly to said axis of revolution; at least one control device including a control lever; a blade pivot with a bottom end and a top end, said top end being connected to the control lever; and first and second swivel bearings, the first swivel bearing being placed at the bottom end of the pivot and the second swivel bearing being placed at the top end of the pivot; and at least one blade oriented along the radial axis placed inside the casing, said blade being fixedly attached to the pivot via the bottom end of said pivot, wherein each of the first and second swivel bearings includes an inner race with a spherical outer surface and an outer race with a spherical inner surface, the spherical outer surface of the inner race cooperating with the spherical inner surface of the outer race to form a swivel connection, and wherein the swivel bearings being placed inside the bore, pivot are prevented from rotating relative to one another. ### Claim 11 A turbomachine comprising: a compressor including a stator, the stator including: a casing with an axis of revolution comprising at least one bore made along a radial axis oriented perpendicularly to said axis of revolution; at least one control device including a control lever; a blade pivot with a bottom end and a top end, said top end being connected to the control lever; and first and second swivel bearings, the first swivel bearing being placed at the bottom end of the pivot and the second swivel bearing being placed at the top end of the pivot; and at least one blade oriented along the radial axis placed inside the casing, said blade being fixedly attached to the pivot via the bottom end of said pivot, wherein each of the first and second swivel bearings includes an inner race with a spherical outer surface and an outer race with a spherical inner surface, the spherical outer surface of the inner race cooperating with the spherical inner surface of the outer race to form a swivel connection, and wherein the swivel bearings being placed inside the bore, wherein the inner race of the swivel bearings and the pivot are prevented from rotating relative to one another. ### Claim 12 (depends on 1) The device for controlling a pivot of a variable-pitch blade as claimed in claim 1, wherein the inner race of each of the first and second swivel bearings has a cylindrical inner surface. ### Claim 13 (depends on 12) The device for controlling a pivot of a variable-pitch blade as claimed in claim 12, wherein the cylindrical inner surface of the inner race of each of the first and second bearings abuts the pivot. ### Claim 14 (depends on 1) The device for controlling a pivot of a variable-pitch blade as claimed in claim 1, wherein the outer race of each of the first and second swivel bearings has a cylindrical outer surface. ### Claim 15 (depends on 1) The device for controlling a pivot of a variable-pitch blade as claimed in claim 1, wherein the top end of the blade pivot includes a threaded rod which cooperates with a nut and a washer to connect the top end of the blade pivot to the control lever.