# US 8,784,043 B2 · Device for controlling variable-pitch blades in a turbomachine compressor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,784,043 B2 - Document ID: US8784043B2 - Status: Granted - Kind: B2 - Application number: 12/937,137 - Filed: 2009-04-10 - Published: 2011-02-10 - Granted: 2014-07-22 - Earliest claimed: 2008-04-24 - Assignees: Snecma - Applicants: Michel Andre Bouru - Inventors: Michel Andre Bouru - Web page: https://patentgrep.com/patent/US8784043B2 ## CPC - F04D 29/563: {specially adapted for elastic fluid pumps} - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) ## Abstract A device for controlling variable-pitch blades in a turbomachine compressor, including at least one control ring surrounding an external casing of the compressor, and a control shaft connected to the ring and to the rod of an actuator, the body of which is mounted such that it can pivot about an axle borne by a support mechanism of the control shaft so as to guarantee a precise relative positioning of the axis of pivoting of the actuator with respect to the control shaft. ## Claims ### Claim 1 A device for controlling variable-pitch blades in a turbomachine compressor, comprising: a control ring connected to a control shaft and rotatably mounted about an external casing of the compressor and to be connected by connecting rods to variable-pitch blades; and a cylinder, wherein a cylinder body can pivot about a fixed axis and wherein a movable rod is connected to the control shaft by connecting rod means carried by the control shaft guided in rotation by supporting members attached to the casing, wherein the pivoting axis of the cylinder body is carried by at least one tab attached on the casing, and wherein the cylinder body comprises a first cylindrical radial blade foot guided in rotation in an orifice of a first tab rigidly connected to one of the supporting members of the control shaft, and a second cylindrical radial blade foot, diametrically opposing said first blade foot, and guided in rotation in an orifice of a second tab which is attached to one of the casing and the first tab, with no pivotal support of the control shaft by the second tab. ### Claim 2 (depends on 1) A device according to claim 1, wherein each blade foot is integral with the cylinder body. ### Claim 3 (depends on 1) A device according to claim 1, wherein the control shaft is supported and guided in rotation by V-shaped supporting members attached to annular flanges of the casing. ### Claim 4 (depends on 1) A device according to claim 1, wherein the control shaft is connected to the cylinder and to the control ring by radial arms with which the control shaft is rotatably rigidly connected. ### Claim 5 (depends on 4) A device according to claim 4, wherein the control shaft is connected by two radial arms, with which the control shaft is rotatably rigidly connected, to two parallel control rings, for control of two annular rows of variable-pitch blades. ### Claim 6 (depends on 1) A device according to claim 1, wherein the pivoting axis of the cylinder is situated substantially mid-way from ends of the cylinder body or in a vicinity of one end of the cylinder body, situated on a side of the rod of the cylinder. ### Claim 7 (depends on 1) A turbomachine compressor, comprising at least one device for controlling variable-pitch blades according to claim 1. ### Claim 8 (depends on 1) A turbomachine, or an aircraft turbojet, or a turboprop, comprising at least one device for controlling variable-pitch blades according to claim 1. ### Claim 9 (depends on 1) A device according to claim 1, wherein the second blade foot is engaged in an eccentric guide ring housed in the orifice of the second tab to compensate for any misalignment between the orifices of the two attachment tabs. ### Claim 10 (depends on 1) A device according to claim 1, wherein each blade foot is integral with the cylinder body. ### Claim 11 A device for controlling variable-pitch blades in a turbomachine compressor, comprising: a control ring connected to a control shaft and rotatably mounted about an external casing of the compressor and to be connected by connecting rods to variable-pitch blades; and a cylinder, wherein a cylinder body can pivot about a fixed axis and wherein a movable rod is connected to the control shaft by connecting rod means carried by the control shaft guided in rotation by supporting members attached to the casing, wherein the pivoting axis of the cylinder body is carried by at least one tab attached on the casing, wherein the cylinder body comprises a first cylindrical radial blade foot guided in rotation in an orifice of a tab rigidly connected to one of the supporting members of the control shaft, and a second cylindrical radial blade foot, diametrically opposing the first blade foot, and guided in rotation in an orifice of a second tab attached on the casing, and wherein the second blade foot is engaged in an eccentric guide ring housed in the orifice of the second tab to compensate for any misalignment between the orifices of the two attachment tabs. ### Claim 12 (depends on 11) A device according to claim 11, wherein two radially grooved washers are engaged on the eccentric ring and inserted between the second tab and an external annular rim of the ring, one of the washers being rigidly connected in rotation with the tab and comprising radial grooves engaging with complementary radial grooves of the other washer which is locked in rotation on the ring. ### Claim 13 (depends on 12) A device according to claim 12, wherein the washers are clamped axially between the tab and the annular rim of the ring by an insert attached to the tab and pressing axially on the annular rim of the ring, on the side opposite the tab. ### Claim 14 A device for controlling variable-pitch blades in a turbomachine compressor, comprising: a control ring connected to a control shaft and rotatably mounted about an external casing of the compressor and to be connected by connecting rods to variable-pitch blades; and a cylinder, wherein a cylinder body can pivot about a fixed axis and wherein a movable rod is connected to the control shaft by connecting rod means carried by the control shaft guided in rotation by supporting members attached to the casing, wherein the pivoting axis of the cylinder body is carried by at least one tab attached on the casing, and wherein the cylinder body comprises two diametrically opposed radial blade feet defining the pivoting axis of the cylinder body and received in orifices or notches of two tabs of a supporting clamp attached on the casing, each blade foot being further connected by a connecting rod to the control shaft. ### Claim 15 (depends on 14) A device according to claim 14, wherein each connecting rod connecting a blade foot to the control shaft comprises at one end an orifice wherein the blade foot is guided in rotation and at the opposite end thereof an orifice whereby the connecting rod is rotatably mounted on the control shaft. ### Claim 16 (depends on 14) A device according to claim 14, wherein both connecting rods are situated between the supporting members. ### Claim 17 (depends on 14) A device according to claim 14, wherein the control shaft is connected to the movable rod and to the control ring by radial arms with which the control shaft is rotatably rigidly connected. ### Claim 18 A device for controlling variable-pitch blades in a turbomachine compressor, comprising: a control ring connected to a control shaft and rotatably mounted about an external casing of the compressor and to be connected by connecting rods to variable-pitch blades; and a cylinder, wherein a cylinder body can pivot about a fixed axis and wherein a movable rod is connected to the control shaft by connecting rod means carried by the control shaft guided in rotation by supporting members attached to the casing, wherein the pivoting axis of the cylinder body is carried by at least one tab attached on the casing, and wherein the cylinder body comprises one cylindrical radial blade foot only, guided in rotation in an orifice of a connecting tab rigidly connected to one of the supporting members of the control shaft which is V-shaped and is attached to the casing by ends of said V-shape.