Abstract: The embodiments of the present disclosure provide a method for troubleshooting potential safety hazards of a compressor in a smart gas pipeline network and an Internet of Things system thereof. The method comprises: performing a purification process on sound data of a gas compressor, and determining a target sound feature; establishing a feature data vector library based on networked data and reference device data; determining a current gas data vector and a current device data vector based on gas data and device data, respectively; searching the feature data vector library based on the current gas data vector and the current device data vector, and determining a reference sound feature and a reference vibration feature that meet a preset condition as a standard sound feature and a standard vibration feature; and predicting whether there is a safety hazard in the gas compressor using a hazard model.

Abstract: A centrifugal compressor includes: a housing including an intake flow path; a compressor impeller arranged in the intake flow path; an accommodation chamber formed upstream of the compressor impeller in a flow of intake air in the housing; a movable member arranged in the accommodation chamber; and an annular path formed in the housing, the annular path being connected to an outside of the housing, a heating medium supplied from the outside of the housing flowing through the annular path, at least a part of the annular path being located between the accommodation chamber and a leading edge of the compressor impeller.

Abstract: In general, techniques are described for fused filament fabrication of abradable coatings. An additive manufacturing system comprising a substrate defining a major surface, a filament delivery device, and a computing device may be configured to perform various aspects of the techniques. The computing device may be configured to control the filament delivery device to deposit a filament on the substrate, the filament including a powder and a binder, wherein the binder is configured to be substantially removed from the filament and the powder includes a metal or alloy configured to be sintered to form an abradable layer.

Abstract: A compressor system includes: a compressor having an upstream region into which a working fluid flows, a downstream region in which the pressure of the working fluid is greater than that in the upstream region, inlet guide vanes that are provided further upstream than the upstream region and capable of altering the flow rate of the inflowing working fluid, and an extraction part that is provided to a portion between the upstream region and the downstream region and capable of extracting at least a portion of the working fluid; detection devices, at least one of which is provided in each of the upstream region and the downstream region, for detecting the physical quantity of the working fluid; and a control device for adjusting, on the basis of changes in the physical quantity, the opening degree of the inlet guide vanes and the amount extracted by the extraction part.

Abstract: The embodiments of the present disclosure provide a method for safety management of a compressor in a smart gas pipeline network and an Internet of Things system thereof. The method is implemented based on a smart gas safety management platform of an Internet of Things system for safety management of a compressor in a smart gas pipeline network. The method comprises: obtaining sound data and a target vibration feature of a gas compressor, and determining a target sound feature based on the sound data; obtaining gas data and device data, and determining a standard sound feature and a standard vibration feature based on the gas data and the device data; and predicting whether there is a safety hazard in the gas compressor based on the target vibration feature and the standard vibration feature, or based on the target sound feature and the standard sound feature.

Abstract: A gas turbine engine for an aircraft. The engine including: an engine core with a turbine, a compressor, a fan located upstream of the compressor and including a plurality of fan blades, and a core shaft connecting the turbine to the compressor; a gearbox which receives an input from the core shaft and outputs drive, via a driveshaft, to the fan so as to drive the fan at a lower rotational speed than the turbine, the drive shaft and core shaft forming a shaft system.

Abstract: Examples described herein provide a computer-implemented method that includes receiving training data indicative of incipient compressor surge for cabin air compressors. The method further includes generating, using the training data, a training spectrogram. The method further includes training, by a processing system, a machine learning model to detect incipient compressor surge events for the cabin air compressors using the spectrogram. The method further includes receiving, at a microcontroller associated with a cabin air compressor, operating data associated with the cabin air compressor. The method further includes generating, at the microcontroller and using the operating data, an operating spectrogram. The method further includes detecting, by the microcontroller associated with the cabin air compressor, an incipient compressor surge event by applying the machine learning model to the operating spectrogram.

Abstract: Methods, apparatus, systems, and articles of manufacture are to control air flow separation of an engine. An example turbofan includes a nacelle having an outer lip surface, an inner lip surface, a first opening and a second opening, the first opening coupled to a first region forward of a fan of the turbofan, the second opening coupled to a second region aft of the fan, the nacelle including a first pressure sensor coupled to the outer lip surface, a second pressure sensor coupled to the inner lip surface, and an actuator, and a conduit coupled to the actuator, the conduit configured to have a first end and a second end, the first end coupled to the first opening, the second end coupled to the second opening.

Abstract: The invention relates to a method for determining a balancing removal process for a balancing device for balancing a rotationally symmetrical component, particularly a rotor component, particularly of a turbomachine, a combination of machining lengths and depths being calculated, taking into account a pre-defined maximum machining length and minimum machining depth, in such a way that, with reliable combinations for compensating the same unbalance, the machining length of the calculated combination is longer than the machining length of at least one other permissible combination and, at the same time, the machining depth of the calculated combination is shallower than the machining depth of said other combination.

Abstract: A method of optimizing probe placement in a turbomachine is disclosed which includes establishing a design matrix A of size m×(2N+1) utilized in developing flow properties around an annulus of a turbomachine, where m represents the number of datapoints at different circumferential locations around the annulus, and N represents dominant wavelets generated by upstream and downstream stators and blade row interactions formed around an annulus, wherein m is greater or equal to 2N+1, and optimizing probe positioning by iteratively modifying probe positions placed around the annulus and for each iteration determining a condition number of the design matrix A for each set of probe positions until a predetermined threshold is achieved for the condition number representing an optimal probe layout.

Abstract: A small gas turbine engine, such as is used to power a UAV, that includes at least one centrifugal compressor having an impeller with blades that form a gap between the blade tips and stationary shroud of the gas turbine engine, and where a resistance heating element, such as an impingement air manifold, is secured to or bonded to a compressor casing of the gas turbine engine in order to use heat to control the gap between the impeller blades and the stationary shroud. The resistance heating element is activated at cruise mode to move the shroud toward the impeller. Additionally or alternatively, the compressor casing is heated with bled-off compressed air to move the shroud toward the impeller. A capacitance tip clearance sensor can be mounted on the impeller shroud to monitor and control tip clearance in real time.

Abstract: A wind tunnel test equipment using wind force integration includes: a structural model whose interior is empty; an internal support disposed inside the structural model; and load sensors disposed outside the internal support and coming into close contact with the inner surfaces of the structural model to measure aerodynamic forces applied to the structural model.

Abstract: A method for detecting at least one roughness in a face of an abradable layer in a fan casing is provided. The method includes a step of depositing on the abradable layer a first coating and a second coating covering the first coating. The first and second coatings have respective thicknesses (N1, N2) and a physical appearance that differ from one another. Local appearance of the first coating is indicative of a need for a localized touch-up, and local disappearance of the first coating and the second coating is indicative of a need for a localized replacement of the abradable layer.

Abstract: An example thermal management system may include a first heat exchanger including a bleed air inlet configured to receive input bleed air from a gas turbine engine and a bleed air outlet configured to output cooled bleed air. A turbine including a turbine inlet may be fluidically coupled to the bleed air outlet. The turbine may be configured to drive a shaft mechanically coupled to the turbine in response to expansion of the cooled bleed air through the turbine. A second heat exchanger may include an expanded bleed air inlet fluidically coupled to a turbine outlet of the turbine. The second heat exchanger may be configured to extract heat from at least one heat source using the expanded bleed air.

Abstract: Disclosed is a generating facility management device capable of automatically calculating and determining inspection intervals of generating facilities using a system. In an example embodiment, the generating facility management device calculates inspection intervals of unit devices constituting each of the generating facilities using a time code index, a stressor index and a degradation mechanism index.

Abstract: An elongate air delivery assembly having a housing extending between two end caps. The housing includes a plurality of exit vents from which airflow is provided in a consistent sheet at a uniform velocity, and the housing is rotatable about a central longitudinal axis to change a direction of the airflow. A method of improving plant cultivation includes positioning one or more elongate air delivery systems adjacent rows of plants such that the sheet of air generated by the elongate air delivery system is directed horizontally across the plants underneath their plant canopy.

Abstract: Methods and systems for operating a gas turbine engine in a multi-engine aircraft are described. The method comprises operating the gas turbine engine in a standby mode to provide substantially no motive power to the aircraft when another engine of the multi-engine aircraft is operated in an active mode to provide motive power to the aircraft, transitioning the gas turbine engine from the standby mode to the non-standby mode, and applying pulse width modulation to an air switching system of the gas turbine engine while transitioning the gas turbine engine from the standby mode to the non-standby mode.

Abstract: A compressor that vibrates a rotary shaft or changes an operating frequency of a motor, in response to a vibration frequency of a discharge passage falling outside of a normal range. The compressor may include one or more impeller configured to draw in and compress refrigerant; a motor configured to rotate the one or more impeller; a rotary shaft, to which the one or more impeller and the motor are coupled; at least two thrust bearings that limit vibration of the rotary shaft; a vibration measuring sensor configured to measure a vibration frequency of a discharge passage; and a controller configured to control the at least two thrust bearings based on the vibration frequency. Upon determining that the vibration frequency falls outside of a normal vibration frequency range, the controller controls the at least two thrust bearings to vibrate the rotary shaft a predetermined number of times.

Abstract: A gas turbine engine includes, among other things, a fan, a fan drive gear system that is coupled with the fan and a fan drive input shaft, a compressor section that includes a first compressor and a second compressor, and a turbine section. The turbine section includes a first turbine coupled with a first shaft and a second turbine coupled through a second shaft to the second compressor. A bearing supports the fan drive input shaft. The bearing is located proximal to, and radially spaced from, a forward end of the first shaft. The bearing includes a speed sensor target that is rotatable with the forward end and that defines a rotation path. A speed sensor probe is situated proximal to the rotation path and is operable to read the speed sensor target.

Abstract: A blade damage evaluation apparatus includes: a registration unit for design information of a turbine and maintenance information; an acquisition processor for detection data of sensors; a first discrimination processor for first facility states of the turbine at a plurality of past time points; a classification processor for classes Cn of a plurality of first facility states; a first determination processor for first operating state values of the turbine; another registration unit for first damage rates at past time points; a setting processor of a characteristic function for each of the classes Cn; a second discrimination processor for a second facility state of the turbine at the current time point; a second determination processor for a second operating state value of the turbine at the current time point; and an analyzer for a second damage rate at the current time point.

Abstract: A smart watch and a method for measuring a pulse information are provided in the present disclosure. The smart watch includes a dial, a watchband, a blood vessel information collecting apparatus, and a processing apparatus. The watchband is connected with the dial. The blood vessel information collecting apparatus is disposed in the watchband and is configured to collect a blood vessel information from an inner side of a wrist of a user. The processing apparatus is connected with the blood vessel information collecting apparatus and is configured to receive and process the blood vessel information to obtain the pulse information of the user.

Abstract: Cooling a torque probe involves an elongated sleeve extending along a sleeve axis between a first sleeve end and a second sleeve end. The sleeve is mountable about the torque probe to define a flow passage between an inner surface of the sleeve and an outer surface of the torque probe. The flow passage is in fluid communication with a flow passage inlet of the sleeve and with a flow passage outlet of the sleeve spaced apart along the sleeve axis from the flow passage inlet. A cooling airflow is configured to flow into the flow passage via the flow passage inlet, through the flow passage along the outer surface of the torque probe to cool the torque probe, and out of the flow passage via the flow passage outlet.

Abstract: The invention relates to a method for determining a fluid conveying parameter, a fluid conveying device, particularly for determining a volumetric flow, comprising the steps of Determining excitation information for mechanical excitation of at least one fluid conveying element of the fluid conveying device in at least one spatial direction by at least one first sensor means, Providing operating information, comprising at least a value of an operating variable of the fluid conveying device by means of a providing means, Analyzing the information provided and determined, Determining a fluid conveying parameter, particularly a volumetric flow, of the fluid conveying device based on the analyzed information.

Abstract: Borescope plugs are described. The borescope plugs include a borescope plug base having a first side configured to support a shank and a second side having a centroid defined as the center of the borescope plug base, a first mounting aperture formed in the second side, and a second mounting aperture formed in the second side. The first and second mounting apertures are configured to each receive a fastener to mount the borescope plug base to a case, and an offset line drawn through the center of the first mounting aperture and through the center of the second mounting aperture does not pass through the centroid or does not include a point defined by the centroid.

Abstract: A method of controlling a blood pump including executing a control command to temporarily displace an impeller of the blood pump within a pump housing from a first axial position relative to the pump housing to a second axial position a distance away from the first axial position using a vector control method, and causing the impeller to move from the second axial position to a third axial position, the third axial position including a positive and a negative displacement of the impeller relative to the first axial position.

Abstract: Disclosed are systems and methods for active inlet turbine control. The systems and methods may include receiving a plurality of signals, determining a temperature gradient across an inlet of a gas turbine engine, and transmitting an activation signal to a modulating valve. Each of the plurality of signals may correspond to a temperature measured by one of a plurality of sensors located proximate the inlet of the gas turbine engine. The temperature gradient across the inlet of the gas turbine engine may be determined based on the plurality of signals. The activation signal may be operative to open or close the modulating valve based on the temperature gradient.

Abstract: The invention describes an optical rotary transmitter with at least two housing parts, which are mounted so as to be rotatable relative to one another about an axis of rotation. An interior space is enclosed together with the at least two housing parts to be fluid impermeable manner by a membrane which completely encloses the interior space along one portion along the axis of rotation in a circumferential direction about the axis of rotation. The membrane is arranged so that at least portions of the surface of the membrane facing away from the interior space are accessible.

Abstract: A method for inspecting a gas turbine engine using a maintenance tool includes assembling a plurality of rail segments of a rail system of the maintenance tool within a core air flowpath of the gas turbine engine. The gas turbine engine includes a compressor section, a combustion section, and a turbine section together defining at least in part the core air flowpath. The method also includes moving a maintenance head of the maintenance tool along the plurality of rail segments of the rail system to perform maintenance operations within the core air flowpath of the gas turbine engine.

Abstract: Methods and systems for detecting and correcting improper operation of a compressor in a refrigeration system and/or an HVAC system include a component level detection and prevention and a system level detection and prevention. The system level detection and prevention can be a backup or a confirmation of the component level detection and prevention. The component level detection and prevention can detect and prevent improper compressor operation within a predetermined time so that the compressor's operation period in an improper direction can be minimized, thereby minimizing wear and damage to the compressor.

Abstract: A maintenance tool for gas turbine engine includes a rail system having a plurality of rail segments insertable through one or more inspection holes of the gas turbine engine for assembly within a core air flowpath of the gas turbine engine. The maintenance tool additionally includes a maintenance head movable along the plurality of rail segments of the rail system for performing maintenance operations within the core air flowpath.

Abstract: A method of assembling a fan wheel includes forming a first wheel portion including a first plurality of impeller blades and a first connector, forming a second wheel portion including a second plurality of impeller blades and a second connector, affixing an end of each of the first plurality of impeller blades to a first surface of a support ring such that the first connector is affixed to the second connector, and affixing an end of each of the second plurality of impeller blades to a second surface of a support ring.

Abstract: A method of controlling at least a part of a start-up or re-light process of a gas turbine engine, the method comprising: controlling rotation of a low pressure compressor using a first electrical machine to increase angular velocity of the low pressure compressor; and controlling rotation of a high pressure compressor using a second electrical machine to restrict angular velocity of the high pressure compressor while the angular velocity of the low pressure compressor is increased.

Abstract: The invention concerns a method for controlling a control valve (20) of a turbomachine operating at an engine speed at a cruise value (Vc) and oscillating around the cruise value (Vc) of same, the method being implemented by a calculation unit (40), and being characterised in that it comprises a step of determining a position control for the control valve (20), filtered of the oscillations of the engine speed around the cruise value (Vc).

Abstract: A system can include a housing that defines an interior space; a shaft disposed at least in part in the interior space of the housing where the shaft includes a longitudinal axis, a curved surface and an end surface; a submersible electric motor operatively coupled to the shaft where the submersible electric motor includes a cable connector; two proximity sensors where each of the proximity sensors includes a sensor aperture disposed in the interior space of the housing; and circuitry operatively coupled to the proximity sensors that determines position values of the shaft with respect to time based at least in part on output of the proximity sensors.

Abstract: A sensor simultaneously determines a maximum rub depth and running clearance of a plurality of blade tips in a jet engine. The sensor includes an inductive component (e.g. inductor) and a resistive component comprising resistor portions each indicative of a depth into a layer of abradable material near the blade tips. When the blade tips move in proximity to the inductor, eddy currents in the blades generates a magnetic field that interact with the magnetic field generated by the inductor, which appears as an AC component in the current. When the blade tips abrade the abradable material, the resistor portions are severed and the DC current changes due to a change in resistance at the resistive component. An amplitude of the AC component indicates a running clearance as the blades move in proximity to the inductor. The frequency of the AC component indicates the rotational speed of the blades.

Abstract: Method and system for implementing health monitoring of downhole tool without disassembly is presented in this disclosure. Investigative equipment can be installed in an exterior housing of the downhole tool so that the investigative equipment is in communication with an interior of the downhole tool. The tool can be positioned in a functional test system so that the tool is at least partially enclosed within the functional test system, and efficiency of the tool can be determined by operating the functional test system. The investigative equipment can be utilized to perform diagnostics on a condition of an internal component on the interior of the tool, and the health of the tool can be predicted based on the determined efficiency and the diagnostics.

Abstract: A shroud segment (100) for disposition on a blade of a turbomachine is provided, in particular a gas turbine, the shroud segment having a stiffening structure raised above a shroud segment surface (15), the stiffening structure including at least three interconnected ribs (3, 5, 7), and a first end portion of the ribs (3, 5, 7) being connected to an upstream sealing tip (11) of the shroud segment (100), and a second end portion of these ribs (3, 5, 7) being connected to a downstream sealing tip (13) of the shroud segment (100). The angles (W1, W2, W3) between the direction of the axis of rotation (a) of the blade and the longitudinal orientations (21, 23, 25) of the ribs (3, 5, 7), as viewed in the direction of flow (9) through the turbomachine, are between zero degrees and eighty degrees. The present invention also relates to a blade (200) of a turbomachine.

Abstract: A luminous fan includes a fan frame, a main circuit board, a light guide element and a light-guiding impeller. The main circuit board is disposed on a bracket of the fan frame and includes a first light-emitting element. The light guide element is located over the main circuit board, and includes a light input surface and light output surface. A light guide post is disposed on the light input surface. A reflective structure is formed on the light output surface. The light-guiding impeller is pivotally coupled to the bracket. The first light-emitting element emits a first light beam. After the first light beam is transmitted to the reflective structure through the light guide post, the first light beam is reflected by the at least one reflective structure and diffused toward a middle region of the light guide element.

Abstract: A method for monitoring an aircraft engine vane wheel (22), which includes: acquiring at least one time signal relative to moments when the vane wheel blades (23) pass in front of a sensor (21); determining a common flight phase of the aircraft; for each flight in a series of flights of the aircraft, correlating at least part of each time signal with a predetermined flight phase; and for each blade (23), each flight, and each predetermined flight phase, measuring the mean position (24C), the so-called “balance position”, of the top of the blade. The invention also relates to a device for implementing such a method. One advantage of the invention is providing a diagnosis of the blades using a small number of sensors and low computing power.

Abstract: A shroud for an aircraft having a noise reducing material on or in an inner surface of the shroud adjacent to one or more tips of the propeller. The noise reducing material is preferably an electrospun nanomaterial, particularly a ridged composite acoustic nanofibre. The interior surface of the shroud may be provided with a plurality of sound deflectors configured to dissipate sound by reflection and refraction, and absorb sound into the shroud body. The sound deflectors may be ribs or arrangements of discrete reflector elements.

Abstract: The subject matter of the present disclosure is directed to a turbine engine having an adaptive prognostic health management control system that passively monitors stall margin reductions and applies corrective trims to a power management schedule of the engine to recover operability over time whilst maintaining a sufficient level of stall margin over the life cycle of the engine. The control system can adjust the power management schedule as needed to sustain a target stall margin, which allows for a more optimized and gradual performance to operability trade-off.

Abstract: In combination a blade clearance sensor and a radial flow separation wall of a gas turbine engine is provided. The blade clearance sensor is embedded in the radial flow separation wall. The radial flow separation wall comprising: a splitter hoop located radially outward from blades in a first flow path of the gas turbine engine, the splitter hoop being about concentric to a blade path of the blades; and one or more guide vane bases attached to a guide vane located radially outward from the splitter hoop in a second flow path, each of the one or more guide vane bases being securely attached to a radially outward surface of the splitter hoop, wherein the blade clearance sensor is configured to detect a blade clearance between the blades and the splitter hoop.

Abstract: Method of reducing loads acting on a wind turbine yaw system in a wind turbine comprising a nacelle (2), a rotor which comprises at least one rotor blade (3) with a pitch control system and further comprising a yaw system that comprises the steps of detecting a yaw misalignment (?), enabling a yaw maneuver and performing a pitch control in order to reduce a yaw moment (Mz) acting on the wind turbine once the yaw misalignment (?) is detected and prior to enabling the yaw maneuver. Thus, when a yaw movement to reduce the yaw misalignment is commanded, the yaw moment (Mz) due to aerodynamic forces has been reduced by means of the pitch control and undesired yaw movements are prevented.

Abstract: A method for outputting control instructions to at least one first wind power installation or at least one first wind farm using an evaluation device or for outputting an event message relating to an operating state of the at least one first wind power installation or the at least one first wind farm using the evaluation device is provided. Data is received by the evaluation device from at least one further wind power installation or from at least one further wind farm and the control instructions or the event messages are generated by evaluating the data and are output by the evaluation device. An evaluation device and a system having the evaluation device for carrying out the method are also provided.

Abstract: A housing includes a pressure relief door and a deflector. The pressure relief door includes a first door end disposed at a first hinge axis of the housing and an opposing second door end. The pressure relief door is rotatable between a first door position and a second door position about the first hinge axis and defines a portion of the housing in the first door position. The deflector includes a first deflector end disposed at a second hinge axis of the housing and an opposing second deflector end. The deflector is rotatable between a first deflector position and a second deflector position about the second hinge axis. Rotation of the pressure relief door from the first door position to the second door position effects rotation of the deflector from the first deflector position to the second deflector position.

Abstract: Disclosed are systems and methods for active inlet turbine control. The systems and methods may include receiving a plurality of signals, determining a temperature gradient across an inlet of a gas turbine engine, and transmitting an activation signal to a modulating valve. Each of the plurality of signals may correspond to a temperature measured by one of a plurality of sensors located proximate the inlet of the gas turbine engine. The temperature gradient across the inlet of the gas turbine engine may be determined based on the plurality of signals. The activation signal may be operative to open or close the modulating valve based on the temperature gradient.

Abstract: A vane (18) has an airfoil section (19) that extends in a radial direction and an outer shroud (20) that is disposed on the radially outward side of the airfoil section (19), and is supported inside a casing by means of a vane support member (24). The outer shroud (20) has a shroud body (31), radial protrusions (36, 37), and a hook section (32) including the radial protrusions (36, 37) and engaging parts (39, 40). A recessed part (50), which is recessed in an axial direction or in the radial direction, is provided in at least a part of the circumference of the hook section (32). The engaging part (39) has a sealing surface that continues along the entire circumference thereof, the sealing surface coming into contact with the vane support member (24) in the radial direction.

Abstract: A fan frame includes a housing, a shaft tube, a circuit board and a plurality of light-emitting elements. The housing includes a base and a plurality of connection members located between the base and a peripheral wall of the housing. The shaft tube is mounted on the base. The circuit board is mounted in the housing and includes a body having a through-hole. The circuit board is fit around the shaft tube via the through-hole and is integrally formed with a plurality of protruding ribs and at least one outer rib. Each protruding rib is aligned with a respective connection member. Each outer rib is located between two adjacent protruding ribs. The light-emitting elements are mounted on the protruding ribs and the outer rib. A fan including the fan frame is also disclosed.

Abstract: The ventilation apparatus (20) according to the invention comprises a fan (30) including a rotary machine (32) and a fan wheel (34), an observation module, a module for connecting the device (20) to a power source (12), the fan wheel (34) being set in rotation by the rotary machine (32) when the apparatus (20) is connected to the power source (12), and rotating freely when the apparatus (20) is disconnected from the power source (12). The device (20) further includes an internal power module electrically connected between the rotary machine (32) and the observation module, the internal power module being able to recover an electric current generated by the rotary machine (32) driven by the fan wheel (34), to power the observation module (62), when the apparatus (20) is disconnected from the power source (12).

Abstract: A turbine-engine compressor, in particular for an aircraft turboprop engine or turbojet engine, comprising an annular casing and at least one annular row of variable-pitch blades, each blade comprising a radially external end comprising a pivot mounted in an orifice in the casing and connected by a link to a control ring able to pivot axially about its axis with respect to the casing. Each link comprises a first end fixed to the pivot of the blade and a second end mounted so as to be able to pivot on the control ring. The pivot axes of first and second links on the control ring are offset from each other along the axis of the compressor, the second end of the second link being mounted on the ring by a connecting member, allowing a connection of the sliding or annular linear pivot type.