Actuator, turbomachine and aircraft comprising such an actuator, and corresponding actuation method
The actuator design addresses slow motion dynamics and integration issues by using a two-way servovalve with a large passage area to achieve rapid and controlled movements, suitable for aircraft applications.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- SAFRAN POWER UNITS
- Filing Date
- 2022-12-13
- Publication Date
- 2026-06-05
Smart Images
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Abstract
Description
Title of the invention: Actuator, turbomachine and aircraft comprising such an actuator, and corresponding actuation method technical field
[0001] The present invention relates to the technical field of high-speed actuators.
[0002] In particular, the present invention relates to an actuator, a turbomachine and an aircraft containing such an actuator, as well as a corresponding actuation method. Previous techniques
[0003] Certain applications, particularly aerial applications, require actuators with rapid movement dynamics, which some actuators do not have.
[0004] For example, an electropneumatic actuator has a slower motion dynamic than a fuel actuator.
[0005] A fuel actuator is, for example, a hydraulic actuator controlled from a pressure taken from a fuel circuit supplying the combustion of a gas turbine.
[0006] Implementing a fuel actuator on a machine requires a complex machine architecture. The fuel requirement of the fuel actuator can lead to an oversizing of the machine's fuel circuit, potentially resulting in leaks or a sloshing effect.
[0007] The machine can create an environment of high temperatures and intense vibrations, making the integration of the actuator difficult and potentially preventing the implementation of certain types of actuators, such as an electric actuator. Description of the invention
[0008] The present invention therefore aims to overcome all or part of the aforementioned drawbacks and to provide a fast-moving dynamic actuator compatible with the thermal and vibratory conditions of an aircraft.
[0009] The invention relates to an actuator comprising a cylinder including a rod equipped with a piston at least partially delimiting a first and a second chamber, the actuator comprising a first and a second fluid line fluidly connected to the first chamber, an elastic return means to a predetermined position disposed in one of the first and second chambers and configured to exert a force on the piston, the first fluid line comprising a calibrated orifice, the actuator comprising a two-way servovalve fluidly connected to the second fluid line, a passage section of the servovalve being greater than or equal to ten times a passage cross-section of the calibrated orifice or the pressure loss in the first fluid line being greater than or equal to ten times the pressure loss in the second fluid line.
[0010] The large passage area of the servovalve compared to the reduced passage area of the calibrated orifice makes it possible to obtain a large dynamic of a movement of the piston in a first direction, in particular during the return of the elastic means to the predetermined position, and a lower dynamic of another movement of the piston in a second direction opposite to the first direction.
[0011] The use of the two-way servovalve ensures a simple actuator design.
[0012] The actuator design is compatible with the thermal and vibrational conditions of an aircraft.
[0013] The actuator may include a common conduit opening into the first chamber, the first and second fluid conduits being fluidly connected to the common conduit.
[0014] The two-way servovalve may include an electromagnetic control.
[0015] In one embodiment, the two-way servovalve is configured to have at least one passing state so that a fluid can flow in the second fluid line through the two-way servovalve and a blocking state so that a fluid cannot flow in the second fluid line through the two-way servovalve.
[0016] The two-way servovalve may include a proportional control configured to position the piston in an intermediate position of a piston stroke.
[0017] The piston can be associated with a sealed rolling membrane to seal the first and second chambers.
[0018] The passage area of the two-way servovalve can be more than twenty times the passage area of the calibrated orifice.
[0019] The invention also relates to a turbomachine comprising an actuator as defined above, a first fluid source and a second fluid source, one of the first and second fluid lines being configured to draw a first fluid from the first fluid source, the other fluid line being configured to draw a second fluid from the second fluid source, the pressure of the first fluid being greater than the pressure of the second fluid.
[0020] The first fluid source may include a compressor, the second fluid comprising air under atmospheric pressure.
[0021] The present invention also relates to an aircraft comprising an actuator as defined above and / or a turbomachine as defined above.
[0022] The present invention also relates to an actuation method implemented by an actuator as defined above, or by a turbomachine as defined above, or by an actuator included in an aircraft as defined above, comprising the following steps: - change of state of the two-way servovalve so that the two-way servovalve is in a first state; - displacement of the piston and rod in a first direction at a first speed, said displacement being due to a first difference in forces acting on the piston depending at least on the pressure in the first chamber and the force exerted by the elastic return means on the piston;
[0023] and / or - a change of state of the two-way servovalve such that the two-way servovalve is in a second state; and - displacement of the piston and rod in a second direction opposite to the first direction at a second speed different from the first speed, said displacement being due to a second difference of forces acting on the piston depending at least on the pressure in the first chamber and the force exerted by the elastic return means on the piston. Brief description of the drawings
[0024] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:
[0025] [Fig.1] schematically illustrates an aircraft comprising a turbomachine and an actuator according to the invention;
[0026] [Fig.2] schematically illustrates an actuator according to a first embodiment of the invention;
[0027] [Fig.3] schematically illustrates an actuator according to a second mode of action implementation of the invention; and
[0028] [Fig.4] schematically illustrates an actuation method according to the invention. Detailed description
[0029] Figure 1 schematically represents an aircraft 2, for example a helicopter or an airplane, comprising an auxiliary turbomachine 4 such as, for example, the turbomachine of an auxiliary power unit (APU). Such an auxiliary turbomachine 4 is distinct from the turbomachines dedicated to the propulsion of the aircraft, but like the latter, it comprises moving parts requiring actuation. These moving parts, also called "variable geometries," are, for example, guide vanes. an inlet or IGV (Inlet Guide Vane) in Anglo-Saxon terminology and / or an anti-pumping valve. Aircraft 2 includes, for example, a starting valve and / or an auxiliary power unit for pressurized air regulation, requiring actuation. Consequently, the aircraft includes at least one actuator 6. The use of an actuator 6 according to the invention is not, however, limited to the scope of an auxiliary turbomachine 4; the actuator 6 can be implemented in a turbomachine of a main engine (i.e., dedicated to the propulsion of the aircraft) or even in an aircraft air system (air conditioning, de-icing, etc.) drawing pressurized air from a turbomachine.
[0030] Fig. 2 schematically represents a first embodiment of actuator 6.
[0031] The actuator 6 comprises a cylinder 8 including a rod 10 equipped with a piston 12. The piston 12 delimits within the cylinder 8 a first chamber 14 and a second chamber 16. The rod 10 is configured to perform a longitudinal movement within the cylinder 8. In the example shown, the rod 10 extends from the piston 12 into the second chamber 16 and passes through a first wall 18 of the cylinder 8. Alternatively, the rod 10 could extend from the piston 12 into the first chamber 14 and pass through a second wall 20 of the cylinder 8 opposite the first wall 18, the cylinder 8 then comprising a sealing element to ensure the sealing of the first chamber 14 at the level of the second wall 20.
[0032] The cylinder 8 includes a first fluid line 22 fluidly connected to the first chamber 14, the first fluid line 22 being here directly connected to the first chamber 14. The cylinder 8 includes a second fluid line 24 fluidly connected to the first chamber 14, the second fluid line 24 being here directly connected to the first chamber 14.
[0033] The cylinder 8 includes an elastic return means 26 in a predetermined position disposed in the second chamber 16 and capable of exerting a force on the piston 12, the elastic return means 26 comprising for example a helical spring surrounding the rod 10 so as to exert a longitudinal force on the piston 12 during the longitudinal movement of the piston 12. Alternatively, the elastic return means 26 may be disposed in the first chamber 14.
[0034] The first and second fluid conduits 22, 24 are, for example, tubular conduits of constant cross-section.
[0035] The first fluid conduit 22 includes a calibrated orifice 28 comprising, for example, a restricting orifice locally reducing the cross-section of the first fluid conduit 22 so that the first fluid conduit 22 locally has a smaller cross-section than a constant cross-section of the second fluid conduit 24. The calibrated orifice 28 is particularly suitable for modifying the pressure and / or flow rate of a fluid circulating in the first fluid line 22, said fluid preferably being gaseous. The actuator 6 includes a two-way servovalve 30 fluidically connected to the second fluid line 24. In a particular embodiment, the two-way servovalve 30 is directly connected to the second fluid line 24 such that a fluid flowing from a first end 32 of the second fluid line 24 to a second end 34 of the second fluid line 24 necessarily flows through the two-way servovalve 30, the first end 32 being here directly connected to the first chamber 14.
[0036] The flow of a fluid through the first fluid line 22 is limited by a cross-sectional area of the calibrated orifice 28, while the flow of a fluid through the second fluid line 24 is limited by a cross-sectional area of the two-way servovalve 30, the cross-sectional area of the two-way servovalve 30 being greater than or equal to ten times the cross-sectional area of the calibrated orifice. Alternatively, the ratio of the two cross-sectional areas may be less than ten, provided that the pressure drop in the first fluid line 22 is greater than or equal to ten times the pressure drop in the second fluid line 24.
[0037] Preferably, the two-way servovalve 30 includes an electromagnetic control 36. The electromagnetic control 36 is compact, requires low electrical power for operation, and offers high responsiveness. Alternatively, the two-way servovalve 30 may include a hydraulic or electrical control.
[0038] In this first embodiment, the two-way servovalve 30 comprises only a first state and a second state. For example, the first state corresponds to a passing state of the two-way servovalve 30, that is to say a state in which a fluid can flow through the two-way servovalve 30 and therefore through the second fluid conduit 24, the second state corresponding to a blocking state of the two-way servovalve 30, that is to say a state in which a fluid cannot flow through the two-way servovalve 30 and therefore through the second fluid conduit 24.
[0039] Advantageously, the piston 12 includes a sealing element configured to prevent fluid circulation between the first and second chambers 14, 16. In the example shown, the actuator 6 includes a sealing roll-up diaphragm 38 associated with the piston 12, the piston 12 and the roll-up diaphragm 38 delimiting the first and second chambers 14, 16 and preventing fluid transfer between the first and second chambers 14, 16.
[0040] The actuator 6 includes a first fluid source 40 and a second fluid source 42.
[0041] The first fluid conduit 22 is capable of drawing a first fluid under a first pressure. The first fluid is, for example, air under high pressure, in particular air under a pressure at least twice that of air at atmospheric pressure. The first fluid is, for example, taken from the first fluid source 40. Preferably, the first fluid source 40 is located near the actuator 6 so as to reduce the length of the first fluid line 22. In the example shown, the first fluid is taken from a compressor, not shown, of a propulsion engine of the aircraft 2. Alternatively, the first fluid can be taken from another fluid source of the propulsion engine, for example, from a fan.
[0042] Advantageously, the calibrated orifice 28 of the first fluid line 22 allows the actuator 6 to be very little disturbing to the first fluid source 40. The first fluid line 22 then draws a small quantity of fluid from the first fluid source 40, the energy requirement of the first fluid source 40 being slightly increased.
[0043] The second fluid line 24 is capable of drawing a second fluid at a second pressure. The second fluid is, for example, drawn from the second fluid source 42. In the example shown, the second fluid source 42 is the atmosphere, the second fluid being the air in which the aircraft 2 is moving, the second fluid therefore being at a lower pressure than the first fluid. The second fluid line 24 then discharges the fluid from the first chamber 14 and the first fluid line 22 into the atmosphere.
[0044] When the two-way servovalve 30 is in the blocked state, the fluid flow in the second fluid line 24 is zero or very low; only the first fluid line 22 is capable of injecting pressurized fluid into the first chamber 14. The pressure in the first chamber 14 increases when the first fluid is injected into the first chamber 14, thus exerting a force on the piston 12 against the elastic return means 26 and an external force from the member controlled by the actuator 6. If the force exerted by the pressure in the first chamber 14 on the piston is sufficiently high, then the piston 12 is set in motion towards the first wall 18.This movement continues until an equilibrium of forces on the piston 12 depends on the force exerted by the elastic return means 26 on the piston 12, the flow rate of fluid circulating in the first fluid conduit 22 and the flow rate of fluid circulating in the second fluid conduit 24.
[0045] When the two-way servovalve 30 is in the open state, the fluid contained in the first chamber 14 is able to flow from the first end 32 of the second fluid line 24 to the second end 34 of the second fluid line 24. If the fluid pressure in the first chamber 14 is sufficiently When the pressure is high, the fluid contained in the first chamber 14 suddenly escapes from the first chamber 14 through the second fluid line 24, causing the pressure in the first chamber 14 to decrease rapidly. The force exerted by the elastic return means 26 on the piston 12 is then greater than the force exerted by the fluid pressure in the first chamber 14 on the piston 12. The piston 12 then moves rapidly towards the second wall of the cylinder 20, the rapid movement of the piston 12 depending at least on the force exerted by the elastic return means 26 on the piston 12, the difference in cross-sectional area of the first and second fluid lines 22, 24 related to the calibrated orifice 28 and the two-way servovalve 30, and an external force from the element controlled by the actuator 6.This movement continues until an equilibrium of forces on the piston 12 depends at least on the force exerted by the elastic return means 26 on the piston 12, the flow rate of fluid circulating in the first fluid conduit 22 and the flow rate of fluid circulating in the second fluid conduit 24.
[0046] In the example of [Fig. 2], the movement of the piston 12 towards the first wall 18 when the two-way servovalve 30 changes from the open to the closed state is slower than the movement of the piston 12 towards the second wall 20 when the two-way servovalve 30 changes from the closed to the open state. The difference in speed between these two movements depends primarily on the ratio between a section of the first fluid line 22, including the calibrated orifice 28, and a section of the second fluid line 24, including the two-way servovalve 30, as well as on the ratio between the first and second pressures. The stiffness of the elastic return means 26 can also influence this difference in speed.The maximum speed of the movement of the piston 12 towards the second wall 20 when the two-way servovalve 30 passes into the open state is guaranteed by the passage area of the two-way servovalve 30 being greater than or equal to ten times the passage area of the calibrated orifice 28. Simultaneously or alternatively, to guarantee the desired speed difference between these two movements, the pressure drop in the first fluid line 22 can be provided to be greater than or equal to ten times the pressure drop in the second fluid line 24. Optionally, the passage area of the two-way servovalve 30 is greater than twenty times the passage area of the calibrated orifice 28 to ensure that the movement of the piston 12 towards the second wall 20, when the two-way servovalve 30 passes into the open state, is much faster than the movement of the piston 12 towards the first wall 18, when the two-way servovalve 30 passes into the closed state.For example, the passage area of the two-way servovalve 30 is on the order of twenty-five times the passage area of the calibrated orifice 28.
[0047] Preferably, the cylinder 8 includes a position sensor 44 measuring the position of the rod 10 of the cylinder 8, the actuator 6 comprising a control unit 46 configured to emit a control signal to control the state of the two-way servovalve 30. For example, the position sensor 44 communicates the position of the rod 10 of the cylinder 8 to the control unit 46, the control unit 46 emitting the control signal according to the communicated position.
[0048] Advantageously, the two-way servovalve 30 is configured so that in the absence of the control signal, for example during an electrical failure of the control unit 46 or of the two-way servovalve 30, the actuator 6 goes into a rest position, the rest position making it possible in particular to address safety issues by positioning the rod 10 of the cylinder 8 in a position that reduces the risks of damage to the actuator 6 and / or the turbomachine 4 and / or the aircraft 2. For example, the two-way servovalve 30 is configured to be in the conducting state in the absence of a command in order to quickly place the actuator 6 into the rest position.
[0049] Fig. 3 schematically represents a second embodiment of actuator 6.
[0050] The actuator 6 includes a common conduit 48 opening into the first chamber 14. The first and second fluid conduits 22, 24 are fluidically connected to the common conduit 48, the first end 32 of the second fluid conduit 24 being directly connected to the common conduit 48. This embodiment simplifies the construction of the actuator 6 and is also compatible with the embodiment of [Fig.2].
[0051] The first fluid line 22 is suitable for drawing the second fluid under the second pressure from the second fluid source 42, the second fluid line 24 being suitable for drawing the first fluid under the first pressure from the first fluid source 40. The first fluid line 22 includes the calibrated orifice 28.
[0052] The two-way servovalve 30 includes the conducting state and the blocking state.
[0053] Advantageously, the two-way servovalve 30 is configured to be in a blocking state in the absence of command in order to quickly place the actuator 6 in the rest position.
[0054] When the two-way servovalve 30 is in the open state, the first fluid drawn from the first fluid source 40 is able to flow from the second end 34 of the second fluid line 24 to the first end 32 of the second fluid line 24, and then from the first end 32 of the second fluid line 24 to the first chamber 14. If the pressure of the first fluid is sufficient, then the first fluid enters the first chamber 14 abruptly, and the pressure in the first chamber 14 increases rapidly. The force exerted by the fluid pressure in the first chamber 14 on the piston 12 is then sustained greater than the sum of the force exerted by the elastic return means 26 on the piston 12 and the external force of the organ controlled by the actuator 6. The piston 12 then moves rapidly towards the first wall 18 of the cylinder 8, the rapid movement being here against the force exerted by the elastic return means 26 on the piston 12. This movement continues until an equilibrium of forces on the piston 12 depends at least on the force exerted by the elastic return means 26 on the piston 12, the flow rate of fluid circulating in the first fluid line 22 and the flow rate of fluid circulating in the second fluid line 24.
[0055] When the two-way servovalve 30 is in the blocked state, the fluid flow in the second fluid line 24 is zero or very low; only the first fluid line 22 is able to allow the fluid from the first chamber 14 to escape from the cylinder 8. The pressure in the first chamber 14 decreases when the fluid from the first chamber 14 escapes from the first chamber 14 through the first fluid line 22. If the force exerted by the elastic return means 26 on the piston 12 is sufficiently high compared to the force exerted by the fluid pressure in the first chamber 14 on the piston 12, then the piston 12 is set in motion towards the second wall 20.This movement continues until an equilibrium of forces on the piston 12 depends at least on the force exerted by the elastic return means 26 on the piston 12, the flow rate of fluid circulating in the first fluid conduit 22 and the flow rate of fluid circulating in the second fluid conduit 24.
[0056] In the example of [Fig. 3], the movement of the piston 12 towards the first wall 18 when the two-way servovalve 30 enters the open state is faster than the movement of the piston 12 towards the second wall 20 when the two-way servovalve 30 enters the closed state. The greater speed of the movement of the piston 12 towards the first wall 18 when the two-way servovalve 30 enters the open state is ensured by the passage area of the two-way servovalve 30 being greater than or equal to ten times the passage area of the calibrated orifice 28. Simultaneously or alternatively, to guarantee the desired speed difference between these two movements, the pressure drop in the first fluid line 22 can be provided to be greater than or equal to ten times the pressure drop in the second fluid line 24.The pressure drop in the common line 48 will preferably be comparable to or less than that in the second fluid line 24. Optionally, the passage area of the two-way servovalve 30 is greater than twenty times the passage area of the calibrated orifice 28 to ensure that the movement of the piston 12 towards the first wall 18 when the two-way servovalve 30 passes into the open state is much faster than the movement of the piston 12 towards the second wall 20 when the two-way servovalve 30 passes into the closed state.
[0057] Advantageously, the two-way servovalve 30 includes a proportional control 50 suitable for positioning the piston 12 in an intermediate position of the piston 12 stroke. For example, the control unit 46 of the actuator 6 controls the proportional control 50 of the two-way servovalve 30 in an intermediate flow state so as to control the air flow through the two-way servovalve 30 and thus the second fluid line 24.
[0058] The control unit 46 is configured to control the position of the piston 12 of the cylinder 8. The control unit 46 includes a control algorithm for controlling the position of the piston 12, in particular based on the position data from the position sensor 44. The control unit 46 allows the piston 12 to be quickly positioned at an intermediate position within the stroke of the piston 12.
[0059] The two-way servovalve 30 cooperates with the first and second fluid conduits 22, 24 and with the elastic return means 26 to place the piston 12 in the intermediate position of the piston stroke 12 when the two-way servovalve 30 is in the intermediate flow state.
[0060] The intermediate position corresponds to an equilibrium of the forces exerted on the piston 12 depending on a stiffness of the elastic return means 26, a flow rate of fluid circulating in the first fluid conduit 22 and a flow rate of fluid circulating in the second fluid conduit 24 when the two-way servovalve 30 is in the intermediate flow state.
[0061] Fig. 4 schematically represents an actuation method implemented by actuator 6.
[0062] During a first state change step 52 of the two-way servovalve 30, the operating state of the two-way servovalve 30 is changed so that the two-way servovalve 30 is in a first state.
[0063] The first state includes, for example, a passing state or a blocking state or an intermediate flow state of the two-way servovalve 30.
[0064] Then, during a first displacement step 54 of the piston 12, the piston 12 and the rod 10 of the cylinder 8 are moved in a first direction at a first speed, for example to bring the piston 12 closer to the first wall 18 or the second wall 20. The displacement of the piston 12 during step 54 is due to a first difference in forces acting on the piston 12 depending at least on the pressure in the first chamber 14 and the force exerted by the elastic return means 26 on the piston 12. An external force must also be taken into account, for example an external force from the component controlled by the actuator 6. Preferably, the displacement of the piston 12 during step 54 ends when an equilibrium of the forces acting on the piston 12 is reached.
[0065] Consequently, during a second state change step 56 of the two-stage servovalve channels 30, we modify the operating state of the two-way servovalve 30 so that the two-way servovalve 30 is in a second state.
[0066] The second state includes, for example, a passing state or a blocking state or an intermediate flow state of the two-way servovalve 30.
[0067] Finally, during a second displacement step 58 of the piston 12, the piston 12 and the rod 10 of the cylinder 8 are moved in a second direction opposite to the first direction at a second speed, for example, to bring the piston 12 closer to the second wall 20 or the first wall 18. The displacement of the piston 12 during step 58 is due to a second difference in forces acting on the piston 12, depending at least on the pressure in the first chamber 14 and the force exerted by the elastic return means 26 on the piston 12, in addition to the external force also being taken into account. Preferably, the displacement of the piston 12 during step 58 ends when an equilibrium of the forces acting on the piston 12 is reached.
[0068] Step 52 includes, for example, in the case of the embodiment shown in [Fig. 2], the transition of the two-way servovalve 30 from the open to the closed state when the piston 12 is in a fixed open state position corresponding to the end of a first transient regime of the movement of the piston 12. Step 54 then includes the movement of the piston 12 from the fixed open state position towards the first wall of the cylinder 18, the movement of the piston 12 ending when the piston 12 is in a fixed closed state position corresponding to the end of a second transient regime of the movement of the piston 12.
[0069] Step 56, for example, in the case of the embodiment shown in [Fig. 2], involves the transition of the two-way servovalve 30 from the blocked to the open state when the piston 12 is in the established blocked position. Step 58 then involves the movement of the piston 12 from the established blocked position towards the second wall of the cylinder 20, the movement of the piston 12 ending when the piston 12 is in the established open position. In this example, the movement of the piston 12 during step 54 is slower than the movement of the piston during step 58.
[0070] Of course, steps 54 and 58 may include moving the piston 12 from the intermediate position of the piston 12 stroke to another position, or moving the piston 12 from the other position to the intermediate position of the piston 12 stroke, or any other movement of the piston 12.
[0071] The actuation method comprises, in order, steps 52, 54, 56 and 58. Alternatively, such an actuation method may comprise only steps 52 and 54 or 56 and 58. Alternatively, the method may also comprise, in order, steps 56, 58, 52 and 54.
Claims
Demands
1. Turbomachine (4) comprising an actuator (6) comprising a cylinder (8) comprising a rod (10) provided with a piston (12) delimiting at least partially within the cylinder (8) a first and a second chamber (14, 16), the actuator (6) comprising a first and a second fluid line (22, 24) fluidly connected to the first chamber (14), an elastic return means (26) in a predetermined position disposed in one of the first and second chambers (14, 16) and configured to exert a force on the piston (12), the first fluid line (22) comprising a calibrated orifice (28), the actuator (6) comprising a two-way servovalve (30) fluidly connected to the second fluid line (24),a two-way servovalve passage cross-section (30) being greater than or equal to ten times a calibrated orifice passage cross-section (28) or the pressure drop in the first fluid line (22) being greater than or equal to ten times the pressure drop in the second fluid line (24), the turbomachine (4) comprising a first fluid source (40) and a second fluid source (42), one of the first and second fluid lines (22, 24) being configured to draw a first fluid from the first fluid source (40), the other fluid line (24, 22) being configured to draw a second fluid from the second fluid source (42), the pressure of the first fluid being greater than the pressure of the second fluid, characterized in that the first fluid source (40) comprises a compressor of the turbomachine (4), the second fluid comprising air at atmospheric pressure.
2. Turbomachine (4) according to claim 1, wherein the actuator (6) comprises a common conduit (48) opening into the first chamber (14), the first and second fluid conduits (22, 24) being fluidly connected to the common conduit (48).
3. Turbomachine (4) according to any one of claims 1 and 2, wherein the two-way servovalve (30) includes an electromagnetic control (36).
4. Turbomachine (4) according to any one of claims 1 to 3, wherein the two-way servovalve (30) is configured to have at least one conducting state such that a fluid can flow in the second fluid line (24) through the two-way servovalve ways (30) and a blocking state so that a fluid cannot flow in the second fluid line (24) through the two-way servovalve (30).
5. Turbomachine (4) according to any one of claims 1 to 4, wherein the two-way servovalve (30) includes a proportional control (50) configured to position the piston (12) in an intermediate position of a piston stroke (12).
6. Turbomachine (4) according to any one of claims 1 to 5, wherein the piston (12) is associated with a sealed uncoiling diaphragm (38) to hermetically separate the first and second chambers (14, 16).
7. Turbomachine (4) according to any one of claims 1 to 6, wherein the passage area of the two-way servovalve (30) is greater than twenty times the passage area of the calibrated orifice (28).
8. Aircraft (2) comprising a turbomachine (4) according to any one of the preceding claims.
9. An actuation method implemented by an actuator (6) included in a turbomachine (4) according to any one of claims 1 to 7, or by an actuator (6) included in a turbomachine (4) included in an aircraft (2) according to claim 8, comprising the following steps: - changing the state of the two-way servovalve (30) such that the two-way servovalve (30) is in a first state; - moving the piston (12) and the rod (10) in a first direction at a first speed, said movement being due to a first difference in forces acting on the piston (12) depending at least on the pressure in the first chamber (14) and the force exerted by the elastic return means (26) on the piston (12); and / or - changing the state of the two-way servovalve (30) such that the two-way servovalve (30) is in a second state; and - displacement of the piston (12) and the rod (10) according to a second direction opposite to the first direction at a second speed different from the first speed, said displacement being due to a second difference of forces acting on the piston (12) depending at least on the pressure in the first chamber (14) and on the force exerted by the elastic return means (26) on the piston (12).