Valve for a rocket engine

Abstract

Valve designed for large flow rates and high pressures, and a rocket engine comprising such a valve, the valve comprising a valve body (11), having a first path (I) and a second path (II), a movable shut-off member (40) configured to adjust the flow cross section between the first path (I) and the second path (II), and an electrical actuator (50) configured to adjust the position of the shut-off member (40), wherein the shut-off member (40) is able to move linearly between a first position and a second position, wherein the actuator (50) comprises a rotor (51) installed in a service cavity (15) of the valve body (11), the service cavity (15) being in fluidic communication with the first path (I) or the second path (II), and wherein the actuator (50) is configured to move the shut-off member (40) via a rotary-linear transmission member (60).

Description

Description Title of the invention: VALVE FOR ROCKET MOTOR Technical Field

[0001] This presentation concerns a valve designed for high flow rates and high pressures. Such a valve is particularly well-suited for rocket engines, especially for controlling the flow of cryogenic propellant into the combustion chamber. However, this type of valve is also perfectly suitable for less demanding applications, such as in the aerospace or naval sectors. Previous technique

[0002] A cryogenic rocket engine operates by burning two propellants, most often liquid hydrogen (LH2) and liquid oxygen (LOX), within a combustion chamber. A classic, intentionally simplified example of a rocket engine is shown in Figure 1.

[0003] Such a rocket engine 1 thus comprises a combustion chamber 2, mounted above a nozzle 3, a primary propellant supply circuit 4, a secondary propellant supply circuit 5, and a drive circuit 6. The primary propellant supply circuit 4 includes a first tank 4a, containing the liquid propellant, here liquid hydrogen LH2, a first shut-off valve 4g, a first turbopump 4b, and a first supply valve, generally called the chamber valve 4c. This chamber valve 4c controls the flow of primary propellant reaching the combustion chamber 2 via a cooling circuit 4d for the nozzle 3.Similarly, the second propellant supply circuit 5 includes a second tank 5a, containing the liquid oxidizer, here liquid oxygen LOX, a second shut-off valve 5g, a second turbopump 5b and a second chamber valve 5c, this chamber valve 5c controls the flow of second propellant reaching the combustion chamber 2. Each propellant supply circuit 4, 5 includes. also a sampling line 4e, 5e whose flow is controlled by a sampling valve 4f, 5f and leading into the combustion chamber of a gas generator 6a of the drive circuit 6. The gases from the combustion of the propellants in the gas generator 6a then drive a turbine 6b before reaching the combustion chamber 2 of the rocket engine, the rotation of the turbine 6b driving together the turbopumps 4b and 5b.

[0004] In such a rocket engine, the combustion chamber valves are particularly critical components, as they are responsible for regulating the propellant flow to the main combustion chamber as precisely and responsively as possible. The correct control of the rocket engine's operating point during the various phases of its mission therefore depends on the proper functioning, precision, and responsiveness of the combustion chamber valves. They must also be capable of completely shutting off the propellant flow in order, for example, to quickly shut down the rocket engine in an emergency.

[0005] Because they are subjected to very high pressures, on the order of 200 bar, and equally high flow rates, on the order of 300 kg / s, these chamber valves must be able to withstand very significant mechanical stresses. Similarly, considerable power is required to actuate the valve.

[0006] Consequently, the chamber valves known to date, most often of the plug or flap type, are very bulky and heavy: these chamber valves are therefore expensive to produce and negatively impact the payload capacity of the rocket. For example, the chamber valves of the Vulcain engine, of the pneumatic ball valve type, weigh over 30 kg. These chamber valves also rely on high-power-density actuation technologies (pneumatic, hydraulic): this helps to limit the mass and size of this equipment to some extent, but these technologies have functional limitations (operating temperature, difficulties or even impossibility of regulation) that restrict the functions these valves can perform and impact engine performance.

[0007] The very high pressures experienced by these valves also pose significant sealing problems, not only at the valve body itself, but also at the interface between the valve body and its actuator located outside the valve body. The very low temperature of the propellants passing through these valves, below 100 K, adds a further constraint by precluding the use of many common materials. The use of specific seals is therefore essential, which raises additional constraints in terms of cost, reliability, wear, and power consumption due to friction. These constraints are all the more critical because these valves, and therefore these seals, are constantly stressed according to the engine's regulation requirements. In particular, these seals wear out quickly, which limits the engine's reusability, unless costly maintenance is performed between each launch.

[0008] Furthermore, due to the very high power required to operate this type of valve, it is currently very difficult to use electric actuators, although they are easier to pilot, unless the total mass of the valve is drastically increased or its actuation dynamics are limited, which becomes problematic for reacting quickly enough in emergency situations.

[0009] There is therefore a real need for a valve and motor that are free, at least in part, from the disadvantages inherent in the aforementioned known configurations. Description of the invention

[0010] This presentation concerns a valve, comprising a valve body having a first port and a second port, a movable disc configured to adjust the passage cross-section between the first and second ports, and an electric actuator configured to adjust the position of the disc, wherein the disc is capable of moving linearly between a first position, in which it is completely interposed between the first and second ports, setting the passage cross-section between the first and second ports to 0, and a second position, in which the passage cross-section between the first and second way is brought to a maximum value, wherein the actuator comprises a rotor installed in a service cavity of the valve body, said service cavity being in fluidic communication with the first or second way, and wherein the actuator is configured to drive the movement of the obturator by means of a rotary-linear transmission element.

[0011] Thanks to this submerged rotor, the valve body can be completely watertight: no seal is required at the interface between the obturator and the actuator, as both are housed within the valve body. The actuator rotor can be driven and actuation externally, as the magnetic flux generated by the electric actuator's stator can pass through the wall of the service cavity. This configuration eliminates the need for complex, expensive, and wear-prone dynamic seals to ensure the valve body's watertightness, except, of course, for the connections to its first and second ports.

[0012] Furthermore, thanks to such a linearly sliding obturator, it is only necessary to ensure the obturator's seal within the valve body when the latter is in its first position, i.e., its closed position. It is therefore possible to design seals that are only stressed in this first position, which significantly reduces their wear and thus makes it feasible to use the valve to control a reusable launcher stage engine without extensive valve maintenance between launches. Moreover, since the sealing devices are not subject to any rotational movement, they can be of a simpler design than, for example, a rotary plug: in particular, it is possible to eliminate the need for an elastic loading device for the seal of these devices.

[0013] Furthermore, and importantly, since these seals are only stressed in the first position, they do not rub and therefore do not impede the movement of the shutter during its normal regulating operation, which significantly reduces the power required for its operation. The actuator's dimensions can thus be reduced, thereby decreasing its size, weight, and cost. It even becomes possible to use an electric actuator, which is more precise than a pneumatic actuator, for example.

[0014] The use of a sliding shutter and a rotary-linear transmission also allows for operation over a very long angular stroke of the actuator, potentially over several revolutions. It is therefore possible to control the shutter position much more precisely than is achievable with a conventional rotary shutter, whose effective stroke rarely exceeds 50°.

[0015] Thanks to these various improvements, it is possible to obtain a compact valve that is significantly lighter than the prior art. Thus, for example, for a valve capable of handling a flow rate greater than 250 L / s, the length of such a valve can be less than 50 cm, or even less than 40 cm, for a mass well below 30 kg.

[0016] In some embodiments, the second port extends along a main axis of the valve, and the first port forms a non-zero angle with said main axis. The first port is therefore not in line with the first port, which leaves sufficient space for the service cavity.

[0017] In some embodiments, this angle is an acute angle, preferably between 10 and 80°, and even more preferably between 30 and 60°. This angle is measured as the deviation from the situation in which the first track is located in line with the second track. An angle that deviates from a right angle helps to reduce the pressure loss at the interface between the first and second tracks.

[0018] In some embodiments, the first port includes a connection orifice and divides into two channels, each channel bypassing the main axis on a different side of the valve before opening into the second port. This configuration limits the valve pressure drop while facilitating the integration of the service cavity. The two channels are preferably symmetrical. They may rejoin before reaching the obturator, or the obturator may be positioned in front of each channel.

[0019] In some embodiments, the two channels of the first channel split at a separating edge facing the connection port of the first channel. This edge is preferably positioned in the axial plane; It forms the most acute angle possible, for example an angle less than 20°, preferably less than 10°, and preferably even less than 5°. This minimizes the impact of this separation on the flow rate of the first track.

[0020] In some embodiments, the diameter of the connection port of the first channel and / or the diameter of the connection port of the second channel is greater than 10 mm, preferably greater than 50 mm. Furthermore, the diameter of the connection port of the first channel and / or the diameter of the connection port of the second channel is preferably less than 300 mm, preferably less than 200 mm.

[0021] In some embodiments, the diameter of the connection port of the first channel is equal to the diameter of the connection port of the second channel.

[0022] In some embodiments, the service cavity is in fluidic communication with the second channel.

[0023] In some embodiments, the first port is the valve inlet and the second port is the valve outlet. However, the reverse configuration is possible, the valve being reversible in particular.

[0024] In some embodiments, the gate takes the form of a cylindrical sleeve, preferably with a circular base. The gate thus progressively closes the passage between the first and second channels in a manner substantially parallel to the interface surface between the first and second channels. Consequently, the angle formed between the direction of movement of the gate and the local flow direction is small, less than 45°, preferably less than 30°; in other words, the gate compresses the flow as it moves, thus without offering significant resistance. In particular, no surface of the gate is oriented substantially perpendicular to either of the two channels. Therefore, operating the gate is particularly easy and requires only minimal power. In particular, this configuration ensures good pressure balancing on both sides of the gate.Indeed, thanks to such a laminating type obturator, the pressure loss of the valve is not directly taken up by the actuator: it is thus possible to decouple the pressure loss and the actuation power. necessary. The power required for the actuator is thus significantly reduced.

[0025] In some embodiments, the peripheral wall of the shutter is solid. The flow regulation is therefore achieved by the progression of the end edge of the shutter.

[0026] In some embodiments, the peripheral wall of the obturator includes at least one cutout. Such a cutout allows for a flow rate regulation law that is not simply proportional to the distance traveled by the obturator. In particular, the width of this cutout can be variable.

[0027] In some embodiments, the valve includes at least one sliding bearing configured to guide the movement of the obturator. This bearing guides the obturator while minimizing frictional forces during movement. The valve may, in particular, include two bearings, mounted, for example, at both ends of the obturator. The bearings may, for example, be mounted in notches formed in the outer surface of the obturator.

[0028] In some embodiments, the valve includes at least one first seal mounted in the second port, upstream of the confluence between the first and second ports. This seal ensures the seal of the obturator, and therefore the complete closure of the valve, when the obturator is in its first position.

[0029] In some embodiments, the valve includes a second seal mounted in the second port, behind the confluence between the first and second ports. This seal ensures the seal of the obturator behind the first port, where the fluid can reach this rear area, particularly when the obturator includes an internal passage.

[0030] In some embodiments, the first seal is compressed against the shutter only when the shutter is in its first position. This reduces wear on the seal. Furthermore, since the first seal does not rub against the shutter except in the first position, the frictional forces acting on the shutter are reduced, making it easier to operate.

[0031] In some embodiments, the second seal is compressed against the shutter only when the shutter is in its first position. This reduces wear on the seal. Furthermore, since the second seal does not rub against the shutter except in the first position, the frictional forces acting on the shutter are reduced, making it easier to operate.

[0032] In some embodiments, the shutter includes at least one shoulder configured to cooperate with at least one seal. Such a shoulder allows the seal to be compressed only when the shutter is in a specific position, typically the first position, i.e., when the seal is directly opposite the shoulder. In particular, such a shoulder may be provided for each seal. Each shoulder may, notably, be preceded by a ramp to progressively compress the seal and reduce the risk of damage.

[0033] In some embodiments, the first and / or second seal is a thrust seal. Specifically, apart from the moment the obturator reaches its initial position and thus compresses the seal(s), these seals do not need to accommodate relative movement between the seal and the obturator. This eliminates the need for dynamic seals, reducing the number of wear parts, the cost, and the complexity of the valve. In particular, dynamic seals have a short service life in cryogenic applications.

[0034] In some embodiments, each seal is a lip seal comprising a metallic expander. Such a configuration is particularly suitable when the valve is traversed by a low-temperature fluid, for example, a cryogenic propellant.

[0035] In some embodiments, the valve includes an anti-rotation device fixedly mounted in the valve body and configured to prevent the rotation of the disc. This anti-rotation device can, in particular, cooperate directly with the disc to prevent its rotation. This anti-rotation device restricts the disc to move exclusively axially. This can, in particular, facilitate the operation of the rotary-linear transmission element.

[0036] In some embodiments, the anti-rotation element includes radial slots in which radial tabs of the obturator are engaged.

[0037] In some embodiments, the valve includes a deflector surface mounted in the second channel, at the confluence of the first and second channels, the deflector surface being profiled to extend the first channel into the second channel. This deflector surface ensures a degree of continuity between the first and second channels despite the angle formed between them, thereby reducing the pressure loss at the interface between the two channels.

[0038] In some embodiments, the deflecting surface is carried by the anti-rotation element.

[0039] In some embodiments, the actuator is an electric motor, preferably synchronous, and even more preferably with permanent magnets. However, the electric motor could be of another type, in particular asynchronous, for example with a squirrel-cage rotor.

[0040] In some embodiments, the actuator rotor includes permanent magnets. The immersed rotor therefore contains no electrical components.

[0041] In some embodiments, the actuator stator is installed in a pilot chamber surrounding the service cavity, the pilot chamber being hermetically sealed from the service cavity by a partition wall. The actuator's electrical components are thus kept separate from the fluid(s) flowing through the valve. In particular, no physical passage of any kind, and therefore no seal, is provided between the service cavity and the pilot chamber.

[0042] In some embodiments, the thickness of the separating wall is less than 10 mm, preferably less than 5 mm, and even more preferably less than 2 mm. Indeed, the smaller this thickness, the smaller the air gap between the stator and the rotor of the actuator can be, and therefore the greater the efficiency of the latter. Furthermore, the smaller this thickness, the more Eddy currents that necessarily appear in the wall are reduced, which further preserves the efficiency of the actuator.

[0043] In some embodiments, the pilot chamber is accessible axially from the rear of the valve body. This allows, where necessary, for easier maintenance of the actuator. A hatch may, in particular, close the rear end of the pilot chamber.

[0044] In some embodiments, the actuator stator is installed in the service cavity. The actuator stator is therefore also immersed: this variant is particularly suitable when the fluid passing through the valve is not electrically conductive and does not present a risk of auto-ignition. This eliminates the need for a separating wall between the rotor and the stator. The actuator's efficiency can also be improved.

[0045] In some embodiments, the valve includes a bearing located between the actuator rotor and the peripheral wall of the service cavity. The bearing is therefore immersed. It may, in particular, be a ball bearing.

[0046] In some embodiments, the valve includes a resolver, the resolver rotor of which is installed in the service cavity, integrally with the actuator rotor. The resolver rotor is therefore also immersed. This resolver allows the angular position of the rotor to be determined, and thus the position of the gate to be deduced. Such a resolver can therefore contribute to actuator control, in particular to the control of the actuator's electrical phases.

[0047] In some embodiments, the resolver stator is installed in the pilot chamber. However, it could also be installed in the service cavity in cases where the actuator stator is also installed in the service cavity.

[0048] In some embodiments, the separating wall comprises at least a first cylindrical portion having a first diameter and at least a second cylindrical portion having a second diameter, different from the first diameter. This allows it to adapt to the respective diameters of the actuator rotor and the resolver rotor.

[0049] In some embodiments, the valve includes a control module configured to control the actuator according to a setpoint.

[0050] In some embodiments, the transmission element comprises a screw-nut assembly. Such a configuration is particularly practical and inexpensive to implement.

[0051] In some embodiments, the screw-nut assembly includes a planetary roller screw. This configuration allows for a very fine pitch with virtually no backlash, ensuring very precise control of the shutter position. However, in other, less demanding embodiments, the screw-nut assembly could include a ball screw or even a conventional screw and nut.

[0052] In some embodiments, the nut is integral with the actuator rotor and the screw is integral with the shutter.

[0053] In some embodiments, the screw pitch is between 0.5 and 1.5 mm.

[0054] In some embodiments, the shutter travel between the first and second positions is greater than 10 mm, preferably greater than 50 mm. It is preferably less than 300 mm.

[0055] In some embodiments, the actuator is configured to move the shutter from the second position to the first position in less than 1000 ms.

[0056] In some embodiments, the actuator is configured to bring the shutter into any intermediate position between the first position and the second position.

[0057] In some embodiments, at least the valve body is manufactured by additive manufacturing. Preferably, this also applies to the obturator and / or the anti-rotation device. The use of additive manufacturing techniques makes it easy and relatively inexpensive to obtain a complex and therefore highly optimized geometry for the valve body: this is particularly useful for producing the partition wall that defines the service cavity. Additive manufacturing is especially advantageous here due to the small surface area that would require machining in conventional processes due to high surface finish or precision requirements.

[0058] In some embodiments, the valve is configured to allow the passage of a liquid, gas, or two-phase fluid. In the most demanding applications, the pressure of this fluid can exceed 200 bar and its flow rate exceed 250 L / s. Similarly, in the most demanding applications, the fluid temperature can range from 15 to 120 K. However, this valve is also perfectly suited for less demanding applications, for example, applications where the fluid pressure is below 15 bar and / or where the fluid temperature is close to ambient temperature, for example, between 270 and 350 K. Depending on the intended application, particularly when the fluid is at ambient temperature, certain components, especially the seals or the transmission mechanism, can be simplified to meet the application requirements at a lower cost.

[0059] In some embodiments, the valve is configured to allow the passage of a propellant, preferably cryogenic. This may include liquid hydrogen (LH2), liquid oxygen (LOX), or liquid methane (LCH4).

[0060] In some embodiments, the valve is configured to allow the passage of hydrogen gas, oxygen gas, methane gas, or kerosene. For example, such a valve could be used on board an aircraft using hydrogen as fuel. Such a valve could also be used on board a ship for its propulsion needs.

[0061] The present presentation also relates to an engine, comprising at least one valve according to any one of the preceding embodiments.

[0062] In some embodiments, this engine is an engine for an astronautical vehicle, for example a launch vehicle or an orbital vehicle. Preferably, it is a rocket engine.

[0063] In some embodiments, this engine is an aircraft engine. In particular, it may be a hydrogen engine.

[0064] In some embodiments, this engine is a marine engine.

[0065] The aforementioned features and advantages, as well as others, will become apparent upon reading the detailed description that follows, along with examples of implementation of the The valve and motor offered are shown in this detailed description, which refers to the attached drawings. Brief description of the drawings

[0066] The attached drawings are schematic and are primarily intended to illustrate the principles of the presentation.

[0067] In these drawings, from one figure to another, identical elements (or parts of elements) are identified by the same reference symbols.

[0068] [Fig. 1] Figure 1 is a schematic diagram of a rocket engine.

[0069] [Fig. 2] Figure 2 is a front view of an example of a valve.

[0070] [Fig. 3] Figure 3 is a cross-sectional view along plane III of Figure 2, with the valve closed.

[0071] [Fig. 4] Figure 4 is a cross-sectional view along plane III of Figure 2, with the valve open.

[0072] [Fig. 5] Figure 5 is a cross-sectional view along plane V of Figure 2, with the valve open. Description of the implementation methods

[0073] To make the explanation more concrete, an example of a valve is described in detail below, with reference to the attached drawings. It should be noted that the invention is not limited to this example.

[0074] Figure 1 schematically represents a rocket engine. As presented in the introductory part of this presentation, each propellant supply circuit 4, 5 includes a chamber valve 4c, 5c regulating the propellant flow reaching the combustion chamber 2.

[0075] Figures 2 to 5 now illustrate an example of a valve 10 as described, suitable for forming such chamber valves 4c, 5c. In this example, valve 10 is configured to allow the passage of a cryogenic propellant, for example LH2 or LOX, at a pressure of approximately 200 bar, a temperature of approximately 20 to 110 K and a flow rate of approximately 250 L / sec. However, this valve could also be adapted to form the 4f, 5f withdrawal valves or the 4g, 5g shut-off valves, even if their dimensions need to be modified.

[0076] The valve 10 includes a valve body 11 having a main part 12, cylindrical and extending along a main axis A, and a volute 20 provided around the rear portion of the main part 12. The valve body 11 is manufactured in one piece using an additive manufacturing technique.

[0077] The front portion of the main part 12 includes an axial passage 13 opening at the front end of the valve body 11 at a connection port 14 surrounded by a connection flange 14a. This axial passage 13 thus forms the second port II of the valve 10.

[0078] The rear portion of the main part 12 includes, in its center, a service cavity 15 open at its front end so as to communicate fluidly with the second port II of the valve 10. The periphery and the rear end of the service cavity 15 are closed by a first separating wall 16.

[0079] The rear portion of the main part 12 also includes, coaxially with the service cavity 15, a maneuvering cavity 17, annular and open at its front end so as to communicate fluidly also with the second track II. It is delimited on its radially inner side by a second separating wall 18.

[0080] The rear portion of the main part 12 also includes, concentrically between the service cavity 15 and the operating cavity 17, a pilot chamber 19. This pilot chamber 19 is hermetically isolated from the second port II of the valve by means of the first and second separating walls 16, 18. It is also closed at its rear end by a removable hatch 19a allowing access to the pilot chamber 19 from outside the valve 10 if necessary.

[0081] The volute 20, for its part, forms the first channel I of the valve 10. The volute 20 thus includes a connection port 21, also surrounded by a flange connection 21 a. This connection orifice 21 has as its central direction an axis B forming an angle 0 of approximately 60° with the main axis A. In the present example, the diameter of the second connection orifice 21 is equal to 90 mm.

[0082] The volute 20 then comprises two channels 22a, 22b dividing from a separating edge 23 extending in an axial plane opposite the connection orifice 21. Each channel 22a, 22b then bypasses the main part 12 of the valve body 11 on one side and the other, symmetrically, until each opens into the axial passage 13 of the main part 12 through an opening 23a, 23b.

[0083] In this example, the first channel I constitutes the entry channel, i.e. the upstream channel, of valve 10, while the second channel II constitutes the exit channel, i.e. the downstream channel; however, the traffic within valve 10 could very well be reversed.

[0084] The valve 10 further includes an anti-rotation element 30 provided in the axial passage 13 of the second channel II. More specifically, this anti-rotation element 30, manufactured by additive manufacturing, is rigidly mounted on a structural ring 16a marking the junction between the first and second separating walls 16 and 18. The anti-rotation element 30 includes a peripheral surface of revolution forming a deflecting surface 31 extending into the second channel II in line with the channels 22a, 22b of the first channel I. The anti-rotation element 30 also includes a central passage 32, extending axially, and a plurality of guide slots 33, here four in number, extending in radial planes between the central passage 32 and the deflecting surface 31.

[0085] The valve 10 further includes a cylindrical sleeve-shaped obturator 40 capable of moving linearly between a first extreme position, shown in Figure 3, and a second extreme position, shown in Figure 4. The obturator 40 is also manufactured by additive manufacturing.

[0086] In the first extreme position, the peripheral wall 41 of the obturator 40, called the obturator wall, extends along the entire peripheral surface of the axial passage 13 of the valve body 11, thus interposing itself between the first channel I and the second channel II. In this position, a stop surface 42 provided at the front end of the obturator 40 is in contact with a shoulder 13a of the axial passage 13 while the rear end of the obturator wall 41 is engaged in the operating cavity 17.

[0087] In the second extreme position, the obturator wall 41 of the obturator 40 is fully retracted into the operating cavity 17, its rear end being against the bottom of the operating cavity 17. In this position, the obturator wall 41 does not protrude at all over the openings 23a, 23b of the channels 22a, 22b of the first channel.

[0088] The external surface of the shutter wall 41 includes, near each of its axial ends, a notch 43 in which a sliding bearing 44 is provided to guide the translational movement of the shutter 40 and reduce the frictional forces exerted during this movement. In particular, this sliding bearing 44 may be of the deformable segment type, for example made of PTFE or a derivative material with a low coefficient of friction.

[0089] The external surface of the obturation wall 41 also includes, near each of its axial ends, a shoulder 45 projecting radially over the entire obturation wall 41. These shoulders 45 are provided here just in front of each notch 43. The rear shoulder 45 is further preceded here by a ramp 46.

[0090] The valve body 11 comprises a first annular seal 47a, mounted in front of the confluence between the first channel I and the second channel II, here at the front end of the passage 13, and a second annular seal 47b, mounted behind the confluence between the first channel I and the second channel II, here at the rear end of the passage 13, just before the operating cavity 17. The axial distance separating the seals 47a, 47b is equal to the axial distance separating the shoulders 45.

[0091] Thanks to this configuration, the seals 47a and 47b are compressed against the shoulders 45 when the obturator 40 is in its first extreme position, thus ensuring the seal of the obturator 40 when the valve 10 is closed. Conversely, in the second extreme position, as well as in any intermediate position, the seals 47a and 47b are not compressed; the first seal 47a no longer located opposite the obturator 40 and the second seal 47b facing a less thick portion of the obturator wall 41.

[0092] In this example, seals 47a and 47b comprise a lip extending radially from a body having an annular cavity into which a metallic expander is inserted. Each seal 47a and 47b also includes a dovetail retaining lug extending from the body to secure it. Specifically, the body of these seals 47a and 47b can be machined from a polymer that retains some elasticity at low temperatures and is compatible with the conveyed fluid, for example, filled PTFE. It should be noted that the structure of these seals 47a and 47b could be simplified for other, less critical applications.

[0093] The obturator 40 also includes ribs 48 extending axially along the inner surface of the obturator wall 41. The number of these ribs 48 is equal to the number of guide slots 33 of the anti-rotation member 30, each rib 48 being engaged in one of the guide slots 33. The ribs 48 extend at their front end by radial connecting tabs 49.

[0094] The valve 10 further includes an actuator 50, of the electric motor type, comprising a rotor 51 and a stator 52. The rotor 51 of the actuator 50, having the main axis A as its axis of rotation, is housed in the service cavity 15 and is therefore immersed when the valve is in operation. More precisely, it is mounted for rotation within the service cavity 15 by means of a roller bearing 53 mounted against the inner surface of the structural ring 16a. A minimal clearance is left between the rotor 51 and the portion 16b of the separating wall 16 that surrounds the rotor 51. In addition, the rotor 51 of the actuator 50 has a central passage 54, extending along the main axis A.

[0095] The stator 52 is housed in the pilot chamber 19, pressed against the portion 16b of the separating wall 16, concentrically with respect to the rotor 51. In order to minimize the air gap between the rotor 51 and the stator 52, at least the first portion 16b of the first separating wall 16 has a thickness of less than 10 mm, preferably less than 5 mm, and preferably even less than 2 mm.

[0096] In this example, actuator 50 is a permanent magnet synchronous electric motor. It is a smooth-pole type with a sinusoidal electromotive force and double star connection. Actuator 50 comprises six pole pairs. The rotor magnets are encapsulated by laser welding and are arranged in either an alternating or a Halbach arrangement.

[0097] The valve 10 also includes a resolver 55, which itself comprises a rotor 56 and a stator 57. The rotor 56 of the resolver 55 is also housed in the service cavity 15 and is therefore immersed when the valve 10 is in operation. The rotor 56 of the resolver 55 is integral with the rotor 51 of the actuator 50, extending from the latter along the main axis A, on its rear side: the rotor 56 of the resolver 55 therefore also has the main axis A as its axis of rotation.

[0098] Since the rotor 56 of the resolver 55 has a smaller diameter than the rotor 51 of the actuator 50, the diameter of the first separating wall 16 decreases from the rear end of its first cylindrical portion 16b until it reaches a second cylindrical portion 16c whose diameter is just slightly larger than that of the rotor 56 of the resolver 55, within a certain clearance. The diameter of the first separating wall then continues to decrease until it becomes zero, thus closing the rear end of the service cavity 15. Furthermore, the rotor 56 of the resolver 55 has a central passage 59 extending along the main axis A.

[0099] The stator 57 of the resolver 55 is housed in the pilot chamber 19, pressed against the portion 16c of the separating wall 16, concentrically with respect to the rotor 56. In the present example, the resolver 55 is a two-wire brushless resolver.

[0100] The valve 10 also includes a control module, housed in the control chamber 19, allowing the actuator to be controlled according to a setpoint transmitted to the valve 10. In this regard, in the present example, the control of the actuator 50 is carried out in a closed loop by a sinusoidal current control via the position feedback provided by the resolver 55.

[0101] The valve 10 further includes a rotary-linear transmission element 60. This transmission component 60 includes, on the one hand, a roller nut 61 integral with the rotor 51 of the actuator 50. This roller nut 61 is more precisely mounted at the front end of the rotor 51, in a manner centered on the main axis A. The roller nut 61 therefore rotates around the main axis A in a manner integral with the rotor 51 of the actuator 50.

[0102] The transmission member 60 also includes a screw 62 extending axially along the main axis A, engaging with the roller nut 61. The rotation of the roller nut 61 therefore causes the translation of the screw 62 along the main axis A, the screw 62 being able to progress forward through the central passage 32 of the anti-rotation member and backward through the central passages 54 and 59 of the rotors 51 and 56 of the actuator 50 and the resolver 55.

[0103] The screw 62 further includes, at its front end, a connecting piece 63 allowing the radial connecting lugs 49 of the shutter 40 to be joined and rigidly connected to the screw 62. Thus, when the screw 62 progresses forward or backward, it drives the shutter 40 in translation.

[0104] In this regard, that this movement of the shutter 40 and the screw 62 is purely axial since the guide slots 32 of the anti-rotation member 30 prevent the shutter 40, and therefore the screw 62, from rotating around the main axis A.

[0105] Thus, the actuator 50 is capable of moving the shutter 40 to any position between its two extreme positions quickly and precisely. In this example, the actuator 50 is therefore capable of moving the shutter 40 from its first extreme position, completely closed, to its second extreme position, completely open, in less than one second with an electrical power of less than 2000 W (with a supply voltage between 50 and 400 V).

[0106] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. In particular, individual features of the various embodiments illustrated / mentioned can be combined in embodiments additional. Therefore, the description and drawings should be considered in an illustrative rather than restrictive sense.

[0107] It is also evident that all the characteristics described with reference to a process are transposable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transposable, alone or in combination, to a process.

Claims

Demands

1. A valve comprising a valve body (11) having a first port (I) and a second port (II), a movable obturator (40) configured to adjust the passage area between the first port (I) and the second port (II), and an electric actuator (50) configured to adjust the position of the obturator (40), wherein the obturator (40) is capable of moving linearly between a first position in which it is completely interposed between the first port (I) and the second port (II), setting the passage area between the first port (I) and the second port (II) to 0, and a second position in which the passage area between the first port (I) and the second port (II) is set to a maximum value, wherein the actuator (50) comprises a rotor (51) installed in a service cavity (15) of the valve body (11), said service cavity (15) being in fluidic communication with the first port (I) or the second port (II). route (II),and in which the actuator (50) is configured to drive the movement of the shutter (40) via a rotary-linear transmission element (60).

2. Valve according to claim 1, wherein the second way (II) extends along a principal axis (A) of the valve (10) and the first way (I) forms a non-zero angle (0) with said principal axis (A).

3. Valve according to claim 1 or 2, wherein the first way (I) includes a connection port (21) and divides into two channels (22a, 22b), each channel (22a, 22b) bypassing the main axis (A) on a different side of the valve (10) before opening into the second way (II).

4. Valve according to any one of claims 1 to 3, wherein the obturator (40) takes the form of a cylindrical sleeve.

5. Valve according to any one of claims 1 to 4, comprising two seals (47a, 47b), a first seal (47a) being mounted in the second way (II), forward of the confluence (23a, 23b) between the first way (I) and the second way (II), and a second seal (47b) being mounted in the second way (II), backward of the confluence (23a, 23b) between the first way (I) and the second way (II).

6. Valve according to claim 5, wherein the first seal (47a) is compressed against the obturator (40) only when the obturator (40) is in its first position, and wherein the second seal (47b) is compressed against the obturator (40) only when the obturator (40) is in its first position.

7. Valve according to any one of claims 1 to 6, comprising an anti-rotation member (30) fixedly mounted in the valve body (11) and configured to block the rotation of the obturator (40).

8. Valve according to any one of claims 1 to 7, comprising a deflecting surface (31) mounted in the second channel (II), at the confluence (23a, 23b) between the first channel (I) and the second channel (II), the deflecting surface (31) being profiled to extend the first channel (I) into the second channel (II).

9. Valve according to any one of claims 1 to 8, wherein the actuator (50) is an electric motor, preferably synchronous, preferably with permanent magnets.

10. Valve according to any one of claims 1 to 9, wherein the stator (52) of the actuator (50) is installed in a pilot chamber (19) surrounding the service cavity (15), said pilot chamber (19) being sealed and separated from the service cavity (15) by a separating wall (16).

11. Valve according to any one of claims 1 to 10, wherein the transmission member (60) comprises a screw (62) and a nut (61), the nut (61) preferably being a roller nut.

12. Motor, comprising at least one valve (10) according to any one of claims 1 to 11.

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