Rocket engine valves

Abstract

A valve suitable for high flow rates and high pressures and a rocket engine equipped with said valve, the valve comprising a valve body 11 having a first flow path I and a second flow path II, a movable shutter 40 configured to adjust the flow area between the first flow path I and the second flow path II, and an electric actuator 50 configured to adjust the position of the shutter 40, the movable shutter 40 being linearly movable between a first position and a second position, the electric actuator 50 comprising a rotor 51 installed in a service cavity 15 of the valve body 11, the service cavity 15 being in fluid communication with the first flow path I or the second flow path II, and the electric actuator 50 configured to drive the movement of the movable shutter 40 via a rotary-to-linear transmission member 60.

Description

[Technical field]

[0001] The present invention relates to a valve suitable for high flow rates and high pressures. Such a valve is particularly suitable for controlling the flow rate of cryogenic propellants in rocket engines, in particular at the inlet of the combustion chamber. However, such a valve is also perfectly suitable for less demanding applications, for example in the aviation or naval fields. [Background technology]

[0002] Cryogenic propellant rocket engines use two propellants, usually liquid hydrogen (LH2) and liquid oxygen (LO), in a combustion chamber. X A conventional example of a rocket engine is shown, intentionally simplified, in Figure 1.

[0003] Such a rocket engine 1 comprises a combustion chamber 2 carrying a nozzle 3, a circuit for supplying a first propellant 4, a circuit for supplying a second propellant 5, and a drive circuit 6. The circuit for supplying the first propellant 4 comprises a first tank 4a containing a liquid fuel, here liquid hydrogen LH2, a first shutoff valve 4g, a first turbopump 4b and a first supply valve, generally known as chamber valve 4c, which controls the flow rate of the first propellant reaching the combustion chamber 2 via a cooling circuit 4d of the nozzle 3. Similarly, the circuit for supplying the second propellant 5 comprises a second tank 5a containing a liquid fuel, here liquid oxygen LO, which is a liquid fuel. X 2, a second shutoff valve 5g, a second turbopump 5b and a second chamber valve 5c, which controls the flow rate of the second propellant arriving at the combustion chamber 2. Each propellant supply circuit 4, 5 also comprises a bleed duct 4e, 5e, the flow rate of which is controlled by a bleed valve 4f, 5f, which arrives at the combustion chamber of a gas generator 6a of the drive circuit 6. The gases resulting from the combustion of the propellant in the gas generator 6a then drive a turbine 6b, which, before rejoining the combustion chamber 2 of the rocket engine, drives the turbopumps 4b and 5b as a single component by the rotation of the turbine 6b.

[0004] In the rocket engine, the chamber valves are particularly important components, since they manage as accurately and responsively as possible the regulation of the propellant flow rate reaching the main combustion chamber, since the correct control of the operating point of the rocket engine in the different phases of its mission depends on their proper operation, accuracy and responsiveness, and must be able to completely cut off the propellant flow rate, for example in order to be able to shut down the rocket engine very quickly in case of an emergency.

[0005] These chamber valves must be able to resist very high mechanical forces, since they are exposed to very high pressures, of the order of 20 MPa (200 bar), and very high flow rates, of the order of 300 kg / s, as well as very high power (electrical power) required to be able to operate the valves.

[0006] Thus, currently known chamber valves are usually of the ball or flap type, very bulky and very heavy, which makes them expensive to manufacture and negatively affects the payload that the rocket can carry. For example, the chamber valve of the Vulcan engine, of the pneumatic ball valve type, has a mass of more than 30 kg. Moreover, these chamber valves are based on actuation technologies (pneumatic, hydraulic) that have a high power density, which makes it possible to limit to a certain extent the mass and bulk of these equipment items, but these technologies also have operational limitations (operating temperature, difficulty or even impossibility of control) that limit the functions that these valves can perform and affect the performance of the engine.

[0007] The very high pressures experienced by these valves also pose considerable sealing challenges, both at the shutter and of course at the interface between the shutter and the actuator located external to its valve body. The very low temperature of the propellant across these valves, below 100K, imposes further limitations that prohibit many commonly used materials. It is therefore mandatory to use special seals, which bring further limitations in terms of cost, reliability, wear and the power dissipated by friction. All these limitations are outweighed by the fact that these valves, and therefore these seals, are in constant use according to the engine's control requirements. In particular, these seals wear out quickly, limiting the possibility of reusing the engine, unless expensive 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, which are easier to control, but would be problematic in reacting quickly enough in an emergency, unless the total mass of the valve were dramatically increased or the actuation force was limited.

[0009] Furthermore, due to the very high power required to actuate this type of valve, it is currently very difficult to use electric actuators, which are easier to control, unless the total mass of the valve is dramatically increased or the actuation force is limited, which would be problematic in reacting quickly enough in an emergency. Summary of the Invention

[0010] Thus, there exists a substantial need for a valve and engine that does not suffer from at least some of the drawbacks inherent in the previously known configurations. The gist of the present invention is a valve body having a first flow path and a second flow path, a movable shutter configured to adjust a flow area between the first flow path and the second flow path, an electrical actuator configured to adjust the position of the shutter; the shutter is linearly movable between a first position, in which the shutter is fully inserted between the first and second flow paths and provides zero flow area between the first and second flow paths, and a second position, in which the flow area between the first and second flow paths is provided at a maximum value; the electrical actuator includes a rotor disposed within a service cavity of the valve body, the service cavity being in fluid communication with the first flow path or the second flow path; The actuator is associated with a valve that is configured to drive movement of the shutter via a rotary-to-linear transmission member.

[0011] Due to such a concealed rotor, the valve body can be completely sealed, and in particular at the interface between the shutter and the actuator no seal is required, since both the shutter and the actuator are located inside the valve body. The control and drive of the actuator rotor can be performed from the outside, since the magnetic flux generated by the stator of the electric actuator can cross the walls of the service cavity. This configuration therefore makes it possible to dispense with complex, expensive and wear-prone dynamic seals, and of course ensures the tightness of the valve body separately from the connections of its first and second flow paths.

[0012] Moreover, for such linearly slidable shutters, it is only necessary to ensure the tightness of the shutter inside the valve body when the valve body is in its first position, i.e. in its closed position. It is therefore possible to provide a seal which is only forced in this first position, which significantly reduces its wear and therefore makes it possible to envisage its use for the control of reusable launch stage engines without extensive maintenance of the valve between each launch. Furthermore, since the sealing devices are not subjected to any rotational movements, they can be of a simpler design than, for example, in the case of rotary ball valves, in particular any elastic device for loading the seal of these sealing devices can be dispensed with.

[0013] Moreover, and importantly, since these joints are only subjected to forces in the first position, they do not rub and therefore do not oppose the movement of the shutter during its normal operation of adjustment, thereby significantly reducing the power required to handle it. The dimensions of the actuator can therefore be reduced, thereby reducing its bulk, mass and cost. It is even possible to use electric actuators, which are more precise than pneumatic actuators, for example.

[0014] The use of a slidable shutter and rotary-to-linear transmission also allows for the option of working with very long angular actuator tracks over several options, so the position of the shutter can be controlled much more precisely than is achievable with conventional rotary shutters, with the useful track rarely exceeding 50°.

[0015] Due to these different gains it is possible to obtain valves that are more compact and significantly lighter than the prior art.Thus, for example, for a valve capable of allowing the passage of a flow rate of more than 250 L / s, the length of such a valve may be less than 50 cm or even less than 40 cm for a mass of less than 30 kg.

[0016] In a particular embodiment, the second flow passage extends along a main axis of the valve and the first flow passage forms a non-zero angle with said main axis, such that the first flow passage is not located in the direction of extension of the first flow passage so as to leave sufficient space to form a service cavity.

[0017] In certain embodiments, the angle is an acute angle, preferably between 10 and 80 degrees, more preferably between 30 and 60 degrees. The angle is measured as a separation from the situation where the first flow path is located in the direction of extension of the second flow path. An angle away from a right angle can reduce load losses at the interface between the first and second flow paths.

[0018] In a particular embodiment, the first flow path is provided with a connecting orifice and splits into two channels, each of which bypasses the main axis on a different side of the valve before opening into the second flow path. Such a configuration makes it possible to limit the load losses of the valve while facilitating the incorporation of a service cavity. The two channels are preferably symmetrical. The two channels meet before meeting the shutter, or a shutter can be inserted before each of the two channels.

[0019] In a particular embodiment, the two channels of the first flow path are separated at the level of a separation ridge facing the connecting orifice of the first flow path, said ridge preferably being located in an axial plane and forming the most acute angle possible, for example an angle of less than 20°, preferably less than 10°, more preferably less than 5°, thereby minimizing the effect of this separation on the flow rate of the first flow path.

[0020] In a particular embodiment, the diameter of the connecting orifice of the first flow path and / or the diameter of the connecting orifice of the second flow path is greater than 10 mm, preferably greater than 50 mm. Furthermore, the diameter of the connecting orifice of the first flow path and / or the diameter of the connecting orifice of the second flow path is preferably less than 300 mm, preferably less than 200 mm.

[0021] In certain embodiments, the diameter of the connecting orifice of the first flow path is equal to the diameter of the connecting orifice of the second flow path.

[0022] In certain embodiments, the service cavity is in fluid communication with the second flow path.

[0023] In certain embodiments, the first flow path is an inlet flow path of the valve and the second flow path is an outlet flow path of the valve, however, the reverse configuration can be envisaged and the valve can in particular be reversible.

[0024] In a particular embodiment, the shutter takes the form of a cylindrical sleeve, preferably with a circular base. The shutter therefore gradually closes the passage between the first and second flow paths in a manner substantially parallel to the interface surface between the first and second flow paths. The angle formed between the direction of movement of the shutter and the local direction of the flow is therefore small, less than 45°, preferably less than 30°, in other words the shutter stacks the flow as it moves and does not create any significant resistance. In particular, no surface of the shutter is oriented substantially perpendicular to one of the two flow paths. Steering of the shutter is therefore particularly easy and requires only small forces (power). In particular, this configuration ensures a good balance of the pressures on both sides of the shutter. In particular, due to such a stacked shutter, the load losses of the valve are not directly absorbed by the actuator, thus managing the load losses and the required actuation forces (power) in an uncoupled manner. The force (power) required for the actuator is therefore significantly reduced.

[0025] In a particular embodiment, the peripheral wall of the shutter is solid, so flow regulation is achieved by the progression of the shutter edge.

[0026] In a particular embodiment, the peripheral wall of the shutter has at least one cutout. Such a cutout makes it possible to obtain a control equation for the flow rate that is not simply proportional to the distance traveled by the shutter. In particular, the width of this cutout can be variable.

[0027] In a particular embodiment, the valve has at least one slidable bearing configured to guide the movement of the shutter. This bearing is used to guide the shutter while minimizing frictional forces during movement. The valve may in particular comprise, for example, two bearings mounted at the two ends of the shutter. The bearings may, for example, be mounted in recesses formed in the outer surface of the shutter.

[0028] In a particular embodiment, the valve comprises at least one first seal attached to the second flow path before the junction between the first and second flow paths, said seal making it possible to ensure the tightness of the shutter and thus to allow full closure of the valve when the shutter is in its first position.

[0029] In a particular embodiment, the valve comprises a second seal attached to the second flow path behind the junction between the first and second flow paths, which makes it possible to ensure the tightness of the shutter behind the first flow path when fluid can reach this rear area, especially if the shutter has an inner passage.

[0030] In certain embodiments, the first seal is compressed against the shutter only when the shutter is in its first position, thus reducing wear on the seal. Additionally, the first seal does not rub against the shutter outside of the first position, reducing frictional forces on the shutter and making it easier to steer.

[0031] In certain embodiments, the second seal is compressed against the shutter only when the shutter is in its first position, thus reducing seal wear. Additionally, the second seal does not rub against the shutter outside of the first position, reducing frictional forces on the shutter and making it easier to steer.

[0032] In a particular embodiment, the shutter comprises at least one shoulder adapted to interact with at least one seal. Such a shoulder makes it possible to only compress the seal when the shutter is in a particular position, usually the first position, i.e. when the seal is facing the shoulder. In particular, such a shoulder can be provided for each seal. Each shoulder can in particular be preceded by a ramp in order to compress the seal gradually and reduce the risk of damaging it.

[0033] In a particular embodiment, the first seal and / or the second seal are stop seals. In particular, these seals do not need to accommodate relative movement between the seal and the shutter apart from the moment when the shutter reaches its first position and thus compresses the seal. It is therefore possible to omit dynamic seals, which can reduce the number of parts subject to wear and also the cost and complexity of the valve. In particular, dynamic seals have a short lifespan in cryogenic applications.

[0034] In a particular embodiment, each seal is a lip seal with a metal expander. Such a configuration is particularly suitable when the valve is traversed by a cryogenic fluid, such as a cryogenic propellant.

[0035] In a particular embodiment, the valve has an anti-rotation member that is fixedly mounted in the valve body and that is configured to lock the shutter against rotation, which can in particular directly interact with the shutter in order to lock its rotation, and which makes it possible to restrict the shutter to movement exclusively in the axial direction, which in particular simplifies the operation of the rotary-to-linear transmission member.

[0036] In certain embodiments, the anti-rotation member comprises a radial slot into which a radial tab on the shutter is engaged.

[0037] In certain embodiments, the valve includes a deflection surface mounted in the second flow path at the junction between the first and second flow paths, the deflection surface being profiled to extend the first flow path into the second flow path, the deflection surface allowing for some continuity between the first and second flow paths despite the angle between the first and second flow paths, thereby reducing load losses at the interface of the two flow paths.

[0038] In certain embodiments, the deflection surface is supported by an anti-rotation member.

[0039] In a particular embodiment, the actuator is an electric motor, preferably of the synchronous type, and more preferably having permanent magnets, although the electric motor may be of another type, such as an asynchronous type, for example with a squirrel cage shaped rotor.

[0040] In certain embodiments, the rotor of the actuator comprises a permanent magnet, and thus the hidden rotor does not include any electrical components.

[0041] In a particular embodiment, the stator of the actuator is installed in a control chamber that surrounds the service cavity, said control chamber being tightly separated from the service cavity by a bulkhead. Thus, the electrical components of the actuator are kept in an area away from the fluid that crosses the valve. In particular, no physical passages, and therefore no seals, of any kind are provided between the service cavity and the control chamber.

[0042] In a particular embodiment, the thickness of the partition is less than 10 mm, preferably less than 5 mm, and more preferably less than 2 mm. In particular, the thinner the thickness, the smaller the gap between the stator and rotor of the actuator, and the more efficient the actuator. Furthermore, the thinner the thickness, the less eddy currents that would inevitably appear in the wall, and thus the more efficient the actuator.

[0043] In certain embodiments, the control device is axially accessible from the rear of the valve disc, which allows for simplified maintenance of the actuator, if applicable. A hatch can in particular close the rear end of the control chamber.

[0044] In a particular embodiment, the stator of the actuator is installed in the service cavity. The stator of the actuator is therefore also hidden, this variant being particularly suitable when the fluid passing through the valve is not conductive and there is no risk of self-ignition. This removes the restriction of having to provide a partition between the rotor and the stator. It also improves the efficiency of the actuator.

[0045] In a particular embodiment, the valve comprises a bearing provided between the rotor of the actuator and the peripheral wall of the service cavity, which is therefore hidden and may in particular be a ball bearing.

[0046] In a particular embodiment, the valve comprises a resolver, the rotor of which is installed in a service cavity fixed to the rotor of the actuator. The resolver rotor is therefore also hidden. This resolver makes it possible to know the angular position of the rotor and therefore to deduce the position of the shutter from the angular position of the rotor. This resolver can therefore contribute to the control of the actuator, in particular to the control of the electrical phase of the actuator.

[0047] In a particular embodiment, the stator of the resolver is located in the control room, however, it can also be located in the service cavity, with the actuator stator itself also being located in the service cavity.

[0048] In a particular embodiment, the bulkhead has at least a first cylindrical portion with a first diameter and at least a second cylindrical portion with a second diameter different from the first diameter, which allows it to be adapted to the diameters of the actuator rotor and the resolver rotor, respectively.

[0049] In certain embodiments, the valve has a control module configured to control the actuator as a function of a set point.

[0050] In a particular embodiment, the transmission member comprises a screw-nut assembly. Such an arrangement is particularly practical and inexpensive to implement.

[0051] In a particular embodiment, the screw-nut assembly comprises a planetary roller screw. Such a configuration makes it possible to obtain a very fine pitch with practically no play, which ensures very precise control of the position of the shutter. However, in other less demanding embodiments, the screw-nut assembly may comprise a ball bearing screw or a conventional screw and nut.

[0052] In a particular embodiment, the nut is fixed to the rotor of the actuator and the screw is fixed to the shutter.

[0053] In a particular embodiment, the pitch of the screw is between 0.5 mm and 1.5 mm.

[0054] In a particular embodiment, the track of the shutter 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 a particular embodiment, the actuator is configured to move the shutter from the second position to the first position in less than 1000 ms.

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

[0057] In a particular embodiment, at least the valve body is manufactured by additive manufacturing. This is preferably also the case for the shutter and / or the anti-rotation member. The use of additive manufacturing techniques makes it possible to easily and relatively cheaply obtain complex geometries, and thus geometries especially optimized for the valve body, which is particularly useful for obtaining partitions that define service cavities. Here, the use of additive manufacturing techniques is particularly beneficial for low surface ratios that, due to the surface condition or the significantly required precision, have to be reworked using conventional machining.

[0058] In a particular embodiment, the valve is configured to be traversed by a liquid, a gas or a two-phase fluid. In the most demanding applications, the pressure of this fluid is in particular above 20 MPa (200 bar) and its flow rate is above 250 L / s. Likewise, in the most demanding applications, the temperature of the fluid may be between 15 K and 120 K. However, the valve is also perfectly suitable for less demanding applications, such as for example applications where the pressure of this fluid is below 1.5 MPa (15 bar) and / or the temperature of this fluid is close to ambient temperature, for example between 270 K and 350 K. Depending on the desired application, in particular when the fluid is at ambient temperature, certain components, in particular seals or transmission components, can be simplified to meet the requirements of the desired application at lower costs.

[0059] In a particular embodiment, the valve is configured to be traversed by a propellant, preferably a cryogenic propellant. The propellant is in particular liquid hydrogen (LH2), liquid oxygen (LO), or the like. X , or liquid methane LCH4.

[0060] In certain embodiments, the valve is configured to be traversed by gaseous hydrogen, gaseous methane, or kerosene. For example, the valve may be used on board an aircraft that uses hydrogen as fuel. The valve may also be used on board a ship for its propulsion.

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

[0062] In a particular embodiment, the engine is an engine of a space vehicle, such as a launch vehicle or an orbital vehicle. Preferably, the engine is a rocket engine.

[0063] In a particular embodiment, the engine is an aircraft engine, which may in particular be a hydrogen engine.

[0064] In a particular embodiment, the engine is a marine engine.

[0065] The aforementioned features and advantages, together with others, will become apparent from reading the following detailed description, exemplary embodiments of the valve and the proposed engine, which description refers to the accompanying drawings, in which:

[0066] The accompanying drawings are schematic and are intended, inter alia, to illustrate the principles of the present invention.

[0067] In the drawings, identical elements (or portions of elements) from one figure to the next are identified by the same reference numbers. [Brief description of the drawings]

[0068] [Figure 1] Figure 1 is a block diagram of a rocket engine. [Diagram 2] FIG. 2 is a front view of an example valve. [Diagram 3] FIG. 3 is a cross-sectional view along plane III of FIG. 2, with the valve in a closed state. [Figure 4] FIG. 4 is a cross-sectional view along plane III of FIG. 2, with the valve open. [Diagram 5] FIG. 5 is a cross-sectional view along plane V of FIG. 2 with the valve open. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0069] In order to make the summary of the invention more practical, an example of a valve will be described in detail below with reference to the accompanying drawings, it being recalled that the invention is not limited to this example.

[0070] A rocket engine is represented diagrammatically in Figure 1. As indicated in the introduction to this overview, each circuit for supplying propellants 4, 5 comprises a chamber valve 4c, 5c that regulates the flow rate of propellants reaching the combustion chamber 2.

[0071] 2 to 5 show an example of a valve 10 according to the invention, which may be any suitable form of this chamber valve 4c, 5c. The valve 10 is thus capable of supplying, in this example, a cryogenic propellant, for example LH2 or LO, at a pressure of the order of 20 MPa (200 bar), a temperature of the order of 20 K to 110 K and a flow rate of the order of 250 L / s. X However, this valve is also suitable for forming a bleed valve 4f, 5f or a shut-off valve 4g, 5g, as long as its dimensions are modified.

[0072] The valve 10 comprises a valve body 11 having a main portion 12 which is cylindrical and extends along a main axis A, and a volute 20 disposed around the rear portion of the main portion 12. The valve body 11 is manufactured as a single piece using additive manufacturing techniques.

[0073] The front part of the main part 12 is provided with an axial passage 13 which leads to the front end of the valve body 11 at the level of a connecting orifice 14 surrounded by a connecting flange 14a. This axial passage 13 thus forms the second flow passage II of the valve 10.

[0074] Meanwhile, the rear part of the main section 12 is provided at its center with a service cavity 15 which communicates at its front end with the second flow passage II of the valve 10. Meanwhile, the periphery and rear end of the service cavity 15 are closed by a first partition wall 16.

[0075] The rear of the main section 12 also comprises, coaxially with the service cavity 15, a pilot cavity 17 which is annular and opens at its forward end in fluid communication with the second flow passage II. The pilot cavity 17 is bounded radially inwardly by a second bulkhead 18.

[0076] The rear part of the main section 12 also comprises, concentrically between the service cavity 15 and the pilot cavity 17, a control chamber 19. This control chamber 19 is tightly isolated from the second flow passage II of the valve by a first bulkhead 16 and a second bulkhead 18. The rear end is also closed by a removable hatch 19a, allowing access to the control chamber 19 from outside the valve 10, if applicable.

[0077] The volute 20 on the other hand forms the first flow passage I of the valve 10. The volute 20 also comprises a connection orifice 21 surrounded by a connection flange 21a. This connection orifice 21a has a central axis B which makes an angle θ of approximately 60° with respect to the main axis A. In this example, the diameter of the second connection orifice 21 is equal to 90 mm.

[0078] The volute 20 comprises two channels 22a, 22b which divide after a separating edge 23 extending in an axial plane facing the connecting orifice 21. Each channel 22a, 22b then bypasses the main part 12 of the valve body 11 symmetrically until it leads into the axial passage 13 of the main part 12 via an opening 23a, 23b, respectively.

[0079] In this example, the first flow path I constitutes the inlet flow path of the valve 10, i.e., the upstream flow path, while the second flow path II constitutes the outlet, i.e., the downstream flow path, although the circulation within the valve 10 can very well be reversed.

[0080] The valve 10 further comprises an anti-rotation element 30 provided in the axial passage 13 of the second fluid passage II. More precisely, this anti-rotation element 30, produced by additive manufacturing, is rigidly mounted on a structural ring 16a marking the joint between the first partition 16 and the second partition 18. The anti-rotation element 30 comprises a peripheral rotation surface forming a deflection surface 31 which runs in the second flow passage II in the extension direction of the channels 22a, 22b of the first flow passage I. The anti-rotation element 30 also comprises an axially extending central passage 32 and a number of guide slots 33, here four, which run in a radial plane between the central passage 32 and the deflection surface 31.

[0081] The valve 10 further comprises a shutter 40 in the form of a cylindrical sleeve that is linearly movable between a first distal position, shown in Figure 3, and a second distal position, shown in Figure 4. The shutter 40 is also manufactured by additive manufacturing.

[0082] In the first distal position, the peripheral wall 41 of the shutter 40, the so-called blocking wall, extends along the entire peripheral surface of the axial passage 13 of the valve body 11 and is therefore interposed between the first flow passage I and the second flow passage II. In this position, the rear end of the blocking wall 41 is engaged in the piloting cavity 17, while a stop face 42 provided at the front of the shutter 40 rests against the shoulder 13a of the axial passage 13.

[0083] In the second distal position, the blocking wall 41 of the shutter 40 is completely retracted into the steering cavity 17, with its rear end positioned against the underside of the steering cavity 17. In this position, the blocking wall 41 does not protrude at all over the openings 23a, 23b of the channels 22a, 22b of the first flow path.

[0084] The outer surface of the blocking wall 41 is provided near its axial end with a cutout 43 provided for a plain bearing 44 in order to guide the translational movement of the shutter 40 and reduce the frictional forces exerted during this movement. In particular, this plain bearing 44 can be of the deformable segment type, for example made of PTFE or a derived material with a low coefficient of friction.

[0085] The outer surface of the blocking wall 41 is also provided, near each of its axial ends, with shoulders 45 which project radially across the entire blocking wall 41. These shoulders 45 are here provided immediately before each of the cutouts 43.

[0086] There is also a rail 46 in front of the rear shoulder 45. The valve body 11, in turn, comprises an annular first seal 47a, mounted before the junction between the first flow path I and the second flow path II, here at the forward end of the passage 13, and an annular second seal 47b, mounted after the junction between the first flow path I and the second flow path II, here at the aft end of the passage 13, just before the pilot cavity 17. The axial distance separating the seals 47a, 47b is equal to the axial distance separating the shoulders 45.

[0087] With this arrangement, when the shutter 40 is in its first distal position, the seals 47a, 47b are compressed against the shoulder 45, thereby ensuring a tight seal of the shutter 40 when the valve 10 is closed. On the other hand, in the second distal position, or in any intermediate position, the seals 47a and 47b are not compressed, the first seal 47a is not positioned opposite the shutter 40, and the second seal 47b faces a thinner portion of the blocking wall 41.

[0088] In this example, the seals 47a, 47b have lips extending radially from a body having an annular cavity into which a metal expander is inserted. Each seal 47a, 47b also has a dovetail-type retaining piece extending from the body to ensure its attachment. In particular, the bodies of these seals 47a, 47b can be machined from a polymer that retains a certain elasticity at low temperatures and is compatible with the fluid to be conveyed, for example filled PTFE. It is noted that the structure of these seals 47a, 47b can be simplified for other less critical applications.

[0089] The shutter 40 also includes a number of ribs 48 extending axially along the inner surface of the blocking wall 41. The number of these ribs 48 is equal to the number of guide slots 33 in the anti-rotation member 30, with each rib 48 engaging one of these guide slots 33. The ribs 48 are terminated at their front ends by radial connecting tabs 49.

[0090] The valve 10 further comprises an actuator 50 of the electric motor type, comprising a rotor 51 and a stator 52. The rotor 51 of the actuator 50, which has as its axis of rotation the main axis A, is housed in the service cavity 15 and is therefore hidden when the valve is in the service state. The rotor 51 of the actuator 50 is more precisely rotatably mounted in the service cavity 15 by means of a roller bearing 53 mounted against the inner surface of the structural ring 16a. A minimum clearance is left between the rotor 51 and the part 16b of the bulkhead 16 which surrounds the rotor 51. Furthermore, the rotor 51 of the actuator 50 comprises a central passage 54 extending along the main axis A.

[0091] Meanwhile, the stator 52 is pressed flat against the portion 16b of the partition 16, pressed concentrically against the rotor 51, and accommodated in the control chamber 19. In order to minimize the gap between the rotor 51 and the stator 52, at least the first portion 16b of the first partition 16 has a thickness of less than 10 mm, preferably less than 5 mm, and more preferably less than 2 mm.

[0092] In this example, the actuator 50 is a synchronous electric motor with permanent magnets. The synchronous electric motor is sinusoidal electromotive force and double star connected non-salient poles. Here, the actuator 50 has six pairs of magnetic poles. The rotor magnets are encapsulated using laser welding and follow an alternating or Halbach arrangement.

[0093] The valve 10 also comprises a resolver 55, which also 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 hidden when the valve 10 is in the service state. The rotor 56 of the resolver 55 is fixed to the rotor 51 of the actuator 50, behind it, in the extension of the rotor 51 of the actuator 50 along the main axis A, the rotor 56 of the resolver 55 therefore also having the main axis A for its axis of rotation.

[0094] 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 partition 16 decreases from the rear end of its first cylindrical portion 16b until it reaches the second cylindrical portion 16c, the diameter of which is slightly larger than the diameter of the rotor 56 of the resolver 55 by a positive or negative play. The diameter of the first partition then continues to decrease until it is removed, thus surrounding 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.

[0095] On the other hand, the stator 57 of the resolver 55 is pressed flat against the portion 16c of the partition wall 16 and is accommodated in the control chamber 19 concentrically with the rotor 56. In this example, the resolver 55 is a two-wire brushless resolver.

[0096] The valve 10 also has a control module, housed within the control room 19, that is used to drive the actuator as a function of a set point communicated to the valve 10. In this regard, in this example, control of the actuator 50 is in a closed loop with a sinusoidal current command via position feedback provided by a resolver 55.

[0097] The valve 10 further comprises a rotary-to-linear transmission member 60. This transmission member 60 comprises, on the one hand, a roller nut 61 fixed to the rotor 51 of the actuator 50. This roller nut 61 is precisely mounted on the front end of the rotor 51 about the main axis A. The roller nut 61 thus rotates about the main axis A as a single piece with the rotor 51 of the actuator 50.

[0098] Furthermore, the transmission member 60 includes a screw 62 that engages the roller nut 61 and extends axially along the main axis A. Rotation of the roller nut 61 thus drives translation of the screw 62 along the main axis A, such that the screw 62 can travel forward through the central passage 32 of the anti-rotation member and rearward through the central passages 54 and 59 of the rotors 51 and 56 of the actuator 50 and resolver 55.

[0099] The screw 62 also comprises at its front end a connecting piece 63 which is used to engage with the radial connecting tabs 49 of the shutter 40 and rigidly connect the radial connecting tabs 49 to the screw 62. Thus, when the screw 62 moves forward or backward, it drives the shutter 40 in a translational motion as a single part.

[0100] In this regard, the guide slots 32 of the anti-rotation member 30 prevent the shutter 40, and thus the screw 62, from rotating about the main axis A, so that movement of the shutter 40 and the screw 62 is purely axial.

[0101] The actuator 50 is therefore capable of quickly and accurately moving the shutter 40 to any position between its two extreme positions. In this example, the actuator 50 is therefore capable of manipulating the shutter 40 from its first extreme position, i.e., fully closed position, to its second extreme position, i.e., fully open position, in less than 1 second with a power of less than 2000 W (power supply voltage between 50 V and 400 V).

[0102] Although the present invention has been described with reference to certain exemplary embodiments, it is clear that modifications and variations can be made to these examples without departing from the general scope of the invention as defined by the scope of the claims. In particular, individual features of the different embodiments shown / mentioned can be combined in additional embodiments. The description and drawings should therefore be considered in an illustrative sense, and not in a restrictive sense.

[0103] It will also be apparent that all features described with reference to a method, either alone or in any combination, can be transformed into an apparatus, and conversely, all features described with reference to an apparatus, either alone or in any combination, can be transformed into a method.

Claims

1. In the valve, The valve is A valve body (11) having a first flow path (I) and a second flow path (II); a movable shutter (40) configured to adjust the flow area between the first flow path (I) and the second flow path; an electric actuator (50) configured to adjust the position of the movable shutter (40); the movable shutter (40) has a first position in which the movable shutter (40) is fully inserted between the first flow path (I) and the second flow path (II) and reduces the flow area between the first flow path (I) and the second flow path (II) to zero, and a second position in which the flow area between the first flow path (I) and the second flow path (II) is reduced to a maximum value; The valve, wherein the electric actuator (50) comprises a rotor (51) installed in a service cavity (15) of the valve body (11), the service cavity (15) being in fluid communication with the first flow path (I) or the second flow path (II), and the electric actuator (50) is configured to drive the movement of the movable shutter (40) via a rotary-to-linear transmission member (60).

2. 2. The valve of claim 1, wherein the second flow path (II) extends along a main axis (A) of the valve (10) and the first flow path (I) forms a non-zero angle (θ) with the main axis (A).

3. 3. A valve according to claim 1 or 2, wherein the first flow path (I) is provided with a connecting orifice (21) and is divided into two channels (22a, 22b), each of which bypasses the main axis (A) on a different side of the valve (10) before opening into the second flow path (II).

4. A valve as claimed in any one of claims 1 to 3, wherein the movable shutter (40) takes the form of a cylindrical sleeve.

5. 5. The valve according to any one of claims 1 to 4, wherein the valve comprises two seals (47a, 47b), a first seal (47a) mounted in the second flow path (II) before a junction (23a, 23b) between the first flow path (I) and the second flow path (II) and a second seal (47b) mounted in the second flow path (II) after the junction (23a, 23b) between the first flow path (I) and the second flow path (II).

6. 6. The valve of claim 5, wherein the first seal (47a) is compressed against the movable shutter (40) only when the movable shutter (40) is disposed in its first position, and the second seal (47b) is compressed against the movable shutter (40) only when the movable shutter (40) is disposed in its first position.

7. The valve according to any one of the preceding claims, comprising an anti-rotation member (30) fixedly mounted within the valve body (11) and configured to lock the movable shutter (40) against rotation.

8. 8. The valve according to claim 1, further comprising a deflection surface (31) mounted in the second flow path (II) at the junction (23a, 23b) between the first flow path (I) and the second flow path (II), the deflection surface (31) being profiled to extend the first flow path (I) into the second flow path (II).

9. A valve according to any one of the preceding claims, wherein the electric actuator (50) is an electric motor, preferably of the synchronous type, and further preferably having a permanent magnet.

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

11. A valve according to any one of the preceding claims, wherein the rotary-to-linear transmission member (60) comprises a screw (62) and a nut (61), said nut (61) being preferably a roller nut.

12. An engine comprising at least one valve (10) according to any one of the preceding claims.

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