Patent Description:
The temperature conditioning of fluids such as gases or liquids is a topic of relevance in buildings and vehicles. In particular, in vehicles using di-hydrogen (H2) as fuel, the H2 is often stored in conditions of very low temperature but must be heated up to be used in an engine.

In aircraft in particular the weight of a system and its energy consumption are critical to the efficiency and fuel-burn of the aircraft. Therefore, when a source of heat is needed for a specific system or device, it is beneficial to harvest this heat from another portion of the aircraft that needs cooling. Calories must therefore be transported through sections of the aircraft in hydraulic circuits. These hydraulic circuits comprise many devices such as pumps and valves to ensure their functionalities with different requirements in different phases of a flights, as well as the safety of the aircraft.

Different types of valves are known which can achieve various functions, such as a three-way valve or a four-way valve. However, in some hydraulic circuits as those that will be presented further in this text in connection with the invention, multiple valves would have to be used, with side effects such as high weight, high complexity, low reliability, etc..

<CIT> discloses a refrigeration cycle including a compressor, an indoor heat exchanger, an expansion, an outdoor heat exchanger and a six-way change-over valve having a refrigerant passage through which refrigerant flows in a refrigerant circuit comprising the compressor, the indoor heat exchanger, the expansion and the outdoor heat exchanger, wherein the six-way change-over valve serves to selectively switch the refrigerant passage so that the refrigerant passing in the indoor and outdoor heat exchangers flows in the same direction at any time when the refrigerant cycle is switched to a cooling operation cycle and to a heating operation cycle.

<CIT> discloses a flow passage switching valve which is capable, with a simple configuration, of preventing an annular seal surface of a slide valve body from catching on a port configured to be open on a valve sheet surface of a main valve seat. A protruding surface part, which has the same height as an annular seal surface, is provided on the outside of a first slide valve body (high-pressure side slide valve body) in the axial direction of the annular seal surface.

<CIT> discloses a back washing valve and filtering apparatus with the same. A backwash valve controls or switch the direction of water flowing through a filter so as to filter foreign materials from water and/or automatically discharge foreign materials previously filtered by the filter. The backwash valve comprises a body hollow in its inner space and a direction control unit movably mounted inside the body in such a manner as to be in close contact with the inner wall of the body. The backwash valve control or switch the flow of water which is automatically of manually introduced/discharged. Also, a backwash filtering device using the backwash valve can easily discharge foreign materials accumulated in the filter without replacing the filter with new one through operation of the backwash valve.

<CIT> discloses a fluid flow control device, comprising a cylindrical casing, a drum rotatable in the casing, a plurality of transverse passages in said drum having their openings on the periphery of said drum, a plurality of ports leading from said cylinder, said openings of said passages and said ports on said cylinder being substantially equally spaced circumferentially for selective alignment of said passages with said ports according to the relative angular position of said drum and said cylinder, and a system of conduits being connected to said ports for conducting the flow through selected drum passages, a fluid pump connected to certain conduits of said system for conveying fluid under pressure, other conduits of said system being connected to the intake of said fluid pump for return flow, a bypass circuit to bypass said fluid under pressure from said pump, a normally open valve adapted to close said bypass circuit, and the remaining ports and conduits being connected to devices operable by said fluid pressure, an adjusting element extended from the drum for adjusting the position of the drum, means on said element to indicate the position of alignment of the respective passages of said drum with respect to the ports of said cylinder, and an actuator member connected to said valve being movable for permitting a buildup of pressure by said pump through said conduit system, said actuator element and said indicator means coacting to allow actuating movement of said member only when said indicating elements indicate an aligned position of said drum passages with respect to ports corresponding to said indication.

The invention aims to provide a hydraulic circuit which provides flexibility in its use so as to be adapted to varying requirements at different instants.

The invention particularly aims to provide a hydraulic circuit for an aircraft that can deliver calories to a specific device in different flight phases.

The invention also aims to provide a valve that allows to divide a hydraulic circuit so as to adapt the hydraulic circuit to different functioning requirements.

The invention aims to provide a hydraulic circuit and a valve which are particularly reliable and safe.

The invention also aims to provide a hydraulic circuit and a valve that are simple to install and maintain.

The invention proposes a valve comprising:.

A valve according to the invention is adapted to receive a coolant and to be mounted on a hydraulic circuit for a coolant. In the present text, the term coolant or cooling liquid refers to a liquid used to transfer heat from a device such as a heat exchanger to another device such as a heat exchanger, even if the main function of the circuit is to harvest heat.

The valve comprises a movable part and a fixed part. The movable part is movable with respect to the fixed part. The fixed part usually comprises the intake ports and exhaust ports as these ports are part of a bigger hydraulic circuit which is generally fixedly mounted, either in a building or in a vehicle. In the whole text the terms "bypass position" and "direct position" referring to a position of the movable part with respect to the fixed part of the valve will also be used to refer to the valve's state in a hydraulic circuit.

A valve of the invention allows to provide a hydraulic circuit with multiple configurations, each configuration corresponding to a position of the movable part of the valve. In particular a valve of the invention allows to form a single hydraulic circuit by joining a first portion of hydraulic circuit to a second portion of hydraulic circuit, or to form two independent hydraulic circuits by the single displacement of one part.

Each passageway is adapted for a fluid to flow through the valve from an intake port to an exhaust port. A passageway according to the invention is within the valve. The passageway may comprise multiple conduit portions, some conduit portions being within the movable part and other conduit portions being within the fixed part. The bypass position and the direct position of the movable part correspond to relative positions of the movable part and the fixed part in which conduits in the fixed part hydraulically connect with conduits in the movable part.

A valve according to the invention provides many benefits.

One of these benefits is that only one valve is needed to separate a main hydraulic circuit into two independent circuits. This limits the weight and costs of such circuit. The reliability of such hydraulic circuit is also very high because its good working depends on a limited number of valves.

Another benefit is that the length of hydraulic conduits which are not used in one or another of the configuration is limited compared to a circuit which would comprise optional conduits with traditional three-way or four-way valves.

A direct hydraulic connection between the first intake port and the second exhaust port allows to bypass completely a fluid flow between these two ports. It may allow in particular to close a first circuit portion on itself. In particular such first circuit portion may comprise devices such as sensors, heat exchangers, valves or a pump for a fluid to continue to flow in this first circuit and in particular in the third passageway and fourth passageway from the first intake port to the second exhaust port. This first circuit is thus easily made independent from any other hydraulic circuit connected to the first exhaust port and/or the second intake port.

With the movable part in bypass position, the second intake port may be hydraulically connected to the first exhaust port by at least a fifth passageway.

A direct hydraulic connection between the second intake port and the first exhaust port allows to bypass completely a fluid flow between these two ports. It may allow in particular to close a second circuit portion on itself. In particular such second circuit portion may comprise devices such as sensors, heat exchangers, valves or a pump for a fluid to continue to flow in this second circuit and in particular in the fifth passageway directly from the second intake port to the first exhaust port. This second circuit is thus easily made independent from any other hydraulic circuit connected to the first intake port and/or the second exhaust port and/or the third intake port and/or the third exhaust port.

In such configuration, the fluid of a circuit portion coming in through the second intake port may be redirected to another circuit portion through the fourth exhaust port. Similarly, a fluid from yet another hydraulic circuit may be injected through the fourth intake port into the circuit portion connected to the first exhaust port.

In cases in which the second intake port and the first exhaust port pertain to the same hydraulic circuit, these characteristics allow to deviate the fluid of this circuit to a circuit portion situated between the fourth exhaust port and the fourth intake port. Additional devices such as sensors for example may be mounted on this circuit portion so as to add functions to the hydraulic circuit portion flowing between the first exhaust port and the second intake port when the valve is in bypass position.

The valve may also comprise a fifth conduit adapted to form part of the fifth passageway in the bypass position.

In embodiments in which the valve also comprises a fourth intake port, the movable part also comprises a sixth conduit adapted to form part of the sixth passageway in the bypass position.

A valve according to the invention may further be adapted such that when displacing the movable part between the direct position and the bypass position, at least one passageway remains at least partially open for each intake port towards at least one exhaust port.

This allows a continuous transition between the two positions of the movable part, such that a fluid circulating in each of the hydraulic circuits connected by the valve will always have an open flow path. Thereby the fluid circulation is not temporarily stopped by the change of position of the movable part in the valve. Any hammer effect in the hydraulic circuit(s) or any other unstable system performance during or after the position change of the valve are thus avoided.

In order to do so, the dimensions of and the distance between the conduits of the movable part and the dimensions of conduits in the fixed part which open on an intake port or on an exhaust port are adapted such that, before a first of these conduits is completely closed to the fixed part conduit by the displacement of the movable part between a direct position and a bypass position, a second of these conduits in the movable part is at least partially open to the fixed part conduit. For example, a conduit portion in the fixed part of the valve opening on the valve's surface at the second intake port will come out:.

Said otherwise, in this example, the opening of the second conduit and the opening of the third conduit overlap the opening of the fixed conduit in an intermediate position between the direct position and the bypass position.

The movable part may be passively maintained in a direct position, and actively actuated towards a bypass position.

By passively it is meant that no actuator needs to be continuously fed with energy to maintain the movable part's position.

Thereby the movable part of the valve is by default in a direct position. In a hydraulic circuit of the invention, this corresponds to a situation in which the coolant circulates from a heat harvesting heat exchanger to a heat providing heat exchanger. When an engine is stopped and cold, the coolant will harvest no heat at the heat harvesting heat exchanger, such that there will be no heat provided to the fuel line and that the engine will not be able to start. Should the valve of the invention be failing before starting the engine, it will remain in the direct position and thus the engine will not be able to start. Thereby a safety is provided in which the engine will not start in case the valve has a defect.

On the contrary, should the valve fail while the engine is working, the hydraulic circuit will continue to ensure its function and the fuel will continue to be heated such that the engine will remain working.

The movable part may be maintained by default in a direct position by springs.

The movable part may be actuated by any known techniques such as an electrical actuator, a hydraulic actuator, a pneumatic actuator, etc..

The movable part may be movable by translation or by rotation around an axis with relation to the fixed part.

A valve according to the invention may further comprise a piston chamber adapted to receive a pressurized fluid so as to actuate the movable part.

The piston chamber may be adapted to receive a pressurized fluid so as to actuate the movable part. The movable part may be mounted as a rotating or translating piston in the fixed part, actuated by a pressurized fluid in the piston chamber. For example in embodiments in which the movable part is by default in the direct position, the piston chamber may be adapted to receive a pressurized fluid which, above said predetermined pressure in the piston chamber, would displace the movable part towards the bypass position.

The movable part may thus be actuated by a hydraulic or pneumatic device.

The movable part may comprise a third predetermined position in which the first intake port, the second intake port, the first exhaust port and the second exhaust port may be hydraulically connected in a different manner than in the bypass position or in the direct position.

The movable part may comprise multiple sets of conduits adapted to connect the first intake port, the second intake port, the first exhaust port and the second exhaust port in various manners depending on its position. The number of predetermined positions each with a set of conduits is not limited to two or three and may be of more within the frame of this invention.

In the same way, the valve may comprise more than four intake ports and/or more than four exhaust ports.

Furthermore, the valve may comprise a sealing device between the movable part and the fixed part in order to avoid any fluid leak or mix of fluids between different hydraulic circuits. The sealing device may comprise one or more seals.

The movable part may comprise at least one functionalized conduit adapted to modify at least one characteristic of a flow of fluid in said functionalized conduit.

The flow of fluid may be only locally modified by the functionalized conduit, or may be modified in a longer portion of or in the whole hydraulic circuit of which it is part. The functionalized conduit may comprise a restrictor, a convergence portion, a divergence portion, etc..

The invention extends to a hydraulic circuit comprising at least one valve according to the invention.

A hydraulic circuit according to the invention may comprise one or more valve(s) according to the invention, with fluid conduits connected to the intake ports and exhaust ports of the valve(s). The hydraulic circuit may be adapted to conduct a cooling liquid - or coolant.

A hydraulic circuit according to the invention may comprise:.

A hydraulic circuit according to the invention may comprise a hot-side circuit portion and a cold-side circuit portion. The hot-side circuit portion and the cold-side circuit portion are joined and form a main circuit when joined by the valve in the direct position. More particularly, the cold-side circuit may be connected to and extending between the first intake port and the second exhaust port of the valve, while the hot side circuit may be connected to and extending between the first exhaust port and the second intake port of the valve.

When the valve is in the bypass position the hot-side circuit portion and the cold-side circuit portion are segregated. For example, the cold-side circuit portion may be deviated to a bypass circuit portion, while the hot-side circuit portion may be directly bypassed so as to close on itself within the valve.

Thereby, in a hydraulic circuit according to the invention with a valve of the invention, a hydraulic circuit may be divided to form two independent hydraulic circuits by the single displacement of one part. This provides a particularly simple, reliable and light hydraulic circuit.

The hydraulic circuit comprises a bypass circuit portion between the third exhaust port and the third intake port.

More specifically, the hydraulic circuit may comprises a third circuit portion, called bypass circuit, comprising a bypass pump and extending between the third exhaust port of the valve and the third intake port of the valve.

The bypass pump may be electrically actuated or otherwise provided.

The bypass pump is adapted to circulate a fluid in the bypass circuit from the third exhaust port towards the third intake port.

The bypass pump is situated on a circuit portion that is only used when the coolant is bypassed by the movable part in the bypass position.

A hydraulic circuit according to the invention may comprise a hydraulic actuating conduit extending from the bypass pump to the piston chamber of the valve.

In such embodiments of the invention, the simple activation of the bypass pump will both circulate the coolant in the bypass circuit - and thereby in the hydraulic circuit connected through the valve to the bypass circuit (for example the cold-side circuit) - and in the movable part of the valve towards a bypass position.

Alternatively, another actuating device may be activated simultaneously or slightly beforehand the bypass pump, for example by a same controller.

A hydraulic circuit according to the invention may comprise a heating device on the bypass circuit.

The heating device may be of different types. It may for example be a heat exchanger, an electrical heating device, etc.. Beneficially in an aircraft of the invention, the heating device is an electrical heating device. Such device would only be used in phases of starting the engine.

In some embodiments, the bypass circuit may comprise a heating device without a pump.

The invention also extends to an aircraft comprising at least one hydraulic circuit according to the invention. In particular the invention extends to an aircraft comprising one or more hydraulic circuit with one or more valve according to the invention.

In an aircraft according to the invention, a heat exchanger of the hot-side circuit may be mounted on an engine exhaust so as to harvest waste heat from the exhaust. For example the engine may be an auxiliary power unit (APU).

Similarly, the heat exchanger of the cold-side circuit may be mounted on the same engine's fuel line, so as to condition - in particular to heat up - a fuel before feeding it to the engine. This would allow to heat up H2 from cryogenic conditions in a tank to a temperature and state that would facilitate its burn in the engine.

The invention also extends to other possible combinations of features described in the above description and in the following description relative to the figures. In particular, the invention extends to valves comprising features described in relation to the hydraulic circuit and/or the aircraft; the invention extends to hydraulic circuits comprising features described in relation to the valve and/or the aircraft; the invention extends to aircrafts comprising features described in relation to the valve and/or the hydraulic circuit.

Some specific exemplary embodiments and aspects of the invention are described in the following description in reference to the accompanying figures.

In <FIG> a specific embodiment of a hydraulic circuit <NUM> according to the invention is represented in its context in an aircraft.

This hydraulic circuit <NUM> is made to transport a heat-transfer fluid, or cooling liquid or coolant.

This hydraulic circuit may be mounted in an aircraft <NUM> of the type represented in figure <NUM>. In this embodiment represented in <FIG>, the aircraft comprises an engine with an exhaust nozzle or exhaust pipe <NUM> for exhausting combusted gases out of a combustion chamber <NUM> of the engine. The engine is at least partially fueled by a fuel stored in a tank <NUM> of the aircraft. The fuel is fed to the engine from the fuel tank <NUM> through a hydraulic circuit for fuel or fuel line <NUM>. The fuel line <NUM> may comprise multiple devices not represented here such as pumps, valves, branches, compressors, etc..

The fuel may be di-hydrogen (H2). in order to be stored in fuel tanks <NUM> of reasonable size for an aircraft, that is to say to reach an energy density compatible with its transport on-board an aircraft as its energy source, the H2 must be stored at very low temperatures at which it is liquid. However, to burn in an aircraft engine the fuel must be heated up.

In <FIG> and <FIG> the same hydraulic circuit is represented, this time only with the hydraulic circuit object of the invention and in a more schematic representation.

In particular this embodiment of a hydraulic circuit <NUM> according to the invention comprises a first heat exchanger <NUM> situated at the exhaust pipe <NUM> so as to be able to harvest calories from hot combusted gases flowing through the exhaust pipe <NUM> when the engine is running.

The hydraulic circuit <NUM> comprises a second heat exchanger <NUM> adapted to deliver calories to a fuel in a fuel line <NUM>.

In other embodiments, the hydraulic circuit <NUM> may comprise more than two heat exchangers. For example it may comprise two successive heat exchangers on the fuel line so as to warm up the fuel in two stages.

The hydraulic circuit <NUM> comprises multiple conduits forming multiple hydraulic circuit portions <NUM>, <NUM>, <NUM>, <NUM>. The hydraulic circuit portions <NUM>, <NUM>, <NUM>, <NUM> are all connected to and extend between intake ports <NUM>, <NUM>, <NUM>, <NUM> and exhaust ports <NUM>, <NUM>, <NUM>, <NUM> of a valve <NUM> according to the invention.

A first hydraulic circuit portion, called hot-side circuit <NUM>, comprises the first heat exchanger <NUM> and a pump <NUM> adapted to circulate the coolant in the hydraulic circuit <NUM>. One side of the hot-side circuit <NUM> is connected to first exhaust port <NUM> of the valve <NUM>, and another side of the hot-side circuit <NUM> is connected to a first intake port <NUM> of the valve <NUM>.

A second hydraulic circuit portion, called cold-side circuit <NUM>, comprises the second heat exchanger <NUM>. One side of the cold-side circuit <NUM> is connected to a first intake port <NUM> of the valve <NUM>, and another side of the cold-side circuit <NUM> is connected to a second exhaust port <NUM> of the valve <NUM>.

In a direct position, the valve is adapted to hydraulically connect:.

Therefore, when the valve <NUM> is in a direct position, the hot-side circuit <NUM> and the cold-side circuit <NUM> are connected to each other in such a way that they form a bigger hydraulic circuit <NUM> together.

More particularly, the valve comprises a movable part <NUM> mounted movable in a fixed part <NUM>. The intake ports <NUM>, <NUM>, <NUM>, <NUM> and exhaust ports <NUM>, <NUM>, <NUM>, <NUM> of the valve <NUM> are all mounted on the fixed part <NUM> of the valve <NUM>. The movable part <NUM> may be displaced between at least two positions with respect to the fixed part <NUM>.

The movable part <NUM> may be in a first position, called direct position, represented in <FIG> and <FIG> with respect to the fixed part <NUM>, or in a second position, called bypass position, represented in <FIG> and <FIG>, with respect to the fixed part <NUM>.

The movable part <NUM> may be displaced by any type of actuator such as electrical, hydraulic, pneumatic, etc..

This configuration corresponds to a functioning mode in which the aircraft engine is hot and running and the coolant transports calories from the first heat exchanger <NUM> to the second heat exchanger <NUM>, such that the fuel in the fuel line <NUM> is adequately heated up before being injected into the engine.

The hydraulic circuit <NUM> further comprises a third hydraulic circuit portion, called bypass circuit <NUM> and a fourth hydraulic circuit portion, called loop circuit <NUM>.

One side of the bypass circuit <NUM> is connected to third exhaust port <NUM> of the valve <NUM>, and another side of the bypass circuit <NUM> is connected to a third intake port <NUM> of the valve <NUM>.

The bypass circuit <NUM> comprises a bypass pump <NUM> adapted to circulate the coolant in at least some portions of the hydraulic circuit <NUM>. More specifically, the bypass pump is adapted to circulate the coolant in the cold-side circuit <NUM> and the bypass circuit <NUM> when they are connected together by the valve <NUM> in the bypass position through the third passageway and fourth passageway, and the two hydraulic circuit portions form a single hydraulic circuit (see <FIG> and <FIG>).

The bypass circuit <NUM> also comprises a heating device <NUM> such as a heat exchanger or an electrical heater adapted to heat the coolant up. This heating device <NUM> is used in phases of starting the engine of the aircraft. Indeed the engine is cold at start and therefore no calories may be extracted by the first heat exchanger <NUM> to heat up the coolant and thus heat up the fuel at the second heat exchanger <NUM>. Thereby, when starting the engine, the valve <NUM> is placed in the bypass position such that the coolant may circulate between the heating device <NUM> and the second heat exchanger <NUM> so as to heat the fuel up upon starting the engine.

The loop circuit <NUM> comprises a conduit connected to a fourth exhaust port <NUM> and a fourth intake port <NUM> of the valve <NUM> so as to close the hot-side circuit <NUM> on itself when the valve <NUM> in a bypass position (see <FIG> and <FIG>).

In other embodiments not represented, the valve may comprise an internal passageway connecting directly the second intake port <NUM> to the first exhaust port <NUM>. This may be beneficial when no additional device is sought to the installed on the loop circuit <NUM>.

In the bypass position of the valve, as represented on <FIG>:.

In the bypass position, while a first portion of the coolant circulates in the cold-side circuit <NUM> and is heated up by the heating device <NUM>, another portion of the coolant circulates independently in the hot-side circuit <NUM> with the pump <NUM>. Thereby as soon as the temperature of the engine is sufficient, the cold-side circuit <NUM> and the hot-side circuit <NUM> may be reconnected to each other by placing the valve in the direct position and all the coolant is at the required temperature in each side of the hydraulic circuit <NUM>.

In some embodiments the loop circuit <NUM> may comprise a temperature sensor in order to trigger the change of position of the valve from a bypass position to a direct position. The sensor may be connected to a controller controlling an actuator of the movable part <NUM>.

The coolant circulates in the cold-side circuit in the same direction whether the valve is in the direct position or in the bypass position. Similarly, the coolant circulates in the hot-side circuit in the same direction whether the valve is in the direct position or in the bypass position.

In <FIG> a detail of an embodiment of a movable part <NUM> of a valve <NUM> of the invention is represented.

In <FIG> a detail of an embodiment of a fixed part <NUM> of a valve <NUM> of the invention is represented connected to hydraulic circuit portions <NUM>, <NUM>, <NUM>, <NUM>.

Moreover the fixed part <NUM> comprises a recess <NUM> for the movable part <NUM>. The movable part may slide in translation in this recess <NUM>. In the representations of <FIG> and <FIG>, the movable part <NUM> may slide vertically with respect to the fixed part <NUM> between the direct position represented in <FIG> and the bypass position represented in <FIG>.

As represented in <FIG>, the fixed part <NUM> comprises conduit portions between the intake ports and exhaust ports and the recess <NUM> so as to connect the intake ports and exhaust ports to respective conduits <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of the movable part <NUM>. In <FIG>, the valve <NUM> is represented in a direct position in which the coolant is circulating from the cold-side circuit <NUM> to the hot-side circuit <NUM> through the first passageway <NUM> and from the hot-side circuit <NUM> to the cold-side circuit <NUM> through the second passageway <NUM>, where the arrows represent the flow direction of the coolant in the hydraulic circuit <NUM>.

In <FIG> on the contrary, the valve <NUM> is represented in a bypass position in which the coolant is circulating independently in two hydraulic circuits, where the arrows represent the flow direction of the coolant in the two hydraulic circuits:.

In <FIG>, an example of a valve according to the invention is schematically represented with a focus on the actuation of the movable part <NUM>. In this embodiment the movable part is movable in translation with respect to the fixed part <NUM>. In particular a specific embodiment of actuation of the movable part <NUM> is represented.

In this embodiment, the valve <NUM> comprises a piston chamber <NUM> and a hydraulic actuating conduit <NUM>. The piston chamber <NUM> is adapted to receive a fluid with a low compressibility. The piston chamber <NUM> is formed within the fixed part <NUM> of the valve, with one face closed by the movable part <NUM>. Upon injection of a low-compressibility fluid in the piston chamber <NUM>, the movable part is displaced with respect to the fixed part.

Moreover, the valve <NUM> may comprise a device to maintain the movable part in the direct position by default. In this example the valve comprises a pair of springs <NUM> which may rest against a portion of the fixed part <NUM> on one side (not shown), and on a face of the movable part <NUM> on another side such that in the absence of a pressurized fluid in the piston chamber <NUM>, the movable part <NUM> is maintained in the direct position.

When such valve <NUM> is mounted in a hydraulic circuit <NUM> of the type presented in <FIG> and <FIG>, the injection of pressurized fluid in the piston chamber <NUM> through the hydraulic actuating conduit <NUM> is beneficially controlled simultaneously or slightly in advance to the actuation of the bypass pump <NUM>.

In some embodiments, the bypass pump <NUM> may be used to both circulate the coolant in the bypass circuit <NUM> and be connected to the hydraulic actuating conduit <NUM> to inject/pressurize a fluid in the piston chamber <NUM> of the valve <NUM>. Thereby the valve is actuated from a direct position to a bypass position simultaneously to the circulation of coolant in the bypass circuit <NUM>; this latter being connected to the cold-side circuit <NUM> as soon as the movable part <NUM> is in the bypass position.

In <FIG> an alternative embodiment of a movable part <NUM> according to the invention is represented. In this embodiment, the movable part <NUM> is cylindrical and may be mounted in a rotatable manner around an axis <NUM> within a cylindrical recess of the fixed part. In such embodiment, the movable part <NUM> would rotate between its direct position and its bypass position.

Similarly to previous embodiments, the movable part <NUM> comprises multiple conduits <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> for connecting intake ports to exhaust ports in at least two different configurations corresponding to the direct position and the bypass position.

In <FIG> a cross section by a horizontal plane of this movable part <NUM> as mounted in a fixed part <NUM> is represented. The cross-section is represented at the height of a plane comprising multiple conduits <NUM>, <NUM>, <NUM>.

In <FIG>, the movable part <NUM> is in a direct position in which it connects a cold-side circuit <NUM> with a hot-side circuit <NUM> through a first intake port <NUM>, a first passageway comprising a first conduit <NUM>, and through a first exhaust port <NUM>. A bypass circuit <NUM> and a loop circuit <NUM> are cut and not used in this direct position.

By a clock-wise rotation of the movable part <NUM> in the fixed part <NUM> around an axis <NUM>, the valve <NUM> is switched from a direct position to a bypass position.

In the bypass position represented in <FIG>, the valve <NUM> is in a bypass position in which it connects:.

In <FIG>, a detail of a valve according to the invention is shown. The valve comprises a conduit <NUM> extending within the fixed part <NUM> from the first intake port <NUM> to an opening <NUM> on the recess in which the movable part <NUM> is mounted. The movable part <NUM> comprises multiple conduits comprising at least a first conduit <NUM> for forming the first passageway in the direct position between the first intake port <NUM> and the first exhaust port, and a third conduit <NUM> for forming the third passageway in the bypass position between the first intake port <NUM> and the third exhaust port.

In this <FIG>, the movable part <NUM> is between the direct position and the bypass position. The diameters of the conduit <NUM>, the first conduit <NUM> and the third conduit <NUM>, and the distances between the first conduit <NUM> and the third conduit <NUM> are such that the opening <NUM> of the conduit <NUM> overlaps the first conduit <NUM> and the third conduit <NUM>. Thereby, by applying the same feature to all hydraulic connections within the valve between conduits of the fixed part and conduits of the movable part, when the movable part <NUM> is displaced between the direct position and the bypass position, the fluid in the hydraulic circuits is never stopped. Any hammer effect in the hydraulic circuit(s) or any other unstable system performance during or after the position change of the valve are thus avoided.

In <FIG>, a detail of a valve according to the invention is shown. The valve comprises a conduit <NUM> to connect an intake port to an exhaust port. The conduit <NUM> comprises a restriction which allows to control the speed and debit of the fluid in the hydraulic circuit, in the corresponding position of the valve.

This conduit <NUM> and other ones may comprise any other functionality that one may want to add to the hydraulic circuit in a given position of the valve.

This conduit <NUM> may connect an intake port to an exhaust port in a third position of the movable part <NUM> with respect to the fixed part <NUM>, the third position being different from the direct position and the bypass position.

A valve according to the invention thereby allows to add or remove functionalities from one or more hydraulic circuits and to easily reconfigure a hydraulic circuit with a simple displacement of a single valve.

Claim 1:
Valve (<NUM>) comprising:
- a first intake port (<NUM>),
- a first exhaust port (<NUM>),
- a second intake port (<NUM>),
- a second exhaust port (<NUM>),
- a movable part (<NUM>) adapted to be displaced between at least:
• a first position, called direct position, in which :
∘ the first intake port (<NUM>) is hydraulically connected to the first exhaust port (<NUM>) by a first passageway, and
∘ the second intake port (<NUM>) is hydraulically connected to the second exhaust port (<NUM>) by a second passageway,
• and a second position, called bypass position,
- the valve (<NUM>) further comprising:
• a third intake port (<NUM>),
• a third exhaust port (<NUM>),
- wherein, with the movable part (<NUM>) in bypass position:
• the first intake port (<NUM>) is hydraulically connected to the third exhaust port (<NUM>) by a third passageway, and
• the third intake port (<NUM>) is hydraulically connected to the second exhaust port (<NUM>) by a fourth passageway
characterized:
- in that the valve (<NUM>) further comprises:
• a fourth intake port (<NUM>),
• a fourth exhaust port (<NUM>),
- and in that, with the movable part (<NUM>) in bypass position:
• the second intake port (<NUM>) is hydraulically connected to the fourth exhaust port (<NUM>) by a fifth passageway, and
• the fourth intake port (<NUM>) is hydraulically connected to the first exhaust port (<NUM>) by a sixth passageway.