3-WAY PROPORTIONAL HYDRAULIC VALVE

Abstract

The invention relates to a motorized hydraulic rotary valve comprising a housing (2) and a core (4), said housing (2) comprising a side wall (8), two end walls (6, 10) defining a hydraulic chamber, in which the core (4) is housed, adapted to rotate within said chamber about an axis (XX') of rotation, at least one supply port (11), and at least two outlet ports (12, 20, 14, 24), which open into the hydraulic chamber with an internal diameter (Δ), the core (4) comprising a lateral surface (32) facing the side wall (8) of the housing (2), an inlet opening (31), at least one lateral outlet (34), and allowing supply to each of said outlet ports (12, 20) according to its angular position within the housing, the inter-port overlap length being less than or equal to 30% of the internal diameter D of each port. Figure 3B

Description

Title of the invention: 3-WAY PROPORTIONAL HYDRAULIC VALVE

[0001] TECHNICAL FIELD AND PRIOR TECHNOLOGY

[0002] The field of the invention is that of motorized hydraulic valves, in particular of the "3-2 proportional" type whose ports are arranged in a "Y" configuration, each port being oriented on the same plane and whose angular operating range of the valve is, for example, greater than 80° C.

[0003] This type of valve is used for example in hydrogen fuel cell cooling circuits, for which it is necessary to reduce pressure losses in the cooling circuit.

[0004] The valve can be used in the following 2 configurations: either in “split” with the two “V” ways at the output and the third way at the input, or in “mix” with the two “V” ways at the input and the third way at the output.

[0005] In the hydrogen mobility sector, the fuel cell system represents a very large volume to be installed on the vehicle equipped with it. This bulk constitutes a major obstacle to the development of this technology. The hydraulic valves of the fuel cell's cooling circuit are bulky components that impact the overall size of the system to be installed on the vehicle.

[0006] In addition, hydraulic valves are distribution elements which dissipate energy by generating pressure losses in the circuit in which they are installed.

[0007] These pressure losses result in a heating of the fluid and a drop in pressure in the cooling circuit, thus reducing the efficiency of the cooling system and impairing the overall performance of the system.

[0008] The two main causes identified by the inventors for these pressure losses are as follows.

[0009] First of all, on 3-2 proportional valves, for use in "split", i.e. when the valve is oriented so as to supply both outlets, the internal cylindrical surface separating the two outlets (called the overlap surface) constitutes a frontal obstacle to the passage of the fluid and thus generates significant pressure losses.

[0010] Furthermore, the volumes of the areas outside the passage of the flow, called "dead volumes", generate areas of depression causing turbulence and recirculation of the fluid, which in turn cause pressure losses.

[0011] The same problems arise for a 3-2 proportional valve used in "mix", that is to say when the valve is oriented so as to supply an outlet with 2 fluids to be mixed from two inlet outlets: depressions and turbulences (at the outlet of the 2 supply outlets) appear, in particular due to the internal cylindrical surface separating the two inlet outlets.

[0012] The problem therefore arises of finding a new type of hydraulic valve that can solve all or part of these problems. Description of the invention

[0013] The invention aims to remedy at least in part the drawbacks of the prior art, and more particularly to provide an improved hydraulic valve, especially for application to hydrogen fuel cell cooling circuits.

[0014] The invention relates first to a hydraulic rotary valve comprising a housing and a core, said housing comprising a side wall, two end walls delimiting a hydraulic chamber, in which is housed the core adapted to rotate in said chamber about an axis (XX') of rotation, the housing comprising at least one supply port, and 2 outlet ports, respectively 2 supply ports and one outlet port, which open into the hydraulic chamber with an internal diameter, the core comprising a lateral surface opposite the side wall of the housing, an inlet opening of a channel, at least one lateral outlet of this channel, and allowing supply to each of said outlet ports, respectively from each of the inlet ports, depending on its angular position in the housing, the overlap length (L) between outlet ports, respectively between inlet ports, being less than or equal to 30%,for example less than or equal to 25%, or between 24% and 27%, of the internal diameter (A) of each of the output channels, respectively of the input channels.

[0015] In the present application, and regardless of the aspect of the invention concerned, the "core" may also be called the "distributor," and the "housing" may also be called the "valve body." The valve comprises the valve body (or housing) and the distributor (or core).

[0016] The invention also relates to a hydraulic rotary valve comprising a housing and a core, said housing comprising a side wall, two end walls delimiting a hydraulic chamber, in which is housed the core adapted to rotate in said chamber about an axis (XX') of rotation, the housing comprising at least one supply channel, and 2 outlet ports, each extended by an outlet conduit, respectively 2 supply ports, each supplied by a supply conduit, and an outlet channel, which open(s) into the hydraulic chamber, the core comprising a lateral surface facing the side wall of the housing, an inlet opening of a channel, at least one lateral outlet of this channel, and allowing a supply of each of said outlet ports, respectively from each of the input channels, according to its angular position in the housing, the passage cross-section of each of the outlet ports, respectively of each of the input ports, being in the shape of a square with rounded corners.

[0017] The passage section:

[0018] - at least of each of the outlet conduits, respectively at least of each the inlet conduits, can change from a square shape with rounded corners, at the outlet, respectively at the inlet, of the hydraulic chamber, to a circular shape, at a distance from the hydraulic chamber;

[0019] - and / or each of the outlet ports, respectively each of the ports The inlet can have a shape comprising 2 first sides parallel to each other, 2 second sides parallel to each other and perpendicular to the first 2 sides, the first 2 sides and the 2 second sides being connected by portions of a circle and evolving, as it moves away from the valve, towards a circular shape.

[0020] The length of the overlap between exit tracks, respectively between tracks entry, may be less than or equal to 30% or 25%, or between 24% and 27%, of the distance between the first 2 sides or between the second 2 sides.

[0021] In all the above cases:

[0022] - the passage section of each of the exit routes, or each of the ducts, respectively, the inlet can be circular, at a distance from the wall of the hydraulic chamber, then evolve, as it approaches the hydraulic chamber, towards a shape having 2 first sides parallel to each other, 2 second sides parallel to each other and perpendicular to the first 2 sides, the first 2 sides and the 2 second sides being connected by portions of a circle;

[0023] - and / or the passage section of each of the routes, or of each of the conduits, The outlet, or inlet respectively, can be modified along the path, with a reduction, towards, or at the level of, the hydraulic chamber, of the flow passage section, for example in the square-shaped section with rounded corners, less than or equal to 14%, for example between 4% and 14%, compared to a circular shape in which the square-shaped section with rounded corners is inscribed.

[0024] A rotary hydraulic valve according to the invention may comprise an inlet orifice extended by an inlet conduit, respectively an outlet orifice extended by an outlet conduit, the passage cross-section of said inlet orifice, respectively of said outlet orifice, being in the form of a square with rounded corners; a square shape with rounded corners comprises two first sides parallel to each other, two second sides parallel to each other and perpendicular to the first 2 sides, the first 2 sides and the second 2 sides being connected by portions of a circle.

[0025] In particular, the passage section of said inlet conduit, respectively of said outlet conduit, can change from said square shape with rounded corners, at the inlet of the hydraulic chamber, to a circular shape, at a distance from the hydraulic chamber.

[0026] The passage section of said inlet conduit, respectively of said outlet conduit, can be modified along the inlet, respectively outlet path, with a reduction of the passage section of the flow in the square-shaped section with rounded corners, for example less than or equal to 14%, compared to a circular shape in which the square-shaped section with rounded corners is inscribed.

[0027] A hydraulic rotary valve according to the invention may comprise:

[0028] - one inlet and two outlets, the valve being of the "3-2" type, or "Y" type ", whose 3 ways are arranged in a "Y"; in this case, the fluid can be introduced through the supply port, and guided by the internal conduit of the core and then, depending on the orientation of the core in the housing, towards one and / or the other of the outlet ports;

[0029] - or comprise one outlet and two inlet ports, the valve again being of the type The "3-2" or "Y" configuration, where the three ports are arranged in a "Y" shape, allows a fluid to be introduced through the two inlet ports, guided by an internal conduit within the core, and then to the outlet port. This allows fluids of different temperatures to be introduced through the two inlet ports.

[0030] -in one of the ways the fluid will have a higher temperature, for example because it will have been used to cool, for example, a fuel cell;

[0031] - and in the other inlet the fluid has nothing to cool, therefore its temperature does not Don't change.

[0032] Thus, a hot fluid can be mixed with a cold fluid and the distribution of the flow rates allows the temperature to be regulated, for example in a fuel cell.

[0033] Preferably, a valve according to the invention is a proportional hydraulic valve.

[0034] In a hydraulic rotary valve according to the invention, the housing and / or the core can / can be made of plastic material.

[0035] The invention also relates to a motorized hydraulic rotary valve comprising a hydraulic rotary valve according to the invention and an actuator, for example a geared motor (MR), driving the core in rotation.

[0036] For example, in such a motorized hydraulic rotary valve, the actuator has an output shaft aligned along the axis (XX') of rotation.

[0037] The invention also relates to a hydrogen fuel cell cooling circuit, comprising a hydraulic rotary valve according to the invention.

[0038] The invention also relates to a method of distributing a fluid using a motorized hydraulic rotary valve or a hydraulic rotary solenoid valve according to the invention, as described above and in the remainder of this application:

[0039] - the fluid being introduced through the supply port, or through the inlet passage, and being guided by an internal channel of the core and then, depending on the orientation of the core in the casing, towards one and / or the other of the exit ports;

[0040] - or, alternatively, or respectively, at least one fluid being introduced by one and / or the other of the 2 inlet paths, guided by the inner conduit of the core then towards the outlet orifice; for example a fluid can be introduced at 2 different temperatures between the 2 inlet orifices.

[0041] For example, the fluid is air or water or a mixture of water and glycol; it may be a coolant fluid (for example a mixture of water and glycol), especially for a fuel cell. Brief description of the drawings

[0042] Other aspects, objectives, advantages and features of the invention will become more apparent upon reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0043] [Fig. 1] is an exploded view of an example of a hydraulic rotary valve according to the invention comprising one inlet and two outlets.

[0044] [Fig.2] is a perspective view of the rotating central part of the valve of [Fig.1], the seals being shown in a position offset from the central part.

[0045] [Fig.3A] and [Fig.3B] are views which illustrate a first aspect of the invention.

[0046] [Fig.4] is a view of a valve according to the invention.

[0047] [Fig.5A] and [Fig.5B] are views which illustrate a second aspect of the invention.

[0048] [Fig.6A] and [Fig.6B] are views which illustrate effects obtained by the invention;

[0049] [Fig.7A] and [Fig.7B] illustrate a comparison between a known valve and a valve according to the invention;

[0050] [Fig.8] is a view which allows comparison of a circular section and a squircle-shaped section;

[0051] [Fig.9] represents a channel having a squircle-shaped cross-section;

[0052] [Fig. 10] is a perspective view of a valve and a geared motor.

[0053] DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0054] In the figures and in the following description, the same reference numerals represent identical or similar elements. Furthermore, the various elements are not drawn to scale in order to prioritize the clarity of the figures. Moreover, the Different embodiments and variants are not mutually exclusive and may be combined. Unless otherwise specified, the terms "approximately," "around," and "in the order of" mean within 10%. Furthermore, the terms "between ... and ..." and equivalents mean that the limits are inclusive, unless otherwise stated.

[0055] Figure 1 shows an example of a hydraulic rotary valve having one inlet and two outlets (type 3-2 valve). It will be understood that the valve may have one or more inlets and one or more outlets. According to another particular embodiment of a type 3-2 valve, it has two inlet ports and one outlet port.

[0056] The valve comprises a housing 2 or valve body, essentially cylindrical in shape around the axis X, and a central part 4, designated core or distributor, mounted in the housing 2 and capable of rotating therein.

[0057] In the example shown, the housing 2 comprises a base 6 and a substantially cylindrical side wall 8 in one piece, and a cover 10 for closing the housing. The cover 10 can be attached to the housing, for example, by screws or by welding, for example, by ultrasonic welding.

[0058] The housing 2 has an opening, called the supply opening, formed in the side wall 8 (but not visible in [Fig. 1]) and a supply conduit 22, for example welded to the base of the supply opening and intended for connection to a liquid source. The housing 2 also has a first outlet opening 20 formed in the side wall 8, extending into a conduit or channel 24 intended to bring the liquid to a given area, for example an area to be cooled, and a second outlet opening 12 (not visible in [Fig. 1], but visible for example in Figures 3A, 3B), also formed in the side wall 8 and extended into a conduit or channel 14. The conduits 14 and 24 are, for example, welded to the base of the respective outlet openings 12 and 20.

[0059] In an alternative (or alternative), not shown, the housing 2 has two supply ports formed in the side wall 8 and two supply conduits, each of which is, for example, welded to the base of the corresponding supply port and intended for connection to a liquid source. The housing 2 also has an outlet port formed in the side wall 8, extending into a conduit or outlet channel intended to carry the liquid to a given area, for example, an area to be cooled. This conduit or outlet channel is, for example, welded to the base of the outlet port.

[0060] The housing 2 defines a hydraulic chamber 26.

[0061] In figures 1 and 2, we can see the core 4, also cylindrical in shape with axis X. The core 4 is mounted in the hydraulic chamber adapted to rotate around the axis X.

[0062] The core 4 has two end faces 28, 30 and a lateral surface 32 which faces the lateral wall 8 of the housing 2.

[0063] The end face 28 faces the bottom of the housing, and the end face 30 faces the cover 10. The end face 30 has means, for example a recess 31, for receiving the end of a shaft of an actuator, for example, a geared motor MR ([Fig. 10]). The cover 10 has an opening 33 opposite the recess 31 to allow coupling with the shaft of the geared motor. Alternatively, the end face 30 has a protruding coupling member for engaging in a recess formed in the shaft of the actuator. A seal 35 is advantageously provided between the end face 30 and the cover bordering the recess 31 to prevent fluid leakage.

[0064] The lateral surface 32 of the core 4 has an inlet orifice 37 and an outlet orifice 34, and a channel or chamber 38 between these two orifices. This channel or chamber allows the fluid to circulate in the core 4, from the inlet orifice 37 of the core to the outlet orifice 34 of the core.

[0065] Depending on the angular position of the core 4 in the housing 2:

[0066] - the inlet orifice 37 of the core is, or is not, positioned opposite the orifice power supply (or opposite one and / or the other of the power supply ports) of the case;

[0067] - and / or the outlet orifice 34 is, or is not, positioned opposite one and / or the other of the outlet ports 12, 20 (or outlet port) of the housing.

[0068] In other words, nucleus 4, and more specifically its channel 38, allows:

[0069] - a power supply to one and / or the other of the output ports 12, 20 of the housing, in function of the angular position of the core (and of channel 38) in the housing; it notably allows simultaneous supply of these 2 output ports 12, 20, as seen in figures 3A, 3B and 4;

[0070] - or (alternatively or respectively) a supply from the orifices the inlet of the case, depending on the angular position of the core (and channel 38) in the case; it notably allows simultaneous feeding from these 2 inlet ports.

[0071] The core 4 may also include a first seal 44 for closing the outlet orifice 12, when they are opposite each other, and a second seal 46 for closing the outlet orifice 20, when they are opposite each other. Alternatively, or respectively, the core 4 may also include a first seal 44 for closing a first orifice The first inlet, when they are facing each other, and a second seal intended to close a second inlet orifice, when they are facing each other. In both cases or variants, the first seal 44 and the second seal 46 are, for example, of identical or similar shape, as is their mounting on the core. They can be mounted in recessed housings 48, 49.

[0072] Examples of joint shapes will not be described in detail but can be found for example in FR 3119656, as well as the operation of the device in [Fig.1].

[0073] The outer diameter of the core 4 is smaller than the inner dimensions of the housing 2, for example the difference between the outer diameter of the core 4 and the inner dimensions of the housing 2 is between 1 mm and a few mm.

[0074] In one embodiment, the chamber 26 has a circular internal cross-section and the joints 44, 46 fill the distance between the outer side wall of the core and the inner face of the chamber, the joints then rub permanently against the inner surface of the chamber.

[0075] The core 4 and the lid 10 are for example made of plastic material by injection molding.

[0076] Preferably, the housing 2 and the core 4 are made of a filled plastic material, reducing the mass of the valve, which is particularly advantageous in the automotive field. For example, the housing and / or the core are made of polyphthalamide, for example of type PA6T / 6LGF30; filled PPS can also be used for a "hydrogen" application.

[0077] In addition, they are preferably made by molding, which simplifies their mass production.

[0078] However, the casing and the core can be made of metallic material, for example stainless steel or aluminium (preferably anodized)

[0079] Preferably, the valve is actuation electrically, for example by means of a geared motor MR whose output shaft enters the recessed cavity 31, as shown in [Fig. 8]. The geared motor is, for example, that described in application WO2019 / 129984. It drives the core in rotation.

[0080] The invention therefore applies to a hydraulic rotary valve comprising a housing 2 and a core 4, said housing 2 comprising a side wall 8, two end walls 6, 10 delimiting a hydraulic chamber, in which is housed the core 4 capable of rotating in said chamber around an axis (XX') of rotation.

[0081] Such a valve comprises:

[0082] - at least one power supply channel 11, and 2 output channels 12, 20, 14, 24,

[0083] - or, alternatively (or respectively), 2 supply paths and one path of exit,

[0084] each of these paths opening into the hydraulic chamber with an internal diameter (A).

[0085] The core 4 has a lateral surface 32 facing the lateral wall 8 of the housing 2, an inlet opening 37 of a channel 38, at least one lateral outlet 34 of this channel, and allowing, depending on the angular position of the core in the housing:

[0086] - if the valve has at least one supply port and two outlet ports: one power supply for each of the aforementioned output channels,

[0087] - if (or alternatively or respectively) the valve has at least 2 ways power supply and output channel: a power supply from the 2 input channels.

[0088] According to the invention, the internal geometry of the valve can be modified, which makes it possible to optimize its compactness and / or to limit the effects of one or both of the main causes of pressure losses described below.

[0089] According to a first aspect of the invention, illustrated in Figures 3A and 3B in the case where the valve has at least one supply port and two outlet ports, the overlap length L, which separates the two outlet ports 12, 20 (or inter-port overlap length), is limited to less than 30% or less than 25% of the internal diameter A of each of the outlet ports 12, 20 (in cylindrical areas or areas supported by a cylinder), in order to limit pressure losses when the valve is open on both outlet ports 12, 20 simultaneously, as in the position illustrated, for example, in [Fig. 4]. In one example, the overlap length is between 24% and 27% of the internal diameter A. The outlet port 34 of the core is then positioned to direct a first portion of the fluid towards one of the outlet ports 14, and a second portion of the fluid towards the other of the exit lanes 24.

[0090] In the case where the valve has at least two inlet ports and one outlet port: the overlap length L, which separates the two inlet ports (or inter-port overlap length), is limited to less than 30% or less than 25% of the inside diameter A of each inlet port (in cylindrical areas or areas supported by a cylinder), in order to limit pressure losses when the valve is open on both inlet ports simultaneously. This case is not shown in the figures, but it suffices to reverse the direction of fluid flow and the functions of the inlet and outlet ports in Figures 3A, 3B, and 4 to obtain the corresponding figure(s).

[0091] According to a second aspect of the invention, illustrated in Figures 5A and 5B for channel 14, the profile of the passage section of each of the channels 14, 24 evolves along the direction of fluid flow, passing from the outlet orifices 12, 20 having a "rounded square" (or "squircle") shape, to a circular shape of diameter D; as explained later in relation to [Fig. 8], the evolution of the shape A circular path with a "squircle" shape can be achieved through progressive truncation. In other words, the cross-section of each output channel is:

[0092] - initially (i.e., exiting chamber 38) in a "squircle", which is a form comprising 2 sides 14b 142 parallel to each other, 2 sides 143, 144 parallel to each other and perpendicular to sides 14b 142, side 14b (respectively 142) being connected to each of sides 143>144 by 2 portions or arcs of circles 145, 146 (respectively 147>148);

[0093] - then evolves, along platform 14, as one moves away from room 38, towards a circular shape.

[0094] Such an evolution is illustrated in [Fig. 8] (circular section 13, section 13', squircle section 13"); in this figure, as in [Fig. 5B], the squircle section 13" can be obtained from an octagon 13', inscribed in the circle 13, where every other side is replaced by a curved segment (preferably an arc of a circle) tangent to the inside of the circle 13, to connect the two adjacent straight sides. This allows for a reduction in the flow passage area (where the section is squircle-shaped) of up to 14% compared to the circular section, for example, between 4% and 14%, which makes it possible to reduce the diameter and height of the valve. Note the presence of so-called "fill" zones 14' in conduit 14 (see figures 5A and 9) to ensure a smooth transition between curved and straight sections. Similar or identical zones are also present in track 24 (not shown).We go from the "squircle" shape (at the outlet orifice 12 or 20), to the circular shape, at a distance d from outlet 12 or 20 (this distance is shown in [Fig.4]); preferably, the transition from squircle to circle takes place over the entire length of available track (in order to be as gradual as possible).

[0095] As illustrated in [Fig.8] (which represents the evolution of the cross-section of the outlet conduit 14, the same evolution being applied to the other outlet conduit): starting from an initial circular cross-section 13 (on the side opposite the distributor), this cross-section evolves towards a 'squircle' shape as one approaches the distributor; the cross-section reduces with the appearance of a cross-section 13' in the shape of an increasingly pronounced 'squircle' until the final profile 13", the cross-section of the final profile being reduced to, for example, 14% (value for an octagon with 4 rounded edges, see [Fig.8]) relative to the initial circular cross-section 13. As can be understood from this figure, the squircle 13" is inscribed within a circle 13.

[0096] Figures 6A and 6B, but also 7B and 9, also represent a case where the outlet conduits 14, 24 have, from the exit of volume 38, a "squircle" shape.

[0097] This modification of the section of tracks 14, 24 allows, as illustrated in figures 6A and 6B:

[0098] - to reduce the overlap area S between the 2 outlet orifices 12, 20, ce which allows a reduction in pressure losses when the valve is open on these 2 outlet ports at a time, the outlet port 34 of the core is then positioned to direct a first part of the fluid towards one of the outlet channels 14, and a second part of the fluid towards the other of the outlet channels 24; it can be noted that this overlap area S is reduced but the passage area is also reduced: without "squircle", the overlap area represents more than 40% of the passage area; with "squircle" the overlap area represents 30% of the passage area, which makes a reduction of more than 25% (therefore less pressure loss);

[0099] - to reduce the diameter and height of the distributor, which makes it possible to achieve a smaller footprint valve; the reduction in the valve's footprint can reach up to 30%, which also allows for a reduction in weight of up to approximately 50%;

[0100] - to reduce dead zones in the channel or chamber 38 (see [Fig. 3B]), that is- that is to say the volume of the zones in which the fluid has no velocity, an advantage being to obtain a well established flow (which remains stable) which promotes flow control when piloting the valves.

[0101] Figures 7A and 7B show a valve with conventional outlet ports 12, 20 ([Fig.7B]) and with outlet ports according to the invention ([Fig.7A]), which allow for a better understanding of the aspects explained above. In [Fig.7B] the squircle shape is represented by dashed lines.

[0102] A valve according to the invention makes it possible to reduce the dimensions of the distributor while reducing the maximum pressure losses of the valve (the losses are reduced in the 50% position (position in which the fluid is distributed in 2 equal quantities between the outlet paths where the pressure losses are at their maximum).

[0103] Preferably, the shape of the ports 14, 24 described above is also applied to the inlet port 22. Having a "squircle" profile also for the inlet orifice, therefore for all 3 ports, allows for good compactness of the valve; there may be small variations in geometry between the inlet and outlet ports, due to the manufacturing process.

[0104] In the case where the valve has at least two supply ports and one outlet port: the "squircle" shape described above applies to each of the two inlet ports or orifices and, preferably, also to the outlet port; in this case, at a distance from the distributor, the shape of each of the supply channels is preferably circular, then evolves, along the channel and as it approaches the distributor, towards the squircle shape. This case is not shown in the figures, but it suffices to reverse the direction of fluid flow and the functions of the inlet and outlet ports in Figures 5A-9 to obtain the corresponding figure(s).

[0105] The first aspect of the invention (L<30% A) allows for a reduction in the overlap area S and a reduction in the diameter of the valve.

[0106] The 2nd aspect of the invention which has just been described may or may not be combined with the 1st aspect described above in connection with figures 3A and 3B. When these aspects are combined, the A to be taken into account in the case where the outlet ports have a "squircle" shape corresponds to the distance between the flat surfaces 14b 142, or between the flat surfaces 143 and 144, that is to say the distance between 2 straight and opposite segments of the "squircle" as illustrated in [Fig.5B] (on which the distance A is indicated) and as is the case in figures 6A, 6B, 7B and 9 (on this last figure, only an inner face of the conduit 14 is visible, the opposite surface being identical), the section of the conduit being in the shape of a "squircle" at the outlet ports of chamber 38 and evolving progressively, along the conduit, towards a circular shape.Here again, we will therefore have an overlap length less than 30% of the distance A (which is then the distance between 2 straight and opposite segments of the "squircle"), or less than 25% of the distance A; according to one example the overlap length is between 24 and 27% of the distance A.

[0107] As already explained above, the invention has been described above for a supply via one channel 22 and a distribution via two channels 14, 24, but it also applies, alternatively or respectively, to a structure with one outlet channel and two inlet channels, the latter bringing a fluid into the chamber 38, for example at different temperatures, and then the fluid being distributed via the outlet channel. In this case, the shape of the channels 14, 24 described above is applied to the inlet channels, but preferably also to the outlet channel.

Claims

Demands

1. A hydraulic rotary valve comprising a housing (2) and a core (4), said housing (2) comprising a side wall (8), two end walls (6, 10) defining a hydraulic chamber, in which the core (4) is housed, adapted to rotate in said chamber about an axis (XX') of rotation, the housing (2) comprising at least one supply port (11), and two outlet ports (12, 20, 14, 24), respectively, opening into the hydraulic chamber with an internal diameter (A), the core (4) comprising a lateral surface (32) facing the side wall (8) of the housing (2), an inlet opening (37) of a channel (38), at least one lateral outlet (34) of this channel, and allowing supply to each of said outlet ports (12, 20, 14, 24), respectively, from each of the ports input, depending on its angular position in the casing,the length (L) of overlap between exit tracks (12, 20), respectively between entry tracks, being less than or equal to 30% of the internal diameter (A) of each of the exit tracks, respectively of the entry tracks.

2. Hydraulic rotary valve according to claim 1, the length (L) of overlap between outlet ports (12, 20), respectively between inlet ports, being less than or equal to 25% of the inside diameter (A) of each of these ports.

3. Hydraulic rotary valve according to claim 1, the length (L) of overlap between outlet ports (12, 20), respectively between inlet ports, being between 24% and 27% of the inside diameter (A) of each of these ports.

4. A hydraulic rotary valve comprising a housing (2) and a core (4), said housing (2) comprising a side wall (8), two end walls (6, 10) defining a hydraulic chamber, in which the core (4) is housed and is adapted to rotate in said chamber about an axis (XX') of rotation, the housing (2) comprising at least one supply port (11), and two outlet ports (12, 20), each extended by an outlet conduit (14, 24), respectively, two supply ports, each supplied by a supply conduit, and an outlet port, which open into the hydraulic chamber, the core (4) comprising a side surface (32) facing the side wall (8) of the housing (2), an inlet opening (37) of a channel (38), at least one side outlet (34) of this channel, and allowing supply of each of said outlet ports (12, 20), respectively from each of the input channels, according to its angular position in the housing, the passage cross-section of each of the outlet ports (12, 20), respectively of each of the input ports, being in the shape of a square with rounded corners.

5. Hydraulic rotary valve according to claim 4, the passage cross-section at least of each of the outlet conduits (14, 24), respectively at least of each of the inlet conduits, passing from a square shape with rounded corners, at the outlet, respectively at the inlet, of the hydraulic chamber, to a circular shape, at a distance from the hydraulic chamber.

6. Hydraulic rotary valve according to any one of claims 4 or 5, the passage section of each of the outlet ports (12, 20), respectively of each of the inlet ports, having a shape comprising 2 first sides (14b 142) parallel to each other, 2 second sides (143,144) parallel to each other and perpendicular to the 2 first sides (14b 142), the 2 first sides (14b 142) and the 2 second sides (143 144) being connected by portions of a circle (145, 146,147>148) and evolving, as they move away from the valve, towards a circular shape.

7. Hydraulic rotary valve according to claim 6, the length (L) of the inter-outlet overlap (12, 20), respectively inter-inlet overlap, being less than or equal to 30% of the distance between the first 2 sides (14b 142) or between the second 2 sides (143,144).

8. Hydraulic rotary valve according to claim 6 or 7, the length (L) of the inter-outlet overlap (12, 20), respectively inter-inlet overlap, being less than or equal to 25% of the distance between the first 2 sides (14b 142) or between the second 2 sides (143,144).

9. Hydraulic rotary valve according to claim 6, the length (L) of overlap between outlet ports (12, 20), respectively between inlet ports, being between 24% and 27% of the distance between the first 2 sides (14b 142) or between the second 2 sides (143>144

10. J- Hydraulic rotary valve according to any one of claims 3 to 5, the passage cross-section of each of the outlet conduits (14, 24), respectively of each of the inlet conduits, being modified along the way, with a reduction of the flow passage section in the square-shaped section with rounded corners, for example less than or equal to 14%, compared to a circular shape in which the square-shaped section with rounded corners is inscribed.

11. Hydraulic rotary valve according to any one of claims 3 to 10, comprising an inlet orifice extended by an inlet conduit (22), respectively an outlet orifice extended by an outlet conduit, the passage section of said inlet orifice, respectively of said outlet orifice, being in the form of a square with rounded corners.

12. Hydraulic rotary valve according to claim 11, the passage section of said inlet conduit (22), respectively of said outlet conduit, passing from a square shape with rounded corners, at the inlet of the hydraulic chamber, to a circular shape, at a distance from the hydraulic chamber.

13. Hydraulic rotary valve according to claim 11 or 12, the passage cross-section of said inlet conduit (22), respectively of said outlet conduit, being modified along the path, with a reduction of the passage cross-section of the flow in the square-shaped section with rounded corners, for example less than or equal to 14%, compared to a circular shape in which the square-shaped section with rounded corners is inscribed.

14. Hydraulic rotary valve according to any one of the preceding claims, comprising one inlet and two outlets, the distributor being of the "3-2" or "Y" type.

15. Hydraulic rotary valve according to any one of claims 1 to 13, comprising one outlet and two inlet ports, the distributor being of the "3-2" or "Y" type.

16. Hydraulic rotary valve according to any one of the preceding claims, wherein the housing and / or the core are made of plastic material.

17. Motorized hydraulic rotary valve comprising a valve according to one of the preceding claims and an actuator (33), for example a geared motor (MR), driving the core in rotation.

18. Motorized hydraulic rotary valve according to the preceding claim, the actuator comprising an output shaft aligned along the axis (XX') of rotation.

19. Hydrogen fuel cell cooling circuit, comprising a hydraulic rotary valve according to any one of the preceding claims.

20. Method of distributing a fluid using a motorized hydraulic rotary valve according to claim 14, the fluid being introduced through the inlet, and being guided by the inner conduit (38) of the core and then, depending on the orientation of the core in the housing (2), towards one and / or the other of the outlet ports (12, 20).

21. Method of distributing a fluid using a motorized hydraulic rotary valve according to claim 15, a fluid being introduced through one and / or the other of the 2 inlet ports, guided by the inner conduit (38) of the core and then towards the outlet port.

22. Method according to claim 21, the fluid being introduced at 2 different temperatures between the 2 inlet ports.

23. A method according to any one of claims 20 to 22, the fluid being air or water or a mixture of water and glycol.

24. Method according to claim 23, the fluid being a fuel cell cooling fluid.

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