Liquid ring pump for aircraft and associated operating method

Abstract

A liquid ring pump (1) configured to circulate a fluid in a fluid circuit and comprising: a cylindrical body (2) defining an internal volume (20) filled with a working fluid forming, in an operating configuration, a liquid ring around the periphery of the internal volume (20); and at least one drive element (9) mounted rotatably offset within the cylindrical body (2), the drive element (9) comprising an impeller (3) having a plurality of cavities (32), each being defined between two adjacent impellers (31). The drive element (9) includes at least a plurality of upstream openings (91) for the circulation of the fluid (F) in the impeller (3), at least a plurality of downstream openings for the distribution of the fluid (F), and at least a plurality of circulation channels formed each between an upstream opening (91) and a downstream opening whose angular positions are offset. (Shortcut figure: Figure 3)

Description

Title of the invention: Liquid ring pump for aircraft and associated method of use. Technical field

[0001] The present invention relates to the field of vacuum pumps, and more particularly to the field of liquid ring pumps.

[0002] Liquid ring pumps are known to be used for example in a fuel circuit for supplying an aircraft turbomachine.

[0003] With reference to [Fig. 1], a liquid ring pump 100 comprises a cylindrical body 200 in which an impeller 300 is mounted. The cylindrical body 200, which extends along an axis of revolution X, is hollow and defines an internal volume 210 partially filled with a working fluid L, for example, fuel. As is known, the cylindrical body 200 has a wall of revolution and two end walls that form the bases of the cylinder and close the internal volume 210. As is known, the cylindrical body 200 includes an inlet port 220 for admitting a pumpable fluid F into the internal volume 210 and an outlet port 230 for discharging the pumpable fluid F. The inlet port 220 and the outlet port 230 are precisely formed and calibrated to allow the admission and discharge of the pumpable fluid F.

[0004] The impeller 300 is rotatably mounted in the cylindrical body 200 and extends, along an axis of rotation A, off-center with respect to the cylindrical body 200, as shown in [Fig. 1]. The impeller 300 comprises a plurality of blades 310, each pair of two adjacent blades 310 defining, in an inter-blade space, a cavity 320 for receiving the fluid to be pumped F.

[0005] In practice, with reference to [Fig. 2], when the impeller 300 rotates in the cylindrical body 200, the operating fluid L is carried along by the effect of centrifugal force and forms a liquid ring W around the periphery of the inner volume 210, which at least partially covers the blades 310. As is known, in each cavity 320, a useful volume VU is defined and corresponds to the volume between the two adjacent blades 310 and the liquid ring W. The latter thus ensures the sealing of each of the useful volumes VU.

[0006] In practice, since the impeller 300 is off-center within the cylindrical body 200, the useful volume VU varies according to the angular position of the cavity 320, as shown in [Fig. 2]. An increasing useful volume VU allows the fluid to be drawn in, via the inlet orifice 220, to be pumped into the cylindrical body 200. A Conversely, a decreasing useful volume VU allows the fluid to be pumped F to be compressed before its discharge through the outlet orifice 230.

[0007] However, such a liquid ring pump 100 requires a sufficient volume at startup to form the liquid ring W and close each useful volume VU. This implies adding a reservoir fluidically connected to the internal volume 210, which allows the operating fluid L to be replenished to form the necessary liquid ring W. Such a reservoir increases the pump's size, which is undesirable for installation in an aircraft where space is limited. Furthermore, when the liquid ring pump 100 allows the circulation of fuel, once primed, the liquid ring W (also containing fuel) pumps fuel back and forth between the reservoir and the reservoir. The energy required for this fuel movement is not accounted for in the pump's energy balance.

[0008] Furthermore, in such a liquid ring pump 100, the inlet and outlet ports 220, 230 have a complex shape to allow for calibrated inlet and outlet. Such a complex shape, generally machined, necessitates a meticulous, lengthy, and laborious manufacturing process to achieve the desired form. Moreover, due to manufacturing tolerances, the calibration may be unsatisfactory, and a significant number of parts are often discarded.

[0009] The invention thus aims to eliminate at least some of these drawbacks by proposing a new, reliable, and efficient liquid ring pump with a limited footprint. In particular, the invention aims to overcome excessive manufacturing constraints. PRESENTATION OF THE INVENTION

[0010] The invention relates to a liquid ring pump configured to circulate a fluid in a fluid circuit, in particular an aircraft fluid circuit, the liquid ring pump comprising: • a cylindrical body extending from upstream to downstream along a principal axis and comprising an upstream end wall and a downstream end wall planar and orthogonal to the principal axis connected by a circumferential wall, the cylindrical body being hollow and defining an internal volume, an operating liquid partially filling the internal volume, the liquid ring pump having an upstream inlet port for admitting the fluid into the internal volume and a downstream outlet port for discharging the fluid, • a drive element mounted in the cylindrical body, the drive element being mounted to rotate about an axis of rotation parallel to the main axis, offset from the center of the cylindrical body, • the operating fluid forming, in an operating configuration, a liquid ring extending radially around the periphery of the internal volume of the cylindrical body, the drive element being, in the operating configuration, at least partially immersed in the operating fluid.

[0011] The liquid ring pump is remarkable in that the drive element understand : • at least one impeller comprising a plurality of impellers, each pair of two adjacent impellers defining an inter-impeller space, a cavity being defined, in the operating configuration, in each inter-impeller space between two adjacent impellers and the liquid ring, • at least a plurality of upstream openings for fluid circulation, at least within the impeller, each upstream opening having an upstream angular position, • at least a plurality of downstream openings for fluid distribution, each downstream opening having a downstream angular position, each upstream and / or downstream opening being formed respectively in one of the cavities of the impeller, and • at least a plurality of circulation channels, each circulation channel being formed between one of the upstream openings and one of the downstream openings whose downstream angular position is angularly offset from the upstream angular position of the upstream opening.

[0012] The liquid ring pump according to the invention allows the fluid to circulate from upstream to downstream of the pump (along the main axis) thanks to the pressure difference between the upstream and downstream openings, which are connected by a circulation channel and whose angular positions are offset. Advantageously, the cavities of the impeller of the drive element, offset relative to the cylindrical body, allow the fluid to be pressurized. The offset angular positions of the upstream and downstream openings create a piston effect between the upstream and downstream openings, which allows the fluid to be discharged towards the downstream outlet. This ensures simple and optimal operation of the pump.

[0013] Such a pump thus allows the fluid to be inlet and / or outlet in the end walls of the cylindrical body, enabling axial circulation of the fluid in the fluid circuit, which limits its size and mass. This is particularly advantageous for installation in an aircraft fluid circuit, for example a fuel circuit, which is generally installed in a constrained and cluttered environment.

[0014] In a first embodiment, the drive element comprises at least one separating wall extending orthogonally to the main axis and configured to separate the waterwheel into at least one adjacent upstream wheel and one adjacent downstream wheel, the upstream wheel comprising a plurality of upstream cavities, the downstream wheel comprising a plurality of downstream cavities, each upstream opening being formed respectively in one of the upstream cavities and each downstream opening being formed in one of the downstream cavities.

[0015] The fluid can thus advantageously flow from the upstream wheel to the downstream wheel through the circulation channel, from an upstream cavity to a downstream cavity that is angularly offset. This allows for a transfer of fluid between the upstream and downstream cavities, creating a piston effect that draws the fluid from the upstream cavity and efficiently expels it. Furthermore, this embodiment is simple to implement because it allows for the formation of a single-piece drive element that is easy to machine.

[0016] In a second embodiment, the drive element comprises: • a plurality of first upstream openings, each first upstream opening having a first upstream angular position, • a plurality of first downstream openings, each first downstream opening having a first downstream angular position, • a plurality of first circulation channels, each first circulation channel being formed between one of the first upstream openings and one of the first downstream openings whose downstream angular position is angularly offset relative to the upstream angular position of the first upstream opening, • a plurality of second upstream openings, each second upstream opening having a second upstream angular position, • a plurality of second downstream openings, each second downstream opening having a second downstream angular position, • a plurality of second circulation channels, each second circulation channel being formed between one of the upstream second openings and one of the downstream second openings whose downstream angular position is angularly offset relative to the upstream angular position of the upstream second opening, the upstream second position corresponding to the downstream first position, so as to fluidly connect each second circulation channel respectively to the first circulation channel, • two separating walls extending orthogonally to the main axis and configured to separate the waterwheel into at least one upstream wheel, one downstream wheel and an intermediate wheel formed between the upstream and downstream wheels, the upstream wheel comprising a plurality of upstream cavities, the downstream wheel comprising a plurality of downstream cavities, the intermediate wheel comprising a plurality of intermediate cavities, • each first upstream opening is formed in one of the upstream cavities, each first downstream opening and each second upstream opening is formed in one of the intermediate cavities and each second downstream opening is formed in one of the downstream cavities.

[0017] Such an embodiment allows for transfer between the upstream and downstream sides of the pump while permitting more flexible positioning of the upstream inlet and downstream outlet ports, thus simplifying pump manufacturing and improving the acceptability of manufacturing tolerances. This reduces the need for discarding non-conforming parts and lowers manufacturing costs. A drive element with three adjacent impellers eliminates fluid transfer between cavities when the upstream and downstream cavities are not aligned with either the suction or discharge ports, thereby improving pump efficiency.

[0018] In a third embodiment, the drive element comprises: • a plurality of first upstream openings, each first upstream opening having a first upstream angular position, • a plurality of first downstream openings, each first downstream opening having a first downstream angular position, • a plurality of first circulation channels, each first circulation channel being formed between one of the first upstream openings and one of the first downstream openings whose downstream angular position is angularly offset relative to the upstream angular position of the first upstream opening, • a plurality of second upstream openings, each second upstream opening having a second upstream angular position, • a plurality of second downstream openings, each second downstream opening having a second downstream angular position, • a plurality of second circulation channels, each second circulation channel being formed between one of the upstream second openings and one of the downstream second openings whose downstream angular position is angularly offset relative to the upstream angular position of the upstream second opening, the upstream second position corresponding to the downstream first position, so as to fluidly connect each second circulation channel respectively to the first circulation channel, • an upstream cylinder connected to an upstream face of the paddle wheel, the plurality of first upstream openings being formed on a circumferential surface of the upstream cylinder, • a downstream cylinder connected to a downstream face of the paddle wheel, the plurality of second downstream openings being formed on a circumferential surface of the downstream cylinder, • the plurality of first downstream openings and the plurality of second upstream openings being formed in the cavities of the paddle wheel.

[0019] Such an embodiment eliminates the need to transfer fluid between several impeller cavities. The fluid is introduced directly into the upstream opening, passes through the impeller cavity where it is pressurized, and is discharged through the downstream opening. This eliminates the need for fluid transfer between different cavities when the upstream and downstream cavities are not aligned with either the suction or discharge ports, thus improving pump efficiency.

[0020] The cylinders also advantageously form sealing walls opposite the upstream and downstream end walls of the cylindrical body, which together form an inlet and outlet passage with the liquid ring. In the operating configuration, the impeller cavities are advantageously sealed, and no fluid leakage is possible into the internal volume. Furthermore, it is not necessary to mount the drive element with reduced clearances in the cylindrical body, which allows for simpler and less expensive pump manufacturing.

[0021] According to a preferred aspect, the drive unit comprises: • an upstream sealing wall mounted in the cylindrical body and fixedly connected to an upstream face of the drive element, and • a downstream sealing wall mounted in the cylindrical body and fixedly connected to a downstream face of the drive element, • the upstream sealing wall and the downstream sealing wall being configured to form with an inner peripheral limit of the liquid ring, respectively an inlet passage into the internal volume and a discharge passage for the fluid.

[0022] Thanks to the sealing walls, the risk of leakage into the internal volume is eliminated. The liquid ring pump thus eliminates the need for tight mounting clearances between the drive element and the end walls of the cylindrical body, resulting in both simpler and less expensive pump manufacturing and faster assembly. The risk of friction between the impeller and the cylindrical body is also advantageously reduced, which limits wear on the parts and ensures the pump's longevity. Furthermore, the risk of overheating is also limited, which is particularly beneficial when the pump is installed, for example, in an aircraft fuel system. The liquid ring pump according to the invention ensures a high level of safety.

[0023] Two sealing walls also allow for inlet and / or outlet between an outer peripheral limit of the sealing wall and an inner peripheral limit of the liquid ring, enabling axial fluid circulation from upstream to downstream and thus reducing the pump's size. This also eliminates the need for a calibrated opening, as was the case in the prior art, advantageously reducing manufacturing costs.

[0024] Preferably, each sealing wall has a circular shape, which limits disturbances to the operating fluid when the pump is in its operating configuration. In other words, the pump can operate optimally and similarly to prior art liquid ring pumps, despite the addition of such walls within the internal volume.

[0025] According to a preferred design, the upstream inlet port for admitting the fluid into the internal volume is formed in the upstream end wall of the cylindrical body. This allows for the formation of an inlet port with a simple geometry, unlike the inlet ports of the prior art. The liquid ring pump is thus less complex to manufacture and therefore less expensive. Manufacturing tolerances are also less stringent, which limits the scrapping of parts. This also allows the fluid to be admitted directly into the cylindrical body, eliminating the need for a complex dedicated circuit that would lead to a hub of the impeller, for example, as was the case in the prior art.

[0026] Preferably, the downstream outlet port for discharging the fluid from the internal volume is formed in the downstream end wall of the cylindrical body. This allows for the formation of an inlet port with a simple geometry, unlike the inlet ports of the prior art. The liquid ring pump is thus less complex to manufacture and therefore less expensive. Manufacturing tolerances are also less stringent, which limits the scrapping of parts. This also allows the fluid to be discharged directly from the cylindrical body, eliminating the need for a complex dedicated circuit connected, for example, to a hub of the impeller, as was the case in the prior art.

[0027] In a preferred embodiment, the upstream inlet port is formed opposite the downstream outlet port along the main axis, allowing axial circulation of the fluid in the pump, which advantageously simplifies the fluid circuit, while limiting the size of the pump.

[0028] The invention also relates to an aircraft comprising a fluid circuit and a liquid ring pump as described above, to allow the circulation of the fluid in the fluid circuit.

[0029] The invention also relates to an aircraft comprising a fuel circuit supplying a turbomachine and a liquid ring pump as described above for supplying the turbomachine.

[0030] Finally, the invention relates to a method of using the liquid ring pump as described above, the liquid ring pump being in an operating configuration, the operating liquid forming a liquid ring around the periphery of the internal volume, the method of use comprising the steps of: • admit the fluid into the internal volume via the upstream inlet port, • introduce the fluid into the circulation channel through the upstream opening, • Transfer the fluid from upstream to downstream through the circulation channel by pressure difference between the upstream and downstream openings, • extract the pressurized fluid from the circulation channel through the downstream opening, and • Displace the fluid from the internal volume via the downstream outlet port. PRESENTATION OF THE FIGURES

[0031] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0032] Fig. 1 is a schematic representation of a liquid ring pump according to the prior art.

[0033] Fig. 2 is a schematic representation of the liquid ring pump of Fig. 1 in an operating configuration.

[0034] Fig. 3 is a schematic representation of a liquid ring pump according to one embodiment of the invention.

[0035] Fig. 4 is a schematic representation of the liquid ring pump of Fig. 3 in use.

[0036] Fig. 5 is a schematic representation of the admission and evolution of a fluid to be pumped in the liquid ring pump of Fig. 3.

[0037] Fig. 6 is a schematic representation of a drive element of the liquid ring pump of Fig. 3 according to a first embodiment.

[0038] Fig. 7 is a partial cross-sectional view of the drive element of Fig. 6.

[0039] Figure 8 is a schematic representation of a drive element of the liquid ring pump of [Fig.3] according to a second embodiment.

[0040] Fig. 9 is a partial cross-sectional view of the drive element of Fig. 8.

[0041] The [Fig. 10] is a schematic representation of a drive element of the liquid ring pump of the [Fig.3] according to a third embodiment.

[0042] Fig. 11 is a partial cross-sectional view of the drive element of Fig. 10.

[0043] The [Fig. 12] is a diagram of the evolution of the transfer and discharge of the fluid to be pumped in the liquid ring pump of the [Fig.3].

[0044] It should be noted that the figures set out the invention in detail to implement the invention, said figures being of course able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0045] The invention relates to a liquid ring pump, used for circulating a fluid in a fluid circuit, in particular a fluid circuit of an aircraft, for example a fuel circuit.

[0046] Figure 3 shows a liquid ring pump 1 according to one embodiment of the invention. The liquid ring pump 1 comprises a cylindrical body 2 and a drive element 9 mounted in the cylindrical body 2. For the sake of brevity, the liquid ring pump 1 will hereafter be referred to as pump 1.

[0047] The cylindrical body 2 extends from an upstream to a downstream along a principal axis X. In this document, the terms upstream and downstream refer to the direction of flow of a fluid F in the pump 1 from upstream to downstream.

[0048] With reference to [Fig.3], the cylindrical body 2 has, in this example, the shape of a right circular cylinder and, as such, comprises an upstream end wall 24 and a downstream end wall 25 connected by a circumferential wall 23. The upstream end wall 24 and the downstream end wall 25 are planar and extend orthogonally to the principal axis X. It is understood that the cylindrical body 2 could alternatively have a different shape, for example an elliptical cylinder.

[0049] The cylindrical body 2 is hollow and defines an internal volume 20 between the circumferential wall 23 and the upstream end walls 24 and downstream end walls 25. The internal volume 20 is partially filled with an operating fluid L, in this example, fuel. It is understood that the operating fluid L could be different. In an operating configuration, i.e., when the pump 1 is in operation, the operating fluid L forms a liquid ring W that extends radially around the periphery of the internal volume 20 of the cylindrical body 2, as shown in [Fig. 5] by the filled volume indicated by the dashed line.

[0050] To allow the circulation of fluid F in the pump 1, with reference to Figures 3 and 4, the latter comprises an upstream inlet port 21 for the admission of fluid F into the internal volume 20 and a downstream outlet port 22 for the discharge of fluid F. The upstream inlet port 21 and the downstream outlet port 22 are through-holes to to allow the circulation of fluid F. Also, the upstream inlet port 21 and the downstream outlet port 22 are preferably connected respectively to a supply pipe and a discharge pipe (not shown).

[0051] In a preferred embodiment, the upstream inlet orifice 21 is formed in the upstream end wall 24 of the cylindrical body 2. It is understood that the upstream inlet orifice 21 could be formed differently, for example in the circumferential wall 23 or in a central portion of the drive member 9.

[0052] Furthermore, in a preferred embodiment, as shown in Figures 3 and 4, the downstream outlet orifice 22 is formed in the downstream end wall 25. More specifically, the downstream outlet orifice 22 is preferably formed in the downstream end wall 25 opposite the upstream inlet orifice 21 along the principal axis X, to allow axial circulation of the fluid F, thereby limiting the size of the fluid circuit. It is understood that the downstream outlet orifice 22 could be formed differently, for example in the circumferential wall 23 or in a central portion of the drive element 9.

[0053] In this example, in which the upstream inlet orifice 21 and the downstream outlet orifice 22 are formed respectively in the upstream end wall 24 and in the downstream end wall 25, the latter preferably have a circular shape, allowing simple manufacturing of the pump 1. The diameter of the upstream inlet orifice 21 and the downstream outlet orifice 22 are calibrated to allow a predetermined flow rate of the fluid F in the pump 1. It is understood that the upstream inlet orifice 21 and the downstream outlet orifice 22 can alternatively have a different shape, for example, whose opening area decreases in a rotational movement about the principal axis X, as is the case in liquid ring pumps of the prior art.

[0054] As described previously, a drive member 9 is mounted in the cylindrical body 2. The drive member 9 is rotatably mounted in the cylindrical body 2 and extends along an axis of rotation R parallel to the main axis X. In particular, the drive member 9 extends off-center with respect to the cylindrical body 2, as shown in Figures 3 to 5.

[0055] With reference to [Fig.3], the drive member 9 has an upstream face 9A mounted opposite the upstream end wall 24 of the cylindrical body 2, and a downstream face 9B mounted opposite the downstream end wall 25 of the cylindrical body 2.

[0056] To be driven in rotation, the drive member 9 is mounted on a drive shaft (not shown), itself connected to a drive device to be driven in rotation about the axis of rotation R. In this example, the drive shaft is connected to an electric motor (also not shown). It goes without saying that the drive element 9 could be driven in rotation in a different way, for example by means of a mechanical device, such as a gear.

[0057] The drive element 9 is configured to drive the operating fluid L to form the liquid ring W under the effect of centrifugal force. In the operating configuration, the drive element 9 is configured to be at least partially immersed in the operating fluid L.

[0058] In practice, with reference to figures 6 to 11, the drive member 9 comprises a paddle wheel 3 and a plurality of openings 91, 92 and circulation channels 90 internal to the drive member 9.

[0059] With reference to [Fig.3], the paddle wheel 3 comprises an upstream face 33 mounted opposite the upstream end wall 24 of the cylindrical body 2, and a downstream face 34 mounted opposite the downstream end wall 25 of the cylindrical body 2. In a first embodiment shown in [Fig.3], the upstream face 33 and the downstream face 34 correspond respectively to the upstream face 9A and the downstream face 9B of the drive member 9.

[0060] The paddle wheel 3 comprises a plurality of blades 31 which extend radially from the axis of rotation R and between the upstream face 33 and the downstream face 34, over the entire circumference of the paddle wheel 3. In this example, the upstream and downstream faces 33, 34 correspond directly to the upstream and downstream edges of the blades 31.

[0061] Each pair of two adjacent blades 31 defines, in an inter-blade space, a cavity 32 for receiving the fluid F. In this example, the impeller 3 has ten identical cavities 32 distributed angularly around its circumference. In practice, in the operating configuration described above, each blade 31 is at least partially immersed in the operating fluid L. Each cavity 32 has its own effective volume VU (shown in [Fig. 5]) defined between the blades 31 and the liquid ring W. The effective volume VU of each cavity 32 is predefined according to its angular position in the cylindrical body 2 and is different from the effective volume VU of the adjacent cavities 32. As is known, when the effective volume VU decreases, the fluid F is compressed, and when the volume increases, the fluid F is expanded.

[0062] According to one aspect of the invention, with reference to figures 6 to 11, the drive member 9 comprises a plurality of openings 91, 92 and circulation channels 90 internal to the drive member 9, for the circulation of the fluid F in the internal volume 20 from upstream to downstream.

[0063] In practice, the drive element 9 comprises at least a plurality of upstream openings 91, a plurality of downstream openings 92 and a plurality of circulation channels 90 formed each respectively between one of the upstream openings 91 and one of the downstream openings 92.

[0064] Preferably, the plurality of upstream openings 91 is distributed circumferentially throughout the drive member 9, so as to admit the fluid F continuously into the internal volume 20 when the drive member 9 rotates around the axis of rotation R, as will be described in more detail later.

[0065] Each upstream opening 91 has an upstream angular position and each downstream opening 92 has a downstream angular position. The upstream angular position of the upstream opening 91 and the downstream angular position of the downstream opening 92, connected by the same circulation channel 90, are angularly offset along the axis of rotation R. This angular offset creates a vacuum between the upstream and downstream sides of the drive element 9, allowing the fluid F to be drawn in and circulated through the pump 1. The angular offset thus allows the upstream inlet orifice 21 and the downstream outlet orifice 22 to be formed respectively in the upstream end wall 24 and in the downstream end wall 25 of the cylindrical body 2, to allow axial circulation along the main axis X and thus limit the size of the pump 1, as will be described in more detail later.For the sake of clarity, the invention will subsequently be described with reference to a first embodiment.

[0066] In this first embodiment, with reference to Figures 6 and 7, the drive element 9 comprises a separating wall 8 extending orthogonally to the axis of rotation R and dividing each cavity 32 into two adjacent cavities 32. In other words, the impeller 3 can be considered as divided into an adjacent upstream impeller 3A and a downstream impeller 3B. More precisely, in this embodiment, the upstream impeller 3A comprises a plurality of upstream cavities 32A, and the downstream impeller 3B, a plurality of downstream cavities 32B. The upstream cavities 32A are aligned with the downstream cavities 32B along the axis of rotation R.

[0067] Preferably, the upstream impeller 3A and the downstream impeller 3B have similar diameters D3 (defined in a plane orthogonal to the axis of rotation R), as shown in [Fig. 6]. The diameter D3 depends on the sizing of the pump 1, the volume of the cylindrical body 2 and the flow rate of fluid F to be pumped.

[0068] In this embodiment, each upstream opening 91 is formed respectively in one of the upstream cavities 32A and each downstream opening 92 is formed in one of the downstream cavities 32B. In this example, each upstream opening 91 and each downstream opening 92 is formed at the bottom of each cavity 32A, 32B, that is to say in a portion of cavity 32 opposite the peripheral radial ends of the blades 31. In other words, each upstream cavity 32A has an upstream opening 91 and each downstream cavity 32B has a downstream opening 92.

[0069] Thus, as shown in [Fig. 7], each circulation channel 90, formed between an upstream opening 91 and a downstream opening 92, is formed between an upstream cavity 32A and a downstream cavity 32B, to allow the circulation of fluid F from the wheel upstream 3A to downstream wheel 3B. More precisely, each circulation channel 90 is formed between an upstream cavity 32A and a downstream cavity 32B whose angular position is offset along the axis of rotation R relative to the angular position of the upstream cavity 32A, as shown in [Fig. 7]. In this example, each downstream cavity 32B is angularly offset relative to the upstream cavity 32A to which it is connected by an angle of 120°, to allow an optimal pressure difference (due to the offset of the drive element 9 relative to the liquid ring W) for conveying the fluid F contained in the upstream cavity 32A to the downstream cavity 32B.

[0070] According to a preferred aspect, the pump 1 comprises an upstream sealing wall 4 and a downstream sealing wall 5 fixedly connected to the drive member 9. The upstream sealing wall 4 and the downstream sealing wall 5 are mounted in the cylindrical body 2.

[0071] More specifically, the upstream sealing wall 4 is fixedly connected to the upstream face 9A of the drive element 9, and the downstream sealing wall 5 is fixedly connected to the downstream face 9B of the drive element 9. Preferably, the upstream sealing wall 4 and the downstream sealing wall 5 are made of the same material as the drive element 9. In other words, the drive element 9 preferably forms a single unit. It is understood that the sealing walls 4 and 5 could be fixed in a different way, for example by welding, bonding, etc.

[0072] In particular, in this example, the upstream sealing wall 4 and the downstream sealing wall 5 are fixedly connected respectively to the upstream face 33 and the downstream face 34 of the impeller 3 (in other words, to the upstream face 33 of the upstream impeller 3A and to the downstream face 34 of the downstream impeller 3B). The upstream sealing wall 4 and the downstream sealing wall 5 thus partially close each cavity 32A, 32B of the impeller 3 upstream and downstream respectively, so as to prevent the transfer of fluid F between two adjacent cavities 32, as shown in [Fig. 6]. The sealing walls 4, 5 thus advantageously eliminate the need for small functional clearances during the manufacture of the liquid ring pump 1.

[0073] In a preferred embodiment, the upstream sealing wall 4 and the downstream sealing wall 5 are mounted symmetrically on the upstream face 33 and on the downstream face 34 of the paddle wheel 3. It is understood that the upstream sealing wall 4 and the downstream sealing wall 5 could alternatively be mounted differently on the upstream face 33 and on the downstream face 34 of the paddle wheel 3.

[0074] Preferably, the upstream sealing wall 4 and the downstream sealing wall 5 are identical. Therefore, only the upstream sealing wall 4 will be described hereafter. Similar characteristics apply, in this example, to the downstream sealing wall 5.

[0075] According to a preferred design, the upstream sealing wall 4 has a circular shape, so as to limit any risk of disturbance of the fluid F in the pump 1, in the operating configuration. With reference to [Fig. 6], the upstream sealing wall 4 preferably has a diameter D4 strictly smaller than the diameter D3 of the impeller 3, so as to allow the fluid F to be admitted directly into the cavities 32 when the upstream inlet orifice 21 is formed in the upstream end wall 24. The thickness of the liquid ring W is thus preferably greater than the difference D3-D4 between the diameter D3 of the impeller 3 and the diameter D4 of the upstream sealing wall 4.

[0076] In particular, with reference to Figures 4 and 5, the diameter D4 of the upstream sealing wall 4 is preferably determined so as to form, in the operating configuration, an inlet passage 6 for the fluid F between an outer peripheral limit 41 of the upstream sealing wall 4 and an inner peripheral limit L1 of the liquid ring W. The inlet passage 6 thus has a crescent shape that allows the fluid F to be progressively admitted into the internal volume 20. In this example, the upstream inlet orifice 21 is formed in the upstream end wall 24 of the cylindrical body 2, opposite the inlet passage 6, as shown in [Fig. 4]. This allows the fluid F from the upstream inlet orifice 21 to be admitted directly into the cavity 32 positioned opposite it, via the inlet passage 6, as will be described in more detail later.

[0077] Similarly, in one embodiment, the downstream sealing wall 5 allows, in the operating configuration, a discharge passage 7 (shown in Figures 4) to be formed for the fluid F between the outer peripheral limit 51 of the downstream sealing wall 5 and the inner peripheral limit L1 of the liquid ring W. Preferably, the downstream outlet orifice 22 is formed in the downstream end wall 25 of the cylindrical body 2, opposite the discharge passage 7, as shown in [Fig. 4].

[0078] By means of such a pump 1, the fluid F is introduced via the upstream inlet port 21 (formed in the upstream end wall 24 of the cylindrical body 2) and through the inlet passage 6 (formed between the upstream sealing wall 4 and the liquid ring W) to fill one of the upstream cavities 32A. By pressure difference, due to the difference in angular position, the fluid F is drawn into the circulation channel 90 (formed between the upstream opening 91 of the upstream cavity 32A and the downstream opening 92 of the downstream cavity 32B) to fill the downstream cavity 32B. When the downstream cavity 32B is positioned opposite the discharge passage 7 (formed between the downstream sealing wall 5 and the liquid ring W), the pressurized fluid F is discharged via the downstream outlet orifice 22 (formed in the downstream end wall 25 of the cylindrical body 2). Pump 1 thus operates optimally with a reduced footprint. This operation will be described in more detail later.

[0079] In a second embodiment, with reference to Figures 8 and 9, the drive element 9 comprises two separating walls 8A, 8B extending orthogonally to the axis of rotation R and dividing each cavity 32 into three adjacent cavities 32. In other words, the impeller 3 can be considered as divided into an upstream impeller 3A, a downstream impeller 3B, and an intermediate impeller 31, formed between the adjacent upstream impeller 3A and downstream impeller 3B. Analogously to the first embodiment, the upstream impeller 3A has a plurality of upstream cavities 32A, the intermediate impeller 31 has a plurality of intermediate cavities 32B, and the downstream impeller 3B has a plurality of downstream cavities 32B. The intermediate cavities 321 are aligned with the upstream cavities 32A and the downstream cavities 32B along the axis of rotation R.

[0080] In practice, in this example, the separation walls 8A, 8B are connected to the upstream and downstream edges of the blades 31 of the intermediate wheel 31. In other words, the separation walls 8A, 8B allow the intermediate cavities 321 to be closed upstream and downstream.

[0081] Preferably, the upstream impeller 3A and the downstream impeller 3B have similar diameters D3A, D3B, as shown in [Fig. 8]. It goes without saying that they could be different. The intermediate impeller 31 has a diameter D3I strictly larger than the diameters D3A, D3B of the upstream impeller 3A and the downstream impeller 3B to allow the admission of fluid F directly into the upstream cavities 32A, as will be described in more detail later.

[0082] In this embodiment, with reference to [Fig. 9], the drive element 9 comprises: • a plurality of first upstream openings 91A, each possessing a first upstream angular position, a plurality of first downstream openings 92A, each possessing a first downstream angular position, and a plurality of first circulation channels 90A, each formed between one of the first upstream openings 91A and one of the first downstream openings 92A, and • a plurality of second upstream openings 91B, each having a second upstream angular position, a plurality of second downstream openings 91B, each having a second downstream angular position, and a plurality of second circulation channels 90B formed each between one of the second upstream openings 91B and one of the second downstream openings 92B.

[0083] As shown in [Fig. 9], each upstream circulation channel 90A is fluidically connected to one of the downstream circulation channels 90B to fluidly connect successively an upstream cavity 32A, an intermediate cavity 321 and a downstream cavity 32B.

[0084] More specifically, in this embodiment, each first upstream opening 91A is formed respectively in one of the upstream cavities 32, each first downstream opening 92A and each second upstream opening 91B are formed in one of the intermediate cavities 321, and each second downstream opening 92B is formed in one of the downstream cavities 32B. Preferably, a first downstream opening 92A and a second upstream opening 91B are formed in the same intermediate cavity 321 to fluidly connect an upstream circulation channel 90A and a downstream circulation channel 90B. In a manner analogous to the first embodiment, in this example each opening 91A, 92A, 91B, 92B is formed at the bottom of a cavity 32A, 321, 32B, that is to say in a portion of cavity 32A, 321, 32B opposite the peripheral radial ends of the blades 31.

[0085] Thus, as shown in [Fig.9], each first circulation channel 90A, formed between a first upstream opening 91A and a first downstream opening 92A, is formed between an upstream cavity 32A and an intermediate cavity 321, and each second circulation channel 90B, formed between a second upstream opening 91B and a second downstream opening 92B, is formed between an intermediate cavity 321 and a downstream cavity 32B, to allow the circulation of the fluid F from the upstream wheel 3A to the downstream wheel 3B.

[0086] According to a preferred aspect, the angular position of each upstream cavity 32A and each intermediate cavity 321 connected by a first circulation channel 90A, and the angular position of each intermediate cavity 321 and each downstream cavity 32B connected by a second circulation channel 90B, are angularly offset from each other along the axis of rotation R, as shown in [Fig. 9]. In this example, each downstream cavity 32B is angularly offset from the intermediate cavity 321 to which it is connected by an angle of 120°, as is each intermediate cavity 321 from the upstream cavity 32A to which it is connected, to allow an optimal pressure difference for circulating the fluid F between the cavities 32A, 321, 32B.In other words, in this example, each upstream cavity 32A and each downstream cavity 32B connected by a first circulation channel 90A and a second circulation channel 90A are angularly offset from each other, along the axis of rotation R, by an angle of 240°.

[0087] With reference to Figures 8 and 9, in the embodiment in which the pump 1 comprises an upstream sealing wall 4 and a downstream sealing wall 5, these are fixedly connected respectively to an upstream face of the upstream impeller 3A and to a downstream face of the downstream impeller 3B. In other words, each upstream cavity 32A is closed upstream by the upstream sealing wall 4 and downstream by one of the separation walls 8A, and each downstream cavity 32B is closed upstream by the other separation wall 8B and downstream by 5, allowing the upstream cavities 32A and the downstream cavities 32B to be closed upstream and downstream by the downstream sealing wall 5. The sealing walls 4, 5 advantageously allow the elimination of reduced functional clearances during the manufacture of the liquid ring pump 1.

[0088] The sealing walls 4, 5 are preferably identical and circular in shape. Preferably, the sealing walls 4, 5 have a diameter D4, D5 identical to the diameter of the upstream impellers D3A and downstream impellers D3B. In other words, the upstream cavities 32A and the downstream cavities 32B are open only on one circumferential face, as shown in [Fig. 8], to allow the admission (or discharge) of the fluid F.

[0089] The operation of pump 1 is then similar to the operation of pump 1 of the first embodiment described above.

[0090] In a third embodiment, with reference to figures 10 and 11, the drive member 9 comprises a single paddle wheel 3, an upstream cylinder 93 connected to the upstream face 33 of the paddle wheel 3 and a downstream cylinder 94 connected to the downstream face 34 of the paddle wheel 3.

[0091] In this example, the paddle wheel 3 is closed at its upstream face 33 by a first closing wall 81 and at its downstream face 34 by a second closing wall 82, in a manner analogous to the intermediate wheel 31 of the previous embodiment whose cavities 321 are closed by the two separating walls 8A, 8B. In this example, the closing walls 81, 82 have a similar diameter substantially equal to the diameter of the paddle wheel D3

[0092] The upstream cylinder 93 and the downstream cylinder 94 have similar diameters D93, D94, as shown in [Fig. 10]. The diameter D3 of the impeller 3 is strictly larger than the diameters D93, D94 of the upstream cylinder 93 and downstream cylinder 94 to allow the admission of the fluid F into the drive element 9, as will be described in more detail later.

[0093] In this embodiment, analogously to the second embodiment, the drive member 9 comprises a plurality of first circulation channels 90A, each formed between an upstream opening 91A of a plurality of first upstream openings 91A and a downstream opening 92A of a plurality of first downstream openings 92A, and a plurality of second circulation channels 90B, each formed between an upstream opening 91B of a plurality of second upstream openings 91B and a downstream opening 91B of a plurality of second downstream openings 92B. Each upstream circulation channel 90A is fluidly connected to one of the downstream circulation channels 90B to fluidly connect the upstream and downstream of the drive member 9, as shown in [Fig. 11].

[0094] More specifically, in this embodiment, the plurality of first upstream openings 91A is formed on a circumferential surface 95 of the upstream cylinder 93, the plurality of first downstream openings 92A and the plurality of second upstream openings 91B are formed in the cavities 32 of the paddle wheel 3, and the plurality of second downstream openings 92B is formed on a circumferential surface 96 of the downstream cylinder 94.

[0095] According to a preferred aspect, the angular position of each first upstream opening 91A and each cavity 32 connected by a first circulation channel 90A, and the angular position of each cavity 32 and each second downstream opening 92B connected by a second circulation channel 90B, are offset from each other along the axis of rotation R, as shown in [Fig. 1 1]. In this example, each second downstream opening 92B is angularly offset from the cavity 32 to which it is connected by an angle of 120°, as is each cavity 32 from the first upstream opening 91A to which it is connected, to allow an optimal pressure difference for circulating the fluid F between the upstream and downstream sides of the drive member 9.In other words, in this example, each first upstream opening 91A and each second downstream opening 92B connected by a first circulation channel 90A and a second circulation channel 90B are offset from each other, along the axis of rotation R, by an angle of 240°.

[0096] In practice, in this example, the upstream cylinder 93 has a front face 93A which fulfills the role of the upstream sealing wall 4 and the downstream cylinder 94 has a rear face 93A which fulfills the role of the downstream sealing wall 5.

[0097] In this embodiment, the inlet passage 6 (shown in [Fig.4]) for the fluid F is formed between the circumferential surface 95 of the upstream cylinder 93 and the inner peripheral limit L1 of the liquid ring W. Similarly, the discharge passage 7 (shown in [Fig.4]) for the fluid F is formed between the inner peripheral limit L1 of the liquid ring W and the circumferential surface 96 of the downstream cylinder 94.

[0098] Also, in this embodiment, the fluid F is introduced via the upstream inlet orifice 21 (formed in the upstream end wall 24 of the cylindrical body 2) and through the inlet passage 6 (formed between the upstream cylinder 93 and the liquid ring W). The fluid is then introduced directly into one of the first circulation channels 90A via the upstream opening 91A to one of the cavities 32 of the impeller 3. The fluid F is then drawn into the second circulation channel 90B, which is fluidly connected to the first circulation channel 90A (due to the angular offset between the first upstream opening 91A and the second downstream opening 92B). When the second downstream opening 92B is positioned opposite the discharge passage 7 (formed between the downstream cylinder 94 and the liquid ring W), the pressurized fluid F is discharged via the downstream outlet orifice 22 (formed in the downstream end wall 25 of the cylindrical body 2).

[0099] A method for using the liquid ring pump 1, according to an embodiment of the invention, with reference to [Fig. 12], will now be described. In this example, the upstream inlet orifice 21 is formed in the upstream end wall 24 of the cylindrical body 2, and the downstream outlet orifice 22 is formed in the downstream end wall 25 of the cylindrical body 2. Furthermore, the method will be described for the first embodiment of the drive element 9 (shown in Figures 3 to 7), which includes a separating wall 8 that separates an upstream impeller 3A and a downstream impeller 3B. The drive element 9 also includes, in this example, an upstream sealing wall 4 connected to the upstream face 33 of the upstream impeller 3A and a downstream sealing wall 5 connected to the downstream face 34 of the downstream impeller 3B. On the [Fig.

[12] For clarity, the cavities in black represent the upstream cavities 32A (formed in the figure in front of the separating wall 8) and the hatched cavities represent the downstream cavities 32B (formed in the figure behind the separating wall 8).

[0100] In a preliminary step, the pump 1 is activated, for example by operating an electric motor to drive the drive shaft of the drive element 9. The impeller 3 is then placed in the operating configuration and the operating fluid L is driven, under the effect of centrifugal force, against the circumferential wall 23 of the cylindrical body 2 and forms a liquid ring W which extends radially around the periphery of the internal volume 20. An inlet passage 6 is formed between the outer peripheral limit 41 of the upstream sealing wall 4 and the inner peripheral limit L1 of the liquid ring W. The upstream inlet orifice 21 is formed, in this example, opposite the inlet passage 6. Similarly, a discharge passage 7 is formed between the outer peripheral limit 51 of the downstream sealing wall 5 and the inner peripheral limit L1 of the liquid ring W.The downstream outlet orifice 22 is formed, in this example, opposite the inlet passage 6 and extends along the axis of rotation R substantially opposite the downstream inlet orifice 21.

[0101] In this example, pump 1 is a pump mounted in a fuel circuit. In other words, the operating fluid L is a fuel. The fluid F to be pumped is also a fuel. As is known, during pump priming, the fluid F to be pumped is initially air until fuel is supplied from a fuel supply line (not shown). When priming is complete and there is no more air to be drawn in, the fluid F increases the volume of the liquid ring W, which then aligns with the intake passage 6, thus limiting any risk of fuel starvation in pump 1. In other words, such a pump 1 eliminates the need for a separate reservoir to supply the liquid ring. W so that the latter has a constant volume, as was the case in the prior art. This makes it possible to limit the size and mass of the pump 1.

[0102] In a first step E1, the fluid F is introduced into the internal volume 20 through the upstream inlet orifice 21 and passes through the inlet passage 6 to be admitted into the upstream cavity 32A opposite the inlet passage 6. The impeller 3 rotates about the axis of rotation R, in this example, in a clockwise direction. The upstream cavity 32A fills until it is no longer opposite the inlet passage 6.

[0103] In a second step E2, as the impeller 3 rotates, due to its offset within the cylindrical body 2, the effective volume VU of the upstream cavity 32A, which has admitted fluid F, decreases, and the fluid F contained in the upstream cavity 32A is compressed. Simultaneously, the downstream cavity 32B, fluidically connected to the upstream cavity 32A, fills as it approaches the discharge passage 7 and its volume increases. In this example, the upstream cavity 32A and the downstream cavity 32B, which are fluidly connected, have angular positions offset by an angle of 120°.

[0104] In a step E3, when the downstream cavity 32B is positioned opposite the discharge passage 7 and more precisely opposite the downstream outlet orifice 22, the compressed fluid F is discharged out of the cylindrical body 2.

[0105] When neither the upstream cavity 32A nor the downstream cavity 32B is located opposite the upstream inlet orifice 21 and the downstream outlet orifice 22, the fluid F that has not been pumped out is transferred from one to the other of the cavities 32A, 32B, according to a communicating vessel principle according to the internal pressures of each cavity 32A, 32B.

Claims

1. Demands Liquid ring pump (1) configured to circulate a fluid (F) in a fluid circuit, in particular an aircraft fluid circuit, the liquid ring pump (1) comprising: • a cylindrical body (2) extending from an upstream to a downstream along a principal axis (X) and comprising an upstream end wall (24) and a downstream end wall (25) planar orthogonal to the principal axis (X) connected by a circumferential wall (23), the cylindrical body (2) being hollow and defining an internal volume (20), an operating liquid (L) partially filling the internal volume (20), the liquid ring pump (1) having an upstream inlet port (21) for the admission of the fluid (F) into the internal volume (20) and a downstream outlet port (22) for the discharge of the fluid (F), • a drive element (9) mounted in the cylindrical body (2), the drive element (9) being mounted to rotate about an axis of rotation (A) parallel to the main axis (X) in a manner offset from the cylindrical body (2), • the operating fluid (L) forming, in an operating configuration, a liquid ring (W) which extends radially around the periphery of the internal volume (20) of the cylindrical body (2), the drive element (9) being, in the operating configuration, at least partially immersed in the operating fluid (L), • the liquid ring pump (1) being characterized in that the drive element (9) comprises: • at least one impeller (3) comprising a plurality of impellers (31), each pair of two adjacent impellers (31) defining an inter-impeller space, a cavity (32) being defined, in the operating configuration, in each inter-impeller space between two adjacent impellers (31) and the liquid ring (W), • at least one plurality of upstream openings (91) for the circulation of fluid (F) at least in the paddle wheel (3), each upstream opening (91) having an upstream angular position, • at least a plurality of downstream openings (92), for the distribution of the fluid (F), each downstream opening (92) having a downstream angular position, each upstream opening (91) and / or each downstream opening (92) being formed respectively in one of the cavities (32) of the paddle wheel (3), and • at least a plurality of circulation channels (90), each circulation channel (90) being formed between one of the upstream openings (91) and one of the downstream openings (92) whose downstream angular position is angularly offset with respect to the upstream angular position of the upstream opening (91).

2. Liquid ring pump (1) according to claim 1, wherein the drive member (9) comprises at least one separating wall (8) extending orthogonally to the main axis (X) and configured to separate the impeller (3) into at least one adjacent upstream impeller (3A) and downstream impeller (3B), the upstream impeller (3A) comprising a plurality of upstream cavities (32A), the downstream impeller (3B) comprising a plurality of downstream cavities (32B), each upstream opening (91) being formed respectively in one of the upstream cavities (32A) and each downstream opening (92) being formed in one of the downstream cavities (32B).

3. Liquid ring pump (1) according to claim 1, wherein the drive member (9) comprises: • a plurality of upstream first openings (91A), each upstream first opening (91A) having a first upstream angular position, • a plurality of downstream first openings (92A), each downstream first opening (92A) having a first downstream angular position, • a plurality of first circulation channels (90A), each first circulation channel (90A) being formed between one of the upstream first openings (91A) and one of the downstream first openings (92A) whose angular position downstream is angularly offset relative to the upstream angular position of the first upstream opening (91A), a plurality of second upstream openings (91B), each second upstream opening (91B) having a second upstream angular position, a plurality of second downstream openings (92B), each second downstream opening (92B) having a second downstream angular position, a plurality of second circulation channels (90B), each second circulation channel (90B) being formed between one of the second upstream openings (91B) and one of the second downstream openings (92B) whose downstream angular position is angularly offset relative to the upstream angular position of the second upstream opening (91B), the second upstream position corresponding to the first downstream position, so as to fluidly connect each second circulation channel (90B) respectively to the first circulation channel (90A), the drive element (9) comprises: • two separating walls (8A, 8B) extending orthogonally to the main axis (X) and configured to separate the paddle wheel (3) into at least one upstream wheel (3A), one downstream wheel (3B) and one intermediate wheel (3C) formed between the upstream wheel (3A) and the downstream wheel (3B), the upstream wheel (3A) comprising a plurality of upstream cavities (32A), the downstream wheel (3B) comprising a plurality of downstream cavities (32B), the intermediate wheel (3C) comprising a plurality of intermediate cavities (32C), • each first upstream opening (91 A) is formed in one of the upstream cavities (32A), each first downstream opening (92A) and each second upstream opening (91B) is formed in one of the intermediate cavities (92C) and each second downstream opening (92B) is formed in one of the downstream cavities (32B).

4. Liquid ring pump (1) according to claim 1, wherein the drive element (9) comprises: • a plurality of first upstream openings (91 A), each first upstream opening (91 A) possessing a first upstream angular position, • a plurality of first downstream openings (92A), each first downstream opening (92A) having a first downstream angular position, • a plurality of first circulation channels (90A), each first circulation channel (90A) being formed between one of the first upstream openings (91A) and one of the first downstream openings (92A) whose downstream angular position is angularly offset relative to the upstream angular position of the first upstream opening (91A), • a plurality of second upstream openings (91B), each second upstream opening (91B) having a second upstream angular position, • a plurality of second downstream openings (92B), each second downstream opening (92B) having a second downstream angular position, • a plurality of second circulation channels (90B), each second circulation channel (90B) being formed between one of the upstream second openings (91B) and one of the downstream second openings (92B) whose downstream angular position is angularly offset relative to the upstream angular position of the upstream second opening (91B), the upstream second position corresponding to the downstream first position, so as to fluidly connect each second circulation channel (90B) respectively to the first circulation channel (90A), • the drive unit (9) comprises: • an upstream cylinder (93) connected to an upstream face (33) of the paddle wheel (3), the plurality of first upstream openings (91 A) being formed on a circumferential surface (95) of the upstream cylinder (93), • a downstream cylinder (94) connected to a downstream face (34) of the paddle wheel (3), the plurality of second downstream openings (92B) being formed on a circumferential surface (96) of the downstream cylinder (94), • the plurality of first downstream openings (92A) and the plurality of second upstream openings (91B) being formed in the cavities (32) of the paddle wheel (3).

5. Liquid ring pump (1) according to any one of claims 1 to 4, wherein the drive element (9) comprises: • an upstream sealing wall (4) mounted in the cylindrical body (2) and fixedly connected to an upstream face (33) of the drive element (9), and • a downstream sealing wall (5) mounted in the cylindrical body (2) and fixedly connected to a downstream face (34) of the drive element (9), • the upstream sealing wall (4) and the downstream sealing wall (5) being configured to form with an inner peripheral boundary (L1) of the liquid ring (W), respectively an inlet passage (6) into the inner volume (20) and a discharge passage (7) for the fluid (F).

6. Liquid ring pump (1) according to claim 5, wherein each sealing wall (4, 5) has a circular shape.

7. Liquid ring pump (1) according to any one of claims 1 to 6, wherein the upstream inlet port (21) for the admission of the fluid (F) into the internal volume (20) is formed in the upstream end wall (24) of the cylindrical body (2).

8. Liquid ring pump (1) according to any one of claims 1 to 7, wherein the downstream outlet port (22) for discharging the fluid (F) from the internal volume (20) is formed in the downstream end wall (25) of the cylindrical body (2).

9. Aircraft comprising a fuel circuit supplying a turbomachine and a liquid ring pump (1) according to any one of claims 1 to 8 for supplying the turbomachine.

10. A method of using the liquid ring pump (1) according to any one of claims 1 to 8, the liquid ring pump (1) being in an operating configuration, the operating fluid (L) forming a liquid ring (W) around the periphery of the internal volume (20), the operating process comprising the steps of: • admit the fluid (F) into the internal volume (20) via the upstream inlet port (21), • introduce the fluid (F) into the circulation channel (90) through the upstream opening (91), • transfer the fluid (F) from upstream to downstream through the circulation channel (90) by pressure difference between the upstream opening (91) and the downstream opening (92), • extract the pressurized fluid (F) from the circulation channel (90) through the downstream opening (92), and • discharge the fluid (F) from the internal volume (20) via the downstream outlet port (22).

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