Reversible Fluid Pump with Pressure Relief Mechanism

Abstract

A reversible fluid pump, such as a screw pump, includes a housing defining a first chamber and a second chamber sealed from the first chamber. The pump further includes a pressure relief mechanism configured to limit excessive pressure during operation of the pump in either direction. The pressure relief mechanism includes at least one fluid passage providing fluid communication between the first chamber and the second chamber, and at least one check valve associated with the fluid passage. The check valve is configured to open when pressure in one of the chambers exceeds a predetermined pressure threshold to permit fluid flow from the higher-pressure chamber to the other chamber through the fluid passage. In this manner, excess pressure in either chamber can be relieved while the chambers remain sealed from each other during normal operating conditions. The pressure relief mechanism thereby reduces the risk of overpressure and improves operational reliability of the reversible fluid pump.

Description

RELATED APPLICATIONS

[0001] The present application claims the benefit of European Patent Application No. 25163875.5, filed Mar. 14, 2025, and German Patent Application No. 10 2026 106 141.9, filed Feb. 13, 2026, each titled “Reversible Fluid Pump with Pressure Relief Mechanism,” the contents of which are hereby incorporated by reference.BACKGROUND

[0002] The disclosure relates to a reversible fluid pump having a pressure relief mechanism. More specifically, but not exclusively, this disclosure relates to a reversible fluid pump being a positive displacement pump, for example a screw pump. This pump can be associated with a cooling circuit, for example in a vehicle.

[0003] An objection of the disclosure is to protect the thermal system from overpressure generated by the pump. The pump moves the fluid from one port to the other and can reverse the direction of the flow. In case of overpressure above a pressure threshold, the thermal system and the components downstream of the pump could be damaged. Known reversible fluid pumps lack a pressure relief mechanism, more specifically a reversible pressure relief mechanism working in both directions between the ports reversibly forming the inlet or outlet for the fluid flow.SUMMARY

[0004] The present disclosure relates generally to a reversible fluid pump, substantially as illustrated by and described in connection with at least one of the figures, as set forth more completely in the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The foregoing and other objects, features, and advantages of the devices, systems, and methods described herein will be apparent from the following description of particular examples thereof, as illustrated in the accompanying figures; where like or similar reference numbers refer to like or similar structures. The figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the devices, systems, and methods described herein.

[0006] FIG. 1 illustrates a pressure relief from a second port to a first port, in a first embodiment of the disclosure.

[0007] FIG. 2 illustrates the pressure relief mechanism in a first position allowing the pressure relief from a second port to a first port.

[0008] FIG. 3 illustrates a pressure relief from the first port to the second port, in the first embodiment of the disclosure.

[0009] FIG. 4 illustrates the pressure relief mechanism in a second position allowing the pressure relief from a first port to a second port.

[0010] FIG. 5 illustrates a balanced position with the absence of any pressure relief from the first or second port, in the first embodiment of the disclosure.

[0011] FIG. 6 illustrates the pressure relief mechanism in a third position not allowing any pressure relief between the first port and the second port.

[0012] FIG. 7 illustrates the disclosure in accordance with a second embodiment.

[0013] FIG. 8 illustrates the disclosure in accordance with a third embodiment.DETAILED DESCRIPTION

[0014] References to items in the singular should be understood to include items in the plural, and vice versa, unless explicitly stated otherwise or clear from the text. Grammatical conjunctions are intended to express any and all disjunctive and conjunctive combinations of conjoined clauses, sentences, words, and the like, unless otherwise stated or clear from the context. Recitation of ranges of values herein are not intended to be limiting, referring instead individually to any and all values falling within and / or including the range, unless otherwise indicated herein, and each separate value within such a range is incorporated into the specification as if it were individually recited herein. In the following description, it is understood that terms such as “first,”“second,”“top,”“bottom,”“side,”“front,”“back,” and the like are words of convenience and are not to be construed as limiting terms. For example, while in some examples a first side is located adjacent or near a second side, the terms “first side” and “second side” do not imply any specific order in which the sides are ordered.

[0015] The terms “about,”“approximately,”“substantially,” or the like, when accompanying a numerical value, are to be construed as indicating a deviation as would be appreciated by one of ordinary skill in the art to operate satisfactorily for an intended purpose. Ranges of values and / or numeric values are provided herein as examples only, and do not constitute a limitation on the scope of the disclosure. The use of any and all examples, or exemplary language (“e.g.,”“such as,” or the like) provided herein, is intended merely to better illuminate the disclosed examples, and does not pose a limitation on the scope of the disclosure. The terms “e.g.,” and “for example” set off lists of one or more non-limiting examples, instances, or illustrations. No language in the specification should be construed as indicating any unclaimed element as essential to the practice of the disclosed examples.

[0016] The term “and / or” means any one or more of the items in the list joined by “and / or.” As an example, “x and / or y” means any element of the three-element set {(x), (y), (x, y)}. In other words, “x and / or y” means “one or both of x and y.” As another example, “x, y, and / or z” means any element of the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, “x, y, and / or z” means “one or more of x, y, and z.”

[0017] The disclosure relates to a reversible fluid pump comprising: a housing having a first chamber and a second chamber sealed from said first chamber, a pressure relief mechanism, said pressure relief mechanism comprising: at least one duct configured to fluidically connect said first chamber and said second chamber; at least one check valve coupled to the at least one duct and configured to relieve an excess pressure above a predetermined pressure threshold in one of the first chamber or the second chamber onto the other of said chambers through said at least one duct.

[0018] In examples, the reversible fluid pump is a positive displacement pump.

[0019] In examples, the reversible fluid pump is a screw pump.

[0020] In examples, the pressure relief mechanism further comprises at least one outlet check valve coupled to the at least one duct.

[0021] In a first embodiment, the at least one duct comprises exactly one duct, and the at least one check valve comprises a first inlet check valve and a second inlet check valve coupled to said duct, and the pressure relief mechanism further comprises selective means configured to selectively open and close said first inlet check valve or second inlet check valve, the pressure relief mechanism being configured to be in either: a first position wherein it is configured to open said first inlet check valve and close said second inlet check valve, or a second position wherein it is configured to close said first inlet check valve and open said second inlet check valve, or a third position wherein it is configured to close said first inlet check valve and close said second inlet check valve, said third position being the rest position of the pressure relief mechanism when the pressure in either one of the first chamber or the second chamber is below the predetermined pressure threshold.

[0022] In examples, the at least one outlet check valve comprises a first outlet check valve and a second outlet check valve, and: in the first position, the pressure relief mechanism further opens said first outlet check valve and further closes second outlet check valve; and in the second position, the pressure relief mechanism further closes said first outlet check valve and opens said second outlet check valve; and in the third position, the pressure relief mechanism further closes said first inlet check valve and closes said second inlet check valve.

[0023] In examples, the selective means are resilient selective means and comprise at least one resilient element and a sliding plate, said sliding plate being configured to be switchable by the excess pressure above the predetermined pressure threshold toward the first position or second position of the pressure relief mechanism from the third position, said sliding plate being configured to selectively obstruct or liberate the at least one check valve for the first and second positions, said at least one resilient element being configured to work against the sliding of the sliding plate apart from the third position under the force exerted by the pressure excess.

[0024] In examples, the selective means comprises two opposite springs.

[0025] In examples, the two opposite springs are on either side of a wall.

[0026] In examples, the selective means further comprise two opposed abutments allowing to configure the stiffness of the two opposite springs regarding the predetermined pressure threshold.

[0027] In a second embodiment and a third embodiment, the at least one duct comprises a first duct and a second duct.

[0028] In examples, the first duct comprises a first inlet check valve.

[0029] In examples, the first duct comprises a first outlet check valve.

[0030] In examples, the second duct comprises a second inlet check valve.

[0031] In examples, the second duct comprises a second outlet check valve.

[0032] In the first embodiment, the first duct and the second duct are outside of the housing.

[0033] In the third embodiment, the first duct and the second duct are inside of the housing and through a sealing interface, said sealing interface being located between the two chambers in the housing and sealing said chambers from each other.

[0034] Referring to FIGS. 1, 3 and 5, the reversible fluid pump 100, 700, 800 of the disclosure is illustrated in its three different ways of functioning.

[0035] The reversible fluid pump 100, 700, 800 can be a positive displacement pump, for example a screw pump.

[0036] The reversible fluid pump 100, 700, 800 comprises a housing 108, 702, 802 having a first chamber 110,712,804 and a second chamber 112, 724, 806 sealed from said first chamber 110, 712, 804.

[0037] The first chamber 110, 712, 804 has a first port 102, 704 and the second chamber 112, 724, 806 has a second port 104, 706.

[0038] The reversible fluid pump 100, 700, 800 further comprises a pressure relief mechanism 106, 708, 808.

[0039] The pressure relief mechanism 106, 708, 808 comprises at least one duct 202, 710, 712, 810, 812.

[0040] The at least one duct 202, 710, 712, 810, 812 is configured to fluidically connect said first chamber 110, 712, 804 and said second chamber 112, 724, 806.

[0041] The pressure relief mechanism 106, 708, 808 further comprises at least one check valve 204, 210, 714, 716, 814, 816.

[0042] The at least one check valve 204, 210, 714, 716, 814, 816 is coupled to the at least one duct 202, 710, 712, 810, 812.

[0043] The at least one check valve 204, 210, 714, 716, 814, 816 is configured to relieve an excess pressure above a predetermined pressure threshold in one of the first chamber 110, 722, 804 or the second chamber 112, 724, 806 onto the other of said chambers 110, 112 through said at least one duct 202, 710, 712, 810, 812.

[0044] The pressure relief mechanism 106, 708, 808 can further comprise at least one outlet check valve 206, 208.

[0045] The at least one outlet check valve 206, 208 is coupled to the at least one duct 202, 710, 712, 810, 812.

[0046] The at least one duct 202, 710, 712, 810, 812 comprises exactly one duct 202.

[0047] The at least one check valve 204, 210, 714, 716, 814, 816 comprises a first inlet check valve 204, 714, 814 and a second inlet check valve 210, 716, 816 coupled to said duct 202.

[0048] The pressure relief mechanism 106, 708, 808 further comprises selective means configured to selectively open and close said first inlet check valve 204, 714, 814 or second inlet check valve 210, 716, 816.

[0049] The pressure relief mechanism 106, 708, 808 is configured to be in either a first position (FIG. 1 and FIG. 2), a second position (FIG. 3 and FIG. 4), or a third position (FIG. 5 and FIG. 6).

[0050] In the first position, the pressure relief mechanism 106, 708, 808 is configured to open said first inlet check valve 204, 714, 814 and close said second inlet check valve 210, 716, 816.

[0051] This first position occurs when the pressure in the first chamber 110 is above a pressure threshold and above the pressure in the second chamber 112.

[0052] In this first position, the high pressure is in the first port and it activates the pressure relief mechanism 106 to the opening of the first inlet check valve 204 and of the first outlet check valve 206, so that the overpressure is released with a gas flow from the first port 102 to the second port 104 and / or from the first chamber 110 to the second chamber 112.

[0053] In the second position, the pressure relief mechanism 106, 708, 808 is configured to close said first inlet check valve 204, 714, 814 and open said second inlet check valve 210, 716, 816.

[0054] This second position occurs when the pressure in the second chamber 112 is above a pressure threshold and above the pressure in the first chamber 110.

[0055] In this second position, the high pressure is in the first port and it activates the pressure relief mechanism 106 to the opening of the first inlet check valve 204 and of the first outlet check valve 206, so that the overpressure is released with a gas flow from the first port 102 to the second port 104 and / or from the first chamber 110 to the second chamber 112.

[0056] In the third position, the pressure relief mechanism 106, 708, 808 is configured to close said first inlet check valve 204, 714, 814 and close said second inlet check valve 210, 716, 816.

[0057] This third position occurs when the pressure in the first chamber 110 and in the second chamber 112 is below a pressure threshold and substantially equal to the pressure in the first chamber 110.

[0058] In this third position, the high pressure is neither in the first port nor in the second port 104 and it does not activate the pressure relief mechanism 106 any opening of the check valves but keeps them closed, so that there is no gas flow between the first port 102 and the second port 104 and / or between the first chamber 110 and the second chamber 112.

[0059] The third position is then the rest position of the pressure relief mechanism 106, 708, 808 when the pressure in either one of the first chamber 110, 722, 804 or the second chamber 112, 724, 806 is below the predetermined pressure threshold and sensibly equal.

[0060] The at least one outlet check valve 206, 208 can further comprise a first outlet check valve 206.

[0061] The at least one outlet check valve 206, 208 can further comprise a second outlet check valve 208.

[0062] The first outlet check valve 206 and second outlet check valve 208 are redundant to the first inlet check valve 204 and second inlet check valve 210.

[0063] In the first position, the pressure relief mechanism 106, 708, 808 further opens said first outlet check valve 206 and further closes second outlet check valve 208.

[0064] In the second position, the pressure relief mechanism 106, 708, 808 further closes said first outlet check valve 206 and opens said second outlet check valve 208.

[0065] In the third position, the pressure relief mechanism 106, 708, 808 further closes said first inlet check valve 204, 714, 814 and closes said second inlet check valve 210, 716, 816.

[0066] The selective means are resilient selective means and comprise at least one resilient element 212, 718, 818 and a sliding plate 220,

[0067] The sliding plate220 is configured to be switchable by the excess pressure above the predetermined pressure threshold toward the first position or second position of the pressure relief mechanism 106, 708, 808 from the third position.

[0068] The sliding plate 220 is configured to selectively obstruct or liberate the at least one check valve 204, 210, 714, 716, 814, 816 for the first and second positions.

[0069] The at least one resilient element 212, 718, 818 is configured to work against the sliding of the sliding plate 220 apart from the third position under the force exerted by the pressure excess from one chamber or the other.

[0070] In examples, the selective means comprising two opposite springs 212, 214, 718, 720, 818, 820.

[0071] The two opposite springs are optionally on either side of a wall 216.

[0072] For example, the two opposite springs work oppositely in compression and in decompression.

[0073] Optionally, the selective means further comprise two opposed abutments 218 allowing to configure the stiffness of the two opposite springs regarding the predetermined pressure threshold.

[0074] Indeed, this stiffness is a parameter that allows the opening or closing of the check valves regarding a specific pressure of the fluid against the springs.

[0075] In the second embodiment illustrated by the FIG. 7 or in the third embodiment illustrated by the FIG. 8, the at least one duct 202, 710, 712, 810, 810, 812 comprises a first duct 710, 810 and a second duct 712, 812.

[0076] The first duct 710, 810 comprises a first inlet check valve 714, 814.

[0077] A first spring 718, 818 can allow to open or close the first inlet check valve 714, 814 in the second or third embodiment, depending on the pressure in the first chamber 722, 804 and the predetermined pressure threshold.

[0078] Optionally in the second or third embodiment, the first duct 710, 810 comprises a first outlet check valve.

[0079] The second duct 712, 812 can comprise a second inlet check valve 716, 816.

[0080] A first spring 718, 720, 818, 820 can allow to open or close the first inlet check valve 714814, depending on the pressure in the first chamber 722, 804 and the predetermined pressure threshold.

[0081] Optionally, the second duct 712, 812 comprises a second outlet check valve.

[0082] In the second embodiment, the first duct 710, 810 and the second duct 712, 812 are outside of the housing 108, 702, 802.

[0083] In the second embodiment, the pump is larger but is easier to manufacture.

[0084] In the third embodiment, the first duct 710, 810 and the second duct 712, 812 are inside of the housing 108, 702, 802 and through a sealing interface 822.

[0085] More specifically, the two ducts are located in the inner housing of the screw pump screws, and inlet and / or outlet check valves are associated within.

[0086] The third embodiment allows to have a more compact pump than in the first and second embodiments, due to the internalization of the pressure relief mechanism.

[0087] The sealing interface 822 is located between the two chambers in the housing and it seals said chambers 110, 112, 712, 724, 804, 806 from each other.

[0088] The pressure relief mechanism also provides different operational modes to the pump, regardless of the pressure threshold, allowing for example different cooling and / or heating purposes in the same pump, based on the flow direction.

[0089] It will be appreciated by persons skilled in the art that the above detailed examples have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the disclosure as defined by the appended claims. Various modifications to the detailed examples described above are possible.

[0090] Through the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to and do not exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0091] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the disclosure are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification including any accompanying claims, abstract and drawings, and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The disclosure is not restricted to the details of any foregoing embodiments. The disclosure extends to any novel one, or any novel combination, of the features disclosed in this specification including any accompanying claims, abstract or drawings, or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0092] While the present method and / or system has been described with reference to certain implementations, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted without departing from the scope of the present method and / or system. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from its scope. For example, block and / or components of examples disclosed may be combined, divided, re-arranged, and / or otherwise modified. Therefore, the present method and / or system are not limited to the particular implementations disclosed. Instead, the present method and / or system will include all implementations falling within the scope of the appended claims, both literally and under the doctrine of equivalents.List of Reference Signs100 Reversible Fluid Pump

[0094] 102 First Port

[0095] 104 Second Port

[0096] 106 Pressure Relief Mechanism

[0097] 108 Housing

[0098] 110 First Chamber

[0099] 112 Second Chamber

[0100] 202 Duct

[0101] 204 First Inlet Check Valve

[0102] 206 First Outlet Check Valve

[0103] 208 Second Outlet Check Valve

[0104] 210 Second Inlet Check Valve

[0105] 212 First Spring

[0106] 214 Second Spring

[0107] 216 Wall

[0108] 218 Abutment

[0109] 220 Sliding Plate

[0110] 700 Reversible Fluid Pump

[0111] 702 Housing

[0112] 704 First Port

[0113] 706 Second Port

[0114] 708 Pressure Relief Mechanism

[0115] 710 First Duct

[0116] 712 Second Duct

[0117] 714 First Inlet Check Valve

[0118] 716 Second Inlet Check Valve

[0119] 718 First Spring

[0120] 720 Second Spring

[0121] 722 First Chamber

[0122] 724 Second Chamber

[0123] 800 Reversible Fluid Pump

[0124] 802 Housing

[0125] 804 First Chamber

[0126] 806 Second Chamber

[0127] 808 Pressure Relief Mechanism

[0128] 810 First Duct

[0129] 812 Second Duct

[0130] 814 First Inlet Check Valve

[0131] 816 Second Inlet Check Valve

[0132] 818 First Spring

[0133] 820 Second Spring

[0134] 822 Sealing Interface

Examples

first embodiment

[0021]In a first embodiment, the at least one duct comprises exactly one duct, and the at least one check valve comprises a first inlet check valve and a second inlet check valve coupled to said duct, and the pressure relief mechanism further comprises selective means configured to selectively open and close said first inlet check valve or second inlet check valve, the pressure relief mechanism being configured to be in either: a first position wherein it is configured to open said first inlet check valve and close said second inlet check valve, or a second position wherein it is configured to close said first inlet check valve and open said second inlet check valve, or a third position wherein it is configured to close said first inlet check valve and close said second inlet check valve, said third position being the rest position of the pressure relief mechanism when the pressure in either one of the first chamber or the second chamber is below the predetermined pressure threshold...

third embodiment

[0033]In the third embodiment, the first duct and the second duct are inside of the housing and through a sealing interface, said sealing interface being located between the two chambers in the housing and sealing said chambers from each other.

[0034]Referring to FIGS. 1, 3 and 5, the reversible fluid pump 100, 700, 800 of the disclosure is illustrated in its three different ways of functioning.

[0035]The reversible fluid pump 100, 700, 800 can be a positive displacement pump, for example a screw pump.

[0036]The reversible fluid pump 100, 700, 800 comprises a housing 108, 702, 802 having a first chamber 110,712,804 and a second chamber 112, 724, 806 sealed from said first chamber 110, 712, 804.

[0037]The first chamber 110, 712, 804 has a first port 102, 704 and the second chamber 112, 724, 806 has a second port 104, 706.

[0038]The reversible fluid pump 100, 700, 800 further comprises a pressure relief mechanism 106, 708, 808.

[0039]The pressure relief mechanism 106, 708, 808 comprises at ...

second embodiment

[0082]In the second embodiment, the first duct 710, 810 and the second duct 712, 812 are outside of the housing 108, 702, 802.

[0083]In the second embodiment, the pump is larger but is easier to manufacture.

[0084]In the third embodiment, the first duct 710, 810 and the second duct 712, 812 are inside of the housing 108, 702, 802 and through a sealing interface 822.

[0085]More specifically, the two ducts are located in the inner housing of the screw pump screws, and inlet and / or outlet check valves are associated within.

[0086]The third embodiment allows to have a more compact pump than in the first and second embodiments, due to the internalization of the pressure relief mechanism.

[0087]The sealing interface 822 is located between the two chambers in the housing and it seals said chambers 110, 112, 712, 724, 804, 806 from each other.

[0088]The pressure relief mechanism also provides different operational modes to the pump, regardless of the pressure threshold, allowing for example diffe...

RELATED APPLICATIONS

[0001] The present application claims the benefit of European Patent Application No. 25163875.5, filed Mar. 14, 2025, and German Patent Application No. 10 2026 106 141.9, filed Feb. 13, 2026, each titled “Reversible Fluid Pump with Pressure Relief Mechanism,” the contents of which are hereby incorporated by reference.BACKGROUND

[0002] The disclosure relates to a reversible fluid pump having a pressure relief mechanism. More specifically, but not exclusively, this disclosure relates to a reversible fluid pump being a positive displacement pump, for example a screw pump. This pump can be associated with a cooling circuit, for example in a vehicle.

[0003] An objection of the disclosure is to protect the thermal system from overpressure generated by the pump. The pump moves the fluid from one port to the other and can reverse the direction of the flow. In case of overpressure above a pressure threshold, the thermal system and the components downstream of the pump could be damaged. Known reversible fluid pumps lack a pressure relief mechanism, more specifically a reversible pressure relief mechanism working in both directions between the ports reversibly forming the inlet or outlet for the fluid flow.SUMMARY

[0004] The present disclosure relates generally to a reversible fluid pump, substantially as illustrated by and described in connection with at least one of the figures, as set forth more completely in the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The foregoing and other objects, features, and advantages of the devices, systems, and methods described herein will be apparent from the following description of particular examples thereof, as illustrated in the accompanying figures; where like or similar reference numbers refer to like or similar structures. The figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the devices, systems, and methods described herein.

[0006] FIG. 1 illustrates a pressure relief from a second port to a first port, in a first embodiment of the disclosure.

[0007] FIG. 2 illustrates the pressure relief mechanism in a first position allowing the pressure relief from a second port to a first port.

[0008] FIG. 3 illustrates a pressure relief from the first port to the second port, in the first embodiment of the disclosure.

[0009] FIG. 4 illustrates the pressure relief mechanism in a second position allowing the pressure relief from a first port to a second port.

[0010] FIG. 5 illustrates a balanced position with the absence of any pressure relief from the first or second port, in the first embodiment of the disclosure.

[0011] FIG. 6 illustrates the pressure relief mechanism in a third position not allowing any pressure relief between the first port and the second port.

[0012] FIG. 7 illustrates the disclosure in accordance with a second embodiment.

[0013] FIG. 8 illustrates the disclosure in accordance with a third embodiment.DETAILED DESCRIPTION

[0014] References to items in the singular should be understood to include items in the plural, and vice versa, unless explicitly stated otherwise or clear from the text. Grammatical conjunctions are intended to express any and all disjunctive and conjunctive combinations of conjoined clauses, sentences, words, and the like, unless otherwise stated or clear from the context. Recitation of ranges of values herein are not intended to be limiting, referring instead individually to any and all values falling within and / or including the range, unless otherwise indicated herein, and each separate value within such a range is incorporated into the specification as if it were individually recited herein. In the following description, it is understood that terms such as “first,”“second,”“top,”“bottom,”“side,”“front,”“back,” and the like are words of convenience and are not to be construed as limiting terms. For example, while in some examples a first side is located adjacent or near a second side, the terms “first side” and “second side” do not imply any specific order in which the sides are ordered.

[0015] The terms “about,”“approximately,”“substantially,” or the like, when accompanying a numerical value, are to be construed as indicating a deviation as would be appreciated by one of ordinary skill in the art to operate satisfactorily for an intended purpose. Ranges of values and / or numeric values are provided herein as examples only, and do not constitute a limitation on the scope of the disclosure. The use of any and all examples, or exemplary language (“e.g.,”“such as,” or the like) provided herein, is intended merely to better illuminate the disclosed examples, and does not pose a limitation on the scope of the disclosure. The terms “e.g.,” and “for example” set off lists of one or more non-limiting examples, instances, or illustrations. No language in the specification should be construed as indicating any unclaimed element as essential to the practice of the disclosed examples.

[0016] The term “and / or” means any one or more of the items in the list joined by “and / or.” As an example, “x and / or y” means any element of the three-element set {(x), (y), (x, y)}. In other words, “x and / or y” means “one or both of x and y.” As another example, “x, y, and / or z” means any element of the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, “x, y, and / or z” means “one or more of x, y, and z.”

[0017] The disclosure relates to a reversible fluid pump comprising: a housing having a first chamber and a second chamber sealed from said first chamber, a pressure relief mechanism, said pressure relief mechanism comprising: at least one duct configured to fluidically connect said first chamber and said second chamber; at least one check valve coupled to the at least one duct and configured to relieve an excess pressure above a predetermined pressure threshold in one of the first chamber or the second chamber onto the other of said chambers through said at least one duct.

[0018] In examples, the reversible fluid pump is a positive displacement pump.

[0019] In examples, the reversible fluid pump is a screw pump.

[0020] In examples, the pressure relief mechanism further comprises at least one outlet check valve coupled to the at least one duct.

[0021] In a first embodiment, the at least one duct comprises exactly one duct, and the at least one check valve comprises a first inlet check valve and a second inlet check valve coupled to said duct, and the pressure relief mechanism further comprises selective means configured to selectively open and close said first inlet check valve or second inlet check valve, the pressure relief mechanism being configured to be in either: a first position wherein it is configured to open said first inlet check valve and close said second inlet check valve, or a second position wherein it is configured to close said first inlet check valve and open said second inlet check valve, or a third position wherein it is configured to close said first inlet check valve and close said second inlet check valve, said third position being the rest position of the pressure relief mechanism when the pressure in either one of the first chamber or the second chamber is below the predetermined pressure threshold.

[0022] In examples, the at least one outlet check valve comprises a first outlet check valve and a second outlet check valve, and: in the first position, the pressure relief mechanism further opens said first outlet check valve and further closes second outlet check valve; and in the second position, the pressure relief mechanism further closes said first outlet check valve and opens said second outlet check valve; and in the third position, the pressure relief mechanism further closes said first inlet check valve and closes said second inlet check valve.

[0023] In examples, the selective means are resilient selective means and comprise at least one resilient element and a sliding plate, said sliding plate being configured to be switchable by the excess pressure above the predetermined pressure threshold toward the first position or second position of the pressure relief mechanism from the third position, said sliding plate being configured to selectively obstruct or liberate the at least one check valve for the first and second positions, said at least one resilient element being configured to work against the sliding of the sliding plate apart from the third position under the force exerted by the pressure excess.

[0024] In examples, the selective means comprises two opposite springs.

[0025] In examples, the two opposite springs are on either side of a wall.

[0026] In examples, the selective means further comprise two opposed abutments allowing to configure the stiffness of the two opposite springs regarding the predetermined pressure threshold.

[0027] In a second embodiment and a third embodiment, the at least one duct comprises a first duct and a second duct.

[0028] In examples, the first duct comprises a first inlet check valve.

[0029] In examples, the first duct comprises a first outlet check valve.

[0030] In examples, the second duct comprises a second inlet check valve.

[0031] In examples, the second duct comprises a second outlet check valve.

[0032] In the first embodiment, the first duct and the second duct are outside of the housing.

[0033] In the third embodiment, the first duct and the second duct are inside of the housing and through a sealing interface, said sealing interface being located between the two chambers in the housing and sealing said chambers from each other.

[0034] Referring to FIGS. 1, 3 and 5, the reversible fluid pump 100, 700, 800 of the disclosure is illustrated in its three different ways of functioning.

[0035] The reversible fluid pump 100, 700, 800 can be a positive displacement pump, for example a screw pump.

[0036] The reversible fluid pump 100, 700, 800 comprises a housing 108, 702, 802 having a first chamber 110,712,804 and a second chamber 112, 724, 806 sealed from said first chamber 110, 712, 804.

[0037] The first chamber 110, 712, 804 has a first port 102, 704 and the second chamber 112, 724, 806 has a second port 104, 706.

[0038] The reversible fluid pump 100, 700, 800 further comprises a pressure relief mechanism 106, 708, 808.

[0039] The pressure relief mechanism 106, 708, 808 comprises at least one duct 202, 710, 712, 810, 812.

[0040] The at least one duct 202, 710, 712, 810, 812 is configured to fluidically connect said first chamber 110, 712, 804 and said second chamber 112, 724, 806.

[0041] The pressure relief mechanism 106, 708, 808 further comprises at least one check valve 204, 210, 714, 716, 814, 816.

[0042] The at least one check valve 204, 210, 714, 716, 814, 816 is coupled to the at least one duct 202, 710, 712, 810, 812.

[0043] The at least one check valve 204, 210, 714, 716, 814, 816 is configured to relieve an excess pressure above a predetermined pressure threshold in one of the first chamber 110, 722, 804 or the second chamber 112, 724, 806 onto the other of said chambers 110, 112 through said at least one duct 202, 710, 712, 810, 812.

[0044] The pressure relief mechanism 106, 708, 808 can further comprise at least one outlet check valve 206, 208.

[0045] The at least one outlet check valve 206, 208 is coupled to the at least one duct 202, 710, 712, 810, 812.

[0046] The at least one duct 202, 710, 712, 810, 812 comprises exactly one duct 202.

[0047] The at least one check valve 204, 210, 714, 716, 814, 816 comprises a first inlet check valve 204, 714, 814 and a second inlet check valve 210, 716, 816 coupled to said duct 202.

[0048] The pressure relief mechanism 106, 708, 808 further comprises selective means configured to selectively open and close said first inlet check valve 204, 714, 814 or second inlet check valve 210, 716, 816.

[0049] The pressure relief mechanism 106, 708, 808 is configured to be in either a first position (FIG. 1 and FIG. 2), a second position (FIG. 3 and FIG. 4), or a third position (FIG. 5 and FIG. 6).

[0050] In the first position, the pressure relief mechanism 106, 708, 808 is configured to open said first inlet check valve 204, 714, 814 and close said second inlet check valve 210, 716, 816.

[0051] This first position occurs when the pressure in the first chamber 110 is above a pressure threshold and above the pressure in the second chamber 112.

[0052] In this first position, the high pressure is in the first port and it activates the pressure relief mechanism 106 to the opening of the first inlet check valve 204 and of the first outlet check valve 206, so that the overpressure is released with a gas flow from the first port 102 to the second port 104 and / or from the first chamber 110 to the second chamber 112.

[0053] In the second position, the pressure relief mechanism 106, 708, 808 is configured to close said first inlet check valve 204, 714, 814 and open said second inlet check valve 210, 716, 816.

[0054] This second position occurs when the pressure in the second chamber 112 is above a pressure threshold and above the pressure in the first chamber 110.

[0055] In this second position, the high pressure is in the first port and it activates the pressure relief mechanism 106 to the opening of the first inlet check valve 204 and of the first outlet check valve 206, so that the overpressure is released with a gas flow from the first port 102 to the second port 104 and / or from the first chamber 110 to the second chamber 112.

[0056] In the third position, the pressure relief mechanism 106, 708, 808 is configured to close said first inlet check valve 204, 714, 814 and close said second inlet check valve 210, 716, 816.

[0057] This third position occurs when the pressure in the first chamber 110 and in the second chamber 112 is below a pressure threshold and substantially equal to the pressure in the first chamber 110.

[0058] In this third position, the high pressure is neither in the first port nor in the second port 104 and it does not activate the pressure relief mechanism 106 any opening of the check valves but keeps them closed, so that there is no gas flow between the first port 102 and the second port 104 and / or between the first chamber 110 and the second chamber 112.

[0059] The third position is then the rest position of the pressure relief mechanism 106, 708, 808 when the pressure in either one of the first chamber 110, 722, 804 or the second chamber 112, 724, 806 is below the predetermined pressure threshold and sensibly equal.

[0060] The at least one outlet check valve 206, 208 can further comprise a first outlet check valve 206.

[0061] The at least one outlet check valve 206, 208 can further comprise a second outlet check valve 208.

[0062] The first outlet check valve 206 and second outlet check valve 208 are redundant to the first inlet check valve 204 and second inlet check valve 210.

[0063] In the first position, the pressure relief mechanism 106, 708, 808 further opens said first outlet check valve 206 and further closes second outlet check valve 208.

[0064] In the second position, the pressure relief mechanism 106, 708, 808 further closes said first outlet check valve 206 and opens said second outlet check valve 208.

[0065] In the third position, the pressure relief mechanism 106, 708, 808 further closes said first inlet check valve 204, 714, 814 and closes said second inlet check valve 210, 716, 816.

[0066] The selective means are resilient selective means and comprise at least one resilient element 212, 718, 818 and a sliding plate 220,

[0067] The sliding plate220 is configured to be switchable by the excess pressure above the predetermined pressure threshold toward the first position or second position of the pressure relief mechanism 106, 708, 808 from the third position.

[0068] The sliding plate 220 is configured to selectively obstruct or liberate the at least one check valve 204, 210, 714, 716, 814, 816 for the first and second positions.

[0069] The at least one resilient element 212, 718, 818 is configured to work against the sliding of the sliding plate 220 apart from the third position under the force exerted by the pressure excess from one chamber or the other.

[0070] In examples, the selective means comprising two opposite springs 212, 214, 718, 720, 818, 820.

[0071] The two opposite springs are optionally on either side of a wall 216.

[0072] For example, the two opposite springs work oppositely in compression and in decompression.

[0073] Optionally, the selective means further comprise two opposed abutments 218 allowing to configure the stiffness of the two opposite springs regarding the predetermined pressure threshold.

[0074] Indeed, this stiffness is a parameter that allows the opening or closing of the check valves regarding a specific pressure of the fluid against the springs.

[0075] In the second embodiment illustrated by the FIG. 7 or in the third embodiment illustrated by the FIG. 8, the at least one duct 202, 710, 712, 810, 810, 812 comprises a first duct 710, 810 and a second duct 712, 812.

[0076] The first duct 710, 810 comprises a first inlet check valve 714, 814.

[0077] A first spring 718, 818 can allow to open or close the first inlet check valve 714, 814 in the second or third embodiment, depending on the pressure in the first chamber 722, 804 and the predetermined pressure threshold.

[0078] Optionally in the second or third embodiment, the first duct 710, 810 comprises a first outlet check valve.

[0079] The second duct 712, 812 can comprise a second inlet check valve 716, 816.

[0080] A first spring 718, 720, 818, 820 can allow to open or close the first inlet check valve 714814, depending on the pressure in the first chamber 722, 804 and the predetermined pressure threshold.

[0081] Optionally, the second duct 712, 812 comprises a second outlet check valve.

[0082] In the second embodiment, the first duct 710, 810 and the second duct 712, 812 are outside of the housing 108, 702, 802.

[0083] In the second embodiment, the pump is larger but is easier to manufacture.

[0084] In the third embodiment, the first duct 710, 810 and the second duct 712, 812 are inside of the housing 108, 702, 802 and through a sealing interface 822.

[0085] More specifically, the two ducts are located in the inner housing of the screw pump screws, and inlet and / or outlet check valves are associated within.

[0086] The third embodiment allows to have a more compact pump than in the first and second embodiments, due to the internalization of the pressure relief mechanism.

[0087] The sealing interface 822 is located between the two chambers in the housing and it seals said chambers 110, 112, 712, 724, 804, 806 from each other.

[0088] The pressure relief mechanism also provides different operational modes to the pump, regardless of the pressure threshold, allowing for example different cooling and / or heating purposes in the same pump, based on the flow direction.

[0089] It will be appreciated by persons skilled in the art that the above detailed examples have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departing from the scope of the disclosure as defined by the appended claims. Various modifications to the detailed examples described above are possible.

[0090] Through the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to and do not exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0091] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the disclosure are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification including any accompanying claims, abstract and drawings, and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The disclosure is not restricted to the details of any foregoing embodiments. The disclosure extends to any novel one, or any novel combination, of the features disclosed in this specification including any accompanying claims, abstract or drawings, or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0092] While the present method and / or system has been described with reference to certain implementations, it will be understood by those skilled in the art that various changes may be made, and equivalents may be substituted without departing from the scope of the present method and / or system. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from its scope. For example, block and / or components of examples disclosed may be combined, divided, re-arranged, and / or otherwise modified. Therefore, the present method and / or system are not limited to the particular implementations disclosed. Instead, the present method and / or system will include all implementations falling within the scope of the appended claims, both literally and under the doctrine of equivalents.List of Reference Signs100 Reversible Fluid Pump

[0094] 102 First Port

[0095] 104 Second Port

[0096] 106 Pressure Relief Mechanism

[0097] 108 Housing

[0098] 110 First Chamber

[0099] 112 Second Chamber

[0100] 202 Duct

[0101] 204 First Inlet Check Valve

[0102] 206 First Outlet Check Valve

[0103] 208 Second Outlet Check Valve

[0104] 210 Second Inlet Check Valve

[0105] 212 First Spring

[0106] 214 Second Spring

[0107] 216 Wall

[0108] 218 Abutment

[0109] 220 Sliding Plate

[0110] 700 Reversible Fluid Pump

[0111] 702 Housing

[0112] 704 First Port

[0113] 706 Second Port

[0114] 708 Pressure Relief Mechanism

[0115] 710 First Duct

[0116] 712 Second Duct

[0117] 714 First Inlet Check Valve

[0118] 716 Second Inlet Check Valve

[0119] 718 First Spring

[0120] 720 Second Spring

[0121] 722 First Chamber

[0122] 724 Second Chamber

[0123] 800 Reversible Fluid Pump

[0124] 802 Housing

[0125] 804 First Chamber

[0126] 806 Second Chamber

[0127] 808 Pressure Relief Mechanism

[0128] 810 First Duct

[0129] 812 Second Duct

[0130] 814 First Inlet Check Valve

[0131] 816 Second Inlet Check Valve

[0132] 818 First Spring

[0133] 820 Second Spring

[0134] 822 Sealing Interface

Examples

first embodiment

[0021]In a first embodiment, the at least one duct comprises exactly one duct, and the at least one check valve comprises a first inlet check valve and a second inlet check valve coupled to said duct, and the pressure relief mechanism further comprises selective means configured to selectively open and close said first inlet check valve or second inlet check valve, the pressure relief mechanism being configured to be in either: a first position wherein it is configured to open said first inlet check valve and close said second inlet check valve, or a second position wherein it is configured to close said first inlet check valve and open said second inlet check valve, or a third position wherein it is configured to close said first inlet check valve and close said second inlet check valve, said third position being the rest position of the pressure relief mechanism when the pressure in either one of the first chamber or the second chamber is below the predetermined pressure threshold...

third embodiment

[0033]In the third embodiment, the first duct and the second duct are inside of the housing and through a sealing interface, said sealing interface being located between the two chambers in the housing and sealing said chambers from each other.

[0034]Referring to FIGS. 1, 3 and 5, the reversible fluid pump 100, 700, 800 of the disclosure is illustrated in its three different ways of functioning.

[0035]The reversible fluid pump 100, 700, 800 can be a positive displacement pump, for example a screw pump.

[0036]The reversible fluid pump 100, 700, 800 comprises a housing 108, 702, 802 having a first chamber 110,712,804 and a second chamber 112, 724, 806 sealed from said first chamber 110, 712, 804.

[0037]The first chamber 110, 712, 804 has a first port 102, 704 and the second chamber 112, 724, 806 has a second port 104, 706.

[0038]The reversible fluid pump 100, 700, 800 further comprises a pressure relief mechanism 106, 708, 808.

[0039]The pressure relief mechanism 106, 708, 808 comprises at ...

second embodiment

[0082]In the second embodiment, the first duct 710, 810 and the second duct 712, 812 are outside of the housing 108, 702, 802.

[0083]In the second embodiment, the pump is larger but is easier to manufacture.

[0084]In the third embodiment, the first duct 710, 810 and the second duct 712, 812 are inside of the housing 108, 702, 802 and through a sealing interface 822.

[0085]More specifically, the two ducts are located in the inner housing of the screw pump screws, and inlet and / or outlet check valves are associated within.

[0086]The third embodiment allows to have a more compact pump than in the first and second embodiments, due to the internalization of the pressure relief mechanism.

[0087]The sealing interface 822 is located between the two chambers in the housing and it seals said chambers 110, 112, 712, 724, 804, 806 from each other.

[0088]The pressure relief mechanism also provides different operational modes to the pump, regardless of the pressure threshold, allowing for example diffe...

Claims

1. A reversible fluid pump (100, 700, 800) comprising:a housing (108, 702, 802) having a first chamber (110, 712, 804) and a second chamber (112, 724, 806) sealed from said first chamber (110, 712, 804),the reversible fluid pump (100, 700, 800) further comprising a pressure relief mechanism (106, 708, 808),said pressure relief mechanism (106, 708, 808) comprising:at least one duct (202, 710, 712, 810, 812) configured to fluidically connect said first chamber (110, 712, 804) and said second chamber (112, 724, 806);at least one check valve (204, 210, 714, 716, 814, 816) coupled to the at least one duct (202, 710, 712, 810, 812) and configured to relieve an excess pressure above a predetermined pressure threshold in one of the first chamber (110, 722, 804) or the second chamber (112, 724, 806) onto the other of said chambers (110, 112) through said at least one duct (202, 710, 712, 810, 812).

2. The reversible fluid pump of claim 1,wherein the pressure relief mechanism (106, 708, 808) further comprises at least one outlet check valve (206, 208) coupled to the at least one duct (202, 710, 712, 810, 812).

3. The reversible fluid pump of claim 1, whereinthe at least one duct (202, 710, 712, 810, 812) comprises exactly one duct (202), andthe at least one check valve (204, 210, 714, 716, 814, 816) comprises a first inlet check valve (204, 714, 814) and a second inlet check valve (210, 716, 816) coupled to said duct (202), andthe pressure relief mechanism (106, 708, 808) further comprises selective means configured to selectively open and close said first inlet check valve (204, 714, 814) or second inlet check valve (210, 716, 816),the pressure relief mechanism (106, 708, 808) being configured to be in either:a first position wherein it is configured to open said first inlet check valve (204, 714, 814) and close said second inlet check valve (210, 716, 816), ora second position wherein it is configured to close said first inlet check valve (204, 714, 814) and open said second inlet check valve (210, 716, 816), ora third position wherein it is configured to close said first inlet check valve (204, 714, 814) and close said second inlet check valve (210, 716, 816), said third position being the rest position of the pressure relief mechanism (106, 708, 808) when the pressure in either one of the first chamber (110, 722, 804) or the second chamber (112, 724, 806) is below the predetermined pressure threshold.

4. The reversible fluid pump of claim 2, wherein the at least one outlet check valve (206, 208) comprises a first outlet check valve (206), and a second outlet check valve (208), and:in the first position, the pressure relief mechanism (106, 708, 808) further opens said first outlet check valve (206) and further closes second outlet check valve (208); andin the second position, the pressure relief mechanism (106, 708, 808) further closes said first outlet check valve (206) and opens said second outlet check valve (208); andin the third position, the pressure relief mechanism (106, 708, 808) further closes said first inlet check valve (204, 714, 814) and closes said second inlet check valve (210, 716, 816).

5. The reversible fluid pump of claim 3, wherein the selective means are resilient selective means and comprise at least one resilient element (212, 718, 818) and a sliding plate (220),said sliding plate (220) being configured to be switchable by the excess pressure above the predetermined pressure threshold toward the first position or second position of the pressure relief mechanism (106, 708, 808) from the third position,said sliding plate (220) being configured to selectively obstruct or liberate the at least one check valve (204, 210, 714, 716, 814, 816) for the first and second positions,said at least one resilient element (212, 718, 818) being configured to work against the sliding of the sliding plate (220) apart from the third position under the force exerted by the pressure excess.

6. The reversible fluid pump of claim 5, wherein the selective means comprises two opposite springs optionally on either side of a wall (216).

7. The reversible fluid pump of claim 6, wherein the selective means comprises two opposed abutments (218) allowing the stiffness of the two opposite springs regarding the predetermined pressure threshold.

8. The reversible fluid pump of claim 1, wherein the at least one duct (202, 710, 712, 810, 812) comprises a first duct (710, 810) and a second duct (712, 812),the first duct (710, 810) comprising a first inlet check valve (714, 814); andthe second duct (712, 812) comprising a second inlet check valve (716, 816).

9. The reversible fluid pump of claim 8, wherein the first duct (710, 810) comprises a first outlet check valve and / or the second duct (712, 812) comprises a second outlet check valve.

10. The reversible fluid pump of claim 8, wherein the first duct (710, 810) and the second duct (712, 812) being either:outside of the housing (108, 702, 802), orinside of the housing (108, 702, 802) and through a sealing interface (822), said sealing interface (822) being located between the two chambers in the housing and sealing said chambers (110, 112, 712, 724, 804, 806) from each other.

11. A reversible fluid pump comprising:a housing defining a first chamber and a second chamber sealed from the first chamber; anda pressure relief mechanism comprising:at least one duct configured to fluidically connect the first chamber and the second chamber; andat least one check valve fluidly coupled to the at least one duct and configured to relieve excess pressure above a predetermined pressure threshold from one of the first chamber or the second chamber to the other of the first chamber and the second chamber through the at least one duct.

12. The reversible fluid pump of claim 11, wherein the pressure relief mechanism further comprises at least one outlet check valve coupled to the at least one duct.

13. The reversible fluid pump of claim 11, wherein:the at least one duct comprises a single duct;the at least one check valve comprises a first inlet check valve and a second inlet check valve coupled to the single duct; andthe pressure relief mechanism further comprises a selector configured to selectively open and close the first inlet check valve and the second inlet check valve.

14. The reversible fluid pump of claim 13, wherein the pressure relief mechanism is movable between:a first position in which the first inlet check valve is open and the second inlet check valve is closed;a second position in which the first inlet check valve is closed and the second inlet check valve is open; anda third position in which the first inlet check valve and the second inlet check valve are both closed, the third position being a rest position when pressure in each of the first chamber and the second chamber is below the predetermined pressure threshold.

15. The reversible fluid pump of claim 12, wherein:the at least one outlet check valve comprises a first outlet check valve and a second outlet check valve;in the first position the pressure relief mechanism opens the first outlet check valve and closes the second outlet check valve; andin the second position the pressure relief mechanism closes the first outlet check valve and opens the second outlet check valve.

16. The reversible fluid pump of claim 13, wherein the selector comprises:a sliding plate configured to selectively obstruct or allow operation of the first inlet check valve and the second inlet check valve; andat least one resilient element configured to bias the sliding plate toward the third position.

17. The reversible fluid pump of claim 16, wherein the sliding plate is movable from the third position to the first position or the second position in response to pressure exceeding the predetermined pressure threshold.

18. The reversible fluid pump of claim 16, wherein the at least one resilient element comprises two opposing springs disposed on opposite sides of a wall.

19. The reversible fluid pump of claim 18, further comprising two opposed abutments configured to adjust stiffness of the two opposing springs and thereby adjust the predetermined pressure threshold.

20. The reversible fluid pump of claim 11, wherein:the at least one duct comprises a first duct and a second duct;the first duct comprises a first inlet check valve; andthe second duct comprises a second inlet check valve.

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