Pump cover for a hydrogen recirculation pump and hydrogen recirculation pump

Abstract

The utility model relates to a pump cover and hydrogen recirculation pump for hydrogen recirculation pump are provided, including: end wall, annular side wall, it extends from end wall, impeller chamber, it is constituted to accommodate impeller to rotate around longitudinal axis in impeller chamber, and impeller chamber is at least partly defined by end wall and annular side wall, impeller chamber includes the support area that sets up in the radial inside of annular side wall, and support area has the center coinciding with longitudinal axis, inlet opening, it sets up in end wall, outlet opening. Inlet opening and outlet opening are spaced apart circumferentially, and are separated by the tongue extending between annular side wall and support area. End wall still includes concave side channel, and side channel makes inlet opening and outlet opening fluid communication, wherein side channel extends circumferentially from inlet opening to outlet opening, and side channel is at least partly defined by support area. Also disclose a kind of hydrogen recirculation pump.

Description

Technical Field

[0001] This disclosure relates to a hydrogen recirculation pump for a fuel cell system, and to components of the hydrogen recirculation pump. Background Technology

[0002] Fuel cells are an alternative power source to internal combustion engines used for vehicle propulsion. Fuel cells can be used in small, medium, and heavy-duty vehicles, as well as trains, airplanes, and ships. Fuel cells generate electricity by combining fuel with an oxidant. The electricity generated by such fuel cells can be used for any electrical purpose, such as powering homes and electronic devices, and powering machinery and vehicles using electric motors. Typically, the fuel used in such fuel cells is hydrogen (H2), however, alkanes such as methane (CH4) or alcohols such as methanol (CH3OH) can be used instead. Similarly, oxygen (O2) is typically used as the oxidant, however, any mixture of oxygen-containing gases, such as atmospheric air (a mixture of nitrogen N2 and oxygen O2), can be used as a substitute.

[0003] Proton exchange membrane (PEM) fuel cells, also known as polymer electrolyte membrane fuel cells, are a type of fuel cell commonly used for vehicle propulsion. A PEM fuel cell comprises an anode and a cathode separated by a polymer electrolyte membrane in a layered structure. The anode and cathode are connected to each other via an electrical load. During operation, hydrogen (fuel) is supplied to the anode side of the cell, and atmospheric air (oxidant) is supplied to the cathode side. A platinum catalyst is provided at the anode, which is used to reduce hydrogen by "stripping" single electrons from it, making the hydrogen positively charged. The hydrogen ions and electrons formed at the catalyst are able to react with oxygen components in the air exposed to the cathode, and are thus attracted to the oxygen by their charge. To reach oxygen, hydrogen ions take a direct path from the anode side to the cathode side by permeating through the polymer electrolyte membrane. However, the polymer electrolyte membrane is constructed to prevent electrons from passing through it. Unable to pass through the membrane, electrons are transferred from the anode to the cathode via the attached electrical load, thus generating electricity that can be extracted for useful purposes. Once hydrogen ions and electrons reach the cathode, they react with the oxygen components in the air exposed to the cathode to form water (H2O).

[0004] There is usually excess hydrogen, and unused hydrogen can be returned to the inlet of the fuel cell via a recirculation path using a hydrogen recirculation pump (also known as an anode or hydrogen recirculation blower or side-channel compressor) to improve the efficiency of the fuel cell.

[0005] Currently, hydrogen recirculation pumps are insufficient to meet the flow requirements of PEM fuel cells. It is also known that hydrogen recirculation pumps suffer from high noise levels, high cost, unacceptable fluid leakage levels, high failure rates, and (in use and associated with) high energy consumption. The purpose of this disclosure is to overcome one or more of these disadvantages. Utility Model Content

[0006] According to a first aspect, a bearing housing for a hydrogen recirculation pump is provided, the bearing housing comprising: a body configured to house one or more bearings configured to support an impeller rotating about a longitudinal axis; and a connecting flange configured to engage the impeller, the connecting flange surrounding the body and extending radially outward along the body; wherein the connecting flange is offset from the axial midpoint of the body along the longitudinal axis.

[0007] The term "offset from the axial midpoint of the body along the longitudinal axis" encompasses the location of the connecting flange toward the first end of the body. The axial midpoint of the body encompasses the midpoint between the farthest first end and the farthest second end opposite that first end along the longitudinal axis. Since the connecting flange is configured to engage the impeller, axial offset of the connecting flange reduces impeller deformation during assembly. Furthermore, axial offset of the connecting flange from the axial midpoint of the body allows for improved dynamic balance adjustment, reduced bearing housing weight, and thereby increased impeller reliability. A bearing housing with a connecting flange is further advantageous for easy assembly of the bearing housing and impeller and / or, in other embodiments, for connection of the bearing housing to other rotatable components.

[0008] The connecting flange includes at least two through holes configured to accommodate a connector passing through the through holes, and wherein the at least two through holes are distributed at equal angles around the longitudinal axis.

[0009] The through holes are distributed at equal angles around the longitudinal axis, which facilitates equal load bearing and load distribution through the connecting flange. The ability to use connectors to engage the impeller also reduces the risk of press-fitting the bearing assembly to the impeller, which could lead to premature impeller failure.

[0010] Each through-hole can define an axis extending in a direction parallel to the longitudinal axis.

[0011] The number of through holes can be even.

[0012] The even number of through holes, distributed at equal angles around the longitudinal axis, provides reflective and rotational symmetry about this axis. This is advantageous because of the equal load distribution through the connecting flange. The even number of through holes further facilitates rotational balance and adequate retention of the connected components to the bearing housing.

[0013] The main body may include a cylindrical wall having a radial outer wall and a radial inner wall, the connecting flange extending around the radial outer wall; the bearing housing may also include an annular inner flange extending radially inward from the inner wall.

[0014] The annular inner flange can be located at the axial midpoint of the body.

[0015] The annular inner flange can be axially spaced from the connecting flange.

[0016] In other words, the connecting flange and the inner flange do not overlap axially.

[0017] The body may define a first cavity for receiving a first bearing, and the first cavity may be at least partially defined by the annular inner flange.

[0018] The inner flange can restrict the axial movement of the first bearing. This is beneficial to improving the reliability of the bearing housing when used in a bearing assembly. The term "first bearing" covers a bearing assembly that may include an inner race and an outer race, as well as at least one bearing (e.g., a ball) between the races.

[0019] The body may further define a second cavity for accommodating a second bearing, the second cavity being at least partially defined by the annular inner flange, wherein the first cavity and the second cavity may be axially spaced apart, and the first cavity and the second cavity may be separated by the annular inner flange.

[0020] The term "second bearing" covers a bearing assembly that may include an inner race and an outer race, as well as at least one bearing (e.g., a ball) between the races.

[0021] The inner flange can restrict the axial movement of the first and second bearings; this helps to improve the reliability of the bearing housing when used in the bearing assembly. The first and second cavities can be of equal size, that is, the first and second cavities can have the same inner diameter and axial length, so the bearing in the first cavity can be the same as the bearing in the second cavity.

[0022] The main body can be rotationally symmetrical about the longitudinal axis. This provides ease of assembly of the bearing housing within the bearing assembly and when assembled within the pump assembly. Rotational symmetry about the longitudinal axis also allows for improved maintainability, enhanced integrity of the impeller to which the bearing housing engages, and improved dynamic balance.

[0023] The connecting flange may include an annular wall.

[0024] According to a second aspect, a hydrogen recirculation pump is provided, the hydrogen recirculation pump comprising:

[0025] Pump assembly, the pump assembly comprising:

[0026] Pump cover, the pump cover defining an inlet and an outlet; and

[0027] An impeller, the impeller being located within a pump chamber at least partially defined by the pump cover;

[0028] A motor assembly comprising a motor housing and a motor, the motor being located within the motor housing and configured to drive the impeller to rotate about a longitudinal axis via a linkage.

[0029] An adapter disposed between the pump cover and the motor housing, the adapter being configured to connect to the motor housing and the pump cover, and providing an interface between the motor housing and the pump cover; and

[0030] A bearing housing, which is a bearing housing according to a first aspect, is at least partially disposed on the radially inner side of the adapter, and wherein the connecting flange engages with the impeller.

[0031] According to a third aspect, an adapter for a hydrogen recirculation pump is provided, wherein the adapter is configured to connect to a motor housing and a pump cover, and provides an interface between the motor housing and the pump cover;

[0032] The adapter defines a longitudinal axis, and the adapter includes:

[0033] The wall surrounding the longitudinal axis;

[0034] The wall has a front face for engaging with the pump cover and a rear face opposite the front face for engaging with the motor housing;

[0035] The wall includes a discharge channel configured to deliver liquid to the outlet channel of the pump cover.

[0036] The adapter encompasses a device for connecting the motor housing to the pump cover. In other words, the adapter allows for the assembly of modular hydrogen recirculation pumps, whereby the motor housing and pump cover can be removed from and reattached to the adapter.

[0037] The wall surrounding the longitudinal axis can be a ring wall.

[0038] It is advantageous to include a discharge channel in the adapter because it allows liquid (primarily water) to drain from the pump assembly. This discharge channel can be in fluid communication with the outlet channel of the pump cover. Specifically, the liquid can be discharged into the hydrogen supply loop, increasing the fluid volume there.

[0039] The front face of the adapter can have a profile complementary to that of the pump cover. In particular, the front face of the adapter can have a profile conforming to the rear face of the impeller located in the pump cover. This is advantageous because it improves flow constraint and reduces leakage, thereby increasing the efficiency of the pump connected to the adapter and allowing for the assembly of a compact hydrogen recirculation pump.

[0040] The cross-sectional profile of the discharge channel can be a groove.

[0041] The term "groove" encompasses a long and narrow opening. In the case where the adapter wall is annular, the term "groove" encompasses an opening extending in the annular wall relative to the longitudinal axis in the axial, radial, and circumferential directions, with its axial length in the circumferential direction greater than its radial or axial length. Specifically, the cross-sectional profile of the discharge channel in a plane perpendicular to the longitudinal channel can be an elongated groove.

[0042] In use, the adapter can be oriented to allow liquid to travel under gravity through the discharge channel to the outlet channel of the pump cover. This reduces liquid buildup in other areas of the pump assembly.

[0043] The adapter may further include a flange, wherein the flange is radially outward of the wall relative to the longitudinal axis. The flange may be an annular flange.

[0044] The adapter may also include at least one tool recess configured to engage a tool. In particular, the tool may be used to retain the adapter element, and the tool may also be used to remove the adapter element from engagement with the pump cover and / or motor housing.

[0045] The term "tool recess" encompasses stepped or recessed grooves.

[0046] The at least one tool recess allows the tool to engage with the adapter, which in turn allows for easy assembly and disassembly of the adapter from the pump cover and / or motor housing. This improves the ease of component replacement in the hydrogen recirculation pump.

[0047] The adapter element may include multiple tool recesses. These multiple tool recesses may be distributed at equal angles around a longitudinal axis.

[0048] The at least one tool recess may be provided in the flange. The tool recess may be circumferentially discrete. That is, the tool recess extends around a portion of the periphery of the flange. In other words, the tool recess may have a circumferential width and an axial depth.

[0049] The adapter may also include at least one through-hole configured to receive a connector for attaching the adapter to the pump cover and the motor housing. The term "connector" encompasses fasteners such as screws or bolts, or any other suitable means of connection. The adapter may be attached to the pump cover and / or motor housing using clamps.

[0050] The at least one through-hole may extend through the flange. The through-hole may include an axis extending in a direction parallel to the longitudinal axis.

[0051] The adapter may include a plurality of through holes configured to receive corresponding connectors for connecting the adapter to the pump cover and the motor housing.

[0052] The plurality of through holes may be distributed at equal angles around the longitudinal axis. In particular, the plurality of through holes may extend through the flange.

[0053] The adapter may include alignment means or alignment features. That is, the adapter may include protrusions or recesses that are complementary to protrusions or recesses on the pump cover and / or motor housing. Providing alignment features ensures that the adapter is installed in the correct orientation relative to the pump cover and / or motor housing. This reduces the likelihood of the adapter being installed in an incorrect orientation. The adapter may include multiple identical alignment features (e.g., protrusions or recesses), and the pump cover and / or motor housing may include complementary recesses or protrusions to allow the adapter to be connected to the pump cover and / or motor housing in multiple orientations. This, in turn, can increase the ease of assembly of the hydrogen recirculation pump including the adapter.

[0054] The plurality of through holes can be distributed at unequal angles around the longitudinal axis, and by being spaced apart at unequal angles, this reduces the risk of the adapter being set in the wrong orientation.

[0055] The adapter may include a recess configured to receive a sealing member for sealing between the adapter and the pump cover. Providing a seal between the adapter and the pump cover helps mitigate fluid leakage from the pump assembly.

[0056] The groove may be an annular groove, and the sealing member may be an annular seal. The annular seal may be a ring seal or an O-ring seal.

[0057] The annular groove can be provided at the interface between the wall and the flange. Providing a groove at the interface between the wall and the flange allows for a compact design, achieves a secure seal between the pump cover and the adapter, and allows the seal to be easily positioned and retained.

[0058] According to a fourth aspect, a hydrogen recirculation pump is provided, the hydrogen recirculation pump comprising:

[0059] Pump assembly;

[0060] Motor components; and

[0061] An adapter, according to a third aspect, for a hydrogen recirculation pump, is connected to the motor assembly and the pump assembly, and provides an interface between the motor assembly and the pump assembly.

[0062] The pump assembly may include:

[0063] Pump cover, which defines the inlet and outlet; and

[0064] The impeller is located inside the pump cover;

[0065] The motor assembly includes:

[0066] Motor housing;

[0067] A motor, located within the motor housing, is configured to drive the impeller to rotate about the longitudinal axis of the pump assembly via a linkage; and

[0068] The adapter provides an interface between the motor housing and the pump cover.

[0069] The front surface of the adapter may have a profile conforming to the adjacent surface of the impeller, the conforming profile being perpendicular to the longitudinal axis. That is, the front surface may conform to the rear cover of the impeller.

[0070] It should be understood that the adapter of the third aspect can be used with the hydrogen recirculation pump of the second aspect. The features of the hydrogen recirculation pump of the fourth aspect can be combined with the hydrogen recirculation pump and bearing housing of the second aspect.

[0071] According to a fifth aspect, a pump cover for a hydrogen recirculation pump is provided, the pump cover comprising:

[0072] The inlet channel is configured to accommodate the incoming fluid.

[0073] An impeller chamber, which is in fluid communication with the inlet passage, is configured to house an impeller for rotation about a longitudinal axis;

[0074] An outlet channel, which is in fluid communication with the impeller chamber;

[0075] End wall, which defines at least a portion of the impeller chamber; and

[0076] A sidewall that extends axially from the endwall, the sidewall defining at least a portion of the outlet passage and the impeller chamber;

[0077] The impeller chamber includes a circumferentially extending concave side channel, concentric with the longitudinal axis and at least partially defined by the end wall and the side wall, the side channel extending between the inlet channel and the outlet channel; and

[0078] The axially extending baffle element is located in the side channel, the baffle element includes ribs, and the ribs extend from the side wall toward the longitudinal axis in both the circumferential and radial directions.

[0079] The term "inlet channel" can be used interchangeably with "inlet". The inlet fluid can be a gas, and in particular, it can be hydrogen, or it can be a mixture of hydrogen and air and / or other gases. The term "outlet channel" can be used interchangeably with "outlet". The sidewall can be annular. The term "side channel" encompasses a circumferentially extending channel configured to allow fluid to flow from the inlet to the outlet.

[0080] The presence of a baffle element is advantageous because it improves the efficiency of the pump assembly by restricting the backflow of gas in the side passage after pressure buildup in the impeller chamber. The term "rib" encompasses a protrusion extending in both the axial and radial directions relative to the longitudinal axis.

[0081] The impeller chamber may include a support region disposed radially inside the sidewall and located on the longitudinal axis. The support region may define at least a portion of the side passage. The rib may be a first rib, and the baffle element may further include a second rib extending from the support region of the impeller circumferentially and radially away from the longitudinal axis. A flow constraint may be formed between the end of the first rib and the opposite end of the second rib.

[0082] The term "support area" encompasses the central portion of the pump cover located radially inward on the sidewall. This support area can be arranged to indirectly support the rotation of the impeller. By way of example, the support area can be configured to receive a plug around which the bearing assembly is arranged.

[0083] The baffle element may include an axially extending intermediate wall portion connecting the first rib and the second rib. The intermediate wall portion may define at least a portion of the flow constraint portion. The axial length of the intermediate wall portion may be less than the axial length of the first rib and / or the second rib.

[0084] The intermediate wall portion may at least partially define the flow constraint portion. The baffle element may extend along the baffle axis in a first plane perpendicular to the longitudinal axis. The intermediate wall portion may have an arcuate profile in a second plane that extends through the baffle axis and is perpendicular to the first plane.

[0085] The intermediate wall portion may have an arcuate profile in a plane perpendicular to the direction of fluid flow through the main body of the flow constraint when in use.

[0086] At least a portion of the baffle element may extend axially over the entire height of the side channel. That is, the baffle element may extend axially over the height of the side channel from its base near the end wall. The baffle element may not have a constant axial depth. The first rib and / or the second rib and / or the intermediate wall portion may not have a constant axial depth.

[0087] The baffle element may not extend axially over the entire height of the side channel.

[0088] The support region may include support walls extending axially and circumferentially, the support walls defining at least a portion of the side passage. The baffle element may extend along a baffle axis in a plane perpendicular to the longitudinal axis; wherein, in this plane, a nominal axis may extend radially from a point on the support wall relative to the longitudinal axis, and the second rib extends from said point. The angle between the baffle axis and the nominal axis may be between 15 degrees and 30 degrees.

[0089] An angle between 15 and 30 degrees can improve the efficiency of the pump assembly, which is part of the pump assembly, during use.

[0090] The outlet channel can extend along an outlet channel axis in a radial direction relative to the longitudinal axis, and the baffle element can extend along the baffle axis in a plane perpendicular to the longitudinal axis. The angle between the baffle axis and the outlet channel axis can be between 15 degrees and 30 degrees.

[0091] The baffle axis can be a curved axis. That is, the baffle axis can follow an arc-shaped path.

[0092] The baffle element can be integrally formed with the pump cover.

[0093] The pump cover may include a second baffle element, which may include a plurality of circumferentially spaced, axially extending deflecting ribs. The term "axially extending deflecting ribs" encompasses protrusions extending at least in an axial direction relative to the longitudinal axis.

[0094] The deflection rib may have a rectangular cross-sectional profile in a plane perpendicular to the longitudinal axis.

[0095] The plurality of deflecting ribs may be circumferentially spaced along the centerline of the side channel. The term "centerline of the side channel" encompasses a line extending along the base of the side channel and equidistant from the support wall and sidewalls. In embodiments excluding the support wall, the centerline may be a line extending along the base of the side channel and equidistant from the longitudinal axis and sidewalls.

[0096] The plurality of deflection ribs may be located radially inside the centerline of the side channel.

[0097] At least a portion of one of the plurality of deflection ribs may extend axially over the entire height of the side channel. While a portion of the deflection rib may extend over the entire axial height of the side channel, that portion may not extend over the entire radial width of the side channel, as this could substantially impede flow through the side channel.

[0098] The plurality of deflection ribs may not extend axially over the entire height of the side channel.

[0099] According to a sixth aspect, a hydrogen recirculation pump is provided, the hydrogen recirculation pump comprising:

[0100] Pump assembly;

[0101] Motor assembly, the motor assembly including a motor housing; and

[0102] adapter,

[0103] The pump assembly includes a pump cover for a hydrogen recirculation pump according to the fifth aspect, wherein the adapter is disposed between the pump cover and the motor housing, the adapter is configured to connect to the motor housing and the pump cover, and provides an interface between the motor housing and the pump cover.

[0104] The pump assembly may include an impeller located within the impeller chamber; and a motor may be located within the motor housing, and the motor may be configured to drive the impeller to rotate about the longitudinal axis via a linkage. A bearing housing may be at least partially disposed radially inside the adapter, and the bearing housing may include a bearing configured to support at least a portion of the linkage.

[0105] In use, the hydrogen recirculation pump can be oriented such that the outlet channel is located at the lowest point relative to gravity.

[0106] It should be understood that the features of the hydrogen recirculation pump in the sixth aspect can be combined with the features of the hydrogen recirculation pump in the second or fourth aspect.

[0107] According to a seventh aspect, a pump cover for a hydrogen recirculation pump is provided, the pump cover comprising:

[0108] end wall;

[0109] An annular sidewall that extends from the endwall;

[0110] An impeller chamber configured to house an impeller for rotation about a longitudinal axis within the impeller chamber, the impeller chamber being at least partially defined by the end wall and the annular side wall;

[0111] The impeller chamber includes a support region disposed on the radially inner side of the annular sidewall, and the support region has a center that coincides with the longitudinal axis.

[0112] Entrance opening; and

[0113] Exit opening;

[0114] The inlet opening is disposed in the end wall, and the inlet opening and the outlet opening are circumferentially spaced apart and separated by a tongue extending between the annular sidewall and the support region; and

[0115] The end wall further includes a concave side channel that provides fluid communication between the inlet opening and the outlet opening, wherein the side channel extends circumferentially from the inlet opening to the outlet opening and is at least partially defined by the support region.

[0116] The outlet opening can be located in the side wall. The outlet opening can be configured to deliver gas (especially hydrogen and / or air) to a pipe, ejector, or any suitable channel or device.

[0117] The tongue essentially prevents gas flow between the inlet and outlet openings without passing through the side channel.

[0118] The side passage may include a baffle.

[0119] The inlet opening is located in the end wall, which is beneficial because it reduces fluid backflow and ice formation at the inlet opening, thus allowing the hydrogen recirculation pump to operate effectively in cold environments.

[0120] The radially inner wall surface of the annular sidewall relative to the farthest end of the end wall may define a main diameter. The annular sidewall may include a first stepped portion adjacent to the farthest end, the first stepped portion defining a first stepped diameter smaller than the main diameter. The annular sidewall may also include a second stepped portion adjacent to the first stepped portion, the second stepped portion defining a second stepped diameter smaller than the first stepped diameter.

[0121] The term "major diameter" encompasses the distance between the radially inner wall surfaces of an annular sidewall passing through the longitudinal axis. A sidewall with a stepped portion includes a sidewall having a diameter different from (and particularly, smaller than) the major diameter. That is, the first stepped portion can be a region with a constant diameter (first stepped diameter) along its axial length, and the first stepped diameter is smaller than the major diameter. The diameter change from the major diameter to the first stepped diameter can be abrupt or gradual. For example, an inclined region can exist between the first stepped portion and the farthest end of the sidewall. Similarly, a second stepped portion can be a region with a constant diameter (first stepped diameter) along its axial length, and the second stepped diameter is smaller than the first stepped diameter. The diameter change from the first stepped diameter to the second stepped diameter can be abrupt or gradual. For example, an inclined region can exist between the first and second stepped portions of the sidewall.

[0122] Providing a first step helps align the impeller in the pump cover with the adapter and / or motor cover. Providing a second step helps reduce leakage from the side passage.

[0123] In use, the pump cover can be oriented to allow condensate to pass through the outlet opening under gravity. Operation of the pump assembly may include start-up and shutdown, and gas flow through the side channel may also facilitate the movement of any condensate through the outlet opening. However, when there is little or no gas flow through the side channel, it is beneficial for condensate to pass through the outlet opening under gravity.

[0124] In use, the outlet opening is located at the lowest periphery of the annular sidewall relative to the direction of gravity.

[0125] The pump cover may also include a liquid discharge opening adjacent to the outlet opening, the liquid discharge opening extending through the annular sidewall. The liquid discharge opening allows water and other liquids to drain from the pump, which helps reduce ice formation in the pump assembly, especially when operating the pump assembly in cold environments.

[0126] A liquid discharge channel extends from the support region through the tongue to the liquid discharge opening, and the liquid discharge channel is configured to guide liquid from the support region to the liquid discharge opening. The extension of the liquid discharge channel from the support region through the tongue helps to reduce ice formation at and near the inlet opening.

[0127] The outlet passage is defined by a cylindrical wall extending radially outward from the sidewall at the outlet opening, and the outer surface of said cylindrical wall may include two spaced-apart grooves extending circumferentially around the outer surface, each groove being configured to receive a sealing element. In some embodiments, a single groove may be provided. Hydrogen gas is known to be difficult to seal; therefore, providing one or more sealing elements mitigates hydrogen leakage from the pump assembly.

[0128] The grooves may be axially spaced relative to the axis of the cylindrical wall. The sealing member may be an annular seal. The sealing member may be an O-ring seal. In the case where the cylindrical wall includes a groove, it is understood that only a single sealing member may be provided.

[0129] The radially outer wall surface of the annular sidewall includes a plurality of circumferentially spaced protrusions. Each of the plurality of protrusions may include an axially extending hole configured to receive a connector for connecting the pump cover to an adapter and / or a motor housing. The term “protrusion” encompasses lugs and / or ears extending from the outer wall surface of the annular sidewall.

[0130] The pump cover may further include a flange adjacent to the end wall and located radially outward of the annular sidewall. The flange may define an interface for mounting the pump cover. The flange may include a plurality of axial through holes configured to receive a connector. The presence of the flange supports mounting the pump cover to a manifold. In other embodiments, the flange may be used to support mounting the pump cover to a chassis or mounting bracket.

[0131] The side channel may include at least one baffle element configured to create a flow constraint in the side channel.

[0132] According to the eighth aspect, a hydrogen recirculation pump is provided, comprising:

[0133] Pump assembly; and

[0134] Motor assembly,

[0135] The pump assembly includes a pump cover for a hydrogen recirculation pump according to the seventh aspect.

[0136] The pump assembly may further include an impeller located within the impeller chamber, the impeller being supported for rotation within the impeller chamber. The motor assembly may include a motor housing. The motor may be located within the motor housing, and the motor may be configured to drive the impeller to rotate about a longitudinal axis via a linkage. An adapter may be disposed between the pump cover and the motor housing, the adapter being connectable to both the motor housing and the pump cover. A bearing housing may be at least partially disposed radially inside the adapter, the bearing housing including a bearing configured to support at least a portion of the linkage.

[0137] It should be understood that the features of the hydrogen recirculation pump in the eighth aspect can be combined with the features of the hydrogen recirculation pump in the second, fourth, or sixth aspects. It should be understood that the features of the pump cover in the seventh aspect can be combined with the features of the pump cover in the fifth aspect.

[0138] According to a ninth aspect, an impeller for a hydrogen recirculation pump is provided, the impeller comprising an impeller body,

[0139] The impeller body includes:

[0140] A disc-shaped back cover defining a central axis, and the back cover having an arcuate profile in a plane parallel to the central axis, the arcuate profile defining a concave surface; and

[0141] A disc-shaped central connecting plate located radially inside the rear cover;

[0142] A plurality of axially extending blades are disposed on the concave surface of the rear cover, and each of the plurality of blades extends from the central connecting plate in both radial and circumferential directions; and

[0143] The outermost radial portion of the rear cover includes an outwardly facing and axially extending protrusion, which is used to form a seal with the pump cover.

[0144] The term "outward-facing" refers to the protrusion extending axially outward relative to the central axis. In other words, the protrusion extends away from the concave surface. The protrusion can be integrally formed with the impeller body.

[0145] The term "outwardly facing and axially extending protrusion" covers the area of ​​the rear cover that deviates from the convex surface of the rear cover, forming an arcuate path. Providing an outwardly facing and axially extending protrusion is advantageous because it increases the axial length of the leakage path between the impeller and the pump cover wall, which in turn reduces overall leakage from the pump assembly and improves impeller efficiency. The term "protrusion" may also include an edge.

[0146] The protrusion may extend around the periphery of the rear cover. The protrusion may extend around the entire periphery of the rear cover.

[0147] The outermost radial portion of the rear cover may include at least one circumferentially extending groove. This is advantageous because, in use, the groove can form a labyrinth seal with the opposing wall of the pump cover. The outermost radial portion of the rear cover may include two circumferentially extending grooves.

[0148] The central connecting plate may include a through hole that coincides with the central axis and is used to accommodate at least a portion of the bearing assembly.

[0149] The central connecting plate may include at least one fastener connection through-hole for accommodating a connector for connection with a magnetic coupling device. The fastener connection through-hole may be located radially outward of the connection through-hole.

[0150] The central connecting plate may include a plurality of fastener connecting through holes, and the plurality of fastener connecting through holes may be circumferentially spaced apart around the central axis. The plurality of fastener connecting through holes may be located radially outside the connecting through holes.

[0151] Each of the plurality of blades may be swept back from the central axis relative to the radial direction. The term swept blade encompasses a blade with a varying blade angle from its tip toward the central connecting plate, the angle of which is swept back in the opposite direction to the impeller's rotation direction during operation. That is, the tilt direction of the impeller blade is opposite to the impeller's rotation direction during operation. Using swept blades is advantageous because swept blades can increase the mass flow rate of the pump assembly during operation.

[0152] Each of the plurality of blades may define a leading edge, which may define a blade tilt angle that is tilted in a negative angular direction relative to the radial direction originating from the central axis and relative to the direction of rotation of the impeller during use. All points on the leading edge may define local blade tilt angles relative to the radial direction, and all local blade tilt angles on the leading edge may be tilted by 10 to 30 degrees relative to the radial direction in the negative angular direction. All local blade tilt angles on the leading edge may be tilted by 20 degrees relative to the radial direction in the negative angular direction.

[0153] When the blade is a straight blade, the tilt angle can be substantially constant for all points on the leading edge. However, in other embodiments, the leading edge can be defined as a local blade tilt angle that varies between the root and tip of the blade, but all local blade tilt angles should be negative, where "negative" means an angle in the opposite direction to the positive rotation of the impeller in use.

[0154] The tilt angle of all local blades on the leading edge can be tilted between 10 and 30 degrees relative to the radial direction in the negative angle direction. The tilt angle of all local blades on the leading edge can be tilted by 20 degrees relative to the radial direction in the negative angle direction.

[0155] The impeller can be made of aluminum alloy or stainless steel.

[0156] The number of blades can be between 30 and 50.

[0157] According to a tenth aspect, a pump assembly for a hydrogen recirculation pump is provided, the pump assembly comprising:

[0158] Pump cover, the pump cover comprising:

[0159] The inlet channel is configured to accommodate the incoming fluid.

[0160] The impeller chamber is in fluid communication with the inlet channel;

[0161] An outlet channel, which is in fluid communication with the impeller chamber;

[0162] End wall, which defines at least a portion of the impeller chamber; and

[0163] A sidewall that extends axially from the endwall and defines at least a portion of the impeller chamber;

[0164] The impeller chamber includes a circumferentially extending concave side passage, concentric with the longitudinal axis of the pump cover and at least partially defined by the end wall and the side wall, the side passage extending between the inlet passage and the outlet passage; and

[0165] An impeller, wherein the impeller is an impeller for a hydrogen recirculation pump according to the ninth aspect, the impeller being disposed in the impeller chamber and supported to rotate about the central axis.

[0166] The inlet passage may be defined at least partially by the end wall. The outlet passage may be defined at least partially by the side wall.

[0167] It should be understood that the pump assembly of the tenth aspect can be combined with the pump cover of the fifth or seventh aspect, and can be combined with the hydrogen recirculation pump of the second, fourth, sixth or eighth aspect.

[0168] According to the eleventh aspect, a hydrogen recirculation pump is provided, the hydrogen recirculation pump comprising:

[0169] Pump assembly;

[0170] Motor assembly, the motor assembly including a motor housing; and

[0171] adapter,

[0172] The pump assembly is the pump assembly for a hydrogen recirculation pump according to the tenth aspect, wherein the adapter is disposed between the pump cover and the motor housing, the adapter is configured to connect to the motor housing and the pump cover, and provides an interface between the motor housing and the pump cover.

[0173] The motor may be located within the motor housing, and the motor may be configured to drive the impeller to rotate about the longitudinal axis via a linkage. A bearing housing may be at least partially disposed radially inside the adapter, the bearing housing including a bearing configured to support at least a portion of the linkage.

[0174] It should be understood that the features of the hydrogen recirculation pump in the eleventh aspect can be combined with the features of the hydrogen recirculation pump in the second, fourth, sixth, or eighth aspects.

[0175] According to a twelfth aspect, a modular hydrogen recirculation pump is provided, the modular hydrogen recirculation pump comprising:

[0176] Pump assembly, the pump assembly comprising:

[0177] Pump cover, the pump cover defining the impeller chamber; and

[0178] Impeller, the impeller being located within the impeller chamber;

[0179] A motor assembly, comprising a motor housing and a motor, wherein the motor is located within the motor housing and the motor is configured to drive the impeller to rotate about a longitudinal axis via a linkage; and

[0180] An adapter is disposed between the pump assembly and the motor assembly, the adapter being mounted to both the motor housing and the pump cover;

[0181] The pump cover is mounted to the adapter via a first connecting device that allows the pump cover to be removed from and reattached to the adapter, and the motor housing is mounted to the adapter via a second connecting device that allows the motor housing to be removed from and reattached to the adapter.

[0182] The term "modular" encompasses two or more components that can be disassembled and reassembled. A first connecting device may include at least one connector or fastener. The first connecting device may include a clamp. The term "installation" encompasses connecting respective components to each other, with the components adjacent to and / or abutting each other. In some cases, "installation" may include components with an interference fit. Providing a modular hydrogen recirculation pump is advantageous because it allows for individual component replacement, such as in the event of a specific component failure, and during repair and maintenance. Having a modular hydrogen recirculation pump also allows pump covers and motor housings of various sizes to be connected to each other via adapters. That is, a single motor housing can be configured to connect to various pump covers, each different in size, and vice versa.

[0183] Unless otherwise stated, the term "linkage" throughout this specification covers any suitable means for transmitting rotation from a motor to an impeller. A linkage can be a mechanical linkage, such as one with a common shaft, or it can be a shaftless linkage, for example, through the use of magnetic coupling.

[0184] The first connecting device and / or the second connecting device may include multiple connectors.

[0185] The bearing housing may be at least partially disposed radially inside the adapter relative to the longitudinal axis, and the bearing housing may include a bearing configured to support at least a portion of the linkage.

[0186] The linkage device may further include a magnetic connection device, the magnetic connection device comprising:

[0187] A first permanent magnet, which is fixedly connected to the drive shaft of the motor; and

[0188] A second permanent magnet is fixedly connected to the impeller;

[0189] The motor end cap can be disposed adjacent to the adapter, and the motor end cap can be located between the first permanent magnet and the second permanent magnet; and

[0190] The first permanent magnet and the second permanent magnet can apply magnetic force to each other, and the magnetic force prevents relative rotation between the first permanent magnet and the second permanent magnet, so that the rotation of the drive shaft and the first permanent magnet is transmitted to the second permanent magnet and the impeller.

[0191] The first permanent magnet and the second permanent magnet may each comprise multiple permanent magnets. The term "the first permanent magnet is fixedly connected to the drive shaft of the motor" encompasses both direct and indirect connections between the permanent magnet and the drive shaft. The term "the second permanent magnet is fixedly connected to the impeller" encompasses both direct and indirect connections between the permanent magnet and the impeller.

[0192] The second permanent magnet can be fixedly connected to the impeller via a magnetic coupling body.

[0193] The motor end cap can be formed of a non-magnetic material.

[0194] The motor end cap can be formed from a polymer or plastic. The motor end cap can be formed from polyetheretherketone (PEEK).

[0195] The motor end cap can be fixed to the motor housing by multiple connectors.

[0196] The motor assembly may include an electrical connection interface configured to connect the motor to a power source for driving the motor. The power source can be any suitable power source, such as a battery or a mains power supply.

[0197] The electrical connection interface can be integrally formed with the motor housing.

[0198] The electrical connection interface may be located radially outward of the motor housing relative to the longitudinal axis.

[0199] The motor assembly may include a temperature sensor configured to sense the temperature inside the motor housing, and the motor assembly may also include a temperature sensor connection interface configured to transmit the sensed temperature.

[0200] The temperature sensor connection interface can be integrally formed with the motor housing.

[0201] The temperature sensor connection interface can be located radially outside the motor housing relative to the longitudinal axis.

[0202] The pump cover may include:

[0203] end wall;

[0204] An annular sidewall extending from the end wall, wherein the end wall and the annular sidewall at least partially define the impeller chamber; and

[0205] A flange, which is adjacent to the end wall and located radially outside the annular sidewall, may define an interface for engaging with a manifold, and the flange includes a plurality of holes configured to receive a connector for securing the flange to the manifold.

[0206] According to aspect thirteen, a parts kit for a modular hydrogen recirculation pump is provided, the parts kit comprising:

[0207] Pump assembly, the pump assembly comprising:

[0208] Pump cover, the pump cover defining the impeller chamber; and

[0209] An impeller, the impeller being configured to be located within the impeller chamber;

[0210] A motor assembly including a motor housing and a motor, wherein the motor is configured to be located within the motor housing and the motor is configured to drive the impeller to rotate about a longitudinal axis via a linkage; and

[0211] An adapter configured to be disposed between the pump assembly and the motor assembly, and configured to be mounted to the motor housing and the pump cover;

[0212] The pump cover is configured to be mounted to the adapter via a first connecting device that allows the pump cover to be removed from and reattached to the adapter, and the motor housing is configured to be mounted to the adapter via a second connecting device that allows the motor housing to be removed from and reattached to the adapter.

[0213] It should be understood that the features of the twelfth and thirteenth aspects can be combined with the features of any one of the first to eleventh aspects.

[0214] According to the fourteenth aspect, a coupling member is provided for a magnetic coupling device of a hydrogen recirculation pump, the coupling member comprising a coupling body.

[0215] The connection body includes:

[0216] The connecting portion is configured to connect the connecting body to the rotatable body; and

[0217] Magnet holding section;

[0218] The permanent magnet is housed in the magnet holding portion.

[0219] The term "rotatable body" at least encompasses the impeller and the shaft including the rotor shaft and drive shaft. In some embodiments, the connecting portion can be integrally formed with the rotatable body, and in particular, the rotatable body can be integrally formed with the shaft. By providing a magnet retaining portion in the connecting body, multiple permanent magnets can be arranged in a split manner with a semi-enclosed structure, thereby facilitating manufacturing and packaging. Compared to a fully enclosed structure, it has lower magnetic coupling loss and lighter weight while transmitting the same torque. In addition, by defining a larger first diameter by the connecting body and a smaller second diameter by the magnet retaining portion, components such as support shafts and bearings can be arranged in the first diameter region and the second diameter region. The connecting body including the connecting portion and the magnet retaining portion can adopt a simple structure for simple and reliable fixation via the connecting portion; for example, the connecting body can be fixed to the impeller using evenly distributed bolts via the connecting portion.

[0220] The connecting body can be a cylindrical body with a central axis;

[0221] The connecting body may include a through hole coinciding with the central axis, the through hole extending through the connecting body and defining at least a portion of the connecting portion; and

[0222] The first end of the connecting body includes an annular recess that defines the magnet holding portion.

[0223] The annular recess may be located radially outward and concentric with the through hole.

[0224] The first end of the connecting body may include a flange, and the flange may define a portion of the annular recess.

[0225] At the first end of the connecting body, the through-hole may have a first diameter; and in a region axially spaced from the magnet, the through-hole may have a second diameter. The second diameter may be larger than the first diameter. This larger diameter allows the bearing assembly to be accommodated within the through-hole. Furthermore, an increased cross-sectional area can be achieved, allowing for a larger area for one or more permanent magnets in the recessed portion.

[0226] The through-hole can be configured to receive at least a portion of a shaft or plug. The through-hole can also receive at least a portion of a bearing assembly that supports the impeller for rotation.

[0227] The wall of the coupling body, which at least partially defines the through hole, can be mounted to the shaft. In some embodiments, the wall of the coupling body may be integrally formed with the shaft.

[0228] The second end of the connecting body, opposite to the first end, may include at least one axially extending fastening hole, which may be configured to receive a connector for attaching the connecting member to the impeller. The connecting body may include multiple fastening holes. These multiple fastening holes may be angularly spaced about a central axis. The fastening holes may be threaded holes. The fastening holes may not extend continuously through the connecting body.

[0229] An adhesive is provided between the permanent magnet and the magnet holding portion for holding the permanent magnet in the magnet holding portion.

[0230] The permanent magnet may have a ring-shaped profile in a plane perpendicular to the central axis of the connecting body.

[0231] Multiple permanent magnets can be disposed in the magnet holding portion.

[0232] The plurality of permanent magnets can be arranged equidistantly around the central axis of the connecting body in the circumferential direction.

[0233] In other words, the plurality of permanent magnets are positioned around a central axis, with equal spacing between each permanent magnet. In some cases, the permanent magnets can be adjacent to each other, such that there is no space between adjacent permanent magnets.

[0234] A gap between 0 mm and 1 mm can be provided between adjacent permanent magnets. A gap between 0.1 mm and 1 mm can be provided between adjacent permanent magnets. A gap of 0.5 mm can be provided between adjacent permanent magnets.

[0235] The gap between adjacent magnets can be constant at different radial positions.

[0236] The connecting body can be formed of a magnetically conductive material.

[0237] According to the fifteenth aspect, a magnetic coupling device for a hydrogen recirculation pump is provided, the magnetic coupling device comprising:

[0238] The first connecting member is configured to be fixedly connected to the drive shaft of the motor;

[0239] The second connecting member is configured to be fixedly connected to the pump impeller;

[0240] Wherein, the first connecting member is a connecting member according to the fourteenth aspect, and the second connecting member is a connecting member according to the fourteenth aspect, and

[0241] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member.

[0242] A gap between 3.5 mm and 4 mm can be provided between the permanent magnet of the first connecting member and the permanent magnet of the second connecting member, and the magnetic connection torque is greater than 3 Nm.

[0243] A 3.5mm gap can be provided between the permanent magnet of the first connecting member and the permanent magnet of the second connecting member, and the magnetic connection torque is greater than 3.4Nm. Alternatively, a 4mm gap can be provided between the permanent magnet of the first connecting member and the permanent magnet of the second connecting member, and the magnetic connection torque is greater than 3Nm.

[0244] According to a sixteenth aspect, a hydrogen recirculation pump is provided, the hydrogen recirculation pump comprising:

[0245] Pump assembly, the pump assembly comprising:

[0246] Pump cover, the pump cover defining the impeller chamber; and

[0247] Impeller, the impeller being located within the impeller chamber;

[0248] Motor assembly, the motor assembly comprising:

[0249] Motor housing; and

[0250] A motor, the motor being disposed within the motor housing; and

[0251] A magnetic coupling is configured to provide a linkage between the motor and the impeller, allowing the motor to rotatably drive the impeller to rotate about a longitudinal axis.

[0252] The magnetic connector includes:

[0253] A first connecting member, configured to be fixedly connected to the drive shaft of the motor; and

[0254] The second connecting member is configured to be fixedly connected to the impeller;

[0255] Wherein, the first connecting member is a connecting member according to the fourteenth aspect, or a first connecting member of a magnetic connecting device for a hydrogen recirculation pump according to the fifteenth aspect, and the second connecting member is a connecting member according to the fourteenth aspect, or a second connecting member of a magnetic connecting device for a hydrogen recirculation pump according to the fifteenth aspect, and

[0256] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member, such that the rotation of the drive shaft and the first connecting member is transmitted to the second connecting member and the impeller.

[0257] The hydrogen recirculation pump may also include an adapter that can be connected to the motor assembly and the pump assembly, and provides an interface between the motor assembly and the pump assembly.

[0258] The first connecting member can be mounted to the drive shaft of the motor.

[0259] At least a portion of the impeller can be connected to the second connecting member via the connecting portion.

[0260] The first connecting member and the second connecting member may be axially separated, and the motor housing end cap is disposed between the first connecting member and the second connecting member.

[0261] The features of the fourteenth, fifteenth, and sixteenth aspects can be combined with features of any one of the first through thirteenth aspects.

[0262] According to the seventeenth aspect, a coupling member is provided for a magnetic coupling device of a hydrogen recirculation pump, the coupling member comprising a coupling body.

[0263] The connection body includes:

[0264] The connecting portion is configured to connect the connecting body to the rotatable body; and

[0265] Magnet holding section;

[0266] The permanent magnet is housed in the magnet holding portion, and the permanent magnet is fixed in the magnet holding portion by a first connector extending through the permanent magnet, and the end of the first connector is housed in a hole in the connecting body.

[0267] The term "rotatable body" at least covers the impeller and the shaft including the rotor shaft and drive shaft. In some embodiments, a connecting portion may be integrally formed with the rotatable body, and in particular, the rotatable body may be integrally formed with the shaft. The first connecting element may be a fastener or a screw. The hole may be a threaded hole.

[0268] The connecting member may further include a plurality of first connectors, wherein the end of each first connector is received in a respective hole in the connecting body. The hole may be located in the connecting portion.

[0269] The connecting body may be a cylindrical body having a central axis. The connecting body may include a through hole coinciding with the central axis, the through hole extending through the connecting body and defining at least a portion of the connecting portion; and wherein a first end of the connecting body may include an annular recess defining the magnet holding portion. The annular recess may be located radially outward and concentric with the through hole.

[0270] The first end of the connecting body may include a flange, and the flange may define a portion of the annular recess.

[0271] At the first end of the connecting body, the through hole may have a first diameter; and in a region that is axially spaced from the magnet, the through hole may have a second diameter; wherein the second diameter may be larger than the first diameter.

[0272] The second diameter is larger than the first diameter, allowing the bearing assembly to be accommodated within the through-hole. Furthermore, an increased cross-sectional area can be achieved, allowing for a larger area within the recessed portion for one or more permanent magnets.

[0273] The through-hole can be configured to receive at least a portion of a shaft or plug. The through-hole can also receive at least a portion of a bearing assembly that supports the impeller for rotation.

[0274] The wall of the coupling body, which at least partially defines the through-hole, can be configured to be mounted to the shaft. In some embodiments, the wall of the coupling body can be integrally formed with the shaft.

[0275] The second end of the connecting body opposite to the first end may include at least one axially extending fastening hole, which may be configured to receive a first connector to connect the connecting member to the impeller.

[0276] The connecting body may include multiple fastening holes. These fastening holes may be spaced at equal angles around a central axis. The fastening holes may be threaded holes. The fastening holes may not extend continuously through the connecting body.

[0277] A magnetically conductive member may be disposed between the permanent magnet and the magnet holding portion. The magnetically conductive member may be formed of silicon steel. The magnetically conductive member can be used to form a closed magnetic circuit.

[0278] The permanent magnet may have a ring-shaped profile in a plane perpendicular to the central axis.

[0279] Multiple permanent magnets can be disposed in the magnet holding portion, and each permanent magnet is fixed in the magnet holding portion by its respective first connector. Up to eight permanent magnets can be disposed in the magnet holding portion.

[0280] The plurality of permanent magnets can be arranged equidistantly around the central axis of the connecting body in a circumferential direction. That is, the plurality of permanent magnets can be positioned around the central axis, wherein the spacing between each permanent magnet is equal. In some cases, the permanent magnets can be adjacent to each other, such that there is no space between adjacent magnets.

[0281] A gap between 0 mm and 1 mm can be provided between adjacent permanent magnets. A gap between 0.1 mm and 1 mm can be provided between adjacent permanent magnets. A gap of 0.5 mm can be provided between adjacent permanent magnets. That is to say, the gap between adjacent magnets can be constant at all radial positions. The connecting body can be formed of a non-magnetic material.

[0282] According to the eighteenth aspect, a magnetic coupling device for a hydrogen recirculation pump is provided, the magnetic coupling device comprising:

[0283] The first connecting member is configured to be fixedly connected to the drive shaft of the motor;

[0284] The second connecting member is configured to be fixedly connected to the impeller of the pump assembly;

[0285] Wherein, the first connecting member is a connecting member according to the seventeenth aspect, and the second connecting member is a connecting member according to the seventeenth aspect, and

[0286] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member, such that rotation of the first connecting member is transmitted to the second connecting member.

[0287] A gap between 3.5 mm and 4 mm can be provided between the permanent magnets of the first and second connecting components, and the magnetic connection torque is greater than 3 Nm. A gap of 3.5 mm can be provided between the permanent magnets of the first and second connecting components, and the magnetic connection torque is greater than 3.4 Nm. A gap of 4 mm can be provided between the permanent magnets of the first and second connecting components, and the magnetic connection torque is greater than 3 Nm.

[0288] According to a nineteenth aspect, a hydrogen recirculation pump is provided, the hydrogen recirculation pump comprising:

[0289] Pump assembly, the pump assembly comprising:

[0290] Pump cover, the pump cover defining the impeller chamber; and

[0291] Impeller, the impeller being located within the impeller chamber;

[0292] Motor assembly, the motor assembly comprising:

[0293] Motor housing; and

[0294] A motor, the motor being disposed within the motor housing; and

[0295] A magnetic coupling is configured to provide a linkage between the motor and the impeller, allowing the motor to drive the impeller to rotate about a longitudinal axis;

[0296] The magnetic connector includes:

[0297] A first connecting member, configured to be fixedly connected to the drive shaft of the motor; and

[0298] The second connecting member is configured to be fixedly connected to the impeller;

[0299] Wherein, the first connecting member is a connecting member according to the seventeenth aspect, or a first connecting member of a magnetic connecting device for a hydrogen recirculation pump according to the eighteenth aspect, and the second connecting member is a connecting member according to the seventeenth aspect, or a second connecting member of a magnetic connecting device for a hydrogen recirculation pump according to the eighteenth aspect, and

[0300] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member, such that the rotation of the drive shaft and the first connecting member is transmitted to the second connecting member and the impeller.

[0301] The hydrogen recirculation pump may also include an adapter connected to the motor assembly and the pump assembly, and providing an interface between the motor assembly and the pump assembly.

[0302] The first connecting member can be mounted to the drive shaft of the motor.

[0303] At least a portion of the plug can be connected to the impeller and can also be connected to the second connecting member. The term "connected to the impeller" encompasses both direct and indirect connections between the plug and the impeller.

[0304] The first connecting member and the second connecting member may be axially separated, and the motor housing end cover may be disposed between the first connecting member and the second connecting member.

[0305] It should be understood that the features of the connecting member in aspect fourteen can be combined with the features of the connecting member in aspect seventeen. It should be understood that the features of aspects seventeen to nineteen can be combined with the features of aspects one to sixteen.

[0306] According to the twentieth aspect, a connecting member is provided for a magnetic coupling device of a hydrogen recirculation pump, the connecting member comprising a cylindrical connecting body having a central axis.

[0307] The connection body includes:

[0308] A connecting portion, configured to connect the connecting body to a rotatable body, wherein a through-hole coinciding with the central axis extends through the connecting body and defines at least a portion of the connecting portion; and

[0309] A magnet holding portion, wherein a first end of the connecting body includes an axially extending annular recess defining the magnet holding portion, and a permanent magnet having an annular profile in a plane perpendicular to the central axis is accommodated in the magnet holding portion;

[0310] The magnet holding portion includes a radially extending protrusion, and the radially extending protrusion is arranged to hold the magnet axially within the magnet holding portion.

[0311] The term "rotatable body" at least encompasses the impeller and the shaft including the rotor shaft and drive shaft. In some embodiments, the connecting portion may be integrally formed with the rotatable body, and in particular, the rotatable body may be integrally formed with the shaft. The term "radially extending protrusion" encompasses a protrusion extending in at least a radial direction relative to the central axis. Providing such a radially extending protrusion is advantageous. For example, such a radially extending protrusion can be formed by flanging the magnet holding portion, thus securing the permanent magnet within the magnet holding portion, thereby improving the reliability of the permanent magnet's fixation. Furthermore, the connecting body can be made of a metal material such as aluminum alloy, resulting in a lighter weight.

[0312] The radially extending protrusion may be an annular protrusion.

[0313] The radially extending protrusion may extend from the radially outer wall of the magnet holding portion in a direction toward the central axis. In other embodiments, the radially extending protrusion extends from the radially inner wall of the magnet holding portion in a direction away from the central axis.

[0314] The permanent magnet may include a recess that may have a profile complementary to the radially extending protrusion. The recess may be a radially extending recess.

[0315] The radially extending protrusion may be a first protrusion, and the magnet holding portion may include a radially extending second protrusion. The permanent magnet may include a second recess. The second recess may have a profile complementary to the second protrusion.

[0316] The radially extending second protrusion can extend from the radial inner wall of the magnet holding portion in a direction away from the central axis.

[0317] At least one of the radially extending first protrusion and second protrusion may be an annular protrusion. Both the first protrusion and the second protrusion may be an annular protrusion.

[0318] The recess of the permanent magnet may be a first recess having a profile complementary to the radially extending first protrusion. The permanent magnet may include a second recess having a profile complementary to the radially extending second protrusion.

[0319] The first end of the connecting body may include a flange, and the flange may define a portion of the axially extending annular recess.

[0320] At the first end of the connecting body, the through-hole may have a first diameter; and in a region axially spaced from the magnet, the through-hole may have a second diameter. The second diameter may be larger than the first diameter. This larger diameter allows the bearing assembly to be accommodated within the through-hole. Furthermore, an increased cross-sectional area can be achieved, allowing for a larger area for one or more permanent magnets in the recessed portion.

[0321] A magnetically conductive member having an annular profile in a plane perpendicular to the central axis can be housed within the magnet holding portion, and the magnetically conductive member can be disposed between the permanent magnet and the magnet holding portion. The magnetically conductive member can be formed of silicon steel. The magnetically conductive member can be used to form a closed magnetic circuit.

[0322] The magnetically conductive member may include a radially extending recess. The magnet retaining portion may include complementary protrusions received within the recess of the magnetically conductive member.

[0323] The through-hole can be configured to receive at least a portion of a shaft or plug. The through-hole can also receive at least a portion of a bearing assembly that supports the impeller for rotation.

[0324] The wall of the coupling body, which at least partially defines the through-hole, can be configured to be mounted to the shaft. In some embodiments, the wall of the coupling body can be integrally formed with the shaft.

[0325] The second end of the connecting body, opposite to the first end, may include at least one axially extending fastening hole, which may be configured to receive a connector for attaching the connecting member to the impeller. The connecting body may include multiple fastening holes. The multiple fastening holes may be angularly spaced about a central axis. The fastening holes may be threaded holes. The fastening holes may not extend continuously through the connecting body.

[0326] The permanent magnet may include a plurality of permanent magnets, and the radially extending protrusion may be arranged to axially retain at least one of the plurality of permanent magnets in the magnet holding portion. Eight permanent magnets may be disposed in the magnet holding portion.

[0327] The plurality of permanent magnets can be arranged circumferentially at equal intervals around the central axis. That is, the plurality of permanent magnets can be positioned around the central axis, wherein the spacing between each permanent magnet is equal. In some cases, the permanent magnets can be adjacent to each other, such that there is no space between adjacent magnets.

[0328] A gap between 0 mm and 1 mm can be provided between adjacent permanent magnets. A gap between 0.1 mm and 1 mm can be provided between adjacent permanent magnets. A gap of 0.5 mm can be provided between adjacent permanent magnets. That is to say, the gap between adjacent magnets can be constant at all radial positions. The connecting body can be formed of a non-magnetic material.

[0329] According to aspect twenty-one, a magnetic coupling device for a hydrogen recirculation pump is provided, the magnetic coupling device comprising:

[0330] The first connecting member is configured to be fixedly connected to the drive shaft of the motor; and

[0331] The second connecting member is configured to be fixedly connected to the impeller of the pump assembly;

[0332] Wherein, the first connecting member is a connecting member according to the twentieth aspect, and the second connecting member is a connecting member according to the twentieth aspect, and

[0333] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member, such that rotation of the first connecting member is transmitted to the second connecting member.

[0334] A gap between 3.5 mm and 4 mm can be provided between the permanent magnets of the first and second connecting components, and the magnetic connection torque is greater than 3 Nm. A gap of 3.5 mm can be provided between the permanent magnets of the first and second connecting components, and the magnetic connection torque is greater than 3.4 Nm. A gap of 4 mm can be provided between the permanent magnets of the first and second connecting components, and the magnetic connection torque is greater than 3 Nm.

[0335] According to a twenty-second aspect, a hydrogen recirculation pump is provided, the hydrogen recirculation pump comprising:

[0336] Pump assembly, the pump assembly comprising:

[0337] Pump cover, the pump cover defining the impeller chamber; and

[0338] Impeller, the impeller being located within the impeller chamber;

[0339] Motor assembly, the motor assembly comprising:

[0340] Motor housing; and

[0341] A motor, wherein the motor is disposed in the motor housing;

[0342] A magnetic coupling device is configured to provide a linkage between the motor and the impeller, allowing the motor to drive the impeller to rotate about a longitudinal axis;

[0343] The magnetic connection device includes:

[0344] A first connecting member, configured to be fixedly connected to the drive shaft of the motor; and

[0345] The second connecting member is configured to be fixedly connected to the impeller;

[0346] Wherein, the first connecting member is a connecting member according to the twentieth aspect, or a first connecting member of a magnetic connecting device for a hydrogen recirculation pump according to the twenty-first aspect, and wherein the second connecting member is a connecting member according to the twentieth aspect, or a second connecting member of a magnetic connecting device for a hydrogen recirculation pump according to the twenty-first aspect, and

[0347] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member, such that the rotation of the drive shaft and the first connecting member is transmitted to the second connecting member and the impeller.

[0348] The hydrogen recirculation pump may also include an adapter that can be connected to the motor assembly and the pump assembly, and provides an interface between the motor assembly and the pump assembly.

[0349] The first connecting member can be mounted to the drive shaft of the motor.

[0350] The first connecting member and the second connecting member may be axially separated, and the motor housing end cover may be disposed between the first connecting member and the second connecting member.

[0351] It should be understood that the features of the hydrogen recirculation pumps of the second, fourth, sixth, eighth, eleventh, twelfth, sixteenth, nineteenth, and twenty-second aspects can be combined. Similarly, the features of the first, third, fifth, seventh, ninth, thirteenth, fourteenth, fifteenth, sixteenth, seventeenth, eighteenth, twentieth, and twenty-first aspects can be combined with the hydrogen recirculation pumps of the second, fourth, sixth, eighth, eleventh, twelfth, sixteenth, nineteenth, and twenty-second aspects. Attached Figure Description

[0352] Embodiments of this disclosure will now be described by way of example only with reference to the accompanying drawings, in which:

[0353] Figure 1 A perspective view of a hydrogen recirculation pump according to this disclosure is shown;

[0354] Figure 2 Show Figure 1 Side view of the hydrogen recirculation pump;

[0355] Figure 3 As shown Figure 1 and Figure 2 A schematic exploded side view of the hydrogen recirculation pump shown;

[0356] Figure 4 Show Figures 1 to 3 A cross-sectional side view of the hydrogen recirculation pump;

[0357] Figure 5 Show Figures 1 to 4 A perspective view of the motor assembly of the hydrogen recirculation pump;

[0358] Figure 6 Show Figures 1 to 4 Front perspective view of the adapter for the hydrogen recirculation pump;

[0359] Figure 7 A cross-sectional side view showing a portion of the bearing assembly of the hydrogen recirculation pump;

[0360] Figure 8 Show Figure 7 A perspective view of the bearing housing of the bearing assembly;

[0361] Figure 9 Show Figure 8 A schematic cross-sectional side view of the bearing housing;

[0362] Figure 10 Show Figure 1 A cross-sectional end view of the pump cover of the hydrogen recirculation pump in the middle;

[0363] Figure 11 Show Figure 10 A sectional side view of the pump cover;

[0364] Figure 12 A perspective view showing an alternative pump cover;

[0365] Figure 13 Show Figure 12 End view of the pump cover;

[0366] Figure 14 An end view of an alternative pump cover is shown;

[0367] Figure 15 An end view of an alternative pump cover is shown;

[0368] Figure 16 Show Figure 1 Front perspective view of the impeller of the hydrogen recirculation pump;

[0369] Figure 17 Show Figure 16 Rear perspective view of the impeller;

[0370] Figure 18 Show Figure 16 A sectional side view of the impeller;

[0371] Figure 19 Showing the location Figure 1 The impeller chamber of the hydrogen recirculation pump Figure 16 A schematic partial sectional side view of the impeller;

[0372] Figure 20 Show Figure 16 A schematic front view of the impeller;

[0373] Figure 21 A partial sectional side view of another impeller is shown;

[0374] Figure 22 A perspective view of the connecting components of the magnetic coupling device is shown;

[0375] Figure 23 Show Figure 22A schematic sectional side view of the connecting components;

[0376] Figure 24 A perspective view of another connecting component of the magnetic coupling device is shown;

[0377] Figure 25 Show Figure 24 A schematic sectional side view of the connecting components;

[0378] Figure 26 Showing from Figure 25 Rotated 45 degrees Figure 24 A schematic sectional side view of the connecting components;

[0379] Figure 27 A perspective view of another connecting component of the magnetic coupling device is shown;

[0380] Figure 28 Show Figure 27 A sectional side view of the connecting components. Detailed Implementation

[0381] Figure 1 and Figure 2 A hydrogen recirculation pump 1 (also referred to as an anode recirculation blower) is depicted. The hydrogen recirculation pump 1 includes a pump assembly 3 and a motor assembly 5. An adapter 7 is disposed between the pump assembly 3 and the motor assembly 5, and the pump assembly 3 and the motor assembly 5 are mounted on opposite sides of the adapter 7.

[0382] Pump assembly 3 includes a pump cover 9 that defines an impeller chamber (in Figures 1 to 3 (Not visible in the center), and the impeller is located in the impeller chamber. The pump cover 9 also includes an inlet configured to contain hydrogen or a hydrogen-containing gas. The inlet is in fluid communication with the impeller. The impeller is configured to perform work on the gas contained from the inlet (i.e., compress the gas). The compressed gas can then exit the pump assembly 3 via an outlet.

[0383] Similarly, the motor assembly 5 includes a motor housing 11 and a motor (in... Figures 1 to 3 (Not visible in the middle). The pump cover 9 and motor housing 11 are generally cylindrical structures that allow the impeller and motor to be mounted in their respective pump covers 9 and motor housings 11 to rotate about a common longitudinal axis 15.

[0384] like Figure 3 As best seen in the diagram, the motor housing 11 is connected to the pump cover 9 via a connecting device comprising a plurality of connectors 13, the term "connector 13" being interchangeably referred to as fastener 13. In other embodiments, the motor housing 11 may be connected to the pump cover 9 using different connection means, such as a single fastener, a clamping mechanism, or any other suitable connection means.

[0385] The motor housing 11 includes a radially and circumferentially extending flange 17 disposed at the end of the motor housing 11 adjacent to the adapter 7. The flange 17 includes a plurality of axially extending through holes, each allowing a corresponding connector 13 to pass through. The adapter 7 (discussed in more detail later) also includes a plurality of axially extending through holes allowing the connector 13 to pass through. The connector 13 is then received in a corresponding axially extending hole 19 in the pump cover 9. The hole 19 may be a threaded hole, and the connector 13 may include a corresponding thread. The hole 19 is a blind hole; in other embodiments, the hole 19 may be a through hole. The hole 19 in the pump cover 9 is located in a circumferentially spaced protrusion 21 surrounding the annular sidewall 23, and the hole 19 extends axially into the protrusion 21. The motor housing 11, adapter 7, and pump cover 9 may all include more through holes and holes than the number of connectors used to secure the adapter 7, pump cover 9, and motor housing 11 together. Furthermore, the motor housing 11, adapter 7, and pump cover 9 may include different numbers of through holes and openings for accommodating connectors to each other. That is, the motor housing 11, adapter 7, and pump cover 9 may include redundant through holes and openings. Having redundant holes and openings allows motor assemblies 5 of different sizes to be connected to a single pump assembly 3, and vice versa. This is advantageous because it allows a single-size pump assembly 3 to be used with a variety of different motor assemblies 5, and vice versa. Furthermore, having redundant through holes and openings reduces assembly time. The redundant through holes also allow the pump cover 9, motor housing 11, and adapter 7 to be mounted in various different orientations.

[0386] The hydrogen recirculation pump 1 is a modular hydrogen recirculation pump, wherein the pump cover 9 is mounted to the adapter 7 via a connector 13, which allows the pump cover 9 to be removed from and reattached to the adapter 7. The motor housing 11 is mounted to the adapter 7 via the connector 13, which allows the motor housing 11 to be removed from and reattached to the adapter 7. This is advantageous because, compared to known hydrogen recirculation pumps, components can be easily replaced, and it offers a compact design that is smaller in size, lighter in weight, and more efficient.

[0387] Go to Figure 4 It shows a cross-sectional side view of the hydrogen recirculation pump 1.

[0388] The pump cover 9 includes an end wall 25 from which an annular side wall 23 extends axially relative to a longitudinal axis 15. The pump cover 9 also includes an impeller chamber 27 in which an impeller 29 is housed. The impeller chamber 27 is partially defined by the end wall 25 and the annular side wall 23, and includes side passages in fluid communication with an inlet and an outlet. The impeller 29 is supported by a bearing assembly 33 for rotation about the longitudinal axis 15. The bearing assembly 33 is disposed radially inward relative to the longitudinal axis 15 of the adapter 7. The bearing assembly 33 is disposed around a spigot 31, which is held in a support region 32 of the pump cover 9.

[0389] The motor 35, including the rotor 37 and the stator 39, is located in the motor housing 11. The rotor 37 is arranged to rotate about the longitudinal axis 15.

[0390] A magnetic coupling device 41 is disposed radially inside the adapter 7 and is used to transmit rotation from the rotor 37 to the impeller 29. Specifically, the magnetic coupling device 41 includes a first coupling member 43 fixedly connected to the rotor 37, thereby allowing the rotor 37 to function as a drive shaft. The first coupling member 43 includes a first coupling body 45, in which a first permanent magnet 47 is held. Specifically, the first coupling body 45 is fixedly connected to the rotor 37 such that rotation of the rotor 37 causes rotation of the first coupling body 45, and thus causes rotation of the first permanent magnet 47 about the longitudinal axis 15. The magnetic coupling device 41 also includes a second coupling member 49. The second coupling member 49 includes a second coupling body 51, in which a second permanent magnet 53 is held. The second coupling body 51 is fixedly connected to the impeller 29 by a plurality of connectors 113, and is partially supported by a bearing assembly 33. The second coupling body 51 is arranged such that the second permanent magnet 53 is opposite the first permanent magnet 47. The first permanent magnet 47 and the second permanent magnet 53 are spaced apart, and the first permanent magnet 47 and the second permanent magnet 53 exert magnetic force on each other. The magnetic force applied between the first permanent magnet 47 and the second permanent magnet 53 prevents relative rotation between the first permanent magnet and the second permanent magnet, and thus prevents relative rotation between the first connecting member 43 and the second connecting member 49. Therefore, when the rotor 37 is rotating about the longitudinal axis 15, the first connecting body 45 and thus the first permanent magnet 47 rotate, and this rotation is transmitted to the second permanent magnet 53, and thus to the impeller 29.

[0391] Using a magnetic coupling device 41 to provide linkage and transmit rotation from the motor 35 to the impeller 29 can be referred to as shaftless drive. That is, there is no mechanically connected shaft from the rotor 37 to the impeller 29. By having shaftless drive, for example by using the magnetic coupling device 41, the individual components of the hydrogen recirculation pump 1 (e.g., pump assembly 3, motor assembly 5, and adapter 7) can be replaced individually, for example if a specific component fails, and during maintenance and repair.

[0392] In addition, such as Figure 4 and Figure 5 As can be best seen, end cap 55 is disposed between the first connecting member 43 and the second connecting member 49. End cap 55 is a motor end cap and may be formed of a non-magnetic material, such as a polymer or plastic, and preferably polyetheretherketone (PEEK). End cap 55 is a generally circular disc mounted to the motor housing 11, and in some embodiments, end cap 55 may be integrally formed with the motor housing 11. End cap 55 prevents exposure of the internal components of the motor assembly 5 during assembly and disassembly of the hydrogen recirculation pump 1. Thus, end cap 55 isolates the motor assembly 5 from the pump assembly 3 and protects the motor components from hydrogen that may be present in the pump assembly 3 during use. End cap 55 also ensures that an axial clearance is maintained between the first permanent magnet 47 and the second permanent magnet 53. The axial clearance between the first permanent magnet 47 and the second permanent magnet 53 is preferably between approximately 3.5 mm and approximately 4 mm. The magnetic connection torque is preferably greater than approximately 3 Nm. When the axial gap between the first permanent magnet 47 and the second permanent magnet 53 is approximately 3.5 mm, the magnetic connection torque is approximately 3.4 Nm. When the axial gap between the first permanent magnet 47 and the second permanent magnet 53 is approximately 4 mm, the magnetic connection torque is approximately 3 Nm.

[0393] It should be understood that in other embodiments, the linkage for transmitting rotation from motor 35 to impeller 29 may not include magnetic coupling device 41. Any other suitable linkage means may be used. For example, rotation may be transmitted via a common shaft between rotor 37 and impeller 29.

[0394] Figure 5 A perspective view of motor assembly 5 is shown. As described above, and as... Figure 5 As depicted, the flange 17 of the motor housing 11 includes an axially extending through hole 57 for connecting the motor housing 11 to the adapter 7 and the pump cover 9. Figure 5In the illustrated embodiment, the end cap 55 is secured to the motor housing 11 by a plurality of connectors 61. The connectors 61 are spaced at equal angles around the longitudinal axis 15. In other embodiments, the connectors 61 may be arranged in different ways, and in other embodiments, the end cap 55 may be secured to the motor housing 11 by any suitable means, or the end cap 55 may be integrally formed with the motor housing 11.

[0395] Motor assembly 5 also includes an electrical connection interface 63. The electrical connection interface 63 allows the motor 35 to be connected to a power source (e.g., a battery or mains power supply). The electrical connection interface 63 is located radially outward relative to the longitudinal axis 15. This radially outward location of the electrical connection interface 63 facilitates easy connection to a power supply device. Figure 5 In the illustrated embodiment, the electrical connection interface 63 is housed in a housing 65, which is integrally formed with the motor housing 11. In other embodiments, the housing 65 of the electrical connection interface may be formed separately from the motor housing 11.

[0396] Despite Figures 1 to 5 Not shown, but motor assembly 5 also includes a temperature sensor located within motor housing 11 and configured to sense the temperature inside motor housing 11. Motor assembly 5 also includes a temperature sensor connection interface 67 (in... Figure 2 As can be seen in the image, the temperature sensor connection interface 67 is housed within the housing 65. The temperature sensor connection interface 67 is configured to transmit sensed data from a temperature sensor. That is, the temperature sensor connection interface 67 allows data to be transmitted to a controller or computer via wires or cables, or wirelessly. The temperature sensor connection interface 67 is located radially outward of the longitudinal axis 15 and in a plane rotated 90 degrees from the electrical connection interface 63. A removable cap 69 is also provided, which can be used to cover the temperature sensor connection interface 67 when not in use. The removable cap 69 protects the temperature sensor connection interface 67 from unwanted particles and debris. Similarly, the electrical connection interface 63 may also be provided with a removable cap. In other embodiments, the temperature sensor connection interface 67 may be housed in a different housing than the housing 65 of the electrical connection interface 63.

[0397] Figure 6 A front perspective view of adapter 7 is shown. As described above, adapter 7 is configured to connect to motor housing 11 and pump cover 9, and provides an interface between motor housing 11 and pump cover 9.

[0398] The adapter 7 includes a generally annular wall 71 surrounding a longitudinal axis 73. In use, the longitudinal axis 73 of the adapter 7 coincides with the longitudinal axis 15 of the hydrogen recirculation pump 1. In other embodiments, the annular wall 71 can be any suitable shape for connection with the corresponding pump cover 9 and motor housing 11. The annular wall 71 includes a front face 75 that provides an interface with the corresponding face of the pump cover 9. In addition to providing an interface with the pump cover 9, the front face 75 is conformable to the rear cover of the impeller 29. That is, the front face 75 has a profile in a plane perpendicular to the longitudinal axis 73 that conforms to the adjacent face of the impeller 29. The front face 75 of the adapter has a profile complementary to the rear cover of the impeller 29, which can improve flow constraint of the pump assembly, reduce leakage from the pump assembly, and provide a compact design. The annular wall 71 includes a rear face 77 opposite to the front face 75 that provides an interface with the corresponding face of the motor housing 11.

[0399] The annular wall 71 also includes a discharge channel 79. The discharge channel 79 allows liquid (primarily condensed water) to be discharged from the pump assembly 3 to its outlet in the area near the motor end cap 55. In the illustrated embodiment, the discharge channel 79 is a groove. This groove extends axially, radially, and circumferentially relative to the longitudinal axis 73, and its circumferential length is greater than its radial or axial length. That is, when the groove is cross-sectioned in a plane perpendicular to the longitudinal axis 73, it is an elongated groove. However, the discharge channel 79 can be of any suitable shape. The area or region of the discharge channel 79 and the front face 75 adjacent to the discharge channel may include a tapered region to further guide liquid into the discharge channel.

[0400] When the hydrogen recirculation pump 1 is in use, the adapter is oriented such that the discharge channel 79 is located in the lowest region. Positioning the discharge channel 79 in the lowest region during use allows liquid to be discharged through the discharge channel 79 under the influence of gravity, and reduces the accumulation of liquid in other regions of the pump assembly 3.

[0401] The annular wall 71 of the adapter 7 also includes a flange 83 radially outward relative to the longitudinal axis 73. In the illustrated embodiment, the flange 83 is an annular flange, but in other embodiments it can be any suitable shape. The flange 83 includes a plurality of axially extending through holes 85 configured to receive a connector 13 for connecting the motor housing 11, the adapter 7, and the pump cover 9. The through holes 85 may also be referred to as boreholes. To provide a compact and lightweight design, radially extending protrusions 87 are provided. At least a portion of the through holes 85 extends through the corresponding protrusions 87. It should be understood that in other embodiments, the protrusions 87 may be omitted. The through holes 85 are positioned to align with corresponding through holes 57 in the motor housing 11 and holes 19 in the pump cover 9. The through holes 85 are circumferentially spaced around the longitudinal axis 73; however, the through holes 85 are not equiangularly spaced, but in other embodiments the through holes 85 may be equiangularly spaced. Because the through holes 85 are not equiangularly spaced around the longitudinal axis 73, in addition to allowing connection between the pump cover 9 and the motor housing 11, the through holes 85 also serve as alignment features. Providing alignment features ensures that the motor housing 11 and the pump cover 9 are installed in the correct orientation and ensures that the discharge passage 79 is oriented to allow liquid to drain under gravity during use. In other embodiments, the adapter 7 can be connected to the motor housing 11 and the pump cover 9 by other connection means (e.g., clamps). Other connection means can be used in addition to or instead of the connector 13.

[0402] The adapter 7 may also be provided with alignment features, which are spaced apart from the through holes 85 so that the through holes 85 serve as alignment features. In particular, the adapter 7 may be provided with one or more axially extending protrusions or recesses configured to be received in complementary recesses or protrusions in the pump cover 9 and / or the motor housing 11. Providing alignment features alleviates the problem of installing the adapter 7 in an incorrect or undesirable orientation.

[0403] The flange 83 of the adapter 7 also includes a plurality of recesses 89 in the front face 75. The recesses 89 allow tools to engage the adapter 7 to aid in the assembly and / or disassembly of the hydrogen recirculation pump 1. Specifically, tools can engage the recesses to pry the adapter off the pump cover 9 and / or the motor housing 11. The recesses 89 are circumferentially discrete, meaning that the recesses 89 extend around a portion of the periphery of the flange 83. The recesses 89 extend in both radial and axial directions relative to the longitudinal axis 73. In other embodiments, a single recess 89 may be provided for tool engagement. In other embodiments, at least one recess 89 may be located in the annular wall 71 of the adapter 7 or in the rear face 77 of the adapter 7. The recesses 89 are spaced at equal angles around the longitudinal axis 73, which facilitates ease of tool engagement and allows for engagement of the adapter 7 using simple tools.

[0404] Furthermore, adapter 7 includes a recess 91. Recess 91 is a circumferentially extending annular recess, and recess 91 is configured to receive a sealing member (not shown). The sealing member provides a seal between adapter 7 and pump cover 9. The sealing member can be an annular seal, and particularly can be an O-ring seal. Providing a seal between adapter 7 and pump cover 9 helps to minimize fluid leakage, especially leakage of hydrogen from pump assembly 3.

[0405] Figure 7 A cross-sectional side view of a portion of the bearing assembly 33 in place within the pump assembly 3 is shown. The bearing assembly 33 includes a bearing housing 93, and a plurality of bearings 95 are housed within the bearing housing 93, which support the impeller 29 and the second coupling member 49 for rotation about a longitudinal axis 15. The bearing assembly 33 also includes two bearing assemblies 34, each bearing assembly having a fixed inner race 97 and an outer race 129. The fixed inner race 97 and the plug 31 do not rotate about the longitudinal axis 15. The outer race 129 is rotatable about the longitudinal axis 15.

[0406] Figure 8 A perspective view of the bearing housing 93 is shown, and Figure 9 A schematic cross-sectional side view of the bearing housing 93 is shown. The bearing housing 93 includes a body 99, which is a generally cylindrical wall. The body 99 defines a longitudinal axis 101, which coincides with a longitudinal axis 15 when the body 99 is positioned in the pump assembly 3. The body 99 is rotationally symmetric, which results in improved maintainability and improved dynamic balance. A plurality of bearings 95 are received in tracks 103 of a fixed inner race 97 and corresponding tracks of an outer race 129.

[0407] The bearing housing 93 also includes a connecting flange 107. This connecting flange 107 is an annular wall extending radially outward from the outer wall surface 109 of the body 99, and extends circumferentially around the outer wall surface 109. The connecting flange 107 includes a plurality of axially extending through holes 111 that allow a connector 113 to extend through the connecting flange 107, through corresponding through holes in the impeller 29, and be received in corresponding holes in the second connecting member 49. Thus, the connector 113 connects the bearing housing 93, the impeller 29, and the second connecting member 49 together. By connecting the bearing housing 93, the impeller 29, and the second connecting member 49 together, they can rotate together about the longitudinal axis 15. Therefore, the bearing housing 93 supports the impeller 29 and the second connecting member 49 to rotate about the longitudinal axis 15. The use of the connector 113 reduces the need for press-fitting the impeller 29 to the second connecting member 49 and / or the bearing housing 93. By avoiding pressure fitting of impeller 29, structural deformation and defects in impeller 29 are reduced.

[0408] The through holes 111 are distributed at equal angles around the longitudinal axis 101; however, in other embodiments, the through holes 111 may not be distributed at equal angles. In the depicted embodiment, the connecting flange 107 includes four through holes 111. In other embodiments, the number of through holes 111 may be different. Preferably, the connecting flange 107 has at least two through holes 111, and preferably, the number of through holes 111 is even. An even number of through holes 111 provides reflective symmetry. An even number of through holes helps to balance and maintain rotation of the connected components (i.e., impeller 29 and second connecting member 49). The through holes 111 extend axially relative to the longitudinal axis 101; however, in other embodiments, the through holes 111 may extend in a direction that includes both axial and radial components relative to the longitudinal axis 101. That is, the central axis of each through hole 111 may be angled relative to the longitudinal axis 101.

[0409] In other embodiments, the connecting flanges 107 may be circumferentially discrete, meaning that the connecting flanges do not extend around the entire periphery of the body 99, and the bearing housing 93 may include multiple connecting flanges 107. In other embodiments, the connecting flanges 107 may include one or more cutouts. Cutouts may be provided to save weight, and / or cutouts may be provided to help with the rotational balance of the bearing housing 93 (to distribute weight evenly), thereby reducing unwanted vibrations of the bearing assembly 33 during use.

[0410] like Figure 7 and Figure 9 Ideally, the connecting flange 107 is offset from the axial midpoint 115 of the body 99 along the longitudinal axis 101. The axial midpoint 115 is the midpoint between the farthest first end 117 on the body 99 along the longitudinal axis 101 and the farthest second end 119 opposite to the farthest first end 117. In other words, the connecting flange 107 is positioned toward the farthest first end 117 of the body 99. By offsetting the connecting flange 107 axially relative to the midpoint 115, deformation of the impeller 29 can be reduced when assembling the pump assembly 3. Other advantages of offsetting the connecting flange 107 axially include ensuring that the connecting flange 107 is installed in the pump assembly 3 with the correct orientation and facilitating dynamic balancing.

[0411] Attached to the connecting flange 107, the bearing housing 93 also includes an inner flange 121, which may be referred to as a shoulder. The inner flange 121 is an annular flange extending radially inward from the inner wall surface 105 toward the longitudinal axis 101. The inner flange 121 extends circumferentially around the axial midpoint 115 of the body 99 and is therefore axially spaced from the connecting flange 107. The inner flange 121 and the connecting flange 107 do not overlap axially, although they may overlap axially in other embodiments. In other embodiments, the inner flange 121 may extend circumferentially only around a portion of the body 99, the inner flange 121 may be axially offset from the midpoint 115, and in some embodiments, the inner flange 121 may be absent.

[0412] The inner flange 121 divides the central inner portion 123 of the main body 99. The inner portion 123 is a through-hole defined by the inner wall surface 105 of the main body 99. (Example...) Figure 4 and Figure 7 Ideally, the inner portion 123 is sized to accommodate two bearing assemblies 34 disposed on opposite sides of the inner flange 121. In other words, the inner flange 121 is positioned between the two bearing assemblies 34 such that the bearing assemblies 34 are axially spaced apart. Therefore, the body 99 includes a first cavity 131 for accommodating the first bearing assembly and a second cavity 133 for accommodating the second bearing assembly. The first cavity 131 is partially defined by the inner wall surface 105 of the body 99 and a first surface 135 of the inner flange 121. Similarly, the second cavity 133 is partially defined by the inner wall surface 105 of the body 99 and a second surface 137 of the inner flange 121, wherein the second surface 137 is opposite to the first surface 135. Providing the inner flange 121 restricts the axial movement of the bearing assemblies 34 and improves the reliability of the bearing assembly 33.

[0413] Bearings of the same type are disposed in the first cavity 131 and the second cavity 133. However, in other embodiments, different bearings (balls, rollers, etc.) may be disposed in different first cavities 131 and second cavities 133. In some embodiments, one of the first cavities 131 and the second cavity 133 may be redundant, that is, only one cavity may include a bearing assembly and a bearing 95. Furthermore, as mentioned above, in some embodiments, the inner flange 121 may not be present; when the inner flange 121 is absent, the bearing assembly 33 may be provided with a single bearing assembly, wherein a single type of bearing 95 is disposed.

[0414] Figure 10 A cross-sectional end view of the pump cover 9 is shown, and Figure 11 A sectional side view of the pump cover 9 is shown. As described above, the pump cover 9 defines an impeller chamber 27 for receiving the impeller 29. For the sake of brevity, the features of the pump cover 9 already described are not described here, but the same reference numerals are used. Features of the pump cover 9 not described above and... Figures 1 to 6 Features that cannot be seen in the text.

[0415] As mentioned above and now in Figure 10 and Figure 11 As can be seen, the pump cover 9 includes an inlet opening 139, an outlet opening 141, and a side passage 143 in fluid communication with the inlet opening 139 and the outlet opening 141. The inlet opening 139 is an opening in the end wall 25 configured to receive gas (typically hydrogen, or a mixture of hydrogen and other gases, such as air) from a manifold cap (not shown). By providing the inlet opening 139 in the end wall, backflow of fluid is mitigated, and icing at the inlet opening 139 is reduced, thereby allowing the hydrogen recirculation pump to operate effectively in cold environments. The outlet opening 141 is also an opening, but it is located in the annular side wall 23. In other embodiments, the outlet opening 141 may be located in the end wall 25. The outlet opening 141 allows gas that has been compressed by the impeller 29 in the pump assembly 3 to exit the pump assembly 3. An outlet passage 142, extending generally radially relative to the longitudinal axis 15, extends from the outlet opening 141 and is defined by an annular wall 145 extending generally radially relative to the longitudinal axis 15, which is integrally formed with the pump cover 9. The outer surface of the radially extending annular wall 145 includes a plurality of grooves 147. These grooves 147 can provide means of connection to downstream passages, pipes, ejectors, or any other suitable system, and / or the grooves 147 can be configured to accommodate one or more sealing elements to mitigate leakage when the radially extending annular wall 145 is connected to a downstream passage. In other embodiments, only a single groove 147 may be present, or no grooves may be present. Other arrangements excluding the radially extending annular wall 145 may be provided.

[0416] Side passage 143 is concave. That is, side passage 143 has a generally semi-circular cross-sectional profile. Side passage 143 extends axially into end wall 25. Side passage 143 provides fluid communication between inlet opening 139 and outlet opening 141, and extends circumferentially from inlet opening 139 to outlet opening 141. When hydrogen recirculation pump 1 is in use, rotation of impeller 29 causes gas delivered to pump assembly 3 through inlet opening 139 to be compressed and driven toward outlet opening 141.

[0417] The inlet opening 139 and the outlet opening 141 are circumferentially spaced apart and separated by a tongue 149. The tongue 149 extends axially relative to the longitudinal axis 15 and radially between the annular sidewall 23 and the support region 32. Therefore, the tongue 149 facilitates gas flow between the inlet opening 139 and the outlet opening 141 via the side channel 143. In other embodiments, the tongue 149 may be omitted.

[0418] The impeller chamber 27 includes a support region 32. The support region 32 is disposed radially inside the annular sidewall 23 and has a center coinciding with the longitudinal axis 15. The support region 32 is configured to receive a plug 31, around which a bearing assembly 33 is disposed. In addition to receiving the plug 31, the support region 32 also defines a portion of a side passage 143. The support region 32 includes a support wall 151 extending generally axially and circumferentially, which defines a portion of the side passage 143.

[0419] Furthermore, a main diameter 153 is defined at the farthest end 155 of the annular sidewall 23 relative to the end wall 25 of the pump cover 9. The main diameter 153 is the distance between the radially inner wall surfaces 157 of the annular sidewall 23, extending through the longitudinal axis 15 at the farthest end 155 of the annular sidewall 23. The impeller chamber 27 includes a first stepped portion 159 defined by the annular sidewall 23. The first stepped portion 159 is a region of the pump cover 9 having a first stepped diameter 161, wherein the first stepped diameter 161 is smaller than the main diameter 153. The first stepped diameter 161 is the distance extending through the longitudinal axis 15 at the first stepped portion 159 between the radially inner wall surfaces 157 of the annular sidewall 23. That is, the diameter of the pump cover 9, measured between the radially inner wall surfaces 157 of the annular sidewall 23, varies along the axial length of the pump cover 9. In other words, the pump cover 9 has a region with a first main diameter at the farthest end 155 and an adjacent region with a second diameter. The diameter change between the region defining the main diameter 153 and the region defining the first step diameter 161 is a sudden, step-like change in diameter. In other embodiments, the diameter change from the main diameter 153 to the first step diameter 161 can be gradual along the axial length. Providing an adjacent region with the main diameter 153 and the first step diameter 161 facilitates the alignment of the impeller 29 when assembling the pump assembly 3. The portion of the pump cover 9 with the main diameter 153 serves as a guide surface for placing the impeller 29 in the impeller chamber 27.

[0420] The impeller chamber 27 also includes a second stepped portion 163 defined by the inner wall surface 157 of the annular sidewall 23. The second stepped portion 163 is adjacent to the first stepped portion 159 and axially spaced from the farthest end of the annular sidewall 23. That is, the first stepped portion 159 is located between the farthest end 155 of the annular sidewall 23 and the second stepped portion 163. The second stepped portion 163 is the region of the pump cover 9 having a second stepped diameter 165, which is smaller than the main diameter 153 and smaller than the first stepped diameter 161. The second stepped diameter 165 is the distance extending through the longitudinal axis 15 between the radially inner wall surfaces 157 of the annular sidewall 23 at the second stepped portion 163. That is, the diameter of the pump cover 9, measured between the radially inner wall surfaces 157 of the annular sidewall 23, further varies along the axial length of the pump cover 9. The change in diameter between the first stepped portion 159 and the second stepped portion 163 is a sudden, step-like change in diameter. In other embodiments, the diameter variation from the first stepped portion 159 to the second stepped portion 163 can be gradually varied along the axial length. Providing a region with the second stepped portion 163 reduces leakage from the side passage 143 because there is a small radial clearance between the outermost radial region of the impeller 29 and the inner wall surface 157 of the annular sidewall 23.

[0421] In use, the hydrogen recirculation pump 1 is oriented such that the outlet opening 141 is oriented to allow liquids or condensates, such as those formed by melting ice, to be discharged under gravity and through the outlet opening 141. In other words, the outlet opening 141 in use is located in the lowest region of the hydrogen recirculation pump 1 (relative to the direction of gravity). The outlet opening 141, located in the lowest region, also reduces the accumulation of liquid in other locations within the pump assembly 3. The pump cover 9 may also be provided with additional liquid discharge openings and channels to allow liquid to flow from the impeller chamber 27 to an area outside the pump cover 9. The liquid discharge opening may be in fluid communication with the adapter's discharge channel 79. The liquid discharge channel may extend through the tongue 149 to allow liquid to flow from the area near the inlet opening 139 to the outlet opening 141. The dimensions of the liquid discharge channel may be configured such that the liquid discharge channel does not obstruct the flow of fluid through the side channel 143 when the pump assembly 3 is in use. Furthermore, the adapter's discharge channel 79 may be in fluid communication with the outlet opening 141.

[0422] The pump cover 9 also includes at least one flange 167 adjacent to the end wall 25 and located radially outward of the annular sidewall 23. The flange 167 provides an interface for mounting the pump cover 9. Specifically, the flange 167 allows the pump cover 9 to be mounted to a manifold cap. The flange 167 also allows the pump cover 9 to be mounted to a suitable support structure. The flange 167 includes a plurality of axially extending through holes 169. The through holes 169 allow a connector to extend through the flange 167 and secure the flange 167 to the manifold cap. The connector may include threaded screws or bolts. In other embodiments, the pump cover 9 may be secured to the manifold cap or support structure by other means (such as clamps), and in these cases, the flange 167 may be omitted. Figure 10 In the illustrated embodiment, the pump cover includes two flanges 167, each flange having two through holes 169. It should be understood that in other embodiments, the pump cover 9 may include any desired number of flanges 167 and through holes 169.

[0423] Figure 12 and Figure 13 A first alternative pump cover 171 that can be used with the hydrogen recirculation pump 1 is depicted. Specifically, Figure 12 A perspective view of the first alternative pump cover 171 is shown, and Figure 13 An end view of pump cover 171 is shown. Features identical to those in pump cover 9 in the first alternative pump cover 171 are provided with the same reference numerals. Only the differences between pump covers 9 and 171 are described.

[0424] The first alternative pump cover 171 differs from pump cover 9 in that it includes a baffle element 173 in the side channel 143. The baffle element 173 extends axially relative to the longitudinal axis 15. The baffle element 173 includes a first rib 175 extending circumferentially and radially toward the longitudinal axis 15 from the inner wall surface 157 of the annular sidewall 23. The baffle element 173 also includes a second rib 177 extending circumferentially and circumferentially away from the longitudinal axis 15 from the support wall 151 of the impeller support region 32. The first rib 175 has an end 179 opposite to the end 181 of the second rib 177. Because the first rib 175 and the second rib 177 are located in the side channel 143, they form a flow constraint. That is, the first rib 175 and the second rib 177 impede fluid flow through the side channel 143. Specifically, fluid is allowed to flow through a gap 183 defined between the end 179 of the first rib 175 and the end 181 of the second rib 177. The baffle element 173 improves the efficiency of the pump assembly 3 by restricting the backflow of gas in the side passage after pressure has accumulated in the impeller chamber 27. Figure 12 and Figure 13In the illustrated embodiment, the baffle element 173 is generally aligned or in line with the radially extending outlet channel 142. That is, the central axis 144 through the outlet channel 142 extends through the baffle element 173. In other embodiments, the baffle element 173 may be positioned at any preferred location in the side channel 143 such that the baffle element 173 is not aligned or in line with the outlet channel 142. In some embodiments, the pump cover 9 may include a plurality of baffle elements 173. The plurality of baffle elements 173 may be spaced apart in the side channel 143.

[0425] The baffle element 173 also includes an axially extending intermediate wall portion 185 connecting the first rib 175 and the second rib 177, and the intermediate wall portion 185 defines at least a portion of the flow constraint portion. The first rib 175, the second rib 177, and the intermediate wall portion 185 are integrally formed with the pump cover 9. In particular, the first rib 175, the second rib 177, and the intermediate wall portion 185 may be integrally formed with the end wall 25 and / or the annular sidewall 23. In other embodiments, the first rib 175, the second rib 177, and the intermediate wall portion 185 may be removable inserts.

[0426] Baffle element 173 extends along baffle axis 187, and baffle axis 187 lies in a first plane perpendicular to longitudinal axis 15. Intermediate wall portion 185 has an arcuate profile in a second plane perpendicular to the first plane. This... Figure 12 As can be best seen in the image, the intermediate wall portion 185 has an arcuate or semi-circular profile between the respective ends 179 and 181 of the first rib 175 and the second rib 177. In other words, the intermediate wall portion 185 has an arcuate profile in a plane perpendicular to the direction of the main fluid flow through the flow constraint portion when in use.

[0427] The first rib 175 and the second rib 177 extend axially over the entire height of the side channel 143. That is, the first rib 175 and the second rib 177 extend axially from the base of the side channel near the end wall 25 to the second stepped portion 163. Conversely, the intermediate wall portion 185 does not extend axially over the entire height of the side channel 143. It should be understood that if the intermediate wall portion 185 extends over the entire axial height of the side channel 143, it would substantially prevent fluid flow through the side channel 143, which is undesirable. In other embodiments, the first rib 175 and / or the second rib 177 may not extend over the entire axial height of the side channel 143. For example, the first rib 175 and / or the second rib 177 may extend axially over approximately 50% of the axial height of the side channel 143.

[0428] As described above, the baffle axis 187 lies in a first plane perpendicular to the longitudinal axis 15. A nominal axis 189 extends radially relative to the longitudinal axis 15 from a point 191 on the support wall 151 within this first plane, and a second rib 177 extends from this point 191. The angle 193 between the baffle axis 187 and the nominal axis 189 is between approximately 15 degrees and approximately 30 degrees. Providing an angle 193 within this range can improve the efficiency of the pump assembly.

[0429] In some embodiments, baffle element 173 may not include the intermediate wall portion 185 or the second rib 177. In embodiments where baffle element 173 does not include the second rib 177, the nominal axis 189 extends from the point where the baffle axis 187 on the support wall 151 intersects with the support wall 151. Pump covers 9, 171 may include a plurality of baffle elements 173. Baffle elements 173 may be circumferentially spaced around the side passage 143.

[0430] Figure 14 An end view of a second alternative pump cover 191 for use in a hydrogen recirculation pump 1 is shown. The second alternative pump cover 191 also includes a baffle element 1931 for constraining flow through the side channel 143. The second alternative pump cover 191 differs from the first alternative pump cover 171 only in that the baffle axis 195 in a first plane perpendicular to the longitudinal axis 15 is a curved axis. That is, the baffle axis 195 follows an arcuate path. Therefore, a tangent 197 of the baffle axis 195 is obtained at the midpoint 199 of the baffle axis 195 in the first plane. A nominal axis 201 extends in the first plane from a point 203 on the support wall 151 in a radial direction relative to the longitudinal axis 15, from which a second rib 177 extends. The angle 205 between the baffle tangent 197 and the nominal axis 201 is between approximately 15 degrees and approximately 30 degrees. In some embodiments, the pump cover 9 may include a plurality of baffle elements 1931. The multiple baffle elements 1931 can be spaced apart in the side channel 143.

[0431] It should be understood that the pump cover 9 may be configured to include a baffle element 173 of a first alternative pump cover 171 and / or a baffle element 1931 of a second alternative pump cover 191.

[0432] Figure 15 An end view of a third alternative pump cover 207 for use in the hydrogen recirculation pump 1 is shown. The third alternative pump cover 207 also includes a baffle element 209. The baffle element 209 and Figures 12 to 14The difference between baffle elements 173 and 1931 is that baffle element 209 includes a plurality of circumferentially spaced, axially extending deflection ribs 211. The deflection ribs 211 have a generally rectangular cross-sectional profile in a plane perpendicular to the longitudinal axis 15, and the deflection ribs 211 can have any suitable cross-sectional shape. The deflection ribs 211 extend in both radial and circumferential directions. Thus, each deflection rib includes a deflection rib axis 215. The deflection rib axis 215, located in a first plane perpendicular to the longitudinal axis 15, is at an angle (i.e., not parallel or perpendicular) to a nominal axis 217, which is an axis in the first plane extending from a point on the support wall 151 along the entire radial direction relative to the longitudinal axis 15 and passing through the centroid of the corresponding deflection rib 211. The angle 219 between the deflection rib axis 215 and the nominal axis 217 is between approximately 15 degrees and approximately 30 degrees. Each deflection rib 211 has the same corresponding angle 219, but in other embodiments, at least the deflection ribs 211 may have different angles 219.

[0433] Deflecting ribs 211 are circumferentially spaced along a centerline 213, which extends along the wall of the side passage and through the centroid of each deflecting rib 211. In some embodiments, the centerline 213 may be the centerline of the side passage 143. The centerline 213 of the side passage 143 is a line extending along the base of the side passage 143 and equidistant from the support wall 151 and the annular sidewall 23. The deflecting ribs 211 are circumferentially spaced along the centerline 213, with the respective centroid of each deflecting rib 211 located on the centerline 213. In other embodiments, at least one deflecting rib of the deflecting ribs 211 may be located radially inward of the centerline 213. In other embodiments, at least one deflecting rib of the deflecting ribs 211 may be located radially outward of the centerline 213.

[0434] Similar to baffle elements 173 and 1931, the presence of deflection ribs 211 creates flow constraints in the side channel 143. Because deflection ribs 211 do not span the entire radial width of the side channel 143 (i.e., from the support wall 151 to the annular sidewall 23), at least one deflection rib of the deflection ribs 211 can extend over the entire axial height of the side channel 143. In other embodiments, at least one deflection rib of the deflection ribs 211 may not extend over the entire axial height of the side channel 143. In some embodiments, baffle element 209 may include a single deflection rib 211.

[0435] It should be understood that the pump cover 9 may be configured to include a baffle element 173 of a first alternative pump cover 171, and / or a baffle element 1931 of a second alternative pump cover 191, and / or a baffle element 209 including at least one deflection rib 211.

[0436] Figure 16 A front perspective view of impeller 29 is shown; Figure 17 A rear perspective view of impeller 29 is shown; Figure 18 A sectional side view of the impeller 29 is shown; Figure 19 A partial sectional side view of the impeller 29 and pump cover 9 in impeller chamber 27 is schematically shown; and Figure 20 A schematic front view of the impeller 29 is shown.

[0437] Impeller 29 includes impeller body 221. Impeller body 221 includes a generally disc-shaped rear cover 223 defining a central axis 225. When impeller 29 is disposed in impeller chamber 27, the central axis 225 coincides with the longitudinal axis 15 of hydrogen recirculation pump 1.

[0438] When cut in a plane parallel to the central axis 225, the rear cover 223 has a generally arc-shaped profile (e.g., Figure 17 , Figure 18 and Figure 19 (Best viewed). Therefore, the back cover 223 has a concave surface 227 and an opposite convex surface 229.

[0439] The impeller body 221 also includes a generally disc-shaped central connecting plate 231. The central connecting plate 231 is located radially inside the rear cover 223 relative to the central axis 225. The central connecting plate 231 is integrally formed with the rear cover 223, but in other embodiments, the central connecting plate 231 and the rear cover 223 may be joined together (e.g., by welding). The central connecting plate 231 allows the impeller to be mounted to the second connecting member 49.

[0440] The central connecting plate 231 includes a central through-hole 233 having a center that coincides with the central axis 225. The central through-hole 233 is sized to accommodate a portion of the bearing assembly 33 and the plug 31 (e.g., Figure 4 (As can be seen). The central connecting plate 231 also includes a plurality of fastening connection through holes 235. The fastening connection through holes 235 are located radially outside the central through hole 233 and are configured to receive the connector 113. In use, the connector 113 extends through its respective fastening through hole 235 and is then received in a corresponding hole in the second connecting member 49. The fastening through holes 235 are angularly spaced around the central axis 225 and are of the same size and located on the same radius from the central axis 225. In other embodiments, only a single fastening through hole 235 may be provided, and in other embodiments, the fastening through hole 235 may be located on different radii relative to the central axis 225, and its size (diameter) may vary.

[0441] Therefore, in use, the first surface 237 of the central connecting plate 231 abuts against the end of the magnetic second connecting member 49, and the first surface 237 of the central connecting plate 231 and the convex surface 229 of the rear cover 223 are located on the same side of the impeller body 221. The first surface 237 is held against the magnetic second connecting member 49 by the connector 113.

[0442] Multiple axially extending blades 239 are disposed on the concave surface 227 of the rear cover 223. Each of the multiple blades 239 extends from the central connecting plate toward the outermost portion 241 of the rear cover 223 in both radial and circumferential directions relative to the central axis 225. Each blade 239 is an inclined blade, which improves the efficiency of the impeller 29. Furthermore, each blade 239 is a backswept blade, meaning that each blade 239 is swept backward from the central axis 225 relative to the radial direction. The backswept blade provides an improved mass flow rate through the pump assembly. Backswept means that the blade 239 is swept backward in the direction opposite to the rotation direction 243 of the impeller during operation; in other words, the inclination direction of the blades 239 of the impeller is opposite to the rotation direction of the impeller during operation. The blades 239 may have varying blade angles, or the blades 239 may have approximately constant blade angles. Each of the plurality of blades 239 defines a leading edge 245, and each leading edge 245 defines a blade tilt angle 247 that is tilted relative to the radial direction 249 originating from the central axis 225 in a negative angular direction relative to the rotational direction 243 of the impeller during use. The blade tilt angle can be between approximately 10 degrees and approximately 30 degrees, preferably approximately 20 degrees. The blade tilt angle 247 can be substantially constant for all points on the leading edge 245. However, in other embodiments, all points on the leading edge 245 can define local blade tilt angles relative to the radial direction 249, and wherein all local blade tilt angles on the leading edge can be tilted in a negative angular direction relative to the radial direction by approximately 10 degrees to approximately 30 degrees, preferably all local blade tilt angles by approximately 20 degrees. Although tilted swept blades 239 are depicted, it should be understood that the blades 239 can have any suitable design. The impeller 29 may include between approximately 30 and approximately 50 blades 239. It should be understood that the number of blades can vary depending on the size (diameter) of the impeller 29.

[0443] The outermost radial portion 241 of the rear cover 223 of the impeller body 221 also includes an outwardly facing and axially extending protrusion 251. That is, the rear cover 223 includes a protrusion 251 relative to the central axis 225 extending from... Figure 19The raised portion 251, indicated by the dashed line 252, extends axially outwards along its nominal profile. In other words, the raised portion 251 does not follow the arcuate profile of the rear cover 223. "Outwards" means that the raised portion 251 extends in a direction away from the concave surface 227 of the rear cover 223. The raised portion 251 extends circumferentially around the radially outermost portion 241 of the rear cover 223. The raised portion 251 is beneficial because it increases the axial length of the leakage path 253 and reduces the radial leakage gap between the impeller 29 and the pump cover 9 in the area adjacent to the convex surface 229 of the rear cover 223 from the side passage 143 to the pump assembly 3. In other words, the raised portion 251 causes the impeller 29 to have a profile resembling the number "7" or a roughly inverted capital letter "L" in a plane parallel to the longitudinal axis 15. This contrasts with the arcuate profile indicated by the dashed line 252 in the absence of the raised portion 251. Therefore, the protrusion 251 can be considered to form a seal with the pump cover 9. That is, the protrusion 251 does not prevent all leakage from the side passage 143, but including the protrusion 251 reduces fluid leakage from the side passage 143. In some embodiments, the protrusion may not extend circumferentially around the entire outermost radial portion 241 of the rear cover 223. Providing the protrusion 251 to the impeller 29 helps to create a localized high back pressure zone, reducing internal leakage and reducing airflow towards the rear of the impeller 29.

[0444] Figure 21 A partial sectional side view of another impeller 255 is shown. Impeller 255 and Figures 16 to 20 The impeller 29 differs only in that the outermost radial portion 241 of the rear cover 223 includes two circumferentially extending grooves 257. In other embodiments, a single circumferentially extending groove 257 may be provided. The circumferentially extending groove 257 serves to provide a labyrinthine seal, thereby further reducing fluid leakage along the leakage path 253. The circumferentially extending groove 257 causes localized flow disturbances (turbulence), which can substantially prevent fluid flow along the leakage path 253 in the generally axial direction. Reducing leakage along the leakage path 253 improves the efficiency of impellers 29, 255.

[0445] Impellers 29 and 255 can be formed of aluminum or stainless steel, as these materials are less susceptible to hydrogen-induced embrittlement. Impellers 29 and 255 can be further processed, for example by using shot peening, and / or by adjusting the material properties of the stainless steel, such as by selecting low-carbon stainless steel or adding titanium, to mitigate hydrogen embrittlement and reduce failures of impellers 29 and 255.

[0446] Figure 22 A perspective view of the second connecting member 49 of the magnetic coupling device 41 is shown, and Figure 23 A schematic cross-sectional side view of the magnetic second connecting member 49 is shown.

[0447] As described above, the magnetic second connecting member 49 includes a second connecting body 51. The second connecting body 51 includes a connecting portion 259 and a magnet holding portion 261. A plurality of permanent magnets 262 are housed in the magnet holding portion 261. In other embodiments, a single permanent magnet 262 may be housed in the magnet holding portion 261. The single permanent magnet 262 may have an annular profile in a plane perpendicular to the central axis 265. Providing multiple permanent magnets 262 is advantageous because multiple magnets can be magnetized more quickly than a single, larger magnet, thereby reducing manufacturing time.

[0448] The second connecting body 51 is a generally cylindrical body defining a central axis 265. The second connecting body 51 is formed of a magnetically conductive material. When the second connecting member 49 is located in the pump assembly 3, the central axis 265 coincides with the longitudinal axis 15. The second connecting body 51 also includes an axially extending through-hole 267 that extends through the entire axial length of the second connecting body 51 and has a center that coincides with the central axis 265. The through-hole 267 defines at least a portion of the connecting portion 259. At a first end 269 of the second connecting body 51, away from the magnet holding portion 261, the through-hole 267 defines a first diameter 271. The first diameter 271 of the through-hole 267 is constant along the axial length of the connecting portion 259. The diameter of the through-hole 267 varies at the magnet holding portion 261, and the through-hole 267 defines a second diameter 273. The second diameter 273 is constant along the remaining axial length of the through hole 267 to the second end 275 of the second connecting body 51, where the second end 275 is opposite to the first end 269. The second diameter 273 is smaller than the first diameter 271. A portion of the bearing assembly 33 is received in the connecting portion 259 having the first diameter 271, and a portion of the plug 31 is received in the portion of the through hole 267 having the first diameter 271 and the second diameter 273. The wall defining the through hole 267 of the second connecting body 51 can form an interference fit with the bearing assembly 33. By making the second diameter 273 smaller than the first diameter 271, the cross-sectional area of ​​the magnet holding portion 261 is increased, thereby increasing the surface area of ​​the permanent magnet 262 disposed in the magnet holding portion 261. Increasing the surface area of ​​the magnet holding portion 261, and thus increasing the surface area of ​​the permanent magnet 262, facilitates providing a robust connection between the second connecting member 49 and the first connecting member 43 of the magnetic connecting device 41. To further increase the cross-sectional area of ​​the magnet holding portion 261, the second end 275 of the second connecting body 51 includes a flange 277 extending radially and circumferentially. In other embodiments, the second connecting body 51 may not include the flange 277.

[0449] The second connecting body 51 includes an annular recess extending axially from the second end 275 toward the connecting portion 259 of the second connecting body 51. The annular recess defines a magnet holding portion 261, and a plurality of permanent magnets 262 are accommodated in the annular recess. To further retain the permanent magnets 262 in the magnet holding portion 261, an adhesive is provided between the permanent magnets 262 and the magnet holding portion 261 of the second connecting body 51.

[0450] like Figure 22 Ideally, multiple permanent magnets 262 are spaced at equal angles around a central axis 265. That is, multiple permanent magnets 262 are arranged circumferentially at equal intervals around the central axis 265. A constant gap 281 is provided between adjacent permanent magnets 262. The gap 281 is between approximately 0 mm and approximately 1 mm, and can be between approximately 0.1 mm and approximately 1 mm, and can be approximately 0.5 mm.

[0451] The connecting portion 259 includes a plurality of axially extending fastening holes 263 configured to receive a connector 113 for connecting the bearing assembly 33 and the impeller 29 to the second connecting member 49. The fastening holes 263 extend axially from a first end 269 of the second connecting body 51 toward the magnet retaining portion 261. The fastening holes 263 may include threaded walls configured to engage with corresponding threads on the connector 113 (e.g., a screw or bolt). In other embodiments, the fastening holes 263 may be omitted, and the connecting members may connect the impeller 29 and / or the bearing assembly 33 by other means. For example, in other embodiments, the second connecting member 49 may be integrally formed with the impeller 29, or the second connecting member 49 and the impeller 29 may be connected by an interference fit.

[0452] Except that the first connecting member 43 does not include the fastening hole 263, the first connecting member 43 is identical to the second connecting member 49. Instead, the rotor 37 of the motor 35, which serves as the drive shaft, is directly mounted to the radial inner wall of a portion of the defining through hole 267 of the connecting portion 259. Thus, the first connecting member 43 and the second connecting member 49 are connected to their respective rotatable bodies (i.e., the rotor 37 and the impeller 29).

[0453] Figure 24 A perspective view of a different second connecting member 349 of the magnetic connecting device 41 is shown. Figure 25 It shows Figure 24 A schematic sectional side view of the connecting components; and Figure 26 It shows Figure 25 A schematic cross-sectional side view of the second connecting member 349 rotated 45 degrees. Figure 22 and Figure 23 The second connecting member 49 is the same as that in the middle. Figures 24 to 26 The second connecting member 349 shown includes a second connecting body 51 having a connecting portion 259 and a magnet holding portion 261. Therefore, Figures 24 to 26 The second connecting member 349 in the previous one Figure 22 and Figure 23 Features described and illustrated in the figures are provided with the same reference numerals. For ease of understanding, only the differences between the second connecting member 349 and the second connecting member 49 are described.

[0454] The second connecting member 349 differs in that the permanent magnet 262 is held in the magnet holding portion by a plurality of connectors 351. The connectors 351 extend through the permanent magnet 262 and are received in corresponding holes 353 in the second connecting body 51. The holes 353 are axially extending holes 353, extending axially from the magnet holding portion 261 and into the connecting portion 259. The holes 353 may include threaded walls configured to engage with corresponding threads on the connectors 351. The holes 353 extend axially in the direction opposite to that of the fastening holes 263. That is, the holes 353 extend in a direction from the second end 275 toward the first end 269, and the fastening holes 263 extend axially in a direction from the first end 269 toward the second end 275. Both the holes 353 and the fastening holes 263 are blind holes; however, in some embodiments, at least one of the fastening holes 263 and the holes 353 may be axially extending through holes. In some embodiments, a single connector 351 can be used to hold the permanent magnet 262 in the magnet holding portion 261. The fastening holes 263 and 353 are circumferentially spaced apart. In the illustrated embodiment, the fastening holes 263 and 353 are angularly spaced apart about 45 degrees about the central axis 265. By offsetting the fastening holes 263 and 353 from each other, the fastening holes 263 and 353 can overlap axially. Therefore, the desired axial depth of the fastening holes 263 and 353 can be obtained without increasing the axial length of the second connecting body 51, and thus without increasing the weight and cost of the second connecting body 51.

[0455] exist Figures 24 to 26 In the diagram, the permanent magnet 262 is shown as a single permanent magnet 262, which has an annular profile in a plane perpendicular to the central axis 265. However, the second connecting member 349 may include multiple permanent magnets 262, such as... Figure 22 and Figure 23 As shown. Each of the plurality of permanent magnets 262 can be held in the magnet holding portion by at least one corresponding connector 351.

[0456] A magnetically conductive member 355 is axially disposed between the second connecting body 51 and the permanent magnet 262. The magnetically conductive member 355 may be made of silicon steel. The magnetically conductive member 355 is an annular sheet. The magnetically conductive member 355 can be of any suitable shape. Distributing the magnetically conductive member 355 between the permanent magnet 262 and the second connecting body 51 allows the second connecting body 51 to be made of a non-magnetically conductive material. By way of example, the second connecting body 51 may be made of a polymer such as polyetheretherketone (PEEK). Forming the second connecting body 51 from a non-magnetically conductive material can allow for reduced manufacturing time.

[0457] Except that the first connecting member does not include the fastening hole 263, the first connecting member, which together with the second connecting member 349 forms part of the magnetic connection device 41, can be aligned with the second connecting member 349. Conversely, the rotor 37 of the motor 35, which serves as the drive shaft, is directly mounted to the radial inner wall of a portion of the defining through hole 267 of the connecting portion 259. Thus, the first connecting member 43 and the second connecting member are connected to their respective rotatable bodies (i.e., the rotor 37 and the impeller 29).

[0458] Figure 27 A perspective view of a different second connecting member 449 of the magnetic connecting device 41 is shown. Figure 28 It shows Figure 27 A sectional side view of the connecting component. Figure 22 and Figure 23 The second connecting member 49 is the same as that in the middle. Figure 27 and Figure 28 The second connecting member 449 shown includes a second connecting body 51 having a connecting portion 259 and a magnet holding portion 261. Therefore, Figure 27 and Figure 28 The second connecting member 449 in the previous one Figure 22 and Figure 23 as well as Figures 24 to 26 Features that are identical to those described and illustrated are given the same reference numerals. For ease of understanding, only the differences between the second connecting member 449 and the second connecting members 49 and 349 are described.

[0459] The second connecting member 449 differs in that the permanent magnet 262 is held in the magnet holding portion by a first protrusion 451 extending radially relative to the central axis 265. Specifically, the radially extending first protrusion 451 is an annular protrusion extending around the periphery of the radially outer wall 453 of the second connecting body 51. The first protrusion 451 extends radially from the radially outer wall 453 toward the central axis 265. In other embodiments, the first protrusion 451 may be circumferentially discrete. That is, the first protrusion 451 may not extend around the entire periphery of the radially outer wall 453. The first protrusion 451 holds the permanent magnet 262 in the magnet holding portion 261 by restricting axial movement of the permanent magnet 262 relative to the central axis 265.

[0460] The permanent magnet 262 includes a radially extending recess 455 complementary to a radially extending first protrusion 451. The radially extending first protrusion 451 is received in the recess 455 of the permanent magnet 262 and abuts against an axially facing, radially extending surface 457 of the permanent magnet 262, the surface 457 defining at least a portion of the recess 455. The first protrusion 451 abuts against the surface 457 of the permanent magnet 262, restricting axial movement of the permanent magnet 262 and retaining the permanent magnet 262 in a magnet holding portion 261. The recess 455 of the permanent magnet 262 has a profile complementary to the first protrusion 451.

[0461] The magnet holding portion 261 also includes a second protrusion 459. Like the first protrusion 451, the second protrusion 459 is a protrusion extending radially relative to the central axis 265. Specifically, the radially extending second protrusion 459 is an annular protrusion extending around the periphery of a radially inner wall 461 defining a portion of the through-hole 267 of the second connecting body 51 within the magnet holding portion 261. The second protrusion 459 extends radially away from the central axis 265 from the radially inner wall 461. In other embodiments, the second protrusion 459 may not extend around the entire periphery of the radially inner wall 461. That is, the second protrusion 459 may extend around a portion of the periphery of the radially inner wall 461. The second protrusion 459 retains the permanent magnet 262 in the magnet holding portion 261 by restricting axial movement of the permanent magnet 262 relative to the central axis 265. The second protrusion 459 can be formed by bending or stamping a portion of the radially inner wall 461.

[0462] The permanent magnet 262 includes an additional radially extending recess 463 complementary to the radially extending second protrusion 459. The radially extending second protrusion 459 is received in the additional recess 463 of the permanent magnet 262 and abuts against an axially facing, radially extending surface 465 of the permanent magnet 262, which defines at least a portion of the recess 463. The second protrusion 459 abuts against the surface 465 of the permanent magnet 262, restricting axial movement of the permanent magnet 262 and retaining the magnet in a magnet holding portion 261. The recess 463 of the permanent magnet 262 has a shape complementary to the second protrusion 459.

[0463] In some embodiments, the magnet holding portion 261 may include only one of the first protrusion 451 and the second protrusion 459. Similarly, the permanent magnet 262 may include only one recess 455, 463 that is complementary to the first protrusion 451 and the second protrusion 459. Likewise, the first protrusion 451, the second protrusion 459, and the recesses 455, 463 may be of any suitable shape.

[0464] and Figures 24 to 26 Similar to the second connecting member 349 shown, the second connecting member 449 includes a magnetically conductive member 467 disposed axially between the second connecting body 51 and the permanent magnet 262. The magnetically conductive member 467 may be made of silicon steel. The magnetically conductive member 467 is a generally annular sheet. That is, the magnetically conductive member 467 has a generally annular profile in a plane perpendicular to the central axis 265. The magnetically conductive member 467 is similar to... Figures 24 to 26 The difference in the magnetic conductor 355 is that the magnetic conductor 467 includes a radially extending recess 469. The magnet holding portion 261 also includes a radially extending protrusion 471 that is complementary to the recess 469 of the magnetic conductor 467. The radially extending protrusion 471 is received in the corresponding recess 469 of the magnetic conductor 467.

[0465] The magnetically conductive member 467 has a profile in a plane parallel to the central axis 265 that corresponds to the profile of the permanent magnet 262. That is, if the permanent magnet 262 includes a first recess, then the magnetically conductive member 467 also includes a first recess. The recesses of the permanent magnet 262 and the magnetically conductive member 467 have the same radial-axial length. However, the recess of the permanent magnet 262 may have a different axial length than the corresponding recess of the magnetically conductive member 467. Similarly, if the permanent magnet 262 has a second recess, then the magnetically conductive member 467 will have a corresponding second recess. In other words, when in the magnet holding portion 261, the magnetically conductive member 467 and the permanent magnet 262 are rotationally symmetrical about the axis 473 of the magnet holding portion 261, which is parallel to the central axis 265. In other embodiments, when in the magnet holding portion 261, the magnetic conductor 467 and the permanent magnet 262 may not be rotationally symmetrical about the axis 473 of the magnet holding portion 261, wherein the axis 473 is parallel to the central axis 265.

[0466] The magnetically conductive member 467 can be of any suitable shape. The axial arrangement of the magnetically conductive member 467 between the permanent magnet 262 and the second coupling body 51 allows the second coupling body 51 to be made of a non-magnetically conductive material. By way of example, the second coupling body 51 can be made of a polymer such as polyetheretherketone (PEEK).

[0467] The through-hole 267 of the second connecting member 449 has a constant diameter along its axial length. In other embodiments, the through-hole 267 may have a variable diameter, such as... Figures 22 to 26 The second connecting members 49 and 349 are shown in the diagram. Furthermore, although in... Figure 27 and Figure 28 The image shows a single permanent magnet 262, but multiple permanent magnets 262 can also be provided, such as... Figure 22 and Figure 23 As shown. When multiple permanent magnets 262 are provided in the magnet holding portion 261, the radially extending first protrusion 451 and second protrusion 459 are configured to restrict axial movement at least in the permanent magnets 262.

[0468] Except that the first connecting member does not include the fastening hole 263, the first connecting member, which together forms part of the magnetic connection device with the second connecting member 449, can be aligned with the second connecting member 449. Conversely, the rotor 37 of the motor 35, which serves as the drive shaft, is directly mounted to the radial inner wall 461 of a portion of the defining through hole 267 of the connecting portion 259. Therefore, the first connecting member 43 and the second connecting member are connected to their respective rotatable bodies (i.e., the rotor 37 and the impeller 29).

[0469] It should be understood that the first connecting member and the second connecting member may include Figures 22 to 28The combination of features of the connecting components described herein. By way of example, through the use of, for example... Figures 24 to 26 The connector 351 shown and as Figure 27 and Figure 28 The combination of the radially extending first protrusion 451 and second protrusion 459 shown can retain the permanent magnet 262 in the magnet holding portion 261. Similarly, the permanent magnet 262 can be retained in the second connecting members 349, 449 using an adhesive as used in the second connecting member 49. In some embodiments, it is also possible for the first connecting member 43 to include a fastening hole 263 to allow the first connecting member 43 to be connected to the rotor 37.

[0470] This disclosure may be further defined by the following numbered clauses:

[0471] 1. A bearing housing for a hydrogen recirculation pump, the bearing housing comprising:

[0472] The body is configured to house one or more bearings, said bearings being configured to support the impeller rotating about a longitudinal axis; and

[0473] A connecting flange configured to engage the impeller, the connecting flange surrounding the body and extending radially outward along the body;

[0474] The connecting flange is offset from the axial midpoint of the body along the longitudinal axis.

[0475] 2. The bearing housing for a hydrogen recirculation pump as described in Clause 1, wherein the connecting flange includes at least two through holes configured to receive a connector passing through the through holes, and wherein the at least two through holes are distributed at equal angles around the longitudinal axis.

[0476] 3. The bearing housing for a hydrogen recirculation pump as described in Clause 2, wherein the number of the through holes is even.

[0477] 4. The bearing housing for a hydrogen recirculation pump according to any of the preceding clauses, wherein the body comprises a cylindrical wall having a radial outer wall and a radial inner wall, and the connecting flange extends around the radial outer wall;

[0478] The bearing housing also includes an annular inner flange that extends radially inward from the radial inner wall surface.

[0479] 5. The bearing housing for a hydrogen recirculation pump as described in Clause 4, wherein the annular inner flange is located at the axial midpoint of the body.

[0480] 6. The bearing housing for a hydrogen recirculation pump as described in Clause 4 or 5, wherein the annular inner flange is axially spaced from the connecting flange.

[0481] 7. A bearing housing for a hydrogen recirculation pump according to any one of clauses 4 to 6, wherein the body defines a first cavity for receiving a first bearing, and the first cavity is at least partially defined by the annular inner flange.

[0482] 8. The bearing housing for a hydrogen recirculation pump according to Clause 7, wherein the body further defines a second cavity for receiving a second bearing, the second cavity being at least partially defined by the annular inner flange, wherein the first cavity and the second cavity are axially spaced apart, and the first cavity and the second cavity are separated by the annular inner flange.

[0483] 9. The bearing housing for a hydrogen recirculation pump according to any of the preceding clauses, wherein the body is rotationally symmetrical about the longitudinal axis.

[0484] 10. The bearing housing for a hydrogen recirculation pump according to any of the preceding clauses, wherein the connecting flange includes an annular wall.

[0485] 11. A hydrogen recirculation pump, the hydrogen recirculation pump comprising:

[0486] Pump assembly, the pump assembly comprising:

[0487] Pump cover, the pump cover defining an inlet and an outlet; and

[0488] An impeller, the impeller being located within a pump chamber at least partially defined by the pump cover;

[0489] A motor assembly comprising a motor housing and a motor, the motor being located within the motor housing and configured to drive the impeller to rotate about a longitudinal axis via a linkage.

[0490] An adapter disposed between the pump cover and the motor housing, the adapter being configured to connect to the motor housing and the pump cover, and providing an interface between the motor housing and the pump cover; and

[0491] A bearing housing, which is a bearing housing according to any of the preceding clauses, the bearing housing being disposed at least partially on the radially inner side of the adapter, and wherein the connecting flange engages with the impeller.

[0492] 12. An adapter for a hydrogen recirculation pump, wherein the adapter is configured to connect to a motor housing and a pump cover, and provides an interface between the motor housing and the pump cover;

[0493] The adapter defines a longitudinal axis, and the adapter includes:

[0494] The wall surrounding the longitudinal axis;

[0495] The wall has a front face for engaging with the pump cover and a rear face opposite the front face for engaging with the motor housing;

[0496] The wall includes a discharge channel configured to deliver liquid to the outlet channel of the pump cover.

[0497] 13. The adapter for a hydrogen recirculation pump as described in Clause 12, wherein the cross-sectional profile of the discharge channel is a groove.

[0498] 14. An adapter for a hydrogen recirculation pump as described in Clause 12 or 13, wherein, in use, the adapter is oriented to allow liquid to travel by gravity through the discharge passage to the outlet passage of the pump cover.

[0499] 15. An adapter for a hydrogen recirculation pump according to any one of clauses 12 to 14, the adapter further comprising a flange, wherein the flange is radially outside the wall relative to the longitudinal axis.

[0500] 16. An adapter for a hydrogen recirculation pump according to any one of clauses 12 to 15, the adapter further comprising at least one tool recess configured to engage a tool.

[0501] 17. An adapter for a hydrogen recirculation pump as described in Clause 16 when subject to Clause 15, wherein the at least one tool recess is provided in the flange.

[0502] 18. An adapter for a hydrogen recirculation pump according to any one of clauses 12 to 17, the adapter further comprising at least one through-hole configured to receive a connector for connecting the adapter to the pump cover and the motor housing.

[0503] 19. An adapter for a hydrogen recirculation pump as described in Clause 18 when it is subordinate to Clause 15 or any provision directly or indirectly subordinate to Clause 15, wherein the at least one through-hole extends through the flange.

[0504] 20. An adapter for a hydrogen recirculation pump as described in Clause 18 or 19, wherein the adapter includes a plurality of through holes configured to receive corresponding connectors for connecting the adapter to the pump cover and the motor housing.

[0505] 21. An adapter for a hydrogen recirculation pump according to any one of clauses 12 to 20, wherein the adapter includes a recess configured to receive a sealing member for sealing between the adapter and the pump cover.

[0506] 22. The adapter for a hydrogen recirculation pump as described in Clause 21, wherein the groove is an annular groove and the sealing member is an annular seal.

[0507] 23. The adapter according to Clause 22 when it is subordinate to Clause 15, wherein the annular groove is provided at the interface between the wall and the flange.

[0508] 24. A hydrogen recirculation pump, the hydrogen recirculation pump comprising:

[0509] Pump assembly;

[0510] Motor components; and

[0511] An adapter, which is an adapter for a hydrogen recirculation pump as described in any one of clauses 12 to 23, is connected to the motor assembly and the pump assembly and provides an interface between the motor assembly and the pump assembly.

[0512] 25. The hydrogen recirculation pump as described in Clause 24, wherein:

[0513] The pump assembly includes:

[0514] Pump cover, which defines the inlet and outlet; and

[0515] The impeller is located inside the pump cover;

[0516] The motor assembly includes:

[0517] Motor housing;

[0518] A motor, located within the motor housing, is configured to drive the impeller to rotate about the longitudinal axis of the pump assembly via a linkage; and

[0519] The adapter provides an interface between the motor housing and the pump cover.

[0520] 26. The hydrogen recirculation pump according to clause 24 or 25, wherein the front face of the adapter has a profile conforming to the adjacent face of the impeller, the conforming profile being perpendicular to the longitudinal axis.

[0521] 27. A pump cover for a hydrogen recirculation pump, the pump cover comprising:

[0522] The inlet channel is configured to accommodate the incoming fluid.

[0523] An impeller chamber, which is in fluid communication with the inlet passage, is configured to house an impeller for rotation about a longitudinal axis;

[0524] An outlet channel, which is in fluid communication with the impeller chamber;

[0525] End wall, which defines at least a portion of the impeller chamber; and

[0526] A sidewall that extends axially from the endwall, the sidewall defining at least a portion of the outlet passage and the impeller chamber;

[0527] The impeller chamber includes a circumferentially extending concave side channel, concentric with the longitudinal axis and at least partially defined by the end wall and the side wall, the side channel extending between the inlet channel and the outlet channel; and

[0528] The axially extending baffle element is located in the side channel, the baffle element includes ribs, and the ribs extend from the side wall toward the longitudinal axis in both the circumferential and radial directions.

[0529] 28. The pump cover for a hydrogen recirculation pump according to Clause 27, wherein the impeller chamber includes a support region disposed radially inside the sidewall and located on the longitudinal axis;

[0530] The support area defines at least a portion of the side channel;

[0531] The rib is a first rib, and the baffle element further includes a second rib, which extends from the support area of ​​the impeller away from the longitudinal axis in both the circumferential and radial directions.

[0532] A flow constraint portion is formed between the end of the first rib and the opposite end of the second rib.

[0533] 29. The pump cover for a hydrogen recirculation pump as described in Clause 28, wherein the baffle element includes an axially extending intermediate wall portion connecting the first rib and the second rib.

[0534] 30. The pump cover for a hydrogen recirculation pump as described in Clause 29, wherein the intermediate wall portion at least partially defines the flow constraint portion; and

[0535] The baffle element extends along the baffle axis in a first plane perpendicular to the longitudinal axis; and

[0536] The intermediate wall portion has an arcuate profile in a second plane that extends through the axis of the baffle and is perpendicular to the first plane.

[0537] 31. A pump cover for a hydrogen recirculation pump according to any one of clauses 27 to 30, wherein at least a portion of the baffle element extends axially over the entire height of the side passage.

[0538] 32. A pump cover for a hydrogen recirculation pump according to any one of clauses 27 to 30, wherein the baffle element does not extend axially over the entire height of the side passage.

[0539] 33. The pump cover for a hydrogen recirculation pump as described in Clause 28, wherein the support region includes a support wall extending axially and circumferentially, the support wall defining at least a portion of the side passage;

[0540] The baffle element extends along the baffle axis in a plane perpendicular to the longitudinal axis;

[0541] In the plane, the nominal axis extends radially from a point on the support wall relative to the longitudinal axis, and the second rib extends from that point; and

[0542] The angle between the baffle axis and the nominal axis is between 15 degrees and 30 degrees.

[0543] 34. A pump cover for a hydrogen recirculation pump according to any one of clauses 27 to 33, wherein the baffle element is integrally formed with the pump cover.

[0544] 35. A pump cover for a hydrogen recirculation pump according to any one of clauses 27 to 34, wherein the pump cover includes a second baffle element comprising a plurality of circumferentially spaced, axially extending deflecting ribs.

[0545] 36. The pump cover for a hydrogen recirculation pump as described in Clause 35, wherein the deflection rib has a rectangular cross-sectional profile in a plane perpendicular to the longitudinal axis.

[0546] 37. A pump cover for a hydrogen recirculation pump as described in clause 35 or 36, wherein the plurality of deflection ribs are circumferentially spaced along the centerline of the side channel.

[0547] 38. A pump cover for a hydrogen recirculation pump as described in clause 35 or 36, wherein the plurality of deflection ribs are located radially inside the centerline of the side passage.

[0548] 39. A pump cover for a hydrogen recirculation pump according to any one of clauses 35 to 38, wherein at least a portion of one of the plurality of deflection ribs extends axially over the entire height of the side passage.

[0549] 40. The pump cover for a hydrogen recirculation pump according to any one of clauses 35 to 38, wherein the plurality of deflection ribs do not extend axially over the entire height of the side passage.

[0550] 41. A hydrogen recirculation pump, the hydrogen recirculation pump comprising:

[0551] Pump assembly;

[0552] Motor assembly, the motor assembly including a motor housing; and

[0553] adapter,

[0554] The pump assembly includes a pump cover for a hydrogen recirculation pump according to any one of clauses 27 to 40, wherein the adapter is disposed between the pump cover and the motor housing, the adapter being configured to connect to the motor housing and the pump cover, and providing an interface between the motor housing and the pump cover.

[0555] 42. The hydrogen recirculation pump as described in Clause 41, wherein:

[0556] The pump assembly includes an impeller located within the impeller chamber; and

[0557] The motor is located within the motor housing, and the motor is configured to drive the impeller to rotate about the longitudinal axis via a linkage; and

[0558] The bearing housing is at least partially disposed radially inside the adapter, and the bearing housing includes a bearing configured to support at least a portion of the linkage.

[0559] 43. The hydrogen recirculation pump according to clause 41 or 42, wherein, in use, the hydrogen recirculation pump is oriented such that the outlet channel is located at the lowest part relative to gravity.

[0560] 44. A pump cover for a hydrogen recirculation pump, the pump cover comprising:

[0561] end wall;

[0562] An annular sidewall that extends from the endwall;

[0563] An impeller chamber configured to house an impeller for rotation about a longitudinal axis within the impeller chamber, the impeller chamber being at least partially defined by the end wall and the annular side wall;

[0564] The impeller chamber includes a support region disposed on the radially inner side of the annular sidewall, and the support region has a center that coincides with the longitudinal axis.

[0565] Entrance opening; and

[0566] Exit opening;

[0567] The inlet opening is disposed in the end wall, and the inlet opening and the outlet opening are circumferentially spaced apart and separated by a tongue extending between the annular sidewall and the support region; and

[0568] The end wall further includes a concave side channel that provides fluid communication between the inlet opening and the outlet opening, wherein the side channel extends circumferentially from the inlet opening to the outlet opening and is at least partially defined by the support region.

[0569] 45. The pump cover for a hydrogen recirculation pump as described in Clause 44, wherein the radially inner wall surface of the annular sidewall relative to the farthest end of the end wall defines the main diameter.

[0570] The annular sidewall includes a first stepped portion adjacent to the farthest end, the first stepped portion defining a first stepped diameter, the first stepped diameter being smaller than the main diameter; and

[0571] The annular sidewall also includes a second step portion adjacent to the first step portion, the second step portion defining a second step diameter, the second step diameter being smaller than the first step diameter.

[0572] 46. ​​A pump cover for a hydrogen recirculation pump as described in Section 44 or 45, wherein, in use, the pump cover is oriented to allow condensate to pass through the outlet opening under gravity.

[0573] 47. A pump cover for a hydrogen recirculation pump according to any one of clauses 44 to 46, wherein, in use, the outlet opening is located at the lowermost periphery of the annular sidewall relative to the direction of gravity.

[0574] 48. A pump cover for a hydrogen recirculation pump according to any one of clauses 44 to 47, the pump cover further comprising a liquid discharge opening adjacent to the outlet opening, the liquid discharge opening extending through the annular sidewall.

[0575] 49. The pump cover for a hydrogen recirculation pump as described in Clause 48, wherein a liquid discharge passage extends from the support region through the tongue to the liquid discharge opening, and the liquid discharge passage is configured to guide liquid from the support region to the liquid discharge opening.

[0576] 50. A pump cover for a hydrogen recirculation pump according to any one of clauses 44 to 49, wherein the outlet passage is defined by a cylindrical wall extending radially outward from the annular sidewall at the outlet opening, and wherein the outer surface of the cylindrical wall includes two spaced-apart grooves extending circumferentially around the outer surface, each groove being configured to receive a sealing member.

[0577] 51. A pump cover for a hydrogen recirculation pump according to any one of clauses 44 to 50, wherein the radially outer wall surface of the annular sidewall includes a plurality of circumferentially spaced protrusions.

[0578] Each of the plurality of protrusions includes an axially extending hole configured to receive a connector for connecting the pump cover to an adapter and / or a motor housing.

[0579] 52. A pump cover for a hydrogen recirculation pump according to any one of clauses 44 to 51, the pump cover further comprising a flange adjacent to the end wall and located radially outward of the annular sidewall;

[0580] The flange defines an interface for mounting the pump cover, and the flange includes a plurality of axial through holes configured to receive a connector.

[0581] 53. A pump cover for a hydrogen recirculation pump according to any one of clauses 44 to 52, wherein the side passage includes at least one baffle element configured to create a flow constraint in the side passage.

[0582] 54. A hydrogen recirculation pump, the hydrogen recirculation pump comprising:

[0583] Pump assembly; and

[0584] Motor assembly,

[0585] The pump assembly includes a pump cover for a hydrogen recirculation pump as described in any one of clauses 44 to 53.

[0586] 55. The hydrogen recirculation pump as described in Clause 54, wherein:

[0587] The pump assembly also includes an impeller located in the impeller chamber, the impeller being supported to rotate within the impeller chamber;

[0588] The motor assembly includes a motor housing and a motor;

[0589] The motor is located within the motor housing and is configured to drive the impeller to rotate about a longitudinal axis via a linkage device.

[0590] An adapter is disposed between the pump cover and the motor housing, and the adapter is connected to both the motor housing and the pump cover; and

[0591] The bearing housing is at least partially disposed radially inside the adapter, and the bearing housing includes a bearing configured to support at least a portion of the linkage.

[0592] 56. An impeller for a hydrogen recirculation pump, the impeller comprising an impeller body,

[0593] The impeller body includes:

[0594] A disc-shaped back cover defining a central axis, and the back cover having an arcuate profile in a plane parallel to the central axis, the arcuate profile defining a concave surface; and

[0595] A disc-shaped central connecting plate located radially inside the rear cover;

[0596] A plurality of axially extending blades are disposed on the concave surface of the rear cover, and each of the plurality of blades extends from the central connecting plate in both radial and circumferential directions; and

[0597] The outermost radial portion of the rear cover includes an outwardly facing and axially extending protrusion, which is used to form a seal with the pump cover.

[0598] 57. The impeller for a hydrogen recirculation pump as described in Clause 56, wherein the protrusion extends around the periphery of the rear cover.

[0599] 58. The impeller for a hydrogen recirculation pump as described in Clause 57, wherein the radially outermost portion of the rear cover includes at least one circumferentially extending groove.

[0600] 59. An impeller for a hydrogen recirculation pump according to any one of clauses 56 to 58, wherein the central connecting plate includes a through hole that coincides with the central axis for receiving at least a portion of a bearing assembly.

[0601] 60. An impeller for a hydrogen recirculation pump according to any one of clauses 56 to 59, wherein the central connecting plate includes at least one fastener connection through hole for receiving a connector for connection with a magnetic coupling device.

[0602] 61. An impeller for a hydrogen recirculation pump as described in Clause 60 when subject to Clause 59, wherein the central connecting plate includes a plurality of fastener connection through holes, and the plurality of fastener connection through holes are circumferentially spaced apart around the central axis.

[0603] 62. An impeller for a hydrogen recirculation pump according to any one of clauses 56 to 61, wherein each of the plurality of blades is swept back from the central axis relative to the radial direction.

[0604] 63. An impeller for a hydrogen recirculation pump as described in Clause 62, wherein each of the plurality of blades defines a leading edge, the leading edge defining a blade tilt angle, the blade tilt angle being tilted relative to a radial direction originating from the central axis in a negative angular direction relative to the direction of rotation of the impeller during use; and

[0605] Wherein, all points on the leading edge define local blade tilt angles relative to the radial direction, and wherein all local blade tilt angles on the leading edge are tilted by 10 to 30 degrees relative to the radial direction in the negative angle direction.

[0606] 64. The impeller for a hydrogen recirculation pump as described in Clause 63, wherein all local blades on the leading edge are tilted at an angle of 20 degrees relative to the radial direction in the negative angular direction.

[0607] 65. An impeller for a hydrogen recirculation pump according to any one of clauses 56 to 64, wherein the impeller is formed of aluminum alloy or stainless steel.

[0608] 66. An impeller for a hydrogen recirculation pump according to any one of clauses 56 to 65, wherein the number of said blades is between 30 and 50.

[0609] 67. A pump assembly for a hydrogen recirculation pump, the pump assembly comprising:

[0610] Pump cover, the pump cover comprising:

[0611] The inlet channel is configured to accommodate the incoming fluid.

[0612] The impeller chamber is in fluid communication with the inlet channel;

[0613] An outlet channel, which is in fluid communication with the impeller chamber;

[0614] End wall, which defines at least a portion of the impeller chamber; and

[0615] A sidewall that extends axially from the endwall and defines at least a portion of the impeller chamber;

[0616] The impeller chamber includes a circumferentially extending concave side passage, concentric with the longitudinal axis of the pump cover and at least partially defined by the end wall and the side wall, the side passage extending between the inlet passage and the outlet passage; and

[0617] An impeller, wherein the impeller is an impeller for a hydrogen recirculation pump according to any one of clauses 56 to 66, the impeller being disposed in the impeller chamber and supported for rotation about the central axis.

[0618] 68. A hydrogen recirculation pump, the hydrogen recirculation pump comprising:

[0619] Pump assembly;

[0620] Motor assembly, the motor assembly including a motor housing; and

[0621] adapter,

[0622] The pump assembly is a pump assembly for a hydrogen recirculation pump as described in Clause 67, wherein the adapter is disposed between the pump cover and the motor housing, the adapter is configured to connect to the motor housing and the pump cover, and provides an interface between the motor housing and the pump cover.

[0623] 69. The hydrogen recirculation pump as described in Clause 68, wherein:

[0624] The motor is located within the motor housing, and the motor is configured to drive the impeller to rotate about the longitudinal axis via a linkage; and

[0625] The bearing housing is at least partially disposed radially inside the adapter, and the bearing housing includes a bearing configured to support at least a portion of the linkage.

[0626] 70. A modular hydrogen recirculation pump, the modular hydrogen recirculation pump comprising:

[0627] Pump assembly, the pump assembly comprising:

[0628] Pump cover, the pump cover defining the impeller chamber; and

[0629] Impeller, the impeller being located within the impeller chamber;

[0630] The motor assembly includes a motor housing and a motor.

[0631] The motor is located within the motor housing and is configured to drive the impeller to rotate about a longitudinal axis via a linkage device; and

[0632] An adapter is disposed between the pump assembly and the motor assembly, the adapter being mounted to both the motor housing and the pump cover;

[0633] The pump cover is mounted to the adapter via a first connecting device that allows the pump cover to be removed from and reattached to the adapter, and the motor housing is mounted to the adapter via a second connecting device that allows the motor housing to be removed from and reattached to the adapter.

[0634] 71. The modular hydrogen recirculation pump according to Clause 70, wherein the first connection device and / or the second connection device comprises a plurality of connectors.

[0635] 72. The modular hydrogen recirculation pump according to any one of clauses 70 to 71, wherein a bearing housing is at least partially disposed radially inside the adapter relative to the longitudinal axis, the bearing housing including a bearing configured to support at least a portion of the linkage.

[0636] 73. The modular hydrogen recirculation pump according to any one of clauses 70 to 72, wherein the linkage further includes a magnetic coupling device, the magnetic coupling device comprising:

[0637] A first permanent magnet, which is fixedly connected to the drive shaft of the motor; and

[0638] A second permanent magnet is fixedly connected to the impeller;

[0639] The motor end cap is disposed adjacent to the adapter, and the motor end cap is located between the first permanent magnet and the second permanent magnet; and

[0640] The first permanent magnet and the second permanent magnet apply magnetic force to each other, and the magnetic force prevents relative rotation between the first permanent magnet and the second permanent magnet, so that the rotation of the drive shaft and the first permanent magnet is transmitted to the second permanent magnet and the impeller.

[0641] 74. The modular hydrogen recirculation pump according to Clause 73, wherein the second permanent magnet is fixedly connected to the impeller via a magnetic coupling body.

[0642] 75. The modular hydrogen recirculation pump according to clause 73 or 74, wherein the motor end cap is formed of a non-magnetic material.

[0643] 76. The modular hydrogen recirculation pump according to any one of clauses 74 to 75, wherein the motor end cap is secured to the motor housing by a plurality of connectors.

[0644] 77. The modular hydrogen recirculation pump according to any one of clauses 70 to 76, wherein the motor assembly includes an electrical connection interface configured to connect the motor to a power source for driving the motor.

[0645] 78. The modular hydrogen recirculation pump according to Clause 77, wherein the electrical connection interface is integrally formed with the motor housing.

[0646] 79. The modular hydrogen recirculation pump according to clause 77 or 78, wherein the electrical connection interface is located radially outside the motor housing relative to the longitudinal axis.

[0647] 80. A modular hydrogen recirculation pump according to any one of clauses 70 to 79, wherein the motor assembly includes a temperature sensor configured to sense the temperature inside the motor housing, and

[0648] The motor assembly also includes a temperature sensor connection interface configured to transmit the sensed temperature.

[0649] 81. The modular hydrogen recirculation pump according to Clause 80, wherein the temperature sensor connection interface is integrally formed with the motor housing.

[0650] 82. The modular hydrogen recirculation pump according to clause 80 or 81, wherein the temperature sensor connection interface is located radially outside the motor housing relative to the longitudinal axis.

[0651] 83. The modular hydrogen recirculation pump according to any one of clauses 70 to 82, wherein the pump cover comprises:

[0652] end wall;

[0653] An annular sidewall extending from the end wall, wherein the end wall and the annular sidewall at least partially define the impeller chamber; and

[0654] A flange, which is adjacent to the end wall and located radially outside the annular sidewall, defines an interface for engaging with a manifold, and the flange includes a plurality of holes configured to receive a connector for securing the flange to the manifold.

[0655] 84. A parts kit for a modular hydrogen recirculation pump, the parts kit comprising:

[0656] Pump assembly, the pump assembly comprising:

[0657] Pump cover, the pump cover defining the impeller chamber; and

[0658] An impeller, the impeller being configured to be located within the impeller chamber;

[0659] A motor assembly including a motor housing and a motor, wherein the motor is configured to be located within the motor housing and the motor is configured to drive the impeller to rotate about a longitudinal axis via a linkage; and

[0660] An adapter configured to be disposed between the pump assembly and the motor assembly, and configured to be mounted to the motor housing and the pump cover;

[0661] The pump cover is configured to be mounted to the adapter via a first connecting device that allows the pump cover to be removed from and reattached to the adapter, and the motor housing is configured to be mounted to the adapter via a second connecting device that allows the motor housing to be removed from and reattached to the adapter.

[0662] 85. A connecting member for a magnetic coupling device of a hydrogen recirculation pump, the connecting member comprising a connecting body,

[0663] The connection body includes:

[0664] The connecting portion is configured to connect the connecting body to the rotatable body; and

[0665] Magnet holding section;

[0666] The permanent magnet is housed in the magnet holding portion.

[0667] 86. The connecting member according to clause 85, wherein the connecting body is a cylindrical body having a central axis;

[0668] The connecting body includes a through hole coinciding with the central axis, the through hole extending through the connecting body and defining at least a portion of the connecting portion; and

[0669] The first end of the connecting body includes an annular recess that defines the magnet holding portion.

[0670] 87. The connecting member according to clause 86, wherein the first end of the connecting body includes a flange, and the flange defines a portion of the annular recess.

[0671] 88. The connecting member according to clause 86 or 87, wherein, at the first end of the connecting body, the through hole has a first diameter; and

[0672] The through-hole has a second diameter in a region that is axially spaced from the magnet.

[0673] The second diameter is larger than the first diameter.

[0674] 89. The connecting member according to any one of clauses 86 to 88, wherein the through hole is configured to receive at least a portion of a shaft or plug.

[0675] 90. The connecting member according to clause 89, wherein at least part of the wall defining the through hole of the connecting body is mounted to the shaft.

[0676] 91. The connecting member according to any one of clauses 86 to 90, wherein a second end of the connecting body opposite to the first end includes at least one axially extending fastening hole, the at least one fastening hole being configured to receive a connector for connecting the connecting member to the impeller.

[0677] 92. The connecting member according to any one of clauses 85 to 91, wherein an adhesive for retaining the permanent magnet in the magnet retaining portion is provided between the permanent magnet and the magnet retaining portion.

[0678] 93. A connecting member according to any one of clauses 85 to 92 when directly or indirectly subordinate to clause 86, wherein the permanent magnet has an annular profile in a plane perpendicular to the central axis of the connecting body.

[0679] 94. The connecting member according to any one of clauses 85 to 93, wherein a plurality of permanent magnets are disposed in the magnet holding portion.

[0680] 95. A connecting member according to clause 94 when directly or indirectly subordinate to clause 86, wherein the plurality of permanent magnets are arranged circumferentially at equal intervals around the central axis of the connecting body.

[0681] 96. The connecting member according to clause 95, wherein a gap between 0 mm and 1 mm is provided between adjacent permanent magnets.

[0682] 97. The connecting member according to any one of clauses 85 to 96, wherein the connecting body is formed of a magnetically conductive material.

[0683] 98. A magnetic coupling device for a hydrogen recirculation pump, the magnetic coupling device comprising:

[0684] The first connecting member is configured to be fixedly connected to the drive shaft of the motor; and

[0685] The second connecting member is configured to be fixedly connected to the pump impeller, wherein;

[0686] Wherein, the first connecting member is a connecting member according to any one of clauses 85 to 97, and the second connecting member is a connecting member according to any one of clauses 85 to 97, and

[0687] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member.

[0688] 99. The magnetic coupling device for a hydrogen recirculation pump as described in Clause 98, wherein a gap between 3.5 mm and 4 mm is provided between the permanent magnet of the first coupling member and the permanent magnet of the second coupling member, and the magnetic coupling torque is greater than 3 Nm.

[0689] 100. A hydrogen recirculation pump, the hydrogen recirculation pump comprising:

[0690] Pump assembly, the pump assembly comprising:

[0691] Pump cover, the pump cover defining the impeller chamber; and

[0692] Impeller, the impeller being located within the impeller chamber;

[0693] Motor assembly, the motor assembly comprising:

[0694] Motor housing; and

[0695] A motor, the motor being disposed within the motor housing; and

[0696] A magnetic coupling is configured to provide a linkage between the motor and the impeller, allowing the motor to rotatably drive the impeller to rotate about a longitudinal axis.

[0697] The magnetic connector includes:

[0698] A first connecting member, configured to be fixedly connected to the drive shaft of the motor; and

[0699] The second connecting member is configured to be fixedly connected to the impeller;

[0700] Wherein, the first connecting member is a connecting member according to any one of clauses 85 to 97, or a first connecting member of a magnetic connecting device for a hydrogen recirculation pump according to clause 98 or 99, and the second connecting member is a connecting member according to any one of clauses 85 to 97, or a second connecting member of a magnetic connecting device for a hydrogen recirculation pump according to clause 98 or 99.

[0701] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member, such that the rotation of the drive shaft and the first connecting member is transmitted to the second connecting member and the impeller.

[0702] 101. The hydrogen recirculation pump according to Clause 100, the hydrogen recirculation pump further comprising an adapter connected to the motor assembly and the pump assembly, and providing an interface between the motor assembly and the pump assembly.

[0703] 102. The hydrogen recirculation pump according to clause 100 or 101, wherein the first coupling member is mounted to the drive shaft of the motor.

[0704] 103. The hydrogen recirculation pump according to any one of clauses 100 to 102, wherein at least a portion of the impeller is connected to the second coupling member via the connecting portion.

[0705] 104. The hydrogen recirculation pump according to any one of clauses 100 to 103, wherein the first connecting member and the second connecting member are axially separated, and a motor housing end cap is disposed between the first connecting member and the second connecting member.

[0706] 105. A connecting member for a magnetic coupling device of a hydrogen recirculation pump, the connecting member comprising a connecting body,

[0707] The connection body includes:

[0708] The connecting portion is configured to connect the connecting body to the rotatable body; and

[0709] Magnet holding section;

[0710] The permanent magnet is housed in the magnet holding portion, and the permanent magnet is fixed in the magnet holding portion by a first connector extending through the permanent magnet, and the end of the first connector is housed in a hole in the connecting body.

[0711] 106. The connecting member according to clause 105, the connecting member further comprising a plurality of first connectors, wherein the end of each first connector is received in a respective corresponding hole in the connecting body.

[0712] 107. The connecting member according to clause 105 or 106, wherein the connecting body is a cylindrical body having a central axis;

[0713] The connecting body includes a through hole coinciding with the central axis, the through hole extending through the connecting body and defining at least a portion of the connecting portion; and

[0714] The first end of the connecting body includes an annular recess that defines the magnet holding portion.

[0715] 108. The connecting member according to clause 107, wherein the first end of the connecting body includes a flange, and the flange defines a portion of the annular recess.

[0716] 109. The connecting member according to clause 107 or 108, wherein, at the first end of the connecting body, the through hole has a first diameter; and

[0717] The through-hole has a second diameter in a region that is axially spaced from the magnet.

[0718] The second diameter is larger than the first diameter.

[0719] 110. The connecting member according to any one of clauses 107 to 109, wherein the through hole is configured to receive at least a portion of a shaft or plug.

[0720] 111. The connecting member according to clause 110, wherein at least part of the wall defining the through hole of the connecting body is configured to be mounted to the shaft.

[0721] 112. The connecting member according to any one of clauses 107 to 109, wherein a second end of the connecting body opposite to the first end includes at least one axially extending fastening hole, the at least one fastening hole being configured to receive a first connector for connecting the connecting member to the impeller.

[0722] 113. The connecting member according to any one of clauses 105 to 112, wherein a magnetically conductive member is provided between the permanent magnet and the magnet holding portion.

[0723] 114. A connecting member according to any one of clauses 105 to 113 when directly or indirectly subordinate to clause 107, wherein the permanent magnet has an annular profile in a plane perpendicular to the central axis of the connecting body.

[0724] 115. The connecting member according to any one of clauses 105 to 114, wherein a plurality of permanent magnets are disposed in the magnet holding portion, and wherein each permanent magnet is fixed in the magnet holding portion by its respective first connector.

[0725] 116. The connecting member according to clause 115 when directly or indirectly subordinate to clause 107, wherein the plurality of permanent magnets are arranged circumferentially at equal intervals around the central axis of the connecting body.

[0726] 117. The connecting member according to clause 115 or 116, wherein a gap between 0 mm and 1 mm is provided between adjacent permanent magnets.

[0727] 118. A magnetic coupling device for a hydrogen recirculation pump, the magnetic coupling device comprising:

[0728] The first connecting member is configured to be fixedly connected to the drive shaft of the motor; and

[0729] The second connecting member is configured to be fixedly connected to the impeller of the pump assembly; and

[0730] Wherein, the first connecting member is a connecting member according to any one of clauses 105 to 117, and the second connecting member is a connecting member according to any one of clauses 105 to 117, and

[0731] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member, such that rotation of the first connecting member is transmitted to the second connecting member.

[0732] 119. The magnetic coupling device for a hydrogen recirculation pump as described in Clause 118, wherein a gap between 3.5 mm and 4 mm is provided between the permanent magnet of the first coupling member and the permanent magnet of the second coupling member, and the magnetic coupling torque is greater than 3 Nm.

[0733] 120. A hydrogen recirculation pump, the hydrogen recirculation pump comprising:

[0734] Pump assembly, the pump assembly comprising:

[0735] Pump cover, the pump cover defining the impeller chamber; and

[0736] Impeller, the impeller being located within the impeller chamber;

[0737] Motor assembly, the motor assembly including

[0738] Motor housing: and

[0739] A motor, the motor being disposed within the motor housing; and

[0740] A magnetic coupling is configured to provide a linkage between the motor and the impeller, allowing the motor to drive the impeller to rotate about a longitudinal axis;

[0741] The magnetic connector includes:

[0742] A first connecting member, configured to be fixedly connected to the drive shaft of the motor; and

[0743] The second connecting member is configured to be fixedly connected to the impeller;

[0744] Wherein, the first connecting member is the connecting member according to any one of clauses 105 to 117, or the first connecting member of the magnetic connecting device for the hydrogen recirculation pump according to clauses 118 or 119, and the second connecting member is the connecting member according to any one of clauses 105 to 117, or the second connecting member of the magnetic connecting device for the hydrogen recirculation pump according to clauses 118 or 119, and

[0745] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member, such that the rotation of the drive shaft and the first connecting member is transmitted to the second connecting member and the impeller.

[0746] 121. The hydrogen recirculation pump according to Clause 120, the hydrogen recirculation pump further comprising an adapter connected to the motor assembly and the pump assembly, and providing an interface between the motor assembly and the pump assembly.

[0747] 122. The hydrogen recirculation pump according to clause 120 or 121, wherein the first coupling member is mounted to the drive shaft of the motor.

[0748] 123. The hydrogen recirculation pump according to any one of clauses 120 to 122, wherein at least a portion of the plug connected to the impeller is connected to the second coupling member.

[0749] 124. The hydrogen recirculation pump according to any one of clauses 120 to 123, wherein the first connecting member and the second connecting member are axially separated, and a motor housing end cap is disposed between the first connecting member and the second connecting member.

[0750] 125. A connecting member for a magnetic coupling device of a hydrogen recirculation pump, the connecting member comprising a cylindrical connecting body having a central axis.

[0751] The connection body includes:

[0752] A connecting portion, configured to connect the connecting body to a rotatable body, wherein a through-hole coinciding with the central axis extends through the connecting body and defines at least a portion of the connecting portion; and

[0753] A magnet holding portion, wherein a first end of the connecting body includes an axially extending annular recess defining the magnet holding portion, and a permanent magnet having an annular profile in a plane perpendicular to the central axis is accommodated in the magnet holding portion;

[0754] The magnet holding portion includes a radially extending protrusion, and the radially extending protrusion is arranged to hold the magnet axially within the magnet holding portion.

[0755] 126. The connecting member according to clause 125, wherein the radially extending protrusion is an annular protrusion.

[0756] 127. The connecting member according to any one of clauses 125 to 126, wherein the radially extending protrusion extends from the radial outer wall of the magnet holding portion in a direction toward the central axis.

[0757] 128. The connecting member according to any one of clauses 125 to 127, wherein the permanent magnet includes a recess having a profile complementary to the radially extending protrusion.

[0758] 129. The connecting member according to any one of clauses 125 to 128, wherein the radially extending protrusion is a first protrusion and the magnet holding portion includes a radially extending second protrusion.

[0759] 130. The connecting member according to clause 129 when directly or indirectly subordinate to clause 127, wherein the radially extending second protrusion extends from the radially inner wall of the magnet holding portion in a direction away from the central axis.

[0760] 131. The connecting member according to clause 130, wherein at least one of the radially extending first protrusion and second protrusion is an annular protrusion.

[0761] 132. A connecting member according to any one of clauses 129 to 131 when subordinate to clause 128, wherein the recess of the permanent magnet is a first recess having a profile complementary to the radially extending first protrusion; and

[0762] The permanent magnet includes a second recess having a profile complementary to the radially extending second protrusion.

[0763] 133. The connecting member according to any one of clauses 125 to 132, wherein the first end of the connecting body includes a flange, and the flange defines a portion of the axially extending annular recess.

[0764] 134. The connecting member according to any one of clauses 125 to 133, wherein, at the first end of the connecting body, the through hole has a first diameter; and

[0765] The through-hole has a second diameter in a region that is axially spaced from the magnet.

[0766] The second diameter is larger than the first diameter.

[0767] 135. The connecting member according to any one of clauses 125 to 134, wherein a magnetically conductive member having an annular profile in a plane perpendicular to the central axis is housed in the magnet holding portion, and the magnetically conductive member is disposed between the permanent magnet and the magnet holding portion.

[0768] 136. The connecting member according to clause 135, wherein the magnetically conductive member includes a radially extending recess; and

[0769] The magnet holding portion includes complementary protrusions housed in the recess of the magnetically conductive member.

[0770] 137. The connecting member according to any one of clauses 125 to 136, wherein the through hole is configured to receive at least a portion of a shaft or plug.

[0771] 138. The connecting member according to clause 137, wherein at least part of the wall defining the through hole of the connecting body is configured to be mounted to the shaft.

[0772] 139. The connecting member according to any one of clauses 125 to 138, wherein a second end of the connecting body opposite to the first end includes at least one axially extending fastening hole, the at least one fastening hole being configured to receive a connector for connecting the connecting member to the impeller.

[0773] 140. The connecting member according to any one of clauses 125 to 139, wherein the permanent magnet comprises a plurality of permanent magnets, and wherein the radially extending protrusion is arranged to axially retain at least one of the plurality of permanent magnets in the magnet retaining portion.

[0774] 141. The connecting member according to clause 140, wherein the plurality of permanent magnets are arranged circumferentially at equal intervals around the central axis.

[0775] 142. The connecting member according to clause 140 or 141, wherein a gap between 0 mm and 1 mm is provided between adjacent permanent magnets.

[0776] 143. A magnetic coupling device for a hydrogen recirculation pump, the magnetic coupling device comprising:

[0777] The first connecting member is configured to be fixedly connected to the drive shaft of the motor; and

[0778] The second connecting member is configured to be fixedly connected to the impeller of the pump assembly;

[0779] Wherein, the first connecting member is a connecting member according to any one of clauses 125 to 142, and the second connecting member is a connecting member according to any one of clauses 125 to 142, and

[0780] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member, such that rotation of the first connecting member is transmitted to the second connecting member.

[0781] 144. The magnetic coupling device for a hydrogen recirculation pump as described in Clause 143, wherein a gap between 3.5 mm and 4 mm is provided between the permanent magnet of the first coupling member and the permanent magnet of the second coupling member, and the magnetic coupling torque is greater than 3 Nm.

[0782] 145. A hydrogen recirculation pump, the hydrogen recirculation pump comprising:

[0783] Pump assembly, the pump assembly comprising:

[0784] Pump cover, the pump cover defining the impeller chamber; and

[0785] Impeller, the impeller being located within the impeller chamber;

[0786] Motor assembly, the motor assembly comprising:

[0787] Motor housing; and

[0788] A motor, the motor being disposed within the motor housing; and

[0789] A magnetic coupling device is configured to provide a linkage between the motor and the impeller, allowing the motor to drive the impeller to rotate about a longitudinal axis;

[0790] The magnetic connection device includes:

[0791] A first connecting member, configured to be fixedly connected to the drive shaft of the motor; and

[0792] The second connecting member is configured to be fixedly connected to the impeller;

[0793] Wherein, the first connecting member is a connecting member according to any one of clauses 125 to 142, or a first connecting member of a magnetic coupling device for a hydrogen recirculation pump according to clause 143 or 144, wherein the second connecting member is a connecting member according to any one of clauses 125 to 142, or a second connecting member of a magnetic coupling device for a hydrogen recirculation pump according to clause 143 or 144, and

[0794] The respective permanent magnets of the first connecting member and the second connecting member are arranged to apply magnetic force to each other, the magnetic force preventing relative rotation between the first connecting member and the second connecting member, such that the rotation of the drive shaft and the first connecting member is transmitted to the second connecting member and the impeller.

[0795] 146. The hydrogen recirculation pump according to clause 145, the hydrogen recirculation pump further comprising an adapter connected to the motor assembly and the pump assembly, and providing an interface between the motor assembly and the pump assembly.

[0796] 147. The hydrogen recirculation pump according to clause 145 or 146, wherein the first coupling member is mounted to the drive shaft of the motor.

[0797] 148. The hydrogen recirculation pump according to any one of clauses 145 to 147, wherein the first connecting member and the second connecting member are axially separated, and a motor housing end cap is disposed between the first connecting member and the second connecting member.

Claims

1. A pump cover for a hydrogen recirculation pump, the pump cover comprising: end wall; An annular sidewall that extends from the endwall; An impeller chamber configured to house an impeller for rotation about a longitudinal axis within the impeller chamber, the impeller chamber being at least partially defined by the end wall and the annular side wall; The impeller chamber includes a support region disposed on the radially inner side of the annular sidewall, and the support region has a center that coincides with the longitudinal axis. Entrance opening, and Exit opening; The inlet opening is characterized in that it is disposed in the end wall, the inlet opening and the outlet opening are circumferentially spaced apart and separated by a tongue extending between the annular sidewall and the support region; and The end wall further includes a concave side channel that provides fluid communication between the inlet opening and the outlet opening, wherein the side channel extends circumferentially from the inlet opening to the outlet opening and is at least partially defined by the support region.

2. The pump cover for a hydrogen recirculation pump according to claim 1, characterized in that, The radial inner wall surface of the annular sidewall relative to the farthest end of the endwall defines the main diameter. The annular sidewall includes a first stepped portion adjacent to the farthest end, the first stepped portion defining a first stepped diameter, the first stepped diameter being smaller than the main diameter; and The annular sidewall also includes a second step portion adjacent to the first step portion, the second step portion defining a second step diameter, the second step diameter being smaller than the first step diameter.

3. The pump cover for a hydrogen recirculation pump according to claim 1 or 2, characterized in that, In use, the pump cover is oriented to allow condensate to pass through the outlet opening under the influence of gravity.

4. The pump cover for a hydrogen recirculation pump according to any one of claims 1 to 3, characterized in that, In use, the outlet opening is located at the lowest periphery of the annular sidewall relative to the direction of gravity.

5. The pump cover for a hydrogen recirculation pump according to any one of claims 1 to 4, characterized in that, The pump cover also includes a liquid discharge opening adjacent to the outlet opening, the liquid discharge opening extending through the annular sidewall.

6. The pump cover for a hydrogen recirculation pump according to claim 5, characterized in that, A liquid discharge channel extends from the support region through the tongue to the liquid discharge opening, and the liquid discharge channel is configured to guide liquid from the support region to the liquid discharge opening.

7. The pump cover for a hydrogen recirculation pump according to any one of claims 1 to 6, characterized in that, The outlet channel is defined by a cylindrical wall extending radially outward from the annular sidewall at the outlet opening, and the outer surface of the cylindrical wall includes two spaced grooves that extend circumferentially around the outer surface, each groove being configured to receive a sealing member.

8. The pump cover for a hydrogen recirculation pump according to any one of claims 1 to 7, characterized in that, The radial outer wall surface of the annular sidewall includes a plurality of circumferentially spaced protrusions; Each of the plurality of protrusions includes an axially extending hole configured to receive a connector for connecting the pump cover to an adapter and / or a motor housing.

9. The pump cover for a hydrogen recirculation pump according to any one of claims 1 to 8, characterized in that, The pump cover also includes a flange adjacent to the end wall and located radially outside the annular sidewall; The flange defines an interface for mounting the pump cover, and the flange includes a plurality of axial through holes configured to receive a connector.

10. The pump cover for a hydrogen recirculation pump according to any one of claims 1 to 9, characterized in that, The side channel includes at least one baffle element configured to create a flow constraint in the side channel.

11. A hydrogen recirculation pump, the hydrogen recirculation pump comprising: Pump assembly; and Motor assembly, The pump assembly is characterized in that it includes a pump cover for a hydrogen recirculation pump according to any one of claims 1 to 10.

12. The hydrogen recirculation pump according to claim 11, characterized in that, The pump assembly also includes an impeller located in the impeller chamber, the impeller being supported to rotate within the impeller chamber; The motor assembly includes a motor housing and a motor, the motor being located within the motor housing, and the motor being configured to drive the impeller to rotate about a longitudinal axis via a linkage. An adapter is disposed between the pump cover and the motor housing, and the adapter is connected to both the motor housing and the pump cover; and The bearing housing is at least partially disposed radially inside the adapter, and the bearing housing includes a bearing configured to support at least a portion of the linkage.

Images