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US20140341764A1 - Wet rotor pump - Google Patents

Wet rotor pump Download PDF

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Publication number
US20140341764A1
US20140341764A1 US14/373,205 US201314373205A US2014341764A1 US 20140341764 A1 US20140341764 A1 US 20140341764A1 US 201314373205 A US201314373205 A US 201314373205A US 2014341764 A1 US2014341764 A1 US 2014341764A1
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US
United States
Prior art keywords
bearing
impeller
rotor pump
stator
pump according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US14/373,205
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English (en)
Inventor
Markus Müller
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yasa Motors Poland Sp zoo
Original Assignee
Yasa Motors Poland Sp zoo
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Filing date
Publication date
Application filed by Yasa Motors Poland Sp zoo filed Critical Yasa Motors Poland Sp zoo
Assigned to Yasa Motors Poland Sp. z.o.o. reassignment Yasa Motors Poland Sp. z.o.o. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MULLER, MARKUS
Publication of US20140341764A1 publication Critical patent/US20140341764A1/en
Abandoned legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/0606—Canned motor pumps
    • F04D13/0633—Details of the bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/021—Units comprising pumps and their driving means containing a coupling
    • F04D13/024—Units comprising pumps and their driving means containing a coupling a magnetic coupling
    • F04D13/026—Details of the bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D1/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/0606—Canned motor pumps
    • F04D13/064—Details of the magnetic circuit
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/0646—Units comprising pumps and their driving means the pump being electrically driven the hollow pump or motor shaft being the conduit for the working fluid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/0666—Units comprising pumps and their driving means the pump being electrically driven the motor being of the plane gap type

Definitions

  • the invention relates to a wet rotor pump for pumping a fluid, in particular a liquid.
  • the wet rotor pump comprises a rotor, which is connected to an impeller and is disposed in a wet zone, through which a pumped fluid flows.
  • the wet zone is separated from a dry zone, in which the stator is disposed.
  • the wet zone is demarcated from the dry zone by means of a printed circuit board, the electric lines of which form the stator such that the printed circuit board functions simultaneously as a containment shell.
  • Further embodiments of wet rotor pumps are described in WO 2006/137496 A1, WO 00/37804, EP 1 130 741 A2, US005332374A and US 2002/0166520.
  • Document DE 102 03 778 A1 makes known an electrically driven pump, which comprises an electric drive motor embodied as a disk rotor.
  • the magnetic ring of the drive motor is disposed in a region through which fluid flows.
  • Document EP 0 401 761 A2 describes a magnetic-drive pump, in which an impeller, in which a permanent magnet is embedded, is set into rotation by means of a magnetic force from outside the impeller.
  • the magnetic drive mechanism is accommodated in a region of the pump housing that does not come into contact with a fluid, wherein the drive mechanism is oriented such that said drive mechanism is positioned opposite the impeller along the rotational axis of the impeller.
  • Axial flux motors are also known per se from the related art.
  • the magnetic flux extends in the air gap of the motor in the axial direction, cf. DE 100 53 400 A1 or DE 1 613 626, for example.
  • the problem addressed by the invention is that of creating an improved wet rotor pump.
  • a wet rotor pump is created, in which an inlet line for the fluid extends through the stator, the containment shell, and the bearing for the impeller.
  • the motor is designed as an axial flux motor and has the advantage, in particular, that the wet rotor pump has a particularly compact design, i.e. a low overall height, combined with high power density.
  • Embodiments of the invention are furthermore particularly advantageous since the bearing functions simultaneously as a seal at the transition between the suction side and the pressure side of the wet rotor pump. The losses due to leakage are minimized due to the relatively small gap widths and the low tolerances of the bearing.
  • the fluid enters through a central opening in the containment shell.
  • the containment shell can form an inlet connecting piece in particular.
  • the stator is formed in the shape of a torus.
  • the stator can comprise an annular stator tooth receptacle, on which stator teeth are disposed.
  • the stator teeth can be attached to the stator tooth receptacle by means of bonding, for example.
  • each of the stator teeth has a receiving region for a coil.
  • Each of the stator teeth has an enlarged cross section at the end on the air-gap side. This has the advantage that the magnetic field is approximately homogeneous in a larger region within the air gap and therefore completely encloses the rotor magnets, which are narrower in the radial direction, thereby supporting the self-centering of the impeller in order to hereby support the self-centering of the impeller.
  • air gap refers to the separation between the ends of the stator teeth and the rotor, even if the gap contains no air or not only air, e.g. the fluid as well.
  • the power electronics which are used to control the coils of the stator, are disposed within the space circumscribed by the stator and the containment shell, as on an annular printed circuit board, for example.
  • the overall height of the wet rotor pump can be further reduced in this manner.
  • the containment shell is formed by an annular disk, which extends into the air gap between the stator and the rotor and separates the dry zone of the wet rotor pump from the wet zone.
  • the annular disk has a central opening, at which the inlet connecting piece is disposed, which said inlet connecting piece extends through the center of the stator.
  • the bearing for the impeller is disposed at the end region of the inlet connecting piece on the disk side, through which the fluid flows into the wet zone after having flowed through the dry zone, through the inlet line.
  • the disk and the inlet connecting piece can be formed as one piece, in particular as a plastic injection-molded part.
  • the containment shell can be embodied, in particular, as a plastic part (e.g. made of PPS/GFK/CFK) or as a non-magnetic, metallic part.
  • the bearing is designed as a plain bearing, wherein a bearing bush of the plain bearing is disposed at the end region of the inlet connecting piece on the disk side, and a plain-bearing element of the plain bearing is attached to the impeller.
  • a sliding surface of the plain-bearing element engages in the bearing bush such that radial support is provided.
  • a further sliding surface can be provided on the bearing for additional axial support on one side in order to absorb the magnetic attraction force of the stator, which acts on the impeller via the rotor.
  • Embodiments of the invention are particularly advantageous since, due to the axial flux motor on the impeller, a magnetic attraction force is exerted in the direction toward the stator such that the impeller requires support on only one side. This simplifies the design and further reduces the required overall height of the wet rotor pump.
  • the plain-bearing element has passage holes in the radial direction, such as lubrication holes approximately 1 mm in size, for example, which are used to direct a very small portion of the volume flow of the fluid through the bearing in order to provide additional lubrication of said bearing.
  • the bearing is coated with a combination of diamond-like carbon and silicon carbide (SiC), in order to ensure a particularly long service life of the bearing.
  • SiC silicon carbide
  • the bearing is designed as a combination of a plain bearing and a rolling bearing, which is designed to provide axial and radial support of the impeller.
  • the rolling bearing is used to absorb the axial forces, while the plain bearing is used to absorb the radial forces, which said plain bearing is formed with consideration for hydrodynamic aspects.
  • Embodiments of the invention are particularly advantageous, since strong forces can occur in the axial direction, in particular, due to the attraction of stator and rotor magnets, which said forces can result in a high amount of wear in a plain bearing.
  • a rolling bearing is characterized by low friction, primarily in the form of rolling friction, and therefore the wear on the bearing is reduced as compared to a plain bearing.
  • the rolling bearing is formed by bearing shells, which have running surfaces for accommodating rolling elements, and rolling elements.
  • a first bearing shell is attached to the impeller, while a second bearing shell is attached to the containment shell.
  • the rolling elements are located in the space circumscribed by the running surfaces of the bearing shells.
  • the plain bearing is formed on the impeller side by the outer jacket surface of the first bearing shell, and by the jacket surface of the containment shell.
  • the plain bearing is formed by the inner jacket surface of the second bearing shell and the jacket surface of the impeller.
  • Embodiments are particularly advantageous, since the bearing shells are part of the plain bearing and are part of the rolling bearing. Therefore, this is a hybrid bearing. This arrangement results in a bearing for a wet rotor pump that is very compact and, simultaneously, has a long service life and is robust.
  • the jacket surfaces and/or the running surfaces of the bearing shells and/or the rolling elements are coated with silicon carbide (SiC) and/or diamond-like carbon (DLC) and/or silicon-doped DLC.
  • the bearing is embodied as a combination of a plain bearing and a magnetic bearing, which is designed to provide radial support of the impeller.
  • the magnetic bearing is used to absorb axial forces, while the plain bearing is used to absorb radial forces, which said plain bearing is formed with consideration for hydrodynamic aspects.
  • Embodiments of the invention are particularly advantageous, since a magnetic bearing is characterized by friction that ideally disappears, which results in a markedly longer service life of the bearing as compared to a plain bearing.
  • the efficiency of the wet rotor pump increases due to the very low losses due to friction.
  • the magnetic bearing is formed by magnetic rings.
  • a first magnetic ring is attached to the impeller, and a second magnetic ring is attached to the containment shell.
  • the magnetization of the magnetic rings is configured such that, in the state in which said magnetic rings are installed in the wet rotor pump, these repel one another in the axial direction.
  • the plain bearing is formed on the impeller side by the outer jacket surface of the first magnetic ring, and by the jacket surface of the containment shell.
  • the plain bearing is formed by the inner jacket surface of the second magnetic ring and the jacket surface of the impeller.
  • Embodiments are particularly advantageous, since the magnetic rings are part of the plain bearing and are part of the magnetic bearing. Therefore, this is a hybrid bearing. This arrangement results in a bearing for a wet rotor pump that is very compact and, simultaneously, has a long service life and is robust.
  • the jacket surfaces of the magnetic rings are coated with silicon carbide (SiC) and/or diamond-like carbon (DLC) and/or silicon-doped DLC.
  • the bearing is protected by a fine-strand filter to ensure that particles do not enter the bearing.
  • the bearing is protected from damage by particles that could be carried along in the medium.
  • the rotor is formed by a permanent-magnet material, namely samarium cobalt (SmCo).
  • a permanent-magnet material namely samarium cobalt (SmCo).
  • Samarium cobalt can be used at high temperatures without negatively affecting the retentivity of the magnetization.
  • the fluid can have a temperature of up to 200° C., for example.
  • Samarium cobalt has excellent corrosion characteristics and can be directly exposed to the fluid with simple corrosion protection or without corrosion protection.
  • the magnetic material can be disposed at the outermost edge of the periphery of the impeller or the drive disk, thereby permitting the permanent-magnet material to be positioned with a maximum radius.
  • the permanent-magnet material forming the rotor can be disposed in the form of a plurality of individual, flat permanent magnets on the periphery of the impeller or in the form of a single magnetic ring having multipolar magnetization.
  • the magnets or the magnetic ring can be attached directly at the periphery of the impeller or can be attached to the impeller via a drive disk.
  • FIG. 1 shows an exploded view of a wet rotor pump according to the invention
  • FIG. 2 a shows a side view of a single stator tooth
  • FIG. 2 b shows a front view of the stator tooth according to FIG. 2 a
  • FIG. 2 c shows a perspective view of the stator tooth according to FIG. 2 a
  • FIG. 3 a shows a top view of the stator
  • FIG. 3 b shows a sectional view of the stator
  • FIG. 4 a shows a top view of an embodiment of the containment shell
  • FIG. 4 b shows a sectional view of the containment shell according to FIG. 4 a
  • FIG. 4 c shows a sectional view of the bearing bush of the containment shell according to FIG. 4 a
  • FIG. 4 d shows a sectional view of an embodiment of the plain-bearing element of the impeller
  • FIG. 5 a shows a top view of an embodiment of the rotor
  • FIG. 5 b shows a sectional view of the rotor according to FIG. 5 a
  • FIG. 6 shows a sectional view of an embodiment of the drive disk
  • FIG. 7 shows a sectional view of an embodiment of the impeller
  • FIG. 8 shows a sectional view of the wet rotor pump according to FIG. 1 , in the installed state
  • FIG. 9 shows a sectional view of a wet rotor pump comprising a hybrid bearing formed of a rolling bearing and a plain bearing,
  • FIG. 10 shows a sectional view of a further wet rotor pump according to the invention.
  • FIG. 1 shows an exploded view of an embodiment of a wet rotor pump 100 according to the invention.
  • the wet rotor pump 100 has a motor cover 102 , which has a circular end face 104 .
  • An opening 106 for the inflow of a fluid 108 is located in the center of the end face 104 .
  • the motor cover 102 is used to cover a stator 110 .
  • the stator 110 has a stator tooth receptacle 112 , which has an annular shape and on which stator teeth 114 are disposed so as to form a circle.
  • Each of the stator teeth has a receiving region 118 , on which a coil is wound (see FIGS. 2 and 3 ).
  • the various coils of the stator teeth 114 are electrically connected to power electronics 120 , which are used to control the coils.
  • the rotor of the axial flux motor is formed of a permanent-magnet material, which, in this case, is disposed on a ring 124 in the form of individual permanent magnets 122 (see FIG. 5 ).
  • the permanent magnets 122 have magnetization in the axial direction such that the magnetic flux also extends in the axial direction of the wet rotor pump 100 , namely between the ends 126 of the stator teeth 114 and the permanent magnets 122 , across an air gap that exists between the ends 126 and the permanent magnets 122 .
  • a magnetic attraction force is exerted by the stator 110 on the permanent magnets 122 and, therefore, on an impeller 128 of the wet rotor pump 100 .
  • a disk 130 of a containment shell 116 extends into the air gap between the ends 126 of the stator teeth 114 and the permanent magnets 122 .
  • the disk 130 has recesses 132 , which accommodate the ends of the stator teeth 114 (see FIGS. 4 a , 4 b ).
  • the bracings located between the recesses increase the mechanical stability of the motor design and make it possible to minimize the material thickness and, therefore, to minimize the air gap.
  • the wall thickness of the containment shell 116 in the recesses 132 is between 0.7 mm and 0.2 mm, for example. Such a thin wall thickness reduces the air gap, which, in turn, increases efficiency and power while using the same certain quantity of rare earth magnets.
  • the mechanical stability of the motor design is improved as a result.
  • the disk 130 has an axial opening, on which an inlet connecting piece 134 is disposed.
  • the inlet connecting piece 134 extends through the stator 110 and the opening 106 of the motor cover 102 , thereby allowing the fluid 108 to flow in via the inlet connecting piece 134 .
  • a space is circumscribed by the containment shell 116 and the stator 110 , in which the power electronics 120 can be disposed, for example on an annular printed circuit board 136 , the outer radius of which is limited by the recesses 132 , and the inner radius of which is limited by the wall of the inlet connecting piece 134 .
  • This printed circuit board 136 can carry the various electric and electronic components that form the power electronics 120 . Since this is disposed in the dry zone of the wet rotor pump 100 , special encapsulation of the power electronics 120 is not absolutely necessary.
  • An attachment region 138 is disposed on the inlet connecting piece 134 with axial separation from the disk 130 , to which said attachment region the motor cover 102 is attached, by means of screwed connections, for example.
  • the stator 110 is then held between the motor cover 102 and the disk 130 , wherein the ends 126 of the stator teeth 114 extend into the recesses 132 and are held there in a form-fit manner, for example.
  • the attachment region 138 can be annular, for example, as shown in FIG. 1 , and can have internal threads for forming screwed connections for attaching the motor cover 102 , which has corresponding holes 140 for passage of the screws.
  • the tubular extension of the containment shell having a disk-shaped portion toward the top is also used to center the stator flux return ring, i.e. the stator tooth receptacle 112 .
  • the wet rotor pump has a first housing half 142 and a second housing half 144 , by means of which the housing of the wet rotor pump 100 is formed.
  • the housing half 142 has an opening 146 in the center thereof, which adjoins the end of the inlet connecting piece 134 on the air-gap side, thereby allowing fluid 108 to flow from the inlet connecting piece 134 through the opening 146 .
  • the disk 130 is attached to the outer side of the housing half 142 , by means of screwed connections, for example, on an annular attachment region 148 of the housing half 142 .
  • the inlet line is therefore formed by the inlet connecting piece 134 with the bearing bush 156 disposed at the end thereof on the air-gap side.
  • the impeller 128 is located between these housing halves 142 and 144 .
  • the rotor is formed at the impeller 128 by virtue of the fact that the ring 124 comprising the permanent magnets 122 is connected to the impeller 128 via a drive disk 150 , by means of screws 153 , for example.
  • the permanent magnets 122 can also be disposed directly on the impeller 128 .
  • the permanent magnets 122 can be disposed between the ring 124 and the drive disk 150 .
  • the impeller has an extension 152 for accommodating a plain-bearing element 154 , which, together with a bearing bush 156 , forms a plain bearing for the radial support of the impeller 128 (see FIGS. 4 c and 4 d ).
  • the bearing supports the impeller 128 such that said impeller has one axial degree of freedom by virtue of the fact that a magnetic attraction force is exerted on the impeller 128 via the permanent magnets 122 in the axial direction toward the stator 110 , whereby the axial position of the impeller 128 is also determined.
  • the bearing formed by the plain-bearing element 154 and the bearing bush 156 can be designed such that this forms an abutment for absorbing the magnetic attraction force on one side in the axial direction (see FIGS. 4 c and 4 d ).
  • This magnetic attraction force of the stator 110 furthermore has a self-centering effect—during rotation—on the impeller 128 , which reduces the load on the plain bearing.
  • the two housing halves 142 and 144 are connected to one another by means of screws or adhesive 158 .
  • An outlet 160 for the fluid 108 is formed in this manner.
  • Embodiments of the invention are particularly advantageous since the fluid 108 flows in on the stator side and, in fact, through the stator. Furthermore, due to the axial flux motor, support for the impeller is required on only one side, without a rotor shaft, which makes it possible overall to obtain a particularly compact design having a high power density.
  • FIG. 2 a shows a front view of one of the stator teeth 126 according to the embodiment shown in FIG. 1 .
  • the receiving region 118 of the stator tooth 126 accommodates a plurality of windings of a coil 162 , which is controlled by the power electronics 120 of the printed circuit board 136 .
  • the receiving region 118 of the stator tooth 114 is closed on the air-gap side by the end 126 of the stator tooth 114 , which has a larger cross section than the receiving region 118 .
  • This larger cross section has the advantage that the magnetic field is widened accordingly in the air gap and is approximately homogeneous in a larger spatial region.
  • the self-centering of the impeller 128 (see FIG. 1 ) is supported as a result, since the permanent magnets 122 of the rotor have a width in the radial direction that is shorter than the stator flux width.
  • FIG. 2 a shows, as an example, how one of the permanent magnets 122 is disposed on the impeller relative to the stator tooth 114 .
  • the permanent magnet 122 is shorter in the radial direction than the extension of the end 126 of the stator tooth 114 in the radial direction, and therefore the stator tooth extends beyond the permanent magnet 122 .
  • the permanent magnet 122 is positioned in the center underneath the receiving region 118 , for example.
  • the stator tooth 114 has a slot-shaped recess 162 in the upper region thereof, which is used to attach the stator tooth 114 to the stator tooth receptacle 112 (see FIG. 3 ).
  • FIG. 2 b shows the stator tooth 114 in a front view
  • FIG. 2 c shows said stator tooth in a perspective view.
  • FIG. 3 a shows a top view of the stator 110 having the annular stator tooth receptacle 112 , which has an opening in the center thereof, through which the inlet connecting piece 134 extends (see FIG. 1 ).
  • the stator teeth 114 including the recesses 162 thereof, are attached on the periphery of the stator tooth receptacle 112 . This can be achieved by the recess 162 and/or the stator tooth receptacle 112 functioning as bonding surfaces in order to bond the stator tooth 114 , including the recess 162 thereof, on the edge of the stator tooth receptacle 112 .
  • FIG. 3 b shows a corresponding sectional view.
  • FIG. 4 a shows a top view of the containment shell 116 , through the inlet connecting piece 134 of which the fluid can flow in.
  • FIG. 4 b shows a sectional view of the containment shell 116 .
  • the end of the inlet connecting piece 134 on the air-gap side is designed to accommodate a bearing bush 156 , as shown in FIG. 4 c .
  • an inner radius R is formed at the end region of the inlet connecting piece 134 , into which the bearing bush 156 can be inserted and affixed, for example with the aid of a press fit.
  • a plain-bearing element 154 is attached to the extension 152 of the impeller 128 (see FIG. 1 ) and functions as the counterpart to the bearing bush 156 .
  • the plain-bearing element 154 is annular and has an end section 164 , the outer diameter of which is reduced such that a circumferential edge 166 is formed externally on the plain-bearing element 154 .
  • the bearing bush 156 therefore accommodates the end section 164 of the plain-bearing element 154 , wherein the inner side of the bearing bush 156 and the outer side of the end section 164 of the plain-bearing element 154 form the sliding surfaces of the plain bearing.
  • the impeller 128 is thereby radially supported.
  • the axial degree of freedom of the impeller 128 is limited by the circumferential edge 166 .
  • the impeller 128 is drawn in the direction of the stator 110 by the magnetic forces that occur, the edge 166 impacts the front side of the bearing bush 156 , thereby forming an abutment for absorbing this magnetic attraction force.
  • the impeller 128 is therefore supported in the containment shell 116 such that said impeller has one axial degree of freedom, i.e. axial play, the axial position of the impeller 128 is defined by the magnetic attraction force during operation of the axial flux motor.
  • At least one of the sliding surfaces of the plain bearing is coated with diamond-like carbon (DLC) and silicon carbide (SiC) or a combination of DLC and SiC, in order to extend the service life of the bearing.
  • DLC diamond-like carbon
  • SiC silicon carbide
  • Embodiments of the invention are particularly advantageous in which the fluid 108 is suctioned through the bearing, which also contributes to the compact design of the wet rotor pump.
  • the plain bearing can have a very narrow gap, which is approximately 0.01 mm to 0.03 mm, for example, and is therefore also simultaneously very well sealed.
  • the plain-bearing element 154 can have one or more radial openings, such as lubrication holes approximately 1 mm in size, for example. By means of these openings, a very small portion of the volume flow of the fluid 108 is directed between the sliding surfaces of the bearing in order to provide additional lubrication of said bearing.
  • This at least one opening is preferably disposed in the end section 164 of the plain-bearing element 154 and is directed toward the center.
  • FIG. 5 shows a top view of the rotor having the permanent magnets 122 , which are disposed on the ring 124 .
  • the permanent magnets 122 are preferably formed of samarium cobalt, which has various advantages:
  • Samarium cobalt can be used in relatively high temperatures without the retentivity being negatively affected thereby; the fluid 108 can have a temperature of up to 200° C., in particular.
  • Samarium cobalt has excellent corrosion characteristics and can therefore be exposed to the fluid 108 without coating and without encapsulation.
  • said permanent magnets 122 can be positioned at a maximum distance away from the rotational axis, thereby ensuring that maximum torque and maximum motor output result for a given amount of magnetic material.
  • the permanent magnets 122 can also be used for the permanent magnets 122 , such as neodymium iron boron.
  • FIG. 6 shows the drive disk 150 in a cross section.
  • the drive disk 150 is used to mechanically connect the rotor, i.e. the ring 124 having the permanent magnets 122 , to the impeller 128 , wherein the extension 152 of the impeller 128 extends through the drive disk 150 , as shown in FIG. 1 .
  • FIG. 7 shows a sectional view of the impeller 128 .
  • FIG. 8 shows a sectional view of the wet rotor pump 100 in the installed state.
  • the coils of the stator teeth 114 are controlled by the power electronics 120 such that torque acts on the impeller 128 via the rotor.
  • the rotor then suctions the fluid 108 through the inlet connecting piece 134 and the bearing such that the fluid 108 is conveyed through the wet rotor pump 100 and exits said wet rotor pump at the outlet 160 .
  • FIG. 9 shows a sectional view of a wet rotor pump according to the invention, wherein the impeller 128 is supported by a combination of a plain bearing and a rolling bearing.
  • the rolling bearing is designed as a ball bearing. It is also feasible, however, to use other variants of rolling bearings, such as roller bearings, cone bearings, needle roller bearings, or the like.
  • the rolling bearing is formed by two bearing shells 170 and 168 , which have running surfaces for accommodating rolling elements 172 .
  • the lower bearing shell 168 is attached to the impeller 128
  • the upper bearing shell 170 is attached to the containment shell.
  • the bearing shells can be bonded, shrunk-fit or pressed onto the corresponding components, or fixedly screwed thereon.
  • the rolling elements are located in the intermediate space between the bearing shells, which said intermediate space is circumscribed by the running surfaces of the bearing shells. If the pump is intended to be operated at high impeller speeds, the rolling bearings can be connected to one another by means of a cage in order to increase the stability of the bearing.
  • the plain bearing is formed by an upper plain-bearing surface 174 between the upper bearing shell 170 and the jacket surface of the impeller 128 , and by a lower plain-bearing surface 176 between the lower bearing shell 168 and the containment shell 116 .
  • the plain bearing has only slight bearing play at the bearing surface 174 in particular, thereby enabling a portion of the fluid 108 to enter the rolling bearing. The penetration of the rolling bearing by the pumped fluid can provide additional lubrication of the rolling bearing.
  • the bearing play which can be considered to be an annular opening, is preferably protected by a fine-strand filter 178 , in order to ensure that foreign objects that can be contained in the pumped fluid are kept away from the bearing region.
  • the fine-strand filter 178 is held in position by a clamping ring 180 .
  • FIG. 10 shows a further embodiment of a wet rotor pump 200 according to the invention.
  • This wet rotor pump differs substantially from the wet rotor pump shown in FIG. 9 by a different geometry and different dimensions of the housing 204 and the motor cover 216 . This is due to the fact that the rotor magnets 206 are now no longer attached to the drive disk, but rather are attached directly on the impeller 202 . In order to ensure that the distance between the lower end of the stator teeth 212 and the rotor magnets is still minimal, the stator teeth 212 have been lengthened in the vertical extension thereof. As a result, the containment shell 222 , including the suction connecting piece 218 , has a different shape.
  • the stator tooth receptacle 214 is unchanged compared to the stator tooth receptacle of the wet rotor pump shown in FIG. 9 .
  • a further difference between the wet rotor pump 200 and the wet rotor pump described with reference to FIG. 9 relates to the support of the impeller 202 in the containment shell 222 .
  • the impeller 202 of the wet rotor pump 200 is supported in the axial direction by two magnetic rings, which are magnetized such that, in the installed state, said magnetic rings repel one another in the axial direction.
  • a lower magnetic ring 208 is attached to the impeller 202
  • an upper magnetic ring 210 is attached to the containment shell.
  • the magnetic rings can be attached by means of bonding, screwing, shrink-fitting, press-fitting, or other attachment methods.
  • the magnetic rings 208 and 210 comprise permanent magnets, such as neodymium iron boron (NdFeB) or samarium cobalt (SmCo), and are metallically completely encapsulated in an air- and water-tight manner.
  • the encapsulation can be implemented by laser- or friction-welding of the encapsulation components, for example.
  • the encapsulation of all sides that do not face one another comprises non-magnetic metal, such as stainless steel, for example, whereas the welded-on cover plate, i.e. the two sides that face one another, comprise soft magnetic material. The magnetic flux is thereby strengthened in the region of the cover plates.
  • the thickness of the encapsulation can be between 1 mm and 2 mm, for example.
  • the magnetic ring 208 which is pressed on on the impeller side, is manufactured in a manner similar to that of the lower bearing shell 168 of the wet rotor pump shown in FIG. 9 such that a hydrodynamic gap forms between the outer jacket surface of the magnetic ring 208 and the inner jacket surface of the containment shell 222 , which said hydrodynamic gap also functions as a sealing gap.
  • the magnetic rings 208 and 210 are preferably magnetized and oriented such that the repellent effect between the magnetic rings is approximately proportional to the square of the distance between the magnetic rings.
  • the thickness of the magnetic rings 208 and 210 is preferably designed such that, in the non-operative state of the wet rotor pump 200 , equilibrium sets in between the attractive force between the rotor magnets 206 and the stator teeth 212 and the repulsive force between the magnetic rings 208 and 210 .
  • an air gap of approximately 1 mm preferably forms between the lower end of the stator teeth 212 and the rotor magnets 206
  • an air gap having a width of 3 mm forms between the magnetic rings 208 and 210 .
  • the magnetic field strength generated by the magnetic rings 208 and 210 is therefore stronger than the field strength between the rotor magnets 206 and the stator teeth 212 .
  • the pressure differential between the suction side and the pressure side of the wet rotor pump 200 and, therefore, the contact pressure of the impeller 202 increases upwardly, in the direction toward the suction connecting piece 218 .
  • the contact pressure on the mutually repellent magnetic rings 208 and 210 also increases such that the air gap between the magnetic rings 208 and 210 and the air gap between the rotor magnets 206 and the stator teeth 12 is reduced. The reduction of the air gaps continues until a new equilibrium has set in between the contact pressure, the attractive force between the rotor magnets 206 and the stator teeth 212 , and the repulsive force between the magnetic rings 208 and 210 .
  • the performance limit of the wet rotor pump can be dimensioned such that the air gap between the rotor magnets 206 and the stator teeth 212 does not fall below a width of 0.2 mm.
  • safety sliding surfaces 220 can be mounted on the rotor, which extend upwardly beyond the rotor magnets 206 by 0.2 mm, for example. In the event that the aforementioned performance limit is exceeded, said safety sliding surfaces can support the rotor at the containment shell 222 and prevent damage to the impeller 202 or the rotor magnets 206 .

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
US14/373,205 2012-01-20 2013-01-17 Wet rotor pump Abandoned US20140341764A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102012200803.9A DE102012200803B4 (de) 2012-01-20 2012-01-20 Nassläuferpumpe
DE102012200803.9 2012-01-20
PCT/EP2013/050816 WO2013107807A2 (de) 2012-01-20 2013-01-17 Nassläuferpumpe

Publications (1)

Publication Number Publication Date
US20140341764A1 true US20140341764A1 (en) 2014-11-20

Family

ID=47594737

Family Applications (1)

Application Number Title Priority Date Filing Date
US14/373,205 Abandoned US20140341764A1 (en) 2012-01-20 2013-01-17 Wet rotor pump

Country Status (3)

Country Link
US (1) US20140341764A1 (de)
DE (1) DE102012200803B4 (de)
WO (1) WO2013107807A2 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200116151A1 (en) * 2018-10-15 2020-04-16 Coavis Impeller for electric water pump
US12483103B2 (en) 2020-04-24 2025-11-25 Jacobi Motors, Llc Flux-mnemonic permanent magnet synchronous machine and magnetizing a flux-mnemonic permanent magnet synchronous machine

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3904393A (en) * 1973-07-13 1975-09-09 Raymond A Morse Venturi-type water aerator
US5149253A (en) * 1989-06-05 1992-09-22 Ebara Corporation Magnet pumps
US6663827B2 (en) * 2001-04-13 2003-12-16 Romain L. Billiet Rare earth magnet rotors for watch movements and method of fabrication thereof
US20090060408A1 (en) * 2005-03-02 2009-03-05 Ebara Corporation Diamond-coated bearing or seal structure and fluid machine comprising the same
US20100158724A1 (en) * 2008-12-19 2010-06-24 Olai Ihle Electrically commutated DC motor for a liquid pump
US20110144744A1 (en) * 2009-12-03 2011-06-16 Richard Wampler Total artificial heart

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1613626A1 (de) * 1967-03-09 1970-05-14 Eberspaecher J Elektromotor
US4880362A (en) * 1988-05-24 1989-11-14 Laing Karsten A Rotor with stabilizing magnets
JP2989233B2 (ja) * 1990-07-31 1999-12-13 エヌティエヌ株式会社 ターボ形ポンプ
US5332374A (en) * 1992-12-30 1994-07-26 Ralph Kricker Axially coupled flat magnetic pump
FR2787527B1 (fr) * 1998-12-22 2001-03-09 Jeumont Ind Dispositif motorise a circulation centrifuge de fluide, tel qu'une motopompe ou un motocompresseur
DE10009376A1 (de) * 2000-02-29 2001-08-30 Wilo Gmbh Saugseitiger Rotor
DE10053400A1 (de) 2000-10-21 2002-05-02 Daimler Chrysler Ag Axialflussmotor mit Flusskonzentration
AT414064B (de) * 2001-05-11 2006-08-15 Tcg Unitech Ag Pumpe für flüssige medien
DE10203778A1 (de) * 2002-01-30 2003-07-31 Siemens Ag Elektrisch angetriebene Pumpe
DE10303778B4 (de) 2003-01-31 2008-04-10 Daimler Ag Betätigungsanordnung zum Öffnen und Schliessen eines Fahrzeugflügels
DE102005015213A1 (de) 2005-04-02 2006-10-05 Pierburg Gmbh Nassläuferpumpe
JP4517076B2 (ja) * 2005-06-23 2010-08-04 独立行政法人産業技術総合研究所 動圧軸受を備えた人工心臓ポンプ
JP5318730B2 (ja) * 2009-11-17 2013-10-16 株式会社荏原製作所 モータポンプ

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3904393A (en) * 1973-07-13 1975-09-09 Raymond A Morse Venturi-type water aerator
US5149253A (en) * 1989-06-05 1992-09-22 Ebara Corporation Magnet pumps
US6663827B2 (en) * 2001-04-13 2003-12-16 Romain L. Billiet Rare earth magnet rotors for watch movements and method of fabrication thereof
US20090060408A1 (en) * 2005-03-02 2009-03-05 Ebara Corporation Diamond-coated bearing or seal structure and fluid machine comprising the same
US20100158724A1 (en) * 2008-12-19 2010-06-24 Olai Ihle Electrically commutated DC motor for a liquid pump
US20110144744A1 (en) * 2009-12-03 2011-06-16 Richard Wampler Total artificial heart

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20200116151A1 (en) * 2018-10-15 2020-04-16 Coavis Impeller for electric water pump
US11873819B2 (en) * 2018-10-15 2024-01-16 Coavis Impeller for electric water pump
US12483103B2 (en) 2020-04-24 2025-11-25 Jacobi Motors, Llc Flux-mnemonic permanent magnet synchronous machine and magnetizing a flux-mnemonic permanent magnet synchronous machine

Also Published As

Publication number Publication date
DE102012200803A1 (de) 2013-07-25
WO2013107807A3 (de) 2013-10-03
WO2013107807A2 (de) 2013-07-25
DE102012200803B4 (de) 2015-04-02

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