This application is a section 371 of PCT/EP05/09443, filed 2 Sep. 2005.
The present invention relates to an arrangement for pumping fluids. As fluids, liquid and/or gaseous media can be pumped.
In computers, components having high heat flux densities (e.g. 60 W/cm2) are in use today. These components must be cooled with suitable cooling arrangements, in order to prevent thermal destruction of the components.
In cooling arrangements of this kind, dissipation of heat from these components is accomplished by means of so-called “heat absorbers” or “cold plates.” In these, heat is transferred to a cooling liquid, to which a forced circulation in a circulation system is usually imparted. In this context, the cooling liquid flows not only through the heat absorber, but also through a liquid pump that produces the forced circulation and produces an appropriate pressure buildup and appropriate volumetric flow through the heat absorber and through an associated liquid/air heat exchanger. The liquid/air heat exchanger serves to discharge heat from the cooling liquid to the ambient air. A fan is usually arranged for this purpose on the liquid/air heat exchanger, which fan produces, on the air side of the heat exchanger, a forced convection of the cooling air, as well as good transfer coefficients.
Because of the limited installation space available in computers, and the consequent high integration density of components arranged therein, a compact design for such cooling arrangements is desirable.
It is therefore an object of the present invention to make available a novel arrangement for delivering fluids.
The object of the present invention is achieved in particular by an arrangement in which a first permanent magnet, forming part of an electronically commutated external-rotor motor, is arranged in an interstice between a stator carrier and a bearing tube, and the first permanent magnet couples magnetically to a second permanent magnet, located on an opposite side of a magnetically transparent fluid-tight partition, the second permanent magnet forming part of a rotor of a fluid pump, so that rotation of the first permanent magnet effectively causes a wheel of the fluid pump to rotate in the same rotational direction. In accordance therewith, an arrangement for delivering fluids encompasses an electronically commutated external-rotor motor having a stator arranged on a stator carrier and having a rotor journaled in a bearing tube, as well as a fluid pump having a pump wheel. The rotor of the electronically commutated external-rotor motor and the pump wheel of the fluid pump are magnetically coupled to one another via a magnetic coupling, in such a way that a rotation of the rotor produces a rotation of the pump wheel. This magnetic coupling is constituted by a first permanent magnet joined to the rotor, in coaction with a second permanent magnet joined to the pump wheel. At least the first permanent magnet is arranged in an interstice between the stator carrier and the bearing tube, and is separated from the second permanent magnet by a liquid-tight but magnetically transparent partition.
A very compact arrangement with a high level of integration and good efficiency, in particular at low and moderate rotation speeds, is thereby obtained; the placement of the first permanent magnet in the interstice between the stator carrier and the bearing tube allows a low overall height to be achieved.
A preferred refinement of the arrangement is to place the first permanent magnet radially between a bearing tube of the motor rotor and the fluid-tight partition, and to place the second permanent magnet radially between the fluid-tight partition and a stator of the motor.
In accordance therewith, the second permanent magnet can likewise be arranged in the interstice between the stator carrier and the bearing tube. This enables a further reduction in overall height and an increase in the integrity of the unit made up of the external-rotor motor, magnetic coupling, and fluid pump.
A further preferred refinement of the arrangement according to the present invention is form the bearing tube, the fluid-tight partition, and a stator carrier as one meander-shaped, integrally-formed part, with one end of the partition joining the bearing tube and the other end of the partition joining the stator carrier.
In accordance therewith, the bearing tube, partition, and stator carrier can be implemented as an integral part that is meander-shaped in cross section. This allows the parts count to be minimized, and assembly of the arrangement thus to be simplified.
Further details and advantageous refinements of the invention are evident from the exemplifying embodiments, in no way to be understood as a limitation of the invention, that are described below and depicted in the drawings. In the drawings:
In the description that follows, the terms “left,” “right,” “top,” and “bottom” refer to the respective figure of the drawings, and can vary from one figure to the next as a function of a particular orientation (portrait or landscape) that is selected. Identical or identically functioning parts are labeled with the same reference characters in the various figures, and usually are described only once.
Internal stator 22 is mounted on an annular stator carrier 34, usually by being pressed on. The shape of stator carrier 34 is particularly clearly evident from
External rotor 26 has a design with a so-called rotor cup 40, which is depicted in
Fan blades 64 are depicted, by way of example, on the outer side of rotor cup 40. For this purpose, rotor cup 40 is by preference surrounded by a plastic part (not depicted; cf.
A shaft 46 is mounted in rotor cup 40 in the manner depicted. Shaft 46 is journaled in two ball bearings 48, 50 that, for example, during assembly are pressed from above (in
The installation of shaft 46 with ball bearings 48, 50 in bearing tube 30 is particularly clearly evident from
Implemented between bearing tube 30 and stator carrier 34 is an interstice in which a so-called “driving” magnet 67 is arranged. This driving magnet 67 provides drive in a magnetic coupling, and in
In
The partitioning can transitions, via the outer periphery of annular flange 74, into a cylindrical portion 94 that, as depicted, serves for mounting a cover 88 in order to form therewith a liquid-tight pump housing 86. Cover 88 can be mounted on cylindrical portion 94, for example, by means of a screw attachment (not shown), a sealing ring (not shown), or by laser welding. Provided on cover 88 is an inlet 96 through which a fluid can travel into pump housing 86, which fluid can emerge from pump housing 86 via a schematically depicted outlet 98.
A pump wheel 90 is provided in the interior space of pump housing 86 to constitute fluid pump 84. In
Pump shaft 106 forms a stationary axle on which pump wheel 90 in
As an alternative to the stationary axle, it is possible to provide a rotating shaft for the journaling of pump wheel 90. This shaft, just like shaft 46 of external rotor 26, is journaled in a bearing tube (not depicted) that is then, like bearing tube 30, implemented integrally with the partitioning can and protrudes downward therefrom, i.e. in mirror-image fashion to bearing tube 30.
Pump wheel 90 is preferably implemented integrally with the driven magnet 92 that, by coaction with driving magnet 67, forms the magnetic coupling; in other words, when driving magnet 67 rotates, driven magnet 92 also rotates and thereby drives pump wheel 90, with the result that the latter draws in a fluid through inlet 96 and pumps it back out through outlet 98, as indicated by arrows. Liquid media, e.g. cooling liquids, and/or gaseous media can be utilized as fluids. Furthermore, any desired other hydraulic machine, e.g. a compressor for a coolant, can be provided, instead of a pump.
In
In contrast to
As is particularly clearly evident from
Because driven magnet 92 is arranged on an axial projection of driving magnet 67, the magnetic coupling is formed by a linkage of the axial magnetic fields of these permanent magnets. This magnetic coupling is therefore referred to hereinafter, for illustrative purposes, as an “axial” magnetic coupling. In order to ensure unhindered functionality of this axial magnetic coupling, a permanent magnet having a strong axial magnetic field, e.g. a rare-earth magnet, is preferably used for driven magnet 92.
Operation
In operation, external-rotor 20 forms, along with external rotor 26, a fan whose fan blades 64 rotate in fan housing 68. In
Upon rotation of external rotor 26, driving magnet 67 (which may be magnetized, for example, with six or eight poles) is also rotated. Driving magnet 67 drives driven magnet 92, which in this case is likewise magnetized with six or eight poles, and causes it also to rotate. If driving magnet 67 rotates, for example, counterclockwise, driven magnet is consequently also rotated by the magnetic coupling counterclockwise at the same speed. The arrangement depicted in
As a result of the imposed rotation of driven magnet 92, pump wheel 90 is also rotated, so that the latter draws in a corresponding fluid through inlet 96 and pumps it back out through outlet 98. An arrangement of this kind can be used, for example, in a water fountain, in order to draw in water and pump it out, or to pump blood in a heart-lung machine, or to transport a cooling liquid in a closed cooling circuit, in which case pump wheel 90 then has the function of a circulating pump.
Because cover 88 is hermetically connected or joined in liquid-tight fashion, e.g. by laser welding, to cylindrical portion 94, when a liquid is delivered out of pump housing 86, said liquid cannot escape to the outside. Contributing to this is the fact that portion 94 has no orifices of any kind. This is possible because electronically commutated external-rotor motor 20 and fluid pump 84 can be assembled independently of one another and in a very simple and reliably processed manner (cf.
As a result of the small physical distance between driving magnet 67 and driven magnet 92 in
Numerous variants and modifications are of course possible within the scope of the present invention.
Number | Date | Country | Kind |
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20 2004 015 933 U | Oct 2004 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2005/009443 | 9/2/2005 | WO | 00 | 4/6/2007 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2006/039965 | 4/20/2006 | WO | A |
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Number | Date | Country | |
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20080038126 A1 | Feb 2008 | US |