MAGNETICALLY DRIVEN ARCHIMEDES SPIRAL SCREW PUMP

POMPE A VIS A SPIRALE D'ARCHIMEDE A ENTRAINEMENT MAGNETIQUE

English Abstract

A pump system comprises a pump assembly and a control assembly.
The pump assembly comprises a casing, a helical vane for moving
fluid, and a permanent magnet. The casing has a fluid inlet and
a fluid outlet. The helical vane is housed inside the casing.
The permanent magnet is securely attached to the bottom portion
of the helical vane. The control assembly comprises a casing, a
control circuitry, and a plurality of electromagnets. The
electromagnets are securely attached to the top portion of the
casing. The helical vane is capable of minimising turbulent flow
and of maximising laminar flow inside the pump assembly. The
control circuitry is capable of generating magnetic field by
energising the electromagnets. Sequentially changing magnetic
field of the electromagnets causes the helical vane to rotate.
This invention relates to pump systems with an Archimedes spiral
screw, and the principal use of the invention is for circulating
fluid.

French Abstract

L'invention a trait à un système de pompe comprenant un ensemble pompe et un ensemble commande. L'ensemble pompe comprend un boîtier, une aube hélicoïdale pour déplacer le fluide et un aimant permanent. Le boîtier est pourvu d'une entrée de fluide et d'une sortie de fluide. L'aube hélicoïdale est logée à l'intérieur du boîtier. L'aimant permanent est fixé solidement à la partie inférieure de l'aube hélicoïdale. L'ensemble commande comprend un boîtier, un circuit de commande et une pluralité d'électroaimants. Ces derniers sont fixés solidement à la partie supérieure du boîtier. L'aube hélicoïdale est en mesure de réduire le flux turbulent et de maximiser le flux laminaire à l'intérieur de l'ensemble pompe. Le circuit de commande est en mesure de générer un champ magnétique en excitant les électroaimants. Le champ magnétique à modification séquentielle des électroaimants entraîne la rotation de l'aube hélicoïdale. La présente invention a trait à des systèmes de pompe comprenant une vis en spirale d'Archimède et la principale utilisation de l'invention consiste à faire circuler du fluide.

Claims

Claims
.cndot. The embodiments of the invention in which an exclusive property
or privilege is claimed are defined as follows:
1. A pump system for circulating fluid, comprising:
.circle. a pump assembly comprising:
~ a casing having a top portion and a bottom portion, the
casing having a fluid inlet and a fluid outlet;
~ a helical vane for moving fluid, the helical vane
having a top portion, a bottom portion and a rotational
axis, the helical vane housed inside the casing;
~ a permanent magnet securely attached to the bottom
portion of the helical vane;
~ a ring-shaped magnetic element having N and S poles,
the ring-shaped magnetic element securely attached to
the top portion of the casing of the pump assembly; and
~ a disc-shaped magnetic element having N and S poles,
the disc-shaped magnetic element securely attached to
the top portion of the helical vane of the pump
assembly; and
.circle. a control assembly comprising:
~ a casing having a top portion, the top portion of the
casing securely attached to the bottom portion of the
casing of the pump assembly;
~ a control circuitry securely housed inside the casing;
~ a set of electrical cables for providing electrical
power and control signals, the electrical cables
electrically connected to the control circuitry; and
~ a plurality of electromagnets securely attached to the
top portion of the casing, the electromagnets
electrically connected to the control circuitry;
in which the helical vane of the pump assembly is capable of
minimising turbulent flow and of maximising laminar flow
inside the pump assembly, in which the control circuitry of
the control assembly is capable of generating magnetic field
by energising the electromagnets of the control assembly, in
which sequentially changing magnetic field of the
electromagnets of the control assembly causes the helical
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vane of the pump assembly to rotate around the rotational
axis, in which magnetic repulsion force between the
ring-shaped magnetic element and the disc-shaped magnetic
element forming passive magnetic bearing in order to avoid
physical contact.
2. The pump system as defined in claim 1, in which the permanent
magnet of the pump assembly is disc-shaped.
3. The pump system as defined in claim 1, in which the permanent
magnet of the pump assembly is a single magnet with multiple
polarisation areas.
4. The pump system as defined in claim 1, in which the permanent
magnet of the pump assembly is made of a rare-earth magnet.
5. The pump system as defined in claim 1, in which the electrical
cables of the control assembly provide AC electrical power.
6. The pump system as defined in claim 1, in which the electrical
cables of the control assembly provide DC electrical power.
7. The pump system as defined in claim 1, in which each
electromagnet of the control assembly is a coreless coil.
8. The pump system as defined in claim 1, in which the ring-shaped
magnetic element is made of a rare-earth magnet.
9. The pump system as defined in claim 1, in which the disc-shaped
magnetic element is made of a rare-earth magnet.
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Description

CA 02602952 2013-12-10
Description
Title
= Magnetically Driven Archimedes Spiral Screw Pump
Technical Field
= This invention relates to pump systems for circulating fluid,
more particularly to a pump system with an Archimedes spiral
screw.
Background Art
= There are many instances where it would be desirable to be able
to move fluids with a magnetically-driven Archimedes spiral
screw as a fluid mover in ultra-long life, ultra-low wear pumps.
= A number of patents disclose various systems for moving fluids
with helical vanes.
= U.S. Patent 4 239 449 discloses "Screw pump construction". A
hydraulic screw pump is provided having a rotatable screw which
may comprise a helical blade disposed within an enclosed full or
open half cylinder. In half-cylindrical constructions the
helical blade rotates relative to a half cylinder which may be
formed of concrete. The enclosed screw pumps may have the
helical blades welded to the inner periphery of a surrounding
metal cylinder so as to rotate therewith, or be welded to said
surrounding metal cylinder and also to an inner cylinder which
provides axial reinforcement.
= U.S. Patent 4 957 504 discloses "Implantable blood pump". The
pump includes a stator having a cylindrical opening, an annular
array of electromagnets carried by the stator concentric with
the cylindrical opening and lying in a plane transverse to the
axis of the opening, a bearing carried by the stator and
extending across the cylindrical opening, and a rotor supported
by the bearing for rotation about the axis of the cylindrical
opening, the rotor being in the form of an Archimedes screw and
having a permanent magnet in its periphery which lies in the
same plane as the array of electromagnets.
= U.S. Patent 6 447 275 discloses "Screw pump". A screw pump
includes a screw rotatably arranged in a housing, the threads of
which are partially in engagement with a rotatable sealing
device having radial sealing discs, whereby the screw area of
the screw, including thread grooves and thread walls, are formed
by a generatrix which is a part of a circle arc, the circle of
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CA 02602952 2013-12-10
which is rotatable around an eccentric rotation axis when the
generatrix rotates around the axis of the screw and is displaced
along this with a velocity being proportional to the rotational
velocity of the screw.
= U.S. Patent 6 527 699 discloses "Magnetic suspension blood
pump". This invention is a non-contact axial flow turbo blood
pump for propelling blood, which is composed of a pump housing
that defines a pump axis, with inlet, outlet openings at
opposite axial ends of the pump housing, a rotor unit that
defines a rotor axis, and opposing rotor axial ends. The pump
magnetically suspends the rotor within the pump housing at the
rotor axial ends so as to avoid causing physical contact between
the housing to define fluid gaps between the rotor axial ends,
and the magnetic suspension elements.
= Canadian Patent 2 327 490 discloses "Magnetically Erected
Wind-Effect Display Device". The wind-effect element of the
rotor assembly is capable of rotating around the central axis of
rotation by an external force exerted by wind pressure. This
prior art demonstrates the effectiveness of the helical vane
with magnetic bearing for moving fluid.
= These prior art arrangements do not have a pump system having
Archimedes spiral screw with edge-energisation and passive
magnetic bearing. The impeller used in conventional centrifugal
pumps causes turbulent flow with high level of noise and
vibration, and may create cavitation which leads to short life
and high wear of the pump mechanism.
Description of the Invention
= It is a primary object of the invention to provide a pump system
for circulating fluid with an Archimedes spiral screw.
= It is another object of the invention to provide a pump system
with a helical vane which is capable of minimising turbulent
flow and of maximising laminar flow.
= It is another object of the invention to provide a pump system
with a helical vane which is housed in a casing without
penetration of a shaft seal which causes liquid leak.
= It is another object of the invention to provide a pump system
with a helical vane which has permanent magnets to be driven by
electromagnets.
= It is another object of the invention to provide a pump system
with a helical vane which rotates around a rotational axis by
sequentially changing magnetic field of the electromagnets.
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= It is another object of the invention to provide a pump system
with passive magnetic bearing in order to avoid physical
contact.
= A pump system comprises a pump assembly and a control assembly.
The pump assembly comprises a casing, a helical vane for moving
fluid, and a permanent magnet. The casing has a fluid inlet and
a fluid outlet. The helical vane is housed inside the casing.
The permanent magnet is securely attached to the bottom portion
of the helical vane. The control assembly comprises a casing, a
control circuitry, and a plurality of electromagnets. The
electromagnets are securely attached to the top portion of the
casing. The helical vane is capable of minimising turbulent flow
and of maximising laminar flow inside the pump assembly. The
control circuitry is capable of generating magnetic field by
energising the electromagnets. Sequentially changing magnetic
field of the electromagnets causes the helical vane to rotate.
Brief Description of the Figures in the Drawings
= In drawings which illustrate embodiments of the invention:
O Figure 1 is a perspective view of one embodiment of a
magnetically-driven Archimedes spiral screw pump according
to the invention;
O Figure 2 is an exploded sectional view of one embodiment of
a magnetically-driven Archimedes spiral screw pump according
to the invention;
O Figure 3 is an exploded sectional view of another embodiment
of a magnetically-driven Archimedes spiral screw pump
according to the invention;
O Figure 4 is a bottom view of the helical vane with permanent
magnets; and
O Figure 5 is a top view of the control assembly with
electromagnets.
Modes for Carrying Out the Invention
= In one embodiment of the invention shown in Figure 1, a pump
system for circulating fluid comprises a pump assembly and a
control assembly.
= Figure 2 shows one embodiment of the pump system. Figure 3 shows
another embodiment of the pump system.
= The pump assembly comprises a casing 1-0, a helical vane 1-3 for
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moving fluid, and a permanent magnet 1-4.
= The casing 1-0 has a top portion and a bottom portion. The
casing 1-0 has a fluid inlet 1-1 and a fluid outlet 1-2.
= The helical vane 1-3 has a top portion, a bottom portion and a
rotational axis. The helical vane 1-3 is housed inside the
casing 1-0.
= The permanent magnet 1-4 is securely attached to the bottom
portion of the helical vane 1-3, as shown in Figure 4.
= The control assembly comprises a casing 2-0, a control circuitry
2-1, a set of electrical cables 2-2 for providing electrical
power and control signals, and a plurality of electromagnets
2-3.
= The casing 2-0 has a top portion. The top portion of the casing
2-0 is securely attached to the bottom portion of the casing 1-0
of the pump assembly.
= The control circuitry 2-1 is securely housed inside the casing.
= The electrical cables 2-2 are electrically connected to the
control circuitry 2-1.
= The electromagnets 2-3 are securely attached to the top portion
of the casing 2-0, as shown in Figure 5. The electromagnets 2-3
are electrically connected to the control circuitry 2-1.
= According to the present invention, the helical vane 1-3 of the
pump assembly is capable of minimising turbulent flow and of
maximising laminar flow inside the pump assembly.
= The control circuitry 2-1 of the control assembly is capable of
generating magnetic field by energising the electromagnets 2-3
of the control assembly.
= Sequentially changing magnetic field of the electromagnets 2-3
of the control assembly causes the helical vane 1-3 of the pump
assembly to rotate around the rotational axis.
= The permanent magnet 1-4 of the pump assembly may be
disc-shaped. Alternatively, the permanent magnet 1-4 of the pump
assembly may be a single magnet with multiple polarisation
areas.
= Preferably, the permanent magnet 1-4 of the pump assembly is
made of a rare-earth magnet.
= The electrical cables 2-2 of the control assembly may provide AC
electrical power. Alternatively, the electrical cables 2-2 of
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the control assembly may provide DC electrical power.
= Each electromagnet 2-3 of the control assembly may be a coreless
coil.
= The pump system may further comprise a first magnetic element
3-1 and a second magnetic element 3-2, as shown in Figure 3.
= The first magnetic element 3-1 has N and S poles. The first
magnetic element 3-1 is securely attached to the top portion of
the casing 1-0 of the pump assembly.
= The second magnetic element 3-2 has N and S poles. The second
magnetic element 3-2 is securely attached to the top portion of
the helical vane 1-3 of the pump assembly.
= Magnetic repulsion force between the first magnetic element 3-1
and the second magnetic element 3-2 forms passive magnetic
bearing in order to avoid physical contact.
= The first magnetic element 3-1 may be ring-shaped. The second
magnetic element 3-2 may be disc-shaped.
= The first magnetic element 3-1 may be made of a rare-earth
magnet. The second magnetic element 3-2 may be made of a
rare-earth magnet.

Representative Drawing