Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02591338 2007-06-04
WO 2006/063267 PCT/US2005/044694
MAGNETIC PULSE PUMP/COMPRESSOR SYSTEM
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a flexible tube pump, and more
particularly to
a pump with a magnetically collapsible elastomeric member which collapses over
a mandrel.
[0002] Reciprocating pumps are highly desirable for use in numerous
applications,
particularly in environments where liquid flow rate is relatively low and the
required liquid
pressure rise is relatively high. For applications requiring less pressure
rise and greater flow rate,
single stage centrifugal pumps are favored because of their simplicity, low
cost, and low
maintenance requirements.
[0003] Another pump type is a flexible tube pump. Such pumps are often used
for
the transportation and pressurization of sensitive media or for applications
in the vacuum field
where the achievement of a "Clean" vacuum is relatively important. Common
foi7ns of pumps
with a flexible member are bellows and diaphragm pumps. The diaphragm is
typically an
elastomer forming part of the volume being pumped. By reciprocating the
flexible member
within the pump head space in which are usually located inlet and outlet one-
way valves, the
media being pumped enters and is then forced out of the pump head. The
mechanism for
actuating the flexible member may be by linkage to a motor or by valved
compressed air.
[0004] Other actuators include a magnetically responsive elastic tube
stretched onto,
thereby sealing to, a shaft with inlet and outlet ports at or adjacent tube
ends. Local to the inlet
port a magnetic field is generated within the enclosing body. This field is
substantially concentric
to the tube, which responds by expanding circumferentially towards the
magnetic field. This
creates a volume between the tube and shaft, the length of the tube outside
the influence of the
magnetic field remains sealed upon the shaft. Subsequent movement of the
magnetic field along
the axis of the pump gives transport to the volume and any media enclosed
within from the inlet
port to the outlet port, whereupon reduction of the magnetic field results in
exhaustion of the
volume. This cycle results in a pumping action.
[0005] Disadvantageously, known flexible tube pumps are complicated,
relatively
costly to manufacture and provide minimal pumping pressure.
[0006] Accordingly, it is desirable to provide an inexpensive flexible tube
pump
which provides increased pressures.
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SUMMARY OF THE INVENTION
100071 The magnetic pump system according to the present invention includes a
ring
shaped electric magnet that when pulsed with high voltage and high current,
causes an
magnetically deflectable elastic member to collapse over a mandrel with an
arcuate outer
surface. The volume between the arcuate outer surface and the inside of the
elastic member is
reduced causing compression and expulsion of the fluid therein througli a one-
way passage
system. When the magnetic field subsides, the tube regains its shape drawing
fluid in through
the one-way passage system.
[0008] When the magnet is energized, an intense magnetic field is created. If
the
elastic member is conductive, eddy currents are generated on the elastic
member. This creates a
magnetic field that is opposite to the ring magnet field. The two fields repel
each other and since
the elastic member is elastic it moves towards the mandrel If the elastic
nleniber is magnetic,
the fields of the magnet and the ring magnet repel each other and the same
action occurs.
[0009] The present invention therefore provides an inexpensive flexible tube
punip
which provides increased pressures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The various features and advantages of this invention will become
apparent to
those skilled in the art from the following detailed description of the
currently prefen=ed
embodiment. The drawings that accompany the detailed description can be
briefly described as
follows:
[0011] Figure 1 is a side view of a pump system according to the present
invention;
[0012] Figure 2 is a sectional side view of a pump system with the elastic
meniber in
an uncompressed state;
[0013] Figure 3 is a top view of a pump system;
[0014] Figure 4 is an expanded sectional side view of a manifold for a pump
system
according to the present invention;
[0015] Figure 5 is a schematic view of a magnetic field for use with the
present
invention;
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[0016] Figure 6a is a schematic top view of a single bitter disc in which a
multiple
thereof forms a magnet for use with the present invention;
[0017] Figure 6b is a schematic top view of a magnetic bitter disc showing
contact
which allows a multiple of stacked bitter discs to form a helical magnetic
coil;
[0018] Figure 6c is a schematic top view of a bitter disc showing contact
areas which
allows a multiple of stacked bitter discs to form a helical magnetic coil;
[0019] Figure 6d is a schematic bottom view of a bitter disc showing a contact
area
which allow a multiple of stacked bitter discs to fonn a helical magnetic
coil;
[0020] Figure 7 is a side view of a bitter disc stack between a pair of
cooling fins;
[0021] Figure 8 is a schematic of a control circuit for the pump system
according to
the present invention; and
[00221 Figure 9 is a sectional side view of a pump system with the elastic
member in
a compressed state.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Figure 1 illustrates a general perspective view of a pump assembly 10.
The
pump assembly 10 generally includes a mandrel 12, a magnetically deflectable
elastic member
14 mounted about said mandrel 12 and a ring magnet 16 about said deflectable
elastic member
14. It should be understood that although the pump assembly 10 is described as
a compressor for
a gas, other uses such as that of a fluid pump will likewise benefit from the
present invention.
[0024] The mandrel 12 defines a longitudinal axis A. The mandrel 12 is a
generally
tubular member with an arcuate outer surface 17 defined about the axis A to
form a generally
hour-glass shape. More preferably, the outer surface 17 is parabolic. A
passage system 18
(Figure 2) having an inlet port 20 and a discharge port 22 are defined within
opposed manifolds
24, 26 attached adjacent to each longitudinal end of the mandrel 12. The
manifolds 24, 26 may
be integral to the mandrel 12 or may be separate components, which are
attached to the mandrel
12 with fasteners F (Figure 3) or the like.
[0025] Referring to Figure 2, the passage system 18 communicates with a
pumping
volume V between the arcuate outer surface 17 defined between the arcuate
outer surface 17 and
the deflectable elastic member 14. The passage system 18 includes a multiple
of longitudinal
passage 18a, 18b (two shown) which are radially located about the axis A. It
should be
understood that a multiple of passages are radially disposed about axis A even
though only
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CA 02591338 2009-05-14
passages 18a, 18b are illustrated in the cross-section of Figure 2. A single
central passage 18c
located on axis A with passage branches 18d which extend off of axis A and
comniunicate witli
the arcuate outer surface 17 are additionally provided to further increase
fluid throughput. It
should be understood that various passage paths may be used with the present
invention.
[0026] Each passage 18a-18c of the passage system 18 includes a one-way check
valve 28 such that fluid will only flow from inlet port 20 to the discharge
port 22. Each passage
is essentially segmented into an input portion, which feeds into volume V, and
a discharge
portion which feeds from the volume V. The input and discharge portions need
not be linearly
aligned. Each check valve 28 is preferably threaded into the inner diameter of
the passages 18a-
18c, however, other mounting arrangements may also be utilized.
[0027] The magnetically deflectable elastic member 14 is preferably a tubular
rubber
material impregnated with conductor or magnetic materials. AIternately,
flexible electrically
conductive strips such as copper plated spring steel strips or wires are
mounted around the tube.
[0028] The deflectable elastic member 14 is mounted to the mandrel 12 adjacent
each manifold 24, 26 through an annular clamp ring 30. The clamp ring 30
includes a wedge
shape 32 which corresponds to a mandrel wedge shape section 34 along each rim
36 thereof.
The clamp ring 30 is attached to the mandrel 12 though fasteners F (also
illustrated in Figure 4)
such as bolts. As the fasteners F are threaded into the clamp ring 30 the
clamp ring 30 clamps
the deflectable elastic member 14 to the mandrel wedge shape section 34.
[0029] The ring magnet 16 is preferably a ring magnet which generates a field
that is
parabolic in shape (Figure 5) to correspond to the arcuate outer surface 17 of
the mandrel 12.
The magnet may be manufactures as a winding of wire around a spool, however,
magnets niade
of discs commonly known as bitter discs 38, are preferred.
[0030] Referring to Figures 5, 6a-6d, the bitter discs 38 are stamped out of
copper or
aluminum of a thickness which depends on the cunrent carrying capability and
rigidity required.
An insulator is stamped out of a thin sheet of insulation, typically
fiberglass. Several of these
disc and insulator sections are interleaved to form a helix or coil by contact
with the adjacent
discs (Figure 7). A contact area C on one side of each bitter disc 38 provides
contact with an
interference area C2 on the opposite side of the next bitter disc 38 (Figure
6B) therebetween
while the insulator prevents the discs 38 from touching except at the
interface I.
[0031] Each bitter disc 38 is rotated relative to the adjacent disc so that
each contact
area C on one side of a bitter disc 38 contacts the contact area C2 on an
opposite side of the
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WO 2006/063267 PCT/US2005/044694
adjacent bitter disc 38. That is, the contact areas C1, C2 on a single bitter
disc are radially
displaced and on opposite sides of each bitter disc 38. By radially displacing
each adjacent bitter
disc 38 in a stack (Figure 7), a continuous helical coil of bitter discs is
formed. After the discs
are stacked, they are clamped together with a multiple of tie bolts 40 or the
like (Figure 7). A
cooling fin 42 may also be located at each end of the bitter disc stack.
[0032] Referring to Figure 8, a power supply and control circuit 44 to drive
the ring
magnet 16 is schematically illustrated. The AC power source is stepped up to a
higher voltage
by a transformer. The AC switch connects the incoming power to a bridge
rectifier. The DC
switch connects the capacitor to the ring magnet 16. The switches may be
SCR's, IGBT
transistors and/or other semiconductor devices. Control logic controls the
charging of the
capacitor and the discharge of the capacitor into the ring magnet 16.
[0033] This control circuit 44 is preferably a single phase supply, however, a
poly-
phase supply may be used by replacing the transformer and bridge with a poly-
phase transformer
and bridge. Depending on the incoming voltage and desired DC voltage the
transformer may not
be required. For example, if the incoming power is 480VAC the DC voltage will
be about 700V.
If the switches are designed to handle these voltages no transformer would be
required.
[0034] The control sequence of operation is generally as follows: 1) initially
AC and
DC switches are open; 2) the AC switch is closed and the capacitor charged for
tiine T1; 3) the
AC switch is opened; 4) the DC switch is closed discharging the capacitor into
the ring magnet;
and 5) the DC switch is opened for time T2.
[0035] Each time this sequence is executed the ring magnet 16 fires and
collapses the
deflectable elastic member 14 (Figure 9). Time TI determines the capacitor
charge. By varying
this time the pressure that the pump 10 develops is controlled. T2 determines
the frequency of
cycles. T2 is preferably a time which allows the deflectable elastic member 14
to regain shape.
Higher frequency of operation may be obtained by pressurizing the inlet port
20 with a first stage
pump or compressor. This will allow the deflectable elastic member 14 to
regain shape faster
after being collapsed. Alternatively, or in addition the magnet may be
reversed to essentially
pull the deflectable elastic member 14 back to the uncollapsed shape (Figure
2). The first stage.
pump or compressor may be of a much lower pressure than the pump system 10.
[0036] One magnet has been illustrated for simplicity of explanation, howevei-
,
multiple magnets are preferably utilized to produce a greater flow velocity.
The magnets are
fired in sequence from inlet port to discharge port. The advantage is that as
one magnet is firing
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WO 2006/063267 PCT/US2005/044694
the firing circuit of the others can be charging. Notably, the deflectable
elastic member may
extend beyond the inlet and discharge such that if the deflectable elastic
member is extended
from the inlet to the source and from the discharge to the destination a
totally lead free system is
achieved.
[0037] It should be understood that relative positional terms such as
"forward," "aft,"
"upper," "lower," "above," "below," and the like are with reference to the
normal operational
attitude of the vehicle and should not be considered otherwise limiting.
[0038] Although particular step sequences are shown, described, and claitned,
it
should be understood that steps may be performed in any order, separated or
combined unless
otherwise indicated and will still benefit from the present invention.
[0039] The foregoing description is exemplary rather than defined by the
limitations
within. Many modifications and variations of the present invention are
possible in light of the
above teachings. The preferred embodiments of this invention have been
disclosed, however,
one of ordinary skill in the art would recognize that certain modifications
would come within the
scope of this invention. It is, therefore, to be understood that within the
scope of the appended
claims, the invention may be practiced otherwise than as specifically
described. For that reason
the following claims should be studied to determine the true scope and content
of this invention.
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