US20060127247A1

US20060127247A1 - Magnetic pulse pump/compressor system

Info

Publication number: US20060127247A1
Application number: US11/009,802
Authority: US
Inventors: Richard Caddell
Original assignee: Hamilton Sundstrand Corp
Current assignee: Hitachi Global Air Power US LLC
Priority date: 2004-12-10
Filing date: 2004-12-10
Publication date: 2006-06-15
Also published as: JP4866859B2; EP1828605A1; CA2591338A1; CN101087957B; JP2008523311A; WO2006063267A1; MX2007006935A; AU2005313898A1; EP1828605B1; CN101087957A; BRPI0518888A2; AU2005313898B2; DE602005019619D1; CA2591338C

Abstract

A magnetic pump system includes a ring shaped electric magnet that when pulsed with high voltage and high current, causes a magnetically deflectable elastic member to collapse over a mandrill 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 through a discharge of a one-way passage system. When the magnetic field subsides, the elastic member regains its shape drawing fluid in through an inlet to the one-way passage system.

Description

BACKGROUND OF THE INVENTION

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.
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.
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 forms 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.
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.
Disadvantageously, known flexible tube pumps are complicated, relatively costly to manufacture and provide minimal pumping pressure.
Accordingly, it is desirable to provide an inexpensive flexible tube pump which provides increased pressures.

SUMMARY OF THE INVENTION

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 mandrill 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 through a one-way passage system. When the magnetic field subsides, the tube regains its shape drawing fluid in through the one-way passage system.
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 mandrill. If the elastic member is magnetic, the fields of the magnet and the ring magnet repel each other and the same action occurs.
The present invention therefore provides an inexpensive flexible tube pump which provides increased pressures.

BRIEF DESCRIPTION OF THE DRAWINGS

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 preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:
FIG. 1 is a side view of a pump system according to the present invention;
FIG. 2 is a sectional side view of a pump system with the elastic member in an uncompressed state;
FIG. 3 is a top view of a pump system;
FIG. 4 is an expanded sectional side view of a manifold for a pump system according to the present invention;
FIG. 5 is a schematic view of a magnetic field for use with the present invention;
FIG. 6 a is a schematic top view of a single bitter disc in which a multiple thereof forms a magnet for use with the present invention;
FIG. 6 b 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;
FIG. 6 c 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;
FIG. 6 d is a schematic bottom view of a bitter disc showing a contact area which allow a multiple of stacked bitter discs to form a helical magnetic coil;
FIG. 7 is a side view of a bitter disc stack between a pair of cooling fins;
FIG. 8 is a schematic of a control circuit for the pump system according to the present invention; and
FIG. 9 is a sectional side view of a pump system with the elastic member in a compressed state.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a general perspective view of a pump assembly 10. The pump assembly 10 generally includes a mandrill 12, a magnetically deflectable elastic member 14 mounted about said mandrill 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.
The mandrill 12 defines a longitudinal axis A. The mandrill 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 (FIG. 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 mandrill 12. The manifolds 24, 26 may be integral to the mandrill 12 or may be separate components, which are attached to the mandrill 12 with fasteners F (FIG. 3) or the like.
Referring to FIG. 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 18 a, 18 b (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 passages 18 a, 18 b are illustrated in the cross-section of FIG. 2. A single central passage 18 c located on axis A with passage branches 18 d which extend off of axis A and communicate with 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.
Each passage 18 a-18 c 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 18 a-18 c, however, other mounting arrangements may also be utilized.
The magnetically deflectable elastic member 14 is preferably a tubular rubber material impregnated with conductor or magnetic materials. Alternately, flexible electrically conductive strips such as copper plated spring steel strips or wires are mounted around the tube.
The deflectable elastic member 14 is mounted to the mandrill 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 mandrill wedge shape section 34 along each rim 36 thereof. The clamp ring 30 is attached to the mandrill 12 though fasteners F (also illustrated in FIG. 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 mandrill wedge shape section 34.
The ring magnet 16 is preferably a ring magnet which generates a field that is parabolic in shape (FIG. 5) to correspond to the arcuate outer surface 17 of the mandrill 12. The magnet may be manufactures as a winding of wire around a spool, however, magnets made of discs commonly known as bitter discs 38, are preferred.
Referring to FIGS. 5, 6 a-6 d, the bitter discs 38 are stamped out of copper or aluminum of a thickness which depends on the current 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 (FIG. 7). A contact area C on one side of each bitter disc 38 provides contact with an interference area C₂on the opposite side of the next bitter disc 38 (FIG. 6B) therebetween while the insulator prevents the discs 38 from touching except at the interface I.
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 C₂on an opposite side of the adjacent bitter disc 38. That is, the contact areas C₁, C₂on 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 (FIG. 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 (FIG. 7). A cooling fin 42 may also be located at each end of the bitter disc stack.
Referring to FIG. 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.
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 480V AC the DC voltage will be about 700V. If the switches are designed to handle these voltages no transformer would be required.
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 time 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.
Each time this sequence is executed the ring magnet 16 fires and collapses the deflectable elastic member 14 (FIG. 9). Time T1 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 (FIG. 2). The first stage pump or compressor may be of a much lower pressure than the pump system 10.
One magnet has been illustrated for simplicity of explanation, however, 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 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.
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.
Although particular step sequences are shown, described, and claimed, 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.
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.

Claims

1. A pump system comprising:

a mandrill with a partially arcuate outer surface; and

a magnetically deflectable elastic member mounted about said partially arcuate outer surface.

2. The pump system as recited in claim 1, wherein said partially arcuate outer surface is parabolic.

3. The pump system as recited in claim 1, wherein said magnetically deflectable elastic member includes a tubular member.

4. The pump system as recited in claim 1, further comprising a clamp ring to retain said magnetically deflectable elastic member to said mandrill.

5. The pump system as recited in claim 1, further comprising a ring magnet mounted about said magnetically deflectable elastic member.

6. The pump system as recited in claim 5, wherein said ring magnet includes a multiple of bitter discs.

7. The pump system as recited in claim 1, further comprising a passage system formed within said mandrill.

8. The pump system as recited in claim 7, further comprising a one-way check valve located within each passage of said passage system.

11. A pump system comprising:

a tubular magnetically deflectable elastic member;

a mandrill with a partially arcuate outer surface mounted at least partially within said tubular magnetically deflectable elastic member to form a pumping volume therebetween, said mandrill defining a passage system which communicates from an input port to said pumping volume and from said pumping volume to a discharge port; and

a ring magnet mounted about said magnetically deflectable elastic member to selectively collapse said tubular magnetically deflectable elastic member toward said partially arcuate outer surface.

12. The pump system as recited in claim 11 wherein said partially arcuate outer surface is parabolic and defined about a longitudinal axis.

13. The pump system as recited in claim 11, wherein said ring magnet includes a multiple of bitter discs.

14. The pump system as recited in claim 11, wherein said passage system includes a one-way check valve within each passage.

15. The pump system as recited in claim 11, further comprising an intake manifold and a discharge manifold in communication with said passage system, said intake manifold and said discharge manifold formed adjacent each longitudinal end of said mandrill.

16. The pump system as recited in claim 15, wherein said passage system includes a multiple of longitudinal passages between said intake manifold and said discharge manifold.

17. The pump system as recited in claim 15, wherein said passage system includes a passage along a longitudinal axis defined by said mandrill, said passage including a passage branch which branches off said axis to communicate with said pumping volume.

18. A method of operating a magnetic pump system comprising the steps of:

(1) energizing a ring magnet; and

(2) magnetically collapsing a tubular magnetically deflectable elastic member toward a partially arcuate outer surface of a mandrill to communicate a fluid from a pumping volume through a discharge.

19. A method as recited in claim 18, further comprising the step of:

communicating the fluid through a one-way passage system which communicates with and from the pumping volume.