Low power electromagnetic pump
First Claim
1. An electromagnetic pump comprising:
- (a) an elongated housing having a longitudinal axis and having an interior fluid containing region including a fluid receiving chamber and a fluid pumping chamber in fluid communication therewith, an inlet in fluid communication with said receiving chamber and an outlet in fluid communication with said pumping chamber;
(b) check valve means operatively associated with said fluid containing region for allowing fluid flow in a direction from said inlet through said outlet and blocking fluid flow in a direction from said outlet through said inlet;
(c) electromagnet means carried by said housing and located external to said fluid containing region;
(d) an armature positioned in said fluid containing region of said housing for movement along said housing longitudinal axis and having a pole portion located for magnetic attraction by said electromagnet means and having a piston portion operatively associated with said fluid receiving and pumping chambers for forcing fluid from said receiving chamber through said outlet;
said armature being movably supported in said housing for movement from a rest position through a forward pumping stroke when attracted by said electromagnet means to force fluid from said receiving chamber through said outlet and for movement in an opposite direction through a return stroke back to said rest position;
(e) means defining a magnetic circuit including said electromagnet means and said armature and a gap between said pole portion of said armature and said electromagnet means for moving said armature toward said electromagnet means to close said gap in response to electrical energization of said electromagnet means;
(f) said check valve means comprising a thin body movably carried by said armature and located in said interior fluid containing region in small clearance relation therewith and between said armature and said inlet, and a conical spring between said valve body and said armature thereby enabling said pump chamber to have dimensions which define a volume not greater than about one and one-half times the stroke volume of the pump which therefore limits the volume of a bubble in the fluid which can be contained in said pump chamber up to a volume of about one and one-half times the stroke volume the pump when said armature is in a rest position so as to enable said pump to operate with bubbles present in the fluid being pumped;
(g) said armature pole portion having a pole face located to define said gap with said electromagnet means; and
(h) said fluid-containing region of said housing and said electromagnet means being in axially spaced relation along said housing longitudinal axis and being separated by barrier means of fluid impervious material having opposite sides, said fluid containing region, inlet, outlet and armature all being located on one side of said barrier means and said electromagnet means being located on the opposite side of said barrier means.
4 Assignments
0 Petitions
Accused Products
Abstract
An electromagnetic pump comprising a housing having a fluid receiving chamber in communication with an inlet, a pair of fluid chambers connected by a fluid bypass passage to accommodate bubbles, one in communication with the fluid receiving chamber and the other in communication with an outlet, an electromagnet carried by the housing located external to the fluid chambers thereof, and a barrier in the form of a thin diaphragm of fluid impermeable material which hermetically isolates the electromagnet from the fluid chambers. An armature in the housing is movable within a body of magnetically permeable material which contains the bypass, has a pole portion located for magnetic attraction by the electromagnet, and has a piston portion, preferably of smaller cross-section than the pole portion, for forcing fluid from the fluid chambers and through the outlet. The armature is moved from a rest position through a forward pumping stroke when attracted by the electromagnet and is moved by a biasing spring in an opposite direction through a return stroke back to the rest position. A main valve is movably carried by the armature and located in the fluid receiving chamber for closing the pump inlet when the armature is in the rest position and allowing opening the inlet after the armature begins the forward pumping stroke. The structure and arrangement of the check valve minimizes the volume of the fluid receiving chamber to limit the maximum size of a bubble contained therein. A bypass passage containing a check valve which opens during the armature return stroke provides a path for bubbles around the piston to the fluid receiving chamber.
80 Citations
20 Claims
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1. An electromagnetic pump comprising:
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(a) an elongated housing having a longitudinal axis and having an interior fluid containing region including a fluid receiving chamber and a fluid pumping chamber in fluid communication therewith, an inlet in fluid communication with said receiving chamber and an outlet in fluid communication with said pumping chamber; (b) check valve means operatively associated with said fluid containing region for allowing fluid flow in a direction from said inlet through said outlet and blocking fluid flow in a direction from said outlet through said inlet; (c) electromagnet means carried by said housing and located external to said fluid containing region; (d) an armature positioned in said fluid containing region of said housing for movement along said housing longitudinal axis and having a pole portion located for magnetic attraction by said electromagnet means and having a piston portion operatively associated with said fluid receiving and pumping chambers for forcing fluid from said receiving chamber through said outlet;
said armature being movably supported in said housing for movement from a rest position through a forward pumping stroke when attracted by said electromagnet means to force fluid from said receiving chamber through said outlet and for movement in an opposite direction through a return stroke back to said rest position;(e) means defining a magnetic circuit including said electromagnet means and said armature and a gap between said pole portion of said armature and said electromagnet means for moving said armature toward said electromagnet means to close said gap in response to electrical energization of said electromagnet means; (f) said check valve means comprising a thin body movably carried by said armature and located in said interior fluid containing region in small clearance relation therewith and between said armature and said inlet, and a conical spring between said valve body and said armature thereby enabling said pump chamber to have dimensions which define a volume not greater than about one and one-half times the stroke volume of the pump which therefore limits the volume of a bubble in the fluid which can be contained in said pump chamber up to a volume of about one and one-half times the stroke volume the pump when said armature is in a rest position so as to enable said pump to operate with bubbles present in the fluid being pumped; (g) said armature pole portion having a pole face located to define said gap with said electromagnet means; and (h) said fluid-containing region of said housing and said electromagnet means being in axially spaced relation along said housing longitudinal axis and being separated by barrier means of fluid impervious material having opposite sides, said fluid containing region, inlet, outlet and armature all being located on one side of said barrier means and said electromagnet means being located on the opposite side of said barrier means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 19, 20)
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8. An electromagnetic pump comprising:
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(a) an elongated housing having a longitudinal axis and having an interior fluid containing region including a fluid receiving chamber, a first fluid chamber in fluid communication therewith, a second fluid chamber in fluid communication with said first fluid chamber, an inlet in fluid communication with said receiving chamber and an outlet in fluid communication with said second fluid chamber; (b) electromagnet means carried by said housing and located external to said fluid containing region; (c) an armature positioned in said fluid containing region of said housing for movement along said housing longituginal axis and having a pole portion located for magnetic attraction by said electromgnet means and having a piston portion operatively associated with said fluid receiving and said first fluid chambers for forcing fluid from said fluid receiving chamber through said first and second chambers and out through said outlet, said armature being movably supported in said housing for movement from a rest position through a forward pumping stroke when attracted by said electromagnet means to force fluid from said chambers through said outlet and for movement in an opposite direction through a return stroke back to said rest position; (d) means for defining a magnetic circuit including said electromagnet means and said armature and a gap between said pole portion of said armature and said electromagnet means for moving said armature toward said electromagnet means to close said gap in response to electrical energization of said electromagnet means; (e) check valve means operatively coupled to said armature and located in said fluid containing region of said housing for closing said inlet when said armature is in said rest position and for opening said inlet after said armature begins movement associated with said forward pumping stroke, said check valve means allowing fluid flow in a direction from said inlet through said outlet and blocking fluid flow in a direction from said outlet through said inlet; (f) said armature piston portion being located between a plunger portion and said pump inlet and movable within said pump housing, there being a relatively small clearance between said armature piston portion and said housing, said armature piston portion including two axially adjacent sections of different cross-section, one of said sections being axially near said plunger portion and of smaller cross-section than the other of said sections, the clearance between said one section and said housing being slightly larger than the clearance between said other section and said housing and thereby serving to prevent entry of bubbles into the clearance between said other section and said housing; (g) said armature pole portion having a pole face located to define said gap with said electromagnet means; and (h) said fluid-containing region of said housing and said electromagnet means being in axially spaced relation along said housing longitudinal axis and being separated by barrier means of fluid impervious material. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. An electromagnetic pump comprising:
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(a) a housing having an interior fluid containing region including a fluid receiving chamber and a fluid pumping chamber in fluid communication therewith, an inlet in fluid communication with said receiving chamber and an outlet in fluid communication with said pumping chamber; (b) check valve means operatively associated with said fluid containing region for allowing fluid flow in a direction from said inlet through said outlet and blocking fluid flow in a direction from said outlet through said inlet; (c) electromagnet means carried by said housing and located external to said fluid containing region; (d) an armature positioned in said fluid containing region of said housing having a pole portion located for magnetic attraction by said electromagnet means and having a piston portion operatively associated with said fluid receiving and pumping chambers for forcing fluid from said receiving chamber though said outlet;
said armature being movably supported in said housing for movement from a rest position through a forward pumping stroke when attracted by said electromagnet means to force fluid from said receiving chamber through said outlet and for movement in an opposite direction through a return stroke back to said rest position, said armature piston portion being located between a plunger portion and said pump inlet and movable within said housing, there being a relatively small clearance between said armature piston portion and said housing;(e) means defining a magnetic circuit including said electromagnet means and said armature and a gap between said pole portion of said armature and said electromagnet meand for moving said armature toward said electromagnet means to close said gap in response to electrical energization of said electromagnet means; and (f) controlled means for providing a bypass path for bubbles in the fluid around said armature piston portion between said fluid pumping chamber and said fluid receiving chamber only during said return stroke of said armature.
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Specification