Disc pump with perimeter valve configuration
View Patent ↗A disc pump valve includes an elliptical pump base having at least one aperture extending through the base. The base comprises a first end wall and a sealing surface. The pump includes an isolator overlying the base and having an isolator valve aperture extending through the isolator at or near the periphery of the isolator and partially overlying a cavity formed by the base to form an outlet. In addition, the disc pump includes a valve flap disposed between the pump base and the isolator. The flap has apertures arranged about its periphery, beyond the periphery of the cavity but underlying an isolator valve aperture. The flap seals against the sealing surface to close the pump outlet and prevent fluid from flowing from the outlet into the cavity and flexes away from the sealing surface to allow fluid to pass from the cavity through the pump outlet.
1. A disc pump comprising:
a pump base having a cylindrical sidewall closed at a first end by a first end wall to form a cavity and an upper surface extending radially outwardly from the sidewall, the upper surface including a sealing surface and at least one indentation;
at least one aperture extending through the pump base into the cavity;
an actuator including a piezoelectric disc and an isolator extending radially outwardly between the piezoelectric disc and the sidewall, the actuator comprising a second end wall on a second end of the cylindrical sidewall and the piezoelectric disc being configured to cause an oscillatory motion of the second end wall, thereby generating displacement oscillations of the second end wall in a direction substantially perpendicular to the second end wall, the displacement oscillations configured to generate corresponding radial pressure oscillations of the fluid within the cavity, and the isolator being configured to reduce dampening of the displacement oscillations;
at least one isolator valve aperture extending through the isolator and having an opening proximate the upper surface of the pump base and a peripheral portion of the cavity; and
a valve flap disposed between the opening of the isolator valve aperture on one side and the upper surface of the pump base and the peripheral portion of the cavity on the other side, the valve flap having at least one valve flap aperture extending between the opening of the isolator valve aperture and the indentation;
wherein the valve flap prevents the flow of fluids through the isolator valve aperture when seated against the sealing surface and permits the flow of fluids through the indentation and the isolator valve aperture when not seated against the sealing surface.
2. The disc pump of claim 1 , wherein the at least one aperture comprises a plurality of apertures circumferentially disposed about a center of the first end wall.
3. The disc pump of claim 1 , wherein the at least one aperture comprises a plurality of apertures circumferentially disposed about a center of the first end wall at a predetermined distance from the center of the first end wall.
4. The disc pump of claim 1 , wherein the at least one aperture comprises a plurality of apertures circumferentially disposed about a center of the first end wall at a predetermined distance from the center of the first end wall corresponding to the radial distance of an annular pressure node from the center of the first end wall.
5. The disc pump of claim 1 , wherein the at least one indentation comprises a plurality of indentations circumferentially disposed in the upper surface proximate to a periphery of the cavity.
6. The disc pump of claim 1 , wherein the at least one isolator valve aperture comprises a plurality of isolator valve apertures circumferentially disposed around a periphery of the isolator.
7. The disc pump of claim 1 , wherein the at least one valve flap aperture comprises a plurality of valve flap apertures circumferentially disposed around a periphery of the valve flap.
8. The disc pump of claim 1 , wherein the at least one indentation comprises a plurality of indentations circumferentially disposed in the upper surface proximate to a periphery of the cavity, the at least one isolator valve aperture comprises a plurality of isolator valve apertures circumferentially disposed around a periphery of the isolator, and the at least one valve flap aperture comprises a plurality of valve flap apertures, and wherein the indentations, the isolator valve apertures, and the valve flap apertures are substantially aligned.
9. The disc pump of claim 1 , wherein the at least one indentation comprises a plurality of indentations circumferentially disposed in the upper surface proximate to a periphery of the cavity, the at least one isolator valve aperture comprises a plurality of isolator valve apertures circumferentially disposed around a periphery of the isolator, and the at least one valve flap aperture comprises a plurality of valve flap apertures, and wherein the indentations and the isolator valve apertures are substantially aligned and each respective indentation and isolator valve aperture is aligned with a respective valve flap aperture of the plurality of valve flap apertures.
10. The disc pump of claim 1 , wherein the valve flap includes at least one perforation disposed on the peripheral portion of the valve flap and adjacent the at least one indentation.
11. The disc pump of claim 1 , wherein the valve flap includes a plurality of perforations disposed on the peripheral portion of the valve flap, the at least one indentation comprises a plurality of indentations, and the plurality of perforations are adjacent the plurality of indentations.
12. The disc pump of claim 1 , wherein the valve flap includes at least one perforation disposed on the peripheral portion of the valve flap and adjacent the at least one indentation, the at least one valve flap aperture comprises a plurality of valve flap apertures, and the at least one perforation includes the plurality of valve flap apertures.
13. The disc pump of claim 1 , wherein the valve flap includes at least one perforation disposed on the peripheral portion of the valve flap and adjacent the at least one indentation, the at least one valve flap aperture comprises a plurality of valve flap apertures, and the at least one perforation includes the plurality of valve flap apertures arranged in an arcuate pattern adjacent the outer periphery of the indentation.
14. The disc pump of claim 1 , wherein the isolator valve aperture extends generally perpendicularly through the isolator.
15. The disc pump of claim 1 , wherein:
the valve flap is motivated away from the sealing surface when the pressure in the cavity exceeds the pressure on an opposing side of the isolator;
the valve flap is motivated against the sealing surface when the pressure on the opposing side of the isolator exceeds the pressure in the cavity.
16. The disc pump of claim 1 , wherein the valve flap is formed from a polymer having a thickness of about 1.5 microns.
17. The disc pump of claim 1 , wherein the valve flap comprises a light-weight material selected from the group consisting of a polymer and a metal.
18. The disc pump of claim 17 , wherein the light-weight material is a polymer having a thickness of less than about 20 microns.
19. The disc pump of claim 18 , wherein the polymer is polyethylene terephthalate having a thickness of about 1.5 microns.
20. The disc pump of claim 18 , wherein the polymer is a liquid crystal film having a thickness of about 1.5 microns.
21. The disc pump of claim 18 , wherein the polymer is a Mylar film having a thickness of about 1.5 microns.
22. The disc pump of claim 1 , wherein the isolator valve aperture is less than about 500 microns in diameter.
23. The disc pump of claim 22 , wherein the valve flap is formed from a polymer having a thickness of about 1.5 microns, and the isolator valve aperture is less than about 500 microns in diameter.
24. The disc pump of claim 1 , wherein the isolator is heat staked to the pump base.
25. The disc pump of claim 1 , wherein the valve flap seats to the sealing surface and flexes away from the sealing surface in response to a change in direction of the differential pressure.
26. The disc pump valve of claim 25 , wherein the valve flap has a response time delay less than about twenty-five percent of a time period of the differential pressure oscillations.
27. The disc pump valve of claim 25 , wherein the change in direction of the differential pressure oscillates at a frequency of greater than about 20 kHz.