Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/10—Valves; Arrangement of valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/16—Casings; Cylinders; Cylinder liners or heads; Fluid connections
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
  • F15B15/02—Mechanical layout characterised by the means for converting the movement of the fluid-actuated element into movement of the finally-operated member
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
  • F16K31/00—Actuating devices; Operating means; Releasing devices
  • F16K31/004—Actuating devices; Operating means; Releasing devices actuated by piezoelectric means
  • F16K31/005—Piezoelectric benders
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2210/00—Working fluid
  • F05B2210/10—Kind or type
  • F05B2210/11—Kind or type liquid, i.e. incompressible

Definitions

• This invention relates to fluid flow control valves, and more particularly to ferroelectric active fluid flow control valves which provide improved passage of the fluid during certain time periods and provides positive closure of the valve during other time periods.
• Fluid flow applications often require a valve which, during certain time periods, allows unimpeded passage of the fluid and, during other time periods, allows no passage of the fluid.
• a "one-way valve”, also known as a “check valve”, is an example of such a valve. It allows unimpeded passage of the fluid in one direction ("with the direction of flow”) and no passage of the fluid in the opposite direction (“against the direction of flow”).
• one object of the invention is to provide an active valve which is controlled and driven by external electrical actuation.
• Another object is to provide a valve which during certain time periods allows unimpeded passage of fluid and during other time periods allows no passage of fluid.
• Another object of the invention is to provide a valve which does not require fluid flow to activate the valving action.
• a further object of the invention is to provide a valve which utilizes a ferroelectric component to open and close fluid flow.
• a further object is to provide a valve which utilizes a dome shaped internally prestressed ferroelectric actuator having a curvature, said dome shaped actuator having a rim and an apex, and a dome height measured from a plane through the rim to the apex that varies with an electric voltage applied between an inside and an outside surface of the dome shaped actuator.
• a still further object is to provide a valve which can operate at higher frequencies before floating occurs.
• Another object is to provide a valve which has chemical and contamination isolation.
• an active valve which is controlled and driven by external electrical actuation to provide for improved passage of the fluid during certain time periods and to provide positive closure of the valve during other time periods.
• the valve provides improved passage in the direction of flow and positive closure in the direction against the flow.
• FIG. 1 is an exploded view of the fluid control valve.
• FIG. 2 is an electrical contact ring according to the present invention.
• FIG. 1 shows an exploded view of the ferroelectric flow control valve.
• the fluid flow enters the valve through the tube-to-pipe fitting inlet 12 mounted in the top cover 10. From the inlet, the fluid flows to valve stop 16.
• a suitable sealing gasket 14 is placed between the top cover 10 and the housing 18.
• the isolation membrane 22 should be compatible with the fluid and possess some elasticity; e.g., latex.
• the isolation membrane 22 is stretched to cover the entire surface of the ferroelectric actuator 26; the membrane stays in contact with the surface of the moving actuator 26 at all times.
• the isolation membrane 22 serves multiple purposes; it serves as a seal and it serves to isolate the fluid eclectically and chemically from the actuator 26.
• Actuator 26 is a dome shaped internally prestressed ferroelectric actuator having a curvature, said dome shaped actuator having a rim and an apex, and a dome height measured from a plane through the rim to the apex that varies with an electric voltage applied between an inside and an outside surface of the dome shaped actuator. Examples of such actuators are shown in U.S. Patent No.
• This ferroelectric actuator can have strains up to several hundred percent and can sustain loads of at least ten pounds.
• the work capacity of the pump can be increased by using multiple ferroelectric actuators mounted on a common manifold. Twice as large excursions can be obtained from a pair of actuators stacked rim against rim in clamshell fashion. Several such clamshell assemblies can be cascaded if still larger excursions are needed.
• Such arrangements are described in U.S. Patent No. 5,471 ,721 , "Method for Making Monolithic Prestressed Ceramic Devices," and in U.S. Patent No. 5,632,841 , "Thin Layer Composite Unimorph Ferroelectric Driver and Sensor.”
• the cylindrical gap is opened and closed in response to displacement of actuator 26. During the periods of time when the cylindrical gap is open the fluid flow leaves the valve through the housing outlet 19.
• the inside diameters of the tube-to-pipe fitting 12 and valve stop 16 should be sized such that the fluid flow velocity remains constant when fluid flows through the gap created by displacement of the actuator 26. This avoids an undesirable pressure drop.
• no pneumatic actuator or solenoid is required to activate a diaphragm.
• the actuator and its associated mounting performs the function of both the diaphragm and pneumatic actuator/solenoid.
• the ferroelectric actuator 26 is mounted such that the mounting configuration isolates the actuator 26 from the fluid, supplies a path for voltage to be applied to the actuator 26, and provides for positive containment of the actuator 26 while allowing displacement of the entirety of the actuator 26 in response to an applied voltage.
• a housing 18 is disposed between the top cover 10 and a bottom cover 34.
• the actuator mount configuration comprises two nonconductive sealing gaskets 20 and 32, an electrical insulator 22, two electrical contact rings 24 and 30, an actuator spacer 28, and an actuator 26. It is preferred that the spacer 28 have the same thickness as the actuator 26.
• the actuator 26 is positioned within the spacer 28 such that the circumference of the actuator 26 is contiguous with the inner circumference of the spacer 28.
• Electrical contact rings 24 and 30 are positioned contiguous to each side of spacer 28 and provide voltage contact to the actuator 26.
• An electrical insulator 22 is positioned contiguous to the outside surface of the upper contact ring 24 and concentric with the actuator 26.
• the insulator 22 should be compatible with the pumped medium and possess some elasticity; e.g. latex.
• a nonconductive fluid such as a silicon fluid, is used between the insulator 22 and the actuator 26.
• the fluid should be chemically stable with the other materials and be of a suitable viscosity to hold the insulator 22 and actuator 26 together. This eliminates air pockets which increases efficiency and capability.
• a sealing gasket 20 having a hole concentric with the contact ring 24 hole is positioned contiguous to insulator 22.
• the sealing gasket 20 is made from a nonconductive material such as rubber.
• the mounting assembly is contained by a fastening means such as set screws. The fastening force required is only the minimum force required to adequately maintain the assembly. No prestress is
• the design is not limited to any particular number, thickness or size of actuators. Each particular application should be considered to design component parameters; e.g., amount of actuator displacement and actuator force capability.
• a voltage lead 36 is positioned in the housing 18 via a drilled hole in the housing 18.
• the lead 36 contacts a set screw spring 38 positioned in the housing 18.
• the set screw spring 38 contacts the electrical contact ring 24 to provide the applied voltage to the ring 24.
• the contact ring 24 overlaps a portion of both the spacer and the actuator. As shown in FIG. 2, the contact ring 24 has a portion 40 overlapping the actuator which is an electrical conductor such as aluminum foil.
• the outer portion 42 of the contact ring 24 that is in contact with the actuator is a nonconductive material which has a conductive portion 44 which contacts the set screw spring 38.
• Masking tape is one example of a suitable nonconductive material. Although circular actuators and associated circular shaped mounting components are preferred, other shapes can be utilized.
• the positive and negative voltage levels applied to the actuator will vary with its thickness, with arc over resulting from too much voltage.
• the isolation membrane 22 described in the previous paragraph is monolithic with the actuator 26.
• the entire actuator 26 (both sides and its edge) is encapsulated with a polymer coating.
• This ferroelectric actuator valving mechanism has lower mass than electromagnetic and pneumatic mechanisms, so it can operate at higher frequencies before the problem of floating occurs.
• the valve eliminates the dead-space found in current valves, especially passive valves and is simpler and more power efficient than current valves.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Electrically Driven Valve-Operating Means (AREA)
• Check Valves (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22268465

Family Applications (1)

Country Status (4)

Families Citing this family (1)

• 1998
  • 1998-12-11 EP EP98962079A patent/EP1137883A1/en not_active Withdrawn
  • 1998-12-11 CA CA002354263A patent/CA2354263A1/en not_active Abandoned
  • 1998-12-11 JP JP2000588514A patent/JP2002532660A/ja not_active Withdrawn
  • 1998-12-11 KR KR1020017007295A patent/KR20010108014A/ko not_active Application Discontinuation

Non-Patent Citations (1)

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