Patent Publication Number: US-10330205-B2

Title: Valve assembly with electronic control

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present disclosure claims priority to U.S. Provisional Patent Application No. 62/085,542, filed Nov. 29, 2014. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     This invention was made with government support under contract number HQ0147-11-C-0017 awarded by the United States Missile Defense Agency. The government has certain rights in the invention. 
    
    
     BACKGROUND 
     Regulator valves may be used in aerospace vehicles, ground vehicles, or other systems for controlling fluid flow between components. For example, space vehicles utilize pressurized fluids for propulsion. Regulator valves may be used as a pressure turn down in order to deliver the pressurized fluid at a lower pressure than at the source. 
     SUMMARY 
     A valve assembly according to an example of the present disclosure includes a housing that has a fluid input and a fluid output, a pintle disposed in the housing, and an actuator operatively coupled to move the pintle. The pintle includes a passage that fluidly couples the fluid output with a pressure balance volume located between the pintle and the housing adjacent the linear actuator. A controller is electrically connected with the actuator. There is a variable flow area from the fluid input to the fluid output defined between the pintle and the housing. 
     In a further embodiment of any of the foregoing embodiments, the actuator is a piezo-electric actuator. 
     In a further embodiment of any of the foregoing embodiments, the pintle includes a shank portion, an enlarged head portion at a first axial end of the shank portion, and an enlarged base portion at a second, opposed axial end of the shank portion. 
     In a further embodiment of any of the foregoing embodiments, the pintle includes a retrograde surface. 
     In a further embodiment of any of the foregoing embodiments, the passage is a linear central passage. 
     In a further embodiment of any of the foregoing embodiments, relative to a direction of movement of the pintle, the fluid input is a radial input and the fluid output is an axial output. 
     In a further embodiment of any of the foregoing embodiments, the controller is configured to move the pintle via the linear actuator responsive to at least an instant input pressure at the fluid input. 
     In a further embodiment of any of the foregoing embodiments, the controller is configured to move the pintle via the actuator responsive to at least an instant output pressure at the fluid output. 
     In a further embodiment of any of the foregoing embodiments, the controller is configured to move the pintle via the actuator responsive to a pressure ratio between an instant input pressure at the fluid input and an instant output pressure at the fluid output. 
     In a further embodiment of any of the foregoing embodiments, the controller is configured to dynamically move the pintle via the actuator responsive to changes in a pressure ratio between an instant input pressure at the fluid input and an instant output pressure at the fluid output. 
     In a further embodiment of any of the foregoing embodiments, the variable flow area is linearly variable with respect to a linear position of the pintle. 
     A further embodiment of any of the foregoing embodiments includes controlling a linear position of the pintle based on electronic feedback signals to the controller. The electronic feedback signals represent at least one of instant pressure or instant pintle position. 
     In a further embodiment of any of the foregoing embodiments, the instant pressure is an instant input pressure at the fluid input. 
     In a further embodiment of any of the foregoing embodiments, the instant pressure is an instant output pressure at the fluid output. 
     In a further embodiment of any of the foregoing embodiments, the instant pressure is a pressure ratio between an instant input pressure at the fluid input and an instant output pressure at the fluid output. 
     In a further embodiment of any of the foregoing embodiments, the controlling includes dynamically changing the linear position of the pintle as the instant pressure changes. 
     A valve assembly according to an example of the present disclosure includes a housing that has a fluid input and a fluid output, a pintle disposed in the housing, an actuator, a controller electrically connected with the actuator, and a variable flow area from the fluid input to the fluid output defined between the pintle and the housing. The actuator is operable to vary a position of the pintle relative to the housing and thereby change the variable flow area. 
     In a further embodiment of any of the foregoing embodiments, the actuator is coupled with the housing and operable to move the housing with respect to the pintle. 
     In a further embodiment of any of the foregoing embodiments, the pintle includes a retrograde surface defining the variable flow area. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
         FIG. 1  illustrates an example valve assembly. 
         FIG. 2  illustrates an example open position of a pintle in a valve assembly. 
         FIG. 3  illustrates another example valve assembly. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a cross-section of an example valve assembly  20  that is electronically controlled and can be used to precisely control flow output. The valve assembly  20  includes a housing  22  with a fluid input  24  and a fluid output  26 . The fluid input  24  and the fluid output  26  are passages that lead into and out of, respectively, an interior cavity  28  in the housing  22 . In this example, the fluid input is a radial passage and the fluid output is an axial passage. 
     A pintle  30  is located in the interior cavity  28 . The pintle  30  is moveable along central axis A between a fully closed position in which the pintle  30  abuts a valve seat  22   a  in the interior cavity  28  of the housing  22  and a plurality of open positions in which the pintle  30  is spaced-apart from the valve seat  22   a . In this example, the pintle  30  includes a shank portion  30   a , an enlarged head portion  30   b , an enlarged base portion  30   c , and a stem  30   d  that extends axially from the base portion  30   c . The term “enlarged” refers to the portions  30   b  and  30   c  being larger in diameter than the shank portion  30   a . The enlarged head portion  30   b  and enlarged base portion  30   c  are situated at opposed axial ends of the shank portion  30   a . The enlarged head portion  30   b  includes a valve trim  31 . The valve trim  31  is a retrograde surface or retrograde portion  30   b  that slopes in an aft direction with respect to the forward flow direction out from the fluid output  26 . In the fully closed position the valve trim  31  abuts that valve seat  22   a.    
     The pintle  30  also includes a passage  32  that fluidly couples the fluid output  26  with a pressure balance volume  34  located behind the base  30   c  of the pintle  30 . For example, the passage  32  in this example is linear and may include one or more radial orifices near the base portion  30   c  that lead into the volume  34 . The passage  32  serves to balance pressures across the pintle  30  and thus reduce the amount of force that is necessary to move the pintle  30 . For instance, pressure from the fluid output  26  is transferred through the passage  32  such that volume  34  is pressurized. The pressurized volume  34  tends to balance the forces on the pintle  30  when fluid flows through the valve assembly  20 . 
     An actuator  36  is operable to vary a position of the pintle  30  relative to the housing  22 . In this example, the actuator  36  is operatively coupled with the stem  30   d  to enable movement of the pintle  30 , while the housing  22  remains stationary. For instance, the actuator is a linear actuator that is operable to move the pintle  30  axially back and forth along the axis A. The actuator  36  includes a housing  36   a  that is secured or fastened to the housing  22 . An actuator element  36   b  is mounted in the housing  36   a  and serves to move the pintle  30 . In one example, the actuator  36  is a piezo-electric actuator that is electrically responsive to move the pintle  30 . The actuator  36  can further include a linear variable displacement transducer  36   c  that is operable to detect linear position of the pintle  30 . 
     A controller  38  is electrically connected with the actuator element  36   b  and linear variable displacement transducer  36   c  of the actuator  36 . For example, the controller  38  can include hardware (e.g., a microprocessor, computer, etc.), software, or both, that is configured and/or programmed to perform the control functions described herein. 
     In  FIG. 1  the pintle  30  is shown in its fully closed position in which the valve trim  31  of the enlarged head portion  30   b  seals with the valve seat  22   a  of the housing  22 .  FIG. 2  shows the pintle  30  in a representative open position in which the pintle has been retracted such that there is a flow area  40  from the fluid input  24  to the fluid output  26 . The flow area  40  is defined between the valve trim  31  of the pintle  30  and the valve seat  22   a  of the housing  22 . The actuator  36  is operable to vary a position of the pintle  30  relative to the housing  22  and thereby change the size of the variable flow area  40  in a controlled manner. For example, the geometry of the valve trim  31  of the pintle  30  and the geometry of the valve seat  22   a  of the housing are such that the flow area  40  changes linearly with respect to the linear position of the pintle  30 . 
     The controller  38  can utilize one or more electronic feedback signals to precisely control position of the pintle  30 . Precise control of the position enables finer control over flow from the fluid output. For example, the electronic feedback signals can include signals representing an instant pressure, instant pintle position, or combinations of these. The instant pressure can be an instant input pressure at the fluid input  24 , an instant output pressure at the fluid output  26 , and/or a pressure ratio between the instant input pressure and the instant output pressure. For instance, the pressures can be obtained from pressure taps in or near the fluid input  24  and the fluid output  26 . 
     In further examples, the controller  38  may utilize both the instant input pressure and the instant output pressure along with the instant pintle position. For example, the controller  38  may re-position the pintle  30  to a pre-selected open position by adjusting the amount of power provided to the piezo-electric actuator. The controller  38  may be pre-programmed with look-up tables or other data relating pre-selected positions to power levels. Thus, when there is a demand for more or less flow than at the instant position of the pintle  30 , the controller  38  can re-position the pintle  30  to a different pre-selected position to adjust the flow, or through series of positions until the flow is adjusted to the desired level. 
     In further examples, the controller  38  can change the pintle position  30  to adjust between different pressure ratios between the instant input pressure and the instant output pressure. The illustrated configuration of the valve assembly  20  may allow for controlled pressure turn down ratios of up to approximately 20:1 between the instant input pressure and the instant output pressure. Moreover, the controller  38  may change the pintle position dynamically with source pressure variations. For example, if the source pressure changes such that the instant input pressure changes, the controller  38  detects that the pressure ratio has changed and thus adjusts the pintle position to re-establish a set-point output pressure. 
     Thus, the configuration of the valve assembly  20 , geometry of the flow area  40 , and the electronic feedback signals permit the controller  38  to adjust the pintle position to finely control output pressure. The ability to precisely control the output flow may enable more efficient use of the fluid. If the fluid is a propellant or fuel in a spacecraft, more efficient use may in turn enable the spacecraft to carry less propellant or fuel, saving weight. If used for a thrust system, this enables variable thrust levels by changing the output pressure during valve operation. 
       FIG. 3  illustrates another example valve assembly  120 . In this disclosure, like reference numerals designate like elements where appropriate and reference numerals with the addition of one-hundred or multiples thereof designate modified elements that are understood to incorporate the same features and benefits of the corresponding elements. In this example, the actuator  136  is operable to vary a position of the pintle  130  relative to the housing  22  and thereby change the variable flow area  40 . However, rather than being coupled to move the pintle, the actuator  136  is coupled to move the housing  22 , and the pintle  130  remains stationary. In this regard, the housing  22  is moveably mounted on one or more guide pins  150 . The guide pin or pins  150  extend axially from a closure portion  152 . The pintle  130  and closure portion  152  are integrally formed as one piece. 
     In this example, the actuator  136  is fixed on the housing  22  and a static actuator member  136   a  is fixed on the closure portion  152 . The static actuator member  136   a  is threaded and the actuator  136  is a rotary actuator that engages the threads to axially move the housing  22 . The actuator  136  is electrically connected with the controller  38  and can be controlled using the control strategies described in the prior examples. 
     Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments. 
     The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.