Abstract:
A valve apparatus for a fluid transmission line. The valve apparatus comprising a housing; a drive mechanism; a leadscrew selectively rotatable in a first or second rotational leadscrew direction by the drive mechanism; a drive gear mounted to the housing, the drive gear configured to be selectively driven in a first or second drive gear direction during rotation of said leadscrew in the first or second leadscrew direction to operate an iris mechanism.

Description:
BACKGROUND AND SUMMARY 
       [0001]    The present disclosure relates generally to a valve apparatus for natural gas flow and other gas and fluid flow. 
         [0002]    The flow of the gases and other fluids piped through lines is controlled with valves. U.S. Pat. No. 8,132,783 discloses a valve apparatus that can be used for such purposes. It is often difficult to protect the mechanical arrangement by which the iris mechanism control element is mechanically adjusted as well as the mechanism which is used to reduce the drive motor revolutions to a single revolution so that it may be used to limit the travel of the control element. 
         [0003]    The present disclosure relates to a valve apparatus for a fluid transmission line. The valve apparatus comprises: a housing; a drive mechanism; a leadscrew selectively rotatable in a first or second rotational leadscrew direction by the drive mechanism; a drive gear mounted to the housing, the drive gear configured to be selectively rotatable in a first or second drive gear direction during rotation of said leadscrew in the first or second leadscrew direction, said drive gear defining a throughhole; a plurality of leaves disposed about said throughhole, each of said leaves including a curvilinear portion and a pair of ends and being pivotally or otherwise mounted to the drive gear, and each of said leaves being oriented to extend radially inward into said throughhole to define an orifice; and a plurality of engagement members biasing said leaves to reduce the orifice when said drive gear rotates in said first drive gear direction and to increase the orifice when said drive gear rotates in said second drive gear direction to adjust a volume of transmission of fluid therethrough. The housing may define a bore, the leadscrew, and the drive gear housed substantially within the bore. 
         [0004]    The valve apparatus may further comprise a fastener threadingly or otherwise engaged with the leadscrew and engage with the drive gear for transferring torque from the leadscrew to the drive gear during rotation of the leadscrew. The fastener travels along a length of the leadscrew during rotation of the leadscrew. The valve apparatus may further comprise a stationary shaft adjacent the leadscrew, the fastener slidably engaged with the shaft for balancing the torque transferred from the leadscrew to the fastener. The valve apparatus may further include a lever arm engaging the fastener and the drive gear. The valve apparatus may further include a bushing engaging the fastener and the lever arm. The lever arm may include two parallel arms, each of which is operatively associated with the bushing. 
         [0005]    The drive mechanism of the valve apparatus includes a motor operatively associated with the leadscrew for selectively rotating the leadscrew in the first or second leadscrew direction. The drive mechanism may also include a planetary gear transmission operatively associated with the motor. The planetary gear transmission comprises a central sun gear, a plurality of planetary gears, and a ring gear. The housing may define a bore and include a casing defining a cavity, the motor and the planetary gear transmission housed substantially within the cavity. 
         [0006]    Features and advantages of the disclosure will be set forth in part in the description which follows and the accompanying drawings described below, wherein an embodiment of the disclosure is described and shown, and in part will become apparent upon examination of the following detailed description taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
           [0008]      FIG. 1  is a perspective of a valve apparatus in accordance with an illustrated embodiment of the present disclosure; 
           [0009]      FIG. 2  is an exploded view of the valve apparatus of  FIG. 1 ; 
           [0010]      FIG. 3  is a side plan view of the housing and valve apparatus of  FIG. 1  with a section of the housing removed to illustrate the drive mechanism, the threaded shaft and the balancing shaft of the valve apparatus; 
           [0011]      FIG. 4  is a cross-section taken along lines  4 - 4  of  FIG. 3 ; 
           [0012]      FIG. 5  is a cutaway side view of the drive gear and the iris mechanism of the valve apparatus of  FIG. 1 ; 
           [0013]      FIG. 6  is an isometric view of a single leaf of the iris mechanism of the valve apparatus of  FIG. 1 ; 
           [0014]      FIG. 7  is a top plan view of the planetary gear transmission of  FIG. 7  with one of the plates removed to illustrate the planetary and sun gears; and 
           [0015]      FIG. 8  is a top plan view of the valve apparatus of  FIG. 1  with the motor casing removed illustrating the sun and ring gears of the planetary gear transmission. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    While the present disclosure may be susceptible to embodiments in different forms, there is shown in the drawings and slides, and will be described herein in additional detail, one or more embodiments with the understanding that the present description is to be considered an exemplification of the principles of the disclosure and is not intended to be exhaustive or to limit the disclosure to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings and slides. 
         [0017]      FIGS. 1-8  illustrate a valve apparatus  10  in accordance with an illustrated embodiment of the present disclosure generally including a housing  12 . The housing  12  includes a pair of housing sections  14 ,  16  defining a bore  18 , a housing plate  20 , and a motor casing  22  defining a cavity  24 . The housing sections  14 ,  16  are secured together by a plurality of fasteners  30  or in any other suitable manner. The motor casing  22  is secured by a nut knob  38  to a threaded shaft  36  secured to the housing plate  20  of the housing  12  or may be secured in any other suitable manner. The valve apparatus  10  may include a power cord. The housing  12  may have any other suitable construction and configuration in accordance with other embodiments of the present disclosure. 
         [0018]    The illustrated valve apparatus  10  further includes a threaded leadscrew  40 , a fastener  42  threadingly engaged with the leadscrew  40 , a lever arm  48 , a bushing  50  engaging the fastener and the lever arm, a stationary shaft  54 , a drive gear  56 , and an iris mechanism  60 , all of which are housed substantially within the bore  18  of the housing  12 . The valve apparatus  10  also includes a motor  62 , electrical circuitry  64 , a planetary gear transmission  66  and electronics associated with the motor housed substantially within the cavity  24  of the casing  22 . The motor  62  and planetary gear transmission  66  are configured to selectively drive the leadscrew  40  in either rotational direction to drive the drive gear  56  and operate the iris mechanism  60 . The fastener  42 , the lever arm  48  and the bushing  50  are configured to transfer torque from the leadscrew  40  to the drive gear  56  to operate the iris mechanism  60 . 
         [0019]    The leadscrew  40  is rotationally mounted to the housing plate  20  of the housing and is drivably engaged with the motor  62 . The stationary shaft  54  is adjacent and parallel to the leadscrew  40 . The stationary shaft  54  is rigidly mounted to the housing plate  20 . The fastener  42  is threadingly engaged with the leadscrew  40  and is engaged with the lever arm  48  by the bushing  50  or may be engaged with the drive gear  56  in any other suitable manner. In the illustrated embodiment, the lever arm  48  includes a pair of parallel arms  70  that define a slot  72  that slidably receives the bushing  50 . The fastener  42  has a rectangular construction and defines a semicircular bore  74  for slidably engaging the stationary shaft  54  so that the torque transferred from the leadscrew  40  to the fastener is balanced. Rotation of the leadscrew  40  causes the fastener  42  to travel along a length of the leadscrew in either direction depending upon the direction of rotation of the leadscrew. This travel causes the lever arm  48  to operate the drive gear  56  and the iris mechanism  60 . 
         [0020]    The housing  12  defines a lumen  58 , the drive gear  56  defines a throughhole  78  and the housing and the iris mechanism  60  define an orifice  76 . The lumen  58 , the orifice  76 , and the throughhole  78  are concentric. The iris mechanism  60  includes a plurality of leaves  82 . The drive gear  56  may be in the form of a ring. The lever arm  48  extends from the leadscrew  40  to the drive gear  56 . 
         [0021]    Each of the illustrated leaves  82  has a substantially flat, curvilinear portion. A first end of each leaf has a pin hole  84  for receiving a pin  86  for mounting the leaf  82  to the drive gear in a pivoting manner. The second end of leaf  82  terminates in a fin or flange  88 . In the illustrated embodiment, the fin  88  is substantially perpendicular to the plane of the curvilinear portion. The flange  88  may be at an angle to the curvilinear portion of the leaf within a range of substantially about 90 degrees to substantially about 135 degrees. The use of flange  88  may facilitate overlapping leaves, including multiple overlaps, that is, more than two leaves overlapping one another relative to the longitudinal axis of the valve apparatus. This feature may facilitate use in high pressure applications as well as other more abusive environmental conditions, such as high temperature or corrosive fluid flow, and promotes tighter sealing. Portions of the leaves, such as its curvilinear portion, may be flared, twisted, torqued or otherwise non-planar to further promote a sealing engagement with neighboring leaves. 
         [0022]    The leaves  82  may be made from any suitable materials, and arranged so that each leaf is a different material than the adjacent leaf. Physical forces, such as magnetism, or an integral torsion in each leaf, may bond the leaves together while allowing them to slide relative to each other. The leaves  82  may have any other suitable configuration in accordance with other embodiments of the present disclosure. 
         [0023]    In assembly, each leaf  82  is pinned to the drive gear  56  by a respective pin  86  or may be secured to the drive gear  56  in any other suitable manner. The fin  88  projects axially downstream in the illustrated embodiment. A bushing or extension  68  engages an O-ring associated with housing section  14 . The bushing  68  fixedly locks into the housing to prevent rotation. Fins  88  engage a protruding ring having thin slots to engage the fins. Another ring may provide a sealing surface. 
         [0024]    In the illustrated embodiment, when assembled, each pin is substantially equidistant radially to a center axis of the through hole  78  and orifice  76 . The slots of the protruding ring are also substantially equidistant radially, and substantially equally spaced circumferentially in the depicted embodiment. Each fin  88  is also substantially linear in the illustrated embodiment. The assembled components of leaves  82 , the protruding ring and drive gear  56  are thereafter further installed with an O-ring into a recess of the housing. Bushing  68  may be fixedly attached to the housing section  14  by means of a key and slot, boss and detent, snap fit, screws or any other suitable means. Another ring may provide a sealing surface. 
         [0025]    The drive gear  56  and iris mechanism  60 , may have any other suitable construction or configuration or may be secured or engaged in any other manner in accordance with other embodiments of the present disclosure. Additionally, the leadscrew  40 , the lever arm  48  and the bushing  50  may be engaged or otherwise associated with each other and the drive gear  56  in any other suitable manner in accordance with other embodiments of the present disclosure. 
         [0026]    The iris mechanism  60  may, for example, be similar to the iris member disclosed in U.S. Pat. No. 8,132,783. In the illustrated embodiment, when assembled, each pin is substantially equidistant radially to the center axis of the throughhole  78  and orifice  76  of the valve apparatus. Slots are also substantially equidistant radially, and substantially equally spaced circumferentially in the illustrated embodiment. Each fin  88  is also substantially linear in the illustrated embodiment. The assembled components of leaves  82 , protruding ring and drive gear  56  may be installed with an O-ring or the like. The protruding ring is fixedly attached to housing section  14  by means of a key and slot, boss and detent, snap fit, screws or in any other suitable manner. The motor  64  and housing section  14  are thereafter installed with housing section  16  encapsulating the components. This iris mechanism may have any other construction and configuration in accordance with other embodiments of the present disclosure. 
         [0027]    The illustrated planetary gear transmission  66  includes a central sun gear  100 , three planetary gears  102 , and a ring gear  104  which is operatively engaged with the motor  62  for driving the ring gear. The planetary gear transmission  66  includes a plate arrangement including a pair of plates  106  sandwiched about the gear transmission  66  and a plurality of shafts  108  that interconnect the plates. The plate arrangement is engaged with the motor  62  and provides a placement for the planetary gears  102  to operatively engage the sun gear  100  and the ring gear  104 . A nonmetallic band is operatively engaged with the ring gear  104  and operatively engages with a switch for disabling the action of the motor  62 .  FIGS. 7 and 8  also include a position encoder  120  for determining the size of the orifice  76 . 
         [0028]    In operation, the motor  62  activates the planetary gear transmission  66  in response to either automatic control or user selection. The protruding ring does not rotate. This causes rotation of the threaded leadscrew  40  which causes the fastener  42  to travel along the leadscrew and slide along the shaft  54 , and causes the drive gear  56  to rotate. As the drive gear  56  rotates, the second inner end of each leaf  82  is held fixed against circumferential displacement by engagement of the fin  88  with its corresponding slot of fixed protruding ring. As the drive gear  56  rotates, it circumferentially turns the outer end of each leaf  82 . Each leaf  82  rotates around its pin hole  84 . Accordingly, traction on each leaf  82  through pin  86  by drive gear  56  causes each leaf to advance radially inward. As drive gear  56  is driven in a first direction, each of the plurality of leaves moves inward to reduce the orifice  76  by reducing its diameter or otherwise reducing its size. An inside edge  102  each leaf advances in a manner reducing the distance between the inner edge  102  of the leaf and a center axis of orifice  76 . Accordingly, the orifice  76  becomes smaller to reduce the volume of fluid or gas to pass therethrough or to close completely. 
         [0029]    To increase the orifice  76  and allow a larger volume of fluid or gas to pass therethrough, the motor  62  is driven in an opposite direction. Each leaf is thereby driven by its pin hole  84  against the slot of the protruding ring. Engagement of each fin  88  against the slot causes the leaf to move radially outward from the center axis of the orifice  76 , thereby opening it. Accordingly, any suitable dual polarity motor or other suitable motor may provide driving force in each of two directions in order to selectively adjust the orifice  76  through which fluid or gas flows. 
         [0030]    In the illustrated embodiment, the orifice  76  is substantially circular. The iris mechanism  60  type configuration illustrated provides for the orifice  76  to remain symmetrical, and as illustrated substantially centered on the valve apparatus axis throughout variations in its size or variations in the flow volume through it. As such, the valve apparatus provides a mathematically predictable proportion between orifice size and flow volume. Because the orifice  76  is centered on the lumen  58  defined by the housing and geometrically symmetrical, the flow of fluid or gas through it is proportional to the opening or closing of the orifice  76 . Accordingly, a more precise control of flow may be achieved. Laminar flow of fluid is re-established immediately after the orifice is increased or decreased and may be established within the lumen of the valve apparatus itself, minimizing turbulence as the fluid exits the valve apparatus. 
         [0031]    The electrical control interface consists of multiple functional components. In one embodiment the main control interface consists of a sealed multi-pin plug. This plug may be wired to a printed circuit board. The PCB contains any suitable circuitry which allow for switching of the polarity of the input drive signal. The PCB also contains limit switches that indicate the valve apparatus position sensed from a mechanical positioning device attached to the secondary output shaft. The PCB may also contain limit switches which detect (as by cam  110 ) and control the travel limits of the drive system which can be positioned by a user. Cam  110  is driven by planetary gear transmission  66 . In one embodiment, a secondary PCB is wired to the primary PCB. The secondary PCB contains electronic control architecture which allows the reception, interpretation, and use of one of several standard control signals, such as 4-20 mA, 0-10 Vdc, etc. for valve apparatus position. The entire electronic control package may be physically contained within the motor casing. There may be a seal between the motor casing and the housing plate  20 . There may also be indicators, which may be mechanical or electrical, on the housing  12  which relay status of the valve apparatus position. Any other suitable electronics may be included in accordance with other embodiments of the present disclosure. 
         [0032]    While embodiments have been illustrated and described in the drawings and foregoing description, such illustrations and descriptions are considered to be exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected. The description and figures are intended as illustrations of embodiments of the disclosure, and are not intended to be construed as having or implying limitation of the disclosure to those embodiments. There are a plurality of advantages of the present disclosure arising from various features set forth in the description. It will be noted that alternative embodiments of the disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of the disclosure and associated methods, without undue experimentation, that incorporate one or more of the features of the disclosure and fall within the spirit and scope of the present disclosure and the appended claims.