Patent Publication Number: US-2020291972-A1

Title: Passive de-aeration barrier for fluid chamber

Description:
FIELD OF INVENTION 
     The present invention relates to a fluid housing and more specifically directed to a de-aeration feature for a fluid housing. 
     BACKGROUND 
     Oil or hydraulic fluid actuators are used in a wide variety of applications. One type of existing hydraulic fluid actuator is a UniAir® system, which controls the opening and closing of engine valves. In all hydraulic fluid actuator systems, it is desirable to reduce aeration of the associated fluid as much as possible, since aerated fluid results in unpredictable levels of lift loss and valve opening delays. 
     One known solution for reducing aeration in fluid is to provide a single de-aeration vent opening, such as a bleed hole, in a portion of the actuator housing, such as a cover. This solution encourages bubbles in the hydraulic fluid to rise up and release through the de-aeration vent opening. However, this solution is only effective when the vehicle is on relatively level ground, and any tilting of the vehicle greatly reduces the effectiveness of this solution. 
     It would be desirable to provide a de-aeration configuration for a fluid housing assembly that is effective for vehicles that are on uneven surfaces or otherwise tilted. 
     SUMMARY 
     A fluid chamber assembly is disclosed that includes a housing defining at least one de-aeration opening, and a barrier within the housing that divides an interior of the housing into a first chamber and a second chamber. The barrier includes at least one perforation. 
     In one embodiment, the barrier has a curved profile. In one embodiment, the barrier has a convex profile that defines an apex inwards with respect to the first chamber. The apex can crest in a direction towards the at least one de-aeration opening. 
     In one embodiment, the at least one de-aeration opening is provided on a surface of the housing that partially defines the first chamber. 
     The at least one perforation can include a plurality of perforations spaced apart from each other in a pattern. In one embodiment, the at least one perforation has a conical profile. 
     The fluid chamber assembly is configured to be installed in a vehicle, such that the first chamber defines an upper chamber and the second chamber defines a lower chamber. A fluid inlet is defined on a bottom surface of the housing and the at least one de-aeration opening is defined on an opposite, top surface of the housing. The barrier is curved upwards towards the at least one de-aeration opening and away from the fluid inlet. In one embodiment, a switching solenoid valve inlet is defined on the bottom surface of the housing. 
     In another embodiment, a fluid chamber assembly is disclosed that includes a medium pressure chamber defining at least one de-aeration opening, and a barrier within the medium pressure chamber that divides the housing into an upper chamber and a lower chamber. The barrier defines a plurality of perforations each having a conical profile, and the barrier has a curved profile that is convex towards the upper chamber. The upper chamber is connected to the at least one de-aeration opening, and the lower chamber is connected to a fluid inlet and a solenoid switching valve inlet that is connected to a high pressure chamber. 
     A method of supplying de-aerated fluid to a switching solenoid valve via a fluid chamber assembly is provided. The method includes providing a fluid chamber assembly including a housing defining an interior and at least one de-aeration opening. The method includes positioning a barrier within the interior of the housing to divide the interior into first chamber and a second chamber. The barrier defines at least one perforation, and the second chamber is connected to a fluid inlet and a switching solenoid valve inlet. The method includes supplying fluid to the second chamber via the fluid inlet. The method includes de-aerating the fluid via passage of air bubbles through the at least one perforation and out of the at least one de-aeration opening. The method includes supplying de-aerated fluid to the switching solenoid valve inlet. 
     Additional embodiments are disclosed herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing Summary and the following detailed description will be better understood when read in conjunction with the appended drawings, which illustrate a preferred embodiment of the invention. In the drawings: 
         FIG. 1A  is top view of a fluid chamber assembly. 
         FIG. 1B  is a cross-sectional view of the fluid chamber assembly along line  1 B- 1 B in  FIG. 1A . 
         FIG. 1C  is a magnified view of a portion of the fluid chamber assembly of  FIGS. 1A and 1B . 
         FIG. 2A  is a magnified view of a barrier within a housing of a fluid chamber assembly. 
         FIG. 2B  is a top perspective view of the barrier within the housing of  FIG. 2A . 
         FIG. 3A  is a side view of a portion of the barrier of  FIGS. 2A and 2B . 
         FIG. 3B  is a top view of the barrier of  FIG. 3A . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Certain terminology is used in the following description for convenience only and is not limiting. The words “front,” “rear,” “upper” and “lower” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from the parts referenced in the drawings. “Axially” refers to a direction along the axis of a shaft. A reference to a list of items that are cited as “at least one of a, b, or c” (where a, b, and c represent the items being listed) means any single one of the items a, b, or c, or combinations thereof. The terminology includes the words specifically noted above, derivatives thereof and words of similar import. 
     Referring to  FIGS. 1A-1C , a fluid chamber assembly  10  is generally illustrated. The fluid chamber assembly  10  is used to provide oil or hydraulic fluid to actuators. Fluid supplied to the fluid chamber assembly  10  (via fluid inlet  40 ) can have some degree of aeration, which is undesirable. Accordingly, fluid within the fluid chamber assembly  10  should be de-aerated as much as possible before being supplied to associated actuators (via switching solenoid valve inlet  50 ). 
     The fluid chamber assembly  10  includes at least one de-aeration opening  12  on a top surface of a housing  11 . This de-aeration opening  12  functions as a bleed hole and allows air bubbles to escape the housing  11  and promotes de-aeration of the fluid therein. The de-aeration opening  12  is provided on a surface of the housing  11  that partially defines the first chamber  14  (i.e. the upper chamber). The housing  11  is also known as a medium pressure chamber. 
     A barrier  20 , also known as a gravitational flow separator, is installed within the housing  11  that further promotes de-aeration. The barrier  20  divides an interior of the housing  11  into a first chamber  14  (i.e. the upper chamber) and a second chamber  16  (i.e. the lower chamber). The barrier  20  includes at least one perforation  22 . The perforation  22  further promotes de-aeration of the fluid within the housing  11 . Air bubbles within the fluid generally tend to stick or adhere to the barrier  20  due to surface tension, and the air bubbles will be pushed upwards through the barrier  20  via the perforation  22  due to curvature of the barrier  20  and due to gravity and buoyancy. Accordingly, air bubbles are urged out of the second chamber  16  and into the first chamber  14 , which is desirable since the second chamber  16  holds the fluid prior to being used in associated actuators via the switching solenoid valve inlet  50 . As shown in the embodiment of  FIG. 1B , the first chamber  14  is smaller than the second chamber  16 . 
     In one embodiment, the barrier  20  has a curved profile. The curved profile further promotes air bubbles to be directed upwards from the second chamber  16  to the first chamber  14  and eventually out of the de-aeration opening  12 . The barrier  20  can have a convex profile defining an apex  24  inwards with respect to the first chamber  14 . The apex  24  crests in a direction towards the de-aeration opening  12  to promote de-aeration and urging air bubbles in a direction of the de-aeration opening  12 . The perforation  22  preferably includes a plurality of perforations  22 , as shown in  FIGS. 2B, 3A, and 3B , to further promote de-aeration. In one embodiment, the perforations  22  include at least twenty perforations  22 , and can include at least thirty perforations  22 . 
     As shown in  FIG. 3A , the perforations  22  have a conical profile, with a wider opening facing the second chamber  16  and a narrower opening facing the first chamber  14 . This tapered profile further promotes de-aeration by urging air bubbles from the second chamber  16  into the first chamber  14 . One of ordinary skill in the art would understand that alternative profiles could be used for the perforation  22 . 
     As shown in  FIG. 1B , the fluid inlet  40  is defined on a bottom surface  11   b  of the housing  11  and the de-aeration opening  12  is defined on an opposite, top surface  11   a  of the housing  11 . The barrier  20  is curved upwards towards the de-aeration opening  12  and away from the fluid inlet  40 . The switching solenoid valve inlet  50  is defined on the bottom surface  11   b  of the housing  11 . 
     In one embodiment, shown in  FIG. 2B , a diameter of the at least one perforation  22  is greater than a diameter of the at least one de-aeration opening  12 . 
     The embodiments disclosed herein generally provide effective de-aeration regardless of whether an associated vehicle including the fluid chamber assembly  10  is on level ground or tilted. The barrier  20  provides passive de-aeration of fluid within the housing  11  and achieves de-aeration of the fluid without the use of centrifugal forces or other active means. 
     The embodiments disclosed herein provide effective de-aeration of fluid in the housing  11  even if the housing  11  is tilted relative to a central axis (X) (illustrated in  FIG. 2A ) by at least 20 degrees-28 degrees, and more preferably of at least 24 degrees. 
     Effective de-aeration of fluid, as used herein, is defined as fluid entering the switching solenoid valve inlet  50  contains less than 4% of air, and more preferably contains less than 2% of air. 
     The barrier  20  can be shaped such that it can be press-fit or installed into a wide range of shapes and configurations of housings  11 . The barrier  20  is preferably formed from stamped sheet metal. The barrier  20  can be perforated to form the perforations  22  via any stamping or punching tool. 
     A method of supplying de-aerated fluid to a switching solenoid valve via a fluid chamber assembly  10  is provided. The method includes providing a fluid chamber assembly  10  including a housing  11  defining an interior and at least one de-aeration opening  12 . The method includes positioning a barrier  20  within the interior of the housing  11  to divide the interior into first chamber  14  and a second chamber  16 . The barrier  20  defines at least one perforation  22 , and the second chamber  16  is connected to a fluid inlet  40  and a switching solenoid valve inlet  50 . The method includes supplying fluid to the second chamber  16  via the fluid inlet  40 . The method includes de-aerating the fluid via passage of air bubbles through the at least one perforation  22  and out of the at least one de-aeration opening  12 . The method includes supplying de-aerated fluid to the switching solenoid valve inlet  50 . 
     Although inlet  50  is described as a switching solenoid valve inlet, one of ordinary skill in the art would recognize that the de-aerated fluid could be provided to any conduit directed to any type of fluid based actuating mechanism. 
     Having thus described the present invention in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the invention, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. 
     The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein. 
     LOG OF REFERENCE NUMERALS 
     fluid chamber assembly  10   
     housing  11   
     top surface of housing  11   a    
     bottom surface of housing  11   b    
     de-aeration opening  12   
     first chamber  14   
     second chamber  16   
     barrier  20   
     perforation  22   
     apex  24   
     fluid inlet  40   
     switching solenoid valve inlet  50