Abstract:
The present invention relates to a self actuating rotary dust valve particularly for discharging dust from an engine air cleaner. The rotary dust valve includes a valve body having an inlet port, an outlet port and a rotor chamber interposed therebetween. A rotary dust ejection member is enclosed in the rotor chamber and supported for rotation about a fixed axis. A plurality of fin members are provided angularly spaced about and secured to the hub member. Adjacent pairs of the fin members define at least one dust pocket therebetween to receive dust from the air cleaner to be ejected. The rotor chamber and the fin members are cooperatively shaped and configured to maintain a continuous air lock closure. The dust valve is operable by any of: gravity and vibration to rotate and thereby to discharge the dust buildup through the outlet port or alternately by other drive means.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/225,708, filed Jul. 15, 2009 entitled “SELF ACTUATING ROTARY DUST VALVE” and which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a rotary dust valve and, more particularly, to a self actuating rotary dust valve for discharging dust from a partial vacuum in an engine intake tract into the outside air. 
     BACKGROUND OF THE INVENTION 
     Internal combustion engines are typically protected from acquiring dust and debris in the intake combustion air by the presence of an air filter or air cleaner in the air intake tract. When operated in dusty or particulate debris laden environments, dust and debris can quickly accumulate in the air cleaner. Further movement of the debris is blocked by the filtering activity of the air filter, and so accumulated debris must be removed to prevent obstruction of the air cleaner filter element. 
     As the engine draws combustion air through the intake tract and air cleaner, the air cleaner operates at a slight vacuum relative to outside air pressure. This vacuum works against urging dust and debris to exit the air cleaner through the dust valve as the vacuum will tend to draw dust and debris back into the air cleaner rather than permitting the debris to exit to the outside. 
     Various types of flap valves are applied as dust valves in the prior art. These valves have lips that are held closed by the vacuum and may be responsive to pressure pulsations in the intake tract, as due to the operation of the engine. In response to momentary pressure fluctuations, such flap valves may momentarily open to discharge dust from within the air cleaner into the environment. If the pressure pulsations are insufficient or the vacuum too strong to permit the flap valve lips to open, then some varieties of the flap valves will open when the engine is shutdown and the vacuum is thereby removed. If the flap valve fails to reliably periodically open (perhaps due to the operating vacuum, insufficient engine air intake pressure pulsations, elastomeric aging or other issues), then dust accumulates in the air cleaner and air filter obstruction is not avoided. 
     With the advent of tier 4 emission standards, engine manufacturers are providing designs that have a steadier air intake pressure and reduce pressure pulsations; therefore engine intake air pressure pulsations may be insufficient to operate dust removal flap valves and the like. 
     Additionally the elastomers of elastomeric dust valves can age, lose their resilience or even disintegrate and therefore fail to close or close fully during operation. This is undesirable as drawing outside air in the reverse direction through the dust valve can draw in outside dust and debris and, due to the vacuum in the air intake tract, prevent accumulated debris in the air cleaner or intake tract from being expelled to the environment. 
     Therefore, there remains a need in the art for a dust valve that avoids elastomeric aging issues, is low in cost, prevents back-flow through the dust valve, is self actuating and is able to eject dust while operating against intake tract vacuum. 
     SUMMARY OF THE INVENTION 
     In aspects of the invention a self actuating rotary dust valve is provided. The present invention is particularly beneficial in ejecting dust from an engine air cleaner, and provides a low cost, self actuating, compact and reliable solution. The rotary dust valve includes a valve body having an inlet port, an outlet port and a rotor chamber interposed therebetween. A rotary dust ejection member is enclosed in the rotor chamber and supported for rotation about a fixed axis within the chamber. The axis of rotation is substantially perpendicular to the alignment between the inlet and outlet ports. The rotary dust valve includes a hub member rotatably supported to rotate in the rotor chamber about the axis of rotation. A plurality of fin members are provided angularly spaced about and secured to the hub member. Each fin member extends radially outwards from the hub member. The fin members share a common size and shape and are configured to rotate in unison about the axis. Adjacent pairs of the fin members define at least one dust pocket therebetween to receive dust from the air cleaner to be ejected. The fin members are arranged such that as the fin members rotate about the axis, the dust pockets are caused to open to the inlet port when in a first position and then to open to the outlet port when in a second position. The fin members are configured to open a dust pocket to no more than one of the ports at any time. The rotor chamber and the fin members are cooperatively shaped and configured to maintain a continuous air lock closure between the inlet and outlet port as the fin members rotate about the axis within the chamber, providing pressure and air flow separation between the inlet and outlet ports. The fin members freely rotate in unison about the axis such that dust buildup in the dust pocket in the first position is operable by gravity and/or vibration to rotate the duct pocket with buildup into the second position to discharge the dust buildup through the outlet port. 
     In another aspect of the invention, the fin members are angularly positioned about the axis for uniform angular displacement between adjacent fin members, relative to the axis of rotation. 
     In another aspect of the invention, cylindrical shaft portions extend axially from opposing ends of the hub member. The shafts are sized to extend to and receive support from opposing sidewalls of the rotor chamber. 
     In another aspect of the invention, two pin members are provided, each secured to an opposing sidewall of the rotor chamber. The pins are positioned along the axis of rotation and protrude inwardly along the axis into the chamber. The opposing ends of the hub member each have a bore. The bores are each configured to receive and rotate about a portion of the pins such that the hub member and fin members are free to rotate in the rotor chamber. 
     In another aspect of the invention, a shaft is provided having a length selected to extend between and receive support from opposing sidewalls of the rotor chamber. The shaft is aligned with the axis and extends through an axially aligned bore in the hub member. 
     In another aspect of the invention, the hub and fin members rotate in unison upon the shaft. 
     In another aspect of the invention, the shaft rotatably supports the hub and fin members on the opposing sidewalls such that the shaft, hub and fin members rotate in unison. 
     In another aspect of the invention, the fin members are substantially planar. 
     In another aspect of the invention, the fin members may be curved, S-shaped, concave or convex. 
     In another aspect of the invention, the dust valve is positioned with the inlet port positioned vertically above the outlet port such that the ejection of dust is aided by gravity. 
     In another aspect of the invention, the inlet port is connected to an air cleaner of an internal combustion engine. 
     The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying Figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention. 
       Features of the present invention, which are believed to be novel, are set forth in the drawings and more particularly in the appended claims. The invention, together with the further objects and advantages thereof, may be best understood with reference to the following description, taken in conjunction with the accompanying drawings. The drawings show a form of the invention that is presently preferred; however, the invention is not limited to the precise arrangement shown in the drawings. 
         FIG. 1  is a schematic diagram of an air intake tract of an internal combustion engine, consistent with the present invention; 
         FIG. 2A  depicts a perspective view of a rotary dust valve, consistent with the present invention; 
         FIG. 2B  is a side sectional view of the rotary dust valve presented in  FIG. 2A ; and 
         FIGS. 2C and 2D  are perspective views of embodiments of exemplary rotary dust ejection members, consistent with the present invention. 
       Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of method steps and apparatus components related to a self actuating rotary dust valve apparatus. Accordingly, the apparatus components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. 
     In this document, relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms “comprises,” “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by “comprises . . . a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. 
       FIG. 1  is a schematic diagram of an air intake tract  100  of an internal combustion engine  102 . Air enters the tangential inlet  124  of the air cleaner  104  where, due to the tangential position of inlet  104  the air flow is cause to rotate or torsionally within the dirty side  106  of the air cleaner  104 . Due to the torsional air flow, preseparation of some, particularly heavier particulates  122  occurs with the dirty side  106  of the air cleaner  104  before the air flow enters the air filter  114 . Air filter  114  includes a filter media adapted to remove additional particulates that were not caught by the preseparation process. Filtered air exits the air filter  114  at the clean side  118  of the air filter  114  and flows along the air intake tract to eventually enter the intake manifold  120  of the internal combustion engine  102 . 
     Particulates  122  present in the combustion air entering the air cleaner  104  are removed by preseparation and filtering and are therefore trapped at the dirty air side  106  of the air cleaner  104  where they may accumulate and eventually occlude portions of the dirty air side  106  of the air cleaner  104 . Due to the swirl of the air flow induced by the tangential inlet of the air cleaner  104 , perhaps 80-90% of the particulate debris is removed in the preseparation process and accumulates at the bottom of the dirty air side  106  of the air cleaner housing. Debris may accumulate to the point at which the debris contacts and begins to occlude the air filter element  114 . As further movement of this particulate debris  122  is blocked by the filtering activity of the air filter  114 , it is advantageous to provide a means of automatically removing the particulate debris  122  to prevent obstruction of the air cleaner  104 . 
     During engine operation the air cleaner  104  operates at a lower absolute pressure (slight vacuum) relative to the outside air pressure, this due to the vacuum generated by operation of the engine  102 . The air inlet  124  is generally positioned to draw outside air at a location where minimal dust is expected and where it may freely draw upon outside air. The air cleaner  104  is generally positioned within the engine compartment of the vehicle, providing a short air duct run with minimal pressure loss to the engine. It is generally undesirable to draw air from within the engine compartment as the air in the engine compartment is warmer (heated by the engine  102 ) than the outside air. It is known that drawing heated combustion air into the engine  102  negatively affects the operating/fuel efficiency of the engine  102 . 
     To vent accumulated dust and debris  122  from the air cleaner  104 , in  FIG. 1  a rotary dust valve  126  according to the prevent invention is advantageously provided and mounted preferably at a low point of the dirty air side  106  of the air cleaner  104 . Preferably the rotary dust valve  126  is positioned such that the inlet port  128  is positioned in elevation above the outlet port  130  such that dust/debris  122  is able to enter the inlet port  126  and exit the outlet port  130  under the motive influence of gravity. 
     As the air cleaner  104  typically operates at a slight vacuum relative to outside air, and due to the fact that it is undesirable to permit air to flow in a reverse direction (i.e. from outlet port  130  to inlet port  128 ) to enter the air cleaner  104 , the rotary dust valve  126  is configured to maintain a continuous air lock closure between the outlet port  130  and the inlet port  128 , as will be described further below. 
       FIG. 2A  depicts a perspective view of a rotary dust valve  126  according to at least one aspect of the present invention. A convex curved valve body  132  that in some aspects of the invention may be spheroidally shaped (as depicted in  FIG. 2A ) is provided with an inlet port  128  and an opposing outlet port  130 . In preferred aspects of the invention the inlet port  128  may have the configuration of a cylindrical pipe section configured for connecting and mounting to a complimentary cylindrical fitting on the air cleaner  104 . 
       FIG. 2B  is a side sectional view of the rotary dust valve  126  presented in  FIG. 2A , illustrating a substantially spherical rotor chamber  138  provided within the valve body  132 . A rotary dust ejection member  140  is disposed and rotatably supported with the rotor chamber  138 . The rotary dust ejection member  140  includes a plurality of fin members  142  secured to a hub member  144 . The hub member is positioned along an axis of rotation  146  about which the hub member  144  may rotate. Fin members  142  are each secured to the hub member  144  such that fin members  142  rotate in unison about the axis or rotation  146 . The fin members  142  share a common size and shape. 
     Advantageously, the rotor chamber  138  is shaped and configured in a complimentary fashion with the fin members  142  so as to provide a continuous closure between the inlet port  128  and the outlet port  130  in all positions of rotation of the rotary dust ejection member  140  about the axis  146 , thereby providing pressure and air flow separation between the inlet port  128  and outlet port  130 . Outer edges of the fin members  142  sweep out a contour as they rotate. The air lock closure between the inlet port  128  and outlet port  130  is accomplished by sizing and shaping the rotor chamber  138  such that the clearance between the fin members  142  (swept contour of) and the rotor chamber  138  is minimal but sufficient that the fin members  142  do not inter or contact the interior of the rotor chamber  138  as they rotate. 
     Any two adjacent fin members taken together (a fin member pair) define a dust pocket  148  therebetween. In general, a quantity ‘n’ of fin members will define a like quantity ‘n’ of dust pockets  148  in the rotary dust ejection member  140 . In any rotational position of the rotary dust ejection member  140 , at least one dust pocket is aligned in a first position in which it is in opened communication with the inlet port  128  and thereby positioned to receive dust/particulates  122  from the inlet port  128  and accumulate the dust in the input port aligned dust pocket  148 . As the dust/particulate  122  mass accumulates in the input port aligned dust pocket  148 , the dust ejection member  140  becomes unbalanced or ‘top heavy’ and is urged by the action of gravity to rotate about the axis  146  into a second position in which the dust laden dust pocket  148  then aligns to open to the outlet port  130 , at which the accumulated dust/particulates  122  are discharged to the outside by the action of gravity. 
     Advantageously, the operation of the engine  102  provides a stream of pressure pulses in the air intake tract  100  that may further act to vibrate or actuate the rotary dust ejection member  140 , the vibration further aiding the rotation of the rotary dust ejection member  140  after it becomes unbalanced or top heavy due to accumulation of particulates  122 . Operation of the engine  102  may by itself provide mechanical vibration additionally operative to aid rotation of a dust laden rotary dust ejection member  140 . As such, the rotary dust valve  126  is preferably (although, not necessarily) self operating and preferably does not require an external drive means to operate the rotary dust ejection member  140  to eject particulates  122  from the air cleaner  104  to the outside. 
     Advantageously in some embodiments a drive means, such as an electric motor drive or a vacuum motor, may be coupled to the rotary dust ejection member  140  to aid in the ejection of particulates  122  from the air cleaner  104 . 
     Advantageously, in preferred embodiments the rotary dust ejection member  140  is freely rotatable within the rotor chamber  138 . 
     Advantageously, the rotary dust valve  126  of the present invention provides a low cost, self actuating dust ejection valve that further advantageously provides an air lock between the engine air cleaner  104  and the outside environment. 
       FIG. 2C  is a perspective view of one embodiment of a rotary dust ejection member  140 . In the embodiment illustrated in  FIG. 2C , the fin members  142  extend radially outwards from the hub member  144 . The hub member  144 , on its opposing ends, is provided with cylindrical shaft portions  136  configured to rotatably support the rotary dust ejection member  140  within the rotor chamber  138 . The rotary dust ejection member embodiment of  FIG. 2C  may be utilized with the rotary dust valve  126  of  FIG. 2A , in which the shaft or shafts  136  extend through and receive support from opposing sidewalls of the rotor chamber  138 . 
     In the embodiment illustrated in  FIG. 2C , the shaft is provided as cylindrical portions extending from opposing ends of the hub member  144 . 
     In alternate embodiments, (see  FIG. 2D ), the shaft  136  may be realized as a separate component extending through a central portion of the hub member  144  and having a length “L” selected to extend between and receive support from opposing sidewalls  162  (see  FIG. 2A ) of the rotor chamber  138 . In some alternate embodiments, the hub member  144  includes a sufficiently sized bore  160  such that the hub member  144  is free to rotate on the shaft  136 . In other alternate embodiments, the hub member  144  may be fixedly secured to the shaft  136  such that the hub member  144  rotates in unison with the shaft  136 . In this case the shaft  136  is rotatably supported at opposing shaft ends by the opposing sidewalls  162  (see  FIG. 2A ) of the rotor chamber  138 . 
     In an aspect of the invention illustrated in  FIG. 2C , the fin members  142  are substantially planar and arranged at equal angular increments about the hub member  144  relative to the axis of rotation  146 . Although this is a preferred embodiment, it should be evident that the fin members  142  may be provided with other non-planar shapes without deviating from the principles of the inventive disclosure presented herein. 
     In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims. The invention is defined solely by the appended claims including any amendments made during the pendency of this application and all equivalents of those claims as issued.