Abstract:
A vibrating screen separator. The vibrating screen separator may be operated in a linear, an elliptical, or in a transition from elliptical to linear modes of operation. In the linear mode of operation, the screen separator moves along a reciprocating straight line path, and, in the elliptical mode of operation, the screen separator moves along an elliptical path. In the transitionary mode of operation, the screen separator is transitioned from movement along the elliptical path to movement along the linear path.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation-in-part of U.S. utility patent application Ser. No. 09/837,098, attorney docket number 20773.27, filed on Apr. 18, 2001, the disclosure of which is incorporated herein by reference. 
     
    
     
         [0002]    This invention relates generally to a screen separator, and in particular to a vibrating screen separator. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0003]    [0003]FIG. 1 a  is an isometric view of an embodiment of a vibrating screen separator assembly.  
         [0004]    [0004]FIG. 1 b  is a fragmentary cross sectional and schematic view of the actuators and controller of the assembly of FIG. 1 a.    
         [0005]    [0005]FIG. 2 is a flow chart that illustrates an embodiment of the operation of the assembly of FIGS. 1 a  and  1   b.    
         [0006]    [0006]FIG. 3 a  is a side view of the operation of the counter-rotating actuators of the assembly of FIGS. 1 a  and  1   b.    
         [0007]    [0007]FIG. 3 b  is a schematic illustration of the forces imparted to the frame of the assembly of FIGS. 1 a  and  1   b  during the operation of the counter-rotating actuators.  
         [0008]    [0008]FIG. 4 is a side view of the operation of the additional rotating actuator of the assembly of FIGS. 1 a  and  1   b.    
         [0009]    [0009]FIG. 5 is a schematic illustration of an embodiment of a control system for controlling the operation of the assembly of FIGS. 1 a  and  1   b.    
         [0010]    [0010]FIGS. 6 a - 6   c  is a flow chart that illustrates an embodiment of the operation of the control system of FIG. 5. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0011]    Referring to FIGS. 1 a  and  1   b , the reference numeral  10  refers, in general, to a vibrating screen separator assembly that includes a frame, or bed,  12  that includes a bottom wall  14  having an opening  16 , a pair of side walls,  18  and  20 , an end wall  22 , and a cross support member  24  coupled between the side walls. An actuator  26  for imparting motion to the frame  12  is coupled to the support member  24  that includes a housing  28  that is coupled to the support member that supports and is coupled to a rotary motor  30  having a rotary shaft  32  having opposite ends that extend out of the housing. A pair of substantially identical unbalanced weights,  34  and  36 , are coupled to the opposite ends of the rotary shaft  30 .  
         [0012]    Actuators,  38  and  40 , respectively, for imparting motion to the frame  12  are also coupled to the support member  24  that include housings,  42  and  44 , respectively, that are coupled to the support member that support and are coupled to rotary motors,  46  and  48 , respectively, having rotary shafts,  50  and  52 , respectively, having opposite ends that extend out of the housings. Pairs of substantially identical unbalanced weights,  54  and  56  and  58  and  60 , respectively, are coupled to the opposite ends of the rotary shafts,  50  and  52 , respectively. In an exemplary embodiment, the rotary shafts,  50  and  52 , are substantially parallel and perpendicular to a common plane, and the size, shape and mass of the unbalanced weights,  54 ,  56 ,  58 , and  60  are substantially identical.  
         [0013]    In an exemplary embodiment, the rotary shaft  32  is perpendicular to a different plane than the rotary shafts,  50  and  52 .  
         [0014]    The rotary motors,  30 ,  46  and  48 , are operably coupled to a controller  62  that provides motive power and controls the operation of the rotary motors. A screen  64  is received within the frame  12  and is adapted to be rigidly coupled to the bottom wall  14  using conventional mechanical fasteners.  
         [0015]    During operation of the assembly  10 , as illustrated in FIG. 2, the controller  62  may implement a motion control program  100  in which a user may initiate operation of the assembly in step  102 . The user may then select linear or elliptical movement to be imparted to the frame  12  of the assembly  10  in step  104 .  
         [0016]    If the user selects linear motion in step  104 , then the controller may operate the actuators,  38  and  40 , for imparting motion to the frame  12  in step  106 . As illustrated in FIG. 3 a , during operation of the actuators,  38  and  40 , for imparting motion to the frame  12 , the unbalanced weights,  54  and  58 , are rotated by the motors,  46  and  48 , respectively, about axes of rotation,  108   a  and  108   b , respectively, in opposite directions,  108   c  and  108   d , respectively, at substantially the same rotational speed with the rotational positions of the centers of mass,  108   e  and  108   f , substantially mirror images of one another. The rotation of the unbalanced weights,  54  and  58 , about the axes of rotation,  108   a  and  108   b , produces centrifugal forces,  108   g  and  108   h , respectively, that are directed from the centers of mass,  108   e  and  108   f , respectively, of the unbalanced weights,  54  and  58 , respectively, in the directions normal to the vectors from the centers of rotation to the corresponding centers of mass.  
         [0017]    The resulting centrifugal forces,  108   g  and  108   h , created during the rotation of the rotation of the unbalanced weights,  54  and  58 , about the axes of rotation,  108   a  and  108   b , impart a reciprocal linear motion to the frame  12  of the assembly  10 . In particular, as illustrated in FIG. 3 b , the centrifugal forces,  108   g  and  108   h , include horizontal components,  108   gx  and  108   hx , respectively, and vertical components,  108   gy  and  108   hy , respectively. Because, the direction and speed of rotation of the unbalanced weights,  54  and  58 , are opposite and equal, the horizontal components,  108   gx  and  108   hx , cancel each other out. As a result, the only forces acting on the frame  12  of the assembly due to the rotation of the unbalanced weights,  54  and  58 , about the axes of rotation,  108   a  and  108   b , are the sum of the vertical forces,  108   gy  and  108   hy . Since the vertical forces,  108   gy  and  108   hy , vary from a positive maximum vertical force to a negative maximum vertical force during the rotation of the unbalanced weights,  54  and  58 , about the axes of rotation,  108   a  and  108   b , the resulting linear motion imparted to the frame  12  of the assembly is a reciprocating linear motion. Thus, the combination of the actuators,  38  and  40 , provides an actuator for imparting linear motion to the frame  12  of the assembly. In an exemplary embodiment, during operation, the rotational positions and centrifugal forces created during the rotation of the unbalanced weights,  54  and  56  and  58  and  60 , about the axes of rotation,  108   a  and  108   b , respectively, are substantially identical.  
         [0018]    If the user selects elliptical motion in step  104 , then the controller may simultaneously operate the actuator  26  for imparting motion to the frame  12  and the actuators,  38  and  40 , for imparting motion to the frame in step  108 .  
         [0019]    As illustrated in FIG. 4, during operation of the actuator  26  for imparting motion to the frame  12 , the unbalanced weight  34  is rotated by the motor  30  about an axis of rotation  106   a . The rotation of the unbalanced weight  34  about the axis of rotation  106   a  produces a centrifugal force  106   b  that is directed from the center of mass  106   c  of the unbalanced weight  34  in the direction normal to the vector from the center of rotation to the center of mass. In an exemplary embodiment, during step  108 , the rotational positions, speeds, and centrifugal forces created during the rotation of the unbalanced weights,  34  and  36 , about the axis of rotation  106   c  are substantially identical. The resulting centrifugal forces created during the rotation of the rotation of the unbalanced weights,  34  and  36 , about the axis of rotation  106   c  would impart a circular motion to the frame  12  of the assembly  10  if the actuator  26  were operated alone.  
         [0020]    Because the rotary shaft  32  of the actuator  26  is perpendicular to a different plane than the rotary shafts,  50  and  52 , of the actuators,  38  and  40 , the simultaneous operation of the actuators, and the forces that are generated, as described above, results in elliptical motion being imparted to the frame  12  of the assembly  10 . Thus, the combination of the actuators,  26 ,  38  and  40 , provides an actuator for imparting elliptical motion to the frame  12 .  
         [0021]    If the user elects to discontinue the operation of the program  100  in step  110 , then the operation of the program ends in step  112 .  
         [0022]    In an exemplary embodiment, during the operation of the assembly  10  using the motion control program  100 , fluidic material including solid particles is injected onto the screen  64 . In an exemplary embodiment, the injection of the fluidic material onto the screen  64  is provided substantially as described in U.S. patent application Ser. No. 09/836,974, attorney docket number 20773.35, filed on Apr. 18, 2001, the disclosure of which is incorporated herein by reference. In this manner, the separation of solid particles from the liquids within the fluidic material is enhanced by the motion imparted to the frame  12  and screen  64 . In an exemplary embodiment, movement of the frame  12  and screen  64  along an elliptical path maintains solid particles on the screen for a longer period of time thereby permitting more liquids to be extracted from the fluidic material thereby providing a drier solid particle discard.  
         [0023]    Referring to FIG. 5, an embodiment of a control system  200  for controlling the operation of the motors,  30 ,  46 , and  48 , of the vibrating screen separator assembly  10  includes a forward motor starter  202  and a reverse motor starter  204  that are operably coupled to the motor  30 , a forward motor starter  206  that is operably coupled to the motor  46 , and a forward motor starter  208  that is operably coupled to the motor  48 . As will be recognized by persons having ordinary skill in the art, motor starters may be used to initiate the operation and rotation of an output shaft of a motor in a predetermined direction by causing the windings of the motor to apply a torque to the output shaft of the motor. A controller  210  is operably coupled to the forward motor starter  202 , the reverse motor starter  204 , the forward motor starter  206 , and the forward motor starter  208  for controlling the operation of the forward and reverse motor starters, and a mode select  212  is operably coupled to the controller  210  for permitting a user to select the mode of operation of the control system  200 .  
         [0024]    During operation of the control system  200 , as illustrated in FIGS. 6 a - 6   c , the controller  210  may implement a motion control program  300  in which a user may initiate operation of the control system in step  302 . The user may then select linear or elliptical movement to be imparted to the frame  12  of the assembly  10  in step  304 .  
         [0025]    If the user selects linear motion in step  304 , then the controller  210  may operate the motors  46  and  48  to impart linear motion to the frame  12  of the assembly  10  in step  306 . In particular, in step  306 , the controller  210  may operate the forward motor starters,  206  and  208 , to operate the motors,  46  and  48 , respectively, in equal and opposite directions of rotation to impart linear motion to the frame  12  of the assembly  10 . Alternatively, If the user selects elliptical motion in step  304 , then the controller  210  may operate the motors  30 ,  46 , and  48  to impart elliptical motion to the frame  12  of the assembly  10  in step  308 . In particular, in step  308 , the controller  210  may operate the forward motor starters,  202 ,  206 , and  208 , to operate the motor  30  and operate the motors,  46  and  48 , respectively, in equal and opposite directions of rotation to impart elliptical motion to the frame  12  of the assembly  10 .  
         [0026]    If the user elects to continue operation in step  310 , then the user may change the mode of operation in step  312 .  
         [0027]    If the user elects to change the mode of operation from linear to elliptical in step  314 , then the controller  210  may operate the forward motor starters,  202 ,  206 , and  208 , to operate the motor  30  and operate the motors,  46  and  48 , respectively, in equal and opposite directions of rotation to impart elliptical motion to the frame  12  of the assembly  10  in step  316 .  
         [0028]    Alternatively, if the user elects to change the mode of operation from elliptical to linear in step  318 , then the controller  210  may stop the operation of the forward motor starters,  206  and  208 , to thereby stop the operation of the motors,  46  and  48 , respectively, and stop the rotation of the motor  30  by stopping the operation of the forward motor starter  202  and operating the reverse motor starter  204  in step  320  to apply a reversing torque to thereby substantially stop the rotation of the motor  30  in step  320 . After a predetermined time period has lapsed in step  322 , after which the rotation of the motor  30  has substantially stopped, the controller  210  may then stop the operation of the reverse motor starter  204  and operate the forward motor starters,  206  and  208 , to operate the motors,  46  and  48 , respectively, in equal and opposite directions of rotation to impart linear motion to the frame  12  of the assembly  10  in step  324 .  
         [0029]    Thus, in the motion control program  300 , changing the mode of operation from elliptical to linear is provided by momentarily reversing the direction of operation of the motor  30 , and momentarily stopping the operation of the motors,  46  and  48 . In this manner, the mechanical energy generated as a result of the rotation of the motors,  46  and  48 , which would otherwise cause the motor  30  to continue rotating, is overcome. In an exemplary embodiment, the amount of time during which the rotation of the motors,  46  and  48 , is stopped and the direction of operation of the motor  30  is reversed in steps  320  and  322  may be determined empirically. Furthermore, in an exemplary embodiment, the momentary reversal of the direction of rotation of the motor  30  in steps  320  and  322  momentarily applies a reversing voltage to the motor  30  which in turn applies a reversing torque upon the rotatable shaft  32  and the unbalanced weights,  34  and  36 . As a result, in an exemplary embodiment, the rotation of the rotatable shaft  32  and the unbalanced weights,  34  and  36 , is substantially stopped.  
         [0030]    The present embodiments of the invention provide a number of advantages. For example, the ability to operate in a linear or an elliptical mode of operation without physical restructuring or mechanical reconfiguration of the assembly provides an efficient, reliable, and cost-effective system for providing both modes of operation.  
         [0031]    It is understood that variations may be made in the foregoing without departing from the scope of the invention. For example, the actuators,  26 ,  38  and  40 , for imparting motion to the frame  12  of the assembly  10  may include one or more unbalanced weights. Furthermore, the controllers  62  and  210  may include a programmable controller and/or hard wired control circuitry.  
         [0032]    Although illustrative embodiments of the invention have been shown and described, a wide range of modification, changes and substitution is contemplated in the foregoing disclosure. In some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.