Patent Publication Number: US-2010120600-A1

Title: Vibrating centrifuge

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Application 61/112,980 filed Nov. 10, 2008, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a vibrating centrifuge, in particular to a drive mechanism for a vibrating centrifuge. 
     BACKGROUND OF THE INVENTION 
     Vibrating centrifuges use radial g force to separate solids and liquids on a screen basket. Materials that are processed by vibrating centrifuges include, for example, coal, salt, potash, with a particle size normally between, for example, 0.5 mm to 75 mm. 
     Vibrating centrifuges use axial vibration to help convey solids axially along the basket. The g force developed in the machine is typically low, less than 60 g&#39;s. Feed is introduced to the small diameter of a rotating screen basket. As the feed accelerates with the basket, it tends to lock to the screen. Axial vibration is added to the basket by rotating eccentric weights attached to the basket drive shaft or to a separate vibration transfer shaft, or by an eccentric shaft attached to a vibration transfer shaft, or by vibratory motors attached to the machine case or the housing vibrating the machine case and/or the housing and the rotating element. The vibration causes the solids retained on the screen to hop from the small to the large diameter of the basket and eventually off the end. 
     Some prior vibrating centrifuges include complicated eccentric weight mechanisms that are either belt driven or directly driven by a motor connected to an eccentric shaft. These arrangements result in high production costs, increased maintenance requirements, and difficulty in adapting the vibrating centrifuge to process changes. 
     Some prior art vibrating centrifuges include two large vibrating motors mounted to the sides of the centrifuge housing to vibrate the entire housing the rotating shaft and the basket. This increases the cost of the housing and may result in frequent cracks in the housing. The vibrating motors are also large and expensive. As the vibrating motors must drive the rotating shaft and basket, including any slurry contained in the basket, and must also drive the housing, power consumption is increased. 
     BRIEF DESCRIPTION OF THE INVENTION 
     According to a sample embodiment, a vibrating centrifuge comprises a housing; a basket rotatably supported by the housing; a main drive motor operatively connected to the basket to rotate the basket; a vibration transfer shaft operatively connected to the basket at a first end of the vibration transfer shaft to vibrate the basket; and a vibration motor resiliently connected to the housing and operatively connected to the vibration transfer shaft at a second end of the vibration transfer shaft. 
     According to another sample embodiment of the invention, a vibration drive for a centrifuge including a basket rotatably supported in a housing comprises a vibration transfer shaft operatively connected to the basket at a first end of the vibration transfer shaft; and a vibration motor connected to a mount, the mount being resiliently connectable to the housing, and the vibration transfer shaft being connected to the mount at a second end of the vibration transfer shaft. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically illustrates a vibrating centrifuge according to a sample embodiment; 
         FIG. 2  schematically illustrates a vibrating centrifuge according to a sample embodiment; 
         FIG. 3  schematically illustrates a cross-section of the vibrating centrifuge of  FIG. 2 ; and 
         FIG. 4  schematically illustrates a vibrating centrifuge according to another sample embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1-3 , a vibrating centrifuge  2  comprises a housing, or frame,  4  and a basket  6 . The housing  4  is supported on a base  8 , for example, a floor or sub-frame, by vibration dampeners, or buffers,  10 . 
     A main drive motor  12  is configured to rotate the basket  6  through an endless belt  16  which is connected to a pulley  14 . The main drive motor  12  may be connected to the housing  4  by a vibration dampener, or buffer,  38 . 
     A vibration motor  20  is connected to a vibration motor mount  36  that is mounted to a vibration shaft mount  34 . The vibration shaft mount  34  is connected to the housing by a plurality of springs  22 , for example, leaf springs. 
     A vibration transfer shaft  18  is connected to the vibration shaft mount  34  at a first end and is supported by bearings  30  at a second end. The second end of the vibration transfer shaft  18  is supported by the bearings  30  and is connected to a resonance buffer  26 . A main buffer  28  is provided between the rotating basket  6  and the resonance buffer  26 . The main buffer  28  is operatively connected to the pulley  14  which is supported in the housing  4  by a plurality of main bearings  24 . 
     The vibration motor  20  comprises two eccentrically mounted weights  58  that are provided in housings  32  at opposite ends of the vibration motor  20 . Rotation of the shaft of the vibration motor  20  causes rotation of the eccentrically mounted weights  58  which causes vibration of the vibration motor  20  which is transferred to the vibration shaft mount  34  which is resiliently connected to the housing  4  by the springs  22 . The vibration of the motor  20  is thus transferred to the vibration shaft mount  34  which is transferred to the vibration transfer shaft  18 . The vibration of the vibration transfer shaft  18  is transferred to the rotating basket  6  through the resonance buffer  26 . 
     Referring to  FIG. 3 , the rotating basket  6  includes a back plate  40  that is connected to the main buffer  28 . The main buffer  28  includes a main buffer outer drum  46  and a main buffer inner drum  48 . A main buffer elastomer material  50  is provided inside the main buffer inner drum  48 . 
     The vibration transfer shaft  18  is connected to the resonance buffer  26  and the resonance buffer  26  is supported in a resonance buffer drum  52  which is connected to the main buffer outer drum  46 . A cover plate  44  covers the resonance buffer  26  and separates the resonance buffer  26  from an acceleration cone  42  which receives material to be processed from an inlet chute (not shown). 
     The main buffer inner drum  48  is connected to a rotation shaft  56  that is connected to the pulley  14  by a rotation shaft mount  54 . Rotation of the pulley  14  through the endless belt  16  from operation of the main drive motor  12  is transferred through the rotation shaft  56  to the main buffer inner drum  48  and subsequently to the main buffer outer drum  46  which is connected to the back plate  40  of the basket  6 . The main buffer  28  dampens vibrations transmitted to the rotating basket  6  by the vibration transfer shaft  18  from being transmitted to the housing  4 . 
     The connection of the vibration transfer shaft  18  to the rotating basket  6  reduces fabrication and maintenance costs. The connection of the vibration transfer shaft  18  to the rotating basket  6  also improves process adaptability. The vibration motor  20  is easily accessible and replaceable and allows the vibrating centrifuge  2  to be standardized and easily adjusted or replaced to facilitate process changes. The vibration motor  20  drives only the “live load” in the rotating basket  6  and therefore the size of the vibration motor  20  may be smaller than prior art arrangements. In addition, no vibration stress is added to the housing, or frame,  4  and the housing  4  may be reduced in size. As the housing  4  is not vibrated by the vibration motor  20  and because the main buffer  28  dampens vibrations transmitted to the housing  4 , housing failures and cracking are reduced. 
     Referring to  FIG. 4 , a vibrating centrifuge  2  according to another sample embodiment comprises a housing, or frame,  4  and a basket  6 . The housing  4  is supported on a base  8 , for example, a floor or sub-frame, by vibration dampeners, or buffers, 10. Two vibration motors  20  are connected to a vibration motor mount  36  that is mounted to a vibration shaft mount in a manner similar to that disclosed above with respect to  FIGS. 1-3 . Each vibration motor  20  comprises two eccentrically mounted weights that are provided in housings  32  at opposite ends of the vibration motor  20 . Rotation of the shafts of the vibration motors  20  causes rotation of the eccentrically mounted weights which causes vibration of the vibration motors  20  which is transferred to the vibration shaft mount which is resiliently connected to the housing  4  by springs in a manner similar to that described above with respect to  FIGS. 1-3 . The vibration of the motors  20  is thus transferred to the vibration shaft mount which is transferred to the vibration transfer shaft. The vibration of the vibration transfer shaft is transferred to the rotating basket  6  through a resonance buffer as described above. 
     As shown in  FIG. 4 , the vibration motors  20  are mounted to the vibration motor mount  36  vertically, i.e. the shafts of the vibration motors are oriented vertically. It should be appreciated that the vibration motors  20  may be mounted to the vibration motor mount horizontally. The vertical orientation of the vibration motors  20  facilitates achieving a counter synchronic rotation direction of the unbalanced weights, thus providing an alternating resulting force in one direction for product conveyance on the basket deck. 
     Although two vibration motors are shown in  FIG. 4 , it should be appreciated that more than two motors may be provided. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.