Rotary device including a counterbalanced seal assembly

Abstract

A rotary device is provided. The rotary device includes a housing having an inner surface and a rotor assembly mounted for rotation in the housing about an axis defining an axial direction of the rotary device. The rotor assembly includes a rotor and a seal assembly. The rotor includes a central portion and a plurality of arms extending radially outward from the central portion. Each arm has a distal end disposed for sliding engagement with the inner surface, and at least one of the arms has a channel defined therein. The seal assembly is disposed within the channel, and includes a seal, a base defining a seal channel configured to receive the seal, and a counterweight mechanism pivotally coupled to the base. The counterweight mechanism is configured to control a contact pressure exerted by the seal on the inner surface resulting from rotation of the rotor.

What is claimed is: 
     
         1 . A rotary device comprising:
 a housing having an inner surface; and   a rotor assembly mounted for rotation in said housing about an axis defining an axial direction of said rotary device, said rotor assembly comprising:
 a rotor comprising a central portion and a plurality of arms extending radially outward from said central portion, each arm having a distal end disposed for sliding engagement with said inner surface, at least one of said arms having a channel defined therein; and 
 a seal assembly disposed within the channel, said seal assembly comprising:
 a seal; 
 a base defining a seal channel configured to receive said seal; and 
 a counterweight mechanism pivotally coupled to said base, said counterweight mechanism configured to control a contact pressure exerted by said seal on said inner surface resulting from rotation of said rotor. 
 
   
     
     
         2 . A rotary device in accordance with  claim 1 , wherein said seal assembly is configured to slide in the axial direction within the channel defined in said at least one arm. 
     
     
         3 . A rotary device in accordance with  claim 1 , wherein said seal is configured to slide independently of said base in the axial direction. 
     
     
         4 . A rotary device in accordance with  claim 1 , wherein said seal comprises a lip, said lip slidably received between said counterweight mechanism and said base, said counterweight mechanism engaging said lip to control the contact pressure exerted by said seal on said inner surface. 
     
     
         5 . A rotary device in accordance with  claim 1 , wherein said base comprises a fulcrum defining a pivot axis about which said counterweight mechanism pivots, the pivot axis substantially perpendicular to the axial direction. 
     
     
         6 . A rotary device in accordance with  claim 1 , further comprising a pin hingedly coupling said counterweight mechanism to said seal. 
     
     
         7 . A rotary device in accordance with  claim 1 , wherein said base comprises a fulcrum defining a pivot axis about which said counterweight mechanism pivots, the pivot axis substantially parallel to the axial direction. 
     
     
         8 . A rotary device in accordance with  claim 1 , wherein said seal includes a first end and a second end distal from said first end, each of said first end and said second end having an end groove defined therein, said seal assembly further comprising a pair of end seals, each end seal disposed within one of the end grooves. 
     
     
         9 . A rotary device in accordance with  claim 1 , wherein said rotor assembly further comprises at least one rocker pivotally coupled to said rotor for pivoting between a first position spaced from said inner surface of said housing and a second position adjacent said inner surface of said housing, wherein pivoting of said rocker causes said rotor to rotate. 
     
     
         10 . A seal assembly for use in a rotary device including a rotor, said seal assembly comprising:
 a seal;   a base defining a seal channel extending in a longitudinal direction, said seal disposed within the seal channel; and   a counterweight mechanism pivotally coupled to said base, said counterweight mechanism configured to control radial displacement of said seal resulting from centrifugal forces imparted on said seal by rotation of the rotor.   
     
     
         11 . A seal assembly in accordance with  claim 10 , wherein said seal is configured to slide independently of said base in the longitudinal direction. 
     
     
         12 . A seal assembly in accordance with  claim 10 , wherein said seal comprises a lip slidably received between said counterweight mechanism and said base, said counterweight mechanism engaging said lip to control radial displacement of said seal. 
     
     
         13 . A seal assembly in accordance with  claim 10 , wherein said base comprises a fulcrum defining a pivot axis about which said counterweight mechanism pivots, the pivot axis substantially perpendicular to the longitudinal direction. 
     
     
         14 . A seal assembly in accordance with  claim 10 , further comprising a pin hingedly coupling said counterweight mechanism to said seal. 
     
     
         15 . A seal assembly in accordance with  claim 10 , wherein said base comprises a fulcrum defining a pivot axis about which said counterweight mechanism pivots, the pivot axis substantially parallel to the longitudinal direction. 
     
     
         16 . A seal assembly in accordance with  claim 10 , wherein said seal assembly is configured to be slidably received within a seal assembly channel defined within one of the arms of the rotor. 
     
     
         17 . A seal assembly in accordance with  claim 10 , wherein said seal includes a first end and a second end distal from said first end, each of said first end and said second end having an end groove defined therein, said seal assembly further comprising a pair of end seals, each end seal disposed within one of the end grooves. 
     
     
         18 . A rotary device comprising:
 a housing having an inner surface; and   a rotor assembly mounted for rotation in said housing about an axis defining an axial direction of said rotary device, said rotor assembly comprising:
 a rotor comprising a central portion and a plurality of arms extending radially outward from said central portion, each arm having a distal end disposed for sliding engagement with said inner surface, at least one of said arms having a channel defined therein; and 
 a seal assembly disposed within the channel, said seal assembly comprising:
 a seal; 
 a base defining a seal channel, said seal disposed within the seal channel, said base comprising a fulcrum; and 
 a counterweight mechanism operatively coupled to said fulcrum, said counterweight mechanism comprising a counterweight and a lever extending away from said counterweight, wherein rotation of said rotor causes said counterweight mechanism to pivot about said fulcrum and causes said lever to exert a radial inward force on said seal. 
 
   
     
     
         19 . A rotary device in accordance with  claim 18 , wherein said fulcrum defines a pivot axis about which said counterweight mechanism pivots, the pivot axis substantially perpendicular to the axial direction. 
     
     
         20 . A rotary device in accordance with  claim 18 , wherein said seal comprises a body and a lip extending outward from said body, wherein rotation of said rotor causes said lever to exert a radial inward force on said lip. 
     
     
         21 . A rotary device in accordance with  claim 18 , further comprising a pin hingedly coupling said counterweight mechanism to said seal. 
     
     
         22 . A rotary device in accordance with  claim 18 , wherein said fulcrum defines a pivot axis about which said counterweight mechanism pivots, the pivot axis substantially parallel to the axial direction. 
     
     
         23 . A rotary device in accordance with  claim 18 , wherein said rotor assembly further comprises at least one rocker pivotally coupled to said rotor for pivoting between a first position spaced from said inner surface of said housing and a second position adjacent said inner surface of said housing, wherein pivoting of said rocker causes said rotor to rotate. 
     
     
         24 . A seal assembly for use in a rotary device including a rotor, said seal assembly comprising:
 a seal;   a base defining a seal channel, said seal disposed within the seal channel, said base comprising a fulcrum; and   a counterweight mechanism operatively coupled to said fulcrum, said counterweight mechanism comprising a counterweight and a lever extending away from said counterweight, wherein rotation of said rotor causes said counterweight mechanism to pivot about said fulcrum and causes said lever to exert a radial inward force on said seal.