Hermetically sealed rotary/nutating drive

Abstract

A nutating drive with hermetic seal which includes a housing with an internal wall and a nutating bar passing through an opening in the wall. A flexible tubular diaphragm seal surrounds the bar and is sealed at one end to the wall about the wall opening and is sealed at its other end to the bar for providing a hermetic seal for the wall opening. A universal joint support mechanism connects the bar to the housing for gimbaled non-axial rotational support of the bar in the housing. An axially rotatable rotor is mounted for axial rotation in the housing and the bar is pivotally connected at one end to the rotor at a position offset from the rotor axis for imparting nutational movement to the gimbaled bar about a geometric center of nutation with axial rotation of the rotor. The tubular diaphragm has a conical configuration tapered from a maximum diameter at the wall and to a minimal diameter at the bar end and the tubular seal encloses the geometric center of the bar. The tubular diaphragm seal may have a bellows configuration. A torsion tube which is very flexible in torsion is coaxially received over the bar with one end of the flexible torsion tube circumferentially sealed and secured to the bar and the other end of the torsion tube circumferentially sealed and secured to the minimal diameter end of the tubular diaphragm seal.

I claim:  
     
         1 . A nutating drive with a hermetic seal comprising: 
 a housing;    a wall in said housing;    a nutating bar passing through an opening in said wall;    a flexible tubular diaphragm seal surrounding said bar and sealed at one end thereof to said wall about said opening and sealed at its other end to said bar for providing a hermetic seal for said wall opening;    universal joint support means connecting said bar to said housing for gimbaled non-axial rotational support of said bar in said housing;    an axially rotatable rotor mounted for axial rotation in said housing;    said bar connected with a bearing at one end thereof to said rotor at a position offset from the rotor axis for imparting nutational movement to said gimbaled bar about a geometric center of nutation with axial rotation of said rotor; and    said diaphragm seal having a tubular conical configuration tapered from a maximum diameter at said wall end to a minimal diameter at said bar end, and enclosing said geometric center of said bar.    
     
     
         2 . The nutating drive of  claim 1 , wherein said tubular diaphram seal has a bellows configuration.  
     
     
         3 . The nutating drive of  claim 1 , wherein said minimum diameter end of said tubular diaphragm seal is positioned adjacent said center of nutation.  
     
     
         4 . The nutating drive of  claim 1 , wherein said bar end bearing is pivotally connected to said rotor.  
     
     
         5 . The nutating drive of  claim 4 , wherein said pivotal connection is a ball and socket pivotal connection.  
     
     
         6 . The nutating drive of  claim 1 , including a second rotor mounted in said housing for axial rotation and axially aligned with the first said rotor, said rotors positioned on opposite sides of said wall and the other end of said bar connected with a bearing to said second rotor at a position offset from the rotor axis, and rotary drive connections on said rotors external of said housing for respectively axially connecting input and output drive shafts to said rotors.  
     
     
         7 . The nutating drive of  claim 6  including annular seal means annularly secured to exterior portions of said housing about one of said rotors and extending from said housing for annular hermetically sealed engagement with a housing for an independent unit to be coupled in driving engagement with said one of said rotors.  
     
     
         8 . The nutating drive of  claim 7 , wherein said housing includes mounting means for securing said housing to a support.  
     
     
         9 . The nutating drive of  claim 1 , including a torsion tube coaxially received over said bar with one end of said tube circumferentially sealed and secured to said bar and the other end of said tube circumferentially sealed and secured to the minimal diameter end of said tubular diaphragm seal.  
     
     
         10 . The nutating drive of  claim 9 , wherein said torsion tube extends through said wall opening.  
     
     
         11 . The nutating drive of  claim 1 , wherein said housing is provided with an access split for providing access to the interior of said housing in the area of said center of nutation for part replacement.  
     
     
         12 . The nutating drive of  claim 1 , including a pump impeller secured to the other end of said bar for providing a centrifugal pump.  
     
     
         13 . A nutating drive with a hermetic seal comprising: 
 a housing;    a wall in said housing;    a nutating bar passing through an opening in said wall;    a flexible tubular diaphragm seal surrounding said bar and sealed at one end thereof to said wall about said opening and sealed at its other end to said bar for providing a hermetic seal for said wall opening;    universal joint support means connecting said bar to said housing for gimbaled non-axial rotational support of said bar in said housing;    an axially rotatable rotor mounted for axial rotation in said housing;    said bar connected with a bearing at one end thereof to said rotor at a position offset from the rotor axis for imparting nutational movement to said gimbaled bar about a geometric center of nutation with axial rotation of said rotor; and    a torsion tube coaxially received over said bar with one end of said tube circumferentially sealed and secured to said bar and the other end of said tube circumferentially sealed and secured to the minimal diameter end of said tubular diaphragm seal.    
     
     
         14 . The nutating drive of  claim 13 , wherein said torsion tube extends through said wall opening.  
     
     
         15 . The nutating drive of  claim 14 , said tubular diaphragm seal having a conical configuration tapered from a maximum diameter at said wall end to a minimal diameter at said bar end thereof, and enclosing said geometric center of said bar.  
     
     
         16 . The nutating drive of  claim 13 , wherein said tubular diaphram seal has a bellows configuration.  
     
     
         17 . The nutating drive of  claim 16 , wherein said minimum diameter end of said tubular diaphragm seal is positioned adjacent said center of nutation.  
     
     
         18 . The nutating drive of  claim 15 , wherein said bar end bearing is pivotally connected to said rotor.  
     
     
         19 . The nutating drive of  claim 18 , wherein said pivotal connection is a ball and ball socket pivotal connection.  
     
     
         20 . The nutating drive of  claim 13 , including a second rotor mounted in said housing for axial rotation and axially aligned with the first said rotor, said rotors positioned on opposite sides of said wall and the other end of said bar connected with a bearing to said second rotor at a position offset from the rotor axis, and rotary drive connections on said rotors external of said housing for respectively axially connecting input and output drive shafts to said rotors.  
     
     
         21 . The nutating drive of  claim 20  including annular seal means annularly secured to exterior portions of said housing about one of said rotors and extending from said housing for annular hermetically sealed engagement with a housing for an independent unit to be coupled in driving engagement with said one of said rotors.  
     
     
         22 . The nutating drive of  claim 21 , wherein said housing includes mounting means for securing said housing to a support.  
     
     
         23 . The nutating drive of  claim 13 , wherein said housing is provided with an access split for providing access to the interior of said housing in the area of said center of nutation for part replacement.  
     
     
         24 . The nutating drive of  claim 13 , including a pump impeller secured to the other end of said bar for providing a centrifuigal pump.