Vacuum pump provided with vibration damper

Abstract

A vacuum pump assembly is provided with a vacuum pump and external unit coupled by a vibration damper. The vibration damper comprises a plurality of piezoelectric actuators and a plurality of sensors. Actuators attenuate vibration propagated from the pump to the external unit to which the pump is connected and/or vice versa, while the sensors are capable of providing a measure of the vibrations to controlling said actuators.

1 . A vacuum pump assembly comprising: 
 an external unit;    a vacuum pump( 100 ) which provides vacuum within the external unit, said pump comprising a body with an inlet port ( 110 ), a discharge port ( 120 ) and means ( 130 ) for pumping a gas from said inlet port to said discharge port; and    a vibration damper ( 14 ;  24 ;  34 ;  44 ;  54 ) attenuating vibration transmission between the body of said pump and the external unit, said vibration damper comprising at least one piezoelectric actuator (A i ).    
   
   
       2 . The vacuum pump assembly as claimed in any  claim 1 , wherein said pump is a turbomolecular pump.  
   
   
       3 . The vacuum pump assembly as claimed in  claim 2 , further comprising a sensor (S i ) controlling said at-least one piezoelectric actuator (A i ).  
   
   
       4 . The vacuum pump assembly as claimed in  claim 3 , wherein said vibration damper ( 14 ;  24 ;  34 ;  44 ;  54 ) is positioned in correspondence with at least one of said input and discharge ports ( 110 ,  120 ).  
   
   
       5 . The vacuum pump assembly as claimed in  claim 4 , wherein said vibration damper further comprises a vacuum-tight bellows ( 17 ) equipped at its ends with a first and a second flanges ( 150 ,  160 ), said first flange and said second flange are coupling said vibration damper to said pump and the external unit, respectively.  
   
   
       6 . The vacuum pump assembly as claimed in  claim 5 , wherein said vibration damper ( 14 ) comprises a plurality of sensors (S 1  . . . S n ) and a plurality of piezoelectric actuators (A 1  . . . A m )( 18 ), wherein said actuators, preferably of parallelepiped or cylindrical shape, are uniformly distributed around said bellows ( 17 ) between said first flange and said second flange.  
   
   
       7 . The vacuum pump assembly as claimed in  claim 3 , wherein said sensor is a piezoelectric sensor.  
   
   
       8 . The vacuum pump assembly as claimed in claims  6 , wherein said sensors are uniformly distributed around said bellows.  
   
   
       9 . The vacuum pump assembly as claimed in  claim 4 , wherein said actuators are formed by washers mounted around securing screws ( 20 ) affixing the pump and the external unit.  
   
   
       10 . The vacuum pump assembly as claimed in  claim 7 , wherein at least one of said piezoelectric actuators is coaxially mounted relative to at least one of said piezoelectric sensors.  
   
   
       11 . The vacuum pump assembly as claimed in  claim 2 , wherein said vibration damper comprises a first and a second piezoelectric actuators ( 581 ,  582 ) damping vibrations in two mutually perpendicular directions.  
   
   
       12 . The vacuum pump assembly as claimed in  claim 11 , wherein said vacuum pump ( 100 ) is a rotary pump and one of said mutually perpendicular directions corresponds with a rotation axis of said vacuum pump.  
   
   
       13 . The vacuum pump assembly as claimed in  claim 3 , further comprising a control system having at least one regulator (R; R i ) controlling one or more of said piezoelectric actuators (A 1  . . . A m ), depending on the signals from said sensors (S 1  . . . S n ).  
   
   
       14 . The vacuum pump assembly as claimed in  claim 2 , further comprising a control system having at least one regulator (R; R i ) controlling one or more of said piezoelectric actuators (A 1  . . . A m ) based on the value of external quantities (E 1  . . . E m ) representative of the external disturbances imposed on said pump.