Pressure fluid actuated device

Abstract

The invention relates to a hydraulic fluid actuator configuration with a working piston ( 2 ) that is guided in an actuating cylinder ( 4 ), with this piston being supplied pressure on both sides. In order to prevent an excursion of the working piston ( 2 ) from its neutral position (x=0) due to leakage, a hydraulic fluid displacement device ( 20 ) is suggested, which supplies a control volume over a period of a harmonic movement of the working piston ( 2 ) to the side of the working piston ( 2 ) to which it traveled.

1 . Hydraulic fluid actuator configuration with a working piston ( 2 ) guided in an actuating cylinder ( 4 ), with this piston separating a first hydraulic fluid chamber (D 1 ) from a second hydraulic fluid chamber (D 2 ) in the actuating cylinder ( 4 ) and due to hydraulic fluid volume flows Qp, which can be fed to or removed from the hydraulic fluid chambers (D 1 ), (D 2 ), being axially displaceable between a first final position ( 16 ) and a second final position ( 18 ), wherein in the first final position ( 16 ) the first hydraulic fluid chamber (D 1 ) has a minimum volume and in the second final position ( 18 ) the second hydraulic fluid chamber (D 2 ) has a minimum volume, and wherein the working piston ( 2 ) can assume a neutral position (x=0) between the two final positions ( 16 ), ( 18 ), wherein a back and forth movement from the neutral position in the direction of the first final position ( 16 ) and back corresponds to a first partial stroke movement and a back and forth movement from the neutral position in the direction of the second final position ( 18 ) and back corresponds to a second partial stroke movement, characterized by the fact that a hydraulic fluid displacement device ( 20 ) is provided, which during the first partial stroke movement of the working piston ( 2 ) removes a hydraulic fluid volume (formula) from the second hydraulic fluid chamber (D 2 ) and during the second partial stroke movement of the working piston ( 2 ) supplies a hydraulic fluid volume (formula) to the second hydraulic fluid chamber (D 2 ), wherein the fed or removed hydraulic fluid volumes are dependent upon the amplitude of the respective partial stroke movement.  
     
     
         2 . Actuator configuration pursuant to  claim 1 , characterized by the fact that the hydraulic fluid displacement device ( 20 ) during the first partial stroke movement of the working piston ( 2 ) feeds a hydraulic fluid volume (formula) to a reservoir ( 70 ) and during the second partial stroke movement of the working piston ( 20 ) removes a hydraulic fluid volume (formula) from the reservoir ( 70 ).  
     
     
         3 . Actuator configuration pursuant to  claim 2 , characterized by the fact that the hydraulic fluid displacement device ( 20 ) comprises a first displacement cylinder ( 22 ) and a second displacement cylinder ( 24 ), wherein a working volume (V 1 ) of the first displacement cylinder ( 22 ) is connected via a line ( 26 ) comprising a one-way valve ( 28 ) that allows a flow in the direction to the first displacement cylinder ( 22 ) with the second hydraulic fluid chamber (D 2 ) and via a line ( 29 ) comprising a pre-stressed one-way valve ( 30 ) that allows a flow in the direction away from the first displacement cylinder ( 22 ) with the reservoir ( 70 ), and wherein a working volume (V 2 ) of the second displacement cylinder ( 24 ) is connected via a line ( 32 ) comprising a one-way valve ( 28 ) that permits a flow in the direction to the second displacement cylinder ( 24 ) with the reservoir ( 70 ) and via a line ( 36 ) comprising a pre-stressed one-way valve ( 38 ) that allows a flow in the direction away from the second displacement cylinder ( 24 ) with the second hydraulic fluid chamber (D 2 ).  
     
     
         4 . Actuator configuration pursuant to  claim 1 , characterized by the fact that the hydraulic fluid displacement device ( 20 ) during the first partial stroke movement of the working piston ( 2 ) feeds a hydraulic fluid volume [formula] to the first hydraulic fluid chamber (D 1 ) and during the second partial stroke movement of the working cylinder ( 2 ) removes a hydraulic fluid volume [formula] from the first hydraulic fluid chamber (D 1 ).  
     
     
         5 . Actuator configuration pursuant to  claim 4 , characterized by the fact that the hydraulic fluid displacement device ( 20 ) comprises a first displacement cylinder ( 22 ) and a second displacement cylinder ( 24 ), wherein a working volume (V 1 ) of the first displacement cylinder ( 22 ) is connected via a line ( 26 ) comprising a one-way valve ( 28 ) that allows a flow in the direction to the first displacement cylinder ( 22 ) with the second hydraulic fluid chamber (D 2 ) and via a line ( 29 ) comprising a pre-stressed one-way valve ( 30 ) that allows a flow in the direction away from the first displacement cylinder ( 22 ) with the first hydraulic fluid chamber (D 1 ), and wherein a working volume (V 2 ) of the second displacement cylinder ( 24 ) is connected via a line ( 32 ) comprising a one-way valve ( 34 ) that allows a flow in the direction to the second displacement cylinder ( 24 ) with the first hydraulic fluid chamber (D 1 ) and via a line ( 36 ) comprising a pre-stressed one-way valve ( 38 ) that allows a flow in the direction away from the second displacement cylinder ( 24 ) with the second hydraulic fluid chamber (D 2 ).  
     
     
         6 . Actuator configuration pursuant to one of the claims  1  through  5 , characterized by the fact that transfer elements ( 14 ), ( 56 ), ( 58 ) are provided, which mechanically couple the hydraulic fluid displacement device ( 20 ) with the working piston ( 2 ).  
     
     
         7 . Actuator configuration pursuant to one of the previous claims, characterized by the fact that the displacement cylinders ( 22 ), ( 24 ) each contain a piston ( 40 ), ( 42 ), which can be displaced by an actuating device ( 50 ), ( 52 ) guided outward, wherein during the first partial stroke movement of the working piston ( 2 ) guided in the actuating cylinder ( 4 ) the actuating device ( 50 ) of the first displacement cylinder ( 22 ) is coupled with the movement of the working piston ( 2 ) and the actuating device ( 52 ) of the second displacement cylinder ( 24 ) is uncoupled from the movement of the working piston ( 2 ), and wherein during the second partial stroke movement of the working piston ( 2 ) guided in the actuating cylinder ( 4 ) the actuating device ( 52 ) of the second displacement cylinder ( 24 ) is coupled with the movement of the working piston ( 2 ) and the actuating device ( 50 ) of the first displacement cylinder ( 22 ) is uncoupled from the movement of the working piston ( 2 ).  
     
     
         8 . Actuator configuration pursuant to  claim 7 , characterized by the fact that the working piston ( 2 ) of the actuating cylinder ( 4 ) is connected with a piston rod configuration ( 14 ,  56 ,  60 ), which has axial stop surfaces ( 54 ,  58 ), which are allocated to the actuating devices ( 50 ,  52 ) of the displacement cylinders, wherein each actuating device ( 50 ,  52 ), respectively, rests against the axial stop surfaces ( 54 ,  58 ) only during a partial stroke movement of the working piston ( 2 ) and is carried along by it and during the other partial stroke movement of the working piston ( 2 ) lifts away from it.  
     
     
         9 . Actuator configuration pursuant to  claim 8 , characterized by the fact that adjusting means for adjusting the position between the pistons ( 40 ), ( 46 ) of the displacement cylinders ( 22 ), ( 24 ) and the axial stop surfaces ( 54 ), ( 58 ) are provided.  
     
     
         10 . Actuator configuration pursuant to one of the previous claims, characterized by the fact that the first hydraulic fluid chamber (D 1 ) is connected via a line ( 10 ) to a hydraulic fluid source ( 12 ) with at least nearly constant pressure and the second hydraulic fluid chamber (D 2 ) is connected via a line ( 6 ) with a control system ( 8 ) that can be controlled.  
     
     
         11 . Module, comprising an actuator configuration pursuant to one of the previous claims for installation in a rotating system of a helicopter main rotor.  
     
     
         12 . Helicopter rotor blade control for several rotor blades arranged evenly on the periphery of a rotor hub, wherein each rotor blade is allocated at least one actuator configuration or one module pursuant to the previous claims, wherein a control system in the form of a hydraulic displacement control system is provided, which is arranged in the rotor head of a helicopter, and wherein transfer elements are provided, which couple the piston rod configuration of the working piston with a helicopter rotor blade, for the purpose of controlling a blade angle movement of the helicopter rotor blade.  
     
     
         13 . Usage of the adjusting means of an actuator configuration pursuant to  claim 6  for adjusting the blade angles of the rotor blades of a helicopter rotor.