Hydro transformer

Abstract

A hydraulic transformer includes a multiplicity of displacers each guided in a displacer chamber. Pressure medium supply and discharge to and from the displacer chambers is controlled through the intermediary of control means provided with control recesses. The effective position of the control recesses in relation to the dead center positions of the displacers is variable, with each displacer volume being adapted to be connected with a dead space in a commutation phase upon transition between two adjacent control recesses.

1 . A hydraulic transformer, comprising a multiplicity of displacers guided in a displacer volume, and commutation means for shifting pressure medium supply and discharge to and from the displacers, wherein said commutation means include at least two control recesses connected with a pressure port, consumer port, or tank port, the relative positions of which are variable in relation to the dead-center positions of said displacers, characterized by a dead space through the intermediary of which the displacer volume is increased in a commutation phase.  
   
   
       2 . The hydraulic transformer in accordance with  claim 1 , wherein said control means include three control recesses ( 18 ,  20 ,  22 ) distributed on the periphery, and said dead spaces open into respective ranges between said control recesses.  
   
   
       3 . The hydraulic transformer in accordance with  claim 2 , wherein said control recesses are control kidneys, and said dead spaces open into respective kidney separation web between two adjacent control kidneys.  
   
   
       4 . The hydraulic transformer in accordance with  claim 2 , wherein said control means include a control disc in which said control kidneys and through bores of said dead spaces are formed.  
   
   
       5 . The hydraulic transformer in accordance with  claim 4 , wherein a part of said dead spaces next to said through bores is formed in a base body of said commutation means, in which base body connection passages leading to said ports are provided at least in portions.  
   
   
       6 . The hydraulic transformer in accordance with  claim 1 , wherein the volume of each dead space is larger than or equal to the displacement volume of a displacer.  
   
   
       7 . The hydraulic transformer in accordance with  claim 6 , wherein the volume of said dead space is less than five times the displacement volume.  
   
   
       8 . The hydraulic transformer in accordance with  claim 1 , wherein one of said dead spaces is formed to be substantially axial, and said two other dead spaces are formed to be substantially offset with respect to the axis of said control member.  
   
   
       9 . The hydraulic transformer in accordance with  claim 1 , wherein said displacers are pistons of an axial piston bent-axis unit.