Working apparatus, in particular excavator or machine for material handling

Abstract

The present disclosure shows a working apparatus, in particular an excavator or a machine for material handling, having an element movable via at least one hydraulic working cylinder, wherein at least one energy recovery cylinder is provided for recovering energy from the movement of the movable element, said energy recovering cylinder being filled with gas at the base side and having an annular space filled with a medium. In this respect, a flow restricting element is provided which restricts the flow of the medium from the annular space on a sudden moving out of the piston rod.

1 . A working apparatus, comprising:
 an element movable via at least one hydraulic working cylinder, wherein at least one energy recovery cylinder is provided for recovering energy from a movement of the movable element, said energy recovering cylinder being filled with gas at a base side and having an annular space filled with a medium, wherein a flow restriction element is provided which restricts a flow of the medium out of the annular space on a sudden moving out of a piston rod.   
     
     
         2 . A working apparatus in accordance with  claim 1 , wherein the flow restriction element is in communication with an external reservoir into which the medium flows on a moving out of the piston rod. 
     
     
         3 . A working apparatus in accordance with  claim 1 , wherein the medium is not compressible. 
     
     
         4 . A working apparatus in accordance with  claim 1 , wherein the flow restriction element is a restrictor, a diaphragm and/or a valve unit. 
     
     
         5 . A working apparatus in accordance with  claim 1 , wherein the annular space is in communication with the base side of the energy recovery cylinder filled with gas via the flow restriction element. 
     
     
         6 . A working apparatus in accordance with  claim 5 , wherein the flow restriction element is a restrictor. 
     
     
         7 . A working apparatus in accordance with  claim 6 , wherein a check valve is arranged parallel to the restrictor. 
     
     
         8 . A working apparatus in accordance with  claim 1 , wherein the energy recovery cylinder has a hollow piston rod. 
     
     
         9 . A working apparatus in accordance with  claim 1 , wherein the flow restriction element is a restrictor, a diaphragm and/or a valve unit having an adjustable volume, wherein the working apparatus is an excavator or a machine for material handling. 
     
     
         10 . A method of operating a working apparatus, having an element movable via at least one hydraulic working cylinder, wherein at least one energy recovery cylinder is provided for recovering energy from a movement of the movable element, said energy recovery cylinder being filled with gas at a base side and having an annular space filled with a medium, comprising: restricting a flow of the medium out of the annular space during an unwanted moving out of a piston rod. 
     
     
         11 . A working apparatus, comprising:
 at least one hydraulic working cylinder;   an element movable via the at least one hydraulic working cylinder;   at least one energy recovery cylinder movable in parallel with the hydraulic working cylinder on a movement of the movable element, the energy recovery cylinder having a cylinder jacket and a piston rod for recovering energy from movement of the movable element, said energy recovering cylinder filled with gas at a base side and having an annular space filled with a hydraulic medium; and   a flow restriction element which restricts a flow of the medium out of the annular space on a sudden moving out of the piston rod, the flow restriction element positioned exterior to the piston rod and the cylinder jacket.   
     
     
         12 . A working apparatus in accordance with  claim 11 , wherein the energy recovery cylinder is coupled to the element. 
     
     
         13 . A working apparatus in accordance with  claim 12 , wherein the flow restriction element is a restrictor, a diaphragm and/or a valve unit. 
     
     
         14 . A working apparatus in accordance with  claim 13 , wherein the annular space is in communication with the base side of the energy recovery cylinder filled with gas via the flow restriction element. 
     
     
         15 . A working apparatus in accordance with  claim 14 , wherein a check valve is arranged parallel to the restrictor.