Hydraulic distributor comprising an input element with a scavenging valve

Abstract

The input element comprises a body provided with openings respectively connecting to the pump, the reservoir and enabling information return to the pump. The body comprises a bore enabling communication between the openings and which are respectively joined to the pump and the reservoir, whereby a piston is mounted therein in order to establish said communication or not, whereby an extremity thereof is subjected to the pressure of the pump and the other extremity is subjected to pressure for information return and subjected to the pressure of a spring. The pressure exerted by the spring is substantially equal to the lift pressure of the pump and the piston and/or body comprise openings for communication of the chambers disposed on the pump side and reservoir side when the distributor is in rest position.

1 . A hydraulic distributor comprising an input element with a scavenging valve, having a body provided with orifices for respective connection to the pump, to the reservoir and for a return of information to the pump, the body having a bore which can place in communication the orifices and respectively connected to the pump and to the reservoir, inside which bore is mounted a piston which is able to establish or not to establish this communication, one end of the piston being subjected to the pressure of the pump and the other end thereof being subjected to the pressure for the return of information and to the pressure of a spring, characterized in that the pressure exerted by the spring is substantially equal to the delivery pressure of the pump, and the piston and/or the body have or has orifices ( 8 ) for placing in communication the chambers situated on the pump side and reservoir side when the distributor is in the rest position.  
   
   
       2 . The hydraulic distributor as claimed in  claim 1 , characterized in that the cross section of the orifices allows the passage of a flow of between 10 and 15% of the maximum installed flow, under a pressure of around 15 bar.  
   
   
       3 . The hydraulic distributor as claimed in  claim 1 , characterized in that the orifices for placing in communication the chambers situated on the pump side and reservoir side consist of cutouts or slots opening into the outer surface of the piston or into the surface of the bodies delimiting the bore for the piston.  
   
   
       4 . The hydraulic distributor as claimed in  claim 1 , characterized in that the orifices for placing in communication the chambers situated on the pump side and reservoir side consist of at least one duct formed in the piston or in the body.  
   
   
       5 . The hydraulic distributor as claimed in  claim 1 , characterized in that the cross section of the orifices for placing in communication the chambers situated on the pump side and reservoir side varies as a function of the characteristics of the distribution slide valve.  
   
   
       6 . The hydraulic distributor as claimed in  claim 2 , characterized in that the orifices for placing in communication the chambers situated on the pump side and reservoir side consist of cutouts or slots opening into the outer surface of the piston or into the surface of the bodies delimiting the bore for the piston.  
   
   
       7 . The hydraulic distributor as claimed in  claim 2 , characterized in that the orifices for placing in communication the chambers situated on the pump side and reservoir side consist of at least one duct formed in the piston or in the body.  
   
   
       8 . The hydraulic distributor as claimed in  claim 2 , characterized in that the cross section of the orifices for placing in communication the chambers situated on the pump side and reservoir side varies as a function of the characteristics of the distribution slide valve.  
   
   
       9 . The hydraulic distributor as claimed in  claim 3 , characterized in that the cross section of the orifices for placing in communication the chambers situated on the pump side and reservoir side varies as a function of the characteristics of the distribution slide valve.  
   
   
       10 . The hydraulic distributor as claimed in  claim 4 , characterized in that the cross section of the orifices for placing in communication the chambers situated on the pump side and reservoir side varies as a function of the characteristics of the distribution slide valve.