Pumping System Employing a Variable-Displacement Vane Pump

Abstract

A pumping system has a variable-delivery vane pump. The pump has hydraulic pressure regulating dissipating devices for imparting to the oil, in a regulating chamber, a pressure lower than the delivery pressure.

1 . A pumping system ( 100 ) comprising a variable-delivery vane pump ( 10 ); the system ( 100 ) also comprising a user device (UT) connected to said pump ( 10 ) by a delivery conduit ( 26 ), and pressure regulating means for adjusting the eccentricity (E) of a ring ( 13 ) with respect to a rotor ( 14 ), both forming part of said pump ( 10 ), so that said pump ( 10 ) assumes a balanced configuration such as to supply the oil flow requested by said user device (UT);
 the system ( 100 ) being characterized in that said pressure regulating means comprise hydraulic dissipating means ( 29 ,  30 ;  50 ;  70 ,  75 ) for imparting to the oil inside a regulating chamber ( 20 ,  22 ) forming part of said pump ( 10 ) a pressure (p 2 ) lower than a control pressure (p 1 ).   
   
   
       2 . A system ( 100 ) as claimed in  claim 1 , characterized in that said hydraulic dissipating means comprise a valve ( 30 ;  70 ) and a dissipating device ( 29 ;  75 ). 
   
   
       3 . A system ( 100 ) as claimed in  claim 1 , characterized in that said hydraulic dissipating means comprise a three-way slide valve ( 50 ). 
   
   
       4 . A system ( 100 ) as claimed in  claim 1 , characterized in that said pump ( 10 ) comprises a hollow main body ( 11 ) having at least one chamber ( 20 ,  22 ); and in that said chamber ( 20 ,  22 ) houses a respective projection ( 19 ,  21 ) integral with said ring ( 13 ). 
   
   
       5 . A system ( 100 ) as claimed in  claim 4 , characterized in that said projection ( 21 ) has a first front surface (A 2 ) greater than a second front surface (A 1 ) of said projection ( 19 ). 
   
   
       6 . A system ( 100 ) as claimed in  claim 4 , characterized in that the size of said first front surface (A 2 ) is 1.4 to 1.7 times said second front surface (A 1 ).