VARIABLE-CAPACITY AXIAL-PLUNGER PUMP Russian patent published in 1998 - IPC

FIELD: mechanical engineering; transfer of materials; pump controls. SUBSTANCE: pump has housing, drive shaft, cylinder block with pistons, control member, pump control system cutting off supply source, spool-type distributor of mechanical control input and electrohydraulic amplifier which serves as second input. It has also two control cylinders 15 with pistons 16 and zero setting springs 17. Both inputs are provided with feedback from pump control member. Spool valve box 5 with control coupling prevents simultaneous action of signals onto pump control member. In other design version additional spool valve box 21 with control coupling is used which connects hydraulic lines of electrohydraulic amplifier and working spaces of control cylinders 15 with drain. To provide independent connection of hydraulic lines from mechanical input and electrical input to working spaces of control cylinders second pistons 22 with zero setting springs 17 can be introduced into control cylinders. EFFECT: enhanced reliability of operation. 3 cl, 3 dwg