HYDRAULIC DRIVE MECHANISM WITH TWO PUMPS

Gear pump 1 delivers fluid to variable-displacement pump 2. Surplus fluid is discharged through valves 3 and 4 to the tank. End a of directional valve 5 is connected to the delivery line of gear pump 1. Pump 2 delivers fluid to the right end of power cylinder 6 through valve 5 at whose end d the pressure is equal to that developed by variable-displacement pump 2. Piston 7 is moved by the fluid to …