Gear pump 1 delivers fluid to power cylinders 2 and 3 through rotary directional valve 6 and gear pumps 5 and 4 with their gears keyed to the same shafts. Gear pumps 4 and 5 operate as hydraulic motors. If motors 4 and 5 are of the same size, equal amounts of fluid are delivered to cylinders 2 and 3 in each revolution of the motors. If a higher resisting force (load) is applied to the piston rod of one of the cylinders than to the other, the hydraulic motor on the side of the overloaded cylinder will operate as an intermediate pump, raising the pressure of the fluid delivered by pump 1 to that required to overcome the resistance of the overloaded cylinder. The second motor will operate as a drive for the first motor. Relief valves 7 and 8 are adjusted to a pressure exceeding the maximum pressure required to accomplish the working operations and less than the pressure setting of relief valve 9.
$4221$CHP,Dr$