Row unit for agricultural implement

A down-force system for an agricultural implement having a towing frame and a plurality of row units movably mounted to the towing frame for vertical movement relative to the towing frame, the down-force system comprising:

• a plurality of attachment frames adapted to be rigidly connected to the towing frame, each of the attachment frames corresponding to a respective row unit of the plurality of row units;
• a plurality of linkages pivotably coupled, respectively, to the plurality of attachment frames;
• a plurality of row unit frames coupled, respectively, to the plurality of linkages, each row unit frame having a leading end pivotably coupled to a corresponding linkage to permit vertical pivoting movement of the row unit frame;
• at least one furrow-forming device mounted on one or more of the plurality of row unit frames;
• at least one hydraulic cylinder between a respective linkage and a respective attachment frame of each row unit to apply a force to each row unit to produce a controllable force acting on the row unit, the controllable force including a force acting on the furrow-forming device, each hydraulic cylinder assigned to one group of at least two groups of hydraulic cylinders, each of the at least two groups of hydraulic cylinders being associated with a respective plurality of row units;
• a control system operably connected to the hydraulic cylinders to control the hydraulic cylinders to vary the force applied by the hydraulic cylinders to the associated row unit, the control system configured to control each group of hydraulic cylinders independent of another group of hydraulic cylinders to enable the hydraulic cylinders of one group to apply a different force to the respective plurality of row units as compared to the hydraulic cylinders of another group;
• and
• a single unitary housing forming the at least one hydraulic cylinder and including a cavity containing at least one energy storage device.