US Patent 10233613 Shovel and method of driving shovel

A shovel includes a swing hydraulic motor configured to swing a rotating structure, a swing drive hydraulic circuit configured to drive the swing hydraulic motor, an assist hydraulic motor connected to an engine and configured to be supplied with hydraulic oil discharged from the swing drive hydraulic circuit, and a controller configured to control the driving of the shovel. The controller is configured to detect the load condition of the engine, and control the supply of the hydraulic oil to the assist hydraulic motor at the time of deceleration of the swing hydraulic motor, based on the detected load condition.