Accumulators in excavators store waste energy during swing acceleration, deceleration, and boom hoisting down. This study explores the dynamic behavior of a valve-controlled hydro-motor powered by pressurized fluid from an accumulator, replacing the traditional pump. A PI-Controller adjusts the valve’s port opening to maintain constant hydro-motor speed under varying loads. The system is modeled using Simscape in MATLAB/Simulink®. Results show the hydro-motor achieves steady speed despite initial high overshoot, long rise time, and extended settling time. Once steady state is reached, load variations at the shaft have minimal impact on speed. The findings suggest this system is ideal for low torque, medium-speed applications.