Abstract
The purpose of this research is to redesign the compressed air driven hydraulic motor system which is designed in the former research and improve the oil line and control method. In this research, the valves in the piping system are rearranged to reduce the energy loss. The influence of the accumulators is also discussed. The use of the flow control valve and pneumatic ball valve controls the flow into the accumulator and adjusts the preload of accumulator to achieve better efficiency. To improve the control method, the system is added a new control phase and the control code are designed to decrease the consumption of power. Besides, the difference between the new piping system and old piping system is compared and measure the efficiency of high pressure/low pressure、constant pressure/expansion operations.