The drive system of the hydraulic press mainly has two types of pump direct drive and pump-accumulator drive. Pump Direct Drive The pump of this drive system provides high-pressure working liquid to the hydraulic cylinder, the distribution valve is used to change the direction of the liquid supply, and the relief valve is used to adjust the limited pressure of the system, and at the same time play a role of safety relief. This kind of drive system has few links and simple structure. The pressure can be automatically increased or decreased according to the required working force, which reduces the power consumption, but the capacity of the pump and its driving motor must be determined by the large working force and high working speed of the hydraulic press. This type of drive system is mostly used in small and medium-sized hydraulic presses, as well as large-scale (such as 120,000 kN) free-forging hydraulic presses directly driven by pumps. Pump-Accumulator Drive In this drive system there is one or a group of accumulators. When the high-pressure working fluid supplied by the pump has a surplus, it is stored by the accumulator; and when the supply is insufficient, it is supplemented by the accumulator. With this system, the capacity of the pump and motor can be selected according to the average consumption of the high-pressure working fluid, but because the pressure of the working fluid is constant, the power consumption is large, and the system has many links and a complex structure. This kind of drive system is mostly used for large hydraulic presses, or a set of drive system drives several hydraulic presses.