The function of Manual Hydraulic Pump is to convert the mechanical energy of power machine (such as motor and internal combustion engine) into the pressure energy of liquid. Working principle:the CAM is driven by an electric motor. When the CAM pushes the plunger upward, the sealing volume formed by the plunger and the cylinder body decreases, and the oil is pushed out of the sealing volume through the one-way valve to the desired place. When the CAM rotates to the lower part of the curve, the spring forces the plunger down to a certain degree of vacuum, and the oil in the tank enters the sealing volume under the action of atmospheric pressure. The CAM keeps the plunger up and down, the sealing volume decreases and increases periodically, and the pump keeps absorbing and discharging oil.