Though partially funded by NASA, it is still a private site. Therefore, before downloading any materials for use, you need to ask permission. The function of the hydraulic system power pump is to change mechanical horsepower to hydraulic horsepower. There are two types of power pumps, a gear pump and a piston pump.
Gear pumps move fluid based upon the number of gear teeth and the volume spacing between gear teeth.
Piston pumps move fluid by pushing it through the motion of the pistons within the pump. As mentioned previously, the volumetric efficiency of gear pumps depends upon the number of teeth, the engine speed and the tooth area. As the liquid comes from the reservoir, it is pushed between the gear teeth. The oil is moved around to the other side by the action of the drive gear itself and sent through the pressure line. To prevent leakage of oil from the high to the low pressure side from occurring, you can make the gears fit better.