As with any pump system, there are some basic components involved — a driver, the impeller/pump and the transmission. The basic difference is that instead of a flexible coupling or gear train, the transmission is a hydraulic system. The hydraulic system is composed of a hydraulic pump, hydraulic motor, supply tank, filtration method, cooling method and transfer lines. The driver puts power to the pump and moves fluid from the reservoir. It converts the energy from mechanical to fluid pressure and volume through the lines to the motor and transfers the energy to the shaft and impeller to move the pumped liquid. The fluid is then routed back to the supply tank through a cooling system and filtration system to repeat the process. So, although there are a few more components than a simple coupling system, hydraulic submersible pumps convert energy through pumped fluid like other pumping units.