Electric hydraulic pumps are hydraulic fluid transmission devices that are powered by electricity. They are often employed for the transmission of hydraulic fluid from a reservoir to an actuator such as a hydraulic cylinder. Such actuation systems are an important part of a wide variety of hydraulic machinery.There are many different hydraulic pump varieties, but the defining figure of each variety is its use of pressurized liquids for the purposes of accomplishing a task. In the case of hydraulic water pumps, for example, the natural properties of water are harnessed in order to move water from one place to another. Hydraulic piston pumps are used to help actuate a piston's movement in a mechanical system, and hydraulic gear pumps operate in a similar way. Though there are many different variations of each of these pump systems, each variety can be powered by electricity. In such cases, an electric current is directed to a motor that turns impellers or other mechanisms that generate pressure differentials within the pump system; these differential pressure levels allow for the movement of liquids through the pump. Such pump systems can be used to direct hydraulic fluid to industrial machinery such as excavators or commercial equipment like elevators.