Piston accumulator
In hydraulics, a piston accumulator is a pressure device made up of a cylindrical tube with a gas-side and oil-side cover and a movable piston for separating hydraulic fluid and gas . The pressure device is used, among other things, to store energy by compressing a gas.
When the accumulator is in use, a hydraulic fluid is pressed against a gas (usually nitrogen). Gas and hydraulic fluid are separated by a freely movable piston with a seal. In the typical work area with low friction between piston and cylinder wall and without an end stop, there is no pressure difference between the gas and oil sides.
In order to increase the storage volume on the oil side in a cost-effective manner, the nitrogen volume can be increased by means of one or more downstream nitrogen pressure vessels (nitrogen bottles). Storage volumes of several thousand liters can be achieved with such arrangements.