Accumulators discharge in times of high demand and recharge during periods of low demand. Often used to supplement pump flow during peak demand.
Accumulators can maintain a high-pressure charge almost indefinitely and serve as an emergency power source should a machine lose electric power or a pump fails.
Vibration & Shock Reduction
Pumps, especially piston and gear types, generate pressure pulsations in hydraulic circuits. Quick deceleration of large cylinders, impacts from excavator buckets, and sudden valve closure can generate pressure spikes. And hydraulic fluid readily transmits shocks and pulsations through hose and tubing, and that can play havoc with downstream components.
Mounting a small accumulator near the outlet of the pump can absorb pulsation, minimize vibration and provide smoother operation. Adding an accumulator into the return line of machines can mitigate shocks and cushion the effects to “water” hammer to prevent damage to the sensitive components.
Leakage & Temperature Compensation
Some hydraulic systems must maintain pressure and force when there is no motion or flow, such as holding a loaded cylinder in an extended position or a keeping a clamp closed for extended periods. In such cases, users often shut down the system to save energy. An accumulator can maintain constant pressure even if fluid slowly leaks internally past piston seals or valve clearances. Only when circuit pressure drops below preset limits does the pump fire up and recharge the accumulator.
An accumulator can compensate for temperature-related pressure differences in a closed hydraulic system. Accumulators minimize the effect of pressure changes by adding or reducing the amount of fluid in a circuit.
Bladder and diaphragm accumulators have a virtually instantaneous response and can quickly supply fluid to a fast-acting servo and proportional valves and improve their performance. Accumulators can also immediately meet peak flow requirements; help keep the pressure constant in systems using variable-displacement pumps; and provide force compensation in continuous processes, such as rolling materials that offer varying working resistances, which ensures consistent output and improves productivity and quality.