Accumulators are installed in hydraulic systems with the main purpose of storing energy and smoothing out pulsations. A such, a hydraulic machine with an accumulator can use a smaller sized pump because the accumulator stores energy from the pump during low demand phases. This energy is can be used instantaneously when there is a demand for it and at a rate much higher than what could be supplied by the pump alone. There are different functions of
hydraulic accumulators which we are presenting below:
Hydraulic Accumulator
Storage of Energy
Hydraulic accumulators incorporate a gas in sync with a hydraulic fluid. The fluid is reduced in volume by only about 1.7% under a pressure of 5,000 psi, which help it for power transmission. On the other hand, gas, which is used at the same time with hydraulic fluid in the accumulator, can be compressed into small volumes at high pressures. As such, energy is stored in the compressed gas , which is released on demand. In the piston type accumulator, the energy in the compressed gas releases pressure against the piston, thereby separating
hydraulic fluid and gas.
Absorption of Pulsation
Pumps generate the required power to be stored or used in a hydraulic system. Many pumps deliver this power in a pulsating flow. The piston pump can produce pulsations harmful to a high-pressure system. An accumulator properly fixed in the hydraulic system will substantially cushion these variations of pressure.
Shock cushioning
In many fluid power applications, when the driven member of the hydraulic system stops suddenly, a pressure wave is created that travels back through the system. This shock wave can develop peak pressures many times much higher than normal working pressures. It can cause system failure or sometimes objectionable noise. An accumulator's gas cushion will reduce this shock.
Supplementing pump flow
A hydraulic accumulator is able to store power which can compensate the hydraulic pump in delivering power to the system. The pump stores potential energy in the accumulator during the periods when there is no work cycle. The accumulator transfers this stored power back to the system when the cycle requires peak power or emergency. This helps the system to use a much smaller pump, resulting in savings in power and cost.
Maintaining pressure
Changes in pressure occurs in a hydraulic system when the liquid is subjected to rising or falling temperatures. Also, there can be drop in pressure due to hydraulic fluid leakage. An accumulator compensates for such pressure changes by delivering or receiving a small amount of hydraulic fluid. If the main power source is stopped, the accumulator would act as an auxiliary power source. This way it can help maintaining pressure in the system.
Fluid dispensing
A hydraulic accumulator is also used to dispense small volumes of fluids, like lubricating greases and oils, on demand.
