Video of the working principle of the accumulator reversing valve

What is the working principle of an accumulator?

The working principle of an accumulator is based on the fact that fluids are virtually incompressible. This means that when a fluid is subjected to pressure, it cannot easily be compressed or reduced in volume. When the accumulator is not being used, the fluid is stored in the reservoir, at a specific pressure.

How does pressure affect the accumulator?

When the system pressure increases, the pressure of the working oil also increases, pushing the piston upward, and the working oil in the system enters the accumulator (the volume increases to V 2 ) until a balanced state is reached, as shown in Figure 1b. At this time, the volume of working oil (V 2 – V 1 ) enters the accumulator for storage.

How does a pilot-operated accumulator work?

The pilot-operated, adjustable-spring shut-off A stays closed until set pressure is reached. Pressure continues to climb until the accumulator is full, as seen in Figure 1-42. When pressure reaches that set on 2-way adjustable-spring valve A, it opens, unloading the pump to tank at low pressure.

How do you retract a accumulator cylinder?

Pre-charge the accumulator to a pressure slightly higher than it takes to retract the cylinder. The cylinder will then retract when directional valve A and normally open, solenoid-operated relief valve H shift. (Also see Figure 1-34 .) The large piston rod reduces the return volume, although retract pressure will be higher.

How does a gas accumulator lose pressure?

Gas- or spring-loaded accumulators lose pressure as fluid discharges and the gas or spring expands. In a typical circuit using this type of accumulator, the maximum system pressure must be higher than working pressure to allow for this pressure drop.

How does a hydraulic accumulator function?

Hydraulic accumulators (HACCs) work by storing and subsequently releasing hydraulic energy. When the variable displacement high pressure pump/motor (P/M) operates as a pump, it pumps hydraulic fluid into the accumulator, compressing the gas (usually nitrogen) in the chamber.