The function of an accumulator is to store the pressure oil in the hydraulic system and discharge it again when needed. Its main functions are manifested in the following aspects.
- As auxiliary power supply
Some hydraulic systems have intermittent actuators that have a short total working time. Although some hydraulic systems do not have intermittent actuators, their speed varies greatly within a working cycle (or stroke). After setting up an accumulator in this system, a smaller pump can be used to reduce the power of the main transmission, making the entire hydraulic system smaller in size, lighter in weight, and cheaper in price.
- As an emergency power source
For certain systems, it is required that in the event of pump failure or power outage (sudden interruption of oil supply to the actuator), the actuator should continue to complete necessary actions. For example, for safety reasons, the piston rod of a hydraulic cylinder must be retracted into the cylinder. In this situation, it is necessary to have an accumulator with appropriate capacity as an emergency power source.
- Replenish leaks and maintain constant pressure
For systems where the actuator does not operate for a long time but needs to maintain a constant pressure, an accumulator can be used to compensate for leakage, thereby keeping the pressure constant.
- Absorb hydraulic impact
Due to sudden reversal of the directional valve, sudden stop of the hydraulic pump, sudden stop of the actuator movement, and even artificial emergency braking of the actuator, the liquid flow in the pipeline can undergo rapid changes, resulting in shock pressure (oil shock). Although there is a safety valve in the system, it is still inevitable to generate a short-term surge and impact of pressure. This type of impact pressure often causes failures or even damage to the instruments, components, and sealing devices in the system, or pipeline rupture. In addition, it can also cause significant vibrations in the system. If an accumulator is installed before the control valve or hydraulic cylinder impact source, this impact can be absorbed and mitigated.
- Absorb pulsations and reduce noise
The pulsating flow rate of the pump can cause pressure pulsation, resulting in uneven movement speed of the actuator, vibration, noise, etc. Parallel connection of a sensitive and inertial accumulator at the outlet of the pump can absorb the pulsation of flow and pressure, reducing noise.