What is an accumulator and its features and functions

The accumulator includes a cylinder tube, a piston installed in the cylinder tube, and an oil-side connecting flange and a gas-side connecting flange respectively fixed at both ends of the cylinder tube; the oil-side connecting flange is provided with an oil hole; the gas-side connecting flange is provided with an oil hole; The side connecting flange is provided with an air nozzle, and the piston is provided with a ring of guide belt grooves, a ring of oil storage grooves, a ring of Chinese Hydraulic Accumulator sealing grooves, a ring of gas storage grooves, and a ring of guide belt grooves in sequence along the axial direction. And two guide belt grooves are provided with guide belts, and a combined seal is provided in the sealing groove; a one-way valve is provided at each end of the piston, and the inlet of one of the one-way valve is connected to the storage tank of the piston cylinder. An oil tank, the outlet of the one-way valve is connected to the oil cavity, the inlet of the other one-way valve is connected to the air storage tank of the cylinder surface of the piston, and the outlet of the one-way valve is connected to the air cavity. The accumulator provided by the invention can effectively prevent gas from penetrating into the oil.
The gas-liquid direct contact accumulator is charged with inert gas. The advantages are large capacity, sensitive response, small inertia of moving parts, and no mechanical wear. However, due to the direct contact between gas and liquid, the size is small, and the inflation pressure is limited; the sealing is difficult, and the possibility of gas and liquid mixing is high. Therefore, the gas consumption of this type of accumulator is large, the components are easy to cavitate, and the volume utilization rate is low. There are many auxiliary equipment and large investment. The piston accumulator uses a piston to separate the gas from the liquid, and there is a seal between the piston and the inner wall of the cylindrical accumulator, so the oil is not easily oxidized. The accumulator has long service life, light weight, easy installation, simple structure and convenient maintenance, but has poor response sensitivity and is not suitable for absorbing pulsation at low pressure. Diaphragm accumulators are two hemispherical shells buckled together with a rubber membrane sandwiched between the two hemispheres to separate oil and gas. Its weight to volume ratio is the smallest, the response is sensitive, and the low pressure has a remarkable effect of eliminating pulsation. Diaphragm accumulators have a small rubber film area, and the gas expansion is limited, so the inflation pressure is limited and the capacity is small.
The functions of accumulators are mainly divided into four categories: energy storage, hydraulic shock absorption, pulsation elimination and energy recovery.
Category 1: Stored Energy
This type of function can be further subdivided into: ①As auxiliary power source to reduce installed capacity; ②Compensate for leakage; ③As thermal expansion compensation; ④As emergency power source; ⑤Constitute constant pressure oil source.
The above five functional principles are basically the same, and they all mainly use the function of accumulator that can store a large amount of energy. The main difference is that the parameter selection is different, and different parameter selection formulas can be used to achieve the required functions and meet the required requirements.
Category 2: Absorbing hydraulic shocks
The sudden change of direction of the reversing valve and the sudden stop of the movement of the actuator will produce a pressure shock in the hydraulic system, which will cause the system pressure to rise rapidly in a short period of time, causing damage to instruments, components and sealing devices, and generating vibration and noise. In order to ensure the absorption effect, the accumulator should be set near the impact point, so the accumulator is generally installed before the shock source such as the control valve or hydraulic cylinder, which can absorb and buffer the hydraulic shock well.
Category 3: Eliminate pulsation and reduce noise
For a hydraulic system using a plunger pump with a small number of plungers, the periodic variation of the pump flow causes the system to vibrate. The accumulator is installed, which can absorb a large amount of energy in the pulsating pressure and flow, within one cycle of the flow pulsation. The part of the oil whose instantaneous flow is higher than the average flow is absorbed by the accumulator, and the part below the average flow is supplemented by the accumulator, which absorbs the energy in the pulsation, reduces the pulsation, and reduces the damage to sensitive instruments and equipment degree.
Category 4: Recovering Energy
Recovering energy with accumulators is a field that has been studied more. Energy recovery can improve energy utilization and is an important way to save energy. Because the accumulator can temporarily store energy, it can be used to recover various functional and positional potential energy. The main researches in this area are: ①Recovery of vehicle braking energy; ②Recovery of potential energy of construction machinery boom mechanism; ③Recovery of hydraulic excavator turntable braking energy; Downward gravitational potential energy.