What Is an Accumulator?
The accumulator is an energy storage device in a hydraulic pneumatic system. It converts the energy in the system into compression energy or potential energy at the appropriate time and stores it. When the system needs it, it converts the compression energy or potential energy into hydraulic or pneumatic energy and releases it to resupply the system. When the system pressure increases momentarily, it can absorb this part of the energy to ensure the normal system pressure.
- Hydraulic oil is an incompressible liquid, so using hydraulic oil cannot accumulate pressure energy. It must rely on other media to convert and accumulate pressure energy. For example, a bladder-type inflatable accumulator developed using the compressible nature of gas (nitrogen) is a device that accumulates hydraulic oil. The bladder-type accumulator is composed of an oil part and a gas part with a gas seal, and the oil located around the bladder is connected to the oil circuit. When the pressure rises, the oil enters the accumulator, and the gas is compressed until the pressure of the system pipeline no longer rises; when the pressure of the pipeline decreases, the compressed air expands, and the oil hydraulic pressure enters the circuit, thereby slowing down the pressure of the pipeline.
- Accumulators can be divided into
- The accumulator serves two purposes. When moving at low speed
- The types of accumulators are mainly divided into: spring type and inflatable type. Functions of the accumulator (1) Short-term large-scale fuel supply (2) System pressure holding 3) Emergency energy (4) Easing shock pressure (5) Absorbing pulsating pressure The function of the accumulator is mainly divided into storing energy, absorbing hydraulic shock, and eliminating Four categories of pulsation and energy recovery.
- The first category: stored energy. This type of function can be further divided into: used as auxiliary power source to reduce installed capacity; compensate for leakage; compensated for thermal expansion; used as emergency power source; constitute a constant pressure oil source.
- The second category: absorb hydraulic shock. The sudden change of direction of the directional valve and the sudden stop of the movement of the actuator will produce pressure shock in the hydraulic system, which will cause the system pressure to rise rapidly in a short time, causing damage to the instruments, components and sealing devices, and generating vibration and noise. 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 impact well.
- The third category: eliminate pulsation and reduce noise. For adoption
- The use and maintenance of the accumulator mainly include the installation and maintenance of the accumulator, fault diagnosis and elimination, and repair. The installation of the accumulator includes inspection, installation, nitrogen filling, etc. before installation. Correct installation, fixation and inflation are important conditions for the normal operation of the accumulator and its proper functioning. The measurement of parameters and the correct use of various tools and meters cannot be ignored.
- The accumulator is to prevent leakage during use, and the airbag should be regularly checked for air tightness and other aspects. Therefore, daily inspection and maintenance are essential. The daily inspection is to check the appearance and condition by simple methods such as visual inspection, hearing, hand touch, and instrumentation. During the inspection, it is necessary to check both the local and the entire equipment. Abnormal conditions found during inspections should be dealt with urgently for those that prevent the accumulator from continuing to work; for others, they should be carefully observed and recorded in the rain, and resolved during regular maintenance. Some damaged parts also need to be replaced in time. Active maintenance is a new equipment management theory put forward internationally after fault maintenance, preventive maintenance, and condition maintenance. Its definition is: repair the root parameters that cause equipment damage, so as to effectively prevent the occurrence of failure and prolong the service life of the equipment. Active maintenance is a measure taken against the root cause of equipment before it wears out, effectively controlling the occurrence of wear and failure, thereby greatly extending the repair cycle. Active maintenance not only guarantees the operation of hydraulic equipment and components, but also significantly reduces maintenance costs.
- Accumulators are dangerous parts in the hydraulic system, so pay special attention to safety during operation. Accumulator fault diagnosis and elimination include both the diagnosis and elimination of the fault of the accumulator itself, and the fault diagnosis and elimination of the hydraulic system where the accumulator is located. The two are intertwined. The main contents of fault diagnosis are as follows: Determine the nature and severity of the fault. According to the site conditions, determine whether there is a fault, what kind of problem (stress, speed, action or other), and the severity of the problem (normal, minor fault, general fault, or serious fault). Find the failed component and its location. According to the symptoms and related information, find the point of failure for further troubleshooting, here mainly to clarify "where is the problem". Further find the initial cause of the failure. Such as hydraulic oil pollution, low component reliability, and environmental factors are not satisfactory. Here, the external cause of the failure is mainly clarified. Mechanism analysis. An in-depth analysis and discussion of the cause-effect chain of the failure to clarify the ins and outs of the problem. Forecast the development trend of the fault. Based on the theoretical and empirical data of system wear and degradation, speed, and component life, predict the future state of the accumulator or hydraulic system. Analysis, comparison, statistics, induction and synthesis to find out the rules.
- Accumulator inflation: There are usually two ways to accumulate nitrogen in the accumulator: 1. When the accumulator uses a pressure lower than 8MPa, nitrogen can be supplemented through a nitrogen bottle and a nitrogen filling tool. One end of the nitrogen filling tool is connected to the nitrogen bottle. The other end is connected to the accumulator, and the nitrogen cylinder valve can be opened to complete the inflation. 2. When the pressure of the accumulator is higher than 8MPa, the inflation cannot be completed by the nitrogen bottle and the nitrogen filling tool. In this case, the nitrogen filling car, the tool and the nitrogen bottle can be used together to supplement the accumulator. Nitrogen. First connect the nitrogen bottle to the inlet of the nitrogen-filled car with a high-pressure hose. The outlet of the nitrogen-filled car is connected to the inlet of the accumulator through a nitrogen-filling tool. Nitrogen cylinder valve, the nitrogen-filled car is connected to the power, and the nitrogen-filled car is turned on to complete the inflation.