Generality - Principle - Applications

It is one of the most characteristic applications of accumulator use. Hydraulic accumulators are increasingly used as a safety element. Electricity may be missing at any time by interrupting the operation of a mechanism. The accumulators maintain the flow for a certain time and therefore protect expensive machines and systems.

The accumulators are used for emergency control of brakes and doors in cable cars, chair lifts, trucks, etc. Accumulators are charged with a motor pump or, in an emergency, with a hand pump. In this way, the energy required to carry out the emergency stop is available at all times.
Many times the command takes place in negative, that is to say that braking occurs through springs; in this case the cylinders for opening the brake are controlled by the accumulator which keeps them open, counteracting the force of the spring.

The safety devices have the purpose of performing particular functions in the event of a fault. These functions can be: bulkhead closures, butterfly valves, exchange valves, drawer valves in tanks, silos or transport systems, the operation of sluice gates in foundries and ladles, the opening and closing of high-level switches potential. In all these cases the accumulator does not work during normal operation; it is filled with oil, the accumulated energy is maintained for an unlimited time and is immediately available upon request for use.

The lack of power during a work cycle of a machine tool or textile machine can cause interruptions to very expensive operations. Accumulators guarantee the completion of an already started work cycle in such cases, protect expensive tools from damage, reduce equipment replacement and minimize machine downtime.

Large machine bearings (turbines, large compressors, water pumps, etc.) must be constantly lubricated. In the event of a power failure, an auxiliary pump is immediately inserted and operated by an additional energy source (diesel engine). However, the start-up of this auxiliary pump creates a transient that interrupts the flow for a few seconds. The accumulators intervene during this time and ensure a constant lubrication pressure.

During the operation of certain machines there are hydrostatic bearings that must always remain under pressure. If there is a lack in the current of the control unit, the necessary pressure is no longer guaranteed. The accumulators guaranteed by the minimum pressure during the stop of the power supply and thus avoid extremely expensive damages to the hydrostatic bearings.