According to the different ways of energy storage, accumulators can be divided into gravity-loaded (hammer type), spring-loaded (spring type) and gas-loaded.
Hammer-type accumulator is by lifting the mass loaded on the sealing piston block, the pressure energy in the hydraulic system into gravity potential energy accumulation. Its advantages are simple structure, stable pressure; disadvantages are installation limitations, only vertical installation, not easy to seal, mass inertia, insensitive. This accumulator is generally only used for fixed heavy-duty hydraulic equipment.
Spring-type accumulator is to rely on the compression of the spring to the hydraulic system of excess pressure energy into a spring potential energy stored, when needed, released. Its structure is simple and low cost. However, because of the limited amount of spring expansion and contraction of the spring is not sensitive to pressure changes, vibration function is poor, so only suitable for small capacity, low-pressure system, or used as a buffer device.
Hammer and spring-type accumulators have certain limitations in the application, and therefore rarely used. Currently used in large quantities is the gas-loaded accumulator.
The operating principle of gas-loaded accumulators is based on Boyle's Law. The use of the first to the accumulator is filled with a predetermined pressure of gas or nitrogen, when the system pressure over the accumulator internal pressure, the oil compressed gas, the pressure in the oil can be converted into gas internal energy; when the system pressure is lower than the accumulator internal pressure, the accumulator in the role of high-pressure gas flow to the external system, the release of energy. Select the appropriate filling pressure is the key to this kind of accumulator. This kind of accumulator according to the structure can be divided into diaphragm type, piston type, airbag type and non-isolated type.
蓄能器性能用途比较
表3-1所示为各种蓄能器的性能和用途比较。
