In the hydropneumatic system, the sealing device is a d […]
In the hydropneumatic system, the sealing device is a device for preventing leakage of a liquid or gas working medium and intrusion of outside air, dust, and the like. Leakage refers to the flow or temporary storage of fluids in the chambers of hydraulic and pneumatic components and systems. A small amount flows over the boundary of the cavity and flows out from the rolling side to the low pressure side. The reason for the leakage is that there is a gap in the joint surface of the part; second, there is a pressure difference on both sides of the joint surface.
Leakage is an internal leakage and an external leakage. The internal leakage is the leakage of the working medium from the high pressure chamber to the low pressure chamber; the external leakage is the leakage of the working medium from the working chamber to the outside of the component and the system. Leakage of working medium can cause the volumetric efficiency of hydraulic and pneumatic systems to drop drastically, failing to reach the required working pressure, and the equipment can not operate normally; external leakage can also cause waste of working medium and environmental pollution, and oil leakage may cause fire.
Intrusion of foreign bodies such as water, gas, and dust into hydraulic and pneumatic systems is the main cause of system failure. Air intrusion into the hydraulic system will reduce the oil's elastic modulus and reduce system performance; generate cavitation, causing vibration and noise of the hydraulic system; causing the oil to 'emulsifie' deteriorate, and severely generate a large amount of foam. Water intrusion into hydraulic and pneumatic systems can reduce lubrication and cause parts to rust. Intrusion of dust can aggravate the wear of the seal and the surface of the library wiper, and even block the tiny passages and jam the precision parts, causing system failure.