Hydraulic working medium

Acting hydraulic machines used for working medium not only to pass the pressure, but also to ensure the machine working parts work is sensitive, reliable, long life and low leakage. Hydraulic basic requirements for working medium are: ① have appropriate liquidity and low compressibility in order to improve the efficiency of the transmission; ② can prevent corrosion; ③ good lubricating properties; ④ easy to seal; ⑤ stable performance, long-term work without deterioration. hydraulic machines with water as the working medium initially, after the switch in water by adding a small amount of emulsified oil emulsion made to increase lubricity and reduce corrosion. Late appeared to mineral oil as the working medium of the hydraulic machine of the 19th century. Oil has good lubricity, corrosion resistance and moderate viscosity, help to improve the performance of hydraulic machines. The second half of the 20th century there has been a new type of water-based emulsion, which emulsion form is "water in oil" instead of the original "oil in water." "Water in oil" emulsion external phase is oil, its lubricity and corrosion resistance close to the oil, and a small amount of oil, non-flammable. But the water-based emulsion expensive, limiting its promotion.