Praca Średni Z Hydrauliczny Prasa

The working medium used in hydraulic presses is not only to transmit pressure, but also to ensure that the working parts of the machine work sensitively, reliably, have a long life and less leakage. The basic requirements of hydraulic presses for working media are: ① suitable fluidity and low compressibility to improve transmission efficiency; ② anti-corrosion; ③ good lubrication performance; ④ easy to seal; ⑤ stable performance, long-term work without deterioration. Hydraulic presses initially used water as the working medium, and later switched to emulsions made by adding a small amount of emulsified oil to water to increase lubricity and reduce rust. In the late 19th century, oil presses with mineral oil as the working medium appeared. Oil has good lubricity, corrosion resistance and moderate viscosity, which is conducive to improving the performance of hydraulic presses. In the second half of the 20th century, a new type of water-based emulsion appeared, whose emulsified form is "oil-in-water" instead of the original "water-in-oil". The external phase of the "oil-in-water" emulsion is oil, and its lubricity and corrosion resistance are close to oil, and it contains very little oil and is not easy to burn. However, the price of water-based emulsions is relatively expensive, which limits its promotion.