Hydraulic Equipment
Hydraulic equipment refers to the general term of hydraulic devices used to drive hydraulic windlass, steering gear, winch, hatch cover and adjustable propeller. It consists of power part - oil pump, actuating part - hydraulic motor (oil cylinder, oil motor), control part - control valves for various pressures, flows and directions, and auxiliary part - oil tank and pipeline. Through these devices, the pressure energy and mechanical energy of the liquid medium in the system can be converted to each other, so as to achieve the purpose of transferring motion, force and torque. The range of energy transmission of hydraulic equipment is large, and stepless speed regulation can be realized in a large range; Stable operation, especially at low speed; Remote control, easy operation and automation; The moving parts are well lubricated and have a long service life. However, the manufacturing accuracy of hydraulic equipment and components and the requirements for hydraulic oil are high; Oil and gas leakage will affect the stability and accuracy of transmission; The transmission efficiency is not as high as that of mechanical transmission.
The working medium used by the hydraulic press not only transfers the pressure, but also ensures that the working parts of the machine work sensitively, reliably, with long service life and less leakage. The basic requirements for working medium of hydraulic press are: ① proper fluidity and low compressibility to improve transmission efficiency; ② Able to prevent corrosion; ③ Good lubrication performance; ④ Easy to seal; ⑤ Stable performance, no deterioration after long-term operation. The hydraulic press used water as the working medium at first, and then used a small amount of lotion made of emulsified oil in water to increase the lubricity and reduce corrosion. In the late 19th century, oil presses with mineral oil as the working medium appeared. The oil has good lubricity, corrosion resistance and moderate viscosity, which is conducive to improving the performance of hydraulic press. In the second half of the 20th century, a new type of water-based lotion appeared, whose emulsification form changed from "oil in water" to "water in oil". The outer phase of the "water in oil" lotion is oil. Its lubricity and corrosion resistance are close to that of oil. The oil content is very small, so it is not easy to burn. However, the high price of water-based lotion limits its popularization.Hydraulic Equipment
