After the metal workpiece of the hydraulic equipment system is rolled on the surface, the surface layer is strengthened and the ultimate strength and yield point are increased, and the workability, fatigue strength, wear resistance and corrosion resistance of the workpiece are significantly improved. After rolling, the hardness can be increased by 15-30%, and the wear resistance can be increased by 15%.
Rolling can improve the surface roughness from Ra6.3 to Ra2.4 ～ Ra0.2. And it has high production efficiency, and some workpieces can be completed in minutes or seconds.
Rolling processing can solve key problems that are difficult to achieve with certain process methods. For example, the processing of extra large cylinders. At the same time, it is also suitable for finishing small holes or finishing of some special materials.
Among them, construction machinery is the largest user of hydraulic products, accounting for 42.3% of the industry's sales, and the proportion will increase in the future, so the development trend of construction machinery is very important. It is estimated that by 2010, the annual demand for hydraulic excavators will reach 60,000 to 80,000 units, nearly 10,000 bulldozers (above 120 horsepower), approximately 100,000 to 120,000 loaders, approximately 2,000 graders, and approximately 1.5 10,000 units, about 20,000 engineering cranes, about 80,000 forklifts, and nearly 10,000 cement mixers. In addition, China currently has about 1.4 million construction machinery units, which is expected to reach 2 million units by 2010. It is also learned that the imported hydraulic parts for excavators, road machinery, cement mixers, etc. produced by domestic enterprises each year amount to more than 150 million US dollars. In short, the market for hydraulics and seals for engineering machinery and maintenance will face a new period of great development.
The function of the actuator (such as hydraulic cylinder and hydraulic motor) is to convert the pressure energy of the liquid into mechanical energy, and drive the load to perform linear reciprocating or rotary motion.
Control elements (ie, various hydraulic valves) control and regulate the pressure, flow, and direction of the liquid in the hydraulic system. According to different control functions, hydraulic valves can be divided into pressure control valves, flow control valves and directional control valves. Pressure control valves are further divided into flow control valves (relief valves), pressure reducing valves, sequence valves, pressure relays, etc .; flow control valves include throttle valves, regulating valves, diverter manifolds, etc .; directional control valves include check valves, Hydraulically controlled check valve, shuttle valve, directional valve, etc. According to different control methods, hydraulic valves can be divided into on-off control valves, fixed value control valves and proportional control valves. Hydraulic equipment system