Hydraulic cylinders are hydraulic actuators that convert hydraulic energy into mechanical energy and perform linear reciprocating motion (or oscillating motion). Its structure is simple and reliable. When it is used to realize reciprocating motion, the deceleration device can be eliminated, and there is no transmission gap and the movement is stable. Therefore, it is widely used in various mechanical hydraulic systems. The output force of the hydraulic cylinder is proportional to the effective area of ​​the piston and the pressure difference between the two sides; the hydraulic cylinder basically consists of a cylinder barrel and a cylinder head, a piston and a piston rod, a sealing device, a buffer device and an exhaust device. The cushioning device and the exhaust device depend on the specific application and other devices are indispensable.
After the metal workpiece is rolled on the surface, the ultimate strength and yield point of the surface layer are increased, and the use performance, fatigue resistance, wear resistance and corrosion resistance of the workpiece are significantly improved. After rolling, the hardness can be increased by 15 to 30%, while the wear resistance is increased by 15%.
Rolling can increase the surface roughness from Ra6.3 to Ra2.4 to Ra0.2. And it has high production efficiency, and some workpieces can be completed in minutes or seconds.
The processing method that transfers to the rolling tool according to external force can be divided into three types: mechanical type, rolling type and spring type.
According to the nature of processing, it can be divided into optical finishing and enhanced processing.