A hydraulic cylinder is a hydraulic actuator which converts hydraulic energy into mechanical energy and makes linear reciprocating motion (or oscillating motion). It is simple in structure and reliable in operation. It is widely used in hydraulic systems of various machines because it can be used to realize reciprocating movement without reducing gear, and has no transmission clearance and smooth movement. The output force of hydraulic cylinder is directly proportional to the effective area of piston and the pressure difference on both sides. The hydraulic cylinder is basically composed of cylinder barrel and cylinder cover, piston and piston rod, sealing device, buffer device and exhaust device. Buffer device and exhaust device depend on the specific application, other devices are essential.
According to the structure form of common hydraulic cylinder, it can be divided into three types. The structure form of the hydraulic cylinder of sanitation garbage truck is various, and its classification method is also various. According to the motion mode, it can be divided into linear reciprocating motion type and rotary swing type. According to the action of liquid pressure, it can be divided into single action type and double action type. According to the structure form, it can be divided into piston type, plunger type, multistage expansion sleeve type , pinion and rack type, etc. According to the installation form, it can be divided into pull rod, earrings, foot, hinge shaft, etc. According to the pressure level, it can be divided into 16Mpa, 25Mpa, 31.5Mpa and so on.