The working principle of hydraulic cylinder


The piston hydraulic cylinder can be divided into two kinds of structures: single lever and double bar. The fixing mode is composed of cylinder block and piston rod. In the single-acting hydraulic cylinder, the pressure oil is only supplied to the cavity of the hydraulic cylinder, and the hydraulic pressure makes the cylinder move in one direction, while in the opposite direction, the pressure (such as spring force, dead weight or external load, etc.) is used to realize the movement. The movement of the piston of double acting hydraulic cylinder in two directions is completed by the action of liquid pressure.

As shown in the figure, the single lever double acting piston hydraulic cylinder is schematic diagram. One side of the piston is provided with piston rod, so the effective area of the two cavities is different. When the oil supply is the same, the pistons move at different speeds. When the load capacity to be overcome is the same as that of the tank, the required oil supply pressure is different. In other words, after the system pressure is adjusted, the load capacity of the hydraulic cylinder of the sanitation garbage truck moving in two directions is different.

The buffer device

In the hydraulic system, the hydraulic cylinder is used to drive the mechanism with a certain quality. When the hydraulic cylinder moves to the end point of the journey, it has greater kinetic energy. If there is no deceleration, mechanical collision will occur between the piston of the hydraulic cylinder and the cylinder cover, resulting in shock, noise and destructiveness. To mitigate and prevent this hazard from occurring, a reduction gear can be installed in the hydraulic circuit or a buffer device in the cylinder.

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