Precautions during the use of hydraulic cylinders

Before disassembling the hydraulic cylinder, make preparations. The first is to relieve the pressure of the hydraulic circuit. Otherwise, when the oil pipe joint connected with the cylinder is loosened, the high-pressure oil in the circuit will be sprayed out quickly. When depressurizing the hydraulic circuit, first loosen the handwheel or pressure regulating screw at the relief valve, etc., to unload the pressure oil, and then cut off the power or power source to stop the hydraulic device.

Next, start to disassemble the hydraulic cylinder

First, in order to prevent the slender parts such as the piston rod from bending or deforming, the stow should be used to support the balance during placement. When disassembling, prevent damage to the top thread of the piston rod, the thread of the oil port, the surface of the piston rod, and the inner wall of the cylinder liner.

Second, the disassembly should be carried out in order. As the structure and size of various hydraulic cylinders are different, the disassembly sequence is also slightly different. Generally, the oil in the two chambers of the cylinder should be drained, then the cylinder head should be removed, and finally the piston and piston rod should be removed. When disassembling the cylinder head of the hydraulic cylinder, special tools should be used for the key or snap ring of the internal key type connection, and the use of flat shovel is prohibited; the flange type end cap must be pushed out with screws, and hammering or hard prying is not allowed . When the piston and piston rod are difficult to withdraw, they should not be forced out. The reason should be found out before disassembly.

Third, try to create conditions before and after disassembly to prevent the parts of the hydraulic cylinder from being contaminated by surrounding dust and impurities. For example, the disassembly should be carried out in a clean environment as much as possible; after disassembly, all parts should be covered with plastic cloth, not cotton cloth or other working cloth.

Fourth, after the oil cylinder is disassembled, check carefully to determine which parts can continue to be used, which parts can be used after repair, and which parts must be replaced.

Fifth, all parts must be carefully cleaned before assembly.

However, it should be noted that the sealing devices must be installed correctly. For example, when installing an O-ring, do not pull it to the extent of permanent deformation, and do not roll it while rolling, otherwise it may cause oil leakage due to distortion. All O-rings and dust-proof rings after disassembly should be replaced with new ones. Or when installing Y-shaped and V-shaped sealing rings, pay attention to the installation direction to avoid oil leakage due to installation. For the Y-shaped sealing ring, its lip should correspond to the pressure oil cavity; in addition, the YX-shaped sealing ring should be distinguished between shaft and hole use, and do not install it wrong. The V-shaped sealing ring is composed of a supporting ring, a sealing ring and a pressure ring of different shapes. When the pressure ring compresses the sealing ring, the supporting ring can make the sealing ring shape and play a sealing role. The opening of the sealing ring should face Pressure oil chamber; when adjusting the pressure ring, it should not leak oil as the limit, and it should not be pressed too tightly to prevent excessive sealing resistance.

Sixth, a special wrench should be used when tightening the threaded connection, and the torque should meet the standard requirements.

Seventh, after assembling the piston and the piston rod, try to measure whether its coaxiality and straightness over the full length are out of tolerance.

Eighth, there should be no sense of blocking and uneven resistance when the piston assembly moves after assembly.

Ninth, when the hydraulic cylinder is installed on the main engine, a sealing ring must be added and fastened between the inlet and outlet joints to prevent oil leakage.