Measures to reduce the failure rate of hydraulic cylinders

In order to reduce the failure rate of hydraulic cylinders, it is necessary to understand several states of hydraulic seals. When the seal is not installed, there are four sizes, namely the inner diameter of the root of the seal, the outer diameter of the root, the inner diameter of the lip, and the outer diameter of the lip. When the seal is installed in the groove and not working, the size of the groove is unchanged, while the size of the seal has changed. The four sizes are the outer diameter of the root of the seal, and the outer lip diameter changes to the outer diameter of the groove at the same time; the inner lip diameter It is the diameter of the piston rod, and the inner diameter of the root is the gap between the seal and the piston rod plus the diameter of the piston rod.

           When the hydraulic cylinder starts to work, the working state of the seal is as follows: the inner and outer lips are close to the inner wall and the outer wall moves slightly backward. The root of the seal is squeezed backwards. As the pressure increases, the force of the hydraulic oil on the seal increases, and the overall deformation of the seal also increases. When the working cycle is completed and the oil cylinder is out of pressure, the seal returns to its original state. Repeated deformation, repeated recovery, until the loss of the seal lips, the seal is not damaged.

           Secondly, it is necessary to match the dimension tolerance of the hydraulic cylinder groove with the seal. There are many forms of reciprocating motion seals, the common ones are L-shaped, U-shaped, V-shaped, and Y-shaped, and their shapes are mostly lip seals. Reciprocating lip seals are widely used in reciprocating cylinders of hydraulic systems.

           The pressure surface of the seal is lip-shaped, and there is a small amount of interference during installation, so that the lip is in contact with the sealing surface to produce a sealing effect. When the oil cylinder works, as the pressure increases, its contact force and contact area increase, and the sealing performance increases with the pressure increase. When the cylinder returns, the pressure drops, the contact area and contact force decrease, and the sealing performance decreases accordingly.