Investigation into characteristics of double-lip cascade boot-shaped reciprocating seals in differential-connection working conditions of hydraulic actuators

The differential connection of the hydraulic actuator deteriorates the working conditions of reciprocating seals at the piston rod, increasing the friction, as well as the chance of overturning. The conventional single-lip reciprocating seal can not meet the requirements of high-reliability seal. The double-lip cascade boot-shaped reciprocating seal was taken as the research object in this paper. This study used the fluid transport velocity conservation criterion to iteratively update the inter-lip pressure and investigate the interface characteristics of the double-lip cascade boot-shaped reciprocating seal under differential working conditions. It was based on the soft elastic flow theory and connected the numerical programming iterative method with the finite element software. The performance of the double-lip cascade boot-shaped reciprocating seal were was compared with that of the traditional VL seal in the same differential working condition. According to the findings, the primary lip of the double-lip cascade boot-shaped reciprocating seal primarily serves to seal and stop oil leaks, while the secondary lip primarily supports and strengthens the sealing structure. The inter-lip pressure helps to reduce the contact force and friction. Under the same differential working conditions, compared with that of the traditional VL seal, the friction of the primary lip of the double-lip cascade boot reciprocating seal is reduced by 36.87%, which can effectively reduce the wear of the lip and the chance of overturning in differential working conditions.