Study on mixed lubrication characteristics of piston/cylinder interface of variable length

Aiming at the lubrication problem of piston/cylinder interface of variable length, a two-dimensional mixed lubrication model was established. This model considers the adaptive eccentricity and the force balance of the piston. The calculation procedure for solving the average Reynolds equation and the nonlinear dynamic equations is established by the finite difference method and the global Newton-Raphaon method. The effects of load pressure and tilting angle of the swash plate on lubrication performance were investigated. The results show that when the supply pressure increases to the maximum, the minimum oil film thickness has a relatively small value. The results further indicate that increasing the lubrication area can decrease the inclination of the piston and the peak pressure of the oil film. Increasing the load pressure and the tilting angle of the swash plate can reduce the minimum oil film thickness and increase the friction force.