2D23 Effect of a DLC-thin film on improving the piston shoe's power losses under mixed friction operating conditions(The 12th International Conference on Motion and Vibration Control)

Abstract

The pumps of electro-hydrostatic actuators operate frequently in mixed lubrication speed range, as they compensate for position control errors as a control element. Therefore, their tribological performance should satisfy much severe working conditions, compared with conventional pumps operating constantly at high speeds. When swash plate type piston pumps are applied to electro-hydrostatic actuators, countermeasures are needed to minimize the frictional power losses as well as wear rate of sliding components such as piston shoes, under the mixed friction condition. In this paper, DLC-coating was applied to the swash plate and the ball joint of pistons, and its effects on reducing the power losses of the piston shoes were investigated which were brought about by frictional solid-to-solid contact and leakage flow rate of their hydrostatic bearing.