Tribological tests of the improved piston mechanism of the axial piston hydraulic machine

Abstract

Axial-piston hydraulic swash plate machines are widely applied in positive displacement hydraulic drives of various purposes. Such drives are highly energy-intensive and have a relatively small control range due to the presence of a large dead-band, which limits their use in reverse action systems. To reduce the dead-band, an improved axial-piston hydraulic swash plate machine was designed. The decrease of the dead-band is achieved by reducing the friction forces in the piston mechanism. This article presents the results of comparative tribological tests of a standard and improved piston mechanisms. The experimental research was conducted in terms of reducing the friction forces in the piston mechanism and their effect on the moment of starting of the hydraulic machine. It was revealed that the use of the improved piston mechanism allows to increase the useful force of the piston up to 20 % in the motor mode and to reduce the dead band by 1.6 times when switching to the pump mode.