Design of Swashplate Axial Piston Machines Having Low Piston Transverse Forces

Abstract

Axial piston machine of swashplate type is the common design widely used for many hydraulic applications because of its simplicity, compact design and low cost. However, this simplicity has a negative effect for piston transverse forces which limits machine performance. The main target of this study is to investigate a feasible design of a fixed displacement swashplate contour in order to minimize piston transverse forces. The design should compensate the contact surface mechanism between swasplate and piston end. Piston slipper is replaced by a ball that is rotatably mounted within a ball socket formed at the piston end. The ball runs on a circumferential contour groove formed on the swashplate surface. The sliding friction between swashplate and slipper is replaced by a rolling friction between ball and circumferential runway groove. Primary results show a rough estimation of 30% reduction of piston transverse forces due to the cam action radial forces elimination. This reduction promises to enhance overall machine performance.