HYDRAULIC MACHINE

摘要

The invention concerns a hydraulic machine (1) with a tooth set (2), having a gear wheel (3), which is arranged to be rotating and orbiting in a toothed ring (4), the tooth set (2) being arranged between two plates (10, 11) in the axial direction. It is desired to extend the life of such a machine, also when operated with an impurified hydraulic fluid. For this purpose, at least a section (9') of the circumferential surface of one of the two components, toothed ring (4) and gear wheel (3), is made of a material, which is substantially harder than the material of the part of the other component, gear wheel (3) and toothed ring (4), bearing on this section.