US Patent 7407374 Hydraulic machine

The invention concerns a hydraulic machine with a toothed set comprising a toothed ring with an inner toothing, whose circumferential surface extends in parallel with its axis, and a gear wheel (3) with an outer toothing, whose circumferential surface (24) extends in parallel with its axis, at least one tooth flank having an edge as an axial end of a section, which is located between the circumferential surface and a surface directed radially inwards. It is endeavored to reduce the wear. For this purpose it is ensured that in the radial direction an edge (22, 23) ends so as to be offset inwards in relation to the circumferential surface (24).