Harmonic Distribution Radial Piston Hydraulic Machine

A hydraulic machine having radial pistons and comprising a cam and a cylinder block that are suitable for turning relative to each other about an axis of rotation, the cylinder block having radial cylinders connected to communication orifices of the cylinder block, pistons mounted to slide in the cylinders being suitable for co-operating with the cam, which has a plurality of lobes, each having two ramps, each of which extends between a top dead center arc and a bottom dead center arc, the machine further comprising a fluid distributor suitable for connecting the communication orifices to a first or second main duct for feed or discharge, in sequences comprising connection stages during which said communication orifices are connected to the first main duct and connection stages during which said communication orifices are connected to the second main duct, which stages are separated by switchover stages that comprise, in succession, closing the connection to one of the main ducts, an isolation stage during which the communication orifices are isolated from the two main ducts, and opening the connection to the other main duct, each isolation stage taking place, for the communication orifice of any given cylinder, while the piston mounted in the cylinder is bearing on a given dead center arc, which is defined as being the dead center arc that is associated with the isolation stage in question, the angular position of the start or of the end of an isolation stage relative to the dead center arc that is associated with said isolation stage being defined as being the angular difference between said start or said end and the bisector of the angle covered by said dead center arc that is associated with said isolation stage;

• wherein the angular position of the start or the end of at least one first isolation stage relative to the dead center arc that is associated with the first isolation stage is different from the angular position of the start or the end of at least one second isolation stage relative to the dead center arc that is associated with said second isolation stage during one revolution cycle of the machine, and wherein the dead center arcs associated with said first and second isolation stages are of the same type.