Abstract: The invention relates to a hydraulic pump having axial pistons, the pump being of the type having intersecting axes, and comprising a rotary rotor with a central axis co-operating with an associated distribution seat via a bearing surface that is substantially perpendicular to said axis, said rotor presenting a plurality of axial bores slidably receiving corresponding pistons. According to the invention, a driver separate from the rotor is provided to rotate about an axis of rotation that essentially coincides with said central axis, said driver serving firstly to center and rotate the rotor about said axis of rotation, and secondly to apply resilient thrust to press the bearing surface of the rotor against the distribution seat.