Abstract: In a vane rotor (1) for a rotary pump, each of the radial slots (4) housing the vanes (5) ends with a widened blind bottom (6) having a cross-sectional profile which is defined by a pair of first arcs (6a) arranged with facing concavities and having radially outer ends joined with a respective wall (4a) of the slot itself, and by a connecting portion (6b) connecting the radially inner ends of the first arcs (6a).

Abstract: A rotary positive displacement pump for fluids for the lubrication oil of a motor vehicle engine, has a displacement that can be regulated by the translation of a stator ring surrounding the rotor of the pump with an eccentricity depending on the position taken by the same ring due to the translation. The translation is guided by guiding fins sliding in contact with a surface of a guiding chamber, communicating with the delivery side of the pump, thanks to the fluid under pressure introduced into the same chamber and acting on the fins. The contact zone is such that a homogeneous contact pressure distribution is ensured as the operating conditions of the pump and, consequently, the position of the stator ring, vary. A method is disclosed of regulating the displacement of the pump and a lubrication system for a motor vehicle engine, in which system the pump is used.