Variable-displacement vane oil pump

A variable-displacement oil vane pump comprising:

• a main body presenting a cavity;
• a mobile ring, accommodated in said cavity, within which there is a hub adapted to turn about an axis;
• said hub being provided with a plurality of vanes, each of which is adapted to slide in a corresponding slot obtained in said hub;
• a moving means of the mobile ring that moves between a position centered on the rotation axis of the hub and a predetermined extreme position, eccentric with respect to the rotation axis of the hub itself;
• said moving means comprising a driving chamber made on a wall of said chamber and a projection overhanging from the mobile ring, said projection being adapted to slide in said driving chamber due to a driving pressure present in said driving chamber;
• a guiding means for guiding a mobile ring in the cavity;
• said guiding means comprising a protrusion coupled with a guiding seat, and elastic means, on the inside of said, and elastic means, on the inside of said guiding seat, which elastically act on said mobile ring;
• friction reducing means disposed between said projection and said driving chamber and said protrusion and said guiding seat adapted to decrease the effects of the friction.