Geared volumetric machine

A geared volumetric machine comprising:

• a first and a second door (91, 92);
• the second door (92) operating at a greater pressure than the first door (91);
• one from between the first and second door (91, 92) being an inlet door of a fluid into the volumetric machine (1) and the other door being an outlet door of the fluid from the volumetric machine (1);
• a first cogged wheel (11) in turn comprising a first and a second lateral flank (111, 112);
• a second cogged wheel (12) enmeshing with the first cogged wheel (11);
• said first wheel (11) comprising a plurality of teeth defining between them a plurality of compartments (9) destined to house teeth of the second wheel (12);
• a first and a second abutment (3, 4) between which the first cogged wheel (11) is interposed and which respectively face the first and the second lateral flank (111, 112) of the first cogged wheel (11);
• a first grooved pathway (31) which at least in a first angular position of the first cogged wheel connects a first and a second zone (51, 52), the first zone (51) comprising at least one of the compartments (9) which is in communication with the second door (92), the second zone (52) being a locus of points interposed between the first abutment (3) and the first flank (111);
• characterised in that said first grooved pathway (31) comprises at least one stretch having a passage section having a surface smaller than 1 mm2;
• a) in each angular position of the first wheel (11) said first grooved pathway (31) connects the first zone (51) and each passageway located at a corresponding interface existing between:
• i) at least 75% of the teeth of the first wheel (11) in communication with the second door (92) and ii) the first abutment (3);
• the first grooved pathway (31) at least partly extends between a radially nearer position and a radially more distant position from a rotation axis of the first cogged wheel (11);
• or
• b) it comprises a plurality of grooved pathways (31, 310) which in combination, in each angular position of the first wheel (11), connect the first zone (51) and each fluid passageway located at an interface existing between:
• i) at least 75% of the teeth of the first wheel (11) in communication with the second door (92) and ii) the first abutment (3);
• each of said grooved pathways (31, 310) at the second zone (52), at least partly extends between a radially nearer position and a radially more distant position from a rotation axis of the first cogged wheel (11);
• said plurality of grooved pathways (31, 310) comprising the first grooved pathway (31).