Geared volumetric machine

A functioning method of a geared volumetric machine, said 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 cogged wheel (11) comprising a plurality of teeth defining between them a plurality of compartments (9) destined to house teeth of the second cogged 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;
• the first and second cogged wheels (11, 12) being cogged wheels having helical teeth;
• a mechanical interaction between the helical teeth of the first and second cogged wheel (11, 12) added to a hydrostatic force generated by the pressure acting in the compartments (9) of the first cogged wheel (11) determine an axial thrust (62) which pushes the first cogged wheel (11) towards the first abutment (3);
• the teeth of the first cogged wheel (11) comprising a first tooth which extends between the first and the second abutment (3, 4) from a first end (113) thereof located at the first flank (111) to a second end (114) thereof located at the second flank (112);
• said first end (113) being more advanced than the second end (114) with respect to a rotation direction of the first cogged wheel (11);
• an axial counter-force (61) exerted by the pressure of a fluid interposed between the first flank (111) and the first abutment (3) being greater than said axial thrust (62);
• a) in each angular position of the first cogged 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 cogged 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 cogged 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 cogged wheel (11) in communication with the second door (92) and ii) the first abutment (3);
• each of said plurality of 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);
• the method being characterised in that it comprises the steps of:
• generating a layer of pressurised fluid between said first abutment (3) and said first flank (111) by distributing, in the second zone (52), a pressure present in the first zone (51) at least by said first grooved pathway (31);
• exerting, by said fluid layer, said axial counter-force (61) having a greater modulus and an opposite direction with respect to the axial thrust (62) induced by the sum of the mechanical interaction between the helical teeth of the first and second cogged wheel (11, 12) and of the hydrostatic force generated by the pressure acting in the compartments (9) of the first cogged wheel (11).

A method for realising a geared volumetric machine, said 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 cogged wheel (11) comprising a plurality of teeth defining between them a plurality of compartments (9) destined to house teeth of the second cogged 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 cogged 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 cogged 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 cogged 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 cogged wheel (11) in communication with the second door (92) and
• ii) the first abutment (3);
• each of said plurality 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);
• the method comprises the steps of:
• realising the first cogged wheel (11), the second cogged wheel (12), the first and second abutment (3, 4);
• carrying out said first grooved pathway (31) by laser incision on the first cogged wheel (11) or the first abutment (3).