Abstract: A geared volumetric machine including: a first and a second door; the second door operating at a greater pressure than the first door; one from between the first and second door being an inlet door of a fluid into the volumetric machine and the other door being an outlet door; a first cogged wheel in turn including a first and a second lateral flank; a second cogged wheel enmeshing with the first cogged wheel; a first and a second abutment between which the first cogged wheel is interposed and that respectively face the first and the second lateral flank of the first cogged wheel; a first grooved pathway which at least in a first angular position of the first cogged wheel connects a first and a second zone, the first zone including at least one of the compartments which is in communication with the second door.

Abstract: A volumetric gear machine interacting with a working fluid comprising: a first toothed wheel (3) with helical teeth comprising a first tooth (31) in turn comprising a first and a second flank (311, 312) opposite each other; a second toothed wheel (4) with helical teeth having two opposite flanks, the first and the second wheel (3, 4) being operatively coupled in a meshing area (2). At a portion of the meshing area (2), the first and the second flank (311, 312) being in simultaneous contact with the second wheel (4).

Abstract: A gear pump comprising:—a pair of gears (2) able to interact with a fluid crossing the pump (1);—a housing seating (3) of said pair of gears (2), said housing seating (3) comprising a rest plane (30) of a shim (4);—a delivery conduit (6) which develops from said housing seating (3) and comprising an inlet mouth (60). The inlet mouth (60) of the delivery conduit (6) is at a distance from an intersection (7) between a rest plane (30) of the shim (4) and remaining parts of the housing seating (3).

Abstract: A variable displacement pump comprising a pumping piston (10), cylinder head (2); a rotating shaft (3); regulating means (4) of the displacement of the pump, said means in turn comprising: a structure (41) having a variable inclination; a fluid-dynamic actuator (42) for regulating an inclination of said structure (41); command means (43) for the actuator (42), which assume a non-equilibrium and an equilibrium position, said command means (43) in turn comprising: a sliding body (431) being able to take at least a first position in which it places a chamber (420) acting on said actuator (42) in communication with a first zone (51) at least initially having a pressure that is different from a pressure present in said chamber (420); a sliding element (432) with respect to the sliding body (431) for resetting said equilibrium configuration, said sliding element (432) being distinct from said actuator (42) and being mechanically actuated in consequence of a variation of an inclination of said structure (41).

Abstract: Problematic noise levels in a hydraulic gear pump are overcome by exerting a radial force on the two shafts with which the gears are associated. The force has a direction and a strength that will combine with the resultant of the pressure forces and gear tooth contact forces, thereby eliminating backlash between the teeth. The system can be mechanical or hydraulic, and is incorporated either into the pump body or into pressure-balanced bearing blocks.