Abstract: Screw assembly (1) for a triple screw pump (10), comprising: a central screw (2) and at least one lateral screw (3), both provided with one or more helicoidal threads, said lateral screw (3) being arranged to mesh with said central screw (2) with a lateral screw axis (z1) parallel to the central screw axis (zc), wherein the distance between the axes of the central screw (2) and of the lateral screw (3) is greater than the half and lower than ? of a central screw (2) external diameter (Øce).

Abstract: Improved bushing assembly (10) for supporting the shafts of the intermeshed rotors of a positive displacement rotary pump avoiding, jamming, said bushing assembly (10) comprising on a lateral surface (13) thereof at least one compensation tank (15; 16) facing a suction side of the pump and at least one bleed channel (14) which connects said compensation tank (15; 16) to the discharge side.

Abstract: A gear wheel (10) for a hydraulic apparatus is rotatable about an axis of rotation (H-H) and comprises a plurality of teeth (11) having a sectional profile (P) and being adapted to mesh with respective teeth of another gear wheel during a rotational motion about the axis of rotation (H-H), wherein at least one tooth (11) is shaped so as to have at least one cutting edge (12) configured to remove material, in particular chips, from a body which is contacted by said cutting edge during the rotation of the gear wheel (10). Suitably, the cutting edge (12) is defined by at least one groove (14) which is lowered by amount from 0.2% to 5% of the height (H?) of the tooth (11), said groove (14) decreasing away from the cutting edge (12) along the profile (P).

Abstract: The invention relates to a bi-helical toothed wheel (1) with non-encapsulating profile for a hydraulic gear apparatus, of the type bound to a support shaft (5) to form a driving or driven wheel of the hydraulic apparatus and comprising a plurality of teeth (6) extended with variable helix angle with continuous function in the longitudinal direction, wherein the teeth profile keeps a shape continuity in each cross section thereof. More particularly, each tooth of the toothed wheel is longitudinally split in three zones: initial (A), central (B) and terminal (C) zones, and the central zone (B) has a variable helix angle, while the initial (A) and terminal (c) zones have a constant helix angle. The invention allows to manufacture contra-rotating rotors, having a non-encapsulating profile and a helix shape such as to suppress the angular point at the center of the rotors themselves and therefore all the problems related to their machining.

Abstract: A geared positive-displacement machine (10), comprising a housing (11) provided with a suction port and with a discharge port, a pair of gearwheels (14, 15) that are housed and supported by respective shafts (16, 18) for the rotation in a space inside the housing (11) and in fluid communication with the suction port and the discharge port, wherein the gearwheels (14, 15) mesh with each other and have parallel or coinciding axes and a first wheel (14) thereof is driving and a second wheel (15) is driven, a pair of containment bodies (19, 20) for axially containing the wheels (14, 15), said containment bodies (19, 20) being associated with the housing (11) and each comprise a first face (19a, 20a) that faces the pair of gearwheels (14, 15) and a second face (19b, 20b) that is axially opposite with respect to the first face (19a, 20a), and, for each of the two wheels (14, 15), a plurality of rolling bodies (21) that form a crown and that are freely housed in an annular seat (22) that is coaxial to the respective

Abstract: The invention relates to a double-helical gear rotary positive displacement pump including a pump housing rotatably supporting at least a driving shaft and at least a driven shaft, at least a first toothing and a second toothing being associated to the driving shaft and at least a third toothing and a fourth toothing being associated to the driven shaft. The toothings have individually a helical profile that allows their mutual herringbone meshing. Three of toothings are rigidly connected to their respective shafts. The fourth toothing, or other suitable one, is idle on the shaft and axially constrained.

Abstract: A gear wheel comprising a plurality of helical teeth, each helical tooth of the gear wheel having a tooth profile meshing with semi-encapsulation in a geared hydraulic apparatus. Each tooth having a profile which falls within a band of tolerance of +? 1/15 of the depth of a nominal tooth defined by a spline function interpolating a plurality of node points having pre-established coordinates {X,Y} with their origin on the gear wheel center.

Abstract: The invention concerns a gear wheel (2) having a plurality of identical teeth suitable for meshing in parallel with a similar second gear wheel in a casing (3) of a hydraulic machine, said gear wheel having a side face of the front toothing (21) and a side face of the rear toothing (22) suitable for dragging in rotation against a front bush (41) and a rear bush (42), respectively, said bushes (41, 42) being slotted onto a sleeve (20) fixedly connected to the gear wheel (2), said helical teeth extending along the entire gear wheel (2) between the front side face (21) and the rear side face (22), where both the side face of the front toothing (21) and the side face of the rear toothing (22) have, at each tooth, a removed rotor portion (2a, 2b, 2c), so as to have an area of the side faces of the toothing that does not come into contact with the bush when the latter is placed in abutment against the respective side face of the toothing of the gear wheel.

Abstract: A gear wheel comprising a plurality of helical teeth, each helical tooth of the gear wheel having a tooth profile meshing with semi-encapsulation in a geared hydraulic apparatus. Each tooth having a profile which falls within a band of tolerance of +? 1/15 of the depth of a nominal tooth defined by a spline function interpolating a plurality of node points having pre-established coordinates {X,Y} with their origin on the gear wheel center.

Abstract: An improved geared hydraulic apparatus, comprising a pair of meshing gearwheels, mounted to be reciprocally rotatable in a casing between an inlet side and an outlet side for a fluid having, in use, a substantially transverse flow with respect to the axes of rotation of the gearwheels. The meshing gearwheels create, during their reciprocal rotation, progressive meshing configurations between respective co-operating teeth. In at least one of said progressive meshing configurations is defined, in at least one cross-section of the gearwheels, at least one closed area between respective fluid entrapment teeth. The closed area decreases until it is substantially cancelled out at and around at least one other, separate progressive meshing configuration between the aforesaid respective co-operating teeth.

Abstract: A geared hydraulic apparatus comprises a pair of gear wheels which mesh with each other with semi-encapsulation. Each gear wheel has a plurality of teeth with a profile which falls within a band of tolerance of ±15, more preferably ±20, and even more preferably ±30 with respect to the height of the tooth, with respect to a profile similar to a profile defined by a predetermined spline function passing through a plurality of nodal points having pre-established coordinates {X,Y} with origin on the rotational axis.

Abstract: An improved geared hydraulic apparatus, comprising a pair of meshing gearwheels, mounted to be reciprocally rotatable in a casing between an inlet side and an outlet side for a fluid having, in use, a substantially transverse flow with respect to the axes of rotation of the gearwheels. The meshing gearwheels create, during their reciprocal rotation, progressive meshing configurations between respective co-operating teeth. In at least one of said progressive meshing configurations is defined, in at least one cross-section of the gearwheels, at least one closed area between respective fluid entrapment teeth. The closed area decreases until it is substantially cancelled out at and around at least one other, separate progressive meshing configuration between the aforesaid respective co-operating teeth.