Abstract: Screw assembly (1) for a triple screw pump (10), comprising: a central screw (2) and at least one lateral screw (3) configured to mesh with said central screw (2) with a lateral screw axis (zl) parallel to the central screw axis (zc), wherein a central screw external diameter (Øce) is greater than a lateral screw external diameter (Øle) and a central screw internal diameter (0ci) is smaller than the lateral screw external diameter (Øle).

Abstract: A screw assembly for a triple screw pump includes a central screw and at least one lateral screw, both provided with one or more helicoidal threads. The lateral screw is arranged to mesh with the central screw, with a lateral screw axis being parallel to a central screw axis. The distance between the axes of the central screw and the lateral screw is greater than the half and lower than 3/5 of a central screw external diameter.

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 the cutting edge during the rotation of the gear wheel (10), wherein 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 the groove (14) decreasing away from the cutting edge (12) along the profile (P).

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: The invention relates to a bi-helical toothed wheel (1) with non-encapsulating profile (4) for hydraulic gear apparatuses (2), of the type bound to a support shaft (5) to form a driving or driven wheel of said 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 (4) 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.