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.

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); the first wheel (11) comprising a plurality of teeth defining between them a plurality of compartments (9) suitable to house teeth of the second wheel (12); a first and the second abutment (3, 4) between which the first cogged wheel (11) is interposed and that 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). The first grooved pathway (31) comprises at least one stretch having a passage section having a surface smaller than 1 mm.sup.2.

A method of manufacturing a metallic rotor of an eccentric screw pump, comprising clamping a workpiece extending along a central longitudinal axis in a workpiece clamping device and removing material from the workpiece by cutting with a cutting tool. The invention further comprises not producing the surface of the rotor in a three-axis whirling process, using the cutting tool to produce the outer surface geometry of the rotor, advancing the cutting tool along an axis of advance that is parallel to the longitudinal axis of the rotor, and rotating the cutting tool about an axis of tool rotation that is parallel to the longitudinal axis of the rotor.

A method of manufacturing a metallic rotor of an eccentric screw pump, comprising clamping a workpiece extending along a central longitudinal axis in a workpiece clamping device and removing material from the workpiece by cutting with a cutting tool. The invention further comprises not producing the surface of the rotor in a three-axis whirling process, using the cutting tool to produce the outer surface geometry of the rotor, advancing the cutting tool along an axis of advance that is parallel to the longitudinal axis of the rotor, and rotating the cutting tool about an axis of tool rotation that is parallel to the longitudinal axis of the rotor.

A light-weight, high-strength compressor component is formed via additive manufacturing that has controlled stiffness and/or deflection levels. The component may have at least one interior region comprising a lattice structure that comprises a plurality of repeating cells. A solid surface is disposed over the lattice structure. The interior region comprises the lattice structure in the body portion of the light-weight, high-strength compressor component. The lattice structure may be used to globally or locally control stiffness and/or deflection levels of the compressor component. Additive manufacturing provides flexibility in forming compressor components with desirably improved strength-to-weight ratios while exhibiting high levels of control over stiffness and/or deflection. Methods of making such compressor components via additive manufacturing processes are also provided.

A gear pump can include at least one gear having a plurality of gear teeth. At least the plurality of gear teeth can be additively manufactured and can include a substrate and a pitting resistant outer coating additively manufactured on the substrate and configured to prevent pitting due to cavitation. The substrate can include a substrate material and the pitting resistant outer coating includes a pitting resistant material different than the substrate material. The pitting resistant outer coating defines an outer surface layer of the gear teeth.

A method of manufacturing a metallic rotor of an eccentric screw pump, comprising clamping a workpiece extending along a central longitudinal axis in a workpiece clamping device and removing material from the workpiece by cutting with a cutting tool. The invention further comprises not producing the surface of the rotor in a three-axis whirling process, using the cutting tool to produce the outer surface geometry of the rotor, advancing the cutting tool along an axis of advance that is parallel to the longitudinal axis of the rotor, and rotating the cutting tool about an axis of tool rotation that is parallel to the longitudinal axis of the rotor.

A stator and a method of manufacturing at least a portion of a progressive cavity motor or pump include disposing a cylindrical shell within a cylindrical housing, disposing a stator mold within the cylindrical shell, disposing an elastomeric material between the stator mold and the cylindrical shell, removing the stator mold from within the elastomeric material, thereby forming an elastomeric material layer having a stator profile within the cylindrical shell, and removing the cylindrical shell from within the cylindrical housing, thereby forming a cartridge having the elastomeric material layer disposed within the cylindrical shell.

A light-weight, high-strength compressor component is formed via additive manufacturing that has controlled stiffness and/or deflection levels. The component may have at least one interior region comprising a lattice structure that comprises a plurality of repeating cells. A solid surface is disposed over the lattice structure. The interior region comprises the lattice structure in the body portion of the light-weight, high-strength compressor component. The lattice structure may be used to globally or locally control stiffness and/or deflection levels of the compressor component. Additive manufacturing provides flexibility in forming compressor components with desirably improved strength-to-weight ratios while exhibiting high levels of control over stiffness and/or deflection. Methods of making such compressor components via additive manufacturing processes are also provided.