Abstract: Devices and systems relating to external gear machines that comprise microsurface shaping on the lateral surfaces of the gear teeth and/or bushing surfaces are provided. Such microsurface shaping may comprise a flat step to linear wedge profile, a flat step to flat step profile, or solely a linear wedge profile. The incorporation of microsurface shaping on the gear teeth and/or bushing plates contributes to improving the lubrication performance within the external gear machine and provides significant benefits, including the improvement of operating efficiency, life, and reliability of the system components. Methods for manufacturing the gear teeth and related bushings are also provided, the methods configured to optimize the overall axial balance within the system.

Abstract: A piston and cylinder assembly of an axial piston machine is disclosed which includes a cylinder having a uniform internal diameter, a cylindrical bushing press-fit against the inner surface of the cylinder and extending at least partially therein, the bushing comprising at least one circumferential groove formed on an outer surface of the bushing against the inner surface of the cylinder, a piston reciprocably disposed within the cylindrical bushing, generating a piston-bushing-interface, the piston and the bushing defining a diametrical clearance therebetween, the diametrical clearance defining a lubrication gap and a fluid-dynamic seal between the piston and the cylindrical bushing.

Abstract: An integrated electromechanical and hydraulic system is disclosed which includes an electric machine, the electric machine includes a casing, a stator adapted to remain stationary within the casing, one or more electrically insulated windings coupled to the stator, a rotor separated from the stator and the one or more windings by a radial diamagnetic gap, electrical power couplings, and a first mechanical power couplings, and a hydraulic machine also disposed in the housing, the hydraulic machine having hydro-mechanical couplings as well as a second mechanical power couplings, wherein the second mechanical power couplings are coupled to the first mechanical power couplings.

Abstract: An example hydraulic motor comprises: a stator comprising (i) a stator body having plurality of roller pockets, wherein the stator body comprises a plurality of grooves that are longitudinally-extending, and (ii) a plurality of rollers disposed respectively in the plurality of roller pockets; a rotor having a plurality of external teeth configured to engage with the plurality of rollers of the stator, such that the plurality of rollers and the plurality of external teeth define fluid chambers therebetween configured to expand and contract as the rotor rotates within the stator; and an anti-cogging passage configured to provide pressurized fluid from at least one of the fluid chambers to at least one groove of the plurality of grooves of the stator body, such that pressurized fluid provided to the at least one groove applies a radially-inward force on a respective roller toward the rotor.

Abstract: A controlled variable delivery external gear machine (VD-EGM). The VD-EGM includes a housing, an inlet, a drive gear, a driven gear, the drive gear configured to engage the driven gear in an angular mesh zone, an outlet, a first slider comprising a first longitudinal portion connected to a second longitudinal portion such that longitudinal forces applied to the first and second longitudinal portions substantially cancel each other thereby requiring between about 0 N to about 20 N to longitudinally moving the first slider, selective positioning of the first slider configured to vary net operational volumes of fluid communication between the inlet and the outlet, for a given rotational speed of the drive gear, and a first drive mechanism coupled to the first slider and configured to cause the first slider to slide in a longitudinal direction.

Abstract: A piston and cylinder assembly of an axial piston machine is disclosed which includes a cylinder having a uniform internal diameter, a cylindrical bushing press-fit against the inner surface of the cylinder and extending at least partially therein, the bushing comprising at least one circumferential groove formed on an outer surface of the bushing against the inner surface of the cylinder, a piston reciprocably disposed within the cylindrical bushing, generating a piston-bushing-interface, the piston and the bushing defining a diametrical clearance therebetween, the diametrical clearance defining a lubrication gap and a fluid-dynamic seal between the piston and the cylindrical bushing.

Abstract: An external gear machine (EGM) includes a housing, an inlet, a drive gear positioned in the housing and configured to be (i) driven by a mechanism when the EGM is operated as a pump, or (ii) drive an external mechanism when the EGM is operated as a motor, the drive gear having a plurality of teeth, a slave gear positioned in the housing having a plurality of teeth and configured to be driven by the drive gear, an outlet formed in the housing and configured to receive at least some of the volume of fluid via an outlet fluid communication channel, a first slider defining an inlet fluid communication channel and the outlet fluid communication channel, selective positioning of the first slider configured to vary net operational volumes of fluid communication between the inlet and the outlet, for a given rotational speed of the drive gear.

Abstract: Methods and apparatus pertaining to positive displacement pumps, and further to hydraulic actuation systems. In some embodiments the pumps are gear pumps with bi-directional operation. In some embodiments the actuation system includes a motor-driven, reversible operation gear pump providing fluid under pressure to a rod and cylinder.

Abstract: A controlled variable delivery external gear machine (VD-EGM). The VD-EGM includes a housing, an inlet, a drive gear, a driven gear, the drive gear configured to engage the driven gear in an angular mesh zone, an outlet, a first slider comprising a first longitudinal portion connected to a second longitudinal portion such that longitudinal forces applied to the first and second longitudinal portions substantially cancel each other thereby requiring between about 0 N to about 20 N to longitudinally moving the first slider, selective positioning of the first slider configured to vary net operational volumes of fluid communication between the inlet and the outlet, for a given rotational speed of the drive gear, and a first drive mechanism coupled to the first slider and configured to cause the first slider to slide in a longitudinal direction.

Abstract: Methods and apparatus pertaining to positive displacement pumps, and further to hydraulic actuation systems. In some embodiments the pumps are gear pumps with bi-directional operation. In some embodiments the actuation system includes a motor-driven, reversible operation gear pump providing fluid under pressure to a rod and cylinder.

Abstract: An external gear machine (EGM) includes a housing, an inlet, a drive gear positioned in the housing and configured to be (i) driven by a mechanism when the EGM is operated as a pump, or (ii) drive an external mechanism when the EGM is operated as a motor, the drive gear having a plurality of teeth, a slave gear positioned in the housing having a plurality of teeth and configured to be driven by the drive gear, an outlet formed in the housing and configured to receive at least some of the volume of fluid via an outlet fluid communication channel, a first slider defining an inlet fluid communication channel and the outlet fluid communication channel, selective positioning of the first slider configured to vary net operational volumes of fluid communication between the inlet and the outlet, for a given rotational speed of the drive gear.

Abstract: Methods and apparatus pertaining to positive displacement pumps, and further to hydraulic actuation systems. In some embodiments the pumps are gear pumps with bi-directional operation. In some embodiments the actuation system includes a motor-driven, reversible operation gear pump providing fluid under pressure to a rod and cylinder.