Abstract: An irradiation device for additively manufacturing three-dimensional objects may include a beam generation device configured to generate an energy beam, an optical modulator including a micromirror array disposed downstream from the beam generation device, and a focusing lens assembly disposed downstream from the optical modulator. The micromirror array may include a plurality of micromirror elements configured to reflect a corresponding plurality of beam segment of the energy beam along a beam path incident upon the focusing lens assembly. The focusing lens assembly may include one or more lenses configured to focus the plurality of beam segments such that for respective ones of a plurality of modulation groups including a subset of micromirror elements, a corresponding subset of beam segments are focused to at least partially overlap with one another at a combination zone corresponding to the respective modulation group.

Abstract: A linear electric machine includes a shaft and at least one piston assembly operably coupled with the shaft. The piston assembly includes a piston, a piston body, and an expansion chamber. The piston body defines a dome structure at the expansion chamber. The piston is a domed piston corresponding to the dome structure. The linear electric machine also includes a heater body positioned at an outer end of the expansion chamber adjacent to the dome structure. The piston body further defines an exterior surface corresponding to a shape of the dome structure. The exterior surface includes a plurality of surface features protruding therefrom and is arranged between the heater body and the dome structure. The plurality of surface features decrease a heat load across the exterior surface of the piston body.

Abstract: A system for energy conversion including a closed cycle engine containing a volume of working fluid is provided. The engine includes a double-ended piston assembly including a pair of pistons coupled to a connection member. An expansion chamber is separated from a compression chamber by the piston. The engine defines an outer end and an inner end relative to a lateral extension of the piston assembly. A heater body is positioned thermally proximal to the expansion chamber and thermally distal to the compression chamber, and the heater body is positioned at the outer end of the engine. A load device is operably coupled to the piston assembly at the inner end of the engine. The load device is positioned between the pair of pistons of the piston assembly.

Abstract: Embodiments of the present disclosure are directed to additive manufacturing apparatuses, cleaning stations incorporated therein, and methods of cleaning using the cleaning stations.

Abstract: A system for energy conversion, the system including a closed cycle engine containing a volume of working fluid, the engine comprising a first chamber defining an expansion chamber and a second chamber defining a compression chamber each separated by a piston attached to a connection member of a piston assembly, and wherein the engine comprises a heater body in thermal communication with the first chamber, and further wherein the engine comprises a cold side heat exchanger in thermal communication with the second chamber, and wherein a third chamber is defined within the piston, wherein the third chamber is in selective flow communication with the first chamber, the second chamber, or both.

Abstract: An irradiation device for additively manufacturing three-dimensional objects may include a beam generation device configured to generate an energy beam, an optical modulator including a micromirror array disposed downstream from the beam generation device, and a focusing lens assembly disposed downstream from the optical modulator. The micromirror array may include a plurality of micromirror elements configured to reflect a corresponding plurality of beam segment of the energy beam along a beam path incident upon the focusing lens assembly. The focusing lens assembly may include one or more lenses configured to focus the plurality of beam segments such that for respective ones of a plurality of modulation groups including a subset of micromirror elements, a corresponding subset of beam segments are focused to at least partially overlap with one another at a combination zone corresponding to the respective modulation group.

Abstract: Embodiments of the present disclosure are directed to additive manufacturing apparatuses, cleaning stations incorporated therein, and methods of cleaning using the cleaning stations.

Abstract: A method of pressurizing a closed-cycle engine includes performing a non-steady state operation in which a working fluid flows to or from a pressurized tank: i) to or from a plurality of sumps defined by respective ones of a plurality of cylinder-piston assemblies of the closed-cycle engine; or ii) to or from one or more air bearings associated with each one of the plurality of the cylinder-piston assemblies; or iii) both and performing, before and/or after performing the non-steady state operation, a steady-state operation in which the working fluid flows through the plurality of sumps and the one or more air bearings along a steady-state loop that is fluidly decoupled from the pressurized tank.

Abstract: The present disclosure generally relates to monolithic superstructures for supporting a rotating shaft coupled to a rotor relative to a stator. An integral superstructure supports the rotating component. The superstructure includes a bearing portion that contacts the shaft. A stator portion, is spaced a critical dimension radially outward, from the rotor. A first annular transfer portion extends axially forward from the bearing to the stator portion. A second annular transfer portion extends axially aft from the stator portion to a mounting flange. The mounting flange connects the superstructure to a frame. The superstructure maintains a critical dimension between the rotor and the stator as the temperature of the superstructure increases. The rotor may be a compressor impeller in a gas turbine engine and the stator may be an aero component that transfers air into a combustor.

Abstract: A fuel nozzle apparatus includes: an outer body having an exterior surface and a plurality of openings in the exterior surface. An inner body is disposed inside the outer body, cooperating with the outer body to define an annular space. A main injection ring is disposed in the annular space and includes an array of fuel posts extending outward therefrom, each fuel post including a perimeter wall defining a lateral surface and a recessed floor. Each fuel post is aligned with one of the openings and separated from the opening by a perimeter gap defined between the opening and the lateral surface. A main fuel gallery extends within the main injection ring. The main injection ring includes plurality of main fuel orifices, each main fuel orifice communicating with the main fuel gallery and extending through one of the fuel posts.

Abstract: An irradiation device for additively manufacturing three-dimensional objects may include a beam generation device configured to generate an energy beam, an optical modulator including a micromirror array disposed downstream from the beam generation device, and a focusing lens assembly disposed downstream from the optical modulator. The micromirror array may include a plurality of micromirror elements configured to reflect a corresponding plurality of beam segment of the energy beam along a beam path incident upon the focusing lens assembly. The focusing lens assembly may include one or more lenses configured to focus the plurality of beam segments such that for respective ones of a plurality of modulation groups including a subset of micromirror elements, a corresponding subset of beam segments are focused to at least partially overlap with one another at a combination zone corresponding to the respective modulation group.

Abstract: An irradiation device for additively manufacturing three-dimensional objects may include a beam generation device configured to generate an energy beam, an optical modulator including a micromirror array disposed downstream from the beam generation device, and a focusing lens assembly disposed downstream from the optical modulator. The micromirror array may include a plurality of micromirror elements configured to reflect a corresponding plurality of beam segment of the energy beam along a beam path incident upon the focusing lens assembly. The focusing lens assembly may include one or more lenses configured to focus the plurality of beam segments such that for respective ones of a plurality of modulation groups including a subset of micromirror elements, a corresponding subset of beam segments are focused to at least partially overlap with one another at a combination zone corresponding to the respective modulation group.

Abstract: The present disclosure generally relates to monolithic superstructures for supporting a rotating shaft coupled to a rotor relative to a stator. An integral superstructure supports the rotating component. The superstructure includes a bearing portion that contacts the shaft. A stator portion, is spaced a critical dimension radially outward, from the rotor. A first annular transfer portion extends axially forward from the bearing to the stator portion. A second annular transfer portion extends axially aft from the stator portion to a mounting flange. The mounting flange connects the superstructure to a frame. The superstructure maintains a critical dimension between the rotor and the stator as the temperature of the superstructure increases. The rotor may be a compressor impeller in a gas turbine engine and the stator may be an aero component that transfers air into a combustor.

Abstract: A piston apparatus includes a plurality of piston assemblies respectively having a first piston body and a first piston disposed within a first volume defined by the first piston body, a second piston body and a second piston disposed within a second volume defined by the second piston body, and a connection member coupled to the first piston and the second piston. The first and second volume respectively include an expansion chamber and a compression chamber defined by opposite sides of the corresponding piston. The respective expansion chambers fluidly communicate with a corresponding compression chamber of another one of the piston assemblies. The first volume of a first piston assembly fluidly communicates with the first volume and the second volume of a second piston assembly, and the first volume of a third piston assembly fluidly communicate with the first volume and the second volume of the second piston assembly.

Abstract: The present disclosure is directed to additive manufacturing systems, components therein, and methods for their use. The additive manufacturing system comprises a powder material handling system comprising a virgin powder inlet. The virgin powder inlet is coupled to a virgin powder drum and configured to receive a virgin powder from the virgin powder drum. The additive manufacturing system further comprises a liquid material handling system comprising a binder inlet. The binder inlet is coupled to a binder drum and configured to receive a binder from the binder drum. The additive manufacturing system also comprises an additive manufacturing machine coupled to the powder material handling system and the liquid material handling system. The additive manufacturing machine receives the virgin powder and the binder from the powder material handling and liquid material handling systems and is configured to manufacture a work product using the virgin powder and the binder.

Abstract: A monolithic heat exchanger body for inputting heat to a closed-cycle engine includes heating walls and heat sink, such as heat transfer regions. The heating walls are configured and arranged in an array of spirals or spiral arcs relative to a longitudinal axis of an inlet plenum. Adjacent portions of the heating walls respectively define corresponding heating fluid pathways fluidly communicating with the inlet plenum. At least a portion of the heat sink is disposed about at least a portion of the monolithic heat exchanger body. The heat sink includes working-fluid bodies including working-fluid pathways that have a heat transfer relationship with the heating fluid pathways. Respective ones of the heat transfer regions have a heat transfer relationship with a corresponding semiannular portion of the heating fluid pathways. Respective ones of the heat transfer regions include working-fluid pathways fluidly communicating between a heat input region and a heat extraction region.

Abstract: A recoat assembly for an additive manufacturing system includes a base member movable in a first lateral direction and a second lateral direction opposite the first lateral direction, a powder spreading member coupled to the base member, and a containment mechanism. The base member includes a primary containment housing at least partially encapsulating the powder spreading member. The containment mechanism is positionable into a first position when the base member is moving in the first lateral direction, and positionable into a second position different from the first position when the base member is moving in the second lateral direction.

Abstract: A constant density heat exchanger and method of operating are provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first plate is positioned at the first end of the housing and rotatable about an axis of rotation such that the first plate selectively allows a working fluid to flow into the inlet of the chamber. A second plate is positioned at the second end of the housing and rotatable about the axis of rotation such that the second plate selectively allows the working fluid to flow out of the outlet of the chamber. The first plate and the second plate are rotatable about the axis of rotation so as to hold a volume of the working fluid at constant density as a heat source imparts thermal energy thereto.

Abstract: A monolithic heat exchanger body for inputting heat to a closed-cycle engine includes heating walls and heat sink, such as heat transfer regions. The heating walls are configured and arranged in an array of spirals or spiral arcs relative to a longitudinal axis of an inlet plenum. Adjacent portions of the heating walls respectively define corresponding heating fluid pathways fluidly communicating with the inlet plenum. At least a portion of the heat sink is disposed about at least a portion of the monolithic heat exchanger body. The heat sink includes working-fluid bodies including working-fluid pathways that have a heat transfer relationship with the heating fluid pathways. Respective ones of the heat transfer regions have a heat transfer relationship with a corresponding semiannular portion of the heating fluid pathways. Respective ones of the heat transfer regions include working-fluid pathways fluidly communicating between a heat input region and a heat extraction region.

Abstract: In embodiments, an additive manufacturing apparatus comprises a chassis assembly and a skin at least partially covering the chassis assembly. The chassis assembly comprises a lower chassis section secured to a low voltage chassis section; an upper environmental chassis section secured to and extending over the low voltage chassis section and the lower chassis section; a high voltage chassis section secured to the upper environmental chassis section and the lower chassis section; and a build receptacle carriage adjustably coupled to the lower chassis section. The skin comprises first and second doors providing access to the low voltage chassis section and the high voltage chassis section; a rear panel providing access to the upper environmental chassis section; a top panel covering a top of the upper environmental chassis section; and at least one hinged door providing access to the lower chassis section.