Abstract: Some heat pumps have displacers mechatronically-controlled via springs and coils acting upon a ferromagnetic plate. In some prior art heat pumps, the components are housed in hot parts of the heat pump and in others, the components are housed in a cold part of the heat pump, but the components are offset from a central axis of the heat pump. A heat pump with the mechatronic driver components collinear with a central axis of the heat pump has the components in a cold part of the heat pump.

Abstract: A four-process cycle is disclosed for a Vuilleumier heat pump that has mechatronically-controlled displacers. Vuilleumier heat pumps that use a crank to drive the displacers have been previously developed. However, mechatronic controls provides a greater degree of freedom to control the displacers. The four-process cycle provides a higher coefficient of performance than prior cycles in the crank-driven Vuilleumier heat pump and those previously disclosed for a mechatronically-driven Vuilleumier heat pump. The four-process cycle can be drawn out to provide a low demand condition by causing both displacers to remain stationary for a period of time. The four processes in which one of the displacers is commanded to move are separated by periods of inactivity in which both displacers remain stationary.

Abstract: A method for providing control data for a generative layer construction device has a first step of accessing a data record which, at least for a partial region of an object cross section, specifies in which temporal sequence an energy beam bundle is to be moved in scanning lines over the places of this partial region to scan the buildup material. In a second step, the data record is changed such that in at least one of the layers for the respective partial region of an object cross-section, a check is carried out to determine whether the scan time required to scan the buildup material along a scanning line falls below a predefined minimum duration tmin and either a lower energy density of the energy beam bundle during scanning of the buildup material along this scanning line is specified and/or a wait time is specified before the energy beam bundle is moved along a further scanning line.

Abstract: A thermodynamic apparatus, such as a Stirling engine or a Vuilleumier heat pump, has a heat exchanger in which energy is exchanged between a working fluid and an exhaust gas stream. On top of the cylinder of the thermodynamic apparatus is a dome-shaped section. By incorporating the heat exchanger within the dome, the flow paths can be simplified, the number of separate components reduced, and overall weight reduced. Flow passages for the working fluid are embedded in the dome. Channels for the exhaust gases are formed in an outer surface. The passages and the channels are helically arranged, one clockwise and one counter clockwise. The dome can be cast with a core for the casting fabricated via three-dimensional printing. In some embodiments, the dome is made of fiber-reinforced material.

Abstract: A thermodynamic apparatus that includes a displacer within a cylinder is disclosed. The displacer reciprocates within the cylinder by a linear actuator that includes electrical coils, an armature, and a coil spring system. The spring system includes collinear first and second coil springs of opposite sense. First ends of the springs are captured in a first plate; second ends of the springs are captured in a second plate. Without constraint, the springs can compensate to forces by bending, rotating, increasing in diameter, and combinations thereof. In certain applications, such as the heat pump, bending should be minimized. By selecting the points of capture of the hooks at the ends of the springs in the plates, bending force of the first spring counteracts the bending force of the second spring.

Abstract: Substituting a solar concentrator for a conventional burner for heating is desirable. However, the sun's energy is diurnal and cannot be counted upon even during daylight hours. To ensure heating is available, a combustor can be provided. According to the present disclosure, a heat exchanger element of the heater assembly is directly acted upon by solar rays via a solar concentrator and by combustion. The heat exchanger also acts as the combustion holder when the burner supplements or supplants the solar radiation. Fuel provided to the outside of the heat exchanger is adjusted based on the demanded for heating and the amount of insolation (rate of delivery of solar radiation) achieved via the solar concentrator. The heat exchanger can be part of a conventional heater or a heat pump for heating water or air.

Abstract: A four-process cycle is disclosed for a Vuilleumier heat pump that has mechatronically-controlled displacers. Vuilleumier heat pumps that use a crank to drive the displacers have been previously developed. However, mechatronic controls provides a greater degree of freedom to control the displacers. The four-process cycle provides a higher coefficient of performance than prior cycles in the crank-driven Vuilleumier heat pump and those previously disclosed for a mechatronically-driven Vuilleumier heat pump. The four-process cycle can be drawn out to provide a low demand condition by causing both displacers to remain stationary for a period of time. The four processes in which one of the displacers is commanded to move are separated by periods of inactivity in which both displacers remain stationary.

Abstract: Some heat pumps have displacers mechatronically-controlled via springs and coils acting upon a ferromagnetic plate. In some prior art heat pumps, the components are housed in hot parts of the heat pump and in others, the components are housed in a cold part of the heat pump, but the components are offset from a central axis of the heat pump. A heat pump with the mechatronic driver components collinear with a central axis of the heat pump has the components in a cold part of the heat pump.

Abstract: A thermodynamic apparatus, such as a Stirling engine or a Vuilleumier heat pump, has a heat exchanger in which energy is exchanged between a working fluid and an exhaust gas stream. On top of the cylinder of the thermodynamic apparatus is a dome-shaped section. By incorporating the heat exchanger within the dome, the flow paths can be simplified, the number of separate components reduced, and overall weight reduced. Flow passages for the working fluid are embedded in the dome. Channels for the exhaust gases are formed in an outer surface. The passages and the channels are helically arranged, one clockwise and one counter clockwise. The dome can be cast with a core for the casting fabricated via three-dimensional printing. In some embodiments, the dome is made of fiber-reinforced material.

Abstract: Reciprocating apparatuses such as a displacer in a Stirling engine or Vuilleumier (thermally-driven) heat pump and such as a poppet valve in an internal combustion engine have been known to be built with a mechatronic actuator. The reciprocating element has two springs in compression biased against each other. It has been found that conventional springs in compression introduce losses. A spring is disclosed in which a portion of the coil is wound in a clockwise direction and a portion is wound in a clockwise direction. Also, in reciprocation, the spring is in compression at one end of travel and in tension at the other end of travel.

Abstract: A four-process cycle is disclosed for a Vuilleumier heat pump that has mechatronically-controlled displacers. Vuilleumier heat pumps that use a crank to drive the displacers have been previously developed. However, mechatronic controls provides a greater degree of freedom to control the displacers. The four-process cycle provides a higher coefficient of performance than prior cycles in the crank-driven Vuilleumier heat pump and those previously disclosed for a mechatronically-driven Vuilleumier heat pump.

Abstract: It is common in heating systems, such as in a hot water heater for there to be a combustor with the exhaust gases from the combustor provided to a heat exchanger to heat up the water. Disclosed herein is an integrated heat exchanger and burner assembly in which the combustion occurs proximate the surface of the heat exchanger. Such a system may include at least one tube that is coiled into a number of turns, that is a tube coil with the at least one tube having an inlet and an outlet and the distance between adjacent turns is less than a predetermined distance, i.e. a the quench distance.

Abstract: A thermally driven heat pump is disclosed in which at least most of the warm heat exchanger is disposed within the cylinder between the hot and cold displacers. Such an arrangement is not suitable for a prior art heat pump in which movement of the displacers is based on a crank because it would lead to too much dead volume in the system. However, with mechatronically-controlled displacers in which the displacers are independently controlled, the displacers can reciprocate up to the heat exchanger. Such a configuration reduces dead volume compared to prior art Vuilleumier heat pumps in which the warm exchanger occupies a portion of an annular space between the cylinder in which the displacers move.

Abstract: A Vuilleumier heat pump is disclosed in which hot and cold displacers are controlled by first and second electromagnetic actuators, respectively. The first actuator is capable of moving the hot displacer between the first and second ends of travel while the cold displacer remains stationary and the second actuator is capable of moving the cold displacer while the hot displacer remains stationary. Prior art crank arrangements are unable to provide dwell in one displacer while moving the other displacer. Actuation of the displacers according to embodiments of the present disclosure provides a higher coefficient of performance than crank arrangements.

Abstract: In a piston-ported engine, a sealing ring may be placed in a groove in the cylinder. As the groove is of greater diameter than the cylinder, the sealing ring overlaps into a helix allowing it to be enter the cylinder. However, such a helix does not fit into a groove without when in the helix. Alternatively, a shorter sealing ring is placed into the groove. However, the gap is too large. According to one embodiment, a groove of double the width of the ring is provided and the helical ring is installed and caused to unwind in the groove so that the ring sits in a plane. A spacer ring is placed in the groove to fill the extra space in the groove. An elastomeric material or a tension spring in an outer groove in the sealing ring can be used to cause the ring to press against the piston.

Abstract: Newly-developed manufacturing techniques have opened up new possibilities in fabricating designs of components that were previously infeasible. One such component is a heat exchanger. A crossflow heat exchanger is disclosed that includes a plurality of internal passages for conducting a first fluid. The internal passages that form a spiral with adjacent passages separated by a gap of a predetermined distance or less. The second fluid passes through the gaps. The internal passages may be a plurality of parallel passages arranged along a first line. From upstream to downstream, each of the passages form an inlet spiral connected to an inner ring connected to an outlet spiral. The gaps are less than a predetermined distance related to a Reynolds number that is less than that at which laminar flow exists.

Abstract: It is common in heating systems, such as in a hot water heater for there to be a combustor with the exhaust gases from the combustor provided to a heat exchanger to heat up the water. Disclosed herein is an integrated heat exchanger and burner assembly in which the combustion occurs proximate the surface of the heat exchanger. Such a system may include at least one tube that is coiled into a number of turns, that is a tube coil with the at least one tube having an inlet and an outlet and the distance between adjacent turns is less than a predetermined distance, i.e. a the quench distance.

Abstract: In some two-stroke engines, a stationary ring is disposed in a groove in the cylinder liner. However, it is a challenge to install such a stationary ring while maintaining a narrow gap to minimize gas flow through the gap. A ring system for an internal combustion engine is disclosed that includes an L-shaped, split ring with a reentrant angle and a nested, split ring with a convex quadrilateral cross section nested with the L-shaped ring proximate the reentrant angle. The two rings are affixed so that the two gaps of the split rings cannot align. Or, in other embodiments, the two are allowed to rotate relative to each other over a predetermined angle.

Abstract: A disclosed lubrication system for an internal combustion engine includes an inertia reactive oil injector in a piston that reacts to convey lubricating oil to the space between the piston and its adjacent cylinder wall immediately below the upper piston rings as the piston reaches top dead center. A first embodiment utilizes a passage and reservoir formed beneath the piston wall with inlet and outlet ports at each end. The oil injector carries the oil past the intake/exhaust ports of the cylinder until the piston decelerates while approaching its TDC position. During that deceleration, the oil carried by the injector reservoir is delivered through the outlet port into the space between the piston and the cylinder liner. A second embodiment utilizes a groove of predetermined length formed in the outer surface of the piston. A reservoir is formed in the groove and defines inlet and outlet ports at each end.

Abstract: A toroidal combustion chamber shape with side injectors is being developed for an opposed-piston engine. Favorable combustion characteristics of such configuration are transferred to a conventional engine, i.e., one with a combustion chamber delimited by a piston, a cylinder wall, and a cylinder head. At least one injector is disposed in the cylinder head at the periphery. The fuel is injected substantially along the plane of interface between the cylinder head and the cylinder block. The intake system is configured to provide a swirling flow in the combustion chamber. The fuel is injected in an angle that is displaced from the central axis of the cylinder and directed along the swirl. In some embodiments, a substantially torus-shaped volume is formed between the piston and the cylinder head when the piston is at top center. The injector or injectors spray fuel into the toroidally-shaped volume substantially tangent to the torus.