Various embodiments of the present invention are directed toward a linear combustion engine, comprising: a cylinder having a cylinder wall and a pair of ends, the cylinder including a combustion section disposed in a center portion of the cylinder; a pair of opposed piston assemblies adapted to move linearly within the cylinder, each piston assembly disposed on one side of the combustion section opposite the other piston assembly, each piston assembly including a spring rod and a piston comprising a solid front section adjacent the combustion section and a gas section; and a pair of linear electromagnetic machines adapted to directly convert kinetic energy of the piston assembly into electrical energy, and adapted to directly convert electrical energy into kinetic energy of the piston assembly for providing compression work during the compression stroke.

Multiphase electromagnetic machines, such as free-piston engines or compressors, may require, or supply, a pulsed power profile from or to a DC bus, respectively. The pulsed power profile may include relatively large fluctuations in instantaneous power. Sourcing, sinking, or otherwise exchanging power with an AC grid, via an inverter, may be accomplished by using an energy storage device and a DC-DC converter coupled to a DC bus. The energy storage device may aid in smoothing the pulsed power profile, while the DC-DC converter may aid in reducing fluctuations in voltage across a DC bus due to energy storage in the energy storage device.

An electric device has a driveshaft with at least one stator cylinder positioned between opposing, curvilinear shaped cams mounted on the driveshaft, where the center axis of the stator cylinder is parallel with but spaced apart from the driveshaft axis. A magnet assembly is disposed in each end of the stator cylinder, with one magnet assembly engaging one cam and the other magnet assembly engaging the other cam. Each magnet assembly includes a cam follower that can move along a curvilinear shaped cam. A magnet slide arm attached to the cam reciprocates magnets carried on the magnet slide arm through electromagnetic windings disposed around the stator cylinder. An electrical input delivered to the windings can reciprocate the arm, driving the cams to rotate the driveshaft. Alternatively, rotation of the driveshaft can be used to reciprocate the arm to induce electric current in the windings.

A system may be used for determining a parameter relating to a piston in an engine. The parameter may be the piston position, speed, etc., which may be determined at a reference point in a cylinder. The system may be controlled based on the determined parameter. The engine may be a linear reciprocating engine, opposed piston engine, etc. The system may include a first sensor provided on a base connected to the engine, and a second sensor provided on the base. The first sensor may be configured to generate a signal in response to a component coupled to the piston being in a region of the first sensor. The second sensor may be configured to generate a signal in response to a component coupled to the piston interacting with the second sensor. The system may include an energy transformer configured to transform motion of the engine to electrical power.

A free piston apparatus includes a piston receptacle in which a piston device having a piston is reciprocable along an axis. The piston receptacle includes or forms a combustion chamber delimited by a wall arrangement forming an inlet opening for the supply of fresh gas and an outlet opening for the removal of exhaust gas. Fresh gas is suppliable via a supply conduit. The free piston apparatus includes a housing for fresh gas which is connected to the supply conduit in a flow direction of the fresh gas being supplied. The housing forms a settling chamber for fresh gas which surrounds the piston receptacle at least in sections in the region of the inlet opening in a circumferential direction of the axis. The settling chamber opens into the combustion chamber via the inlet opening.

A system may be used for determining a parameter relating to a piston in an engine. The parameter may be the piston position, speed, etc., which may be determined at a reference point in a cylinder. The system may be controlled based on the determined parameter. The engine may be a linear reciprocating engine, opposed piston engine, etc. The system may include a first sensor provided on a base connected to the engine, and a second sensor provided on the base. The first sensor may be configured to generate a signal in response to a component coupled to the piston being in a region of the first sensor. The second sensor may be configured to generate a signal in response to a component coupled to the piston interacting with the second sensor. The system may include an energy transformer configured to transform motion of the engine to electrical power.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a driver section may be provided in a free-piston combustion engine for storing energy during an expansion stroke. The driver section may be configured to store sufficient energy to perform the subsequent stroke. In some embodiments, the driver section may be configured to store sufficient energy so as to enable the engine to operate continuously across engine cycles without electrical energy input. A linear electromagnetic machine may be provided in a free-piston combustion engine for converting the kinetic energy of a piston assembly into electrical energy.

A load adaptive linear electrical generator system is provided for generating DC electrical power. The electrical generation system includes one or more power generation modules which will be selectively turned on or off and additively contribute power depending on the DC power demand. Each power generating module includes a pair of linear electrical generators connected to respective ones of a pair of internal combustion piston based power assemblies. The piston in the internal combustion assembly is connected to a magnet in the linear electrical generator. The piston/magnet assembly oscillates in a simple harmonic motion at a frequency dependent on a power load of the electrical generator. A stroke limiter constrains the piston/magnet assembly motion to preset limits.

Systems and methods for converting energy are provided. In one aspect, the system includes a closed cycle engine having a piston body and a piston assembly movable within the piston body. An electric machine is operatively coupled with the piston assembly and operable to generate electrical power. An electrical device is in communication with the electric machine. The system includes a control system having sensors, a controllable device, and a controller. The controller is configured to determine whether a load change on the electric machine is anticipated based at least in part on received data indicative of a load state of the electrical device; in response to whether the load change is anticipated, determine a control command for adjusting an output of at least one of the engine and the electric machine; and cause the controllable device to adjust the output based at least in part on the control command.

A pump includes a cylinder having a working chamber which contains a fluid. A drive system including at least two linear motors which are connected electrically and/or mechanically in parallel moves a piston in the working chamber to bound the working chamber in the cylinder and to pressurize the fluid in the working chamber. A piston rod is connected to the piston and bundles a force applied by the drive system.