An improved electromechanical transducer is provided. In an embodiment, the transducer comprises at least two flux modules, each defining a magnetic circuit having a gap; an armature configured to move along a longitudinal axis passing through the gaps; and a gas containment structure laterally surrounding the armature, wherein: the at least two flux modules are provided outside the gas containment structure; and the armature comprises a reinforcing portion laterally outside of the gaps that is wider in a direction parallel to the flux in the gaps than at least one of the gaps.

Aircraft with an emission-free drive and method for emission-free driving of an aircraft. The aircraft includes an aircraft thruster structured and arranged to generate thrust force on the aircraft, an aircraft lift device structured and arranged to generate lift on the aircraft, and a heat engine, which is structured and arranged to convert thermal energy into kinetic energy to drive the aircraft thruster, that includes at least one flat-plate Stirling engine drivable by solar thermal radiation.

Aircraft with an emission-free drive and method for emission-free driving of an aircraft. The aircraft includes a drive device structured and arranged to generate thrust, a lift device structured and arranged to generate lift, and a heat engine structured and arranged to convert thermal energy into kinetic energy to drive the drive device. The heat engine includes at least one flat-plate Stirling engine drivable by solar thermal radiation.

A free-piston Stirling cycle engine includes a hermetically sealed pressure housing with a working section and at least one displacement section adjacent to the working section. At least one working piston, which forms part of a linear generator, is movably arranged in the interior of the working section and a regenerator is arranged in the at least one displacement section such that mechanical work can be performed by the working piston when the pressure housing is filled with a working gas and under the influence of a temperature difference between the displacement section with an elevated temperature and the remainder of the pressure housing with a lower temperature and the mechanical work can be converted into electrical energy by the linear generator.

An alpha type Stirling engine, comprising four pistons housed in respective chambers for reciprocating movement, at least two linear motors/generators configured to cause said pistons to move in the respective chambers, each one of said pistons defining in its respective chamber a primary chamber side located on one side of the piston and a secondary chamber side located on the other side of the piston. The Stirling engine comprises two primary gas channels, each one fluidly interconnecting two primary chamber sides. The Stirling engine also comprises two secondary gas channels, each one fluidly interconnecting two secondary chamber sides in different chamber combinations than the interconnections achieved by the primary gas channels.

Multiple free-piston stirling-cycle machine modules are connected together in double-acting configurations that may be used as engines or heat pumps and scaled to any power level by varying the number of modules. Reciprocating piston assemblies oriented in balanced pairs reduce vibration forces. There are no buffer spaces. Linear motors or generators are packaged inside piston cavities entirely within the module working spaces. The external heat-accepting and heat-rejecting surfaces in one embodiment are directed along inward-facing and outward facing cylinders, and in another embodiment along parallel planes, simplifying thermal connections to the external heat source and sink.

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.

Provided is a free-piston Stirling engine that can be easily manufactured by reducing manufacturing processes. A free-piston Stirling refrigerator comprises: a piston capable of reciprocating inside a first cylinder; a first leaf spring for controlling the reciprocating motion of the piston; a connection body for connecting the piston to the movable portion of the first leaf spring; a support arm portion for supporting the fixation portion of the first leaf spring in a state where the positional relation with the first cylinder is fixed; a washer for adjusting the movable mass mp of a piston assembly; and an attachment portion that is disposed on the connection body 13 and to which the washer is attached, and the attachment portion is disposed in such position as to enable the washer to be attached while the piston assembly is assembled, thereby reducing disassembly and reassembly processes and allowing easy manufacturing.

A new thermal engine design and novel hot air inlet provide a high-efficiency hot-gas free-piston Stirling engine design.