Abstract: The present invention relates to a resonant piston compressor in which a double-sided piston reciprocates within a cylinder and defines a valved compression space on one side of the piston and a balance chamber on its other side. The invention further includes a movable head adjustable between first and second positions to effect a large change in the total volume of the balance chamber between the two positions. In one position, of the movable head an extended balance chamber volume is coupled to the balanced chamber while in the other position of the movable head, the extended balance chamber volume is decoupled from the balance chamber.

Abstract: An electrodynamic motor having a flat plunger core arrangement formed out of alternating layers of magnetic and insulating strips clamped together and maintained on respective bearing sleeves which reciprocate on guide members with the gap between stator members.

Abstract: A free-piston reciprocating compressor includes a reciprocating piston disposed within a cylinder such that one end of the piston-cylinder provides for a compression space and the other end of the piston-cylinder provides for a balancing space. The piston is coupled to and reciprocatingly driven by the armature of a linear electrodynamic motor, which armature reciprocates on guide means. The compressor also includes porting means operative to establish a stabilizing gradient sufficient to keep the piston operating at a related fixed mid-stroke position. The motor armature is also coupled to a centering-resonance spring.

Abstract: In a resonant piston compressor utilizing a balance chamber to provide a gas spring effect for use in a heat pump arrangement and the like, an adjustable balance cylinder head which adjusts so as to increase or decrease the balance chamber volume so as to increase or decrease the stiffness of the balance chamber, depending upon the mode of operation desired.

Abstract: A resonant reciprocating compressor wherein a reciprocating assembly comprising the movable armature of an electric reciprocating motor and a piston means coupled to the armature is driven cyclically when the electric motor is energized from an alternating current source to compress a working fluid, and including means operatively associated with the reciprocating assembly for producing a stabilizing force gradient in a direction to maintain or restore the reciprocating assembly to a centered operating position.

Abstract: A method and apparatus for controlling a resonant piston compressor of the type comprising an electrodynamic linear reciprocating motor adapted to be driven cyclically by an alternating current power source and having at least one piston coupled to and adapted to be driven within a selectively valved working cylinder by the linear reciprocating motor in synchronism with the frequency of the alternating current power source. Enclosed volumes of gas act as resilient gas springs coacting with the piston and with the linear reciprocating motor to form a mechanical resonant system having a resonant frequency substantially centered on the frequency of the alternating current power source. A midstroke porting arrangement is responsive to the position of the resonant piston for selectively communicating a gas spring control valve with said gas springs.