US 4,199,945 A · Method and device for balanced compounding of Stirling cycle machines

Abstract

A multi-cycle thermal reciprocating machine of the type commonly known as Stirling engine, which operates on a closed cycle with a compressible fluid as the operational medium. Double-acting pistons are combined into reciprocating members, each of which is in contact with the operational medium of at least four different Stirling cycles. These cycles occur simultaneously and are symmetrically phased, each performed in at least two different expansible chambers at two different temperatures, typically one hot expansion chamber connected to a cold compression chamber through a conduit containing two heat exchangers and one regenerator. The piston surfaces are arranged in opposed pairs, two pairs of surfaces being maintained at a constant distance apart and so located that the movement of each reciprocating member is caused by one co-acting pair of expansion chambers being part of one pair of thermodynamic cycles in phase opposition to each other, and a second co-acting pair of compression chambers being part of a second pair of cycles also in phase opposition to each other, and in a quadrature relationship with the first pair of cycles. Each cycle is effected by two reciprocating members in such a manner that the compression forces of one cycle are internally balanced by the expansion forces of another cycle, so that in consequence there is a smooth flow of power and the forces transmitted are reduced. The resulting Stirling engines are flexible in design and versatile in application.

Claims16

Dependent claims

In a method of operating a Stirling cycle machine incorporating a plurality of Stirling thermodynamic cycles each of which comprises the steps of successively expanding, cooling, compressing and heating a compressible operational medium, wherein each thermodynamic cycle is performed in an expansible compression space maintained at a first temperature and at least one interconnected expansible expansion space maintained at a different temperature, the improvement comprising:

arranging said spaces in a plurality of generally coaxial pairs separated by a double-acting reciprocating piston having two opposed surfaces, the first of which defines in part a first expansible space associated with one thermodynamic cycle and the second of which defines in part a second expansible space associated with a different thermodynamic cycle,
the volume of said second space varying inversely with the volume of said first space,
said pistons being arranged to form at least two reciprocable piston assemblies, each comprising at least two axially rigidly interconnected pistons, whereby reciprocating movement of each said assembly produces simultaneous variations in the volumes of at least four expansible spaces,
exposing one surface of a first opposed pair of piston surfaces in an assembly to the time-variable pressure in the compression space of a first thermodynamic cycle, and
exposing the second surface of said pair to the time-variable pressure in the compression space of a second thermodynamic cycle in phase opposition to said first cycle, whereby the forces exerted on said surfaces by said pressures are combined to produce a fluctuating output force acting along a straight line which is stationary in space.

2 more elements

A Stirling cycle machine comprising in combination:

one or more cylinders each having means defining in part a plurality of internal chambers for the containment of a compressible operational medium;
at least two reciprocating members each comprising at least one pair of rigidly interconnected double-acting pistons, mounted for reciprocating movement within said chambers along a straight line which is fixed in space between a first position spaced a substantial distance from one end of said cylinders and a second position more closely adjacent to said end, each of said reciprocating members defining in part at least four expansible subchambers within said chambers, including
a first upright subchamber,
a first inverted subchamber,
a second upright subchamber, and
a second inverted subchamber,
where the orientation of said subchambers is defined such that an upright subchamber has a maximum volume for said first position and a minimum volume for said second position, and an inverted subchamber has a minimum volume for said first position and a maximum volume for said second position;
means for maintaining said first upright and inverted subchambers at a first temperature,
means for maintaining said second upright and inverted subchambers at a second temperature;
a plurality of conduit means for fluid flow interconnecting said subchambers to form thermodynamic systems for the performance of a plurality of Stirling cycles therein, said conduit means including an interconnection between each first subchamber and a second subchamber,
said interconnected subchambers being defined in part by different reciprocating members;
and
heat exchange means for exchanging heat between said operational medium and external sources and sinks of heat.

10 more elements

Dependencies are inferred from the claim text.

Method and device for balanced compounding of Stirling cycle machines

Life of this patent

Method and device for balanced compounding of Stirling cycle machines

Life of this patent

Abstract

Claims16