Abstract: A clamping apparatus for allowing pre-close-out access to the head of a Stirling machine and facilitating subsequent close-out welding of the head. The head is axially separable into removable and fixed portions, each portion having an end that engages the other. Each portion has an annular flange extending radially outwardly at its engaging end, and each flange has an annular groove. O-rings are seated in the grooves. A temporary sealing ring surrounds and engages the O-rings. Clamping rings, having axially facing end surfaces along their interfacing axial edges, seat against axially opposite sides of the abutting annular flanges. The clamping rings have a plurality of holes spaced annularly around the rings and the holes of one ring are axially aligned with the holes in the other. Fasteners pass through each pair of holes and draw the rings together when tightened, thereby drawing the fixed and removable portions of the head together and securing them against relative axial movement.

Abstract: A Stirling cycle machine heat exchanger and a method for making the heat exchanger including, forming an annular ring of a solid heat conductive mass, the annular ring having a central axis and having axially opposite faces. A plurality of passages are drilled through the annular ring and through the opposite faces to provide passages for the flow of a fluid through the passages and transfer of heat energy between the mass and the fluid. The passages are preferably parallel to the axis and have a circular cross section and are arranged in a plurality of circumferentially spaced sets of passages, each set having a plurality of radially spaced passages.

Abstract: A regenerator having a plurality of involute foils disposed in an annular gap between an inner cylindrical tube and an outer cylindrical tube. The involute shape of the foils provides uniform spacing throughout the entire regenerator and substantial surface area for fluid contact.

Abstract: An apparatus for detecting and reducing excessive amplitude of oscillation of a free piston slidably mounted in a housing. The housing has a vibration absorber, including a mass mounted through a spring to the housing. The mass reciprocates relative to the housing along a path in a phase relationship to the piston. A sensor is mounted near the mass for detecting the amplitude of oscillation of the mass. A controller is connected to the sensor for reducing the amplitude of oscillation of the piston when the amplitude of oscillation of the mass reaches a predetermined maximum.

Abstract: A regenerator having a plurality of involute foils disposed in an annular gap between an inner cylindrical tube and an outer cylindrical tube. The involute shape of the foils provides uniform spacing throughout the entire regenerator and substantial surface area for fluid contact.

Abstract: An apparatus for detecting and reducing excessive amplitude of oscillation of a free piston slidably mounted in a housing. The housing has a vibration absorber, including a mass mounted through a spring to the housing. The mass reciprocates relative to the housing along a path in a phase relationship to the piston. A sensor is mounted near the mass for detecting the amplitude of oscillation of the mass.

Abstract: A vibration-reducing apparatus mounted to a machine that vibrates during operation. The apparatus includes a spring and mass combination tuned to a natural frequency of oscillation substantially equal to the fundamental frequency of the machine's vibration at operating speed. The apparatus also includes at least one additional mass and spring combination tuned to a natural frequency of oscillation substantially equal to another harmonic, such as the second harmonic, frequency of the machine's vibration at operating speed. Thus, the apparatus absorbs the machine's vibration, resulting in a quieter, smoother machine.