Abstract: An improved dividing assembly, useful in dividing the high pressure gas system from the lubricating system in a regenerative type Stirling engine, is disclosed. The closed thermally cycled gas system of a Stirling engine may vary between 20-200 atmospheres which complicates sealing and separation problems between fluid systems in the engine. One interface between said fluid occurs at the piston rods which reciprocate between an oil flushed environment within the driven assembly and the pure high pressure gas environment of the thermal cycling assembling. The two systems must be separated and yet allow access of each system to said rods. A piston rod sealing assembly is employed which uses a bleed of high pressure gas to (a) assist in forcing a tighter wiping of the piston rod surfaces, and (b) to convey wiped oil as a mixture away from the sealing assembly. A separator assembly is employed to reclaim substantially pure gas from said mixture and return separated oil to the oil system.

Abstract: A closed working fluid system for a regenerative Stirling engine is disclosed. The system employs double-acting pistons arranged with each low temperature (compression) space connected to one hot (expansion) space of an adjacent piston. The low temperature spaces are all connected to a reservoir system employing two separate chambers, one at a high pressure and another at a relatively low pressure. Control means select the reservoir for communication with the working system depending on the torque demand of the engine; the control means also permits fluid flow to pass from any one low temperature space to the selected reservoir when the pressure condition in the low temperature space exceeds the associated reservoir pressure.