Stirling cycle machine

A rocking beam drive mechanism for a machine comprising:

• a rocking beam having a fixed rocker pivot;
• a crankshaft;
• a connecting rod coupling the crankshaft to the rocking beam, whereby an oscillatory motion of the rocking beam is converted to rotary motion of the crankshaft;
• at least one cylinder;
• at least one piston, the at least one piston housed within the at least one cylinder respectively whereby the at least one piston is capable of substantially linearly reciprocating within the at least one cylinder;
• at least one piston rod having a proximal end and a distal end, the proximal end being connected to the at least one piston and the distal end being connected to the rocking beam by a coupling assembly, whereby linear motion of the at least one piston is converted to the oscillatory motion of the rocking beam;
• a working space housing the at least one cylinder and the at least one piston;
• a crankcase housing the rocking beam, the crankshaft, the connecting rod, and the coupling assembly and the crankcase being filled with a crankcase gas;
• an airlock located between the crankcase and the working space, the airlock being in fluid communication with the working space, the airlock being filled with a working gas, and the airlock housing a portion of the at least one piston rod between the proximal end and the distal end of the at least one piston rod;
• a dynamic seal between the airlock and the crankcase, the dynamic seal sealably connected to the portion of the at least one piston rod, the dynamic seal sealing the working gas in the airlock from the crankcase gas, and the dynamic seal being a rolling diaphragm comprising non-woven fabric;
• and
• an airlock pressure regulator fluidically coupled to the crankcase and to the airlock, the airlock pressure regulator being configured to transfer the crankcase gas and/or the working gas in the airlock between the crankcase and the airlock, wherein the working gas in the airlock is at a first pressure and the crankcase gas is at a second pressure.