US Patent 9828940 Stirling cycle machine

A rod seal assembly. The rod seal assembly includes a housing between two spaces configured to receive a reciprocating rod, the reciprocating rod disposed within a first space and a second space, a floating bushing configured to move axially and radially within the housing and disposed coaxially around the reciprocating rod, a rod seal configured to seal the outside diameter of the reciprocating rod relative to an inside surface of the floating bushing, and at least one stationary bushing fixed within the housing that may form a seal with the floating bushing to the axial flow of fluid in the presence of a pressure difference between the two spaces.