Free Piston Engine Generator

Abstract

A free-piston engine generator comprising an engine cylinder, a piston configured to move within the cylinder, a cylinder housing having a bore for receiving the engine cylinder and a plurality of magnetisable elements arranged within the cylinder housing to be adjacent the cylinder along at least a portion of its length.

1 .- 30 . (canceled) 
     
     
         31 . A method of manufacturing an engine, comprising providing a cylinder configured to accommodate at least one piston that is free to reciprocate within the cylinder, extruding a cylinder housing that is arranged to retain and provide structural support for the cylinder, and securing the cylinder within the cylinder housing such that the cylinder wall is reinforced by the structure of the cylinder housing. 
     
     
         32 . The method of  claim 31 , further comprising arranging the one or more magnetisable elements to provide load-bearing support to the cylinder. 
     
     
         33 . The method of  claim 31 , further comprising securing the cylinder within the cylinder housing an adhesive material on the outside of the cylinder, wherein the adhesive material provides thermal insulation between the cylinder and cylinder housing. 
     
     
         34 . The method of  claim 31 , further comprising providing the cylinder housing with cooling means for cooling the cylinder. 
     
     
         35 . The method of  claim 31 , further comprising coating the interior wall of the cylinder with friction-reducing material between the interior wall and a piston passing along it. 
     
     
         36 . The method of  claim 31 , further comprising reducing the thickness of the cylinder wall to a thickness that is less than 5% of the cylinder's internal diameter. 
     
     
         37 . The method of  claim 36 , further comprising limiting the thickness of the cylinder wall to less than about 2 mm. 
     
     
         38 . The method of  claim 31 , further comprising constructing the piston using alternating magnetisable elements and non-magnetisable spacer elements. 
     
     
         39 . The method of  claim 31 , further comprising providing one or more recesses in the cylinder housing that permit a plurality of magnetisable elements to be positioned adjacent the cylinder.