STM Corporation (previously Stirling Thermal Motors, Inc., STM Power Corp now defunct) developed this engine to answer the automotive industry's needs for the Hybrid Electric Vehicle Aux. Power Unit. STM was developing this Stirling engine as part of the General Motors HEV Propulsion Systems program. A new company Stirling Biopower has acquired assets and employees of STM Power and plans an announcement and new web site soon. At right the 40kw Stirling HEV APU from STM. The picture that introduces this page is the SAIC/STM Solar dish/Stirling System operating on sun producing about 25 kW of electric power at a light to power efficiency of almost 30 percent. STM appears to be assigned most of the Patents from Phillips (Einhoven, NL) and as recently as March 1997 received a U.S. Patent 5611201 covering the "Double-acting, Parallel-cylinder, Variable-swashplate engine and the methods of manufacture. Click here to see the patent from the IBM archives
Stirling Thermal Motors was founded by Dr. R.J. Meijer (now retired), holder of numerous patents on the
Stirling engine and inventor of the 'Rhombic Drive'. Mr. William Houtman listed as the inventor in
Patent 5611201 is the Chief Engineer for STM. Lennart N. Johannson is the current President.