MM14 - The LEHMANN engine (small version)

Technical details
Year of construction 2001
Power piston stroke 10 mm
  diameter 10 mm
Displacer piston stroke 15 mm
  diameter 11 mm
Flywheel  diameter 43,5 mm
  material brass
Idle speed 550 rpm
Energy source alcohol
Mass 170g 


In the yahoo-group "Stirlingmotor" a question concerning the  Lehmann engine appeared. Quickly somebody found an animated gif of this engine. The original engine as well as a model of it can be viewed in the "Deutsches Museum" in Munich, and a build instruction can be found in the book "Hei▀luftmotoren VI" (Neckar-Verlag Villingen-Schwenningen; 2000 ISBN: 3-7883-0667-x) by Udo Mannek. I intended to build a smaller and transparent model. By using glass and acrylic material it is even possible to cool the engine with water. However, the water level should not reach the crankshaft bearing. Short trial runnings are possible without cooling water.