Microgen Engine Corp., based in Peterborough, UK, has developed a piston-free Stirling Engine for its “microCHP” (Combined Heat and Power) appliance which incorporates inner stators made from Somaloy soft magnetic composite powder produced by Höganäs AB, Sweden.
The microCHP appliance produces 1kW of electrical power which can be used to run household appliances as well as providing heating and hot water.
Unlike most Stirling engines which are kinetic with a crankshaft and rotary motion, the Microgen Engine version has a piston-free linear motion, and thus is not subject to wear and needs no lubrication.
The first piston-free Stirling engines have been incorporated into wall mounted, high efficiency boilers for domestic heating.
By using Somaloy powder in its stator, Microgen was able to improve the production of its Stirling Engine significantly. If laminated steel would have been used for the stator it would have required the production of a laminated stack of 500 sheets with very fine dimensional limits. The Somaloy stator required the compaction of only one part.
The operation of the microCHP appliance can be seen on the company’s website