A Brief History of the Stirling Engine

1600 to the present

As far back as at least the 1600's there had been various kinds of hot-air engines, but they were not developed to the point of really being useful as a general purpose engine.

In the early 1800's steel had not been invented yet, but the steam engine had. The iron of the day was not really up to the job and as a result boilers would rupture often killing anyone working nearby.

Concerned about the number of deaths from steam engines, Dr. Rev. Robert Stirling, a minister of the church of Scotland and an inventor, had been experimenting with hot air engines and in 1816 he patented the first practical hot air engine with a new feature he called an "economizer", known today as a "regenerator". His first engines were put to such uses as pumping out a rock quarry and powering equipment in his work shop.

In the mid 1800's good steel was invented and so the steam engines became both safer and more powerful, and so tended to over shadow the hot air engine.

In the early or mid 1900's the term "Stirling engine" was coined and came into common use.

In the U.S.A. Capt. John Ericsson, famous for the USS Monitor, was a hot air engine enthusiast and in 1826 got his first patent related to hot air engines. He designed a series of the same engine scaled to different sizes for pumping domestic water. They ranged in bore size from 5" to 12".

Some where between 1842 and 1890 an improved version of these engines started being manufactured by the De Lamater Iron Works, est. 1842 in New York city. This company was brought out by a competitor, the Rider Engine Co., est. 1870, which became the Rider-Ericsson Engine Co. around 1906 or before. This consolidated the entire Stirling engine industry in the U.S.A..

Today the Stirling engine is being reinvented and is about to become a prominent fixture in electrical power generation as well as in refrigeration. They have been sent into space as components of space craft, are in use in Swedish submarines as the main propulsion engines, and are now being used to build the first major solar electric project in the world, this in Southern CA. In years to come they will probably be used in hybrid cars instead of the IC engine.

Modern Stirling engines tend to be sealed high pressure units which allows them to obtain both a high power to weight ratio and a reasonably high efficiency. Probably the most interesting of the new designs is the Quasi-turbine version, which holds the promise of another dramatic improvement in the power to weight ratio. These will likely be a critical factor in the colonizing of mars.

Terry Mackintosh
Many sources on the web, some of which I've lost track of, as well as reprints of old catalogs were used as the basis for this paper.