Steam engine Polzunov's steam engine

Polzunov's machine was the world's first two-cylinder engine with the cylinders working on one common shaft, which allowed the engine to operate without any use of hydraulic power.

This was a huge step forward compared to the steam engines that existed at the time, which could not operate without an auxiliary hydraulic drive.

However, it was still a steam-atmospheric engine, that is, steam was used only to create a vacuum when it condensed in the cylinder, and the piston did useful work, descending under the action of atmospheric pressure.

Catherine II was informed of Polzunov's project, she awarded him 400 rubles and promoted him to captain-lieutenant.

In 1764–1766 Polzunov designed a new steam engine to drive blast in smelting furnaces. The engine had a record power of 32 hp for its time and for the first time made it possible to abandon water wheels in real factory production.

Polzunov died a week before the test run of the machine. It was tested by the master's students, paid for itself and even managed to make a profit. However, due to a breakdown after three months of operation, it was disassembled and replaced with a conventional hydraulic drive.

The operation of modern multi-cylinder engines is based on the principle used by Polzunov: the action of several cylinders on one shaft.