A geared turbine is an axial-flow steam engine attached to a set of reduction gears. It has been used to power freight and military ships since the beginning of the 20th century. It was invented by Charles Parsons, who designed the first steam turbine with speed reducing gears in 1896. It was a small 10-HP geared steam turbine that drove a small, 22-foot-long boat on an experimental basis. The gear reduction he had conceived was 14 to 1, with the prop running at 1,400 rmp. Although the speed of the boat was only 9 mph, the performance was good as it encouraged him to keep working on the project.
Charles Parsons would design a double helical gear in 1909, with a speed reduction ratio of 19 to 9, to drive a single prop with a high-pressure (HP) turbine driving one side of the large central gear and a low-pressure (LP) turbine propelling the other side of the gear. This gear was connected to a steam engine on a cargo vessel. The steam that drove the turbine was produced by coal-fired or oil-fired boilers. This type of steam turbine would also be used for power generation as it would be attached to an AC generator.
Charles Parsons had found out that steam turbine could be made smaller but capable of rotating at much higher rpm if a speed reducing gear could successfully be made. He was able to design and produce one. Thus, the geared steam turbine would be used as the propulsion systems of both merchant and warships, especially to power battleships and aircraft carriers in the first half of the 20th century.
Below, a steam turbine, which used a set of reduction gears, on an open museum.
0 Comments