A turboshaft is a type of engine that is built to provide the maximum amount of shaft power; in contrast, other types of engines are often built to produce thrust. Turboshaft engines are used for applications such as helicopters and hovercrafts that require stability and reliability rather than raw power. Because they are lighter and smaller than other types of engines, turboshafts are useful for stationary equipment.
The first turboshaft engine was built in the late 1940s. It was designed by a company from France and was called the 100shp 782. An engineer, Joseph Szydlowski, was the leader of the operation. The company later went on to design an upgraded model, which was used in a number of helicopters of the time. Since then this type of engine has been integral to the development in a number of different forms of vehicle.
A turboshaft engine is, in general, quite similar to a turbojet engine. The main difference is that a turboshaft utilizes another turbine that is used to take heat and turn it into energy that is used for the shaft. Other than that, the function and construction is very similar to other engines used for different purposes.
The main section of the engine is called the gas generator. This contains a number of important parts including combustion chambers, compressor and various other components. The generator's goal is to create hot gases that can be used to drive other parts of the engine — namely the turbines in the power section. Accessories of the engine may also be powered by hot gas from the generator although this varies depending on design.
There are several different types of turboshaft engines, which are named according to where the gas generator is placed in relation to the power section. The most common is the free power turbine. This is built so that the generator and power section are separated in design so that they are free to rotate independently of one another. These types of engine are most commonly used in vehicles.
Aside from the location of the gas and power sections, the turboshaft is designed to be similar in layout to a turboprop. The primary difference is that while a turboprop is designed to drive a propeller instead of a transmission. In reality, this is only a minor difference and hence many engines actually come in both turbo shaft and prop versions.