Sources
Help build the largest human-edited directory on the web.
Submit a site - Become an editor
Wikipedia. Licensed under the GNU Free Documentation License.
Are you an expert in this subject? Join the discussion and share your knowledge at Wikipedia.org.
Twin-screw type supercharger
From Wikipedia, the free encyclopedia
Note the complex shape of each rotor. The rotors run at high speed and with closely engineered tolerances.
The twin-screw type supercharger is a positive displacement type device that operates by pulling air through a pair of meshing high tolerance screws not dissimilar to a set of worm gears. Twin-screw superchargers are also known as Lysholm superchargers (or compressors).
The intake is located at one end of the two screws, which overlap, but not completely, leaving a small pocket open. As the screws turn the pocket moves towards the exhaust side, pulling air in from the intake. The screws are machined so the pocket gets smaller, compressing the air as it moves through them. The supercharger is typically driven directly from the engine's crankshaft via a belt or cog drive. Unlike the Roots type supercharger, the twin-screw exhibits internal compression. This increases the thermal efficiency of the supercharger beyond that of the more common Roots type superchargers.
The twin-screw supercharger has more performance potential than the Roots or centrifugal type superchargers. High precision CNC manufacturing techniques make the screw type supercharger an equal or better value to other forms of available forced induction. Also due to the internal compression the air exiting the supercharger exhaust "pops", this can lead to a whining, whistling or screaming noise. This has all been eliminated on most all current applications. All supercharger types benefit from the use of an intercooler to reduce heat produced during compression. With the high efficiency and low discharge temperatures of the screw compressor, lower boost application can easily run without the use of an intercooler.
Companies manufacturing twin-screw superchargers include Lysholm, Autorotor, and Warner-Ishi/IHI (Ishikawajima Harima Industries).
The Ford GT, Mercedes-Benz SLR McLaren, Mazda Millenia S, and the Koenigsegg CC8S have Lysholm type superchargers.
This article about an automotive part or component is a stub. You can help Wikipedia by expanding it.