Roots blowers
Roots compressors, Roots type supercharger, Positive displacement lobe pump The Roots type supercharger or Roots blower is a positive displacement lobe pump which operates by pumping a fluid with a pair of meshing lobes not unlike a set of stretched gears. Fluid is trapped in pockets surrounding the lobes and carried from the intake side to the exhaust. It is frequently used as a supercharger in engines, where it is driven directly from the engine's crankshaft via a belt or, in a two-stroke diesel engine, by spur gears.
It is named for the American inventors and brothers Philander and Francis Marion Roots, founders of the Roots Blower Company, Connersville, Indiana, who first patented the basic design in 1860 as an air pump for use in blast furnaces and other industrial applications. In 1900, Gottlieb Daimler included a Roots-style supercharger in a patented engine design, making the Roots-type supercharger the oldest of the various designs now available. Roots blowers are commonly referred to as air blowers or PD (positive displacement) blowers,[1] and can be commonly called "huffers" when used with the gasoline-burning engines in hot rod customized cars.[