| has gloss | eng: Contra-rotating, also referred to as coaxial contra-rotating, is a technique whereby propellers or fan blades mounted on a common axle rotate in opposite directions. It is used in aircraft engines, resulting in the maximum power of a single piston or turboprop engine to drive two propellers in opposite rotation. Contra-rotating propellers are also common in some marine transmission systems, in particular for large speed boats with planing hulls. Two propellers are arranged one behind the other, and power is transferred from the engine via planetary gear transmission. The configuration can also be used in helicopter designs, where similar issues and principles of torque apply. |
