Before revision: Constant speed drive for Boeing 727, made by Sundstrand Corporation A constant speed drive (CSD) is a type of transmission that takes an input shaft rotating at a wide range of speeds, delivering this power to an output shaft that rotates at a constant speed, despite the varying input.
After revision: also known as a constant speed generator,Constant speed drive for Boeing 727, made by Sundstrand Corporation A constant speed drive (CSD) is a type of transmission that takes an input shaft rotating at a wide range of speeds, delivering this power to an output shaft that rotates at a constant speed, despite the varying input.