Question

What is the difference between shaft and rotor shaft?

Answer 1

The rotor shaft , more commonly called the "mast" is the vertical sharton which the rotor head and blades are attached.it comes up from the transmission and it is what spins the rotor and supports the entire flight loads of the rotor down into the helicopters structure.
While
A shaft is a rotating machine elements., usually circular in cross section ,which is used to transmit power from one part to another , or from a machine which produces power to a machine which absorbs power.the various members such as pulleys and gears are mounted on it.