generator unit
Device with a turbine that transmits the water’s mechanical energy to the generator’s rotor to make it turn to produce electricity.
bottom ring 
Circular part under the wicket gates that holds them in place.
generator 
Machine that consists of a rotor and a stator; it produces an electric current.
runner blade 
Stationary curved plate on the turbine’s runner; it receives the thrust of the water to turn the runner.
runner 
Movable part of the turbine that transmits the movement of the water to the shaft to which it is attached to turn the rotor.
draft tube 
Conduit at the base of the turbine that increases the runner’s output by reducing the pressure of the water as it exits.
draft tube liner 
Covering that is usually made of steel; it protects the draft tube from erosion.
spiral case 
Duct shaped like a spiral staircase that is used to distribute water uniformly around the turbine to make it turn smoothly.
turbine headcover 
Structure that covers the upper part of the turbine’s runner.
stator 
Stationary part of the generator that consists of a coil of copper conductors, which collects the electric current produced by the rotor.
gate operating ring 
Movable device that controls the opening and closing of the wicket gates.
thrust bearing 
Unit that bears the thrust of the turbine and the weight of the rotating parts of the generator unit.
exciter 
Device that supplies electric current to the rotor’s electromagnets.
rotor 
Movable part of the generator that is made up of electromagnets; its rotation induces an electric current in the stator.
stay vane blade 
Fixed panel that receives pressurized water from the spiral case and directs it over the wicket gates.
wicket gate 
Movable panel that regulates the flow of water entering the turbine to ensure a constant rotational speed of the runner.
stay ring 
Set of two rings linked together by the stay vanes.
shaft 
Cylindrical part that communicates the movement of the turbine’s runner to the generator’s rotor.
hydraulic turbine 
Machine whose runner is powered by water; it transmits mechanical energy to the rotor to make it turn.