Hydrogenerator Braking

Wicket gates at the spiral casing assemly are closed to shut off water flow to the turbine.

To avoid friction on thurst bearing, pressurized oil through pours of the thurst bearing slightly lifts up the shaft assembly.

There are several methods for braking a hydrogenerator, depending on the type and size of unit. mountk2 has described a very common method for vertically-mounted units, but that design doesn't work well on horizontal units.

All of the hydro units in my system have integral disc brakes. The rotor is installed on the generator shaft near the turbine coupling. Smaller units (<5MW) have one brake caliper. Larger units may have up to 4 calipers. All use high pressure hydraulics to operate the brake.

One brake caliper is brake with one cylinder?

regards,

Yes. The braking system on my units is very similar to disc brakes found on automobiles. Here's a drawing and explanation of how they work.

The disc is mounted on the generator shaft. The caliper is a 2-piece U-shaped steel frame containing a cylinder and brake pads. It is mounted so the disc passes through the open end of the U. When hydraulic pressure is applied to the cylinder, the piston causes the caliper to squeeze the pads against the disc.