Patent ID: 7494193

Claim:
A wind energy plant with a hydraulically actuated rotor brake for a drive train, which has at least one hydraulically actuated brake cylinder ( 38 ), a braking moment of which gets stronger when hydraulic pressure increases, comprising: a first pressure reducing valve ( 20 ) which reduces an applied system pressure (p S ) to a brake pressure (p B ); a second pressure reducing valve ( 22 ) which reduces the system pressure (p S ) to a holding pressure (p H ); an accumulator ( 28 ) with hydraulic fluid which is connected to a first pressure line ( 24 ), the first pressure line ( 24 ) connecting the first pressure reducing valve ( 20 ) with the brake cylinder ( 38 ); a second pressure line ( 30 ); the first and second pressure lines ( 24 , 30 ) departing from the first and second pressure reducing valves ( 20 , 22 ) being alternatively connectable to a pressure line ( 36 ) to the brake cylinder ( 38 ) via a switchover valve ( 34 ).