Vertical Turbine Generator Brake

Summary;
     The vertical water turbine generator brake is an important safety device used to quickly and smoothly stop the rotating part (rotor) during the shutdown process of the water turbine generator unit.
     It is usually hydraulic or mechanical and installed on the lower frame of the generator, directly acting on the rotor brake ring. It is mainly used in vertical water turbine generator sets with sliding bearings above 1MVA.  
     Application scope: Mainly used in vertical hydroelectric generators with sliding bearing structures to achieve controlled deceleration during shutdown and prevent friction damage to thrust bearings at extremely low speeds.
     Composition structure: commonly known as piston type hydraulic brake, mainly including brake seat (base and cylinder), piston, brake block (friction material), and travel switch.
     Working principle: Using hydraulic oil to drive the piston, pushing the brake pad to press against the rotating brake ring, and generating braking torque through friction.
     Type: Divided into hydraulic and manual mechanical (less commonly used, usually manual backup).
Main functions
    1. Quick shutdown: Reduce shutdown time, speed up the restart of the unit after maintenance, or quickly stop the rotor in emergency situations.
    2. Protection of thrust bearings: When the generator speed is below 20% -30% of the rated speed, the brake is activated to prevent the rotor from generating dry friction due to the absence of oil film at low speeds, thereby protecting the thrust bearing bushings.
    3. Prevent low-speed crawling: Prevent reverse rotation caused by turbine leakage after stopping.  
    Brake seat: installed on the frame.
    Piston: Pushing after oil pressure enters.
    Brake pad: friction material, directly in contact with the brake ring.
    Brake ring: installed on the lower end face of the rotor center body.