Idraulico

Idraulicadescrive un metodo di attuazione del freno che utilizza un fluido pressurizzato e incomprimibile (tipicamente olio) per trasmettere e amplificare la forza, basato sul principio di Pascal. Nei freni industriali, questo metodo è impiegato in due modi fondamentalmente diversi, definendo lo scopo operativo del freno:

1. Hydraulic-Applied (Active Braking): In this configuration, the brake is disengaged by default. To apply the brake, a hydraulic power unit (HPU) or a manual pump generates fluid pressure, which is transmitted through hoses to a caliper or actuator. This pressure drives pistons that clamp friction pads onto a disc, creating braking torque. This system is used for dynamic or service braking, where controlled stopping is required by an active command from an operator or control system. It is common on large wind turbines, rolling mills, and mobile equipment.
2. Hydraulic-Released (Fail-Safe Braking): This is the most common configuration for safety-critical holding applications. The brake is spring-applied by default, with powerful mechanical springs providing the clamping force. The hydraulic system’s role is to rilascio the brake. The HPU generates pressure to work contro the springs, retracting the pistons and allowing the shaft to rotate. If hydraulic pressure is lost for any reason (e.g., power failure to the HPU, a broken hose), the spring force is unopposed and instantly engages the brake. This fail-safe principle is essential for holding brakes on mine hoists, large inclined conveyors, and drawworks. A self-contained electro-hydraulic thruster is a specific, integrated device that perfectly embodies this principle for drum and disc brakes.

I principali vantaggi dell'attuazione idraulica sono la capacità di generare forze estremamente elevate in uno spazio compatto e di trasmettere quella forza in modo affidabile su distanze, rendendolo la soluzione preferita per le applicazioni di frenatura industriale ad alta coppia più esigenti.