Hydraulic brake device for a wind turbine

A method for braking a shaft (4) of a wind turbine by way of at least one brake cylinder (2), which upon presence of a hydraulic pressure can be brought from an open position into a braking position, comprising:

• providing a hydraulic actuation device (1) of the wind turbine, the hydraulic actuation device (1) comprising a hydraulic control line (10) that communicates hydraulic fluid from a connection (5) for a hydraulic system circuit (P) of the wind turbine to a connection (6) for the at least one brake cylinder (2) of a brake device of the wind turbine, at least one throttle (13) is arranged in the control line (10), and at least one branch line (14) having a pressure regulating member (15) that is connected in parallel to the at least one throttle (13), wherein the at least one branch line (14) branches off from the control line (10) upstream of the throttle (13) in a pressure build-up direction so as to bypass the throttle (13) and lead back into the control line (10) downstream of the throttle (13), wherein the pressure regulating member (15) is open when the pressure on an output side is low so as to allow the hydraulic fluid to the at least one brake cylinder (2) at a volume that is greater than a volume of the hydraulic fluid that is supplied through the at least one throttle (13), but closes when the pressure at the pressure regulating member (15) on the output side of the pressure regulating member (15) exceeds a preset closing pressure (PS) such that a load limit of the wind turbine is not exceeded while braking a drive train of the wind turbine,
• wherein upon initiating a braking procedure in a presence of low hydraulic pressure (PB) at the brake cylinder (2), a pressure build-up at the brake cylinder (2) occurs in the hydraulic actuation device (1), with a high volume flow of hydraulic fluid, until a closing pressure (PS) is attained, and
• wherein after exceeding the closing pressure (PS), the pressure build-up at the brake cylinder (2) occurs with a lower or throttled volume flow (VL) until attaining a maximum brake pressure (Pmax).