An apparatus for a self-centering plunger for a hydraulic yaw brake having improved load distribution and ability to accommodate system forces, torques, stresses, etc. is disclosed. A lower section of the self-centering hydraulic plunger has a reduced diameter and does not include a bottom collar, which minimizes torque transfer from a brake piston. A brake piston seat washer is thicker, more robust and has increased surface area to better distribute the load onto the brake piston. The geometry of the piston seat washer also minimizes the torque transferred from the brake piston to the self-centering hydraulic plunger. A friction sleeve assembly improves load distribution at a plunger-housing interface by improving sliding contact surface area.

A wind turbine system includes: a ring gear; a yaw drive unit including a pinion gear meshing with the ring gear, the yaw drive unit being configured to rotate the pinion gear; a yaw brake unit configured to generate a braking force for inhibiting rotation of the ring gear; a load information acquiring unit configured to acquire an external load applied to the ring gear; and a control unit configured to release the braking force of the yaw brake unit when a rotational torque generated on the ring gear by the yaw drive unit has been larger than the external load acquired by the load information acquiring unit, in switching the ring gear from a stationary state to a rotating state.

Embodiments herein describe validating an emergency stop signal before activating a brake within a wind turbine. The emergency stop signal is received from a control node of a plurality of control nodes distributed throughout the wind turbine, and the emergency stop signal indicates that the wind turbine should be shut down. The wind turbine is shut down by transmitting a shutdown signal to the plurality of control nodes. Upon determining there is no indication a person is present within the wind turbine, the emergency stop signal is validated. Additionally, upon determining the emergency stop signal is valid, a brake within the wind turbine is activated to bring the rotor to a stop.

A gliding yaw bearing system (20) for use in a wind turbine comprising a first bearing assembly configured for being attached to a tower (2) of the wind turbine, a second bearing assembly configured for being attached to a nacelle (4) of the wind turbine, an upwind section of the second bearing assembly is different from a downwind section of the second bearing assembly. Wind turbines, specifically direct drive wind turbines, comprising gliding yaw bearings are also disclosed.

The present disclosure is directed to a method for responding to a friction coefficient signal of a pitch bearing of a pitch drive mechanism of a wind turbine and/or for controlling the pitch drive mechanism(s) and/or a bank of ultracapacitors. The method and system include: accessing high-frequency measurement data of the at least one pitch bearing; estimating, via a torque balance model implemented by a controller, a frictional torque of the at least one pitch bearing based, at least in part, on the high-frequency measurement data; estimating, via the controller, a friction coefficient signal of the at least one pitch bearing based, at least in part, on the frictional torque; comparing the friction coefficient signal with a friction threshold; determining whether the friction coefficient signal deviates from the friction threshold based, at least in part, on the comparison; and, if so, acting.

A system includes a wind turbine having a fixed part and a rotational part and a brake having a brake disk mounted to the rotational part for rotation with the rotational part. At least one brake block is fixed relative to the fixed part and has a friction surface facing the brake disk. The brake block is shiftable between a first position with the friction surface spaced from the brake disk and a second position with the friction surface in contact with and pressed against the brake disk, and the friction surface and/or the brake disk are configured such that pressing the at least one brake block against the brake disk creates a micro-interference fit between the at least one brake block and the brake disk.

A system and method for monitoring and maintaining loading of a yaw brake assembly for use with windmills. A bolt assembly attaches to the yaw brake assembly and provides a compressive load to a brake piston within the yaw brake assembly. A load indicator attached to the bolt assembly provides a measurement of load applied to the brake piston by the bolt assembly.

The invention relates to a method for controlling a wind turbine system, more particular for a controlled sliding strategy to lower loads on the yaw system by controlling mechanical brakes and motor brakes in the yaw drive actuators. When the yaw system being in the non-yawing operational state, and the mechanical brake(s) being in an engaged state, and the yaw controller determines or receives a signal indicative of a yaw moment, and if the signal indicative of a yaw moment is above a signal threshold, then the yaw controller sends a braking signal to the yaw drive actuators to enter the motors into the brake state to apply a braking torque.

Direct-drive wind turbines (160) are disclosed. The wind turbine comprise a generator (3) mounted on a frame (1), the generator (3) comprising a generator stator (32) and a generator rotor (31) configured to rotate about a rotation axis (RA), the frame (1) has a protruding portion (11) extending beyond the generator (3), the protruding portion (11) comprising a first structure and a second structure; wherein the first and second structures are configured to rotate relative to each other and about the rotation axis (RA); wherein the first structure is attached to the generator stator (32) and the second structure is attached to the generator rotor (31); a brake system (2) attached to the first and second structures, the brake system (2) being spaced away from the generator (3) along the rotation axis (RA). Also disclosed are methods (200) for braking a direct-drive wind turbine (160).

A method is provided for braking a rotor of a wind turbine. The rotor comprises rotor blades. The wind turbine comprises a pitch adjustment system for adjusting a pitch of the rotor blades. The method comprises detecting a system failure of the pitch adjustment system, estimating a current wind speed, estimating an available brake torque and estimating a required brake torque, based on the estimated current wind speed. The method further comprises determining a suitable point in time for activating a rotor brake, based on the estimated available brake torque and the estimated required brake torque. The rotor brake is then activated at the determined suitable point in time.