DYNAMICALLY ENGAGING BLADE PITCH LOCK TOOL FOR WIND TURBINE
Publication Date: 2013-Jun-03
The IP.com Prior Art Database
A technique for mechanically braking and locking a wind turbine blade with a hub of a wind turbine is proposed herein. The technique includes a dynamically engaging blade pitch lock tool. The tool includes an assembly of several components, such as, pinion, pin, spline, spline disc, friction plates, and nuts. A technique for mechanically braking and locking a wind turbine blade with a hub of a wind turbine is proposed herein. The technique includes a dynamically engaging blade pitch lock tool. The tool includes an assembly of several components, such as, pinion, pin, spline, spline disc, friction plates, and nuts.
The present invention relates generally to a wind turbine, and more particularly to a blade pitch lock tool for wind turbine.
Generally, rotational speed of a wind turbine is regulated by adjusting pitch angle of turbine blades. In order to reduce wind turbine load or completely stop rotation of the wind turbine blades, the blades are directed to a feathered position where the wind is not engaged with the blade. The blades are forced to stall and rotation of the turbine decreases and/or stops. In such an instance when the turbine is stopped and the blades are put into a parked position, pitch angle of the blades is required to remain constant and does not accidentally change. In case the pitch angle changes, the blades catch the air to start an uncontrolled rotation of the turbine.
During pitch drive replacement or due to failure inside a pitch gearbox, the wind turbine blade acquires an unlocked state. As a result, the blade becomes free to move due to wind. Therefore, the blade is required to be mechanically locked to enable pitch drive replacement. Further, the locking mechanism is required for the blades during maintenance work where events of accidental rotation may cause substantial damages to components and indeed to personnel performing such maintenance on the wind turbine.
Several conventional techniques are known for locking the blade of a wind turbine. A conventional technique includes a device for locking a rotor blade of a wind turbine. The device includes an adjustment system for a blade pitch angle of the rotor blade. The adjustment system has a drive which includes a motor and a gearbox with an input shaft that bears an external toothing. The adjustment system includes a locking pin rotatably mounted around a longitudinal axis. The locking pin engages with the external toothing in a locking position, and releases the external toothing in an unlocked position. Further, the locking pin has an end portion whose free end stands eccentric to the longitudinal axis of the locking pin.
Another conventional technique includes a locking device for locking a turbine blade of a wind power plant at a predetermined pitch angle. Such device for locking the turbine blade includes a mechanical snap-in mechanism. The snap-in mechanism provides a locked position of the blade, thereby, preventing the turbine blade from turning about its longitudinal axis. As a result, the mechanism fixes the turbine blade in a predetermined pitch angle.
However, the above mentioned techniques do not provide a lock in the blade when the blade moves or rotates freely due to wind in an instance the blade is not braked by a pitch motor brake.
It would be desirable to have an efficient and cost effective technique for locking the blade of a wind turbine.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 depicts a cross sectional arrangement of the locking tool assembly as describe in the proposed in...