Wind Turbine Rotor Blade Locking Pin Mechanism
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Solution Overview
Problem
Existing wind turbine maintenance procedures lack a reliable and effective means to securely fix rotor blades in any desired position, posing risks to maintenance personnel due to the inability to positively lock the blades during maintenance, especially when the drive motor brake is engaged.
Innovation Solution
A locking device with a rotatably mounted locking pin that engages with external teeth on the gear shaft, featuring an eccentric end section allowing it to lock between teeth, and a spring-pretensioned mechanism to prevent unintentional locking, facilitated by a tool for precise operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the drive motor brake is used to fix the rotor blade position, then the blade can be held stationary, but the position is not fixed positively and maintenance work on the brake is not possible
Solution Approach 1:
The locking pin serves as an intermediary mechanism between the drive shaft and the locking requirement. It engages with the external toothing of the drive shaft to provide positive mechanical locking, independent of the brake system. This allows maintenance personnel to work on the brake without concern for blade position stability, as the locking pin provides redundant secure fixation.
2Reliability
If a locking mechanism is added to achieve positive fixation, then position reliability improves, but device complexity increases
Solution Approach 1:
The locking pin is designed as a separate, modular component that can be independently installed and removed. It features an eccentric end section that segments the locking function into a simple rotational engagement mechanism. This segmentation allows the locking function to be added without complicating the existing brake and pitch adjustment systems, maintaining overall system simplicity while achieving reliable positive fixation.
Solution Approach 2:
The eccentric end section of the locking pin automatically engages with the external toothing through its own rotational movement. When the locking pin is inserted and rotated, the eccentric geometry self-generates the locking action by forcing the free end into the tooth spaces. This self-service mechanism eliminates the need for additional actuators, springs, or complex engagement systems, keeping the device simple while achieving reliable locking.
3Force
If the locking pin free end hits a tooth directly, then locking is achieved, but the high brake moment cannot be overcome
Solution Approach 1:
The locking pin is rotatably mounted rather than being rigidly fixed, allowing it to dynamically adjust its orientation during engagement. When the free end of the eccentric section contacts a tooth, the rotatable mounting enables the locking pin to rotate and follow the tooth profile, forcing the free end into the space between teeth. This dynamic adaptation allows the locking mechanism to overcome high brake moments by progressively engaging with the toothing rather than relying on a single static contact point.
Solution Approach 2:
The eccentric end section creates an asymmetric geometry where the free end is offset from the longitudinal axis of the locking pin. This asymmetry ensures that during rotational engagement, the free end does not contact the tooth tip directly but instead rides along the tooth flank and settles into the tooth space. The asymmetric design distributes the locking force more effectively, enabling the mechanism to overcome high brake moments while maintaining ease of operation through natural rotational guidance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables reliable locking of rotor blades in any position, overcoming braking torque and ensuring safe maintenance by preventing unintentional locking, allowing for single-tool operation and clear indication of locked status.
Implementation Method 1
The locking pin is pretensioned in its unlocked position by a spring element
Data Source
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AI summary
Device for locking a rotor blade of a wind turbine, which has an adjustment device for the blade pitch angle of the rotor blade, wherein the adjustment device has a drive comprising a motor and a gearbox with a drive shaft carrying external teeth, characterized by - a locking pin rotatably mounted about its longitudinal axis, which engages in the external teeth in a locked position and releases the external teeth in a non-locked position, - wherein the locking pin has an end section whose free end is eccentric to the longitudinal axis of the locking pin.