Wind Turbine Main Shaft Removal Using a Downwind Push-Pull System
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Solution Overview
Problem
Current methods for repairing, replacing, or upgrading the main shaft bearing in wind turbines require removing the rotor and main shaft, which is time-consuming and expensive, and there is no viable method for doing so with the bedplate remaining installed or removed from the tower in a horizontal position.
Innovation Solution
A system and method using an assist motive system at the downwind end of the main shaft to facilitate pushing or pulling the main shaft in and out of the bedplate, supported by a rigging system and hydraulic ram assembly, allowing for removal and installation without the need to vertically stand the bedplate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If traditional methods are used to remove the main shaft and bearing assembly, then the bearing can be replaced or repaired, but the turbine head must be removed from atop the nacelle and the bedplate must be stood up vertically, which is very time-consuming and expensive
Solution Approach 1:
Instead of removing the turbine head and standing the bedplate vertically to access the main shaft bearing, the patent inverts the approach by keeping the bedplate horizontal and using a specialized pulling device that can extract the bearing assembly while the bedplate remains in its normal operating position. This reversal of the traditional sequence eliminates the need for complex repositioning operations.
Solution Approach 2:
The patent introduces a pulling device as an intermediary mechanism between the main shaft bearing assembly and the external lifting equipment. This device is specifically designed to engage the bearing assembly and extract it horizontally from the bedplate, serving as a mediator that enables bearing replacement without requiring the bedplate to be repositioned vertically.
2Ease of repair
If traditional methods are used to remove the main shaft and bearing assembly, then the bearing can be replaced or repaired, but the turbine head must be removed from atop the nacelle and the bedplate must be stood up vertically, which is very expensive
Solution Approach 1:
The patent inverts the traditional maintenance approach by maintaining the bedplate in its horizontal operating position throughout the bearing replacement process. This eliminates the need for expensive crane operations and specialized equipment required to remove and reposition the turbine head and stand the bedplate vertically, significantly reducing maintenance costs.
Solution Approach 2:
The pulling device serves as a cost-effective intermediary that enables bearing extraction using existing horizontal space and equipment. By mediating between the bearing assembly and standard lifting equipment, it avoids the need for expensive specialized tools and procedures required by traditional vertical extraction methods.
3Ease of repair
If the bedplate is stood up vertically to remove the main shaft and bearing assembly, then the bearing can be accessed for replacement, but the procedure becomes very time-consuming
Solution Approach 1:
The patent inverts the traditional approach by accessing the bearing horizontally while the bedplate remains in its operational horizontal position. This eliminates the time-consuming steps of removing the turbine head, repositioning the bedplate vertically, performing the bearing replacement, and then returning everything to its original configuration.
Solution Approach 2:
The pulling device is designed to be installed and configured in advance to enable direct horizontal extraction of the bearing assembly. This preliminary preparation allows the actual bearing replacement to proceed efficiently without interruptions for repositioning operations, maintaining high productivity throughout the maintenance procedure.
4Ease of operation
If there is no assist motive system at the downwind end of the main shaft, then the structure remains simple, but the main shaft cannot be efficiently pushed or pulled into or out of the bedplate
Solution Approach 1:
The assist motive system is segmented into separate functional components: a pushing mechanism for initial insertion, a pulling device for extraction, and support structures. This segmentation allows each component to be optimized for its specific function and enables the system to be assembled and disassembled easily, reducing overall complexity while maintaining operational effectiveness.
Solution Approach 2:
The assist motive system acts as an intermediary between the main shaft and external handling equipment. By providing dedicated pushing and pulling mechanisms at the downwind end, it mediates the force transmission required for shaft installation and removal, making the process manageable without requiring overly complex direct manipulation of the entire shaft assembly.
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 efficient and cost-effective maintenance of wind turbine main shaft bearings by allowing removal and installation while the bedplate remains horizontal, reducing time and expense associated with traditional methods.
Implementation Method 1
an assist system is fixed to the downwind end of the bedplate and used to push the downwind end of the main shaft partway through the bedplate
Data Source
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AI summary
A method and system for removing or installing a main shaft and attached main bearing assembly of a wind turbine from a bedplate installed atop a wind turbine tower using an assist motive system configured at a downwind end of the main shaft to push or pull the main shaft out of or into the bedplate.