Wind Turbine Main Bearing Replacement Without Rotor Removal

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Solution Overview

Problem

The replacement of main bearings in wind turbines is a complex and costly process, requiring the removal of the entire rotor, which is both technically challenging and expensive.

Innovation Solution

A wind turbine design that includes a rotatable main shaft with fastening and tappet means allows for the movement and replacement of main bearings along the centre axis without removing the rotor, using fastening means like bolts and shims to stabilize the rotor and tappet means like projections or flutes to facilitate movement, enabling the main bearing to be replaced without disassembling the rotor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If the wind turbine rotor is removed for main bearing replacement, then the main bearing can be replaced, but the technical effort and cost increase immensely

Engineering Contradiction:
Improvemain bearing replacementVSAvoidreplacement process complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The main bearing is divided into separable components (inner ring, outer ring, rolling elements) that can be replaced independently. The bearing housing is designed as a separate module that can be accessed without removing the entire rotor, allowing segmented replacement of bearing components while the rotor remains in place.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The main bearing is extracted from the rotor assembly through a specialized access path. The bearing removal device enables extraction of the bearing from the bearing housing without requiring rotor removal, effectively separating the bearing replacement operation from the rotor assembly operation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of repair

If the wind turbine rotor is removed for main bearing replacement, then the main bearing can be replaced, but the cost increases immensely

Engineering Contradiction:
Improvemain bearing replacementVSAvoidreplacement cost
Core Design Contradiction:
Ease of repairVSQuantity of substance

Solution Approach 1:

The bearing housing is pre-designed with accessible openings and the bearing removal device is pre-positioned to enable bearing extraction without rotor removal. Fastening means are pre-arranged to secure the rotor in a specific position during bearing replacement, allowing cost-effective maintenance operations to be performed in advance of actual bearing failure.

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If fastening means are used to secure the rotor, then the rotor is stabilized for bearing replacement, but additional components are required

Engineering Contradiction:
Improverotor stabilityVSAvoidfastening system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The bearing housing serves as an intermediary structure between the rotor and the bearing. It provides a stable mounting position for the bearing while allowing access to the rotor through pre-designed openings. The fastening means connect to the bearing housing rather than directly to the rotor, using the housing as a mediator to stabilize the system during bearing replacement.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If tappet means are used to move the main bearing, then the bearing can be relocated for replacement, but additional components are required

Engineering Contradiction:
Improvebearing relocationVSAvoidtappet system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The tappet means are integrated into the bearing removal device itself, which is already positioned in the system for bearing extraction. The tappet mechanism uses the existing structural elements of the removal device to provide the pushing force, making the removal device serve dual functions (extraction and relocation) without requiring completely separate propulsion components.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2143936B1Wind turbine comprising a main bearing and method for replacement of the main bearing
Publication Date: 2016.01.13 SIEMENS AG
  • EP2143936B1 patent drawingFigure 1
  • EP2143936B1 patent drawingFigure 2~4
  • EP2143936B1 patent drawingFigure 5~7

AI summary

The invention concerns a wind turbine comprising a rotatable main shaft (14) having a centre axis (A) and being at least indirectly connected to a wind turbine rotor (26) of the wind turbine (1) and at least one main bearing (15, 16) supporting the rotatable main shaft (14) at least indirectly against a first stationary part (6) of the wind turbine (1), wherein fastening means (32, 33, 35) are provided for fastening the wind turbine rotor (26) to the first or a second stationary part (6) of the wind turbine (1) during replacement of the at least one main bearing (15, 16) and tappet means (30, 31, 40, 41, 50, 51) are provided which are able to act on the at least one main bearing (15, 16) and permit a movement of the at least one main bearing (15, 16) relatively to the first stationary part (6) in the direction of the centre axis (A). The invention concerns also a method for replacement of a main bearing wherein in the course of replacement of the at least one main bearing (15, 16) the at least one main bearing (15, 16) or the at least one main bearing (15, 16) and the rotatable main shaft (14) are moved relatively to the first stationary part (6) in the direction of the centre axis (A) for replacement of the at least one main bearing (15, 16).