Variable-Thickness Pitch Bearing Reinforcement for Wind Turbines

Solution Overview

Problem

Modern wind turbines face challenges with pitch bearings that experience varying stress concentrations due to increased loads and blade sizes, leading to potential failure and inefficiencies, as existing solutions either oversize the bearings or introduce uneven stiffness with local reinforcements.

Innovation Solution

A pitch bearing design featuring a bearing reinforcement with a variable thickness along the circumferential direction, strategically placed to enhance stiffness in high-stress areas while maintaining a reduced thickness elsewhere, using either continuous or discontinuous variations achieved through stacked reinforcing plates, ensuring smooth stiffness distribution and reduced weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the pitch bearing is made bigger (larger diameter, thickness or height) to handle increased loads, then the bearing strength is improved, but the bearing weight and cost increase significantly

Engineering Contradiction:

Improvebearing strengthVSAvoidbearing weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The patent applies local quality by providing reinforcing plates only at specific circumferential positions where stress concentrations occur (such as near bolt holes and defect-prone areas) rather than uniformly throughout the bearing. This allows the bearing to have enhanced strength at critical locations while maintaining thinner and lighter sections in non-critical areas, thus resolving the contradiction between overall strength improvement and weight reduction.

Inventive Principle:

Principle #3Local quality

2Strength

If local reinforcements are added to specific areas of the bearing, then the bearing strength at stress concentration points is improved, but the stiffness distribution becomes uneven

Engineering Contradiction:

Improvebearing strength at stress concentrationVSAvoidstiffness distribution uniformity

Core Design Contradiction:

StrengthVSStability of the object's composition

Solution Approach 1:

The patent employs dynamics by making the bearing reinforcement adaptable to varying operational conditions. The reinforcing plates are designed to be positioned at circumferential locations that experience different stress levels during operation, allowing the bearing to dynamically adjust its effective stiffness distribution. This ensures that reinforcement is provided where needed during different pitch angles and load conditions while maintaining overall stiffness balance.

Inventive Principle:

Principle #15Dynamics

3Reliability

If the bearing is designed considering maximum stresses can appear all around, then the bearing reliability is improved, but the bearing is oversized for other pitch angles

Engineering Contradiction:

Improvebearing reliabilityVSAvoidbearing weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent applies local quality by providing reinforcing plates only at specific circumferential positions where stress concentrations occur (such as near bolt holes and defect-prone areas) rather than uniformly throughout the bearing. This allows the bearing to have enhanced strength at critical locations while maintaining thinner and lighter sections in non-critical areas, thus resolving the contradiction between overall strength improvement and weight reduction.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3312414B1Wind turbine and pitch bearing of the wind turbine

Publication Date: 2021.03.03 NORDEX ENERGY SPAIN SAU

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AI summary

Wind turbine comprising at least a pitch bearing comprising at least two rings, each of the at least two rings attached to a wind turbine component, being a first wind turbine component a blade and a second wind turbine component a hub, and further comprising at least one bearing reinforcement attached to at least one of the two rings. The invention also relates to the pitch bearing of the wind turbine.