Wind Turbine Generator Mounting for Bending Load Isolation

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Solution Overview

Problem

Conventional wind turbines face issues with gearbox maintenance, high bending loads causing air gap instability and structural damage in generators due to the transmission of cyclical loads through the rotor shaft, leading to premature component replacement and increased costs.

Innovation Solution

A wind turbine design where the rotor hub is rotatably mounted on a frame with the generator and tower on the same side of the rotor, and the generator stator is attached in a plane perpendicular to the rotor's axis, with the generator rotor mounted on the stator to minimize relative displacement and use flexible couplings to reduce bending load transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a gearbox is used to increase generator speed, then electricity generation efficiency is improved, but maintenance requirements increase and component lifespan decreases

Engineering Contradiction:
Improveelectricity generation efficiencyVSAvoidgearbox service life
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent removes the gearbox from the wind turbine drive train, creating a direct drive system where the rotor hub connects directly to the generator. This extraction of the problematic gearbox component eliminates maintenance issues and reliability problems while accepting the trade-off of requiring a larger generator to operate at lower speeds.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a flexible coupling as an intermediary element between the rotor hub and generator shaft. This flexible coupling transmits torque while isolating the generator from bending loads and cyclic forces, protecting the generator from damage without requiring a gearbox for speed multiplication.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a direct drive generator is used without a gearbox, then maintenance requirements decrease, but the generator size and cost increase

Engineering Contradiction:
Improvemaintenance requirementsVSAvoidgenerator size
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent employs a flexible coupling that dynamically adapts to the varying loads and movements of the rotor system. This flexible connection allows the generator to operate at lower speeds without requiring excessive oversizing, as the coupling accommodates the dynamic nature of wind turbine operation.

Inventive Principle:
Principle #15Dynamics

3Power

If bending loads are transmitted through the rotor shaft to the generator, then torque transmission is achieved, but air gap stability deteriorates and structural damage occurs

Engineering Contradiction:
Improvetorque transmissionVSAvoidair gap stability
Core Design Contradiction:
PowerVSStability of the object's composition

Solution Approach 1:

The flexible coupling acts as a mediator that transmits torque from the rotor hub to the generator shaft while blocking the transmission of bending loads and cyclic forces. This intermediary element protects the generator from load-induced deformations that would cause air gap instability and potential structural damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses a flexible coupling element that can deform elastically to accommodate rotor movements while maintaining torque transmission. This flexibility allows the coupling to absorb bending loads and prevent their transmission to the generator, preserving air gap stability.

Inventive Principle:
Principle #30Flexible shells and thin films

4Power

If the rotor hub is mounted on one end of the rotor shaft forming an overhanging structure, then torque transmission to the generator is achieved, but cyclical bending loads are transmitted to the generator

Engineering Contradiction:
Improvetorque transmissionVSAvoidbending loads
Core Design Contradiction:
PowerVSForce

Solution Approach 1:

The flexible coupling serves as an intermediary between the rotor hub and generator shaft, transmitting torque while isolating the generator from bending loads. This mediator allows the overhanging rotor structure to function while protecting the generator from the harmful cyclic forces generated by blade loading and hub weight.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This configuration enhances air gap stability, reduces structural damage, and minimizes the transfer of bending loads, thereby extending the lifespan of components and reducing maintenance costs.

Implementation Method 1

one or more flexible elements are arranged between one or more of said axial protrusions and said carrying structure

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2593674B8Wind turbine
Publication Date: 2016.10.19 ALSTOM RENEWABLE TECH

AI summary

Wind turbine comprising a rotor, a generator and a tower, said rotor comprising a rotor hub and one or more rotor blades and said generator comprising a generator stator and a generator rotor, wherein the rotor hub is rotatably mounted on a frame and the generator and tower are arranged on the same of the rotor, and the generator stator is attached to said frame substantially in a plane perpendicular to the rotor's rotational axis, and wherein the generator rotor is rotatably mounted on a part of the generator stator.